PCB Solder Joint Shear

Case study

PCB solder joint test close up and schematic of the custom fixture

PCB solder joint testing on a touch-screen tester with magnifying accessory

Solution

Software-controlled touch screen test stand
Custom fixture to support the delicate test specimen
Magnifier eyepiece to enable the operator to move to each joint

Benefits

Precise alignment of the test piece
Quick and repeatable testing with touch screen and software control

Requirement

Millennnium Microtech Thailand, part of Microchip Technology Inc Thailand operates a manufacturing, packaging and testing plant for Printed Circuit Board (PCB) Integrated Circuit (IC) components. The company wanted to perform shear tests on surface-mount solder joints in a fast, repeatable, way, with customer service that would meet the unique challenges of some of the designs. Certain components are especially small and mounted on extremely thin boards.

Solution

The Mecmesin Asia team worked with the company to specify a custom fixture to perform the shearing test. Great precision was needed for the quality control personnel to align the individual solder joints with the angle-tipped probe in the upper fixture. The jig holding the PCB needed to hold the delicate component securely and was attached to an adustable X-Y table to enable the operator to locate the test piece quckly in two dimensions. Additionally, the integration of a stereo microscope (7-30x magnification) with a 56 LED ring light provided a clear view of the individual joint under test.

Once the sample is in position, the MultiTest 2.5-xt runs the test, initiated from its touch screen interface, to move the crosshead down a fixed distance and return the peak compressive shear force value. The data is used to monitor production and keep the manufacturing tolerances within specification.