A polyimide film cold-pressed composite busbar for automotive capacitors and a preparation method thereof

Abstract

The present invention provides a polyimide film cold-pressed composite busbar for automobile capacitors and a preparation method thereof. The composite busbar comprises an upper busbar unit and a lower busbar unit. The upper busbar unit comprises an L-shaped upper busbar and an upper busbar insulating film. The L-shaped upper busbar comprises an upper busbar vertical plate and an upper busbar drainage flat plate, and the upper busbar insulating film is attached to the inner side of the upper busbar vertical plate; the lower busbar unit comprises an L-shaped lower busbar and a lower busbar insulating film. The L-shaped lower busbar comprises a lower busbar vertical plate and a lower busbar drainage flat plate, and the lower busbar vertical plate comprises a lower busbar positioning plate and a connecting plate located on the upper side, and the lower busbar insulating film is attached to the inner side of the lower busbar positioning plate; the materials of the upper busbar insulating film and the lower busbar insulating film are both polyimide; the composite busbar provided by the present invention solves the problems of insufficient high temperature resistance grade, insufficient high voltage resistance grade, insufficient wear resistance and early failure in the prior art.

Description

Technical Field

[0001] The invention belongs to an electrical connection component between power modules, and in particular relates to a polyimide film cold-pressed composite busbar for automobile capacitors and a preparation method thereof. Background Art

[0002] Composite busbars, also known as laminated busbars, generally consist of a conductive layer, an insulating layer, and necessary positioning and bonding components. They are a multi-layer composite structure. Using composite busbars for connecting bars can reduce the parasitic inductance of the circuit, protect switching devices (such as IGBT) from breakdown due to reverse voltage, and reduce EMI electromagnetic interference in the circuit. At the same time, it can improve system heat dissipation and assembly connection problems, and is widely used in the field of power conversion.

[0003] When designing and selecting materials for traditional composite busbars, the conductive layer is generally made of copper (such as T2) or aluminum alloy (such as 1060), the insulating layer is generally made of polyester film (such as PET) or Nomex paper (NOMEX), and the adhesive material is generally made of acrylic hot melt adhesive. The material price is relatively low, but when used in some fields, there are problems such as insufficient high temperature resistance, insufficient high voltage resistance, and insufficient wear resistance. In particular, there is a risk of early failure in electric vehicle applications. Summary of the invention

[0004] In view of the above-mentioned defects, the present invention provides a polyimide film cold-pressed composite busbar for automotive capacitors having excellent high temperature resistance, high high voltage resistance and strong wear resistance, and a preparation method thereof.

[0005] The present invention provides the following technical solution: a polyimide film cold-pressed composite busbar for automotive capacitors, characterized in that the composite busbar comprises an upper busbar unit and a lower busbar unit, the upper busbar unit comprises an L-shaped upper busbar and an upper busbar insulating film, the L-shaped upper busbar comprises an upper busbar vertical plate and an upper busbar drainage flat plate, the upper busbar insulating film is attached to the inner side of the upper busbar vertical plate by a cold-pasting and cold-pressing process in a single-sided or double-sided polyethylene adhesive coating;

[0006] The lower busbar unit includes an L-shaped lower busbar and a lower busbar insulation film, the L-shaped lower busbar includes a lower busbar vertical plate and a lower busbar drainage flat plate, the lower busbar vertical plate includes a lower busbar positioning plate and a connecting plate located on the upper side, four holes are evenly distributed on the connecting plate, and the lower busbar insulation film is attached to the inner side of the lower busbar positioning plate by cold pasting and cold pressing process in the form of single-sided or double-sided polyethylene adhesive coating;

[0007] The upper busbar insulation film and the lower busbar insulation film are both made of polyimide;

