A connection method for improving the electrical lap joint performance of a glue film composite copper mesh

Abstract

The present invention belongs to the field of circuit processes, and particularly relates to a connection method for improving the electrical lap joint performance of a film composite copper mesh. During the forming process of the composite structure of the airframe, an insulating adhesive layer is formed at the interface between the copper mesh and the copper sheet, and the area and thickness of the adhesive liquid are randomly generated, and the electrical lap joint performance cannot meet the design requirements. The connection method of the present invention includes removing the film of the film composite copper mesh in the area where electrical lap joint is required; cleaning the area where the film is removed, using a clean and oil-free metal plate as a support backing plate, placing the film composite copper mesh with the film removed on the metal plate, laying a layer of filter paper between the metal plate and the composite copper mesh, selecting an oil painting brush to dip an appropriate amount of methyl ethyl ketone or alcohol and gently and repeatedly brush the area where the film is removed until the solvent on the filter paper does not change color significantly; selecting a copper sheet consistent with the copper mesh material and performing surface treatment; welding the copper sheet. It can effectively solve the problems of easy damage to the electrical lap joint interface and unstable lap joint performance of the film composite copper mesh composite material.

Description

Technical Field

[0001] The present invention belongs to the field of circuit processes, and particularly relates to a connection method for improving the electrical lap joint performance of a film composite copper mesh. Background Art

[0002] As Figure 1 shown, a metal connection frame 2 is provided inside a helicopter tail beam 1. To avoid damage to the helicopter caused by lightning strikes, a copper mesh 4 is often laid on the surface of the composite material structure 3 of the helicopter tail beam 1 to achieve the function of conducting current. At the same time, a large number of communication and navigation devices are installed on composite material parts, which poses relatively high requirements for the conductivity of the connection path between the parts and the devices (see Figure 1 ).

[0003] With the development of materials, in order to improve the overall performance of the helicopter, a weight reduction design is carried out on the helicopter, and the film composite copper mesh has been widely used in the composite material body structure of the helicopter. The conventional operation is to directly place the copper sheet 5 in Figure 1 on the film composite copper mesh. An airborne equipment connection point 6 is provided on the copper sheet 5. During the forming process of the composite material structure of the body, the glue carried by the composite material and the glue liquid on the film composite copper mesh will flow under heat and penetrate into the interface between the copper mesh and the copper sheet under the action of pressure to form an insulating glue layer, and the area and thickness of the glue liquid are randomly generated. This operation directly results in that the electrical lap joint performance of a large number of communication and navigation devices cannot meet the design requirements and the product quality is extremely unstable.

[0004] In addition, once the electrical lap joint of the composite material structure is unqualified, the electrical lap joint part must be repaired. The repair method is as follows: First, the copper sheet at the electrical lap joint point is peeled off, and then the interface between the copper mesh and the copper sheet is polished to remove the insulating layer. Since the copper mesh is extremely fine (the wire diameter is only 0.05 mm), the copper mesh is often polished off, directly causing the circuit to be interrupted. If the polishing is not in place, it is extremely easy to cause the electrical lap joint performance of the subsequent film composite copper mesh composite material to be unqualified. The repair is not only difficult to operate, greatly increases the manufacturing cost, but more importantly, the repair effect is poor and it is difficult to meet the design requirements. Summary of the Invention

[0005] Objective of the present invention: To solve the problem that the electrical lap joint interface of the film composite copper mesh composite material is easily damaged.

[0006] The present invention provides a connection method for improving the electrical lap joint performance of a film composite copper mesh, which is characterized in that the method includes the following steps:

[0007] S1. Remove the glue film of the film composite copper mesh in the area where electrical lap joint is required;

[0008] S2. Clean the area where the glue film is removed

[0009] Use a clean and oil-free metal plate as the support liner, place the composite copper mesh with the adhesive film removed on the metal plate, and place a layer of filter paper between the metal plate and the composite copper mesh. Select an oil painting brush, dip it in an appropriate amount of methyl ethyl ketone or alcohol, and gently and repeatedly brush the area where the adhesive film has been removed until the solvent on the filter paper does not change color significantly;

