JP2017179605A - Taiko wafer protecting tape, and taiko wafer processing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a TAIKO wafer protecting tape, which is adhered at the time of performing an electroless plating treatment to a TAIKO wafer polished only at an inner side region while leaving a periphery, and a TAIKO wafer processing method using said TAIKO wafer protecting tape.SOLUTION: A TAIKO wafer protecting tape is applied to a TAIKO wafer which has been polished only at the region of an inner side while leaving a periphery, thereby to protect the TAIKO wafer at an electroless plating treatment time. The TAIKO wafer protecting tape is composed of a substrate and an adhesive layer formed on one face of the substrate. The substrate has a 5% tension strength of 60 MPa or less, and a water vapor permeability measured by the Lyssy method conforming to JIS K7129 is 3 g/mday or less.SELECTED DRAWING: None

Description

The present invention relates to a TAIKO wafer protection tape that can be attached and protected when an electroless plating process is applied to a TAIKO wafer in which only the inner region is ground with the outer peripheral part being ground, and the TAIKO wafer protection tape The present invention relates to a processing method of a TAIKO wafer using a tape.

In recent years, semiconductor wafers have become thinner for the purpose of improving functional characteristics. Such a thinned semiconductor wafer has a problem of poor handling. Therefore, a so-called TAIKO wafer has been proposed in which only the inner region is ground leaving the outer peripheral portion (for example, Patent Document 1). The introduction of TAIKO wafers in various semiconductor fields such as power semiconductors has progressed because sufficient strength is maintained by a thick outer peripheral portion and excellent handleability.

Since power semiconductors can handle higher voltages and larger currents than in the past, they are mainly used for applications such as voltage and frequency conversion, power conversion for converting direct current to alternating current, and alternating current to direct current. In such a power semiconductor, the surface of the wafer may be subjected to UBM plating, and the UBM plating is subjected to electroless plating. In electroless plating treatment, masking tape is applied to protect the parts that do not require plating. However, even if the TAIKO wafer is protected using conventional masking tape, sufficient protection may not be achieved. There was a problem.

JP 2014-107312 A

In view of the above situation, the present invention is a TAIKO wafer protection tape that can be applied and protected when an electroless plating process is performed on a TAIKO wafer in which only an inner region is ground with the outer peripheral portion being ground, and It is an object of the present invention to provide a TAIKO wafer processing method using the TAIKO wafer protection tape.

The present invention is a TAIKO wafer protection tape for applying a protection to an electroless plating process by attaching to a TAIKO wafer in which only an inner region is ground, leaving an outer peripheral portion. It consists of a pressure-sensitive adhesive layer formed on one surface, and the substrate has a 5% tensile strength of 60 MPa or less, and a water vapor permeability of 3 g / m ² · day or less measured by the Lyssy method according to JIS K7129. This is a tape for protecting a TAIKO wafer.
The present invention is described in detail below.

The inventors of the present invention have examined the cause of insufficient protection when a conventional masking tape is used to protect a TAIKO wafer. As a result, it has been found that the conventional masking tape cannot sufficiently follow the step on the outer peripheral portion of the TAIKO wafer. In the electroless plating process, heating at about 80 to 100 ° C. is performed in the plating solution. In such a heated plating treatment solution, it was thought that the adhesive layer could not sufficiently maintain the adhesive force due to the influence of moisture that permeated the base material, which also caused the protection failure.
As a result of further intensive studies, the present inventors use a substrate having a 5% tensile strength of 60 MPa or less and a water vapor permeability of 3 g / m ² · day or less measured by the Lyssy method according to JIS K7129. The TAIKO wafer protection tape has been found to be capable of exhibiting sufficient level-step following ability and maintaining sufficient adhesive strength even with a heated plating solution, and can reliably protect the TAIKO wafer. Completed the invention.

The TAIKO wafer protection tape of the present invention is a TAIKO wafer protection tape that is attached to a TAIKO wafer for protection during electroless plating.
In this specification, the TAIKO wafer means a wafer in which only the inner region is ground except for the outer peripheral portion. The outer peripheral portion usually has a width of about 0.5 to 1 mm, and the step between the outer peripheral portion and the inner region is usually about 550 to 650 μm. The TAIKO wafer may have a circuit formed on one side.

