Electronic component temporary fixing member

Abstract

Provided is an electronic component temporary fixing member that can conform to surface unevenness of an electronic component before ultraviolet curing and can be reliably peeled off from the electronic component with weak force after ultraviolet curing.　This electronic component temporary fixing member, which is used for temporarily fixing an electronic component, comprises: a base material film; a first adhesive layer provided on one surface of the base material film; and a second adhesive layer provided on the other surface of the base material film. The first adhesive layer has ultraviolet reactivity at 405 nm. Where the total light transmittance at 405 nm in the thickness direction of the entire electronic component temporary fixing member is T% and the thickness of the first adhesive layer is t μm, the following expression (1) is satisfied: (1) 0.01 < T / t < 0.2.

Description

Member for temporarily fixing electronic components

[0001] The present invention relates to a member for temporarily fixing electronic components.

[0002] Mounting technologies for electronic components such as semiconductors are evolving day by day, and various element structures have been developed to enable high integration density and high-speed operation. For example, as an integration technology using a base die bonded to a substrate via bumps, a technology of bonding a plurality of chips to the back surface (the surface opposite to the bump surface) of a thinned base die is known. Here, the thinning of the base die is performed for space saving and other purposes. Since a thinned base die does not have sufficient rigidity to withstand chip bonding, support by a supporting substrate is required.

[0003] That is, by bonding a supporting substrate such as a glass substrate to the bump surface of the base die, the base die is supported by the supporting substrate. Thereafter, chips are bonded to the back surface of the base die. Here, as a technology for bonding the supporting substrate to the bump surface of the base die, a technology using an adhesive is known. However, adhesives have a problem of poor conformability to bumps formed on the bump surface, that is, to the unevenness. Therefore, as disclosed in Patent Document 1, a technology using a double-sided adhesive tape has been proposed. In the technology disclosed in Patent Document 1, the adhesive layer of the double-sided adhesive tape is formed thick so that the adhesive layer sufficiently conforms to the unevenness of the bump surface.

[0004] Japanese Unexamined Patent Publication No. 2014-175334

[0005] On the other hand, in the late stage of processing, it is necessary to peel the double-sided adhesive tape from the bump surface with a weak force, and as a technology for this purpose, a technology of ultraviolet-curing the adhesive layer has been proposed. However, when the adhesive layer is formed thick to conform to the unevenness of the bump surface, there is a problem that the ultraviolet transmittance of the adhesive layer is insufficient, and the portion on the bump surface side may not be sufficiently cured. In this case, problems such as heavy peeling, damage to the bump surface, and residue of the adhesive layer on the bump surface may occur.

[0006] The present invention was made to solve the above problems, and its objective is to provide a temporary fixing member for electronic components that can conform to the unevenness of electronic components before UV curing, and can be reliably peeled off from electronic components with weak force after UV curing.

[0007] According to one aspect of the present invention, the following invention is provided.

[0008] (1) An electronic component temporary fixing member used for temporarily fixing electronic components, comprising: a base film; a first adhesive layer provided on one side of the base film; and a second adhesive layer provided on the other side of the base film, wherein the first adhesive layer has ultraviolet reactivity at 405 nm, and when the total light transmittance at 405 nm in the thickness direction of the entire electronic component temporary fixing member is T%, and the thickness of the first adhesive layer is t μm, the following equation (1) 0.01 < T / t < 0.2 (1) is satisfied.

[0009] (2) The electronic component temporary fixing member according to (1), wherein the thickness of the base film is 10 to 50 μm.

[0010] (3) The electronic component temporary fixing member according to (1) or (2), wherein the thickness of the first adhesive layer is 20 to 300 μm.

[0011] (4) The first adhesive layer contains a resin having (meth)acryloyl groups, the electronic component temporary fixing member according to any one of (1) to (3).

[0012] According to one aspect of the present invention, the material can conform to the uneven surface of electronic components before UV curing, and can be reliably peeled off from electronic components with weak force after UV curing.

