This is the simplest structure at the beginning. The metal shrapnel is located under the Mylar (a layer of glued PET). A vent is reserved for each shrapnel in order to have a good rebound and ensure basic feel and use.

Features:
1. The product is light and small.
2. Good feel and rebound, there are air holes in the shrapnel.
3. Mainly used in cheaper single-layer PCB.

Different from the single-layer metal dome array, it has an extra layer of Spacer (spacer), the metal dome is better attached to the Mylar, and maintains good contact with the circuit board, with a better feel. In addition, the vents on the double-layer conductive film can more effectively prevent the PET layer from being scratched by the dome burr, and at the same time prevent dust from entering the PET layer.

Features:
1. The product is light and small.
2. Good feel and rebound, there are ventilation grooves on the spacer.
3. Excellent performance of moisture, heat and cold protection.
4. Due to the use of the spacer, it is equivalent to the sealing and dustproof treatment of the metal dome, and at the same time can prevent the oxidation of the shrapnel itself.

There is a layer of silver paste printed on top of the Myalr, that is, ESD (Electrostatic Discharge Control). EMI is mainly used to prevent the harm of static electricity generated by electronics and its surrounding products to the target electrical appliances.

Features:
1. On the existing metal dome switch, EMI printing is used to control the impedance of the printing surface below 5.0ohms to produce electric wave and electrostatic blocking effect, so as to achieve the effect of floating sound quality.
2. It acts as a protective circuit when static electricity permeates.
3. Compared with the existing single-layer or double-layer metal dome array, the manufacturing engineering is more complicated.
4. Adaptable to the ever-changing climate.

A layer of Rubber glue (silica gel) is printed on top of the Mylar or EMI layer, so this type of product can stick firmly to circuit boards such as PCB/FPC.

Features:
1. Use special glue surface treatment, paste button tightly.
two. On the existing METAL DOME switch, EMI printing is used. The advantage of EMI is that the impedance of the printed surface is controlled below 5.0ohms, which produces electric wave and electrostatic blocking effect, so as to achieve the effect of floating sound quality.
3. It can protect the circuit when static electricity permeates.
4. Adaptable to the ever-changing climate.
5. Compared with the existing single-layer, double-layer, EMI and other structures of metal dome key patch, the manufacturing engineering is more complex.

An additional bump of height 0.1~0.35mm and diameter 1.0mm~3.0mm is added to the Myalr of single-layer or double-layer metal dome switch array to meet the specific structural combination and improve the feel of dome. Use a 4mm or 5mm round dome or elliptical dome with convex metal dome button patch, the total height is 0.35~0.50mm.