A membrane switch

Abstract

The film switch comprises a partition plate and a diaphragm attached to the upper and lower sides of the partition plate, a vertical through hole is formed in the partition plate, a pressing cavity is formed by the inner wall of the through hole and the opposite side surface of the diaphragm, a contact and a conductive wire formed by solidifying conductive paste coated on the surface of the diaphragm are arranged in the pressing cavity, a relay part is arranged on the opposite side surface of the diaphragm, the relay part is located at the opening of the through hole, the inner and outer edges of the relay part are located on the inner and outer sides of the inner wall of the through hole, the length of the relay part in the circumferential direction of the through hole is greater than or equal to the width of the conductive wire, the thickness of the relay part is equal to the thickness of the conductive wire, the inner edge of the relay part is in conduction with the contact through the conductive wire, and the outer edge of the relay part is in conduction with the circuit outside the pressing cavity, so that the pressing signal can be transmitted by the relay part and the pressure can be received by the relay part, at least two relay parts are arranged at intervals, the receiving area can be effectively increased, multi-point support can be formed, the pressure can be reduced, long-term pressing can be adapted, and the service life can be prolonged.

Description

Technical Field

[0001] This invention belongs to the field of electrical switch technology, specifically relating to a membrane switch that can be pressed for a long time and has a long service life. Background Technology

[0002] Membrane switches are a new type of electronic switch used to control the on / off state of their circuits and are widely used in assembling various keypads, computer keyboards and other products.

[0003] Most existing membrane switches consist of a partition and diaphragms attached to both sides of the partition. The partition has through holes punched in it, and the edges of these openings are sharp and prone to leaving burrs. The inner wall of the through holes and the opposing surfaces of the diaphragms form a pressing cavity. When pressed, the diaphragms deform to bring the contacts on their surfaces into contact, and then the signal is transmitted through the conductive wires on the diaphragms. For the signal to be transmitted, the conductive wires need to pass through the openings of the through holes. When pressed, the diaphragms are subjected to force and the force is transmitted to the surrounding areas. Pressure is applied to the conductive wires through the openings of the through holes, creating pressure. Because the conductive wires are narrow and protrude from the diaphragm surface, and because they only pass through the openings of the through holes at one point, the pressure on the conductive wires at the openings of the through holes is high. The sharp edges and residual burrs at the openings of the through holes can easily compress the conductive wires under strong pressure, or even cut into them. After long-term pressing, this can damage the wires, leading to open circuits or poor contact, and affecting the service life of the membrane switch. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the prior art and provide a membrane switch that can be pressed for a long time and has a long service life.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is a membrane switch, comprising a partition extending in a horizontal direction and a diaphragm attached to the upper and lower sides of the partition. The partition has a vertical through hole, and the inner wall of the through hole and the opposing side surface of the diaphragm form a pressing cavity. The pressing cavity is provided with contacts and conductive wires, and the contacts and conductive wires are formed by curing a conductive paste coated on the surface of the diaphragm. The diaphragm also has a relay portion on its opposing side surface. The relay portion is located at the opening of the through hole. The inner and outer edges of the relay portion are located on the inner and outer sides of the inner wall of the through hole, respectively. The length of the relay portion in the circumferential direction of the through hole is greater than or equal to the width of the conductive wire. The thickness of the relay portion is equal to the thickness of the conductive wire. The inner edge of the relay portion is connected to the contact point through the conductive wire. The outer edge of the relay portion is connected to the circuit located outside the pressing cavity. There are at least two relay portions, which are arranged at intervals.

[0006] Preferably, the included angle between the two relays in the circumferential direction of the through hole is greater than or equal to 30°.

[0007] More preferably, the included angle is 45°, 135° or 180°.

[0008] Preferably, the distances between the inner and outer edges of the relay section and the inner wall of the through hole are equal.

[0009] More preferably, the distance is greater than or equal to 0.1 mm.

[0010] Preferably, all the relay units are interconnected to form a complete ring or a ring with an opening.

[0011] More preferably, the inner edge of the relay portion and the outer edge of the contact are integrated.

[0012] Preferably, the relay section is composed of the portion of the conductive wire passing through the opening of the through hole.

[0013] Preferably, the relay section is also formed by curing a conductive paste coated on the surface of the diaphragm.

[0014] Preferably, there are at least two conductive wires between the relay and the contact.

[0015] Due to the application of the above technical solution, the present invention has the following advantages compared with the prior art: 1. The inner edge of the relay section is connected to the contact point through a conductive wire, and the outer edge of the relay section is connected to the circuit outside the pressing cavity. This allows the relay section to transmit pressing signals and also to receive the pressure applied by the through hole opening.