[0010] S3. Select a copper sheet consistent with the copper mesh material and perform surface treatment

[0011] Clean the copper sheet and tin-plate one side;

[0012] S4. Weld the copper sheet

[0013] Place the side of the copper sheet with the tin layer in the center against the composite copper mesh with the adhesive film removed. Heat the soldering iron and press the tip of the soldering iron from the bottom on the center of the copper sheet. When the tin layer starts to melt from the center, keep an appropriate force and move the tip of the soldering iron in a spiral trajectory with the center of the copper sheet as the origin, and press the copper mesh into the melted tin layer to connect with the copper sheet.

[0014] Advantageously, in step S1, use a utility knife to draw a circle on the protective film of the adhesive film composite copper mesh according to the template. Place the adhesive film composite copper mesh at room temperature not exceeding 30°C to warm up. After waiting for the adhesive film to have adhesiveness, remove the protective paper on the surface of the adhesive film composite copper mesh in the area where the circle is drawn.

[0015] Advantageously, the waiting time is about 0.5 hours.

[0016] Advantageously, remove it by tearing or sticking according to the viscosity and density of the adhesive film.

[0017] Advantageously, when sticking, use a single-sided tape to stick away the softened adhesive film in multiple times.

[0018] Advantageously, the adhesive force of the single-sided tape is 3.5 - 4.5 N / cm.

[0019] Advantageously, in step S2, it is necessary to select an oil painting brush that does not shed hair.

[0020] Advantageously, the width of the oil painting brush is 5 - 7 mm.

[0021] Advantageously, in step S2, the thickness of the tin layer is controlled at 8 - 12 μm.

[0022] Advantageously, in step S4, heat the soldering iron to 195 ± 10°C.

[0023] Beneficial effects: It can effectively solve the problems of easy damage to the electrical lap interface and unstable lap performance of the adhesive film composite copper mesh composite material. Description of the Drawings

[0024] The exemplary embodiments and preferred modes of use, other objects and descriptions thereof will be best understood by reference to the following detailed description of examples of the invention when read in conjunction with the accompanying drawings, in which:

[0025] Figure 1 It is an electrical bonding structure diagram at the helicopter tail boom. Detailed implementation manners

[0026] The disclosed examples will be described more fully with reference to the accompanying drawings, in which some, but not all, of the disclosed examples are shown. In fact, many different examples may be described and these examples should not be construed as limited to the examples set forth herein. Rather, these examples are described so that this disclosure will be thorough and complete and will fully convey the scope of the disclosure to those skilled in the art.

[0027] An embodiment of a connection method for improving the electrical bonding performance of a glue film composite copper mesh includes the following steps:

[0028] S1. Remove the glue film in the area of the glue film composite copper mesh that needs electrical bonding

[0029] Use a craft knife to draw a circle on the protective film of the glue film composite copper mesh according to a template (1 mm larger than the diameter of the electrical bonding copper sheet) so as not to damage the copper mesh. Place the glue film composite copper mesh at room temperature (≤30°C) to warm up, and remove the protective paper in the circular area on the surface of the glue film composite copper mesh. In this embodiment, after waiting for about 0.5 hour, the glue film on the surface of the glue film composite copper mesh has adhesiveness, and use a single-sided tape (3.5 - 4.5 N / cm) to stick away the softened glue film in multiple times. It should be noted that if the viscosity of the tape is too high, it is very easy to tear or stretch and deform the copper mesh; if the viscosity is too low, the glue film cannot be effectively removed.

[0030] S2. Clean the area where the glue film is removed

[0031] Use a clean and oil-free metal plate as a support liner, place the composite copper mesh with the glue film removed on the metal plate, and place a layer of filter paper between the metal plate and the composite copper mesh. Select a non-fuzzy oil painting brush (width 6 mm), dip it in an appropriate amount of methyl ethyl ketone or alcohol, and gently brush it repeatedly until the solvent on the filter paper does not change color significantly. Tools such as wiping cloths or cotton swabs that can scratch the copper mesh cannot be selected, and the solvent dipped by the oil painting brush cannot be too much, otherwise the solvent will infiltrate the glue film around the copper sheet, causing the glue film to foam.