[0013] This figure schematically shows a cross-section of an electronic component temporary fixing member according to an embodiment of the present invention.

[0014] The following examples illustrate embodiments for implementing the electronic component temporary fixing member according to the present invention, along with the drawings. The embodiments illustrated below are provided to facilitate understanding of the present invention and are not intended to limit its interpretation. The present invention can be modified and improved from the following embodiments without departing from its spirit. In addition, in the above drawings, the dimensions of each component may be exaggerated or reduced, or hatching may be omitted, in order to facilitate understanding.

[0015] <Temporary Fixing Member for Electronic Components> First, the configuration of the temporary fixing member 1 for electronic components according to an embodiment of the present invention will be described based on Figure 1. Figure 1 is a schematic diagram showing a cross-section of the temporary fixing member for electronic components 1 (a cross-section perpendicular to the length direction and parallel to the thickness direction of the temporary fixing member 1 for electronic components). As shown in Figure 1, the temporary fixing member for electronic components 1 is a so-called double-sided tape and includes a base film 10, a first adhesive layer 20, and a second adhesive layer 30. The temporary fixing member for electronic components 1 is used to temporarily fix electronic components such as semiconductors. Examples of use of the temporary fixing member for electronic components 1 will be described later.

[0016] The material constituting the base film 10 is not particularly limited, and materials used for known base films can be used. However, it is preferable that the base film 10 is made of a material that is not easily deformed during the processing of electronic components (for example, when bonding multiple chips to the back surface of a thinned base die) and is not easily decomposed by heat (not easily decomposed and generating gas). That is, during the processing of electronic components, the electronic components may be pressed or heated. It is preferable that the base film 10, the first adhesive layer 20, and the second adhesive layer 30 have deformation resistance and heat resistance. Examples of materials constituting the base film 10 include polyethylene naphthalate, polyether ketone, polyether ether ketone, polyether sulfone, polyamide, polyarylate, etc. One or more of these materials may be selected. The base film 10 may be a single-layer film or a multi-layer film. The thickness of the base film 10 is not particularly limited, but it is preferably 10 to 50 μm. In this case, it becomes easier to adjust the total light transmittance so that formula (1), which will be described later, is satisfied.

[0017] Both sides of the base film 10 may be subjected to release treatments such as silicone treatment, long-chain alkyl treatment, or fluorine treatment, as needed, in order to improve the release properties from the first adhesive layer 20 and the second adhesive layer 30.

[0018] The first adhesive layer 20 is provided on one side of the base film 10. The first adhesive layer 20 is a layer that adheres to an electronic component and is ultimately peeled off from the electronic component. The surface of an electronic component (for example, the bump surface of a base die) often has irregularities. In addition to bumps, electrodes and the like can be used to form these irregularities. Therefore, the first adhesive layer 20 is required to be able to follow the irregularities of the electronic component. This is to improve the processing accuracy of the electronic component after the first adhesive layer 20 has been adhered to it. On the other hand, as mentioned above, it is preferable that the first adhesive layer 20 has deformation resistance and heat resistance.

[0019] To achieve this, the first adhesive layer 20 has some kind of trigger, specifically responsiveness to ultraviolet light at 405 nm (i.e., UV curability). This causes the first adhesive layer 20 to form a cross-linked structure and harden. In other words, before hardening, the first adhesive layer 20 has the flexibility to conform to the irregularities of the electronic component, and after adhesion, it hardens under UV light and has deformation resistance and heat resistance. Since the first adhesive layer 20 is hardened, final removal is also easy.

