JP2015010098A - Thermobonding sheet and article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a thermobonding sheet having excellent thermal conductivity and also having excellent thermal bonding properties on a level at which deterioration in bonding force is not caused even in the case of being exposed to a high temperature environment.SOLUTION: Provided is a thermobonding sheet comprising: a modified epoxy resin (A) including a polyoxyalkylene-modified epoxy resin (a1) or a polyolefin-modified epoxy resin (a2) and in which the weight average molecular weight is 1,000 or higher; and a cresol novolac type epoxy resin (B), and having a thermal conductivity of 1 W/m K or higher.

Description

  The present invention relates to a thermal adhesive sheet that can be used for fixing various members, particularly heat generating members used in the manufacture of electronic devices, for example.

  In recent years, with the miniaturization, high density, and high output of electronic devices and semiconductors, higher integration of members constituting them has been advanced. Since various members are arranged in a limited space without gaps inside the highly integrated device, the heat generated by the members may increase, and the members themselves may become relatively hot. In particular, semiconductor elements such as CPUs, LED backlights, batteries, etc. often emit temperatures of about 100 ° C. or more, and heat tends to accumulate inside them, and members malfunction due to the heat. In some cases, problems such as causing

  Examples of a method for dissipating heat from the inside of the electronic device include a method using a heat sink or a heat sink member. At that time, in order to efficiently transmit heat generated by the heat generating member to the heat receiving member, a method of bonding both members with a heat conductive sheet is known.

  As the thermal conductive sheet, for example, an insulating sheet containing a curable compound having an epoxy group or an oxetanyl group and a primary amine curing agent having a polyether skeleton is known (see, for example, Patent Document 1).

  However, when the insulating sheet is exposed to a relatively high temperature environment for a long period of time, the adhesive strength is remarkably lowered, which may cause peeling from the heat generating member and the heat receiving member.

JP 2012-174533 A

  The problem to be solved by the present invention is a thermal adhesive sheet having excellent heat conductivity and a level of excellent heat-resistant adhesive that does not cause a decrease in adhesive strength even when exposed to a high temperature environment. Is to provide.

  The present invention contains a modified epoxy resin (A) having a weight average molecular weight of 1000 or more, which contains a polyoxyalkylene-modified epoxy resin (a1) or a polyolefin-modified epoxy resin (a2), and a cresol novolac-type epoxy resin (B). The present invention relates to a thermal adhesive sheet having a thermal conductivity of 1 W / m · K or more.

  The thermal adhesive sheet of the present invention has good adhesiveness to various members such as aluminum, copper, and glass epoxy, and has excellent adhesiveness even when left at a high temperature of about 100 ° C. for a long time. Therefore, for example, it can be suitably applied to bonding and fixing a heat generating member such as a semiconductor installed inside an electronic device and other members. Moreover, since the thermal adhesive sheet of this invention has the outstanding heat conductivity, it can be used suitably for adhesion | attachment with heat generating members, such as a semiconductor, and heat receiving members, such as aluminum and copper.

  The thermal adhesive sheet of the present invention comprises a modified epoxy resin (A) having a weight average molecular weight of 1000 or more, which contains a polyoxyalkylene-modified epoxy resin (a1) or a polyolefin-modified epoxy resin (a2), and a cresol novolac epoxy resin (B). And having a thermal conductivity of 1 W / m · K or more.

  The heat-bonding sheet of the present invention is a sheet-like material having almost no tackiness at room temperature, but melts when heated to a temperature of about 100 ° C. or higher, and bonds (joins) two or more adherends. It is possible.

  In order to obtain a thermal adhesive sheet having excellent thermal conductivity, it is essential to use a thermal adhesive sheet having a thermal conductivity of 1 W / m · K or more, and 2 W / m · K. It is preferable to use those having a range of ˜100 W / m · K, and it is more preferable to use those having a range of 3 W / m · K to 50 W / m · K.

  In addition, the said thermal conductivity points out the value measured using quick thermal conductivity meter QTM-500 (made by Kyoto Electronics Industry Co., Ltd.).

  The thermal conductivity of the thermal adhesive sheet is adjusted by appropriately selecting the modified epoxy resin (A) and the cresol novolac type epoxy resin (B) and appropriately combining an inorganic filler (C) and the like as necessary. can do.

  The thermal adhesive sheet can be produced by molding a thermal adhesive composition containing the modified epoxy resin (A) and the cresol novolac epoxy resin (B) into a sheet shape. The thermobonding sheet may have a support on one side as necessary. Moreover, one said adherend may be previously affixed on the single side | surface as needed.

[Thermal adhesive composition]
A thermal adhesive composition that can be used for producing the thermal adhesive sheet of the present invention is a modified epoxy resin (A) containing a polyoxyalkylene-modified epoxy resin (a1) or a polyolefin-modified epoxy resin (a2) and having a weight average molecular weight of 1000 or more. And a cresol novolac type epoxy resin (B).

  As the modified epoxy resin (A), it is preferable to use a resin having a weight average molecular weight of 1000 or more because it is excellent in adhesiveness and can be easily formed into a sheet shape, and is in the range of 10,000 to 300,000. Is more preferable, and it is more preferable to use those in the range of 10,000 to 150,000.

  As said modified epoxy resin (A), what contains any one or both of a polyoxyalkylene modified epoxy resin (a1) and a polyolefin modified epoxy resin (a2) can be used. Among the above-mentioned modified epoxy resins (A), it is preferable to use the polyoxyalkylene-modified epoxy resin (a1) among them as described above in order to give even better adhesiveness. The polyoxyalkylene-modified epoxy resin (a1) is included in the range of 50% by mass to 100% by mass with respect to the total amount of the modified epoxy resin (a1) in order to give even better adhesiveness. preferable.

