JPS6120728A - Preparation of laminate board - Google Patents

Abstract

PURPOSE:To prepare a laminate board free from warpage, by cutting off the excessive resin parts of the laminate board generated to both sides thereof at the time of preheating curing. CONSTITUTION:A substrate 2 such as paper is immersed in a varnish tank 5 to be impregnated with a thermosetting resin. Subsequently, a required number of the substrates are stacked and passed through a pair of upper and lower squeeze rolls 6 and adhered under pressure to form a laminated base material 3. Next, this laminated base material 3 is preheated by heaters 9 to be subjected to preparatory curing (to a degree not fluidizing the impregnated resin). Then, a metal foil 8 is adhered to this pre-cured base material 3 through a laminate roll 7. Thereafter, tab parts 4, 4 comprising the excessive resin formed to both sides of the base material 3 are cut off by a cutter 13. Finally, the trimmed one is perfectly cured in a heating drying oven 10. The obtained laminated base material becomes uniform in strain and residual stress and generates almost no warpage or twisting.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field 1] The present invention relates to a continuous non-pressure forming method for producing a laminate without warping or twisting.

[Background technology] Conventionally, a required number of resin-impregnated base materials are pressure-bonded, the laminated base material is preheated to pre-cure the impregnated resin to the extent that it does not flow, and then further heated to completely cure the resin. However, when the resin was preheated and precured, the curing shrinkage of the edges formed by the excess resin that flowed out from both sides of the laminated base material caused the curing shrinkage of the laminated base material of the main body. This is larger than the curing shrinkage rate, and the strain residual stress on both sides of the laminated base material near the ears is larger than that at the center of the laminated base material, resulting in large warps and twists in the fully cured laminate. have done.

[Objective of the Invention 1 The present invention has been made in view of the above-mentioned circumstances, and its purpose is to provide a manufacturing method for obtaining a laminate with little warpage or twist in pressureless continuous forming of the laminate. There is a particular thing.

[Disclosure of the Invention] In the manufacturing method of the present invention, a required number of base materials 2 impregnated with a thermosetting resin 1 are bonded together to form a laminated base material 3, and then this laminated base material 3 is preheated. The impregnated resin is precured to the extent that it does not flow, and then the ears 4 formed with excess resin on both sides of the laminated base material 3 are cut, and then the laminated base material 3 is heated to completely cure the resin. It is characterized by being cured, and with this configuration, the above object can be achieved. That is, before the resin of the laminated base material 3 is completely cured, by cutting off the edges with a large curing shrinkage rate,
The strain residual stress of the laminated base material 3 can be made uniform.

Hereinafter, the present invention will be explained based on the accompanying drawings.

This example concerns the production of metal-clad laminates. As shown in FIG. 1, a base material 2 such as paper or glass cloth is unwound from a take-up roll 11, and a varnish bath 5 of a thermosetting resin 1 such as phenol resin, epoxy resin, area resin, unsaturated polyester resin, etc. Thermosetting resin 1 is applied to base material 2 through
is impregnated via the dipping roll 12. Next, a required number of base materials 2 (four in this example) are passed between a pair of upper and lower squeeze rolls 6 and pressed together to form a laminated base material 3. Thereafter, the laminated base material 1 is preheated in a heater or a preheating furnace to be precured. Here, precuring refers to the degree to which the impregnated resin does not flow. Note that the preheating may be performed after laminating the metal foil 8. Next, metal foils 8 such as copper foil or aluminum foil are attached to the upper and lower surfaces of the base material via a laminating roll 7. Thereafter, as shown in FIG. 2, the edges 4 made of excess resin formed on both sides of the laminated base material 3 before being precured are cut off by a cutter 13. Next, the laminated base material 3 from which the ears 4 have been cut is sent into a heating drying oven 10 and heated under no pressure, for example, at 120° C.
The thermosetting resin M1 is completely cured in minutes. In this way, a metal-clad laminate A is obtained. 250 x this thing
Sample A1 was cut to 250+ am, and as shown in Fig. 3, the three corners were held down and supported at three points on a surface plate, and the lifting height H (mm) of the remaining point was measured, and it was found to be 0.
5-2. It was On+m.

It can be seen that there is almost no warping or twisting. On the other hand, when a metal-clad laminate obtained by a conventional method was similarly measured, H was 5.0 to 10.0+am.

Even if a printed wiring board was formed using this conventional method, it lacked reliability and could not be put to practical use.

[Effects of the Invention] In the present invention, after the laminated base material is preheated and the impregnated resin is precured to the extent that it does not flow, ears formed with excess resin on both sides of the laminated base material are formed. By cutting the edges that have a high curing shrinkage rate and are made only of thermosetting resin (fat), the strain and residual stress of the laminated base material can be made uniform, and the laminated base material is then heated. The laminate obtained by completely curing the resin has almost no warping or sagging.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram showing an apparatus for carrying out an embodiment of the present invention, Fig. 2 (,) (b) is a cross-sectional view showing the cutting process of the ear part in the above, and Fig. 3 is a warpage and twisting. FIG. 1 is an explanatory diagram showing a method for measuring , in which 1 is a thermosetting resin, 2 is a base material,
3 is a multilayer base material, and 4 is an ear portion. Agent Patent Attorney Ishi 1) Ai Seven Procedural Amendments (Forms) February 15, 1985

Claims (1)

[Claims] (1) A required number of base materials impregnated with a thermosetting resin are pressed together to form a laminated base material, and then this laminated base material is preheated to precure to an extent that the impregnated resin does not flow; A method for producing a laminate board, which comprises: cutting the edges formed of excess resin on both sides of the laminate base material, and then heating the laminate base material to completely cure the resin.