[0020] However, the above-mentioned characteristics cannot be obtained simply by having the first adhesive layer 20 have UV reactivity at 405 nm. 405 nm UV is a long wavelength and therefore has low reactivity. One might consider adding a large amount of photoinitiator to the first adhesive layer 20, but this method reduces the reactivity of the side of the first adhesive layer 20 opposite to the UV-irradiated surface (i.e., the side adhering to the electronic component). In other words, the side adhering to the electronic component does not harden sufficiently. This tendency becomes stronger the thicker the first adhesive layer 20 is. Therefore, the inventor focused on the balance between the thickness of the first adhesive layer 20 and the total light transmittance at 405 nm in the thickness direction of the entire electronic component temporary fixing member 1, and found that the above-mentioned characteristics can be obtained when the following equation (1) is satisfied.

[0021] 0.01 < T / t < 0.2 (1) Here, T is the total light transmittance (%) at 405 nm in the thickness direction of the entire electronic component temporary fixing member 1, and t is the thickness (μm) of the first adhesive layer 20. Here, the total light transmittance is the ratio of the light incident on the sample and the light obtained by adding the forward transmitted light and diffuse transmitted light that passes through the entire electronic component temporary fixing member 1.

[0022] In other words, the first adhesive layer 20 has UV reactivity to 405 nm and satisfies equation (1), so that the first adhesive layer 20 can follow the irregularities of the electronic component before UV curing. Furthermore, after UV curing, the entire thickness of the first adhesive layer 20 hardens, providing deformation resistance and heat resistance, and ultimately making it possible to reliably peel it off the electronic component with weak force.

[0023] The total light transmittance of the entire electronic component temporary fixing member 1 in the thickness direction at 405 nm can be adjusted by the material, thickness, etc., of the base film 10, the first adhesive layer 20, and the second adhesive layer 30.

[0024] The thickness of the first adhesive layer 20 can be any value as long as it satisfies equation (1), but considering the light transmittance of the first adhesive layer 20 itself, a thickness of 20 to 300 μm is preferred.

[0025] Specific examples of the resin constituting the first adhesive layer 20 include silicone resin, (meth)acrylic resin, epoxy resin, polyimide resin, and urethane resin. One or more of these resins may be selected. Among these, (meth)acrylic resin is most preferred from the viewpoint of initial flexibility and curability after crosslinking.

[0026] (Meth)acrylic resins can be obtained, for example, by copolymerizing alkyl acrylates and / or alkyl methacrylates having alkyl groups with typically 2 to 18 carbon atoms, functional group-containing monomers, and other modifying monomers that can be copolymerized with these as needed.

[0027] The mass-average molecular weight of (meth)acrylic resin is not particularly limited, but is usually around 50,000 to 2,000,000. The mass-average molecular weight can be determined using gel permeation chromatography. For example, it can be determined by using an HSPgelHR MB-M 6.0 × 150 mm column and tetrahydrofuran (THF) as the eluent, measuring at 40°C, and determining the molecular weight using a polystyrene standard.

[0028] It is preferable to leave unreacted (meth)acryloyl groups in the (meth)acrylic resin, but if none remain, a second resin component having (meth)acryloyl groups may be added to the resin.

[0029] Furthermore, from the viewpoint of conforming to the unevenness of electronic components, it is preferable that the (meth)acrylic resin has a maximum loss tangent value of 0.01 to 0.6 between 10 and 70°C.

[0030] The loss tangent can be measured, for example, by pressing a cone plate of a viscoelasticity measuring device (manufactured by T.A. Instruments, product name "ARES") against the first adhesive layer 20 side of the temporary fixing member 1 for electronic components. Specifically, after attaching the second adhesive layer 30 to the support substrate, a load is applied to the first adhesive layer 20 such that the cone plate is embedded 10 μm deep. Then, a strain of 1 Hz is applied to the temporary fixing member 1 for electronic components, and the loss tangent is measured from -50 to 150°C to obtain the loss tangent value from 10 to 70°C.

