Investigations on the Robustness of a Solderless Assembled Electronic Module

The paper presents some new contributions to the mechanical characterization of products obtained through the new concept of solderless assembly for electronics. In one of the implementation methods, the resulting electronic module is presented as a compact structure of dielectric material embedding surface mount components. The solder joint is replaced by direct contact between the component terminal and the interconnection track made of electrically conductive composite material. Although the contact strength between the two parts based solely on adhesiveness is weaker, strong improvement is expected due to the encapsulation. With no direct access to the component for shear force measurement, the mechanical resistance of the bonding is investigated by vibration testing. Because an encapsulated solderless module has a nonhomogeneous structure, its resonance frequency cannot be calculated based on the classic formulas for printed circuit boards and flat plates. Therefore, the robustness of a solderless assembled electronic module was investigated following very closely the operating conditions for the airplane domain: vibration frequency band 10 to 1000 Hz, vibration amplitude: 1 to 5g, and maximum amplitude in the 100 to 400 Hz bandwidth. The test duration was 3 hours with the module fixed horizontally. The final functional test validated the choice of material and the design of the module at least for this preliminary test.