[0008] The vertical width of the upper busbar vertical plate is equal to the vertical width of the lower busbar positioning plate, the upper busbar vertical plate is provided with 2 to 3 circular upper busbar positioning holes, the lower busbar positioning plate is provided with the same number of circular lower busbar positioning holes at positions corresponding to the circular upper busbar positioning holes, the upper busbar positioning holes and the lower busbar positioning holes are provided with flying saucer-shaped positioning pins, the upper busbar unit and the lower busbar unit are fixed by the flying saucer-shaped positioning pins, the upper busbar insulating film is provided with upper busbar insulating film positioning holes corresponding to the upper busbar positioning holes, the lower busbar insulating film is provided with lower busbar insulating film positioning holes corresponding to the lower busbar positioning holes, and thus the lower busbar insulating film is located between the lower busbar positioning plate and the upper busbar vertical plate;

[0009] The edge of the upper busbar insulating film is 5mm longer than the edge of the upper busbar vertical plate, that is, 5mm longer in both length and width directions; the edge of the lower busbar insulating film is 5mm longer than the edge of the lower busbar positioning plate, that is, 5mm longer in both length and width directions.

[0010] Furthermore, the flying saucer-shaped positioning pin includes an annular butterfly wing and a positioning pin cylinder embedded in the middle of the annular butterfly wing and located at the upper and lower end surfaces thereof.

[0011] Furthermore, the annular butterfly wing and the positioning pin cylinder are integrally formed.

[0012] Furthermore, the height of the positioning pin cylinder is greater than or equal to the thickness of the plates of the upper busbar unit and the lower busbar unit.

[0013] Furthermore, the diameter of the positioning pin cylinder is equal to the inner diameter of the annular butterfly wing, and is equal to the diameter of the upper busbar positioning hole and the lower busbar positioning hole, which is 3mm to 6mm.

[0014] Furthermore, the outer diameter of the annular butterfly wing is 5 mm larger than the inner diameter thereof, and 5 mm is the creepage distance required to meet safety regulations.

[0015] Furthermore, the thickness of the insulating film is 0.2 mm.

[0016] Furthermore, the upper busbar and the lower busbar are made of T2Y2 copper plate with a thickness of 1.5 mm.

[0017] Furthermore, the flying saucer-shaped positioning pin is made of PPS-50GF material, and the positioning pin is cylindrical.

[0018] The present invention also provides a method for preparing the above-mentioned polyimide film cold-pressed composite busbar for automobile capacitors, comprising the following steps:

[0019] 1) Using a 1.5 mm thick T2Y2 copper plate, the L-shaped upper busbar and the L-shaped lower busbar are respectively manufactured through laser cutting, bending, deburring, surface drawing, riveting terminals, pickling, and electroplating processes;

[0020] 2) Use PPS-50GF material mold injection molding or 3D printing to form the flying saucer-shaped positioning pin;

[0021] 3) coating one side or both sides of the upper busbar insulation film with polyvinyl alcohol adhesive and protecting it with release paper; coating one side or both sides of the lower busbar insulation film with polyvinyl alcohol adhesive and protecting it with release paper, and forming the desired pattern through mold stamping or laser cutting process;

[0022] 4) The upper busbar unit and the lower busbar unit are placed on the tooling respectively, and the upper busbar insulation film is attached to the inner side of the upper busbar vertical plate by cold lamination and cold pressing process by coating polyvinyl alcohol adhesive on one side or both sides; the lower busbar insulation film is attached to the inner side of the lower busbar positioning plate by cold lamination and cold pressing process by coating polyvinyl alcohol adhesive on one side or both sides, and the insulation layer with the release paper torn off is attached to the surface of the upper busbar and the lower busbar, and then an elastic rubber pad is placed, and a pressure device is used to operate within the pressure holding time to complete the attachment of the upper busbar insulation film to the upper busbar and the lower busbar insulation film to one side of the lower busbar. If the other side also needs to be attached, bend the insulation layer to the other side along the hemming direction;

[0023] 5) The upper busbar unit and the lower busbar unit are positioned and assembled by setting the flying saucer-shaped positioning pins on the respective positioning holes of the busbar unit and the insulating layer to obtain the polyimide film cold-pressed composite busbar for automotive capacitors.

[0024] The beneficial effects of the present invention are:

[0025] 1. The polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention can be applied to electric vehicles, especially hybrid HEVs and other fields that require high temperature resistance, high voltage resistance and high reliability.