[0031] The first adhesive layer 20 may contain a curing agent (crosslinking agent) and a photoinitiator to accelerate the curing of the resin. Examples of curing agents include isocyanates that can react with hydroxyl groups in the polymer. Specifically, polyvalent isocyanate compounds such as 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4'-diisocyanate, diphenylmethane-2,4'-diisocyanate, 3-methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate can be used. Furthermore, adducts of these isocyanate compounds with polyol compounds such as trimethylolpropane; bilets or isocyanurates of these isocyanate compounds; and so on. Other examples include polyepoxy compounds having glycidyl at the end that can react with an acid value (carboxylic acid), such as 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, 1,3-bis(N,N-diglycidylaminomethyl)toluene, 1,3-bis(N,N-diglycidylaminomethyl)benzene, and N,N,N,N'-tetraglycidyl-m-xylenediamine. Metal chelate complexes are also acceptable. The amount of curing agent added may be 0.1 to 10 parts by mass when the mass of the resin component of the first adhesive layer 20 is set to 100. The photoinitiator may be, for example, isopropylbenzoin ether, isobutylbenzoin ether, benzophenone, Michlar's ketone, chlorothioxanthone, benzyl methyl ketal, α-hydroxycyclohexylphenyl ketone, oxime ester photoinitiators, or 2-hydroxymethylphenylpropane, of which oxime ester photoinitiators are preferred. The amount of photoinitiator added is preferably greater than 0.8 and less than 2.0 when the mass of the resin component of the first adhesive layer 20 is set to 100.

[0032] The second adhesive layer 30 is provided on the other side of the base film 10. The second adhesive layer 30 is a layer that adheres to a support substrate such as a glass substrate and is ultimately peeled off from the support substrate. In this way, the temporary fixing member 1 for electronic components is a member for temporarily fixing electronic components to a support substrate or the like. When the electronic component is a thin-film base die, the support substrate can support the electronic component.

[0033] The resin constituting the second adhesive layer 30 is not particularly limited as long as it can adhere to the support substrate, but from the viewpoint of deformation resistance and heat resistance, it may be, for example, silicone resin, (meth)acrylic resin, epoxy resin, polyimide resin, and urethane resin. One or more of these resins may be selected. Among these, epoxy resin is preferred from the viewpoint of heat resistance, and it is more preferable to include phenoxy resin or urethane resin from the viewpoint of adhesion to the support substrate. Furthermore, from the viewpoint of deformation resistance, it is preferable that the resin contains an inorganic filler. Examples of inorganic fillers include silicon dioxide, aluminum oxide, aluminum nitride, and carbon. Among these, silicon dioxide is more preferable from the viewpoint of thermal expansion coefficient with respect to the support substrate.

[0034] The thickness of the second adhesive layer 30 is not particularly limited, but may be, for example, 5 to 50 μm.

[0035] <Method for Manufacturing Electronic Component Temporary Fixing Member> The method for manufacturing the electronic component temporary fixing member 1 is not particularly limited. For example, the first adhesive layer 20 may be formed by applying a slurry in which the material constituting the first adhesive layer 20 is dispersed and dissolved to one side of the base film 10 and drying it, and the second adhesive layer 30 may be formed by applying a slurry in which the material constituting the second adhesive layer 30 is dispersed and dissolved to the other side of the base film 10 and drying it.

