The automotive electronic control unit outputs control signals using electrical signals of various input sensors installed in the vehicle to control the state of the engine, automatic transmission, and electric power steering (EPS). These units are installed inside the vehicle or engine room, and the temperature rises and falls by several tens of degrees due to the heat of the engine and the self-heating of the electronic control unit. Therefore, it was exposed to a thermal fatigue environment due to the difference in the coefficient of thermal expansion between the components, which caused frequent component damage. Solder cracks due to thermal fatigue in electronic control units are a key failure mode. However, because of its great heat capacity, the electronic control unit for automobiles took a long time to attain the desired temperature of high or low, and as a result, the 1,000-cycle test for thermal fatigue life verification required 3,167 hours (or 4.4 months). Therefore, in this study, the thermal shock cycle test time for the verification of the thermal fatigue life of electronic control units for automobiles was reduced by dividing it into two types.

Since the fuel consumption of automobiles increases in proportion to the weight of automobiles, and the emission of exhaust increases in proportion to the amount of fuel consumed, to improve fuel efficiency and reduce exhaust emissions, it is necessary either to develop a highly efficient engine or reduce the weight of the vehicle. In this study, we studied weight reduction using lightweight materials such as aluminum alloys to increase fuel economy. For this purpose, we propose a lightweight design process of the shock tower mounting bracket, which is the largest loaded part among the vehicle parts. The change in strength and dynamic strength was investigated by replacing the existing cast iron material with 320 MPa of aluminum A356 casting material. For strength and dynamic stiffness analysis of the shock tower mounting bracket, the load on the peripheral members was calculated. As a result of the dynamic stiffness analysis, we identified the weak part and calculated that the lifetime of the shock tower mounting bracket is safe for the calculated load conditions. Through this study, we provide a guide for lightweight design and suggest optimal design conditions for development of a vehicle shock tower mounting bracket.

It was a requirement to use electronic components developed and operated by MANPAD in the military wheel vehicle with greatly improved operational radius and quickness and maneuverability. The objective of this study was to add the structure of the newly developed equipment for future compatibility with each other, and design it according to the requirements of vehicle installation. As the operating environment changes from one type of equipment to another, that is operated by a person, the differences between the environmental specifications and characteristics of the two types of weapons are compared. In addition, dynamic characteristics analysis and testing of equipment units were carried out in order to confirm whether the equipment can be normally operated with the disturbance (vibration / shock) that will be continuously received as the operating environment changes. The physical properties of the PCB components were verified through actual environmental tests after confirming the difference between the values shown between the commercial program and the reference documents.