The TAIKO wafer protection tape of the present invention comprises a base material and an adhesive layer formed on one surface of the base material.
The base material has a 5% tensile strength of 60 MPa or less. Thereby, it is possible to sufficiently follow the step on the outer peripheral portion of the TAIKO wafer. The 5% tensile strength is preferably 55 MPa or less. The lower limit of the 5% tensile strength is not particularly limited, but is preferably 10 MPa or more from the viewpoint of the handleability of the TAIKO wafer protection tape.
In this specification, 5% tensile strength means that when a sample having a width of 10 mm and a length of 15 cm is subjected to a tensile test with a tensile tester at 80 ° C. and a chucking distance of 10 cm, an elongation ratio of 5% is obtained. It means the tensile strength at%.

The base material has a water vapor permeability of 3 g / m ² · day or less as measured by the Lysy method based on JIS K7129. As a result, the pressure-sensitive adhesive layer can maintain a sufficient adhesive force even in the heated plating treatment solution during the electroless plating treatment, and the TAIKO wafer can be reliably protected. The water vapor permeability is preferably 2.7 g / m ² · day or less. The lower limit of the water vapor permeability is not particularly limited, but the lower limit is substantially about 0.0001 g / m ² · day.

The material constituting the substrate is not particularly limited, and examples thereof include acrylic, olefin, polycarbonate, vinyl chloride, polyethylene terephthalate (PET), nylon, urethane, and polyimide.
In order to satisfy the 5% tensile strength and water vapor permeability, not only a single-layer base material using the above material but also a base material composed of a laminate of two or more layers may be used. For example, a base material obtained by laminating a flexible layer made of relatively soft polypropylene or polyethylene and a water vapor shielding layer made of an ethylene-vinyl alcohol copolymer resin having low water vapor permeability has the above 5% tensile strength and water vapor permeability. And can satisfy.
As resin which comprises the said flexible layer, in addition to polypropylene, polyethylene, etc., an ethylene vinyl acetate copolymer etc. are mentioned, for example. Although the thickness of the said flexible layer is not specifically limited, 5-45 micrometers is preferable. The resin constituting the water vapor shielding layer is not particularly limited, and examples thereof include polyvinyl chloride, polyvinylidene chloride, and ethylene-vinyl alcohol copolymer resin. The thickness of the water vapor barrier layer is not particularly limited, but is preferably 5 μm or more.
As such a laminate-type base material, for example, trade name “QH-1” (biaxially stretched polypropylene layer / ethylene-vinyl alcohol copolymer resin layer / biaxially stretched polypropylene layer manufactured by Futamura Chemical Co., Ltd.) Commercial products such as (structure) can also be used.

Further, for example, the above 5% tensile strength and water vapor permeability can also be satisfied by performing aluminum vapor deposition or the like on the surface of a flexible layer made of relatively flexible polypropylene or polyethylene.
As resin which comprises the said flexible layer, in addition to polypropylene, polyethylene, etc., an ethylene vinyl acetate copolymer etc. are mentioned, for example. Although the thickness of the said flexible layer is not specifically limited, 10-50 micrometers is preferable. Although the thickness of an aluminum vapor deposition film is not specifically limited, 1 micrometer or less is preferable.

Although the thickness of the said base material is not specifically limited, A preferable minimum is 10 micrometers and a preferable upper limit is 50 micrometers. When the thickness of the substrate is within this range, it is possible to sufficiently follow the step of the outer peripheral portion of the TAIKO wafer while ensuring the handleability. The minimum with more preferable thickness of the said base material is 16 micrometers, and a more preferable upper limit is 30 micrometers.

It does not specifically limit as an adhesive which comprises the said adhesive layer, The adhesive etc. which are conventionally used for the adhesive layer of a masking tape can be used. Specifically, for example, a segment derived from an alkyl acrylate ester whose alkyl group has 5 or less carbon atoms, a segment derived from an acrylic monomer whose homopolymer has a glass transition temperature of 80 to 120 ° C., and a side chain And a pressure-sensitive adhesive containing a copolymer having a segment having a radical polymerizable unsaturated bond (hereinafter also simply referred to as “copolymer”).

