Touch: long life, but no touch; 2) film convex touch: a good sense of touch, but the service life is relatively short; 3) convex frame type no touch: beautiful appearance, a strong sense of three-dimensionality, but no sense of touch; 4) convex frame touch: beautiful appearance, a strong sense of three-dimensionality, and have a sense of touch; 5) the face of the plate to hit the convex touch type: ( (a) type: the design is not then, easy to have two sections of the phenomenon, but the faceplate damage, electrical performance also exists; (b) type: there is no two sections of the phenomenon, and the structure of the layer is less, more economical, if the faceplate damage, the electrical performance will not exist; (6) the metal shrapnel type: (a) type: for the most basic and the most commonly used structure. Shrapnel both the role of touch and the role of the upper line; (b) type: complex structure, used for more dense shrapnel and do not have to jump the line of the occasion. Shrapnel placed in the upper line, on the upper and lower lines of the conductive surface are up, on the line to be punched. This structure of the four feet and the center of the shrapnel conductive point is not in the same plane, there are "two sections" of the situation. At the same time, the shrapnel is often in excessive anti-concave state, time, the shrapnel will not rebound phenomenon, is not recommended; (c) type: the shrapnel is placed in the upper line, only to play a tactile role, the conductive side of the line on the conductive side down, the conductive side of the line under the upper line, the "two sections" of the situation, is not recommended; (d) type: shrapnel in the lower line, the upper and lower lines need to be punched. Line, the upper and lower lines are aligned, the shrapnel both play a tactile role and the role of the upper and lower lines connected together; for more shrapnel, more dense and do not have to jump the line of the occasion, more (b) type structure is simple. Design should pay attention to the line alignment to avoid the four legs of the shrapnel to ensure that there is no short circuit. (7) light-emitting body type: must open the bottom rubber mold; (a) LED line and the lower line of the same layer: simple structure, but the LED window should be convex, otherwise, the LED lights will top the face plate; suitable for the selection of shorter height of the small LED lights or LED lights less number of occasions; (b) LED line and the lower line of the different layers: complex structure, but the LED window does not have to be convex, suitable for the selection of two-color LED lights or LED lights a greater number of occasions; need to open the punch mold and the bottom of the rubber mold; (8) folded: this type of more to avoid skipping lines and do not need to make the conductive surface can be down, the disadvantages of this structure in the folded easily line is easy to break. (9) inside and outside the frame waterproof type: the outer frame is a closed frame, no line, the inner frame to play a protective role in preventing moisture from the line notch into the chassis.