柯伐合金应力腐蚀与电镀层质量的关系研究

The effect of the Electroless Plating Quality to the Stress-corrosion Fracture of Kovar Alloy

柯伐合金用来制作电子元件的外引线时常用镀层进行保护。但是这种外引线易发生应力腐蚀断裂。在镀层存在缺陷时,镀金、镀镍层均促进柯伐合金的应力腐蚀开裂。其断裂机理为氢致开裂。减少镀层缺陷可大大减少外引线的应力腐蚀断裂。

The Kovar alloy used for the outlet of fixed circuit often is plated to preserve from corrosion. But the outlet of fixed circuit often is plated to preserve from corrosion. But the outlet of fixed circuit made of the alloy is ease to occur delay fracture. When the plating exist defect,the gold-plating nickel-plating both promote the stress-corrosion fracture of Kovar alloy. The reason of fracture is hydrogen brittleness. The reduce of plating defect will greatly reduce the stress-corrosion fracture of the outlet.