Composite busbar

Abstract

The utility model discloses a composite busbar, and the main points of the technical scheme are that the composite busbar comprises flat plate type conductive layers and lap joint terminals extending from the edges of the conductive layers, a middle insulating layer is arranged between the adjacent conductive layers, and the outermost conductive layer of the composite busbar is wrapped by an outer insulating layer; the middle insulating layer comprises an insulating sheet, an insulating bonding sheet is bonded between the insulating sheet and the adjacent conductive layer, and an insulating bonding sheet is also bonded on the surface, attached to the conductive layer, of the outer insulating layer; through the insulating sheet and the insulating bonding sheet which have different melting points and are bonded together, the insulating bonding sheet with a lower melting point can bear a higher temperature in a melting point range, so that the insulating bonding sheet can be fully heated and softened to be bonded with the conductive layer, and the insulating layer with a higher melting point is used as a backup to ensure that the conductive layer is bonded with the conductive layer. And the insulating property between the conductive layers can still be ensured after the insulating bonding sheet is melted and deformed due to too high hot pressing temperature or too long hot pressing time.

Description

Technical Field

[0001] The utility model relates to the technical field of busbars, and particularly relates to a composite busbar. Background Art

[0002] A composite busbar, also known as a composite bus, busbar (mother) board, low-inductance busbar, laminated busbar, etc., adopts a composite structure of a conductive material and an insulating material, and encapsulates a single-layer or multi-layer conductor with an insulating strength material to form a low-inductance composite structure; due to its low impedance and strong heat dissipation and cooling ability, the existing composite busbar has the effects of smaller temperature rise and reduced inductance, and also has a relatively high usage frequency in IGBT modules.

[0003] The traditional composite busbar is a laminated structure formed by bonding a conductive layer and an insulating layer through a high-temperature hot pressing process. During the production process, it is necessary to ensure that the adhesive layer between the conductive layer and the insulating layer can melt and bond the two to ensure the insulation effect. Therefore, the insulating layer needs to be fully heated and softened; however, the insulating layer is usually a polyester film. During the high-temperature hot pressing process, since the polyester film is thin and the temperature during the hot pressing process is critical to its melting point, and it is also deformed by the extrusion force, it is easy to melt and deform due to being in a high temperature for a long time during the hot pressing process, resulting in the exposed conductive layer being isolated, affecting the electrical performance of the busbar and increasing the rejection rate. Summary of the Utility Model

[0004] The utility model provides a composite busbar. Through insulating sheets and insulating adhesive sheets with different melting points pasted together, the insulating adhesive sheet with a lower melting point can withstand a higher temperature within its melting point range, so as to ensure that the insulating adhesive sheet can be fully heated and softened and bonded with the conductive layer, while the insulating layer with a higher melting point serves as a backup to ensure the insulation performance between the conductive layers after the insulating adhesive sheet melts and deforms due to too high hot pressing temperature or too long hot pressing time.

[0005] To achieve the above object, the technical solution adopted by the utility model is: a composite busbar, including at least two flat conductive layers and a lapping terminal extending from the edge of the conductive layer. An intermediate insulating layer is arranged between adjacent conductive layers, and an outer insulating layer is wrapped on the outermost conductive layer of the composite busbar; a plurality of mounting holes penetrating up and down are opened on the conductive layer, the outer insulating layer and the intermediate insulating layer; the intermediate insulating layer includes an insulating sheet, and an insulating adhesive sheet is bonded between the insulating sheet and the adjacent conductive layer. An insulating adhesive sheet is also bonded on the surface of the outer insulating layer in contact with the conductive layer, and the melting point of the insulating adhesive sheet is lower than the melting points of the insulating sheet and the outer insulating layer.

[0006] The present utility model is further configured such that a positioning groove for embedding a conductive layer is provided in the middle of one side of the insulating sheet, and the insulating adhesive sheet is pasted on the bottom of the positioning groove and on the other side of the insulating sheet relative to the positioning groove; a notch is further provided at the edge of the positioning groove, and the overlapping terminal leaks to the outside through the notch.

[0007] The present utility model is further configured such that the outer insulating layer includes an upper insulating sleeve and a lower insulating sleeve. The upper insulating sleeve and the lower insulating sleeve respectively cover the outer sides of the two outermost conductive layers to seal the conductive layer and the middle insulating sleeve, and the upper insulating sleeve and the lower insulating sleeve are mutually engaged through a connection structure.

