PCB copper line off the three main reasons

Printed Circuit Board printed circuit board laminate raw material reasons.

1, as mentioned above, the general electrolytic copper foil is through the wool foil plating or copper plating treatment of the product. Assuming that the peak of the wool foil production process is not normal, or perhaps the galvanizing/copper plating process is poor in the crystalline branch of the plating, the peeling strength of the copper foil itself does not work. When a bad foil is pressed into a sheet to form a printed circuit board, the copper wire will fall under the impact of external forces when pierced into the electronics factory. When the rough surface of the copper foil (i.e., the touching surface with the substrate) is stripped, this bad copper extrusion will not cause significant side corrosion, but the peeling strength of the entire copper foil will be very poor.

2, copper foil to the poor adaptability of the resin: due to the different resin system, some special function laminate (such as HTg sheet) used in the curing agent is generally PN resin. The molecular chain structure of the resin is abbreviated and the cross-linking degree in the curing process is low. Therefore, the use of copper foil with special peaks to match it is unavoidable. When producing laminates, the use of copper foil and resin system does not match, resulting in the lack of peeling strength of metal foil covered by metal sheets, and poor peeling of copper lines when stabbing.

2, printed circuit board printed circuit board laminate production reasons.

Under normal circumstances, only the hot pressed high temperature part of the laminate lasts more than 30 minutes, copper foil and prepreg blanks are basically thoroughly bonded, so the adhesion between the copper foil and the substrate in the laminate is generally not affected. However, during the, stacked lamination process, assuming that the polypropylene is contaminated or the copper foil exterior is damaged, the bond between the laminated copper foil and the substrate will be lacking, resulting in positioning (only for large boards) or scattered copper wire falling off. However, the peel strength of the copper foil is not abnormal in the vicinity of the off-line measurement.