JPS63207631A - Treatment method of laminated sheet - Google Patents

Abstract

PURPOSE:To improve dimensional slability of a laminated sheet by reducing a warp without deteriorating roughness of the surface, by a method wherein the laminated sheet is heated at least at a temperature of the glass transition point of resin contained in the laminated sheet, and quanching is performed in a longitudinal direction of a base material. CONSTITUTION:A base material is impregnated with resin, dried through heating by passing through a drying furnace and a prepreg is manufactured. The prepreg is cut into pieces of predetermined size, necessary number of sheets of them are piled up, upon which a metallic foil is put, which is heated, pressurized and then a laminated sheet is obtained. To improve dimensional stability of the manufactured laminated sheet, the laminated sheet is aged by heating. A heating temperature is set up at least at the glass transition point of the resin contained in the laminated sheet. In the case where the resin constituting the laminated sheet, for example, is epoxy resin, the same is heated at about 130-180 deg.C and after aging treatment, the same is quenched at a temperature of the glass transition point or lower. The quenching is performed by method wherein a conveyor belt 4 is arranged slantwise in a water tank 3 filled with cool water 2, the laminated sheet A is put on the conveyor belt 4 so that a longitudinal direction of the base material runs parallel with a running direction of the conveyor belt and shifted into the cool water 2 from air. As the treatment is performed along the longitudinal direction of the base material, texture irregularity is removed and generation of a warp is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a method for processing a laminate used for processing into a printed wiring board.

[Background Art 1] A laminate is produced as a metal-clad laminate with metal foil such as copper foil covered on one or both sides, and then processed into a printed wiring board for use. That is, a circuit pattern is created by etching the metal foil on the surface, and electrical components are mounted by soldering to create a finished printed wiring board. However, the laminate has a problem in that it does not have sufficient dimensional stability and is prone to warping during the soldering process and the like.

EObjective of the Invention 1 The present invention has been made in view of the above points, and an object thereof is to provide a method for processing a laminate that can reduce warping and increase the dimensional stability of the laminate. That is.

[Disclosure of the Invention J] However, the method for processing a laminate according to the present invention is a laminate made by laminating and molding a plurality of prepregs prepared by impregnating and drying a long base material with a resin. is heated to a temperature equal to or higher than the glass transition point of the resin contained in the laminate, and then quenched by cooling the laminate along the longitudinal direction of the base material. The present invention will be described in detail below.

As the base material, glass cloth such as woven fabric or non-woven fabric made of plus fibers, or other materials can be used, and while the long base material is unwound from the roll, it is coated with a thermosetting resin face such as epoxy resin or polyimide 7 varnish. A prepreg is created by continuously passing through a varnish layer to impregnate the base material with resin, and then continuously passing it through a drying oven and drying it by heating. Then, the prepreg created in a long state using this long base material is cut into pieces to a predetermined size, and the required number of pieces of prepreg cut into pieces are piled up.C)
A laminate can be obtained by overlaying a metal foil such as copper foil on the outer layer on one side or the outer layer on both sides, and then heating and pressurizing this to form a laminate.

Here, each prepreg is laminated and molded in a stacked state with the base materials aligned in the same direction (the longitudinal direction of the base material in a 1-scale state).

In order to increase the dimensional stability of the laminate thus produced, the laminate is heated and subjected to 21v. The heating temperature during acing is set to be higher than the glass transition point of the resin contained in the laminate. No upper limit is set! It is necessary to maintain a temperature that does not deteriorate MN. For example, if the resin constituting the laminate is an epoxy resin,
It is generally preferred to heat at a temperature of about 30 to 180°C.

After knee song treatment as described above, the 4RI@ plate is rapidly cooled to a temperature below the glass transition point. If the laminate is knee-thong treated and then left indoors to slowly cool, the dimensional stability will actually deteriorate, so in the present invention, quenching is performed.Quick cooling is performed using cold water or cold air at room temperature or below (approximately 35°C or below). For example, this can be done by immersing a laminate heated to a temperature equal to or higher than the glass transition point in cold water.

