PROVISIONAL FIXATION MATERIAL AND METHOD FOR PRODUCING ELECTRONIC COMPONENT

Abstract

The present invention aims to provide a temporary fixing material that is easily separable even after high-temperature processing at 300° C. or higher with an adherend fixed thereon. The present invention also aims to provide a method for producing an electronic component using the temporary fixing material. Provided is a temporary fixing material containing a photocurable adhesive, the photocurable adhesive containing a reactive resin containing a resin (1) having an imide skeleton in a backbone repeating unit, the temporary fixing material having a light transmittance at 405 nm of 10% or greater and a 5% weight loss temperature of 350° C. or higher.

Claims

1. A temporary fixing material comprising a photocurable adhesive, the photocurable adhesive containing a reactive resin containing a resin (1) having an imide skeleton in a backbone repeating unit, the temporary fixing material having a light transmittance at 405 nm of 10% or greater and a 5% weight loss temperature of 350° C. or higher.

2. The temporary fixing material according to claim 1, wherein a photocurable adhesive layer containing the photocurable adhesive has a modulus of elasticity at 25° C. of 1 × 10.sup.7 Pa or greater after being cured.

3. The temporary fixing material according to claim 1, wherein a photocurable adhesive layer containing the photocurable adhesive has a modulus of elasticity at 300° C. of 1 × 10.sup.8 Pa or less after being cured.

4. The temporary fixing material according to claim 1, wherein the resin (1) having an imide skeleton in a backbone repeating unit contains an aliphatic group derived from a dimer diamine.

5. The temporary fixing material according to claim 4, wherein the aliphatic group derived from a dimer diamine is at least one selected from the group consisting of a group represented by the following formula (4-1), a group represented by the following formula (4-2), a group represented by the following formula (4-3), and a group represented by the following formula (4-4): [Chem. 1] ##STR00017## ##STR00018## ##STR00019## ##STR00020## wherein R.sup.1 to R.sup.8 and R.sup.13 to R.sup.20 each independently represent a linear or branched hydrocarbon group.

6. The temporary fixing material according to claim 1, wherein the resin (1) having an imide skeleton in a backbone repeating unit contains a resin (1-II) not containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit, and the resin (1-II) not containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit has a weight average molecular weight (Mw) of 20,000 or greater.

7. The temporary fixing material according to claim 6, wherein the resin (1-II) not containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit is a resin (2-i) containing a structural unit represented by the following formula (1d) and a structural unit represented by the following formula (1e), and having ends represented by X.sup.4 and X.sup.5: [Chem. 2] ##STR00021## ##STR00022## wherein s > 0 and t ≥ 0 are satisfied; P.sup.4 and P.sup.5 each independently represent an aromatic group; Q.sup.3 represents a substituted or unsubstituted linear, branched, or cyclic aliphatic group; Q.sup.4 represents a substituted or unsubstituted aromatic structure-containing group; and X.sup.4 and X.sup.5 represents groups not containing a double bond-containing functional group.

8. The temporary fixing material according to claim 1, wherein the resin (1) having an imide skeleton in a backbone repeating unit contains a resin (1-I) containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit.

9. The temporary fixing material according to claim 8, wherein the resin (1-I) containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit is a compound (1-i) containing a structural unit represented by the following formula (1a), a structural unit represented by the following formula (1b), and a structural unit represented by the following formula (1c), and having ends represented by X.sup.1 and X.sup.2: [Chem. 3] ##STR00023## ##STR00024## ##STR00025## wherein s > 0, t ≥ 0, and u ≥ 0 are satisfied; P.sup.1, P.sup.2, and P.sup.3 each independently represent an aromatic group; Q.sup.1 represents a substituted or unsubstituted linear, branched, or cyclic aliphatic group; Q.sup.2 represents a substituted or unsubstituted aromatic structure-containing group, R represents a substituted or unsubstituted branched aliphatic or aromatic group; and at least one selected from the group consisting of X.sup.1, X.sup.2, and X.sup.3 represents a double bond-containing functional group.

10. The temporary fixing material according to claim 8, wherein the double bond-containing functional group is an optionally substituted maleimide group.

11. The temporary fixing material according to claim 1, wherein the reactive resin further contains a polyfunctional monomer or polyfunctional oligomer (2) containing two or more double bond-containing functional groups in a molecule and having a molecular weight of 5,000 or less.

12. The temporary fixing material according to claim 11, wherein the amount of the polyfunctional monomer or polyfunctional oligomer (2) containing two or more double bond-containing functional groups in a molecule and having a molecular weight of 5,000 or less is 5 parts by weight or greater and 100 parts by weight or less in 100 parts by weight of the reactive resin.

13. The temporary fixing material according to claim 8, wherein the amount of the resin (1-I) containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit is 10 parts by weight or greater and 100 parts by weight or less in 100 parts by weight of the reactive resin.

14. The temporary fixing material according to claim 6, wherein the amount of the resin (1-II) not containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit is 10 parts by weight or greater and 90 parts by weight or less in 100 parts by weight of the reactive resin.

