| This dissertation explores the development of fixturing foundation in flexible circuit board assembly. Flexible circuit board assembly technologies present formidable challenges to conventional fixturing technologies and theories. To meet such a severe fixturing challenge, the Network fixturing technique and the Pin-array fixturing technique are developed. Furthermore, a thermodynamic-based fixturing analysis is studied for an attempt to establish a theoretical foundation for these new fixturing techniques. By applying it, the global optimal fixturing configuration for flexible circuit board assembly is theoretically derived. More importantly in practice, the Network locating principle is developed to fixture both small-deformed and large-deformed flexible circuit boards.;Based on a feasible platform of the substrate displacement model, the optimum fixturing design problem is formulated in equation system (6.1). The object function of this problem is the function MCF, which describes the fixturing interference of firmly clamping features with assembly processes. The Network locating principle, the substrate displacement model, and assembly mis-registration tolerance requirements are constraint conditions. Partition lines are design variables. Two fixturing design cases of the above optimization problem are discussed. The first case is to design a fixturing configuration for symmetrical flexible circuit assembly. Necessary conditions of the optimum partition line are derived from a viewpoint of the minimum deformation energy. Algorithm and numerical simulations of the optimum fixturing design are studied. The second case is to design a fixturing configuration of constraining assembly mis-registrations in the direction of assembly loading in thin flexible circuit assembly. An algorithm is developed for achieving an optimum solution among feasible closed partition lines, each of which intersects at vertices of assembly cell boundaries and divides the initial substrate cell into two smaller parts. It consists of two sub-algorithms, which either optimizes the line segments of a feasible closed partition line determining the maximum deflections inside assembly cells or minimizes the total number of assembly cell edges added to the feasible closed partition line.;The primary contribution of this dissertation is the development of the new fixturing techniques, the Network locating principle, and underlying fixturing design techniques for flexible circuit board assembly. |
