When we pull off the key of computer keyboard we see a small hole on the plastic base of keyboard known as Hinge. Below the key there is a long bar which fits on the plastic base. The bar is used to touch the contact layer and holds button bar. When we push it get bounce and when release it, it comes to its real shape and pushes back the button. This little tiny piece of rubber is known as keycups. These keycups work as spring for keys. Below keycup there is circular disc at the top, this circular disc is known as keytop. Keytops play vital role in Keyboard. On the bases of keytops, there is sublimation printing. Sublimation printing is done by painting special ink. Now inside keyboard, there are three green colored LEDs on the PCB(Printed Circuit Board). PCB is connected with connecting cables as well as White colored plastic plate. The white colored plastic plate is known as “Monoblock”. Monoblock is strong housing for switch keys because of molding techniques which provides very tight tolerances for the switch-plunger holes and guides across the width of the keyboard. This gives the key plunger-to-housing clearances. And they were in balanced condition, not too loose or too tight, either of these causes the keys to bind. Between monoblocks there is switch membrane known as contact-switch membrane. In the switch membrane there is a printed inside of top and bottom layer. This causes direct electrical contact when button is pressed on the top layer.
