JPH0230333B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to a method for producing addition-type imide resin prepreg. [Background technology] Conventionally, epoxy resin materials with excellent adhesive properties, chemical resistance, electrical properties, mechanical properties, etc. have been often used as resins for manufacturing laminates such as multilayer printed wiring boards. When used in a high-multilayer printed wiring board for mounting, there are problems with heat resistance on the mounting surface and a reduction in continuity reliability due to resin smear and thermal expansion in the thickness direction. In order to solve these problems, heat-resistant resins such as polyimide have been developed and put into practical use as resins for manufacturing laminates. In particular, addition-type polyimide, which is made by reacting unsaturated bisimide with diamine, has a low coefficient of thermal expansion in the thickness direction and can be processed with high precision, such as thinning wires for high density and making micro holes. High continuity reliability due to plating
There is no smearing during the drilling process, and the conductor adhesion and hardness at high temperatures improve mounting performance.
Because it has features such as being able to withstand continuous use at high temperatures (200°C), it has come to be widely used as a material for multilayer printed wiring boards. However, in recent years, multilayer printed wiring boards such as those used in large computers have become more densely packaged and multilayered, resulting in smaller circuits and through-hole diameters. There is an increasing demand for miniaturization, and in order to meet this demand, substrates are required to have a higher level of adhesion than before. Regarding adhesion, it is natural that the adhesion between the circuit and the resin must be high due to the miniaturization of the circuit, but the adhesion between the resin and the base material impregnated with the resin must also be high. This is because if the adhesion between the base material and the resin is low, there will be an inconvenience in that minute peeling will occur between the base material and the resin when drilling holes in a multilayer printed wiring board. be. However, when preparing a prepreg by impregnating a base material with the above-mentioned addition-type polyimide varnish and drying it, and using this prepreg to create a substrate for a printed wiring board, the resin can be used at the level of a multilayer printed wiring board for large computers, etc. It was not possible to obtain sufficient adhesion between the resin and the base material, and in many cases, fine interfacial peeling between the base material and the resin was likely to occur during the drilling process. [Purpose of the Invention] The present invention has been made in view of the above points, and an object thereof is to provide a method for manufacturing an addition-type imide resin prepreg for laminates that has excellent adhesion and allows for high-density mounting. be. [Disclosure of the Invention] In order to achieve the above object, the inventors have solved the cause of insufficient adhesion between the base material and the resin when using a generally known addition type imide resin prepreg. Researched. As a result, it was found that more common addition-type imide resin prepolymers have unsaturated imide groups at the end of the prepolymer than amino groups. Generally, epoxysilane-based, chlorosilane-based, cationic silane-based processing agents are used as surface treatment agents for glass substrates, etc.
These surface treatment agents tend to react more easily with amino groups than with maleimide groups, so general addition-type imide resin prepolymers, which have many unsaturated imide groups at their ends, have insufficient adhesion to the substrate. I realized that I am getting used to it. In addition, prepolymers containing a large number of amino group terminals are not only highly reactive with surface treatment agents, but also highly reactive with ordinary varnish applied in the subsequent secondary impregnation. It has been found that excellent adhesion can be obtained between the processing agent and the common resin because both are strongly bonded to each other. As a result of further research, the inventors found that
We have discovered an addition-type imide resin with sufficient adhesion between the resin and the base material and a method for producing the same, and have now completed the following invention. That is, in the present invention, when producing an addition-type imide resin prepreg by impregnating a base material with an addition-type imide resin prepolymer synthesized from unsaturated bisimide and diamine, the bisimide/diamine ratio is 2.0.
A prepolymer solution synthesized at a ratio of mol/1.1 mol to 2.0 mol/3.0 mol and having a solid content concentration of 1 to 30% is first impregnated into a base material and dried to obtain a primary prepreg, which is further prepared separately. The gist of this paper is a method for producing an addition-type imide resin prepreg, which is characterized by impregnating and drying an addition-type imide resin prepolymer solution. This invention will be explained in detail below. Here, the unsaturated bis-imide is represented by formula (1), and the diamine is represented by formula (2). (In the formula, D represents a divalent group containing a carbon-carbon double bond, and A represents a divalent group containing at least two carbon atoms.) H ₂ N-B-NH ₂ (2) ( In the formula (B represents a divalent group having 30 or less carbon atoms) A and B in the above formulas (1) and (2) may be the same or different; linear or branched alkylene groups with 5 or 6 carbon atoms in the ring, O,N
and a heterocyclic group containing at least one S atom, or a phenylene or polycyclic aromatic group. These various groups may have substituents that do not give rise to unnecessary side reactions under the reaction conditions. The above A and B can also be a large number of phenylene groups, or an alicyclic group bonded directly or with divalent atoms or the following groups. Thus, for example, they are oxygen or sulfur, the group of alkylenes of 1 to 3 carbon atoms, or one of the following groups: -NR ₄ -, -P(O)R ₃ -, -N=N-,

