KR20060111409A - Multi-layered rubber sheet for thermocompression bonding - Google Patents

Abstract

A multi-layered rubber sheet for thermo-compression bonding is provided to reduce degradation even in repeatedly using the rubber sheet and to secure good durability by stacking a fluorine rubber layer on silicon rubber. The multi-layered rubber sheet for thermo-compression bonding has multiple rubber layers provided with a fluorine rubber layer and formed on at least one surface of a silicon rubber layer. The silicon rubber layer is formed by molding and hardening a silicon rubber composition. The silicon rubber composition consists of organopolysiloxane with average polymerization over 200 about 100wt.%, carbon black and/or granule silica fillers of 0~150wt.%, metal, at least one of metal oxide, metal nitride, and metal carbide except for granule silica, about 0~1,600wt.%, and a hardening agent.

Description

Multi-layered Rubber Sheet for Thermocompression Bonding}

<Patent Document 1> Japanese Patent Application Laid-Open No. 8-174765

<Patent Document 2> Japanese Patent Application Laid-Open No. 2001-18330

<Patent Document 3> Japanese Patent Application Laid-Open No. 7-214728

<Patent Document 4> Japanese Patent Application Laid-Open No. 2004-273669

The present invention relates to a thermocompression multi-layer rubber sheet used for the purpose of uniformly applying pressure while transferring heat, and in particular, a thermocompression sheet which is excellent in surface releasability and is not bonded to a peripheral device component or a to-be-adhered object. A multilayer rubber sheet for thermocompression bonding, specifically for forming a laminate or a flexible printed circuit board, or when the electrode connected to a liquid crystal panel or the like and the lead electrode of the flexible printed circuit board are electrically and mechanically connected through an anisotropic conductive adhesive, or the like. It relates to a multilayer rubber sheet for thermocompression bonding.

In recent years, the use of liquid crystal panels is increasing as a display for mobile phones, portable computers, computer monitors, video cameras, digital cameras, navigation systems, portable televisions, and thin televisions. In manufacture of this liquid crystal panel, in order to drive a liquid crystal, the transparent lead electrode of a liquid crystal panel and the lead electrode of the flexible printed circuit board on which the LSI for a drive was mounted are thermally crimped | bonded through an epoxy-type anisotropic conductive adhesive, and electrically and mechanically The connection is performed.

In this case, the sheet for thermocompression bonding is used for the purpose of sandwiching between a pressurizing / heating tool and a flexible printed circuit board, transferring heat from a pressurizing / heating tool to an anisotropic conductive adhesive, and applying uniform pressure. As this thermocompression bonding sheet, a fluororesin film such as polytetrafluoroethylene (PTFE) may be used, but in order to apply pressure evenly, a silicone rubber sheet having low elasticity, flexibility and good thermal conductivity It is common to use.

However, the silicone rubber sheet tends to deteriorate because components contained in the anisotropic conductive adhesive tend to migrate into the sheet as compared with the fluororesin film, and as a result, the peeling with the anisotropic conductive adhesive increases, resulting in adhesion and finally. In order to cause breakage, there was a problem in durability as the crimping sheet.

In particular, when used in an anisotropic conductive adhesive using a resin of the type cured by radical polymerization recently appeared, the sheet deteriorates early due to the effect of the components transferred into the sheet, the life of the sheet is extremely shortened There was.

In response to such a problem, a silicone rubber sheet and a fluororesin film are separately prepared, and these two kinds of sheets are superimposed and used. However, in this method, two kinds of sheets are required, resulting in high cost and two kinds of sheets. The need for equipment for feeding sheets also leads to an increase in the cost of the manufacturing apparatus.

A thermocompression bonding sheet for laminating and compounding heat resistant resin films such as a silicone rubber sheet and a fluororesin film has been proposed (Japanese Patent Application Laid-Open No. Hei 8-174765, Japanese Patent Laid-Open No. 2001-18330, and Japanese Patent). Publication No. 7-214728: Patent Documents 1 to 3). However, when these sheets are used, since silicone rubber adheres to the heat resistant resin film, the flexibility is less than that of rubber alone. Therefore, uniform pressure is hardly applied at the time of pressurization, and it is necessary to increase the pressing force, but there is a limit in the strength of the to-be-adhered body, which may not be a problem, and because the heat-resistant resin film is expensive, the cost is increased. There was a flaw in the connection.

On the surface which contacts anisotropically conductive adhesive on a silicone rubber sheet, the thermocompression sheet which laminated | stacked the thin silicone mold release layer of a different composition and improved peelability with anisotropically conductive adhesive is proposed (Japanese Patent Laid-Open No. 2004-273669). Publication: Patent Document 4). However, when this sheet is applied to an anisotropic conductive adhesive that is cured by radical polymerization, the component of the anisotropic conductive adhesive that is cured by radical polymerization transfers to the release layer portion, and deterioration progresses rapidly, and the expected release durability is not obtained. .

This invention is made | formed in view of the said situation, and an object of this invention is to provide the multilayer rubber sheet for thermocompression bonding excellent in the durability to the anisotropic conductive adhesive which used the resin of a radical reaction system.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to achieve the said objective, the multilayer rubber sheet for thermocompression bonding which consists of a multilayer rubber layer provided with the fluorine-type rubber layer in at least one surface of a silicone rubber layer, In this case, Preferably the said silicone rubber layer Organopolysiloxane having an average degree of polymerization (A) of 200 or more: 100 parts by mass, (B) carbon black and / or fine powder silica filler: 0 to 150 parts by mass, (C) metal, fine powder in component (B) At least one member selected from metal oxides, metal nitrides and metal carbides other than silica: 0 to 1,600 parts by mass (the total of (B) component and (C) component is 10 to 1,600 parts by mass), and (D) curing agent A layer formed by molding and curing a silicone rubber composition containing a fluorine-containing rubber, and the fluorine-based rubber layer forms and hardens a perfluoropolyether-based rubber composition containing perfluoropolyether as a main component. The multi-layered rubber sheet for a layer, thermocompression bonding, the surface releasing property is excellent, it is not bonded to the surrounding device components or blood squeezed water, and found that the durability of the anisotropically conductive adhesive using resin of a radical reaction system can be made excellent.

