JP2005068420A - Pressure-sensitive adhesive sheet - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prepare an environment-friendly pressure-sensitive adhesive sheet useful for a surface protective application associated with cutting processing, especially, useful for the surface protective application, a chemical treatment application, and a dicing application requiring excellent cutting processability in fields of an electronic circuit material, a semiconductor material, an optical material, and the like, for which high performance and quality are required. <P>SOLUTION: This pressure-sensitive adhesive sheet 10 is formed by laminating at least one of surfaces of a base material layer 1 with a pressure-sensitive adhesive layer 2, wherein the base material layer 1 contains an olefinic polymer, and the sheet has a modulus in tension and tear strength each of which is in a specified range. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a pressure-sensitive adhesive sheet, and particularly relates to a pressure-sensitive adhesive sheet used in a processing step involving cutting.

    Conventionally, pressure-sensitive adhesive sheets have been developed in which a soft vinyl chloride (PVC) sheet with a plasticizer added to a vinyl chloride resin is used as a base material layer and a pressure-sensitive adhesive is applied on the base material layer. And used. Applications of the PVC-based pressure-sensitive adhesive sheet include a surface-protective pressure-sensitive adhesive sheet, a coating masking pressure-sensitive adhesive sheet, and a marking sheet.

    However, most PVC-based pressure-sensitive adhesive sheets are landfilled because they generate corrosive gas containing chlorine gas or hydrogen chloride gas when incinerated for disposal, and damage the incinerator. Even in that case, since the PVC pressure-sensitive adhesive sheet contains a plasticizer that may affect the ecosystem, it is desired not to use a PVC pressure-sensitive adhesive sheet that has a large environmental load.

Various types of polyolefin (hereinafter referred to as PO) pressure-sensitive adhesive sheets that do not contain chlorine or a plasticizer have been proposed and developed as substitutes for PVC-based pressure-sensitive adhesive sheets.
In JP-A-2004-35687 (Patent Document 1), by making the 2% modulus of the base material layer, the tear strength and adhesive strength of the pressure-sensitive adhesive sheet within a specific range, marking applications that do not cause cutting or tearing during the peeling operation. A PO-based pressure-sensitive adhesive sheet suitable for use is disclosed.
In JP-A-11-193367 (Patent Document 2), the resin composition of the base material is set to a specific composition, or the thickness, tensile elastic modulus and 90 degree tear strength of the base material are set within a specific range. Thus, a PO-based pressure-sensitive adhesive sheet for surface protection with further improved tear resistance is disclosed.

    Japanese Patent Application Laid-Open No. 11-21528 (Patent Document 3) discloses a pressure-sensitive adhesive sheet characterized by a base material layer provided with a laminate layer on at least one surface of a polyolefin resin fabric. In the present invention, particularly, the laminate layer is an ethylene / α-olefin copolymer or syndiotactic polypropylene having a melting point lower than that of the polyolefin-based resin used for the fabric, thereby suppressing thermal deterioration of the fabric constituting the base material layer. It is described that a PO-based pressure-sensitive adhesive sheet having excellent mechanical strength and good hand cutting properties can be obtained.

    WO 00/05305 (Patent Document 4) discloses a PO-based pressure-sensitive adhesive sheet characterized by a base material layer composed of a blend of a first polymer and a second polymer each having a melting temperature of at least about 93 ° C. As disclosed and as its third invention, in the composition used for the substrate layer, the first polymer is at least about 20% atactic and relatively soft and the second polymer is at least about 80% syndiotactic and / or It is disclosed that it is an isotactic polypropylene and is not relatively soft. The PO-based pressure-sensitive adhesive sheet obtained by the present invention is described as being excellent in masking properties when painting an automobile and further exhibiting tearing properties equivalent to those of a PVC-based pressure-sensitive adhesive sheet.

Japanese Patent Application Laid-Open No. 2002-265892 (Patent Document 5) discloses a pressure-sensitive adhesive sheet having at least one layer composed of a specific propylene polymer or at least one resin composition containing a specific propylene polymer and an olefin polymer. A substrate and an adhesive sheet are disclosed. Stereoregularity of propylene triad chain, meso-pendant fraction is 0.2-0.6, and racemic pendant ratio is 0.1 or less (ie, showing regularity related to atactic structure) It is described that the base material and the pressure-sensitive adhesive sheet containing the propylene polymer specified in (1) have the same flexibility as the polyvinyl chloride base material and the PVC-based pressure-sensitive adhesive sheet.
Japanese Patent No. 3007081 (Patent Document 6) discloses a PO-based pressure-sensitive adhesive sheet having a base layer composed of a resin composition having an olefin-based polymer as a base polymer and not containing a halogen element and having an oxygen index of 22 or more. ing. In this invention, it is described that the same stretch condition and hand cutting feeling as the PVC pressure-sensitive adhesive sheet can be obtained.
However, the above adhesive sheets are all related to adhesive sheet for surface protection, adhesive sheet for coating masking, marking sheet, etc., such as electronic circuit materials, semiconductor materials, optical materials, etc. that are demanding for performance and quality. There is no specific description regarding the use with various cutting processes in the field.
In the field of electronic circuit materials, for example, pressure-sensitive adhesive sheets used in chemical processing such as plating solutions and rust preventive liquids (hereinafter referred to as chemical-treatment pressure-sensitive adhesive sheets) have flexibility and plating that can follow the unevenness of electronic circuits. It is required to have a punching workability that can accurately process an opening window in a portion to be processed or rust-proofed. In the field of electronic circuit materials, especially for adhesive sheets used for plating and rust prevention treatment of flexible printed circuit boards, which are strict in performance and quality, PO-based adhesive sheets have poor punching workability. -Based adhesive sheet is used.

    In the semiconductor material field and the optical material field, for example, a pressure-sensitive adhesive sheet is used for processing a wafer such as a silicon wafer. Particularly, a pressure-sensitive adhesive sheet used for cutting (dicing) processing (hereinafter referred to as a pressure-sensitive adhesive sheet for dicing) is used. In addition, it is required that chip chipping and cutting dust contamination be small, and further, after dicing the wafer into small pieces, the adhesive sheet is extended to uniformly spread the intervals between the small pieces (hereinafter referred to as expandability). In the dicing process, a PVC-based pressure-sensitive adhesive sheet is employed when chip chipping and cutting dust contamination are required to be as small as possible and demand for expandability is high.

As a pressure-sensitive adhesive sheet for dicing other than the PVC-based pressure-sensitive adhesive sheet, Japanese Patent Application Laid-Open No. 2002-155249 (Patent Document 7) discloses a pressure-sensitive adhesive sheet made entirely of a PO-based polymer. In this publication, it is described that chip chipping can be greatly suppressed particularly under evaluation conditions for dicing a 3 × 3 mm size chip.
Japanese Unexamined Patent Publication No. 2002-226803 (Patent Document 8) discloses a polyolefin film having a three-layer structure in which a polypropylene resin layer, an ethylene copolymer resin layer, and a polypropylene resin layer are sequentially laminated. The polypropylene resin layer uses a polypropylene resin including syndiotactic polypropylene, random polypropylene, etc., while the ethylene copolymer resin layer has an ethylene-vinyl acetate copolymer, an ethylene- (meth) acrylic acid copolymer. It is described that the substrate film for dicing which is excellent in uniform expandability can be provided by using the above. However, there is no mention of processing quality such as chip chipping and cutting dust contamination under dicing processing conditions.
JP 2004-35687 A JP-A-11-193367 Japanese Patent Laid-Open No. 11-21528 WO00 / 05305 Publication JP 2002-265892 A Japanese Patent No. 3007081 JP 2002-155249 A JP 2002-226803 A

According to the present invention, it is possible to obtain a system pressure-sensitive adhesive sheet having an appropriate tensile elastic modulus and tear strength and excellent in uniformity in the longitudinal direction and the transverse direction, so that the cutting process does not cause thread-like burrs on the cut surface. You can gain sex.
Furthermore, according to the present invention, it is an environment-friendly material, and it has energy-saving properties, stability, characteristics that do not substantially contain corrosive ions and metal ions, and therefore, electronic circuit materials that are particularly demanding for performance, quality, and environmental load, In the fields of semiconductor materials, optical materials, etc., it is possible to provide a PO-based pressure-sensitive adhesive sheet that is suitable for chemical liquid processing involving cutting and dicing.
More specifically, for example, with the adhesive sheet of the present invention, even if the terminal portion of the flexible printed circuit board is subjected to rust prevention treatment or gold plating treatment by opening a window in the adhesive sheet and partially treating it with a chemical solution, the cut surface of the window remains. Since it is good in any direction without burrs, it can provide a high-quality flexible printed circuit board, and the adhesive sheet of the present invention can eliminate chip contamination and chip chipping when a semiconductor wafer is diced. A semiconductor chip can be provided.

    An object of the present invention is to provide a pressure-sensitive adhesive sheet suitable for a surface protection application involving cutting processing, and more specifically, a chemical solution involving cutting processing in the fields of electronic circuit materials, semiconductor materials, optical materials and the like that have strict requirements for performance and quality. The object is to provide a pressure-sensitive adhesive sheet suitable for uses such as processing and dicing. Furthermore, it is providing the adhesive sheet which reduced the load to an environment.

    In view of the above problems, the present inventors have earnestly researched pressure-sensitive adhesive sheets having high performance and quality required in the fields of electronic circuit materials, semiconductor materials, optical materials, etc., and particularly excellent in cutting workability. By making the tensile modulus and tear strength within a specific range, it has excellent cutting workability, and furthermore, it can have high performance and quality by using a specific resin. The headline and the present invention were completed.

That is, the present invention
The pressure-sensitive adhesive sheet has a pressure-sensitive adhesive layer laminated on at least one surface of the base material layer, and is a pressure-sensitive adhesive sheet characterized by the following requirements (a) to (c).
(A) The longitudinal tensile modulus (MD-M) and the transverse tensile modulus (TD-M) at 23 ° C. are in the range of 50 to 2000 MPa, and the longitudinal tensile modulus (MD-M) ) And the tensile modulus of elasticity (TD-M) in the transverse direction {(MD-M) / (TD-M)} is in the range of 0.5-2 (b) longitudinal tear at 23 ° C The strength (MD-T) and the transverse tear strength (TD-T) are in the range of 1-100 N / mm, the longitudinal tear strength (MD-T) and the transverse tear strength. The ratio {(MD-T) / (TD-T)} to (TD-T) is in the range of 0.5 to 2 (c) The base material layer contains an olefin polymer. However, containing a syndiotactic propylene polymer is a preferred embodiment because it can have both high performance and quality.
Furthermore, a pressure-sensitive adhesive sheet in which the pressure-sensitive adhesive layer contains an α-olefin copolymer as a main component and is molded by a coextrusion method is a preferred embodiment.
The pressure-sensitive adhesive sheet of the present invention can be suitably used for surface protection applications involving cutting processing, and is particularly suitable for chemical liquid treatment applications and dicing applications of flexible printed circuit boards.