[Formula] -CO-O-, -SO ₂ -, - SiR ₃ R ₄ -, -CONH-, -NY-CO-X-CO-
NY―, -O―CO―X―CO―O―,

【formula】 【formula】

【formula】

[Formula] In the above formula, R ₃ , R ₄ and Y are each an alkyl group having 1 to 4 carbon atoms, a cyclic alkyl group having 5 or 6 carbon atoms in the ring, or phenyl or a polycyclic aromatic group. a straight-chain or branched alkylene group having less than 13 carbon atoms, a cyclic alkylene group having 5 or 6 carbon atoms in the ring, or a monocyclic or polycyclic group; Represents an arylene group. Group D is derived from the ethylenic anhydride (unsaturated dicarboxylic anhydride) of formula (3), such as maleic anhydride, citraconic anhydride, tetrahydrophthalic anhydride, itaconic anhydride, and the products of the Diels-Alder reaction which take place between cyclodienes and one of these anhydrides. Preferred unsaturated bis-imides of formula (1) that can be used include the following. Maleic acid N・N′-ethylene-bis-imide, maleic acid N・N′-hexamethylene-bis-imide, maleic acid N・N′-metaphenylene-bis-imide, maleic acid N・N′-paraphenylene-bis-imide -imide, maleic acid N・N'-4,
4'-diphenylmethane-bis-imide, <N.
N'-methylenebis(N-phenylmaleimide)
Also referred to as>, maleic acid N・N′-4,4′-diphenyl ether-bis-imide, maleic acid N・N′-4,4′-diphenyl ether-bis-imide
N′-4,4′-diphenylsulfone-bis-imide, maleic acid N・N′-4,4′-dicyclohexylmethane-bis-imide, maleic acid N・N′-
These include α·α′-4.4′-dimethylenecyclohexane-bis-imide, maleic acid N·N′-methaxylylene-bis-imide, maleic acid N·N′-diphenylcyclohexane-bis-imide, and the like. Further, as preferred diamines of formula (2) that can be used, the following can be mentioned.
4,4'-diaminodicyclohexylmethane, 1.
4'-diaminocyclohexane, 2,6-diaminopyridine, metaphenylenediamine, paraphenylenediamine, 4,4'-diamino-diphenylmethane, 2,2-bis-(4-aminophenyl)propane, benzidine, 4,4'- Diaminodiphenyl oxide, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl sulfone, bis-(4-aminophenyl) diphenylsilane, bis-(4-aminophenyl)methylphosphine oxide, bis- (3-aminophenyl)methylphosphine oxide, bis-(4
-aminophenyl) phenylphosphine oxide, bis-(4-aminophenyl) phenylamine, 1,5-diaminonaphthalene, metaxylylene diamine, paraxylylene diamine, 1,1-
Bis-(para-aminophenyl) phthalane, hexamethylene diamine, etc. A prepolymer solution is prepared by reacting the unsaturated bisimide and diamine in a polar solvent.
Preferred examples include -methylpyrrolidone, N·N-dimethylformamide, N·N-dimethylacetamide, and dimethyl sulfoxide, and these can be used alone or in combination of two or more. The prepolymer used in the method for producing the addition-type imide resin prepreg according to the present invention is obtained by reacting the above-mentioned unsaturated bisimide and diamine, but the molar ratio of the ingredients must be as described above. That is, for 2.0 moles of bisimide,
If the amount of diamine is less than 1.1 mol, the resulting prepolymer will have many unsaturated imide groups at the ends. Also, bisimide 2.0
If the amount of diamine is more than 3.0 moles per mole, the resin will have a short gelation time, and it will be difficult to control the drying conditions when drying the impregnated base material. Therefore, the amount of diamine needs to be 1.1 to 3.0 moles per 2.0 moles of bisimide. Also,
In a prepolymer solution synthesized from bisimide and diamine, if the solid content concentration is less than 1%, the viscosity of the prepolymer solution is too low and an appropriate amount of resin will not adhere during impregnation. Solid content concentration is 30%
If it exceeds this value, the varnish will not penetrate sufficiently between the fibers of the base material during impregnation, which is undesirable when considering the adhesion of the laminated board. Therefore, it is necessary that the solid content concentration of the prepolymer solution is 1 to 30%. Next, the drying temperature during the primary impregnation is
