JP2023183850A - transfer sheet - Google Patents

Abstract

To provide a transfer sheet that can create an alignment mark at any position in any step, and is highly versatile.SOLUTION: The transfer sheet of the present invention is used for receiving electronic component. The transfer sheet of the present invention contains a color-changing component that can change color due to external stimulation. The transfer sheet of the present invention has an adhesive layer, and the adhesive layer preferably contains the color-changing component.SELECTED DRAWING: None

Description

The present invention relates to a transfer sheet. More specifically, the present invention relates to a transfer sheet that can be suitably used for transferring electronic components such as semiconductor chips.

In the manufacturing process of semiconductor devices, generally, a semiconductor wafer is diced into individual pieces while temporarily fixed on a dicing tape, and the diced semiconductor chips are pushed by a pin member from the dicing tape side on the back side of the wafer, and then placed into a collet. The semiconductor device is picked up by a suction jig called ``3'' and mounted on a mounting board such as a circuit board (for example, Patent Document 1).

However, with advances in microfabrication technology, semiconductor chips have become smaller and thinner, and there have been cases where semiconductor chips have been damaged when picked up by a collet. Additionally, semiconductor devices are becoming smaller and more multi-layered, and it is becoming necessary to densely mount a large number of microscopic semiconductor chips on a mounting board in multiple layers, and it is inefficient to mount them individually using collets. There was also the problem.

As a means to solve the above problem, a method has been adopted in which individualized semiconductor chips are transferred to a transfer sheet and the transferred semiconductor chips are collectively mounted on a mounting board such as a circuit board (for example, Patent Document 2).

JP 2019-9203 Publication Japanese Patent Application Publication No. 2021-197400

A transfer sheet used for transferring a semiconductor chip is sometimes provided with an alignment mark for positioning the semiconductor chip at a predetermined position. Such alignment marks need to be provided at different positions for each mounting board so that the semiconductor chip is accurately placed in the circuit on the mounting board, and because they are made to order, they are less versatile and cost-effective. There is a problem that the amount is high.

The present invention has been made in view of the above problems, and its purpose is to provide a highly versatile transfer sheet that allows alignment marks to be created at any position in any process.

As a result of intensive studies to achieve the above object, the present inventors found that an alignment mark can be created at any position and in any process by including a color-changing component that can change color due to external stimulation in the transfer sheet. I discovered that it can be done. The present invention was completed based on these findings.

That is, a first aspect of the present invention provides a transfer sheet used for receiving electronic components, which contains a color-changing component that can change color due to external stimulation. In this specification, the transfer sheet of the first aspect of the present invention may be referred to as "the transfer sheet of the present invention".

The transfer sheet of the present invention is for receiving electronic components instead of picking them up individually with a collet or the like when mounting fine, thin electronic components such as semiconductor chips on a mounting board such as a circuit board. By using the transfer sheet of the present invention for mounting electronic components, it becomes possible to receive multiple electronic components that have been diced into individual pieces at once, eliminating the need to pick them up individually. Since components can be mounted by transferring them all at once onto a large-area mounting board, manufacturing efficiency can be significantly improved.

The position where the transfer sheet receives the electronic component needs to be placed accurately at a position corresponding to the circuit on the mounting board. Therefore, the transfer sheet is generally provided with alignment marks for aligning the electronic components. Alignment marks need to be provided at different positions for each mounting board on which electronic components are mounted, and are manufactured to order, resulting in problems of low versatility and high cost.

The transfer sheet of the present invention contains a color-changing component that can change color due to external stimulation. The configuration in which the transfer sheet of the present invention contains the discoloration component is such that by applying the external stimulus to the transfer sheet, the discoloration component changes color at the location where the external stimulus has been applied, and the discoloration location is transferred to the electronic component. It can be used as an alignment mark for alignment of the receiving position. This alignment mark can be created at any position on the transfer sheet in any process, making it extremely versatile, greatly improving production efficiency and significantly reducing costs. can.

In the transfer sheet of the present invention, a semiconductor chip can be suitably used as the electronic component. Moreover, it is preferable that the major axis of the electronic component is 500 μm or less. Advances in microfabrication technology have led to miniaturization and thinning of electronic components such as semiconductor chips, and by mounting electronic components using the transfer sheet of the present invention, there is no need to pick them up individually with a collet. Therefore, damage to electronic components can be prevented.

It is preferable that one embodiment of the transfer sheet of the present invention has an adhesive layer. The configuration in which the transfer sheet of this embodiment has an adhesive layer is suitable in that it can serve as an adhesive layer for temporarily fixing the transfer sheet to a base substrate (carrier substrate). Alternatively, when the adhesive layer receives an electronic component, it is also preferable in that the force applied to the electronic component can be reduced and damage to the electronic component can be suppressed. Further, when the adhesive layer receives an electronic component without contacting the adhesive layer, the electronic component is easily caught by the adhesive layer without bouncing and can be received with high positional accuracy.

In the transfer sheet of the above embodiment, the pressure-sensitive adhesive layer preferably contains the color-changing component. This configuration is preferable because it is easy to prepare a transfer sheet containing the color-changing component, and the content of the color-changing component is easy to adjust.

In the transfer sheet of the above embodiment, the adhesive constituting the adhesive layer is preferably an acrylic adhesive or a urethane adhesive. This configuration is suitable from the viewpoint that acrylic adhesives and urethane adhesives have high transparency and good visibility of alignment marks.

Another embodiment of the transfer sheet of the present invention preferably has a laminated structure in which the adhesive layer, the base material, and another adhesive layer different from the adhesive layer are laminated in this order. . In this embodiment, the base material functions as a support for the transfer sheet of the present invention. Further, the other adhesive layer may constitute a double-sided adhesive sheet together with the adhesive layer, and one adhesive layer may be temporarily fixed to the carrier substrate, and the other adhesive layer may receive the electronic component. This is preferable because it can be done.

In the transfer sheet of the present invention, the discoloration component changes color by applying an external stimulus, and an alignment mark can be created at any position on the transfer sheet in any process. Therefore, it is applicable to all processing techniques including the transfer process of electronic parts, and has extremely high versatility, and can significantly improve production efficiency and significantly reduce costs.

FIG. 1 is a schematic cross-sectional view showing an embodiment of a transfer sheet of the present invention. It is a cross-sectional schematic diagram which shows other embodiment of the transfer sheet of this invention. FIG. 2 is a schematic cross-sectional view showing an embodiment of the first step in the electronic component transfer method using the transfer sheet shown in FIG. 1. FIG. FIG. 2 is a schematic cross-sectional view showing an embodiment of the second step in the electronic component transfer method using the transfer sheet shown in FIG. 1. FIG. FIG. 5 is a schematic cross-sectional view showing an embodiment of a method for mounting electronic components using a transfer sheet onto which the electronic components shown in FIG. 4 are transferred.

[Transfer sheet]
The transfer sheet of the present invention is a transfer sheet used for receiving electronic components, and contains a color-changing component that can change color due to external stimulation.

The transfer sheet of the present invention is for receiving electronic components instead of picking them up individually with a collet or the like when mounting fine, thin electronic components such as semiconductor chips on a mounting board such as a circuit board. By using the transfer sheet of the present invention for mounting electronic components, it becomes possible to receive multiple electronic components that have been diced into individual pieces at once, eliminating the need to pick them up individually. Since components can be mounted by transferring them all at once onto a large-area mounting board, manufacturing efficiency can be significantly improved.

[Discoloration component that can change color due to external stimulation]
The position where the transfer sheet receives the electronic component needs to be placed accurately at a position corresponding to the circuit on the mounting board. Therefore, the transfer sheet is generally provided with alignment marks for aligning the electronic components. Alignment marks need to be provided at different positions for each mounting board on which electronic components are mounted, and are manufactured to order, resulting in problems of low versatility and high cost.

The transfer sheet of the present invention contains a color-changing component (hereinafter, hereinafter, sometimes referred to as "the color-changing component of the present invention") that can change color due to external stimulation. The configuration in which the transfer sheet of the present invention contains the discoloration component of the present invention is such that by applying the external stimulus to the transfer sheet, the discoloration component changes color at the location where the external stimulus has been applied, and the discoloration location is It can be used as an alignment mark for aligning the receiving position of parts.
Therefore, since the transfer sheet of the present invention can create alignment marks at any position and in any process, it is applicable to all processing techniques including the transfer process of electronic components, and is extremely versatile. It is possible to significantly improve production efficiency and significantly reduce costs.

Examples of the external stimulus include electron beam irradiation, ultraviolet ray irradiation, active energy ray irradiation such as laser light irradiation, and heating. Energy ray irradiation is preferable, ultraviolet ray irradiation is more preferable, and ultraviolet laser beam irradiation is even more preferable since alignment marks can easily be formed at specific positions.

"Can change color" due to external stimulation means that the color can change due to external stimulation, and from the viewpoint of use as an alignment mark, "coloring" that changes from colorless (transparent) to colored is preferable.

The color-changing component of the present invention is not particularly limited as long as it can change color by the external stimulus, but includes a combination of "a compound that changes color by reaction with an acid" and an "acid generator," a combination of "a compound that changes color by reaction with an acid," and a combination of "a compound that changes color by reaction with a base." Examples include combinations of "compounds that act as base generators" and "base generators," and photochromic compounds.

[Compound that changes color due to reaction with acid]
The compound that changes color upon reaction with an acid constituting the color-changing component of the present invention is preferably a compound that changes from colorless (transparent) to colored due to the acid, such as a leuco dye. Leuco dyes are organic dyes whose color tone reversibly changes with redox. The absorption wavelength may change depending on the pH. More specifically, it refers to a reduced type dye having one or more hydrogen atoms that forms a dye and develops color by adding or removing electrons. Leuco dyes are colorless or weakly colored in neutral or alkaline media, but when reacted with acidic substances or electron-withdrawing substances, the lactone ring becomes open and colored as shown in the formula below. By selecting a leuco dye that is substantially colorless or has a weak color before electrons are removed, the change in coloration becomes noticeable and the visibility of the alignment mark is improved. becomes possible.

In the above formula, R ¹ and R ² may be the same or different and represent a hydrogen atom or a hydrocarbon group. Alternatively, R ¹ and R ² may form a 5- or 6-membered nitrogen-containing heterocycle together with the nitrogen atom to which they are bonded. R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and R ⁹ may be the same or different and represent a hydrogen atom, a halogen atom, a hydrocarbon group, or -NR ¹⁰ R ¹¹ . R ¹⁰ and R ¹¹ may be the same or different and represent a hydrogen atom or a hydrocarbon group. Alternatively, R ¹⁰ and R ¹¹ may form a 5- or 6-membered nitrogen-containing heterocycle together with the nitrogen atom to which they are bonded. Alternatively, R ⁶ and R ⁷ , R ⁷ and R ⁸ , and R ⁸ and R ⁹ may be combined to form an aromatic hydrocarbon ring such as a benzene ring together with the benzene ring to which they are combined.

Examples of the hydrocarbon group include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, s-butyl group, t-butyl group, n-pentyl group, isopentyl group, s - C _1-6 alkyl groups such as pentyl group, t-pentyl group, neopentyl group; C _3-6 cycloalkyl groups such as cyclohexyl group; C _6-10 aryl groups such as phenyl group; C _7- such as benzyl group Examples include ₁₁ aralkyl groups and the like. The hydrocarbon group has a substituent such as a C _1-6 alkyl group, a halo C _1-6 alkyl group, a halogen atom, a C _1-6 alkoxy group, a C _1-6 alkoxycarbonyl group, or a tetrahydrofuryl group. Good too. Examples of the 5- or 6-membered nitrogen-containing heterocycle include pyrrolidine, piperidine, and morpholine.

The leuco dye is colored by the acid generated by irradiating the acid generator with active energy rays or heating it.

Furthermore, after the lactone ring of the leuco dye is colored in an open state, it is possible to cause the lactone ring to close and decolorize by reacting with a base. The above base can also be generated by irradiating the base generator described below with active energy rays or by heating it.

Examples of leuco dyes include phthalide dyes (indolinophthalide series, triphenylmethane phthalide series, etc.), fluoran dyes, triarylmethane dyes, diphenylmethane dyes, phenothiazine dyes, auramine dyes, spiropyran dyes, and rhodamine dyes. Examples include compounds.

From the viewpoint of excellent color development, the leuco dye is preferably at least one leuco dye selected from the group consisting of phthalide dyes and fluoran dyes.
One type of leuco dye may be used alone, or two or more types may be used in combination.

Specific examples of leuco dyes include the following compounds.
2'-anilino-6'-(N,N-dipentan-1-ylamino)-3'-methyl-3H-spiro[isobenzofuran-1,9'-xanthene]-3-one, 2-anilino-3- Methyl-6-dibutylaminofluorane, 2-anilino-3-methyl-6-dipentylaminofluorane, 2-anilino-3-methyl-6-[ethyl(4-methylphenyl)amino]fluorane, 3,3- Bis(p-dimethylaminophenyl)-phthalide, 3,3-bis(p-dimethylaminophenyl)-6-dimethylaminophthalide (also known as crystal violet lactone), 3,3-bis(p-dimethylaminophenyl) -6-diethylaminophthalide, 3,3-bis(p-dimethylaminophenyl)-6-chlorophthalide, 3,3-bis(p-dibutylaminophenyl)phthalide, 3-cyclohexylamino-6-chlorofluoran, 3 -dimethylamino-5,7-dimethylfluorane, 3-(N-methyl-N-isobutyl)-6-methyl-7-anilinofluorane, 3-(N-ethyl-N-isoamyl)-6-methyl -7-anilinofluorane, 3-diethylamino-7-chlorofluorane, 3-diethylamino-7-methylfluorane, 3-diethylamino-7,8-benzfluorane, 3-diethylamino-6-methyl-7- Chlorfluorane, 3-(N-p-tolyl-N-ethylamino)-6-methyl-7-anilinofluorane, 3-pyrrolidino-6-methyl-7-anilinofluorane, 2-{N- (3'-trifluoromethylphenyl)amino}-6-diethylaminofluorane, 2-{3,6-bis(diethylamino)-9-(o-chloroanilino)xanthylbenzoic acid lactam}3-diethylamino-6-methyl- 7-(m-trichloromethylanilino)fluoran, 3-diethylamino-7-(o-chloroanilino)fluoran, 3-dibutylamino-7-(o-chloroanilino)fluoran, 3-(N-methyl-N-amylamino) -6-Methyl-7-anilinofluorane, 3-(N-methyl-N-cyclohexylamino)-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-anilinofluorane , 3-diethylamino-6-methyl-7-(2',4'-dimethylanilino)fluoran, 3-(N,N-diethylamino)-5-methyl-7-(N,N-dibenzylamino)fluoran , benzoylleucomethylene blue, 6'-chloro-8'-methoxy-benzoindolino-spiropyran, 6'-bromo-3'-methoxy-benzoindolino-spiropyran, 3-(2'-hydroxy-4'-dimethylamino) phenyl)-3-(2'-methoxy-5'-chlorophenyl) phthalide, 3-(2'-hydroxy-4'-dimethylaminophenyl)-3-(2'-methoxy-5'-nitrophenyl) phthalide , 3-(2'-hydroxy-4'-diethylaminophenyl)-3-(2'-methoxy-5'-methylphenyl)phthalide, 3-(2'-methoxy-4'-dimethylaminophenyl)-3- (2'-Hydroxy-4'-chloro-5'-methylphenyl)phthalide, 3-morpholino-7-(N-propyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-trifluoromethylanilinofluor Orane, 3-diethylamino-5-chloro-7-(N-benzyl-trifluoromethylanilino)fluorane, 3-pyrrolidino-7-(di-p-chlorophenyl)methylaminofluorane, 3-diethylamino-5- Chlor-7-(α-phenylethylamino)fluoran, 3-(N-ethyl-p-toluidino)-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-(o-methoxycarbonylphenylamino) Fluoran, 3-diethylamino-5-methyl-7-(α-phenylethylamino)fluoran, 3-diethylamino-7-piperidinofluorane, 2-chloro-3-(N-methyltoluidino)-7-(p- n-butylanilino)fluorane, 3-(N-methyl-N-isopropylamino)-6-methyl-7-anilinofluorane, 3-dibutylamino-6-methyl-7-anilinofluorane, 3,6- Bis(dimethylamino)fluorenespiro(9,3')-6'-dimethylaminophthalide, 3-(N-benzyl-N-cyclohexylamino)-5,6-benzo-7-α-naphthylamino-4' -Bromofluorane, 3-diethylamino-6-chloro-7-anilinofluorane, 3-{N-ethyl-N-(2-ethoxypropyl)amino}-6-methyl-7-anilinofluorane, 3 -{N-ethyl-N-tetrahydrofurfurylamino}-6-methyl-7-anilinofluorane, 3-diethylamino-6-methyl-7-mesitidino-4',5'-benzofluorane, 3-( p-dimethylaminophenyl)-3-{1,1-bis(p-dimethylaminophenyl)ethylene-2-yl}phthalide, 3-(p-dimethylaminophenyl)-3-{1,1-bis(p -dimethylaminophenyl)ethylene-2-yl}-6-dimethylaminophthalide, 3-(p-dimethylaminophenyl)-3-(1-p-dimethylaminophenyl-1-phenylethylene-2-yl)phthalide , 3-(p-dimethylaminophenyl)-3-(1-p-dimethylaminophenyl-1-p-chlorophenylethylene-2-yl)-6-dimethylaminophthalide, 3-(4'-dimethylamino- 2'-methoxy)-3-(1"-p-dimethylaminophenyl-1"-p-chlorophenyl-1",3"-butadien-4"-yl)benzophthalide, 3-(4'-dimethylamino-2 '-benzyloxy)-3-(1''-p-dimethylaminophenyl-1''-phenyl-1'',3''-butadien-4''-yl)benzophthalide, 3-dimethylamino-6-dimethylamino-fluorene- 9-spiro-3'(6'-dimethylamino)phthalide, 6-(diethylamino)-2-[(3-trifluoromethyl)anilino]xanthene-9-spiro-3'-phthalide, 3,3-bis{ 2-(p-dimethylaminophenyl)-2-(p-methoxyphenyl)ethenyl}-4,5,6,7-tetrachlorophthalide, 3-bis{1,1-bis(4-pyrrolidinophenyl) ethylene-2-yl}-5,6-dichloro-4,7-dibromophthalide, bis(p-dimethylaminostyryl)-1-naphthalenesulfonylmethane, bis(p-dimethylaminostyryl)-1-p-tolyl Sulfonylmethane.

Compounds that change color due to reaction with acids may be used singly or in combination of two or more.
The amount of the compound that changes color due to reaction with an acid is preferably 0.01 to 30 parts by weight, more preferably 0.1 to 30 parts by weight, and 0.1 to 20 parts by weight per 100 parts by weight of the transfer sheet. The amount is more preferably 1 to 10 parts by weight, and even more preferably 1 to 10 parts by weight. By being within the above range, alignment marks can be efficiently formed by discoloration caused by a compound that discolors due to reaction with an acid.

