Thermally conductive adhesive sheet, and semiconductor device and method for manufacturing same

Abstract

Disclosed is, for example, a thermally conductive adhesive sheet which is obtained by forming a resin composition into a sheet-shape, the resin composition containing: a resin (A) which comprises a structural unit (1) represented by formula (1) and a structural unit (2) represented by formula (2), has a structure represented by formula (3) at both ends, and has a weight average molecular weight of 4,000 or less; a resin (B) which comprises a structural unit (4) represented by formula (4) and a structural unit (5) represented by formula (5), has a structure represented by formula (6) at both ends, has a weight average molecular weight of 10,000 or more, and has a glass transition temperature (Tg) of 60°C or less; a resin (C) which has an epoxy group at an end, has a weight average molecular weight of 10,000 to 80,000, and has a glass transition temperature (Tg) of 65°C to 160°C; and silver particles (D).

Description

Thermally conductive adhesive sheet, semiconductor device, and method for manufacturing the same

[0001] The present disclosure relates to a thermally conductive adhesive sheet, an element with a thermally conductive adhesive sheet and a method for manufacturing the same, and a semiconductor device and a method for manufacturing the same.

[0002] Die attach materials are used to bond semiconductor elements (dies) to supports (substrates, lead frames, etc.) Examples of die attach materials include paste-type materials such as silver paste and film-type materials such as conductive die attach films.

[0003] For example, Patent Document 1 describes a bonding material made of a silver paste in which silver particles and a solvent are mixed, characterized in that the solvent is a diol, a triol is mixed as an additive, and a dicarboxylic acid is mixed as a sintering accelerator. Patent Document 2 describes an adhesive film made of an adhesive layer containing a thermosetting resin, a thermoplastic resin, and a thermally conductive filler, wherein the thermally conductive filler has a thermal conductivity of 12 W / m·K or more and is contained in the adhesive film at a content of 30 to 50% by volume, the thermoplastic resin contains at least one type of phenoxy resin, and the adhesive layer after curing has a reliability coefficient S1 calculated by the following mathematical formula (1) of 50 to 220 (×10 －６ GPa), and the reliability coefficient S2 calculated by the following formula (2) is 10 to 120 (×10 －８ The document describes an adhesive film characterized by a thermal conductivity of 0.5 W / m K or more, where S1=(Tg-25[°C])×(CTEα1[ppm / K])×(storage modulus E′[GPa]at 260°C) (1) S2=S1×(saturated water absorption WA[mass%]) (2)

[0004] JP 2017-101264 A JP 2018-188540 A

[0005] After extensive research, the inventors have discovered that a thermally conductive adhesive sheet formed from a specific resin composition in sheet form can produce a semiconductor device that is resistant to peeling (highly reliable) even when subjected to repeated thermal cycles.

[0006] That is, the present disclosure relates to the following: [1] A thermally conductive adhesive sheet obtained by forming into a sheet a resin composition containing: a resin (A) that includes a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), both terminals of which have a structure represented by the following formula (3), and a weight-average molecular weight of 4,000 or less; a resin (B) that includes a structural unit (4) represented by the following formula (4) and a structural unit (5) represented by the following formula (5), both terminals of which have a structure represented by the following formula (6), and a weight-average molecular weight of 10,000 or more and a glass transition temperature (Tg) of 60°C or less; a resin (C) that has epoxy groups at its terminals, a weight-average molecular weight of 10,000 to 80,000, and a glass transition temperature (Tg) of 65 to 160°C; and silver particles (D).

[0007]

[0008] [In formula (1), r １ is an integer of 2 to 10. In formula (2), R １ and R ２ are each independently a hydrogen atom or a methyl group. ２ is an integer of 2 to 10. In formula (5), R ３ and R ４ are each independently a hydrogen atom or a methyl group.] [2] The thermally conductive adhesive sheet according to the above [1], wherein the resin (A) is a resin (A2) represented by the following formula (7), and the resin (B) is a resin (B2) represented by the following formula (8):

[0009]

[0010] [In formula (7), r １ is an integer from 2 to 10, and R １ and R ２ are each independently a hydrogen atom or a methyl group. ２ is an integer from 2 to 10, and R ３ and R ４are each independently a hydrogen atom or a methyl group.] [3] The thermally conductive adhesive sheet according to [1] or [2] above, wherein the resin (A) is a copolymer of bisphenol F and 1,6-hexanediol diglycidyl ether. [4] The thermally conductive adhesive sheet according to any one of [1] to [3] above, wherein the resin (B) is a copolymer of bisphenol F and 1,6-hexanediol diglycidyl ether. [5] The thermally conductive adhesive sheet according to any one of [1] to [4] above, wherein the silver particles (D) have an average particle size (D50) of 0.5 to 5.0 μm. [6] The thermally conductive adhesive sheet according to any one of [1] to [5] above, wherein the silver particles (D) are hollow particles. [7] The thermally conductive adhesive sheet according to any one of [1] to [6] above, further comprising a silicon-containing triazine compound (E). [8] The thermally conductive adhesive sheet according to the above [7], wherein the silicon-containing triazine compound (E) is represented by the following general formula (13): [9] The thermally conductive adhesive sheet according to any one of [1] to [8] above, wherein the content of the resin (A) is 20 to 80% by mass, the content of the resin (B) is 10 to 60% by mass, and the content of the resin (C) is 10 to 60% by mass, based on 100% by mass of the total amount of the resins (A), (B), and (C).

[10] The thermally conductive adhesive sheet according to any one of [1] to [9] above, wherein the content of the silver particles (D) is 70 to 95% by mass, based on 100% by mass of the solid content of the resin composition.

[11] A semiconductor element with a thermally conductive adhesive sheet, comprising a semiconductor element and an adhesive layer laminated on the semiconductor element, wherein the adhesive layer is the thermally conductive adhesive sheet according to any one of [1] to

[10] above.

[12] A method for manufacturing a semiconductor element with a thermally conductive adhesive sheet, comprising the steps of laminating a semiconductor wafer and the thermally conductive adhesive sheet described in any one of [1] to

[10] above to obtain a semiconductor wafer with the thermally conductive adhesive sheet, and singulating the semiconductor wafer with the thermally conductive adhesive sheet.

[13] A semiconductor device comprising a support member and a semiconductor element mounted on the support member via an adhesive layer, wherein the adhesive layer is a cured product of the thermally conductive adhesive sheet described in any one of [1] to

[10] above.

[14] A method for manufacturing a semiconductor device, comprising arranging a support member, the thermally conductive adhesive sheet described in any one of [1] to

[10] above, and a semiconductor element in this order, and curing the thermally conductive adhesive sheet.

[0011] The bonding material described in Patent Document 1 is paste-like, and when a semiconductor device is manufactured by mounting a semiconductor element on a support using the paste, the paste may creep up onto the surface of the semiconductor element, contaminating the semiconductor element and resulting in quality defects, or the paste may bleed out onto the surface of the support, making it difficult to miniaturize the semiconductor device. Furthermore, there is a concern that the surface of the semiconductor element may be tilted relative to the surface of the support due to the creeping up or bleed-out of the paste, resulting in reduced reliability of the semiconductor device and making it difficult to miniaturize or thin the semiconductor device. In contrast, the adhesive film described in Patent Document 2 is film-like, and therefore does not suffer from the above-mentioned problems associated with pastes. However, the adhesive film described in Patent Document 2 has an epoxy equivalent of 150 to 300 g / eq of the epoxy resin, and therefore, when a semiconductor device is manufactured by mounting a semiconductor element using the adhesive film on a support, there is a concern that the stress relaxation property is low and peeling may occur due to repeated thermal cycling.

[0012] The present disclosure aims to provide a thermally conductive adhesive sheet that has good sheet properties (no stickiness) and sheet processability (no tearing, ripping, chipping, etc. when manufacturing the sheet) and that can produce a semiconductor device that is resistant to peeling even after repeated thermal cycles (high reliability); an element with a thermally conductive adhesive sheet that has the sheet and an element and a method for manufacturing the same; and a semiconductor device that has the sheet and a semiconductor element and a method for manufacturing the same.

[0013] According to the present disclosure, there are provided a thermally conductive adhesive sheet that has good sheet properties (no stickiness) and sheet processability (no tearing, ripping, chipping, etc. when manufacturing the sheet) and that can produce a semiconductor device that is resistant to peeling even after repeated thermal cycles (high reliability); an element with a thermally conductive adhesive sheet having the sheet and an element and a method for manufacturing the same; and a semiconductor device having the sheet and a semiconductor element and a method for manufacturing the same.

[0014] The present disclosure will be described in detail below with reference to one embodiment. In this disclosure, the term "XX to YY" means "XX or more and YY or less." Furthermore, in this disclosure, for numerical ranges (e.g., ranges of content, etc.), lower and upper limits described in stages can be independently combined. Furthermore, in the numerical ranges described in this disclosure, the upper or lower limit of the numerical range may be replaced with a value shown in the examples. A "thermally conductive adhesive sheet" may be simply referred to as a "sheet." In this disclosure, "solid content" refers to components excluding the solvent. In the present disclosure, the "structural unit (x) derived from compound (X)" in resin Y is not limited to the structural unit (x1) derived from compound (X) (provided that x1 and x have the same structure) that is actually present in the structure of resin Y produced using compound (X) as a monomer; when a structural unit (x2) present in the structure of resin Y produced without using compound (X) is identical to the structural unit (x1), the structural unit (x2) is also included in the "structural unit (x) derived from compound (X)." In other words, in the present disclosure, the "structural unit (x) derived from compound (X)" in resin Y means all structural units (x) present in resin Y, regardless of the raw material monomer from which the structural unit (x) is derived. For example, in the production method of resin (B) described below, the "structural unit derived from compound (11)" in resin (B) may be, but is not limited to, the structural unit P (corresponding to the structural unit (x1)) derived from compound (11) when resin (B) is produced by a two-step process in which compound (11) represented by formula (11) and compound (12) represented by formula (12) are reacted. That is, although a specific description is omitted, when resin (B) is produced by a one-step process in which compound (11A) represented by formula (11A) below, compound (12) represented by formula (12), and epichlorohydrin are directly reacted, the structural unit Q (corresponding to the structural unit (x2)) derived from compound (11A) is the same as the structural unit P formed by the two-step process, and is therefore included in the "structural unit derived from compound (11)" in resin (B).

