JP7011420B2 - Removable Adhesive Composition and Adhesive Tape - Google Patents

Description

INDUSTRIAL APPLICABILITY The present invention is a removable pressure-sensitive adhesive composition for affixing and protecting a bump-formed surface of a semiconductor device, which has high adhesive strength and can be peeled off while suppressing adhesive residue. The present invention relates to a removable pressure-sensitive adhesive composition.

In the manufacturing process of a semiconductor device, an adhesive composition is attached and protected in order to facilitate handling during processing and prevent damage (for example, Patent Document 1 and the like). In recent years, semiconductor devices use bump connections in order to improve the reliability of electrical connections, and semiconductor devices having bump heights of up to about 100 to 200 μm have also come to be used. The pressure-sensitive adhesive composition for affixing and protecting the bump-formed surface of a semiconductor device having such bumps is required to have an adhesive force that does not peel off during processing of the semiconductor device.

Japanese Unexamined Patent Publication No. 5-32946

The pressure-sensitive adhesive composition for affixing and protecting the bump-formed surface of a semiconductor device having bumps as described above is required to have an adhesive force that does not peel off during processing of the semiconductor device.

However, the pressure-sensitive adhesive composition having high adhesive strength has a problem that the adhesive may remain on the surface of the semiconductor device at the time of peeling. For example, when the pressure-sensitive adhesive adhered to the surface of the semiconductor device opposite to the surface on which the bumps are formed is peeled off, a large load is applied to the surface side on which the bumps are formed, and the adhesive is easily peeled off. When a pressure-sensitive adhesive composition having a high adhesive strength that does not peel off even in such a case is used, adhesive residue is likely to be generated on the surface of the semiconductor device at the time of peeling.

In view of the above situation, the present invention is a removable pressure-sensitive adhesive composition for affixing and protecting a bump-formed surface of a semiconductor device, which has high adhesive strength and suppresses adhesive residue. It is an object of the present invention to provide a removable pressure-sensitive adhesive composition that can be peeled off.

In one embodiment of the present invention, it is a removable pressure-sensitive adhesive composition for affixing and protecting a bump-formed surface of a semiconductor device, and a vertical peeling force measured by a tack measuring machine is 10 to 40 N. Provided is a removable pressure-sensitive adhesive composition having a breaking elongation of 130 to 200% measured with a sample having a thickness of 350 μm, a width of 5 mm and a length of 50 mm.
The present invention will be described in detail below.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to achieve both high adhesive strength when affixed to a surface on which a bump of a semiconductor device is formed and excellent peelability in which adhesive residue at the time of peeling is suppressed.

In the removable pressure-sensitive adhesive composition of the present invention, the lower limit of the vertical peeling force measured by the tack measuring machine is 10 N, and the upper limit is 40 N. By adjusting the vertical peeling force within this range, excellent adhesive force that can sufficiently protect the semiconductor device when it is attached to the bump-formed surface and excellent adhesive residue during peeling are suppressed. Both peelability can be achieved. If the vertical peeling force is less than 10 N, the re-peelable pressure-sensitive adhesive composition may be peeled off during processing of the semiconductor device and may not be sufficiently protected. If it exceeds 40 N, it becomes difficult to peel off at the time of peeling and glue. May cause the rest. The preferable lower limit of the vertical peeling force is 13N, the preferable upper limit is 22N, the more preferable lower limit is 15N, and the more preferable upper limit is 20N.
In the present specification, the vertical peeling force means a SUS probe processed to a probe diameter of Φ5.8 mm and a tip R2.9 using a tack tester, and a load of 10000 gf from the vertical direction with respect to the removable pressure-sensitive adhesive composition. It means the peeling force when peeling at a speed of 0.8 m / s in the vertical direction after pressing at / cm ² for 1 second. As the tack tester, for example, a tack tester TA-500 manufactured by UBM can be used.

