JPH0367648A - Manufacture of phenol resin copper clad laminated sheet - Google Patents

Abstract

PURPOSE:To obtain a stable phenol resin copper clad laminated sheet excellent in dimensional stability and reduced in the irregularity of quality by repeating a heating/standing-to-cool cycle from 100 deg.C or higher two or more times when a prepreg and a copper foil are heated and pressed to raise temp. in a wavy form to mold both of them. CONSTITUTION:A predetermined number of prepregs and a copper foil (laminating material) are held between mirror surface plates and two or more sets thereof are inserted between the hot plates of a press and subsequently pressed, for example, under pressure 1 of 100 kg/cm<2> to be heated to a point 2 where the max. temp. on the hot plate side is about 100 deg.C. When the product max. temp. on the hotplate side reaches 100 deg.C, the laminate is allowed to stand to cool up to a point 3 where the product temp. on the hot plate side falls by 20 deg.C and subsequently heated to the max. temp. of 120 deg.C. This heating/standing- to-cool cycle is successively repeated two or more times and the laminate is heated in a wavy form to be subjected to press molding for 70 min under heating. On and after 70 min, heating is stopped while pressure is held as it is to allow the laminate to stand to cool. After sufficient standing to cool, pressure is released.

Description

[Detailed Description of the Invention] [Object of the Invention] (Industrial Application Field) The present invention provides a phenolic resin #J! which has excellent dimensional stability and less variation in quality. Laminated board 11! Regarding the method of sending.

(Prior Art) Phenolic resin copper-clad laminates have been widely used in consumer electronic devices. A phenolic resin copper-clad laminate is made of one or more sheets of prepreg made by impregnating and drying a phenolic resin into a paper base material. It is manufactured by combining metal foils such as A foil and sandwiching them between mirror plates, and laminating and molding the plurality of sets into one body under heat and pressure using a multi-stage hot press. The heating method for this laminated molding is to raise the temperature in -air and hold it at a predetermined high temperature for molding.

(Problem to be solved by the invention) For this reason, in the conventional manufacturing method, during molding in a multi-stage press, the internal temperature difference between the product opened on the hot plate and the product in the middle stage is too large, so the resulting copper-clad laminate It has the drawback of large dimensional changes and variations in warping and twisting characteristics.

The present invention aims to provide a method for manufacturing a phenolic resin steel-clad laminate with stable properties, which has little dimensional change, no warping or twisting, and little variation in quality.

[Structure of the Invention] (Means for Solving the Problems) The present inventors have made this work in view of the above-mentioned circumstances, and have developed a product in which the molding temperature is increased in a wave-like manner, and a hot plate open product during heat molding is formed. The present invention was completed by discovering that the above object can be achieved by reducing the internal temperature difference between the product and the product in the middle row. That is, the present invention provides a method for manufacturing a phenolic resin copper-clad laminate in which a prepreg and a copper foil are integrally heated and pressure molded, in which heating and cooling cycles are repeated multiple times from 100°C or higher to raise the temperature in a wavy shape. This is a method for producing a phenolic resin copper-clad laminate, which is characterized by molding.

The prepreg used in the present invention is obtained by coating a paper base material with a phenol resin, impregnating it, and drying it. Examples of paper base materials used here include cotton paper, linter paper, kraft paper, mixed paper of these, glass paper, etc.
Use in combination of more than one species. Furthermore, as the phenolic resin, all those commonly used for laminated boards can be used.

As the copper foil used in the present invention, all those commonly used for copper-clad laminates can be used.
For example, it may be an electrolytic copper foil, a rolled copper foil, a treated copper foil, an untreated copper foil, or any thickness, and is not particularly limited.

A phenolic resin copper-clad laminate can be manufactured by stacking predetermined sheets of the prepreg and copper foil described above and integrally molding them by heating and pressing according to a specific schedule according to the present invention.

Next, a method for manufacturing a phenolic resin copper-clad laminate according to the present invention will be explained using the drawings. Figure 1 is a diagram showing the relationship between molding time (horizontal axis), molding temperature (left vertical axis), and molding pressure (right vertical axis) for a phenolic resin copper-clad laminate. The temperature curve of the embodiment of the invention is shown, and the example 4IC shows the temperature curve of the conventional method, and the dashed-two dotted line shows the common pressure curve.

To explain the schedule regarding broken line A, a predetermined sheet of prepreg and copper foil (hereinafter referred to as laminated material) are sandwiched between IA face plates, and a plurality of sets thereof are inserted between hot discs of a press. Next, a pressure 1 of 100 hg/cn' is applied, and the temperature is raised to a point 2 where the maximum temperature on the heating platen side is about 100°C. When the maximum temperature of the product on the hot platen side reaches 100°C, let it cool until the temperature of the product on the hot platen side drops by 20°C. Temperature: 40℃〉, then repeat this heating/cooling cycle (from 120℃)
, 140° C., 16 G'C) The temperature is raised several times to create a wave-like shape, and heat and pressure molding is performed for 70 minutes.After 70 minutes, the pressure is maintained, heating is stopped, and the product is allowed to cool (hereinafter overlapped with solid line C).

After cooling down sufficiently, stop applying pressure.