15. The temporary fixing material according to claim 1, wherein the photocurable adhesive further contains a polymerization initiator, and the polymerization initiator is a photopolymerization initiator, and the photopolymerization initiator contains a photopolymerization initiator having a molar absorption coefficient at 405 nm of 1 or greater.

16. The temporary fixing material according to claim 1, wherein the photocurable adhesive further contains a silicone compound or a fluorine compound.

17. The temporary fixing material according to claim 1, wherein the photocurable adhesive further contains an inorganic filler.

18. The temporary fixing material according to claim 17, wherein the inorganic filler has an average particle size of 5 nm or greater and 20 .Math.m or less.

19. The temporary fixing material according to claim 17, wherein the amount of the inorganic filler is 1 part by weight or greater and 20 parts by weight or less relative to 100 parts by weight of the reactive resin.

20. The temporary fixing material according to claim 1, wherein the photocurable adhesive further contains a gas generating agent.

21. The temporary fixing material according to claim 20, wherein the gas generating agent has a weight loss rate at 300° C. of 5% or less when heated from 30° C. to 300° C. at a heating rate of 10° C./min in a nitrogen atmosphere in thermogravimetry-differential thermal analysis (TG-DTA) measurement.

22. The temporary fixing material according to claim 20, comprising: a first photocurable adhesive layer containing the photocurable adhesive; and a second adhesive layer.

23. The temporary fixing material according to claim 22, further comprising a substrate, wherein the first photocurable adhesive layer and the second adhesive layer are stacked on one surface and an opposite surface of the substrate, respectively.

24. The temporary fixing material according to claim 1, having an adhesion to glass at 25° C. of 1.5 N/inch or less after being cured and heated at 300° C. for 10 minutes.

25. The temporary fixing material according to claim 1, used for a production process of an electronic component.

26. A method for producing an electronic component, comprising: a temporary fixing step of temporarily fixing an electronic component to the temporary fixing material according to claim 1 ; a curing step of curing the photocurable adhesive of the temporary fixing material; a heat treatment step of heat-treating the electronic component; and a separation step of separating the electronic component from the temporary fixing material.

27. A method for producing an electronic component using the temporary fixing material according to claim 22, comprising: a support bonding step of bonding the first photocurable adhesive layer of the temporary fixing material and a support; an adherend bonding step of bonding the second adhesive layer of the temporary fixing material and an electronic component; a curing step of curing the first photocurable adhesive layer and the second adhesive layer; a heat treatment step of heat-treating the electronic component; a gas generation step of generating gas from the first photocurable adhesive layer; and a separation step of separating the support and the temporary fixing material from each other.

Description

DESCRIPTION OF EMBODIMENTS

[0159] Embodiments of the present invention are more specifically described in the following with reference to, but not limited to, examples.

(Preparation of Resin (1-I) Containing Double Bond-Containing Functional Group and Having Imide Skeleton in Backbone Repeating Unit)

(Synthesis Example 1)

[0160] A 500-mL round flask with a Teflon(®) stirrer placed therein was charged with 250 mL of toluene. Then, 35 g (0.35 mol) of triethylamine and 35 g (0.36 mol) of methanesulfonic anhydride were added, and the mixture was stirred to form salt. After stirring for 10 minutes, 56 g (0.1 mol) of dimer diamine (Produced by Croda, Priamine 1075) and 19.1 g (0.09 mol) of pyromellitic anhydride were added in this order. A Dean-Stark trap and a condenser were fitted to the flask and the mixture was refluxed for two hours for formation of amine-terminated diimide. After cooling to room temperature or lower, the reaction product was blended with 12.8 g (0.13 mol) of maleic anhydride and then with 5 g (0.05 mol) of methanesulfonic anhydride. The mixture was further refluxed for 12 hours and then cooled to room temperature. To the flask was added 300 mL of toluene, and the flask was allowed to stand still for removal of precipitated impurities. The obtained solution was filtered through a glass frit funnel filled with silica gel, followed by removal of the solvent in vacuum. Thus, an amber wax-like resin (1-I) represented by the following formula (A), containing maleimide groups at both ends and having an imide skeleton in a backbone repeating unit, was obtained.

[0161] The weight average molecular weight of the obtained resin was 5,000, as determined by gel permeation chromatography (GPC) in which the eluent used was THF and the column used was HR-MB-M (trade name, produced by Waters Corporation). [Chem. 5]

##STR00013##

Preparation of Resin 1-I Containing Double Bond-Containing Functional Group and Having Imide Skeleton In Backbone Repeating Unit

(Synthesis Example 2)

