Membrane switch principle membrane switch composit

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Membrane switch, also known as light touch keyboard, adopts the overall sealing structure composed of plane and multi layers. It is a new electronic component integrating light, machine and electricity that seals the key switch, panel, mark, symbol display and lining plate together. It is a fundamental change in the appearance structure of electronic products. It can replace the keys of conventional discrete components and perform the tasks of the operating system more reliably

membrane switch sounds quite professional. In fact, the popular one is panel type button. This name is familiar. Membrane switch is used in the control panel of many devices, which is widely used in electronic communication, electronic measuring instruments, industrial control, medical equipment, automotive industry, intelligent toys, household appliances and other fields. Next, I will introduce the principle and composition of membrane switch

principle of membrane switch

membrane switch is a multi-layer structure (plane) type (non locking) key switch composed of a certain elastic insulating material layer, which is an integrated circuit Buttons, indicating elements, instrument panel and other functions are integrated. The action of the membrane switch is only realized by the elastic membrane bouncing in the vertical direction. Although the elastic membrane has undergone millions of peristalsis, the amplitude of peristalsis is very small, only 0.1-0.3mm. In addition to the rationality of the material selection, the membrane material can withstand more than one million times of large life without deformation, which determines the durability of the membrane switch

membrane switches have the characteristics of beautiful appearance, long service life, simple structure, convenient installation, good hand feeling and small occupied area. They are widely used in all walks of life, ranging from household appliances to high-tech products. They slowly replace some light touch switches in the market and occupy a great share and advantage in the market

membrane switch composition

1. Panel: the panel is the “ Coat ”, On the basis of proper arrangement of keys, different colors, patterns and key shapes play a necessary decorative role for the whole membrane switch. The main function of the panel layer is to mark and press keys, so the selected materials must have the characteristics of high transparency, high ink adhesion, high elasticity, folding resistance, etc

2. Upper and lower circuits: the upper and lower circuits are the electrical components of the membrane switch and also the “ Off &rdquo& ldquo; Key ” Its performance directly affects the performance of switching devices, which is mainly formed by printing a layer of conductive material on the film. The upper and lower circuits play the two necessary roles of electric shock when the switch is closed. Their thickness is generally within 0.05--0.175mm, and the most common is 0.125mm pet

3. Top glue, isolation layer and bottom glue: the materials of these three layers are double-sided glue, which have different names due to their different positions in the switch structure. The thickness of the three layers of double-sided tape varies according to their respective layers, which is mainly determined by the thickness of the switch and the operating force of the key

membrane switches are classified according to structure

1. Planar non tactile type

has long service life, but no tactile

2. The convex tactile type of film

has good tactility, but its service life is relatively short

3. Convex frame non tactile type

beautiful appearance, strong three-dimensional feeling, but no tactility

4. Convex frame tactile type

beautiful appearance, strong three-dimensional sense, and tactile

5. Convex touch type of surface plate

(a): when the design is not appropriate, it is easy to have two sections, but the surface plate is damaged, and the electrical performance also exists

(b) type: there is no two-stage phenomenon, and there are few structural layers, which is more economical. If the surface plate is damaged, the electrical performance will not exist

6, metal shrapnel type

(a): it is the most basic and commonly used structure Shrapnel not only plays the role of tactility, but also plays the role of wiring

(b) type: complex structure, used for occasions with many and dense shrapnel and no jumper The shrapnel is placed on the upper and lower routes, and the conductive surfaces of the upper and lower routes are upward. The upper route needs punching. When this structure is connected, the four legs of the shrapnel are not in the same plane with the center point, and there are “ Two paragraphs ” The situation occurs. At the same time, shrapnel is often in a strong state of excessive anti concave. Over time, shrapnel will not rebound, so it is not recommended to use

(c) type: the shrapnel is placed on the upper line, which only plays the role of touch. The upper line conductivity is facing down, and the lower line conductivity is facing up, with “ Two paragraphs ” Is not recommended

(d) type: the shrapnel is placed on the lower line, and the upper and lower lines have wiring. The shrapnel not only plays the role of touch, but also plays the role of connecting the upper and lower lines; It is used where there are many shrapnel, dense and there is no jumper. Its structure is simpler than that of type (b). During the design, attention should be paid to avoiding the four legs of the shrapnel to ensure that there is no short circuit

7. Luminous type: be sure to open the bottom glue mold

(a) the LED line is on the same layer as the lower line: the structure is simple, but if the selected LED lamp is high, the LED lamp will jack up the panel. At this time, the LED window on the panel should be convex, or the thickness of the surface glue layer should be thickened to make its thickness greater than the thickness of the LED lamp

(b) the LED line is different from the lower line: the structure is complex, but the LED window does not have to be convex, but the upper area of the LED lamp must be hollowed out to prevent light from passing through the LED lamp hole. Note: at this time, it is necessary to avoid wiring around the LED light hole when lowering the line

8. Folding type

this type can avoid jumpers and the conductive surface can be downward without filling holes. The disadvantage of this structure is that the circuit is easy to break at the folding position

9. The inner and outer frame is waterproof

the outer frame is a closed frame without wiring, which protects the inner frame and prevents moisture from entering the chassis from the outlet groove

editor's summary: This is the introduction of the principle and composition of membrane switches. I hope it will be helpful to you. If you want to know more, you can pay attention to information




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