1, it is mentioned above that ordinary electrolytic copper foil is galvanized or copper-plated products, if the peak value of the wool foil production is abnormal, or galvanized/copper plating, the coating crystal branch is bad, resulting in the peel strength of the copper foil itself is not enough, the bad foil pressing board is made of PCB plug-in in the electronics factory, the copper wire will fall off by external impact. This kind of bad copper stripping copper wire to see the copper foil surface (that is, the contact surface with the substrate) will not be obvious side corrosion, but the peeling strength of the whole copper foil will be very poor.

　　2, poor adaptability of copper foil and resin: some special properties of laminates now used, such as HTg sheet, because the resin system is not the same, the curing agent used is generally PN resin, resin molecular chain structure is simple, the degree of cross-linking is low when curing, is bound to use special peak copper foil and match. When the copper foil is used in the production of laminate, it does not match the resin system, resulting in insufficient peeling strength of the metal foil covered by sheet metal, and poor copper wire shedding will occur when inserting.