Foil type resistance sensitive element

Abstract

The utility model discloses a foil type resistance sensitive element, which comprises a substrate, a protective film adhered to the top of the substrate, a plurality of foil wire grids adhered between the substrate and the protective film, two welding pieces fixedly connected to the inner wall of each foil wire grid, and a plurality of through holes arranged on the protective film. According to the foil type resistance sensitive element provided by the utility model, the through holes are formed in the protective film, when an external lead is welded with the welding sheets by virtue of tin soldering, the lead passes through the through holes to be in contact with the corresponding welding sheets, then tin soldering can be carried out, the flowing range of liquid tin can be limited by the through holes, and the resistance of the foil type resistance sensitive element is improved. And the risk that adjacent soldering tin flows to make contact is reduced, the situation of short circuit or poor welding quality is reduced, and the practicability of the device is improved.

Description

Technical Field

[0001] This utility model relates to the field of sensor technology, and in particular to a foil-type resistive sensing element. Background Technology

[0002] A foil resistive sensor is a sensor element based on a metal foil material, typically used to measure changes in physical quantities such as strain, pressure, force, or torque. When an external force is applied to the foil resistive sensor, its surface undergoes minute deformation, causing a change in resistance. By accurately measuring this change in resistance, physical information related to the external force can be obtained.

[0003] For example, Chinese invention patent (CN108328561A) discloses a metallic glass micron foil resistive strain sensor and its preparation method. It states: "This invention utilizes metallic glass foil as the sensitive material to improve the range and performance of commercially available traditional foil strain sensors, realizing an ideal resistive strain sensor; the preparation process of this invention is compatible with existing foil strain gauge production processes, facilitating its commercialization." It also describes the technical problem: "When the measured strain exceeds this strain range, the sensitive grid inside the strain gauge will undergo plastic deformation, or even break. Although some strain gauges have a strain measurement limit as high as 20%, due to plastic deformation, the strain gauge cannot be reused. Therefore, strain gauges generally only operate within the elastic strain limit range of the sensitive grid."

[0004] In summary, existing technologies utilize coating a layer of adhesive on the surface of a metal-glass sensitive grid to fill the gaps between the grid wires and form a film on the foil grid surface (exposing the soldered ends of the sensitive grid). However, this method has the following technical problems: In practice, foil-type resistive sensitive elements of different sizes exist. When the substrate width is small and the overall shape is close to a long strip, the distance between the two soldered ends of the metal-glass sensitive grid will decrease accordingly. This may cause the two solder balls to accidentally contact each other when the operator connects the soldered ends to the leads by soldering, thereby causing a short circuit. Therefore, this application proposes a foil-type resistive sensitive element to provide a new technical solution to solve the technical problems mentioned in the above-mentioned patent. Utility Model Content

[0005] Therefore, it is necessary to provide a foil-type resistive sensing element to address the above-mentioned technical problems. By opening through holes in the protective film, when external leads are soldered to the solder pads by means of soldering, the leads are passed through the through holes to contact the corresponding solder pads, and soldering can then be performed. The through holes can restrict the flow range of liquid solder, reduce the risk of adjacent solder flowing into contact, reduce the occurrence of short circuits or poor soldering quality, and improve the practicality of the device.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A foil-type resistive sensing element used in sensors.

[0008] The foil-type resistive sensing element specifically includes:

[0009] A substrate, on the top of which a protective film is attached, and between the substrate and the protective film, several foil grids are attached. Two welding pieces are fixedly connected to the inner wall of the foil grids, and multiple through holes are provided on the protective film.

[0010] In a preferred embodiment of the foil-type resistive sensing element provided by this utility model, the number of foil wire grids is at least one, and the number of through holes is at least two.

[0011] As a preferred embodiment of the foil-type resistive sensitive element provided by this utility model, the protective film is made of a transparent material, specifically any one or a mixture of epoxy resin, polyimide, or glass fiber cloth.

[0012] In a preferred embodiment of the foil-type resistive sensing element provided by this utility model, the through hole is circular or elliptical in shape.

[0013] In a preferred embodiment of the foil-type resistive sensing element provided by this utility model, the substrate material is any one of phenolic resin, epoxy resin, polyimide, or glass fiber cloth.

[0014] Compared with the prior art, the present invention has the following beneficial effects:

[0015] The foil-type resistive sensing element provided by this utility model has through holes in the protective film. When the external lead wire is soldered to the soldering plate by means of soldering, the lead wire passes through the through hole and connects with the corresponding soldering plate, and soldering can then be performed. The through hole can limit the flow range of liquid solder, reduce the risk of adjacent solder flowing into contact, reduce the situation of short circuit or poor soldering quality, and improve the practicality of the device.

[0016] The foil-type resistive sensing element provided by this utility model connects the solder pad to the lead wire by soldering. The through hole restricts the flow of solder at high temperature, and the solder flows naturally in the through hole. This makes it easy to completely cover the exposed solder pad with solder, reducing the situation where the exposed part of the solder pad is not completely covered by solder during soldering. This reduces the situation where the solder pad is partially exposed to air after soldering, thereby reducing the risk of the solder pad being corroded.