Hereinafter, the pressure-sensitive adhesive sheet of the present invention will be specifically described with reference to the accompanying drawings. In all the drawings, the same or corresponding parts are denoted by the same reference numerals.
FIG. 1 is a cross-sectional view showing an embodiment of the pressure-sensitive adhesive sheet of the present invention. As shown in the figure, the pressure-sensitive adhesive sheet 10 of the present invention comprises a base material layer 1 and a pressure-sensitive adhesive layer 2 laminated on one surface of the base material layer 1.

The pressure-sensitive adhesive sheet 10 according to the present invention has a longitudinal tensile modulus (MD-M) and a transverse tensile modulus (TD-M) at 23 ° C. in the range of 50 to 2000 MPa, preferably 70 to It is in the range of 1500 MPa, and the ratio {(MD-M) / (TD-M)} between the tensile modulus (MD-M) in the longitudinal direction and the tensile modulus (TD-M) in the transverse direction is 0.5. In the range of ˜2, preferably in the range of 0.7 to 1.5, the cutting workability is excellent and preferable. The tensile modulus is measured according to JISK 6781.
When the tensile elastic modulus of the pressure-sensitive adhesive sheet 10 is less than 50 MPa, the film is stretched at the time of affixing work or peeling and the workability is deteriorated, and further, characteristics such as accuracy required even when the pressure-sensitive adhesive sheet is normally applied are achieved. Can be difficult. On the other hand, if it exceeds 2000 MPa, the softness following the shape of the adherend may decrease, which may be undesirable. When the ratio {(MD-M) / (TD-M)} of the tensile modulus (MD-M) in the machine direction and the tensile modulus (TD-M) in the transverse direction is less than 0.5 or more than 2, The characteristic difference between the vertical direction and the horizontal direction increases, and it may be difficult to obtain uniform characteristics in all directions.

The pressure-sensitive adhesive sheet 10 according to the present invention has a longitudinal tear strength (MD-T) and a transverse tear strength (TD-T) at 23 ° C. in the range of 1 to 100 N / mm, preferably The ratio {(MD-T) / (TD-T)} of the longitudinal tear strength (MD-T) and the transverse tear strength (TD-T) is in the range of 5 to 80 N / mm. , In the range of 0.5 to 2, and more preferably in the range of 0.7 to 1.5.
The tear strength is measured according to JIS K 7128 (Elmendorf tear method). If the tear strength is less than 1 N / mm, the PSA sheet may not be obtained. On the other hand, if it exceeds 100 N / mm, cutting may be difficult, and special processing may be required, which may not be suitable. When the ratio {(MD-T) / (TD-T)} between the tear strength (MD-T) in the machine direction and the tear strength (TD-T) in the transverse direction is less than 0.5 or more than 2, In some cases, the difference in characteristics between the vertical and horizontal directions becomes large, and uniform characteristics cannot be obtained in all directions.

For the base material layer 1 of the present invention, a material that has both a strength for fixing and holding the adherend and a softness that follows the shape of the adherend, a low cost and excellent energy saving property, and a material having a wide variety of characteristics are selected. It can be easily combined with other materials to provide functions, has a low environmental impact, does not substantially contain corrosive ions and metal ions, and has a strong bond with each other when it consists of multiple layers. In view of easy formation, those having an olefin polymer as a main component are preferred. In the present invention, the main component refers to a constituent component that is contained in a relatively large ratio as compared to constituent components contained in the other components.
Specific examples of the olefin polymer include low density polyethylene, ultra low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, and 3 to 12 carbon atoms mainly composed of ethylene. Examples thereof include polyethylene-based polymers which are copolymers having various vinyl compounds selected from α-olefin, styrene, vinyl acetate, (meth) acrylic acid, (meth) acrylic acid ester, ionomer, etc. as secondary components. A polymer or a block copolymer may be used. In addition, a propylene-only polymer, a polypropylene-based polymer which is a copolymer having ethylene as a main component and propylene as a main component or an α-olefin having 4 to 12 carbon atoms as a secondary component may be mentioned. A polymer may be used. Furthermore, C4 or more alpha olefin copolymers, such as polybutene and polymethylpentene, can be mentioned.

    As the component constituting the base material layer 1 of the present invention, one containing a syndiotactic propylene polymer is particularly preferable.

The syndiotactic propylene polymer will be described below.
The syndiotactic propylene polymer may be syndiotactic homopolypropylene, or propylene and ethylene, and a copolymer having 4 to 20 carbon atoms, that is, a syndiotactic propylene / ethylene copolymer or A syndiotactic propylene / ethylene / α-olefin copolymer may be used. The molar ratio of the comonomer constituting the copolymer is preferably 90 to 99% propylene, 0.5 to 9 mol% ethylene, and 0 to 9.5 mol% α-olefin. The α-olefin used in the syndiotactic propylene / ethylene / α-olefin copolymer is used as long as it does not impair the cutting processability, flexibility, and mechanical properties of the pressure-sensitive adhesive sheet of the present invention. Examples thereof include 3-methyl-1-butene, 1-hexene, vinylcyclohexene, 1-decene, 1-hexadecene, cyclopentene and norbornene.
The syndiotactic propylene copolymer is obtained by copolymerizing propylene and a small amount of a comonomer in the presence of a known catalyst that gives a poly-α-olefin having good syndiotacticity.

Moreover, the repeating unit derived from propylene constituting the syndiotactic propylene polymer used in the present invention has a substantially syndiotactic structure. The syndiotacticity of the propylene triad chain is preferably 0.6 or more, more preferably 0.7 or more. When the syndiotacticity is within the above range, the crystallization speed is high and the processability is excellent. In addition, that it is a syndiotactic structure substantially means that the syndiotacticity seen by the triad chain | strand of propylene is 0.6 or more.
As the catalyst used for the production of the syndiotactic propylene polymer, a metallocene catalyst is preferable. Specifically, the catalyst system described in JEwen et al., "J. Am. Chem. Soc., 1988, 110, 6255-6256", JP-A-2-41303, JP-A-2-41305, Asymmetric coordination with each other as described in JP-A-2-274703, JP-A-2-274704, JP-A-3-179005, JP-A-3-179006, and JP-A-4-69394. A catalyst system comprising a bridged transition metal compound having a child and a cocatalyst can be mentioned. Even if the catalyst system has a structure different from that of the catalyst system, when a homopolymer of propylene is produced, the syndiotactic triad fraction of the resulting polymer (A. Zambelli et al. Macromolecules vol 6 687 (1973). 8 925 (1975)) can be used as long as the catalyst system provides a polymer having a relatively high tacticity of the above-described value, for example, about 0.6 or more. As the polymerization method, any of a liquid phase polymerization method such as suspension polymerization and solution polymerization or a gas phase polymerization method can be used.
The molecular weight of the syndiotactic propylene polymer is preferably from 0.1 to 10 dl / g, more preferably from 0.5 to 5.0 dl / g, as the intrinsic viscosity measured in a tetralin solution at 135 ° C. The melt flow rate (according to ASTM D-1238, temperature 230 ° C. load 21.18 N load) is preferably 0.5 to 70 g / 10 min, more preferably 5 to 30 g / 10 min. Further, examples of the density is preferably a 0.81~0.96g / cm ^3, it is more preferred 0.85~0.93g / cm ^3.

    When a resin containing a syndiotactic propylene polymer is used as a component constituting the base material layer 1, the tensile modulus and tear strength of the pressure-sensitive adhesive sheet 10 can be set within a preferable range, and the longitudinal and lateral directions are uniform. This is preferable because the properties can be improved, and a property that does not generate thread-like burrs on the cut surface can be imparted. The content of the syndiotactic propylene polymer with respect to all the components of the resin constituting the base material layer 1 of the present invention is preferably about 10 to 100% by weight, more preferably about 30 to 100% by weight. Specific examples of this syndiotactic propylene polymer include those commercially available from ATOFINA PETROCHEMICALS, INC. Under the trade name: FINAPLAS (registered trademark).

    The content of the olefin polymer in the base material layer 1 is preferably about 30 to 100% by weight, more preferably about 50 to 100% by weight. Specific examples of the ethylene and α-olefin copolymer, which is an example of an olefin polymer that enhances flexibility and extensibility, include Tuffmer A, Tuffmer P and the like (manufactured by Mitsui Chemicals), and propylene and α- Specific examples of the olefin copolymer include Tuffmer XR, Tuffmer S and the like (manufactured by Mitsui Chemicals, Inc.), and specific examples of polybutene include buron (manufactured by Mitsui Chemicals, Inc.).

    As a constituent component of the base material layer 1, in addition to the olefin-based polymer, the synthetic resin and the thermoplastic elastomer are improved in mechanical properties, heat resistance properties, flexibility properties, etc. to such an extent that the performance and quality of the pressure-sensitive adhesive sheet 10 are not deteriorated. Therefore, it can be added as needed. Examples of synthetic resins for improving mechanical properties and heat resistance include polyamides, polyesters, polyethers, polycarbonates, and polyurethanes. Thermoplastic elastomers for improving flexibility include polystyrene elastomers and polyamide elastomers. And polyurethane elastomers and polyester elastomers.

The base material layer 1 may contain various additives generally used for the base material layer of this type of pressure-sensitive adhesive sheet. For example, various additives such as various fillers, pigments, dyes, ultraviolet absorbers, antioxidants, heat stabilizers, lubricants, weather stabilizers, plasticizers, crystal nucleating agents, and the performance and quality of the pressure-sensitive adhesive sheet 10 It may be contained to such an extent that it does not affect.
There is no restriction | limiting in particular about the thickness of the base material layer 1, If it considers the cutting workability, mechanical strength, a softness | flexibility etc. which are requested | required according to the intended purpose, it is about 10 micrometers-1 mm normally, and wrinkle prevention property and sticking From the viewpoint of workability and cost, about 25 μm to 250 μm is preferable.

