High-safety connection module design method

Abstract

The invention discloses a design method of a high-safety connection module, and relates to the technical field of power electronics, the high-safety connection module is designed, the high-safety connection module comprises a connection module, and the connection module is arranged among a power module, a direct current power supply and a thin film capacitor; at least one group of protection circuits is integrated in the connection module, and each group of protection circuits corresponds to one independent bridge arm in the power module and is used for cutting off the connection between the bridge arm and a direct-current power supply when the bridge arm fails; each group of protection circuit comprises a high-speed switching device which is used for quickly cutting off the connection with the positive electrode and the negative electrode of the direct-current power supply when the corresponding bridge arm has a fault; connecting terminals for laser welding are arranged at the two ends of the connecting module, the material of a copper terminal is the same as the material of a terminal of the power module, and the material of an aluminum terminal is the same as the material of a terminal of the thin-film capacitor, so that laser welding between different materials is compatible; the problem that laser welding materials are not matched in the customer production process is effectively solved.

Description

Technical Field

[0001] This invention relates to the field of power electronics technology, and in particular to a design method for a high-safety connection module. Background Technology

[0002] In current power module applications, the power terminals of the power module are generally directly connected to the film capacitor, lacking the high-safety connection module described in this article. If one or more chips in the power module fail, the controller will malfunction and shut down directly, posing unpredictable risks to system functionality. For example, in automotive applications, a sudden malfunction at high speed could cause the vehicle to lose power, posing a significant safety hazard.

[0003] In current module application system design, power modules are mainly connected to film capacitors in four ways: terminal laser welding, bolt connection, soldering, and spring sheet crimping. High-current applications currently primarily use terminal laser welding and bolt connection.

[0004] Laser welding of terminals is suitable for applications with high current and high switching frequency, but the equipment and process costs increase with the size of the device terminals, and there are requirements for the materials used in the device terminals, resulting in high costs at present. Using bolted connections results in significant contact resistance and parasitic inductance due to the contact interface at the bolted joint. Although this reduces manufacturing difficulty, it greatly limits the module's output current and switching frequency. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the shortcomings of existing technologies in module applications that lack highly reliable connectors. The invention provides a high-safety connection module design method that effectively solves the problem that laser welding cannot be completed because the power module and the film capacitor terminal materials are different.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A high-safety connection module design method is provided, wherein a high-safety connection module is designed, the high-safety connection module includes a connection module, and the connection module is disposed between the power module and the DC power supply and the thin film capacitor; The connection module integrates at least one set of protection circuits. Each set of protection circuits corresponds to an independent bridge arm in the power module and is used to disconnect the bridge arm from the DC power supply when the bridge arm fails. Each of the protection circuits includes a high-speed switching device for quickly disconnecting the corresponding bridge arm from the positive and negative terminals of the DC power supply in the event of a fault in the corresponding bridge arm. The connection module has connection terminals for laser welding at both ends. The connection terminals include copper terminals and aluminum terminals. The copper terminals are made of the same material as the terminals of the power module, and the aluminum terminals are made of the same material as the terminals of the thin film capacitor, which facilitates laser welding between different materials.

[0007] As a further preferred embodiment of the high-safety connection module design method of the present invention, the protection circuit includes a positive protection circuit and a negative protection circuit; The positive protection circuit includes a battery positive terminal connecting to the positive terminal of the battery and a power module positive terminal connecting to the positive terminal of the power module, as well as a series high-speed switching device. The circuit formed by the battery positive terminal connecting to the power module positive terminal is the power module positive protection, which is responsible for cutting off the positive connection. The negative protection circuit includes a battery negative connection segment connecting the battery negative terminal and a power module negative connection terminal connecting the power module negative terminal, as well as a series high-speed switching device. The circuit formed by the power module negative connection terminal and the battery negative connection segment is the power module negative protection, responsible for cutting off the negative connection.

[0008] As a further preferred embodiment of the high-safety connection module design method of the present invention, the positive protection circuit and the negative protection circuit are stacked to counteract the magnetic field and thus reduce the stray inductance introduced into the system.