A segment derived from an alkyl acrylate ester having 5 or less carbon atoms in the alkyl group serves as the base of the copolymer. When the copolymer constituting the pressure-sensitive adhesive layer has a segment composed of an alkyl acrylate ester having an alkyl group having 5 or less carbon atoms, the pressure-sensitive adhesive layer can be used in a heated plating treatment solution during electroless plating treatment. Can exhibit high adhesive strength.

Examples of the acrylic acid alkyl ester having 5 or less carbon atoms in the alkyl group include ethyl acrylate, methyl acrylate, butyl acrylate, isobutyl acrylate, and t-butyl acrylate. Of these, ethyl acrylate and methyl acrylate are preferred.

The minimum with preferable content of the segment which consists of an alkyl acrylate ester whose carbon number of the said alkyl group in the said copolymer is 5 or less is 40 weight%, and a preferable upper limit is 90 weight%. If the content of the segment composed of an alkyl acrylate ester having 5 or less carbon atoms in the alkyl group is less than 40% by weight, sufficient cohesive force of the adhesive in the heated plating solution may not be obtained. If it exceeds 90% by weight, the stress relaxation force as a pressure-sensitive adhesive is reduced, and the adhesive strength may be impaired. The more preferable lower limit of the content of the segment composed of an alkyl acrylate ester having 5 or less carbon atoms in the alkyl group is 50% by weight, and the more preferable upper limit is 80% by weight.

A segment derived from an acrylic monomer having a glass transition temperature of 80 to 120 ° C. of the homopolymer has a role of adjusting the glass transition temperature of the copolymer. In the homopolymer of acrylic acid alkyl ester in which the carbon number of the alkyl group in the copolymer is 5 or less, the glass transition temperature is less than −20 ° C., and the necessary elastic modulus cannot be adjusted at high temperature. By copolymerizing an acrylic monomer having a glass transition temperature of 80 to 120 ° C., the glass transition temperature of the copolymer can be adjusted.

As for the acrylic monomer whose glass transition temperature of the said homopolymer is 80-120 degreeC, methyl methacrylate, isoboronyl acrylate, acrylonitrile, acrylic acid etc. are mentioned, for example. Of these, methyl methacrylate and acrylonitrile are preferable.

The content of the segment derived from the acrylic monomer having a glass transition temperature of the homopolymer of 80 to 120 ° C in the copolymer is appropriately determined so that the glass transition temperature of the copolymer is -5 to 15 ° C. Adjust it. In general, the preferable lower limit of the content of the segment derived from the acrylic monomer having a glass transition temperature of 80 to 120 ° C. of the homopolymer in the copolymer is 10% by weight, and the preferable upper limit is 40% by weight. . When the content of the segment derived from the acrylic monomer having a glass transition temperature of 80 to 120 ° C. of the homopolymer is less than 10% by weight, the cohesive force in the heated plating treatment liquid may not be obtained. If it exceeds 40% by weight, the adhesive strength may be significantly reduced. The more preferable lower limit of the content of the segment derived from the acrylic monomer having a glass transition temperature of 80 to 120 ° C. of the homopolymer is 15% by weight, and the more preferable upper limit is 35% by weight.

The segment having a radical polymerizable unsaturated bond in the side chain has a role of imparting photocurability to the copolymer. If the copolymer constituting the pressure-sensitive adhesive layer has a segment having a radical polymerizable unsaturated bond in the side chain, the TAIKO wafer protection tape can be irradiated with light after the electroless plating treatment. Is cured. The cured pressure-sensitive adhesive layer can be easily peeled off because the elastic modulus is remarkably increased and most of the adhesive force is lost.

The method of inserting a segment having a radical polymerizable unsaturated bond in the side chain into the copolymer is, for example, copolymerizing an acrylic monomer having a functional group in the molecule and then reacting with the functional group. Examples thereof include a method of reacting with a compound having a functional group and a radical polymerizable unsaturated bond (hereinafter referred to as a functional group-containing unsaturated compound).

Examples of acrylic monomers having functional groups in the molecule include carboxyl group-containing monomers such as acrylic acid and methacrylic acid, hydroxyl group-containing monomers such as hydroxyethyl acrylate and hydroxyethyl methacrylate, glycidyl acrylate, and methacrylic acid. Examples thereof include epoxy group-containing monomers such as glycidyl acid, isocyanate group-containing monomers such as isocyanate ethyl acrylate and isocyanate ethyl methacrylate, and amino group-containing monomers such as aminoethyl acrylate and aminoethyl methacrylate.

