High Reliability Testing for Flip Chip Gold to Gold Interconnect

Ultrasonic Flip chip gold to gold interconnect (GGI) offers a productive monolithic gold bond die attach process. In many flip chip GGI applications underfill is not required to strengthen the gold bond. This abstract will discuss test and inspection methods used to determine the gold bond strength. Three common areas that are used to measure the quality of bond strength include: 1) Bump shear 2) Bump transfer 3) Die Shear.

The bump shear test is used to measure the strength of the stud or plated bump. The die shear test is used to measure the strength of the die bonded to the substrate. This test takes into consideration the bump geometry, bump material, and number of bumps transferred to the substrate during ultrasonic die attaches process Bump geometry is measured using a microscope to measure overall bump height, diameter, and quality of bump tail. A C-Scan microscope and IR scan of the bonded die can be used to inspect bonded die. A Dage 4000 shear tester can be used to shear test the die. The shear mode and number of bump transferred of the sheared die is inspected by microscope.

Ultrasonic GGI flip chip die attach offers a reliable, clean, die attach process to organic and ceramic substrates. The ultrasonic die attach process using less manufacturing steps with less heat and load stress to the die.