[0015]

[0016] [Thermal conductive adhesive sheet] The thermal conductive adhesive sheet of the present disclosure is a thermal conductive adhesive sheet obtained by forming into a sheet a resin composition containing: a resin (A) that includes a structural unit (1) represented by formula (1) below and a structural unit (2) represented by formula (2) below, and that has a structure represented by formula (3) at both ends and has a weight average molecular weight of 4,000 or less; a resin (B) that includes a structural unit (4) represented by formula (4) below and a structural unit (5) represented by formula (5) below, and that has a structure represented by formula (6) at both ends and has a weight average molecular weight of 10,000 or more and a glass transition temperature (Tg) of 60°C or less; a resin (C) that has epoxy groups at its terminals and has a weight average molecular weight of 10,000 to 80,000 and a glass transition temperature (Tg) of 65 to 160°C; and silver particles (D).

[0017]

[0018] [In formula (1), r １ is an integer of 2 to 10. In formula (2), R １ and R ２ are each independently a hydrogen atom or a methyl group. ２ is an integer of 2 to 10. In formula (5), R ３ and R ４ are each independently a hydrogen atom or a methyl group.

[0019] The thermally conductive adhesive sheet of the present disclosure has good sheetability (no stickiness) and sheet processability (no tearing, ripping, chipping, etc. during sheet production), and can provide a highly reliable semiconductor device that is resistant to peeling even after repeated thermal cycling. While the details of the reasons for this are unclear, the following is presumed to be the case. The thermally conductive adhesive sheet of the present disclosure contains a resin (A) having a highly flexible structural unit (1), a highly heat-resistant structural unit (2), and a structure represented by formula (3) containing an epoxy group and having a weight-average molecular weight (Mw) of 4,000 or less. Because the resin (A) has a low weight-average molecular weight (Mw) of 4,000 or less, the melt viscosity during temporary adhesion of the sheet can be reduced. As a result, when the sheet is adhered to an adherend, the sheet exhibits good wettability and improved adhesion to the adherend. Furthermore, because the resin (A) contains the highly flexible structural unit (1), it can alleviate stress even when temperature changes occur, improving the reliability of the semiconductor device. Furthermore, resin (A) contains a highly heat-resistant structural unit (2), which improves heat resistance during adhesion and enhances reliability. Furthermore, resin (A) has a structure represented by formula (3), which undergoes ring-opening during adhesion to form a chemical bond with the adherend, thereby improving adhesion and, as a result, reliability. The thermally conductive adhesive sheet of the present disclosure also contains resin (C) having terminal epoxy groups, a Mw of 10,000 to 80,000, and a glass transition temperature (Tg) of 65 to 160°C. Resin (C) has a high Tg of 65°C or higher, resulting in a non-sticky sheet and improved sheetability. Furthermore, because resin (C) has a Mw of 10,000 or higher, the thermally conductive adhesive sheet is less likely to tear during the process of peeling the unnecessary non-circular portions from the release film when processing the sheet into a circular shape during the production of the thermally conductive adhesive sheet, thereby improving sheet processability. Furthermore, since resin (C) has an Mw of 80,000 or less, its melt viscosity is low, and it wets the adherend during temporary bonding, improving adhesion and reliability. Thus, the combined use of resin (A) and resin (C) achieves both sheet processability and semiconductor device reliability to some extent, but further improvement in reliability is desired.To meet this demand, the thermally conductive adhesive sheet of the present disclosure further contains a resin (B) having a highly flexible structural unit (4), a highly heat-resistant structural unit (5), and a structure represented by formula (6) containing an epoxy group, and having an Mw of 10,000 or more and a Tg of 60°C or less. Because the resin (B) has a low Tg of 60°C or less, it adheres to the wafer without wrinkles or voids even at low temperatures (70°C), improving wafer lamination. Furthermore, because the resin (B) has a higher Mw than the resin (A), the thermally conductive adhesive sheet is less likely to tear during the process of peeling the unnecessary non-circular portions from the release film when processing the sheet into a circular shape during the production of the thermally conductive adhesive sheet, thereby improving sheet processability. Furthermore, because the resin (B) contains the highly flexible structural unit (4), it can relieve stress even when temperature changes occur, improving the reliability of the semiconductor device. Furthermore, the resin (B) contains the highly heat-resistant structural unit (5), which improves heat resistance during adhesion and reliability. Furthermore, because it has a structure represented by formula (6), it undergoes ring opening during adhesion to form a chemical bond with the adherend, improving adhesion and, as a result, reliability. Since the inclusion of resin (C) with a high Tg ensures sufficient sheetability, resin (B) with a low Tg can be included in the resin composition. Therefore, the effect of improving the reliability of semiconductor devices due to stress relaxation caused by the flexible skeleton of structural unit (4) in resin (B) can be fully demonstrated. Furthermore, by incorporating resin (B) instead of resin (A), the optimal melt viscosity is achieved, improving temporary adhesion, and since the Mw is 10,000 or greater, sufficient sheet processability can be ensured. Furthermore, as is clear from a comparison of the structure represented by structural units (1)-(2) and formula (3) with the structure represented by structural units (4)-(5) and formula (6), resin (B) is structurally similar to resin (A). Furthermore, resin (B) has a similar Mw to resin (C) compared to resin (A). As a result, the thermally conductive adhesive sheet of the present disclosure is more easily compatible with the resin composition than a sheet containing resin (A) and resin (C) but not resin (B), and as a result, it is thought that the sheet properties, sheet processability, and reliability of the semiconductor device are further improved.As described above, according to the thermally conductive adhesive sheet of the present disclosure, the synergistic interaction of these resins (A), (B), and (C) achieves a balance between the contradictory properties of improved sheet properties, sheet processability, and reliability of the semiconductor device.

[0020] [Resin Composition] The resin composition of the present disclosure contains the resin (A), the resin (B), the resin (C), and the silver particles (D). In addition to these components, the resin composition may also contain a silicon-containing triazine compound (E), a curing agent, a catalyst, a solvent, and other components.

[0021] <Resin (A)> Resin (A) is a resin that contains a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), both ends of which have a structure represented by the following formula (3), and has a weight average molecular weight (Mw) of 4,000 or less.

[0022]

[0023] Because resin (A) contains structural unit (1), the flexibility of the sheet is improved, thereby improving the reliability of the semiconductor device. Furthermore, because resin (A) contains structural unit (2), it has the effect of improving heat resistance and improving the reliability of the semiconductor device. Furthermore, because resin (A) has a structure represented by structural unit (3) at both ends, by reacting using a catalyst or the like, it has the effect of improving adhesion to the adherend during bonding and improving the heat resistance of the adhesive layer, thereby improving the reliability of the semiconductor device. Furthermore, the interaction with resin (B) improves adhesion and heat resistance, thereby improving the reliability of the semiconductor device.

[0024] In formula (1), r １ is 2 to 10. １ When r is in this range, the elasticity of the sheet can be reduced, and the reliability of the semiconductor device is improved. １ may be 4 to 8, or may be 4 to 6.

[0025] In formula (2), R １ and R ２are each independently a hydrogen atom or a methyl group. This reduces the melt viscosity of the sheet and improves the reliability of the semiconductor device. １ and R ２ At least one of R may be a hydrogen atom; １ and R ２ may be a hydrogen atom.

[0026] The content of the structural unit (1) may be 50 to 300 parts by mole, 70 to 200 parts by mole, 90 to 150 parts by mole, or 100 to 120 parts by mole, relative to 100 parts by mole of the structural unit (2).

[0027] The content of the structural unit (1) in the resin (A) relative to 100 parts by mole of the structural unit (2) can be measured by NMR, and can be calculated from the amount of the monomer derived from the structural unit (1) and the amount of the monomer derived from the structural unit (2).

[0028] The Mw of resin (A) is 4,000 or less. Having a Mw of 4,000 or less reduces the melt viscosity during temporary bonding, improving wettability with the adherend and improving the reliability of the semiconductor device. Alternatively, the Mw may be 400 or more. Having a Mw of 400 or more reduces the crosslink density of the cured resin, lowering the elastic modulus and enabling stress relaxation during thermal cycling, resulting in improved reliability. From this perspective, the Mw of resin (A) may be 400 to 4,000, 660 to 3,670, 660 to 3,240, or 1,090 to 2,380.

[0029] The epoxy equivalent of resin (A) may be 200 to 2,000 g / eq. If it is 200 g / eq or more, flexibility is improved without excessively increasing the crosslink density, allowing stress relaxation during thermal cycling and, as a result, improved reliability. If it is 2,000 g / eq or less, the number of OH groups after ring-opening of the epoxy groups increases, allowing for many chemical bonds with the adherend, improving adhesion during bonding and, as a result, improving reliability.

[0030] From this viewpoint, the epoxy equivalent of the resin (A) may be 300 to 1,750 g / eq, or 400 to 1,500 g / eq.

[0031] The resin (A) may be a resin (A1) containing a structural unit derived from a compound (9) represented by the following formula (9) and a structural unit derived from a compound (10) represented by the following formula (10):

[0032]

[0033] r in formula (9) １ and R in formula (10) １ and R ２ is as described above. Compound (9) represented by formula (9) may be 1,6-hexanediol diglycidyl ether. Compound (10) represented by formula (10) may be one or more compounds selected from the group consisting of bisphenol F, bisphenol E, and bisphenol A, or may be bisphenol F.

