Thin film touch switch structure and forming method thereof
By designing the top surface open-shaped base, conductive shrapnel and tear-slit structure in the light-touch switch, the rosin penetration path is extended, and the problem of rosin affecting conduction in the prior art is solved, and a smaller switching volume and higher switching volume are achieved. conduction reliability.
Patent Information
- Application Number
- CN202411293318.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-14
- Publication Date
- 2024-12-13
AI Technical Summary
During the high-temperature welding process of existing light-touch switches, the rosin produced by the flux causes thermal expansion and contraction, forming gaps and penetrating to the contact point, affecting the conduction performance, resulting in an increase in the volume of the product, making it difficult to achieve lighter and thinner.
Design a thin film light touch switch structure, including an open-shaped base on the top surface, a conductive sheet and a conductive shrapnel are provided in the inner cavity, and the top seals the film and glue dots. The conductive shrapnel is formed between the glue dots and the second conductive sheet by laser welding. The sealing line, the middle part of the conductive shrapnel is raised upward to extend the rosin penetration path, and a tear joint is provided on the conductive shrapnel to block the rosin.
The penetration path of the rosin is effectively extended, allowing it to cool and solidify before reaching the conductive part, reducing the risk of insulation, ensuring the conduction performance of the switch, and reducing the total length and volume of the switch.
Smart Images
Figure CN119132857A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of switch structures, and in particular to a film touch switch structure and a molding method thereof. Background Art
[0002] A touch switch is a switch structure that connects the circuit by lightly pressing the spring. It is thin and small, and is often used in electronic products such as digital 3C, AR / VR, instruments, cameras, wearable devices, etc.
[0003] The pins of the touch switch are soldered by applying solder paste. The solder paste contains a flux. After the flux passes through the high temperature of the furnace, it will produce a gas (rosin), and after cooling, it will form a layer of insulating viscous body; when the rosin is soldered in the furnace, due to thermal expansion and contraction, a gap is formed between the base and the metal surface, and the rosin will penetrate along the gap on the metal surface. If it penetrates into the switch contact point of the product, it will affect the switch conduction performance. The straight-line distance between the contact point and the pin of the existing touch switch is the penetration path of the rosin. The rosin penetration path is short, so before the rosin reaches the switch contact point, the rosin still does not cool and solidify. Therefore, the rosin penetrates to the position of the contact point to form an insulating layer, making the switch ineffective. Therefore, in order to extend the rosin penetration path when designing the existing touch switch, the rosin needs to be increased in width, which increases the volume of the product and makes it difficult to make it thinner. Summary of the invention
[0004] The object of the present invention is to provide a membrane touch switch structure and a forming method thereof in view of the defects and shortcomings of the prior art.
[0005] To achieve the above object, the technical solution adopted by the present invention is: A membrane touch switch structure described in the present invention comprises a base with an open top surface; a first conductive sheet and a second conductive sheet are arranged in the inner cavity of the base; at least one conductive spring sheet is arranged in the inner cavity of the base; a film is arranged on the top surface of the base to seal the top surface of the base; a glue point is arranged between the film and the conductive spring sheet; the first conductive sheet and the second conductive sheet both penetrate the left and right sides of the base; the conductive spring sheet is arranged between the glue point and the second conductive sheet; The first conductive sheet is provided with a first conductive part and two first pins; the first conductive part is provided in the inner cavity of the base; the end of the first pin extends out of the base; a first tear seam is provided on the first conductive sheet; the first pin and the first conductive part are respectively provided on both sides of the first tear seam; a first connecting part for connecting the two first pins is provided in the middle of the first conductive sheet; the first pin is connected to the first conductive part through the first connecting part; The second conductive sheet is provided with a middle connecting sheet and two second pins; the middle connecting sheet is provided in the middle of the inner cavity of the base; the second pins extend out of the second conductive sheet; the second pins are connected to the middle connecting sheet through the second connecting portion; The second conductive sheet is provided with a second tearing seam; the second pin and the middle connecting sheet are respectively provided on both sides of the second tearing seam; The conductive spring sheet is provided with an upwardly protruding shape at a position directly opposite to the middle connecting sheet.