    The pressure-sensitive adhesive layer 2 of the present invention is formed of various conventionally known components and is not limited in any way, but is a rubber-based pressure-sensitive adhesive material, an acrylic pressure-sensitive adhesive material, a silicone-based pressure-sensitive adhesive material, a polyvinyl ether-based pressure-sensitive adhesive material, An olefin-based adhesive material or the like can be used. In addition, an adhesive material that is cured by ultraviolet rays or an electron beam, or an adhesive material that foams when heated can be used. Examples of the olefin-based adhesive material include, for example, JP-A-7-233354, JP-A-10-298514, JP-A-11-80233, JP-A-11-43655, JP-A-11-21519, The α-olefin copolymers described in Kaihei 11-106716, JP-A 2002-155249, and JP-A 2002-226814 are preferable, but are not limited thereto.

The pressure-sensitive adhesive layer 2 has both a fixing holding force to the adherend and ease of peeling, a point that the adherend is substantially free of contamination, a point that the pressure-sensitive adhesive force is stable in a storage and transportation environment, It is preferable to use an α-olefin copolymer as a main component because it has a low load, hardly contains corrosive ions and metal ions, and easily forms a strong bond with the base material layer.
Furthermore, the main component is one or a mixture of two or more α-olefin copolymers containing at least two α-olefins selected from α-olefins having 2 to 12 carbon atoms as main unit components. Those are preferred. Examples of the α-olefin having 2 to 12 carbon atoms include ethylene, propylene, 1-butene, 1-pentene, 3-methyl-1-butene, 1-hexene, 4-methyl-1-pentene, and 3-methyl. Examples include -1-pentene, 1-heptene, 1-octene, 1-decene, and 1-dodecene. When a copolymer composed of at least two monomers selected from these α-olefins is used as the main component of the pressure-sensitive adhesive layer 2, the total content of the α-olefin copolymer in the pressure-sensitive adhesive layer 2 is: It is preferably 30% by weight or more, particularly preferably 50% by weight or more.

As a constituent component of the adhesive layer 2, in addition to the α-olefin copolymer, a co-oligomer of ethylene and another α-olefin or a thermoplastic elastomer containing no halogen element can be appropriately added. When a co-oligomer of ethylene and other α-olefin or a thermoplastic elastomer containing no halogen element is added to the adhesive layer 2, the glass transition temperature is lowered, and the initial adhesive strength can be adjusted to an appropriate range. This is preferable in that the viscosity can be adjusted to an appropriate range.
Adhesion after being attached to the adhesive layer 2 by appropriately introducing a polar group containing oxygen or nitrogen or a group having an unsaturated bond into a part of the α-olefin copolymer or thermoplastic elastomer. It is preferable because it is possible to prevent changes in strength over time (due to heating, pressurization, humidity, ultraviolet rays, etc.) and to optimize processing conditions and adhesion properties to adherends.

The co-oligomer of ethylene and other α-olefin is a low molecular weight copolymer of ethylene and other α-olefin, and usually has a number average molecular weight in the range of 100 to 10,000, more preferably The number average molecular weight is preferably in the range of 200 to 5,000.
Examples of the thermoplastic elastomer include styrene / butadiene block copolymer (SBR), styrene / isoprene / styrene block copolymer (SIS), styrene / butadiene / styrene block copolymer (SBS), and styrene / ethylene. Butylene / styrene block copolymer (SEBS), styrene / ethylene / propylene / styrene block copolymer (SEPS), hydrogenated styrene / butadiene block copolymer (HSBR), styrene / ethylene / butylene / olefin (crystal) ) Block copolymer (SEBC), olefin (crystalline) / ethylene / butylene / olefin (crystalline) block copolymer (CEBC), and the like. Specific examples of the SIS include those commercially available from JSR Corporation under the trade name: JSRSIS (registered trademark) or from Shell Chemical Co., Ltd. under the trade name: Clayton D (registered trademark). Specific examples of SEPS include those commercially available from Kuraray Co., Ltd. under the trade name: Septon (registered trademark). Specific examples of HSBR, SEBS, SEBC, and CEBC include those commercially available from JSR Corporation under the trade name: DYNARON (registered trademark).

In addition to the α-olefin copolymer, ethylene and other α-olefin co-oligomers, and thermoplastic elastomers, the adhesive layer 2 further contains various subcomponents within a range that does not impair the object of the present invention. You may go out. For example, a plasticizer such as liquid butyl rubber, a tackifier such as polyterpene, and the like may be included. Of these subcomponents, functional groups that impart adhesion and groups that have unsaturated bonds do not cause changes over time in the adhesive strength after application (due to heating, pressure, humidity, ultraviolet rays, etc.). In addition, it is preferable to select the type and adjust the blending amount to the minimum necessary.
Moreover, the adhesive layer of the present invention may contain various additives generally blended with this type of adhesive material. For example, it may contain pigments, dyes, ultraviolet absorbers, antioxidants, heat stabilizers, weather stabilizers, and the like.

The thickness of the pressure-sensitive adhesive layer 2 is not particularly limited, and is usually about 1 to 200 μm, preferably considering cutting workability, adhesive strength, adhesion to the surface irregularities of the adherend, and the like that are required according to the purpose of use. Is about 5 to 50 μm.
The total thickness of the pressure-sensitive adhesive sheet 10 is usually about 10 μm to 1 mm, and preferably about 30 to 300 μm from the viewpoint of wrinkle prevention, attaching workability, and price.
Furthermore, there is no restriction | limiting in particular about the adhesive force of the adhesive sheet 10, It is about 0.05-50N / 25mm normally with respect to the various adherends used according to a use, Preferably, 0.1-0.1 It is about 20 N / 25 mm. Moreover, in order to peel an adhesive sheet after use, the adhesive layer 2 which consists of a well-known switch type adhesive which makes an adhesive force zero or reduce by heat | fever, electromagnetic waves, etc. may be sufficient.

FIG. 2 is a cross-sectional view showing another embodiment of the pressure-sensitive adhesive sheet of the present invention. As shown in the figure, the pressure-sensitive adhesive sheet 10 of the present invention comprises a base material layer 1 composed of two layers, an intermediate layer 3 and an outer layer 4, and a pressure-sensitive adhesive layer 2 laminated on one surface of the intermediate layer 3. The intermediate layer 3 adjacent to the adhesive layer 2 preferably contains an olefin polymer containing a syndiotactic propylene polymer, and its content is usually about 10 to 100% by weight, preferably 30 About 100% by weight. Examples of the olefin polymer are the same as those described above.
The main component of the outer layer 4 is low density polyethylene, ultra low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, ethylene and an α-olefin having 3 to 12 carbon atoms, styrene, vinyl acetate. Polyethylene polymers such as copolymers with various vinyl compounds such as (meth) acrylic acid, (meth) acrylic acid esters and ionomers are preferred. In addition to these, it is preferable to blend 0.1 to 5% by weight of a release agent such as a reaction product of a small amount of polyvinyl alcohol or an ethylene / vinyl alcohol copolymer and a long-chain alkyl isocyanate, even when there is no release sheet. An adhesive sheet having a rewinding force of 5 N / 25 mm or less can be obtained.

When the base material layer 1 consists of the intermediate | middle layer 3 and the outer layer 4, there is no restriction | limiting in particular about the thickness of the intermediate | middle layer 3 and the outer layer 4, The thickness of the intermediate | middle layer 3 becomes like this. Preferably it is about 10 micrometers-0.8 mm, Most preferably It is about 20-200 micrometers, and the thickness of the outer layer 4 becomes like this. Preferably it is about 3-200 micrometers, Most preferably, it is about 5-50 micrometers.
If the thickness ratio of the layer containing as a main component an olefin polymer containing a syndiotactic propylene polymer in the pressure-sensitive adhesive sheet 10 is too small, thread-like burrs may be generated on the cut surfaces of the base material layer and the pressure-sensitive adhesive layer. Yes, there is a risk of worsening the cutting processability. Therefore, it is preferable that the thickness of the base material layer 1 in which the adhesive layer 2 is laminated on one surface of the base material layer 1 composed of a single layer is at least 30% or more with respect to the entire thickness of the adhesive sheet 10. When the pressure-sensitive adhesive layer 2 is laminated on one surface of the base material layer 1 made of a layer, the thickness of the intermediate layer 3 adjacent to the pressure-sensitive adhesive layer 2 is at least 30% or more with respect to the total thickness of the pressure-sensitive adhesive sheet 10. It is preferable.

FIG. 3 is a cross-sectional view showing another embodiment of the pressure-sensitive adhesive sheet of the present invention. As shown in the figure, the pressure-sensitive adhesive sheet 10 of the present invention is provided with a base material layer 1, a pressure-sensitive adhesive layer 2 laminated on the surface of the base material layer 1, and a release sheet 5 on the pressure-sensitive adhesive layer 2 side. .
FIG. 4 is a cross-sectional view showing another embodiment of the pressure-sensitive adhesive sheet of the present invention. As shown in the figure, the pressure-sensitive adhesive sheet 10 of the present invention comprises a base material layer 1 composed of two layers, an intermediate layer 3 and an outer layer 4, and a pressure-sensitive adhesive layer 2 laminated on the surface of the intermediate layer 3. A release sheet 5 is provided on the layer 2 side.
In the pressure-sensitive adhesive sheet 10 of the present invention, the release sheet 5 is laminated on the pressure-sensitive adhesive layer side in order to facilitate rewinding of the pressure-sensitive adhesive sheet, to improve the smoothness of the pressure-sensitive adhesive layer surface, and to improve punching workability. Is preferred. Furthermore, in applications involving punching and applications that require an adhesive layer on both sides, a release sheet is usually used to protect the adhesive layer.