That is, the component contained in an anisotropic conductive adhesive using a resin of a radical reaction system is placed into the sheet by disposing a fluorine-based rubber layer that is hard to shift in the component contained in the anisotropic conductive adhesive of the multilayer rubber sheet for thermal compression bonding in contact with the anisotropic conductive adhesive. Transition can be prevented, and as a result, the degradation by the radical hardening type anisotropic conductive adhesive is very small, and it discovered that it became excellent in durability by repeated use, and came to complete this invention.

Therefore, this invention provides the multilayer rubber sheet for thermocompression bonding shown below.

[1] A multilayer rubber sheet for thermocompression bonding, comprising at least one surface of a silicone rubber layer, a multilayer rubber layer provided with a fluorine-based rubber layer.

[2] The silicone rubber layer is (A) organopolysiloxane having an average degree of polymerization of 200 or more: 100 parts by mass, (B) carbon black and / or fine powder silica-based filler: 0 to 150 parts by mass, (C) metal, the above ( At least one selected from metal oxides, metal nitrides and metal carbides other than fine powder silica in component B): 0 to 1,600 parts by mass (the total of component (B) and component (C) is 10 to 1,600 parts by mass), And (D) The multilayer rubber sheet for thermocompression bonding of [1], which is a layer formed by molding and curing a silicone rubber composition containing a curing agent.

[3] The multilayer rubber sheet for thermocompression bonding [1] or [2], wherein the fluorine-based rubber layer is a layer formed by molding and curing a perfluoropolyether-based rubber composition containing perfluoropolyether as a main component.

[4] The perfluoropolyether-based rubber composition is a linear fluoropolyether compound having two or more alkenyl groups in one molecule of (E) and a perfluoropolyether structure in the main chain, and one molecule of (F). The multilayer rubber sheet for thermocompression bonding of [3], which comprises an organosilicon compound having two or more hydrogen atoms bonded to a silicon atom in the compound, and (G) a hydrosilylation reaction catalyst.

Best Mode for Carrying Out the Invention

The multilayer rubber sheet for thermocompression bonding of the present invention includes a plurality of rubber layers provided with a fluorine-based rubber layer on at least one side of the silicone rubber layer.

It is preferable that the silicone rubber layer in this invention contains the hardened | cured material of the silicone rubber composition containing the following (A)-(D) component.

(A) organopolysiloxane having an average degree of polymerization of 200 or more,

(B) carbon black and / or fine powder silica based filler,

At least one selected from metal (C), metal oxides other than fine powder silica in component (B), metal nitrides and metal carbides,

(D) hardener.

It is preferable that organopolysiloxane more than average polymerization degree 200 which is the said (A) component is represented by the following average composition formula (1).

R ¹ _a SiO _{(4-a) / 2} (1)

(Wherein R ¹ is an unsubstituted or substituted monovalent hydrocarbon group, and a is a positive number of 1.95 to 2.05.)

R ¹ in the above formula is an unsubstituted or substituted monovalent hydrocarbon group, and specific examples of the monovalent hydrocarbon group include an alkyl group such as methyl group, ethyl group and propyl group, cycloalkyl group such as cyclopentyl group and cyclohexyl group, vinyl group and allyl And aryl groups such as alkenyl groups such as groups, phenyl groups and tolyl groups, or halogenated hydrocarbon groups in which these hydrogen atoms are partially substituted with chlorine atoms, fluorine atoms and the like. In this invention, it is preferable that 0.001-5 mol%, especially 0.01-1 mol% of R <^1> is an alkenyl group.

As said organopolysiloxane, it is preferable that a principal chain contains a dimethylsiloxane unit, or the vinyl group, the phenyl group, etc. were introduce | transduced into the principal chain of this organopolysiloxane. In addition, the terminal of the molecular chain may be sealed with a triorganosilyl group or a hydroxyl group. Examples of the triorganosilyl group include trimethylsilyl group, dimethylvinylsilyl group, trivinylsilyl group and the like.

In addition, the average degree of polymerization of the organopolysiloxane is 200 or more, preferably 3,000 to 20,000. If the average degree of polymerization is less than 200, the mechanical strength after curing is poor and may be weak. Moreover, it is preferable that the viscosity in 25 degreeC measured with the B-type rotational viscometer of (A) component is 10 Pa.s or more, especially 50-10,000 Pa.s.

Carbon black, which is component (B), preferably has a volatile content of 0.5% by mass or less, except for moisture, and not only improves the heat resistance and thermal conductivity of the silicone rubber layer, but also improves mechanical strength and conducts the silicone rubber sheet to be conductive. It provides antistatic property. Generally, since the heat resistance of silicone rubber is influenced by pH, moisture, or impurities in the composition, it is necessary to pay careful attention to the selection of the additive. Although carbon black can improve the heat resistance of silicone rubber, it is necessary to consider its impurities and volatile matter. Volatiles of carbon black correspond to the mass of oxygen compounds (acidic components such as carboxyl, quinone, lactone, hydroxyl, etc.) chemically adsorbed on the surface, but since the oxygen compounds vaporize from the surface by heating, Provides adverse effects on heat resistance. Therefore, by using the carbon black whose volatile matter is 0.5 mass% or less, especially 0.2 mass% or less, the heat resistance which can be used even at high temperature 300 degreeC or more can be implement | achieved.

Here, the measuring method of the volatile matter in this invention uses the method described in "the carbon black test method for rubber | gum" of JISK6122. Specifically, the carbon black is charged in a crucible, and the volatile loss after heating for 7 minutes at 950 ° C is measured.