In the removable pressure-sensitive adhesive composition of the present invention, the lower limit of the elongation at break measured with a sample having a thickness of 350 μm, a width of 5 mm and a length of 50 mm is 130%, and the upper limit is 200%. If the breaking elongation is less than 130%, the removable pressure-sensitive adhesive composition is fragile and cannot be stretched at the time of peeling, and is torn and leaves adhesive residue. If the breaking elongation exceeds 200%, the re-peelable pressure-sensitive adhesive composition that has stretched too much at the time of peeling is torn and adhesive remains. When the breaking elongation is adjusted within the above range, it is possible to exhibit excellent peelability in which adhesive residue at the time of peeling is suppressed when the semiconductor device is first attached to the surface on which the bumps are formed. The preferable lower limit of the elongation at break is 140%, the preferable upper limit is 190%, the more preferable lower limit is 150%, and the more preferable upper limit is 180%.
In the present specification, the elongation at break is a sample when a test piece having a thickness of 350 μm and a width of 5 mm is subjected to a tensile test at a speed of 300 mm / min with a sample chuck distance of 50 mm using a tensile tester. It is measured by the elongation at the time of breaking. For example, when the breaking elongation is 500 mm, the breaking elongation is 1000% when the 50 mm sample is stretched to 500 mm.

The removable pressure-sensitive adhesive composition of the present invention contains a pressure-sensitive adhesive component.
The pressure-sensitive adhesive component is not particularly limited, and may contain either a non-curable pressure-sensitive adhesive or a curable pressure-sensitive adhesive. Above all, it is preferable to contain a curable pressure-sensitive adhesive because the adhesive residue can be further suppressed.
When the removable pressure-sensitive adhesive composition of the present invention contains a curable pressure-sensitive adhesive as a pressure-sensitive adhesive component, the re-peelable pressure-sensitive adhesive composition after stimulating and curing the curable pressure-sensitive adhesive can be used. The vertical peeling force and the breaking elongation may be satisfied.

Examples of the curable pressure-sensitive adhesive include a photo-curable pressure-sensitive adhesive that is cross-linked and cured by light irradiation, and a thermosetting pressure-sensitive adhesive that is cross-linked and cured by heating. Examples of the photocurable pressure-sensitive adhesive include a photo-curable pressure-sensitive adhesive containing a polymerizable polymer as a main component and using a photopolymerization initiator as a polymerization initiator. Examples of the thermosetting pressure-sensitive adhesive include a thermosetting pressure-sensitive adhesive containing a polymerizable polymer as a main component and using a thermosetting initiator as a polymerization initiator. The polymerizable polymer and the polymerization initiator may be used independently or in combination of two or more.

For the polymerizable polymer, for example, a (meth) acrylic polymer having a functional group in the molecule (hereinafter referred to as a functional group-containing (meth) acrylic polymer) is synthesized in advance and reacted with the functional group in the molecule. It can be obtained by reacting the functional group to be subjected to a compound having a radically polymerizable unsaturated bond (hereinafter referred to as a functional group-containing unsaturated compound).

The functional group-containing (meth) acrylic polymer uses a (meth) acrylic acid alkyl ester having an alkyl group having a carbon number in the range of 2 to 18 as a main monomer, and this, a functional group-containing monomer, and further, if necessary. It is obtained by copolymerizing these with other modifying monomers that can be copolymerized by a conventional method.
By using a (meth) acrylic acid alkyl ester in which the number of carbon atoms of the alkyl group is in the range of 2 to 18, the tackiness can be exhibited at room temperature.
The weight average molecular weight of the functional group-containing (meth) acrylic polymer is usually about 200,000 to 2,000,000.

Examples of the functional group-containing monomer include a carboxyl group-containing monomer such as acrylic acid and methacrylic acid, a hydroxyl group-containing monomer such as hydroxyethyl acrylate and hydroxyethyl methacrylate, and an epoxy such as glycidyl acrylate and glycidyl methacrylate. Examples thereof include a group-containing monomer, an isocyanate group-containing monomer such as ethyl isocyanate and ethyl methacrylate, and an amino group-containing monomer such as aminoethyl acrylate and aminoethyl methacrylate.

Examples of the other copolymerizable monomer for modification include various monomers used as general (meth) acrylic polymers such as vinyl acetate, acrylonitrile, and styrene.

As the functional group-containing unsaturated compound to be reacted with the functional group-containing (meth) acrylic polymer, the same one as the above-mentioned functional group-containing monomer is used depending on the functional group of the functional group-containing (meth) acrylic polymer. can. For example, when the functional group of the functional group-containing (meth) acrylic polymer is a carboxyl group, an epoxy group-containing monomer or an isocyanate group-containing monomer is used. When the functional group is a hydroxyl group, an isocyanate group-containing monomer is used. When the functional group is an epoxy group, a carboxyl group-containing monomer or an amide group-containing monomer such as acrylamide is used. When the functional group is an amino group, an epoxy group-containing monomer is used.

