A plastic-encapsulated power semiconductor module

Abstract

The utility model discloses a kind of plastic power semiconductor modules, including heat dissipation bottom plate, insulating substrate, chip, signal control component, power end and the plastic package of epoxy resin material, one side of heat dissipation bottom plate is heat dissipation surface and opposite another side is equipped with multiple first welding surfaces, one side of insulating substrate is second welding surface and opposite another side is circuit pattern surface, each first welding surface is welded with second welding surface respectively, chip, signal control component and power end are located circuit pattern surface, circuit pattern surface is equipped with for realizing the clamping and / or bonding wire between chip, between chip and circuit pattern surface, plastic package covers each first welding surface, insulating substrate, chip, clamping, bonding wire, signal control component and power end, plastic package top surface and signal control component and power end corresponding place are hollow structure, signal control component penetrates hollow structure. Three-phase inverter function can be realized by single module, multiple modules are not needed Parallel connection, convenient wiring, be conducive to saving space.

Description

Technical Field

[0001] This utility model relates to the field of power semiconductor packaging technology, and in particular to a plastic-encapsulated power semiconductor module. Background Technology

[0002] Currently, the mainstream power modules on the market are basically silicone gel encapsulated modules. Encapsulated modules have a complete range of packaging types and circuit topologies, and the manufacturing process is relatively mature. Therefore, encapsulated modules occupy a dominant position in the market. However, they have obvious deficiencies in moisture resistance and corrosion resistance. The silicone gel itself and the interface between the silicone gel and the shell are easily penetrated by corrosive gases and moisture, which can damage the internal chips and other components of the product and reduce the overall reliability of the product. At the same time, the high coefficient of thermal expansion of silicone gel can cause tension on the bonding wires inside the product during use, which can also reduce the overall reliability of the product.

[0003] There are relatively few types of molded modules on the market, mainly Tpak (Tesla Pack), DSC (double-sided heat dissipation), and DCM (direct cooling injection molding) modules. Power and signal terminals are all led out from the side of the module, making wiring inconvenient and prone to cable crossing. Furthermore, due to product size limitations, existing molded module circuit topologies are relatively simple, primarily using SingleSwitch and Half-Bridge topologies. At least three modules need to be connected in parallel for use. Currently, there is a lack of molded modules with Full-Bridge topologies on the market. Utility Model Content

[0004] The technical problem to be solved by this utility model is to overcome the shortcomings of the prior art and provide a plastic-encapsulated power semiconductor module that can realize three-phase inverter function with a single module, without the need for multiple modules in parallel, which is convenient for wiring and helps to save space.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: A molded power semiconductor module includes a heat dissipation base plate, an insulating substrate, a chip, a signal control component, a power terminal, and a molding compound made of epoxy resin. The heat dissipation base plate has a heat dissipation surface on one side and multiple first welding surfaces on the opposite side. The insulating substrate has a second welding surface on one side and a circuit pattern surface on the opposite side. Each first welding surface is welded to a second welding surface of the insulating substrate. The chip, the signal control component, and the power terminal are disposed on the circuit pattern surface. The circuit pattern surface has clamps and / or bonding wires for establishing connections between chips and between the chip and the circuit pattern surface. The molding compound covers each first welding surface, the insulating substrate, the chip, the clamps, the bonding wires, the signal control component, and the power terminal. The top surface of the molding compound has a hollow structure corresponding to the signal control component and the power terminal, and the signal control component passes through the hollow structure.

[0006] As a further improvement to the above technical solution: the heat dissipation surface is provided with a boss, and the boss is provided with a heat dissipation pin fin structure.

[0007] As a further improvement to the above technical solution: each side of the heat dissipation base plate is provided with a stepped structure, and the plastic sealant engages with the stepped structure.

[0008] As a further improvement to the above technical solution: the signal control component includes a pin holder and a pin, the bottom surface of the pin holder is welded to the circuit pattern surface and the top surface is exposed through the hollow structure, the height of the top surface of the pin holder is less than the height of the top surface of the hollow structure, the lower end of the pin is inserted into the pin holder and the upper end penetrates through the hollow structure; or, the signal control component includes a pin, the lower end of the pin is welded to the circuit pattern surface and the upper end penetrates through the hollow structure.

[0009] As a further improvement to the above technical solution: the power end is a conductive block, and the height of the top surface of the conductive block is less than the height of the top surface of the hollow structure; or the power end is a nut, and the height of the top surface of the nut is not less than the height of the top surface of the hollow structure.

