JPH04268784A - Copper plated laminated board - Google Patents

Abstract

PURPOSE:To enable a copper plated laminated board to be enhanced in thermal resistance, processability, and dimensional stability by a method wherein a prepreg prescribed in composition is laminated on another prepreg treated as prescribed, and a copper foil is laid at least on one of the sides of the laminate concerned, which is formed into an integral structure through thermocompression. CONSTITUTION:Thermosetting resin is applied to a glass woven cloth to impregnate and dried up to form a prepreg, which is laid on both the sides of another prepreg formed through such a manner that thermosetting resin is applied to a glass nonwoven cloth which contains 10 to 50% of aramide fiber to impregnate and dried up. Furthermore, a copper foil is made to overlap at least one side of the laminated prepreg, which is formed into an integral structure by thermocompression. When the mixing ratio of aramide fiber to the nonwoven cloth is set to be less than 10%, a laminated board is lessened in dimensional stability. When the mixing ratio exceeds 50%, the laminated board is lessened in processability.

Description

[Detailed description of the invention]

0001

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

0002

BACKGROUND OF THE INVENTION In recent years, with the remarkable development of electronic technology, the use of copper-clad laminates has become more diverse, and there has been a demand for copper-clad laminates with even better characteristics. Epoxy laminates based on non-woven glass fabric have the same electrical properties as epoxy laminates based on woven glass fabric, and are easier to punch, so their production volume is rapidly increasing. ing. Copper-clad laminates with a non-woven fabric base material are manufactured by applying epoxy resin to a non-woven glass fabric with a thickness of 100 to 600 μm, impregnating it, heating and drying it to obtain a prepreg, and then layering copper foil over this and molding it into an integral piece under heating and pressure. be done. Compared to copper-clad laminates based on woven glass fabric, this copper-clad laminate has superior hole clarity through drilling and punching, but has the disadvantage of inferior dimensional characteristics and through-hole reliability. Ta. To improve this, copper-clad laminates in which 20 to 70% by weight of an inorganic filler such as aluminum hydroxide powder or E-glass powder is added to epoxy resin have been commonly used.

However, when this inorganic filler is added, the impregnating property of the epoxy resin deteriorates, and a laminate using the filler tends to leave voids during molding, which has the disadvantage that the soldering heat resistance decreases. In addition, in order to improve resin impregnation, there is a method of using glass paper with an inorganic filler injected into the base material in advance, but inorganic fillers are difficult to fix in glass paper, and ionic fixatives Since the fixation is carried out using a laminate using this method, the laminate using this method has disadvantages such as discoloration after heating and a decrease in solder heat resistance.

0004

[Problems to be Solved by the Invention] The present invention has been made to eliminate the above-mentioned drawbacks, and has excellent heat resistance, processability, and dimensional stability, and is free from voids and discoloration, and is highly reliable. The purpose is to provide copper-clad laminates.

[0005]

[Means for Solving the Problems] As a result of extensive research in an attempt to achieve the above object, the present inventors have found that the above object can be achieved by using a glass nonwoven fabric made of a mixture of aramid fibers and glass fibers as a base material. The inventors have found that the object has been achieved and have completed the present invention.

That is, the present invention applies a thermosetting resin to a glass woven fabric on both sides of a prepreg (I), which is prepared by applying a thermosetting resin to a nonwoven glass fabric containing 10 to 50% of aramid fibers, impregnating it, and drying it. The coated, impregnated and dried prepregs (II) are layered together, and then the prepregs (II)
This is a copper-clad laminate, characterized in that copper foil is superimposed on at least one side of the copper foil and integrally formed by heating and pressing.

As the glass nonwoven fabric containing aramid fibers used in the present invention, a mixed nonwoven fabric containing 10 to 50% aramid fibers is used. If the proportion of aramid fibers is less than 10%, the dimensional stability of the laminate will be poor, which is not preferable. Moreover, if the proportion of aramid fibers exceeds 50%, the processability of the laminate deteriorates, which is not preferable.

The glass woven fabric used in the present invention is not particularly limited as long as it is commonly used for laminated boards.

[0009] Thermosetting resins used in the present invention include epoxy resins, unsaturated polyester resins, phenol resins, etc., and these may be used alone or in combination of two or more.

The prepreg (I) used in the present invention includes the above-mentioned mixed nonwoven fabric of glass fiber and aramid fiber,
A resin obtained by coating, impregnating and drying the above-mentioned thermosetting resin by a conventional method is used. Prepreg (I) is usually used by stacking a plurality of sheets depending on the desired thickness, but the number is not particularly limited.