The release sheet 5 is formed of various conventionally known components and is not limited at all. However, a synthetic resin or processed paper that does not generate a toxic gas such as a halogen compound when incinerated is preferable. Among them, polyester film and paper are characterized in that they have rigidity that can be accurately punched by suppressing deformation of the pressure-sensitive adhesive sheet 10, and that they have thickness and flexibility that do not hinder roll winding and reduce the amount of disposal. A processed paper having a surface coated with a synthetic resin such as polyethylene is preferred. The synthetic resin used for the release sheet 5 may contain, for example, various fillers, pigments, ultraviolet absorbers, antioxidants, heat stabilizers, lubricants and the like to the extent that they do not affect the adhesive sheet.
A release layer may be formed on the surface of the release sheet 5 in contact with the pressure-sensitive adhesive sheet 10. For this release layer, various release agents generally used for the release layer of this type of release sheet 5 are used. Examples include long-chain alkyl release agents such as long-chain alkyl acrylate copolymers, long-chain alkyl vinyl ester copolymers, and long-chain alkyl vinyl ether copolymers, silicone-based release agents, and fluorine-based release agents. . Moreover, since the unevenness | corrugation of a release sheet is transcribe | transferred to the surface of an adhesion layer, surface roughness Ra has the preferable range of about 1-0.01 micrometer. Also. The thickness of the release sheet 5 is a thickness that does not hinder roll winding, and is preferably as thin as possible from the viewpoint of reducing the amount of disposal, and is preferably about 5 to 300 μm, more preferably about 15 to 150 μm. Specific examples of the release sheet made of polyethylene terephthalate (PET) include those commercially available from Tosero Co., Ltd. under the trade name: Tosero Separator SP (registered trademark). Specific examples of the release sheet made of processed paper include those commercially available from Oji Paper Co., Ltd. as “Separate” under the trade name Oji Paper.

    In order to produce the pressure-sensitive adhesive sheet, the method for laminating the pressure-sensitive adhesive layer on one surface of the base material layer 1 is not particularly limited. For example, an olefin polymer that has been molded in advance by a known inflation method, T-die method, calendar method, or the like. The base material sheet (base material layer) is subjected to a surface treatment such as corona treatment, and then the adhesive material is applied and dried, or the base material of the olefin polymer preformed after the adhesive material is applied to the release sheet and dried. It can be produced by a method of pressure bonding with a sheet (base material layer), a co-extrusion method in which the adhesive layer and the base material layer are integrally formed simultaneously, or a method in which the adhesive layer is melt-extruded and laminated on a preformed base material layer. Among these production methods, the co-extrusion method is a method of producing a laminated sheet having a multilayer structure having a predetermined thickness by melting and heating the materials constituting the base layer and the adhesive layer, respectively. High efficiency and energy saving are preferable because they can be manufactured at low cost. Moreover, the pressure-sensitive adhesive sheet having one or more base material layers and the pressure-sensitive adhesive layer can be simultaneously formed by a coextrusion method using two or more multilayer T-dies. As a co-extrusion method using a multilayer T die, for example, a method in which melts of layers are combined in advance in a layered form and fed into a flat die and adhered in a die (feed block method), and a melt of each layer is flattened. Sending to another manifold in the die, and joining the layers together in layers at a common location in the die (generally before the entrance to the die lip) and feeding them to the flat die and bonding them in the die (multiple manifolds And a combination of a feed block method and a multi-manifold method.

There is no restriction | limiting in particular in the method of laminating | stacking the adhesive sheet 10 and the peeling sheet 5 which were manufactured in this way, For example, it can laminate | stack with a normal sheet laminating apparatus.
As shown in FIG. 5, the pressure-sensitive adhesive sheet 10 of the present invention can be wound around the core material 6 and stored in a roll shape, and can be used by being pulled out by a necessary amount.
As shown in FIG. 6, the release sheet 5 can be attached to the adhesive layer side of the adhesive sheet 10 of the present invention, wrapped around the core material 6 and stored in a roll shape, and the required amount can be pulled out while peeling the release sheet 5. Can be used.

As shown in FIG. 7, the pressure-sensitive adhesive sheet 10 of the present invention can be punched and held on the release sheet 5 in a shape (for example, a circle) optimum for the application used, and can be wound around the core material 6 and stored in a roll shape. The required amount can be pulled out and used while peeling the release sheet 5. Although the shape is not limited at all, it may be any of a circle, a square, a rectangle, etc. For example, a part of the pressure-sensitive adhesive sheet 10 may be left on the release sheet 5 in a required shape and punched out. The pressure-sensitive adhesive sheet 10 according to the present invention is used for various known applications. The application in which the pressure-sensitive adhesive sheet is used is not limited in any way, but is suitable for surface protection applications involving cutting, chemical treatment applications, and dicing applications. Hereinafter, these uses will be described.

    The pressure-sensitive adhesive sheet 10 of the present invention can be preferably used for surface protection including cutting into a desired shape with the pressure-sensitive adhesive sheet attached to the surface of the adherend. For the cutting process, a rotating blade made of metal or diamond, a laser, a water jet, or the like is usually used. Since the pressure-sensitive adhesive sheet 10 of the present invention has a specific tensile elastic modulus and tear strength, it can be processed with high accuracy without occurrence of chipping on the cut surface, and further, generation of thread-like burrs and adhesion of cutting chips can be suppressed. Therefore, it can be preferably used for a pressure-sensitive adhesive sheet for surface protection that involves cutting processing of electronic circuit materials, semiconductor materials, optical materials, and the like that are demanding for performance and quality.

Hereinafter, as an example of a chemical treatment application, a method used in a plating process in the field of electronic circuit materials will be described.
First, the pressure-sensitive adhesive sheet 10 is punched into a shape corresponding to the shape of the printed circuit board and the circuit pattern, and the pressure-sensitive adhesive sheet 10 is bonded to the printed circuit board, and in some cases, is heat-pressed to complete the space between the pressure-sensitive adhesive sheet and the printed circuit board. Adhere closely. Next, the parts such as terminals to be plated and the parts not to be plated and circuits, etc. are protected with high precision, soaked in a plating solution heated to about 40 ° C to about 95 ° C, washed with water and dried, then the adhesive sheet Peel off. The used pressure-sensitive adhesive sheet is subjected to disposal such as incineration.
Examples of the printed board include a board formed of a metal such as copper or aluminum as a conductor on a board formed of a glass, ceramic, plastic, or the like as an insulator. The thickness of the printed board is usually several tens of μm to several mm, the area is usually several cm ² to several thousand cm ² , and the shape is various such as a circle, a square, and a rectangle. The adhesive sheet used is also cut into various shapes.
As plating, electroplating and electroless plating are generally known. Electroplating is a method in which an aqueous solution of an acidic or alkaline metal electrolyte is used as a plating solution, and a desired metal is deposited by electric energy using an object to be plated as a cathode. On the other hand, electroless plating is a method in which a metal film can be obtained by immersing an object to be plated in a metal salt solution containing a soluble reducing agent, a pH adjuster, a plating solution stabilizer and the like. This is the method used. On a printed board, various metals and alloy plating such as copper plating, nickel plating, gold plating, palladium plating and tin plating are performed by electroplating or electroless plating. However, electroless plating is mainly used for printed circuit boards that require thinning and densification, especially flexible printed circuit boards, because there is no need to wire the object to be plated and the uniformity of the plated metal film is excellent. It is done.

    However, electroless plating has a problem in productivity because the deposition rate of metal is slower than electroplating. The electroless plating includes electroless nickel plating, electroless copper plating, electroless cobalt plating, electroless tin plating, electroless palladium plating, electroless silver plating, electroless gold plating, etc. For plating, nickel plating, gold plating, copper plating, palladium plating, and tin plating are used as appropriate to meet various requirements such as electrical conductivity, wear resistance, rust prevention, hardness, dimensional accuracy, weather resistance, and chemical resistance. . The temperature of the nickel plating solution is, for example, about 60 to about 95 ° C., and the pH is, for example, about 3 (acidic) to about 11 (alkaline). The temperature of the gold plating solution is about 70 ° C. to about 80 ° C., and the pH is about 12 to about 14, for example. The temperature of the copper plating solution is about 40 ° C. to about 60 ° C., and the pH is about 12 to about 13, for example. In addition, as a pretreatment for plating, an etching process such as sulfuric acid and various surface activation processes are appropriately performed in order to remove an oxide film such as copper oxide.

Recently, thinning of a flexible printed circuit board has progressed. For example, a polyimide base sheet having a thickness of 13 μm and a circuit formed of a copper foil having a thickness of 18 μm or less are generally used. There is a stricter requirement for the pressure-sensitive adhesive sheet used in the process of processing a flexible printed circuit board in which the circuit density and the thickness have been reduced.
In other words, it is highly resistant to chemical treatment solutions such as plating solutions and etching solutions that show acidity to alkalinity heated to about 40 ° C to about 95 ° C, and high punching workability with high accuracy of flexible printed circuit boards. Required for the sheet.
The pressure-sensitive adhesive sheet of the present invention is free from the occurrence of thread-like burrs due to punching and has excellent processing accuracy and stability against chemical treatment liquids such as plating solutions and etching solutions. There is no adhesion of contaminants from the adhesive sheet. Therefore, the pressure-sensitive adhesive sheet 10 of the present invention can be used without any problem in quality without washing the printed circuit board or the flexible printed circuit board with a chlorofluorocarbon organic solvent, thereby reducing the burden on the environment.
Further, the pressure-sensitive adhesive sheet 10 of the present invention protects the non-chemically treated surface when various kinds of adherends are treated with acid-alkali chemicals other than the plating process in the manufacturing process of electronic circuit materials and semiconductor materials. It is suitable as a protective sheet.

Next, a method used for dicing will be described.
In the dicing application, the pressure-sensitive adhesive sheet 10 of the present invention and the adherend wafer are pressure-bonded at room temperature or heated, and then the wafer is cut into chips (dicing), washed and dried in a room temperature environment, and then the pressure-sensitive adhesive sheet. The process of expanding the sheet and then picking up the chip and peeling it from the adhesive sheet is performed. In the case of the pressure-sensitive adhesive sheet 10 of the present invention, the pressure-sensitive adhesive sheet and the wafer can be closely attached to each other with no gap therebetween, so that the chip does not fall off during the respective steps.
The wafer may be any general solid material. For example, semiconductor materials include elemental semiconductors such as silicon, germanium, selenium, and tellurium; binary compound semiconductors such as GaAs, GaP, and InSb. Ternary compound semiconductors such as AlGaAs; quaternary compound semiconductors such as AlGaInAs; metal oxide semiconductors such as SnO ₂ , ZnO, TiO ₂ , and Y ₂ O ₅ . Examples of the electronic circuit material include those obtained by covering an electronic circuit formed on the wafer made of the semiconductor material with a hard plastic material, and examples of the optical material include glass and ceramic. The wafer has a thickness of about several tens of μm to several mm, and the wafer has an area of about several tens of mm ² to several 1000 cm ^2. The shape of the wafer may be any of a circle, a square, a rectangle, and the like.