[0034] The resin (A) may be a copolymer of bisphenol F and 1,6-hexanediol diglycidyl ether.

[0035] Resin (A1) may or may not contain structural units other than the structural unit (9) derived from compound (9) and the structural unit (10) derived from compound (10), as long as the effects of the present disclosure are not impaired. The total content of the structural unit (9) derived from compound (9) and the structural unit (10) derived from compound (10) in 100% by mass of resin (A1) may be 80% by mass or more, 90% by mass or more, 95% by mass or more, or even 100% by mass.

[0036] The resin (A) may be a resin (A2) represented by the following formula (7).

[0037]

[0038] [In formula (7), r １ is an integer from 2 to 10, and R １ and R ２are each independently a hydrogen atom or a methyl group. １ , R １ , and R ２ The range of n is as described above. １ may be 1 to 10, 2 to 8, or 2 to 6 from the viewpoint of improving the sheet properties, sheet processability, and reliability of the semiconductor device.

[0039] Resin (A) is commercially available, and examples of such commercially available products include YX7105 (trade name, manufactured by Mitsubishi Chemical Corporation, an adduct of 1,6-hexanediol diglycidyl ether and bisphenol F, epoxy equivalent weight 480) and YX7110 (trade name, manufactured by Mitsubishi Chemical Corporation, an adduct of 1,6-hexanediol diglycidyl ether and bisphenol F, epoxy equivalent weight 1100).

[0040] <Resin (B)> Resin (B) is a resin that contains a structural unit (4) represented by the following formula (4) and a structural unit (5) represented by the following formula (5), both ends of which have a structure represented by the following formula (6), and has a weight-average molecular weight of 10,000 or more and a glass transition temperature (Tg) of 60°C or less.

[0041] [In formula (4), r ２ is an integer of 2 to 10. In formula (5), R ３ and R ４ are each independently a hydrogen atom or a methyl group.

[0042] Resin (B) contains structural unit (4), which improves the flexibility of the sheet and the reliability of the semiconductor device. Resin (B) also contains structural unit (5), which improves heat resistance and the reliability of the semiconductor device. Furthermore, resin (B) has a structure in which both ends are represented by structural unit (6), which, when reacted with a catalyst or the like, improves adhesion to the adherend during bonding and improves the heat resistance of the adhesive layer, thereby improving the reliability of the semiconductor device.

[0043] In formula (4), r ２ is 2 to 10. ２By setting r in this range, it is possible to reduce the elasticity of the sheet, and the reliability of the semiconductor device is improved. ２ may be 4 to 8, or may be 4 to 6.

[0044] In formula (5), R ３ and R ４ are each independently a hydrogen atom or a methyl group. This reduces the melt viscosity of the sheet and improves the reliability of the semiconductor device. ３ and R ４ At least one of R may be a hydrogen atom; ３ and R ４ may be a hydrogen atom.

[0045] The content of the structural unit (4) may be 50 to 300 parts by mole, 70 to 200 parts by mole, 90 to 150 parts by mole, or 100 to 120 parts by mole, relative to 100 parts by mole of the structural unit (5).

[0046] The content of the structural unit (4) in the resin (B) relative to 100 parts by mole of the structural unit (5) can be measured by NMR, and can be calculated from the amount of the monomer derived from the structural unit (4) and the amount of the monomer derived from the structural unit (5).

[0047] The Mw of resin (B) is 10,000 or more. By having it be 10,000 or more, sheet processability is improved. Furthermore, although there is no particular upper limit for the Mw, it may be 80,000 or less. When it is 80,000 or less, the melt viscosity is reduced during temporary bonding of the sheet, thereby improving the reliability of the semiconductor device. From this viewpoint, the Mw of resin (B) may be 10,000 to 80,000, 15,000 to 70,000, 20,000 to 60,000, or 30,000 to 50,000.

[0048] The structural unit (4) represented by formula (4) in resin (B) may be identical to the structural unit (1) represented by formula (1) in resin (A), and the structural unit (5) represented by formula (5) in resin (B) may be identical to the structural unit (2) represented by formula (2) in resin (A). When resins (A) and (B) have the same skeleton, the compatibility between resins (A) and (B) is improved, resulting in improved reliability of the semiconductor device. However, in the present disclosure, the structural unit (4) represented by formula (4) in resin (B) may be different from the structural unit (1) represented by formula (1) in resin (A), and the structural unit (5) represented by formula (5) in resin (B) may be different from the structural unit (2) represented by formula (2) in resin (A).

[0049] The glass transition temperature (Tg) of resin (B) is 60°C or lower. When the temperature is 60°C or lower, the melt viscosity during temporary adhesion of the sheet decreases, and the sheet adheres to the wafer without wrinkles or voids even at low temperatures, improving wafer lamination properties. Although the lower limit of Tg is not particularly specified, Tg may be -60°C or higher. When Tg is -60°C or higher, the temporary adhesion strength is improved, and the adhesiveness of the sheet and the reliability of the semiconductor device are improved. From this perspective, the Tg may be -60 to 60°C, -40 to 50°C, -30 to 40°C, or -20 to 30°C. The Tg can be measured by a DSC method, and more specifically, it can be measured by the method described in the examples.

[0050] The epoxy equivalent of resin (B) may be 5,000 to 40,000 g / eq. When it is 5,000 g / eq or more, the effect of improving the processability of the sheet is achieved. When it is 40,000 g / eq or less, the effect of reducing the melt viscosity and improving the temporary adhesiveness is achieved. From this viewpoint, the epoxy equivalent of resin (B) may be 6,000 to 20,000 g / eq, or may be 7,000 to 10,000 g / eq.

[0051] The resin (B) may be a resin (B1) containing a structural unit derived from a compound (11) represented by the following formula (11) and a structural unit derived from a compound (12) represented by the following formula (12):

[0052]

[0053] r in formula (11) ２ and R in formula (12) ３ and R ４ is as described above. The compound (11) represented by formula (11) may be 1,6-hexanediol diglycidyl ether. The compound (12) represented by formula (12) may be one or more compounds selected from the group consisting of bisphenol F, bisphenol E, and bisphenol A, or may be bisphenol F.

[0054] The compound (11) represented by formula (11) in the resin (B) may be the same as the compound (9) represented by formula (9) in the resin (A), and the compound (12) represented by formula (12) in the resin (B) may be the same as the compound (10) represented by formula (10) in the resin (A). In this way, when the resins (A) and (B) have the same skeleton, the compatibility between the resins (A) and (B) is improved, resulting in improved reliability.

[0055] Resin (B) may be a copolymer of bisphenol F and 1,6-hexanediol diglycidyl ether.

[0056] Resin (B1) may or may not contain structural units other than the structural unit (11) derived from compound (11) and the structural unit (12) derived from compound (12), as long as the effects of the present disclosure are not impaired. The total content of the structural unit (11) derived from compound (11) and the structural unit (12) derived from compound (12) in 100% by mass of resin (B1) may be 80% by mass or more, 90% by mass or more, 95% by mass or more, or even 100% by mass.

[0057] The resin (B) may be a resin (B2) represented by the following formula (8).

[0058]

[0059] [In formula (8), r ２ is an integer from 2 to 10, and R ３ and R ４are each independently a hydrogen atom or a methyl group. ２ , R ３ , and R ４ The preferred range of n is as described above. ２ From the viewpoint of improving the sheet processability and the reliability of the semiconductor device, the average molecular weight may be 20 to 190, 45 to 139, 70 to 127, or 92 to 115.

[0060] (Method for Producing Resin (B)) The method for producing resin (B) is not particularly limited as long as it contains the structural unit (4) represented by formula (4) and the structural unit (5) represented by formula (5), and a structure in which both terminals are represented by formula (6) is obtained. For example, resin (B) can be obtained by a two-stage method in which a bifunctional epoxy resin is reacted with a divalent hydroxyl group-containing compound.

[0061] The two-stage method for reacting a bifunctional epoxy resin with a divalent hydroxyl group-containing compound is not particularly limited and may be carried out by a conventional method. Examples of the method for producing resin (B) by the two-stage method include a method of reacting a compound (11) represented by the above formula (11) with a compound (12) represented by the above formula (12).

[0062] (Catalyst) A catalyst may be used in the synthesis of resin (B). The catalyst may be any compound with catalytic activity that promotes the reaction between an epoxy group and a phenolic hydroxyl group, an alcoholic hydroxyl group, or a carboxyl group. Examples of the catalyst include alkali metal compounds, organic phosphorus compounds, tertiary amines, quaternary ammonium salts, cyclic amines, and imidazoles. A single catalyst may be used, or two or more catalysts may be used in combination. The amount of catalyst used may typically be 0.001 to 1% by mass of the reaction solids. Here, the reaction solids refer to the total amount of reaction substrates other than the solvent in the reaction system.

[0063] (Solvent) Resin (B) may or may not use a solvent in the synthesis reaction step during its production. Any solvent capable of dissolving epoxy resins may be used. Examples include aromatic solvents, ketone solvents, amide solvents, and glycol ether solvents. Specific examples include benzene, toluene, acetone, methyl ethyl ketone (hereinafter sometimes referred to as "MEK"), cyclohexanone, N,N-dimethylformamide, N-methylpyrrolidone, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, and propylene glycol monomethyl ether acetate. These solvents may be used alone or in combination of two or more. The solids concentration in the synthesis reaction during the production of resin (B) may be 35 to 100% by mass. After completion of the reaction, the solvent may be removed, if necessary.

[0064] (Reaction Conditions) In producing the resin (B), the polymerization reaction between the bifunctional epoxy resin and the divalent hydroxyl group-containing compound may be carried out at a reaction temperature at which the catalyst used does not decompose, and the reaction temperature may be, for example, 50 to 230° C. The reaction time may usually be 1 to 12 hours.