[0036] <Applications of the temporary fixing member for electronic components> Next, we will explain the applications of the temporary fixing member for electronic components. Here, we will explain the case where the electronic component is a base die. Before use, the temporary fixing member for electronic components 1 is protected on both sides (exposed surfaces of the first adhesive layer 20 and the second adhesive layer 30) by release tape. First, the release tape on the side of the second adhesive layer 30 is peeled off and the second adhesive layer 30 is adhered to a support substrate such as a glass substrate. Next, the release tape on the side of the first adhesive layer 20 is peeled off and the first adhesive layer 20 is adhered to the bump surface of the base die. Here, since the first adhesive layer 20 satisfies equation (1), it can sufficiently follow the irregularities of the bump surface of the base die. Next, ultraviolet light of 405 nm is irradiated from the support substrate side. As a result, the first adhesive layer 20 hardens. Here, since the first adhesive layer 20 satisfies equation (1), it hardens over the entire thickness direction of the first adhesive layer 20. In other words, the bump surface side is also sufficiently hardened. Next, the base die is thinned. Then, multiple chips are bonded to the back surface of the base die (the side opposite the bump surface). That is, electronic components are processed. At this time, the first adhesive layer 20 may be pressed or heated, but since the first adhesive layer 20 is sufficiently hardened, it has high deformation resistance and heat resistance. Next, various other processing (molding, etc.) is performed. Next, the support substrate is peeled off the second adhesive layer 30 by irradiating the second adhesive layer 30 with laser light, etc. The method of peeling off the support substrate from the second adhesive layer 30 is not particularly limited. Next, the temporary fixing member 1 for electronic components is peeled off from the base die. Here, since the first adhesive layer 20 is hardened over the entire thickness, it can be easily peeled off with a weak force. That is, heavy peeling, damage to the bump surface, and residue of the adhesive layer on the bump surface hardly occur.

[0037] As described above, according to this embodiment, the first adhesive layer 20 has UV reactivity to 405 nm and satisfies formula (1), so the first adhesive layer 20 can follow the irregularities of the electronic component before UV curing. Furthermore, after UV curing, the entire thickness of the first adhesive layer 20 hardens, providing deformation resistance and heat resistance, and ultimately making it possible to reliably peel it off the electronic component with weak force.

[0038] Next, an embodiment of this design will be described. In this embodiment, the following tests were conducted to confirm the effectiveness of the temporary fixing member for electronic components according to this design.

[0039] <Example 1> <Preparation of temporary fixing member for electronic components> (Preparation of base polymer) 100 parts by mass of 2-ethylhexyl acrylate (HA), 8 parts by mass of 2-hydroxyethyl acrylate, 0.3 parts by mass of azobisisobutyronitrile, and 60 parts by mass of ethyl acetate were placed in a reaction vessel equipped with a cooling tube, a nitrogen inlet tube, a thermometer, and a stirring device. A polymerization reaction was carried out at 65°C for 6 hours in a nitrogen stream to obtain a solution of acrylic resin (acrylic resin 1). The mass-average molecular weight of acrylic resin 1 was 100,000, and the maximum loss tangent value at 10 to 70°C was 0.5.

[0040] (Preparation of the first adhesive layer) To 100 parts by mass (solids) of the above-mentioned acrylic resin, 100 parts by mass of polyfunctional acrylate oligomer KRM8200 (manufactured by Daicel Ornex Co., Ltd.) was added as a reactive material, 0.5 parts by mass of epoxy compound (trade name: tetrad C, 1,3-bis(N,N-diglycidylaminomethyl)cyclohexane, Mitsubishi Gas Chemical Company, Inc.) was added as an acrylic resin curing agent (crosslinking agent), and 5 parts by mass of oxime ester-based photoinitiator N1919-T (manufactured by ADEKA) was added as a photoinitiator to prepare an adhesive solution. The obtained adhesive solution was applied to a release-treated PET film (release film), heated and dried at 120°C for 2 minutes, and laminated to form a first adhesive layer (adhesive layer A) with a thickness of 120 μm. A Mitutoyo "Digimatic Indicator ID-H" was used to measure the thickness. The thickness was measured at multiple locations, and the average value was taken as the thickness of adhesive layer A.