Also, to explain the - dotted chain line B, when the maximum temperature of the product on the hot platen side reaches 100°C, as in the case of broken line A, let it cool until the temperature on the hot platen side drops by 20°C, and then heat it until it reaches the maximum temperature. Raise the temperature to 130℃ (50' from the cooling temperature)
C), This heating/cooling cycle is performed sequentially (130℃,
160℃) Repeat several times to raise the temperature to a wave-like shape and heat and press mold for 70 minutes. After 70 minutes, the pressure remains unchanged.
Stop heating and allow to cool (hereinafter overlapped with solid line C). Once cooled sufficiently, stop pressurizing.

By raising the molding temperature in a wavy manner in this way, it is possible to prevent the temperature of the product on the hot platen side of the copper-clad laminate from rising too high, and to bring the temperature of the product on the hot platen side close to the temperature of the middle product. By reducing this temperature difference, the difference in final heat receiving capacity due to the loading position of the multi-stage press for @-clad laminates is eliminated, and by keeping it constant, twisting and warping of the copper-clad laminates can be suppressed, and variations in quality can be reduced. This means that fewer copper-clad laminates can be obtained. As shown by the solid line C in FIG. 1, it is not possible to obtain a product with little warpage or twisting by increasing the molding temperature using the conventional method.

The phenolic resin copper-clad laminate thus obtained is suitable for use in consumer electronic devices and the like.

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

The present invention is not limited to these examples.

Example 1 Eight sheets of prepreg made by coating, impregnating, and drying a phenolic resin on a paper base material were stacked together, a 35 μ-thick copper foil was layered on one side, and this was sandwiched between 1.51-thick mirror plates. , place it between the hot plates of the press, then start heating at a pressure of 100 kg/cm', and when the maximum temperature on the hot plate side reaches 100℃, the temperature between the hot plates will drop by 20℃ (80℃)
Leave to cool until After that, the maximum temperature was raised by 20℃ (1
20'C), leave to cool until the temperature drops by 20°C (100°C). In this way, each time the maximum temperature is increased by 20'C (140'C, 1f30°C), the temperature is allowed to cool down by 20'C, and the heating and cooling cycle is repeated several times in a wave-like pattern, and heated for 70 minutes. A phenolic resin copper-clad laminate was manufactured by pressure molding.

The molding temperature-molding time-pressure curve at this time is shown by the broken line A in FIG.

Implementation pA2 8 sheets of Gripreg made by coating, impregnating, and drying a phenolic resin on a paper base material were stacked together, a 35 μm thick copper foil was layered on one side, and this was sandwiched between 1.5 μm thick mirrored plates. , inserted between the hot plates of the press, then 100kg/C1
Heating starts at a pressure of 1', and the a high temperature between the heating plates is 100
℃, the temperature between the heating plates will drop by 20℃ (8℃).
Leave to cool to 0℃). Thereafter, the maximum temperature is raised by 30°C (130°C), and then left to cool until it drops by 20°C (110°C). In this way, each time the maximum temperature was increased by 30°C (160°C), it was left to cool down by 20°C, and the heating/cooling cycle was repeated several times in a wave-like pattern, followed by hot molding for 70 minutes, and the phenol resin was A copper-clad laminate was manufactured. The molding temperature-molding time-pressure curve at this time is shown by the single-dot chain BB in FIG.

Comparative Example Eight sheets of prepreg made by coating, impregnating, and drying a phenolic resin on a paper base material were stacked together, a copper foil with a thickness of 35μ was layered on one side, and this was sandwiched between mirror plates with a thickness of 1.511.
Insert between the hot discs of the press. Then 100kg/
Heating was started at a pressure of cn2, the temperature was raised to 1170°C, and heat and pressure molding was performed for 70 minutes to produce a phenolic resin steel-clad laminate. The molding temperature-molding time-pressure curve at this time is shown by the solid line C in FIG.

The phenolic resin steel-clad laminates produced in Examples 1 and 2 and Comparative Examples were tested for warpage, insulation resistance, and soldering heat resistance, and the results are shown in Table 1. In the phenolic resin copper-clad laminate of the present invention, it was found that there was almost no difference in the amount of warpage between the hot plates and the center of the step, and the amount of warpage was small, confirming the effects of the present invention.

Table 1 (Units) *1: A 200x2 (10n11) test piece was etched on its entire surface, and the warpage after heating at 150°C for 30 minutes was measured in accordance with JIS-C-6481.

*2: Measured in accordance with JI 5-C-6481.

[Effects of the Invention] As is clear from the above explanation and Table 1, according to the method for producing a phenolic resin copper-clad laminate of the present invention, 8 panels 1
11! Whether it is an IJ product or a middle-stage product, it is a stable phenolic resin fl that has almost the same heat receiving capacity without warping or twisting, has excellent dimensional stability, and has little variation in quality.
A stretched laminate is obtained.

[Brief explanation of drawings]

FIG. 1 is a diagram showing the relationship between molding time, molding temperature, and molding pressure. A, B... Molding temperature curve of the present invention, C... Molding temperature curve of conventional method.

Claims (1)

[Claims] 1. A method for manufacturing a phenolic resin copper-clad laminate in which prepreg and copper foil are heated and pressed, which is characterized in that the phenol resin is molded by repeating a heating/cooling cycle from 100°C or higher multiple times to raise the temperature into a wavy shape. Method for manufacturing copper-clad laminates.