[0162] A 500-mL round flask with a Teflon(®) stirrer placed therein was charged with 250 mL of toluene. Then, 35 g (0.35 mol) of triethylamine and 35 g (0.36 mol) of methanesulfonic anhydride were added, and the mixture was stirred to form salt. After stirring for 10 minutes, 36 g (0.1 mol) of 4,4′-bis(4-aminophenoxy)biphenyl (produced by Tokyo Chemical Industry Co., Ltd.) and 19.1 g (0.09 mol) of pyromellitic anhydride were added in this order. A Dean-Stark trap and a condenser were fitted to the flask and the mixture was refluxed for two hours for formation of amine-terminated diimide. After cooling to room temperature or lower, the reaction product was blended with 12.8 g (0.13 mol) of maleic anhydride and then with 5 g (0.05 mol) of methanesulfonic anhydride. The mixture was further refluxed for 12 hours and then cooled to room temperature. To the flask was added 300 mL of toluene, and the flask was allowed to stand still for removal of precipitated impurities. The obtained solution was filtered through a glass frit funnel filled with silica gel, followed by removal of the solvent in vacuum. Thus, an amber wax-like resin (1-I) represented by the following formula (B), containing maleimide groups at both ends and having an imide skeleton in a backbone repeating unit, was obtained.

[0163] The weight average molecular weight of the obtained resin was 1,0000, as determined by gel permeation chromatography (GPC) in which the eluent used was THF and the column used was HR-MB-M (trade name, produced by Waters Corporation). [Chem. 6]

##STR00014##

Preparation of Resin 1-I Containing Double Bond-Containing Functional Group and Having Imide Skeleton In Backbone Repeating Unit

(Synthesis Example 3)

[0164] A 500-mL round flask with a Teflon(®) stirrer placed therein was charged with 250 mL of toluene. Then, 35 g (0.35 mol) of triethylamine and 35 g (0.36 mol) of methanesulfonic anhydride were added, and the mixture was stirred to form salt. After stirring for 10 minutes, 200 g (0.1 mol) of polyethyleneoxide diamine (JEFFAMINE D-2000, produced by Huntsman Corporation) and 20 g (0.09 mol) of 1,2,4,5-cyclohexanetetracarboxylic dianhydride (produced by Mitsubishi Gas Chemical Company, Inc., HPMDA) were added in this order. A Dean-Stark trap and a condenser were fitted to the flask and the mixture was refluxed for two hours for formation of amine-terminated diimide. After cooling to room temperature or lower, the reaction product was blended with 12.8 g (0.13 mol) of maleic anhydride and then with 5 g (0.05 mol) of methanesulfonic anhydride. The mixture was further refluxed for 12 hours and then cooled to room temperature. To the flask was added 300 mL of toluene, and the flask was allowed to stand still for removal of precipitated impurities. The obtained solution was filtered through a glass frit funnel filled with silica gel, followed by removal of the solvent in vacuum. Thus, an amber wax-like resin (1-I) containing maleimide groups at both ends and having an imide skeleton in a backbone repeating unit, was obtained.

[0165] The weight average molecular weight of the obtained resin was 40,000, as determined by gel permeation chromatography (GPC) in which the eluent used was THF and the column used was HR-MB-M (trade name, produced by Waters Corporation).

Preparation of Resin 1-II Not Containing Double Bond-Containing Functional Group and Having Imide Skeleton In Backbone Repeating Unit

[0166] A 500-mL round flask with a Teflon(®) stirrer placed therein was charged with 250 mL of toluene. Then, 35 g (0.35 mol) of triethylamine and 35 g (0.36 mol) of methanesulfonic anhydride were added, and the mixture was stirred to form salt. After stirring for 10 minutes, 31.9 g (0.06 mol) of dimer diamine (Produced by Croda, Priamine 1075), 5.5 g (0.015 mol) of Bis-AP-AF, and 39 g (0.075 mol) of 4,4′-(4,4′-isopropylidenediphenoxy)diphthalic anhydride were added in this order. A Dean-Stark trap and a condenser were fitted to the flask and the mixture was refluxed for two hours and cooled to room temperature. To the flask was added 300 mL of toluene, and the flask was allowed to stand still for removal of precipitated impurities. The obtained solution was filtered through a glass frit funnel filled with silica gel, followed by removal of the solvent in vacuum. Thus, a brown, solid resin (1-II) represented by the following formula (D), not containing a double bond-containing functional group and having an imide skeleton in a backbone repeating unit, was obtained.

[0167] The weight average molecular weight of the obtained resin was 72,000, as determined by gel permeation chromatography (GPC) in which the eluent used was THF and the column used was HR-MB-M (trade name, produced by Waters Corporation). [Chem. 7]

##STR00015##

Preparation of Polyfunctional Monomer or Polyfunctional Oligomer 2

[0168] A 500-mL round flask with a Teflon(®) stirrer placed therein was charged with 250 mL of toluene. Then, 56 g (0.1 mol) of dimer diamine (produced by Croda, Priamine 1075) and 19.6 g (0.2 mol) of maleic anhydride were added, and subsequently 5 g of methanesulfonic anhydride was added. The solution was refluxed for 12 hours and then cooled to room temperature. To the flask was added 300 mL of toluene, and the flask was allowed to stand still for removal of precipitated salt. The obtained solution was filtered through a glass frit funnel filled with silica gel, followed by removal of the solvent in vacuum. Thus, a brown, liquid bismaleimide monomer (2) represented by the following formula (E) was obtained. [Chem. 8]