[0041] (Preparation of the second adhesive layer composition) 50 parts by mass of liquid epoxy resin (product name: YD-128, bisphenol A type epoxy resin, mass average molecular weight: 400, epoxy equivalent: 190, Nippon Steel Chemical & Material Co., Ltd.), 20 parts by mass of solid epoxy resin (product name: EPPN-501H, triphenylmethane type epoxy resin, mass average molecular weight: 1000, epoxy equivalent: 167, manufactured by Nippon Kayaku Co., Ltd.), and 30 parts by mass of phenoxy resin (product name: YP-50, bisphenol A type phenoxy resin, mass average molecular weight: 70000, Nippon Steel Chemical & Material Co., Ltd.) were heated and stirred with methyl ethyl ketone (MEK) in a 1000 ml separable flask at a temperature of 110°C for 2 hours to obtain a resin varnish. Next, the obtained resin varnish was transferred to an 800 ml planetary mixer, and 70 parts by mass of particulate silica filler (product name: FB-5SDX, D10: 1.1 μm, D50: 4.2 μm, D90: 9.5 μm, specific surface area: 2.7 m² / g, Denka Co., Ltd.) was added as a filler, 3 parts by mass of imidazole-type curing agent (product name: 2PHZ-PW, epoxy resin curing agent, Shikoku Chemicals Co., Ltd.) and 0.35 parts by mass of epoxy silane coupling agent (product name: KBM-403, 3-glycidoxypropyltrimethoxysilane, Shin-Etsu Silicone Co., Ltd.) were added, and after stirring and mixing at room temperature for 1 hour, vacuum degassing was performed to obtain a mixed varnish (second adhesive layer composition).

[0042] (Preparation of base film) A 25 μm thick PEEK (polyether ether ketone) film (EXPEEK manufactured by Kurabo Corporation) was prepared as the base film.

[0043] (Production of Temporary Fixing Member for Electronic Components) The obtained mixed varnish was applied to the other surface of the base film, and heated and dried at 130° C. for 5 minutes, thereby forming a second adhesive layer with a thickness of 20 μm on the other surface of the base film. The thickness of the second adhesive layer was measured by the same method as that for measuring the thickness of the first adhesive layer. A release-treated PET film (release tape) having a thickness of 20 μm was bonded onto the second adhesive layer. Meanwhile, the first adhesive layer (adhesive layer A) produced above was bonded onto one surface of the base film. A release-treated PET film (release tape) having a thickness of 20 μm was bonded onto the first adhesive layer. Through the above steps, the temporary fixing member for electronic components according to Example 1 was obtained. The composition of the temporary fixing member for electronic components is shown in Table 1-1.

[0044] <Evaluation of Temporary Fixing Member for Electronic Components> (Total Light Transmittance at 405 nm) The release tapes were peeled off from both surfaces of the temporary fixing member for electronic components, ultraviolet light of 405 nm was irradiated from the second adhesive layer side using NDH8000 manufactured by Nippon Denshoku Industries Co., Ltd., and the total light transmittance was measured. T / t (parameter A) was calculated from the obtained value and the thickness of the first adhesive layer. The results are shown in Table 1-1.

[0045] (10 μm Electrode Embeddability) The release tape was peeled off from the second adhesive layer of the temporary fixing member for electronic components, and the second adhesive layer of the temporary fixing member for electronic components was heat-bonded to a 1 mm-thick quartz glass (glass substrate) using a laminator (DR3000 manufactured by Nitto Seiki) under the conditions of 70° C., a roll bonding speed of 2 mm / sec, and a bonding pressure of 0.2 MPa. Subsequently, the release tape was peeled off from the first adhesive layer, and a dummy bump wafer having a bump height of 10 μm and a bump pitch of 40 μm was vacuum-bonded on the first adhesive layer side using a pressure bonding apparatus (GWSM-300M manufactured by Takatori Corporation). Thus, a laminate consisting of a glass substrate, the temporary fixing member for electronic components, and the dummy bump wafer was obtained.

[0046] Next, the size of air pockets formed around the bumps was measured from the quartz glass side of the laminate using a digital microscope (HRX-01 manufactured by Hirox Corporation). Larger air pockets indicate that the first adhesive layer does not sufficiently conform to the bumps, so conformability was evaluated on a three-level scale as described below. The diameter of an air pocket was calculated as the average diameter of a plurality of air pockets. The results are shown in Table 1-1.

