Abstract: The PCB assembly in the load distribution between the different assembly equipments in SMT production line is an important class of optimization problems in the electronics industry. Given the takt time and the actual production process constraints,its optimization objective is to make different placers load balanced and task allocation optimal,so that improving production efficiency and equipment utilization. Firstly, in order to balance the workload among different placers, based on a variety of different types of the surface mounters, nozzles and component matching particularity, the problem of task allocation optimization of placement machines is proposed; Secondly, the actual production line design information factor parameter components, assembly feasibility, the actual placement time, as well as the placement relationship optimization are analyzed, the mathematical model of load distribution combinatorial optimization is set up given optimization maximizing equilibrium conditions; Finally, aiming at the complexity and particularity of load distribution problems in SMT production line, the mathematical models are optimized through the combination of improved encoding of DNA genetic algorithm to calculate the fitness,and the problem is solved by using MATLAB, and then the optimal solution is found. The results show that:the load distribution optimization method proposed in this paper can effectively solve the problems in load optimization distribution of printed circuit board(PCB)assembly,advance the utilization and equilibrium of equipment,and promote the operation optimization of the production line.

Key words: SMT, DNA genetic algorithm, load balancing, optimal allocation