  As the polyoxyalkylene-modified epoxy resin (a1), it is preferable to use a resin having a weight average molecular weight of 1000 or more because it is excellent in adhesiveness and can be easily formed into a sheet shape. It is more preferable to use what is, and it is still more preferable to use what is the range of 10,000-150,000.

  As the polyoxyalkylene-modified epoxy resin (a1), for example, a polyoxyalkylene-modified bisphenol type epoxy resin can be used. Specifically, as the polyoxyalkylene-modified epoxy resin (a1), for example, a polyoxyalkylene-modified epoxy resin (a1) obtained by reacting polyoxyalkylene polyol polyglycidyl ether, bisphenol, diglycidyl ether of bisphenol, or the like is used. Can do.

  As the polyoxyalkylene glycol polyglycidyl ether, for example, polyoxyalkylene glycol diglycidyl ether such as polyoxytetramethylene glycol diglycidyl ether, polyoxyethylene glycol diglycidyl ether or the like is used. can do.

  As the polyoxyalkylene polyol polyglycidyl ether, those obtained by reacting polyoxyalkylene polyol with epichlorohydrin or the like can be used.

  As said bisphenol, bisphenol A, bisphenol F, etc. can be used.

  As the diglycidyl ether of bisphenol, for example, bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, or the like can be used.

  The bisphenol diglycidyl ether can be produced by reacting the bisphenol A, bisphenol F or the like with m-epichlorohydrin or the like.

  When reacting the polyoxyalkylene polyol polyglycidyl ether, bisphenol, diglycidyl ether of bisphenol, and the like, a catalyst can be used as necessary. As said catalyst, alkali metal compounds, such as sodium hydroxide, an organic phosphorus compound, a tertiary amine, etc. can be used, for example.

  When reacting the polyoxyalkylene polyol polyglycidyl ether, bisphenol, diglycidyl ether of bisphenol, and the like, a solvent can be used as necessary. As the solvent, benzene, toluene, acetone, methyl ethyl ketone, cyclohexanone, or the like can be used.

  The temperature at the time of reacting the polyoxyalkynylene polyol polyglycidyl ether, bisphenol, diglycidyl ether of bisphenol and the like is preferably in the range of 50 ° C to 250 ° C, and in the range of 100 ° C to 200 ° C. More preferably.

  The bisphenol is preferably used in the range of 50 parts by mass to 200 parts by mass with respect to 100 parts by mass of the polyoxyalkynylene polyol polyglycidyl ether. Moreover, it is preferable to use the diglycidyl ether of the bisphenol in the range of 50 parts by mass to 300 parts by mass with respect to 100 parts by mass of the polyoxyalkylene polyol polyglycidyl ether.

  As the polyolefin-modified epoxy resin (a2), for example, a polyolefin-modified bisphenol type epoxy resin can be used.

  As the polyolefin-modified epoxy resin (a2), it is preferable to use a resin having a weight average molecular weight of 1000 or more because it is excellent in adhesiveness and easily molded into a sheet shape, and is in the range of 10,000 to 300,000. It is more preferable to use a thing, and it is still more preferable to use what is the range of 10,000-150,000.

  As the polyolefin-modified epoxy resin (a2), for example, those obtained by reacting diglycidyl ether of an aliphatic diol with bisphenol or the like can be used.

  As the diglycidyl ether of the aliphatic diol, for example, those obtained by reacting an aliphatic diol such as ethylene glycol, propylene glycol, butylene glycol, 1,6-hexanediol and epichlorohydrin can be used. .

  As said bisphenol, bisphenol A, bisphenol F, etc. can be used.

  When the diglycidyl ether of the aliphatic diol is reacted with bisphenol or the like, a catalyst can be used as necessary. As said catalyst, alkali metal compounds, such as sodium hydroxide, an organic phosphorus compound, a tertiary amine, etc. can be used, for example.

  When the diglycidyl ether of the aliphatic diol is reacted with bisphenol or the like, a solvent can be used as necessary. As the solvent, benzene, toluene, acetone, methyl ethyl ketone, cyclohexanone, or the like can be used.

  The temperature at which the diglycidyl ether of the aliphatic diol is reacted with bisphenol or the like is preferably in the range of 50 ° C to 250 ° C, and more preferably in the range of 100 ° C to 200 ° C.

  The bisphenol is preferably reacted in the range of 50 to 300 parts by mass with respect to 100 parts by mass of the diglycidyl ether of the aliphatic diol.

  As the modified epoxy resin (A), one having an epoxy equivalent of 2000 g / eq or more is preferably used, and one having an epoxy equivalent of 4000 g / eq or more is used for various adherends, particularly aluminum. It is more preferable because adhesion to a metal adherend such as copper can be further improved, particularly heat-resistant adhesion. The upper limit of the epoxy equivalent is preferably 10,000 g / eq or less.

  The modified epoxy resin (A) is preferably contained in the range of 20% by mass to 90% by mass with respect to the total mass of the modified epoxy resin (A) and the cresol novolac epoxy resin (B), and is 40% by mass. It is more preferable that it is contained in the range of ˜70% by mass because adhesion to various adherends, particularly metal adherends such as aluminum and copper, and particularly heat resistant adhesiveness can be further improved.

  The thermal adhesive composition used in the present invention uses a cresol novolac type epoxy resin (B) in order to obtain a thermal adhesive sheet having both excellent adhesiveness at room temperature and excellent heat resistant adhesiveness. .

