Patent ID: 8122598

Claim:
A method of mounting a component on a multilayer printed wiring board, the method comprising: forming a first solder bump on either a front side or a back side of the multilayer printed wiring board, the first solder bump having a first melting point temperature; forming a second solder bump on either the front side or the back side of the multilayer printed wiring board, the second solder bump having a second melting point temperature which is less than the first melting point temperature; forming a third solder bump on either the front side or the back side of the multilayer printed wiring board, the third solder bump having a third melting point temperature which is less than the first melting point temperature and less than the second melting point temperature; and mounting at least one electronic component on the multilayer printed wiring board by performing a first soldering operation using the first solder bump, performing a second soldering operation using the second solder bump, and performing a third soldering operation using the third solder bump, wherein the first, second and third soldering operations are performed sequentially, wherein: the first melting point temperature is a first temperature range, the second melting point temperature is a second temperature range and the third melting point temperature is a third temperature range, a low range endpoint of the second temperature range is higher than a low range endpoint of the third temperature range by 25° C., a low range endpoint of the first temperature range is higher than a low range endpoint of the second temperature range by 24° C., a high range endpoint of the second temperature range is higher than a high range endpoint of the third temperature range by 30° C., and a high range endpoint of the first temperature range is higher than a high range endpoint of the second temperature range by 30° C., and the first, second and third temperature ranges do not overlap with each other.