Custom membrane keypad manufacturing process

  • After the membrane switch design, we begin to make products. The manufacture of them include these processes. 

    1 Heat shaping PET

    Place the PET material on the grill and push it into the oven for baking. In general, the baking temperature is 160 degrees, and the baking time is 25 minutes. This process is to reduce the heat shrinkage of the PET.

    2 Screen Printing

    A good performance polyester film (PET) is used as a carrier for the switching circuit pattern. Screen printing the conductive silver paste, conductive carbon paste and UV layer. Then the switch keypad will have conductive property. What’s more, the UV layer is used to protect the circuit effectively.

    3 Baking

    After screen printing the conductive inks and silver paste, we adopt hot air circulating tunnel furnace for baking. Furthermore, the baking temperature is 110 degrees, and the speed is 5 meters per minute. While, a UV curing oven is used for baking the screen printed UV layer, and the parameter is 500 joules.

    4 Positioning hole

    During the screen printing process, we design positioning holes on the PET. While, in this process, we use a laser punch machine through the holes. As we all know, the role of positioning holes is to ensure the smooth going of later testing and lamination.

    5 ICT test

    This is a process that we test the conductivity and insulation of the printed lower circuit layer. (Parameter: 300V/100M)After testing, we can make sure that the circuit characteristics of the lower circuit can meet customer requirements.