Patent ID: 8952267
Filing Date: 2015-02-10
Classification: B23K,H01L,H01R,Y10T

Abstract:
1. A method for fabricating an electric connecting structure comprising preferred oriented Cu 6 Sn 5 grains, which comprises the following steps: (A) providing a first substrate; (B) forming a first nano-twinned copper layer on a part of a surface of the first substrate; (C) using a solder to connect the first substrate with a second substrate having a second electrical pad, in which the second electrical pad comprises a second nano-twinned copper layer, and the solder locates between the first nano-twinned copper layer and the second nano-twinned copper layer; and (D) performing a reflow process between 200° C. and 300° C. to transform at least part of the solder into an intermetallic compound (IMC) layer, in which the IMC layer comprises plural Cu wherein at least 50% in volume of the first nano-twinned copper layer and the second nano-twinned copper layer respectively comprises plural crystal grains.