##STR00016##

Preparation of Acrylic Curable Resin

[0169] A reactor equipped with a thermometer, a stirrer, and a condenser was charged with 94 parts by weight of 2-ethylhexyl acrylate as a (meth)acrylic acid alkyl ester, 6 parts by weight of hydroxyethyl methacrylate as a functional group-containing monomer, 0.01 parts by weight of lauryl mercaptan, and 80 parts by weight of ethyl acetate. The reactor was then heated to initiate reflux. To the reactor was subsequently added 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane as a polymerization initiator to initiate polymerization under reflux. Then, 0.01 parts by weight of 1,1-bis(t-hexylperoxy)-3,3,5-trimethylcyclohexane was added one hour after and two hours after the start of the polymerization. Four hours after the start of the polymerization, 0.05 parts by weight of t-hexyl peroxypivalate was added to continue the polymerization reaction. Eight hours after the start of the polymerization, an ethyl acetate solution of a functional group-containing (meth)acrylic polymer having a solid content of 55% by weight and a weight average molecular weight of 500,000 was obtained.

[0170] To 100 parts by weight of the resin solid content of the obtained ethyl acetate solution containing a functional group-containing (meth)acrylic polymer was added 3.5 parts by weight of 2-isocyanatoethyl methacrylate as a functional group-containing unsaturated compound and reacted. Thus, an acrylic reactive resin was obtained.

[0171] The weight average molecular weight of the obtained acrylic reactive resin was 550,000, as determined by gel permeation chromatography (GPC) in which the eluent used was THF and the column used was HR-MB-M (trade name, produced by Waters Corporation).

Example 1

Production of Temporary Fixing Material

[0172] To 150 mL of toluene were added 70 parts by weight of the resin (1-II) obtained above and 30 parts by weight of the bismaleimide monomer (2) obtained above. Further, 2 parts by weight of Irgacure 819 (produced by BASF, molar absorption coefficient at 405 nm: 450) was added as a photopolymerization initiator, whereby a toluene solution of a photocurable adhesive was prepared.

[0173] A 50-.Math.m-thick PET film one surface of which was release-treated was provided. The obtained toluene solution of a photocurable adhesive was applied with a doctor knife to the release-treated surface to a dry film thickness shown in Table 1, and the applied solution was dried by heating at 130° C. for 10 minutes. Thus, a temporary fixing material (non-supported) including a photocurable adhesive layer was obtained.

Examples 2 to 14 and Comparative Examples 1 to 4

[0174] A toluene solution of a photocurable adhesive and a temporary fixing material were obtained as in Example 1 except that the composition and thickness of the photocurable adhesive were changed as shown in Table 1 or 2. The materials used are as follows. [0175] Acrylic non-curable resin (SK-Dyne 1604N, produced by Soken Chemical & Engineering Co., Ltd.) [0176] Polyfunctional acrylic monomer (SR-387, produced by Arkema Inc., Tris(2-acryloxyethyl)Isocyanurate) [0177] Silicone compound (bifunctional silicone acrylate, produced by Daicel-Allnex Ltd., EBECRYL 350) [0178] Silicone compound (polyether-modified polydimethylsiloxane containing an acrylic group, produced by BYK-Chemie, BYK-UV3500) [0179] Crosslinking agent (isocyanate crosslinking agent, Coronate L, produced by Nihon Urethane Kogyo)

Example 15

Formation of First Photocurable Adhesive Layer (Gas Generating Agent-Containing Curable Adhesive Layer)

[0180] To 300 mL of toluene were added 100 parts by weight of the reactive resins shown in Table 3, 30 parts by weight of 5,5′-bi-1H-tetrazole disodium salt (BHT-2Na) as a gas generating agent, 5 parts by weight of EBECRYL 350 as a silicone compound, and 2 parts by weight of Irgacure 819 (produced by BASF) as a photopolymerization initiator. Thus, a toluene solution of a photocurable adhesive in which 5,5′-Bi-1H-tetrazole disodium salt (BHT-2Na) was dispersed was prepared.

[0181] A 50-.Math.m-thick polyethylene terephthalate film having a release-treated surface was provided as a separator. The obtained toluene solution of a photocurable adhesive was applied with a doctor knife to the film to a dry film thickness of 50 .Math.m. The applied solution was dried by heating for 10 minutes in an oven preheated to 110° C. Thus, a first photocurable adhesive layer (gas generating agent-containing curable adhesive layer) was obtained.

Formation of Second Adhesive Layer

[0182] To 300 mL of toluene were added 100 parts by weight of the reactive resins shown in Table 3, 5 parts by weight of EBECRYL 350 as a silicone compound, and 2 parts by weight of Irgacure 819 (produced by BASF) as a photopolymerization initiator. Thus, a toluene solution of a photocurable adhesive was prepared.