  As the cresol novolac type epoxy resin (B), for example, a cresol novolac type epoxy resin represented by the following formula (3) can be used.

(I in the formula (1) represents an average number of 1 or more.)

  Examples of the cresol novolac type epoxy resin (B) are commercially available as Epicron N-680, N-695 (manufactured by DIC Corporation), YDCN-700-7, YDCN-704 (manufactured by Nippon Steel & Sumikin Chemical Co., Ltd.), and the like. Can be used.

  As said cresol novolak type epoxy resin (B), it is preferable to use what i is in the range of 1-50 in Formula (1), and it is heat to use what is in the range of 1-30. It is preferable for achieving both excellent adhesion and thermosetting of the adhesive sheet. In terms of molecular weight, the cresol novolac epoxy resin (B) preferably has a molecular weight in the range of 500 to 10,000, and more preferably in the range of 1000 to 6000.

  The cresol novolac type epoxy resin (B) is preferably used in the range of 10% by mass to 80% by mass with respect to the total mass of the modified epoxy resin (A) and the cresol novolac type epoxy resin (B), 30 It is more preferable to use in the range of mass% to 60 mass% in order to further improve the adhesiveness, particularly heat resistant adhesiveness.

  In addition, the thermal adhesive composition used in the present invention is given more excellent thermal conductivity by the thermal adhesive sheet of the present invention, and when producing a thermal adhesive sheet having a predetermined thermal conductivity. It is preferable to use various fillers.

  As the filler, it is preferable to use an inorganic filler (C) because it is easy to adjust the thermal conductivity of the thermal adhesive sheet.

  Examples of the inorganic filler (C) include electrically insulating inorganic fillers such as aluminum hydroxide, aluminum oxide, aluminum nitride, magnesium hydroxide, magnesium oxide, talc, and boron nitride; gold, silver, copper, nickel, Conductive inorganic fillers such as aluminum, carbon, and graphite can be used alone or in combination of two or more.

  In particular, as the inorganic filler (C), the use of an electrically insulating inorganic filler is compatible with, for example, the promotion of heat dissipation when used inside an electronic device and the prevention of a short circuit between components. More specifically, specific examples include aluminum nitride, aluminum oxide, barium titanate, beryllium oxide, boron nitride, silicon carbide, and zinc oxide. Of these, aluminum nitride, boron nitride, and aluminum oxide are preferable.

  As the inorganic filler (C), those having a regular shape or an irregular shape can be used. Examples of the shape include a polygonal shape, a cubic shape, an elliptical shape, a spherical shape, a needle shape, a flat plate shape, a scale shape, and a mixture or aggregate thereof. Among them, it is preferable to use a spherical one because the thermal adhesive sheet can be filled with a high density, and more excellent thermal conductivity can be imparted.

  Moreover, you may use together the said inorganic filler (C) 2 or more types for the purpose of improving thermal conductivity more. Among these, the use of a spherical material and a flat or scale-like material together allows the inorganic filler (C) to be filled in a close-packed manner in the heat-adhesive composition. It is preferable because it can impart the properties.

  The average particle diameter of the inorganic filler (C) is preferably 1 μm to 50 μm, for example, when the thickness of the obtained thermal adhesive sheet is about 100 μm.

  As a compounding quantity of the said inorganic filler (C), it may be 40 volume%-80 volume% with respect to the volume (It is limited to the part formed using the heat adhesive composition) of the said heat bond sheet. It is more preferable to obtain a heat-bonding sheet that achieves both ease of forming into a sheet and excellent thermal conductivity.

  As the inorganic filler (C), in order to impart excellent thermal conductivity to the thermal adhesive sheet of the present invention, it is preferable to use those having a thermal conductivity of 10 W / m · K or more. It is more preferable to use those that are at least / m · K. The upper limit of the thermal conductivity of the inorganic filler (C) is preferably 100 W / m · K or less.

  As the thermal adhesive composition used in the present invention, it is preferable to use one containing a curing agent.

  As the curing agent, one having a functional group capable of reacting with the epoxy group of the modified epoxy resin (A) and the cresol novolac type epoxy resin (B) is preferably used.

  Examples of the curing agent include bisphenol A, bisphenol F, bisphenol AD, hydroquinone, resorcin, methyl resorcin, biphenol, tetramethylbiphenol, dihydroxynaphthalene, dihydroxydiphenyl ether, phenol novolac resin, bisphenol A novolac resin, dicyclopentadiene phenol resin. Various polyphenol resins such as terpene phenol resin, naphthol novolac resin, biphenyl phenol resin, polyhydric phenol resins obtained by condensation reaction of various phenols with various aldehydes such as hydroxybenzaldehyde, crotonaldehyde, glyoxal, And a modified phenol obtained by polycondensation of heavy oil or pitch, phenol and formaldehyde compounds Various phenolic resins such as resins, acid anhydrides such as methyltetrahydrophthalic anhydride, hexahydrophthalic anhydride, pyromellitic anhydride, methylnadic acid, amines such as diethylenetriamine, isophoronediamine, diaminodiphenylmethane, diaminodiphenylsulfone, dicyandiamide, etc. Is mentioned.

  The curing agent is preferably used in the range of 1 part by mass to 60 parts by mass with respect to 100 parts by mass of the total mass of the modified epoxy resin (A) and the cresol novolac type epoxy resin (B). It is more preferable to use in the range of ˜30 parts by mass since the shrinkage when the modified epoxy resin (A) and the cresol novolac type epoxy resin (B) are cured can be suppressed.