[0065] <Resin (C)> The compound (C) is a resin having an epoxy group at its terminal, a weight average molecular weight of 10,000 to 80,000, and a glass transition temperature (Tg) of 65 to 160°C.

[0066] The resin composition of the present disclosure contains the resin (C), and thus the thermally conductive adhesive sheet can adequately retain its sheet shape.

[0067] The Mw of resin (C) is 10,000 to 80,000. Having a Mw of 10,000 or more improves sheet processability. Furthermore, having a Mw of 80,000 or less reduces the melt viscosity during temporary bonding of the sheet, thereby improving the reliability of the semiconductor device. From this perspective, the Mw of resin (C) may be 15,000 to 70,000, 20,000 to 60,000, or 30,000 to 50,000.

[0068] (Glass transition temperature (Tg)) The glass transition temperature (Tg) of the resin (C) is 65 to 160°C. When the temperature is 65°C or higher, the sheet property is improved. When the temperature is 160°C or lower, the melt viscosity at the time of adhesion of the sheet is reduced, and the reliability of the semiconductor device is improved. From this viewpoint, the Tg may be 70 to 160°C, 80 to 160°C, 85 to 160°C, or 90 to 160°C. The Tg can be measured by a DSC method, and in detail, it can be measured by the method described in the examples.

[0069] The epoxy equivalent of resin (C) may be 5,000 to 40,000 g / eq. When it is 5,000 g / eq or more, the effect of improving sheet properties is achieved. When it is 40,000 g / eq or less, the melt viscosity is reduced, improving adhesion during temporary bonding, and improving the adhesiveness of the sheet and the reliability of the semiconductor device. From this perspective, the epoxy equivalent of resin (C) may be 5,500 to 20,000 g / eq, 6,000 to 17,500 g / eq, or 6,500 to 15,000 g / eq.

[0070] Examples of the resin (C) include phenoxy resins having one or more skeletons selected from the group consisting of bisphenol A, bisphenol F, bisphenol S, bisphenolacetophenone, novolac, biphenyl, fluorene, dicyclopentadiene, norbornene, naphthalene, anthracene, adamantane, terpene, and trimethylcyclohexane. The resin (C) has an epoxy group at its terminal. The resin (C) may or may not have a structural unit derived from an alkanediol diglycidyl ether, but may not have one from the viewpoint of improving sheet processability.

[0071] Specific examples of resin (C) include "1256" and "4250" manufactured by Mitsubishi Chemical Corporation (both of which are phenoxy resins containing a bisphenol A skeleton); "YX8100" (phenoxy resin containing a bisphenol S skeleton) manufactured by Mitsubishi Chemical Corporation; "YX6954" (phenoxy resin containing a bisphenol acetophenone skeleton) manufactured by Mitsubishi Chemical Corporation; "FX280" and "FX293" manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.; and "YL7500BH30," "YX6954BH30," "YX7553," "YX7553BH30," "YL7769BH30," "YL6794," "YL7213," "YL7290," "YL7482," and "YL7891BH30" manufactured by Mitsubishi Chemical Corporation. <Silver particles (D)>

[0072] Silver particles (D) are a component for imparting good thermal conductivity to the resin composition and may be non-aggregated primary particles or secondary particles formed by aggregation of primary particles. The average particle diameter (D50) of the non-aggregated primary particles and secondary particles formed by aggregation of primary particles may be 0.5 to 5.0 μm, 0.5 to 3.0 μm, or 1.0 to 3.0 μm. An average particle diameter (D50) of 0.5 μm or more results in good dispersibility, while an average particle diameter (D50) of 5.0 μm or less improves thermal conductivity. The average particle diameter of the silver particles (D) refers to the particle diameter at which the cumulative volume is 50% in a particle size distribution measured using a laser diffraction particle size distribution analyzer (50% particle diameter D50), and can be specifically measured by the method described in the Examples.

[0073] When silver particles (D) are secondary particles formed by agglomeration of primary particles, the average primary particle diameter of the primary particles may be 10 to 100 nm, 10 to 50 nm, or 20 to 50 nm. Within these ranges, sufficient thermal conductivity can be obtained. The average primary particle diameter of the secondary particles formed by agglomeration of primary particles of silver particles (D) can be determined by number-averaging the particle diameters of the silver particles measured by observing the cross-sections of the silver particles with a field emission scanning electron microscope; specifically, it can be measured by the method described in the Examples.

[0074] The shape of the silver particles (D) is not particularly limited and may be, for example, spherical, flake-like, scale-like, etc. The shape of the silver particles (D) may be spherical.

[0075] The secondary particles of silver particles (D), formed by agglomeration of primary particles, may be solid or hollow. When the secondary particles formed by agglomeration of primary particles are hollow, the voids in the agglomerated particles make them prone to expansion in the temperature range of 150°C to 300°C. It is believed that the expansion of silver particles (D) during adhesion increases the opportunities for contact between silver particles, resulting in high thermal conductivity. In particular, thermally conductive adhesive sheets containing resins (B) and (C) as essential components have a low proportion of reactive functional groups, resulting in a small volume exclusion effect associated with resin cure shrinkage. Therefore, during curing of the thermally conductive sheet, silver particles are less likely to approach each other and the degree of freedom of the silver particles is reduced. Therefore, by including silver particles (D) containing voids in the agglomerated particles, a sheet with high thermal conductivity can be obtained.

[0076] The tap density of silver particles (D) is 4.0 g / cm ３ Above, 7.0g / cm ３ or less, and ３ Above, 7.0g / cm ３ The tap density of the silver particles (D) may be 4.0 g / cm or less. ３ If the thermal conductivity is 7.0 g / cm or more, the sheet can have a high thermal conductivity. ３ When the tap density of the silver particles (D) is not more than 1000 ppm, sedimentation of the silver particles (D) can be reduced during sheet production. The tap density of the silver particles (D) can be measured using a tap density measuring device.

[0077] The specific surface area of ​​silver particles (D) measured by the BET method is 0.5 m ２ / g or more, 1.5m ２ / g or less, and ２ / g or more, 1.2m ２ The specific surface area of ​​the silver particles (D) may be 0.5 m / g or less. ２ When the thickness is 1.5 m / g or more, the sheetability is improved. ２The specific surface area of ​​the silver particles (D) can be measured by a BET single-point method using a specific surface area measuring device based on nitrogen adsorption.

[0078] The content of silver particles (D) may be 40.0% by mass or more and 95.0% by mass or less, 45.0% by mass or more and 92.0% by mass or less, or 50.0% by mass or more and 90.0% by mass or less, based on the total amount of the resin composition. When the content of silver particles (D) is 40.0% by mass or more, the thermal conductivity of the sheet can be increased, and when it is 95.0% by mass or less, the sheet properties can be improved.

[0079] <Silicon-Containing Triazine Compound (E)> The resin composition of the present disclosure may further contain a silicon-containing triazine compound (E). The silicon-containing triazine compound (E) is a silicon-containing triazine compound having a triazine skeleton and containing a silicon atom in its side chain. When the resin composition of the present disclosure contains the silicon-containing triazine compound (E), the adhesive strength with the frame after moisture absorption treatment is improved. This is thought to be due to the high coordination ability of the triazine ring with the silicon chip. Furthermore, in consideration of the corrosion resistance of copper wires and the like, it is more preferable that the silicon-containing triazine compound (E) does not contain a sulfur atom.

[0080] The silicon-containing triazine compound (E) is preferably a compound (13) represented by the following general formula (13).

[0081]

[0082] In the formula, a is an integer of 3 to 10, and may be an integer of 3 or 4. b is an integer of 0 to 2. R ５ and R ６ are each independently a halogen atom, an amino group, a hydroxyl group, an alkylimino group, an arylimino group, or an iminoalkylsilyl group, and may be a halogen atom. The halogen atom may be chlorine or bromine. R ７ is an alkyl group or an alkoxy group. ８ is an alkoxy group. ７is preferably an alkyl group or alkoxy group having 1 to 4 carbon atoms, and examples of the alkyl group include a methyl group, an ethyl group, and a propyl group, and examples of the alkoxy group include a methoxy group, an ethoxy group, and a propoxy group. ８ is preferably an alkoxy group having 1 to 4 carbon atoms, and more preferably, for example, a methoxy group, an ethoxy group, a propoxy group, or the like.

[0083] R in compound (13) ５ and R ６ When is an amino group, the coordinating ability to the silicon chip is increased, thereby improving the adhesion to bare silicon.

[0084] The silicon-containing triazine compound (E) can be produced, for example, by reacting an organosilicon compound containing an aminoalkylsilyl group, represented by the following general formula (15), with at least one halogen atom bonded to a cyanuric halide, represented by the following general formula (14). The other two halogen atoms on the cyanuric halide can be reacted with an aminoalkylsilicon compound or can remain attached to the triazine ring. Furthermore, one or both of these two remaining halogen atoms can be reacted with water, ammonia, or an organic primary amine.

[0085]

[0086] R in formula (14) and formula (15) ５ , R ６ , R ７ , a, and b are R in formula (13). ５ , R ６ , R ７ , R ８ , a, and b. In formula (14), R ９ is a halogen atom, an amino group, a hydroxyl group, an alkylimino group, an arylimino group, or an iminoalkylsilyl group, and may be a halogen atom. The halogen atom may be chlorine or bromine.

[0087] The organosilicon compound represented by general formula (15) may be an aminoalkylalkoxysilane, an aminoalkylalkylsilane, or an aminoalkylpolysiloxane. More specifically, it may be γ-aminopropylmethyldiethoxysilane, γ-aminopropylethyldiethoxysilane, γ-aminopropylphenyldiethoxysilane, γ-aminopropyltrimethylsilane, γ-aminopropylphenyldimethylsilane, deltaaminobutylthienyldiethoxysilane, deltaaminobutylphenyldiethoxysilane, or omegaaminohexyltriethylsilane. The reaction between the cyanuric halide and the aminoalkylsilicon compound may be carried out in the presence of an inert gas in an inert liquid organic solvent. The inert liquid organic solvent may be diethyl ether, toluene, benzene, acetone, ethanol, or carbon tetrachloride.