[0183] A 50-.Math.m-thick polyethylene terephthalate film having a release-treated surface was provided as a separator. The obtained toluene solution of a photocurable adhesive was applied with a doctor knife to the film to a dry film thickness of 50 .Math.m. The applied solution was dried by heating for 10 minutes in an oven preheated to 110° C. Thus, a second adhesive layer was obtained.

Production of Temporary Fixing Material

[0184] The adhesive layer surfaces of the first photocurable adhesive layer (gas generating agent-containing curable adhesive layer) and the second adhesive layer were laminated, whereby a temporary fixing material in which both surfaces were covered with separators were obtained.

Example 16

[0185] A photocurable adhesive and a temporary fixing material were obtained as in Example 15 except that the composition and the thickness of the photocurable adhesive layer and the adhesive layer were changed as shown in Table 3.

Examples 17 to 22

[0186] A toluene solution of a photocurable adhesive and a temporary fixing material were obtained as in Example 1 except that the composition and thickness of the photocurable adhesive and the amount of the inorganic filler were changed as shown in Table 4. The materials used are as follows. [0187] Fluorine compound (photoreactive fluorine compound, produced by DIC Corporation, MEGAFACE RS-56) [0188] Inorganic filler (silica particles, produced by Tokuyama Corporation, MT-10, average particle size 15 nm) [0189] Inorganic filler (silica particles, produced by Tatsumori Ltd., 5x, average particle size 1 .Math.m)

<Measurement of Physical Properties>

(Measurement of Light Transmittance)

[0190] Each obtained temporary fixing material was attached to the light receiver of a UV integrating illuminometer (UVPF-A2, produced by Eye Graphics Co., Ltd.), and the integrated amount of light (I.sub.1) was measured when the temporary fixing material was irradiated with UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2 for 10 seconds. The integrated amount of light (I.sub.0) was measured when irradiation with UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2 was performed for 10 seconds. The light transmittance at 405 nm of the temporary fixing material was calculated by the following equation. Light transmittance at 405 nm (%) = 100 × I.sub.1/I.sub.0

(Measurement of 5% Weight Loss Temperature)

[0191] Each obtained temporary fixing material was irradiated with 1,000 mJ/cm.sup.2 of UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2, and 10 mg of the material was weighed into an aluminum pan. The aluminum pan was set in the device, and heated from 30° C. to 500° C. at 10° C./min in a nitrogen atmosphere. The temperature at which a 5% weight loss of the sample occurred compared to the weight before heating was determined as the 5% weight loss temperature.

Measurement of Adhesion to Glass at 25° C. After Curing and Heating at 300° C. for 10 Minutes

[0192] Each obtained temporary fixing material was cut into a width of 1 inch and then heat-laminated onto a 1-mm-thick glass (produced by Matsunami Glass Ind., Ltd., Large white glass slide with polished edges No. 2) using a laminator (produced by Lami Corporation Inc., Leon13DX, speed 5 on the scale) at 100° C. After lamination, the temporary fixing material was irradiated from the glass side with 1,000 mJ/cm.sup.2 of UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2. After curing, the release PET film of the temporary fixing material was removed, followed by heating from the glass side on a hot plate at 300° C. for 10 minutes.

[0193] The temporary fixing material after being cured and heated at 300° C. for 10 minutes (heated and left to cool) was subjected to a 180° peel test under the conditions of 25° C. and a tensile speed of 300 mm/min.

[0194] In Examples 15 and 16, the measurement was performed on the surface of the first photocurable adhesive layer and the surface of the second photocurable adhesive layer separately. For the adhesion of the first photocurable adhesive layer to glass, the temporary fixing material after heating at 300° C. for 10 minutes and being left to cool was irradiated from the glass side with UV light at 254 nm at an intensity of 20 mW/cm.sup.2 for 180 seconds using a high pressure mercury lamp so that gas was generated. The 180° peel test was then performed under the conditions of 25° C. and a tensile speed of 300 mm/min.

(Measurement of Modulus of Elasticity)

[0195] A specimen having a size of 5 mm × 35 mm × thickness 0.03 mm was prepared from each obtained temporary fixing material. The obtained specimen was cured by irradiation with 1,000 mJ/cm.sup.2 of UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2. The cured specimen was immersed in liquid nitrogen and cooled to -50° C. The sample was then heated to 300° C. using a viscoelastic spectrometer (DVA-200, produced by IT Measurement Co., Ltd.) under the conditions of a constant-rate heating tensile mode, a heating rate of 10° C./min, and a frequency of 10 Hz, and the storage modulus of elasticity was measured. From the obtained results of the storage modulus of elasticity, the modulus of elasticity at 25° C. and the modulus of elasticity at 300° C. were determined.

<Evaluation>

[0196] The temporary fixing materials obtained in the examples and the comparative examples were evaluated by the following methods. Tables 1 to 4 show the results.

Measurement of Gel Fraction After Curing

[0197] The photocurable adhesive layer of each obtained temporary fixing material was irradiated with 1,000 mJ/cm.sup.2 of UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2. The gel fraction was then measured by the following method.

