Preparation method of protective layer of strain gauge and strain gauge
Through film cutting, bonding, laser cutting and hot pressing curing, the complex operation and inefficiency of the strain gauge protective layer preparation are solved, and efficient and automated protective layer preparation is achieved, which improves the quality and consistency of the strain gauge.
Patent Information
- Application Number
- CN202510257563.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-03-05
- Publication Date
- 2025-07-04
AI Technical Summary
The existing preparation methods for strain gauge protective layers have problems such as complex operation, serious pollution, low efficiency and unstable product quality.
The protective layer is prepared by means of film cutting, bonding, laser cutting and hot pressing curing, so that the pads of the sensitive gate are exposed outside the protective layer. The film in the pad area is cut by laser cutting equipment, and hot pressing curing is performed in a flat plate hot press.
It realizes simple and efficient protective layer preparation, improves product quality and yield, reduces labor costs, and is suitable for strain gauges of various materials and sizes.
Smart Images
Figure CN120245451A_ABST
Abstract
Description
Technical Field
[0001] The embodiments of the present invention relate to the technical field of sensors, and particularly to a method for preparing a protective layer of a strain gauge and a strain gauge. Background Art
[0002] The structure of a strain gauge consists of a substrate, a sensitive grid (sensitive metal layer), and a protective layer, forming a three-layer structure. The protective layer on the top (outermost layer) can play roles such as waterproofing, moisture-proofing, dust-proofing, mechanical protection, and electrical insulation to ensure the long-term stability of the strain gauge. The coating method and the film laminating method are commonly used methods for preparing the protective layer of the strain gauge.
[0003] The coating method requires the use of colloids, has a strong smell, serious pollution, is unfriendly to operators and the environment, and has complex operations and long processing times. The film laminating method usually cuts the protective layer film into strip-shaped films with the same width as the sensitive grid first, and then manually attaches them to the surface of the sensitive grid with the assistance of a jig. For small-sized sensitive grids, preparation needs to be carried out with the aid of a microscope, with high operation difficulty, low efficiency, and large fluctuations in product quality with personnel, making it difficult to ensure the stability of product quality. Summary of the Invention
[0004] The main technical problem to be solved by the embodiments of the present invention is to provide a method for preparing a protective layer of a strain gauge and a strain gauge, which overcomes or at least partially solves the above problems.
[0005] According to one aspect of the embodiments of the present invention, a method for preparing a protective layer of a strain gauge is provided, including: providing a film and a full-panel strain gauge; cutting the film; laminating and pre-pressing the cut film with the full-panel strain gauge; using a laser cutting device to cut the film in the pad area of the full-panel strain gauge after laminating and pre-pressing; peeling the film in the pad area of the cut full-panel strain gauge; stacking the peeled full-panel strain gauge into a flat hot press for hot pressing and curing.
[0006] In some embodiments, the film includes at least one of polyester resin, epoxy resin, and polyimide resin.
[0007] In some embodiments, after the step of cutting the film, the size of the film is greater than or equal to the size of the full-panel strain gauge.
[0008] In some embodiments, the full-panel strain gauge includes a substrate and a plurality of sensitive grids disposed on the surface of the substrate; after the step of laminating and pre-pressing the cut film with the full-panel strain gauge, the film covers the plurality of sensitive grids.
[0009] In some embodiments, the sensing grid includes at least one of a wire, a metal foil, a thick film metal, and a thin film metal.
[0010] In some embodiments, the sensing grid includes a grid body and pads, the pads are electrically connected to the grid body, and all the pads together form the pad area; after the step of peeling the adhesive film in the pad area of the cut whole - sheet strain gauge, the pads are exposed outside the adhesive film.
[0011] In some embodiments, in the step of stacking the peeled whole - sheet strain gauge into a flat hot press for hot - pressing and curing, the time for hot - pressing and curing is 1 hour to 2 hours.
[0012] In some embodiments, the step of laminating and pre - pressing the cut adhesive film with the whole - sheet strain gauge further includes: laminating the cut adhesive film with the whole - sheet strain gauge using a laminating jig; pre - pressing the laminated adhesive film and the whole - sheet strain gauge using a pre - pressing device.
[0013] In some embodiments, in the step of pre - pressing the laminated adhesive film and the whole - sheet strain gauge using a pre - pressing device, the time for pre - pressing is 5 minutes to 10 minutes.
[0014] According to one aspect of the embodiments of the present invention, a strain gauge is provided, which is prepared by using the above - mentioned method for preparing the protective layer of the strain gauge.