  As the thermal adhesive composition used in the present invention, one containing a curing accelerator can be used. As the curing accelerator, an amine compound, imidazole, or the like can be used. When the curing accelerator is used, the amount used is 0.1 to 5 parts by mass with respect to a total of 100 parts by mass of the modified epoxy resin (A) and the cresol novolac epoxy resin (B). Preferably, it is in the range of 0.5 to 3 parts by mass.

  As the curing agent and curing accelerator, it is preferable to use a powdery one. The powdery curing accelerator suppresses the thermosetting reaction at low temperatures compared to the liquid curing accelerator, and thus further improves the storage stability of the thermobonded sheet before thermosetting at room temperature. I can do it.

  As the thermal adhesive composition used in the present invention, one containing a solvent can be used for improving the easiness of molding into a sheet.

  Examples of the solvent include ester solvents such as methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ketyl ketone, methyl isobutyl ketone, diisobutyl ketone, and cyclohexanone; aromatics such as toluene and xylene. Hydrocarbons and the like can be used.

  As said thermal adhesive composition, what contains an additive can be used in the range which does not impair the effect of this invention other than an above-described thing.

  Examples of the additive include fillers, softeners, stabilizers, adhesion promoters, leveling agents, antifoaming agents, plasticizers, tackifying resins, fibers, antioxidants, ultraviolet absorbers, and hydrolysis inhibitors. Additives such as thickeners, plasticizers, colorants such as pigments, fillers and the like can be used as necessary.

  As the additive, other resins such as an epoxy resin other than the modified epoxy resin (A) and the cresol novolac type epoxy resin (B) can be used.

  The other resin is preferably 20% by mass or less of the resin component contained in the thermal adhesive composition, more preferably 10% by mass or less, and particularly preferably not substantially contained.

  The thermal adhesive composition can be produced, for example, by mixing the modified epoxy resin (A), the cresol novolac epoxy resin (B), and a solvent or the like as necessary.

  When using the said inorganic filler (C) etc. as an additive, a thermal adhesive composition can also be manufactured by mixing the mixture obtained above and an inorganic filler (C).

  When producing the thermal adhesive composition, if necessary, a dissolver, a butterfly mixer, a BDM biaxial mixer, a planetary mixer, etc. can be used, and the inorganic filler (C) can be used more. Since it can disperse | distribute uniformly, it is preferable to use a planetary mixer.

  The curing agent and curing accelerator are preferably used by mixing with the mixture before applying the thermal adhesive composition to a substrate or the like.

  The thermal adhesive sheet of the present invention, for example, using a roll coater, a die coater or the like on a release liner, applies a thermal adhesive composition containing the curing agent or the like, and the coating layer is about 50 ° C to 120 ° C. It can be manufactured by drying under an environment to remove the solvent and removing the release liner.

  In the drying, heating may be performed at a temperature of about 50 ° C. to 100 ° C., but it is preferable that the temperature is relatively low in order to suppress the progress of the curing reaction of the thermal adhesive sheet.

  The thermal adhesive sheet may be sandwiched by the release liner until it is used.

  Examples of the release liner include paper such as kraft paper, glassine paper, and high-quality paper; resin films such as polyethylene, polypropylene (OPP, CPP), and polyethylene terephthalate; laminated paper in which the paper and the resin film are laminated, and the paper A material obtained by applying a release treatment such as a silicone-based resin to one or both surfaces of a material subjected to a sealing treatment with clay or polyvinyl alcohol can be used.

  The total thickness of the thermal adhesive sheet obtained by the above method is preferably 300 m or less, more preferably 200 μm or less, and even more preferably 150 μm or less. The lower limit value of the total thickness of the heat bonding sheet is preferably 80 μm or more. The total thickness is a thickness not including the thickness of the support (thickness of only the layer formed by the thermal adhesive composition) when a support is laminated on the thermal adhesive sheet. Point to.

  By using the thermal adhesive sheet having the total thickness, the thermal conductivity can be improved while maintaining the adhesiveness of the thermal adhesive sheet. In addition, the total thickness of the said heat bonding sheet points out the thickness which does not contain the said release liner.

  Since the thermal adhesive sheet of the present invention is excellent in thermal conductivity and excellent in heat-resistant adhesiveness, it can be suitably used for adhesion between various heat generating members and heat receiving members.

  Examples of the heat generating member include heat generating members that can generate heat at about 100 ° C. or more, and examples thereof include a semiconductor element such as a CPU, an LED backlight, and a battery.

  On the other hand, as the other member, it is preferable to use a heat receiving member in order to efficiently dissipate heat. Examples of the heat receiving member include a stainless casing, an aluminum substrate, glass epoxy, and the like.

  Further, as the adherend that can be bonded by the thermal adhesive sheet, in addition to the above-mentioned ones, resins such as polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polyethylene, polypropylene, polycarbonate, polyamide, polyimide, and ABS are used. The adherend to be formed can be used. In addition, as the adherend, an adherend containing the resin and various additives, beads, glass flakes, nonwoven fabrics, films and the like can be used. In particular, the adherend containing the glass flakes and the resin is preferably used because it is generally excellent in heat resistance.

  Moreover, as said adherend, iron, copper, stainless steel, aluminum, a magnesium containing alloy, an aluminum containing alloy etc. can also be used, for example.

  Examples of the article bonded by the thermal bonding sheet include electronic devices and batteries including a semiconductor element such as a CPU, an LED backlight, a battery, and the like.

