Method For Soldering/Unsoldering HeatSensitive Parts
Original Publication Date: 1979-Oct-01
Included in the Prior Art Database: 2005-Feb-20
No fully satisfactory methods have been evolved to remove and replace semiconductor chips (using flip-chip joints). Conventional methods currently employed include microflame, infrared heating, localized hot gas, immersion in heated liquid, and use of a furnace. Each method suffers from its own set of disadvantages, but in general, they have one or more of the following problems: 1. The unselected components in the assembly are subjected to unnecessary thermal cycles which can produce damage or incipient deterioration. 2. The temperatures the selected component receives, either in removal or replacement, cannot be precisely controlled. In many cases it is desireable to preserve the removed chip for diagnostic purposes or for salvage and reuse.