Examples of the functional group-containing unsaturated compound include an epoxy group-containing monomer and an isocyanate group-containing monomer when the functional group of the acrylic monomer having a functional group in the molecule is a carboxyl group, and the functional group is a hydroxyl group. Is an isocyanate group-containing monomer, when the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide, and when the functional group is an amino group, an epoxy group-containing monomer is used. Can be mentioned.

The minimum with preferable content of the segment which has a radically polymerizable unsaturated bond in the said side chain in the said copolymer is 0.1 meq / g, and a preferable upper limit is 2 meq / g. When the content of the segment having a radical polymerizable unsaturated bond in the side chain is less than 0.1 meq / g, sufficient photocurability cannot be imparted, and a TAIKO wafer protection tape can be obtained even when irradiated with light. When it exceeds 2 meq / g, the cured adhesive may become brittle. The minimum with more preferable content of the segment which has a radically polymerizable unsaturated bond in the said side chain is 0.2 meq / g, and a more preferable upper limit is 1.5 meq / g.

The copolymer may contain a segment derived from another copolymerizable monomer within the range not impairing the object of the present invention. Examples of the other copolymerizable monomers include acrylic monomers having a side chain having 6 or more carbon atoms, such as 2-ethylhexyl acrylate, isooctyl acrylate, and cyclohexyl acrylate.

The pressure-sensitive adhesive layer preferably contains a gas generating agent that generates gas when irradiated with light. When the pressure-sensitive adhesive layer containing such a gas generating agent is irradiated with light, the copolymer is cross-linked and cured to increase the elastic modulus of the entire pressure-sensitive adhesive layer, and is generated in such a hard pressure-sensitive adhesive layer. Since the gas is released from the pressure-sensitive adhesive layer to the bonding interface and peels at least part of the bonding surface, the TAIKO wafer protection tape can be peeled off more easily.

Although the said gas generating agent is not specifically limited, For example, an azide compound, an azo compound, etc. are mentioned. Of these, an azide compound having excellent heat resistance is preferable.
The azide compound is not particularly limited. For example, glycidyl obtained by ring-opening polymerization of 3-azidomethyl-3-methyloxetane, terephthalazide, p-tert-butylbenzazide, 3-azidomethyl-3-methyloxetane. Examples thereof include a polymer having an azide group such as an azide polymer (GAP).
In addition, since it has particularly excellent heat resistance, a carboxylic acid compound or a salt thereof, a tetrazole compound or a salt thereof that generates a gas (carbon dioxide gas) when irradiated with light such as ultraviolet rays, and the like are also used as the gas generating agent. be able to.

The pressure-sensitive adhesive layer preferably contains a photopolymerization initiator.
Examples of the photopolymerization initiator include those that are activated by irradiation with light having a wavelength of 250 to 800 nm. Examples of such photopolymerization initiators include acetophenone derivative compounds such as methoxyacetophenone, benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyldimethyl ketal and acetophenone diethyl ketal, Phosphine oxide derivative compound, bis (η5-cyclopentadienyl) titanocene derivative compound, benzophenone, Michler ketone, chlorothioxanthone, dodecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexyl phenyl ketone, 2-hydroxymethylphenylpropane, etc. These radical photopolymerization initiators. These photoinitiators may be used independently and 2 or more types may be used together.

The pressure-sensitive adhesive layer preferably contains a polyfunctional oligomer or monomer. The polyfunctional oligomer or monomer has a role of improving curability when the copolymer is irradiated with light.
The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5, so that the three-dimensional network of the pressure-sensitive adhesive layer can be efficiently formed by heating or light irradiation. 000 or less and the number of radically polymerizable unsaturated bonds in the molecule is 2 to 20. Such more preferred polyfunctional oligomers or monomers are, for example, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or Examples thereof include the same methacrylates as described above. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and methacrylates similar to those described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

The pressure-sensitive adhesive layer may appropriately contain various polyfunctional compounds that are blended in a general pressure-sensitive adhesive such as an isocyanate compound, a melamine compound, and an epoxy compound for the purpose of adjusting the cohesive force as the pressure-sensitive adhesive. In addition, known additives such as an antistatic agent, a plasticizer, a resin, a surfactant, a wax, and a fine particle filler can be added. Furthermore, you may mix | blend a heat stabilizer and antioxidant in order to improve stability of an adhesive.