[0006] Furthermore, the first conductive portion is provided with an upward convex shape at an edge close to the first tear seam.
[0007] Furthermore, a slot hole is provided on the top surface of the middle connecting piece.
[0008] Furthermore, the number of the conductive spring sheets is three; the three conductive spring sheets are stacked in a height direction.
[0009] Furthermore, the second pin is provided with a convex strip protruding toward the outside of the base; after the base is formed, the convex strip extends outward.
[0010] Furthermore, the bottom surface of the second conductive sheet is provided with a concave shape.
[0011] Furthermore, the first conductive sheet is in a "U"-shaped structure; the second conductive sheet is in a "T"-shaped structure; an opening is provided in the middle of the first conductive sheet; and the middle connecting sheet extends into the opening.
[0012] A method for forming a membrane touch switch structure comprises the following steps: Step 1: Place the first conductive sheet and the second conductive sheet into a mold, and use an in-mold insert molding process to mold the base formed in the mold and the first conductive sheet and the second conductive sheet into a base assembly with an integrated structure; Step 2: Place the conductive spring into the inner cavity of the base assembly; Step 3: Place the base assembly with the conductive spring in place, first place the glue point and then cover the top surface of the base with a film; Step 4: Use laser welding to weld the glue point and the film together, and fix the edge of the film to the edge of the base, so that a sealing line is formed between the base and the film.
[0013] Furthermore, the surface of the base away from the film is the bottom surface of the base; when the base is molded in the step, glue is injected on one side of the bottom surface of the base; the base is molded by multi-point glue injection; the glue inlet in the mold for molding the base is arranged opposite to the first conductive sheet and the second conductive sheet.
[0014] By adopting the above structure and method, the beneficial effects of the present invention are as follows: the film seals and fixes the glue point and the conductive spring sheet in the inner cavity of the base; the edge of the conductive spring sheet is attached to the first conductive part; and because the middle part of the conductive spring sheet bulges upward and is separated from the middle connecting sheet, the switch is in an off state; by pressing the middle part of the film, the glue point squeezes the middle part of the conductive spring sheet, so that the middle part of the conductive spring sheet is connected to the middle connecting sheet, so that the first conductive sheet is connected to the second conductive sheet through the conductive spring sheet; after releasing the squeezing of the film, the conductive spring sheet resets itself to restore its shape, so that the first conductive sheet is disconnected from the second conductive sheet; the second conductive sheet is pressed and fixed by the plastic edge; in the welding furnace When the rosin of the first pin flows along the first pin, since the first tear seam is filled when the base is formed, a retaining edge is formed at the position of the first tear seam to block the rosin; therefore, the trajectory of rosin penetration needs to reach the first connecting part along the first pin and then enter the first conductive part. Through the first tear seam within the limited length space of the first conductive sheet, the path of rosin penetration can be greatly extended, so that the rosin has cooled and solidified before entering the first conductive part, reducing the chance of rosin solidifying in the first conductive part; similarly, a second tear seam is set between the middle connecting sheet and the second pin, which is also used to extend the path of rosin entering the middle connecting sheet. In this way, under the premise of ensuring that the switch will not be insulated by rosin, the total length of the entire touch switch can be made smaller, and the volume of the switch can be made smaller. BRIEF DESCRIPTION OF THE DRAWINGS
[0015] Figure 1 It is a schematic diagram of the structure of the present invention; Figure 2 is a cross-sectional view of the present invention; Figure 3 It is an exploded view of the first conductive sheet of the present invention using multiple short convex structures; Figure 4 It is an exploded view of the first conductive sheet of the present invention adopting a long convex structure; Figure 5 It is a structural diagram of a combination of a first conductive sheet and a second conductive sheet using a plurality of short convex structures; Figure 6 It is a structural diagram of a combination of a first conductive sheet and a second conductive sheet using a single long convex structure; Figure 7 is a first conductive structure diagram of a plurality of short convex structures; Figure 8 It is a first conductive structure diagram of a single long convex structure; Fig. 9 is a structural diagram of a second conductive sheet; Description of reference numerals: 1. film; 2. base; 201. plastic edge; 3. first conductive sheet; 301. first conductive part; 301a, convex; 302, first pin; 303, first connecting portion; 304, first tear seam; 305, opening; 4, second conductive sheet; 401, second pin; 402, second connecting portion; 403, second tear seam; 404, convex strip; 405, middle connecting piece; 405a, slot hole; 406, concave; 5, glue point; 6, conductive spring DETAILED DESCRIPTION
[0016] The present invention will be further described below in conjunction with the accompanying drawings.