[0009] As a further preferred embodiment of the high-security connection module design method of the present invention, the packaging structure of the connection module includes a ceramic copper-clad laminate (DBC), epoxy resin, and signal terminals. Among them, the ceramic copper-clad laminate (DBC) is used as the carrier and electrical insulation layer of the high-speed switching device; Epoxy resin is used for molding to form the outer envelope of modules; Signal terminals are used to receive external control and detection signals.

[0010] As a further preferred embodiment of the high-safety connection module design method of the present invention, the packaging structure is a double-sided heat dissipation structure, and its internal power circuit is connected to the copper sheet by the Clip welding process, and insulation and support are achieved by the insulating spacer block.

[0011] As a further preferred embodiment of the high-security connection module design method of the present invention, the power module is a large half-bridge module composed of three independent small half-bridges.

[0012] As a further preferred embodiment of the high-safety connection module design method of the present invention, the connection module can be packaged as an independent module, or multiple protection circuits required for an inverter can be packaged in the same module.

[0013] Compared with the prior art, the present invention, employing the above technical solution, has the following technical effects: This invention discloses a high-safety connection module design method, comprising a connection module disposed between a power module, a DC power supply, and a film capacitor. The connection module integrates at least one set of protection circuits, each corresponding to an independent bridge arm in the power module, used to disconnect the bridge arm from the DC power supply in the event of a bridge arm failure. Each set of protection circuits includes a high-speed switching device, used to quickly disconnect the corresponding bridge arm from the positive and negative terminals of the DC power supply in the event of a bridge arm failure. During normal operation, the device is normally open, allowing multiple bridge arm modules to be used in parallel. In the event of an anomaly, a detection signal detects a failure in one bridge arm, controlling a failure switch to shut down the corresponding half-bridge. Other normal half-bridges of the same module continue to operate, and the system operates at reduced throttle. This process continues until all bridge arms of the module fail, at which point the system shuts down, reducing the risk of no power output. This invention addresses the terminal materials of film capacitors and power modules by fabricating corresponding and suitable laser welding materials at both ends of the invention. These materials are then laser welded to the terminals of the film capacitor and the power module, respectively, effectively solving the problem of mismatched laser welding materials during customer production. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the packaging structure of the high-security connection module of the present invention; Figure 2 This is a schematic diagram of the internal structure of the high-safety connection module of the present invention after the plastic sealant has been removed; Figure 3 This is a top view of the high-security connection module of the present invention; Figure 4 This is a bottom view of the high-security connection module of the present invention; Figure 5 This is a schematic diagram of the high-security connection module of the present invention.

[0015] The numbers in the diagram are as follows: P-1: Copper terminal; P-2: Ceramic copper clad laminate (DBC); P-3: Epoxy resin; P-4: Signal terminal; P-5: Aluminum terminal; P-6: Insulating spacer; P-7: Copper sheet; P-8: Power module negative connection terminal; P-9: Battery negative connection terminal; P-10: Battery positive connection terminal; P-11: Power module positive connection terminal; U-1, U-3: High-safety connection modules; U-2: Power module composed of multiple independent small half-bridges. Detailed Implementation

[0016] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings: The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention. The present invention will be described in detail below with reference to the accompanying drawings and preferred embodiments. The purpose and effects of the present invention will become clearer. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention.

[0017] A high-safety connection module design method is provided, wherein a high-safety connection module is designed, the high-safety connection module includes connection module U-1 and connection module U-3, and the connection module U-1 and connection module U-3 are disposed between power module U-2 and DC power supply and film capacitor; The connection module U-1 and the connection module U-3 have at least one set of protection circuits integrated inside. Each set of protection circuits corresponds to an independent bridge arm in the power module U-2 and is used to disconnect the connection between the bridge arm and the DC power supply when the bridge arm fails. Each of the protection circuits includes a high-speed switching device for quickly disconnecting the corresponding bridge arm from the positive and negative terminals of the DC power supply in the event of a fault in the corresponding bridge arm. The connection module has connection terminals for laser welding at both ends. The connection terminals include copper terminal P-1 and aluminum terminal P-5. The copper terminal P-1 is made of the same material as the terminal material of the power module U-2, and the aluminum terminal P-5 is made of the same material as the terminal material of the thin film capacitor, which facilitates laser welding between different materials.

