JPS62254493A - Manufacture of printed circuit 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 [Industrial Field of Application] The present invention relates to the production of multilayer printed circuit boards, and particularly to a jig used for multilayer adhesion and a multilayer adhesion method.

[Conventional technology]

Conventional multilayer adhesion, as described in the "Printed Circuit Handbook" published by Kindai Kagakusha, involves overlapping a circuit laminate board and an adhesive sheet prepreg, fixing them with positioning pins and jigs, and then using a press hot plate. This is done while heating and applying pressure. There are two methods for starting the temperature of the hot plate: low temperature and high temperature.In either case, the prepreg resin between the adhesive layers costs $4 in a few minutes! 1 and then harden. At this time, in order to promote the removal of gas and air between the adhesive layers, a vacuum sealing frame 1 is placed between the hot plates, and the adhesive is bonded together with vacuum degassing. But with the onset of vacuum,
No consideration was given to S melting of the prepreg resin by increasing the temperature of the press hot plate.

The 5th diagram is the conventional one! FIG. 6 is a front view of the inner substrate fixed with a mirror plate placed in the contact press under a711 press conditions. In the conventional bonding method, a vacuum-sealed frame 16 is provided on a press hot plate 9, a mirror plate 6 is inserted between the hot plates 9, and a movable bolster 10 is pushed by a hydraulic ram 12 on top of a fixed bolster.
11, and heated and pressurized while degassing with a vacuum pump at 8 degrees. At this point, separate pressure, 7FO heat, and vacuum degassing are performed at t.
Start at the same time with o. Pressure 14 is maintained at p (1 to 5 kgI/cd) until the resin of the prepreg is uniformly melted, and then p is applied to flush out the resin and fill the inner layer board circuit.
; Increase the pressure to (10 to 40 kt/j). Temperature 15 is a temperature suitable for melting the prepreg resin and filling the circuit of the inner layer board (12 cf'e ~ 140 ° C.) and holding it until t, and then T (17 (1°
C) to 200'C) and then heated to t; In this case, since the resin of the prepreg melts in a few minutes, the air trapped between the adhesive layers is trapped in the resin, making it difficult to remove by vacuum degassing, and causing the problem that air bubbles remain.

[Problem that the invention seeks to solve]

The above conventional technology does not take into account the timing of the melting of the prepreg resin by heating the press and the vacuum degassing, and as the prepreg resin melts within a few minutes after the start of the press, it becomes difficult for air to escape by vacuum degassing, and some There was a problem that the resin could not be completely removed and the resin solidified and remained as bubbles.

An object of the present invention is to prevent bubbles from remaining during multilayer adhesion, which is a conventional problem.

[Means for solving problems]

The above purpose is to stack the inner layer substrate and the prepreg, align and fix them using guide pins and a board, and then vacuum degas for a predetermined period of time before heating and pressurizing with a press in a sealed body. Then heat it with a layer press.

The time during which the prepreg resin is molten can be achieved by applying pressure and also using vacuum degassing.

[Effect]

Vacuum degassing before heating and pressurizing with a press removes air trapped between the inner layer substrate and the prepreg. Thereby, since there is no air between the adhesive layers at the stage when the prepreg is melted and hardened by heating and pressurizing with a press, it is possible to prevent air from remaining as bubbles between the adhesive layers. Furthermore, vacuum degassing while the prepreg is in the melting stage serves to remove volatile matter generated from the inner layer base material or the prepreg.

Here, the sealing body for vacuum degassing is a flat plate that covers the upper and lower surfaces of the specular plate to which the inner layer substrate and the prepreg are fixed, and is covered with an elastic body such as an unevenly placed rubber band. Create a structure that can be deformed under pressure. As a result, multi-layer bonding is possible while vacuum degassing is continued by heating with a press and applying 7FD pressure while the mirrored plate is in a sealed body.

〔Example〕

Examples of the present invention are shown below in Figure 1, Figure 2, Figure 3, and Figure 4.
This will be explained with reference to the figure.

FIG. 1 is a perspective view of a vacuum-sealed body according to the present invention.

FIG. 2 shows a vacuum degassing sealed body of the present invention, an inner layer substrate 4, and a prepreg 5 aligned and fixed by a guide bin 7 and a mirror plate 6.
It is a sectional view at A- in FIG. FIG. 3 is a front view of the sealed body when it is placed in an adhesive press. Figure 744 shows vacuum degassing during multilayer adhesion and 7111 heat.

This shows the method of pressurization.

The sealing body consists of flat plates 1 and 3 that cover the mirror plate 6 from above and below, an elastic seal 72 and a vacuum degassing port 8, and the seal 2 is fixed to the cover upper plate 1 and can be freely expanded and contracted by pressure. transform. A portion 3° of the lower cover plate 30 is a portion that becomes a hook plate for lifting and transporting the sealed body.

In the multilayer bonding method according to the present invention, vacuum degassing 13 is started at t before heating and pressurizing with the bonding press shown in FIG. After that, at t1, the sealed body is placed on the hot plate gap 9 of the adhesive press while being vacuum degassed, the movable bolster 10 is pushed up by the hydraulic ram 12, and fixed by the fixed bolster 11, and at t, the pressurization profile 1ζ heating profile 15 is applied. Start. Low pressure P, (
The pressure is then increased to a high pressure (10◆~40 kv'al), and the resin is flushed out and buried in the circuit of the inner layer substrate. Temperature 15 is maintained until temperature 11 at T* (1209C to 140°C), which is suitable for melting the prepreg resin and filling the circuit of the inner layer board, and then Tt (170C to 140C) to promote curing.
Heat to 200°C for 1 hour. t.

Cooling is performed at ~t, and the pressure is removed to complete the multi-I# press cycle. Here, the vacuum degassing 13 is continued until t, when the resin of the prepreg loses its fluidity as it melts and hardens.

According to this embodiment, by performing vacuum degassing before heating and pressurizing with a press, air trapped between adhesive layers can be removed and air bubbles can be prevented from remaining as air bubbles.

〔Effect of the invention〕

According to the present invention, since air trapped between the inner layer substrate and the prepreg can be removed, it is possible to prevent air bubbles from remaining between the adhesive layers.

[Brief explanation of drawings]

FIG. 1 is a perspective view of a device related to the present invention, FIG. 2 is a sectional view taken along the line A-A' in FIG. Fig. 5 is a diagram showing a bonding process using the present invention, Fig. 5 is a diagram showing a conventional bonding process, and Fig. 6 is a front view of a conventional bonding press. -1...Sealing cover upper plate, 2...Sealing gasket, 5--Bride sealing cover lower plate, 8...Vacuum degassing port. 2nd Figure 1: $monka de Ichijoblade (2: Kenmon par, Kin 3: Sealing cover T1 (8: Vacuum degassing port #5 figure load amount (f)

Claims (1)

[Claims] 1 In a method in which a substrate on which an inner layer circuit is formed and a prepreg are stacked in multiple layers, aligned and fixed using guide pins and a mirror plate, and then both sides of the mirror plate are covered with protective plates and bonded by heating and pressure. A method for manufacturing a printed circuit board, characterized in that an elastic body such as packing rubber is provided around a protective plate to form a sealed body, and the inside of the sealed body is vacuum degassed while multilayer bonding is performed.