Production and problem elaboration of copper thickness in multi-layer PCB circuit board holes?

Date of release:2018-09-27 Author:admin Click:

Production and problem elaboration of copper thickness in multi-layer PCB circuit board holes

　The reasons for the absence of copper in the holes of the PCB board and the improvement briefly describe the
　　PCB circuit board and the double-sided circuit board above all need to sink copper in the hole, so that there is copper in the via hole and become a via hole.
　　However, the manufacturer will occasionally find that there is no copper or unsaturated copper in the hole after copper sinking after inspection during the production process. Now our company briefly describes several reasons. The reasons for producing holes without copper are nothing more than:
　　1. Drilling dust plug holes or thick holes.
　　2. There are bubbles in the potion when sinking copper, and no copper sinks in the hole.
　　3. There is circuit ink in the hole, no protective layer is applied, and there is no copper in the hole after etching.
　　4. The acid-base liquid in the hole is not cleaned after the copper is deposited or after the board is electrified, and the parking time is too long, resulting in slow bite corrosion.
　　5. Improper operation, the stay time is too long during the micro-etching process.
　　6. The pressure of the punching plate is too large, (the designed punching hole is too close to the conductive hole) and the middle is neatly disconnected.
　　7. The penetration ability of electroplating potions (tin, nickel) is poor.
　　Improvements are made to these 7 reasons for the problem of copper-free holes.
　　1. Add high-pressure water washing and slag removal processes for holes that are prone to dust (such as 0.3mm or less with a diameter of 0.3mm).
　　2. Improve potion activity and shock effect.
　　3. Change the printing screen and counterpoint film.
　　4. Extend the washing time and specify how many hours to complete the graphic transfer.
　　5. Set the timer.
　　6. Increase explosion-proof holes to reduce the force on the board.
　　7. Regularly do penetration testing.