[0017] like Figures 1 to 9 As shown, a membrane touch switch structure of the present invention comprises a base 2 with an open top surface; a first conductive sheet 3 and a second conductive sheet 4 are arranged in the inner cavity of the base 2; at least one conductive spring sheet 6 is arranged in the inner cavity of the base 2; a film 1 is arranged on the top surface of the base 2 to seal the top surface of the base 2; a glue point 5 is arranged between the film 1 and the conductive spring sheet 6; the first conductive sheet 3 and the second conductive sheet 4 both pass through the left and right sides of the base 2; the conductive spring sheet 6 is arranged between the glue point 5 and the second conductive sheet 4; The first conductive sheet 3 is provided with a first conductive part 301 and two first pins 302; the first conductive part 301 is provided in the inner cavity of the base 2; the end of the first pin 302 extends out of the base 2; the first conductive sheet 3 is provided with a first tear seam 304; the first pin 302 and the first conductive part 301 are respectively provided on both sides of the first tear seam 304; the middle part of the first conductive sheet 3 is provided with a first connecting part 303 connecting the two first pins 302; the first pin 302 is connected to the first conductive part 301 through the first connecting part 303; The second conductive sheet 4 is provided with a middle connecting sheet 405 and two second pins 401; the middle connecting sheet 405 is provided in the middle of the inner cavity of the base 2; the second pins 401 extend out of the second conductive sheet 4; the second pins 401 are connected to the middle connecting sheet 405 through the second connecting portion 402; The second conductive sheet 4 is provided with a second tearing seam 403; the second pin 401 and the middle connecting sheet 405 are respectively provided on both sides of the second tearing seam 403; The conductive spring piece 6 is provided with an upward convex shape at a position directly facing the middle connecting piece 405; The first tear seam 304 and the second tear seam 403 are respectively formed on the first conductive sheet 3 and the second conductive sheet 4; The film 1 seals and fixes the glue point 5 and the conductive spring 6 in the inner cavity of the base 2; the edge of the conductive spring 6 is attached to the first conductive part 301; and because the middle part of the conductive spring 6 bulges upward and is separated from the middle connecting piece 405, the switch is in an off state; by pressing the middle part of the film 1, the glue point 5 squeezes the middle part of the conductive spring 6, so that the middle part of the conductive spring 6 is connected to the middle connecting piece 405, so that the first conductive sheet 3 is connected to the second conductive sheet 4 through the conductive spring 6; after releasing the squeezing of the film 1, the conductive spring 6 resets itself to restore its shape, so that the first conductive sheet 3 is disconnected from the second conductive sheet 4; the second conductive sheet 4 is pressed and fixed by the plastic edge 201; During the welding process, the rosin of the first pin 302 flows along the first pin 302. Since the first tear seam 302 is filled when the base 2 is formed, a retaining edge is formed at the position of the first tear seam 304 to block the rosin. Therefore, the trajectory of the rosin penetration needs to reach the first connecting portion 303 along the first pin 302 and then enter the first conductive portion 301. Through the first tear seam 304, the path of the rosin penetration can be greatly extended within the limited length space of the first conductive sheet 3, so that the rosin has been cooled and solidified before entering the first conductive portion 301, reducing the chance of the rosin solidifying in the first conductive portion 301. Similarly, a second tear seam 403 is provided between the middle connecting sheet 405 and the second pin 401, which is also used to extend the path of the rosin entering the middle connecting sheet 405. In this way, the total length of the entire touch switch can be made smaller, and the volume of the switch can be made smaller, while ensuring that the switch will not be insulated by the rosin.
