During the design process of silicone rubber keypads, our customer engineers will often ask our engineer's team about the reasonable gap between the silicone keypad with the panel, and the shell. Our professional engineers generally recommend no less than 0.2mm on one side, and 0.3mm is optimal. More than 10 years of experience in keypad design have concluded that silicone rubber keypad designed with a 0.2-0.3mm gap suits most industries' application scenarios.
The gap of 0.2-0.3mm is a non-standard value. Strictly speaking, the Key's shape, size, stroke, and other data determine the gap between the silicone rubber keypad with panel and shell. The key shape of the silicone rubber keypad is irregular with a larger dimension and stroke, a larger gap will be reserved. On the contrary, a smaller gap can meet the appearance and functional requirements.
A: Shell opening dimension
B: Silicone rubber keypad KEY dimension
C: The distance between the shell and the keypad KEY
The keypad to function and appearance of the assembled silicone rubber keypad lie in leaving the correct gap between the silicone button with shell and panel. The gap between the silicone keypads with panel and shell is too small, which will lead to poor user experience or key jamming problems. However, the gap is too large and does not meet the appearance requirements.
The gap between the silicone buttons with panel and shell will be designed according to the different strokes of the keypads. The design specifications are as follows:
Silicone keypad stroke ≤1.0mm.
Key shape | Silicone rubber keypad KEY dimension(mm） |
| ＜10 | 10～20 | 20～30
| 30～40 | 40～50 | ＞50 |
| Round | 0.10mm | 0.15mm | 0.20mm | 0.25mm | 0.30mm | / |
| Triangle | 0.10mm | 0.15mm | / | / | / | / |
| Quadrangle | 0.10mm | 0.15mm | 0.20mm | 0.25mm | 0.30mm | / |
| Polygon | / | / | 0.20mm | 0.30mm | 0.35mm | / |
| Special-shaped | / | 0.15mm | 0.20mm | / | / | / |
Silicone keypad stroke ≤1.5mm
Key shape | Silicone rubber keypad KEY dimension(mm） |
| ＜10 | 10～20 | 20～30
| 30～40 | 40～50 | ＞50 |
| Round | 0.10mm | 0.15mm | 0.20mm | 0.30mm | / | / |
| Triangle | 0.12mm | 0.15mm | 0.25mm | / | / | / |
| Quadrangle | 0.12mm | 0.20mm | 0.30mm | / | / | / |
| Polygon | / | / | 0.25mm | 0.30mm | / | / |
| Special-shaped | / | 0.16 | 0.30 | / | / | / |
Silicone keypad stroke ≤2.0mm
Key shape | Silicone rubber keypad KEY dimension(mm） |
| ＜10 | 10～20 | 20～30
| 30～40 | 40～50 | ＞50 |
| Round | 0.10mm | 0.15mm | 0.20mm | 0.30mm | / | / |
| Triangle | 0.12mm | 0.15mm | 0.25mm | / | / | / |
| Quadrangle | 0.12mm | 0.20mm | 0.30mm | / | / | / |
| Polygon | / | / | 0.30mm | 0.35mm | / | / |
| Special-shaped | / | 0.20mm | 0.30mm | / | / | / |
Note: "/" indicates not recommended the Key's dimension.
