Reliability of microsoldered thin copper-lead by low melting point Au/Sn microsoldering -a study on microjoining of leadframe for LSI package (No. 5)-

摘要

This report considers the low melting point Au-Sn microsoldering (utilizing the Au 10 mass %-Sn eutectic; melting point/ 490K, bonding heat tool temperature/523 K and bonding time/5 s)which is applied to the 400~600 pin count and 0.10~0.15 mm lead pitch connection with 0.018 mmt thin copper lead. This method is performed by heat and press tool gang bonding of tin electroplated (3.5μ mthick) copper pattern on substrate and gold electroplated (0.5μm thick) thin copper lead with non flux in air.Au-Sn microsoldered layer has the high peel strength and has the high reliability in 218 K×30 min~423 K×30 min temperature cycle test and 423 K storage test in air that is higher than 37 mass % Pb-Sn microsoldering. As a result of this reserch, it isdetermined that the low melting point Au-Sn microsoldering is an excellent method for thin copper lead micro connection to the copper pattern routed substrate and the board.