[0047] ◎: Air pocket diameter of 15 μm or less 〇: Air pocket diameter more than 15 μm and 50 μm or less ×: Air pocket diameter more than 50 μm

[0048] (Mass reduction rate after 30 minutes at 20°C) Ultraviolet light of 405 nm at 6000 mJ / cm was irradiated from the second adhesive layer side of the temporary fixing member for electronic components ２ after irradiation, followed by curing at 180°C for 1 hour. Next, the release tape was peeled from the temporary fixing member for electronic components, and the temporary fixing member for electronic components was collected in an aluminum pan. The aluminum pan was then set in a simultaneous thermogravimetry-differential scanning calorimeter ("STA7200" manufactured by Hitachi High-Tech Science Corporation) and heated at 250°C for 30 minutes under a nitrogen atmosphere, and the mass reduction rate was determined. The mass reduction rate is expressed as the ratio of the weight after heating to the weight before heating. A lower mass reduction rate indicates better heat resistance. The results are shown in Table 1-1.

[0049] (Peeling force after heating step) The release tape on the first adhesive layer side was peeled off, and the first adhesive layer was adhered onto a silicon wafer. Next, ultraviolet light of 405 nm at 6000 mJ / cm was applied from the release tape side of the second adhesive layer ２ after irradiation, followed by curing at 180°C for 1 hour. Thereafter, the peeling force was measured when the temporary fixing member for electronic components, which had been heated in nitrogen at 250°C for 30 minutes, was peeled using an autograph (AGX-V2 manufactured by Shimadzu Corporation) at a peeling angle of 90° and a peeling speed of 50 mm / min. A lower peeling force is preferable because it is less likely to leave damage on electronic components. The results are shown in Table 1-1.

[0050] (Amount of adhesive residue) The surface of the silicon wafer peeled under the above peeling force conditions was observed using a digital microscope (HRX-01 manufactured by Hirox Corporation).

[0051] ○: One or fewer adhesive residues of 5 μm or more when observing a 1 cm square. △: More than one, but 10 or fewer, adhesive residues of 5 μm or more when observing a 1 cm square. ×: Adhesive residues that can be seen with the naked eye. Since a smaller amount of adhesive residue is preferable, △ or higher was considered an acceptable level. The results are shown in Table 1-1.

[0052] (Overall Assessment) The overall assessment was made based on the following criteria. A score of ○ or higher indicates a passing level.

[0053] ◎: The best level, where the detached device can be applied to the next process without cleaning and has good processability. 〇: An acceptable level where it can be applied with additional cleaning of the device, etc. ×: One or more evaluation items are at an unacceptable level.

[0054] <Example 2> The composition of the first adhesive layer was as shown in Table 1-1 (Adhesive Layer B), and the same treatment as in Example 1 was carried out. The results are shown in Table 1-1.

[0055] <Example 3> The composition of the first adhesive layer was as shown in Table 1-1 (adhesive layer C), and the same treatment as in Example 1 was carried out. The results are shown in Table 1-1. Here, KRM8452 is a urethane oligomer manufactured by Daicel Ornex, Inc., and NCI-831E is an oxime ester type photoinitiator manufactured by ADEKA Corporation.

[0056] <Example 4> The composition of the first adhesive layer was as shown in Table 1-1 (adhesive layer D), and the same treatment as in Example 1 was carried out. The results are shown in Table 1-1.

[0057] <Example 5> The composition of the first adhesive layer was as shown in Table 1-1 (adhesive layer E), and the same treatment as in Example 1 was carried out. The results are shown in Table 1-1.

[0058] <Example 6> The composition of the first adhesive layer was as shown in Table 1-2 (adhesive layer F), and a 25 μm thick polyamide film (UNIAMIDI Ex-25 manufactured by Unitika Corporation) was used as the base film. The same treatment as in Example 1 was carried out. The results are shown in Table 1-2.

