Flux-free chip to substrate joint serial linear thermal processor arrangement

A flux-free, serial thermal processing arrangement for treating a pre-assembled chip/substrate assembly of spaced-apart, pre-soldered semiconductor components in a linear chip processor, through a series of independent, linearly adjacent chambers, wherein:

• the pre-assembled chip/substrate is loaded onto a support plate in a chamber at an initial Load/Lock station of the processor, the pre-assembled chip/substrate being held at atmospheric pressure, and the chamber is purged with nitrogen gas;
• the pre-assembled chip/substrate is advanced into a first treatment chamber or station, and the pre-assembled chip/substrate assembly is heated to below solder melt temperature, the first chamber being held below atmospheric pressure, and formic acid vapor vent is introduced therein;
• the pre-assembled chip/substrate assembly is advanced to a second chamber or station, the pre-assembled chip/substrate assembly being heated to a temperature above the melting temperature of the solder, the second chamber being held at a vacuum, and a formic acid vapor vent is then introduced;
• the pre-assembled chip/substrate assembly is advanced from the second station to a third chamber or station, the pre-assembled chip/substrate assembly is heated to a temperature above the melting point of the solder, then holding a vacuum, and a formic acid vapor vent is introduced to the chamber;
• the pre-assembled chip/substrate assembly is advanced from the third station to a fourth station, and the pre-assembled chip/wafer assembly is heated at an elevated solder-melt temperature to further melt the solder between the spaced-apart chip and substrate to electrically join the solder of the chip and the substrate, a formic acid vapor vent then being introduced to the chamber;
• the heated, joined chip/substrate assembly is advanced to a fifth station, and the now pre-assembled chip/substrate assembly is heated to a peak temperature of from about 150° C. to about 270° C., with an applied vacuum and the chamber is vented with nitrogen;
• the joined chip/substrate assembly is advanced from the fifth station to a sixth station and is cooled at ambient or room temperature;
• and
• the chip/substrate assembly is shuttled to a final downstream Load/Lock station for unloading the joined chip/substrate assembly from the chamber at the Load/Lock station;
• wherein the first, second, third stations and fourth are each individually heated to a pre-set temperature of from about 150° C. to about 270° C., and wherein the fifth station is heated to a highest peak solder melting temperature of the series of stations, at a pressure of about 760 torr for a period of about 10 to about 300 seconds.

An electronic semiconductor component manufactured by a flux-free, serial thermal processing arrangement for sequentially treating a pre-assembled chip/substrate assembly of spaced-apart, pre-soldered semiconductor components in a linear chip processor, through a series of independent, linearly adjacent chambers, wherein:

• the pre-assembled chip/substrate is loaded onto a support plate in a chamber at an initial Load/Lock station of the processor, the pre-assembled chip/substrate being held at atmospheric pressure, and the chamber is purged with nitrogen gas;
• the pre-assembled chip/substrate is advanced into a first treatment chamber or station, and the pre-assembled chip/substrate assembly is heated to below solder melt temperature, the first chamber being held below atmospheric pressure, and a formic acid vapor vent is introduced;
• the pre-assembled chip/substrate assembly is advanced to a second chamber or station, the pre-assembled chip/substrate assembly is heated to a temperature above the melting temperature of the solder, the second chamber being held at a vacuum, and a formic acid vapor vent is introduced the chamber;
• the pre-assembled chip/substrate assembly is advanced from the second station to a third chamber or station, the pre-assembled chip/substrate assembly is heated to a temperature above the melting point of the solder, held to a vacuum, and a formic acid vapor vent is introduced to the chamber;
• the pre-assembled chip/substrate assembly is advanced from the third station to a fourth station, and the pre-assembled chip/wafer assembly is heated at an elevated temperature to further treat the solder between the spaced-apart chip and substrate to electrically join the solder of the chip and the substrate, and a formic acid vapor vent is introduced to the chamber;
• the heated, joined chip/substrate assembly is advanced to a fifth station, and the assembly is heated to a peak solder melt temperature of from about 150° C. to about 270° C. to melt and join the pre-assembled chip/substrate assembly under a vacuum, wherein the chamber is vented with nitrogen;
• the joined chip/substrate assembly is advanced from the fifth station to a sixth station and cooled at ambient or room temperature;
• and
• the chip/substrate assembly is shuttled to a final downstream Load/Lock station, the joined chip/substrate assembly is unloaded from the chamber at the Load/Lock station;
• wherein the first, second, third and fourth stations are each individually heated to a pre-set temperature of from about 150° C. to about 270° C., and at a pressure of about 760 torr for a period of about 10 to about 300 seconds.