JPH09201906A - Manufacture of laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To carry out on uniform heating and high speed heating between unit pressed bodies possible at a heat so as to reduce the scattering of the rates of the dimensional change among the laminated sheets obtained from the unit pressed bodies different in the position of stage, improve moisture absorbing resistance and prevent blur as the surface characteristics of a laminated sheet from developing in the manufacturing method of the laminated sheet by pressurizing from above and below a multi-stage pressed body prepared by alternately stacking unit pressed body consisting of prepregs, the base material of each of which is impregnated with semi-cured resin, and metal foil, and metal mirror plates. SOLUTION: A pressed body 3 consists of prepregs 1, the base material of each of which is impregnated with semi-cured resin, and metal foils 2 and is employed as a unit pressed body 4. By alternately stacking the unit pressed body 4 and a metal mirror plate 5, a multi-stage pressed body 6 is formed. Under the state that the multi-stage pressed body 6 is pinched from above and below between electrode plates 7 and a high frequency voltage is applied to the electrode plates 7, the multi-stage pressed body 6 is pressurized so as to obtain laminated sheets.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a laminated board, and more particularly to a method for manufacturing a laminated board in which a pressure-sensitive body composed of a prepreg and a metal foil impregnated with a semi-cured resin is hot pressed. .

[0002]

2. Description of the Related Art For example, a laminated board for electrical use is a prepreg obtained by impregnating a base material such as a woven or non-woven fabric made of glass fiber or pulp paper with a thermosetting resin such as a phenol resin, an epoxy resin, an imide resin or a polyester resin and drying the same. It is manufactured by sandwiching a pressed body on which a metal foil such as copper foil and the like is stacked between hot plates and hot pressing. In this case, in order to enhance the production of one molding cycle from the start of pressurization to depressurization, a pressure-sensitive body composed of a prepreg and a metal foil in which a substrate is impregnated with a semi-cured resin is used as a unit pressure-sensitive body. The unit pressure body and the metal mirror plate are alternately stacked to form a multi-stage pressure body, and the multi-stage pressure body is sandwiched between the heating plates that apply pressure from above and below, and the heat conduction from this heating plate is used. Since it was to be heated, the difference in the thermal curing conditions of the semi-cured resin in the prepreg due to the difference in the temperature rising rate due to the step of each unit pressure body due to the difference in heat conduction,
The difference in the impregnability due to the difference in the viscosity reduction rate of the resin and the difference in the curing rate of the resin, resulting in a large variation in the dimensional change rate and moisture absorption resistance of the laminate obtained from each unit pressure body. , And the presence or absence of scratches on the surface.

[0003]

SUMMARY OF THE INVENTION In view of the above situation, an object of the present invention is to provide a unit pressure-receiving member which is a pressure-receiving member composed of a prepreg in which a substrate is impregnated with a semi-cured resin and a metal foil. In the manufacturing method of the laminated plate in which the unit pressure bodies and metal mirror plates are alternately stacked to form a multi-stage pressure body, and the multi-stage pressure bodies are pressed from above and below, each unit pressure body constituting the multi-stage pressure body is pressed. By enabling uniform heating and high-speed heating all at once, it is possible to reduce the variation in the dimensional change rate between the laminated plates obtained from the unit pressure bodies with different steps, improve the moisture absorption resistance, and further It is intended to provide a method for producing a laminated plate which avoids the generation of scratches which are surface characteristics.

[0004]

In the method for producing a laminated board according to the first to fourth aspects of the present invention, a prepreg 1 and a metal foil 2 in which a base material is impregnated with a semi-cured resin are formed. The pressure-receiving body 3 is a unit pressure-receiving body 4, and the unit pressure-receiving body 4 and the metal mirror plate 5 are alternately stacked to form a multi-stage pressure-receiving body 6. It sandwiches and pressurizes the multi-stage pressed body 6 while applying a high frequency voltage to the electrode plate 7, and the total thickness of the metal including the metal foil 2 and the mirror surface plate 5:
The total thickness of the prepreg 1 is 30: 1 to 0.5: 1, the high frequency is 5 to 80 MHz, and under these conditions, the prepreg 1 having a high insulating property internally generates heat. The heat generation in the prepreg 1 is uniform even at different stages and is heated at a high speed. Therefore, the viscosity of the semi-cured resin in the prepreg 1 is decreased uniformly and at a high speed, so that the resin impregnation is uniform and at a high speed. In addition, the resin can be cured uniformly and at high speed.

