It is difficult to eliminate this problem only by optimizing the processing parameters. If multiple gates can be used, it may help multi-directional flow, thereby reducing warpage. The two most affected areas are the temperature of the injection mold and the location and type of the gate. It is difficult to give specific suggestions without knowing the configuration or process, but to consider the parts on the molecular scale. Imagine that the surface of the part is interconnected crystals, and the cooling starts from the coldest surface of the injection mold.