Title :
Package cracking in plastic surface mount components as a function of package moisture content and geometry
Author :
Pope, D. Elaine ; Clifton, Lisa M.
Author_Institution :
Intel Corp., Chandler, AZ, USA
Abstract :
In this work, a critical moisture level of 0.11% by weight is identified for which plastic surface-mount components may be exposed to the stresses of SMT solder reflow without cracking jeopardy. An ´algorithm´ for determining crack susceptibility as a function of package/die geometry is presented. Package absorption characteristics were measured, and exposure times for various factory floor environments were calculated. A desiccant pack and shipping procedure is described which maintains the components in a benign environment for the duration of a 12-month shelf-life. This desiccant pack process has been confirmed to be effective in preventing moisture absorption above the safe allowable moisture content level.<>
Keywords :
cracks; packaging; surface mount technology; SMT solder reflow; benign environment; crack susceptibility; cracking; critical moisture level; desiccant pack; factory floor environments; geometry; package moisture content; package/die geometry; plastic surface mount components; safe allowable moisture content level; shipping procedure; Absorption; Geometry; Infrared heating; Lead; Moisture; Plastic packaging; Reflow soldering; Surface cracks; Temperature; Thermal stresses;
Conference_Titel :
Electronic Manufacturing Technology Symposium, 1988, Design-to-Manufacturing Transfer Cycle. Fifth IEEE/CHMT International
Conference_Location :
Lake Buena Vista, FL, USA
DOI :
10.1109/EMTS.1988.16155