[0198] The temporary fixing material was cut into a flat rectangular specimen having a size of 50 mm × 100 mm. The specimen was immersed in toluene at 23° C. for 24 hours, then taken out of the toluene, and dried at 110° C. for one hour. The weight of the dried specimen was measured, and the gel fraction was calculated using the following equation (1). No release film to protect the photocurable adhesive layer was stacked on the specimen.

[0199] In Examples 15 and 16, the second adhesive layer was cured by irradiation with 1,000 mJ/cm.sup.2 of UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2 and then weighed out as a specimen. The specimen thus weighed out was used to measure the gel fraction in the same manner. As this specimen included no substrate, W.sub.0 was 0. Gel fraction (% by weight) = 100 × (W.sub.2 - W.sub.0)/(W.sub.1 - W.sub.0) (1) (W.sub.0: the weight of the substrate, W.sub.1: the weight of the specimen before immersion, W.sub.2: the weight of the specimen after immersion and drying)

[0200] The gel fraction was evaluated in accordance with the following criteria. [0201] ◯◯ (Excellent): Gel fraction of 80% or greater [0202] ◯ (Good): Gel fraction of 60% or greater and less than 80% [0203] Δ (Fair): Gel fraction of 20% or greater and less than 60% [0204] × (Poor): Gel fraction of less than 20%

Evaluation of Residues After Curing and Heating at 300° C. for 10 Minutes

[0205] The temporary fixing material was cut into a width of 1 inch and heat-laminated onto 1-mm-thick glass (produced by Matsunami Glass Ind., Ltd., Large white glass slide with polished edges No. 2) using a laminator (produced by Lami Corporation Inc., Leon13DX) at 100° C. In heat lamination, the temporary fixing material was laminated onto the glass once at a temperature setting value of 100° C. and a speed setting value of 5. After heat lamination, the temporary fixing material was irradiated from the glass side with 1,000 mJ/cm.sup.2 of UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2 using an ultra-high pressure mercury lamp. After curing, the release PET film of the temporary fixing material was removed, followed by heating from the glass side on a hot plate at 300° C. for 10 minutes.

[0206] After the temporary fixing material after being cured and heated at 300° C. was left to cool, the test sample was subjected to a 180° peel test under the conditions of 25° C. and a tensile speed of 300 mm/min. In Examples 15 and 16, the second adhesive layer was attached to the glass, and the test sample was prepared in the same manner to perform evaluation.

[0207] The glass surface after the separation of the temporary fixing material was visually observed and evaluated in accordance with the following criteria. [0208] ◯◯ (Excellent): No adhesive deposits were observed. [0209] ◯ (Good): Adhesive deposits were observed in less than 5% of the glass area. [0210] Δ (Fair): Adhesive deposits were observed in 5% or more and less than 10% of the glass area. [0211] × (Poor): Adhesive deposits were observed in 10% or more of the glass area.

Evaluation of Detachment and Separability After Curing and Heating at 300° C. for 20 Minutes

[0212] The temporary fixing materials obtained in Examples 1, 10, and 17 to 22 were further evaluated as follows.

[0213] Each obtained temporary fixing material was cut into a width of 1 inch and heat-laminated onto a 1-mm-thick glass using a heat laminator (Leon13DX) at 100° C. with the speed set at 3 on the scale. After lamination, the temporary fixing material was irradiated from the glass side with 1,000 mJ/cm.sup.2 of UV light at 405 nm at an irradiation intensity of 70 mW/cm.sup.2 using an ultra-high pressure mercury lamp. After curing, the release PET film was removed, followed by heating from the glass side on a hot plate at 300° C. for 20 minutes. This test was performed five times. The appearance of the temporary fixing material after being cured and heated at 300° C. for 20 minutes was visually observed and evaluated in accordance with the following criteria. [0214] ◯ (Good): No detachment was observed between the temporary fixing material and the glass in any of the five tests. [0215] × (Poor): Partial detachment was observed in some portion(s) between the temporary fixing material and the glass in one or more of the five tests.

[0216] The temporary fixing material after being cured and heated at 300° C. for 20 minutes was subjected to a 180° peel test under the conditions of 25° C. and a tensile speed of 300 mm/min. This test was performed five times. The separability of the temporary fixing material was evaluated in accordance with the following criteria. The temporary fixing materials in which partial detachment occurred in the above detachment test were not evaluated. [0217] ◯◯ (Excellent): Separable in all the five tests. [0218] ◯ (Good): Separable in one to four tests. [0219] × (Poor): Not separable in all the five tests.