[Acid generator]
The acid generator constituting the color-changing component of the present invention is a compound that generates an acid (cation) when the external stimulus is applied. The generated acid causes discoloration of compounds that change color upon reaction with the acid. When the external stimulus is active energy ray irradiation, a photoacid generator is used, and when the external stimulus is heating, a thermal acid generator is used. A photoacid generator is preferable from the viewpoint of easily providing an alignment mark at any position on the transfer sheet of the present invention by irradiation with active energy rays.

Photoacid generators are not limited to light such as ultraviolet rays, visible light, and infrared rays, but can also irradiate active energy rays such as α rays, β rays, γ rays, electron beams, neutron rays, and X-rays. It is a compound that can generate acids (cations) by By using a photoacid generator together with a compound that changes color upon reaction with the acid, the transfer sheet of the present invention is irradiated with active energy rays to change color at any location and at any time, thereby creating an alignment mark. can be formed.

The photoacid generator is not particularly limited as long as it is a compound that can generate acids (cations) by irradiation with active energy rays, such as sulfonium salt compounds, iodonium salt compounds, aromatic N -oxyimidosulfonates, sulfonic acid ester compounds, and halomethyl-substituted -S-triazine derivatives.

From the viewpoint of good compatibility with the below-mentioned adhesive that constitutes the transfer sheet of the present invention, the photoacid generator is particularly suitable for sulfonium salt compounds, iodonium salt compounds, and aromatic N-oxyimide sulfonate compounds. At least one compound selected from the group consisting of phonates is preferred, and sulfonium salt compounds are particularly preferred.

Specific examples of sulfonium salt compounds include dimethylphenacylsulfonium, dimethylbenzylsulfonium, dimethyl-4-hydroxyphenylsulfonium, dimethyl-4-hydroxynaphthylsulfonium, dimethyl-4,7-dihydroxynaphthylsulfonium, dimethyl-4 , 8-dihydroxynaphthylsulfonium, triphenylsulfonium, p-tolyldiphenylsulfonium, p-tert-butylphenyldiphenylsulfonium, diphenyl-4-phenylthiophenylsulfonium, diphenyl-4-phenylthiophenylsulfonium, and chloride, Bromide, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenylgallate, hexafluorophosphate, hexafluoroarsenate, hexafluoroantimonate, nonafluorobutanesulfonate, etc. Examples include salts consisting of the anion.

Examples of iodonium salt compounds include diphenyliodonium, bis(p-chlorophenyl)iodonium, ditolyliodonium, bis(p-tert-butylphenyl)iodonium, p-isopropylphenyl-p-methylphenyliodonium, bis(m-nitro Cations such as phenyl)iodonium, p-tert-butylphenylphenyliodonium, p-methoxyphenylphenyliodonium, bis(p-methoxyphenyl)iodonium, p-octyloxyphenylphenyliodonium, p-phenoxyphenylphenyliodonium, and chloride, Bromide, p-toluenesulfonate, trifluoromethanesulfonate, tetrafluoroborate, tetrakispentafluorophenylborate, tetrakispentafluorophenylgallate, hexafluorophosphate, hexafluoroarsenate, hexafluoroantimonate, nonafluorobutanesulfonate, etc. Examples include salts consisting of the anion.

Examples of aromatic N-oxyimidosulfonates include N-(trifluoromethylsulfonyloxy)succinimide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenylmaleimide, N- Examples include (trifluoromethylsulfonyloxy)bicyclohept-5-ene-2,3-dicarboximide and N-(trifluoromethylsulfonyloxy)naphthylimide.

Examples of the sulfonic acid ester compound include benzoin tosylate, α-methylolbenzoin tosylate, o-nitrobenzyl p-toluenesulfonate, p-nitrobenzyl-9,10-diethoxyanthracene-2-sulfonate, and the like. . Specific examples of halomethyl-substituted -S-triazine derivatives include 2,4,6-tris(trichloromethyl)-S-triazine, 2-methyl-4,6-bis(trichloromethyl)-S-triazine, 2-phenyl -4,6-bis(trichloromethyl)-S-triazine, 2-methyl-4,6-bis(tribromomethyl)-S-triazine, and the like.

A thermal acid generator is a compound that can generate an acid (cation) when heated. By using a thermal acid generator together with a compound that changes color upon reaction with the acid, the transfer sheet of the present invention is heated to change color or color at any location at any time, thereby forming an alignment mark. be able to.

Examples of the thermal acid generator include arylsulfonium salts, aryliodonium salts, arene-ion complexes, quaternary ammonium salts, aluminum chelates, and boron trifluoride amine complexes. Examples of the anion include anions similar to those of the photoacid generator, and may also be antimony fluoride ions such as SbF ₆ ^- .

These acid generators can be used alone or in combination of two or more.
The amount of the acid generator is preferably 0.001 to 30 parts by weight, more preferably 0.01 to 25 parts by weight, and 0.1 to 30 parts by weight per 100 parts by weight of the transfer sheet of the present invention. More preferably, the amount is 0.1 to 20 parts by weight. By being within the above range, acid can be efficiently generated by active energy ray irradiation or heating, and alignment marks can be efficiently formed by discoloration caused by a compound that changes color due to reaction with acid.

[Base generator]
The transfer sheet of the present invention may contain a base generator. The base generator is a compound that generates a base when the external stimulus is applied. When the external stimulus is active energy ray irradiation, a photobase generator is used, and when the external stimulus is heating, a thermal base generator is used. From the viewpoint of efficiently erasing the alignment marks formed on the transfer sheet of the present invention, a photobase generator is preferred.

When the transfer sheet of the present invention contains a photoacid generator, the photoacid generator should be combined with the photoacid generator so that the base generator does not generate a base at the same timing as the photoacid generator generates an acid by irradiation with active energy rays. It is preferable to set a combination with a thermal base generator.
In addition, when the transfer sheet of the present invention contains a thermal acid generator, the thermal acid generator and the light are It is preferable to set a combination with a base generator.

The photobase generator is not limited to light such as ultraviolet rays, visible light, and infrared rays, but can also be used to irradiate active energy rays such as α rays, β rays, γ rays, electron beams, neutron rays, and X-rays. It is a compound that can generate a base (anion) by By using a photobase generator together with a compound that changes color upon reaction with the acid, the alignment mark can be made to disappear at any timing by irradiating the transfer sheet of the present invention with active energy rays.

The photobase generator is not particularly limited as long as it is a compound that can generate a base (anion) by irradiation with active energy rays, such as transition metal complexes, compounds having a benzyl carbamate structure, ortho-substituted compounds, etc. Compounds having a nitrobenzene structure, oximes, imidazole derivatives, benzoin compounds, compounds having an N-formylated aromatic amino group, compounds having an N-acylated aromatic amino group, compounds having an alkoxybenzyl carbamate group, 1 , 4-dihydropyridine skeletons, oxime esters, quaternary ammonium salts, and the like.

A thermal base generator is a compound that can generate a base (anion) by heating. By using a thermal base generator together with a compound that changes color upon reaction with the acid, the transfer sheet of the present invention can be heated to make the alignment mark disappear at an arbitrary timing.

The thermal base generator is not particularly limited as long as it is a compound that can generate a base (anion) by heating, such as 2-(4-biphenyl)-2-propyl carbamate and 1,1-dimethyl- From acids and bases such as carbamate derivatives such as 2-cyanoethyl carbamate, urea derivatives such as urea and N,N,N'-trimethylurea, dihydropyridine derivatives such as 1,4-dihydronicotinamide, dicyandiamide, organic salts and inorganic salts. Examples include salts such as

These base generators can be used alone or in combination of two or more.
The amount of the base generator is preferably 0.001 to 30 parts by weight, more preferably 0.01 to 25 parts by weight, and 0.1 to 20 parts by weight per 100 parts by weight of the transfer sheet of the present invention. It is even more preferable that there be. By being within the above range, a base can be efficiently generated by active energy ray irradiation or heating, and the alignment mark can be discolored.

[Combination of a compound that decolorizes by reaction with a base and a base generator]
The compound that decolorizes by reaction with a base constituting the color-changing component of the present invention is preferably a compound that changes from colored to colorless (transparent) with a base. For example, the above-mentioned leuco dye can be discolored ( Examples include colored compounds.
A compound that is decolored by reaction with a base can also be produced, for example, by a reaction between a leuco dye and an acid generated by heating the above-mentioned thermal acid generator.

Compounds that are decolored by reaction with a base may be used singly or in combination of two or more. The content of the compound that discolors when reacted with a base is the same as the above-mentioned compound that discolors when reacted with an acid.

The base generator used in combination with the compound that decolorizes by reaction with a base includes the same ones as mentioned above, and can be used in the same content.

A preferred embodiment of the combination of a base generator and a compound that decolorizes when reacted with a base is, for example, a combination of a base generated by a reaction between a leuco dye and an acid generated by heating the above-mentioned thermal acid generator. The entire surface of the transfer sheet is colored with a compound that decolorizes by reaction, and an external stimulus such as light is applied to a predetermined position to decolorize that position with a base generated from a base generator, and the decolored part is used as an alignment mark. It can be used as

[Photochromic compound]
The photochromic compound constituting the color-changing component of the present invention is a compound whose molecular structure reversibly changes upon irradiation with light of a specific wavelength, and the color changes accordingly. As an external stimulus, a location that changes color due to irradiation with light of a specific wavelength can be used as an alignment mark.

The photochromic compound is not particularly limited, and any compound can be appropriately selected and used from conventionally known compounds. For example, one or more of spiropyran compounds, spirooxazine compounds, fulgide compounds, naphthopyran compounds, bisimidazole compounds, etc. can be used depending on the desired coloring.
The photochromic compound is preferably 0.01 to 30 parts by weight, more preferably 0.1 to 30 parts by weight, and even more preferably 0.1 to 20 parts by weight, per 100 parts by weight of the transfer sheet. The amount is preferably 1 to 10 parts by weight, and more preferably 1 to 10 parts by weight. By being within the above range, alignment marks can be efficiently formed by discoloration caused by the photochromic compound.

One embodiment of the transfer sheet of the present invention (herein sometimes referred to as "first embodiment") has an adhesive layer, and the adhesive layer contains the color-changing component of the present invention. It is preferable.
The configuration in which the transfer sheet of the first embodiment has an adhesive layer is suitable in that it can serve as an adhesive layer for temporarily fixing the transfer sheet to a base substrate (carrier substrate). Alternatively, when the adhesive layer receives an electronic component, it is also preferable in that the force applied to the electronic component can be reduced and damage to the electronic component can be suppressed. Further, when the adhesive layer receives an electronic component without contacting the adhesive layer, the electronic component is easily caught by the adhesive layer without bouncing and can be received with high positional accuracy.

In the first embodiment, the configuration in which the adhesive layer contains the color-changing component is advantageous in that it is easy to prepare a transfer sheet containing the color-changing component of the present invention, and that the content of the color-changing component of the present invention can be easily adjusted. This is preferable because it is easy.

In addition, in another embodiment of the transfer sheet of the present invention (herein sometimes referred to as "second embodiment"), the adhesive layer, the base material, and the adhesive layer are different from each other. It is also preferable that the pressure-sensitive adhesive layer has a laminated structure in which the adhesive layers are laminated in this order. In the second embodiment, the base material functions as a support for the transfer sheet of the present invention. Further, the other adhesive layer may constitute a double-sided adhesive sheet together with the adhesive layer, and one adhesive layer may be temporarily fixed to the carrier substrate, and the other adhesive layer may receive the electronic component. This is preferable because it can be done.

In the second embodiment, the adhesive layer and the other adhesive layer may be made of the same adhesive or may be made of different adhesives.
Furthermore, in the second embodiment, the discoloration component of the present invention may be contained only in the adhesive layer, or may be contained in both the adhesive layer and the other adhesive layer. good.

In the transfer sheet of the second embodiment, the adhesive layer for receiving the electronic component is referred to as the "first adhesive layer", and the adhesive layer for temporarily fixing it to the carrier substrate is referred to as the "second adhesive layer". do.

In the second embodiment, the first adhesive layer and the second adhesive layer may be made of the same adhesive or may be made of different adhesives.
Further, in the second embodiment, the discoloration component of the present invention may be contained in only one of the first adhesive layer and the second adhesive layer, and the discoloration component of the present invention may be contained in only one of the first adhesive layer and the second adhesive layer. may be included in both.

In the second embodiment, when the first adhesive layer is processed using active energy ray irradiation such as laser light irradiation when or after receiving the electronic component, the transfer sheet is processed by the active energy ray irradiation. Discoloration is undesirable. Therefore, it is preferable that the first adhesive layer does not contain a color-changing component and the second adhesive layer contains a color-changing component.

In the first and second embodiments, the amount of the compound that changes color due to reaction with an acid is 0.01 to 30 parts by weight per 100 parts by weight of the adhesive layer (first adhesive layer or second adhesive layer). The amount is preferably from 0.1 to 30 parts by weight, even more preferably from 0.1 to 20 parts by weight, and even more preferably from 1 to 10 parts by weight. By being within the above range, alignment marks can be efficiently formed by discoloration caused by a compound that discolors due to reaction with an acid.

In the first and second embodiments, the amount of the acid generator is preferably 0.001 to 30 parts by weight per 100 parts by weight of the adhesive layer (first adhesive layer or second adhesive layer), and 0.01 parts by weight. It is more preferably 25 parts by weight, even more preferably 0.1 to 30 parts by weight, even more preferably 0.1 to 20 parts by weight. By being within the above range, acid can be efficiently generated by active energy ray irradiation or heating, and alignment marks can be efficiently formed by discoloration caused by a compound that changes color due to reaction with acid.

In the first and second embodiments, the base generator is preferably 0.001 to 30 parts by weight per 100 parts by weight of the adhesive layer (first adhesive layer or second adhesive layer), and preferably 0.001 to 30 parts by weight. The amount is more preferably 0.1 to 25 parts by weight, and even more preferably 0.1 to 20 parts by weight. By being within the above range, a base can be efficiently generated by active energy ray irradiation or heating, and the alignment mark can be discolored.

In the first and second embodiments, the content of the photochromic compound, which is a compound that discolors when reacted with a base, in the adhesive layer is the same as that of the compound that discolors when reacted with an acid.

Although one embodiment of the transfer sheet of the present invention may be described below with reference to the drawings, the transfer sheet of the present invention is not limited to the embodiment. FIG. 1 is a schematic cross-sectional view showing one embodiment (second embodiment) of a transfer sheet of the present invention, where 1 is a transfer sheet, 10 is a base material, 11 is a first adhesive layer, and 12 is a second adhesive layer. The agent layer is shown.

As shown in FIG. 1, the transfer sheet 1 has a laminated structure in which a first adhesive layer 11, a base material 10, and a second adhesive layer 12 are laminated in this order. When mounting a thin electronic component on a mounting board such as a circuit board, the first adhesive layer 11 receives the electronic component. By using the transfer sheet 1 for mounting electronic components, it becomes possible for the first adhesive layer 11 to receive a plurality of electronic components that have been diced into individual pieces at once, without having to pick them up individually. Furthermore, since the electronic components received by the first adhesive layer 11 can be mounted by transferring them all at once onto a large-area mounting board, manufacturing efficiency can be significantly improved.

In this embodiment, when the first adhesive layer 11 is processed using active energy ray irradiation such as laser light irradiation when receiving or after receiving the electronic component, the first adhesive layer 11 is formed by active energy ray irradiation. In order to suppress discoloration of the adhesive layer 11, the first adhesive layer does not contain a discoloring component, and the second adhesive layer contains a discoloring component (not shown).

[First adhesive layer]
The first adhesive layer is an adhesive layer for receiving and holding an electronic component, and is preferably a low-tack adhesive layer. The configuration in which the first adhesive layer is made of a low-tack adhesive layer is preferable in that it is possible to reduce the force applied to the electronic component when receiving it, and to suppress damage to the electronic component. Further, when the first adhesive layer receives the electronic component without contact, for example, the electronic component is peeled off from the dicing tape by pushing with a pin member and dropped onto the first adhesive layer. However, when the first adhesive layer receives a dropped electronic component, it may bounce and may not be received accurately. If this phenomenon occurs, the positional accuracy of the electronic product may decrease and poor contact may occur. The configuration in which the first adhesive layer is made of a low-tack adhesive layer allows the electronic component to be easily caught by the first adhesive layer without bouncing when the first adhesive layer receives the electronic component in a non-contact manner. , it is also suitable in that it can be received with high positional accuracy. Furthermore, it is also preferable in that the electronic component can be easily peeled off from the first adhesive layer when the electronic component received by the transfer sheet is mounted on the mounting board.

The first adhesive layer has low adhesiveness by adjusting the type, composition, degree of crosslinking, etc. of the constituent adhesive, and by forming a WBL (Weak Boundary Layer) by incorporating a light release agent and a plasticizer. It can be made into an agent layer.

The 180° peeling adhesion of the first adhesive layer to the PET film at 25°C is not particularly limited, but it allows electronic components to be received with good positional accuracy without being damaged, and also allows for good transfer to the mounting board. From the viewpoint of performance, it is preferably 100 mN/25 mm or less, more preferably 50 mN/25 mm or less, and even more preferably 10 mN/25 mm or less. Further, from the viewpoint of adhesion of the electronic component to the first adhesive layer, the 180° peeling adhesive force of the first adhesive layer to the glass plate at 25°C is preferably 0.1 mN/25 mm or more, More preferably, it is 1 mN/25 mm or more.

The thickness of the first adhesive layer is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more. It is preferable that the thickness is at least a certain value because the first adhesive layer can easily receive electronic components with high accuracy. Moreover, the upper limit of the thickness of the first adhesive layer is not particularly limited, but is preferably 100 μm or less, more preferably 75 μm or less. It is preferable that the thickness is below a certain level because it facilitates the accurate transfer of electronic components onto a mounting board.

The haze (according to JIS K7136) of the first adhesive layer is not particularly limited, but is preferably 10% or less, more preferably 5.0% or less. It is preferable that the haze is 10% or less, since excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. The above-mentioned haze can be applied, for example, by forming the first adhesive layer on a release liner and leaving it for at least 24 hours under normal conditions (23° C., 50% RH), then peeling off the release liner and attaching it to a slide glass (for example, Measured using a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., product name "HM-150") using a sample pasted onto a glass with a total light transmittance of 91.8% and a haze of 0.4%. can do.