[0017] The foil-type resistive sensing element provided by this utility model can help control the flow of high-temperature liquid tin by opening through holes, and help the tin to be evenly distributed above the soldering sheet and located in the through holes, thereby reducing the unevenness of soldering. Attached Figure Description

[0018] To more clearly illustrate the solutions in this utility model, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0019] Figure 1 A schematic diagram of the overall structure of the foil-type resistive sensing element provided by this utility model;

[0020] Figure 2 A schematic diagram of the structure of lifting the protective film portion of the foil-type resistive sensing element provided by this utility model;

[0021] Figure 3 A schematic diagram of the separated structure of the foil-type resistive sensing element provided by this utility model;

[0022] Figure 4 A top view of the foil-type resistive sensing element provided by this utility model;

[0023] Figure 5 An enlarged schematic diagram of the foil grid and welding sheet of the foil-type resistive sensing element provided by this utility model.

[0024] The markings in the diagram are explained as follows:

[0025] 1. Substrate; 2. Protective film; 3. Through hole; 4. Foil grid; 5. Welding piece. Detailed Implementation

[0026] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of the present invention.

[0027] As described in the background art, in practice, there are foil-type resistive sensing elements of different sizes. When the substrate width is small and the overall shape is close to a strip, the distance between the two solder ends of the metal glass sensing grid will decrease accordingly. This may cause the two solder balls to accidentally contact each other when the operator connects the solder ends to the lead wire by soldering, thereby causing a short circuit problem.

[0028] To address this technical problem, this invention provides a foil-type resistive sensing element, which is used in sensors.

[0029] For details, please refer to Figures 1-2 The foil-type resistive sensing element specifically includes:

[0030] A base 1 has a protective film 2 attached to its top. Several foil grids 4 are attached between the base 1 and the protective film 2. Two welding pieces 5 are fixedly connected to the inner wall of the foil grids 4. Multiple through holes 3 are provided on the protective film 2.

[0031] The foil-type resistive sensing element provided by this utility model has through holes 3 on the protective film 2. When the external lead wire is soldered to the soldering piece 5 by means of soldering, the lead wire passes through the through hole 3 and contacts the corresponding soldering piece 5, and then soldering can be performed. The through hole 3 can limit the flow range of liquid solder, reduce the risk of adjacent solder flowing to contact each other, reduce the situation of short circuit or poor soldering quality, and improve the practicality of the device.

[0032] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0033] Example 1:

[0034] Please refer to Figures 1-5 A foil-type resistive sensing element, comprising:

[0035] A base 1 has a protective film 2 attached to its top. Several foil grids 4 are attached between the base 1 and the protective film 2. Two welding pieces 5 are fixedly connected to the inner wall of the foil grids 4. Multiple through holes 3 are provided on the protective film 2.

[0036] The minimum number of foil wire grids 4 is one, and the minimum number of through holes 3 is two. Different numbers of foil wire grids 4 can be installed on the substrate 1 according to actual needs. Each foil wire grid 4 is provided with two welding pieces 5, which also corresponds to two through holes 3.

[0037] The protective film 2 is made of a transparent material, specifically one or more of epoxy resin, polyimide, or fiberglass cloth.

[0038] The through-hole 3 is circular or elliptical. It is worth mentioning that the circular and elliptical through-hole 3 have uniform boundaries, which can ensure that the solder can flow evenly into the soldering area during soldering. Holes with corners, such as square or triangular corners, may cause the solder to concentrate or flow poorly, resulting in uneven soldering.

[0039] The material of substrate 1 is any one of phenolic resin, epoxy resin, polyimide or fiberglass cloth.

[0040] With the above structural design, during production, the foil grid 4 needs to be glued to the top of the substrate 1 first, and then the protective film 2 is fixed to the foil grid 4 with glue. At this time, the foil grid 4 is sandwiched between the substrate 1 and the protective film 2. The position of the through hole 3 is aligned with the solder piece 5. Then, the lead wire is passed through the through hole 3 and contacts the solder piece 5. Then, soldering is performed, so that the high temperature solder flows in the through hole 3, covers the solder piece 5, and connects the lead wire to the solder piece 5.

Claims

1. A foil-type resistive sensing element, comprising a substrate (1), characterized in that: A protective film (2) is pasted on the top of the substrate (1), and several foil grids (4) are pasted between the substrate (1) and the protective film (2). Two welding pieces (5) are fixedly connected to the inner wall of the foil grids (4), and multiple through holes (3) are opened on the protective film (2).

2. The foil-type resistive sensing element according to claim 1, characterized in that, The minimum number of the foil wire grid (4) is one, and the minimum number of the through holes (3) is two.

3. The foil-type resistive sensing element according to claim 1, characterized in that, The protective film (2) is made of a transparent material, which is any one of epoxy resin, polyimide or glass fiber cloth.

4. The foil-type resistive sensing element according to claim 1, characterized in that, The through hole (3) is circular or elliptical in shape.

5. The foil-type resistive sensing element according to claim 1, characterized in that, The material of the substrate (1) is any one of phenolic resin, epoxy resin, polyimide or glass fiber cloth.

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