What is a membrane switch

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. When the membrane switch is pressed, the contacts of the upper circuit deform downwards, and are in contact with the plates of the lower circuit. After the fingers are released, the upper circuit contacts bounce back, the circuit is disconnected, and the circuit triggers a signal. The membrane switch has a rigorous structure, beautiful appearance and good airtightness. It has the characteristics of moisture resistance and long service life. It is widely used in electronic communication, electronic measuring instruments, industrial control, medical equipment, automobile industry, smart toys, household appliances and other fields.

Membrane switch, also known as light touch keyboard, adopts a flat multi-layer combination of integral sealing structure. It is a kind of integration of light, mechanism and electricity that seals the key switch, panel, mark, symbol display and liner together. New electronic components are a fundamental change in the appearance and structure of electronic products. They can replace the buttons of conventional discrete components and perform the tasks of the operating system more reliably.

The membrane switch has good waterproof, dust-proof, oil-proof, harmful gas erosion, stable and reliable performance, light weight, small size, long life, convenient assembly, the panel can be washed without damage to the characters, rich in color, beautiful and generous, etc. advantage. Use membrane switches to make your products more characteristic of the times. The main type of membrane switch The membrane switch panel is a rigid or flexible printed circuit board as the base body, and it is installed with hand-feeling or non-hand-feeling keys, and then covered with plastic (polycarbonate PC, polyester PET) printed with colorful decorative patterns. Etc.) Electronic components composed of thin-film panels and integrating switch functions and decorative functions are a new type of man-machine dialogue interface. The connection between the switch circuit and the whole machine can be done by welding or plugging.

　　Polyvinyl chloride PVC\60℃\0.175~0.5/smooth surface\Stable to acid, alkali and salt under normal temperature. Good abrasion resistance, flame resistance and self-extinguishing, noise reduction and shock absorption, and good electrical insulation. Poor thermal stability. Inexpensive common signs and panels.

Polycarbonate PC\-60~120℃\0.175~1.0\ glossy surface has high light transmittance, low water absorption, good dimensional stability, excellent bending, tensile, and compressive strength, heat resistance, cold resistance, electricity Excellent insulation and weather resistance. Poor chemical resistance, poor fatigue resistance, and stress cracking. The output interface terminal circuit is generally printed with carbon material and has no protective coating. It will gradually form a peeling layer due to air oxidation, which will cause the circuit to be broken and the life will end. This is where the membrane switch is prone to failure. It is mainly determined by the environment. No matter whether it is used or not, the physical damage time is 3-10 years. Generally, it has a wide range of applications. In addition to meeting the requirements of most membrane switch panels, the high light transmittance of glossy PC can also meet the requirements of LCD windows.

　　Sand surface polyester (PET)\-30~120℃\0.1~0.2 smooth surface Good chemical resistance, insoluble in general organic solvents, and not alkali resistant. It has excellent mechanical properties, electrical properties, rigidity, hardness, and greater strength and toughness among thermoplastics, low water absorption, excellent wear and friction resistance, and high dimensional stability. The tensile strength is comparable to that of aluminum film, much higher than that of PC and PVC. Inexpensive Because the surface is difficult to process into a matte type, textured PET is more expensive. It is an ideal substrate for making membrane switch circuits. Among them, textured PET is suitable for products with higher surface requirements or liquid crystal display windows.

Plastic substrate thickness of 0.25mm and below is called film, which is mainly used as the panel layer of membrane switch. Various indicative patterns and texts are printed on the back side to indicate the operation area of the corresponding switch key position. The thickness selection should be based on Depending on the size of the panel and buttons, the material is thick, the touch force is increased, and the response is slow; the material is too thin, the hand feel is poor when touched, and the rebound is not obvious. The thickness of 0.25mm or more is called a plate, which is not suitable for three-dimensional key forming. It can be used as an indicative sign panel for a keyless operation area, and can also be used as a lining board for a membrane switch to improve its hardness.

　　 Line layer printing materials:

　　The substrate for making the circuit should be made of polyester (polyethylene phthalate) film (Potyester referred to as PET). It has good insulation and heat resistance, high mechanical strength, transparency and air tightness, especially bending resistance and high elasticity. It is an ideal material for making membrane switch circuits.