CN2279690Y - Film switch - Google Patents

Abstract

The utility model relates to a film switch. The utility model comprises an electric conduction supporting board, a thin film, a rubber dome body and an insulating layer. The thin film is provided with a bottom surface, and the bottom surface of the thin film is printed with a circuit pattern. The rubber dome body is provided with an actuator which is arranged on the thin film, and a thin film switch is actuated by the actuator. The insulating layer is arranged on the presumptive area of the circuit pattern, and the insulating layer is contacted with the electric conduction supporting board. When the dome body is borne by the force, the circuit pattern can be contacted with the electric conduction supporting board, the thin film switch is switched on. When the dome body is not borne by the force, the circuit pattern can not contacted with the electric conduction supporting board, and the thin film switch is switched off.

Description

Thin film switch

The utility model relates to a kind of thin film switch, and it is a kind of one chip macromolecule membrane layer film switch.

Thin film switch has extensively been applied to for example is used for the keyboard of portable computer in the input unit of electronic equipment.Shown in Figure 1A and Figure 1B, traditional thin film switch comprises that a plantation rubber acrosome 11, a supporting bracket 13, a thin layer 12, a conductive pad 111 and are printed on a circuit patterns 121A and the 121B on the thin layer 12.When an external force put on dome body 11 and causes its distortion downwards, conductive pad 111 contacted with circuit patterns 121A and 121B, connects this thin film switch.One commercial popular name of thin layer 12 is that wheat reins in (Mylar).

Conventional films switch shown in Figure 1A and the 1B mainly contains two shortcomings.At first, with the increase of number of operations, the conductive capability of conductive pad 111 may reduce; Oxidation or sulfurization also can cause the reduction of specific conductance in addition.The second, this design need provide a conductive pad 111 at the corresponding inner surface of dome body 11, and this conductive pad 111 needs manufacturing process or the cost on the volume.

The purpose of this utility model is, a kind of thin film switch of designs simplification is provided.

The purpose of this utility model is achieved in that promptly provides a kind of thin film switch, and it comprises: a conductive supporting plate; One film, it has a bottom surface, printed circuit pattern on the bottom surface; One plantation rubber acrosome, it has one and is placed in actuator on the film, that activate this thin film switch; One insulating barrier that is arranged on the circuit patterns presumptive area and contacts with described conductive supporting plate.

The advantage of the utility model thin film switch is that it improves the reliability of conduction, simplifies manufacturing process.

By accompanying drawing, embodiment of the present utility model is described below, wherein:

Figure 1A is the cutaway view of existing thin film switch;

Figure 1B is circuit patterns view in the existing thin film switch;

Fig. 2 A is the utility model first embodiment cutaway view;

Fig. 2 B is the circuit patterns view among the utility model first embodiment;

Fig. 3 is the utility model second embodiment cutaway view.

Shown in Fig. 2 A and 2B, thin film switch of the present utility model has a plantation rubber acrosome 21, the supporting bracket 23 of a conduction, the circuit patterns that a thin layer 22, is positioned at the bottom surface, this pattern comprises pattern 221A, pattern 221B and conductive circuit layer 221C three parts, all is printed in the bottom surface of thin layer 22.The plantation rubber acrosome also has an actuator and is placed on the film to activate this thin film switch.In addition, on conductive circuit layer 221C, print an insulating barrier 26, insulation function is provided and provides thin film switch required minimum constructive height.The thickness of insulating barrier 26 depends on the speed of rebounding of the internal diameter and the switch of dome body 21.In general, the thickness of insulating barrier 26 is between 0.04mm and 0.110mm.The view of circuit patterns 221A, 221B is shown in Fig. 2 B.When dome body 21 is stressed when causing circuit patterns 221A, 221B to contact with conductive supporting plate 23, this thin film switch is connected, and when dome body 21 was not stressed, circuit patterns 221A, 221B did not contact with conductive supporting plate 23, the thin film switch disconnection.

Second embodiment of the present utility model, as shown in Figure 3, it comprises that a plantation rubber acrosome 21, a conductive supporting plate 23, a thin layer 22, are positioned at the conducting channel pattern of bottom surface, and this pattern comprises pattern 221A, 221B and conductive circuit layer 221C three parts, all is printed in the bottom surface of thin layer 22.The plantation rubber acrosome also has an actuator and is placed on the film to activate this thin film switch.In addition, on conductive circuit layer 221C, provide a printing layer 25, to provide thin film switch required minimum constructive height.This printed layers 25 can be electric conducting material or be non-conducting material, between printed layers 25 and conductive supporting plate, prints an insulating barrier 26 again, and insulation function is provided.The gross thickness of insulating barrier 26 and printed layers 25 depends on the speed of rebounding of the internal diameter and the switch of dome body 21, and its general value is between 0.04mm and 0.110mm.The view of circuit patterns 221A, 221B can be with reference to figure 2B.When dome body 21 is stressed when causing circuit patterns 221A, 221B to contact with conductive supporting plate 23, this thin film switch is connected, and when dome body 21 was not stressed, circuit patterns 221A, 221B did not contact with conductive supporting plate 23, the thin film switch disconnection.

Aforesaid circuit patterns is a layer of conductive material in the prior art, and as the colloid of silver or silver/graphite mixture, this colloid at first is printed on the thin layer, dries with proper temperature then.The predetermined edge palpiform of thin layer becomes a golden finger (finger array), this golden finger as with the interface of other electronic equipments.When making golden finger, be usually directed to the printing process of a carbon-coating or graphite linings.Carbon in the utility model or graphite linings 25 can be printed simultaneously when golden finger is printed and finish, and do not need extra process.In order to improve reliability, generally speaking, can be in the bottom surface of thin layer 22 provide one deck insulating varnish (paint), to prevent between circuit patterns or the short circuit of 23 of conductive circuit layer 221C and conductive supporting plates.Therefore, insulating barrier 26 also can be printed simultaneously when insulating varnish is printed and finish.

Claims (8)

1, a kind of thin film switch is characterized in that, it comprises: a conductive supporting plate; One film, it has a bottom surface, printed circuit pattern on the bottom surface; One plantation rubber acrosome, it has one and is placed in actuator on the film, that activate this thin film switch; One insulating barrier that is arranged on the circuit patterns presumptive area and contacts with described conductive supporting plate.

2, thin film switch as claimed in claim 1 is characterized in that, described insulating barrier is printed on the presumptive area of circuit patterns.

3, thin film switch as claimed in claim 1 is characterized in that, the thin layer that described insulating barrier is established for other.

4, a kind of thin film switch is characterized in that, it comprises: a conductive supporting plate; One film, it has a bottom surface, printed circuit pattern on the bottom surface; One plantation rubber acrosome, it has one and is placed in actuator on the film, that activate this thin film switch; One printed layers, it is arranged on the presumptive area of described circuit patterns; One insulating barrier is between described printed layers and described conductive supporting plate.

5, thin film switch as claimed in claim 4 is characterized in that, described insulating barrier is printed on the presumptive area of described printed layers.

6, thin film switch as claimed in claim 4 is characterized in that, the thin layer that described insulating barrier is established for other.

7, thin film switch as claimed in claim 4 is characterized in that, described printed layers is a non-conducting material.

8, thin film switch as claimed in claim 4 is characterized in that, this printed layers is an electric conducting material.

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