[0088] <Curing Agent> The resin composition of the present disclosure may further contain a curing agent, or may not contain a curing agent. However, a curing agent may be included to improve curability. The curing agent is not particularly limited, and examples thereof include aliphatic amines, aromatic amines, dicyandiamide, dihydrazide compounds, acid anhydrides, and phenolic resins. Examples of aromatic amines include diaminodiphenylmethane, m-phenylenediamine, 4,4'-diaminodiphenylsulfone, 3,3'-diaminodiphenylsulfone, diethyltoluenediamine, trimethylenebis(4-aminobenzoate), polytetramethyleneoxide-di-p-aminobenzoate, and 4,4'-diamino-3,3'-diethyldiphenylmethane. Examples of dihydrazide compounds include carboxylic acid dihydrazides such as adipic acid dihydrazide, dodecanoic acid dihydrazide, isophthalic acid dihydrazide, and p-oxybenzoic acid dihydrazide. Examples of acid anhydrides include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, endomethylenetetrahydrophthalic anhydride, dodecenylsuccinic anhydride, a reaction product of maleic anhydride and polybutadiene, a copolymer of maleic anhydride and styrene, etc. From the viewpoints of adhesiveness after curing and reliability of the semiconductor device, the curing agent may be an aromatic diamine containing a sulfonyl group.

[0089] When the resin composition of the present disclosure contains a curing agent, the content of the curing agent may be 0.5 to 50% by mass, 1 to 30% by mass, or 1 to 15% by mass relative to the resin (A) from the viewpoint of reliability.

[0090] <Catalyst (Curing Accelerator)> The resin composition of the present disclosure may further contain a curing accelerator (catalyst), or may not contain a curing accelerator (catalyst), but may contain a curing accelerator (catalyst) to accelerate curing. Specific examples of the curing accelerator include imidazoles, triphenylphosphine or tetraphenylphosphine and salts thereof, and amine compounds such as diazabicycloundecene and salts thereof. The curing accelerator may be, for example, an imidazole compound such as 2-methylimidazole, 2-ethylimidazole, 2-phenylimidazole, 2-phenyl-4-methylimidazole, 2-phenyl-4-methyl-5-hydroxymethylimidazole, 2-phenyl-4,5-dihydroxymethylimidazole, 2-C11H23-imidazole, or an adduct of 2-methylimidazole and 2,4-diamino-6-vinyltriazine, or an imidazole compound having a melting point of 180°C or higher. From the viewpoint of improving heat resistance, the curing accelerator may be an imidazole containing no active hydrogen, such as 1-benzyl-2-phenylimidazole, 1-benzyl-2-methylimidazole, or 1,2-dimethylimidazole.

[0091] When the resin composition of the present disclosure contains a curing accelerator, the content of the curing accelerator may be 0.5 to 30% by mass, or 1.0 to 15% by mass, relative to the resin (A) from the viewpoint of storage stability of the sheet.

[0092] <Solvent (Diluent)> The resin composition of the present disclosure may contain a diluent or may not contain a diluent. However, from the viewpoint of workability, a diluent may be further contained. Examples of diluents include methyl ethyl ketone, toluene, butyl carbitol, cellosolve acetate, ethyl cellosolve, butyl cellosolve, butyl cellosolve acetate, butyl carbitol acetate, diethylene glycol dimethyl ether, diacetone alcohol, cyclohexanone, N-methyl-2-pyrrolidone (NMP), dimethylformamide, N,N-dimethylacetamide (DMAc), γ-butyrolactone, 1,3-dimethyl-2-imidazolidinone, and 3,5-dimethyl-1-adamantanamine (DMA). These may be used alone or in combination of two or more.

[0093] When the resin composition of the present disclosure contains a diluent, the content of the diluent may be 3 parts by mass or more and 40 parts by mass or less, 4 parts by mass or more and 38 parts by mass or less, or 5 parts by mass or more and 36 parts by mass or less, relative to 100 parts by mass of the solid content of the resin composition. When the content of the diluent is 3 parts by mass or more, the viscosity of the resin composition can be reduced by dilution, and when it is 40 parts by mass or less, the amount of solvent remaining in the sheet is small, and the generation of voids when the resin composition is cured can be reduced.

[0094] <Other Components> In addition to the above-described components, the resin composition of the present disclosure may contain, as necessary, various additives that are generally added to compositions of this type, such as coupling agents, antifoaming agents, surfactants, colorants (pigments, dyes), various polymerization inhibitors, antioxidants, inorganic ion exchangers, and the like, as long as the effects of the present invention are not impaired. Each of these additives may be used alone or in combination of two or more.

[0095] Examples of the coupling agent include silane coupling agents such as epoxysilane, mercaptosilane, aminosilane, alkylsilane, ureidosilane, vinylsilane, and sulfidosilane, as well as titanate coupling agents, aluminum coupling agents, and aluminum / zirconium coupling agents. Examples of the colorant include carbon black. Examples of the inorganic ion exchanger include hydrotalcite.

[0096] <Content of each component in the resin composition> The content of resin (A) may be 20 to 80 mass% relative to 100 mass% of the total amount of resin (A), resin (B), and resin (C). A content of 20 mass% or more improves the reliability of the semiconductor device, while a content of 80 mass% or less improves sheet processability. From these viewpoints, the content of resin (A) may be 25 to 75 parts by mass, 30 to 70 parts by mass, or 35 to 65 parts by mass.

[0097] The content of resin (B) may be 10 to 60 mass% relative to the total amount of resins (A), (B), and (C), which is 100 mass%. Within this range, both sheet processability and a high level of semiconductor device reliability can be achieved. From this perspective, the content of resin (B) may be 10 to 50 mass parts, or 15 to 45 mass parts.

[0098] The content of resin (C) may be 8 to 60% by mass relative to the total amount of resins (A), (B), and (C), which is 100% by mass. A content of 8% by mass or more improves sheet properties and sheet processability, while a content of 60% by mass or less improves the reliability of the semiconductor device. From this perspective, the content of resin (C) may be 10 to 50 parts by mass or less, 10 to 40 parts by mass or less, or 10 to 30 parts by mass or less.

[0099] The content of the resin (B) relative to 100 parts by mass of the resin (A) may be 12.5 to 250 parts by mass. Within this range, both sheet processability and a high level of reliability of the semiconductor device can be achieved. From this viewpoint, the content may be 12.5 to 240 parts by mass, 12.5 to 230 parts by mass, or 15 to 210 parts by mass.

[0100] The total content of resin (A) and resin (B) in 100% by mass of the total amount of resin (A), resin (B), and resin (C) may be 20 to 95% by mass. Within this range, both sheet processability and a high level of semiconductor device reliability can be achieved. From this perspective, the content may be 30 to 93 parts by mass, 35 to 93 parts by mass, or 40 to 92 parts by mass.

[0101] The total content of resin (B) and resin (C) in a total of 100% by mass of resin (A), resin (B), and resin (C) may be 10 to 90% by mass. Within this range, both sheet processability and a high level of semiconductor device reliability can be achieved. From this perspective, the content may be 15 to 90 parts by mass, 15 to 85 parts by mass, or 18 to 82 parts by mass.

[0102] The content of the resin (C) may be 5 to 200 parts by mass relative to 100 parts by mass of the total of the resins (A) and (B). Within this range, both sheet processability and a high level of reliability of the semiconductor device can be achieved. From this viewpoint, the content may be 5 to 180 parts by mass, 7 to 160 parts by mass, or 8 to 150 parts by mass.

[0103] The content of the silver particles (D) in 100% by mass of the solid content of the resin composition may be 70 to 95% by mass. When the content is 70% by mass or more, a sheet with high thermal conductivity can be obtained. When the content is 95% by mass or less, a sheet with excellent sheet properties, sheet processability, and reliability for semiconductor devices can be obtained. The content may be 75 to 93% by mass, 80 to 92% by mass, or 85 to 91% by mass.

[0104] The total amount of resin (A), resin (B), and resin (C) in 100% by mass of the resin component of the resin composition may be 60 to 100% by mass, or 80 to 100% by mass, from the viewpoint of obtaining a sheet with high sheet properties, sheet processability, and reliability for semiconductor devices.

[0105] The total amount of the resin (A), the resin (B), the resin (C), and the silver particles (D) in 100% by mass of the solid content of the resin composition may be 60 to 100% by mass or may be 90 to 100% by mass, from the viewpoints of sheet properties, sheet processability, and obtaining a sheet with high reliability for semiconductor devices.

[0106] When the resin composition contains a silicon-containing triazine compound (E), the content of the silicon-containing triazine compound (E) may be 0.01 to 8% by mass relative to a total of 100 parts by mass of the resin (A), the resin (B), the resin (C), and the silver particles (D). When the content is 0.01 parts by mass or more, sufficient adhesive strength is obtained after moisture absorption treatment for semiconductor insert components. When the content is 5% by mass or less, the adhesive strength is improved and a decrease in thermal conductivity is suppressed. From this perspective, the content of the silicon-containing triazine compound (E) may be 0.01 to 5% by mass relative to a total of 100 parts by mass of the resin (A), the resin (B), the resin (C), and the silver particles (D). The total amount of the resin (A), the resin (B), the resin (C), the silver particles (D), and the silicon-containing triazine compound (E) in 100% by mass of the solid content of the resin composition may be 60 to 100% by mass, 90 to 100% by mass, or 95 to 100% by mass, from the viewpoints of sheet properties, sheet processability, and obtaining a highly reliable sheet for semiconductor devices.

