Reliability is the answer. A more complete annular ring gives a stronger
joint
both electrically and mechanically. Vibrations may pose a problem in the
z-axis.
Alain Savard, B.Sc.
Chemical Process Analyst
CAE Electronics Ltd.
e-mail: [log in to unmask]
-----Original Message-----
From: Ken Patel [mailto:[log in to unmask]]
I have the basic question:
Why do we need annular ring on inner layers? If the answer is no then why
IPC is asking for 1 mil annular ring on Class 3 products. The problem arisen
due to microBGA application.
re,
ken patel