Examples of the photopolymerization initiator include those that are activated by irradiating with light having a wavelength of 250 to 800 nm. Examples of such a photopolymerization initiator include acetophenone derivative compounds such as methoxyacetophenone, benzoin ether compounds such as benzoin propyl ether and benzoin isobutyl ether, ketal derivative compounds such as benzyl dimethyl ketal and acetophenone diethyl ketal, and the like. Phosphine oxide derivative compound, bis (η5-cyclopentadienyl) titanosen derivative compound, benzophenone, Michler ketone, chlorothioxanthone, todecylthioxanthone, dimethylthioxanthone, diethylthioxanthone, α-hydroxycyclohexylphenylketone, 2-hydroxymethylphenylpropane Examples thereof include photoradical polymerization initiators such as. These photopolymerization initiators may be used alone or in combination of two or more.

In the photocurable pressure-sensitive adhesive, the preferable lower limit of the blending amount of the photopolymerization initiator with respect to 100 parts by weight of the polymerizable polymer is 0.1 part by weight, and the preferable upper limit is 8 parts by weight. When the blending amount of the photopolymerization initiator is within this range, the photocurable pressure-sensitive adhesive can be reliably crosslinked and cured by irradiating with light, and the adhesive residue can be further suppressed. The more preferable lower limit of the blending amount of the photopolymerization initiator is 0.3 parts by weight, the more preferable upper limit is 5 parts by weight, and the further preferable upper limit is 3 parts by weight.

Examples of the thermal polymerization initiator include those that generate active radicals that are decomposed by heat to initiate polymerization curing. Specifically, for example, dicumyl peroxide, di-t-butyl peroxide, t-butylperoxybenzoale, t-butylhydroperoxide, benzoyl peroxide, cumenehydroperoxide, diisopropylbenzenehydroperoxide, etc. Examples thereof include paramentan hydroperoxide and di-t-butyl peroxide.
However, in order for the curable pressure-sensitive adhesive to exhibit high heat resistance, it is preferable to use a thermal polymerization initiator having a thermal decomposition temperature of 200 ° C. or higher. Examples of such a thermal polymerization initiator having a high thermal decomposition temperature (for example, a thermal polymerization initiator having a thermal decomposition temperature of 200 ° C. or higher) include cumene hydroperoxide, paramentan hydroperoxide, and di-t-butyl. Examples thereof include peroxide.
Among these thermal polymerization initiators, commercially available ones are not particularly limited, but for example, perbutyl D, perbutyl H, perbutyl P, perpenta H (all of which are manufactured by NOF CORPORATION) and the like are suitable. These thermal polymerization initiators may be used alone or in combination of two or more.

In the thermosetting pressure-sensitive adhesive, the preferable lower limit of the blending amount of the thermal polymerization initiator with respect to 100 parts by weight of the polymerizable polymer is 0.01 parts by weight, and the preferable upper limit is 5 parts by weight. When the blending amount of the thermosetting initiator is within this range, the thermosetting pressure-sensitive adhesive can be reliably crosslinked and cured by heating, and the adhesive residue can be further suppressed. The more preferable lower limit of the blending amount of the thermal polymerization initiator is 0.05 parts by weight, and the more preferable upper limit is 3 parts by weight.

The curable pressure-sensitive adhesive layer preferably contains a radically polymerizable polyfunctional oligomer or monomer. By containing a radically polymerizable polyfunctional oligomer or monomer, photocurability and thermosetting are improved.
The polyfunctional oligomer or monomer preferably has a molecular weight of 10,000 or less, and more preferably has a molecular weight of 5000 so that the curable pressure-sensitive adhesive layer can be efficiently reticulated by heating or irradiation with light. The number of radically polymerizable unsaturated bonds in the molecule is 2 to 20 below.