The total light transmittance of the first adhesive layer in the visible light wavelength region (according to JIS K7361-1) is not particularly limited, but is preferably 85% or more, more preferably 88% or more. It is preferable that the total light transmittance is 85% or more because excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. The above total light transmittance is determined by, for example, forming the first adhesive layer on a release liner and leaving it for at least 24 hours under normal conditions (23° C., 50% RH), then peeling off the release liner and applying it to a slide glass. (for example, one with a total light transmittance of 91.8% and a haze of 0.4%) as a sample, and a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., product name "HM-150"). It can be measured using

The adhesive constituting the first adhesive layer is not particularly limited, but includes, for example, a silicone adhesive, a urethane adhesive, an acrylic adhesive, a rubber adhesive, a polyester adhesive, and a polyamide adhesive. , epoxy adhesives, vinyl alkyl ether adhesives, fluorine adhesives, and the like. Among these, it is possible to receive electronic components with good positional accuracy without damaging them, has good transferability to the mounting board, and has high transparency and good visibility of alignment marks. , silicone-based adhesives, urethane-based adhesives, and acrylic-based adhesives are preferred, and silicone-based adhesives and urethane-based adhesives are more preferred; More preferred.

[Silicone adhesive]
The silicone-based adhesive is not particularly limited, and any known or commonly used silicone-based adhesive can be used, such as addition-type silicone-based adhesives, peroxide-curing silicone-based adhesives, and condensation-type silicone-based adhesives. Agents etc. can be used. The silicone adhesive may be either a one-component type or a two-component type. Silicone adhesives can be used alone or in combination of two or more.

The addition-type silicone adhesive is generally produced by addition reaction ( This is an adhesive that generates a silicone polymer through a hydrosilylation reaction. A peroxide-curable silicone-based adhesive is generally an adhesive in which an organopolysiloxane is cured (crosslinked) with a peroxide to produce a silicone-based polymer. Furthermore, a condensed silicone adhesive is generally an adhesive that produces a silicone polymer through a dehydration or dealcoholization reaction between polyorganosiloxanes having a hydrolyzable silyl group such as a silanol group or an alkoxysilyl group at the end. .

Examples of silicone-based adhesives include silicone-based adhesive compositions containing silicone rubber and silicone resin because they can be easily controlled to have low adhesiveness and low tackiness.

The silicone rubber is not particularly limited as long as it is a silicone-based rubber component, but for example, organopolysiloxanes whose main constituent units are dimethylsiloxane, methylphenylsiloxane, etc. can be used. Also, depending on the type of reaction, silicone rubber having an alkenyl group bonded to a silicon atom (alkenyl group-containing organopolysiloxane; addition reaction type), silicone rubber having at least a methyl group (peroxide curing type) ), a silicone rubber having a silanol group or a hydrolyzable alkoxysilyl group at the end (in the case of a condensed type), etc. can be used. The weight average molecular weight of the organopolysiloxane in the silicone rubber is usually 150,000 or more, preferably 280,000 to 1,000,000, and particularly preferably 500,000 to 900,000.

The silicone resin is not particularly limited as long as it is a silicone resin used in silicone adhesives, but for example, M units consisting of the structural unit "R ₃ Si _1/2 ", structural units "SiO Consisting of a ₍ co)polymer having at least one type of unit selected from a Q unit consisting of ``2'', a T unit consisting of a structural unit ``RSiO _3/2 '', and a D unit consisting of a structural unit ``R ₂ SiO'' Examples include silicone resin made of organopolysiloxane. Note that R in the above structural unit represents a hydrocarbon group or a hydroxyl group. Examples of the hydrocarbon group include aliphatic hydrocarbon groups (alkyl groups such as methyl and ethyl groups), alicyclic hydrocarbon groups (cycloalkyl groups such as cyclohexyl), aromatic hydrocarbon groups ( aryl groups such as phenyl group, naphthyl group, etc.). The ratio (ratio) between the M unit and at least one unit selected from Q units, T units and D units is, for example, former/latter (molar ratio) = 0.3/1 to 1.5. /1 (preferably 0.5/1 to 1.3/1) is desirable. Various functional groups such as vinyl groups may be introduced into the organopolysiloxane in such silicone resins, if necessary. Note that the introduced functional group may be a functional group capable of causing a crosslinking reaction. As the silicone resin, MQ resin consisting of M units and Q units is preferable. The weight average molecular weight of the organopolysiloxane in the silicone resin is usually 1,000 or more, preferably 1,000 to 20,000, particularly preferably 1,500 to 10,000.

The blending ratio of silicone rubber and silicone resin is not particularly limited, but from the viewpoint of easy control of low adhesiveness and low tackiness, for example, 100 to 220 parts by weight of silicone resin to 100 parts by weight of silicone rubber. (In particular, 120 to 180 parts by weight) is preferable.

In addition, in the silicone adhesive composition containing silicone rubber and silicone resin, the silicone rubber and silicone resin may be in a mixed state where they are simply mixed, or they may react with each other to form a condensate (especially partially (condensation product), a crosslinking reaction product, an addition reaction product, etc.

Furthermore, silicone pressure-sensitive adhesive compositions containing silicone rubber and silicone resin usually contain a crosslinking agent to form a crosslinked structure in order to easily control low adhesiveness and low tackiness. Such crosslinking agents are not particularly limited, but siloxane crosslinking agents (silicone crosslinking agents) and peroxide crosslinking agents can be suitably used. One type of crosslinking agent can be used alone or two or more types can be used in combination.

As the siloxane-based crosslinking agent, for example, polyorganohydrogensiloxane having two or more hydrogen atoms bonded to silicon atoms in the molecule can be suitably used. In such a polyorganohydrogensiloxane, various organic groups may be bonded to the silicon atom to which the hydrogen atom is bonded, in addition to the hydrogen atom. Examples of the organic group include alkyl groups such as a methyl group and an ethyl group; aryl groups such as a phenyl group; and halogenated alkyl groups; however, from the viewpoint of synthesis and handling, a methyl group is preferred. Further, the skeletal structure of the polyorganohydrogensiloxane may be linear, branched, or cyclic, but linear is preferable.

As the peroxide crosslinking agent, for example, diacyl peroxide, alkyl peroxy ester, peroxy dicarbonate, monoperoxy carbonate, peroxy ketal, dialkyl peroxide, hydroperoxide, ketone peroxide, etc. can be used. . More specifically, for example, benzoyl peroxide, t-butyl peroxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, di-t-butyl peroxide, 2,5-dimethyl-2,5-dicumyl peroxide, -t-butylperoxyhexane, 2,4-dichloro-benzoyl peroxide, di-t-butylperoxy-diisopropylbenzene, 1,1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane , 2,5-dimethyl-2,5-di-t-butylperoxyhexine-3, and the like.

Examples of addition-type silicone adhesives include, for example, the product name "KR-3700", the product name "KR-3701", the product name "X-40-3237-1", the product name "X-40-3240", and the product name "X-40-3291-1" and trade name "X-40-3306" (all manufactured by Shin-Etsu Chemical Co., Ltd.) are commercially available. In addition, examples of peroxide-curing silicone adhesives include the product name "KR-100", the product name "KR-101-10", and the product name "KR-130" (manufactured by Shin-Etsu Chemical Co., Ltd.). It is commercially available.

The addition type silicone pressure-sensitive adhesive composition preferably contains a curing catalyst such as a platinum catalyst. As platinum catalysts, for example, the product names "CAT-PL-50T" (manufactured by Shin-Etsu Chemical Co., Ltd.), "DOWSIL NC-25 Catalyst" or "DOWSIL SRX212 Catalyst" (all manufactured by Dow Toray Industries, Inc.) are commercially available. From the viewpoint of the balance of the first adhesive layer's ability to receive electronic components, positional accuracy, transferability to the mounting board, tack strength, etc., the content of the curing catalyst should be determined based on the silicone-based polymer (silicone rubber, silicone It is preferably about 0.1 to 10 parts by weight per 100 parts by weight (including resin, etc.).

[Urethane adhesive]
The urethane adhesive is not particularly limited, and any known or commonly used urethane adhesive can be used, and polyols, polyfunctional isocyanate compounds, and catalysts can be used since they can be easily controlled to have low adhesiveness and low tackiness. A urethane pressure-sensitive adhesive composition containing the following is preferred.

As the polyol, any suitable polyol can be used as long as it has two or more hydroxyl groups. Examples of such polyols include polyols (diols) having two hydroxyl groups, polyols (triols) having three hydroxyl groups, polyols (tetraols) having four hydroxyl groups, and polyols having five hydroxyl groups. (pentaol), a polyol having six hydroxyl groups (hexaol), and the like. The polyol may be one type or two or more types.

The polyol preferably includes a polyol having a number average molecular weight (Mn) of 400 to 20,000. The content of polyols having a number average molecular weight (Mn) of 400 to 20,000 in the total amount of polyols is preferably 50 to 100% by weight, more preferably 70 to 100% by weight, and even more preferably 90 to 100% by weight. 100% by weight, particularly preferably 95-100% by weight, most preferably substantially 100% by weight. By adjusting the content of a polyol with a number average molecular weight (Mn) of 400 to 20,000 in the polyol within the above range, a urethane pressure-sensitive adhesive with controlled low adhesiveness and low tackiness is provided, for example. be able to.

Examples of the polyols include polyester polyols, polyether polyols, polycaprolactone polyols, polycarbonate polyols, and castor oil polyols.

The polyester polyol can be obtained, for example, by an esterification reaction between a polyol component and an acid component.

Examples of the polyol component include ethylene glycol, diethylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2-butyl-2-ethyl- 1,3-propanediol, 2,4-diethyl-1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,8-octanediol, 1,9-nonanediol, 2- Examples include methyl-1,8-octanediol, 1,8-decanediol, octadecanediol, glycerin, trimethylolpropane, pentaerythritol, hexanetriol, polypropylene glycol, and the like.

Examples of the acid component include succinic acid, methylsuccinic acid, adipic acid, pimelic acid, azelaic acid, sebacic acid, 1,12-dodecanedioic acid, 1,14-tetradecanedioic acid, dimer acid, and 2-methyl-1 , 4-cyclohexanedicarboxylic acid, 2-ethyl-1,4-cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 4,4'-biphenyldicarboxylic acid , and their acid anhydrides.

Examples of the polyether polyol include water, low-molecular polyols (propylene glycol, ethylene glycol, glycerin, trimethylolpropane, pentaerythritol, etc.), bisphenols (bisphenol A, etc.), dihydroxybenzene (catechol, resorcinol, hydroquinone, etc.) Examples include polyether polyols obtained by addition polymerizing alkylene oxides such as ethylene oxide, propylene oxide, butylene oxide, etc. using as an initiator. Specific examples include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and the like.

Examples of the polycaprolactone polyol include caprolactone-based polyester diols obtained by ring-opening polymerization of cyclic ester monomers such as ε-caprolactone and σ-valerolactone.

Examples of the polycarbonate polyol include polycarbonate polyol obtained by polycondensation reaction of the polyol component and phosgene; the polyol component and dimethyl carbonate, diethyl carbonate, diprobyl carbonate, diisopropyl carbonate, dibutyl carbonate, ethyl butyl carbonate, and ethylene carbonate. , propylene carbonate, diphenyl carbonate, dibenzyl carbonate, and other carbonic acid diesters by transesterification; copolymerized polycarbonate polyols obtained by using two or more of the above polyol components in combination; the above various polycarbonate polyols and carboxyl groups; polycarbonate polyols obtained by esterifying the various polycarbonate polyols and hydroxyl group-containing compounds; polycarbonate polyols obtained by etherifying the various polycarbonate polyols and ester compounds; polycarbonate polyols obtained by transesterifying the various polycarbonate polyols and ester compounds; Polycarbonate polyols obtained by transesterification of the various polycarbonate polyols and hydroxyl group-containing compounds; Polyester-based polycarbonate polyols obtained by polycondensation reaction of the various polycarbonate polyols and dicarboxylic acid compounds; Examples include copolymerized polyether-based polycarbonate polyols obtained by copolymerizing polyols and alkylene oxides; and the like.

Examples of the castor oil polyol include castor oil polyols obtained by reacting castor oil fatty acids with the polyol components. Specifically, for example, castor oil-based polyols obtained by reacting castor oil fatty acids and polypropylene glycol may be mentioned.

As the polyol, it is preferable to use a polyol (triol) having three hydroxyl groups as an essential component from the viewpoint of low adhesion, low tackiness, and wettability of the first adhesive layer to electronic components. The content of the polyol (triol) having three hydroxyl groups is preferably 50 to 100% by weight, more preferably 70 to 100% by weight, based on the total amount of components constituting the polyol.

Examples of the polyfunctional isocyanate compounds include aliphatic polyisocyanates, alicyclic polyisocyanates, and aromatic polyisocyanate compounds.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, 2,4,4- Examples include trimethylhexamethylene diisocyanate.

Examples of the alicyclic polyisocyanate include 1,3-cyclopentene diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, isophorone diisocyanate, hydrogenated diphenylmethane diisocyanate, hydrogenated xylylene diisocyanate, and hydrogenated tolylene diisocyanate. Examples include hydrogenated isocyanate tetramethylxylylene diisocyanate.

Examples of the aromatic polyisocyanate include phenylene diisocyanate, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, , 4'-toluidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4'-diphenyl diisocyanate, 1,5-naphthalene diisocyanate, xylylene diisocyanate and the like.

Among these, aliphatic polyisocyanates and modified products thereof are preferred. Aliphatic polyisocyanates and modified products thereof have a more flexible crosslinked structure than other isocyanate-based crosslinking agents, and can be easily controlled to have low adhesiveness and low tackiness. As the aliphatic polyisocyanate and its modified product, hexamethylene diisocyanate and its modified product are particularly preferred.

The polyfunctional isocyanate compound and the polyol are selected from the viewpoints of low adhesion, low tackiness, and wettability of the first pressure-sensitive adhesive layer to electronic components. The equivalent ratio of hydroxyl groups (NCO/OH) is preferably from 1 to 5, more preferably from 1.1 to 3, even more preferably from 1.2 to 2.

The urethane pressure-sensitive adhesive composition preferably contains a catalyst such as an iron-based compound and/or a tin-based compound. Specifically, tin-based catalysts such as dibutyltin dilaurate and dioctyltin dilaurate, tris(acetylacetonato)iron, tris(hexane-2,4-dionato)iron, tris(heptane-2,4-dionato)iron , tris(heptane-3,5-dionato)iron, tris(5-methylhexane-2,4-dionato)iron, tris(octane-2,4-dionato)iron, tris(6-methylheptane-2,4) -dionato)iron, tris(2,6-dimethylheptane-3,5-dionato)iron, tris(nonane-2,4-dionato)iron, tris(nonane-4,6-dionato)iron, tris(2, 2,6,6-tetramethylheptane-3,5-dionato)iron, tris(tridecane-6,8-dionato)iron, tris(1-phenylbutane-1,3-dionato)iron, tris(hexafluoroacetyl) acetonate) iron, tris (ethyl acetoacetate) iron, tris (n-propyl acetoacetate) iron, tris (isopropyl acetoacetate) iron, tris (n-butyl acetoacetate) iron, tris (acetoacetate -sec- butyl) iron, tris (tert-butyl acetoacetate) iron, tris (methyl propionyl acetate) iron, tris (ethyl propionylacetate) iron, tris (n-propyl propionyl acetate) iron, tris (isopropyl propionyl acetate) iron, Tris (n-butyl propionyl acetate) iron, tris (sec-butyl propionyl acetate) iron, tris (tert-butyl propionyl acetate) iron, tris (benzyl acetoacetate) iron, tris (dimethyl malonate) iron, tris Examples include iron-based catalysts such as (diethyl malonate) iron, trimethoxy iron, triethoxy iron, triisopropoxy iron, and ferric chloride.

The content (amount used) of the catalyst contained in the urethane adhesive composition is preferably 0.002 to 0.5 parts by weight, and 0.005 to 0.3 parts by weight based on 100 parts by weight of the polyol. More preferably, 0.01 to 0.1 part by weight is even more preferable. If it is within this range, the rate of crosslinking reaction will be fast when forming the adhesive layer, and the pot life of the adhesive composition will be long, which is a preferred embodiment.

Further, as the urethane-based adhesive, a urethane-based adhesive composition containing a urethane prepolymer is also preferred since it is easy to control low adhesiveness and low tackiness.

Examples of urethane pressure-sensitive adhesive compositions containing a urethane prepolymer include pressure-sensitive adhesive compositions containing a polyurethane polyol as a urethane prepolymer and a polyfunctional isocyanate compound. The number of urethane prepolymers may be one, or two or more. The number of polyfunctional isocyanate compounds may be one, or two or more.

The polyurethane polyol as the urethane prepolymer is preferably one obtained by reacting a polyester polyol and a polyether polyol with an organic polyisocyanate compound in the presence of a catalyst or in the absence of a catalyst.

Any suitable polyester polyol can be used as the polyester polyol. Examples of such polyester polyols include polyester polyols obtained by reacting acid components and glycol components. Examples of the acid component include terephthalic acid, adipic acid, azelaic acid, sebacic acid, phthalic anhydride, isophthalic acid, and trimellitic acid. Examples of glycol components include ethylene glycol, propylene glycol, diethylene glycol, butylene glycol, 1,6-hexane glycol, 3-methyl-1,5-pentanediol, 3,3'-dimethylolheptane, polyoxyethylene glycol, Examples include polyoxypropylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, and polyol components such as glycerin, trimethylolpropane, and pentaerythritol. Other examples of the polyester polyol include polyester polyols obtained by ring-opening polymerization of lactones such as polycaprolactone, poly(β-methyl-γ-valerolactone), and polyvalerolactone.

The molecular weight of the polyester polyol can range from low molecular weight to high molecular weight. The number average molecular weight of the polyester polyol is preferably 500 to 5,000. If the number average molecular weight is less than 500, the reactivity may be high and gelation may occur easily. If the number average molecular weight exceeds 5,000, the reactivity may decrease, and furthermore, the cohesive force of the polyurethane polyol itself may decrease. The amount of polyester polyol used is preferably 10 to 90 mol % in the polyol constituting the polyurethane polyol.

Any suitable polyether polyol can be used as the polyether polyol. Examples of such polyether polyols include oxirane compounds such as ethylene oxide, propylene oxide, butylene oxide, and tetrahydrofuran using water, low molecular weight polyols such as propylene glycol, ethylene glycol, glycerin, and trimethylolpropane as initiators. Examples include polyether polyols obtained by polymerization. Specific examples of such polyether polyols include polyether polyols having two or more functional groups, such as polypropylene glycol, polyethylene glycol, and polytetramethylene glycol.

The molecular weight of the polyether polyol can range from low molecular weight to high molecular weight. The number average molecular weight of the polyether polyol is preferably 1,000 to 5,000. If the number average molecular weight is less than 1000, the reactivity may be high and gelation may occur easily. If the number average molecular weight exceeds 5,000, the reactivity may decrease, and furthermore, the cohesive force of the polyurethane polyol itself may decrease. The amount of polyether polyol used is preferably 20 to 80 mol% of the polyol constituting the polyurethane polyol.

