The secret of membrane switch principle

The emergence of an industrial technology is often the result of the efforts of many people or even generations. The purpose of continuous research and deliberation is to bring people a more comfortable and convenient life. The birth of new industrial products is more subtle. They are integrated into people's daily life. You may not fully understand these products, but you will definitely encounter them in your life. If you know how they work, it can be helpful to solve some small problems. Here is a new type of industrial product, the editor will take you to understand its principle. ?? Membrane switch is an operating system that integrates key functions, indicating elements and instrument panels. It consists of four parts: panel, upper circuit, isolation layer and lower circuit. It is a light touch normally open switch. Under normal circumstances, the upper and lower contacts of the membrane switch are disconnected. When the membrane switch is pressed, the contacts of the upper circuit are deformed downward, making contact with the pole plates of the lower circuit. After the finger is released, the contacts of the upper circuit bounce back, the circuit is disconnected, and the circuit triggers the signal. The membrane switch has compact structure, beautiful appearance and good sealing performance. It has the characteristics of moisture resistance and long service life. Widely used in electronic communications, electronic measuring instruments, industrial control, medical equipment, automotive industry, smart toys, household appliances and other fields.

The multi-layer structure (flat) type (non-locking) key switch composed of a certain elastic insulating material layer is often called a membrane switch. It has the characteristics of beautiful appearance, long service life, simple structure, convenient installation, good use feeling and small footprint. Tact switch market. It has a large share in the market.

The structure of membrane switch: panel, panel glue, upper circuit, isolation layer (circuit key, surface key), lower circuit and glue layer. The mask layer, the upper wiring layer and the lower wiring layer are transparent films. The main materials used are PC, PET, PVC. The material of mask glue, isolation layer and glue layer is double-sided tape (commonly known as sandwich). Key trigger principle: When the mask is not pressed, the isolation layer will isolate the upper and lower lines. When the mask layer is pressed, the upper circuit is activated and overlaps with the lower circuit, making the circuit conductive. Wires provide signals to externally connected devices (substrates). realize its corresponding function. The surface of the substrate should be flat and free of rust, and it should be cleaned with alcohol or gasoline before installation.

The life of the membrane switch can generally reach more than 10,000 times. The action of the switch can only be achieved by the vertical orientation of the elastic membrane. Although the elastic film undergoes a million times of creep, the magnitude of the creep is very small. Only 0.1-0.3MM, plus the rationality of material selection, so the membrane material can withstand more than one million times of ultra-long life without deformation, which determines the durability of the membrane switch.

The sealing requirements are strict, but after the production is completed, the switch contacts will not be eroded by harmful gases, not easy to be oxidized, waterproof, dustproof, oilproof, suitable for various harsh environments. Membrane switches are designed to be arranged to form membrane keyboards, with high density and a hermetically sealed sheet structure composed of multiple layers of membranes. All connections and pin assignments between switches are silkscreened once. The total thickness is 1-3MM. The volume is greatly reduced. Light weight and reliable quality. Compared with traditional mechanical switches, the installation is convenient and simple. Gently stick it, tear off the tape, then fix the surface of the whole machine, insert the lead wire into the circuit socket on the back of the whole machine, the circuit is instantly connected, and it is used after the whole machine is completed. In terms of styling design, according to the user's design concept, the color pattern can reflect the personality, and the decorative effect can reflect the beauty of the material and production process.