[0026] 2. The polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention has the following three advantages due to the use of a polyimide film PI insulation layer:

[0027] A. Wide applicable temperature range: The high temperature characteristic decomposition temperature is about 500℃, and the temperature can be used for a long time at -200~300℃, with no obvious melting point. The low temperature characteristic will not be brittle in liquid helium at -269℃;

[0028] B. Strong mechanical properties: The tensile strength of unfilled polyimide is above 100Mpa, such as the film of homophenyl polyimide is above 170Mpa, and the biphenyl polyimide reaches 400Mpa;

[0029] C. Good insulation performance: Good dielectric properties, the dielectric constant is about 3.4. By introducing fluorine or dispersing air nanometer size in polyimide, the dielectric constant can be reduced to about 2.8.

[0030] 3. The automotive capacitor provided by the present invention has a higher temperature resistance level and can be used in high-temperature occasions. The traditional composite busbar uses polyimide film PI as the insulation layer, and the high temperature resistance level is 105°C. The polyimide film PI is used as the insulation layer, and the high temperature resistance level is 220°C (see the data in the table below), which can meet the high temperature requirements of hybrid electric vehicles HEV.

[0031] 4. The automotive capacitor provided by the present invention has a higher withstand voltage level and can use thinner films to achieve higher voltage capacitors. The traditional composite busbar uses polyester film PET as the insulation layer, with a dielectric strength of 120KV / mm, and uses polyimide film PI as the insulation layer with a dielectric strength of 170KV / mm. Under the same application conditions, the film thickness can be reduced by 1 / 3.

[0032] 5. The automotive capacitor provided by the present invention uses a cold-lamination and cold-pressing composite process during the preparation process. The insulating film is not damaged during the process, and the polyvinyl alcohol backing layer does not undergo chemical reactions, thereby extending the life of the capacitor and increasing its reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be described in more detail below based on embodiments and with reference to the accompanying drawings, wherein:

[0034] Figure 1 This is an overall schematic diagram of a polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention;

[0035] Figure 2 This is a structural exploded view of the upper busbar unit of the polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention;

[0036] Figure 3 This is a structural exploded view of the lower busbar unit of the polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention;

[0037] Figure 4 A top side view of a flying saucer-shaped positioning pin of a polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention;

[0038] Figure 5 The present invention is a side view of the flying saucer-mounted positioning pins of the polyimide film cold-pressed composite busbar for automobile capacitors provided by the present invention. DETAILED DESCRIPTION

[0039] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] Example 1

[0041] like Figure 1 As shown, a polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention comprises an upper busbar unit 1 and a lower busbar unit 2. Figure 2 As shown, the upper busbar unit 1 includes an L-shaped upper busbar 1-1 and an upper busbar insulating film 1-2, the L-shaped upper busbar 1-1 includes an upper busbar vertical plate 1-11 and an upper busbar drain plate 1-12, and the upper busbar insulating film 1-2 is attached to the inner side of the upper busbar vertical plate 1-11 by cold pasting and cold pressing process in the manner of coating polyethylene adhesive on one side or both sides;

[0042] like Figure 3 As shown, the lower busbar unit 2 includes an L-shaped lower busbar 2-1 and a lower busbar insulating film 2-2. The L-shaped lower busbar 2-1 includes a lower busbar vertical plate 2-11 and a lower busbar flat plate 2-12. The lower busbar vertical plate 2-11 includes a lower busbar positioning plate 2-111 and a connecting plate 2-112 located on the upper side. Four holes 2-113 are evenly distributed on the connecting plate 2-112. The lower busbar insulating film 2-2 is attached to the inner side of the lower busbar positioning plate 2-111 by cold pasting and cold pressing process in the form of single-sided or double-sided polyethylene adhesive coating;

[0043] The materials of the upper busbar insulation film 1-2 and the lower busbar insulation film 2-2 are both polyimide;

