Keypad Technical Details
Specialist keypad technical guidance.
Custom design and engineering of geometry and physical characteristics creates keypads that fit your application
at a low cost per key.
A host of design-in technical features are available enabling you to get exactly the right combination that will improve user engagement and enhance both the aesthetic and the function of your product – often with little or no additional cost.
How Interface Controls can work with you to get your keypad technical specifications right:
The special circumstances in which many devices are operated in demand specific design requirements.
This is when silicone rubber keypads really come into their own.
You can submit your design data files to us in a range of CAD formats, including: DWG DXF IGES STEP and SolidWorks.
See below for further information outlining basic technical guidance to take into account when designing silicone rubber keypads –
also referred to as silicone buttons or elastomeric keypads.
Scroll and expand to view.
Silicone Rubber Keypads Dimension Detail | |
General 1 – Typical outside radius 1.0mm to 1.5mm 2 – Minimum radius 0.3mm 3 – Minimum inside radius 0.2mm 4 – Minimum spacing between edges of rubber dome and guide hole 1.0mm 5 – Guide holes minimum 1.0mm diameter 6 – Width of rubber button base typically 2.0mm greater than ‘a’ 7 – Minimum radius for the side of the keytop 0.25mm 8 – Minimum radius for the top edges of the keytop 0.2mm |
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Key Height H = Dimensions from keytop to front panel S = Key stroke H-S > 1.5mm |  |
Key Corner Radius R = Corner radius of cut-out r = Corner radius of rubber 1.0mm < R < 1.25mm 0.75mm < r < 1.0mm |  |
Key Clearance A & B = Dimensions of front panel cut-out a & b = Dimensions of rubber A-a > 0.4mm B-b = 0.3mm |  |
Silicone Rubber Keypads Mechanical Detail | |
PCB Location Pull through interference fit ‘a’ Push through hollow to aid insulation ‘b’ |  |
Silicone Rubber Keypad Hardness Base typically 55% shore Keytops up to 90% shore |  |
Control of Keystroke Mechanical stops for controlling keystroke when using plastic keytops |  |
Anti-rocking Device P = Diameter of post P = 1.0mm t = Height difference between post and conductive pill t = 0.1#0.15mm |  |
Silicone Rubber Keypads Illumination Options | |
Keytop Illumination Translucent rubber Selective carbon printing or array contact pills |  |
Light Guide Illumination LED window in keytop Translucent rubber insert light guide |  |
Status Indication Construction showing LED indicator |  |
Silicone Rubber Keypad Electrical Detailing | |
Conductive Carbon Pills Sizes available, 0.2mm to 10.0mm dia. in 0.5mm increments Conductive pill resistance: less than 150 ohms with 100 gram loading Life expectancy: 30 millon operations Gold-plated nickel options | |
Selective Carbon Printing Size and layout customised to key shape Conductive printing resistance: less than 800 ohms with 300 gram loading Life expectancy: 1 million operations Silver ink options Maximum Contact Pill Size Silicone Rubber Keypads electrical: Contact pill size d = D-1.5~2.0mm | |
Recommended PCB Electrode Patterns Layout available as AutoCAD dwg file (contact office for further details) Suggested PCB coating – gold, selective carbon |  |
FREE Desktop Design Sample
Our handy desktop design sample is great to use when looking at options for your