Microelectronic flip chip packages with solder wetting pads and associated methods of manufacturing

摘要

Processes of assembling microelectronic packages with lead frames and/or other suitable substrates are described herein. In one embodiment, a method for fabricating a semiconductor assembly includes forming an attachment area and a non-attachment area on a lead finger of a lead frame. The attachment area is more wettable to the solder ball than the non-attachment area during reflow. The method also includes contacting a solder ball carried by a semiconductor die with the attachment area of the lead finger, reflowing the solder ball while the solder ball is in contact with the attachment area of the lead finger, and controllably collapsing the solder ball to establish an electrical connection between the semiconductor die and the lead finger of the lead frame.

主权项

1. A method for fabricating a semiconductor assembly, comprising:
forming an attachment area and a non-attachment area on a lead finger of a lead frame, the attachment area being more wettable to a solder ball than the non-attachment area during reflow, and wherein the attachment area having an area comprising silver, and the non-attachment area having an area comprising copper oxide; contacting a solder ball carried by a semiconductor die with the attachment area of the lead finger; reflowing the solder ball while the solder ball is in contact with the attachment area of the lead finger; and controllably collapsing the solder ball to establish an electrical connection between the semiconductor die and the lead finger of the lead frame; and wherein controllably collapsing includes:
preventing the solder ball from migrating away from the silver the attachment area into the copper oxide area of the non-attachment area.