JPH1143649A - Insulating adhesive sheet and laminate prepared by using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a laminate excellent in heat resistance and glass transition temp. by using an insulating adhesive sheet which is formed by sheeting a compsn. prepd. by compounding an epoxy resin, a curative, and an elastomer each in a specified amt. SOLUTION: A compsn. prepd. by compounding 100 pts.wt. sum of an epoxy resin and a curative with 20-50 pts.wt. elastomer is formed into a sheet. The epoxy resin used is one having at least two epoxy groups per molecule and is selected from among bisphenol A and F type epoxy resins, phenol-novolak type epoxy resins, etc. The curative used is an amide-base or phenol-base curative or an acid anhydride. The elastomer is pref. a cross-linked one, and SBR, SBS, SIS, butyl rubber, a silicone rubber, an acrylic rubber, etc., can be used. The compsn. may be formed into a sheet by casting or may be applied to one side of a copper foil, etc., to give an adhesive sheet.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an insulating adhesive sheet,
And, regarding a laminated board using this insulating adhesive sheet, specifically, a laminated board used for manufacturing a printed wiring board,
And an epoxy resin composition and an insulating adhesive sheet or an insulating adhesive sheet with a metal foil used in the production of the laminate.

[0002]

2. Description of the Related Art A multilayer printed wiring board used for electric / electronic equipment is manufactured by, for example, the following method. As a material, a prepreg and a copper foil, which are obtained by impregnating a thermosetting resin composition such as an epoxy resin composition into a base material such as a copper foil-clad laminate and a glass cloth, and then drying by heating and semi-curing, are used. Then, after the copper foil on the surface of the copper foil-clad laminate is etched to form a copper circuit for the inner layer, if necessary, a surface treatment is performed on the copper circuit to increase the adhesive strength, and then for the inner layer, A required number of prepregs are stacked on the surface of the copper circuit, and copper foil for the outer layer is arranged outside the prepreg, laminated and heated and pressed to form a base between the inner layer copper circuit and the outer layer copper foil. A multilayer laminate having an insulating layer made of a material and a thermosetting resin composition is manufactured.

[0003] Next, after punching a hole in the multilayer laminate, a plating metal film is formed on the wall surface of the hole to connect the inner layer copper circuit and the outer layer copper foil, and then the outer layer copper foil is etched. Printed wiring boards are manufactured by forming outer layer circuits.

[0004] With the recent demand for higher density and higher productivity of printed wiring boards, an insulating layer made of a thermosetting resin composition alone without using a base material between an inner copper circuit and an outer copper foil is required. The use of a formed multi-layer laminate generally called a build-up substrate is being studied. This build-up board is a laminated board manufactured by alternately stacking the insulating layer and the conductor layer of the thermosetting resin composition alone on the surface of the copper circuit for the inner layer, and is not limited by the thickness of the base material. There is a feature that the thickness of the layer can be reduced, and a feature that the drilling can be performed by a laser because a base material is not used, and that the productivity of the drilling is high.

[0005] As a method of forming the insulating layer of the build-up substrate, a method of applying a liquid thermosetting resin composition to the surface of a copper circuit for an inner layer and then curing the same is generally performed. .

[0006]

However, in the case of this method, the thermosetting resin composition flows because of the liquid state, and the thickness of the insulating layer tends to vary, and bubbles are formed in the insulating layer. There was a problem that it was easy to be. Therefore, a method has been studied in which an adhesive sheet of a thermosetting resin composition is overlaid on the surface of a copper circuit for an inner layer, and then pressed to form an insulating layer.

[0007] Since a thermosetting resin composition using an epoxy resin is generally brittle and it is difficult to form a practical adhesive sheet, it is softened by blending an elastomer such as a styrene-butadiene copolymer. The use of the structured epoxy resin composition to form a sheet has been studied. However, when the epoxy resin composition containing this elastomer is used, there are problems that the heat resistance of the obtained laminate is low and that the glass transition temperature is low.

