This paper presents a dynamic batching heuristic for controlling batch processing machine in semiconductor manufacturing. The batch processing machines process several jobs, at the same time, as a batch. When a batch process machine complete its task and ready to start new process, real-time loading strategies should be made to check whether it is best to start the process right away with current products in queue, or to wait for the upcoming products. A new real-time batching heuristic is proposed in multiple-product type single-machine environment with tardiness minimization as a key performance measure. Look-ahead information about future job arrivals is incorporated in decision making. Simulation experiments show that the new batching strategy provides performance of good quality. 