Polyether polyol can be partially mixed with glycols such as ethylene glycol, 1,4-butanediol, neopentyl glycol, butylethylpentanediol, glycerin, trimethylolpropane, pentaerythritol, ethylenediamine, N -Can be used in combination with polyvalent amines such as aminoethylethanolamine, isophoronediamine, and xylylenediamine.

As the polyether polyol, only a bifunctional polyether polyol may be used, or a polyether polyol having a number average molecular weight of 1000 to 5000 and having at least 3 or more hydroxyl groups in one molecule may be used. Part or all may be used. When a polyether polyol having an average molecular weight of 1,000 to 5,000 and having at least three or more hydroxyl groups in one molecule is used in part or in whole as the polyether polyol, a good balance between adhesive strength and removability is achieved. obtain. In such a polyether polyol, if the number average molecular weight is less than 1000, the reactivity becomes high and there is a risk that gelation may occur easily. In addition, in such a polyether polyol, if the number average molecular weight exceeds 5000, the reactivity may be lowered, and furthermore, the cohesive force of the polyurethane polyol itself may be reduced. The number average molecular weight of such polyether polyol is more preferably 2,500 to 3,500.

Any suitable organic polyisocyanate compound can be used as the organic polyisocyanate compound. Examples of such organic polyisocyanate compounds include aromatic polyisocyanates, aliphatic polyisocyanates, araliphatic polyisocyanates, and alicyclic polyisocyanates.

Examples of the aromatic polyisocyanate include 1,3-phenylene diisocyanate, 4,4'-diphenyl diisocyanate, 1,4-phenylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4-tolylene diisocyanate, 2,6 -tolylene diisocyanate, 4,4'-toluidine diisocyanate, 2,4,6-triisocyanate toluene, 1,3,5-triisocyanate benzene, dianisidine diisocyanate, 4,4'-diphenyl ether diisocyanate, 4,4', Examples include 4''-triphenylmethane triisocyanate.

Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate, pentamethylene diisocyanate, 1,2-propylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, dodecamethylene diisocyanate, Examples include 2,4,4-trimethylhexamethylene diisocyanate.

Examples of the aromatic aliphatic polyisocyanate include ω,ω'-diisocyanate-1,3-dimethylbenzene, ω,ω'-diisocyanate-1,4-dimethylbenzene, and ω,ω'-diisocyanate-1,4-diethylbenzene. , 1,4-tetramethylxylylene diisocyanate, 1,3-tetramethylxylylene diisocyanate, and the like.

Examples of the alicyclic polyisocyanate include 3-isocyanate methyl-3,5,5-trimethylcyclohexyl isocyanate, 1,3-cyclopentane diisocyanate, 1,3-cyclohexane diisocyanate, 1,4-cyclohexane diisocyanate, and methyl-2 , 4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 4,4'-methylenebis(cyclohexyl isocyanate), 1,4-bis(isocyanatemethyl)cyclohexane, 1,4-bis(isocyanatemethyl)cyclohexane, etc. It will be done.

As the organic polyisocyanate compound, a trimethylolpropane adduct, a biuret compound reacted with water, a trimer having an isocyanurate ring, etc. can also be used in combination.

Any suitable catalyst can be used as the catalyst that can be used to obtain the polyurethane polyol. Examples of such catalysts include tertiary amine compounds and organometallic compounds.

Examples of the tertiary amine compound include triethylamine, triethylenediamine, and 1,8-diazabicyclo[5.4.0]-undecene-7 (DBU).

Examples of the organometallic compound include tin-based compounds and non-tin-based compounds.

Examples of tin-based compounds include dibutyltin dichloride, dibutyltin oxide, dibutyltin dibromide, dibutyltin dimaleate, dibutyltin dilaurate (DBTDL), dibutyltin diacetate, dibutyltin sulfide, tributyltin sulfide, tributyltin oxide, and tributyltin. Examples include tin acetate, triethyltin ethoxide, tributyltin ethoxide, dioctyltin oxide, tributyltin chloride, tributyltin trichloroacetate, tin 2-ethylhexanoate.

Examples of non-tin compounds include titanium compounds such as dibutyltitanium dichloride, tetrabutyl titanate, and butoxytitanium trichloride; lead compounds such as lead oleate, lead 2-ethylhexanoate, lead benzoate, and lead naphthenate. ; Iron-based compounds such as iron 2-ethylhexanoate and iron acetylacetonate; Cobalt-based compounds such as cobalt benzoate and cobalt 2-ethylhexanoate; Zinc-based compounds such as zinc naphthenate and zinc 2-ethylhexanoate; Examples include zirconium compounds such as zirconium naphthenate.

When using a catalyst to obtain a polyurethane polyol, in a system where two types of polyols, polyester polyol and polyether polyol, are present, due to the difference in their reactivity, a system with a single catalyst may cause gelation or reaction solution. Problems such as turbidity are likely to occur. Therefore, by using two types of catalysts when obtaining a polyurethane polyol, the reaction rate, catalyst selectivity, etc. can be easily controlled, and these problems can be solved. Examples of combinations of two types of catalysts include tertiary amine/organometallic, tin-based/non-tin-based, and tin-based/tin-based, preferably tin-based/tin-based, and more preferably tin-based/tin-based. is a combination of dibutyltin dilaurate and tin 2-ethylhexanoate. The weight ratio of tin 2-ethylhexanoate/dibutyltin dilaurate is preferably less than 1, more preferably 0.2 to 0.6. If the blending ratio is 1 or more, gelation may occur easily due to the balance of catalyst activity.

When a catalyst is used to obtain a polyurethane polyol, the amount of the catalyst used is preferably 0.01 to 1.0% by weight based on the total amount of the polyester polyol, polyether polyol, and organic polyisocyanate compound.

If a catalyst is used in obtaining the polyurethane polyol, the reaction temperature is preferably below 100°C, more preferably between 85°C and 95°C. When the temperature exceeds 100° C., it may become difficult to control the reaction rate and crosslinked structure, and it may become difficult to obtain a polyurethane polyol having a predetermined molecular weight.

When obtaining polyurethane polyol, it is not necessary to use a catalyst. In that case, the reaction temperature is preferably 100°C or higher, more preferably 110°C or higher. Further, when obtaining a polyurethane polyol without a catalyst, it is preferable to react for 3 hours or more.

Methods for obtaining polyurethane polyol include, for example, 1) a method in which a polyester polyol, a polyether polyol, a catalyst, and an organic polyisocyanate are charged into a flask, and 2) a method in which a polyester polyol, a polyether polyol, and a catalyst are charged in a flask and an organic polyisocyanate is obtained. An example is a method of adding dropwise. As a method for obtaining a polyurethane polyol, method 2) is preferable in terms of controlling the reaction.

Any suitable solvent may be used in obtaining the polyurethane polyol. Examples of such solvents include methyl ethyl ketone, ethyl acetate, toluene, xylene, and acetone. Among these solvents, toluene is preferred.

As the polyfunctional isocyanate compound, those mentioned above can be used.

As a method for producing a polyurethane composition obtained from a composition containing a urethane prepolymer, any suitable method can be used as long as it is a method for producing a polyurethane resin composition using a so-called "urethane prepolymer" as a raw material. Manufacturing methods may be adopted.

[Acrylic adhesive]
The acrylic adhesive is not particularly limited, and any known or commonly used acrylic adhesive can be used.For example, acrylic adhesives containing an acrylic polymer as a base polymer can be easily controlled to have low adhesiveness and low tackiness. Examples include acrylic pressure-sensitive adhesive compositions.

The above-mentioned acrylic polymer is a polymer containing, as a polymer structural unit, a structural unit derived from an acrylic monomer (a monomer component having a (meth)acryloyl group in the molecule). It is preferable that the acrylic polymer is a polymer containing the largest amount of structural units derived from (meth)acrylic acid ester in mass proportion. In addition, only one type of acrylic polymer may be used, or two or more types may be used. Furthermore, in this specification, "(meth)acrylic" refers to "acrylic" and/or "methacrylic" (either or both of "acrylic" and "methacrylic"), and the same applies to the others. .

Examples of the above (meth)acrylic esters include hydrocarbon group-containing (meth)acrylic esters. Examples of the hydrocarbon group-containing (meth)acrylic ester include (meth)acrylic acid alkyl ester, (meth)acrylic acid cycloalkyl ester, (meth)acrylic acid aryl ester, and the like. Examples of the (meth)acrylic acid alkyl ester include methyl ester, ethyl ester, propyl ester, isopropyl ester, butyl ester, isobutyl ester, s-butyl ester, t-butyl ester, pentyl ester, Isopentyl ester, hexyl ester, heptyl ester, octyl ester, 2-ethylhexyl ester, isooctyl ester, nonyl ester, decyl ester, isodecyl ester, undecyl ester, dodecyl ester (lauryl ester), tridecyl ester, tetradecyl ester , hexadecyl ester, octadecyl ester, eicosyl ester and the like. Examples of the above-mentioned (meth)acrylic acid cycloalkyl ester include cyclopentyl ester and cyclohexyl ester of (meth)acrylic acid. Examples of the above-mentioned (meth)acrylic acid aryl ester include phenyl ester and benzyl ester of (meth)acrylic acid.

The above hydrocarbon group-containing (meth)acrylic esters may be used alone or in combination of two or more. In order to form an acrylic polymer, the basic properties such as tackiness due to hydrocarbon group-containing (meth)acrylic acid ester are appropriately expressed in the first adhesive layer, and it is easy to control low tackiness and low tackiness. The proportion of the hydrocarbon group-containing (meth)acrylic acid ester in all monomer components is preferably 40% by mass or more, more preferably 60% by mass or more.

The above acrylic polymer is a structural unit derived from another monomer component that can be copolymerized with the above hydrocarbon group-containing (meth)acrylic acid ester for the purpose of modifying cohesive force, heat resistance, adhesiveness, tackiness, etc. May contain. Examples of the other monomer components include carboxy group-containing monomers, acid anhydride monomers, hydroxy group-containing monomers, glycidyl group-containing monomers, sulfonic acid group-containing monomers, phosphoric acid group-containing monomers, and functional group-containing monomers such as acrylamide and acrylonitrile. Examples include monomers, vinyl ester monomers, and the like. Examples of the carboxy group-containing monomer include acrylic acid, methacrylic acid, carboxyethyl (meth)acrylate, carboxypentyl (meth)acrylate, itaconic acid, maleic acid, fumaric acid, crotonic acid, and the like. Examples of the acid anhydride monomer include maleic anhydride, itaconic anhydride, and the like. Examples of the hydroxy group-containing monomer include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, Examples include 8-hydroxyoctyl (meth)acrylate, 10-hydroxydecyl (meth)acrylate, 12-hydroxylauryl (meth)acrylate, and (4-hydroxymethylcyclohexyl)methyl (meth)acrylate. Examples of the glycidyl group-containing monomer include glycidyl (meth)acrylate, methylglycidyl (meth)acrylate, and the like. Examples of the sulfonic acid group-containing monomers include styrene sulfonic acid, allyl sulfonic acid, 2-(meth)acrylamido-2-methylpropanesulfonic acid, (meth)acrylamidopropanesulfonic acid, sulfopropyl (meth)acrylate, and (meth)acrylamidopropanesulfonic acid. ) Acryloyloxynaphthalene sulfonic acid and the like. Examples of the phosphoric acid group-containing monomer include 2-hydroxyethyl acryloyl phosphate. Examples of the vinyl ester monomer include vinyl acetate, vinyl propionate, vinyl butyrate, vinyl pivalate, vinyl cyclohexanecarboxylate, and vinyl benzoate. The above-mentioned other monomer components may be used alone or in combination of two or more. In order to form an acrylic polymer, the basic properties such as tackiness due to hydrocarbon group-containing (meth)acrylic acid ester are appropriately expressed in the first adhesive layer, and it is easy to control low tackiness and low tackiness. The total proportion of the other monomer components in the total monomer components is preferably 60% by mass or less, more preferably 40% by mass or less.

The acrylic polymer may contain a structural unit derived from a polyfunctional monomer copolymerizable with the monomer component forming the acrylic polymer in order to form a crosslinked structure in the polymer skeleton. Examples of the polyfunctional monomer include hexanediol di(meth)acrylate, (poly)ethylene glycol di(meth)acrylate, (poly)propylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, and pentyl glycol di(meth)acrylate. Erythritol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, epoxy(meth)acrylate (e.g. polyglycidyl(meth)acrylate), polyester Examples include monomers having a (meth)acryloyl group and other reactive functional groups in the molecule, such as (meth)acrylate and urethane (meth)acrylate. The above polyfunctional monomers may be used alone or in combination of two or more. In order to form an acrylic polymer, the basic properties such as tackiness due to hydrocarbon group-containing (meth)acrylic acid ester are appropriately expressed in the first adhesive layer, and it is easy to control low tackiness and low tackiness. The proportion of the polyfunctional monomer in all monomer components is preferably 40% by mass or less, more preferably 30% by mass or less.

Acrylic polymers are obtained by subjecting one or more monomer components containing acrylic monomers to polymerization. Examples of polymerization methods include solution polymerization, emulsion polymerization, bulk polymerization, and suspension polymerization.

The weight average molecular weight of the acrylic polymer is preferably 100,000 or more, more preferably 200,000 to 3,000,000. When the mass average molecular weight is 100,000 or more, the amount of low molecular weight substances in the adhesive layer tends to be small, and contamination of electronic components and the like can be further suppressed.

The acrylic adhesive composition forming the first adhesive layer may contain a crosslinking agent. For example, the acrylic polymer can be crosslinked to further reduce the amount of low molecular weight substances in the first adhesive layer. Furthermore, the weight average molecular weight of the acrylic polymer can be increased to control low adhesiveness and low tackiness. Examples of the crosslinking agent include polyisocyanate compounds, epoxy compounds, polyol compounds (polyphenol compounds, etc.), aziridine compounds, melamine compounds, etc., with isocyanate crosslinking agents and/or epoxy crosslinking agents being preferred. When a crosslinking agent is used, the amount used is preferably about 20 parts by weight or less, more preferably 0.1 to 15 parts by weight, based on 100 parts by weight of the acrylic polymer.

Examples of the isocyanate-based crosslinking agent include aliphatic isocyanates, alicyclic isocyanates, and aromatic isocyanates. Examples of aliphatic isocyanates include trimethylene diisocyanate, butylene diisocyanate, hexamethylene diisocyanate, and dimer acid diisocyanate. Examples of the alicyclic isocyanates include cyclopentylene diisocyanate, cyclohexylene diisocyanate, isophorone diisocyanate, and 1,3-bis(isocyanatomethyl)cyclohexane. Examples of aromatic isocyanates include 2,4-tolylene diisocyanate, 4,4'-diphenylmethane diisocyanate, and xylylene diisocyanate. In addition, as the isocyanate-based crosslinking agent, trimethylolpropane adduct of tolylene diisocyanate (product name "Coronate L", manufactured by Tosoh Corporation) and isocyanuric form of hexamethylene diisocyanate (product name "Coronate HX", manufactured by Tosoh Corporation) are used. ) can also be mentioned.

Examples of the epoxy crosslinking agent (polyfunctional epoxy compound) include N,N,N',N'-tetraglycidyl-m-xylene diamine, diglycidylaniline, 1,3-bis(N,N-diglycidylamino methyl) cyclohexane, 1,6-hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, ethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, sorbitol polyglycidyl ether, Glycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitan polyglycidyl ether, trimethylolpropane polyglycidyl ether, adipic acid diglycidyl ester, o-phthalic acid diglycidyl ester, triglycidyl-tris(2- Examples include hydroxyethyl) isocyanurate, resorcin diglycidyl ether, and bisphenol-S-diglycidyl ether, and also epoxy resins having two or more epoxy groups in the molecule. Examples of commercially available epoxy crosslinking agents include "Tetrad C" manufactured by Mitsubishi Gas Chemical Co., Ltd.

The adhesive composition constituting the first adhesive layer preferably contains an easy-release agent. By including the light release agent, a WBL (Weak Boundary Layer) is formed on the surface of the first adhesive layer, making it easier to control low adhesiveness and low tackiness.

The light release agent is not particularly limited, and any known light release agent may be used without restriction, such as silicone release agents, fluorine surfactants, aliphatic esters, etc. One type can be used alone or two or more types can be used in combination.

The above-mentioned silicone release agent is not particularly limited, and examples thereof include a thermosetting silicone release agent, an ionizing radiation-curable silicone release agent, and the like. Further, the silicone release agent may be either a solvent-free type that does not contain a solvent or a solvent type in which it is dissolved or dispersed in an organic solvent. Note that the silicone release agent can be used alone or in combination of two or more.

The thermosetting silicone release agent is not particularly limited, but preferably contains an organohydrogenpolysiloxane and an organopolysiloxane having an aliphatic unsaturated group. Further, the silicone-based release agent is preferably a heat-addition reaction-curable silicone-based release agent that cures by crosslinking due to a heat-addition reaction.

The heat addition reaction curable silicone release agent is not particularly limited, but may include polysiloxanes having hydrogen atoms (H) bonded to silicon atoms (Si) in the molecule (Si--H group-containing polysiloxanes); A polysiloxane (Si-H group-reactive polysiloxane) containing a functional group (Si-H group-reactive functional group) that is reactive with Si-H bonds (covalent bonds between Si and H). Preferred examples include release agents containing: Note that this release agent is cured by crosslinking through an addition reaction between the Si--H group and the Si--H group-reactive functional group.

In the Si--H group-containing polysiloxane, the H-bonded Si may be either Si in the main chain or Si in the side chain. The Si-H group-containing polysiloxane is preferably a polysiloxane containing two or more Si-H groups in the molecule. Preferred examples of the polysiloxane containing two or more Si--H groups include dimethylhydrogensiloxane-based polymers such as poly(dimethylsiloxane-methylsiloxane).

In addition, the Si--H group-reactive polysiloxane has a Si--H group-reactive functional group or a side chain containing such a functional group that forms the main chain (skeleton) of the siloxane polymer (for example, Si (main chain Preferred examples include polysiloxanes bonded to Si at the terminals and Si within the main chain. Among these, polysiloxanes in which a Si--H group-reactive functional group is directly bonded to Si in the main chain are preferred. Furthermore, as the Si--H group-reactive polysiloxane, polysiloxanes containing two or more Si--H group-reactive functional groups in the molecule are also preferably mentioned.

