Come join us March 24, 2016 from 5-7pm for a Tour, Dinner, and a presentation.

We will be featuring Carter Ralph from Southern Research Inc.

STI, Madison, Al will be hosting our tour and meeting.

You must be a U.S. citizen to participate in the Tour.

Carter Ralphis an engineering experimentalist at Southern Research, specializing in mechanical and thermal testing for electronic and aerospace applications. He has particular interest in composite materials and developing new test methods. He worked previously in Intel Corporation’s Assembly/Test Technology Development Division doing customer manufacturing support, new product qualification, and mechanical testing. He is a graduate of Georgia Tech and Auburn, and chairman of the Composites Technical Division of the Society for Experimental Mechanics. When not breaking and burning things at work, he repairs things at home.

Subject: Using Acoustic Emissions to Detect Solder Joint Cracks

Detecting mechanical damage in solder joints is a challenge for the electronics industry, and acoustic emission is a tool that has recently been demonstrated to have the capability to detect interconnect cracks at the instant they occur. During qualification testing for new products, test units are usually instrumented with strain gages and electrical daisy chains to monitor damage during bending and mechanical shock. Daisy chains fail only after extensive damage has occurred, and strain gages typically provide only relative indications of damage, so post-test failure analysis is required. Common failure analysis techniques are dye stain and cross-section, both of which are labor-intensive and add significantly to throughput time. These same basic techniques are also often employed on the production line only after product failures have been detected with electrical tests, and have the same drawbacks. Acoustic emission detection has been used for several decades to detect cracks as they occur in civil structures and aircraft. Cracking in brittle materials causes a sudden release in energy that emits sound waves, and these can be recorded with acoustic transducers to determine the time and location of the failures. This technique has recently been successfully applied to the problem of solder joint cracking in bend and shock tests by Southern Research, HP, and Keysight. This presentation will tell the story of how this study came about, present test results demonstrating the capability, and speculate on potential future development and applications.