Patent ID: 6713318
Filing Date: 2004-03-30
Classification: B23K,H01L,H05K

Abstract:
A method, comprising:placing a substrate against a first fixture, the substrate having deposited thereon a plurality of solder bumps and a flux, the solder bumps having a melting point at a first temperature, and the flux having a volatilization temperature at which substantially all of the constituents of the flux volatilize, the volatilization temperature being less than or equal to the first temperature, the first fixture being maintained at a second temperature below the first temperature; placing a chip against a second fixture, the chip having affixed thereto a plurality of metal protrusions, the second fixture coupled with a heater, the heater being maintained at a third temperature, the third temperature being less than the first temperature; bringing the plurality of solder bumps into contact with the plurality of metal protrusions by moving one or both of the first and second fixtures towards each other; rapidly increasing the temperature of the heater from a third temperature to a fourth temperature, the fourth temperature being higher than the first temperature; and holding a pulse heat tool approximately at or above the fourth temperature until the plurality of solder bumps have melted and wetted the plurality of metal protrusions.