[0018] As a preferred embodiment of the present invention, the first conductive portion 301 is provided with an upward convex shape 301a at an edge close to the first tear seam 304; When the switch is turned on, the conductive spring piece 6 and the convex shape 301a are more easily contacted and conducted, and the base 2 also forms an upward protrusion at the bottom of the convex shape 301a, which enables the first conductive sheet 3 to be on the base 2; the convex shape 301a can be multiple short convex shapes or a long convex shape.
[0019] As a preferred embodiment of the present invention, a slot 405a is provided on the top surface of the middle connecting piece 405; the slot 405a is used not only to enhance the strength of the middle connecting piece 405, but also to form a chip space to accommodate metal chips generated by friction.
[0020] As a preferred embodiment of the present invention, the number of the conductive spring sheets 6 is three; the three conductive spring sheets 6 are stacked in the height direction.
[0021] As a preferred embodiment of the present invention, the second pin 401 is provided with a convex strip 404 protruding toward the outside of the base 2; after the base 2 is formed, the convex strip 404 extends outward, and the convex strip 404 forms a terminal gold leakage mark, which facilitates the judgment of the wiring direction of the switch.
[0022] As a preferred embodiment of the present invention, the bottom surface of the second conductive sheet 4 is provided with a concave shape 406 ; when the base 2 is formed, the inner cavity surface of the base 2 forms a convex shape matching with the concave shape 406 , so as to position the second conductive sheet 4 on the base 2 .
[0023] As a preferred embodiment of the present invention, the first conductive sheet 3 is in a "U"-shaped structure; the second conductive sheet 4 is in a "T"-shaped structure; an opening 305 is provided in the middle of the first conductive sheet 3; the middle connecting sheet 405 extends into the opening 305; the first conductive sheet 3 and the second conductive sheet 4 match in shape, making full use of the space of the base 2, so that the volume of the entire switch structure is smaller.
[0024] A method for forming a membrane touch switch structure comprises the following steps: Step 1, placing the first conductive sheet 3 and the second conductive sheet 4 into a mold, and using an in-mold insert molding process to mold the base 2 formed in the mold and the first conductive sheet 3 and the second conductive sheet 4 into a base assembly with an integrated structure; Step 2, placing the conductive spring 6 into the inner cavity of the base assembly; Step 3: Place the base assembly with the conductive spring 6, first place the glue point 5 and then cover the top surface of the base 2 with a film 1; Step 4: Use laser welding to weld the glue point 5 and the film 1 together, and fix the edge of the film 1 to the edge of the base 2, so that a sealing line is formed between the base 2 and the film 1.
[0025] Furthermore, the surface of the base 2 away from the film 1 is the bottom surface of the base; when the base 2 is formed in step 1, the glue is injected on one side of the bottom surface of the base; the base 2 is formed by multi-point injection; the injection port for molding the base 2 in the mold is arranged opposite to the first conductive sheet 3 and the second conductive sheet 4; A plurality of glue inlets are provided on the mold for molding the base 2. When the base 2 is molded, the first conductive sheet 3 and the second conductive sheet 4 are supported and pressed against the mold surface by the pressure of the glue inlet. In this way, when the base 2 is injection molded, there is no need to support the first conductive sheet 3 and the second conductive sheet 4 with an ejector pin, thereby solving the problem of leakage of the conductive sheet.
[0026] After adopting the above structure, the beneficial effects of the present invention are: 1. Under the premise of ensuring that the switch will not be insulated by rosin, the total length of the entire touch switch can be made smaller and the volume of the switch can be made smaller.
[0027] 2. In addition to increasing the strength of the middle connecting piece, adding slots can also form a chip holding space to accommodate metal chips generated by friction.
[0028] 3. The bottom surface of the second conductive sheet is provided with a concave shape; when the base is formed, the inner cavity surface of the base forms a convex shape matching the concave shape, so as to position the second conductive sheet on the base.
[0029] 4. The first conductive sheet and the second conductive sheet match in shape, which fully utilizes the space of the base and makes the volume of the entire switch structure smaller.
[0030] 5. The film and base are packaged using laser welding technology, which has fast molding efficiency, stronger adsorption, better waterproofness, no rosin, and meets outdoor dust and waterproof requirements; the film and point connection also use laser welding technology, which has stronger welding force and is not easy to fall off.
