Conclusion

AN3431

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Doc ID 019017 Rev 1

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Conclusion

The deformation of the metal layer which leads to a touch detection depends on several

parameters which are summarized in Table 4.

Table 4.

Mechanical parameters and recommendations

Other factors influence how the buttons affect each other including the elasticity of the top

cover material or how well the top cover and spacer layers are merged with the adhesive.

Such factors can also be reduced by placing the buttons at least half the diameter of a

button away from each other.

Mechanical parameters

Recommendations

Top cover material type

Aluminium

Top cover material thickness

0.7 mm

Spacer thickness

0.1 mm to 0.5 mm

Sensor size

Hole size

110 % to 130 % of the button size

Force applied

Roughly between 1 N and 10 N