LEANNE K. MOYER’s research while affiliated with Northeastern University and other places

This paper proposes a methodology to improve the process time required for the component placement process of the printed circuit board assembly with an X-Y positioning table. The methodology is applied to a previously published subproblem as well as a real-life working board configuration. Even with high speed assembly machines placing in excess of 40000 components per hour (cph), process improvements are possible. Concentrating on the path planning portion is a valid method to increase efficiency, but as the problem approaches optimality, the planning process essentially becomes counterproductive due to the time and effort required. This paper presents an algorithm for system time improvement for use after a board placement path is established. In order to take advantage of the machine's capability to move the positioning table along each axis simultaneously, the board is physically rotated with respect to the positioning table. This paper steps through the theoretical development of a method to determine the proper angle of rotation, first for a regular 'rectangular' board configuration, and then for a more applicable 'general' configuration.

This paper proposes a sequencing approach to develop a competent path for the printed circuit board assembly process. An efficient heuristic is developed that determines the component placement sequence, also referred to as the placement path. This NP-complete problem best resembles a Traveling Salesman Problem.(1) Thus, it is inherently difficult. The heuristic approach is tested against a previously published subproblem as well as a real-life working board configuration. This heuristic is intended to provide a good, feasible component placement sequence for the assembly of a batch of printed circuit boards with a machine configuration consisting of a moveable X-Y positioning table and a tape-and-reel sliding feeder rack. Even with high speed assembly machines placing in excess of 40000 components per hour (cph), process improvements are possible by increasing the efficiency of the planned placement sequence. This heuristic is developed to identify an improved component placement sequence in a reasonable computation time to allow for future implementation of the methodology in applied situations where time constraints are unavoidable.

This paper reviews the problems that many electronics manufacturers are facing in a society of rules and regulations that are becoming increasingly environmentally conscious. The effect of electronics assembly, disassembly, and disposal on the environment is reviewed, and the potential hazards of continuing the present trends in electronics parts disposal is discussed. The paper contains a comprehensive survey of previous works related to environmentally conscious manufacturing practices, recycling, and the complexities of disassembly in the electronics industry. Interest in this area has intensified in recent years due to an increased awareness of the problem in a world of high technology where electronic products dominate. Industrial applications of recycling programs are presented and existing methodologies and evaluation systems are discussed. In order to promote and support this new environmental ethic in electronics assembly and disassembly, the need for improved methods of electronics reuse, minimization of life-cycle scrap, development of planning tools, and an increase in research activity in this area are also highlighted.

This paper proposes a methodology for efficient process planning of concurrent machines in electronics assembly. The particular machine type under consideration is the High Speed Chip Shooter (HSCS) for surface mount assembly. Currently, most surface mount assembly operations are modeled in a cyclic manner. The model that is proposed herein is an asynchronous (acyclic) model that augments the benefits of the unique features of this assembly machine. A heuristic algorithm is developed, referred to as the Acyclic Assembly Time (AAT) algorithm, which is based on the asynchronous model. The algorithm is thoroughly tested with orthogonal arrays, compared against previously published problems, and applied to a real life example. The AAT algorithm produced excellent results throughout the test process. By increasing the utilization of the individual mechanisms, the efficiency of the overall system naturally improves and the ultimate goal of reducing the total assembly time is achieved.

Surface Mount Technology (SMT) is a popular method of Printed Circuit Board (PCB) assembly in which high speed automated assembly machines are capable of placing in excess of 40,000 components per hour. In order to achieve these impressive assembly rates, complex placement machines must be programmed efficiently. Intrinsic to the configuration of these machines and the assembly process are some well established Operations Research problems. This paper addresses the feeder sequencing problem for an assembly machine with a sliding feeder rack in conjunction with a X-Y positioning table and a turret placement mechanism. This problem is a Quadratic Assignment Problem, and is proven to be NP-complete.1 Two different heuristic methods are proposed, each with unique characteristics that have the potential to be beneficial to an assembly operation dependent upon the restrictions of the planning task. One method is to assign feeder slots based on the transition between component types that naturally occur in the board placement path. The second method begins with an initial slot assignment and identifies exchanges between pairs of slots that generate improvements in the objective function. Minimizing the feeder travel distance over an assembly is the goal of each heuristic. A comparative analysis between the two heuristics is performed. Examples are presented and the attributes of each method are discussed. Arguments are presented to support "near-optimal" solutions to the problem. Given the complexities of the system, proper planning of the assembly process can take advantage of the independent control of each mechanism to create a natural relaxation of specific constraints.