2019-BTU-web-Vacuum-reflow-Dimock.pdf - 第23页

QFN V oid Distrib ution Analys is: QFN100 At 120 T orr and lower vacuum levels, the odds of getting a voi d larger than 1% is small

Things to consider

 Voids located at critical points (“hot spots”)

may be the real issue

 Void Size

Large voids are most likely the primary concern

Small voids may not be troublesome

Cumulative voiding may only have a secondary affect

QFN Void Distribution Analysis: QFN100

At 120 Torr and

lower vacuum

levels, the odds of

getting a void larger

than 1% is small

Fred Dimock

Mgr, Process Technology IntInternational

Thank you!

Mike Meilunas Universal Instruments - Advanced Process Lab

Arvind Srinivasan Karthikeyan Auburn University