The base material layer 1 of the present invention is made of an olefin polymer having an excellent elongation characteristic and has an excellent cutting workability, so that the cutting waste derived from cutting does not grow and is washed in a fine state. It flows out by water, there is no sticking of cutting waste to the chip, and it has sufficient expandability after dicing.
In addition, since the pressure-sensitive adhesive sheet 10 of the present invention can suppress the growth of cutting waste even under dicing conditions in which cutting waste is likely to be generated, the diamond rotary blade does not meander with the cutting waste, so that chip chipping can be reduced. .
Furthermore, the pressure-sensitive adhesive sheet 10 of the present invention can reduce the amount of wear of metal blades and diamond blades used for punching and dicing.
In addition, the pressure-sensitive adhesive sheet 10 of the present invention can be machined with high accuracy without any occurrence of chipping on the cut surface, and can further suppress the occurrence of thread-like burrs and the attachment of cutting waste. It can also be applied to adhesive sheets.

  Examples The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The physical property test methods (A) to (C) used in the present invention are described below.

(A) Tensile modulus In accordance with the test method for plastic tensile properties described in JIS K7161, specimens in the longitudinal and transverse directions are prepared from an adhesive sheet and pulled in an environment of a temperature of 23 ° C. and a relative humidity of 50%. The test was conducted. From the stress-strain curve obtained from this tensile test, the tensile modulus was calculated from the tensile stress measured at two specified strains. The tensile elastic modulus (23 ° C.) shown in the examples described later is an average value measured at least 5 times, and the unit is MPa.

(B) Tear strength Plastics described in JIS K7128-2-Test method for tear strength of films and sheets-Part 2: Preparation of longitudinal and lateral specimens from adhesive sheet in accordance with Elmendorf tear method The tear strength test was conducted in an environment at a temperature of 23 ° C. and a relative humidity of 50%. The tear strength (23 ° C.) shown in the examples described later is an average value measured at least 5 times, and the unit is N / mm.

(C) Adhesive strength In accordance with the adhesive sheet test method described in JIS Z0237, an adhesive strength test was performed in an environment of a temperature of 23 ° C. and a relative humidity of 50%. Affix the adhesive sheet to the SUS-BA board with a pressure of about 2kg with a rubber roll and place it on the test board for 30 minutes in a constant environment at a temperature of 23 ° C and a relative humidity of 50%. The adhesive strength was measured while peeling from the test plate at a speed of 300 mm / min. The adhesive strength (23 ° C.) shown in the examples described later is an average value measured at least twice, and the unit is N / 25 mm.
In Examples 1 to 3, specific examples suitable for surface protection applications will be described based on (D) evaluation of surface protection suitability, but the present invention is not limited to these Examples.

(Example 1)
The following materials were used as the material of each layer constituting the pressure-sensitive adhesive sheet 10. That is, as a component constituting the base material layer 1, 30 parts by weight of a syndiotactic propylene polymer (s-PP; manufactured by ATOFINA PETROCHEMICALS, INC .: FINAPLAS ^™ 1571; density 0.87 g / cm ³ ) and high-density polyethylene (HDPE; density 0.96 g / cm ³ ) 10 parts by weight and low density polyethylene (LDPE; density 0.92 g / cm ³ ) 60 parts by weight. 60 parts by weight of a butene / 4-methyl-1-pentene copolymer (PB (4-MP); propylene component 43 mol%, 1-butene component 26 mol%, 4-methyl-1-pentene component 31 mol%) , ethylene-propylene copolymer (EP-A; ethylene component 81 mol%, of propylene 19 mol%, a density 0.87g / ^cm 3) 5 15 parts by weight of the same LDPE as the base material layer 1, 15 parts by weight of styrene / isoprene / styrene block copolymer (SIS; SIS5229N manufactured by JSR Corporation), ethylene and α-olefin co-oligomer ( LEO; 5 parts by weight of Lucant ^™ HC-20 manufactured by Mitsui Chemicals, Inc. was used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were adhesive layer 2: 220 ° C. and base material layer 1: 230 ° C. The two layers of molten resin were laminated in a multilayer die (co-extrusion temperature: 230 ° C.). The extruded adhesive sheet was cooled, slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate of a base material layer 1 and a pressure-sensitive adhesive layer 2 made of a single layer, and the thickness of each layer is pressure-sensitive adhesive layer 2: 8 μm and base material layer 1: 42 μm. The total thickness was 50 μm.
(A) Tensile elastic modulus, (B) Tear strength, (C) Adhesive strength were tested according to the physical property test method described above, and the results are shown.

(A) Tensile modulus (23 ° C)
Tensile modulus in the machine direction (MD-M): 240 MPa
Transverse tensile modulus (TD-M): 170 MPa
(B) Tear strength (23 ° C)
Longitudinal tear strength (MD-T): 30 N / mm
Lateral tear strength (TD-T): 58 N / mm
(C) Adhesive strength (23 ° C. vs. SUS-BA plate)
1.2N / 25mm
Next, the obtained adhesive sheet 10 was evaluated according to the following (D) surface protection suitability.

(D) Surface protection suitability
A pressure-sensitive adhesive sheet as a test piece was affixed on a 300 mm × 300 mm × 1 mm thick acrylic plate without any gaps, placed in a drying oven set at a temperature of 80 ° C. for 30 minutes, and then cut with a rotary saw blade.
As evaluation criteria, a case where no thread-like burrs are generated on the cut surface and there is no contamination such as attachment of cutting waste is accepted (indicated by a circle), and a case where thread-like burrs are generated on the cut surface or cutting is performed. A case where there was contamination such as adhesion of waste was regarded as rejected (indicated by x). In addition, the presence or absence of contaminants such as thread-like burrs and adhesive residue was determined by observation with an optical microscope (magnification 200 times).
The obtained adhesive sheet 10 showed that it was excellent in the surface protection use accompanying a cutting process.
Table 1 shows the layer configuration of the pressure-sensitive adhesive sheet 10, the components constituting each layer and their weight ratios, and the thickness of each layer. Table 2 shows the results of testing the obtained adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. In addition, Table 3 shows the results of evaluating the (D) surface protection suitability of the obtained pressure-sensitive adhesive sheet 10.

(Example 2)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, 60 parts by weight of the same s-PP as in Example 1 and a propylene / ethylene / 1-butene random copolymer (r -PP; ethylene component 5 mol%, 1-butene component 5 mol%) 30 parts by weight and HDPE 10 parts by weight as in Example 1 were used. 80 parts by weight of the same HDPE and 20 parts by weight of the same LDPE as in Example 1, and 60 parts by weight of PB (4-MP) as in Example 1 as the component of the adhesive layer 2 and the same EP as in Example 1 -A 5 parts by weight, propylene polymer (h-PP; density 0.91 g / cm ³ ) 10 parts by weight, styrene / ethylene / butylene / styrene block copolymer (SEBS-A; DYNARON manufactured by JSR Corporation) ^TM 9901P) 10 weight It was used and the same SIS 10 parts by weight as in Example 1, and the same LEO 5 parts by weight as in Example 1.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 230 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded adhesive sheet was cooled, slit and wound around the core material 6. The pressure-sensitive adhesive sheet 10 thus obtained is a laminate of a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers. The thickness of each layer is pressure-sensitive adhesive layer 2: 8 μm, intermediate layer 3: 34 μm, outer layer. 4: 8 μm, and the total thickness was 50 μm.
Table 1 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 2 shows the results of testing the obtained pressure-sensitive adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. In addition, Table 3 shows the results of evaluating the (D) surface protection suitability of the obtained pressure-sensitive adhesive sheet 10.

(Example 3)
As the material of each layer constituting the pressure-sensitive adhesive sheet 10, 90 parts by weight of the same s-PP as in Example 1 and 10 parts by weight of HDPE as in Example 1 are used as the components of the intermediate layer 3 in the base material layer 1. In the material layer 1, the same components and weight ratio as in Example 2 were used as the components of the outer layer 4, and the same components and weight ratio as in Example 2 were used as the components of the adhesive layer 2.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 230 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded adhesive sheet was cooled, slit and wound around the core material 6. The pressure-sensitive adhesive sheet 10 thus obtained is a laminate of a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers. The thickness of each layer is pressure-sensitive adhesive layer 2: 8 μm, intermediate layer 3: 24 μm, outer layer. 4: 8 μm, and the total thickness was 40 μm.
Table 1 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 2 shows the results of testing the obtained adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. In addition, Table 3 shows the results of evaluating the (D) surface protection suitability of the obtained pressure-sensitive adhesive sheet 10.

In Examples 4 to 6 and Comparative Example 1, specific examples suitable for chemical treatment applications will be described based on (E) evaluation of chemical treatment suitability, but the present invention is not limited to these examples.

Example 4
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, 80 parts by weight of s-PP same as that of Example 1 and 20 parts by weight of h-PP same as those of Example 2 are used as components of the base material layer 1. As components, 70 parts by weight of the same PB (4-MP) as in Example 1, 5 parts by weight of EP-A as in Example 1, 10 parts by weight of h-PP as in Example 2, and olefin (crystallinity) And 15 parts by weight of ethylene / butylene / olefin (crystalline) block copolymer (CEBC; DYNARON ^™ 6200P, manufactured by JSR Corporation).
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were pressure-sensitive adhesive layer 2: 230 ° C. and base material layer 1: 230 ° C. These two layers of molten resin were laminated in a multilayer die (co-extrusion temperature: 230 ° C.). The extruded pressure-sensitive adhesive sheet was cooled, and Tosero Separator ^TM SP T18 (PET-SP, thickness 50 μm) manufactured by Tosero Co., Ltd. was provided on the pressure-sensitive adhesive layer surface as a release sheet 5, and then slit and wound. The pressure-sensitive adhesive sheet 10 thus obtained is a laminate of a base material layer 1 and a pressure-sensitive adhesive layer 2 consisting of two layers. The thickness of each layer is: pressure-sensitive adhesive layer 2: 20 μm, base material layer 1: 100 μm. The total thickness was 120 μm.
Next, the obtained adhesive sheet 10 was evaluated according to the following (E) chemical treatment suitability.