Although the thickness of the said adhesive layer is not specifically limited, A preferable minimum is 10 micrometers and a preferable upper limit is 50 micrometers. When the thickness of the pressure-sensitive adhesive layer is within this range, it is possible to achieve both sufficient adhesive strength that does not peel off during electroless plating and sufficient followability to the step on the outer peripheral portion of the TAIKO wafer. The minimum with more preferable thickness of the said adhesive layer is 20 micrometers, and a more preferable upper limit is 40 micrometers.

The method for producing the TAIKO wafer protection tape of the present invention is not particularly limited. For example, conventional methods such as applying a pressure-sensitive adhesive containing the copolymer on the base material using a doctor knife, a spin coater, or the like. A well-known method is mentioned.

By using the TAIKO wafer protection tape of the present invention, when performing electroless plating treatment on a TAIKO wafer in which only the inner region is ground leaving the outer peripheral portion, the tape can be adhered sufficiently following the step of the outer peripheral portion, And since sufficient adhesive force can be maintained even with the heated plating process liquid, a TAIKO wafer can be protected reliably.
A step of applying the TAIKO wafer protection tape of the present invention to the side of the TAIKO wafer on which only the inner region is ground leaving the outer peripheral portion is not subjected to electroless plating, and a TAIKO wafer having the TAIKO wafer protection tape attached A TAIKO wafer processing method comprising a step of performing electroless plating on the TAIKO wafer and a step of peeling the TAIKO wafer protection tape from the TAIKO wafer after the electroless plating is also one aspect of the present invention.

The TAIKO wafer processing method of the present invention includes the step of applying the TAIKO wafer protection tape of the present invention to the side where the electroless plating process is not performed on the TAIKO wafer in which only the inner region is ground except the outer peripheral portion. By applying the TAIKO wafer protection tape, it is possible to protect a portion that does not require plating.

In the TAIKO wafer processing method of the present invention, a step of performing an electroless plating process on the TAIKO wafer to which the TAIKO wafer protection tape is attached is then performed. The method of the electroless plating treatment is not particularly limited, and a conventionally known method can be used.

In the TAIKO wafer processing method of the present invention, a step of peeling the TAIKO wafer protection tape from the TAIKO wafer after the electroless plating process is then performed. In particular, when the pressure-sensitive adhesive layer of the TAIKO wafer protection tape is composed of the above-mentioned copolymer, the pressure-sensitive adhesive layer is cured by irradiating light prior to peeling and can be peeled more easily. In addition, when the adhesive layer of the TAIKO wafer protection tape contains the gas generating agent, gas is generated from the gas generating agent by irradiating light prior to peeling, and the pressure is further easily increased. Can be peeled off.

According to the present invention, a TAIKO wafer protection tape that can be attached and protected when an electroless plating process is performed on a TAIKO wafer in which only the inner region is ground with the outer peripheral portion being ground, and the TAIKO wafer A method for processing a TAIKO wafer using a protective tape can be provided.

It is a schematic diagram explaining the evaluation method of the followable | trackability to the level | step difference of a TAIKO wafer.

Hereinafter, embodiments of the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

Example 1
(1) Preparation of pressure-sensitive adhesive The following compound was dissolved in ethyl acetate and polymerized by irradiating with ultraviolet rays to obtain an ethyl acetate solution of photocurable pressure-sensitive adhesive A comprising a copolymer having a weight average molecular weight of 500,000. .
Ethyl acrylate 75 parts by weight Methyl methacrylate 20 parts by weight Acrylic acid 3 parts by weight 2-hydroxyethyl acrylate 2 parts by weight Photopolymerization initiator 1 part by weight (Irgacure 651, 50% ethyl acetate solution)
Lauryl mercaptan 0.01 parts by weight

(2) Preparation of composition solution for pressure-sensitive adhesive layer 3.5 parts by weight of 2-isocyanatoethyl methacrylate was added to 100 parts by weight of resin solid content of the ethyl acetate solution of photocurable pressure-sensitive adhesive A obtained. Furthermore, with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution after the reaction, 5 parts by weight of a photopolymerization initiator (Irgacure 651), 10 parts by weight of an azo compound (manufactured by Wako Pure Chemical Industries, Ltd., VAM110), 0.5 parts by weight of isocyanate was mixed to prepare a pressure-sensitive adhesive layer composition solution.

