Printed circuit board manufacturing industry more and more need high aspect ratio, small hole printed circuit board plating process. It is the driving force to promote the development of high-level multi-layer printed circuit board manufacturing technology. Because of the reliability of the hole coating, it plays a key role in the use of printed circuit boards. How to ensure the problem of high aspect ratio deep hole plating is the scientific and technological task of all printed circuit workers, and it is the most important problem that must be faced. To this end, many research departments began to carry out planned research and development. There are many methods reported from the current scientific and technological data, including pulse plating technology, chemical vapor deposition technology, solution impact plating technology, full electroless copper plating technology and improved (high acid and low copper) air stirring technology. This part of the technology is introduced as follows:

　　Pulse electroplating technology, already used in electroforming process, is a relatively mature technology. However, a large number of process tests must be carried out for small hole electroplating with high aspect ratio. Because the pulse power supply is different from the general DC power supply, it makes the rectifier open/close at the speed of US through a switching element, and provides a pulse signal to the cathode. When the rectifier is in the off state, it is more effective than the direct current to supplement the copper ions to the boundary layer in the hole, so that the high aspect ratio of the printed circuit board deposition layer is more uniform. At present, the developed pulse rectifier has been applied to the completely enclosed horizontal plating production line, and the use effect has obtained very obvious economic and technical results.

　　The "timing reverse pulse" is used to make the current alternately positive plating and reverse plating (that is, anodic dissolution) on the power supply mode according to the time ratio, so that the deposition of electroplated copper is difficult to obtain the corresponding copper layer thickness in the conventional power supply mode and can be solved. When the printed circuit board on the cathode is in the reverse current, the copper layer in the high current density area of the orifice can be quickly dissolved. Due to the effect of additives, the effect on the low current density area is very small, so the thickness of the copper layer in the hole and the thickness of the copper surface tend to be equal

Read recommendations:

New energy circuit board

4layers rigid-flex board with buried vias and via-in-pad

Impendacne Control PCB Assembly

Aluminum PCB Manufacturing

PCBA Coating Process manufacture