The polyfunctional oligomer or monomer is, for example, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol monohydroxypentaacrylate, dipentaerythritol hexaacrylate or the same methacrylate. Kind and the like. Other examples include 1,4-butylene glycol diacrylate, 1,6-hexanediol diacrylate, polyethylene glycol diacrylate, commercially available oligoester acrylate, and the same methacrylates as described above. These polyfunctional oligomers or monomers may be used alone or in combination of two or more.

In the curable pressure-sensitive adhesive, the preferable lower limit of the blending amount of the polyfunctional oligomer or the monomer with respect to 100 parts by weight of the polymerizable polymer is 3 parts by weight, and the preferable upper limit is 35 parts by weight. When the blending amount of the polyfunctional oligomer or the monomer is within this range, the curable pressure-sensitive adhesive can be reliably crosslinked and cured by irradiating or heating with light, and the adhesive residue can be further suppressed. .. The more preferable lower limit of the blending amount of the polyfunctional oligomer or the monomer is 5 parts by weight, and the more preferable upper limit is 30 parts by weight.

When the removable pressure-sensitive adhesive composition of the present invention contains the curable pressure-sensitive adhesive as a pressure-sensitive adhesive component, for example, a curable pressure-sensitive adhesive having a carboxyl group and a hydroxyl group is selected and used as a cross-linking agent. It is preferable to contain an epoxy compound and an isocyanate compound. By using two kinds of cross-linking agents in combination with the curable pressure-sensitive adhesive having such a functional group, it becomes easy to adjust the vertical peeling force and the breaking elongation within a desired range.

The removable pressure-sensitive adhesive composition of the present invention may further contain a gas generating agent that generates a gas by stimulation. When the gas generating agent is contained, when the removable pressure-sensitive adhesive composition is peeled off from the semiconductor device, a stimulus is applied to generate a gas from the gas generating agent, thereby making it easier and glue. The removable pressure-sensitive adhesive composition can be peeled off while suppressing the residue.

The above gas generating agent is not particularly limited, but is excellent in resistance to treatments involving heating, and therefore, carboxylic acid compounds such as phenylacetic acid, diphenylacetic acid, and triphenylacetic acid or salts thereof, 1H-tetrazole, 5-phenyl-1H- Tetrazole compounds such as tetrazole and 5,5-azobis-1H-tetrazole or salts thereof are suitable. While such a gas generating agent generates a gas by irradiating it with light such as ultraviolet rays, it has high heat resistance that does not decompose even at a high temperature of about 200 ° C.

When the removable pressure-sensitive adhesive composition of the present invention contains the above-mentioned gas generating agent, it may further contain a photosensitizer. Since the photosensitizer has the effect of amplifying the stimulation of the gas generating agent by light, the gas can be released by irradiation with less light. In addition, the gas can be emitted by light in a wider wavelength region.
Examples of the photosensitizer include thioxanthone compounds such as 2,4-diethylthioxanthone, anthracene compounds such as dibutylanthracene and dipropylanthracene, and 2,2-dimethoxy-1,2-diphenylethan-1-one. , Benzophenone, 2,4-dichlorobenzophenone, methyl o-benzoylbenzoate, 4,4'-bis (dimethylamino) benzophenone, 4-benzoyl-4'methyldiphenylsulfide and the like. These photosensitizers may be used alone or in combination of two or more.

When the removable pressure-sensitive adhesive composition of the present invention contains the curable pressure-sensitive adhesive as a pressure-sensitive adhesive component, the re-peelable pressure-sensitive adhesive composition is a silicone compound having a crosslinkable functional group with the curable pressure-sensitive adhesive. (Hereinafter, also simply referred to as "silicone compound A") may be contained. Since the silicone compound A has excellent heat resistance, it prevents the adhesive from being scorched even after being treated with heating at 200 ° C. or higher, and bleeds out to the interface of the adherend at the time of peeling to facilitate peeling. Since the silicone compound A has a functional group that can be crosslinked with the curable pressure-sensitive adhesive, the functional group chemically reacts with the curable pressure-sensitive adhesive and is incorporated into the curable pressure-sensitive adhesive by light irradiation or heating. Therefore, it is possible to prevent the silicone compound from adhering to the adherend and contaminating it. Further, by blending the silicone compound A, the effect of further suppressing the adhesive residue on the semiconductor device is exhibited.

