Ibiden Company Limited

Tsutomu Iwai

Kiyotaka Tsukada

Hiroyuki Watanabe

Yoshihiro Kodera

Shinya Maeda

Kazunari Suzuki

A composite layer composed of an Ni layer and a Pd layer is formed on a solder pad, and a solder on the composite layer is composed of a solder containing no lead. Because a Pd layer (palladium layer) reduces phenomenons such as repellency of the solder, adhesiveness with the solder can be enhanced. Because a Pd layer has a higher degree of rigidity than a gold layer, thermal stress is absorbed into the Pd layer and buffered so as to reduce the degree of transmission of stress to the solder bump, or to the solder layer, by thermal stress.

Method for manufacturing printed wiring board

A composite layer composed of an Ni layerand a Pd layeris formed on a solder padU, and a solder&#x3b1; on the composite layer is composed of a solder containing no lead. Because a Pd layer (palladium layer) reduces phenomenons such as repellency of the solder, adhesiveness with the solder can be enhanced. Because a Pd layer has a higher degree of rigidity than a gold layer, thermal stress is absorbed into the Pd layer and buffered so as to reduce the degree of transmission of stress to the solder bump, or to the solder layer, by means of thermal stress.

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Ogaki, Japan

Tsutomu Iwai