(E) Chemical treatment suitability As shown in the wafer surface schematic diagram of FIG. 8, a silicon wafer having a diameter of 100 mm is adopted as the chemical suitability test wafer 21, and a pH test paper 20 is placed thereon, and the wafer cross-sectional schematic diagram of FIG. As shown in Fig. 1, the adhesive sheet 10 which is a test piece punched out to φ98mm is pasted without any gaps, and placed in an environment at a temperature of 23 ° C and a relative humidity of 50% for 30 minutes, and then HF / HNO ₃ / CH ₃ COOH = 1 / 9/3 (hydrofluoric acid / nitric acid / acetic acid mixed solution), HCl / HNO ₃ = 1/3 (aqua regia), 10% NH ₄ OH (ammonia water) in 3 types of chemical solutions at a temperature of 23 ° C. And soaked for 30 minutes.

As an evaluation standard, a case where the pH test paper retains the pH 7 color and there is no contamination such as adhesive residue on the chemical aptitude test wafer 21 is accepted (indicated by a circle), and the pH test paper has a pH 7 color. When the contaminant is generated only in the peripheral part of the adhesive sheet 10 that is held and stuck on the chemical aptitude test wafer 21, it is determined to be inappropriate (indicated by Δ), and the PH test paper changes, or for the chemical aptitude test A case where contamination such as adhesive residue occurred on the wafer 21 was determined to be rejected (indicated by x). In addition, the presence or absence of contaminants such as adhesive residue was determined by observation with an optical microscope (magnification 200 times). In the case of the unsuitability, the contaminants generated in the peripheral part of the pressure-sensitive adhesive sheet 10 can be removed by washing with water.
The obtained pressure-sensitive adhesive sheet 10 was found to be excellent in acidic to alkaline chemical treatment applications with no change in pH test paper, no contamination, and any chemical solution of hydrofluoric acetic acid, aqua regia or ammonia water. .

    Table 4 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 5 shows the results of testing the obtained adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 6 shows the results of evaluating the (E) chemical treatment suitability of the obtained pressure-sensitive adhesive sheet 10.

(Example 5)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, 40 parts by weight of the same s-PP as in Example 1 and 40 parts by weight of h-PP as in Example 2 as components of the intermediate layer 3 in the base material layer 1, Using 10 parts by weight of HDPE as in Example 1 and 10 parts by weight of a PP blue pigment (b-dye; 5B-E5133MB blue manufactured by Nippon Pigment Co., Ltd.) 100 parts by weight of HDPE as in Example 1 above, 70 parts by weight of PB (4-MP) as in Example 1 and 6 parts by weight of CEBC as in Example 4 and Example 1 as components of the adhesive layer 2 6 parts by weight of the same SIS, 15 parts by weight of styrene / ethylene / butylene / olefin (crystalline) block copolymer (SEBS-A; DYNARON ^™ 9901P manufactured by JSR Corporation), and 3 parts by weight of LEO as in Example 1 And were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded adhesive sheet 10 was cooled, and the same PET-SP (thickness 50 μm) as that of Example 4 was provided on the adhesive layer surface as the release sheet 5, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2: 20 μm, intermediate layer 3: 70 μm, outer layer 4: 10 μm, and the total thickness was 100 μm.
Table 4 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 5 shows the results of testing the obtained pressure-sensitive adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 6 shows the results of evaluating the (E) chemical treatment suitability of the obtained pressure-sensitive adhesive sheet 10.

(Example 6)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, as a component of the intermediate layer 3 in the base layer 1, 40 parts by weight of s-PP same as Example 1, 40 parts by weight of r-PP same as Example 2, 10 parts by weight of HDPE as in Example 1 and 10 parts by weight of b-dye as in Example 5 were used, and 100 parts by weight of HDPE as in Example 1 was used as a component of the outer layer 4 in the base material layer 1. As the adhesive layer 2, the same components and weight ratio as those of the adhesive layer 2 of Example 5 were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 was cooled, and the same PET-SP (thickness 50 μm) as that of Example 4 was provided on the pressure-sensitive adhesive layer surface as the release sheet 5, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2: 20 μm, intermediate layer 3: 70 μm, outer layer 4: 10 μm, and the total thickness was 100 μm.
Table 4 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 5 shows the results of testing the obtained pressure-sensitive adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 6 shows the results of evaluating the (E) chemical treatment suitability of the obtained pressure-sensitive adhesive sheet 10.

(Comparative Example 1)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, 70 parts by weight of the same h-PP as in Example 2 and 20 parts by weight of HDPE as in Example 1 are used as components of the intermediate layer 3 in the base material layer 1. 10 parts by weight of b-dye same as 5 and 100 parts by weight of HDPE same as that of Example 1 as a component of the outer layer 4 in the base material layer 1, and the adhesive layer 2 of Example 5 as the adhesive layer 2 The same components and their weight ratios were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 was cooled, and the same PET-SP (thickness 50 μm) as that of Example 4 was provided on the pressure-sensitive adhesive layer surface as the release sheet 5, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2: 20 μm, intermediate layer 3: 70 μm, outer layer 4: 10 μm, and the total thickness was 100 μm.
Table 4 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 5 shows the results of testing the obtained pressure-sensitive adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 6 shows the results of evaluating the (E) chemical treatment suitability of the obtained pressure-sensitive adhesive sheet 10.

    In the pressure-sensitive adhesive sheet 10 of Comparative Example 1, the tensile modulus ratio {(MD-M) / (TD-M)} in the machine direction and the transverse direction exceeds 2, and the tear strength ratio in the machine direction and the transverse direction {( MD-T) / (TD-T)} is less than 0.5. (E) Evaluation of chemical treatment suitability is based on PH test paper because chemicals penetrated from the burr part generated around the adhesive sheet during punching. Discolored and failed (x).

    In Examples 7 to 9 and Comparative Example 2, specific examples suitable for chemical treatment of flexible printed circuit boards will be described based on (F) evaluation of plating suitability, but the present invention is limited to these examples. Not a thing.

(Example 7)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, as a component of the base material layer 1, 60 parts by weight of s-PP same as Example 1, 32 parts by weight of h-PP same as Example 2, and the same as Example 1 2 parts by weight of HDPE and 6 parts by weight of b-dye as in Example 5, and 62 parts by weight of PB (4-MP) as in Example 1 as the component of the adhesive layer 2 and the same as in Example 2 3 parts by weight of PP, 10 parts by weight of CEBC as in Example 4, 22 parts by weight of SIS as in Example 1, and 3 parts by weight of LEO as in Example 1 were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were adhesive layer 2: 220 ° C. and base material layer 1: 230 ° C. The two layers of molten resin were laminated in a multilayer die (co-extrusion temperature: 230 ° C.). After the extruded pressure-sensitive adhesive sheet was cooled and a release sheet 5 was provided with a separator 64GPA (P) white (GP-SP; processed sheet with glassine paper as a core material, thickness 95 μm) manufactured by Oji Paper Co., Ltd. on the pressure-sensitive adhesive layer surface , Slit and wound up. The pressure-sensitive adhesive sheet 10 thus obtained is a laminate of a base material layer 1 and a pressure-sensitive adhesive layer 2 consisting of two layers. The thickness of each layer is: pressure-sensitive adhesive layer 2: 15 μm, base material layer 1: 60 μm. The total thickness was 75 μm.
Next, the obtained adhesive sheet 10 was evaluated according to the suitability for plating (F) shown below.

(F) Plating suitability The plating suitability of the present invention was evaluated based on the observation results on 1) plating resistance and 2) plating workability, after plating on a flexible printed circuit board under the test conditions shown below.
As shown in the surface schematic diagram of FIG. 9, the plating aptitude test substrate 30 has a neoprex (product type: NEX-131R (13H), polyimide substrate thickness 13 μm, copper foil thickness 18 μm) manufactured by Mitsui Chemicals, Inc. A flexible printed circuit board (copper wire width 25 μm, interval 25 μm) in which a circuit made of copper foil was formed on a base material made of polyimide by etching with a ferric chloride aqueous solution was used. An acidic etching solution consisting of sulfuric acid and ammonium hydrogen fluoride is formed by punching and opening a 5 mm × 10 mm window in the center of a 40 mm × 100 mm plating test substrate 10 and heating it to 80 ° C. with a roll. (PH = 1) to remove oxides such as copper oxide and wash with water, soak in nickel plating solution (pH = 4) heated to 85 ° C. for 30 minutes, wash with 20 ° C. water, and further to 80 ° C. It was immersed in a heated gold plating solution (pH = 13) for 20 minutes, washed with water at 20 ° C., dried, and then peeled off the adhesive sheet of the test piece to prepare a plated evaluation substrate. The nickel plating solution includes nickel sulfate (0.1M), sodium phosphinate (0.3M), sodium acetate (0.12M), succinic acid (0.08M), lactic acid (0.33M), citric acid. An electroless Ni-P alloy plating bath (pH 4) mainly composed of acid (0.05M) and phosphonic acid (0.38M) is used, and the gold plating solution includes potassium gold cyanide (0.03M) and potassium cyanide. An electroless gold plating bath (pH 13) containing (0.1M), potassium hydroxide (0.2M) and potassium borohydride (0.1M) as main components was used. The plated test substrate is not cleaned with an organic solvent such as chlorofluorocarbon, using an optical microscope (200 times magnification), as shown in FIG. 9, the presence of adhesive residue 31 and the presence of plating solution soak 32 The plating resistance was evaluated according to the following criteria.

1) Evaluation Criteria for Plating Resistance As shown in the schematic diagram of the surface after plating in FIG. 9, the plating suitability test substrate 30 in which the test piece 10 is peeled off after plating is a non-plated portion where the test piece is covered. A portion not covered with the test piece becomes a plated portion, and a boundary thereof becomes a plated end portion. As shown in the example of contaminants in FIG. 9, the adhesive residue 31 is contamination derived from the adhesive layer generated in the non-plated portion, while the soaking residue 32 is contamination of the plating bath generated at the plating end portion or contamination from the adhesive layer. It is. A case where no adhesive residue and no soaking residue was observed even when observed with an optical microscope with a magnification of 200 was used as a criterion for determination that no adhesive residue or soaking residue was present.
5 plating test substrates with no glue residue and no soaking residue were accepted (indicated by ◯), and one with no glue residue and soaking residue was judged as unacceptable (indicated by x). .
Furthermore, the five plating test substrates used in the test were visually observed for abnormalities such as creases and wrinkles, and the plating workability was evaluated according to the following criteria.