[0015] The beneficial effects of the embodiments of the present invention are as follows: Different from the prior art, the embodiments of the present invention provide a method for preparing the protective layer of a strain gauge, including: providing an adhesive film and a whole - sheet strain gauge; cutting the adhesive film; laminating and pre - pressing the cut adhesive film with the whole - sheet strain gauge; using a laser cutting device to cut the adhesive film in the pad area of the laminated and pre - pressed whole - sheet strain gauge; peeling the adhesive film in the pad area of the cut whole - sheet strain gauge; stacking the peeled whole - sheet strain gauge into a flat hot press for hot - pressing and curing. Through this method for preparing the protective layer of the strain gauge, a protective layer can be covered on the surface of the grid body of the sensing grid, and the pads of the sensing grid can be exposed outside the protective layer, so that the protective layer is not likely to affect the electrical connection between the pads and the outside. The method for preparing the protective layer of the strain gauge is simple and efficient in operation, the size consistency of the prepared protective layer of the strain gauge is good, the quality and yield are high, it is less affected by personnel, the degree of automation is high, the preparation efficiency is high, and the labor cost can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS
[0016] To more clearly illustrate the technical solutions of the embodiments of the present application, the accompanying drawings required for use in the embodiments of the present application will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other accompanying drawings can also be obtained based on the accompanying drawings.
[0017] Figure 1 is a flowchart of a method for preparing a protective layer of a strain gauge according to an embodiment of the present invention;
[0018] Figure 2 is a schematic diagram of a whole - sheet strain gauge before bonding and pre - pressing a glue film according to an embodiment of the present invention;
[0019] Figure 3 is a schematic diagram of a whole - sheet strain gauge after being bonded and pre - pressed with a glue film according to an embodiment of the present invention;
[0020] Figure 4 is a schematic diagram of a whole - sheet strain gauge after peeling off the glue film in the pad area according to an embodiment of the present invention.
[0021] The reference numerals in the drawings are as follows:
[0022] 1. Whole - sheet strain gauge; 11. Substrate; 12. Sensing grid; 121. Grid body; 122. Pad; 13. Pad area;
[0023] 2. Glue film. Detailed implementation manners
[0024] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and detailedly described below in conjunction with the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are some, but not all, of the embodiments of the present application. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.
[0025] The technical features involved in the various embodiments of the present application described below do not conflict with each other and can be combined with each other.
[0026] Although functional module division is carried out in the device schematic diagram and the logical order is shown in the flowchart, in some cases, the module division in the device can be different, or the steps can be executed in an order different from that shown in the flowchart.
[0027] When an element is expressed as "connected" to another element, it can be directly connected to the other element, or there can be one or more intermediate elements therebetween.
[0028] The terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects, rather than to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of this application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are usually of the same category, and the number of objects is not limited. For example, the first object can be one or multiple.
[0029] In addition, "and / or" in the description and claims means at least one of the connected objects. The character " / ", generally represents an "or" relationship between the associated objects before and after.
[0030] The structure of the strain gauge consists of a substrate, a sensitive grid (sensitive metal layer), and a protective layer, which is a three-layer structure. The protective layer on the top (outermost layer) can play the roles of waterproofing, moisture-proofing, dust-proofing, mechanical protection, and electrical insulation to ensure the long-term stability of the strain gauge. The coating method and the film pasting method are commonly used methods for preparing the protective layer of the strain gauge.
[0031] The coating method requires the use of colloid, has a strong smell, serious pollution, is not friendly to operators and the environment, and has complex operations and long processing times. The film pasting method usually cuts the protective layer film into strip-shaped films with the same width as the sensitive grid first, and then manually pastes them on the surface of the sensitive grid with the assistance of a jig. For small-sized sensitive grids, preparation with the aid of a microscope is required, with high operation difficulty, low efficiency, large fluctuations in product quality with personnel, and it is difficult to ensure the stability of product quality.
[0032] The embodiment of the present invention provides a method for preparing a protective layer of a strain gauge. Through this method for preparing the protective layer of the strain gauge, a protective layer can be covered on the grid body surface of the sensitive grid, and the pads of the sensitive grid can be exposed outside the protective layer, so that the protective layer is not likely to affect the electrical connection between the pads and the outside. The method for preparing the protective layer of the strain gauge is simple and efficient in operation, has good dimensional consistency of the prepared protective layer of the strain gauge, high quality and yield, is less affected by personnel, has a high degree of automation, and high preparation efficiency, and can reduce labor costs.
[0033] To facilitate the reader's understanding of the inventive concept of this application, the following specifically describes the steps of the method for preparing the protective layer of the strain gauge:
[0034] Figure 1 The flowchart of the method for preparing the protective layer of the strain gauge according to an embodiment of the present invention is shown. Please refer to Figure 1 and this method includes the following steps:
[0035] Step S1: Provide a film and a full-panel strain gauge.