[0031] The above description is only a preferred embodiment of the present invention, so all equivalent changes or modifications made according to the structure, characteristics and principles described in the scope of the patent application of the present invention are included in the scope of the patent application of the present invention.
Claims
1. A membrane touch switch structure, characterized in that: It comprises a base (2) with an open top surface; the inner cavity of the base (2) is provided with a first conductive sheet (3) and a second conductive sheet (4); the inner cavity of the base (2) is provided with at least one conductive spring sheet (6); the top surface of the base (2) is provided with a film (1) for sealing the top surface of the base (2); a glue point (5) is provided between the film (1) and the conductive spring sheet (6); the first conductive sheet (3) and the second conductive sheet (4) both penetrate the left and right sides of the base (2); the conductive spring sheet (6) is provided between the glue point (5) and the second conductive sheet (4); The first conductive sheet (3) is provided with a first conductive portion (301) and two first pins (302); the first conductive portion (301) is arranged in the inner cavity of the base (2); the ends of the first pins (302) extend out of the base (2); a first tear seam (304) is provided on the first conductive sheet (3); the first pins (302) and the first conductive portion (301) are respectively arranged on both sides of the first tear seam (304); a first connecting portion (303) for connecting the two first pins (302) is provided in the middle of the first conductive sheet (3); the first pin (302) is connected to the first conductive portion (301) via the first connecting portion (303); The second conductive sheet (4) is provided with a middle connecting sheet (405) and two second pins (401); the middle connecting sheet (405) is provided in the middle of the inner cavity of the base (2); the second pins (401) extend to the outside of the second conductive sheet (4); the second pins (401) are connected to the middle connecting sheet (405) via the second connecting portion (402); The second conductive sheet (4) is provided with a second tear seam (403); the second pin (401) and the middle connecting sheet (405) are respectively provided on both sides of the second tear seam (403); The conductive spring sheet (6) is provided with an upwardly protruding shape at a position directly opposite to the middle connecting sheet (405).
2. A membrane touch switch structure according to claim 1, characterized in that: The first conductive portion (301) is provided with an upward convex shape (301a) at an edge close to the first tear seam (304).
3. A membrane touch switch structure according to claim 1, characterized in that: The top surface of the middle connecting piece (405) is provided with a slot hole (405a).
4. A membrane touch switch structure according to claim 1, characterized in that: The number of the conductive spring sheets (6) is three; the three conductive spring sheets (6) are stacked in a height direction.
5. The membrane touch switch structure according to claim 1, characterized in that: The second pin (401) is provided with a convex strip (404) protruding toward the outside of the base (2); after the base (2) is formed, the convex strip (404) protrudes outward.
6. A membrane touch switch structure according to claim 1, characterized in that: The bottom surface of the second conductive sheet (4) is provided with a concave shape (406).
7. A membrane touch switch structure according to claim 1, characterized in that: The first conductive sheet (3) has a "U"-shaped structure; the second conductive sheet (4) has a "T"-shaped structure; an opening (305) is provided in the middle of the first conductive sheet (3); and the middle connecting sheet (405) extends into the opening (305).
8. The method for forming a thin film touch switch structure according to any one of claims 1 to 7, characterized in that: The steps include: Step 1: Place the first conductive sheet (3) and the second conductive sheet (4) into a mold, and use an in-mold insert molding process to mold the base (2) molded in the mold and the first conductive sheet (3) and the second conductive sheet (4) into a base assembly with an integrated structure; Step 2: Place the conductive spring (6) into the inner cavity of the base assembly; Step 3: Place the conductive spring (6) in the base assembly, first place the glue point (5) and then cover the top surface of the base (2) with a film (1); Step 4: Using a laser welding process to weld and fix the glue point (5) and the film (1), the edge of the film (1) is fixed to the edge of the base (2), so that a sealing line is formed between the base (2) and the film (1).
9. The method for forming a thin film touch switch structure according to claim 8, characterized in that: The surface of the base (2) away from the film (1) is the bottom surface of the base; when the base (2) is molded in step 1, glue is injected on one side of the bottom surface of the base; the base (2) is molded by multi-point glue injection; the glue injection port in the mold for molding the base (2) is arranged opposite to the first conductive sheet (3) and the second conductive sheet (4).