Therefore, there is a need for an epoxy resin composition that can form an adhesive sheet and that can provide a laminate having excellent heat resistance and glass transition temperature.

The present invention has been made to solve the above problems, and an object of the present invention is to provide an insulating adhesive sheet for manufacturing a laminated board, which has excellent heat resistance and glass transition temperature. It is to provide an insulating adhesive sheet from which a board can be obtained. Another object of the present invention is to provide a laminate having excellent heat resistance and glass transition temperature.

[0010]

According to a first aspect of the present invention, there is provided an insulating adhesive sheet comprising a total of 100 parts by weight of an epoxy resin and a curing agent of an epoxy resin, and 20 parts of an elastomer.
It is characterized in that the epoxy resin composition containing up to 50 parts by weight is formed into a sheet.

[0011] The insulating adhesive sheet according to claim 2 of the present invention has a total of 10 including epoxy resin and epoxy resin curing agent.
A layer of an epoxy resin composition containing 20 to 50 parts by weight of an elastomer with respect to 0 parts by weight is formed on one surface of a metal foil.

The insulating adhesive sheet according to claim 3 of the present invention is characterized in that the elastomer is crosslinked.

According to a fourth aspect of the present invention, there is provided a laminate according to any one of the first to third aspects.
Is bonded to the surface of the substrate (2) having a conductor circuit on the surface.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail.

FIG. 1 is a schematic view showing a laminated plate according to one embodiment of the present invention. The epoxy resin contained in the epoxy resin composition of the present invention is not particularly limited as long as it is an epoxy resin having two or more epoxy groups in one molecule. For example, bisphenol A type epoxy resin, bisphenol F type epoxy resin Resin, bisphenol S type epoxy resin, phenol novolak type epoxy resin, cresol novolak type epoxy resin, bisphenol A
Novolak epoxy resin, 2,6-xylenol dimer glycidyl etherified resin, bisphenol F
Novolak epoxy resin, isocyanurate epoxy resin, hydantoin epoxy resin, polyfunctional epoxy resin such as trifunctional epoxy resin and tetrafunctional epoxy resin, glycidylamine epoxy resin, glycidylated epoxy resin of diaminophenyl ether , An alicyclic epoxy resin, or a halogenated flame-retardant resin thereof. These epoxy resins can be used alone or in combination of a plurality of types. Further, an epoxy resin having one epoxy group in one molecule can be used in combination.

Examples of the epoxy resin curing agent contained in the epoxy resin composition include amide-based curing agents such as dicyandiamide and aliphatic polyamide, amine-based curing agents such as diaminodiphenylmethane, triethylamine and diethylamine, bisphenol A and bisphenol. F, phenol novolak resin, cresol novolak resin,
Examples thereof include phenol-based curing agents such as p-xylene-novolak resin, and acid anhydrides, and two or more kinds may be used in combination.

It is practical to add a curing accelerator to the epoxy resin composition in order to accelerate the curing reaction. Examples of the curing accelerator that can be contained include imidazoles such as 2-methylimidazole, 2-ethyl-4-methylimidazole, and 2-phenylimidazole;
1,8-diaza-bicyclo [5.4.0] undecene-
7, tertiary amines such as triethylenediamine and benzyldimethylamine; organic phosphines such as tributylphosphine and triphenylphosphine; and tetraphenylboron salts such as tetraphenylphosphonium tetraphenylborate and triphenylphosphine tetraphenylborate. Two or more types may be used in combination.

The elastomer contained in the epoxy resin is not particularly limited, whether it is reactive or non-reactive, but an elastomer called a crosslinked rubber is preferred.

The amount of the elastomer is 10% in total of epoxy resin and epoxy resin curing agent.
It is preferable to contain 20 to 50 parts by weight with respect to 0 parts by weight. When the amount is less than 20 parts by weight, the effect of making the thermosetting resin composition a flexible structure is small, and it is difficult to form an insulating adhesive sheet. If the amount exceeds 50 parts by weight, the heat resistance of the obtained laminate may decrease.