The prepreg (II) used in the present invention is obtained by coating, impregnating and drying the above-mentioned thermosetting resin on the glass woven fabric used in the present invention by a conventional method. The number of prepregs (II) to be used is not particularly limited, and can be arbitrarily selected and used.

[0012] As the copper foil used in the present invention, a wide variety of copper foils that are normally used for laminated boards can be used, and there are no particular restrictions. Ordinary electrolytic copper foil, rolled copper foil, etc. are used.

The method for producing the copper-clad laminate of the present invention is not particularly limited, and any conventional method may be used. For example, an epoxy varnish is prepared by adding a curing agent and an organic solvent to an epoxy resin. Next, a non-woven glass fabric containing aramid fibers is impregnated with epoxy varnish using a coating machine and dried to obtain a prepreg, which is then laminated in a predetermined number of layers to form an epoxy resin prepreg with a glass woven fabric as a base prepared separately and a copper foil. A copper-clad laminate can be manufactured by stacking them together and molding them together under heat and pressure.

[0014]

EXAMPLES Next, the present invention will be explained by examples, but the present invention is not limited by these examples. In the following Examples and Comparative Examples, "parts" means "parts by weight" unless otherwise specified.

Example 1 Glass fibers with a fiber diameter of 9 μm were mixed with 25% aramid fibers with a fiber diameter of 3 μm and paper-formed to obtain a mixed glass nonwoven fabric. Next, brominated epoxy resin (epoxy equivalent: 470 g/
eq, bromine content 20.5%) 100 parts, dicyandiamide 3 parts, 2-ethyl-4-methylimidazole
An epoxy resin varnish consisting of 0.1 part and an appropriate amount of acetone was applied and impregnated onto the mixed nonwoven fabric, and heated to 160°C.
Prepreg (I) was prepared by drying at a temperature of . Next, the above-mentioned epoxy resin varnish was applied to a glass woven fabric, impregnated, and dried to produce a prepreg (II). Prepreg (I
) are stacked on top of each other, and prepreg (II
) are layered one by one, and a layer of 35 μm thick is placed on both sides.
Layer each sheet of copper foil at 170℃, 4
Heat and pressurize for 90 minutes at a pressure of 0 kg/cm2 to reduce the plate thickness.
A 1.6 mm copper clad laminate was manufactured. Various properties of the thus produced copper-clad laminate were tested, as shown in Table 1, and it was found to be excellent in heat resistance, workability, and dimensional stability, confirming the effects of the present invention.

Comparative Example 1 A copper-clad laminate was produced in the same manner as in Example 1, except that instead of the glass nonwoven fabric made from a mixture of aramid fibers and glass fibers, a nonwoven fabric made from a mixture of cotton linter fibers and glass fibers was used. was manufactured. Various properties of this copper-clad laminate were tested 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 a nonwoven fabric made only of aramid fibers was used instead of the glass nonwoven fabric made of a mixture of aramid fibers and glass fibers. We conducted tests on various properties of this copper-clad laminate.
The results are shown in Table 1.

Comparative Example 3 A copper-clad laminate was produced in the same manner as in Example 1, except that a nonwoven fabric made only of glass fibers was used instead of the glass nonwoven fabric made of a mixture of aramid fibers and glass fibers. We conducted tests on various properties of this copper-clad laminate.
The results are shown in Table 1.

[0019]

[Table 1] *1: Measured the time until blistering occurred when a sample with copper foil was floated in a solder bath at 260°C. *2
: Regarding the sample where the copper foil was etched away, 121℃,
Moisture absorption treatment was performed under PCT conditions at 2 atm for 1 to 7 hours, and the presence or absence of blisters was tested when immersed in a 260°C solder bath for 30 seconds. *3: Outer punching was performed at a temperature of 80°C. *4: The copper foil was etched over the entire surface, and the dimensional change rate in the vertical and horizontal directions was measured after heating at 170° C. for 30 minutes.

[0020]

Effects of the Invention As is clear from the above explanation and Table 1, the copper-clad laminate of the present invention has excellent heat resistance, workability, and dimensional stability, does not generate voids or discolors, and has good formability and reliability. It is highly sexual.

Claims (1)

[Claims] Claim 1: Prepreg (I), which is prepared by applying a thermosetting resin to a glass nonwoven fabric containing 10 to 50% aramid fibers, impregnating it, and drying it; What is claimed is: 1. A copper-clad laminate, characterized in that the prepregs (II) made by the prepregs (II) are superimposed, and then copper foil is superimposed on at least one side of the prepregs (II), and the prepregs (II) are integrally formed by heating and pressing.