[0018] The protection circuit includes a positive protection circuit and a negative protection circuit; The positive protection circuit includes a battery positive terminal P-10 connected to the positive terminal of the battery and a power module positive terminal P-11 connected to the positive terminal of the power module, as well as a series high-speed switching device. The circuit formed by the battery positive terminal P-10 and the power module positive terminal P-11 is the power module positive protection, which is responsible for cutting off the positive connection. The negative protection circuit includes a battery negative connection segment P-9 that connects to the battery negative terminal and a power module negative connection terminal P-8 that connects to the power module negative terminal, as well as a series high-speed switching device. The circuit formed by the power module negative connection terminal P-8 and the battery negative connection segment P-9 is the power module negative protection, responsible for cutting off the negative connection. The positive protection circuit and the negative protection circuit are stacked to counteract the magnetic field and thus reduce the stray inductance introduced into the system.

[0019] The encapsulation structure of the connection module U-1 and the connection module U-3 includes a ceramic copper-clad laminate DBC P-2, an epoxy resin P-3, and a signal terminal P-4; Among them, the ceramic copper-clad laminate DBC P-2 is used as the carrier and electrical insulation layer of the high-speed switching device; Epoxy resin P-3 is used for molding to form the outer envelope of the module; Signal terminal P-4 is used to receive external control and detection signals.

[0020] The device has a double-sided heat dissipation structure. Its internal power circuit is connected to the copper sheet P-7 using the Clip welding process, and insulation and support are achieved through the insulating spacer P-6.

[0021] This invention uses different terminal materials, which can be compatible with laser welding between different materials, and can effectively reduce connection resistance and parasitic inductance; The present invention adopts a stacked arrangement of positive and negative protection circuits, which can further reduce the stray inductance introduced into the system; This invention provides independent positive and negative protection for each small half-bridge, which can selectively shut down the faulty small half-bridge, reduce the output, and prevent the system from being completely without power output and causing danger, thus greatly improving the system's safety redundancy.

[0022] This patent can effectively solve the problem that laser welding cannot be completed because the power module and the film capacitor terminal materials are different.

[0023] This patent can significantly improve system security. Its working principle and effects are described below. Figure 5 As shown.

[0024] The power module U-2 is a large half-bridge module composed of three independent small half-bridges; An inverter requires three complete power modules U-2; The circuits of connection module U-1 and connection module U-3 are placed in the same package module, forming the circuit topology of this invention patent; An inverter requires a combination circuit of three connection modules U-1 and U-3; The combined circuit of connection module U-1 and connection module U-3 can be packaged into one module in one set, or into three modules in one set. The number of protection circuits in connection module U-1 and connection module U-3 can be increased or decreased as needed.

[0025] When a fault occurs in the “V1+, Vo-1, V1-” bridge arm in power module U-2, Pre1+ and Pre4- will be immediately shut down according to the protection signal, and the drive output will be turned off at the same time. At the same time, the system quickly checks the normal status of the "V2+, Vo-2, V2-" and "V3+, Vo-3, V3-" circuits; Based on the detected normal half-bridge condition, reopen the corresponding driver and prompt the user with the maximum output capability that can be provided at present; From the moment a fault occurs and zero power output occurs until reduced power output resumes, the entire process can be controlled within 10ms, greatly improving the system's functional safety.

[0026] In this embodiment, the physical structure of the high-security connection module is as follows: Figures 1 to 4 As shown. Its manufacturing process includes: soldering or bonding high-speed switching chips onto the ceramic copper-clad laminate DBC P-2; constructing a low-inductance multilayer power circuit (P-8 to P-11) using the Clip process with copper sheet P-7 and insulating spacer block Spacer P-6; installing laser-welded terminals (copper terminal P-1 and aluminum terminal P-5) and signal terminal P-4 that match the materials of external components; and finally encapsulating the entire circuit with epoxy resin P-3.

