No pumping at 450°C with electrodeposited copper TSV

Abstract

Thermal expansion coefficient(TEC) mismatch between the silicon and copper causes serious problems in on chip and microelectronics packaging. One example is TSV pumping for the via middle process. Higher temperature exposure of 400-600°C during the wiring process causes TSV pumping. The filled copper destroys wiring above TSV. Our additive A shows no pumping of electrodeposited copper TSV. The resistivity of electrodeposited copper TSV after 450°C annealing for the wiring is only 1.09 of conventional electrodeposited copper. Another example is the PCB warpage in solder bumps reflow process. The PCB is initially annealed at 200°C for 60min for the resin solidification. Next, the solder bumps are formed. Then comes the chip and PCB interconnection of 250°C, 10sec with solder bumps retlow. This chip and PCB interconnection annealing at 250°C, 10sec has used to cause PCB warpage. The 34% TEC reduction has been realized at 230 °C . This 34% reduction has been obtained after the second annealing after 200°Cx60min with our additive B. The resistivity of PCB copper after annealing is only 1.32 of conventional electrodeposited copper.