Question

PCB circuit board factory: What are the reasons why there is no copper in the PCB board holes?

Answer 1

In the PCB circuit board factory, the reasons why there is no copper in the PCB board holes may be as follows:

1. Insufficient or excessive desmear removal: This will cause resin changes and poor water washing, resulting in no copper in the holes.

2. Drilling dust clogs the hole or the hole is thick: These conditions will prevent the copper layer in the hole from being deposited normally.

3. Cracks in the hole wall or splitting between inner layers after drilling: These damages may cause the copper layer in the hole to be damaged during subsequent processing.

4. Insufficient neutralization treatment after removing slag: This will cause alkaline stannate compounds to remain in the holes, affecting the deposition of the copper layer.

5. The cleaning and degreasing liquid concentration and other ratios are out of balance: This will affect the adsorption of Pd, thereby affecting the deposition of the copper layer.

6. The concentration of the activation solution is low: This will affect the adsorption of Pd and prevent the copper layer from being deposited normally.

7. Excessive acceleration processing: Pd is also removed when Sn is removed, resulting in the inability to deposit the copper layer normally.

8. The chemical copper potion potion has poor activity: This will affect the deposition effect of the copper layer.

9. There are bubbles in the holes: This may be because the circuit ink in the holes has not been electrolyzed with a protective layer, and there is no copper in the holes after etching.

10. The PCB substrate absorbs moisture or part of the resin itself is poorly cured when pressed into the substrate: This will lead to insufficient strength of the resin itself during drilling, resulting in poor drilling quality, excessive drilling dirt, or serious tearing of the hole wall resin, etc., affecting the copper layer. of deposition.

In general, to solve the problem of no copper in the PCB board holes, it is necessary to analyze and troubleshoot from multiple aspects, and then take corresponding measures for improvement and optimization.

Answer 2

The main reasons why there is no copper in the PCB board holes are as follows:

1. The quality of drilling is not good, resulting in the inner wall of the hole being uneven or containing residue, which affects the adhesion of the copper layer.
2. Improper copper deposition process, such as improper selection of potion, inappropriate concentration, inappropriate temperature, etc., resulting in the failure of the copper layer to deposit normally.
3. Incomplete or excessive desmear removal will lead to resin changes and poor washing, affecting the adhesion of the copper layer.
4. The circuit ink in the hole is not electrically coated with a protective layer, and there is no copper in the hole after etching.
5. The chemical copper potion potion has poor activity or is over-accelerated, causing the copper layer to fail to deposit normally.
6. The PCB substrate absorbs moisture or part of the resin itself is poorly cured when pressed into the substrate, resulting in insufficient strength of the resin itself during drilling, resulting in poor drilling quality and affecting the adhesion of the copper layer.
7. Improper operation, such as staying too long during the micro-etching process, will cause damage to the inner wall of the hole and affect the deposition of the copper layer.

To solve the problem of no copper in PCB board holes, it is necessary to analyze and troubleshoot from many aspects, including drilling quality, copper sinking process, slag removal treatment, line ink treatment, chemical copper cylinder potion selection, PCB substrate quality and operation Specifications etc. Then take corresponding measures to improve and optimize to ensure that every link meets the process requirements, thereby improving the adhesion and quality of the copper layer in the PCB hole.