PCB Technical - What are the reasons why there is no copper in the PCB board hole?

1. PCB board manufacturers occasionally find that there is no copper in the hole or copper is not saturated during the production process. The following reasons will produce the hole without copper:

   
   

1. Drilling dust plug holes or holes will cause the holes to be copper-free.

2. There is ink in the hole, and the protective layer is not electrified. After etching, there will be a hole without copper.

3. The acid-base solution in the hole is not cleaned after the copper is deposited or after the board is electrified. If it is parked for too long, it will cause slow bite corrosion.

4. Improper operation of the operator during the production process, too long residence time in the micro-etching process will lead to no copper in the hole.

5. Poor penetration of electroplating chemicals (tin, nickel).

2.What is the difference between different materials of PCB board?

The flammability of PCB materials is also called flame retardancy, self-extinguishing, flame resistance, flame resistance, fire resistance, flammability, etc. The flammability is to evaluate the ability of a material to resist combustion.

PCB flammable material samples meet the required flammability. The flammability level is evaluated according to the degree of combustion of the sample. There are three levels, namely FH1, FH2, and FH3.

PCB board is divided into HB board and V0 board.

HB sheet has low flame retardancy and is mostly used for single-sided boards.

VO sheet has high flame retardancy and is mostly used in double-sided and multi-layer boards