Solder splash control through seal profile optimization and material loading management

• Main Author: Tirol, D.J. Rean D.
• Format: text
• Published: Animo Repository 1996
• Subjects: Solder and soldering; Splashes; Manufacturing processes; Production engineering; Physics
• Online Access: https://animorepository.dlsu.edu.ph/faculty_research/13344
• Institution: De La Salle University

A low yield of 99.6% was experienced in the A2 Seal process in ww39, 1996. Solder splash, occurring at 0.3% was the main defect at this time when 4708 ceramic packages were introduced. To confront this challenge, the seal yield recovery task force was formed to bring yields to the 99.85% target and eventually to super 99.9% yields. The team leveraged on experimental and theoretical approaches to searching for the dwell time and the peak temperature with minimum solder splash and open seal. Passive data collection and theoretical modeling were done to analyze the behavior of the above mentioned process variables. An early ramp profile was introduced to maximize soak, thereby lessening solder splash occurrence. Considering furnace robustness variability, furnace dedication was done according to specific package and lid vendor factories or sources. With the cooperation of manufacturing and support groups, continuity was established with adjustments in the materials administration systems. Differences in piece-parts were analyzed with evidence that air gap variability on lids significantly affected yields resulting to piece-parts vendor preferences and supplier improvement for this material. The shift's Indicator ownership was transferred to technicians, assuring continued sensitivity and response to process fluctuations. Risk taking and results orientation were reinforced by this indicator ownership system. These activities resulted in a 99.95% yield with splash reduction to 0.021%, highest yield ever (WW13'97). Improvements in the seal process gave A2 corresponding R/D (return to die) leap from 99.51% (WW39) to 99.79% (WW13'97), exceeding the worldwide target of 99.6%.