Nondestructive method of TIM bondline measurement in Flip Chips package

Abstract

This paper describes the method of using Acoustic Micro Imaging (AMI) technique as nondestructive method to measure the bond line thickness (BLT) of the thermal interface material (TIM) in Flip Chips package; this is an alternative to destructive physical analysis. The purpose of this study is to demonstrate the capability of AMI used to measure the BLT of TIM. The two interfaces of interest are Lid-to-TIM. and TIM-to-Silicon chip. AMI is a nondestructive inspection technique that utilizes high frequency ultrasound in the range of 5 to 500 MHz to: -determine interface bonding/adhesion detect -defects -characterize & measure material properties Acoustic Micro Imaging instrument shown here is an effective technique for nondestructively evaluating the TIM thickness. The images in this report demonstrate a few of many imaging and analysis techniques within AMI technology that are useful for production screening and in laboratory. These capabilities make it an excellent choice for a fast, reliable and accurate to measure the thermal interface material after joining the lid with the backside of the flip chip without manual cross section.