TABLE-US-00001 Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Photocurable adhesive (parts by weight) Reactive resin Resin (1) having imide skeleton in backbone repeating unit Resin (1-I) Contain double bond-containing functional group Synthesis Example 1 - - - 50 50 50 50 60 80 60 60 25 70 50 Synthesis Example 2 (aromatic group) - - - - - - - - - - - - - - Synthesis Example 3 (aliphatic group) - - - - - - - - - - - - - - Resin (1-II) Not contain double bond-containing functional group (weight average molecular weight of 20,000 or greater) - 70 70 70 50 50 50 50 40 20 40 40 50 - 50 Polyfunctional monomer or polyfunctional oligomer (2) Bismaleimide monomer - 30 30 30 - - - - - - - - 25 30 - Polyfunctional acrylic monomer - - - - - - - - - - - - - - - Other resins Acrylic curable resin - - - - - - - - - - - - - - - Acrylic non-curable resin - - - - - - - - - - - - - - - Silicone compound EBECRYL 350 - - - - - - - - - - 5 5 - - - BYK-UV3500 - - - - - - - - 5 5 - - - - - Crosslinking agent Coronate L - - - - - - - - - - - - - - - Photopolymerization initiator Irgacure 819 - 2 2 2 2 2 2 2 2 2 2 2 2 2 2 Physical properties Thickness (.Math.m) - 8 20 50 110 150 200 400 100 100 100 8 46 105 521 Light transmittance (405 nm) (%) - 86 79 73 50 42 38 16 55 61 57 84 72 65 11 5% Weight loss temperature (°C) - 417 417 417 424 424 424 424 397 403 428 428 421 411 424 Modulus of elasticity at 25° C. (Pa) - 1.2×10.sup.9 1.2×10.sup.9 1.2×10.sup.9 9.7×10.sup.8 9.7×10.sup.8 9.7×10.sup.8 9.7×10.sup.8 8.3×10.sup.8 4.3×10.sup.8 8.5×10.sup.8 8.5×10.sup.8 1.5×10.sup.8 1.1×10.sup.9 9.7×10.sup.8 Modulus of elasticity at 300° C. (Pa) - 3.9×10.sup.6 3.9×10.sup.6 3.9×10.sup.6 3.5×10.sup.6 3.5×10.sup.6 3.5×10.sup.6 3.5×10.sup.6 3.9×10.sup.6 4.7×10.sup.6 4.1×10.sup.6 4.1×10.sup.6 4.2×10.sup.6 1.3×10.sup.6 3.5×10.sup.6 Adhesion to glass at 25° C. after curing and heating at 300° C. for 10 minutes (N/inch) - 0.5 0.7 0.8 0.4 0.5 0.8 1.1 0.2 0.1 0.2 0.1 0.7 1.3 1.3 Evaluation Gel fraction after curing (% by weight) - ◯◯ ◯◯ ◯ Δ Δ Δ Δ ◯ ◯ ◯ ◯◯ ◯◯ ◯◯ Δ Residues after curing and heating at 300° C. for 10 minutes - ◯ ◯ ◯ ◯ ◯ ◯ Δ ◯◯ ◯◯ ◯◯ ◯◯ ◯ Δ Δ

TABLE-US-00002 Comparative Example 1 2 3 4 Photocurable adhesive (parts by weight) Reactive resin Resin (1) having imide skeleton in backbone repeating unit Resin (1-I) Contain double bond-containing functional group Synthesis Example 1 - - - - Synthesis Example 2 (aromatic group) 100 - - - Synthesis Example 3 (aliphatic group) - 90 - - Resin (1-II) Not contain double bond-containing functional group (weight average molecular weight of 20,000 or greater) - - - - - Polyfunctional monomer or polyfunctional oligomer (2) Bismaleimide monomer - - - - - Polyfunctional acrylic monomer - - 10 10 - Other resins Acrylic curable resin - - - 100 - Acrylic non-curable resin - - - - 100 Silicone compound EBECRYL 350 - - 10 10 - BYK-UV3500 - 5 - - - Crosslinking agent Coronate L - - 1 1 - Photopolymerization initiator Irgacure 819 - 2 2 2 - Physical properties Thickness (.Math.m) - 100 100 70 25 Light transmittance (405 nm) (%) - 3 67 65 80 5% Weight loss temperature (°C) - 451 343 322 275 Modulus of elasticity at 25° C. (Pa) - 1.7×10.sup.9 9.2×10.sup.7 1.1×10.sup.7 4.0×10.sup.5 Modulus of elasticity at 300° C. (Pa) - 3.8×10.sup.5 9.6×10.sup.5 1.0×10.sup.7 1.7×10.sup.5 Adhesion to glass at 25° C. after curing and heating at 300° C. for 10 minutes (N/inch) - Not separable 0.5 1.8 Not separable Evaluation Gel fraction after curing (% by weight) - × ◯ ◯ Not cured Residues after curing and heating at 300° C. for 10 minutes - × × × ×

