JPH08244167A - Copper-clad laminate - Google Patents

Abstract

PURPOSE: To manufacture a prepreg in which partial gelatinization is not generated, the control of characteristics and molding conditions is easy, resistance to soldering heat, resistance to smear, resistance to measling and the like are superior, and blister or warping is not generated at the time of soldering. CONSTITUTION: In a copper-clad laminate formed by laminating prepregs using an epoxy resin composition, overlapping copper foils and forming integrally, an epoxy resin composition carrying bromated epoxy resin prepared by reacting bisphenol A type epoxy resin, tetrabromobisphenol A and low-molecular-weight novolak epoxy resin of average nuclear logarithm of 3-4 one another and kaoline clay as essential components and containing kaoline clay of 30-10wt.% to the resin composition unit is used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flame-retardant copper-clad laminate having excellent heat resistance, moldability and workability.

[0002]

2. Description of the Related Art In recent years, the development of electronic equipment has been remarkable, and particularly glass epoxy copper clad laminates are used not only in industrial equipment such as computers, communication equipment and industrial measuring equipment, but also in consumer products such as televisions, video recorders and audio equipment. The increase in the use for industrial equipment and the rapid increase in the production volume. Along with this, the required characteristics of glass epoxy copper clad laminates have diversified,
The conventional heat resistance is no longer satisfactory. In particular, due to the speeding up of the drill during drilling, the problem of smear that occurs when the temperature inside the hole rises, the problem of blistering that occurs during soldering due to moisture absorption after processing, etc. have appeared.

Generally, an epoxy resin composition used for a glass epoxy copper clad laminate is a bisphenol A type epoxy resin or a tetrabromobisphenol A type epoxy resin, and a curing agent such as amine or acid anhydride and a small amount of curing. It contains a promoter. In this case, in order to improve heat resistance, a method of blending a novolac epoxy resin is used.

[0004]

However, the conventional novolac epoxy resin has a large average number of nuclides of 9 to 10 and is more effective as a curing agent than the bisphenol A type epoxy resin or the tetrabromobisphenol A type epoxy resin. The reaction is fast, and the epoxy resin composition containing this has a drawback that it is easy to partially gel, and it is difficult to control the properties of the prepreg and the press molding conditions. Therefore, it is difficult to increase the amount of the novolac epoxy resin compounded. Met.

Further, when flame-retarded by using a brominated epoxy resin obtained by reacting a bisphenol A type epoxy resin with tetrabromobisphenol A, the resin becomes highly viscous, so that the impregnation property into the prepreg is remarkably lowered. There was a drawback to

The present invention has been made to solve the above-mentioned drawbacks, and is excellent in heat resistance, moldability, dimensional stability and resistance to measling, does not cause smear, blisters and warp, and is prepreg. An object of the present invention is to provide a flame-retardant copper-clad laminate in which it is easy to control the properties of the above and press molding conditions.

[0007]

Means for Solving the Problems As a result of intensive research aimed at achieving the above-mentioned object, the present inventor has found that the above-mentioned object can be achieved by using a resin composition described below, and the present invention has been completed. It was done.

That is, the present invention is a copper clad laminate obtained by laminating a plurality of prepregs obtained by impregnating a base material with an epoxy resin composition and drying the prepregs, and laminating a copper foil on at least one surface of the prepreg to form an integral body. (A) (a) bisphenol A type epoxy resin, and (b) tetrabromobisphenol A
And (c) a brominated epoxy resin obtained by reacting a low molecular weight novolak epoxy resin having an average number of nuclides of 3 to 4, and (B) kaolin clay as an essential component, with respect to the entire resin composition. Kaolin clay from (B) above
It is a copper clad laminate characterized by using an epoxy resin composition containing 3 to 10% by weight.

The present invention will be described in detail below.

The epoxy resin composition used in the present invention is
(A) brominated epoxy resin and (B) kaolin clay are essential components, and (A) brominated epoxy resin includes (a) bisphenol A type epoxy resin and (b)
Tetrabrom bisphenol A and (c) average number of nuclides
It is prepared by reacting a low molecular weight novolak epoxy resin of 3 to 4.

The bisphenol A type epoxy resin (a) which is the first component of the (A) brominated epoxy resin is as follows:
It is an epoxy resin obtained by reacting bisphenol A with epichlorohydrin, and can be used from liquid to solid resins. Among these, a liquid epoxy resin containing as a main component a reaction product of 1 molecule of bisphenol A and 2 molecules of epichlorohydrin is preferably used.

