THE NETWORK LOCATING PRINCIPLE IN FLEXIBLE CIRCUIT BOARD ASSEMBLY

This paper focuses on developing the Network Locating Principle for fixturing tooling design in flexible circuit board assembly. From a viewpoint of Thermodynamics, a flexible circuit board populated with electronic components on the first side is a closed thermodynamic system. It experiences deformation energy change, assembly load work, and heat transfer during an isothermal assembly process on the second side, such as solder paste deposit printing and electronic component placement processes. Based on the First and Second Laws of Thermodynamics and Energy Equation of Thermoelastic Theory, a fixturing analysis is developed to investigate the deformation energy change, and furthermore the theoretical fixturing solution is derived to minimize the assembly load work during the isothermal assembly processes. To this end, the Network Locating Principle is proposed to guide fixturing tooling design for the isothermal assembly processes on the second side. Effectiveness of the Network Locating Principle is verified in numerical and experimental studies of flip chip placement processes on a thin flexible circuit