Although carbon black is classified into furnace black, channel black, thermal black, acetylene black, etc. by the manufacturing method, acetylene black, conductive carbon black, etc. are preferable as carbon black whose volatile matter is 0.5 mass% or less (for example, a Japanese patent) 3rd page 36, line 40 of publication (Pac.) 1-272667).

In the present invention, it is preferable to use carbon black having a BET specific surface area of 30 m ² / g or more because carbon black having a large specific surface area has a greater effect of improving heat resistance and suppressing a decrease in mechanical strength at high temperatures. It is especially preferable that it is 50 m <^2> / g or more, and it is more preferable that it is 100 m <^2> / g or more. Moreover, it is preferable that the upper limit of BET specific surface area is 800 m <^2> / g or less, especially 500 m <^2> / g or less.

The fine powder silica is preferably one having a BET specific surface area of 50 m ² / g or more and used as a reinforcing component of silicone rubber. The fine powder silica may be hydrophilic or hydrophobic, but in terms of reinforcement, the BET specific surface area is preferably 50 to 800 m ² / g, and particularly preferably 100 to 500 m ² / g. If the BET specific surface area is less than 50 m ² / g, the reinforcing effect may not be sufficiently obtained.

Both carbon black and fine powder silica which are (B) component have a role which reinforces silicone rubber. In the case of carbon black having a volatilization content of 0.5% by mass or less excluding moisture, the contribution to improving heat resistance is greater than that of fine powder silica having a BET specific surface area of 50 m ² / g or more, but the contribution to strength at room temperature is smaller. These two types of reinforcement components can be adjusted and used according to the use temperature of the multilayer rubber sheet for thermocompression bonding of this invention.

It is preferable that the compounding quantity of (B) component is 0-150 mass parts with respect to 100 mass parts of (A) component, It is especially preferable that it is 10-120 mass parts, It is most preferable to use in the range of 20-100 mass parts. When more than 150 mass parts, not only compounding becomes difficult but molding workability may worsen.

(C) component is 1 or more types chosen from metal, metal oxides other than (B) component, metal nitride, and a metal carbide, and provides thermal conductivity to the multilayer rubber sheet for thermocompression bonding of this invention. Specific examples thereof include silver powder, copper powder, iron powder, nickel powder and aluminum powder as metals, oxides such as zinc, magnesium, aluminum, silicon and iron as metal oxides and nitrides such as boron, aluminum and silicon as metal nitrides. Examples of the metal carbides include carbides such as silicon and boron.

Although the compounding quantity of (C) component is 0-1,600 mass parts with respect to 100 mass parts of (A) component, It is preferable to use especially in the range of 10-1,000 mass parts. When more than 1,600 mass parts, not only compounding becomes difficult but molding workability may worsen.

Moreover, although it is preferable that the total compounding quantity of (B) component and (C) component in this invention is 10-1,600 mass parts with respect to 100 mass parts of (A) component, It is more preferable that it is 20-1,200 mass parts, 30 It is more preferable to use in the range of -1,000 mass parts.

In the case where the rubber strength and heat resistance of the multilayer rubber sheet for thermocompression bonding of the present invention are emphasized, it is preferable to increase the blending amount of carbon black or fine powder silica, which is the component (B), relative to the component (C). In the case where importance is placed on thermal conductivity, it is preferable to increase the compounding amount of the heat conduction imparting material which is the component (C) relative to the component (B). Specifically, it is preferable that the compounding quantity of (B) component is 10-50 mass parts and (C) component is 50-1,000 mass parts with respect to 100 mass parts of (A) component.

The hardening | curing agent as (D) component can be suitably selected from the well-known hardening | curing agents normally used for hardening of a silicone rubber. Examples of these curing agents include organic peroxides such as di-t-butylperoxide, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane and dicumylperoxide used for radical reaction, (A) In the case where the organopolysiloxane as a component has two or more alkenyl groups in one molecule, an organohydrogenpolysiloxane and a platinum-based catalyst containing two or more hydrogen atoms bonded to a silicon atom in one molecule as an addition reaction curing agent, When organopolysiloxane (A) component contains 2 or more silanol groups in 1 molecule, it is a condensation reaction hardening | curing agent, Comprising: Hydrolysable groups, such as an alkoxy group, an acetoxy group, a ketooxime group, a propenoxy group, are 1 The organosilicon compound etc. which have two or more in a molecule | numerator are mentioned. In this invention, it is preferable to harden | cure by radical reaction and / or addition reaction.

Although the addition amount of these hardening | curing agents can be made to be the same as the case of normal silicone rubber, in the case of radical reaction, organic peroxide is 0.1-10 mass parts with respect to 100 mass parts of (A) component, In the case of addition reaction, It is preferable to use in the amount which the SiH group of the organohydrogenpolysiloxane becomes 0.5-5 mol with respect to the alkenyl group of (A) component, and the amount which a platinum-type catalyst becomes 1-2,000 ppm.

In the silicone rubber composition which forms the silicone rubber layer of the present invention, the viscosity of the non-reactive organopolysiloxane and the low-viscosity organopolysiloxane whose terminal is sealed with a hydroxysilyldimethyl group, if necessary, within a range that does not impair the object of the present invention. And diluents for controlling hardness, fillers such as clay, calcium carbonate and diatomaceous earth, inorganic pigments such as cobalt blue, colorants such as organic dyes, heat resistance such as zinc carbonate, manganese carbonate, iron red oxide, platinum group metal catalysts, and the like. Can also be added as other components, such as a flame retardant improver, a low molecular siloxane ester, a dispersing agent such as silanol, a silane coupling agent, an adhesion imparting agent such as a titanium coupling agent, and tetrafluoropolyethylene particles which raise the green strength of the rubber compound.

In the production of the silicone rubber composition, each of the components may be kneaded using a mixer such as a planetary mixer, a kneader, a biaxial roll, a triaxial roll, a Benbury mixer, etc. It is preferable to add.