[0044] The vertical width of the upper busbar vertical plate 1-11 is equal to the vertical width of the lower busbar positioning plate 2-111. The upper busbar vertical plate 1-11 is provided with 2 to 3 circular upper busbar positioning holes 1-3. The lower busbar positioning plate 2-111 is provided with the same number of circular lower busbar positioning holes 1-4 at positions corresponding to the circular upper busbar positioning holes 1-3. Flying saucer-shaped positioning pins 3 are provided in the upper busbar positioning holes 1-3 and the lower busbar positioning holes 1-4. The upper busbar unit 1 and the lower busbar unit 2 are fixed by the flying saucer-shaped positioning pins 3. The upper busbar insulating film 1-2 has an upper busbar insulating film positioning hole 1-21 corresponding to the upper busbar positioning hole 1-3, and the lower busbar insulating film 2-2 has a lower busbar insulating film positioning hole 2-21 corresponding to the lower busbar positioning hole 1-4, so that the lower busbar insulating film 2-2 is located between the lower busbar positioning plate 2-111 and the upper busbar vertical plate 1-11;

[0045] The edge of the upper busbar insulating film 1-2 is 5mm longer than the edge of the upper busbar vertical plate 1-11, that is, 5mm longer in both length and width directions; the edge of the lower busbar insulating film 2-2 is 5mm longer than the edge of the lower busbar positioning plate 2-111, that is, 5mm longer in both length and width directions.

[0046] The upper busbar 1-1 and the lower busbar 2-1 are made of 1.5 mm thick T2Y2 copper plate.

[0047] like Figure 4-5 As shown, the flying saucer-shaped positioning pin 3 includes an annular butterfly wing 3-1 and a positioning pin cylinder 3-2 embedded in the middle of the annular butterfly wing 3-1 and located at its upper and lower end faces. The annular butterfly wing 3-1 and the positioning pin cylinder 3-2 of the flying saucer-shaped positioning pin 3 are integrally formed with PPS-50GF material, and the positioning pin cylinder 3-2 is chamfered for easy assembly. The pattern of the 0.2mm thick insulating film is generally designed according to the shape of the busbar, and the insulating layer is 5mm longer than the upper and lower busbar edges as the safety distance. The patent of the present invention has holes of the same diameter at the corresponding positions of the insulating layer busbar, which are used as attachment and assembly positioning holes.

[0048] The height of the positioning pin cylinder 3 - 2 is greater than or equal to the plate thickness of the upper busbar unit 1 and the lower busbar unit 2 .

[0049] The diameter of the positioning pin cylinder 3-2 is equal to the inner diameter of the annular butterfly wing, and is equal to the diameter of the upper busbar positioning hole 1-3 and the lower busbar positioning hole 1-4, which is 3mm to 6mm.

[0050] The outer diameter of the annular butterfly wing 3 - 1 is 5 mm larger than its inner diameter, and 5 mm is the creepage distance required to meet safety regulations.

[0051] Example 2

[0052] This embodiment provides a method for preparing a polyimide film cold-pressed composite busbar for automotive capacitors in Embodiment 1, comprising the following steps:

[0053] 1) Using 1.5mm thick T2Y2 copper plate, through laser cutting, bending, deburring, surface drawing, riveting terminals, pickling, electroplating processes, respectively, to make L-shaped upper busbar 1-1 and L-shaped lower busbar 2-1;

[0054] 2) Use PPS-50GF material mold injection molding or 3D printing to form a flying saucer-shaped positioning pin 3;

[0055] 3) Coating one or both sides of the upper busbar insulation film 1-2 with polyvinyl alcohol adhesive and protecting it with release paper; coating one or both sides of the lower busbar insulation film 2-2 with polyvinyl alcohol adhesive and protecting it with release paper, and then forming the desired pattern through mold stamping or laser cutting process;

[0056] 4) Place the upper busbar unit 1 and the lower busbar unit 2 on the tooling respectively, and the upper busbar insulation film 1-2 is attached to the inner side of the upper busbar vertical plate 1-11 by cold lamination and cold pressing process by coating polyvinyl alcohol adhesive on one side or both sides; the lower busbar insulation film 2-2 is attached to the inner side of the lower busbar positioning plate 2-111 by cold lamination and cold pressing process by coating polyvinyl alcohol adhesive on one side or both sides, and the insulation layer with the release paper torn off is attached to the surface of the upper busbar 1-1 and the lower busbar 2-1, and then an elastic rubber pad is placed, and the pressure equipment is used to operate within the pressure holding time to complete the attachment of the upper busbar insulation film 1-2 to the upper busbar 1-1 and the lower busbar insulation film 2-2 to one side of the lower busbar 2-1. If the other side also needs to be attached, bend the insulation layer to the other side along the edge wrapping direction;