Examples of the Si--H group-reactive functional group in the Si--H group-reactive polysiloxane include alkenyl groups such as a vinyl group and a hexenyl group. In addition, examples of the siloxane-based polymer forming the main chain portion of the Si-H group-reactive polysiloxane include polydialkylsiloxanes such as polydimethylsiloxane, polydiethylsiloxane, and polymethylethylsiloxane (two alkyl groups are the same). ); polyalkylarylsiloxane; poly(dimethylsiloxane-methylsiloxane); polymers formed by polymerizing a plurality of Si-containing monomers; and the like. Among these, polydimethylsiloxane is preferred as the siloxane polymer forming the main chain portion.

In particular, the heat addition reaction curable silicone release agent contains a polysiloxane containing two or more Si-H groups in the molecule and a polysiloxane containing two or more Si-H group-reactive functional groups in the molecule. It is preferable to use a heat-addition reaction curable silicone release agent.

The ionizing radiation-curable silicone release agent is not particularly limited, but preferably includes a UV-curable silicone release agent that undergoes a crosslinking reaction and is cured by ultraviolet (UV) irradiation.

The UV-curable silicone release agent is a release agent that cures when exposed to UV irradiation through a chemical reaction such as cationic polymerization, radical polymerization, radical addition polymerization, or hydrosilylation reaction. The UV-curable silicone release agent is particularly preferably a UV-curable silicone release agent that is cured by cationic polymerization.

The cationically polymerizable UV-curable silicone release agent is not particularly limited, but at least two epoxy groups form the main chain (skeleton) of the siloxane polymer (for example, Si at the end of the main chain, (Si inside the chain) and/or Si contained in the side chain, respectively, directly or via a divalent group (alkylene group such as methylene group, ethylene group; alkyleneoxy group such as ethyleneoxy group, propyleneoxy group, etc.). Preferred examples include release agents containing polysiloxanes containing epoxy groups bonded together. The manner in which these at least two epoxy groups are bonded to Si may be the same or different. That is, a release agent containing a polysiloxane containing two or more side chains containing one or more types of epoxy groups is preferably mentioned. Examples of the epoxy group-containing side chain include a glycidyl group, a glycidoxy group (glycidyloxy group), a 3,4-epoxycyclohexyl group, and a 2,3-epoxycyclopentyl group. The epoxy group-containing polysiloxane may be linear, branched, or a mixture thereof.

In particular, in the transfer sheet of the second embodiment, from the viewpoint of easily controlling the first adhesive layer to have low adhesiveness and low tackiness, it is preferable that the silicone adhesive contains a thermosetting silicone release agent. It is more preferable to include a heat addition reaction curable silicone release agent.

When the first adhesive layer in the transfer sheet of the second embodiment contains a silicone adhesive, the content of the silicone release agent is not particularly limited, but is based on 100 parts by weight of the silicone polymer as the base polymer. The content is preferably 0.5 parts by weight or more and 100 parts by weight or less. When the content is 0.5 parts by weight or more, it becomes easier to control the first adhesive layer to have low adhesiveness and low tackiness, and it is more preferably 1 part by weight or more, and even more Preferably it is 3 parts by weight or more. Further, if the content is 100 parts by weight or less, sufficient adhesiveness cannot be obtained and it becomes easier to suppress the problem that it becomes difficult to receive electronic components, and it is more preferably 30 parts by weight or less, and even more Preferably it is 25 parts by weight or less.

By using the fluorine-based surfactant as a light release agent, it is possible to exhibit a light release effect due to the low surface free energy of the fluorine moiety.

The fluorine-based surfactant is not particularly limited, but includes, for example, fluorine-based oligomers, perfluorobutane sulfonates, perfluoroalkyl group-containing carboxylates, hexafluoropentane trimer derivative-containing sulfonates, and hexafluoropentane trimer. Examples include derivative-containing carboxylic acid salts, hexafluoropentane trimer derivative-containing quaternary ammonium salts, hexafluoropentane trimer derivative-containing betaine, and hexafluoropentane trimer derivative-containing polyoxyethylene ethers, among which fluorine-based oligomers are preferred. Note that the fluorine-based surfactants can be used alone or in combination of two or more.

Specific examples of the fluorine-based surfactants include commercially available products with trade names such as Megafac F-114, F-410 (manufactured by DIC Corporation), Surflon S-211, S-221, and S- 231, S-232, S-233, S-241, S-242, S-243, S-420 (manufactured by AGC Seimi Chemical Co., Ltd.), Futergent 100, 100C, 110, 150, 150CH, 300, 310 , 320, 400SW, 251, 212M, 215M, 250, 209F, 222F, 245F, 208G, 218GL, 240G, 212P, 220P, 228P, FTX-218, DFX-18 (manufactured by NEOS), and the like. These compounds may be used alone or in combination of two or more.

The weight average molecular weight (Mw) of the fluorine-based oligomer is preferably 3,500 or more, more preferably 5,000 or more, still more preferably 10,000 or more, particularly preferably 20,000 or more. When the weight average molecular weight of the fluorine-based oligomer is 3,500 or more, it becomes easy to control low adhesiveness and low tackiness. Furthermore, it is preferable that the weight average molecular weight is 20,000 or more because foaming can be suppressed during blending of the adhesive (composition) and the appearance after application of the adhesive is excellent. Further, the upper limit of the weight average molecular weight (Mw) of the fluorine-based oligomer is preferably 200,000 or less, more preferably 100,000 or less. By setting it to 200,000 or less, the fluorine-based oligomer is likely to be unevenly distributed on the surface and the light peeling effect is more easily exhibited, which is preferable.

Further, as the fluorine-based oligomer, for example, as a commercially available product, the trade names are Megafac F-251, F-253, F-281, F-410, F-430, F-444, F-477, F -510, F-511, F-551, F-552, F-553, F-554, F-555, F-556, F-557, F-558, F-559, F-560, F-561 , F-562, F-563, F-565, F-568, F-569, F-570, F-571, F-572 (manufactured by DIC), Surflon S-611, S-651, S -386 (manufactured by AGC Seimi Chemical Co., Ltd.), Ftergent 610FM, 710FL, 710FM, 710FS, 730FL, and 730LM (manufactured by Neos Corporation). These compounds may be used alone or in combination of two or more.

When the first adhesive layer contains a fluorosurfactant, the content of the fluorosurfactant is not particularly limited, but is 0.01 parts by weight based on 100 parts by weight of the silicone polymer as the base polymer. The amount is preferably 5 parts by weight or less. When the content is 0.01 parts by weight or more, it is easier to control the first adhesive layer to have low adhesiveness and low tackiness, and more preferably it is 0.05 parts by weight or more. Even more preferably it is 0.1 part by weight or more. In addition, if the content is 5 parts by weight or less, sufficient adhesiveness cannot be obtained, which makes it easier to suppress the problem of making it difficult to receive electronic components, and from the viewpoint of suppressing a decrease in transparency. It is more preferably 3 parts by weight or less, and even more preferably 2 parts by weight or less.

By containing the fatty acid ester in the adhesive composition constituting the first adhesive layer, low adhesion, low tackiness, and wettability of the first adhesive layer to electronic components can be expected.

Examples of the fatty acid ester include polyoxyethylene bisphenol A laurate, butyl stearate, 2-ethylhexyl palmitate, 2-ethylhexyl stearate, behenic acid monoglyceride, cetyl 2-ethylhexanoate, isopropyl myristate, and palmitic acid. Isopropyl, cholesteryl isostearate, lauryl methacrylate, methyl coconut fatty acid, methyl laurate, methyl oleate, methyl stearate, myristyl myristate, octyldodecyl myristate, pentaerythritol monooleate, pentaerythritol monostearate, pentaerythritol tetra Palmitate, stearyl stearate, isotridecyl stearate, 2-ethylhexanoic acid triglyceride, butyl laurate, octyl oleate, tridecyl isononanoate, and the like. The number of fatty acid esters may be one, or two or more.

The content of the fatty acid ester contained in the urethane adhesive composition is determined from the viewpoints of low adhesion of the first adhesive layer to electronic components, low tackiness, wettability, and contamination to adherends. For example, it is preferably 1 to 50 parts by weight, more preferably 2 to 40 parts by weight, and even more preferably 3 to 30 parts by weight, based on 100 parts by weight of the polyol.

When the adhesive composition constituting the first adhesive layer contains a light release agent, the content (total amount) is determined to improve the low adhesion, low tackiness, and wettability of the first adhesive layer to electronic components. From the viewpoint of contaminating properties and electronic components, for example, the amount is preferably 0.1 parts by weight or more, more preferably 1 part by weight or more, and even more preferably 3 parts by weight or more, based on 100 parts by weight of the base polymer. From the viewpoint of preventing coloration of the first pressure-sensitive adhesive layer, the content is preferably 50 parts by weight or less, more preferably 30 parts by weight or less, and even more preferably 10 parts by weight or less.

The first adhesive layer may contain an ultraviolet absorber. When the first adhesive layer contains an ultraviolet absorber, discoloration due to active energy ray irradiation can be suppressed. Therefore, it is possible to prevent discoloration of the transfer sheet when the first adhesive layer receives the electronic component, or when the first adhesive layer receives the electronic component and performs processing using active energy ray irradiation such as laser light irradiation.

The UV absorbers are not particularly limited, but include, for example, triazine UV absorbers, benzotriazole UV absorbers, benzophenone UV absorbers, oxybenzophenone UV absorbers, salicylic acid ester UV absorbers, and cyanoacrylate UV absorbers. Examples include ultraviolet absorbers, and these can be used alone or in combination of two or more. Among these, triazine-based ultraviolet absorbers and benzotriazole-based ultraviolet absorbers are preferred, and triazine-based ultraviolet absorbers having two or less hydroxyl groups in one molecule, and benzotriazole-based ultraviolet absorbers having one benzotriazole skeleton in one molecule. The at least one UV absorber selected from the group consisting of triazole UV absorbers has good solubility in the monomer used for forming the acrylic pressure-sensitive adhesive composition, and has a wavelength of around 380 nm. It is preferable because of its high ultraviolet absorption ability.

Specifically, triazine-based ultraviolet absorbers having two or less hydroxyl groups in one molecule include 2,4-bis-[{4-(4-ethylhexyloxy)-4-hydroxy}-phenyl]-6 -(4-methoxyphenyl)-1,3,5-triazine (Tinosorb S, manufactured by BASF), 2,4-bis[2-hydroxy-4-butoxyphenyl]-6-(2,4-dibutoxyphenyl) -1,3,5-triazine (TINUVIN 460, manufactured by BASF), 2-(4,6-bis(2,4-dimethylphenyl)-1,3,5-triazin-2-yl)-5-hydroxyphenyl and [(C ₁₀ -C ₁₆ (mainly C ₁₂ -C ₁₃ )alkyloxy)methyl]oxirane (TINUVIN400, manufactured by BASF), 2-[4,6-bis(2,4-dimethylphenyl)] -1,3,5-triazin-2-yl]-5-[3-(dodecyloxy)-2-hydroxypropoxy]phenol), 2-(2,4-dihydroxyphenyl)-4,6-bis-( Reaction product of 2,4-dimethylphenyl)-1,3,5-triazine and (2-ethylhexyl)-glycidic acid ester (TINUVIN405, manufactured by BASF), 2-(4,6-diphenyl-1,3,5 -triazin-2-yl)-5-[(hexyl)oxy]-phenol (TINUVIN1577, manufactured by BASF), 2-(4,6-diphenyl-1,3,5-triazin-2-yl)-5-[ 2-(2-ethylhexanoyloxy)ethoxy]-phenol (ADK STAB LA46, manufactured by ADEKA), 2-(2-hydroxy-4-[1-octyloxycarbonylethoxy]phenyl)-4,6-bis(4 -phenylphenyl)-1,3,5-triazine (TINUVIN479, manufactured by BASF), and the like.

Furthermore, as a benzotriazole UV absorber having one benzotriazole skeleton in one molecule, 2-(2H-benzotriazol-2-yl)-6-(1-methyl-1-phenylethyl)-4- (1,1,3,3-tetramethylbutyl)phenol (TINUVIN 928, manufactured by BASF), 2-(2-hydroxy-5-tert-butylphenyl)-2H-benzotriazole (TINUVIN PS, manufactured by BASF), benzene Ester _compound (TINUVIN384-2, (manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN900, manufactured by BASF), 2-(2H-benzotriazol-2-yl) yl)-6-(1-methyl-1-phenylethyl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN928, manufactured by BASF), methyl-3-(3-(2H-benzo Reaction product of triazol-2-yl)-5-t-butyl-4-hydroxyphenyl)propionate/polyethylene glycol 300 (TINUVIN1130, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-p-cresol (TINUVIN P, manufactured by BASF), 2(2H-benzotriazol-2-yl)-4-6-bis(1-methyl-1-phenylethyl)phenol (TINUVIN234, manufactured by BASF), 2-[5-chloro( 2H)-benzotriazol-2-yl]-4-methyl-6-(tert-butyl)phenol (TINUVIN326, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4,6-di-tert -Pentylphenol (TINUVIN328, manufactured by BASF), 2-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol (TINUVIN329, manufactured by BASF), methyl 3-( Reaction product of 3-(2H-benzotriazol-2-yl)-5-tert-butyl-4-hydroxyphenyl)propionate and polyethylene glycol 300 (TINUVIN213, manufactured by BASF), 2-(2H-benzotriazole-2 -yl)-6-dodecyl-4-methylphenol (TINUVIN571, manufactured by BASF), 2-[2-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole (Sumisorb 250, manufactured by Sumitomo Chemical Industries, Ltd.).

In addition, examples of the benzophenone ultraviolet absorber (benzophenone compound) and oxybenzophenone ultraviolet absorber (oxybenzophenone compound) include 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2-hydroxybenzophenone. -4-Methoxybenzophenone-5-sulfonic acid (anhydride and trihydrate), 2-hydroxy-4-octyloxybenzophenone, 4-dodecyloxy-2-hydroxybenzophenone, 4-benzyloxy-2-hydroxybenzophenone, 2, Examples include 2',4,4'-tetrahydroxybenzophenone and 2,2'-dihydroxy-4,4-dimethoxybenzophenone.

Examples of the salicylic acid ester ultraviolet absorber (salicylic acid ester compound) include phenyl-2-acryloyloxybenzoate, phenyl-2-acryloyloxy-3-methylbenzoate, phenyl-2-acryloyloxy -4-methylbenzoate, phenyl-2-acryloyloxy-5-methylbenzoate, phenyl-2-acryloyloxy-3-methoxybenzoate, phenyl-2-hydroxybenzoate, phenyl-2-hydroxy -3-methylbenzoate, phenyl-2-hydroxy-4methylbenzoate, phenyl-2-hydroxy-5-methylbenzoate, phenyl 2-hydroxy-3-methoxybenzoate, 2,4-di-tert Examples include -butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate (TINUVIN120, manufactured by BASF).

Examples of the cyanoacrylate ultraviolet absorber (cyanoacrylate compound) include alkyl-2-cyanoacrylate, cycloalkyl-2-cyanoacrylate, alkoxyalkyl-2-cyanoacrylate, alkenyl-2-cyanoacrylate, and alkynyl-2-cyanoacrylate. Examples include 2-cyanoacrylate.

The maximum absorption wavelength of the absorption spectrum of the ultraviolet absorbent is preferably in the wavelength range of 300 to 400 nm, more preferably in the wavelength range of 320 to 380 nm.

The ultraviolet absorbers may be used alone or in combination of two or more. The content of the ultraviolet absorber contained in the adhesive composition is, for example, 0.01 to 10 parts by weight based on 100 parts by weight of the adhesive composition, from the viewpoint of preventing discoloration due to irradiation with active energy rays. is preferable, 0.03 to 5 parts by weight is more preferable, and even more preferably 0.1 to 3 parts by weight.

The first adhesive layer may contain an antioxidant. When the first adhesive layer contains an antioxidant, deterioration such as discoloration during storage of the transfer sheet of the second embodiment can be suppressed.

Examples of the antioxidant include phenol-based, phosphorus-based, sulfur-based, and amine-based antioxidants, and at least one selected from these is used. Among these, phenolic antioxidants are preferred, and hindered phenolic antioxidants are particularly preferred.

Specific examples of phenolic antioxidants include monocyclic phenol compounds such as 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol, and 2,6-di-t-butyl-p-cresol. Dicyclohexyl-4-methylphenol, 2,6-diisopropyl-4-ethylphenol, 2,6-di-t-amyl-4-methylphenol, 2,6-di-t-octyl-4-n-propylphenol, 2,6-dicyclohexyl-4-n-octylphenol, 2-isopropyl-4-methyl-6-t-butylphenol, 2-t-butyl-4-ethyl-6-t-octylphenol, 2-isobutyl-4-ethyl- 6-t-hexylphenol, 2-cyclohexyl-4-n-butyl-6-isopropylphenol, styrenated mixed cresol, DL-α-tocopherol, stearyl β-(3,5-di-t-butyl-4-hydroxy phenyl) propionate, etc. as two-ring phenol compounds, 2,2'-methylenebis(4-methyl-6-t-butylphenol), 4,4'-butylidenebis(3-methyl-6-t-butylphenol), 4, 4'-thiobis(3-methyl-6-t-butylphenol), 2,2'-thiobis(4-methyl-6-t-butylphenol), 4,4'-methylenebis(2,6-di-t-butylphenol) ), 2,2'-methylenebis[6-(1-methylcyclohexyl)-p-cresol], 2,2'-ethylidenebis(4,6-di-t-butylphenol), 2,2'-butylidenebis(2 -t-butyl-4-methylphenol), 3,6-dioxaoctamethylenebis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], triethylene glycol bis[3-( 3-t-butyl-5-methyl-4-hydroxyphenyl)propionate], 1,6-hexanediol bis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate], 2,2 '-thiodiethylenebis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate] etc. as a three-ring phenol compound, -5-t-butylphenyl)butane, 1,3,5-tris(2,6-dimethyl-3-hydroxy-4-t-butylbenzyl)isocyanurate, 1,3,5-tris[(3,5 -di-t-butyl-4-hydroxyphenyl)propionyloxyethyl]isocyanurate, tris(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)isocyanurate, 1,3,5-trimethyl-2 , 4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, etc., as a four-ring phenol compound, tetrakis[methylene-3-(3,5-di-t-butyl-4 -hydroxyphenyl)propionate]methane, etc., as a phosphorus-containing phenol compound, bis(3,5-di-t-butyl-4-hydroxybenzylethylphosphonate)calcium, bis(3,5-di-t-butyl- Examples include nickel (ethyl 4-hydroxybenzylphosphonate).

The antioxidants may be used alone or in combination of two or more. The content of the antioxidant contained in the adhesive composition is, for example, from 0.01 to 100 parts by weight per 100 parts by weight of the adhesive composition, from the viewpoint of suppressing deterioration such as discoloration during storage and processability of the transfer sheet. It is preferably 10 parts by weight, more preferably 0.03 to 5 parts by weight, even more preferably 0.1 to 3 parts by weight.