Here, although the curing conditions at the time of hardening the said silicone rubber composition are selected suitably, as heat-hardening conditions, it is made into 30 second-60 minutes, especially 1 minute-30 minutes at 60-200 degreeC, especially 80-150 degreeC. desirable.

In addition, the JIS K 6253 durometer hardness test type A hardness of the cured product of the silicone rubber composition is preferably 20 or more, particularly preferably 20 to 100. When hardness is too low, it may adhere to a heating heater etc. at the time of crimping, and it may not peel.

In the multilayer rubber sheet for thermocompression bonding of the present invention, the fluorine-based rubber layer is an essential part of the present invention, and is particularly provided to prevent migration of an anisotropic conductive adhesive component using a resin of a radical reaction system. Since this fluorine-type rubber layer also functions as a mold release layer, the multilayer rubber sheet for thermocompression bonding of this invention can maintain the outstanding mold release durability.

The fluorine-based rubber layer is a cured product of the fluorine-based rubber composition, and examples of the fluorine-based rubber composition include a perfluoropolyether-based rubber composition containing perfluoropolyether as a main component. Here, as the perfluoropolyether rubber composition, specifically, (E) a linear fluoropolyether compound having two or more alkenyl groups in one molecule and having a perfluoropolyether structure in the main chain, (F) The thing containing the organosilicon compound which has two or more hydrogen atoms couple | bonded with the silicon atom in 1 molecule, and (G) hydrosilylation reaction catalyst is mentioned.

The linear fluoropolyether compound as the component (E) is a linear fluoropolyether compound having two or more alkenyl groups in one molecule and a perfluoropolyether structure in the main chain.

As an alkenyl group in this linear fluoropolyether compound, a C2-C8 thing is preferable, For example, at the terminal, such as a vinyl group, an allyl group, a propenyl group, an isopropenyl group, butenyl group, a hexenyl group, etc. Groups having a CH ₂ = CH- structure, in particular vinyl groups, allyl groups and the like are preferred. This alkenyl group may be directly bonded to both terminal portions of the linear fluoropolyether compound main chain, and is a divalent linking group such as -CH _2- , -CH ₂ O- or -Y-NR ² -CO- ( Provided that Y represents -CH ₂ -or the following structural formula (Z)

Or o, m or p-dimethylsilylphenylene group, R ² is a hydrogen atom, a methyl group, a phenyl group or an allyl group). Moreover, it is preferable that (E) component has 2 or more alkenyl groups in 1 molecule.

The component (E) has a perfluoropolyether structure in the main chain, but the perfluoropolyether structure will be described below.

As (E) component, the polyfluorodialkenyl compound which has the branch represented by following General formula (2) is mentioned.

CH ₂ = CH- (X) _b -Rf- (X ') _b -CH = CH ₂ (2)

[Wherein X is -CH _2- , -CH ₂ O-, -CH ₂ OCH ₂ -or -Y-NR ² -CO- (Y is -CH ₂ -or the following structural formula (Z)

Is an o, m or p-dimethylsilylphenylene group, R ² is a hydrogen atom, a methyl group, a phenyl group or an allyl group), X 'is -CH _2- , -OCH _2- , -CH ₂ OCH ₂ -or -CO-NR ² -Y '-(Y' is -CH ₂ -or the following structural formula (Z ')

O, m or p-dimethylsilylphenylene group, R ² is the same as above), Rf is a divalent perfluoropolyether group, b is independently 0 or 1.]

Here, Rf of the formula (2) is a divalent perfluoropolyether structure, and the compounds represented by the following formulas (i) and (ii) are preferable.

(In formula, p and q are integers of 1-150, and the average of the sum of p and q is 2-200. Moreover, r is an integer of 0-6, t is 2 or 3.)

(Wherein u is an integer from 1 to 200, v is an integer from 1 to 50, and t is the same as above).

As a preferable example of the polyfluorodialkenyl compound represented by the said General formula (2), the compound represented by following General formula (3) is mentioned.

[Wherein X is -CH _2- , -CH ₂ O-, -CH ₂ OCH ₂ -or -Y-NR ² -CO- (Y is -CH ₂ -or the following structural formula (Z)

Is an o, m or p-dimethylsilylphenylene group, R ² is a hydrogen atom, a methyl group, a phenyl group or an allyl group), X 'is -CH _2- , -OCH _2- , -CH ₂ OCH ₂ -or -CO-NR ² -Y '-(Y' is -CH ₂ -or the following structural formula (Z ')

O, m or p-dimethylsilylphenylene group, R ² is the same as described above). b is independently 0 or 1, e is an integer of 2-6, c and d are each an integer of 0-200.]

(F) component of this invention is an organosilicon compound which has 2 or more of hydrogen atoms couple | bonded with the silicon atom in 1 molecule. The component (F) functions as a crosslinking agent to a chain length extender of the component (E), and has one or more fluorine-containing groups in one molecule in view of compatibility with the component (E), dispersibility, and uniformity after curing. It is preferable.

As this fluorine-containing group, what is represented, for example by the following formula is mentioned.

C _g F _{2g + 1-}

(Wherein g is an integer of 1 to 20, preferably 2 to 10).

-C _g F _2g-

(Wherein g is an integer of 1 to 20, preferably 2 to 10).

(In formula, f is 2-200, Preferably it is an integer of 2-100, h is an integer of 1-3.)

(Wherein j and k are integers of 1 or more, and the average of j + k is 2 to 200, preferably 2 to 100.)

As (F) component which has such a fluorine-containing group, the following compound is mentioned, for example. These compounds may be used alone or in combination of two or more kinds thereof. In the following chemical formulae, Me represents a methyl group and Ph represents a phenyl group.