  Examples and comparative examples will be specifically described below.

(Preparation Example 1)
[Preparation of polyoxyalkylene-modified epoxy resin solution (A-1)]
100 mass of polyoxytetramethylene glycol diglycidyl ether (obtained by reacting polyoxytetramethylene glycol and epichlorohydrin, epoxy equivalent 428 g / eq) to a flask equipped with a thermometer, stirrer and nitrogen gas supply device Parts, 124 parts by mass of bisphenol A (hydroxyl equivalent: 114 g / eq) and 173 parts by mass of bisphenol A diglycidyl ether (epoxy equivalent: 186 g / eq) are charged for 30 minutes in a nitrogen gas atmosphere. After adjusting to 140 ° C., 0.38 parts by mass of a 50 mass% tetramethylammonium chloride aqueous solution was charged as a catalyst.

  Next, the temperature in the reaction vessel was raised to 150 ° C. over 30 minutes, and further reacted at 150 ° C. for 3 hours.

  Next, the reaction product and 595 parts by mass of methyl ethyl ketone were mixed to obtain a polyoxyalkylene-modified epoxy resin (A-1) solution having a nonvolatile content of 40% by mass. The epoxy equivalent of the polyoxyalkylene-modified epoxy resin (A-1) was 5593 g / eq, and the weight average molecular weight was 40,500.

(Preparation Example 2)
[Preparation of polyolefin-modified epoxy resin solution (A-2)]
In a flask equipped with a thermometer, a stirrer, and a nitrogen gas supply device, 100 parts by mass of 1,6-hexanediol diglycidyl ether (epoxy equivalent 124 g / eq) and 78 parts by mass of bisphenol F (hydroxyl equivalent 100 g / eq) After adding 53 parts by mass of cyclohexanone and heating in a nitrogen gas atmosphere for 30 minutes and adjusting to 140 ° C., 0.05 part by mass of a 49% by mass aqueous sodium hydroxide solution was added.

  Next, the temperature in the reaction vessel was raised to 150 ° C. over 30 minutes, and further reacted at 150 ° C. for 3 hours.

  Next, a polyolefin-modified epoxy resin (A-2) solution having a nonvolatile content of 40% by mass was obtained by mixing the reactant and 347 parts by mass of methyl ethyl ketone. The polyolefin-modified epoxy resin (A-2) had an epoxy equivalent of 8240 g / eq and a weight average molecular weight of 53,000.

  The weight average molecular weights of the polyoxyalkylene-modified epoxy resin (A-1) obtained in Preparation Example 1 and the polyolefin-modified epoxy resin (A-2) obtained in Preparation Example 2 are the product names “HLC- 8320 GPC "(manufactured by Tosoh Corporation) was measured under the following GPC measurement conditions in terms of polystyrene.

<GPC measurement conditions>
Sample concentration: 0.5% by mass (tetrahydrofuran solution)
Sample injection volume: 100 μL
Eluent: Tetrahydrofuran (THF)
Flow rate (flow rate): 1 mL / min
Column temperature (measurement temperature): 40 ° C
Column (passed in the following order): “TSKguardcolumnHXL-H / TSKgelGMHHR-H (20) / TSKgelGMHHR-H (20)” (both manufactured by Tosoh Corporation)

Example 1
60 parts by mass of the polyoxyalkylene-modified epoxy resin (A-1) solution obtained in Preparation Example 1 and N-680 (cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, nonvolatile content 75% by mass ) 21.4 parts by mass was mixed, and then 18.6 parts by mass of methyl ethyl ketone was mixed to prepare a thermal adhesive composition (X-1) having a nonvolatile content of 40% by mass.

  Next, 260 parts by mass of DAW-20 (produced by Denki Kagaku Kogyo Co., Ltd., aluminum oxide, average particle size 20 μm) as inorganic filler (C) is added to 100 parts by mass of the thermal adhesive composition (X-1). The mixture was stirred for 30 minutes using a planetary mixer. Next, the mixture was mixed with 0.4 part by mass of Curesol 2MAOK-PW (manufactured by Shikoku Kasei Co., Ltd., imidazole dispersion type curing accelerator) and stirred for 10 minutes. Was extracted to obtain a thermosetting adhesive composition (Y-1).

  Next, the thermosetting adhesive composition (Y-1) is applied to the surface of the release film in which one side of a polyethylene terephthalate film having a thickness of 75 μm is peeled with a silicone compound, using a rod-shaped metal applicator. The coating was performed so that the thickness after drying was 100 μm.

  Next, the coated product is put into a drier at 85 ° C. for 5 minutes and dried, and then a release film in which one side of a polyethylene terephthalate film having a thickness of 38 μm is peeled off with a silicone compound is attached to the coated surface. As a result, a laminated body in which a heat-adhesive sheet (Z-1) having a thickness of 100 μm was sandwiched between the two types of release films was obtained. The thermal adhesive sheet (Z-1) had a thermal conductivity of 2.3 W / m · K.

(Example 2)
The amount of the polyoxyalkylene-modified epoxy resin (A-1) solution obtained in Preparation Example 1 was changed from 60 parts by mass to 90 parts by mass, and N-680 (a cresol novolac epoxy resin solution manufactured by DIC Corporation, epoxy Equivalent amount 215 g / eq, non-volatile content 75% by mass) was changed from 21.4 parts by mass to 5.3 parts by mass, and methyl ethyl ketone was changed from 18.6 parts by mass to 4.7 parts by mass. A thermal adhesive composition (Y-2) was obtained in the same manner as in Example 1 except that.