The adhesive composition constituting the first adhesive layer may contain any other appropriate components within a range that does not impair the effects of the present invention. Examples of such other components include tackifiers, inorganic fillers, organic fillers, metal powders, pigments, foils, softeners, plasticizers, conductive agents, surface lubricants, leveling agents, and heat-resistant stabilizers. agent, polymerization inhibitor, lubricant, solvent, etc.

[Second adhesive layer]
The second adhesive layer is an adhesive layer for temporary fixing to the carrier substrate, and is preferably made of a removable adhesive layer. The configuration in which the second adhesive layer is a removable adhesive layer is preferable because the second adhesive layer can be peeled off from the carrier substrate without contamination such as adhesive residue, and reworkability can be improved.
The second adhesive layer can be made into a removable adhesive layer by adjusting the adhesiveness by adjusting the type and composition of the adhesive, the degree of crosslinking, etc., or by reducing the adhesive force by physical stimulation such as heat, electromagnetic waves such as ultraviolet rays, etc. It can be done.

The 180° peeling adhesive force of the second adhesive layer to the glass plate at 25° C. is not particularly limited, but from the viewpoint of being able to be peeled off from the carrier substrate without any contamination such as adhesive residue, and improving reworkability, it is 5000 mN. /25mm or less, more preferably 3000mN/25mm or less, still more preferably 1000mN/25mm or less. In addition, from the viewpoint of the adhesiveness of the carrier substrate to the second adhesive layer, the 180° peeling adhesive force of the second adhesive layer to the glass plate at 25°C is preferably 1 mN/25 mm or more, more preferably is 5 mN/25 mm or more.

The 180° peeling adhesive strength of the second adhesive layer at 25° C. can be measured in the same manner as the first adhesive layer.
The adhesive strength of the second adhesive layer can be adjusted by adjusting the type and composition of the constituent adhesive, the degree of crosslinking, etc., and by forming a WBL (Weak Boundary Layer) by adding a light release agent and a plasticizer. Can be adjusted.

The thickness of the second adhesive layer is not particularly limited, but is preferably 1 μm or more, more preferably 3 μm or more. It is preferable that the thickness is at least a certain value because it facilitates stable fixation of the second adhesive layer to the carrier substrate. Moreover, the upper limit of the thickness of the second adhesive layer is not particularly limited, but is preferably 30 μm or less, more preferably 20 μm or less. When the thickness is below a certain level, the second adhesive layer can be easily peeled off from the carrier substrate, and reworkability is improved, which is preferable.

The haze (according to JIS K7136) of the second adhesive layer is not particularly limited, but is preferably 10% or less, more preferably 5% or less. It is preferable that the haze is 10% or less, since excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. The above-mentioned haze can be obtained, for example, by forming the second adhesive layer on a release liner and leaving it for at least 24 hours under normal conditions (23° C., 50% RH), then peeling off the release liner and attaching it to a slide glass (for example, Measured using a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., product name "HM-150") using a sample pasted onto a glass with a total light transmittance of 91.8% and a haze of 0.4%. can do.

In the transfer sheet of the second embodiment, the total light transmittance of the second adhesive layer in the visible light wavelength region (according to JIS K7361-1) is not particularly limited, but is preferably 85% or more, more preferably 88%. That's all. It is preferable that the total light transmittance is 85% or more because excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. The above total light transmittance is determined by, for example, forming the second adhesive layer on a release liner and leaving it for at least 24 hours under normal conditions (23° C., 50% RH), then peeling off the release liner and applying it to a slide glass. (for example, one with a total light transmittance of 91.8% and a haze of 0.4%) as a sample, and a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., product name "HM-150"). It can be measured using

The adhesive constituting the second adhesive layer is not particularly limited, but examples include the silicone adhesive, urethane adhesive, acrylic adhesive, and rubber adhesive used in the first adhesive layer above. Examples include adhesives, polyester adhesives, polyamide adhesives, epoxy adhesives, vinyl alkyl ether adhesives, and fluorine adhesives. Among these, silicone adhesives, which can be peeled off from carrier substrates without contamination such as adhesive residue, improve reworkability, and have high transparency and good visibility of alignment marks, Urethane adhesives and acrylic adhesives are preferred, urethane adhesives and acrylic adhesives are more preferred, and acrylic adhesives are even more preferred.

The second adhesive layer is an adhesive layer (adhesive force-reducible type adhesive layer) whose adhesive force can be intentionally reduced by an external action during the use process of the transfer sheet of the second embodiment. Alternatively, it may be an adhesive layer (adhesive force non-reducing type adhesive layer) whose adhesive force is hardly or not reduced by external action during the process of using the transfer sheet, and the transfer sheet of the second embodiment It can be selected as appropriate depending on the method and conditions for transferring electronic components using a sheet.

In the case where the second adhesive layer is a pressure-sensitive adhesive layer that can reduce the adhesive strength, in the process of manufacturing or using the transfer sheet of the second embodiment, the second adhesive layer exhibits a relatively high adhesive strength. This makes it possible to selectively use a state that exhibits low adhesive strength. For example, in the process of using the transfer sheet of the second embodiment, in the step where the first adhesive layer receives an electronic component, the state where the second adhesive layer exhibits relatively high adhesive strength is used to transfer electronic components from the carrier substrate. It becomes possible to suppress and prevent lifting of the transfer sheet. On the other hand, in the subsequent process of peeling off the transfer sheet of the second embodiment from the carrier substrate, reworkability can be improved by reducing the adhesive force of the second adhesive layer.

Examples of the adhesive that forms such a pressure-sensitive adhesive layer that can reduce adhesive strength include radiation-curable adhesives, heat-foaming adhesives, and the like. As the adhesive forming the adhesive layer that can reduce the adhesive strength, one type of adhesive or two or more types of adhesives may be used.

As the radiation-curable adhesive, for example, a type of adhesive that is cured by irradiation with electron beams, ultraviolet rays, alpha rays, beta rays, gamma rays, or X-rays can be used; Adhesives (ultraviolet curable adhesives) can be particularly preferably used.

The radiation-curable adhesive may include, for example, an additive containing a base polymer such as an acrylic polymer and a radiation-polymerizable monomer component or oligomer component having a radiation-polymerizable functional group such as a carbon-carbon double bond. Examples include radiation-curable adhesives of the type.

As the base polymer, the same acrylic polymer as the first adhesive layer can be used. From the viewpoint of appropriately expressing basic properties such as tackiness due to hydrocarbon group-containing (meth)acrylic ester in the second adhesive layer and easily controlling tackiness and releasability, it is possible to The proportion of the hydrocarbon group-containing (meth)acrylic acid ester in the monomer component is preferably 40% by mass or more, more preferably 60% by mass or more.

The acrylic polymer may include a hydroxy group-containing monomer. When the acrylic polymer in the second adhesive layer contains a hydroxy group-containing monomer, it is easy to obtain an appropriate cohesive force in the second adhesive layer. From the viewpoint of achieving appropriate adhesion and cohesive force in the second pressure-sensitive adhesive layer, the proportion of the hydroxy group-containing monomer in the acrylic polymer is, for example, 0.1 to 30% by mass, preferably 0.1 to 30% by mass. It is 5 to 20% by mass.

The acrylic polymer may include a carboxy group-containing monomer. When the acrylic polymer in the second adhesive layer contains a carboxyl group-containing monomer, appropriate adhesion reliability is likely to be obtained in the second adhesive layer. From the viewpoint of achieving appropriate adhesion reliability in the second adhesive layer, the proportion of the carboxy group-containing monomer in the acrylic polymer is, for example, 0.1 to 30% by mass, preferably 0.5 to 30% by mass. It is 20% by mass.

The acrylic polymer may include a vinyl ester monomer. When the acrylic polymer in the second adhesive layer contains a vinyl ester monomer, an appropriate cohesive force is likely to be obtained in the second adhesive layer. From the viewpoint of realizing appropriate cohesive force in the second adhesive layer, the proportion of vinyl ester monomer in the acrylic polymer is, for example, 0.1 to 60% by mass, preferably 0.5 to 50% by mass. Mass%.

The acrylic adhesive composition forming the second adhesive layer may contain a crosslinking agent. For example, the acrylic polymer can be crosslinked to further reduce the amount of low molecular weight substances in the second adhesive layer. Furthermore, it is possible to increase the weight average molecular weight of the acrylic polymer and control the adhesiveness and peelability to be low. Examples of the crosslinking agent include polyisocyanate compounds, epoxy compounds, polyol compounds (polyphenol compounds, etc.), aziridine compounds, melamine compounds, etc., with isocyanate crosslinking agents and/or epoxy crosslinking agents being preferred. When used, the amount used is preferably about 10 parts by weight or less, more preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the acrylic polymer.

The acrylic adhesive composition forming the second adhesive layer may contain a crosslinking accelerator. The type of crosslinking promoter can be appropriately selected depending on the type of crosslinking agent used. In addition, in this specification, a crosslinking accelerator refers to a catalyst that increases the rate of crosslinking reaction by a crosslinking agent. Such crosslinking accelerators include tin (Sn)-containing compounds such as dioctyltin dilaurate, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin diacetylacetonate, tetra-n-butyltin, trimethyltin hydroxide; N,N, Examples include amines such as N',N'-tetramethylhexanediamine and triethylamine, and N-containing compounds such as imidazoles. Among these, Sn-containing compounds are preferred. The use of these crosslinking accelerators is particularly effective when a hydroxyl group-containing monomer is used as the above-mentioned submonomer and an isocyanate-based crosslinking agent is used as the crosslinking agent. The amount of the crosslinking accelerator contained in the adhesive composition is, for example, about 0.001 to 0.5 parts by weight (preferably about 0.001 to 0.1 parts by weight) based on 100 parts by weight of the acrylic polymer. ).

Examples of the radiation-polymerizable monomer components include urethane (meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol monohydroxypenta( Examples include meth)acrylate, dipentaerythritol hexa(meth)acrylate, and 1,4-butanediol di(meth)acrylate. Examples of the radiation-polymerizable oligomer component include various oligomers such as urethane-based, polyether-based, polyester-based, polycarbonate-based, and polybutadiene-based oligomers, and those having a molecular weight of about 100 to 30,000 are preferred. The content of the radiation-curable monomer component and oligomer component in the radiation-curable adhesive forming the second adhesive layer is, for example, 5 to 500 parts by weight, preferably 40 parts by weight, based on 100 parts by weight of the base polymer. ~150 parts by weight. Further, as the additive-type radiation-curable adhesive, for example, one disclosed in JP-A-60-196956 may be used.

The above-mentioned radiation-curable adhesive is an intrinsic radiation-curable adhesive containing a base polymer having a radiation-polymerizable functional group such as a carbon-carbon double bond in the polymer side chain, in the polymer main chain, or at the end of the polymer main chain. Also included are adhesives. When such an internal radiation-curable adhesive is used, it tends to be possible to suppress unintended changes in adhesive properties over time due to the movement of low molecular weight components within the formed second adhesive layer. be.

The base polymer contained in the above-mentioned internal radiation-curable adhesive is preferably an acrylic polymer. As a method for introducing a radiation-polymerizable carbon-carbon double bond into an acrylic polymer, for example, an acrylic polymer may be obtained by polymerizing (copolymerizing) a raw material monomer containing a monomer component having a first functional group. After that, a compound having a second functional group capable of reacting with the first functional group and a radiation-polymerizable carbon-carbon double bond is added to an acrylic polymer while maintaining the radiation-polymerizable carbon-carbon double bond. Examples include a method of conducting a condensation reaction or an addition reaction.

Combinations of the first functional group and the second functional group include, for example, a carboxy group and an epoxy group, an epoxy group and a carboxy group, a carboxyl group and an aziridyl group, an aziridyl group and a carboxy group, a hydroxy group and an isocyanate group, Examples include isocyanate groups and hydroxy groups. Among these, a combination of a hydroxy group and an isocyanate group, and a combination of an isocyanate group and a hydroxy group are preferred from the viewpoint of ease of tracking the reaction. Among these, it is technically difficult to produce a polymer having a highly reactive isocyanate group.On the other hand, from the viewpoint of ease of production and availability of an acrylic polymer having a hydroxy group, it is difficult to produce a polymer having a highly reactive isocyanate group. A combination in which the functional group is a hydroxy group and the second functional group is an isocyanate group is preferred. Examples of compounds having an isocyanate group and a radiation-polymerizable carbon-carbon double bond, that is, radiation-polymerizable isocyanate compounds containing an unsaturated functional group, include methacryloyl isocyanate, 2-methacryloyloxyethyl isocyanate, m-isopropenyl- Examples include α,α-dimethylbenzyl isocyanate. In addition, examples of acrylic polymers having hydroxy groups include those containing structural units derived from the above-mentioned hydroxy group-containing monomers and ether compounds such as 2-hydroxyethyl vinyl ether, 4-hydroxybutyl vinyl ether, and diethylene glycol monovinyl ether. can be mentioned.

The radiation-curable adhesive preferably contains a photopolymerization initiator. Examples of the photopolymerization initiator include α-ketol compounds, acetophenone compounds, benzoin ether compounds, ketal compounds, aromatic sulfonyl chloride compounds, photoactive oxime compounds, benzophenone compounds, thioxanthone compounds, Examples include camphorquinone, halogenated ketones, acylphosphinoxides, acyl phosphonates, and the like. Examples of the above α-ketol compounds include 4-(2-hydroxyethoxy)phenyl(2-hydroxy-2-propyl)ketone, α-hydroxy-α,α'-dimethylacetophenone, and 2-methyl-2-hydroxy Examples include propiophenone and 1-hydroxycyclohexylphenyl ketone. Examples of the acetophenone compounds include methoxyacetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxyacetophenone, 2-methyl-1-[4-(methylthio)-phenyl]-2 -morpholinopropane-1 and the like. Examples of the benzoin ether compounds include benzoin ethyl ether, benzoin isopropyl ether, anisoin methyl ether, and the like. Examples of the above-mentioned ketal compounds include benzyl dimethyl ketal. Examples of the aromatic sulfonyl chloride compounds include 2-naphthalenesulfonyl chloride. Examples of the photoactive oxime compounds include 1-phenyl-1,2-propanedione-2-(O-ethoxycarbonyl) oxime. Examples of the benzophenone compounds include benzophenone, benzoylbenzoic acid, 3,3'-dimethyl-4-methoxybenzophenone, and the like. Examples of the thioxanthone compounds include thioxanthone, 2-chlorothioxanthone, 2-methylthioxanthone, 2,4-dimethylthioxanthone, isopropylthioxanthone, 2,4-dichlorothioxanthone, 2,4-diethylthioxanthone, 2,4-diisopropyl Examples include thioxanthone. The content of the photopolymerization initiator in the radiation-curable adhesive is, for example, 0.05 to 20 parts by weight based on 100 parts by weight of the base polymer.

The heat-foaming adhesive is an adhesive containing components that foam or expand when heated (foaming agents, heat-expandable microspheres, etc.). Examples of the foaming agent include various inorganic foaming agents and organic foaming agents. Examples of the inorganic blowing agent include ammonium carbonate, ammonium hydrogen carbonate, sodium hydrogen carbonate, ammonium nitrite, sodium borohydride, and azides. Examples of the organic blowing agent include salt fluorinated alkanes such as trichloromonofluoromethane and dichloromonofluoromethane; azo compounds such as azobisisobutyronitrile, azodicarbonamide, and barium azodicarboxylate; paratoluene; Hydrazine compounds such as sulfonyl hydrazide, diphenylsulfone-3,3'-disulfonyl hydrazide, 4,4'-oxybis(benzenesulfonyl hydrazide), allylbis(sulfonyl hydrazide); p-tolylenesulfonyl semicarbazide, 4,4'- Semicarbazide compounds such as oxybis(benzenesulfonyl semicarbazide); Triazole compounds such as 5-morpholyl-1,2,3,4-thiatriazole; N,N'-dinitrosopentamethylenetetramine, N,N'-dimethyl- Examples include N-nitroso compounds such as N,N'-dinitrosoterephthalamide. Examples of the thermally expandable microspheres include microspheres in which a substance that easily gasifies and expands when heated is enclosed in a shell. Examples of substances that easily gasify and expand upon heating include isobutane, propane, pentane, and the like. Thermally expandable microspheres can be produced by encapsulating a substance that easily gasifies and expands upon heating into a shell-forming substance by a coacervation method, an interfacial polymerization method, or the like. As the shell-forming substance, a substance exhibiting thermal melting property or a substance capable of bursting due to the action of thermal expansion of the encapsulating substance can be used. Examples of such substances include vinylidene chloride-acrylonitrile copolymer, polyvinyl alcohol, polyvinyl butyral, polymethyl methacrylate, polyacrylonitrile, polyvinylidene chloride, polysulfone, and the like.

Examples of the adhesive layer that does not reduce adhesive strength include a pressure-sensitive adhesive layer. Note that the pressure-sensitive adhesive layer includes a pressure-sensitive adhesive layer formed from the radiation-curable adhesive described above in connection with the adhesive force-reducible adhesive layer, which is cured by radiation irradiation in advance, but has a certain adhesive force. Contains an adhesive layer. As the adhesive forming the non-reduced adhesive layer, one type of adhesive or two or more types of adhesives may be used. Further, the entire second adhesive layer may be a non-reduced adhesive layer, or a portion thereof may be a non-reduced adhesive layer. For example, when the second adhesive layer has a single-layer structure, the entire second adhesive layer may be a non-adhesive adhesive layer, or a specific portion of the second adhesive layer may have an adhesive strength. The adhesive layer may be a non-reducible adhesive layer, and the other portion may be an adhesive layer whose adhesive force can be reduced. In addition, when the second adhesive layer has a laminated structure, all the adhesive layers in the laminated structure may be non-adhesive adhesive layers, or some adhesive layers in the laminated structure may be adhesive layers. It may also be a non-force reducing adhesive layer.

An adhesive layer formed from a radiation-curable adhesive (non-irradiated radiation-curable adhesive layer) is cured by radiation irradiation (irradiated radiation-curable adhesive layer). Even if the adhesive force is reduced by the irradiation, it exhibits the adhesive force due to the contained polymer component, and it is possible to exhibit the minimum adhesive force required for the transfer sheet of the second embodiment. When using a radiation-irradiated radiation-curable adhesive layer, the entire second adhesive layer may be an irradiated radiation-curable adhesive layer in the surface spreading direction of the second adhesive layer; A part of the agent layer may be a radiation-curable adhesive layer that has been irradiated, and the other part may be a radiation-curable adhesive layer that has not been irradiated. In addition, in this specification, the "radiation-curable adhesive layer" refers to an adhesive layer formed from a radiation-curable adhesive, and includes a radiation-curable adhesive layer that has radiation curability and has not been irradiated with radiation, and the adhesive. It includes both a radiation-cured adhesive layer and a radiation-cured adhesive layer after the adhesive layer has been cured by radiation irradiation.