As for the compounding quantity of the said (F) component, the hydrosilyl group of (F) component, ie, Si-H group, is preferable with respect to 1 mol of alkenyl groups, such as a vinyl group, an allyl group, and a cycloalkenyl group normally contained in (E) component. Preferably it is 0.5-5 mol, More preferably, it is the quantity which can supply 1-2 mol. If it is less than 0.5 mole, the degree of crosslinking may be insufficient, and if it exceeds 5 moles, the chain length extension may take precedence, and curing may be insufficient, foaming, heat resistance, compression set, and distortion may deteriorate.

Component (G) of the present invention is a hydrosilylation reaction catalyst. The hydrosilylation reaction catalyst is a catalyst for promoting the addition reaction of the alkenyl group in the component (E) and the hydrosilyl group in the component (F). This hydrosilylation reaction catalyst is generally a noble metal compound, and a platinum or platinum compound which is relatively easy to obtain because of its high price is often used.

Examples of the platinum compound include complexes of chloroplatinic acid or chloroplatinic acid with olefins such as ethylene, complexes of alcohols and vinylsiloxanes, metal platinum carrying silica, alumina, carbon and the like. As platinum group metal catalysts other than the platinum compound, rhodium, ruthenium, iridium and palladium-based compounds are also known. For example, RhCl (PPh ₃ ) ₃ , RhCl (CO) (PPh ₃ ) ₂ , Ru ₃ (CO) ₁₂ , IrCl (CO) (PPh ₃ ) ₂ , Pd (PPh ₃ ) ₄ and the like can be exemplified.

Although the compounding quantity of a hydrosilylation reaction catalyst can be made into a catalytic amount, it is preferable to mix | blend in the mass ratio of 0.1-100 ppm (platinum conversion) with respect to the total amount of (E) and (F) component normally.

In the fluorine-based rubber composition of the present invention, in addition to the components (E) to (G), various fillers may be added for the purpose of improving mechanical strength, improving mold release durability, and imparting thermal conductivity.

Examples of the filler include fumed silica, wet silica, pulverized silica, calcium carbonate, diatomaceous earth, plastic spherical fillers, silicon powder, carbon black, various metals and metal oxides, and these may be treated with various surface treatment agents. Among them, fumed silica is particularly preferable from the viewpoint of release durability improvement, and from the viewpoint of dispersibility improvement, it is preferable that the fumed silica is treated with a silane-based surface treatment agent.

As addition amount of a filler, 5-200 mass parts is preferable with respect to 100 mass parts of (E) component. In particular, 10-60 mass parts is preferable at the point of stability of mold release characteristics.

Moreover, the fluorine-type rubber composition of this invention can also mix | blend a suitable pigment, dye, etc. as needed. Moreover, various compounding agents can be added in the range which does not impair the objective of this invention. As such optional components, for example, 1-ethynyl-1-hydroxycyclohexane, 3-methyl-1-butyn-3-ol, 3,5-dimethyl-1-hexyn-3-ol, 3-methyl- Acetylene alcohols such as 1-penten-3-ol and phenylbutenol, 3-methyl-3-pentene-1-yne, 3,5-dimethyl-3-hexene-1-yne, or polymethylvinylsiloxane cyclic compounds And control agents for hydrosilylation reaction catalysts such as organophosphorus compounds, whereby curing reactivity and storage stability can be appropriately maintained.

The production of the fluorine-based rubber composition of the present invention is not particularly limited and can be produced by mixing the above components with each other. Moreover, it can also be made into 2 compositions and to mix at the time of use.

 Here, the curing conditions at the time of curing the fluorine-based rubber composition is appropriately selected, but as the heat curing conditions, usually 10 to 30 minutes at a temperature of 100 to 180 ℃, especially 120 to 150 ℃, especially 1 to 5 minutes It is preferable to make it to an extent.

In addition, the JIS K 6253 durometer hardness test type A hardness of the cured product of the fluorine-based rubber composition is preferably 20 or more, particularly preferably 30 to 95. When hardness is less than 20, there exists a possibility that it may become easy to adhere to each to-be-pressed member at the time of crimping | compression-bonding.

The manufacturing method of the multilayer rubber sheet for thermocompression bonding of this invention applied the said fluorine-type rubber composition directly or on the silicone rubber layer containing the hardened | cured material of the silicone rubber composition containing the said (A)-(D) component, or apply | coating a primer directly. After coating, it is performed by a conventionally well-known method, such as hardening.

Here, although the following method is mentioned as a method of manufacturing the multilayer rubber sheet for thermocompression bonding of this invention, it is not limited to this.

(1) Knife coating, coma coating, and bar coating of a silicone rubber composition on a embossed carrier film after calender molding, extrusion molding or heat curing, followed by dissolving the fluorine-based rubber composition in a fluorine-based solvent and liquefying it. Coating molding by methods such as dip coating and dip coating, and removing the solvent and heating and curing in the air as it is. In this case, when the viscosity of a fluorine-type rubber composition is low, it can also coat shape as it is, without melt | dissolving in a fluorine-type solvent.

(2) After dissolving the silicone rubber composition in a solvent such as toluene and liquefying, coating molding, solvent removal, and heat curing on the embossed carrier film, the fluorinated rubber composition is dissolved in the fluorine solvent to liquefy the material. A method of coating molding by knife coating, coma coating, bar coating, dip coating or the like, and then removing the solvent and heating and curing in the air as it is. In this case, when the viscosity of a fluorine-type rubber composition is low, it can also coat shape as it is, without melt | dissolving in a fluorine-type solvent.

(3) The silicone rubber composition is dissolved in a solvent such as toluene and liquefied to form a coating on an embossed carrier film. The solvent powder is removed and left uncured, and the fluorine-based rubber composition is dissolved in a fluorine-based solvent to liquefy. A method of further coating molding one material by a method such as knife coating, coma coating, bar coating, dip coating, and the like and removing the solvent in the air as it is, followed by heat curing of the two layers. In this case, when the viscosity of a fluorine-type rubber composition is low, it can also coat shape as it is, without melt | dissolving in a fluorine-type solvent.