[0005]

Embodiments of the present invention will be specifically described below.

As shown in FIG. 1, the unit pressure member 4 in the method for producing a laminated plate of the present invention is, for example, a woven or non-woven fabric made of glass fiber or a base material such as pulp paper, and a phenol resin.
It is composed of a prepreg 1 impregnated with a thermosetting resin such as an epoxy resin, an imide resin, a polyester resin, etc. and dried, and a pressed body 3 on which a metal foil 2 such as a copper foil is stacked. It should be noted that the metal foils 2 may be arranged above and below the plurality of prepregs 1 to form the unit pressure body 4, or the metal foils may be arranged between the plurality of prepregs 1 to form the unit pressure body 4. .

The unit pressure bodies 4 and the metal mirror plate 5 are alternately stacked to form a multi-stage pressure body 6. This multi-stage pressure body 6
Is the total thickness of the metal foil 2 and the metal including the mirror surface plate 5 that form the unit pressure body 4: the total thickness of the prepreg 1 is 30:
1 to 0.5: 1 is preferred. As the metal mirror plate 5, for example, a stainless plate is used.

A feature of the present invention is that the multi-stage pressured body 6 is sandwiched between electrode plates 7 from above and below, and a high frequency voltage is applied to the electrode plates 7 above and below. That is, when a high-frequency voltage is applied, the prepregs 1 of the unit pressure-receiving members 4 that are vertically stacked via the mirror plate 5 generate heat. This heat generation is uniform and faster than the conventional heat conduction as long as it is the same material regardless of the stage of the unit pressure-subjected body 4. Therefore, the viscosity decrease as the semi-cured resin in the prepreg 1 melts. The resin is uniformly and rapidly impregnated into the base material, and the resin is uniformly and rapidly cured.
As a result, the degree of curing of the resin of the laminated plate obtained from the unit pressure-sensitive members 4 having different steps is uniform irrespective of the steps, so that variations in dimensional stability and moisture resistance are reduced, and the temperature rising rate is the same as before. It is possible to eliminate the presence or absence of blurring due to the size of the laminate, and it is possible to obtain a laminate having uniform surface characteristics without blurring. The applied high frequency is preferably 5 to 80 MHz. The reason for this is that if the temperature is out of this range, the rate of temperature rise is too slow to complete the curing of the resin because the heat generation is too small, and the temperature rise rate is too high to cure the resin because the heat generation is too large. This is because it is likely to be decomposed beyond.

Hereinafter, examples and comparative examples will be described.

[0010]

【Example】

 Example 1 A glass cloth having a thickness of 190 μm and epoxy crocodile
Prepreg coated with rubber (resin content 47 weight
%), And 18 μm electrolytic copper foil is placed above and below this
As a unit pressure body, and twelve of these unit pressure bodies of 2 mm
Alternately stacked with stainless steel plates to form a multi-stage pressure body (metal foil
Thickness of the metal including the mirror plate and mirror plate: Total thickness of the prepreg
= 30: 42.7). The prepreg is semi-cured
The resin has a gel time of 30 seconds at 170 ° C.
Was. Stainless steel plate and electric heater on the outside of this multi-stage pressure body
0.2mm craft between the upper and lower electrode plates
5 sheets of paper are placed, and this electrode plate is heated by an electric heater to generate 6
Preheat to 0 ℃, high frequency output 3.5kw on the upper and lower electrode plates,
High frequency voltage of 13.56MHZ is applied and molding pressure
5 kg / cm ^TwoMolded. After applying high frequency voltage
The temperature of the unit pressured body of the 6 steps from the bottom with the passage of time
When the degree was measured (Table 1), it was 1 in 17 minutes.
Reached 70 ° C. Thermoforming was carried out at this temperature for 50 minutes.

