Patent attributes
A chip module assembly includes a CO2 getter exposed through a gas-permeable membrane to a chip cavity of a chip module. One or more chips is/are enclosed within the cavity. The CO2 getter comprises a liquid composition including 1,8-diaza-bicyclo-[5,4,0]-undec-7-ene (DBU) in a solvent that includes an alcohol, preferably, 1-hexanol. In one embodiment, a sheet of gas-permeable membrane is heat-welded to form a pillow-shaped bag in which the liquid composition is sealed. The pillow-shaped bag containing the liquid composition is preferably disposed in a recess of a heat sink and exposed to the cavity through a passage between the recess and the cavity. The CO2 getter can remove a relatively large amount of carbon dioxide from the cavity, and thus effectively prevents solder joint corrosion. For example, based on the formula weights and densities of the DBU and 1-hexanol, 200 g of the liquid composition can remove over 34 g of carbon dioxide.
