JPS6221539A - Manufacture of laminated board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] 〔Technical field〕 The present invention relates to a method for manufacturing a laminate.

[Background technology]

Regarding laminates, the distribution of residual strain is different between normal molded products (batch type molded products) and continuous molded products, and it can be easily assumed that continuous molded products are more advantageous in terms of uniformity of the distribution of residual strain. In a typical molded product, the distribution of residual strain is radial from the center of the laminate toward its edges. On the other hand, as shown in FIG. 1, in the continuous molded product 1, all cross sections perpendicular to the direction of movement (direction of arrow A) (indicated by a dashed line in the figure) have the same strain. For example, even if it is cut along the solid line B, the results are almost the same. Even if the strain is removed by heating or the like, the tendencies of each of these molded products basically remain unchanged, and this causes a large difference when etching is performed later.

[Purpose of the invention]

In view of the above, an object of the present invention is to provide a method for manufacturing a laminate having high dimensional stability.

[Disclosure of the invention]

The inventors believe that even if a fully cured laminate is strained, the effect is small, but that it is best to remove strain in a semi-cured state, with no stress or pressure applied. Obtained knowledge and completed this invention. Therefore, this invention is based on a cured product obtained by stacking a predetermined number of elongated sheets made of at least a resin-impregnated base material and continuously molding them under a pressure of 5 to 50 kg/crA. After cutting a 15-60% semi-cured board, the temperature is 50% higher than the glass transition temperature of the semi-cured resin.
The gist is a method for manufacturing a laminate that is post-cured in a stress-free state at a temperature higher than ~120°C.

The present invention will be explained in detail below.

In the method for manufacturing a laminate according to the present invention, continuous molding is used because it is advantageous in terms of uniformity of distribution of residual strain after molding, that is, it is advantageous in terms of dimensional stability of the laminate. Continuous molding can be carried out by various means such as double belt press (W belt press) and roll press, and there are no particular limitations.

The pressure applied during molding is 5 to 50 kg/ant, and if it deviates from this range, the physical properties such as the dimensional stability of the resulting laminate will be adversely affected. That is, the pressure is 5 kg/c
If the pressure is less than 50 kg/m2, voids may occur.
If it exceeds cm2, the flow of the resin will increase, resulting in a resin shortage.

A predetermined number of sheet-like elongated objects made of a resin-impregnated base material and, if necessary, a sheet-like elongated object made of metal foil on one or both sides thereof, are stacked one on top of the other, and continuously molded under the above conditions to obtain a hardening degree of 15-15. The board is 60% semi-cured. If the degree of curing of the semi-cured resin is out of this range, it will adversely affect the physical properties of the resulting laminate. That is, if the degree of hardening is less than 15%, the degree of hardening is too low and may cause problems in subsequent processing, and if the degree of hardening exceeds 60%, there are problems such as insufficient strain relief in post-curing. Examples of the resin impregnated into the base material include thermosetting resins or resin compositions such as epoxy resins, phenol resins, polyimide resins, and polyester resins, and those with good dimensional stability are preferable. Not limited. Examples of the base material include glass cloth and paper, and those with good dimensional stability are preferred, but are not limited to these. Examples of the metal foil include, but are not limited to, copper foil and aluminum foil. The semi-cured plate formed as described above is cut into predetermined dimensions depending on the intended use, and then post-cured at a temperature 50 to 120° C. higher than the glass transition temperature of the semi-cured resin. If the temperature is below this range, strain relief will be insufficient, and if it is above this range, the resin etc. will be adversely affected.

Post-curing also serves to remove distortion from semi-cured plates. The temperature at which the strain is removed is preferably higher than the glass transition temperature (also referred to as glass transition point, hereinafter referred to as rTgJ) of the semi-cured resin. However, the resin in the cured state or
When the degree of curing is close to the cured state (specifically, the degree of curing is higher than 60%), the temperature is 50 to 120°C higher than the Tg of the semi-cured resin.
At high temperatures, discoloration, burning, and decomposition of resin, copper foil, and other metal foils occur, making it practically impossible to remove distortion. In addition,
Post-curing must be carried out in a stress-free manner, without applying tension, compression, or pressure to the semi-cured plate.

As seen above, the method for manufacturing a laminate according to the present invention is as follows:
By selecting a highly effective post-curing temperature, a highly effective degree of curing, and a highly effective molding method, a laminate with high dimensional stability, such as a copper clad laminate (CCL), can be easily obtained. In other words, the obtained laminate has a small absolute value of the dimensional change rate in the longitudinal and lateral directions, a small difference in the dimensional change rate in the longitudinal and lateral directions, and a small variation in the dimensional change rate from laminate to laminate. be. Moreover, this effect becomes more effective as the thickness of the laminate becomes thinner (particularly when the thickness is 0°05 to 0.05°).
80m), larger than regular products.

Examples and comparative examples are shown below, but the invention is not limited to these examples.

(Example 1) An epoxy resin composition consisting of 100 parts by weight of epoxy resin, 4 parts by weight of dicyandiamide as a hardening agent, and 0.2 parts by weight of imidazole was applied to a 216 type glass substrate so that the amount of resin adhesion was 50%. Two long sheets made of a resin-impregnated base material (molded base material) impregnated with a resin are stacked, and two long sheets made of copper foil (thickness 18 μm) are stacked on each of the top and bottom surfaces. A semi-cured plate with a degree of hardening of 35% was obtained by continuous lamination molding using a double belt press method at a pressure of 15 kg/ca. The Tg of the semi-cured resin of this plate was 80°C. This plate was cut to a predetermined size and then post-cured at a temperature of 170° C. in a stress-free state to obtain a laminate.

