The single-layer structure metal dome conductive film (metal dome sticker) is mainly used in some early membrane switches, contact sheets and other industries. There are also some mobile phones with special structures, such as Moto. single layer structure metal dome. At the same time, if there is not enough height between the Keypad and the PCB or FPC below, it is also necessary to use a single-layer structure of conductive film (Dome sheet), because it is less than a double-layer structure of spacer. So the thickness will be about 0.05mm thinner.
The conductive film of the single-layer metal dome has only one layer of PET, and the metal dome is directly pasted and positioned under the Mylar sheet (English: Mylar, a layer of PET film with glue). At the same time, one or two vents are reserved for each metal dome on the PET, so that the air flow under the metal dome in the pressure will have a good rebound (hand feeling), also known as a single-layer Dome sheet.
The conductive film of the double structure metal dome is similar to the conductive film of the single-layer structure, the difference is that in the double-layer structure of the conductive film, a layer of spacer is added under the Mylar sheet. At the same time, set aside corresponding vent slots on the spacers (single-layer structure is on Myalr). When pressing the metal dome, the air is discharged through the exhaust slot reserved on the spacer, so it can provide better rebound (hand feeling) for each metal dome.
In addition, the spacer layer of the double-layer structure conductive film can also prevent the burrs, drape and other defects of the pan sheet from scratching the PET, and at the same time prevent dust from entering the gap between the PET and the shrapnel, making the product cleaner ,More dustproof. This product is called Double Layer Dome Array in English, also called Double Layer Metal dome Stickers
The conductive film of the double-layer structure metal dome generally uses transparent PET for the top layer (Mylar), while the spacer layer has two options: transparent and white. White is a common practice. If the product is difficult to paste, or you still need to see the bottom PCB or FPC after assembly, you can just choose a transparent spacer
We often encounter phenomena such as weak signal and slow response due to interference caused by electromagnetic waves and electronic components. In order to prevent the product from producing such interference phenomenon, so as to better exert its operating function, we generally screen a layer of silver paste on the surface of Mylar to prevent this interference. EMI structures are generally divided into two types: one is Partially covered "grid-like" structure, one is a structure that completely covers the full screen, the two structures are the same in practical effect (playing the role of shielding interference), which is only different from the degree of appearance effect of different models. The EMI structure has the characteristics of high conductivity and high electromagnetic shielding efficiency.We use a metal shrapnel of 5mm and a strength of 180gf.
The high temperature resistant metal dome sticker uses a round 4mm metal dome with four touch buttons. The operation force of the metal dome has three kinds of 250gf, 300gf, and 350gf. The service life is equal to or greater than 500,000 times and can be at 85℃± It works normally at a temperature of 3°C, the stroke of the metal dome is between 0.1mm-0.3mm, and the maximum engineering range does not exceed 0.3mm. The use of stainless steel sus301 has a good operating feel.
The initial state of the circular metal dome is convex. After receiving a certain amount of force, the metal dome will be concave downward and contact the conductive part of the PCB board below to form electricity. In order to avoid the four contacts on the round 4mm metal dome from deviating from the conductive part during operation, increase the friction between the sticker and the metal dome, so that it will not easily deviate from the position under improper operation.
The heat-resistant metal dome sticker is a single sticker switch with good compatibility and a wide range of applications. It can be applied to various high-temperature products, such as induction cookers, rice cookers, microwave ovens, and electric ovens.
LGF light guide film/light guide sheet, it is to add a layer of LGF to the existing ordinary double-layer structure or EMI structure conductive film to achieve a good light distribution effect. The working principle of LGF light guide film/light guide film is to use the principle of light reflection and refraction, combined with special optical software design, and do microstructure processing on the optical fiber film, thereby expanding the "point light source" into a "surface light source". The light beam propagates out of the medium at a suitable angle and density to achieve an excellent effect of uniform light emission. The LGF conductive film/light guide sheet design can reduce the design of several LED lights and solve the problems of uneven brightness distribution, high power consumption, large space occupation, and high cost.