Rubber Keypad Design Guide


Silicone Rubber Keypad - Rubber Key Diagram


Button Travel (mm)


Silicone Rubber Keypad - Button Travel (mm)


Typical Effects


Actuation Force Tolerance Tactile Feel
50 grams ± 15 - ± 20 Excellent
70 grams ± 20 - ± 25 Excellent
90 grams ± 20 - ± 30 Excellent
100 grams ± 25 - ± 35 Excellent
120 grams ± 25 - ± 35 Excellent
150 grams ± 30 - ± 40 Good
170 grams ± 35 - ± 50 Good
200 grams ± 50 Fair

Silicone Rubber Keypad - General Specifications


Travel 0.8 - 1.5 mm
Force 60 - 300 grams
Tactile Response Yes
Life Cycles 1,000,000
Operating Temperature -40° to + 150° C
Storage Temperature -50° to + 170° C
Dielectric Strength >1 min @ 500 VRMS
ESD Breakdown >20KV/MM
Contact Bounce <5MS
Contact Resistance <200 Ohms

Physical Properties of Silicone Rubber


Typical Physical Property Carbon Conductor Silicone Insulator
Specific Gravity@ 72° C 1.18 1.17
Durometer Hardness (Shore A) 65 ± 5 30-80 ± 5
Tensile Strength (KG/CM) >50 >70
Elongation (%) >100 >250
Tear Strength (KG/CM) >9 >12
Linear Shrinkage (%) 3 - 5 3 -4.5
Volume Resistivity (Ohm/CM) <5 1x1015

Dimensional Tolerances


Dimension Tolerances
Inches MM Inches MM
0 - .987 0 - 25 .005 .13
.998 - 1.460 25.1 - 37 .008 .20
1.461 - 1.971 37.1 - 50 .010 .25
1.972 - 2.444 50. - 1-62 .012 .31
2.445 - 2.956 62.1 - 75 .015 .38
2.957 - 3.428 75.1 - 87 .017 .44
3.429 - 3.940 87.1 - 100 .020 .50
3.491 - 5.908 100.1 - 150 .024 .62
5.909 - OVER 150.1 - OVER 0.5% 0.5%

Tactile Characteristics of Keys


Item Cone Double Cone Bell Double Bell Flat
Type Keypad Type - Cone Keypad Type - Double Cone Keypad Type - Bell Keypad Type - Double Bell Keypad Type - Flat
Range of Pressure (Grams) 30-250 50-250 80-200
10-200
(non-click)
30-200 -
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