Integrated busbar of power battery

Abstract

An integrated busbar of a power battery comprises a circuit board, a plurality of aluminum bars and a thermistor, the circuit board is provided with a circuit, and the aluminum bars are welded and fixed with the circuit board and are electrically connected with the circuit of the circuit board; the integrated busbar further comprises a hanging piece, the hanging piece is provided with a circuit, the hanging piece and the circuit board are welded and fixed, the circuit of the hanging piece is electrically connected with the circuit of the circuit board, and the thermistor and the hanging piece are welded and fixed, and the thermistor is electrically connected with the circuit of the hanging piece. According to the utility model, the integrated busbar is provided with the pendants which are welded and fixed with the thermistors, so that the SMT technology and the ultrasonic welding technology can be respectively and independently carried out, and the problem that the aluminum bar is not firmly welded due to over-high temperature of the SMT technology is avoided.

Description

Technical Field

[0001] The utility model relates to an integrated busbar, in particular to an integrated busbar of a power battery. Background Art

[0002] The integrated busbar (CCS) is an electrical connection structure within a power battery that enables high-voltage series and parallel connection of battery cells, temperature and cell voltage sampling, and overcurrent fuse functions. An integrated busbar typically consists of a circuit board, several aluminum busbars, and components such as a thermistor (NTC). The aluminum busbar and the thermistor are connected via the circuit board's temperature collection circuit. The aluminum busbar transmits the collected temperature information to the thermistor, which then determines the power battery temperature based on the thermistor's resistance value.

[0003] Traditional integrated busbars typically have a nickel plate placed on the circuit board and the aluminum busbar welded to it. To reduce manufacturing costs, some integrated busbars have eliminated the nickel plate and replaced it with a solder pad directly on the circuit board. The aluminum busbar is then welded to the pad using ultrasonic welding.

[0004] However, thermistors need to be soldered to the circuit board using the SMT process. The maximum temperature of the reflow step in the SMT process can reach 265±5°C. Most existing solder pads are made of copper with an OSP layer. This temperature will destroy the OSP layer on the solder pad, causing the copper to be exposed to air and oxidized. The oxidized copper will lead to insufficient solder peel strength, which will cause the solder pad to corrode and potentially fail. Utility Model Content

[0005] In order to overcome the shortcomings and deficiencies in the prior art, the purpose of the present invention is to design an integrated busbar for a power battery, which can weld the thermistor and the aluminum busbar separately, thereby avoiding the problem of loose welding of the aluminum busbar due to excessively high temperature.

[0006] To achieve the above objectives, the present invention provides an integrated busbar for a power battery, comprising: a circuit board, a plurality of aluminum busbars, and a thermistor, wherein the circuit board is provided with a circuit, the aluminum busbars are welded and fixed to the circuit board, and the aluminum busbars are electrically connected to the circuit of the circuit board; the integrated busbar further comprises: a hanger, wherein the hanger is provided with a circuit, the hanger is welded and fixed to the circuit board, and the circuit of the hanger is electrically connected to the circuit of the circuit board, and the thermistor is welded and fixed to the hanger, and the thermistor is electrically connected to the circuit of the hanger.

[0007] Furthermore, the integrated busbar further includes a reinforcing plate, which is welded to the circuit board and located directly below the hanger. The reinforcing plate provides rigid support, enhances the pressure resistance of the weld between the hanger and the circuit board, and improves firmness.

[0008] Furthermore, the circuit board is provided with a hanger welding portion protruding from the side and several aluminum bar welding portions protruding from the side. The hanger is welded to the upper surface of the hanger welding portion, the reinforcement plate is fixedly connected to the lower surface of the hanger welding portion, and the aluminum bar is welded to the aluminum bar welding portion. By welding the hanger and aluminum bar to the hanger welding portion and aluminum bar welding portion, respectively, the hangers and aluminum bars can be distributed on both sides of the circuit board and the aluminum bar is located in the temperature collection position.

[0009] Furthermore, the hanger welding portion is provided with a middle positioning hole, the hanger is provided with an upper positioning hole, and the reinforcing plate is provided with a lower positioning hole. The upper positioning hole, middle positioning hole, and lower positioning hole are arranged from top to bottom and have the same shape and size. Since the hanger, hanger welding portion, and reinforcing plate all have positioning holes, they can be positioned during welding, ensuring the accuracy of the welding position.

[0010] Furthermore, there are two upper positioning holes, two middle positioning holes, and two lower positioning holes, wherein the above structure can achieve the effect of two-point positioning to prevent the components from rotating relative to each other.

