SOLDER HIERARCHY FOR LEAD FREE SOLDER JOINT,申请号PL20030374701-传众专利搜索

SOLDER HIERARCHY FOR LEAD FREE SOLDER JOINT

申请公布号：PL374701(A1)

申请号：PL20030374701

申请日期：2003.09.12

申请公布日期：2005.10.31

申请人：

INTERNATIONAL BUSINESS MACHINES CORP.

发明人：INTERRANTE MARIO;FAROOQ MUKTA G.;SABLINSKI WILLIAM EDWARD

分类号：B23K1/00;B23K35/14;B23K35/26;B23K101/40;B23K101/42;C22C13/00;H05K3/34

主分类号：B23K1/00

摘要：A lead free solder hierarchy for use in the second level solder connection of electronic components such as joining an electronic module to a circuit board. An off-eutectic solder concentration of SnCu or SnAg is used for the module side connection. This off-eutectic solder contains sufficient intermetallics to provide the module side connection with a robust second level assembly and rework process. The off-eutectic composition provides an inter-metallic phase structure in the module side fillet during assembly. The inter-metallic phase structure eliminates problems of tilt and collapse during second level assembly and aids in rework by providing a more cohesive joint allowing removal of the columns from the board without simultaneous removal from the module.