[0107] [Method for producing thermally conductive adhesive sheet] The thermally conductive adhesive sheet of the present disclosure can be produced by forming a resin composition into a sheet. For example, a method for producing a thermally conductive adhesive sheet of the present disclosure includes mixing resin (A), resin (B), resin (C), silver particles (D), and various other components that are added as needed to form a resin composition, and then forming the resin composition into a sheet. The thermally conductive adhesive sheet of the present disclosure may be formed on a release film.

[0108] The resin composition can be prepared by thoroughly mixing resin (A), resin (B), resin (C), silver particles (D), and various other components that are blended as needed, using a disperse mixer, kneader, planetary mixer, etc. The resin (A), resin (B), resin (C), silver particles (D), and various other components that are blended as needed can be those described above.

[0109] Next, the resin composition is coated on a release film and dried to form a sheet. Examples of coating methods include known methods such as gravure coating, die coating, comma coating, lip coating, cap coating, and screen printing. The drying temperature may be 70°C or higher and 120°C or lower, or 80°C or higher and 100°C or lower. A drying temperature of 70°C or higher reduces the amount of solvent remaining in the sheet, reducing the occurrence of voids when curing the resin composition. A drying temperature of 120°C or lower improves film-forming properties and sheet properties. A specific example of a coating device is the μ-Coat 350 manufactured by Yasui Seiki Co., Ltd.

[0110] As the release film, a plastic film having a release agent layer on one or both sides thereof, such as polyethylene, polypropylene, polyester, polycarbonate, polyarylate, polyacrylonitrile, etc. is used. From the viewpoint of sheet processability, the thickness of the release film is usually 10 μm or more and 100 μm or less, and may be 20 μm or more and 60 μm or less.

[0111] The thickness of the thermally conductive adhesive sheet may be 10 μm or more and 100 μm or less, or 10 μm or more and 50 μm or less. By making the thickness of the thermally conductive adhesive sheet 10 μm or more, the sheet processability of the sheet is stabilized, and by making the thickness 100 μm or less, stickiness due to residual solvent in the sheet can be reduced.

[0112] [Content of each component in the thermally conductive adhesive sheet] The composition of the thermally conductive adhesive sheet is the composition obtained by removing the solvent from the composition of the resin composition. The content of each component in the thermally conductive adhesive sheet is the content of each component in the solid content of the resin composition.

[0113] [Physical properties of thermally conductive adhesive sheet] (Thermal conductivity) The thermal conductivity of the thermally conductive adhesive sheet may be 5 W / m·K or more. When it is 5 W / m·K or more, the thermal conductivity of the sheet is high. There is no particular upper limit, but it may be 30 W / m·K or less. By setting it to 30 W / m·K or less, the sheet shape can be maintained even when the silver particles (D) content is high. From these viewpoints, the thermal conductivity of the thermally conductive adhesive sheet may be 10 W / m·K or more, or may be 15 W / m·K or more. The thermal conductivity of the sheet can be measured by the method described in the examples.

[0114] (Elastic Modulus) The elastic modulus of the thermally conductive adhesive sheet may be 15 GPa (25°C) or less. If it is 15 GPa (25°C) or less, stress relaxation is possible, thereby improving the reliability of the semiconductor device. From these viewpoints, the elastic modulus of the thermally conductive adhesive sheet may be 10 GPa (25°C) or less, 8 GPa (25°C) or less, or 5 GPa (25°C) or less. The elastic modulus of the sheet can be measured by the method described in the examples.

[0115] (Melt Viscosity) The melt viscosity of the thermally conductive adhesive sheet may be 500 to 5,000 Pa·s (120°C). If it is 500 Pa·s (120°C) or higher, the formation of fillets during temporary bonding can be reduced, and if it is 5,000 Pa·s (120°C) or lower, the adhesiveness during temporary bonding can be improved. From these perspectives, the melt viscosity of the thermally conductive adhesive sheet may be 1,000 to 4,000 Pa·s (120°C), 1,500 to 3,500 Pa·s (120°C), or 1,500 to 2,000 Pa·s (120°C). The melt viscosity of the sheet can be measured by the method described in the examples.

[0116] (Adhesion Area Ratio) The adhesion area ratio of the thermally conductive adhesive sheet may be 95% or more. When the adhesion area ratio is 95% or more, temporary adhesion is good. From this viewpoint, the adhesion area ratio may be 98% or more, or may be 99% or more.

[0117] (Temporary adhesive strength) The temporary adhesive strength of the thermally conductive adhesive sheet may be 1.0 N or more. If it is 1.0 N or more, the adhesive strength with the support member is high, and the transport of the support member is excellent. From these viewpoints, the temporary adhesive strength of the thermally conductive adhesive sheet may be 2.0 N or more, 3.0 N or more, or 3.5 N or more. There is no particular upper limit. The temporary adhesive strength of the sheet can be measured by the method described in the examples.

[0118] (Adhesive strength) The adhesive strength of the thermally conductive adhesive sheet may be 10 N or more. If it is 10 N or more, the adhesiveness to the support member is good and reliability is improved. From these viewpoints, the adhesive strength of the thermally conductive adhesive sheet may be 20 N or more, 25 N or more, or 30 N or more. There is no particular upper limit. The adhesive strength of the sheet can be measured by the method described in the examples.

[0119] [Semiconductor element with thermally conductive adhesive sheet and manufacturing method thereof] The semiconductor element with thermally conductive adhesive sheet of the present disclosure is a semiconductor element with a thermally conductive adhesive sheet, comprising a semiconductor element and an adhesive layer bonded and laminated onto the semiconductor element, wherein the adhesive layer is the thermally conductive adhesive sheet. The manufacturing method of the semiconductor element with thermally conductive adhesive sheet of the present disclosure can be manufactured by laminating a semiconductor wafer and the thermally conductive adhesive sheet to obtain the semiconductor wafer with the thermally conductive adhesive sheet, and singulating the semiconductor wafer with the thermally conductive adhesive sheet.

[0120] The semiconductor element with the thermally conductive adhesive sheet of the present disclosure can be manufactured, for example, by laminating the thermally conductive adhesive sheet onto a silicon wafer or the like under conditions of a temperature of 50° C. or higher and 80° C. or lower, a pressure of 0.1 MPa or higher and 1 MPa or lower, and a heating and pressing time of 0.1 minute or longer and 1 minute or shorter, and then dicing the silicon wafer into individual pieces.

[0121] The elements include semiconductor elements such as ICs, LSIs, diodes, thyristors, and transistors.

[0122] [Semiconductor device and manufacturing method thereof] The semiconductor device of the present disclosure comprises a support member and a semiconductor element mounted on the support member via an adhesive layer, the adhesive layer being a cured product of the thermally conductive adhesive sheet described above. The semiconductor device of the present disclosure can be manufactured by arranging the support member, the thermally conductive adhesive sheet, and the semiconductor element in this order and curing the thermally conductive adhesive sheet.

[0123] The semiconductor device of the present disclosure can be manufactured by heating and pressing an element with a thermally conductive sheet to a support member such as a copper frame under conditions of a temperature of 80°C or higher and 200°C or lower, a pressure of 0.1 MPa or higher and 5 MPa or lower, and a heating and pressing time of 0.1 minute or higher and 1 minute or shorter, and then further heating and curing under conditions of 150°C or higher and 200°C or lower for 0.5 minutes or higher and 2 hours or shorter.

[0124] Examples of the support member include metal substrates such as copper frames, aluminum, and iron plates, ceramic substrates, and glass epoxy substrates. Examples of the semiconductor element include ICs, LSIs, diodes, thyristors, and transistors.

[0125] Next, the present disclosure will be specifically described using examples, but the present disclosure is not limited to these examples in any way.

[0126] <Raw Materials, etc.> The following were used as raw materials, etc. (Resin (A)) YX7105: Trade name, manufactured by Mitsubishi Chemical Corporation, adduct type of 1,6-hexanediol diglycidyl ether and bisphenol F (resin (B2) represented by formula (7)), Mw: 1090, epoxy equivalent: 480 YX7110: Trade name, manufactured by Mitsubishi Chemical Corporation, adduct type of 1,6-hexanediol diglycidyl ether and bisphenol F (resin (B2) represented by formula (7)), Mw: 2,300, epoxy equivalent: 1,100 (Resin (A')) YL980: Trade name, manufactured by Mitsubishi Chemical Corporation, bisphenol A type, Mw: 370, epoxy equivalent: 185

[0127] (Resin (B)) Resin produced in Synthesis Example 1 described later (1,6-hexanediol diglycidyl ether and bisphenol F adduct (resin (B2) represented by formula (8)), epoxy equivalent 9,000, Mw 40,000, Tg 15°C)

[0128] (Resin (C)) YX6954BH30: Trade name, manufactured by Mitsubishi Chemical Corporation, Mw 38,000, Tg 135°C, bisphenol acetophenone type, epoxy equivalent 12,000 YX7553BH30: Trade name, manufactured by Mitsubishi Chemical Corporation, Mw 40,000, Tg 155°C, modified bisphenol type epoxy resin, epoxy equivalent 11,000 jER1256B40: Trade name, manufactured by Mitsubishi Chemical Corporation, Mw 40,000, Tg 95°C, bisphenol A type, epoxy equivalent 7,000

[0129] (Silver particles (D)) Hollow silver particles D1: Silver particles having hollows produced by Synthesis Example 2 described later (average particle size of primary particles: 20 nm, average particle size of secondary particles: 1.1 μm, tap density: 5.2 g / cm ３, Specific surface area: 1.2m ２ / g) Solid silver particles D2: SL01 (trade name, manufactured by Mitsui Mining & Smelting Co., Ltd., irregular shape, average particle diameter: 1.23 μm, tap density: 5.6 g / cm ３ , specific surface area: 0.68m ２ / g)

[0130] (Silicon-containing triazine compound (E)) 2,4-diamino-6-(3-triethoxysilylpropylamino)-1,3,5-triazine produced in Synthesis Example 3

[0131] (Curing agent) Dicyandiamide (manufactured by Mitsubishi Chemical Corporation, trade name: DICY-7) (Catalyst (curing accelerator)) Imidazole compound (2-phenyl-4-methyl-5-hydroxymethylimidazole, manufactured by Shikoku Chemical Industry Co., Ltd., trade name: Curesol 2P4MHZ-PW) (Solvent) Cyclohexanone (manufactured by Kanto Chemical Co., Ltd.)

