Patent ID: 8252678

Claim:
A serial thermal processing arrangement for treating a pre-assembled chip/wafer assembly of spaced-apart, pre-soldered semiconductor components in a rotary processor, through a series of independent, circumferentially disposed chambers, wherein: a pre-assembled chip/wafer is loaded onto a support plate in a chamber at an initial Load/Lock station of the rotary processor, the support plate being mounted on a rotatable table at atmospheric pressure and wherein the chamber is purged with nitrogen gas; the pre-assembled chip/wafer is rotated into a heated first treatment chamber or station to heat the pre-assembled chip/wafer assembly, wherein the first chamber is held below atmospheric pressure, and formic acid vapor is introduced; the pre-assembled chip/wafer assembly is rotated to a heated second chamber or station, and the second chamber is held at a vacuum, and a formic acid vapor is introduced; the pre-assembled chip/wafer assembly is rotated from the second station to a heated third chamber or station and held to a vacuum, and wherein a formic acid vapor vent is introduced; the pre-assembled chip/wafer assembly is rotated from the third station to a fourth station, and the pre-assembled chip/wafer assembly is heated at an elevated solder-melt temperature to melt the solder between the spaced-apart chip and wafer to electrically join the chip and the wafer, wherein a formic acid vapor vent is introduced; the heated, joined chip/wafer assembly is rotated to a fifth subsequent station, and the joined pre-assembled chip/wafer assembly is cooled at ambient atmospheric pressure; and the joined chip/wafer assembly is rotated from the fifth station back to the Load/Lock station and the joined chip/wafer assembly is unloaded from the chamber at the Load/Lock station.