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-2) was used instead of the thermal adhesive composition (Y-1). 2) obtained a laminate sandwiched between the two types of release films. The thermal adhesive sheet (Z-2) had a thermal conductivity of 2.3 W / m · K.

Example 3
Instead of N-680 (a cresol novolac epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, non-volatile content 75 mass%), N-690 (a cresol novolac epoxy resin solution manufactured by DIC Corporation, epoxy equivalent) A thermal adhesive composition (Y-3) was obtained in the same manner as in Example 1 except that 21.4 parts by mass of 225 g / eq and 75% by mass of the non-volatile content was used.

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-3) was used instead of the thermal adhesive composition (Y-1). 3) obtained a laminate sandwiched between the two types of release films. The thermal adhesive sheet (Z-3) had a thermal conductivity of 2.2 W / m · K.

Example 4
Example, except that 60 parts by mass of the polyolefin-modified epoxy resin (A-2) solution obtained in Preparation Example 2 was used instead of the polyoxyalkylene-modified epoxy resin (A-1) solution obtained in Preparation Example 1. 1 was used to obtain a thermal adhesive composition (Y-4).

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-4) was used instead of the thermal adhesive composition (Y-1). 4) obtained a laminate sandwiched between the two types of release films. The thermal adhesive sheet (Z-4) had a thermal conductivity of 2.1 W / m · K.

(Example 5)
Further, heat bonding was performed in the same manner as in Example 1 except that 1.2 parts by mass of Jeffamine D2000 (a polyether skeleton primary amine curing agent manufactured by Huntsman Co., Ltd., hydrogen equivalent of 500 g / eq) was used as a curing agent. An agent composition (Y-5) was obtained.

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-5) was used instead of the thermal adhesive composition (Y-1). 5) obtained a laminate sandwiched between the two types of release films. The thermal adhesive sheet (Z-5) had a thermal conductivity of 2.1 W / m · K.

(Example 6)
Other than using 260 parts by mass of DAW-45 (manufactured by Denki Kagaku Kogyo Co., Ltd., aluminum oxide, average particle size 45 μm) instead of DAW-20 (Denki Kagaku Kogyo Co., Ltd., aluminum oxide, average particle size 20 μm) Obtained a thermal adhesive composition (Y-6) in the same manner as in Example 1.

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-6) was used instead of the thermal adhesive composition (Y-1). 6) obtained a laminate sandwiched between the two types of release films. The thermal adhesive sheet (Z-6) had a thermal conductivity of 2.5 W / m · K.

(Example 7)
Other than using 72 parts by mass of SP-3 (manufactured by Denki Kagaku Kogyo Co., Ltd., boron nitride, average particle size 4 μm) instead of DAW-20 (Denki Kagaku Kogyo Co., Ltd., aluminum oxide, average particle size 20 μm) Obtained a thermal adhesive composition (Y-7) in the same manner as in Example 1.

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-7) was used instead of the thermal adhesive composition (Y-1). 7) obtained a laminate sandwiched between the two types of release films. The thermal conductivity of the thermal adhesive sheet (Z-7) was 2.1 W / m · K.

(Example 8)
Furthermore, a thermal adhesive composition (Y-8) was obtained in the same manner as in Example 1 except that 16 parts by mass of SP-3 (manufactured by Denki Kagaku Kogyo Co., Ltd., boron nitride, average particle size 4 μm) was used. It was.

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-8) was used instead of the thermal adhesive composition (Y-1). 8) obtained a laminate sandwiched between the two types of release films. The thermal adhesive sheet (Z-8) had a thermal conductivity of 3.9 W / m · K.

Example 9
Instead of DAW-20 (made by Denki Kagaku Kogyo Co., Ltd., aluminum oxide, average particle size 20 μm), 260 parts by mass of DAW-45 (made by Denki Kagaku Kogyo Co., Ltd., aluminum oxide, average particle size 45 μm) is used. A thermal adhesive composition (Y-9) was obtained in the same manner as in Example 1 except that 16 parts by mass of SP-3 (manufactured by Denki Kagaku Kogyo Co., Ltd., boron nitride, average particle size 4 μm) was used. .

  A thermal adhesive sheet (Z-) having a thickness of 100 μm was prepared in the same manner as in Example 1 except that the thermal adhesive composition (Y-9) was used instead of the thermal adhesive composition (Y-1). 9) obtained a laminate sandwiched between the two types of release films. The thermal adhesive sheet (Z-9) had a thermal conductivity of 4.9 W / m · K.

(Comparative Example 1)
Thermal adhesive composition in the same manner as in Example 1 except that the amount of DAW-20 (manufactured by Denki Kagaku Kogyo Co., Ltd., aluminum oxide, average particle size 20 μm) is changed from 260 parts by mass to 80 parts by mass. (Y′-1) was obtained.

  A thermal adhesive sheet (Zm) having a thickness of 100 μm is the same as in Example 1 except that the thermal adhesive composition (Y′-1) is used instead of the thermal adhesive composition (Y-1). A laminate having '-1) sandwiched between the two types of release films was obtained. The thermal conductivity of the thermal adhesive sheet (Z′-1) was 0.8 W / m · K.

(Comparative Example 2)
The amount of the polyoxyalkylene-modified epoxy resin (A-1) solution obtained in Preparation Example 1 was changed from 60 parts by mass to 100 parts by mass, and N-680 (a cresol novolac epoxy resin solution manufactured by DIC Corporation) , Epoxy equivalent 215 g / eq, non-volatile content 75 mass%) and methyl ethyl ketone were not used, and a thermal adhesive composition (Y′-2) was obtained in the same manner as in Example 1.