At this time, in the present invention, cooling of the MM plate is carried out in the longitudinal direction of the base material 1 (indicated by the arrow a in FIG. 1).
Please follow the instructions below. For example, as shown in FIG. 2, a conveyor belt 4 is arranged diagonally in a water tank 3 filled with cold water 2, and the laminated fEA is placed on this conveyor belt 4 so that the longitudinal direction of the base material is parallel to the running direction of the conveyor belt 4. The laminate A is transferred from the air to the cold water 2 according to the operation of the conveyor belt 4.
The cooling can be performed along the longitudinal direction of the base material 1. When rapidly cooling the laminate A, the base material 1 is
In addition to cooling the laminate A along the lateral direction,
This can be done along the direction perpendicular to the longitudinal direction of the long base material 1 (the lateral direction of the base material 1 indicated by the arrow b in Figure 1), or the laminate A can be placed horizontally on the surface of cold water. Although it is possible to immerse the laminate A at once to quickly cool the surface, cooling the laminate A along the lateral direction of the base material 1 has the effect of reducing the occurrence of warping.
This causes streak-like unevenness to occur along the lateral direction of the base material 1, and plane quenching cannot sufficiently reduce the occurrence of warpage in the laminate A. In the present invention, the laminate is cooled along the longitudinal direction of the base material 1, thereby reducing the occurrence of warping without generating streaks (on the side A in Fig. 1 or Cooling of the laminate A may be started from either side of the mouth). Here, when transferring the laminate A into the cold water 2 to rapidly cool it as shown in FIG. 2, it is generally preferable to set the transfer speed of the laminate A to 5 DEG -17 seconds or more. If the migration speed is too slow, dimensional stability and surface roughness may deteriorate.

The invention will now be illustrated by examples.

A long piece of lath woven fabric was used as the K19 base material, and this base material was impregnated with epoxy resin face to a resin content of 40%, and this was dried to create a long prepreg. Further, this long prepreg was cut at intervals of 1 to obtain prepregs cut into regular size pieces. 8 sheets of this prepreg were stacked, and copper foil with a thickness of 18μ was stacked on both outer surfaces, and this was molded under a molding pressure of 50 kg/am.
2. A laminate with a thickness of 1.6 points was prepared by hot-pressing molding at a molding temperature of 165° C. and a molding time of 100 minutes.

The laminate thus obtained is subjected to an acing treatment by heating at 170° C. for 20 minutes, and then the heated laminate is transferred to cooling water using an inclined conveyor belt as shown in FIG. was rapidly cooled from a temperature above the positive transition temperature of the epoxy resin to a temperature near room temperature. Here, the temperature of the cooling water was set to 25°C, and the running speed of the conveyor belt was set to 500+as/sec. Then, the laminate is placed in the longitudinal direction of the base H (a in the m1 diagram).
Place the base material on the conveyor belt so that the longitudinal direction of the base material (as indicated by the arrow) is parallel to the longitudinal direction of the conveyor belt, and move along the longitudinal direction of the base material 8! The laminate was transferred to the cooling water so that the laminate was cooled along the longitudinal direction of the base material.

Le Jl! JLL When rapidly cooling the laminate, place the laminate on a conveyor belt so that the direction perpendicular to the longitudinal direction of the substrate (the lateral direction of the substrate indicated by arrow b in Figure 1) is parallel to the longitudinal direction of the conveyor belt. The same as in the example except that the cooling water was transferred to the laminate along the lateral direction of the base material, and the laminate was cooled along the lateral direction of the base material. I made it.

Shionei JLL When rapidly cooling the laminate, we used flat quenching in which the laminate was immersed in cooling water while still in its flat state.
The same procedure as in the example was carried out.

The laminates subjected to the quenching process in Examples and Comparative Examples 1 and 2 were visually inspected to determine whether streaks were generated on the surface and whether warpage was occurring. The results are shown in the table below.

As shown in the table, in the example in which the laminate was rapidly cooled along the longitudinal direction of the base material, there were no streaks on the surface, the surface roughness was small, and there was no warping. In Comparative Example 1, in which the laminate was rapidly cooled along the lateral direction of the substrate, no warpage occurred, but streaks appeared on the surface, and in Comparative Example 2, in which the laminate was rapidly cooled in a plane. It has been confirmed that warping occurs in the case of .

[Effect of the invention 1 As described above, in the present invention, after heating the resin contained in the laminate to a temperature of ζ or higher, the resin is rapidly cooled along the longitudinal direction of the base material. Since the laminate is rapidly cooled by cooling the laminate, it is possible to reduce warpage and improve the dimensional stability of the laminate without worsening the surface roughness.

[Brief explanation of the drawing]

FIG. 1 is a schematic plan view showing the relationship between the laminate and the longitudinal direction of the base material, and FIG. 2 is a schematic sectional view showing an example of a gc position for rapid cooling of the laminate. 1 is a base material, and A is a laminate.

Claims (1)

[Claims] (1) A laminate made by stacking and laminating multiple prepregs prepared by impregnating and drying a long base material with a resin at a temperature above the glass transition point of the resin contained in the laminate. 1. A method for processing a laminate, which comprises heating the laminate and then rapidly cooling the laminate by cooling the laminate along the longitudinal direction of the base material.