The silicone skeleton of the silicone compound A is not particularly limited, and may be either a D-form or a DT-form.
The silicone compound A preferably has the functional group on the side chain or the end of the silicone skeleton.
Among them, when a silicone compound having a D-form silicone skeleton and having a functional group crosslinkable with the above-mentioned curable adhesive at the end is used as the silicone compound A, it is treated with a chemical solution while exhibiting high initial adhesive strength. It can be peeled off without adhesive residue even after high temperature treatment of 200 ° C or higher.

As the functional group of the silicone compound A, an appropriate one is selected and used depending on the curable adhesive. For example, the curable adhesive is a photocurable adhesive or a heat-curable adhesive containing a (meth) acrylic acid alkyl ester-based polymerizable polymer having a radically polymerizable unsaturated bond in the molecule as a main component. In some cases, a (meth) acrylic group and a crosslinkable functional group are selected.
The functional group that can be crosslinked with the (meth) acrylic group is a functional group having an unsaturated double bond, and specific examples thereof include a vinyl group, a (meth) acrylic group, an allyl group, and a maleimide group. ..

The functional group equivalent of the silicone compound A is not particularly limited, but the preferred lower limit is 1 and the preferred upper limit is 20. When the functional group equivalent is 1 or more, the silicone compound A is sufficiently incorporated into the curable adhesive when the obtained removable pressure-sensitive adhesive composition is cured, and contamination of the adherend can be suppressed. Further, sufficient peelability can be exhibited, and when it is 20 or less, sufficient adhesive strength can be obtained. The more preferable upper limit of the functional group equivalent is 10, the more preferable lower limit is 2, and the more preferable upper limit is 6.

The molecular weight of the silicone compound A is not particularly limited, but the preferred lower limit is 300 and the preferred upper limit is 50,000. When the molecular weight is 300 or more, the chemical resistance and heat resistance of the obtained removable pressure-sensitive adhesive composition are sufficient, and when the molecular weight is 50,000 or less, the mixture with the curable adhesive is good. The more preferable lower limit of the molecular weight is 400, the more preferable upper limit is 10,000, the further preferable lower limit is 500, and the further preferable upper limit is 5000.

The method for synthesizing the silicone compound A is not particularly limited, and for example, a silicone resin having a SiH group is reacted with the curable adhesive and a vinyl compound having a crosslinkable functional group by a hydrosyllation reaction. Examples thereof include a method of introducing a crosslinkable functional group with the above-mentioned curable adhesive into a silicone resin. Further, a method of condensing a siloxane compound with the above-mentioned curable adhesive and a siloxane compound having a crosslinkable functional group can also be mentioned.

Among the above silicone compounds A, commercially available ones are, for example, X-22-164, X-22-164AS, X-22-164A, X-22-164B, X-22-164C manufactured by Shin-Etsu Chemical Co., Ltd. , X-22-164E and other silicone compounds having methacrylic groups at both ends, and Shin-Etsu Chemical's X-22-174DX, X-22-2426, X-22-2475 and the like with methacrylic groups at one end. Silicone compounds having an acrylic group such as EBECRYL350 and EBECRYL1360 manufactured by Daisel Cytec, and silicone compounds having an acrylic group such as AC-SQ TA-100 and AC-SQ SI-20 manufactured by Toa Synthetic Co., Ltd. , MAC-SQ TM-100, MAC-SQ SI-20, MAC-SQ HDM and other silicone compounds having a methacrylic group manufactured by Toa Synthetic Co., Ltd. can be mentioned.

Among them, the silicone compound A has particularly high chemical resistance and heat resistance, and since it has high polarity, it is easy to bleed out from the removable pressure-sensitive adhesive composition. Therefore, the following general formula (I), general A silicone compound having a (meth) acrylic group in a siloxane skeleton represented by the formula (II) and the general formula (III) is suitable.

In the formula, X and Y represent integers from 0 to 1200 (except when X and Y are both 0), and R represents a functional group having an unsaturated double bond.

Among the silicone compounds represented by the general formula (I), the general formula (II), and the general formula (III) having a (meth) acrylic group in the siloxane skeleton, commercially available silicone compounds are manufactured by Daicel Cytec Co., Ltd., for example. EBECRYL350, EBECRYL1360 (both R is an acrylic group) and the like.