[0008] The present utility model is further configured such that the connection structure includes sealing edges extending outward from the edges of the upper insulating sleeve and the lower insulating sleeve, and one side of the two sealing edges is in contact; a plurality of clamping blocks are convexly provided on one side of the sealing edge of the upper insulating sleeve relative to the lower insulating sleeve, and a plurality of clamping holes for clamping with the clamping blocks are provided on the sealing edge of the lower insulating sleeve.

[0009] The present utility model is further configured such that the insulating adhesive sheet is a polyester film.

[0010] The present utility model is further configured such that the insulating sheet and the outer insulating layer are made of polyimide.

[0011] The present utility model is further configured such that an insulating gasket is provided on the outside of the outer insulating layer and on the outer circumference of the mounting hole.

[0012] The present utility model is further configured such that the overlapping terminals of the conductive layer are arranged in a staggered manner.

[0013] The present utility model is further configured such that the insulating adhesive sheet is pasted on the insulating sheet and the outer insulating layer through hot melt adhesive.

[0014] In summary, the beneficial effects of the present utility model are as follows:

[0015] Compared with the prior art, in the present application, the insulating sheet and the insulating adhesive sheet with different melting points pasted together enable the insulating adhesive sheet with a lower melting point to withstand a higher temperature within the melting point range, so as to ensure that the insulating adhesive sheet can be fully heated and softened to bond with the conductive layer. The outer insulating layer and the insulating sheet with a higher melting point serve as a backup to ensure that the insulation performance between adjacent conductive layers can still be guaranteed even if the insulating adhesive sheet melts and deforms due to too high hot pressing temperature or too long hot pressing time, effectively reducing the rejection rate caused by the melting and damage of the insulating adhesive sheet and improving the production efficiency. The composite of the two insulating layers with different melting points and the insulating adhesive sheet also helps to reduce the failure or damage of the insulating layer caused by high temperature, further reducing the rejection rate. Description of the Drawings

[0016] Figure 1It is the three-dimensional structure diagram of this embodiment.

[0017] Figure 2 It is the exploded structure diagram of this embodiment.

[0018] Figure 3 It is the schematic diagram of the intermediate insulating layer structure of this embodiment.

[0019] Figure 4 It is the schematic diagram of the outer insulating layer structure of this embodiment.

[0020] Reference numerals: 1, conductive layer; 2, overlapping terminal; 3, intermediate insulating layer; 31, insulating sheet; 311, positioning groove; 312, notch; 32, insulating adhesive sheet; 4, outer insulating layer; 41, upper insulating sleeve; 42, lower insulating sleeve; 43, connecting structure; 431, sealing edge; 432, clamping block; 433, clamping hole; 5, mounting hole; 6, insulating gasket. Detailed implementation manners

[0021] Next, in combination with the embodiments of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts fall within the scope of the present invention.

[0022] As Figure 1-2 shown, this embodiment discloses a composite busbar, which includes at least two flat conductive layers 1 and overlapping terminals 2 extending from the edge of the conductive layer 1. Through the overlapping terminals 2, the wire can be electrically connected to the composite busbar; the conductive layer 1 is made of a copper sheet, and its shape and size can be determined according to the style and size required by the device; an intermediate insulating layer 3 is provided between adjacent conductive layers 1, and an outer insulating layer 4 is wrapped around the outermost conductive layer 1 of the composite busbar; a plurality of mounting holes 5 penetrating up and down are provided on the conductive layer 1, the outer insulating layer 4, and the intermediate insulating layer 3; through the penetrating mounting holes 5, the composite busbar can be installed on the IGBT module by bolts to realize the connection of the device. And the insulating gasket 6 provided on the surface of the outer insulating layer 4 at the edge of the mounting hole 5 can avoid damage to the surface of the outer insulating layer 4 by the bolt when installing the conductive layer 1.

[0023] As Figure 3 shown, the intermediate insulating layer 3 includes an insulating sheet 31, an insulating adhesive sheet 32 is bonded between the insulating sheet 31 and the adjacent conductive layer 1, and an insulating adhesive sheet 32 is also bonded to the surface of the outer insulating layer 4 that is in contact with the conductive layer 1. The melting point of the insulating adhesive sheet 32 is lower than the melting points of the insulating sheet 31 and the outer insulating layer 4.