(3) Gas barrier OPP (biaxially stretched polypropylene layer / ethylene-vinyl alcohol copolymer resin layer / biaxially stretched polypropylene layer three-layer structure, thickness 30 μm, manufactured by Futamura Chemical Co., Ltd.) QH-1) was used.
A sample is prepared by chopping the substrate into a width of 10 mm and a length of 15 cm, and a tensile test is performed with a tensile tester under conditions of 80 ° C. and a chucking distance of 10 cm. The measured 5% tensile strength was 53 MPa. Moreover, when water vapor permeability was measured by the Lyssy method based on JIS K7129, it was 2.7 g / m ² · day.

The obtained pressure-sensitive adhesive layer composition solution was coated on a substrate with a doctor knife so as to have a thickness of about 30 μm, and heated at 110 ° C. for 5 minutes to dry the coating solution. The pressure-sensitive adhesive layer after drying showed adhesiveness in a dry state. Next, a PET film that was subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive layer. Then, static curing was performed at 40 ° C. for 3 days to obtain a TAIKO wafer protection tape.

(Examples 2 and 3)
A TAIKO wafer protection tape was obtained in the same manner as in Example 1 except that the amount of polyisocyanate mixed in the pressure-sensitive adhesive layer composition solution was changed.

Example 4
(1) Preparation of pressure-sensitive adhesive The following compound was dissolved in ethyl acetate and polymerized by irradiating with ultraviolet rays to obtain an ethyl acetate solution of photocurable pressure-sensitive adhesive B comprising a copolymer having a weight average molecular weight of 250,000. .
Ethyl acrylate 55 parts by weight Methyl methacrylate 25 parts by weight 2-hydroxyethyl acrylate 10 parts by weight Methacrylic acid 1 part by weight Photopolymerization initiator 1 part by weight (Irgacure 651, 50% ethyl acetate solution)
Lauryl mercaptan 0.01 parts by weight

(2) Preparation of composition solution for pressure-sensitive adhesive layer 3.5 parts by weight of 2-isocyanatoethyl methacrylate was added to 100 parts by weight of resin solid content of the obtained photocurable pressure-sensitive adhesive B in ethyl acetate solution. Furthermore, with respect to 100 parts by weight of the resin solid content of the ethyl acetate solution after the reaction, 5 parts by weight of a photopolymerization initiator (Irgacure 651), 10 parts by weight of an azo compound (manufactured by Wako Pure Chemical Industries, Ltd., VAM110), 0.5 parts by weight of isocyanate was mixed to prepare a pressure-sensitive adhesive layer composition solution.

(3) Gas barrier OPP (biaxially stretched polypropylene layer / ethylene-vinyl alcohol copolymer resin layer / biaxially stretched polypropylene layer three-layer structure, thickness 30 μm, manufactured by Futamura Chemical Co., Ltd.) QH-1) was used.
A sample is prepared by chopping the substrate into a width of 10 mm and a length of 15 cm, and a tensile test is performed with a tensile tester under conditions of 80 ° C. and a chucking distance of 10 cm. The measured 5% tensile strength was 53 MPa. Moreover, when water vapor permeability was measured by the Lyssy method based on JIS K7129, it was 2.7 g / m ² · day.

The obtained pressure-sensitive adhesive layer composition solution was coated on a substrate with a doctor knife so as to have a thickness of about 30 μm, and heated at 110 ° C. for 5 minutes to dry the coating solution. The pressure-sensitive adhesive layer after drying showed adhesiveness in a dry state. Next, a PET film that was subjected to a release treatment was attached to the surface of the pressure-sensitive adhesive layer. Then, static curing was performed at 40 ° C. for 3 days to obtain a TAIKO wafer protection tape.

