Process for laminating printed circuit board (PCB) with buried/blind via structure

Abstract

The invention discloses a process for laminating a printed circuit board (PCB) with a buried / blind via structure. The process comprises the following steps of: (1) drilling via holes on an upper core board and a lower core board to be laminated, electroplating the via holes to transfer patterns, arranging a prepreg between the upper core board and the lower core board, and connecting the upper core board, the prepreg and the lower core board through rivets; (2) laying a release film, the prepreg, the release film, an aluminum sheet and laminated steel on an upper surface of the upper core board in turn from bottom to top, and laying the release film, the prepreg, the release film, the aluminum sheet and the laminated steel on a lower surface of the lower core board in turn from top to bottom; (3) laminating; and (4) removing the aluminum sheet, and detaching the prepreg to which the release film is attached so as to obtain the finished product. The process is convenient to operate, the labor cost is saved, the processing time is shortened, the working efficiency is improved, the labor intensity is reduced, and the yield of the product is improved.

Description

technical field [0001] The invention relates to a pressing process of a PCB board, in particular to a pressing process of a PCB board with a buried blind hole structure. Background technique [0002] With the advancement of science and technology, the number of layers of PCB boards is increasing, and the structure is becoming more and more complex. PCB boards are formed by laminating core boards and semi-cured laminates, and multilayer boards are composed of multiple core boards. . At present, when the PCB board with buried blind hole structure is manufactured in multi-layer lamination, a via hole is drilled on the core board, and a prepreg is placed between the two core boards. During the lamination process, the resin on the prepreg will be squeezed into the core. In the via hole on the board, after continuing to press, the resin in the via hole will flow out of the via hole and stick to the surface of the core board. It needs to be grinded many times by a grinder to elim...

AI Technical Summary

Problems solved by technology

At present, when the PCB board with buried blind hole structure is manufactured in multi-layer lamination, a via hole is drilled on the core board, and a prepreg is placed between the two core boards. During the lamination process, the resin on the prepreg will be squeezed into the core. In the via hole on the board, after continuing to press, the resin in the via hole will flow out of the via hole and stick to the surface of the core board. It needs to be grinded many times by a grinder to eliminate the sticking on the surface of the core board. During the grinding process, the core board and the copper foil on its surface are easily damaged, so that it is scrapped, and due to mechanical equipment and human factors, sometimes it cannot be ground cleanly, which affects the subsequent use performance

[0003] In addition, during processing, the current practice is generally to rivet the two core plates with rivets first. During the processing, the rivets are basically in hard contact with the tool steel plate, and the riveting point is also the stress point, which will easily cause the rivet to be deformed by force and cause layer damage. misalignment

Since the riveting point is higher than the surface of the core plate, the flatness of the core plate surface is poor. The rivet is basically in hard contact with the steel plate, and the riveting point is also a stress point. From the appearance, it is obvious that there are depressions or protrusions in the blind hole. , When SMT is assembled, the unevenness of the pad induces residual air in the solder paste, which affects the soldering strength

In addition, the rivets will leave imprints on the processed steel plate, destroying the flatness of the steel plate, and will be transferred to the surface of the product during subsequent processing, affecting the appearance. In severe cases, the steel plate will be scrapped and the cost will be increased.

[0004] The patent application number is 201010213171.4, and the application name is a Chinese invention patent application for a PCB board lamination process with an internal via hole structure. It better solves the problem of resin overflow during the lamination process, but does not solve the problem of multiple cores. The problem of misalignment between layers, the amount of misalignment between layers is large, resulting in a low yield of products

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