In general, the keys of the membrane switch only use color to express the position, shape, and size of the key body. In this way, the accuracy of the operation can only be recognized by the operator's visual sense, because there is no proper feedback information indicating whether the finger is pressed in the effective range of the switch to make the switch act, thereby affecting the confidence of the whole machine monitoring and the speed of the operation.

However, the key switch of the membrane switch is more visually enhanced, not only can accurately give the scope of the key body, improve the recognition speed, make the operator's touch more sensitive, but also enhance the appearance of the product's decorative effect. Therefore, the button bulging is increasingly welcomed by users and manufacturers.