Motorola's first DCA product: the Gold Line Pen Pager

Abstract

The Gold Line Pen Pager is the first Motorola product to use the Direct Chip Attachment (DCA) process for placing and packaging its microprocessor, an integrated circuit chip (IC). Motorola's Gold Line Pen Pager began shipping March 1995. However, several specific challenges had to be overcome to achieve ship acceptance. Motorola fulfilled its first major challenge when the DCA Pen Module passed reliability requirements. One major issue arose during biased temperature and humidity qualification testing. A vendor's DCA solder bump fluxing process caused solder pad corrosion problems. The corrosion issue was corrected by changing the vendor's DCA site reflow process. Motorola solved DCA IC light sensitivity by protecting the DCA IC from stimulating light. Broken waffle packer separation needles initiated DCA IC cracks. The broken separation needles were replaced. A periodic IC backside inspection procedure was then implemented to monitor the waffle packing process. Inadequate vendor testing permitted several bad DCA Printed Wire Boards (PWBs) to be marked good. The vendor began a DCA site electrical opens test and improved their visual DCA solder bump inspection process to address the testing problems. Motorola confirmed DCA production readiness when the Gold Line Pen Pager achieved ship acceptance in February 1995. This paper summarizes solutions to the issues that arose during the implementation of the DCA IC package on the Gold Line Pen Pager.