The substrate of membrane switch, which is generally used in PET/PC. Among them, PET is used more and is also known as a high-temperature-resistant polyester film. It is a thin, flex, transparent sheet, made of plastic material. With excellent heat resistance, dimensional stability, good transparency, etc.
1. It is flexiable, can be bent
PET is often as the best material of flexiable circuit board printed, because is so flexiable, can be bent. Just for such its properties, people found that FPC membrane switch can be utilized for some wearable devices ,such as socks , cold suit and warming pad, which can warming bodies in extremely cold weather. In general, PET Material sheet can be used for wearable devices in largely .
2. Formed easily, cutting to various shape pieces any time
PET is thin piece, more easilier to be cutted into many small size pieces according to different demands. Sometimes, a piece of big size thin piece can cut into various shaped pieces of substrate for electric circuit printing. even cutting it is simply and easy thing. A knife or cutting and stamping machine all finish it.
3. Printable, has a strong adhension force, color is not fade off
As the printing substrate for Flexiable Electric circuit layer, which can directly print any paint on it without any treatment of the surface. Generally, we can print some of electric circuits with silver or carbon ink on the PET sheet, which is known as a controlling circuit to complete some functions for a membrane switch. So it have had same functions as some of PCB board, one differnet point, that is it is flexiable , and easy to bend available.
After the silver or carbon ink pinted on the shaped PET sheet, they will have a strong adhension force. This due to PET special properties, which it can have a strong adsorption capacity for inks printed on it. So ink is not fall off and color is not fade off.
4. It is chemical erosion protection, use normally in special environments
Membrane switches for Some of Inspection and testing instruments in special environments, they need more rigid requirements in its electric circuit and operation interface. Because of some special reasons, these equipments are exposed in strong acid and alkali atomsphere an air. PET is what they choose best. they choose PET sheet as the substrate of printed circuit for membrane switch.
5. Good Mechanical Strength, Flat and not any crease
As PET material , which good mechnical strength, flat, never any crease found. it is flex,so easy to be bent, but it still be flat, have a good strength property, and toughness. As the electric circuit is on base of PET substrate, has a good strength, too, can have a good angle bending comes with body’s part when it is used for wearable device. This is its advantage of mechanical strength.