In the present invention, a method such as primer treatment may be appropriately used in order to secure the adhesion between the silicone rubber layer and the fluorine rubber layer. In addition, although the fluorine-type rubber layer may be provided in both surfaces of a silicone rubber layer, and it can be set as a three-layer structure, in this case, the material of two layers of the fluorine-type rubber layer may be different, or may be the same.

The multilayer rubber sheet for thermocompression bonding of this invention can also be reinforced by the reinforcement containing the cross or glass cross containing resin with glass transition temperature of 200 degreeC or more.

In the multilayer rubber sheet for thermal compression of the present invention, the thickness of the fluorine-based rubber layer is 1 to 50 µm, and the thickness of the entire multilayer rubber sheet in which the silicon rubber layer and the fluorine-based rubber layer are combined is preferably 0.1 to 10 mm, particularly the fluorine-based rubber layer. It is preferable that the thickness of is 2-30 micrometers, and the thickness of the whole multilayer rubber sheet which combined the said silicone rubber layer and the fluorine-type rubber layer is 0.2-10 mm. If the thickness of the fluorine-based rubber layer is less than 1 µm, sufficient releasability may not be expressed. If it exceeds 50 µm, the thermal conductivity may deteriorate. In addition, when the thickness of the whole multilayer rubber sheet which combined the silicone rubber layer and the fluorine-based rubber layer is less than 0.1 mm, since it cannot fully follow a to-be-adhered body, the direction in which pressure is applied may become nonuniform, and when it exceeds 10 mm, thermal conductivity This may deteriorate.

It is preferable that the volatile matter at the time of heating at 150 degreeC for the multilayer rubber sheet for thermocompression bonding of this invention is 0.2 mass% or less, and also 0.1 mass% or less. When volatile matter exceeds 0.2 mass%, the cyclic polysiloxane which is a main component of volatile matter may contaminate surrounding electronic equipment. For this purpose, it is preferable to heat-process a multilayer rubber sheet at high temperature, and to heat-process at temperature 150 degreeC or more in a dryer or a continuous heating furnace.

<Example>

Hereinafter, although an Example and a comparative example are shown and this invention is demonstrated concretely, this invention is not limited to a following example. In addition, in the following example, a viscosity shows the value in 25 degreeC measured by JIS K 7117, an average particle diameter shows the value measured by the particle analyzer, and a volatile matter shows the "rubber carbon black test of JIS K 6221. Method according to the method ".

Example 1

Aluminum oxide powder Alumina AL-45 (manufactured by Showa Denko Co., Ltd.) as a good thermally conductive filler, 100 parts by mass of methylvinylpolysiloxane having an average degree of polymerization of 8,000, containing 99.85 mol% of dimethylsiloxane units and 0.15 mol% of methylvinylsiloxane units. ) 400 parts by mass, 30 parts by mass of fine silica aerosil 200 (manufactured by Nippon Aerosil Co., Ltd.) having a BET specific surface area of 200 m ² / g, and α, ω- represented by the following general formula (4): 5 mass parts of dihydroxymethyl polysiloxane was knead | mixed uniformly using the kneading machine, and it heat-processed at 150 degreeC for 2 hours.

After cooling, 0.5 parts by mass of cerium oxide powder having a BET specific surface area of 140 m ² / g and 1.5 parts by mass of organic peroxide C-23 (manufactured by Shin-Etsu Chemical Co., Ltd.) as 100 parts by mass of this silicone rubber compound, The mixture was added and mixed using a biaxial roll, spouted to a thickness of 0.30 mm using a calender molding machine, and then placed on a 125 µm thick PET film embossed on one side with a centerline surface roughness Ra of 0.7 µm. The silicone rubber layer of the multilayer rubber sheet for thermocompression bonding of this invention was manufactured by hardening | curing by passing through the inside of a 160 degreeC heating furnace for 5 minutes.

Subsequently, fumed silica having a BET specific surface area of 200 m ² / g treated with a dimethylsiloxy group in 100 parts by mass of a polymer represented by the following general formula (5) (viscosity 8,500 cs, average molecular weight 22,000, vinyl group amount 0.009 mol / 100 g) After adding 15 parts by mass, mixing, heat treatment and mixing on a triaxial roll mill, 20 parts by mass of a silicone rubber powder having an average particle diameter of 5 μm having a structure of crosslinking linear dimethylpolyorganosiloxane and 20 parts by mass of a BET specific surface area 0.5 mass part of cerium oxide powders which are 140 m <^2> / g were added, it mixed at room temperature for 1 hour, and further mixed with the triaxial roll. Also, 2.74 parts by mass of a fluorine-containing organosilicon compound represented by the following formula (6), 0.2 parts by mass of a toluene solution (platinum concentration 1.0 mass%) and fluorine of a catalyst obtained by modifying chloroplatinic acid with a compound represented by the following formula (7) 0.4 mass part of modified acetylene alcohol was added, and it mixed and manufactured the fluorine-type rubber composition.

The composition was defoamed under reduced pressure, placed in a rectangular frame having a thickness of 2 mm, degassed again, and press cured for 5 minutes at 100 kgf / cm ² and 150 ° C. The test piece was cut out from the hardened sample, and the type A hardness by the durometer hardness test measured in accordance with JIS K 6253 was 38.

The uncured composition of the fluorine-based rubber composition was dissolved in FR thinner (a fluorine-based solvent manufactured by Shin-Etsu Chemical Co., Ltd.), adjusted to 40 mass%, and coated and molded to a thickness of 15 μm by a knife coater on the silicone rubber layer. Thereafter, the inside of the furnace at 50 ° C. was passed through for 5 minutes to remove the FR thinner, and then the inside of the furnace at 150 ° C. was passed through for 5 minutes for crosslinking and curing. Subsequently, the multilayer rubber sheet having a two-layer structure was peeled from the PET film and post-cured at 200 ° C. for 4 hours. The fluorine-based rubber layer had a thickness of 15 μm, and the silicon rubber layer and the fluorine-based rubber layer were combined to have a thickness of 0.315 mm. The multilayer rubber sheet for thermocompression bonding of this invention was manufactured.