TABLE-US-00003 Example 15 16 First photocurable adhesive layer Photocurable adhesive (parts by weight) Reactive resin Resin (1) having imide skeleton in backbone repeating unit Resin (1-I) Contain double bond-containing functional group Synthesis Example 1 60 - Synthesis Example 2 (aromatic group) - - Synthesis Example 3 (aliphatic group) - - Resin (1-II) Not contain double bond-containing functional group (weight average molecular weight of 20,000 or greater) - 40 70 Polyfunctional monomer or polyfunctional oligomer (2) Bismaleimide monomer - - 30 Polyfunctional acrylic monomer - - - Silicone compound EBECRYL350 - 5 5 BYK-UV3500 - - - Photopolymerization initiator Iraacure 819 - 2 2 Gas generating agent BHT-2Na - 30 30 Thickness (.Math.m) 50 50 Modulus of elasticityat 25° C. (Pa) - 8.5×10.sup.8 1.0×10.sup.9 Modulus of elasticity at 300° C. (Pa) - 4.1×10.sup.6 3.6×10.sup.6 Second adhesive layer Photocurable adhesive (parts by weight) Reactive resin Resin (1) having imide skeleton in backbone repeating unit Resin (1-I) Contain double bond-containing functional group Synthesis Example 1 60 Synthesis Example 2 (aromatic group) - - Synthesis Example 3 (aliphatic group) - - Resin (1-II) Not contain double bond-containing functional group (weight average molecular weight of 20,000 or greater) - 40 70 Polyfunctional monomer or polvfunctional oliaomer (2) Bismaleimide monomer - - 30 Polvfunctional acrylic monomer - - - Silicone compound EBECRYL 350 - 5 5 Photopolymerization initiator Iraacure 819 - 2 2 Thickness (.Math.m) - 50 50 Modulus of elasticity at 25° C. (Pa) - 8.5×10.sup.8 1.0×10.sup.9 Modulus of elasticity at 300° C. (Pa) - 4.1×10.sup.6 3.6×10.sup.6 Physical properties Light transmittance (405 nm) (%) - 46 50 5% Weiaht loss temperature (°C) - 417 419 Adhesion of second adhesive layer to glass at 25° C. after curing and heating at 300° C. for 10 minutes (N/inch) - 0.5 0.4 Adhesion of first photocurable adhesive layer to glass at 25° C. after curing and heating at 300° C. for 10 minutes (N/inch) - 0.1 0.1 Evaluation Gel fraction of second adhesive layer after curing (% by weiaht) - Δ Δ Residues after curing and heating at 300° C. for 10 minutes - ◯ ◯

TABLE-US-00004 Example 1 10 17 18 19 20 21 22 Photocurable adhesive (parts by weight) Reactive resin Resin (1) having imide skeleton in backbone repeating unit Resin (1-I) Contain double bond-containing functional group Synthesis Example 1 - 60 60 60 60 60 60 - Synthesis Example 2 (aromatic group) - - - - - - - - Synthesis Example 3 (aliphatic group) - - - - - - - - Resin (1-II) Not contain double bond-containing functional group (weight average molecular weight of 20,000 or greater) - 70 40 40 40 40 40 40 70 Polyfunctional monomer or polyfunctional oligomer (2) Bismaleimide monomer - 30 - - - - - - 30 Polyfunctional acrylic monomer - - - - - - - - - Other resins Acrylic curable resin - - - - - - - - - Acrylic non-curable resin - - - - - - - - - Silicone compound/fluorine compound EBECRYL 350 - - 5 5 5 5 - 5 5 MEGAFACE - - - - - - 5 - - Photopolymerization initiator Irgacure 819 - 2 2 2 2 2 2 2 - Inorganic filler MT-10 (15 nm) - - - 1 5 15 1 - 5 5X (1 .Math.m) - - - - - - - 5 - Physical properties Thickness (.Math.m) - 8 100 100 100 100 100 100 100 Liaht transmittance (405 nm) (%) - 86 57 59 63 64 58 60 52 5% Weiaht loss temperature (°C) - 417 428 430 433 436 425 434 414 Modulus of elasticity at 25° C. (Pa) - 1.2×10.sup.9 8.5×10.sup.8 8.9×10.sup.8 9.3×10.sup.8 1.0×10.sup.9 8.6×10.sup.8 9.9×10.sup.8 1.4×10.sup.9 Modulus of elasticity at 300° C. (Pa) - 3.9×10.sup.6 4.1×10.sup.6 7.7×10.sup.6 8.0×10.sup.6 8.9×10.sup.6 5.7×10.sup.6 9.1×10.sup.6 4.1×10.sup.6 Adhesion to glass at 25° C. after curing and heating at 300° C. for 10 minutes (N/inch) - 0.5 0.2 0.2 0.3 0.6 0.2 0.5 0.5 Evaluation Gel fraction after curing (% by weight) - ◯◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ Residues after curing and heating at 300° C. for 10 minutes - ◯ ◯◯ ◯◯ ◯◯ ◯ ◯◯ ◯ ◯ After curing and heating at 300° C. for 20 minutes Detachment during high-temperature processing ◯ × ◯ ◯ ◯ ◯ ◯ ◯◯ Separability ◯ × ◯◯ ◯◯ ◯ ◯◯ ◯ ◯◯

INDUSTRIAL APPLICABILITY

[0220] The present invention can provide a temporary fixing material that is easily separable even after high-temperature processing at 300° C. or higher with an adherend fixed thereon. The present invention can also provide a method for producing an electronic component using the temporary fixing material.