In the production process of PCB circuit boards, the copper wires of the circuit boards often fall off badly, which is also often said to be thrown off copper, which affects the quality of the product. So, what are the common reasons why PCB circuit boards dump copper?

　　 One, PCB circuit board manufacturing 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 plating (commonly known as red foil). Commonly thrown copper is generally more than 70um ashing foil , The red foil and the ash foil below 18um basically did not have batch copper rejection.

　　2. A local collision occurred in the PCB process, and the copper wire was separated from the substrate by external mechanical force. This poor performance is poor positioning or orientation, the copper wire will be obviously twisted, or scratches/impact marks in the same direction.

　　3. The PCB circuit design is unreasonable. Using thick copper foil to design a circuit that is too thin will also cause the circuit to be over-etched and the copper will be thrown away.

　　 2. Reasons for laminate manufacturing process:

　　 Under normal circumstances, as long as the laminate is hot pressed for more than 30 minutes at a high temperature, the copper foil and the prepreg are basically completely combined, so the pressing will generally not affect the bonding force of the copper foil and the substrate in the laminate. However, in the process of stacking and stacking laminates, if the PP is contaminated or the matte surface of the copper foil is damaged, the bonding force between the copper foil and the substrate after lamination will also be insufficient, resulting in positioning (only for large plates) Words) or sporadic copper wires fall off.

　　 3. Reasons for laminate raw materials:

1. Ordinary electrolytic copper foil is a product that has been galvanized or copper-plated on the wool foil. If the peak value is abnormal during the production of the wool foil, or when galvanizing/copper plating, the plating crystal branches are poor, resulting in insufficient peel strength of the copper foil itself. , The copper wire will fall off due to the impact of external force when the defective foil pressed sheet material is made into PCB and plug-in in the electronics factory.

　　2. Poor adaptability of copper foil and resin: when the laminate is produced, the copper foil used does not match the resin system, resulting in insufficient peeling strength of the sheet metal-clad metal foil, and poor copper wire shedding when inserting.