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How to choose the three materials of PC, PVC and PET for the Membrane panel

The membrane material suitable for making the membrane panel layer, according to its type, we know from the above content that there are often three kinds of PC, PVC and PET:

The comprehensive index of physical properties and chemical properties of PC materials is good, and it is suitable for a wide range of inks. It is the most commonly used material for thin-membrane panel layers in Shanghai.

The price of PVC membrane material is low, about half of that of PC material. When producing popular products for civilian use, if PVC material is selected, the production cost can be reduced. At the same time, PVC material has good ductility and can be processed by cold pressing. Three-dimensional graphics.

The surface state of PET membrane is generally smooth and transparent membrane, and there are also sand-surfaced products in a few cases.

Materials and Characteristics of Membrane Panels

The membrane keys of Xiamen Mingcai membrane panel occupy most of the market with the advantages of low cost, simple process and good hand feel. The keys used in daily life are basically membrane keys. The structure of membrane keys is very simple and can be directly After touching the upper and lower covers and key caps of the keys, you can see the silicone caps, thin-membrane circuits and circuit boards under the keys.

By looking at the thin-membrane circuit, it can be found that it is composed of upper, middle and lower layers, of which the upper and lower layers are printed with conductive paint, and there are corresponding contacts under the buttons. The key part is also provided with circular contacts (or hollowed out), and when the key cap is pressed, the connection between the upper and lower layers of circuits is realized, and corresponding signals are generated.

The keys of Xiamen Mingcai membrane panel can be divided into two structures: crater and scissor foot (X structure). Among them, the crater structure is the most commonly used design in the button. After the button is inserted into the interface on the button, the bottom is directly connected to the silicone The touch of the cap is affected by the length of the key post and the elasticity of the silicone cap. The keys of the crater structure are all designed with high key caps and long key travel, so that a good sense of feedback can be obtained. It's thicker, and the keys are slightly less stable, prone to wobble, and can't get a very consistent feel when clicking. The substrates suitable for making membrane switch panels are PC, PVC, PET, etc.:

Polycarbonate Membrane (PC)

PC material has the distinction of sand surface and smooth surface. The comprehensive index of physical and chemical properties of PC material is better, and it is suitable for a wide range of inks. It is the most commonly used material for membrane panels in Shanghai. Polycarbonate membrane has a wide temperature range (-135~135℃), when the temperature or humidity changes, the performance of this material does not change much, thus ensuring that the panel can be used in various instruments and various harsh environments. . However, its disadvantage is that it is more sensitive to solvents, and the solvent with strong solvation effect is easy to embrittle and crack.

Polyvinyl Chloride Membrane (PVC)

The price of PVC membrane material is low, about half of that of PC material. When producing popular products for civilian use, if PVC material is selected, the production cost can be reduced. At the same time, PVC material has good ductility and can be processed by cold pressing. Three-dimensional graphics. Polyvinyl chloride membrane has poor temperature resistance, especially under high temperature conditions, its softening temperature is 59 ℃, and its elasticity is not as good as that of polycarbonate membrane. But it has a high elongation (130%), and because of its low price, it is suitable for use under general conditions.

Polyester Membrane (PET)

The surface state of the PET membrane is generally a glossy transparent membrane, and in a few cases, there are also products with a sandy surface, such as KB products from Japan's Kimoto Company. Polyester membrane has good elasticity and temperature resistance, and the price is between polycarbonate membrane and polyvinyl chloride membrane. However, because the surface of the membrane is difficult to be processed into a matte texture, it is mostly a transparent sheet. At the same time, the surface of the polyester membrane cannot obtain a satisfactory printing effect for most plastic inks. Generally, special special inks are required to be used. Guarantee good subsequent processing performance. Because the general properties of PET membrane can be replaced by PC membrane, it is not used for Shanghai membrane panel materials too much, except in some special occasions, such as insulation, rebound, solvent resistance, etc., which cannot be used by other membranes. Only a small number of applications are required under the conditions of satisfaction.

The main type of membrane switch Membrane switch panel is a kind of rigid or flexible printed circuit board as the base, with or without touch on the device, and then covered with printed colorful decorative materials Shanghai membrane panel, which integrates switch functions and The electronic component with decorative functions is a new type of human body dialogue interface. The connection method between the switch circuit and the whole machine can be completed by welding or plugging.

What factors should be considered in the selection of Membrane panels

There are many processing methods for Xiamen Mingcai membrane panels, but most of them are printed on the raw materials with some exquisite patterns and signs required by customers. The most important thing is to play a decorative role, and it is still on the surface, so it will not be damaged for a long time. Because printing requires materials, not all membrane materials are suitable for ink printing. The membrane material cannot be too thin, because the material cannot be flattened when printing, which will have an impact on the printing effect. It is also necessary to ensure that the material can be suitable for most of the inks on the market. Different ink manufacturers have different processes, so the quality cannot be guaranteed to be the same.

Xiamen Mingcai membrane panel mainly plays the role of beauty and decoration, so the transparency of the material is very important. At least a transparency of more than 90% must be achieved. Only such materials can be used as the production materials of Shanghai membrane panels, and they must also be able to resist high temperature, sunscreen, waterproof, and friction for a long time. The application range of Shanghai membrane panels and membrane keys is very wide, and each area has different characteristics. For example, it is required to be resistant to high temperature on large-scale high-temperature machinery, and it is required to have the characteristics of sun protection and waterproofing when it is decorated outdoors. .

In the same membrane switch, the size of the metal shrapnel below is generally the same, but the key area above the panel layer is different in size. In such a case, some problems are prone to occur. Since the size of the metal shrapnel of the button is limited, the problem of inaccurate buttons will occur. But how do we avoid this and solve these problems in the process of making and producing?

First of all, because the size of the metal shrapnel is limited, but the drawings provided by our customers are different, and the size of the button display area on the drawings is different. Using the same type of metal shrapnel, such an operator has no way to accurately find the position of the lower metal shrapnel during the operation, and cannot make the current of the lower conductive layer complete the return flow of the circuit and form the current command. instruction.

During the installation process of Xiamen Mingcai membrane switch, the center point of the metal shrapnel must be aligned with the center point of the conductive circuit, and it must be fixed well. The letters above the key display area of the panel layer are generally abbreviated in order to save space, and their size is generally no larger than twice the size of the lower metal shrapnel. If it is too large, the balance will be lost, and the precise position of the metal shrapnel will not be found during the operation.

Types and Structures of Membrane Switch Panels

1. Flat non-tactile type: The service life is about 300,000 times, but there is no tactile feeling (it will be affected according to the use environment)

2. Shanghai membrane switch panel bulging and pressing type: has a good touch, but the service life is relatively short about 300,000-500,000 times (the use environment is affected)

3. Convex frame type non-tactile type: elegant appearance, has a strong sense of plane, but no tactile (the lifespan is the same as that of the plane type)

4. Shanghai membrane switch panel button dome type: elegant appearance, strong sense of plane, and 280g pressing feel (lifespan is more than 600,000 times, the longest lifespan)

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