Views: 43 Author: Site Editor Publish Time: 2021-01-20 Origin: Site
Metal dome array, is a piece of PET sheet containing a snap dome, used as a switch on PCB or FPC and other circuit boards, and it plays an important role of touch switch between the user and the instrument. Compared with traditional silicone keys, the conductive film has a better hand feel, longer life, and can indirectly improve the production efficiency of various types of switches using conductive film. The metal shrapnel on the custom snap dome patch is located on the conductive part of the PCB board (mostly located above the golden fingers on the circuit board). When pressed, the center point of the shrapnel is concave and touches the circuit on the PCB, thus forming Through the loop, the current passes through, and the whole product can work normally. This is how it works.
We can make the non-standard conductive film (membrane switch) according to the requirements of customers. In fact, this kind of product is made according to the drawings or requirements of customers, and there are no so-called standard parts or stocks. But we can be divided into four categories according to the product structure:
1. Single-layer structure This is the simplest structure at the beginning. The metal shrapnel is located under Mylar (a layer of PET with glue), and there are vents to ensure the basic feel and use.
2. The difference between the double-layer structure and the single-layer conductive film is that it has an extra layer of Spacer (spacer), the shrapnel is better attached to the Mylar, and maintains good contact with the circuit board, and has a better hand feeling ( Some are similar to the bulge' of membrane switches) In addition, the vent holes on the double-layer structure conductive film can more effectively prevent the PET layer from being scratched by the burrs of the shrapnel, and also prevent dust from entering the PET layer.
3. EMI is printed on the top of Mylar (observed from the front of the product), a layer of silver paste is printed - that is, ESD (Electrostatic Discharge Control). EMI is mainly used to prevent static electricity generated by electronics and peripheral products from damaging target electrical appliances.
4. Rubber glue A layer of Rubber glue (silicone) is printed on the Mylar or EMI layer, so this type of product can be firmly glued to PCB/FPC and other circuit boards. Mainly used in mobile phones, Internet phones, various remote controls, MP3/MP4, radios, digital cameras, learning machines, game control keyboards, microwave ovens, car dashboards, binoculars, toys, etc. Compared with the polyester membrane switch used before, it has a better hand feeling and longer service life. Application areas: mobile phones, handheld computers, electronic dictionaries, GPS systems, sales terminals, automotive fields, digital cameras, learning machines, game control keyboard remotes (RKE), toy phones, Internet phones, walkie-talkies, MP3/MP4, CD/VCD/ DVD, microwave oven, dishwasher, dryer, and other electronic products