[0132] <Evaluation of Physical Properties of Silver Particles (D)> The physical properties of silver particles (D) were evaluated as follows. [Average Particle Diameter of Hollow Particles] The average particle diameter of primary particles was determined by averaging the particle diameters of 200 silver particles measured by observing the cross sections of spherical silver particles cut with a focused ion beam (FIB) device (JEM-9310FIB manufactured by JEOL Corporation) with a field emission scanning electron microscope (FE-SEM) (JSM-6700F manufactured by JEOL Corporation). The average particle diameter of secondary particles was determined from the particle diameter at which the cumulative volume is 50% (50% particle diameter D50) in the particle size distribution measured with a laser diffraction particle size distribution analyzer (manufactured by Shimadzu Corporation, trade name: SALAD-7500nano).

[0133] [Average particle size of solid particles] The average particle size of solid particles was determined from the particle size at which the cumulative volume was 50% (50% particle size D50) in the particle size distribution measured using a laser diffraction particle size distribution analyzer (manufactured by Shimadzu Corporation, product name: SALAD-7500 nano).

[0134] [Tap Density] The tap density (TD) was measured using a tap density measuring device (Tap-Pak Volumeter, manufactured by Thermo Scientific) as the mass per unit volume (unit: g / cm) of silver particles in a vibrated container. ３) was measured.

[0135] [Specific Surface Area] After degassing at 60° C. for 10 minutes, the specific surface area was measured by the BET single-point method using nitrogen adsorption using a specific surface area measuring device (Monosorb, manufactured by QuantaChrome).

[0136] <Evaluation of Physical Properties of Resins> The physical properties of resins (A) to (C) were evaluated as follows. [Weight average molecular weight (Mw)] Using Tosoh Corporation's "HLC-8320GPC EcoSEC (registered trademark)", a calibration curve was created using standard polystyrenes such as TSKStandard Polystyrene: F-128 (Mw 1,090,000, Mn 1,030,000), F-10 (Mw 106,000, Mn 103,000), F-4 (Mw 43,000, Mn 42,700), F-2 (Mw 17,200, Mn 16,900), A-5000 (Mw 6,400, Mn 6,100), A-2500 (Mw 2,800, Mn 2,700), and A-300 (Mw 453, Mn 387), and the weight average molecular weight and number average molecular weight were measured as polystyrene equivalent values. Column: "TSKGEL Super HM-H + H5000 + H4000 + H3000 + H2000" manufactured by Tosoh Corporation Eluent: Tetrahydrofuran Flow rate: 0.5 ml / min Detection: UV (wavelength 254 nm) Temperature: 40 ° C. Sample concentration: 0.1 mass% Injection amount: 10 μl [Glass transition temperature (Tg)] The glass transition temperature of the resin was measured using a differential scanning calorimeter "DSC7020" manufactured by SII Nanotechnology Co., Ltd., by heating from 30 to 200 ° C. at a rate of 10 ° C. / min. The glass transition temperature here was measured based on the "midpoint glass transition temperature: Tmg" described in JIS K7121:2012 "Method for measuring transition temperature of plastics." [Epoxy equivalent] Measured in accordance with JIS K7236:2009 and expressed as a solids equivalent value.

[0137] Synthesis Example 1 (Production of Resin (B)) 100 parts by mass of 1,6-hexanediol diglycidyl ether, 83.7 parts by mass of bisphenol F, 0.63 parts by mass of a 27% by mass aqueous solution of tetraammonium hydroxide (catalyst), and 67.94 parts by mass of cyclohexanone (solvent) were placed in a pressure-resistant reaction vessel equipped with a stirrer, and a reaction was carried out for 7 hours at 145°C under a nitrogen gas atmosphere. The solvent was removed from the reaction product by a standard method, and the resulting epoxy resin was then analyzed.

[0138] Synthesis Example 2 (Production of Silver Particles (Hollow Particles)) 40 g of silver nitrate was dissolved in 10 L of ion-exchanged water to prepare a silver nitrate aqueous solution. 203 mL of 26% by mass aqueous ammonia was added to the solution and stirred to obtain a silver ammine complex aqueous solution. The solution was brought to a liquid temperature of 10°C, and 28 mL of a 20% by mass aqueous hydrazine monohydrate solution was added dropwise over 60 seconds while stirring to precipitate silver particles, thereby obtaining a silver particle-containing slurry. 1% by mass of oleic acid relative to the amount of silver was added to the slurry and stirred for 10 minutes. The slurry was filtered, and the residue was washed with water and methanol and dried at 60°C in a vacuum atmosphere for 24 hours, resulting in an average particle size of primary particles of 20 nm, an average particle size of secondary particles of 1.1 μm, and a tap density of 5.2 g / cm. ３ , specific surface area: 1.2m ２ When the cross section of the obtained silver particles was observed with a field emission scanning electron microscope (FE-SEM) (JSM-6700F manufactured by JEOL Corporation), it was confirmed that the silver particles were hollow particles having a void in the center.

[0139] Synthesis Example 3 (Preparation of Silicon-Containing Triazine Compound (E)) A 250 mL three-neck flask was equipped with a stirrer, a dropping funnel, a condenser, and a thermometer. 100 mL of anhydrous diethyl ether and 28.4 g of cyanuric chloride were added to the three-neck flask, and the mixture was stirred and cooled to 0°C. 50 mL of anhydrous diethyl ether solution containing 22.1 g of γ-aminopropyltriethoxysilane and 10.1 g of triethylamine was added dropwise to the solution in the flask at 0°C over 30 minutes, followed by stirring for 30 minutes. The precipitated triethylamine hydrochloride was filtered under a nitrogen atmosphere, and ether was distilled from the filtrate at room temperature under reduced pressure. The residue was fractionally distilled to obtain 10 g of 2,4-dichloro-6-(3-triethoxysilylpropylimino)-triazine. At approximately 0°C, a mixture of 50 g of 2,4-dichloro-6-(3-triethoxysilylpropylimino)-triazine saturated with anhydrous ammonia and 500 mL of absolute ethanol was placed in a 3-liter stainless steel autoclave. The autoclave was sealed and rocked at approximately 130°C for 10 hours. After cooling to room temperature, the reaction mixture was removed from the autoclave with approximately 100 mL of absolute ethanol. The ethanol was removed by distillation under reduced pressure at room temperature, and the residue was then extracted with a total volume of 100 mL of dry chloroform. The chloroform was removed under reduced pressure, yielding 37.5 g of 2,4-diamino-6-(3-triethoxysilylpropylamino)-1,3,5-triazine.

[0140] [Examples 1 to 14 and Comparative Examples 1 to 5] (1) Preparation of Resin Compositions The components of the types and amounts listed in Tables 1 and 2 were mixed at 25°C using a planetary mixer (Thinky Corporation, model number: ARV-310) to prepare resin compositions. In Tables 1 and 2, blank spaces indicate no blending. (2) Preparation of Thermally Conductive Adhesive Sheets Using a μ-Coat 350 manufactured by Yasui Seiki Co., Ltd., the resin composition was applied to one release surface of a release film (material: polyester, manufactured by Toyobo Co., Ltd., product name: TN-200, thickness: 25 μm) by gravure coating to form a thermally conductive adhesive sheet with a thickness of 20 μm. The drying conditions were a temperature of 80°C and a speed of 1 m / min.

[0141] <Evaluation items>

[0142] (1) Thermal conductivity (cured at 200 ° C) A thermally conductive adhesive sheet was laminated, the thickness was adjusted by lamination at 70 ° C, and a sample was cut out to a size of 1 cm length x 1 cm width x 200 μm thickness. The sample was cured at 200 ° C for 1 hour, and the thermal conductivity of the sample was measured by the laser flash method in accordance with JIS R 1611:1997 using a thermal conductivity meter (manufactured by Advance Riko Co., Ltd., device name: TC7000). A thermal conductivity of 15 W / m K or more was considered acceptable.

[0143] (2) Elastic Modulus A thermally conductive adhesive sheet was laminated, the thickness was adjusted by laminating at 70°C, and a sample was cut out to a size of 5.5 cm length x 1 cm width x 200 μm thickness. The sample was cured at 200°C for 1 hour, and the sample was heated from -50°C to 300°C at a rate of 10°C per minute using a thermomechanical analyzer (manufactured by Seiko Instruments Inc., device name: DMA) to measure the elastic modulus at 25°C.

[0144] (3) Sheet Properties The resin composition was coated onto a release film in a length of 30 m, dried, and formed into a sheet. The formed thermally conductive adhesive sheet was wound up around a take-up core in a coating machine with a tension of 16 N. The wound roll sheet was released, and the surface of the sheet was pressed with a thumb with a force of approximately 50 N to check for fingerprint residue and stickiness, and the sheet properties were evaluated according to the following criteria. Evaluation Criteria AA: No fingerprint residue or stickiness after touching with a finger, and the thermally conductive adhesive sheet did not stick to the release film on the opposite side. A: Fingerprint residue after touching the sheet surface, but the thermally conductive adhesive sheet did not stick to the release film on the opposite side. B: Fingerprint residue and stickiness after touching with a finger, and the thermally conductive adhesive sheet stuck to the release film on the opposite side in some areas.

