Selective PWB Surface Finishes to Accommodate both Conventional and Aduanced Attachment Procedures

摘要

The high I/O interconnections required by recent innovations in component technology are causing eelctronic manufactureers to evaluate presetn assembly procedures. Although wave and solder paste reflow are currently employed for bonding the vast majority of components, these techniques may no longer by yield or cost competitive for ultra-fine pitch < 0.038 mm and odd form components. ANalyzed are all options in use or under evaluation to produce the most appropriate surface finish for various bonding procedures presently under consideration. These include a more uniform tin/lead, tin, nicke/gold, nickel/palladium, and preflux or inhibitor coated copper. The pragmatism of selective finishes to accommodate multiple attachment methods is clanified.