Example 2

Aluminum oxide powder Alumina AL-45 (manufactured by Showa Denko Co., Ltd.) as a good thermally conductive filler, 100 parts by mass of methylvinylpolysiloxane having an average degree of polymerization of 8,000, containing 99.85 mol% of dimethylsiloxane units and 0.15 mol% of methylvinylsiloxane units. ) 400 parts by mass, 30 parts by mass of fine silica aerosil 200 (manufactured by Nippon Aerosil Co., Ltd.) having a BET specific surface area of 200 m ² / g, and α, ω- represented by the following general formula (4): 5 mass parts of dihydroxymethyl polysiloxane was knead | mixed uniformly using the kneading machine, and it heat-processed at 150 degreeC for 2 hours.

After cooling, 0.5 parts by mass of cerium oxide powder having a BET specific surface area of 140 m ² / g and 1.5 parts by mass of organic peroxide C-23 (manufactured by Shin-Etsu Chemical Co., Ltd.) as 100 parts by mass of this silicone rubber compound, Add and mix using a biaxial roll, blow off using a calender molding machine to a thickness of 0.30 mm, transfer to a PET film having a thickness of 125 μm on one side embossed with a centerline surface roughness Ra of 0.7 μm, 160 The inside of the furnace at 5 ° C. was allowed to pass through for 5 minutes to cure, thereby producing a silicone rubber layer of the multilayer rubber sheet for thermal compression of the present invention.

Subsequently, the fluorine rubber composition was manufactured like Example 1 except having used 4.39 mass parts of fluorine-containing organosilicon compounds represented by following General formula (8) instead of General formula (6) of Example 1.

The composition was defoamed under reduced pressure, placed in a rectangular frame having a thickness of 2 mm, degassed again, and press cured for 5 minutes at 100 kgf / cm ² and 150 ° C. The test piece was cut out from the hardened sample, and the type A hardness by the durometer hardness test measured in accordance with JIS K 6253 was 33.

The uncured composition of the fluorine-based rubber composition was dissolved in FR thinner (a fluorine-based solvent manufactured by Shin-Etsu Chemical Co., Ltd.), adjusted to 40 mass%, and coated and molded to a thickness of 15 μm by a knife coater on the silicone rubber layer. Thereafter, the inside of the furnace at 50 ° C. was passed through for 5 minutes to remove the FR thinner. Then, the inside of the furnace at 150 ° C. was passed through for 5 minutes for crosslinking and curing. Subsequently, the multilayer rubber sheet having a two-layer structure was peeled from the PET film and post-cured at 200 ° C. for 4 hours. The thickness of the fluorine-based rubber layer was 15 μm, and the total thickness of the multilayer rubber sheet was 0.315 mm by combining the silicone rubber layer and the fluorine-based rubber layer. The multilayer rubber sheet for thermocompression bonding of this invention was manufactured.

Example 3

To 100 parts by mass of methylvinylpolysiloxane having an average degree of polymerization of 8,000 containing 99.85 mol% of dimethylsiloxane units and 0.15 mol% of methylvinylsiloxane units, the average particle diameter is 23 nm, the volatile content is 0.10 mass%, and the BET specific surface area is 130 m ² / g. the acetylene black of 50 parts by weight and a BET specific surface area of 120 m ² / g of hydrophobic silica (H be in the R-972: trade name, manufactured by Degussa Co., Ltd.) 5 parts by weight, and a BET specific oxidizing a surface area of 140 m ² / g 0.5 mass part of cerium powder was mix | blended with the biaxial roll, it knead | mixed, and it was uniformized.

0.1 mass part of isopropyl alcohol solution (platinum 2 mass%) of a chloroplatinic acid, 0.1 mass part of ethynylcyclohexanol which are reaction inhibitors, and 100 mass parts of this silicone rubber compound, and following General formula (9)

1.2 mass parts of methylhydrogen polysiloxanes represented by were added, and it knead | mixed well by the biaxial roll, and the curable silicone rubber compound which turns into the silicone rubber layer of the multilayer rubber sheet for thermocompression bonding of this invention was manufactured.

The silicone rubber compound was ejected to a thickness of 0.25 mm using a calender molding machine, and then transferred onto a 125 μm-thick polyethylene terephthalate (PET) film having a single-side embossed surface having a centerline surface roughness Ra of 0.7 μm, followed by 160 ° C. The inside of the furnace was cured by passing through the inside for 5 minutes to prepare a silicone rubber layer of the multilayer rubber sheet for thermocompression bonding of the present invention.

The composition and molding method of the fluorine-based rubber composition were carried out in the same manner as in Example 1, and the thickness of the entire multilayer rubber sheet was 0.265 mm, with the thickness of the fluorine-based rubber layer being 15 µm, the silicon rubber layer, and the fluorine-based rubber layer being the same, as in Example 1. It post-cured and manufactured the multilayer rubber sheet for thermocompression bonding of this invention.

Example 4

A silicone rubber layer was prepared in the same manner as in Example 3, a fluorine-based rubber layer was prepared in the same manner as in Example 2, and the multilayer rubber sheet for thermal compression of the present invention was manufactured.

Comparative Example 1

In the same manner as in Example 1, a first silicone rubber layer having a thickness of 0.2 mm was prepared.