[0016] 2. By having at least two relay sections spaced apart, the total bearing area of ​​the relay sections can be effectively increased and multiple points of support can be formed, thereby reducing pressure. Under the same pressing force, the depth of the through hole opening edge and burrs pressed into the relay section is shallow, making it less likely to cut off the relay section. This allows it to adapt to long-term pressing and extend its service life. Attached Figure Description

[0017] Figure 1 This is a top view of Embodiment 1 of the present invention. For ease of observation, the colors of the partition and the membrane itself have been omitted.

[0018] Figure 2 yes Figure 1 Cross-sectional view along the AA direction.

[0019] Figure 3 yes Figure 1 A schematic diagram of the unfolded structure after being split in half along the thickness direction.

[0020] Figure 4 This is a schematic diagram of the unfolded parts after being split in half along the thickness direction according to Embodiment 2 of the present invention.

[0021] Figure 5 This is a schematic diagram of the unfolded parts after being split in half along the thickness direction according to Embodiment 3 of the present invention.

[0022] Figure 6 This is a schematic diagram of the unfolded parts after being split in half along the thickness direction according to Embodiment 4 of the present invention.

[0023] Figure 7 This is a schematic diagram of the unfolded parts after being split in half along the thickness direction according to Embodiment 5 of the present invention.

[0024] Among them: 10. partition; 11. through hole; 20. diaphragm; 21. relay section; 30. pressing cavity; 41. contact point; 42. conductive wire; 50. unfolding line; 60. circuit. Detailed Implementation

[0025] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that the advantages and features of the present invention can be more easily understood by those skilled in the art, thereby providing a clearer and more explicit definition of the scope of protection of the present invention.

[0026] The vertical direction described in this invention refers to Figure 2 The up and down directions in the middle.

[0027] Example 1: like Figures 1 to 3 As shown, the membrane switch provided by the present invention includes a partition 10 extending horizontally and a diaphragm 20 attached to the upper and lower sides of the partition 10. A vertical through hole 11 is formed on the partition 10. The inner wall of the through hole 11 and the opposing surface of the diaphragm 20 form a pressing cavity 30. A contact 41 and a conductive wire 42 are provided inside the pressing cavity 30. The contact 41 and the conductive wire 42 are formed by curing a conductive paste coated on the surface of the diaphragm 20. A relay portion 21 is also provided on the opposing surface of the diaphragm 20. Located at the opening of the through hole 11, the inner and outer edges of the relay part 21 are located on the inner and outer sides of the inner wall of the through hole 11, respectively. The length of the relay part 21 in the circumferential direction of the through hole 11 is equal to the width of the conductive wire 42. The thickness of the relay part 21 is equal to the thickness of the conductive wire 42. The inner edge of the relay part 21 is connected to the contact 41 through the conductive wire 42. The outer edge of the relay part 21 is connected to the circuit 60 located outside the pressing cavity. There are two relay parts 21, which are arranged alternately.

[0028] The advantage of this setting is that: 1. It can both transmit pressing signals using the relay section and receive pressure applied by the through hole opening using the relay section.

[0029] 2. It can effectively increase the total bearing area of ​​the relay section and form multi-point support, thereby reducing pressure. Under the same pressing force, the depth of the through hole opening edge and burrs pressed into the relay section is shallow, making it less likely to cut off the relay section. This allows it to adapt to long-term pressing and extend its service life.

[0030] To ensure the support effect of the relay section, the distance between the inner and outer edges of the relay section 21 and the inner wall of the through hole 11 is equal. This distance should ensure that, when the through hole 11 is within the allowable error range, the inner wall of the through hole 11 is between the inner and outer edges of the relay section 21. At the same time, this distance should also be greater than the maximum allowable residual burr length at the opening of the through hole 11. Generally speaking, the punching tolerance of the through hole 11 is 0.03-0.05mm, and the allowable residual burr length is about 0.02mm. In addition to the safety margin, in this embodiment, this distance is set to be greater than or equal to 0.1mm. To save costs and facilitate manufacturing, the fluctuation range of this distance should be controlled below 10%, that is, the distance is greater than or equal to 0.1mm and less than or equal to 0.11mm.

[0031] In this embodiment, for ease of processing, the relay part 21 is composed of the portion of the conductive wire 42 passing through the opening of the through hole 11. That is to say, the relay part 21 is also formed by curing the conductive paste coated on the surface of the diaphragm 20, and the conductive paste has the same composition as the conductor paste that constitutes the contact and the conductive wire, which is conductive silver paste.