(Examples 5 and 6)
A tape for protecting a TAIKO wafer was obtained in the same manner as in Example 4 except that the amount of polyisocyanate mixed in the composition solution for the pressure-sensitive adhesive layer was changed.

(Examples 7 and 8)
A TAIKO wafer protecting tape was obtained in the same manner as in Example 1 except that the photocurable pressure-sensitive adhesive shown in Table 1 was used and a polyethylene film having an aluminum vapor deposition thickness of 50 μm was used as the substrate.

(Comparative Examples 1-7)
A TAIKO wafer protecting tape was obtained in the same manner as in Example 1 except that the photocurable pressure-sensitive adhesive shown in Table 1 was used and the following substrate was used.
PET: Polyethylene terephthalate film, thickness 25 μm, manufactured by Unitika, Emblet S-25
Gas barrier PET: thickness 25 μm, manufactured by Mitsubishi Plastics,
OPP: Biaxially stretched polypropylene film, thickness 50 μm, manufactured by Futamura Chemical Co., Ltd., FOS-BT
CPP: Polypropylene film, thickness 50 μm, manufactured by Futamura Chemical Co., Ltd., FHK2
PE: polyethylene film, thickness 30 μm, manufactured by Tamapoly, GE-301

(Evaluation)
The TAIKO wafer protection tapes obtained in Examples and Comparative Examples were evaluated by the following methods.
The results are shown in Table 1.

(1) Evaluation of followability to step of TAIKO wafer FIG. 1 is a schematic diagram for explaining an evaluation method of followability to a step of TAIKO wafer. In FIG. 1, a TAIKO wafer 2 is a TAIKO wafer in which only an inner region is ground leaving an outer peripheral portion, and the difference between the outer peripheral portion and the inner region is 0.55 mm. The TAIKO wafer protection tape 1 follows the stepped portion of the TAIKO wafer 2 by placing the TAIKO wafer protection tape 1 so as to include the outer peripheral portion and the inner region of the TAIKO wafer 2 and reducing the pressure in this state. And stick. When the step portion is observed in detail in this state, a slight region where the TAIKO wafer protecting tape 1 cannot follow is recognized. The width d of this region was measured, and the step following ability was evaluated according to the following criteria.
○: d is 0.5 mm or less x: d exceeds 0.5 mm

(2) Hot water bath immersion test A sample was prepared by chopping the obtained TAIKO wafer protection tape into a width of 25 mm and a length of 10 cm. The sample was attached to the surface of a silicone wafer on which no circuit was formed and immersed in distilled water heated to 90 ° C. for 15 minutes. After immersing, after peeling the TAIKO wafer protection tape from the silicone wafer, the peeled surface of the silicone wafer and the TAIKO wafer protection tape was visually observed. The case where penetration was observed was evaluated as “x”.

Further, before and after the immersion, the adhesive strength was measured by a 180 ° peel measurement method based on JIS Z0237, and the residual adhesive strength ratio (adhesive strength after immersion / adhesive strength before immersion × 100) was calculated.

According to the present invention, a TAIKO wafer protection tape that can be attached and protected when an electroless plating process is performed on a TAIKO wafer in which only the inner region is ground with the outer peripheral portion being ground, and the TAIKO wafer A method for processing a TAIKO wafer using a protective tape can be provided.

1 TAIKO wafer protection tape 2 TAIKO wafer

Claims (2)

A tape for protecting a TAIKO wafer for protecting an electroless plating process by attaching it to a TAIKO wafer in which only an inner region is ground while leaving an outer peripheral part,
It consists of a base material and an adhesive layer formed on one side of the base material,
The TAIKO wafer protection tape, wherein the substrate has a 5% tensile strength of 60 MPa or less and a water vapor permeability of 3 g / m ² · day or less as measured by a Lyssy method according to JIS K7129. The step of applying the TAIKO wafer protection tape according to claim 1 and the TAIKO wafer protection tape on the side of the TAIKO wafer on which only the inner region of the outer peripheral portion is ground is not subjected to electroless plating treatment. A method of processing a TAIKO wafer, comprising: a step of performing an electroless plating process on a TAIKO wafer; and a step of peeling a TAIKO wafer protection tape from the TAIKO wafer after the electroless plating process.

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