[0059] <Example 7> The composition of the first adhesive layer was as shown in Table 1-2 (adhesive layer F), and a PEEK film with a thickness of 12 μm (EXPEEK manufactured by Kurabo Industries Ltd.) was used as the base film. The same treatment as in Example 1 was carried out. The results are shown in Table 1-2.

[0060] <Example 8> The composition of the first adhesive layer was as shown in Table 1-2 (adhesive layer F), and a transparent PI (polyimide) film with a thickness of 12 μm (tormed, manufactured by IST Co., Ltd.) was used as the base film. The same treatment as in Example 1 was carried out. The results are shown in Table 1-2.

[0061] <Example 9> The composition of the first adhesive layer was as shown in Table 1-2 (adhesive layer F), and the thickness of the first adhesive layer was set to 40 μm. The same procedure as in Example 1 was performed. The results are shown in Table 1-2.

[0062] <Example 10> The composition of the first adhesive layer was as shown in Table 1-2 (adhesive layer F), and the thickness of the first adhesive layer was set to 150 μm. The same procedure as in Example 1 was performed. The results are shown in Table 1-2.

[0063] <Comparative Example 1> The composition of the first adhesive layer was as shown in Table 1-3 (Adhesive Layer A), and the thickness of the first adhesive layer was 200 μm. The same procedure as in Example 1 was performed. The results are shown in Table 1-3.

[0064] <Comparative Example 2> The composition of the first adhesive layer was as shown in Table 1-3 (adhesive layer G), and the same treatment as in Example 1 was carried out. The results are shown in Table 1-3.

[0065] <Comparative Example 3> The composition of the first adhesive layer was as shown in Table 1-3 (Adhesive Layer A), and the thickness of the first adhesive layer was set to 10 μm. The same procedure as in Example 1 was performed. The results are shown in Table 1-3.

[0066] <Comparative Example 4> The composition of the first adhesive layer was as shown in Table 1-3 (adhesive layer H), and the same treatment as in Example 1 was carried out. The results are shown in Table 1-3. Here, Irgacure 184 is α-hydroxyalkylphenone manufactured by IGM Resins.

[0067]

[0068]

[0069]

[0070] <Discussion> In all of Examples 1 to 10, parameter A satisfies equation (1). Therefore, good results were obtained for all evaluation items.

[0071] In contrast, in Comparative Examples 1 and 2, parameter A was below the lower limit of equation (1), while in Comparative Examples 3 and 4, it exceeded the upper limit of equation (1). In all of Comparative Examples 1 to 4, the temporary fixing member for electronic components could not be peeled off in the evaluation of peeling force after the heating process. This is presumed to be because the first adhesive layer had not hardened sufficiently. In Comparative Example 3, the evaluation of the conformability of the first adhesive layer was also poor.

[0072] Although the present invention has been described above with reference to the above embodiments, the present invention is not limited thereto. Those skilled in the art can modify the electronic component temporary fixing member of the present invention as appropriate in accordance with conventionally known knowledge. Such modifications, insofar as they still possess the configuration of the present invention, are of course included within the scope of the present invention.

[0073] 1. Temporary fixing member for electronic components, 10. Base film, 20. First adhesive layer, 30. Second adhesive layer

Claims

1. An electronic component temporary fixing member used for temporarily fixing electronic components, comprising: a base film; a first adhesive layer provided on one side of the base film; and a second adhesive layer provided on the other side of the base film, wherein the first adhesive layer has ultraviolet reactivity at 405 nm, and when the total light transmittance at 405 nm in the thickness direction of the entire electronic component temporary fixing member is T%, and the thickness of the first adhesive layer is t μm, the following equation (1) 0.01 < T / t < 0.2 (1) holds true.

2. The temporary fixing member for electronic components according to claim 1, wherein the thickness of the base film is 10 to 50 μm.

3. The electronic component temporary fixing member according to claim 1, wherein the thickness of the first adhesive layer is 20 to 300 μm.

4. The electronic component temporary fixing member according to claim 1, wherein the first adhesive layer contains a resin having (meth)acryloyl groups.

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