2) Evaluation criteria for plating workability 5 plating test substrates with no creases or wrinkles are accepted (indicated by a circle), and folds or wrinkles that have occurred at one location are rejected (× Show).
As described above, the evaluation standard of the plating suitability test is that an adhesive sheet that has passed both 1) plating resistance and 2) plating workability has excellent plating suitability of the present invention.
The obtained pressure-sensitive adhesive sheet 10 was excellent in 1) plating suitability and 2) plating workability and was suitable for plating applications.

    Table 7 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. In Table 8, the test result of the obtained adhesive sheet 10 is shown about (A) tensile elasticity modulus, (B) tear strength, and (C) adhesive force. Table 9 shows the evaluation results of (F) plating suitability.

(Example 8)
As the material of each layer constituting the pressure-sensitive adhesive sheet 10, as the intermediate layer 3 of the base material layer 1, the same components and weight ratio as those of the base material layer 1 of Example 7 are used. As components, 80 parts by weight of HDPE as in Example 1 and 20 parts by weight of LDPE as in Example 1 are used. As components of the adhesive layer 2, the same components and weight ratio as those of the adhesive layer 2 in Example 7 are used. Using.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 was cooled, and the same GP-SP (thickness 95 μm) as that of Example 7 was provided as the release sheet 5 on the pressure-sensitive adhesive layer surface, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2: 15 μm, intermediate layer 3: 52 μm, outer layer 4: 8 μm, and the total thickness was 75 μm.
Table 7 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 8 shows the results of testing the obtained adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 9 shows the results of evaluating the suitability of the obtained pressure-sensitive adhesive sheet 10 for (F) plating.

Example 9
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, as a component of the intermediate layer 3 in the base material layer 1, 42 parts by weight of s-PP same as Example 1, 42 parts by weight of r-PP same as Example 2, Using 10 parts by weight of an ethylene / butene copolymer (EB-A; density 0.87 g / cm ³ ) and 6 parts by weight of b-dye as in Example 5 as the outer layer 4 of the substrate layer 1 The same components and weight ratio as those of the outer layer 4 in Example 8 were used, and the same components and weight ratio as those of the adhesive layer 2 of Example 7 were used as the adhesive layer 2.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 was cooled, and the same GP-SP (thickness 95 μm) as that of Example 7 was provided as the release sheet 5 on the pressure-sensitive adhesive layer surface, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2: 15 μm, intermediate layer 3: 52 μm, outer layer 4: 8 μm, and the total thickness was 75 μm.
Table 7 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 8 shows the results of testing the obtained adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 9 shows the results of evaluating the suitability of the obtained pressure-sensitive adhesive sheet 10 for (F) plating.

(Comparative Example 2)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, 84 parts by weight of the same r-PP as in Example 2 and 10 parts by weight of EB-A as in Example 9 as components of the intermediate layer 3 in the base material layer 1, Using 6 parts by weight of the same b-dye as in Example 5, using the same components and weight ratio as those of the outer layer 4 of Example 8 as the outer layer 4 in the base material layer 1, and using as the adhesive layer 2 Example 7 The same components and weight ratio as those of the adhesive layer 2 were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 was cooled, and the same GP-SP (thickness 95 μm) as that of Example 7 was provided on the pressure-sensitive adhesive layer surface as the release sheet 5, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2: 15 μm, intermediate layer 3: 52 μm, outer layer 4: 8 μm, and the total thickness was 75 μm.
Table 7 shows the layer structure of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 8 shows the results of testing the obtained pressure-sensitive adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 9 shows the results of evaluating the suitability of the obtained pressure-sensitive adhesive sheet 10 for (F) plating.

    In the pressure-sensitive adhesive sheet 10 of Comparative Example 2, the tear strength (MD-T) in the longitudinal direction is higher than the tear strength ratio {(MD-T) / (TD-T)} in the longitudinal direction and the transverse direction. (F) Evaluation of plating suitability is as follows. 1) Regarding plating resistance, a chemical solution used in the plating test entered from a burr generated around the adhesive sheet at the time of punching, as shown in FIG. A soaking residue 32 was generated and the result was rejected (x).

In Examples 10 to 11 and Comparative Example 3, specific examples suitable for dicing use will be described based on (G) evaluation of dicing suitability, but the present invention is not limited to these examples.

(Example 10)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, 20 parts by weight of s-PP same as Example 1 and 40 parts by weight of EB-A same as Example 9 as a component of the intermediate layer 3 in the base material layer 1, The same LDPE as in Example 1 was used, 40 parts by weight, the same as in Example 1 as the component of the adhesive layer 2, using 100 parts by weight of the same LDPE as in Example 1 as the component of the outer layer 4 in the base material layer 1 60 parts by weight of PB (4-MP), 10 parts by weight of CEBC as in Example 4, 10 parts by weight of SIS as in Example 1, and a styrene / ethylene / butylene / styrene block copolymer (SEBS-B; JSR) 15 parts by weight of DYNARON ^™ 8601P manufactured by Co., Ltd. and 5 parts by weight of the same LEO as in Example 1 were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 is cooled, and a Tocelo separator ^TM SP T18 (PET-SP, thickness 31 μm) manufactured by Tosero Co., Ltd. is provided as a release sheet 5 on the surface of the pressure-sensitive adhesive layer. It was.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2:15 μm, intermediate layer 3:75 μm, outer layer 4:10 μm, and the total thickness was 100 μm.
Next, the obtained adhesive sheet 10 was evaluated according to the following (G) dicing suitability.

(G) Dicing suitability The dicing suitability of the present invention is as follows. 1) Chip fixing force, 2) Chip chipping, 3) Contamination, 4) Expandability, 5) Pickup Evaluation was made based on the observation results regarding sex.

    1) Tip fixing force

As shown in the attaching step of FIG. 10, using a mounter (HS-7800 manufactured by Hugle Electronics) at the attaching temperature (50 ° C.) at which no chip jump occurs, the adhesive sheet 10 as a test piece is interposed. Then, as the wafer 21 for dicing aptitude test, a back ground surface (finish roughness # 2000) of φ150 mm silicon wafer 40 (P type, thickness 600 μm) is attached to a frame 41 (MDFTF-2-6-1-H manufactured by DISCO). Then, set it on a dicer (DAD320 manufactured by DISCO) and rotate the blade (type: NBC-ZH-205F-SE, size: 27HEGH) at a rotational speed of 40000 rotations / min, cutting speed 60 mm / sec, cutting depth is full cut The film is cut to a depth of 30 μm, and the amount of cutting water (using constant temperature water at 20 ° C.) is 1.0 L / min from the nozzle to the wafer surface, and 1.0 L / min from the rotating blade incident nozzle. And, it was diced into 1mm × 1mm angle size of the chip.
As an evaluation standard of the chip fixing force, a case where a triangular chip on the periphery of a wafer having a chip area exceeding about 0.1 mm ² per one 6-inch wafer does not scatter is indicated as pass (indicated by a circle), and the triangle A case where even one or more chips were scattered was regarded as a failure (indicated by x).

    2) Chip chipping and 3) Contamination

    As shown in the attaching step of FIG. 10, using a mounter (HS-7800 manufactured by Hugle Electronics) at the attaching temperature (50 ° C.) at which no chip jump occurs, the adhesive sheet 10 as a test piece is interposed. Then, as the wafer 21 for dicing aptitude test, a back ground surface (finish roughness # 2000) of φ150 mm silicon wafer 40 (P type, thickness 600 μm) is attached to a frame 41 (MDFTF-2-6-1-H manufactured by DISCO). And then set on a dicer (DAD320 manufactured by DISCO), the blade (type: NBC-ZH-205F-SE, size: 27HEGH) rotation speed 40000 rotation / min, cutting speed 60mm / sec, cutting depth is full cut The film is cut to a depth of 30 μm, and the amount of cutting water (using constant temperature water at 20 ° C.) is 1.0 L / min from the nozzle to the wafer surface, and 1.0 L / min from the rotating blade incident nozzle. And, it was diced into chips of 0.95mm × 17.39mm angle size.

    2) As an evaluation standard for chip chipping, as shown in a schematic cross-sectional view at the time of cutting shown in FIG. 10, with respect to 100 chips randomly selected from one wafer, an optical microscope (200 times magnification) was used. The maximum length (μm) of the chip chip 42 generated from the cut surface of the chip was measured. In 100 chips, the case where all chip chips 42 were within 15 μm was determined to be acceptable (indicated by ◯), and the case where even one chip chip 42 exceeding 15 μm occurred was determined to be unacceptable (indicated by ×).

    3) As an evaluation standard for contamination, as shown in the cross-sectional schematic diagram in the cutting process shown in FIG. 10, 100 chips randomly selected from one wafer were examined with an optical microscope (200 times magnification). The presence or absence of cutting waste 43 was observed. In 100 chips, a case where there is no chip to which cutting waste 43 and contaminants such as cutting contaminated water are attached is regarded as acceptable (indicated by a circle), and contaminants such as cutting scrap 43 or cutting contaminated water are attached. A case where even one chip occurred was regarded as a failure (indicated by x).

4) Evaluation of extensibility As shown in the attaching step in FIG. 10, it is a test piece using a mounter (HS-7800 manufactured by Hugle Electronics) at an attaching temperature (50 ° C.) at which no chip jump occurs. A back ground surface (finish roughness # 2000) of a silicon wafer 40 (P type, thickness 400 μm) having a diameter of 150 mm as a dicing suitability test wafer 21 is attached to a frame 41 (MDFTF-2-6-1 manufactured by DISCO) through the adhesive sheet 10. -H) and fixed, then set on a dicer (Disco 320 manufactured by DISCO), blade (type: NBC-ZH-205O-SE, size: 27HEDD) rotation speed 30000 rotations / min, cutting speed 70 mm / sec. The cutting depth is a full cut so that the film is cut to a depth of 30 μm. The cutting water volume (using constant temperature water at 20 ° C) is 1.5 L / min from the nozzle to the wafer surface. And 1.0 L / min, was diced into 3mm × 3mm square size of the chip.
Next, using a wafer expander (HS-1800 manufactured by Hugle Electronics), the pressure-sensitive adhesive sheet after dicing is subjected to room temperature environment (23 ° C., relative humidity 50%), and the pressure-sensitive adhesive sheet portion to which the wafer is attached is diameter. The distance between the chips attached on the pressure-sensitive adhesive sheet was expanded by pushing it up to a stroke of 20 mm with a 180 mm cylindrical pressing tool. As in the cross-sectional schematic diagram at the time of expansion shown in the process of peeling and collecting in FIG. 10, the evaluation of expandability is a pass (indicated by a circle) when all of the following three criteria (a) to (c) are satisfied. The case where any one item could not be achieved was regarded as a failure (indicated by x).
Reference | standard (a): The adhesive sheet thickness which contacted the edge part of the said pressing tool is 90% or more with respect to the thickness of a non-contact part. That is, do not neck.
Standard (b): The extended chip interval is 200 μm or more.
Reference | standard (c): Ratio of the vertical direction of a chip | tip space | interval and a horizontal direction is 0.7 or more and 1.3 or less.

