Production of Copper Thickness in Holes of Multilayer PCB Circuit Boards and Explanation of Problems

Production of Copper Thickness in Holes of Multilayer PCB Circuit Boards and Explanation of Problems

Brief description of the reasons and improvement of copper without PCB holes

PCB circuit board Double-sided circuit board and above will need to sink copper in the hole, so that there is copper in the via and it becomes a via hole.

However, after inspection, the manufacturer will occasionally find that there is no copper or copper unsaturation in the hole after sinking copper. Now our company briefly describes several reasons. The reason for producing copper without holes is nothing more than:

1. Drilling dust plug holes or thick holes.

2. There is air bubble in the potion when the copper is sinking, there is no copper sinking in the hole.

3. There is circuit ink in the hole, no protective layer is applied, and the hole is free of copper after etching.

4. The acid-alkaline solution in the hole is not cleaned after the copper is deposited or after the board is electrified.

5. Improper operation, too long residence time during micro-etching.

6. The pressure of the punching plate is too high, and the design punching hole is too close to the conductive hole.

7. Electroplating solution (tin, nickel) has poor permeability.

Improve the causes of copper-free problems in these 7 major holes.

1. Increase the high-pressure water washing and degreasing process for the holes that are prone to dust (such as 0.3mm below 0.3mm).

2. Improve potion activity and shake effect.

3. Change printing screen and counter film.

4. Extend the washing time and specify the number of hours to complete the pattern transfer.

5. Set the timer.

6. Increase explosion-proof holes and reduce the force on the board.

7. Do regular penetration test.