[0011] Furthermore, the upper surface of the hanger's soldering portion is provided with a first groove, and the upper and lower surfaces of the hanger are both provided with a second groove. A through hole is provided between the second grooves on the upper and lower surfaces of the hanger, and the first groove is arranged opposite the second groove on the lower surface of the hanger. The provision of the first and second grooves provides space for solder paste, allowing users to pre-tinn and improve soldering security; the provision of the through hole allows solder paste in the second groove on the upper surface to flow into the second groove on the lower surface, thereby increasing the amount of pre-tinning.

[0012] Furthermore, two through holes are provided between the second grooves on the upper and lower surfaces of the hanger, wherein the provision of the two through holes can improve the flow efficiency of the solder paste.

[0013] Furthermore, the upper surface of the hanger welding portion is provided with two first grooves, and the hanger is provided with two hanging arms, which are spaced apart. Each hanging arm has a second groove on its upper and lower surfaces, and the two first grooves are respectively arranged opposite the second grooves on the lower surfaces of the two hanging arms. The two hanging arms enable two-point welding, improving welding strength; the spacing between the two hanging arms can separate the two welding positions to prevent short circuits.

[0014] Furthermore, the first groove and the second groove are both provided with a copper layer, wherein the copper layer can improve the adhesion of the solder paste, making the soldering of the hanger to the circuit board more secure.

[0015] Furthermore, the aluminum busbar welding portion is provided with a bare copper portion, and the aluminum busbar is fixedly connected to the bare copper portion. The provision of the bare copper portion can improve the adhesion of the solder paste, making the aluminum busbar and the circuit board more firmly welded.

[0016] After adopting the above technical solution, the beneficial effect is: since the integrated busbar of the utility model is provided with a hanger welded and fixed to the thermistor, the SMT process and the ultrasonic welding process can be carried out independently, avoiding the problem of loose welding of the aluminum busbar due to excessively high temperature of the SMT process. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the integrated busbar involved in the present utility model;

[0018] Figure 2 A schematic diagram of a circuit board involved in the present utility model;

[0019] Figure 3 This is a schematic diagram of the pendant involved in the present utility model;

[0020] Figure 4 This is a schematic diagram of the reinforcing plate involved in the present invention.

[0021] The accompanying drawings are marked as follows: 1. Circuit board; 11. Pendant welding part; 111. Middle positioning hole; 112. First groove; 12. Aluminum busbar welding part; 121. Bare copper part; 2. Aluminum busbar; 3. Pendant; 30. Hanging arm; 31. Upper positioning hole; 32. Second groove; 33. Through hole; 4. Thermistor; 5. Reinforcement plate. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below by way of embodiments:

[0023] The utility model provides an integrated busbar of a power battery, such as Figure 1 As shown, the integrated busbar includes: a circuit board 1, several aluminum busbars 2, hangers 3, thermistors 4, and reinforcement plates 5. The aluminum busbars 2, hangers 3, and reinforcement plates 5 are all welded to the circuit board 1. The reinforcement plates 5 are located directly below the hangers 3. Thermistors 4 are welded to the hangers 3. The circuits of the circuit board 1 and the hangers 3 are both provided. The circuits of the aluminum busbars 2 and hangers 3 are electrically connected to the circuits of the circuit board 1. Thermistors 4 are also electrically connected to the circuits of the hangers 3. In this embodiment, the hangers 3 are welded to the top surface of the circuit board 1, the reinforcement plates 5 are welded to the bottom surface of the circuit board 1, and the aluminum busbars 2 are welded to the bottom surface of the circuit board 1.

[0024] When manufacturing this integrated busbar, the aluminum busbar 2 is first ultrasonically welded to the circuit board 1. The thermistor 4 is then soldered to the hanger 3 using the SMT process. Finally, the hanger 3 and the reinforcing plate 5 are soldered to the circuit board 1 using a hot press process. Aluminum busbar 2 collects power battery temperature information. After this temperature information is transmitted to thermistor 4, its resistance changes, and the power battery temperature is determined based on this resistance.

[0025] Specifically, the circuit board 1 is provided with a hanger welding portion 11 protruding from the side and several aluminum bar welding portions 12 protruding from the side. The hanger 3 is welded and fixed to the upper surface of the hanger welding portion 11, the reinforcement plate 5 is fixedly connected to the lower surface of the hanger welding portion 11, and the aluminum bar 2 is welded and fixed to the aluminum bar welding portion 12.

[0026] It is worth mentioning that although in the present embodiment, there is one aluminum bar 2, in other embodiments, there may be multiple aluminum bars 2, and accordingly, there may be multiple aluminum bar welding portions 12. The multiple aluminum bar welding portions 12 are arranged in two rows on both sides of the circuit board 1, and the multiple aluminum bars 2 are respectively welded and fixed to the multiple aluminum bar welding portions 12.

