JPS63118240A - Continuous preparation of laminated sheet for electrical use - Google Patents

Abstract

PURPOSE:To shorten the time required for impregnation to a large extent, to prevent the involution of air at the time of lamination and to efficiently perform the defoaming and degassing of a resin solution, by a method wherein the vacuum degassing treatment of each of the base materials before impregnation, the individual impregnation of each base material with the curable resin solution and the lamination of the impregnated base materials are continuously performed in the same vacuum chamber and, at the same time, the resin solution is subjected to degassing treatment in the vacuum chamber to be supplied to each base material. CONSTITUTION:Base materials 1 pass through a preparatory vacuum box 3 to enter a vacuum chamber 6. The vacuum chamber 6 is sealed and connected to a high vacuum source to be evacuated to 50Torr or less. A resin solution is continuously supplied to the vacuum chamber 6 from a tank through a resin supply line 11 and a dispersing pipe 7 and degassed while flows down on the mesh tray 18 obliquely arranged in the vacuum chamber 6 and moisture is removed from the resin solution. The degassed resin solution is accumulated on the bottom of the vacuum chamber 6 and supplied to each of coaters 5 through a resin recirculation line 14. The base materials 1 entering the vacuum chamber 6 are individually separated to fall toward each of the coaters 5 and again rise after the resin solution is supplied to be united and laminated. The base materials 1 are subjected to vacuum degassing treatment before reaching the coaters 5 and, therefore, the penetration of the resin solution is facilitated.

Description

[Detailed description of the invention] A small portion... The present invention relates to a continuous manufacturing method for electrical laminates.

Here, the electrical laminate refers to an insulating laminate used as a substrate for various electrical and electronic components, and a fully bent foil-covered laminate used as a printed circuit board.

A laminate made of paper, glass cloth, glass paper, etc. as a base material, laminated with a plurality of resin-impregnated base materials impregnated with a resin liquid, and cured, and a laminate made of paper, glass cloth, glass paper, etc. Metal foil laminates, which are made by laminating metal foil on one or both sides, are widely used as insulating boards and printed wiring boards.

Conventionally, these laminates have been manufactured using a bunch method in which the base material is impregnated with resin face, dried, and then the resulting Buripure Puffer is layered and formed by pressing and heating in a press.
Recently, a continuous method for impregnating, laminating, and curing a long base material while continuously conveying it with a resin has been developed, and was industrialized for the first time by the present applicant. For example, the present applicant's Japanese Patent Application Laid-open No. 55-
4838, 56-98136, etc.

In the continuous method described above, curing and molding is performed virtually without pressure without using a press, so in order to obtain a product that does not contain air bubbles or voids, the substrate after impregnation must not contain air bubbles or voids. Therefore, it is necessary to take measures such as applying the resin liquid to one side of the base material and spending a certain amount of time impregnating it so that the applied resin liquid penetrates to the other side while eliminating the air inside the base material. be. The time required to complete this impregnation is a function of resin properties (mainly viscosity), substrate density, substrate temperature, etc., but these parameters cannot be changed arbitrarily. Therefore, in order to impregnate the base material as completely as possible, it is necessary to take a longer transport path for the base material after the resin liquid is applied and until it is laminated, or to slow down the overall line speed.

Voids in the product also occur due to air being drawn in when the impregnated base materials are laminated and combined. Furthermore, it is also effective to supply the resin liquid to be impregnated after being defoamed and deaerated in advance.

The present invention significantly shortens the time required for impregnation in the continuous method described above, enables selection of resin liquid and base material parameters from a wide range, prevents air entrainment during lamination of impregnated base materials, and An improved method for efficiently defoaming and degassing a resin liquid is provided.

Solution A According to the present invention, a plurality of sheet-like base materials are impregnated with a curable resin liquid while being conveyed continuously, the impregnated base materials are laminated, and metal foil is applied to the upper and lower surfaces of the laminated impregnated base materials. and/or a continuous manufacturing method for electrical laminates in which a carrier film is laminated and cured continuously, comprising: vacuum degassing treatment of the base material before impregnation; and individual impregnation of each base material with the resin liquid;
Continuous production of electrical laminates, characterized in that the impregnated base materials are laminated continuously under reduced pressure in the same vacuum chamber, and at the same time, the resin liquid is deaerated in the vacuum chamber and then supplied to each base material. provide a method.

The method of the present invention reduces the time required for impregnation to less than half that of the conventional method in which these steps are carried out at normal pressure,
The impregnation time is significantly reduced regardless of variations in resin liquid and substrate parameters, allowing for a wide variety of resin and substrate selections.

It also prevents air from being drawn in when laminating impregnated base materials.
The conveyance path from resin liquid application to lamination can be shortened, and the apparatus can be made more compact accordingly.

Long conveyor paths and slow line speeds are generally disadvantageous because they require long changeover times when switching to manufacturing a different type of III-layer slope 0 using the same equipment. Furthermore, in the method of using a separate deaeration tower for deaeration of the resin liquid, the resin liquid remaining in the deaeration tower and the resin liquid supply line at the time of switching is lost. The method of the present invention is economical because the switching time is shortened and the amount of resin lost during switching can be reduced. Furthermore, it is not necessary to separately install a resin degassing tower, and the associated equipment such as a liquid feed pump and a vacuum pump can be omitted, resulting in savings in equipment costs.

Thank you for the pressure FIG. 1 is a schematic diagram illustrating the method of the present invention.

