Patent ID: 7566835

Claim:
A multilayer printed wiring board comprising: a substrate having an interlayer resin insulating layer and a conductor circuit, the substrate having a front side and a back side opposed to the front side; and a plurality of solder bumps formed on the front side of the substrate or the back side of the substrate, or on both the front side and back side of the substrate, for mounting a plurality of electronic components, wherein said plurality of solder bumps comprise first solder bumps for mounting a first electronic component, second solder bumps for mounting a second electronic component and third solder bumps for mounting a third electronic component, and the first solder bumps, second solder bumps and third solder bumps have different melting points respectively, with the respect to differences in melting point ranges of the solder bumps, a low range endpoint of the second solder bump is higher than a low range endpoint of the third solder bump by 25° C. and a low range endpoint of the first solder bump is higher than a low range end point of the second solder bump by 24° C., and a high range endpoint of the second solder bump is higher than a high endpoint of the third solder bump by 30° C. and a high range endpoint of the first solder bump is higher than a high endpoint of the second solder bump by 30° C., and the melting point ranges of the first, second and third solder bumps do not overlap with each other.