Regarding the content of the silicone compound A, the preferable lower limit is 0.5 parts by weight and the preferable upper limit is 50 parts by weight with respect to 100 parts by weight of the curable adhesive. When the content of the silicone compound A is 0.5 parts by weight or more, the adhesive force is sufficiently reduced when irradiated with light or heated, and the adhesive force is easily peeled off from the adherend. When the content is 50 parts by weight or less, the cover is covered. It is possible to suppress the contamination of the body. The more preferable lower limit of the content of the silicone compound A is 1 part by weight, and the more preferable upper limit is 40 parts by weight.

The removable pressure-sensitive adhesive composition of the present invention may contain an inorganic filler.
Examples of the inorganic filler include hydroxides and oxides of metals such as aluminum hydroxide, magnesium hydroxide, calcium oxide, magnesium oxide, aluminum oxide, zinc oxide, titanium oxide and antimony oxide, and metal powders such as zinc. , Metal carbonates such as calcium carbonate, magnesium carbonate, barium carbonate, zinc carbonate, alkali metal hydrogen carbonates such as sodium hydrogencarbonate and potassium hydrogencarbonate, alkaline earth metal carbonates such as calcium hydrogencarbonate and magnesium hydrogencarbonate. Examples thereof include hydrogen salts, calcium sulfate, barium sulfate, calcium silicate, mica, talc, bentonite, zeolite, silica gel and the like. However, when a strong acid is used as an acid catalyst, metal powder and carbonate should be added within a range that does not affect the adjustment of pot life. These inorganic fillers may be used alone or in combination of two or more.

Adhesive tapes can be produced using the removable pressure-sensitive adhesive composition of the present invention.
The pressure-sensitive adhesive tape may be a support tape having a pressure-sensitive adhesive layer made of the removable pressure-sensitive adhesive composition of the present invention on one or both sides of a base material, and may be a non-support tape having no base material. May be good.

When the adhesive tape is a support tape, the base material is transparent such as acrylic, olefin, polycarbonate, vinyl chloride, ABS, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), nylon, urethane, and polyimide. Examples thereof include a sheet made of resin, a sheet having a mesh-like structure, a sheet having holes, and the like.

The method for producing the adhesive tape is not particularly limited. For example, a pressure-sensitive adhesive solution containing a removable pressure-sensitive adhesive composition is applied to a release-treated PET film and then dried to form a pressure-sensitive adhesive layer. Examples thereof include a method of transferring the obtained pressure-sensitive adhesive layer to one side or both sides of the base material. Another example is a method in which the pressure-sensitive adhesive solution is directly applied to the substrate and then dried. The pressure-sensitive adhesive layer formed by applying the pressure-sensitive adhesive solution to a PET film that has been mold-released and then drying it may be used as it is as a non-support type double-sided pressure-sensitive adhesive tape without a base material.

The adhesive tape may be subjected to pre-UV treatment.
The pre-UV treatment means a treatment of irradiating the adhesive layer of the adhesive tape before or after being attached to the adherend with ultraviolet rays. By the pre-UV treatment, various physical properties of the adhesive tape can be adjusted, and for example, the elongation at break can be controlled.
Specifically, in the pre-UV treatment, for example, an ultraviolet ray having a wavelength of 300 to 450 nm is applied to the adhesive layer of the adhesive tape with an illuminance of 10 to 100 mW / cm ² and an integrated irradiation amount of 3000 mJ / cm ² . It can be done by irradiating under the conditions of. As the UV lamp, for example, a high-pressure mercury lamp or the like can be used.

The removable pressure-sensitive adhesive composition of the present invention is a re-peelable pressure-sensitive adhesive composition for affixing and protecting a bump-formed surface of a semiconductor device.
The method for protecting the bump-formed surface of the semiconductor device by the removable pressure-sensitive adhesive composition according to the present invention is not particularly limited, and for example, the re-peelable surface according to the present invention is formed on the bump-formed surface of the semiconductor device. A method of directly applying the adhesive composition to protect it can be mentioned. Further, a method of attaching and protecting a non-support tape made of the removable pressure-sensitive adhesive composition according to the present invention can be mentioned. Further, a method of attaching a support tape having a pressure-sensitive adhesive layer made of the removable pressure-sensitive adhesive composition according to the present invention to one surface of the base material to protect the base material can be mentioned.
When the surface of the semiconductor device on which the bumps are formed is protected by the removable pressure-sensitive adhesive composition of the present invention, the thickness of the re-peelable pressure-sensitive adhesive composition can further suppress adhesive residue. It is preferably 70% or less with respect to the bump height of the semiconductor device.
The thickness of the removable pressure-sensitive adhesive composition is usually higher than 0% with respect to the height of the bump of the semiconductor device.