[0027] Principle: During normal system operation, all high-speed switches in the protection circuits are in the ON state, and each bridge arm operates in parallel. When the system detects a fault in the "V1+, Vo-1, V1-" bridge arm in power module U-2, the control unit immediately sends a command to the corresponding connection modules U-1 and U-3 via signal terminal P-4 to shut down the high-speed switches responsible for the positive Pre1+ and negative Pre4- paths of that bridge arm. Simultaneously, the drive signal for the faulty bridge arm is also turned off. The system then checks the status of the remaining bridge arms and recalculates and outputs the dated power based on the normal "V2+, Vo-2, V2-" and "V3+, Vo-3, V3-" bridge arms. This fault switching and system recovery process is extremely rapid, completing within 10ms, thus achieving seamless dated operation and greatly improving safety and user experience.

[0028] It will be understood by those skilled in the art that the above descriptions are merely preferred examples of the invention and are not intended to limit the invention. Although the invention has been described in detail with reference to the foregoing examples, those skilled in the art can still modify the technical solutions described in the foregoing examples or make equivalent substitutions for some of the technical features. All modifications and equivalent substitutions made within the spirit and principles of the invention should be included within the scope of protection of the invention. All technical features in this embodiment can be freely combined according to actual needs.

[0029] Finally, it should be noted that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A high-security connection module design method, characterized in that, Design a high-safety connection module, which includes connection modules (U-1, U-3), and the connection modules (U-1, U-3) are disposed between the power module (U-2) and the DC power supply and the film capacitor; The connection modules (U-1, U-3) integrate at least one set of protection circuits. Each set of protection circuits corresponds to an independent bridge arm in the power module (U-2) and is used to disconnect the bridge arm from the DC power supply when the bridge arm fails. Each of the protection circuits includes a high-speed switching device for quickly disconnecting the corresponding bridge arm from the positive and negative terminals of the DC power supply in the event of a fault in the corresponding bridge arm. The connection module has connection terminals for laser welding at both ends. The connection terminals include copper terminals (P-1) and aluminum terminals (P-5). The copper terminal (P-1) is made of the same material as the terminal material of the power module (U-2), and the aluminum terminal (P-5) is made of the same material as the terminal material of the thin film capacitor, which facilitates laser welding between different materials.

2. The high-security connection module design method according to claim 1, characterized in that, The protection circuit includes a positive protection circuit and a negative protection circuit; The positive protection circuit includes a battery positive terminal (P-10) connected to the positive terminal of the battery and a power module positive terminal (P-11) connected to the positive terminal of the power module, as well as a series high-speed switching device. The circuit formed by the battery positive terminal (P-10) and the power module positive terminal (P-11) is the positive protection circuit for the power module, which is responsible for cutting off the positive connection. The negative protection circuit includes a battery negative connection segment (P-9) connecting the battery negative terminal and a power module negative connection terminal (P-8) connecting the power module negative terminal, as well as a series high-speed switching device. The circuit formed by the power module negative connection terminal (P-8) and the battery negative connection segment (P-9) is the power module negative protection, responsible for cutting off the negative connection.

3. The high-security connection module design method according to claim 2, characterized in that, The positive protection circuit and the negative protection circuit are stacked to counteract the magnetic field and thus reduce the stray inductance introduced into the system.

4. The high-security connection module design method according to claim 1, characterized in that, The encapsulation structure of the connection module (U-1, U-3) includes a ceramic copper-clad laminate (DBC) (P-2), epoxy resin (P-3), and signal terminals (P-4). Among them, the ceramic copper-clad laminate DBC (P-2) is used as the carrier and electrical insulation layer of the high-speed switching device; Epoxy resin (P-3) is used for molding to form the outer envelope of the module; The signal terminal (P-4) is used to receive external control and detection signals.

5. The high-security connection module design method according to claim 4, characterized in that, The package structure is a double-sided heat dissipation structure. Its internal power circuit is connected to the copper sheet (P-7) using the Clip soldering process, and insulation and support are achieved through the insulating spacer (P-6).

6. The high-security connection module design method according to claim 1, characterized in that, The power module (U-2) is a large half-bridge module, which consists of three independent small half-bridges.

7. The high-security connection module design method according to claim 1, characterized in that, The connection modules (U-1, U-3) can be packaged as a separate module, or multiple protection circuits required for an inverter can be packaged in the same module.

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