Method of manufacturing high-aperture ratio fine printed circuit board

Abstract

The invention relates to a method of manufacturing a high-aperture ratio fine printed circuit board. The method is characterized by comprising the following steps: (1) a multi-layered board is manufactured; (2) drilling is carried out; (3) hole technology is carried out; (4) first pattern transfer is carried out; (5) electroplating is carried out; (6) polishing is carried out; (7) second pattern transfer is carried out; and (8) alkaline etching is carried out and then the printed circuit board is manufactured. Compared with the prior art, the problems that surface copper is added and surface copper is uneven can be solved, etching amount at the etching side is changed, the etching difficulty is reduced, and the method can be applied to the 3 / 3mil line production.

Description

technical field [0001] The present invention relates to a method for manufacturing a PCB board, in particular to a high-aperture-ratio fine-density circuit board suitable for non-HDI boards, board thickness ≤ 2.0mm, A / R>6, and outer circuit design of 3 / 3mil Production Method. Background technique [0002] At present, the conventional process of making fine-density circuit boards in the industry is: cutting and thinning copper or pressing and using thin copper foil → drilling → hole formation → full board electroplating → pattern transfer → pattern electroplating → alkaline etching → post-production. Among them, the plate is made of 0.5oz thinned copper to 0.3oz, or it is directly made of 0.25oz copper foil when laminating, that is, it is made of thin bottom copper as much as possible; the whole plate electroplating uses a small current to increase the time to improve the uniformity of the surface copper thickness, Use pulse electroplating equipment or improve the existin...

AI Technical Summary

Problems solved by technology

[0003] The traditional production method has the following disadvantages: 1. When using thin copper, the thinnest is 9μm. If a thinner bottom copper is used, it is inevitable that there will be micro-etching or the phenomenon of substrate exposure after grinding. It is prone to copper layer separation and line shedding; 2. The pulse electroplating equipment used in the full-board electroplating requires high costs and is difficult to be accepted by the majority of manufacturers. At present, the promotion is small, so vertical electroplating is still the mainstream; 3. General The uniformity level of the vertical plating line is acceptable when cov6, the ratio of surface copper to hole copper is 1:0.7, and as the A / R value increases, the surface copper and hole copper The ratio of copper will reach 1:0.5. In order to ensure the thickness of the copper in the hole, the copper on the surface of the board will be thickened when the full board is electroplated, which will undoubtedly increase the amount of side corrosion. In addition, the inherent cov<10%, resulting in surface copper Uneven, so when making 3 / 3mil lines, there will be problems of over-etching and etching residual copper on the same board