Solder paste manufacturers and electronics packaging experts are constantly formulating new compositions of solder alloys and flux materials to address assembly challenges. Type 6 solder powder, with a particle size of 10 µm and below, is preferred over type 4 and type 5 solder pastes for the assembly of 0201s chip components. Ball grid array packages (BGA) that are attached on the substrate using solder bumps on the bottom of the package are trending towards smaller size solder bumps. As a result, it is important to perform mechanical testing on the solder bumps, or solder balls, in order to understand the maximum load sustainable before failure. One effective way to test these solder balls is through compression. By applying a compressive load to a single solder ball, maximum force can be estimated before the ball cracks to failure. This helps in characterizing the bump strength of solder for package assemblies.
The Instron® 5900 Series systems are ideal for conducting this micro-precision compression test. Depending on the force required to break, either a single or a dual column system can be used. Custom pin type probes of various dimensions are available to perform accurate compression tests on the solder ball. A multitude of clamping solutions are offered for accurate clamping and positioning of package assemblies for conducting this test. Instron’s motorized XY stages offer an automated solution for performing compression tests on multiple solder balls in a single test run. The TestCam module in Bluehill® Universal software can be used for real-time live feedback of the compression test, allowing for a visual review of the bump compression for qualitative analysis. In cases where you need to introduce a high temperature before performing the test, custom heating stages are available, allowing you to heat the package or the substrate prior to compression.