Validation of PCB Strain-Based Methodology for Structural Design of Spaceborne Electronic Equipment Under Vertical Mounting Conditions in Launch Environments

Spaceborne electronic equipment printed circuit boards (PCBs) installed under vertical mounting boundary conditions are exposed to a tougher environment than horizontal mounting due to the boundary conditions under the launch environment. Steinberg’s theory, which was previously applied to evaluate the structural safety of spaceborne electronic equipment, generates large errors and leads to inaccurate results. Although the vertical mounting of spaceborne electronic equipment is increasing due to its thermal/structural advantages, no high-reliability methodology or research has been developed to secure structural safety in the launch environment. In this study, the Oh-Park methodology, a highly reliable technique for evaluating the structural safety of solder joints in space-use electrical components based on the strain of the PCB, was verified for vertical spaceborne electronic equipment. Consequently, fatigue life tests were performed on specimens with structures similar to those of the actual spaceborne electronic equipment. The results were compared and analyzed with predictions made using Steinberg’s theory and Oh-Park methodology, respectively. The structural safety assessment using the Oh-Park methodology represented the test results more accurately, indicating that the critical strain-based methodology is effective for the design of vertical spaceborne electronic equipment exhibiting more complex behaviors due to their structural characteristics.