Further, 85 parts by mass of dimethylpolysiloxane having an average degree of polymerization of 180 parts by which both ends of the molecular chain are blocked with vinyldimethylsilyl group, 10 parts by mass of dimethylpolysiloxane having an average degree of polymerization of 510, which is enclosed by vinyldimethylsilyl groups by both ends of the molecular chain, and dimethylsiloxane Hydrophilic silica (Aerosil 300) having a BET specific surface area of about 300 m ² / g in 5 parts by mass of methylvinylpolysiloxane having an average degree of polymerization of 8,000 comprising 90.25 mole percent units and 9.75 mole percent methylvinylsiloxane units. : After adding 5 mass parts of Nippon Aerosil Co., Ltd. brand names, and adding 1 mass part of hexamethyldisilazane and 0.5 mass part of water in a planetary mixer for 1 hour, after mixing at room temperature, It heat-processed 160 degreeC for 4 hours, and lowered temperature to normal temperature.

Then, dimethyl polyorganosiloxane having structure having an average particle size of the silicone rubber powder to 30 parts by weight and the BET specific surface area of 5 ㎛ crosslinking of straight chain is 140 m ² / g is added cerium powder, 0.5 parts by weight of oxide, and 1 at room temperature After time mixing, the mixture was further mixed with a triaxial roll.

In addition, 50 parts by mass of chloroplatinic acid as platinum mass and ethanol cyclohexanol as a reaction inhibitor with respect to dimethylpolysiloxanes other than silicone powder were 0.2 parts by mass based on 100 parts by mass of dimethylpolysiloxane other than silicon powder.

8 mass parts of methylhydrogenpolysiloxanes represented by are added while mixing, and the composition used as the 2nd silicone rubber layer of a uniform composition was manufactured. The type A hardness by JISK6225 durometer hardness test after heating and hardening this composition at 150 degreeC for 5 minutes, and post-curing at 200 degreeC for 4 hours was 40.

The uncured composition of the second silicone rubber layer was dissolved in toluene, adjusted to 40 mass%, coated on a first silicone rubber layer by a knife coater to a thickness of 15 μm, and then in a 50 ° C. heating furnace as it was. Was passed through for 5 minutes to remove toluene, and then passed through a 150 ° C heating furnace for 5 minutes to crosslink and harden. Subsequently, the silicone rubber sheet having a two-layer structure was peeled from the PET film and post-cured at 200 ° C. for 4 hours. The thickness of the second silicone rubber layer was 15 μm, and the first silicone rubber layer and the second silicone rubber layer were combined to form the entire silicone rubber sheet. A thermocompression silicone rubber sheet having a thickness of 0.315 mm was prepared.

(Compression test evaluation)

The sheet for thermocompression bonding has a part directly contacting the anisotropic conductive adhesive at the time of thermocompression bonding. Therefore, in order to show the adhesiveness to this anisotropically conductive adhesive agent, the anisotropically conductive adhesive agent is used under the multilayer rubber sheet for thermocompression bonding of this invention manufactured by Examples 1-4 and Comparative Example 1, and the silicone rubber sheet for thermocompression bonding. The anisotropic conductive film to be included was placed directly, and a pressurizer was placed therebetween so as to sandwich a 100 μm-thick polyimide film therebetween, and the film was pressed for 20 seconds using a pressing tool heated to 320 ° C. The rubber sheet for thermocompression being an object to be evaluated has a silicone rubber layer in the case of Examples 1 to 4 on the pressing tool side, a first silicone rubber layer in the case of Comparative Example 1, and a fluorine-based rubber layer in the case of Examples 1 to 4 on the anisotropic conductive film side. In the case of Comparative Example 1, the second silicon rubber layer was set to be disposed. After the completion of one crimping, the anisotropic conductive film is replaced with a new material, and the rubber sheet for thermocompression bonding is repeated using the same object as it is, and the number of times until the anisotropic conductive adhesive adheres to the rubber sheet for thermocompression bonding is measured. It was.

In this evaluation, the epoxy-based anisotropic conductive film Ani-Sorme AC-2052 (trade name manufactured by Hitachi Kasei), which has been widely used in the past, and Aniso AC-9051 (Hitachi Kasei manufactured by Hitachi Chemical Co., Ltd.) ) Was used.

The results are summarized in Table 1. The multilayer rubber sheet for thermocompression bonding of Examples 1 to 4 according to the present invention was found to have very little deterioration due to a radically curable anisotropic conductive adhesive, and to have good durability due to repeated use.

In the multilayer rubber sheet for thermocompression bonding of the present invention, since the fluorine-based rubber layer is laminated on the silicone rubber excellent in thermal conductivity, the silicone rubber alone causes components contained in the anisotropic conductive adhesive to move into the sheet and rapidly deteriorate. Even if it is used repeatedly, the deterioration is very low and shows excellent durability as a sheet for thermocompression bonding.

Claims (4)

The multilayer rubber sheet for thermocompression bonding containing the multilayer rubber layer in which the fluorine-type rubber layer was provided in at least one surface of a silicone rubber layer. The organopolysiloxane according to claim 1, wherein the silicone rubber layer (A) has an average degree of polymerization of 200 or more: 100 parts by mass, (B) carbon black and / or fine powder silica filler: 0 to 150 parts by mass, (C) metal 1 or more types chosen from metal oxides, metal nitrides, and metal carbides other than fine powder silica in the said (B) component: (The sum total of (B) component and (C) component is 10-1,600 mass) And (D) a multilayer rubber sheet for thermocompression bonding, which is a layer formed by molding and curing a silicone rubber composition containing a curing agent. The multilayer rubber sheet for thermocompression bonding according to claim 1 or 2, wherein the fluorine-based rubber layer is a layer formed by molding and curing a perfluoropolyether-based rubber composition containing perfluoropolyether as a main component. The linear fluoropolyether compound according to claim 3, wherein the perfluoropolyether rubber composition has (E) at least two alkenyl groups in one molecule and a perfluoropolyether structure in the main chain, (F) The multilayer rubber sheet for thermocompression bonding comprising an organosilicon compound having two or more hydrogen atoms bonded to silicon atoms in one molecule, and (G) a hydrosilylation reaction catalyst.