As the adhesive forming the pressure-sensitive adhesive layer, any known or commonly used pressure-sensitive adhesive can be used, and an acrylic adhesive having an acrylic polymer as a base polymer can be preferably used. When the second adhesive layer contains an acrylic polymer as a pressure-sensitive adhesive, the acrylic polymer is a polymer containing a structural unit derived from a (meth)acrylic acid ester as the largest structural unit in mass proportion. It is preferable. As the acrylic polymer, for example, the acrylic polymer described as an acrylic polymer that can be included in the above-mentioned additive-type radiation-curable adhesive can be employed.

[Base material]
The base material in the transfer sheet of the second embodiment is an element that functions as a support. Examples of the base material include plastic base materials (especially plastic films). The base material may be a single layer or a laminate of base materials of the same type or different types.

Examples of the resin constituting the plastic base material include low-density polyethylene, linear low-density polyethylene, medium-density polyethylene, high-density polyethylene, ultra-low-density polyethylene, random copolymerized polypropylene, block copolymerized polypropylene, and homopolyprolene. , polybutene, polymethylpentene, ethylene-vinyl acetate copolymer (EVA), ionomer, ethylene-(meth)acrylic acid copolymer, ethylene-(meth)acrylic acid ester (random, alternating) copolymer, ethylene- Polyolefin resins such as butene copolymers and ethylene-hexene copolymers; polyurethanes; polyesters such as polyethylene terephthalate (PET), polyethylene naphthalate, and polybutylene terephthalate (PBT); polycarbonates; polyimides; polyether ether ketones; polyether imides Polyamides such as aramid and wholly aromatic polyamide; polyphenylsulfide; fluororesins; polyvinyl chloride; polyvinylidene chloride; cellulose resins; silicone resins; cellulose triacetate (TAC), and the like. When the transfer sheet of the second embodiment transfers and mounts the electronic components received by thermocompression bonding (e.g., 150° C.) onto a mounting board, it exhibits good heat resistance that does not easily cause expansion or contraction due to heat, From the viewpoint of accurate mounting, the base material is mainly heat-resistant resin such as polyimide (PI), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyamide (PA), and polyether ether ketone (PEEK). It is preferably included as a component, and more preferably contains polyimide as a main component.
In addition, from the viewpoint of preventing discoloration of the transfer sheet of the second embodiment when the transfer sheet receives electronic components or when processing using active energy ray irradiation such as laser light irradiation after receiving the electronic components. , polyimide (PI), polyethylene terephthalate (PET), cellulose triacetate (TAC), etc., which exhibit ultraviolet absorbing properties, are also preferable.
Moreover, the main component of the base material is defined as the component that occupies the largest mass proportion among the constituent components. The above resins may be used alone or in combination of two or more.

When the base material is a plastic film, the plastic film may be non-oriented or oriented in at least one direction (uniaxial direction, biaxial direction, etc.), but non-orientation may reduce heat shrinkability. This is preferable because it is difficult to show.

The surface of the base material on the side of the first adhesive layer and/or the second adhesive layer may be subjected to, for example, corona discharge treatment, plasma treatment, sand mat processing, Physical treatments such as ozone exposure treatment, flame exposure treatment, high voltage electric shock exposure treatment, and ionizing radiation treatment; chemical treatments such as chromic acid treatment; coating agents (undercoat); surface treatments such as easy adhesion treatment using silicone primer treatment. may have been applied. Further, in order to impart antistatic ability, in addition to providing a conductive vapor deposition layer containing a metal, an alloy, an oxide thereof, etc. on the surface of the base material, a conductive polymer such as PEDOT-PSS may be coated. The surface treatment for improving adhesion is preferably applied to the entire surface of the base material on the pressure-sensitive adhesive layer side.

The thickness of the base material is preferably 5 μm or more, more preferably 10 μm or more, and even more preferably 15 μm or more, from the viewpoint of ensuring the strength for the base material to function as a support in the transfer sheet of the second embodiment. , particularly preferably 20 μm or more. Further, from the viewpoint of achieving appropriate flexibility in the transfer sheet of the second embodiment, the thickness of the base material is preferably 200 μm or less, more preferably 180 μm or less, and still more preferably 150 μm or less.

In the transfer sheet of the second embodiment, the haze of the base material (according to JIS K7136) is not particularly limited, but is preferably 10% or less, more preferably 5.0% or less. It is preferable that the haze is 10% or less, since excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. Note that the haze can be measured using a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., trade name "HM-150").

In the transfer sheet of the second embodiment, the total light transmittance of the base material in the visible light wavelength region (according to JIS K7361-1) is not particularly limited, but is preferably 85% or more, more preferably 88% or more. . It is preferable that the total light transmittance is 85% or more because excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. Note that the above-mentioned total light transmittance can be measured using a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., trade name "HM-150").

In the transfer sheet of the second embodiment, the base material may contain the color changing component of the present invention. That is, the base material may include a compound that changes color upon reaction with an acid, an acid generator, and, if necessary, a base generator, and may change color upon external stimulation to form an alignment mark. Alternatively, the base material may include a compound that decolorizes by reaction with a base, a base generator, or a photochromic compound, and may change color due to external stimulation to form an alignment mark.

The amount of the compound that changes color due to reaction with an acid is preferably 0.01 to 30 parts by weight, more preferably 0.1 to 30 parts by weight, and 0.1 to 20 parts by weight per 100 parts by weight of the base material. The amount is more preferably 1 to 10 parts by weight, and even more preferably 1 to 10 parts by weight. By being within the above range, alignment marks can be efficiently formed by discoloration caused by a compound that discolors due to reaction with an acid.

The amount of the acid generator is preferably 0.001 to 30 parts by weight, more preferably 0.01 to 25 parts by weight, and even more preferably 0.1 to 30 parts by weight per 100 parts by weight of the base material. The amount is preferably 0.1 to 20 parts by weight, and more preferably 0.1 to 20 parts by weight. By being within the above range, acid can be efficiently generated by active energy ray irradiation or heating, and alignment marks can be efficiently formed by discoloration caused by a compound that changes color due to reaction with acid.

The base generator is preferably used in an amount of 0.001 to 30 parts by weight, more preferably 0.01 to 25 parts by weight, and preferably 0.1 to 20 parts by weight per 100 parts by weight of the base material. More preferred. By being within the above range, a base can be efficiently generated by active energy ray irradiation or heating, and the alignment mark can be discolored.

The content of the photochromic compound, which is a compound that discolors when reacted with a base, in the base material is the same as that of the compound that discolors when reacted with an acid.

[Release liner]
The adhesive layer surface (the adhesive surface of the first adhesive layer and/or the second adhesive layer) of the transfer sheet of the second embodiment may be protected by a release liner until use. The release liner is used as a protective material for the adhesive layer, and is peeled off when the adhesive sheet is attached to an adherend. FIG. 2 is a schematic cross-sectional view showing one embodiment (second embodiment) of a transfer sheet of the present invention, in which 1 is a transfer sheet, 10 is a base material, 11 is a first adhesive layer, and 12 is a second adhesive layer. Agent layers 110 and 120 represent release liners. Note that the release liner does not necessarily have to be provided.

As the above-mentioned release liner, a conventional release paper or the like can be used, and specifically, in addition to a base material having a release treatment layer formed by a release agent on at least one surface, fluorine-based polymers (such as polytetrafluorocarbon ethylene, polychlorotrifluoroethylene, polyvinyl fluoride, polyvinylidene fluoride, tetrafluoroethylene-hexafluoropropylene copolymer, chlorofluoroethylene-vinylidene fluoride copolymer, etc.), and non-polar A low adhesive base material made of a polymer (for example, an olefin resin such as polyethylene or polypropylene) can be used.

As the release liner, for example, a release liner in which a release treatment layer is formed on at least one surface of a release liner base material can be suitably used. Such base materials for release liners include polyester films (polyethylene terephthalate films, etc.), olefin resin films (polyethylene films, polypropylene films, etc.), polyvinyl chloride films, polyimide films, polyamide films (nylon films), and rayon films. In addition to plastic base films (synthetic resin films) such as (composite of two to three layers).

The release agent constituting the release layer is not particularly limited, but for example, a silicone release agent, a fluorine release agent, a long chain alkyl release agent, and the like can be used. The release agent can be used alone or in combination of two or more.
Note that since the first adhesive layer is composed of a low-tack adhesive layer, it is also possible to use a base material that has not been treated with a release agent as a release liner.

In the above-mentioned release liner, an antistatic layer may be formed on at least one surface of the release liner base material in order to prevent an adverse effect on electronic components. The antistatic layer may be formed on one side (release treated side or untreated side) of the release liner, or may be formed on both sides (release treated side and untreated side) of the release liner.

The antistatic agent contained in the antistatic resin forming the antistatic layer is a cationic type having a cationic functional group such as a quaternary ammonium salt, a pyridinium salt, or a primary, secondary, or tertiary amino group. Antistatic agents, anionic antistatic agents with anionic functional groups such as sulfonates, sulfate ester salts, phosphonates, phosphate ester salts, alkyl betaines and their derivatives, imidazolines and their derivatives, alanine and its derivatives, etc. amphoteric antistatic agents, amino alcohols and their derivatives, glycerin and its derivatives, polyethylene glycol and its derivatives, and other nonionic antistatic agents; Examples include ion-conductive polymers obtained by polymerizing or copolymerizing monomers having the same. These compounds may be used alone or in combination of two or more.

The thickness of the release liner is not particularly limited, and may be appropriately selected from the range of 5 to 100 μm.

The method for manufacturing the transfer sheet of the second embodiment varies depending on the composition of the adhesive composition, etc., and is not particularly limited, and any known forming method can be used. For example, the following (1) to (4) ).
(1) The above adhesive composition is applied (coated) onto a base material to form a composition layer, and the composition layer is cured (for example, by thermosetting or curing by irradiation with active energy rays such as ultraviolet rays). (2) The above adhesive composition is applied (coated) onto a release liner to form a composition layer, and the composition layer is cured (e.g. , heat curing or curing by irradiation with active energy rays such as ultraviolet rays) to form a pressure-sensitive adhesive layer, and then transferring the pressure-sensitive adhesive layer onto a substrate to produce a pressure-sensitive adhesive sheet (3) Method of manufacturing the pressure-sensitive adhesive composition above A method of manufacturing a pressure-sensitive adhesive sheet by applying (coating) on a base material and drying to form an adhesive layer (4) Applying (coating) the above-mentioned pressure-sensitive adhesive composition onto a release liner, A method of manufacturing an adhesive sheet by drying to form an adhesive layer and then transferring the adhesive layer onto a base material.

As the curing method in (1) to (4) above, a thermal curing method is preferable because it has excellent productivity and can form a pressure-sensitive adhesive layer with a homogeneous and smooth surface.

As a method for applying (coating) the above-mentioned pressure-sensitive adhesive composition onto a predetermined surface, a known coating method can be adopted, and examples thereof include, but are not limited to, roll coating, kiss roll coating, gravure coating, and reverse coating. , roll brush coating, spray coating, dip roll coating, bar coating, knife coating, air knife coating, curtain coating, lip coating, and extrusion coating using a die coater.

The thickness (total thickness) of the transfer sheet of the second embodiment is not particularly limited, but is preferably 10 μm or more, more preferably 15 μm or more. It is preferable that the thickness is at least a certain level because the first adhesive layer can easily receive electronic components with high precision. Further, the upper limit of the thickness (total thickness) of the transfer sheet of the second embodiment is not particularly limited, but is preferably 500 μm or less, more preferably 300 μm or less. It is preferable that the thickness is below a certain level because it facilitates the accurate transfer of electronic components onto a mounting board. Note that the thickness of the transfer sheet in the second embodiment does not include the thickness of the release liner.

The haze (according to JIS K7136) of the transfer sheet of the second embodiment is not particularly limited, but is preferably 10% or less, more preferably 5.0% or less. It is preferable that the haze is 10% or less, since excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. The above-mentioned haze can be measured by, for example, leaving the transfer sheet in a normal state (23°C, 50% RH) for at least 24 hours, then peeling off the release liner if it has a release liner, and applying it to the slide glass (for example, total light transmittance). 91.8%, haze 0.4%) as a sample, and can be measured using a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., trade name "HM-150"). .

The total light transmittance of the transfer sheet of the second embodiment in the visible light wavelength region (according to JIS K7361-1) is not particularly limited, but is preferably 85% or more, more preferably 88% or more. It is preferable that the total light transmittance is 85% or more because excellent transparency can be obtained and, for example, the visibility of the alignment mark formed by applying an external stimulus to the transfer sheet of the second embodiment is improved. The above total light transmittance is determined by, for example, leaving the transfer sheet in normal conditions (23°C, 50% RH) for at least 24 hours, then peeling off the release liner if it has a release liner, and applying it to the slide glass (for example, completely The sample is pasted onto a sheet (with a light transmittance of 91.8% and a haze of 0.4%), and is measured using a haze meter (manufactured by Murakami Color Research Institute Co., Ltd., trade name "HM-150"). be able to.

The transfer sheet of the present invention is suitably used for receiving (transferring) electronic components. The method for transferring electronic components using the transfer sheet of the present invention preferably includes the following steps.
Applying external stimulation to the transfer sheet of the present invention to form alignment marks (first step)
A step in which the transfer sheet of the present invention receives the diced electronic component using the alignment mark as an index (second step)

FIG. 3 is a schematic cross-sectional view showing one embodiment of the first step in the electronic component transfer method using the transfer sheet of the second embodiment.
In FIG. 3A, the transfer sheet 1 has a laminated structure in which a first adhesive layer 11, a base material 10, and a second adhesive layer 12 are laminated in this order. In this embodiment, the second adhesive layer 12 contains the color changing component of the present invention, and the first adhesive layer 11 does not contain the color changing component of the present invention. In this embodiment, the color changing component contained in the second adhesive layer 12 includes a compound that changes color due to reaction with an acid, and a photoacid generator. The adhesive surface of the second adhesive layer 12 is attached to the carrier substrate 21 . As the carrier substrate, a plastic substrate similar to the above substrate or a glass substrate can be used, and a highly transparent glass substrate is preferable.

A photomask 22 is arranged on the surface of the carrier substrate 21 that is not attached to the second adhesive layer 12. The opening of the photomask 22 corresponds to a position where an electronic component 31, which will be described later, is placed on the second adhesive layer 11.

In FIG. 3A, active energy rays U are irradiated onto the photomask 22 side. The active energy ray U passes through the opening of the photomask 22 and the highly transparent carrier substrate 21, reaches the second adhesive layer 12, and the photoacid generator decomposes to generate acid. The compound that changes color due to the reaction with the photomask 22 changes color (coloring), and an alignment mark 23 is formed at a position corresponding to the opening of the photomask 22.

Active energy rays include light such as ultraviolet rays, visible rays, and infrared rays, and radiation such as α rays, β rays, γ rays, electron beams, neutron beams, and X rays, and preferably electron beams, ultraviolet rays, and laser light. , ultraviolet light is more preferred. The alignment mark 23 may be formed by irradiating a laser beam onto a position corresponding to the opening of the photomask 22 without using the photomask 22.

FIG. 4 is a schematic cross-sectional view showing an embodiment of the second step in the electronic component transfer method using the transfer sheet of the second embodiment.

In FIG. 4A, on the upper part of the adhesive surface of the first adhesive layer 11 of the transfer sheet 1, a plurality of electronic components 31 separated by dicing are attached to a dicing tape 30. 1 are arranged to face the adhesive surface of the adhesive layer 11 and to be spaced apart from each other.

Although the electronic component is not particularly limited, it can be suitably used for fine and thin semiconductor chips and LED chips. The electronic component can be thin and fine; for example, the major axis may be 500 μm or less, or 100 μm or less; the minor axis may be 400 μm or less, or 50 μm or less. The lower limits of the major axis and minor axis are not particularly limited, but may be 5 μm or more.
Further, the thickness of the electronic component is also not particularly limited, but may be 100 μm or less, or 50 μm or less. The lower limit of the thickness of the electronic component is also not particularly limited, but may be 5 μm or more.

In FIG. 4B, the electronic component 31 is pushed with the pin member 32 from the surface of the dicing tape 30 to which the electronic component 31 is not attached, and the electronic component 31 is brought close to the adhesive surface of the first adhesive layer 11. , is received by the adhesive surface of the first adhesive layer 11. The positions at which the first adhesive layer 11 receives the electronic components 31 are aligned to corresponding positions using the alignment marks 23 as indicators.

The electronic component 31 may be received by bringing the electronic component 31 into contact with the first adhesive layer 11, or may be received without contact. When receiving the electronic component 31 without contact, the electronic component 31 is pushed until the electronic component 31 is peeled off from the dicing tape 30, and the electronic component 31 is dropped onto the adhesive surface of the electronic component 31. When the electronic component 31 is received in contact, the adhesive surface of the first adhesive layer 11 has low adhesiveness, so the stress applied when the electronic component 31 is received is weak, so that damage to the electronic component 31 can be suppressed. When receiving the electronic component 31 without contact, the adhesive surface of the first adhesive layer 11 has low adhesiveness, so that the dropped electronic component 31 can be caught with high positional accuracy.

Note that the electronic component 31 may be peeled off from the dicing tape 30 by irradiating radiation such as ultraviolet rays or laser beams instead of the pin member 32. When the electronic component 31 is peeled off from the dicing tape 30 by irradiation with radiation, the first adhesive layer 11 preferably contains an ultraviolet absorber. Since the first adhesive layer 11 contains the ultraviolet absorber, radiation is absorbed by the first adhesive layer 11, so that discoloration of the second adhesive layer 12 can be suppressed.

The electronic components 31 may be received individually into the first adhesive layer 11, or a plurality of electronic components 31 may be received at once. FIG. 4C is a schematic cross-sectional view showing a state in which all the electronic components 31 of the dicing tape 20 are received on the adhesive surface of the first adhesive layer 11 of the transfer sheet 1.

The electronic component 31 transferred onto the first adhesive layer 11 of the transfer sheet 1 is mounted onto a mounting board. FIG. 5 is a schematic cross-sectional view showing a method for mounting electronic components transferred onto a transfer sheet. In this embodiment, the electronic component 31 is formed at a position where it can be accurately mounted on each circuit formed on the circuit surface 41 of the mounting board 40 using the alignment mark 23 as an index.

As shown in FIG. 5(a), electrons are arranged on the adhesive surface of the first adhesive layer 11 of the transfer sheet 1, facing and spaced apart from the circuit surface 41 (circuit pattern not shown) of the mounting board 40. Place the parts 31. Next, as shown in FIG. 5B, the electronic components 31 arranged on the circuit surface 41 of the mounting board 40 and the adhesive surface of the first adhesive layer 11 of the transfer sheet 1 are brought close to each other. and the circuit surface 41 of the mounting board 40 are brought into contact with each other.

