These keypads incorporate a moulded silicon layer which sits on a PCB assembled with snap dome switches (see diagram).

The basic specifications are similar to the Snap Dome Keyboards and the main difference is that the Overlay is made of Silicon Rubber in place of Polyester.

In order to get the best Cost Benefit Ratio for Silicon Rubber Keypads, off takes should be relatively high
(> 10000 nos per annum). This is because a die mould is required for achieving the emboss and shape of the silicon layer.

The Solar Biotronic Laboratories Silicon Rubber Keypads offers the following features:

1. Gold plated contacts for superior switch performance.
2. Industrial grade adhesives used to withstand harsh environmental factors.
3. Silicon Rubber Overlay used to withstand harsh environment.
4. Overlay legends can be printed on keys as per Customer's requirements.
5. Can accomodate LEDs / Components thus saving space inside the equipment.

Electrical:         Contact Arrangement :   SPST Normally Open   Current / Voltage Rating :   10 mA at 24 VDC (max) in to resistive load only   Contact Resistance :   Compatible with MOS, TTL & DTL Circuits   Contact Bounce :   Less than 10 milliseconds at make & 20 milliseconds at break         Mechanical:         Operating Temperature :   -20oC to + 65oC   Key Travel :   380 microns   Life expectancy :   One million to Three million operations   Operating Temperature :   -20 deg to 65 deg centigrade   Humidity :   95% RH at 40oC         Materials:         Base :   Glass Epoxy PCB FR4 Grade in thickness ranging from 0.4 mm to 3.2 mm   Plating :   Bright Acid Tin; Nickel, Gold over Nickel   Adhesives :   Industrial Grade from 3M , Avery Dennision   Overlays :   Silicon Rubber