MaxQFP: A High Density QFP

Abstract

A high density QFP called MaxQFP which combines both QFP (quad flat pack) gull-wing (GW) leads and PLCC (plastic leaded chip carrier) J-leads has been developed and offered 172-lead (16x16 mm body size) and 100-lead (10x10 mm body size) MaxQFP’s and 172 MaxQFP_EP (exposed pad). The advantage of MaxQFP as compare to standard LQFP/QFP packages will be outlined at introduction section. Typical device design required data such as thermal resistance and electrical simulation works have been completed and shared in the paper. The challenges in manufacturing, designs and concerns of tighter lead pitches for MaxQFP are briefly addressed. Sn whisker stress data were collected and shown passing requirements. The board-level solder joint reliability (SJR) data and component level package reliability data have proven passing AEC G1 (Automotive Electronic Council Grade 1) and summarized in this paper. Visual inspection methods and requirements on AOI (Automated Object Inspection) systems on solider joints of J-leads of MaxQFP are proposed and results of detecting several failure modes of solder joints are presented. Assembly challenges are briefly described. Future works will also be summarized.