The electronic component 31 may be transferred onto the circuit surface 41 of the mounting board 40 by thermocompression bonding (for example, at 150° C. for 1 minute). Since the base material 10, the first adhesive layer 11, and/or the second adhesive layer 12 that constitute the transfer sheet 1 have excellent heat resistance, they will not expand, contract, or change their adhesive strength due to thermocompression bonding. Therefore, the electronic component 31 can be transferred onto the circuit surface 41 of the mounting board 40 with high precision.

Next, as shown in FIG. 5(c), by separating the transfer sheet 1 and the mounting board 40, the electronic component 31 is peeled off from the first adhesive layer 11 and transferred to the circuit surface 41 of the mounting board 40. Ru. Since the first adhesive layer 11 is composed of a low-tack adhesive layer, the electronic component 31 can be easily peeled off, and the electronic component 31 can be efficiently mounted on the mounting board 40 without being damaged. .

After the electronic component 31 is mounted on the mounting board 40, the transfer sheet 1 shown in FIG. 5(c) may be peeled off from the carrier board 21 (not shown). Since the second adhesive layer 12 is composed of a removable adhesive layer, it can be peeled off without leaving any adhesive residue, and has excellent reworkability, so that the carrier substrate 21 can be easily reused.

The present invention will be explained in more detail with reference to Examples below, but the present invention is not limited to these Examples in any way.

[Production Example 1]: Production of acrylic copolymer (1) 95 parts by weight of butyl acrylate (manufactured by Nippon Shokubai Co., Ltd.) was placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a condenser. , acrylic acid (manufactured by Toagosei Co., Ltd.): 5 parts by weight, 2,2'-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator: 0.2 parts by weight, ethyl acetate: 156 parts by weight. was charged, nitrogen gas was introduced with gentle stirring, and the polymerization reaction was carried out for 10 hours while maintaining the liquid temperature in the flask at around 63°C. Solid content: 40% by weight) was prepared.

[Production Example 2]: Production of acrylic copolymer (2) 2-ethylhexyl acrylate (2EHA) (manufactured by Nippon Shokubai Co., Ltd.) was placed in a four-necked flask equipped with a stirring blade, a thermometer, a nitrogen gas introduction tube, and a condenser. ): 100 parts by weight, 2-hydroxyethyl acrylate (HEA) (manufactured by Toagosei Co., Ltd.): 4 parts by weight, 2,2'-azobisisobutyronitrile (manufactured by Wako Pure Chemical Industries, Ltd.) as a polymerization initiator: 0 02 parts by weight of ethyl acetate and 180 parts by weight of ethyl acetate were introduced, nitrogen gas was introduced while stirring gently, and the polymerization reaction was carried out for 6 hours while maintaining the liquid temperature in the flask at around 65°C. A solution (solid content: 35% by weight) of acrylic copolymer (2) was prepared.

[Example 1]
(Preparation of transfer sheet)
Silicone adhesive 1 (addition reaction silicone adhesive, product name "X-40-3306", manufactured by Shin-Etsu Chemical Co., Ltd.): 100 parts by weight, platinum catalyst 1 (product name "CAT-PL-50T") , manufactured by Shin-Etsu Chemical Co., Ltd.): 1.4 parts by weight, silicone release agent 1 (addition reaction type silicone release agent containing dimethylpolysiloxane as the main component, trade name "KS-776A", Shin-Etsu Chemical Co., Ltd.) company): 5 parts by weight was added, diluted with toluene so that the total solid content was 25% by weight, and mixed with a disper to prepare a silicone adhesive composition (silicone adhesive composition 1). .
Silicone-based adhesive is applied to the silicone-primed surface of the base film (1) (polyester film treated with silicone primer on one side, thickness 25 μm, product name "Diafoil MRF#25", manufactured by Mitsubishi Plastics Corporation). Agent Composition 1 was applied so that the glue thickness after drying was 10 μm, and cured and dried at a drying temperature of 120° C. and a drying time of 5 minutes. In this way, a film having a silicone adhesive layer (1) on the silicone primer treated layer of the base film (1) was obtained.
In addition, a release liner (1) (unreleased polyethylene terephthalate film, thickness 25 μm, trade name "Lumirror S10#25", manufactured by Toray Industries, Inc.) is laminated on the adhesive surface of the silicone adhesive film, and A laminate (1) was obtained that protected the adhesive layer and had a laminated structure of [Release liner (1) layer]/[Silicone adhesive (1) layer]/[Base film (1) layer] .
Next, TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) was added as a crosslinking agent to the solution of the acrylic copolymer (1) obtained in Production Example 1, based on 100 parts by weight of the solid content, in terms of solid content. 0 parts by weight, 2 parts by weight of a leuco dye (trade name "S-205", manufactured by Yamada Chemical Industry Co., Ltd.), and 7 parts by weight of a photoacid generator (trade name "CPI-100P", manufactured by San-Apro Co., Ltd.) were added. A release liner (2) (release-treated polyethylene terephthalate film, thickness 38 μm, product name "MRF #38'' (manufactured by Mitsubishi Chemical Corporation) was coated on the release layer side using a fountain roll so that the thickness after drying was 25 μm, and was cured and dried at a drying temperature of 130° C. and a drying time of 30 seconds. In this way, the acrylic adhesive layer (1) was formed on the release liner (2).
Next, the base film (1) side (silicone primer-untreated side) of the laminate (1) obtained above was bonded to the surface of the acrylic adhesive layer (1), and the release liner (1) layer ] / [Silicone adhesive (1) layer (first adhesive layer)] / [Base film (1) layer] / [Acrylic adhesive (1) layer (second adhesive layer)] / [Peeling A transfer sheet having a laminated structure of "liner (2) layer" was obtained.

[Example 2]
Except that 7 parts by weight of a photoacid generator (trade name "CPI-110P", manufactured by San-Apro Co., Ltd.) was added instead of the photo-acid generator (trade name "CPI-100P", manufactured by Sun-Apro Co., Ltd.). In the same manner as in Example 1, [Release liner (1) layer]/[Silicone adhesive (1) layer (first adhesive layer)]/[Base film (1) layer]/[Acrylic adhesive A transfer sheet having a laminated structure of layer (2) (second adhesive layer)/layer release liner (2) was obtained.

[Example 3]
Except that 7 parts by weight of a photoacid generator (trade name "CPI-310B", manufactured by San-Apro Co., Ltd.) was added instead of the photo-acid generator (trade name "CPI-100P", manufactured by Sun-Apro Co., Ltd.). In the same manner as in Example 1, [Release liner (1) layer]/[Silicone adhesive (1) layer (first adhesive layer)]/[Base film (1) layer]/[Acrylic adhesive A transfer sheet having a laminated structure of layer (3) (second adhesive layer)/layer release liner (2) was obtained.

[Example 4]
Instead of a photoacid generator (trade name "CPI-100P", manufactured by Sun-Apro Co., Ltd.), 7 parts by weight of a photoacid generator (trade name "SP-056", manufactured by ADEKA Corporation) was blended, and the base film ( Example 1 was repeated in the same manner as in Example 1, except that base film (2) (polyimide film, thickness 25 μm, trade name "Kapton 100H", manufactured by DuPont Toray) was used in place of 1). 1) layer] / [Silicone adhesive (1) layer (first adhesive layer)] / [Base film (2) layer] / [Acrylic adhesive (4) layer (second adhesive layer)] A transfer sheet having a laminated structure of /[release liner (2) layer] was obtained.

[Example 5]
In the same manner as in Example 4, except that the base film (3) (TAC film, thickness 80 μm, trade name "FujiTac TD80UL", manufactured by Fuji Film Corporation) was used instead of the base film (2), [Release liner (1) layer] / [Silicone adhesive (1) layer (first adhesive layer)] / [Base film (3) layer] / [Acrylic adhesive (4) layer (second adhesive layer) A transfer sheet having a laminated structure of [agent layer)]/[release liner (2) layer] was obtained.

[Example 6]
To 100 parts by weight of the solid content of the acrylic copolymer (2) obtained in Production Example 2, 4.0 parts by weight of Coronate HX (manufactured by Tosoh Corporation) was added as a crosslinking agent in terms of solid content, and as a crosslinking catalyst. 0.02 parts by weight of Enbilizer OL-1 (manufactured by Tokyo Fine Chemical Co., Ltd.) in terms of solid content, 2 parts by weight of leuco dye (product name "S-205", manufactured by Yamada Chemical Co., Ltd.), photoacid generator (product name) 7 parts by weight of SP-056 (manufactured by ADEKA) were added, diluted with ethyl acetate so that the total solid content was 25% by weight, stirred with a disper, and the resulting acrylic adhesive composition [Release liner (1) layer]/[Silicone adhesive (1) layer (first adhesive layer)]/[Substrate material] A transfer sheet having a laminated structure of film (1) layer/acrylic adhesive (5) layer (second adhesive layer)/release liner (2) layer was obtained.

[Example 7]
As a prepolymer type urethane adhesive composition (1), Coronate HX (manufactured by Tosoh Corporation) was added as a crosslinking agent to a solution of Siabain SH-109 (manufactured by Toyochem Corporation) based on 100 parts by weight of its solid content. 3.0 parts by weight in terms of solid content, 2 parts by weight of leuco dye (product name "S-205", manufactured by Yamada Chemical Industry Co., Ltd.), photoacid generator (product name "SP-056", manufactured by ADEKA) 7 parts by weight was added, diluted with ethyl acetate so that the total solid content was 25% by weight, stirred with a disper, and the resulting urethane adhesive composition was applied to the release liner (2). , in the same manner as in Example 1, [Release liner (1) layer]/[Silicone adhesive (1) layer (first adhesive layer)]/[Base film (1) layer]/[Urethane adhesive layer] A transfer sheet having a laminated structure of agent (1) layer (second adhesive layer)/release liner (2) layer was obtained.

[Example 8]
Silicone adhesive 1 (addition reaction silicone adhesive, product name "X-40-3306", manufactured by Shin-Etsu Chemical Co., Ltd.): 100 parts by weight, platinum catalyst 1 (product name "CAT-PL-50T") , manufactured by Shin-Etsu Chemical Co., Ltd.): 1.4 parts by weight, silicone release agent 1 (addition reaction type silicone release agent containing dimethylpolysiloxane as the main component, trade name "KS-776A", Shin-Etsu Chemical Co., Ltd.) 5 parts by weight of ultraviolet absorber (product name: "TINUVIN 384-2", manufactured by BASF), diluted with toluene so that the total solid content was 25% by weight, and dispersed. A silicone adhesive composition (Silicone adhesive composition 2) was prepared.
Silicone adhesive composition 2 was applied to the base film (4) (COP film, thickness 55 μm, trade name “ZeonorFilm”, manufactured by Nippon Zeon Co., Ltd.) so that the glue thickness after drying was 10 μm, and the drying temperature was adjusted to It was cured and dried at 120° C. for 5 minutes. In this way, a film having the silicone adhesive layer (2) on the base film (4) was obtained.
In addition, a release liner (1) (unreleased polyethylene terephthalate film, thickness 25 μm, trade name "Lumirror S10#25", manufactured by Toray Industries, Inc.) is laminated on the adhesive surface of the silicone adhesive film, and A laminate (2) was obtained that protected the adhesive layer and had a laminated structure of [release liner (1) layer]/[silicone adhesive (2) layer]/[base film (4) layer] .
Next, Coronate HX (manufactured by Tosoh Corporation) was added as a crosslinking agent to the solution of the acrylic copolymer (2) obtained in Production Example 2, based on 100 parts by weight of the solid content, in terms of 4.0 parts by weight in terms of solid content. %, 2 parts by weight of leuco dye (trade name "S-205", manufactured by Yamada Chemical Industry Co., Ltd.), and 7 parts by weight of a photoacid generator (trade name "SP-056", manufactured by ADEKA), and the total solid Release liner (2) (release-treated polyethylene terephthalate film, thickness 38 μm, product name "MRF #38") Mitsubishi Chemical Corporation) was coated on the release-treated layer side with a fountain roll so that the thickness after drying was 25 μm, and was cured and dried at a drying temperature of 130° C. and a drying time of 30 seconds. In this way, an acrylic adhesive layer (6) was formed on the release liner (2).
Next, the base film (4) side of the laminate (2) obtained above is bonded to the surface of the acrylic adhesive layer (6), and the [Release liner (1) layer]/[Silicone adhesive layer] (2) layer (first adhesive layer)]/[base film (4) layer]/[acrylic adhesive (6) layer (second adhesive layer)]/[release liner (2) layer] A transfer sheet having a laminated structure was obtained.

[Comparative example 1]
For 100 parts by weight of the solid content of the acrylic copolymer (2) obtained in Production Example 2, 6.0 parts by weight of TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a crosslinking agent in terms of solid content; 4.0 parts by weight of Coronate HX (manufactured by Tosoh Corporation) in terms of solid content and 2 parts by weight of Leuco dye (trade name "S-205", manufactured by Yamada Chemical Industry Co., Ltd.) were added, resulting in a total solid content of 25% by weight. [Release liner (1)] was prepared in the same manner as in Example 1, except that the acrylic adhesive composition was diluted with ethyl acetate so that ) layer] / [Silicone adhesive (1) layer (first adhesive layer)] / [Base film (1) layer] / [Acrylic adhesive (7) layer (second adhesive layer)] / A transfer sheet having a laminated structure of [release liner (2) layer] was obtained.

[Comparative example 2]
For 100 parts by weight of the solid content of the acrylic copolymer (2) obtained in Production Example 2, 6.0 parts by weight of TETRAD-C (manufactured by Mitsubishi Gas Chemical Co., Ltd.) as a crosslinking agent in terms of solid content; 4.0 parts by weight of Coronate HX (manufactured by Tosoh Corporation) in terms of solid content and 7 parts by weight of a photoacid generator (trade name "SP-056", manufactured by ADEKA Corporation) were added, so that the total solid content was 25% by weight. [Release liner (1)] was prepared in the same manner as in Example 1, except that the acrylic adhesive composition was diluted with ethyl acetate and stirred with a disper, and the resulting acrylic adhesive composition was applied to release liner (2). layer] / [Silicone adhesive (1) layer (first adhesive layer)] / [Base film (1) layer] / [Acrylic adhesive (8) layer (second adhesive layer)] / [ A transfer sheet having a laminated structure of release liner (2) layer was obtained.

<Evaluation>
The transfer sheets obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Table 1.

(Total light transmittance change)
After peeling off the release liner on both sides of the transfer sheet having the laminated structure according to each example, a haze meter ("HM-150" manufactured by Murakami Color Research Institute) was used so that the first adhesive layer side was placed on the light source side. , the initial total light transmittance was measured.
Next, using a UV irradiation device (UV LIGHT SOURCE UL750, manufactured by HOYA) through the release liner (2), light was irradiated with an illumination intensity of 100 mW/cm ² and an integrated light amount of 1000 mJ/cm ² to form the second adhesive layer. After discoloring and peeling off the release liner on both sides, measure the total light transmittance after discoloration using a haze meter as in the initial stage, and calculate the absolute value of the difference between the initial and post-discoloration total light transmittance as the total light transmittance. The amount of change was taken as the amount of change.

(alignment)
A photomask equipped with an alignment mark with a line width of 300 μm was placed on the release liner (2) of the transfer sheet according to each example, and a UV irradiation device (UV LIGHT SOURCE UL750, manufactured by HOYA) was used to pass through the photomask. , an alignment mark was produced by irradiating light with an illuminance of 100 mW/cm ² and an integrated light amount of 1000 mJ/cm ² . Thereafter, the release liner (2) was peeled off, the second adhesive layer was bonded to alkali-free glass, and the alignment mark was read and evaluated through the glass using the method described below.
CCD camera: CA-H500C (manufactured by Keyence Corporation)
Analysis: ShapeTrax3 (manufactured by Keyence Corporation)
Judgment: If the correlation value is 90 or more, it is judged as ○, and if it is less than 90, it is judged as ×.

(Discoloration due to external light irradiation from the sheet side)
After peeling off the release liner (2) of the transfer sheet according to each example, the second adhesive layer was bonded to alkali-free glass to prepare a sample for evaluation. After that, the release liner (1) was peeled off, and the adhesive sheets of each example and each comparative example were left for 240 hours so that the first adhesive layer side was irradiated with fluorescent light, and the presence or absence of discoloration was visually observed. Confirmed at. Those in which no discoloration was observed were rated as ○, and those in which discoloration was observed were rated as ×. In Comparative Examples 1 and 2, since there is no alignment property (discoloration property), naturally no discoloration is observed.

Variations of the present invention are additionally described below.
[Appendix 1]
A transfer sheet used for receiving electronic components, the transfer sheet comprising:
A transfer sheet containing a color-changing component that can change color due to external stimulation.
[Appendix 2]
The transfer sheet according to supplementary note 1, wherein the electronic component is a semiconductor chip.
[Appendix 3]
The transfer sheet according to Supplementary Note 1 or 2, wherein the electronic component has a major axis of 500 μm or less.
[Appendix 4]
The transfer sheet has an adhesive layer,
The transfer sheet according to any one of Supplementary Notes 1 to 3, wherein the adhesive layer contains the color-changing component.
[Appendix 5]
The transfer sheet according to appendix 4, wherein the adhesive constituting the adhesive layer is an acrylic adhesive or a urethane adhesive.
[Appendix 6]
The transfer sheet according to appendix 4 or 5, wherein the transfer sheet has a laminated structure in which the adhesive layer, a base material, and another adhesive layer different from the adhesive layer are laminated in this order. .

1 Transfer sheet 10 Base material 11 First adhesive layer 12 Second adhesive layer 110, 120 Release liner 21 Carrier substrate 22 Photomask U Active energy ray 23 Alignment mark (discolored part)
30 dicing tape 31 electronic component 32 pin member 40 mounting board 41 circuit surface

Claims (6)

A transfer sheet used for receiving electronic components, the transfer sheet comprising:
A transfer sheet containing a color-changing component that can change color due to external stimulation. The transfer sheet according to claim 1, wherein the electronic component is a semiconductor chip. The transfer sheet according to claim 1 or 2, wherein the electronic component has a major axis of 500 μm or less. The transfer sheet has an adhesive layer,
The transfer sheet according to claim 1 or 2, wherein the adhesive layer contains the color changing component. The transfer sheet according to claim 4, wherein the adhesive constituting the adhesive layer is an acrylic adhesive or a urethane adhesive. The transfer sheet according to claim 4, wherein the transfer sheet has a laminated structure in which the adhesive layer, a base material, and another adhesive layer different from the adhesive layer are laminated in this order.

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