Analysis Of The Cause Of No Copper In The Hole Of PCB Board

- Sep 15, 2018-

With different resin systems and material substrate, different resin systems will result in significant difference between activation effect and copper precipitation process.In particular, some CEM composite base plates and high frequency silver base plates are specific. Some special methods should be adopted to deal with the chemical copper sinking. It is sometimes difficult to achieve good results if the copper sinking is normal.

The reason for the absence of copper in the hole is as follows:

1. Hole with dust or hole.

2. When copper is sunk, the potion has air bubbles, but copper is not sunk in the hole.

3. There is line ink inside the hole, no protective layer, no copper after etching.

4. The acid and alkali solution in the hole after the copper deposit or after the plate electricity is not cleaned, and the parking time is too long, resulting in slow bite erosion.

5. Improper operation, too long staying time during microerosion.

6. If the pressure of the punching plate is too high, (the designed punching hole is too close to the conductive hole), it shall be disconnected in the middle.

7. Poor penetration of electroplating solution (tin, nickel).

For the reasons of the 7 major problems of no copper hole, improvement was made:

1. Add high pressure water washing and stripping process to the holes that are prone to dust (such as holes with a diameter of 0.3mm or less).

2. Improve drug activity and shock effect.

3. Change the screen version and the film.

4. Extend the washing time and specify how many hours to complete the figure transfer.

Set a timer.Add blast holes.Reduce the force on the board.

7. Conduct regular infiltration capacity test.