Possible reasons for 5G antenna PCB copper falling off

The copper wire of the 5G antenna PCB falls off (also known as copper dumping) is not good. PCB manufacturers all say that it is a problem of laminates, and their production factories are required to bear the bad losses.

1. PCB factory process factors

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

When the customer's circuit board is designed to pass the etching line, if the copper foil specification is changed but the etching parameters remain unchanged, the copper foil stays in the etching solution for too long. Because zinc is an active metal, when the copper wire on the LED advertising screen PCB is immersed in the etching solution for a long time, it will inevitably lead to excessive side etching of the circuit, causing the backing zinc layer of some thin circuits to be completely reacted and the base. The material is detached, that is, the copper wire falls off.

Another situation is that there is no problem with the PCB etching parameters, but the washing and drying after etching are not good, causing the copper wire to be surrounded by the etching solution left on the PCB surface. Dump copper. This situation is generally concentrated on thin lines, or during humid weather, similar defects will appear on the entire PCB. Strip the copper wire to see that the color of the contact surface with the base layer (the so-called roughened surface) has changed. The color of the copper foil is different from that of the normal copper foil. The original copper color of the bottom layer is seen, and the peeling strength of the copper foil at the thick circuit is also normal.

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