公开(公告)号：JPH10163590A

公开(公告)日：1998-06-19

申请号：JP29070397

申请日：1997-10-23

Applicant: IBM

Inventor： SAAYANARAYANA KAJA ,  ERIC D PERFECT ,  CHANDRICA PRAZADO ,  KIM H LEFING ,  PAUL A TOTTA

IPC: H05K1/09 ,  H01L23/14 ,  H05K3/24 ,  H05K3/34

Abstract: PROBLEM TO BE SOLVED: To allow wave front of a flat surface and formation of a plurality of small voids to be hardly affected by enhancing reliability, even after reflow of a plural number of times by depositing Ni-Au-Ni-Au layer on a base metallization of electroplated copper. SOLUTION: Mutual connecting metallurgy stack 41 of a substrate 40 suitably contains a chromium layer 42, a copper layer 43, a nickel layer 44, a gold layer 45, a nickel layer 46 and another gold layer 47. The layer 47 is formed by covering the layer 46 by gold plating. In such a structure, the layer 46 is sandwiched between the electrolytic gold layer 45 and the layer 47 to promote diffusing process and hence nickel and gold are mixed in a satisfactory shape necessary for connecting chips. The layer 45 protect the lower nickel 44, and hence damage of pit by solvent or removing material is limited to the upper layer 46.