Trace Design for Bump-on-Trace (BOT) Assembly

摘要

A bump-on-trace (BOT) interconnection in a package and methods of making the BOT interconnection are provided. An embodiment BOT interconnection comprises a landing trace including a distal end, a conductive pillar extending at least to the distal end of the landing trace; and a solder feature electrically coupling the landing trace and the conductive pillar. In an embodiment, the conductive pillar overhangs the end surface of the landing trace. In another embodiment, the landing trace includes one or more recesses for trapping the solder feature after reflow. Therefore, a wetting area available to the solder feature is increased while permitting the bump pitch of the package to remain small.

主权项

1. A method of forming a bump-on-trace (BOT) assembly, comprising:
forming a landing trace on a substrate; positioning a conductive pillar over the landing trace such that the conductive pillar extends at least to an end of the landing trace; and reflowing a solder feature between the landing trace and the conductive pillar to electrically couple the landing trace to the conductive pillar.