JPH07100360B2 - Copper clad laminate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) The present invention relates to a copper clad laminate excellent in solder heat resistance and punching workability.

(Prior Art) In recent years, the development of electronic devices has been remarkable, and the use of copper-clad laminates has become widespread, and there has been a demand for even more excellent properties. The copper-clad laminate based on glass nonwoven fabric has the same electrical characteristics as the glass epoxy laminate based on glass woven fabric, and the punching process is easy. ing. This non-woven substrate copper clad laminate is
It is manufactured by coating and impregnating a glass non-woven fabric having a thickness of 100 to 600 μm with an epoxy resin, heating and drying to obtain a prepreg, and superimposing the foil on the prepreg, and integrally molding under heating and pressing. Copper-clad laminates based on non-woven glass fabric are superior to the copper-clad laminates based on woven glass fabric in drilling and punching, but have better dimensional characteristics and through-hole reliability. It had the drawback of being inferior. To improve this, use epoxy resin
Copper clad laminates with 20 to 70% by weight inorganic fillers such as aluminum hydroxide powder and E-glass powder are commonly used.

However, when this inorganic filler is added, there is a drawback that the viscosity of the epoxy resin increases, the impregnation property of the resin into the glass non-woven fabric deteriorates, and the solder heat resistance of the laminate using the same decreases. There is also a drawback that the shear resistance of the laminated plate increases and cracks are likely to occur during punching.

(Problems to be Solved by the Invention) The present invention has been made to solve the above-mentioned conventional drawbacks, and has good resin impregnation property, excellent solder heat resistance, punching processability, and dimensional stability. Another object of the present invention is to provide a copper clad laminate having high through hole reliability.

[Structure of the Invention] (Means and Actions for Solving Problems) The inventors of the present invention have earnestly studied to achieve the above object, and as a result, have found that the average particle diameter of the inorganic filler contained in the thermosetting resin is large. It was found that a copper clad laminate having good impregnation property, solder heat resistance, punching workability and the like can be obtained by using a resin having a thickness of 1 μm or more and less than 5 μm, thus completing the present invention. That is, the present invention provides a glass nonwoven fabric with an average particle size of 1 μm.
A prepreg (I) obtained by applying, impregnating and drying a thermosetting resin containing an inorganic filler having a size of less than 5 μm and a plurality of prepregs (I) and a glass woven fabric are applied, impregnated and dried. And a prepreg (II) superposed on the upper and lower surfaces of the plurality of prepregs (I),
A copper clad laminate characterized by being formed by integrally heating and pressurizing a copper foil laminated on at least one surface of the above-mentioned laminated prepreg (II).

As the inorganic filler used in the present invention, any one having an average particle diameter of 1 μm or more and less than 5 μm can be used, and specifically, E glass powder, aluminum hydroxide, magnesium hydroxide, alumina. , Magnesium oxide, titanium dioxide, potassium titanate, calcium silicate, aluminum silicate, calcium carbonate and the like, and these may be used alone or in admixture of two or more.

If the average particle size of the inorganic filler is 1 μm or more and less than 5 μm, the average diameter of the glass fibers constituting the non-woven fabric is smaller than 8 to 10 μm, so that it is easy to impregnate with the thermosetting resin in the gaps of the glass fibers, and the wettability is also high. The cracks do not occur even during punching.

When the average particle diameter is 5 μm or more, impregnation property to glass fiber is deteriorated, which is not preferable. On the other hand, if it is less than 1 μm, the viscosity of the thermosetting resin containing it becomes high, and the particles are secondarily aggregated to have a particle diameter of several μm, which impairs the impregnation into glass fiber, which is not preferable.

The glass nonwoven fabric used in the present invention includes a wide range of commonly used glass nonwoven fabrics.

As the thermosetting resin used in the present invention, polyester resin, epoxy resin, polyimide resin or the like is used.

The prepreg (I) used in the present invention is obtained by applying and impregnating the above-mentioned ordinary glass nonwoven fabric base material with a thermosetting resin in which the above-mentioned inorganic filler is blended by an ordinary method, and drying the prepreg.