If the temperature is lower than 140°C, it becomes difficult to sufficiently evaporate high-boiling polar solvents such as N-methylpyrrolidone and dimethylacetamide. If the drying temperature exceeds 165°C, polymerization of the prepolymer will occur rapidly, making drying difficult to control. Therefore, the drying temperature during the primary impregnation is preferably 140 to 165°C. In addition, the resin molecular weight distribution of the prepolymer solution used for secondary impregnation is 30 to 55% of the unreacted raw material, and the molecular weight
39-65% of components are 400 to 15,000, molecular weight is
Preferably, the amount of components exceeding 15,000 is 1.8 to 6.8%. The resin molecular weight distribution of the primary prepreg is preferably such that unreacted raw materials account for 18 to 35%, components with a molecular weight of 400 to 15,000 account for 51 to 70%, and components with a molecular weight of over 15,000 account for 5 to 15%. . Here, the molecular weight distribution was determined using DMF solvent and the separation column was Showa Denko AD-803/S (8.0×
Gel permeation chromatograph (Toyo Soda HLC-803D) equipped with two 250 mm, 6000 theoretical plates)
It was measured by Calculation of molecular weight involves finding a cubic regression curve from the retention times of five types of monodisperse polyethylene glycol and ethylene glycol monomer and the common logarithm of the molecular weight, applying this to the sample, and calculating from the retention time of the sample. On the other hand, we used the method of determining the molecular weight. In addition, the proportion (%) of each component was determined using a differential refractometer (128×10 ^-8 RI
The sample concentration was 0.5 ± 0.2%, the sample injection amount was 100μ, the refractometer output was 0 to 1V, the recorder output was 0 to 10mV, and the chart speed was 5mm/min. It was divided into necessary molecular weight categories and the respective ratios were determined by the cut-out weight method. The addition-type imide resin prepolymer solution used at the time of secondary impregnation can be prepared by reacting bisimide and diamine in a polar solvent, or by using a commercially available addition-type imide resin in a polar solvent. It can also be dissolved to form a prepolymer solution. Next, examples and comparative examples of the present invention will be described. (Varnish 1) 1074g of N・N'-methylenebis (N-phenylmaleimide, hereinafter referred to as "BMI"), 4,
4'-diamino-diphenylmethane (hereinafter referred to as
400g of N/N-dimethylacetamide (hereinafter referred to as "DMAC"),
Each was weighed and charged into a 34-necked flask, and a stirring rod, thermometer, and condenser were attached to the flask, and then heated in an oil bath and reacted for 300 minutes at a reaction temperature of 70°C. ,
Next, the mixture was cooled to room temperature for 15 minutes to obtain a prepolymer solution. 1,000 g of this prepolymer solution was taken, 2,000 g of DMAC was added thereto, and the mixture was stirred until homogeneous to obtain a varnish for primary impregnation. (Varnish 2) 1074 g of BMI, 600 g of DDM, and 1116 g of DMAC were reacted in the same manner as in the case of producing Varnish 1 to obtain a prepolymer solution. 1,000 g of this prepolymer solution was taken, 2,000 g of DMAC was added thereto, and the mixture was stirred until homogeneous to obtain a varnish for primary impregnation. (Varnish 3) Take 100g of the prepolymer solution (undiluted solution) obtained in the production of Varnish 1, add 2900g of DMAC,
The mixture was stirred until it became uniform to obtain a varnish for primary impregnation. (Varnish 4) BMI1500g, DDM198g, and DMAC1132g were reacted in the same manner as in the case of producing Varnish 1 to obtain a prepolymer solution. 1,000 g of this prepolymer solution was taken, 2,000 g of DMAC was added thereto, and the mixture was stirred until homogeneous to obtain a varnish for primary impregnation. (Varnish 5) 10 g of the prepolymer solution (undiluted solution) obtained in the production of Varnish 1 was taken, 2990 g of DMAC was added thereto, and the mixture was stirred until homogeneous to obtain a varnish for primary impregnation. The characteristics of each varnish are shown in Table 1.