(Example 2) Two long sheets made of the same molded base material as in Example 1 were stacked, and two long sheets made of the same copper foil as in Example 1 were stacked on each of the upper and lower surfaces. , Pressure 15 kg/a+! in the same manner as in Example 1! Continuously laminated and molded with a hardening degree of 2.
A 0% semi-cured board was obtained.

The Tg of the semi-cured resin of this plate was 70°C. This plate was cut to a predetermined size and then post-cured at a temperature of 170° C. in a stress-free state to obtain a laminate.

(Example 3) Two long sheets made of the same molded base material as in Example 1 were stacked, and two long sheets made of the same copper foil as in Example 1 were stacked on each of the upper and lower surfaces. , was laminated continuously at a pressure of 15 kg/cn in the same manner as in Example 1, and the degree of hardening was 55.
% semi-cured board was obtained.

The Tg of the semi-cured resin of this plate was 100°C.

This plate was cut to a predetermined size and then post-cured at a temperature of 170° C. in a stress-free state to obtain a laminate.

(Example 4) Two long sheets made of the same molded base material as in Example 1 were stacked, and two long sheets made of the same copper foil as in Example 1 were stacked on each of the upper and lower surfaces. , Continuous lamination molding was carried out in the same manner as in Example 1 at a pressure of 8 kg/ca to obtain a semi-cured plate with a degree of hardening of 35%. Tg of the semi-cured resin of this board
was 80°C. After cutting this board to the specified size,
A laminate was obtained by post-curing at a temperature of 95° C. in a stress-free state.

(Example 5) Two long sheets made of the same molded base material as in Example 1 were stacked, and two long sheets made of the same copper foil as in Example 1 were stacked on each of the upper and lower surfaces. , Continuous lamination molding was carried out in the same manner as in Example 1 at a pressure of 45 kg/cl to obtain a semi-cured plate with a degree of hardening of 35%.

The Tg of the semi-cured resin of this plate was 80°C. This plate was cut to a predetermined size and then post-cured at a temperature of 135° C. in a stress-free state to obtain a laminate.

(Comparative Example 1) The same molding base material as in Example 1 was cut to a predetermined size and two sheets were stacked, and on both the top and bottom sides, two sheets of the same copper foil as in Example 1 were cut to a predetermined size and stacked one by one. Laminated molding was performed at a pressure of 15 kg/cJ by molding (batch molding), and the degree of hardening was 35%.
A semi-cured board was obtained. The Tg of the semi-cured resin of this board is 80
This board was post-cured at a temperature of 170°C to obtain a laminate.

(Comparative Example 2) The same molded base material as in Example 1 was cut to a predetermined size and two sheets were stacked, and on the top and bottom sides of the same molded base material as in Example 1 was cut to a predetermined size and two sheets were stacked one by one. By molding, the pressure is 15k.
Laminate molding was performed at g/cJ to obtain a plate with a degree of hardening of 95%. The Tg of the cured resin of this plate was 140°C. This board is 17
A laminate was obtained by post-curing at a temperature of 0'c.

(Comparative Example 3) Two long sheets made of the same molded base material as in Example 1 were stacked, and two long sheets made of the same copper foil as in Example 1 were stacked on each of the upper and lower surfaces. A plate with a degree of hardening of 80% was obtained by continuous lamination molding using a double belt press method at a pressure of 15 kg/cJ.

The Tg of the cured resin of this plate was 130°C. This plate was cut into predetermined dimensions and post-cured at a temperature of 170°C to obtain a laminate.

Each laminate obtained in Examples 1 to 5 and Comparative Examples 1 to 3 was
It was cut into 0 x 250 mm squares, the vertical and horizontal dimensions were measured after etching and after heating, and the dimensional change rate and the variation in the dimensional change rate for each laminate after heating were calculated, and the results are shown in Table 1. Ta.

In addition, in Examples 1 to 5 and Comparative Examples 1 to 3, the degree of curing was determined by the ratio of epoxy groups by infrared absorption spectrum analysis.

As shown in Table 1, the laminates obtained in Examples 1 to 5 have a smaller absolute value of the dimensional change rate in the longitudinal direction than the laminates in Comparative Examples 1 to 3. The absolute values of the dimensional change rates are almost the same.

Moreover, the laminates obtained in Examples 1 to 5 did not have much difference in the dimensional change rates in the longitudinal and lateral directions, whereas Comparative Examples 1 to 5
The laminate plate No. 3 has a very large difference in dimensional change rate in the vertical and horizontal directions. The variation in the dimensional change rate of each laminate after heating is also much smaller in the laminates of Examples 1 to 5 than in the laminates of Comparative Examples 1 to 3.

〔Effect of the invention〕

As described above, the method for producing a laminate according to the present invention is to cut a semi-cured plate with a degree of hardening of 15 to 60% that has been continuously molded under a pressure of 5 to 50 kg/c111, and then cut the semi-cured plate. 50~12 higher than the glass transition temperature of the resin
Since post-curing is carried out in a stress-free state at a temperature 0°C higher, the absolute value of the dimensional change rate in the longitudinal and lateral directions is small, and the difference between the dimensional change rates in the longitudinal and lateral directions is small. A laminate with high dimensional stability and small variations in dimensional stability can be easily obtained.

[Brief explanation of drawings]

Claims (2)

[Claims] (1) A predetermined number of elongated sheets made of at least a resin-impregnated base material were piled up, and semi-cured plates with a degree of hardening of 15 to 60% were cut by continuously molding them under pressure of 5 to 50 kg/cm^2. A method for manufacturing a laminate in which the semi-cured resin is then post-cured in a stress-free state at a temperature 50 to 120° C. higher than the glass transition temperature of the semi-cured resin. (2) The method for manufacturing a laminate according to claim 1, wherein the laminate has a thickness of 0.05 to 0.80 mm.