[0036] In some embodiments, the adhesive film comprises at least one of polyester resin, epoxy resin, and polyimide resin.
[0037] In some embodiments, please refer to Figure 2 , the full - sheet strain gauge 1 includes a substrate 11 and a plurality of sensitive grids 12 disposed on the surface of the substrate 11.
[0038] In some embodiments, the plurality of sensitive grids 12 are uniformly arranged in an array on the surface of the substrate 11, which is beneficial to improving the convenience of preparing the full - sheet strain gauge 1.
[0039] In some embodiments, the sensitive grid 12 comprises at least one of metal wire, metal foil, thick - film metal, and thin - film metal, which is beneficial to expanding the applicable range of the sensitive grid 12.
[0040] Step S2: Cut the adhesive film.
[0041] Among them, step S2 can make the size of the adhesive film match the size of the full - sheet strain gauge, which is beneficial to reducing the possibility of waste of the adhesive film material.
[0042] In some embodiments, after step S2, the size of the adhesive film is greater than or equal to the size of the full - sheet strain gauge, so that the cut adhesive film can cover the full - sheet strain gauge in subsequent steps, which is beneficial to improving the protection effect of the adhesive film on the full - sheet strain gauge. It can be understood that the size of the adhesive film being greater than or equal to the size of the full - sheet strain gauge means that the surface area of the adhesive film is greater than or equal to the surface area of the full - sheet strain gauge. When the shapes of the adhesive film and the full - sheet strain gauge are rectangular, the length of the adhesive film is greater than or equal to the length of the full - sheet strain gauge, and the width of the adhesive film is greater than or equal to the width of the full - sheet strain gauge.
[0043] In some embodiments, in step S2, a cutting device can be used to cut the adhesive film, and the cutting device can be a paper cutter, which is beneficial to improving the cutting progress and efficiency of the adhesive film.
[0044] Step S3: Bond and pre - press the cut adhesive film with the full - sheet strain gauge.
[0045] Please refer to Figure 3 , among which, step S3 can make the cut adhesive film 2 adhere to the surface of the full - sheet strain gauge 1, and the adhesive film 2 can cover the sensitive grid 12.
[0046] In some embodiments, after step S3, the adhesive film 2 covers the plurality of sensitive grids 12, which is beneficial to improving the protection effect of the adhesive film 2 on the sensitive grid 12.
[0047] In some embodiments, step S3 further includes: using a laminating fixture to laminate the cut adhesive film with the full - sheet strain gauge. Using a pre - pressing device to pre - press the laminated adhesive film and the full - sheet strain gauge.
[0048] Among them, the time of the pre - pressing is 5 minutes to 10 minutes, and the temperature of the pre - pressing is 80 °C to 120 °C. It can be understood that the time of the pre - pressing can be adjusted according to the material of the adhesive film, and the temperature of the pre - pressing can also be adjusted according to the material of the adhesive film. The pre - pressing device can be one of a blower box, a dryer, an infrared machine, and a vacuum machine.
[0049] Step S4: Use a laser cutting device to cut the adhesive film in the pad area of the full - sheet strain gauge after lamination and pre - pressing.
[0050] Among them, step S4 is beneficial to the peeling off of the adhesive film in the pad area of the full - sheet strain gauge.
[0051] In some embodiments, please refer to Figure 4 , the sensitive grid 12 includes a grid body 121 and pads 122, the pads 122 are electrically connected to the grid body 121, and all the pads 122 together form the pad area 13.
[0052] Step S5: Peel off the adhesive film in the pad area of the cut full - sheet strain gauge.
[0053] Among them, step S5 can expose the pad area 13 outside the adhesive film 2, which is beneficial to the electrical connection between the pad area 13 and the outside world. However, the grid body 121 of the sensitive grid 12 is still covered by the adhesive film 2, and the adhesive film 2 can protect the grid body 121 of the sensitive grid 12.
[0054] In some embodiments, after step S5, the pads 122 are exposed outside the adhesive film 2, which is beneficial to the electrical connection between the pads 122 and the outside world.
[0055] Step S6: Stack the peeled full - sheet strain gauges into a flat hot press for hot - pressing and curing.
[0056] Among them, step S6 can make the adhesive film in the non - pad area of the full - sheet strain gauge firmly adhere to the full - sheet strain gauge to form a protective layer, which is beneficial to further improving the protection effect of the adhesive film on the grid body of the sensitive grid.
[0057] In some embodiments, in step S6, the time of the hot - pressing and curing is 1 hour to 2 hours. It can be understood that the time of the hot - pressing and curing can be adjusted according to the material of the adhesive film.
