Why does the copper throwing phenomenon occur in the process of PCB board production?

“PCB is one of the indispensable parts of Electronic equipment. It appears in almost every electronic equipment. In addition to fixing various large and small parts, the main function of PCB is to make the electrical connection of various parts. Because the raw material of the PCB board is a copper clad laminate, there will be a phenomenon of copper rejection during the PCB manufacturing process. What are the reasons for the copper rejection of the PCB board?

“

PCB is one of the indispensable parts of electronic equipment. It appears in almost every electronic equipment. In addition to fixing various large and small parts, the main function of PCB is to make the electrical connection of various parts. Because the raw material of the PCB board is a copper clad laminate, there will be a phenomenon of copper rejection during the PCB manufacturing process. What are the reasons for the copper rejection of the PCB board? Here to tell you about.

Why does the copper throwing phenomenon occur in the process of PCB board production?

1. The PCB circuit design is unreasonable. Designing too thin circuits with thick copper foil will also cause excessive circuit etching and copper rejection.

2. The copper foil is over-etched. The electrolytic copper foil used in the market is generally single-sided galvanized (commonly known as ashing foil) and single-sided copper-plated (commonly known as reddish foil). The common copper rejection is generally more than 70um of galvanized copper Foils, red foils and ashing foils below 18um have basically not experienced batch copper rejection.

Zhongguan Yuankun Intelligent Manufacturing Workshop is committed to providing customers with one-stop online procurement services for electronic components, providing thousands of electronic components procurement, price inquiries and transactions, to ensure that all components are purchased from the original factory or the official channel of the agent , Guaranteed original authentic, is a professional electronic components procurement website in China

3. A local collision occurs in the PCB process, and the copper wire is separated from the substrate by external mechanical force. This defect is manifested as poor positioning or orientation, and there will be obvious twists in the dropped copper wire, or scratches/impact marks in the same direction. Peel off the bad copper wire and look at the rough surface of the copper foil. It can be seen that the color of the rough surface of the copper foil is normal, there will be no bad side corrosion, and the peeling strength of the copper foil is normal.

4. Under normal circumstances, as long as the laminate is hot-pressed for more than 30 minutes in the high temperature section, the copper foil and the prepreg are basically completely combined, so the pressing generally does not affect the bonding force between the copper foil and the substrate in the laminate. However, in the process of stacking and stacking laminates, if PP is contaminated, or the rough surface of copper foil is damaged, it will also lead to insufficient bonding force between copper foil and substrate after lamination, resulting in positioning (only for large boards and language) or sporadic copper wires fall off, but there is no abnormality in the peeling strength of copper foil near the off-wire.