  A thermal adhesive sheet (Z) having a thickness of 100 μm is the same as in Example 1 except that the thermal adhesive composition (Y′-2) is used instead of the thermal adhesive composition (Y-1). A laminate obtained by sandwiching '-2) between the two types of release films was obtained. The thermal conductivity of the thermal adhesive sheet (Z′-2) was 2.1 W / m · K.

(Comparative Example 3)
Without using the polyoxyalkylene-modified epoxy resin (A-1) solution obtained in Preparation Example 1, N-680 (cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, nonvolatile content 75% by mass ) Is changed from 21.4 parts by mass to 53.3 parts by mass, and the amount of methyl ethyl ketone used is changed from 18.6 parts by mass to 46.7 parts by mass. Thus, a thermal adhesive composition (Y′-3) was obtained.

  A thermal adhesive sheet (Z) having a thickness of 100 μm is the same as in Example 1 except that the thermal adhesive composition (Y′-3) is used instead of the thermal adhesive composition (Y-1). A layered product in which '-3) was sandwiched between the two types of release films was obtained. The thermal conductivity of the thermal adhesive sheet (Z′-3) was 2.0 W / m · K.

(Comparative Example 4)
Instead of N-680 (Cresol novolac type epoxy resin solution manufactured by DIC Corporation, epoxy equivalent 215 g / eq, non-volatile content 75% by mass), jer1256 (Bisphenol A type phenoxy resin manufactured by Mitsubishi Chemical Corporation, epoxy equivalent 8000 g / eq, 70% nonvolatile content), and the same method as in Example 1 except that the amount of methyl ethyl ketone used is changed from 18.6 parts to 17.1 parts by weight. A thermal adhesive composition (Y′-4) was obtained.

  A thermal adhesive sheet (Z) having a thickness of 100 μm is the same as in Example 1 except that the thermal adhesive composition (Y′-4) is used instead of the thermal adhesive composition (Y-1). A layered product obtained by sandwiching '-4) between the two types of release films was obtained. The thermal conductivity of the thermal adhesive sheet (Z′-4) was 2.1 W / m · K.

(Comparative Example 5)
In place of the polyoxyalkylene-modified epoxy resin (A-1) solution obtained in Preparation Example 1, Epogosay PT (epoxy resin having a polytetramethylene glycol structure manufactured by Yokkaichi Gosei Co., Ltd., weight average molecular weight 870, epoxy equivalent 435 g / eq, non-volatile content of 100% by mass), and the amount of methyl ethyl ketone used is changed from 18.6 parts by mass to 54.7 parts by mass. A composition (Y′-5) was obtained.

  A thermal adhesive sheet (Z) having a thickness of 100 μm is the same as in Example 1 except that the thermal adhesive composition (Y′-5) is used instead of the thermal adhesive composition (Y-1). A laminate in which '-5) was sandwiched between the two types of release films was obtained. However, the thermal adhesive sheet (Z′-5) could not be peeled from the release film, and the thermal conductivity could not be measured. Moreover, since the said heat bonding sheet (Z'-5) was not able to peel from a release film, evaluation, such as the handling property mentioned later, thermal conductivity, adhesiveness, and heat resistance, was not performed.

[Handling evaluation method]
A laminate in which a thermal adhesive sheet was sandwiched between the two types of release films was cut into a size of 200 mm wide × 400 mm long was used as a test film.

  Based on the peelability when the release film was removed from the test film at 23 ° C. and the presence or absence of deformation of the thermal adhesive sheet, the handling property of the thermal adhesive sheet was evaluated according to the following criteria.

  ○: The thermal adhesive sheet was not deformed, and the release film and the thermal adhesive sheet could be easily peeled off.

  (Triangle | delta): Although the release film and the heat bonding sheet were able to be peeled easily, deformation | transformation, such as elongation and a fracture | rupture, was seen in a part of heat bonding sheet.

  X: The release film and the thermal adhesive sheet could not be peeled off.

[Method for evaluating thermal conductivity (method for measuring thermal resistivity)]
The heat bonding sheet obtained by removing the release film was laminated so as to have a thickness of 400 μm or more and less than 500 μm, and it was heat-bonded at 180 ° C. for 10 minutes while applying a pressure of 1 MPa by a hot press machine. It was left to stand in a 50 ° C. environment for 50 minutes for thermosetting. A test sample was obtained by cutting the obtained cured product into 10 mm square. The thermal resistivity at 25 ° C. in the thickness direction of the test sample was measured by a laser flash method (manufactured by NETZSCII, LFA447 Nanoflash).

[Measurement method of thermal conductivity]
Ten thermal adhesive sheets obtained by removing the release film were laminated.

  A polyethylene terephthalate film having a thickness of 6 μm was laminated on both sides of the laminate composed of the ten heat-bonding sheets, and heat-bonded at 180 ° C. for 10 minutes while maintaining a pressure of 1 MPa with a hot press machine. The test sample was left to stand in a 50 ° C. environment for 50 minutes, thermally cured, and cut into 5 cm × 15 cm.

  The thermal conductivity of the obtained test sample was measured using a rapid thermal conductivity meter QTM-500 (manufactured by Kyoto Electronics Industry Co., Ltd.).

[Method of evaluating heat resistance (solder heat resistance)]
The thermal adhesive sheet obtained by removing the release film was sandwiched between two rolled copper foils having a thickness of 35 μm, and thermally bonded at 180 ° C. for 10 minutes while maintaining a pressure of 1 MPa with a hot press machine, and thereafter By leaving still in a 180 degreeC environment for 50 minutes and thermosetting a thermobonding sheet, the copper foil adhesion laminated body to which two rolled copper foils were adhere | attached with the said thermobonding sheet was produced.