[Table] (Primary prepregs 1 to 3, 5 to 6) The varnishes obtained as above were
Transfer to an impregnating vat, and impregnate a 300 x 300 mm 105 g/m ² glass cloth whose surface has been treated with a chlorosilane treatment agent by dipping it into the varnish in the vat.
Drying was performed in a steam dryer at 150°C for 10 minutes to obtain a primary prepreg. (Primary prepreg 4) A primary prepreg was obtained in the same manner as in the production of primary prepreg 1, except that drying was performed at 160° C. for 5 minutes. (Primary prepreg 7) A primary prepreg was obtained in the same manner as in the production of primary prepreg 1, except that drying was performed at 120° C. for 30 minutes. The characteristics of each primary prepreg are shown in Table 2.

[Table] (Examples 1 to 4 and Comparative Examples 1 to 3) Next, primary prepregs 1 to 7 obtained above
Then, prepolymer solution (BMI1074g, DDM297
g, was obtained by reacting 914 g of DMAC at 70°C for 300 minutes. ) and dried at 150°C for 10 minutes to obtain the final prepreg. (Example 5) A commercially available addition type imide resin was added to the primary prepreg 1.
A final prepreg was obtained by impregnating 1500 g of a prepolymer solution uniformly dissolved in 1000 g of DMAC and drying at 150° C. for 10 minutes. Table 3 shows the properties of each final prepreg.

[Table] Example 5 is secondary impregnation with commercially available varnish. 30 final prepreg sheets obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were placed between plate molds with release paper interposed, and the actual weight was 40 kg/cm. ² , molding was carried out at 170°C for 90 minutes, and after cooling, it was taken out and subjected to post-curing at 20°C for 2 hours to obtain a laminate with a thickness of 3 mm. This laminate was fixed on the table of a high-speed drill machine, and a 0.5 mmφ drill blade (manufactured by Union Tool Co., Ltd.) was used to rotate at a rotation speed of 80,000 rpm and a feed rate of 1.0 m/min.
1000 holes were continuously drilled under min drilling conditions. The wall surface of the 1000th hole was then observed using a scanning electron microscope to check for interfacial delamination. The results are shown in Table 4.

【table】
Less than that ○
[Effects of the Invention] As described above, the present invention can provide a laminate prepreg that can be mounted at high density.

Claims (1)

[Claims] 1. When manufacturing an addition-type imide resin prepreg by impregnating a base material with an addition-type imide resin prepolymer synthesized from unsaturated bisimide and diamine, bisimide/diamine is 2.0 mol/1.1 mol to 2.0 mol. /3.0 mol ratio, solid content concentration 1~
An addition-type imide resin characterized in that a base material is first impregnated with a 30% prepolymer solution and dried to obtain a primary prepreg, which is further impregnated with a separately prepared addition-type imide resin prepolymer solution and dried. Prepreg manufacturing method. 2. The method for producing an addition type imide resin prepreg according to claim 1, wherein drying during the primary impregnation is carried out at 140 to 165°C.