[0145] (4) Melt Viscosity The thermally conductive adhesive sheets were stacked and laminated at 70°C to obtain a sheet with a thickness of 500 μm. The obtained sheet was cut into a 1 cm x 1 cm measurement sample. The melt viscosity was measured using an ARES-G2 (manufactured by TA Instruments). The measurement conditions were a temperature increase of 10°C per minute from room temperature to 200°C, and the viscosity at 120°C was taken as the melt viscosity.

[0146] (5) Adhesion Area Ratio Dicing tape (F-0805TA, manufactured by Denka Co., Ltd.) was laminated onto the thermally conductive adhesive sheet with release film obtained in each example and comparative example using a laminating roll machine (MCK Corporation, machine name: MRK-500JK) to obtain a laminated sheet in which the release film, thermally conductive adhesive sheet, and dicing tape were laminated in this order. Next, the release film was peeled off and an 8-inch silicon wafer was laminated onto the exposed thermally conductive adhesive sheet surface using a wafer laminator (Omiya Kogyo Co., Ltd., machine name: OTM-800DWP) at 70 ° C, a table speed of 10 mm / sec, and a pressure of 1 MPa. This silicon wafer was cut into 4 mm x 4 mm pieces using a dicing saw (Disco Corporation, machine name: OTM-800DWP). Using a die bonder (Besi, device name: 2200 EVO-plus), the individualized elements were heat-pressurized and pressure-bonded to a solid copper frame at 120°C for 1 second at a pressure of 1 MPa to obtain a bonded sample for measuring the bonded area ratio. The obtained sample was observed using an ultrasonic microscope (sonoscan, device name: C-SAM GEN6) to calculate the bonded area ratio. Bonded area ratio = bonded area of ​​bonded body / semiconductor element area x 100 - Evaluation criteria - AA: 99% or more A: 95% or more but less than 99% B: Less than 95%

[0147] (6) Temporary Adhesion Strength Dicing tape (Denka F-0805TA) was laminated onto the thermally conductive adhesive sheet with release film obtained in each example and comparative example using a laminating roll machine (MCK MRK-500JK) to obtain a laminated sheet in which the release film, thermally conductive adhesive sheet, and dicing tape were laminated in that order. Next, the release film was peeled off and an 8-inch silicon wafer was laminated onto the exposed thermally conductive adhesive sheet surface using a wafer laminator (Omiya Kogyo Co., Ltd. OTM-800DWP) at 70 ° C, a table speed of 10 mm / sec, and a pressure of 1 MPa. This silicon wafer was then cut into 4 mm x 4 mm pieces using a dicing saw (Disco OTM-800DWP). Using a die bonder (Besi, model 2200 EVO-plus), the individualized elements were heat-pressurized and pressed to a solid copper frame at 120°C for 1 second at a pressure of 1 MPa to obtain a sample for evaluating temporary adhesion.The temporary adhesion strength of the obtained sample at 25°C was measured using a mount strength measuring device (Nordson, model DAGE-4000plus).

[0148] (7) Adhesion Strength An individual element prepared in the same manner as in the temporary adhesion evaluation was heated and cured at 200°C for 1 hour to obtain an adhesion strength evaluation sample. The adhesion strength of the obtained sample was measured at 25°C using a mount strength measuring device (Nordson Corporation, device name: DAGE-4000plus).

[0149] (8) Wafer Lamination Properties As in the evaluation of temporary adhesion and adhesion, a dicing tape was laminated onto the thermally conductive adhesive sheet with release film obtained in each Example and Comparative Example, and the 8-inch silicon wafer and the thermally conductive adhesive sheet were laminated using a wafer laminator at 70-80°C, a table speed of 10 mm / sec, and a pressure of 1 MPa. The laminated surfaces of the silicon wafer and the thermally conductive adhesive sheet were visually inspected and the wafer lamination properties were evaluated according to the following criteria. Evaluation Criteria AA: Bonding was possible at 70°C without wrinkles or voids A: Bonding was possible at 80°C without wrinkles or voids B: Bonding was possible at 80°C, but wrinkles and voids occurred.

[0150] (9) Reliability Test (Cold-Heat Cycle) The samples prepared in "(7) Adhesion Strength" above were placed in a cold-heat cycle tester, and the test was carried out for 500, 1000, and 2000 cycles, each cycle consisting of holding the sample at -55°C for 30 minutes, raising the temperature to 150°C, holding the temperature for 30 minutes, and then cooling to -55°C. The test was carried out to check the incidence of defects (peeling defects) (number of samples = 24). A score of 4 or less defects was evaluated as ◯, a score of 5 to 19 defects as △, and a score of 20 to 24 defects as ×.

[0151] (10) Sheet processability A 280 mm wide, 10 m long thermally conductive adhesive sheet formed on a 300 mm wide release film was half-cut into 30 circles with a diameter of 230 mm. The remaining part, excluding the circles, which were unnecessary, was rolled up at a constant speed. The thermally conductive adhesive sheet was checked for tearing during this roll-up process. Evaluation criteria: AA: When rolled up at a speed of 20 m / min, the thermally conductive adhesive sheet did not tear. A: When rolled up at a speed of 20 m / min, the thermally conductive adhesive sheet broke, but when rolled up at a speed of 10 m / min, the thermally conductive adhesive sheet did not tear. B: The thermally conductive adhesive sheet could not be rolled up.

[0152]

[0153]

[0154] The sheets of the Examples had good sheet properties, sheet processability, and semiconductor device reliability (heat cycle test). In contrast, the sheet of Comparative Example 1 did not contain resin (A), and therefore had poor reliability. The sheet of Comparative Example 2 did not contain resin (C), and therefore the sheet surface was sticky, and the sheet could not be manufactured. The sheet of Comparative Example 3 did not contain resin (B), and therefore had poor reliability and poor wafer lamination properties. The sheet of Comparative Example 4 used resin (A') that did not have the structural unit (1) represented by formula (1) instead of resin (A), and therefore had poor reliability. The sheet of Comparative Example 5 did not contain resin (B) or resin (C), and therefore had poor sheet processability, and the sheet could not be rolled up.

Claims

A resin (A) containing a structural unit (1) represented by the following formula (1) and a structural unit (2) represented by the following formula (2), both ends of which have a structure represented by the following formula (3), and having a weight average molecular weight of 4,000 or less: A resin (B) containing a structural unit (4) represented by the following formula (4) and a structural unit (5) represented by the following formula (5), both ends of which have a structure represented by the following formula (6), and having a weight average molecular weight of 10,000 or more and a glass transition temperature (Tg) of 60°C or less: A resin (C) having an epoxy group at its terminal, a weight average molecular weight of 10,000 to 80,000, and a glass transition temperature (Tg) of 65 to 160°C; and silver particles (D), A thermally conductive adhesive sheet obtained by forming a resin composition containing the above into a sheet. [In formula (1), r １ is an integer of 2 to 10. In formula (2), R １ and R ２ are each independently a hydrogen atom or a methyl group. ２ is an integer of 2 to 10. In formula (5), R ３ and R ４ are each independently a hydrogen atom or a methyl group. 　 The resin (A) is a resin (A2) represented by the following formula (7): The resin (B) is a resin (B2) represented by the following formula (8): The thermally conductive adhesive sheet according to claim 1 . [In formula (7), r １ is an integer from 2 to 10, and R １ and R ２ are each independently a hydrogen atom or a methyl group. ２ is an integer from 2 to 10, and R ３ and R ４ are each independently a hydrogen atom or a methyl group.

3. The thermally conductive adhesive sheet according to claim 1, wherein the resin (A) is a copolymer of bisphenol F and 1,6-hexanediol diglycidyl ether.

4. The thermally conductive adhesive sheet according to claim 1, wherein the resin (B) is a copolymer of bisphenol F and 1,6-hexanediol diglycidyl ether. 　 The thermally conductive adhesive sheet according to any one of claims 1 to 4, wherein the silver particles (D) have an average particle diameter (D50) of 0.5 to 5.0 µm. 　 The thermally conductive adhesive sheet according to any one of claims 1 to 5, wherein the silver particles (D) are hollow particles. 　 The thermally conductive adhesive sheet according to any one of claims 1 to 6, further comprising a silicon-containing triazine compound (E). 　 The thermally conductive adhesive sheet according to claim 7 , wherein the silicon-containing triazine compound (E) is represented by the following general formula (13): 　 The content of the resin (A) is 20 to 80 mass%, the content of the resin (B) is 10 to 60 mass%, and the content of the resin (C) is 10 to 60 mass%, in a total of 100 mass% of the resin (A), the resin (B), and the resin (C). The thermally conductive adhesive sheet according to any one of claims 1 to 8. 　 The thermally conductive adhesive sheet according to any one of claims 1 to 9, wherein the content of the silver particles (D) is 70 to 95 mass% in 100 mass% of the solid content of the resin composition. 　 A semiconductor element with a thermally conductive adhesive sheet, comprising: a semiconductor element; and an adhesive layer laminated on the semiconductor element, wherein the adhesive layer is the thermally conductive adhesive sheet according to any one of claims 1 to 10. 　 A step of laminating a semiconductor wafer and the thermally conductive adhesive sheet according to any one of claims 1 to 10 to obtain a semiconductor wafer with the thermally conductive adhesive sheet; A step of dividing the semiconductor wafer with the thermally conductive adhesive sheet into individual pieces; A method for manufacturing a semiconductor element with a thermally conductive adhesive sheet, comprising: 　 A semiconductor device comprising a support member and a semiconductor element mounted on the support member via an adhesive layer, wherein the adhesive layer is a cured product of the thermally conductive adhesive sheet according to any one of claims 1 to 10. 　 A method for manufacturing a semiconductor device, comprising arranging a support member, the thermally conductive adhesive sheet according to any one of claims 1 to 10, and a semiconductor element in this order, and curing the thermally conductive adhesive sheet.

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