5) Pick-up property As shown in the step of pasting in FIG. 10, using a mounter (HS-7800 manufactured by Hugle Electronics), the pressure-sensitive adhesive sheet as a test piece at a pasting temperature (50 ° C.) at which chip skipping does not occur. 10 is used as a dicing aptitude test wafer 21 and a back ground surface (finish roughness # 2000) of a silicon wafer 40 (P type, thickness 400 μm) of φ150 mm is attached to a frame 41 (MDFTF-2-6-1-H made by DISCO). ), And then set on a dicer (DAD320 manufactured by DISCO), the blade (type: NBC-ZH-205O-SE, size: 27HEDD) rotation speed of 30000 rotations / min, cutting speed of 70 mm / sec, cutting The amount is full cut so that the film is cut to a depth of 30 μm, and the amount of cutting water (using constant temperature water at 20 ° C.) is 1.5 L / min from the nozzle to the wafer surface. And 1.0 L / min from and diced into 5mm × 5mm square size of the chip.
Furthermore, using a pick and place device (DE35 manufactured by Hugle Electronics), the pressure-sensitive adhesive sheet after the dicing process was pulled down at room temperature (23 ° C.) by 5 mm to expand the distance between the tips, and then the needle tip was set to r = 250 μm. The push-up needle rounded to a height of 0.8 mm was examined, and the capture rate (%) under the condition that the pick-up interval was picked up after 0.8 seconds was investigated. The pick-up property was evaluated according to the following criteria. 49 chips (1 tray) were picked up three times, and when all could be picked up, it was accepted (indicated by ◯), and when even one chip could not be picked up, it was rejected (indicated by x).
The obtained pressure-sensitive adhesive sheet 10 is excellent in all of 1) chip fixing force, 2) chip chipping, 3) contamination, 4) expandability, and 5) pick-up property, and is suitable for dicing of silicon wafers. showed that.
Table 10 shows the layer configuration of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 11 shows the results of testing the obtained adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 12 shows the results of evaluating the (G) dicing suitability of the obtained pressure-sensitive adhesive sheet 10.

(Example 11)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, 70 parts by weight of the same s-PP as in Example 1 and 28 parts by weight of EB-A as in Example 9 as components of the intermediate layer 3 in the base material layer 1, Using 2 parts by weight of HDPE as in Example 1, using the same components and weight ratio as those of the outer layer 4 of Example 10 as the components of the outer layer 4 in the base material layer 1, and implementing as components of the adhesive layer 2 The same components and weight ratio as those of the adhesive layer 2 of Example 10 were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 was cooled, and the same PET-SP (thickness 31 μm) as that of Example 10 was provided on the pressure-sensitive adhesive layer surface as the release sheet 5, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2:15 μm, intermediate layer 3:75 μm, outer layer 4:10 μm, and the total thickness was 100 μm.
Table 10 shows the layer configuration of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 11 shows the results of testing the obtained pressure-sensitive adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 12 shows the results of evaluating the (G) dicing suitability of the obtained pressure-sensitive adhesive sheet 10.
FIG. 11 shows a photograph of the back side of the chip observed with an optical microscope as a representative example of 100 chips that were evaluated for 2) chip chipping and 3) contamination. In FIG. 11, the chip chip 42 and the cutting waste 43 shown in the schematic cross-sectional view at the time of cutting in FIG.

(Comparative Example 3)
As a material of each layer constituting the pressure-sensitive adhesive sheet 10, as a component of the intermediate layer 3 in the base material layer 1, 70 parts by weight of r-PP same as Example 2, 28 parts by weight of EB-A same as Example 9, The same HDPE as in Example 1 is used, 2 parts of the base material layer 1 is used as the outer layer 4, and the same components and weight ratio as those of the outer layer 4 in Example 10 are used. The same components and weight ratios as in layer 2 were used.
Next, the material of each layer was melted by an extruder equipped with a flurlite type screw. The molding conditions (melting temperature) were: adhesive layer 2: 220 ° C., intermediate layer 3: 230 ° C., outer layer 4: 220 ° C., and these three layers of molten resin were laminated in a multilayer die (coextrusion temperature: 230). ° C). The extruded pressure-sensitive adhesive sheet 10 was cooled, and the same PET-SP (thickness 31 μm) as that of Example 10 was provided on the pressure-sensitive adhesive layer surface as the release sheet 5, and then slit and wound around the core material 6.
The pressure-sensitive adhesive sheet 10 thus obtained is a laminate in which a base material layer 1 and a pressure-sensitive adhesive layer 2 composed of two layers are laminated, and a release sheet 5 is provided on the pressure-sensitive adhesive layer side. 2:15 μm, intermediate layer 3:75 μm, outer layer 4:10 μm, and the total thickness was 100 μm.
Table 10 shows the layer configuration of the pressure-sensitive adhesive sheet 10, the components constituting each layer, the weight ratio thereof, and the thickness of each layer. Table 11 shows the results of testing the obtained pressure-sensitive adhesive sheet 10 for (A) tensile elastic modulus, (B) tear strength, and (C) adhesive strength. Table 12 shows the results of evaluating the (G) dicing suitability of the obtained pressure-sensitive adhesive sheet 10.
The pressure-sensitive adhesive sheet 10 of Comparative Example 3 has a longitudinal tear strength (MD-T) exceeding 100 N / mm, and the longitudinal to lateral tear strength ratio {(MD-T). / (TD-T)} was a value exceeding 2, and (G) dicing suitability evaluation was 2) chip missing and 3) contamination was rejected (x).

    FIG. 12 shows a photograph of the back side of the chip observed with an optical microscope as a representative example of 100 chips that were evaluated for 2) chip chipping and 3) contamination. In FIG. 12, cutting waste 43 assumed to generate the chip chip 42 shown in the schematic cross-sectional view at the time of cutting in FIG. 10 was observed.

    The pressure-sensitive adhesive sheet of the present invention is used for surface protection with cutting processing, chemical solution processing such as etching solution and plating solution, silicon, especially in the fields of electronic circuit materials, semiconductor materials, optical materials and the like that have strict requirements for performance and quality. It can be used as a surface protection sheet for dicing applications such as wafers, can be used under the strictest usage conditions and processing conditions, and has very high industrial applicability.

    The pressure-sensitive adhesive sheet of the present invention is a pressure-sensitive adhesive sheet that can solve the environmental problems of PVC-based pressure-sensitive adhesive sheets, and further provides a pressure-sensitive adhesive sheet that can solve problems such as adhesive residue contamination. The above availability is very high.

It is a schematic sectional drawing which shows an example of the adhesive sheet which concerns on this invention. It is a schematic sectional drawing which shows an example of the adhesive sheet which concerns on this invention. It is a schematic sectional drawing which shows an example of the adhesive sheet which concerns on this invention. It is a schematic sectional drawing which shows an example of the adhesive sheet which concerns on this invention. It is a perspective view which shows an example of the state which wound up the adhesive sheet of this invention in roll shape. It is another perspective view which shows an example of the state which wound up the adhesive sheet of this invention in roll shape. It is another perspective view which shows an example of the state which wound up the adhesive sheet of this invention in roll shape. It is a schematic diagram which shows the test piece of chemical suitability evaluation. It is the schematic which shows plating suitability evaluation. It is the schematic which shows dicing aptitude evaluation. It is the photograph which observed the chip | tip back surface state processed in Example 12. FIG. It is the photograph which observed the chip | tip back surface state processed in the comparative example 3. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Base material layer 2 ... Adhesive layer 3 ... Intermediate layer 4 ... Outer layer 5 ... Release sheet 6 ... Core material 10 ... Adhesive sheet 20 ... pH test paper 21 ... Chemical aptitude test wafer 30 ... Plating aptitude test substrate 31 ... Glue Remaining 32 ... Leakage residue 40 ... Dicing aptitude test wafer 41 ... Frame 42 ... Chip chip 43 ... Cutting waste

Claims (7)

A pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer laminated on at least one surface of a base material layer, characterized by the following requirements (a) to (c).
(A) The longitudinal tensile modulus (MD-M) and the transverse tensile modulus (TD-M) at 23 ° C. are in the range of 50 to 2000 MPa, and the longitudinal tensile modulus (MD-M) ) And the tensile modulus of elasticity (TD-M) in the transverse direction {(MD-M) / (TD-M)} is in the range of 0.5-2 (b) longitudinal tear at 23 ° C The strength (MD-T) and the transverse tear strength (TD-T) are in the range of 1-100 N / mm, the longitudinal tear strength (MD-T) and the transverse tear strength. The ratio {(MD-T) / (TD-T)} to (TD-T) is in the range of 0.5 to 2 (c) The base material layer contains an olefin polymer. The pressure-sensitive adhesive sheet according to claim 1, wherein the base material layer contains a syndiotactic propylene polymer. The pressure-sensitive adhesive sheet according to claim 1, wherein the pressure-sensitive adhesive layer contains an α-olefin copolymer as a main component and is molded by a coextrusion method. The pressure-sensitive adhesive sheet according to any one of claims 1 to 3, wherein a release sheet is laminated on the pressure-sensitive adhesive layer side. It is used for the surface protection use accompanying a cutting process, The adhesive sheet as described in any one of Claims 1-4 characterized by the above-mentioned. It is used for the chemical | medical solution process use of a flexible printed circuit board, The adhesive sheet as described in any one of Claims 1-4 characterized by the above-mentioned. It is used for a dicing use, The pressure sensitive adhesive sheet according to any one of claims 1 to 4 characterized by things.