[0024] The insulating adhesive sheet 32 can be bonded to the insulating sheet 31 and the outer insulating layer 4 through hot melt adhesive. During the production process of the composite busbar, the insulating adhesive sheet 32 and the insulating sheet 31, and between the outer insulating layer 4 and the insulating adhesive sheet 32 can be first pasted through hot melt adhesive, so as to reduce the gap between the two. Then, the insulating sheet 31 with the insulating adhesive sheet 32 pasted on it, the outer insulating layer 4 and the conductive layer 1 are spliced and then hot-pressed.

[0025] As Figure 2 shown, through the composite setting of the insulating adhesive sheet 32, the insulating sheet 31 with a melting point lower than it, and the outer insulating layer 4, when hot-pressing the completed composite busbar, first, due to the relatively low melting point of the insulating adhesive sheet 32, it will be heated and softened. Then, under the action of pressure, it will be tightly bonded to the conductive layer 1, thus preventing current leakage and short circuit, and protecting the conductive layer 1 from the influence of the external environment. And the outer insulating layer 4 and the insulating sheet 31, because their melting points are much higher than that of the insulating adhesive sheet 32, so at the same temperature and pressure as the insulating adhesive sheet 32, their softening degree will be less than that of the insulating adhesive sheet 32, so that the structures of the insulating sheet 31 and the outer insulating layer 4 are in a complete state, ensuring that when the hot-pressing temperature is too high or the hot-pressing time is too long, resulting in the melting and deformation of the insulating adhesive sheet 32, the insulating sheet 31 and the outer insulating layer can still ensure the insulation performance between adjacent conductive layers 1. At the same time, during the hot-pressing process, the insulating adhesive sheet 32 can also be mutually extruded and bonded with the insulating sheet 31 and the outer insulating layer 4, so as to ensure the tight fit between the insulating adhesive sheet 32 and the insulating sheet 31 and the outer insulating layer 4, and avoid the occurrence of gaps between them, which will affect the insulation performance.

[0026] At the same time, the insulating adhesive sheet 32 is pasted to the insulating sheet 31 and the outer insulating layer 4 through hot melt adhesive. When the insulating layer reaches an appropriate temperature, the hot melt adhesive will melt and fill the tiny gaps between the insulating sheet 31 and the insulating adhesive sheet 32, and between the insulating adhesive sheet 32 and the outer insulating layer 4, and then solidify during the cooling process to achieve tight fit.

[0027] Among them, the insulating adhesive sheet 32 is a polyester film, and the insulating sheet 31 and the outer insulating layer 4 are made of polyimide. The melting point temperature of the polyester film is about 200 degrees Celsius, while polyimide can withstand high temperatures up to more than 400 degrees Celsius and can be used at a high temperature of 300 degrees Celsius for a long time. Therefore, although it has no obvious melting point, its melting point is much higher than that of the polyester film.

[0028] As Figure 3As shown in the figure, a positioning groove 311 for embedding the conductive layer 1 is provided in the middle of one side of the insulating sheet 31. The insulating adhesive sheet 32 is arranged at the bottom of the positioning groove 311 and on the other side of the insulating sheet 31 relative to the positioning groove 311. A notch 312 is further included and arranged at the edge of the positioning groove 311. The overlapping terminal 2 leaks to the outside through the notch 312. By providing the positioning groove 311 on the insulating sheet 31, when the staff assembles and joins the conductive layer 1 and the insulating layer, the relative position between the insulating layer and the conductive layer 1 can be more accurate, the installation is more precise and convenient, and the relative position of the conductive layer 1 during the installation process can be avoided from shifting.

