1991 Fiscal Year Final Research Report Summary
Lead Migration of Solder Alloys used for Finely Wired Microelectronis
| Project/Area Number |
02650531
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
溶接工学
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| Research Institution | Osaka University |
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Principal Investigator |
TAKEMOTO Tadashi Osaka University, Welding Research Institute Assosiate Professor, 溶接工学研究所, 助教授 (60093431)
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| Project Period (FY) |
1990 – 1991
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| Keywords | Solder Alloys / Migration / Sn-Pb alloys / Voltage / Corrosion / Sloldering Flux / Electronic Circuits / Micro-soldering |
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| Research Abstract |
Migration behavior of lead in solder alloys used for connecting the electronic components to finely wired printed circuit board was investigated in water atmospher in relations to the solder alloy composition, test methods and composition of water. The main obtained results are summarized as follows.
(1) The effect of solder composition on the occurrence of migration were investigated using a power supplier applying constant voltage to the specimen. Pure lead showed the shortest time for the initiation of migration. The addition of tin to lead increased the initiation time, and pure tin was found to be remarkably resistant to migration. Similar results were obtained by the test using a potentio scanning method.
(2) The analysis of migration products revealed that lead was the main constituents even in the alloys containing more tin than lead.
(3) The addition of various activators to pure water changed the migration characteristics of solder alloys, however, the precise mechanism of varrying the migration behavior is not clear.
(4) The alloys without lead showed superior resisitant to migration.
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