Rubber Keypad Manufacturing Process

Making the Tool
In-house tool making with state-of-the-art EDM and CNC milling machines.

Conductive Pills
Carbon impregnated silicone pills are the most frequently used contact with silicone rubber keypads. The silicone in the conductive pill allows enables it to securely co-mold with the keypad.

Placing the Silicone Rubber on the Tool
Gum stock silicone rubber is placed directly on tool. Heat and pressure will form the silicone into the configuration of the mold tool.

Stage 2 – Keypad After Molding Cycle
Pressure and heat are maintained until the material has cured. The mold is opened and the keypad sheets are removed for further processing.

Adding Several Colors
Pigmented silicone rubber is hand placed onto the base mat in preparation for molding. The silicone will blend together to form the keypad base while the keys will retain their specific colors. Only the key tops will be seen through the bezel.

Removing the Keypad from the Tool
Air hoses are used to assist in removing the keypads from the mold tool. The carbon pills were placed in the bottom of the tool prior to adding silicone and molding. As you can see, they are now molded to the keypad.

Silkscreen
Molded silicone keypads are placed in a vacuum fixture for screen printing. Silicone in the inks bond to the keypad during the curing process and flexes during keypad actuation.

Screen Printing
A stencil is placed over the keypad. The stencil exposes only the key tops that are to receive ink on this screen printing pass. Each screen print color will have a stencil.

Testing
The silicone rubber keypads are tested to insure they meet our customers' mechanical and dimensional tolerances. The technician is testing the operating force of a key.

Quality Control
After the molding process and post curing the silicone rubber keypads are removed from the sheet and inspected for quality issues.