The constituents of the crosslinked elastomer are not particularly limited, but include SBR (styrene-butadiene rubber), SBS (styrene-butadiene-styrene copolymer), and SEBS (styrene-ethylene-butene-styrene). Styrene copolymer), SIS (styrene-
Isoprene-styrene copolymer), butyl rubber, urethane rubber, silicone rubber, polysulfide rubber, hydrogenated nitrile rubber, polyether special rubber, fluoro rubber, tetrafluoroethylene propylene rubber, acrylic rubber, epichlorohydrin rubber, propylene oxide rubber , Ethylene vinyl acetate copolymer, ethylene acrylic rubber, norpolene rubber, thermoplastic elastomer and the like having a chemical composition are used.

The epoxy resin composition may contain an inorganic filler, a solvent, and the like, if necessary. Examples of the inorganic filler that can be contained include titanium dioxide-based ceramics, barium titanate-based ceramics, lead titanate-based ceramics, strontium titanate-based ceramics, calcium titanate-based ceramics, bismuth titanate-based ceramics, and magnesium titanate-based ceramics. ceramic,
Examples include inorganic fillers having a dielectric constant of 100 or more, such as lead zirconate-based ceramics, silica powder, glass fiber, and talc. Two or more kinds may be used in combination. Examples of the solvent that can be contained include organic solvents such as toluene, xylene, benzene, ketone, and alcohols.

The resulting epoxy resin composition is formed into a sheet to produce an insulating adhesive sheet (1). The method of forming this sheet is not particularly limited,
For example, after applying the epoxy resin composition to a sheet that does not dissolve in the epoxy resin composition such as a polyester film or a polyimide film to a thickness of 5 to 700 μm, drying the sheet, and then peeling off the sheet, a method generally called a casting method is used. It is formed by heat-melting a solid epoxy resin composition and forming it into a sheet by extrusion molding. In addition, in the case of the method of manufacturing by applying to a sheet, the sheet can be more easily formed at a relatively low temperature as compared with the extrusion molding method, which is preferable. The sheet to which the epoxy resin composition is applied is preferably excellent in productivity because the use of a sheet surface-treated with a release agent facilitates peeling.

Further, the obtained epoxy resin composition is applied to one surface of a metal foil and then dried to form an adhesive sheet having a layer of the epoxy resin composition formed on one surface of the metal foil. Is also good. When this adhesive sheet is used, air bubbles are rarely generated between the metal foil and the insulating layer of the obtained laminate, and a laminate having excellent insulation reliability is obtained, which is preferable. In addition, as the metal foil, a copper foil, an aluminum foil or the like is used, and a thickness of 0.01 to 0.070 mm is generally used.

Further, as shown in FIG. 1, the laminated board of the present invention is formed by adhering any one of the above-mentioned insulating adhesive sheets (1) to the surface of a substrate (2) having a conductor circuit on the surface. Is what it is.

That is, the adhesive sheet is adhered to the conductor circuit on the surface of the substrate (2) having the conductor circuit on the surface to produce a laminate. In the case of an adhesive sheet of the epoxy resin composition alone, the substrate (2)
An adhesive sheet is superimposed on the conductor circuit on the surface, and a metal foil is further superimposed on the adhesive sheet to form a pressurized body, and the pressurized body is heated and pressed to produce a laminate. As the metal foil, the same metal foil as used in the production of the adhesive sheet in which the layer of the epoxy resin composition is formed on one surface of the metal foil is used. Also,
When the epoxy resin composition layer is bonded using an adhesive sheet formed on one surface of a metal foil, the side of the epoxy resin composition layer of the adhesive sheet is superimposed on a conductor circuit on the surface of the substrate (2). A pressed body is heated and pressed to produce a laminated plate. The laminate thus obtained is a laminate having excellent heat resistance and glass transition temperature.