FIG. 1 is a cross-sectional view schematically showing a state in which a surface on which a bump of a semiconductor device is formed is protected by the removable pressure-sensitive adhesive composition of the present invention. In the semiconductor device 1, the bump 12 is formed on one surface, and the pressure-sensitive adhesive layer 2 made of the removable pressure-sensitive adhesive composition of the present invention is formed on one surface of the base material 3 on the surface on the bump 12 side. It is protected by affixing the laminated support tape. A support plate 5 is attached to the surface of the semiconductor device 1 on the side where the bump 12 is not formed via the temporary fixing pressure-sensitive adhesive composition 4, and the surface side is protected.

According to the present invention, it is a removable pressure-sensitive adhesive composition for affixing and protecting a bump-formed surface of a semiconductor device, which has high adhesive strength and peels off while suppressing adhesive residue. It is possible to provide a removable pressure-sensitive adhesive composition that can be used.

It is sectional drawing which shows typically the state which the surface where the bump of the semiconductor device was formed | protected by the removable pressure-sensitive adhesive composition of this invention. It is the whole view and sectional drawing of the jig A made of SUS420 used in the heat resistance evaluation of an Example.

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

(Synthesis of resin A)
A reactor equipped with a thermometer, a stirrer, and a cooling tube is prepared. In this reactor, 85 parts by weight of 2-ethylhexyl acrylate as a (meth) acrylic acid alkyl ester and 10 parts by weight of hydroxyethyl methacrylate as a functional group-containing monomer are prepared. , 5 parts by weight of acrylic acid, 0.01 part by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate were added. The reactor was heated to initiate reflux. Subsequently, 0.01 part by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane as a polymerization initiator was added into the reactor to initiate polymerization under reflux. rice field. Next, 0.01 parts by weight of 1,1-bis (t-hexylperoxy) -3,3,5-trimethylcyclohexane was added 1 hour and 2 hours after the start of the polymerization, and further, the polymerization was started. After 4 hours from the above, 0.05 part by weight of t-hexyl peroxypivalate was added to continue the polymerization reaction. Then, 8 hours after the start of the polymerization, an ethyl acetate solution of a functional group-containing (meth) acrylic polymer having a solid content of 30% by weight and a weight average molecular weight of 900,000 was obtained.

As the resin B, 1604N manufactured by Soken Chemical Co., Ltd. was used, and as the resin C, 1495C manufactured by Soken Chemical Co., Ltd. was used.

(Example 1)
(1) Production of Removable Adhesive Composition and Adhesive Tape 1 part by weight of photopolymerization initiator and 0.2 part by weight of cross-linking agent with respect to 100 parts by weight of the resin solid content of the obtained ethyl acetate solution of resin A. , 15 parts by weight of the polyfunctional acrylate, 20 parts by weight of the silicone compound, and 5 parts by weight of the inorganic filler were added and mixed well to obtain a removable pressure-sensitive adhesive composition.
The obtained ethyl acetate solution of the removable pressure-sensitive adhesive composition was applied onto the corona-treated surface of a transparent polyethylene naphthalate film having a thickness of 50 μm and one side of which was corona-treated so that the thickness of the dry film was 40 μm. Was coated with a doctor knife and heated at 110 ° C. for 5 minutes to dry the coating solution. Then, it was statically cured at 40 ° C. for 3 days to obtain an adhesive tape.
As the photopolymerization initiator, Esacure One manufactured by Nippon Sibel Hegner Co., Ltd. was used. As the cross-linking agent, Coronate L-45 manufactured by Tosoh Corporation was used. As the polyfunctional acrylate, UN5500 manufactured by Negami Kogyo Co., Ltd. was used. As the silicone compound, Evecryl 350 manufactured by Dycel Ornex Co., Ltd. was used. As the inorganic filler, MT-10 manufactured by Tokuyama Corporation was used.