[0058] In some embodiments, there are several whole-plate strain gauges after peeling. In step S6, several whole-plate strain gauges after peeling can be stacked and placed on a flat-plate hot press for hot pressing and curing, which is beneficial to improving the efficiency of hot pressing and curing of the whole-plate strain gauges.
[0059] It can be seen that the preparation method of the protective layer of the strain gauge provided in the embodiment of the present invention is simple and efficient to operate, and the prepared protective layer of the strain gauge has good dimensional consistency, high quality and yield, is less affected by personnel, has a high degree of automation, and has high preparation efficiency, which can reduce labor costs. In addition, the preparation method can be used for 1 / 4 bridge structure, 1 / 2 bridge structure and full bridge structure strain gauges, and the applicable sensitive grid materials include wire type, foil type, thick film metal, thin film metal, etc. At the same time, for small-sized and micro-sized strain gauges, compared with the existing preparation methods, the preparation efficiency and quality of the present application are higher, and it is suitable for products of various sizes. In summary, the preparation method of the protective layer of the strain gauge of the present application has a simple operation procedure, is easy for personnel to use, has a short processing cycle and high efficiency, and the protective layer of the strain gauge has high dimensional accuracy, good consistency effect, uniform thickness, and the preparation method is environmentally friendly. Personnel do not need to contact chemicals, and can be applied to a variety of materials and various types of strain gauges.
[0060] An embodiment of the present invention provides a strain gauge, which is prepared by the above-mentioned method for preparing a protective layer of a strain gauge. The strain gauge includes a substrate, a sensitive grid and a protective layer. The sensitive grid is arranged on the surface of the substrate, a portion of the protective layer is arranged on the surface of the substrate facing the sensitive grid, and a portion of the protective layer is arranged on the surface of the sensitive grid away from the substrate. The protective layer covers the grid body of the sensitive grid to protect the grid body of the sensitive grid. The pad of the sensitive grid is exposed outside the protective layer, and the protective layer is formed by the above-mentioned adhesive film.
[0061] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.
Claims
1. A method for preparing a protective layer of a strain gauge, characterized in that, Including: Providing a glue film and a full - sheet strain gauge; Cutting the glue film; Bonding and pre - pressing the cut glue film with the full - sheet strain gauge; Using a laser cutting device to cut the glue film in the pad area of the full - sheet strain gauge after bonding and pre - pressing; Peeling off the glue film in the pad area of the cut full - sheet strain gauge; Stacking the peeled full - sheet strain gauge into a flat hot press for hot - pressing and curing.
2. The method for preparing the protective layer of the strain gauge according to claim 1, wherein The glue film includes at least one of polyester resin, epoxy resin, and polyimide resin.
3. The method for preparing the protective layer of the strain gauge according to claim 1, wherein, After the step of cutting the glue film, the size of the glue film is greater than or equal to the size of the full - sheet strain gauge.
4. The method for preparing the protective layer of the strain gauge according to claim 1, characterized in that, The full - sheet strain gauge includes a substrate and a plurality of sensitive grids disposed on the surface of the substrate; After the step of bonding and pre - pressing the cut glue film with the full - sheet strain gauge, the glue film covers the plurality of sensitive grids.
5. The method for preparing the protective layer of the strain gauge according to claim 4, characterized in that, The sensitive grid includes at least one of metal wire, metal foil, thick - film metal, and thin - film metal.
6. The method for preparing the protective layer of the strain gauge according to claim 4, wherein The sensitive grid includes a grid body and pads, the pads are electrically connected to the grid body, and all the pads together form the pad area; After the step of peeling off the glue film in the pad area of the cut full - sheet strain gauge, the pads are exposed outside the glue film.
7. The method for preparing a protective layer of a strain gauge according to claim 1, characterized in that, In the step of stacking the peeled full - sheet strain gauge into a flat hot press for hot - pressing and curing, the time for hot - pressing and curing is 1 hour to 2 hours.
8. The method for preparing the protective layer of the strain gauge according to claim 1, characterized in that, The step of bonding and pre - pressing the cut glue film with the full - sheet strain gauge further includes: Using a bonding fixture to bond the cut glue film with the full - sheet strain gauge; Using a pre - pressing device to pre - press the bonded glue film and full - sheet strain gauge.
9. The method for preparing the protective layer of the strain gauge according to claim 8, characterized in that, In the step of using a pre - pressing device to pre - press the bonded glue film and full - sheet strain gauge, the time for pre - pressing is 5 minutes to 10 minutes.
10. A strain gauge, characterized in that, Prepared by using the preparation method of the protective layer of the strain gauge according to any one of claims 1 - 9.