[0057] 5) The upper busbar unit 1 and the lower busbar unit 2 are positioned and assembled by setting a flying saucer-shaped positioning pin 3 on the respective positioning holes of the busbar unit and the insulation layer, thereby obtaining a polyimide film cold-pressed composite busbar for automotive capacitors.

[0058] The upper and lower busbars are connected to the polyimide by single-sided or double-sided polyvinyl alcohol adhesive as an adhesive, and a cold pressing and cold lamination process is used. The polyvinyl alcohol adhesive layer will not undergo a chemical reaction and will not solidify to cause stress puncture to the polyimide.

[0059] The upper and lower busbars are designed with positioning holes and positioning pins for limiting and insulation, which can avoid damage to the busbar electroplating layer due to the use of tooling during the assembly process. It has the advantages of precise positioning and easy assembly.

[0060] The upper and lower busbars are designed with positioning holes and positioning pins for limiting and insulation, which can avoid damage to the busbar electroplating layer due to the use of tooling during the assembly process. It has the advantages of precise positioning and easy assembly.

[0061] According to tests, the polyimide film cold-pressed composite busbar for automotive capacitors provided by the present invention has a higher withstand voltage level, and a capacitor with a higher voltage can be realized with a thinner film. The conventional composite busbar uses polyester film PET as the insulation layer, and the dielectric strength is 120KV / mm, while the polyimide film PI is used as the insulation layer, and the dielectric strength is 170KV / mm (see Table 1 data). Under the same application conditions, the film thickness can be reduced by 1 / 3.

[0062] Table 1

[0063] Although the present invention has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present invention. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no conflict of technical solutions. The present invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A polyimide film cold-pressed composite busbar for automotive capacitors, characterized in that: The composite busbar comprises an upper busbar unit (1) and a lower busbar unit (2); the upper busbar unit (1) comprises an L-shaped upper busbar (1-1) and an upper busbar insulating film (1-2); the L-shaped upper busbar (1-1) comprises an upper busbar vertical plate (1-11) and an upper busbar drain plate (1-12); the upper busbar insulating film (1-2) is attached to the inner side of the upper busbar vertical plate (1-11) by cold pasting and cold pressing in a manner of coating polyethylene adhesive on one side or both sides; The lower busbar unit (2) comprises an L-shaped lower busbar (2-1) and a lower busbar insulating film (2-2); the L-shaped lower busbar (2-1) comprises a lower busbar vertical plate (2-11) and a lower busbar flat plate (2-12); the lower busbar vertical plate (2-11) comprises a lower busbar positioning plate (2-111) and a connecting plate (2-112) located on the upper side; four holes (2-113) are evenly distributed on the connecting plate (2-112); the lower busbar insulating film (2-2) is attached to the inner side of the lower busbar positioning plate (2-111) by cold pasting and cold pressing in a manner of coating polyethylene adhesive on one side or both sides; The upper busbar insulation film (1-2) and the lower busbar insulation film (2-2) are both made of polyimide; The vertical width of the upper busbar vertical plate (1-11) is equal to the vertical width of the lower busbar positioning plate (2-111); the upper busbar vertical plate (1-11) is provided with 2 to 3 circular upper busbar positioning holes (1-3); the lower busbar positioning plate (2-111) is provided with the same number of circular lower busbar positioning holes (1-4) at positions corresponding to the circular upper busbar positioning holes (1-3); and flying saucer-shaped positioning pins (3) are provided in the upper busbar positioning holes (1-3) and the lower busbar positioning holes (1-4). The upper busbar unit (1) and the lower busbar unit (2) are fixed by means of a flying saucer-shaped positioning pin (3); the upper busbar insulating film (1-2) has an upper busbar insulating film positioning hole (1-21) corresponding to the upper busbar positioning hole (1-3); the lower busbar insulating film (2-2) has a lower busbar insulating film positioning hole (2-21) corresponding to the lower busbar positioning hole (1-4); and the lower busbar insulating film (2-2) is located between the lower busbar positioning plate (2-111) and the upper busbar vertical plate (1-11); The edge of the upper busbar insulating film (1-2) is 5 mm longer than the edge of the upper busbar vertical plate (1-11), and the edge of the lower busbar insulating film (2-2) is 5 mm longer than the edge of the lower busbar positioning plate (2-111).

2. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 1, characterized in that: The flying saucer-shaped positioning pin (3) comprises a circular ring-shaped butterfly wing (3-1) and a positioning pin cylinder (3-2) embedded in the middle of the circular ring-shaped butterfly wing (3-1) and located at the upper and lower end surfaces thereof.

3. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 2, characterized in that: The annular butterfly wing (3-1) and the positioning pin cylinder (3-2) are integrally formed.

4. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 2, characterized in that: The height of the positioning pin cylinder (3-2) is greater than or equal to the thickness of the plates of the upper busbar unit (1) and the lower busbar unit (2).

5. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 2, characterized in that: The diameter of the positioning pin cylinder (3-2) is equal to the inner diameter of the annular butterfly wing, and is equal to the diameter of the upper busbar positioning hole (1-3) and the lower busbar positioning hole (1-4), and is 3 mm to 6 mm.

6. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 2, characterized in that: The outer diameter of the annular butterfly wing (3-1) is 5 mm larger than its inner diameter.

7. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 1, characterized in that: The thickness of the insulating film is 0.2 mm.

8. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 1, characterized in that: The upper busbar (1-1) and the lower busbar (2-1) are made of T2Y2 copper plate with a thickness of 1.5 mm.

9. The polyimide film cold-pressed composite busbar for automotive capacitors according to claim 1, characterized in that: The flying saucer-shaped positioning pin (3) is made of PPS-50GF material, and the positioning pin cylinder (3-2) is chamfered to facilitate assembly.

10. A method for preparing a cold-pressed composite busbar of a polyimide film for automotive capacitors according to any one of claims 1 to 9, characterized in that: The following steps are involved: 1) Using a 1.5 mm thick T2Y2 copper plate, and subjecting it to laser cutting, bending, deburring, surface drawing, riveting terminals, pickling, and electroplating, the L-shaped upper busbar (1-1) and the L-shaped lower busbar (2-1) are respectively manufactured; 2) Using PPS-50GF material mold injection molding or 3D printing to form the flying saucer-shaped positioning pin (3); 3) coating one side or both sides of the upper busbar insulation film (1-2) with polyvinyl alcohol adhesive and protecting it with release paper; and coating one side or both sides of the lower busbar insulation film (2-2) with polyvinyl alcohol adhesive and protecting it with release paper, and then performing mold stamping or laser cutting to produce the desired pattern; 4) The upper busbar unit (1) and the lower busbar unit (2) are respectively placed on the tooling, and the upper busbar insulation film (1-2) is attached to the inner side of the upper busbar vertical plate (1-11) by cold lamination and cold pressing by coating polyvinyl alcohol adhesive on one side or both sides; the lower busbar insulation film (2-2) is attached to the inner side of the lower busbar positioning plate (2-111) by cold lamination and cold pressing by coating polyvinyl alcohol adhesive on one side or both sides, and the insulation layer with the release paper torn off is attached to the surface of the upper busbar (1-1) and the lower busbar (2-1), and then an elastic rubber pad is placed, and a pressure device is used to operate within the pressure holding time to complete the attachment of the upper busbar insulation film (1-2) to the upper busbar (1-1) and the lower busbar insulation film (2-2) to one side of the lower busbar (2-1). If the other side also needs to be attached, the insulation layer is bent along the edge wrapping direction to the other side; 5) The upper busbar unit (1) and the lower busbar unit (2) are positioned and assembled by arranging the flying saucer-shaped positioning pins (3) on the respective positioning holes of the busbar unit and the insulating layer, thereby obtaining the polyimide film cold-pressed composite busbar for automotive capacitors.

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