On the other hand, the prepreg (II) is obtained by applying, impregnating and drying a thermosetting resin such as a polyester resin, an epoxy resin or a polyimide resin on a commonly used glass woven fabric by a conventional method.

The copper clad laminate of the present invention is manufactured by an ordinary method and is not particularly limited to the manufacturing method. For example, an epoxy varnish is obtained by adding a curing agent, an appropriate amount of an inorganic filler, and an organic solvent to an epoxy resin. Next, the epoxy varnish is impregnated into a glass nonwoven fabric with a coating machine and dried to obtain a prepreg, a predetermined number of these are laminated, and an epoxy resin prepreg and a copper foil, which are separately prepared glass woven fabrics as a base material, are stacked,
A copper clad laminate is manufactured by heating, pressing, and laminating and integrating.

(Examples) Next, the present invention will be specifically described with reference to Examples.

Example 1 100 parts by weight of a brominated epoxy resin (epoxy equivalent: 470 g / eq, bromine content: 20.5%), 3 parts by weight of dicyandiamide, 2
-Ethyl-methylimidazole (0.1 part by weight) and an appropriate amount of acetone were added and stirred, and 55 parts by weight of aluminum hydroxide having an average particle diameter of 2 μm was added as an inorganic filler to prepare an epoxy resin varnish. Next, a glass non-woven fabric with a thickness of 400 μm is coated and impregnated with the above epoxy resin varnish.
A prepreg (I) was prepared by drying at a temperature of ° C. Six prepregs (I) were superposed on each other, and a glass woven cloth was coated and impregnated with the above-mentioned epoxy resin varnish containing no aluminum hydroxide as an inorganic filler on the upper and lower surfaces thereof, and prepregs (II) obtained respectively were dried. One piece is piled up, and one piece of copper foil with a thickness of 35 μm is piled up on the upper and lower surfaces of prepreg (II), and heated and pressed at 170 ° C., 40 kg / cm ² for 90 minutes, and copper-clad with a thickness of 1.6 mm. Laminates were manufactured. Various properties of this copper-clad laminate were tested, and the results are shown in Table 1. It was confirmed that the soldering heat resistance and the punching workability were excellent, and the effect of the present invention was confirmed.

Comparative Example 1 A copper clad laminate was manufactured in the same manner as in Example 1 except that aluminum hydroxide having an average particle size of 10 μm was used instead of aluminum hydroxide having an average particle size of 2 μm. . Various characteristics tests were conducted on this copper clad laminate, and the results are shown in Table 1.

Comparative Example 2 A copper clad laminate was produced in the same manner as in Example 1 except that aluminum hydroxide having an average particle size of 0.5 μm was used instead of aluminum hydroxide having an average particle size of 2 μm. Moreover, various characteristics were tested in the same manner, and the results are shown in Table 1.

Comparative Example 3 A copper clad laminate was manufactured in the same manner as in Example 1 except that an epoxy resin varnish containing no inorganic filler was used, and various properties were tested in the same manner. The results are shown in Table 1.

[Effects of the Invention] As is clear from the above description and Table 1, the copper-clad laminate of the present invention has good impregnability and uneven impregnation due to the use of the inorganic filler having an average particle size of 1 μm or more and less than 5 μm. It is possible to obtain excellent solder heat resistance, punching workability, dimensional stability, and through hole reliability, and it is suitable for electronic devices.

Claims (1)

[Claims] 1. A glass nonwoven fabric having an average particle size of 1 μm or more and 5 μm or more.
A prepreg (I) obtained by applying, impregnating and drying a thermosetting resin containing less than 1% of an inorganic filler, and a glass woven cloth is applied, impregnating and drying the thermosetting resin. At the same time, the prepreg (II) superposed on the upper and lower surfaces of the plurality of prepregs (I) and the copper foil superposed on at least one surface of the superposed prepregs (II) were integrally molded by heating and pressing. Characteristic copper clad laminate.