[0011]

[Table 1]

(Example 2) Two prepregs (resin content 47% by weight) obtained by coating the epoxy varnish of Example 1 on a glass cloth having a thickness of 200 μm are stacked, and 18 layers are provided on the upper and lower sides.
The electrolytic copper foil of μm is arranged to form a unit pressure body, and 8 sheets of this unit pressure body are alternately stacked with a 2 mm stainless steel plate to form a multi-stage pressure body (total of metal foil and metal including mirror surface plate). Thickness: total thickness of prepreg = 30: 17.14). Five 0.2 mm kraft papers were placed between the stainless plate on the outer side of the multi-stage pressure body and the upper and lower electrode plates containing the electric heater.
High frequency output 3.5kw, frequency 13.5 on upper and lower electrode plates
Applying high frequency voltage of 6MHZ, molding pressure 15kg / cm
Molded in ² . The hot-pressing time was 170 ° C. and 50 minutes.

[0013]

[Comparative example]

(Comparative Example 1) The same multi-stage pressure-sensitive body as in Example 1 was sandwiched between upper and lower heat conduction type heating plates heated by high-pressure steam and hot-pressed. In this case, the heating rate of the hot platen was 8.8 ° C./min, and the thermocompression molding was 40 kg / cm ² and 170 ° C. for 50 minutes. When the temperature of the unit pressure body of the 6 steps from the bottom was measured with the lapse of time after heating with high pressure steam, as shown in Table 2 (Table 2), it remained at 162 ° C even after 25 minutes. .

[0014]

[Table 2]

(Comparative Example 2) The same multistage pressed body as in Example 2 was sandwiched between the hot plates of Comparative Example 1 and hot pressed. In this case, the heating rate of the heating platen is 5.9 ° C./min, and the thermocompression molding is 40 k.
G / cm ² and 170 ° C. for 60 minutes.

The dimensional change rate, moldability and measling property of Example 1 and Comparative Example 1, and the moldability, measling property and halo resistance of Example 2 and Comparative Example 2 are as shown in (Table 3). The laminated sheets according to the examples were excellent in all performances.

[0017]

[Table 3]

[0018]

According to the method for producing a laminated sheet of the present invention, the variation in the dimensional change rate between laminated sheets obtained from unit pressure-sensitive bodies having different steps is reduced, the moisture absorption resistance is improved, and the surface of the laminated sheet is further improved. By looking at the characteristics, it is possible to eliminate the occurrence of blurring.

[Brief description of drawings]

FIG. 1 is a side view showing a multi-stage pressure body and an electrode plate to which a high frequency voltage is applied according to an embodiment of the present invention.

FIG. 2 is a cross-sectional view showing an example of a laminated board according to an embodiment of the present invention.

[Explanation of symbols]

 1 prepreg 2 metal foil 3 pressure body 4 unit pressure body 5 mirror plate 6 multi-stage pressure body 7 electrode plate

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI technical display location // B29K 105: 08 309: 08 B29L 9:00

Claims (4)

[Claims] 1. A unit pressure body (4) is a pressure body (3) comprising a prepreg (1) and a metal foil (2) in which a substrate is impregnated with a semi-cured resin. (4) and a mirror plate (5) made of metal are alternately stacked to form a multi-stage pressure-receiving body (6),
This multistage pressure body (6) is sandwiched between the electrode plates (7) from above and below,
A process for producing a laminated plate, which comprises pressurizing a multi-stage pressure-receiving body (6) while applying a high-frequency voltage to the electrode plate (7). 2. The total thickness of the metal including the metal foil (2) and the mirror plate (5): the total thickness of the prepreg is 30: 1 to 1.
The manufacturing method of the laminated board of Claim 1 which is 0.5: 1. 3. The method for producing a laminated plate according to claim 1, wherein the high frequency is 5 to 80 MHZ. 4. The method for producing a laminated plate according to claim 1, wherein the base material is a glass cloth.