| 摘要 |
A populated printed wiring board (PWB) ( 100 ) and method of manufacturing the populated PWB are taught. The populated PWB is manufactured by fabricating a PWB ( 102, 402 ) with exposed copper pads ( 302 ), coating the copper pads with an organic solderability preservative (OSP) ( 404 ), depositing a solder paste that includes lead-free solder on the OSP covered copper pads ( 406 ), placing components ( 408 ) and heating the PWB above a liquidous temperature of the lead-free solder in an air atmosphere ( 410 ). The process allows very close spacing of components and component leads while forming reliable solder joints to components that are mechanically stressed and components that have non-negligible planarity or coplanarity tolerances.
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