Since the crosslinking reaction of the adhesive sheet mainly depends on the reaction temperature of the curing agent for the epoxy resin, the heating temperature and the heating time may be selected according to the type of the curing agent for the epoxy resin. In general, the temperature is 150 ° C. to 300 ° C.,
Heating and pressurizing are performed under the conditions of a pressure of 1 to 7 MPa and a time of about 10 to 180 minutes.

The substrate (2) having a conductor circuit on the surface on which the adhesive sheet is to be laminated is not particularly limited. For example, a heat-sensitive substrate such as an epoxy resin, a phenol resin, a polyimide resin, or an unsaturated polyester resin may be used. Curable resins and boards in which a copper foil or the like is affixed to one or both sides of a board of a material obtained by blending an inorganic filler or the like with these thermosetting resins,
A base material such as cloth of inorganic fiber such as glass or organic fiber such as polyester, polyamide or cotton, paper or the like is bonded with the above-mentioned thermosetting resin or the like, and a plate or the like having a copper foil or the like on one or both surfaces is bonded. And copper conductors formed on the surface by etching a copper foil or the like, and those obtained by plating a surface of the above-mentioned plate on which the copper foil or the like is not adhered to form a conductor circuit on the surface.

[0028]

EXAMPLES The present invention will be described below with reference to examples, but it goes without saying that the present invention is not limited to these examples.

Example 1 As a resin component, brominated bisphenol A type epoxy resin (YDB manufactured by Toto Kasei Co., Ltd.)
-500, epoxy equivalent 500 g / equivalent) diluted with methyl ethyl ketone (MEK) to a solid concentration of 80% by weight 109.4 g and a novolak type epoxy resin (epoxy equivalent 210 g / equivalent) diluted with MEK to solidify And 17.9 g of a mixture having a concentration of 70% by weight, and dicyandiamide (Dic
2.8 g of y) and 0.06 g of 2-ethyl-4-methylimidazole (2E4MZ) were used as a curing accelerator.
Further, 166.7 g of a crosslinked NBR (XER-91 manufactured by Nippon Synthetic Rubber Co., Ltd.) diluted with MEK to a solid concentration of 15% by weight was used as an elastomer component. These were then combined with 20 g of dimethylformamide (DMF) and 17.5 ethylene glycol monomethyl ether (MC).
An epoxy resin composition varnish was prepared by mixing with g of the mixed solvent.

Next, the obtained epoxy resin composition is
After coating with a bar coater on a polyethylene terephthalate film surface-treated with a release agent, the coating was treated at 160 ° C. for 6 minutes, and then the polyethylene terephthalate film was peeled off to obtain an adhesive sheet having a thickness of 80 μm.

Next, a copper foil (0.035 mm thick) of a copper-clad laminate (trade name: R-1766, manufactured by Matsushita Electric Works, Ltd.)
Was etched to obtain a substrate having conductor circuits formed on both sides. Then, an adhesive sheet is laminated on each of the front and back surfaces of the substrate, and a copper foil having a thickness of 18 μm is further laminated on the outside thereof,
Heating for 180 minutes at a temperature of 180 ° C and a pressure of 30 kg /
Pressure was applied to obtain a laminate having copper foil adhered to both sides.

Example 2 The amount of the crosslinked NBR was 23
An adhesive sheet was produced in the same manner as in Example 1 except that the amount was 3.3 g, and a laminate having copper foils adhered to both surfaces was obtained.

Example 3 The amount of the crosslinked NBR was 33
An adhesive sheet was produced in the same manner as in Example 1 except that the amount was 3.3 g, and a laminate having copper foils adhered to both surfaces was obtained.

Example 4 The amount of the crosslinked NBR was 26
An epoxy resin composition varnish was prepared in the same manner as in Example 1 except that the amount was changed to 6.7 g.

Next, the obtained epoxy resin composition is
After coating on one side of 18 μm copper foil,
Then, an adhesive sheet having a layer of the epoxy resin composition formed on one surface of the metal foil was obtained.