[0032] S3. Select a copper sheet with the same material as the copper mesh

[0033] S4. Perform pre-surface treatment on the copper sheet

[0034] Clean the copper sheet and perform single-sided tin plating treatment on the copper sheet, and control the thickness of the tin layer at 8 - 12 μm.

[0035] S5. Connect the copper sheet using a specific process at the positions where electrical connection is required.

[0036] Place the side of the copper sheet with the tin layer centered facing the exposed copper mesh. Heat the soldering iron to 195 ± 10 °C. Press the center of the copper sheet from the bottom with the tip of the soldering iron. Observe with the naked eye that the tinned tin layer starts to melt from the center. The tip of the soldering iron moves in a spiral trajectory with the center of the copper sheet as the origin. The tip of the soldering iron needs to maintain an appropriate amount of force at all times, then the copper mesh can be pressed into the melted tin layer and connected to the copper sheet without breaking the copper mesh.

[0037] The different examples of the systems, devices, and methods disclosed herein include various components, features, and functions. It should be understood that the various examples of the systems, devices, and methods disclosed herein may include any components, features, and functions of any one of the other examples of the systems, devices, and methods disclosed herein in any combination or any sub - combination, and all such possibilities are intended to fall within the scope of the present invention.

[0038] The description of the different advantageous arrangements has been presented for purposes of illustration and description, but the description is not intended to be exclusive or limited to the examples in the disclosed forms. Many modifications and variations will be obvious to those of ordinary skill in the art. Additionally, different advantageous examples may describe different advantages compared to other advantageous examples. The selected example or examples are chosen and described in order to best illustrate the principles, practical applications, and to enable those of ordinary skill in the art to understand the disclosure having various examples that have been modified for the particular use contemplated.

Claims

1. A connection method for improving the electrical lap joint performance of a glue film composite copper mesh, characterized in that, The method comprises the following steps: S1. Remove the adhesive film on the adhesive film composite copper mesh in the area requiring electrical connection Use a craft knife to draw a circle on the protective film of the adhesive film composite copper mesh according to a template. Place the adhesive film composite copper mesh at room temperature not exceeding 30°C to warm up for about 0.5 hours. After the adhesive film becomes sticky, remove the protective paper on the surface of the adhesive film composite copper mesh in the circular area, and use a single-sided tape to stick away the softened adhesive film in multiple times; S2. Clean the area where the adhesive film has been removed Use a clean and oil-free metal plate as a support backing plate. Place the composite copper mesh with the adhesive film removed on the metal plate, and place a layer of filter paper between the metal plate and the composite copper mesh. Select an oil painting brush, dip it in an appropriate amount of methyl ethyl ketone or alcohol, and gently and repeatedly brush the area where the adhesive film has been removed until the solvent on the filter paper shows no obvious color change; S3. Select a copper sheet consistent with the copper mesh material and perform surface treatment Clean the copper sheet and tin-plate it on one side, with the tin layer thickness controlled at 8 - 12 μm; S4. Weld the copper sheet Centrally place the side of the copper sheet with the tin layer against the composite copper mesh with the adhesive film removed. Heat the soldering iron to raise the temperature of the soldering iron to 195 ± 10°C, and press the head of the soldering iron from the lower part on the center of the copper sheet. When the tin layer starts to melt from the center, move the head of the soldering iron with appropriate force in a spiral trajectory with the center of the copper sheet as the origin, and press the copper mesh into the melted tin layer to connect with the copper sheet.

2. The connection method according to claim 1, characterized in that: Remove it by tearing or sticking according to the viscosity and density of the adhesive film.

3. The connection method according to claim 1, characterized in that: The adhesive force of the single-sided tape is 3.5 - 4.5 N / cm.

4. The connection method according to claim 1, characterized in that: In step S2, an oil painting brush that does not shed hair needs to be selected.

5. The connection method according to claim 1, characterized in that: The width of the oil painting brush is 5 - 7 mm.

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