PCB depth control hole etching production method

Abstract

The invention discloses a PCB depth control hole etching production method. For the production plate with deep control hole and in a positive film flow, A deep control hole is sealed by making a dry film again after the pattern plating is completed, Then etching is performed to ensure that the copper layer at the bottom of the depth control hole is not bitten off during etching, thereby protectingthe copper layer at the bottom of the depth control hole to a great extent, reducing the hidden danger of copper loss at the bottom of the hole caused by the difficulty in tin plating at the bottom of the depth control hole, reducing the risk of defective products flowing into the client, and providing a powerful guarantee for product development and production.

Description

technical field [0001] The invention relates to the field of PCB preparation, in particular to a production method of PCB controlled deep hole etching. Background technique [0002] At present, there are two main production processes for the production of PCB with controlled deep holes: one is the board without copper clad or half-hole design, which is produced by the negative process after electroplating; the other is the board with copper clad or half-hole, etc. If it cannot be produced by the negative process after electroplating, it will be produced by the positive process. However, there are two major disadvantages in the two production methods: one is that some boards with controlled deep holes cannot be produced by the negative film process and must be produced by the positive film process. The effect of tin plating on the bottom is not good, and the tin layer is prone to be thinner, and in severe cases, there may even be some parts that are not plated with tin. Sec...

AI Technical Summary

Problems solved by technology

However, there are two major disadvantages in the two production methods: one is that some boards with controlled deep holes cannot be produced by the negative film process and must be produced by the positive film process. The effect of tin plating on the bottom is not good, and the tin layer is prone to be thinner, and in severe cases, there may even be some parts that are not plated with tin

Second, because the tin layer at the bottom of the deep hole is thin or partly not coated with tin, the tin protective layer at the bottom cannot effectively protect the copper layer, and the copper layer will be bitten off during etching, resulting in copper deficiency at the bottom of the deep hole, or even or affect the electrical conduction performance, there is a risk