[0029] As Figure 4 shown in the figure, the outer insulating layer 4 includes an upper insulating sleeve 41 and a lower insulating sleeve 42. The upper insulating sleeve 41 and the lower insulating sleeve 42 respectively cover the outer sides of the two outermost conductive layers 1 to seal the conductive layer 1 and the intermediate insulating sleeve. The upper insulating sleeve 41 and the lower insulating sleeve 42 are mutually clamped through a connecting structure 43. The connecting structure 43 includes a sealing edge 431 extending outward from the edges of the upper insulating sleeve 41 and the lower insulating sleeve 42, and one side of the two sealing edges 431 is in contact. A plurality of clamping blocks 432 are convexly arranged on one side of the sealing edge 431 of the upper insulating sleeve 41 relative to the lower insulating sleeve 42, and a plurality of clamping holes 433 for clamping with the clamping blocks 432 are arranged on the sealing edge 431 of the lower insulating sleeve 42. The upper insulating sleeve 41 and the lower insulating sleeve 42 can clamp and wrap the conductive layer 1 and the intermediate insulating layer 3 in the middle. After the staff assembles the composite busbar, through the connection of the sealing edges 431 of the lower insulating sleeve 42 and the upper insulating sleeve 41 and the clamping holes 433 and clamping blocks 432 on the sealing edges 431, the fixation of the upper and lower insulating sleeves 42 can be realized, so as to facilitate the staff to uniformly perform unified hot pressing after assembling the assembled composite busbar. It is ensured that during the hot pressing process, the structure between the layers of the composite busbar will not be misaligned or displaced due to the extrusion force, and there is no need to install other positioning structures, and the assembly is more convenient and fast, improving the production efficiency.

[0030] The above are only the preferred embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the design concept of the present invention shall be included within the protection scope of the present invention.

Claims

1. A composite busbar, characterized in that, It includes at least two flat conductive layers (1) and overlapping terminals (2) extending from the edges of the conductive layers (1). An intermediate insulating layer (3) is provided between adjacent conductive layers (1), and an outer insulating layer (4) wraps the conductive layer (1) on the outermost side of the composite busbar; a number of mounting holes (5) penetrating up and down are provided on the conductive layer (1), the outer insulating layer (4) and the intermediate insulating layer (3); the intermediate insulating layer (3) includes an insulating sheet (31), and an insulating adhesive sheet (32) is bonded between the insulating sheet (31) and the adjacent conductive layer (1). An insulating adhesive sheet (32) is also bonded to the surface of the outer insulating layer (4) that is in contact with the conductive layer (1). The melting point of the insulating adhesive sheet (32) is lower than the melting points of the insulating sheet (31) and the outer insulating layer (4).

2. The composite busbar according to claim 1, wherein A positioning groove (311) for embedding the conductive layer (1) is provided in the middle of one side of the insulating sheet (31). The insulating adhesive sheet (32) is pasted at the bottom of the positioning groove (311) and on the other side of the insulating sheet (31) relative to the positioning groove (311); a notch (312) is further provided at the edge of the positioning groove (311), and the overlapping terminal (2) is exposed to the outside through the notch (312).

3. The composite busbar according to claim 2, wherein, The outer insulating layer (4) includes an upper insulating sleeve (41) and a lower insulating sleeve (42). The upper insulating sleeve (41) and the lower insulating sleeve (42) respectively cover the outer sides of the two outermost conductive layers (1) to seal the conductive layer (1) and the intermediate insulating sleeve. The upper insulating sleeve (41) and the lower insulating sleeve (42) are mutually engaged through a connecting structure (43).

4. A composite busbar according to claim 3, wherein, The connecting structure (43) includes sealing edges (431) extending outward from the edges of the upper insulating sleeve (41) and the lower insulating sleeve (42). One side of the two sealing edges (431) is in contact; a number of clamping blocks (432) are convexly provided on the side of the sealing edge (431) of the upper insulating sleeve (41) opposite to the lower insulating sleeve (42), and a number of clamping holes (433) for clamping with the clamping blocks (432) are provided on the sealing edge (431) of the lower insulating sleeve (42).

5. A composite busbar according to claim 1, characterized in that, The insulating adhesive sheet (32) is a polyester film.

6. The composite busbar according to claim 5, characterized in that, The insulating sheet (31) and the outer insulating layer (4) are made of polyimide.

7. A composite busbar according to claim 1, characterized in that, An insulating gasket (6) is provided on the outside of the outer insulating layer (4) and on the outer circumference of the mounting hole (5).

8. A composite busbar according to claim 1, characterized in that, The overlapping terminals (2) of the conductive layer (1) are arranged in a staggered manner.

9. The composite busbar according to claim 2, characterized in that, The insulating adhesive sheet (32) is pasted to the insulating sheet (31) and the outer insulating layer (4) through hot melt adhesive.

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