As the second component (b) tetrabromobisphenol A, a usual one can be used without any particular limitation.

The third component (c) has an average number of nuclides of 3 to
The low molecular weight novolac epoxy resin having a molecular weight of 4 may have an average number of cores of 3 to 4, and can be used without particular limitation. Specific examples thereof include a phenol novolac type epoxy resin and a cresol novolac type epoxy resin, and these can be used alone or in combination of two or more kinds. It is desirable that the low molecular weight novolak epoxy resin having an average number of nuclei of 3 to 4 be contained in an amount of 5 to 40% by weight based on the brominated epoxy resin. If the compounding ratio is less than 5% by weight, the reaction with the curing agent will be slow, and if it exceeds 40% by weight, the reaction with the curing agent will be fast and it will be easy to partially gel, and the viscosity of the reaction product will be high and the impregnability will be high. Is also bad and not preferable.

For the reaction of the first to third components, Na 2 O 3 is used.
Examples thereof include inorganic bases such as H and Na ₂ CO ₃ , inorganic salts, tertiary amines, quaternary ammonium salts, quaternary phosphonium salts, etc. These can be used alone or in admixture of two or more. .

Although a brominated epoxy resin can be obtained by reacting the above-mentioned components, other components can be blended within the range not deviating from the object of the present invention.

As the kaolin clay (B) of the epoxy resin composition used in the present invention, those usually used are not particularly limited. The kaolin / clay content is preferably 3 to 10% by weight based on the total resin composition. The blending ratio is 3
If it is less than 10% by weight, it has no effect on moisture resistance and heat resistance, and if it exceeds 10% by weight, the peeling strength is lowered, which is not preferable.

The thus obtained (A) brominated epoxy resin, (B) kaolin clay and other components can be blended to easily produce an epoxy resin composition.

The base material and the copper foil used in the present invention are not particularly limited as long as they are usually used as a glass epoxy copper clad laminate, and can be widely used.

A copper clad laminate can be easily manufactured by a conventional method using the above-mentioned epoxy resin composition, substrate and copper foil.

[0020]

The present invention provides heat resistance, moldability, measling resistance, and workability by using a brominated epoxy resin obtained by reacting a low molecular weight novolac epoxy resin having an average number of cores of 3 to 4. An excellent copper clad laminate could be obtained. That is, by using a low molecular weight novolak epoxy resin with an average number of nuclides of 3 to 4, the reaction rate with the curing agent is suppressed, partial gelation is prevented, and prepreg characteristics and press molding are stable. Made into Also, even if a relatively large amount is blended, gelation is unlikely to occur, so that some heat resistance is secured. On the other hand, since it is a low molecular weight novolac epoxy resin, it does not have a high viscosity, and it has excellent workability without lowering impregnating properties and the like. In addition, by blending kaolin and clay, the warp is prevented without reducing the peel strength,
The humidity resistance and heat resistance could be improved.

[0021]

EXAMPLES The present invention will now be described with reference to examples. The invention is not limited by these examples.

Example 1 A four-necked flask equipped with a condenser was charged with 210 g of bisphenol A type epoxy resin (epoxy equivalent 189), 130 g of tetrabromobisphenol A, 60 g of phenol novolac epoxy resin having an average number of nuclei of 3.2, and 0.02 g of tetraethylammonium chloride. The inside of the flask was replaced with nitrogen. Then, after reacting at a temperature of 140 ° C for 5 hours, 135 g of methyl ethyl ketone was added to give a brominated epoxy resin solution having a resin solid content of 75% by weight, a viscosity of 4.2 poise (25 ° C), an epoxy equivalent of 450, and a bromine content of 19%. Manufactured. Next, 30 g of kaolin clay, 11.2 g of dicyandiamide, 0.05 g of 2-ethyl-4-methylimidazole and acetone were added to prepare a varnish having a resin solid content of 65% by weight.

Example 2 A four-necked flask equipped with a condenser was charged with 150 g of bisphenol A type epoxy resin (epoxy equivalent 189), 130 g of tetrabromobisphenol A, 120 g of phenol novolac epoxy resin having an average number of cores of 3.8, and 0.02 g of tetraethylammonium chloride. The inside was replaced with nitrogen. Then, after reacting at a temperature of 140 ° C for 5 hours, 135 g of methyl ethyl ketone was added to give a brominated epoxy resin solution having a resin solid content of 75% by weight, a viscosity of 5.2 poise (25 ° C), an epoxy equivalent of 460, and a bromine content of 19%. Manufactured. Next, 30 g of kaolin clay, 11.0 g of dicyandiamide, 0.05 g of 2-ethyl-4-methylimidazole and acetone were added to prepare a varnish having a resin solid content of 65% by weight.