Next, the side of the epoxy resin composition layer of the obtained adhesive sheet was superposed on the conductor circuit on the substrate surface as in Example 1 to form a pressure-receiving body, and molded under the same conditions as in Example 1. Thus, a laminate having copper foil adhered to both sides was obtained.

Comparative Example 1 An epoxy resin composition was prepared in the same manner as in Example 1 except that the elastomer component was not blended. No sheet was obtained from this composition.

(Comparative Example 2) The added amount of the cross-linked NBR was 400
An adhesive sheet was prepared in the same manner as in Example 1 except that g was used, and a laminate having copper foils bonded to both surfaces was obtained.

(Evaluation and Results) The heat resistance of the laminates obtained in each of Examples and Comparative Example 2 was measured. The measuring method is JI
Based on S Standard C6481, treated at 230 ° C for 60 minutes and evaluated for 5 sheets. If no abnormality such as blister peeling was observed,
The case where abnormalities such as blister peeling were observed in all the evaluation samples was evaluated as x.

As an alternative to measuring the glass transition temperature of the laminates obtained in Examples 1 to 3 and Comparative Example 2, the adhesive sheets obtained in Examples 1 to 3 and Comparative Example 2 were
The glass release temperature is measured using a measurement sample obtained by heating and pressing under the same conditions as in Examples 1 to 3 and Comparative Example 2 by pressing a release film on both outer sides of the zero-stacked one to form a pressure-receiving body. did. The measurement method was evaluated based on the DMA method (bending and tensile method) of JIS standard C6481.

The results are shown in Table 1 below, and it was confirmed that each example was superior to Comparative Example 2 in heat resistance and glass transition temperature. That is, it was confirmed that in each example, it is possible to form an adhesive sheet, and to obtain a laminate having excellent heat resistance and glass transition temperature.
Each comparative example is difficult to form an adhesive sheet,
Alternatively, it was confirmed that the obtained laminate had poor heat resistance and glass transition temperature.

[0042]

[Table 1]

[0043]

When the insulating adhesive sheet according to claim 1 or 2 of the present invention is used, a laminate having excellent heat resistance and glass transition temperature can be obtained.

When the insulating adhesive sheet according to the third aspect of the present invention is used, a laminate having excellent heat resistance and glass transition temperature can be obtained more reliably.

The laminate according to claim 4 of the present invention is a laminate having excellent heat resistance and glass transition temperature.

[Brief description of the drawings]

FIG. 1 is a schematic view showing a laminate according to an embodiment of the present invention.

[Explanation of symbols]

 1 Insulating adhesive sheet 2 Substrate

[Procedure amendment]

[Submission date] September 11, 1997

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0031

[Correction method] Change

[Correction contents]

Next, a copper foil (0.035 mm thick) of a copper-clad laminate (trade name: R-1766, manufactured by Matsushita Electric Works, Ltd.)
Was etched to obtain a substrate having conductor circuits formed on both sides. Then, an adhesive sheet is laminated on each of the front and back surfaces of the substrate, and a copper foil having a thickness of 18 μm is further laminated on the outside thereof,
100 at a temperature of 180 ° C. and a pressure of 30 kgf / cm ²
After heating and pressing for a minute, a laminate having copper foil adhered to both sides was obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification symbol FI // (C09J 163/00 121: 00)

Claims (4)

[Claims] 1. An elastomer is used in an amount of 20 to 5 parts by weight based on 100 parts by weight of a total of an epoxy resin and a curing agent for an epoxy resin.
An insulating adhesive sheet formed by forming a sheet of an epoxy resin composition containing 0 parts by weight. 2. An elastomer is used in an amount of 20 to 5 parts by weight based on 100 parts by weight of the epoxy resin and the curing agent for the epoxy resin.
An insulating adhesive sheet, wherein a layer of an epoxy resin composition containing 0 parts by weight is formed on one surface of a metal foil. 3. The insulating adhesive sheet according to claim 1, wherein the elastomer is cross-linked. 4. A laminate comprising the insulating adhesive sheet according to claim 1 and a surface of a substrate having a conductor circuit on the surface thereof.