[0027] More specifically, the hanger welding portion 11 has a central positioning hole 111, the hanger 3 has an upper positioning hole 31, and the reinforcing plate 5 has a lower positioning hole 51. The upper positioning hole 31, the central positioning hole 111, and the lower positioning hole 51 are arranged from top to bottom and have the same shape and size. During hot press welding, the jig's positioning pins can be inserted through the upper positioning hole 31, the central positioning hole 111, and the lower positioning hole 51 before welding.

[0028] As a preferred solution, there are two upper positioning holes 31 , two middle positioning holes 111 and two lower positioning holes 51 .

[0029] More specifically, the upper surface of the hanger welding portion 11 is provided with a first groove 112, and the upper and lower surfaces of the hanger 3 are both provided with a second groove 32. A through hole 33 is provided between the second grooves 32 on the upper and lower surfaces of the hanger 3. The first groove 112 is arranged opposite the second groove 32 on the lower surface of the hanger 3. During hot press welding, solder paste can be applied to the second groove 32 on the upper surface of the hanger 3, and the solder paste flows through the through hole 33 into the space between the second groove 32 and the first groove 112 of the hanger 3.

[0030] As a preferred solution, two through holes 33 are provided between the second grooves 32 on the upper and lower surfaces of the hanger 3 .

[0031] More specifically, the upper surface of the hanger welding portion 11 is provided with two first grooves 112, and the hanger 3 is provided with two hanging arms 30, which are spaced apart. Each hanging arm 30 has a second groove 32 on its upper and lower surfaces, and the two first grooves 112 are respectively arranged opposite the second grooves 32 on the lower surfaces of the two hanging arms 30. In the hot press welding method, the two hanging arms 30 are simultaneously welded to the upper surface of the hanger welding portion 11.

[0032] As a preferred solution, both the first groove 112 and the second groove 32 are provided with a copper layer.

[0033] As a preferred solution, the aluminum busbar welding portion 12 is provided with a bare copper portion 121 , and the aluminum busbar 2 is fixedly connected to the bare copper portion 121 .

[0034] Specifically, the reinforcing plate 5 is formed of one of FR-4, steel and PI materials.

Claims

1. An integrated busbar for a power battery, comprising: A circuit board, several aluminum busbars and a thermistor, wherein the circuit board is provided with a circuit, the aluminum busbars are welded and fixed to the circuit board and electrically connected to the circuit of the circuit board; the characteristic is that the integrated busbar further comprises: a hanger, wherein the hanger is provided with a circuit, the hanger is welded and fixed to the circuit board and the circuit of the hanger is electrically connected to the circuit of the circuit board, and the thermistor is welded and fixed to the hanger and electrically connected to the circuit of the hanger.

2. The integrated busbar of the power battery according to claim 1, characterized in that: The integrated busbar further comprises a reinforcing plate, which is welded and fixed to the circuit board and is located directly below the hanger.

3. The integrated busbar of the power battery according to claim 2, characterized in that: The circuit board is provided with a hanger welding portion protruding from the side and several aluminum bar welding portions protruding from the side. The hanger is welded and fixed to the upper surface of the hanger welding portion, the reinforcement plate is fixedly connected to the lower surface of the hanger welding portion, and the aluminum bar is welded and fixed to the aluminum bar welding portion.

4. The integrated busbar of the power battery according to claim 3, characterized in that: The hanger welding portion is provided with a middle positioning hole, the hanger is provided with an upper positioning hole, and the reinforcing plate is provided with a lower positioning hole. The upper positioning hole, the middle positioning hole and the lower positioning hole are arranged from top to bottom and have the same shape and size.

5. The integrated busbar of the power battery according to claim 4, characterized in that: There are two upper positioning holes, two middle positioning holes and two lower positioning holes.

6. The integrated busbar of the power battery according to claim 3, characterized in that: A first groove is provided on the upper surface of the hanger welding part, a second groove is provided on the upper and lower surfaces of the hanger, and a through hole is provided between the second grooves on the upper and lower surfaces of the hanger, and the first groove is arranged opposite to the second groove on the lower surface of the hanger.

7. The integrated busbar of the power battery according to claim 6, characterized in that: Two through holes are provided between the second grooves on the upper and lower surfaces of the hanging piece.

8. The integrated busbar of the power battery according to claim 6, characterized in that: Two first grooves are provided on the upper surface of the hanger welding part, and the hanger is provided with two hanging arms, which are arranged at a distance from each other. Second grooves are provided on the upper surface and lower surface of each hanging arm, and the two first grooves are respectively arranged opposite to the second grooves on the lower surfaces of the two hanging arms.

9. The integrated busbar of the power battery according to claim 6, characterized in that: The first groove and the second groove are both provided with a copper layer.

10. The integrated busbar of the power battery according to claim 1, characterized in that: The aluminum bar welding portion is provided with a bare copper portion, and the aluminum bar is fixedly connected to the bare copper portion.

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