Comparative Example 1 A four-necked flask equipped with a condenser was charged with 210 g of bisphenol A type epoxy resin (epoxy equivalent) 189), 130 g of tetrabromobisphenol A, 60 g of phenol novolac epoxy resin having an average number of cores of 9.5, and 0.02 g of tetraethylammonium chloride. The inside of the flask was replaced with nitrogen. Then, after reacting at a temperature of 140 ° C for 5 hours, 135 g of methyl ethyl ketone was added to the mixture to give a resin solid content of 75% by weight and a viscosity of 9.2
A brominated epoxy resin solution having a poise (25 ° C.), an epoxy equivalent of 450 and a bromine content of 19% was produced. Next, dicyandiamide 11.2 g, 2-ethyl-4-methylimidazole 0.02
A varnish having a resin solid content of 65% by weight was prepared by adding 5 g and acetone.

Comparative Example 2 Brominated epoxy resin (epoxy equivalent 480, bromine content
21.5%, resin solids 75% by weight) 445 g, average number of cores 9.8 phenol novolac epoxy resin (epoxy equivalent 210
80 g of a resin solid content of 75% by weight was blended to prepare a brominated epoxy resin solution having a viscosity of 6.0 poise (25 ° C.), an epoxy equivalent of 405 and a bromine content of 18.3%. Next, 10.5 g of dicyandiamide, 0.05 g of 2-ethyl-4-methylimidazole and acetone were added to prepare a varnish having a resin solid content of 65% by weight.

Using the varnishes prepared in Examples 1 and 2 and Comparative Examples 1 and 2, the surface treated with epoxysilane.
It was impregnated and coated on a 0.18 mm glass substrate and dried at a temperature of 160 ° C. to prepare a prepreg having a resin content of 43% by weight. Eight layers of this prepreg are laminated, and copper foil with a thickness of 18 μm is laminated on both sides, and the temperature is 170 ° C and the pressure is 40 kg / cm ²
By heating and pressurizing for one minute, a copper-clad laminate having a plate thickness of 1.6 mm was manufactured. For these copper clad laminates, flame retardant,
The glass transition point, solder heat resistance and measling resistance were tested, and the results are shown in Table 1. In all cases, the present invention was excellent, and the effects of the present invention could be confirmed.

[0027]

[Table 1] * 1: Measured according to JIS-C-6481. * 2: Midpoint method by DSC (Differential Scanning Calorimeter). * 3: Each sample shown in the table was floated on a solder bath at 260 ° C and tested for blisters. ◎ mark: None at all
○ mark: There is a part, △ mark: There is a large part, × mark: There is all. * 4: After treatment in steam at 120 ° C and 2 atm for each time shown in the table, the specimen was immersed in a solder bath at 260 ° C for 30 seconds and observed for blisters. ◎: Nothing, ○: Some, △: Most, X: All * 5: A copper-clad laminate was cut into 200 x 200 mm pieces, a copper foil was removed by etching to prepare a sample, which was heated at 150 ° C for 2 hours and then the warpage was measured.

[0028]

As is clear from the above description and Table 1, the copper clad laminate of the present invention is excellent in heat resistance, dimensional stability and measling resistance, and can sufficiently cope with smear due to high speed drilling. Also, no blistering or warpage occurs during soldering due to moisture absorption after processing the laminated plate. Further, it is easy to control the characteristics of the prepreg and the molding conditions without causing gelation partially, and the moldability is excellent.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display location C08K 3/20 C08K 3/20 C08L 63/02 NKV C08L 63/02 NKV H05K 1/03 610 7511- 4E H05K 1/03 610L 7511-4E 610R

Claims (1)

[Claims] 1. A copper clad laminate obtained by laminating a plurality of prepregs obtained by impregnating and drying a base material with an epoxy resin composition, and superimposing a copper foil on at least one surface of the prepreg and integrally molding the prepregs. Brominated epoxy resin obtained by reacting (a) bisphenol A type epoxy resin, (b) tetrabromobisphenol A, and (c) low molecular weight novolac epoxy resin having an average nucleus number of 3 to 4, and (B) )
A copper clad laminate comprising an epoxy resin composition containing kaolin clay as an essential component and 3 to 10% by weight of the kaolin clay of (B) with respect to the entire resin composition. .