  A test sample was prepared by cutting the copper foil-clad laminate into a size of 50 mm × 50 mm.

  The test sample was left in an oven preheated to 260 ° C. for 2 minutes and 30 seconds (first heating). The appearance of the test sample taken out from the oven was confirmed, and the presence or absence of swelling or peeling of the rolled copper foil was confirmed.

  Next, the test sample was again left in an oven preheated to 260 ° C. for 2 minutes and 30 seconds (second heating). The appearance of the test sample taken out from the oven was confirmed again, and the presence or absence of swelling or peeling of the rolled copper foil was confirmed.

  Next, the test sample was again left in an oven preheated to 260 ° C. for 2 minutes and 30 seconds (third heating). The appearance of the test sample taken out from the oven was confirmed again, and the presence or absence of swelling or peeling of the rolled copper foil was confirmed.

  Evaluation of heat resistance (solder heat resistance) was performed according to the following criteria.

  (Double-circle): The test sample after the said 3rd heating did not cause the swelling and peeling of a rolled copper foil.

  ○: The test sample after the third heating described above caused swelling and peeling of the rolled copper foil.

  (Triangle | delta): The test sample after heating the said 2nd time caused the swelling and peeling of the rolled copper foil.

  X: The test sample after the said 1st heating had caused the swelling and peeling of the rolled copper foil.

[Evaluation method of room temperature adhesion (peel strength at 23 ° C.)]
The thermal adhesive sheet obtained by removing the release film was cut into a size of 20 mm wide × 100 mm long.

  The cut thermal adhesive sheet is sandwiched between an aluminum plate having a thickness of 1.5 mm and an electrolytic copper foil having a thickness of 35 μm, and is thermally bonded at 180 ° C. for 10 minutes while maintaining a pressure of 1 MPa with a hot press machine. By leaving still at 180 degreeC environment for 50 minutes and thermosetting a thermobonding sheet, the copper foil adhesion laminated body with which the aluminum plate and the electrolytic copper foil were adhere | attached with the said thermobonding sheet was produced.

  The copper foil-clad laminate was allowed to stand in an atmosphere of 23 ° C. × 50% RH for 1 hour, and then the peel strength in the 180 ° direction (peel rate 50 mm / min) was measured in the same environment.

[Method for evaluating heat-resistant adhesiveness (peel strength at 150 ° C.)]
The thermal adhesive sheet obtained by removing the release film was cut into a size of 20 mm wide × 100 mm long.

  The cut thermal adhesive sheet is sandwiched between an aluminum plate having a thickness of 1.5 mm and an electrolytic copper foil having a thickness of 35 μm, and is thermally bonded at 180 ° C. for 10 minutes while maintaining a pressure of 1 MPa with a hot press machine. By leaving still at 180 degreeC environment for 50 minutes and thermosetting a thermobonding sheet, the copper foil adhesion laminated body with which the aluminum plate and the electrolytic copper foil were adhere | attached with the said thermobonding sheet was produced.

  The copper foil-clad laminate was allowed to stand in an atmosphere of 150 ° C. × 50% RH for 1 hour, and then the peel strength in the 180 ° direction (peel rate 50 mm / min) was measured in the same environment.

  Based on the decrease rate of the peel strength at 150 ° C. relative to the peel strength at 23 ° C. [[(peel strength at 150 ° C.) / (Peel strength at 23 ° C.)] × 100], the following evaluation criteria The heat-resistant adhesion was evaluated according to

  A: The peel strength at 150 ° C. was a decrease rate of 0% or more and less than 20% compared to the peel strength at 23 ° C.

  A: The peel strength at 150 ° C. was a decrease rate of 20% to less than 60% compared to the peel strength at 23 ° C.

  Δ: The peel strength at 150 ° C. was a decrease rate of 60% to less than 90% compared to the peel strength at 23 ° C.

  X: The peel strength at 150 ° C. was a reduction rate of 90% or more compared with the peel strength at 23 ° C., or no adhesive strength was developed.

Claims (7)

A modified epoxy resin (A) containing a polyoxyalkylene-modified epoxy resin (a1) or polyolefin-modified epoxy resin (a2) having a weight average molecular weight of 1000 or more, and a cresol novolac type epoxy resin (B), and containing 1 W / m A thermal adhesive sheet characterized by having a thermal conductivity of K or higher. The thermal adhesive sheet according to claim 1, wherein the polyoxyalkylene-modified epoxy resin (a1) is obtained by reacting polyoxyalkylene polyol polyglycidyl ether, bisphenol, and diglycidyl ether of bisphenol. The thermal adhesive sheet according to claim 1 or 2, wherein the modified epoxy resin (A) has a weight average molecular weight in the range of 10,000 to 200,000. Furthermore, an inorganic filler (C) is contained, The said inorganic filler (C) is contained in the range of 40 volume%-80 volume% with respect to the volume of the said thermobonding sheet. The thermal adhesive sheet as described in 1. The article | item characterized by adhere | attaching the heat generating member and the heat receiving member through the heat bonding sheet of any one of Claims 1-4. An article characterized in that a heat generating member capable of generating heat at 100 ° C. or more and a heat receiving member are bonded via the thermal bonding sheet according to claim 1. The article according to claim 6, wherein the heat generating member capable of generating heat at 100 ° C. or higher is a semiconductor or an LED.