Title:

Resolution of Pin#17 Broken Wire Customer Complaint

Author(s):

Benedict Dimanalata, Salvador Augusto Galang, Elmer Visconde, Amkor/Anam Pilipinas, Inc.

Gist:

When the package used for an old 28-lead device was changed from the 68.11-mil thick 28-L SSOP to the 35.42-mil thick 30-L TSSOP, failures due to broken wires at pin # 17 started to be encountered. The break in the wire is occurring at the neck of the bond. This 'neck break' issue could not be detected in Assembly, even with 100% inspection after the wirebond process. This paper describes how this broken wire issue was resolved through a series of steps, namely, failure analysis, conduct of evaluations, replication of the problem, and implementation of appropriate corrective actions. This pin 17 neck break issue was subsequently isolated to unoptimized wirebond parameters, i.e, insufficient loop height and improper in-board bond parameters of the device. This problem was eliminated by: 1) switching from 1-mil wire to 1.2-mil wire; 2) use of special loop parameters from pins 17-29, which are in-board bonds; 3) optimization of the loop parameters to increase the maximum loop height from 6 mils to 7 mils; and 4) enhancement of the wirebond set-up activities.

Published in :

ASEMEP 1999 Proceedings; July, 1999