WETTING AND JOINING OF Sn-BASED ACTIVE SOLDERS ON SIALON CERAMIC IN ROUGH VACUUM
粗真空条件下锡基钎料与Sialon陶瓷的润湿和连接

The sessile drop method and four points bending test were used to study the wettability and joining strength of Sn-based solders on Sialon substrates. Under vacuum of 1.33 Pa and holding 20 min at 1173 K, the contact angle of Sn-based is lower than 20 degree,while the joining strength of the soldering joints on rough vacuum may be markedly improved with the addition of zinc or lead, The average joining strength of Sialon/Sialon joints, soldered with Sn-5Cu-STi, Sn-5Cu-5Ti-20Zn, Sn-5Cu-5Ti-10Pb, are 90.8, 154.3 and 169.1 MPa respectively. And the maximums of joining strength are respectively 119.8, 200 and 216.1 MPa for three solders. In rough vacuum, Sn-based active solders may finish the joining of Sialon/Sialon, and the residual stress is reduced. On the other hand, alloy component zinc in Sn-based solders obviously affects precursor film in rough vacuum.