The working principle of membrane buttons and their common types in instruments and meters
The working principle of membrane keysis that when a key is pressed, the Conductive part under the key (such as conductive adhesive material or metal spring) will contact the preset metal point on the circuit board, thereby connecting the circuit and sending the corresponding command or signal. The following is a detailed introduction to the working principle.
1，When the key is pressed, the panel layer will deform downward, driving the conductive parts on the surface glue layer and the control circuit layer to press down together.
2，If there is a conductive glue material under the key, the conductive glue will contact the metal point on the circuit board, thereby connecting the circuit.
3，If there is a metal shrapnel under the key, the metal shrapnel will be concave and contact the circuit on the PCB, forming a loop and current passing through.
4，When the finger is released, the key and the conductive part will bounce back, the circuit is disconnected, and a key operation is completed.
Advantages:
Membrane keys have the advantages of rigorous structure, beautiful appearance, good sealing, moisture resistance, and long service life.
It is also dustproof, waterproof, and corrosion-resistant, and is suitable for various harsh environments. 6.
In summary, the working principle of membrane keys is to control the contact and separation of the conductive part with the metal point on the circuit board through the pressing and releasing actions of the key, thereby realizing the connection and disconnection of the circuit, and then sending commands or signals to electronic devices.
1. Multilayer membrane keys:
This type of membrane key forms a staggered multilayer structure of resin film and conductive metal film. It has the advantages of high sensitivity and long life. In instruments, the multilayer structure is widely used due to its stability and reliability.
2. Single-layer membrane keypad:
The single-layer structure is a single-layer structure composed of resin film and conductive material. It is characterized by low cost and simple production.
In some instruments and meters that have certain cost requirements, single-layer membrane keys are an economical choice.
3. Metal perforated film buttons:
Different cutting methods are used to perforate conductive metal to form buttons. The distinctive feature is its high water and dust resistance.
It is especially suitable for instruments and meters in harsh environments such as oceans and outdoors to ensure stable operation under harsh conditions.
4. Metal dome (pot) type membrane key:
Use metal dome as the conducting medium. The key has a good feel, uniform force, and high travel accuracy. In instruments and meters, this type is favored for its good feel and accuracy.
Address:2003,LongGuangJiuZuan Building 5A,Tenglong Road，Hongshan, Longhua District, ShenZhen,518131
Email:contact@cmaisilicone.com