(2) Measurement of vertical peeling force With respect to the pressure-sensitive adhesive layer of the obtained adhesive tape, a SUS probe processed with a probe diameter of Φ5.8 mm and a tip R2.9 was used as a re-peelable pressure-sensitive adhesive composition. On the other hand, the peeling force when the adhesive was pressed from the vertical direction with a load of 10000 gf / cm ² for 1 second and then peeled off at a speed of 0.8 m / s in the vertical direction was measured. Of the 9-point measurements, the average value of the median 5 points was taken as the vertical peeling force.
As the tack tester, a tack tester TA-500 manufactured by UBM was used.

(3) Measurement of breaking elongation The breaking elongation is a test piece when a test piece having a thickness of 350 μm and a width of 5 mm is subjected to a tensile test at a speed of 300 mm / min with a sample chuck distance of 50 mm in a tensile tester. Was determined by measuring the elongation at break.

For the adhesive tapes of Example 1 and Comparative Examples 3 and 4, the elongation at break was measured after performing the pre-UV treatment.
The pre-UV treatment was performed by irradiating the adhesive layer of the adhesive tape with ultraviolet rays having a wavelength of 405 nm using a high-pressure mercury lamp as a UV lamp under the conditions of an illuminance of 100 mW / cm ² and an irradiation time of 30 seconds. .. The illuminance was measured using a UV illuminance meter "UVPF-A1" manufactured by Eye Graphics.

(Examples 2 to 9, Comparative Examples 1 to 6)
A removable pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape were obtained in the same manner as in Example 1 except that the type of resin, the type of cross-linking agent, the blending amount and the like were as shown in Table 1. With respect to the obtained removable pressure-sensitive adhesive composition, the vertical peeling force and the elongation at break were measured by the same method as in Example 1.

(evaluation)
The removable pressure-sensitive adhesive compositions obtained in Examples and Comparative Examples were evaluated for heat resistance by the following method. The results are shown in Table 1.

For heat resistance evaluation, a chip with a bump (WALTS-TEG FC150SCJY LF (PI) Type A) manufactured by Waltz is placed in the center of the jig A made of SUS420 shown in FIG. 2, and a speed of 10 mm / sec is used using a 2 kg roller. An adhesive tape cut into a size of 40 mm in length and 40 mm in width was attached and cured at room temperature for 15 minutes.
Then, a heat treatment step was performed at 180 ° C. for 6 hours in an oven and 250 ° C. for 10 minutes on a hot plate. By observing visually, heat resistance was evaluated according to the following criteria.
A: No peeling was observed during the process, and no adhesive residue was observed during the process. B: Peeled during the process, but no adhesive residue was observed during the process. C: Peeling was not observed during the process. No, but adhesive residue was observed at the time of peeling D: It was peeled off during the process, and adhesive residue was observed at the time of peeling.

According to the present invention, it is a removable pressure-sensitive adhesive composition for affixing and protecting a bump-formed surface of a semiconductor device, which has high adhesive strength and peels off while suppressing adhesive residue. It is possible to provide a removable pressure-sensitive adhesive composition that can be used.

1 Semiconductor device 12 Bump 2 Adhesive layer composed of the removable adhesive composition of the present invention 3 Base material 4 Temporary fixing adhesive composition 5 Support plate

Claims (3)

A removable pressure-sensitive adhesive composition for affixing and protecting a bump-formed surface of a semiconductor device.
It contains a (meth) acrylic polymer having a functional group in the molecule as a photocurable pressure -sensitive adhesive, a silicone compound having a functional group crosslinkable with the photo-curable pressure-sensitive adhesive, and a cross-linking agent .
The vertical peeling force measured by a tack measuring machine for a sample composed of a pressure-sensitive adhesive layer having a thickness of 40 μm is 10 to 40 N, and the breaking elongation measured by a sample having a thickness of 350 μm, a width of 5 mm and a length of 50 mm is 130 to 200%. A removable pressure-sensitive adhesive composition. The removable pressure-sensitive adhesive composition according to claim 1, wherein the curable pressure-sensitive adhesive has a carboxyl group and a hydroxyl group, and further contains an epoxy compound and an isocyanate compound as a cross-linking agent. An adhesive tape having an adhesive layer comprising the removable adhesive composition according to claim 1 or 2.

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