[0032] There are two conductive wires 42 between the relay part 21 and the contact 41, which are used to form two relay parts 21. The included angle between the two relay parts 21 in the circumferential direction of the through hole 11 is greater than or equal to 30°. The advantage of this setting is that it can increase the support spacing. When the pressing pressure is biased towards one of the relay parts 21, causing that relay part 21 to be pressed in or even cut off, the pressing depth of the other relay part 21 is reduced, and it is prevented from being cut off. This ensures that there is always a relay part that can conduct signals, thereby adapting to long-term pressing and extending the service life. In order to facilitate the integration into the existing production system, the included angle is preferably 45°, 135° or 180°. In this embodiment, the included angle is 45°.

[0033] Example 2 like Figure 4 As shown, Embodiment 2 is basically the same as Embodiment 1. The difference is that in Embodiment 2, several relays are provided between the two relays 21. All relays 21 are connected to form an open ring. The advantage of this arrangement is that it can further increase the total bearing area of ​​the relays, greatly reduce the pressure, avoid the cutting phenomenon, and thus adapt to long-term pressing and extend the service life.

[0034] Example 3 like Figure 5As shown, Embodiment 3 is basically the same as Embodiment 2, except that in Embodiment 3, only one conductive line 42 is retained between the contact 41 and the relay part 21. This arrangement can further reduce costs while ensuring signal transmission and service life.

[0035] Example 4 like Figure 6 As shown, Embodiment 4 is basically the same as Embodiment 2, except that in Embodiment 4, the inner edge of the ring formed by the relay part 21 is connected to the outer edge of the contact 41, which can reduce the control difficulty during the coating of conductive wires and facilitate efficient production.

[0036] Example 5 like Figure 7 As shown, Embodiment 5 is basically the same as Embodiment 2, except that all relay parts 21 are connected to form a complete ring (relay ring). To further reduce costs, only one conductive line 42 is retained between the contact 41 and the relay part 21. The relay part 21 is not composed of the part of the conductive line 42 passing through the opening of the through hole 11, but is formed by the curing of conductive carbon paste coated on the surface of the diaphragm 20. Since the paste does not contain silver, its cost is greatly reduced. Moreover, the hardness of the cured conductive carbon paste is much greater than that of the conductive silver paste, and the support is stronger. This can further reduce the depth of the through hole opening edge and burrs pressed into the relay part, avoid the phenomenon of the relay part being cut off, thereby adapting to longer pressing and further extending the service life.

[0037] It should be noted that the pressing chamber of this membrane switch must be connected to the outside world in order to be pressed. The connection method can be achieved by setting an exhaust channel or exhaust hole, etc. (not shown in the figure).

[0038] The above embodiments are only for illustrating the technical concept and features of the present invention, and are intended to enable those skilled in the art to understand the content of the present invention and implement it accordingly. They should not be construed as limiting the scope of protection of the present invention. All equivalent changes or modifications made in accordance with the spirit and essence of the present invention should be covered within the scope of protection of the present invention.

Claims

1. A membrane switch, comprising a partition extending in a horizontal direction and a diaphragm attached to the upper and lower sides of the partition, wherein a vertical through hole is formed in the partition, the inner wall of the through hole and the opposing side surface of the diaphragm form a pressing cavity, the pressing cavity is provided with a contact and a conductive wire, the contact and the conductive wire being formed by curing a conductive paste coated on the surface of the diaphragm; Its features are: The diaphragm also has a relay portion on its opposing side surface. The relay portion is located at the opening of the through hole. The inner and outer edges of the relay portion are located on the inner and outer sides of the inner wall of the through hole, respectively. The length of the relay portion in the circumferential direction of the through hole is greater than or equal to the width of the conductive wire. The thickness of the relay portion is equal to the thickness of the conductive wire. The inner edge of the relay portion is connected to the contact point through the conductive wire. The outer edge of the relay portion is connected to the circuit located outside the pressing cavity. There are at least two relay portions, which are arranged at intervals.

2. The membrane switch according to claim 1, characterized in that: The angle between the two relays in the circumferential direction of the through hole is greater than or equal to 30°.

3. The membrane switch according to claim 2, characterized in that: The included angle is 45°, 135° or 180°.

4. The membrane switch according to claim 1, characterized in that: The distances between the inner and outer edges of the relay section and the inner wall of the through hole are equal.

5. The membrane switch according to claim 4, characterized in that: This distance is greater than or equal to 0.1 mm.

6. The membrane switch according to claim 1, characterized in that: All the aforementioned relays are connected to form a complete ring or a ring with an opening.

7. The membrane switch according to claim 6, characterized in that: The inner edge of the relay unit is connected to the outer edge of the contact point.

8. The membrane switch according to claim 1, characterized in that: The relay section is also formed by curing a conductive paste coated on the surface of the diaphragm.

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