The method of the present invention is carried out in accordance with the method described in Japanese Patent Application Laid-Open No. 55-4838 cited above, except as otherwise specified herein. Since this method is the same as the method disclosed in Japanese Patent Publication No. 56-98136, the common parts will not be explained repeatedly.

In FIG. 1, a plurality of substrates 1 pass between seal rolls 2 on the entrance side and enter a pre-decompression box 3. A seal material 4 is attached to each seal roll 2 and seals the Fo-rule z. The outlet side of the preliminary decompression box 3 is sealed by a similar seal roll 2, and the inside is connected to a vacuum source (not shown). It is preferable to provide such a preliminary decompression box 3 adjacent to the decompression chamber 6 in order to increase the degree of vacuum within the decompression chamber 6.

The substrate 1 passes through the pre-decompression box 3 and then enters the decompression chamber 6. The decompression chamber 6 is sealed by an inlet side seal roll 2 and a squeeze roll 7 which also serves as an outlet side seal roll, and each base material is depressurized and degassed before applying the resin liquid, and each degassed base material is individually After the resin liquid is applied, it has a space necessary for individually and continuously conveying the resin liquid inside the decompression chamber 6 until the resin liquid completely fills the void inside the base material and is laminated and combined. The reduced pressure chamber 6 is connected to a high vacuum source (not shown) and is reduced in pressure to 50 Torr or less, preferably 10 to 20 Torr. The degree of decompression in the preliminary decompression box 3 is maintained at a lower degree of vacuum than in the decompression chamber 6.

The substrates 1 that have entered the reduced pressure chamber 6 are separated individually, descended toward their respective coaters 5, and after being supplied with resin liquid rise again to be combined and laminated. The base material 1 is degassed under reduced pressure before reaching the coater 5, thereby facilitating penetration of the resin liquid. Each coater 5 is configured to supply a resin liquid to one side of each base material 1, and the supplied resin liquid permeates toward the opposite side while eliminating remaining air.

The resin liquid is continuously supplied from a resin mixing tank (not shown) to the decompression chamber 6 through the resin supply line 11 and the dispersion pipe 17, and slowly flows down over the perforated plate 18 installed diagonally in the decompression chamber 6. Degassed to remove gas and moisture. The degassed resin liquid accumulates at the bottom of the vacuum chamber 6 and is supplied from there to each coater 5 through the resin circulation line 14, and the remaining resin liquid accumulates at the bottom of the vacuum chamber 6 again and is circulated and used. Ru.

The base materials individually impregnated with the resin liquid in this manner are stacked together on the exit side of the vacuum chamber 6 and passed between seal rolls 7 on the exit side of the vacuum chamber 6 .

It is preferable to provide a preliminary decompression box 9 on the outlet side of the decompression chamber 6, similar to that on the inlet side. The outlet side of the preliminary decompression box 9 is sealed with a seal roll 10 similar to the seal roll 2, and the inside thereof is depressurized to a low degree of vacuum by a low vacuum source (not shown). The seal rolls 7 and 10 are sealed with a seal material 8 similar to the seal material 4.

The laminate that has exited the outlet side pre-decompression box 9 passes between squeege rolls 19 in a known manner, then is laminated with metal foil and/or carrier film 12 on the upper and lower surfaces by laminating rolls 13, and then transferred to a curing furnace (not shown). While passing through, it undergoes hardening and is cut into desired dimensions to become products.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram for explaining the present invention. 1 is a base material, 3 is a preliminary vacuum box, 6 is a vacuum chamber, 5 is a coater, 7 is a seal roll, 9 is a preliminary vacuum box, 1
1 is a resin liquid supply line, 14 is a resin liquid circulation line, 17
1 is a dispersion tube, 18 is a perforated plate, 12 is a metal foil or carrier film, 13 is a laminate roll, and 19 is a squeeze roll.

Claims (5)

[Claims] (1) impregnating a plurality of sheet-like base materials with a curable resin liquid while continuously conveying them, laminating the impregnated base materials, and laminating metal foil and/or carrier film on the upper and lower surfaces of the laminated impregnated base materials; In a continuous manufacturing method for electrical laminates in which curing is performed continuously, the substrates are degassed under reduced pressure before being impregnated, each substrate is individually impregnated with the resin liquid, and the impregnated substrates are laminated in the same vacuum chamber. 1. A method for continuously manufacturing an electrical laminate, characterized in that the resin liquid is continuously carried out under reduced pressure in the reduced pressure chamber, and at the same time, the resin liquid is deaerated in the reduced pressure chamber and then supplied to each base material. (2) The first one in which the degree of vacuum in the vacuum chamber is 10 to 20 Torr.
Continuous manufacturing method for electrical laminates. (3) The continuous manufacturing method for electrical laminates according to item 1 or 2, wherein the impregnation is performed by individually applying the resin liquid to one side of each base material. (4) The degassing treatment of the resin liquid is carried out by causing a new resin liquid to flow down along a perforated plate provided in the decompression chamber. Continuous manufacturing method. (5) Preliminary decompression chambers with a lower degree of vacuum than the decompression chamber are provided on the upstream and downstream sides of the decompression chamber, and the preliminary decompression chambers are provided before the substrate enters the decompression chamber and after the impregnated substrate is laminated and combined. 4. The continuous manufacturing method for an electrical laminate according to any one of paragraphs 1 to 4, wherein