[0010] As a further improvement to the above technical solution: the conductive block is a copper block, and the clip is a copper clip.

[0011] As a further improvement to the above technical solution: the circuit pattern surface is also provided with a thermistor for detecting temperature, and the thermistor is located inside the plastic encapsulation.

[0012] As a further improvement to the above technical solution: the top surface of the molding compound has strip-shaped protrusions on both sides opposite to each other for supporting the PCB board.

[0013] As a further improvement to the above technical solution: the top surface of the molding compound is provided with a through groove along the short side of the module to relieve stress.

[0014] As a further improvement to the above technical solution, the top surface of the plastic sealant is also provided with an isolation groove for increasing the creepage distance.

[0015] Compared with the prior art, the advantages of this utility model are: This utility model discloses a plastic-encapsulated power semiconductor module that can achieve three-phase inverter functionality with a single plastic-encapsulated module. It overcomes the limitation of traditional half-bridge plastic-encapsulated modules, which require at least three modules in parallel. Through a single injection molding process, a three-phase full-bridge topology is achieved within one module. Compared to traditional plastic-encapsulated half-bridge modules, this utility model simplifies the overall process, reduces costs, and achieves higher power density while maintaining the same power output. Furthermore, the signal and power terminals are located on the upper surface of the plastic-encapsulated module, reducing cable crossings and facilitating routing on the PCB (printed circuit board) or in the system, especially saving space in compact devices. Compared to traditional potted HPD (HybridPACK™ Drive) packaged three-phase full-bridge modules, this invention uses epoxy resin as the sealing material in its molding compound. This results in superior moisture and sulfur resistance, higher strength after curing, and, compared to silicone gel, less thermal expansion after curing, better constraint on pins and bonding wires, leading to stronger PC cycle capability (power cycle capability). The overall module volume is approximately one-third that of a potted HPD module, reducing installation costs for users. Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] Figure 1 This is a partial cross-sectional structural diagram of Embodiment 1 of this utility model.

[0017] Figure 2 This is a schematic diagram of the back structure of the heat dissipation base plate according to Embodiment 1 of this utility model.

[0018] Figure 3 This is a schematic diagram of the structure of the insulating substrate of Embodiment 1 of this utility model, wherein (a) is the upper surface, (b) is the side surface, and (c) is the lower surface.

[0019] Figure 4 This is a schematic diagram of the signal control component in Embodiment 1 of this utility model.

[0020] Figure 5 This is a schematic diagram of the encapsulation component according to Embodiment 1 of this utility model.

[0021] Figure 6 This is the half-bridge topology implementation method and circuit topology diagram corresponding to Embodiment 1 of this utility model, wherein (a) is the half-bridge topology implementation method and (b) is the circuit topology diagram.

[0022] Figure 7 This is a partial cross-sectional structural diagram of Embodiment 2 of this utility model.

[0023] Figure 8 This is the half-bridge topology implementation method and circuit topology diagram corresponding to Embodiment 2 of this utility model, wherein (a) is the half-bridge topology implementation method and (b) is the circuit topology diagram.

[0024] Figure 9 This is a schematic cross-sectional view of the connection between Embodiment 2 of this utility model and the PCB board.

[0025] The labels in the diagram represent: 01. Heat sink base plate; 011. Heat sink surface; 012. Boss; 013. Heat sink fin structure; 014. Step structure; 02. Insulating substrate; 021. Second welding surface; 022. Circuit pattern surface; 03. Chip; 04. Clip; 05. Bonding wire; 06. Signal control component; 061. Pin holder; 062. Pin; 07. Conductive block; 08. Thermistor; 09. Bushing; 10. Molded component; 101. Strip-shaped raised structure; 102. Through groove; 103. Isolation groove; 11. Nut; 12. PCB board; 13. Bolt. Detailed Implementation

[0026] In the description of this utility model, it should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0027] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.

[0028] In this utility model, unless otherwise explicitly specified and limited, the terms "assembly," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0029] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] Example 1 Figures 1 to 6 An embodiment of the plastic-encapsulated power semiconductor module of this utility model is shown: like Figure 1 and Figure 2 As shown, preferably, the heat dissipation base plate 01 used in this invention has a protrusion 012 on its heat dissipation surface 011 (specifically, the bottom surface of the heat dissipation base plate 01) that is slightly higher than the bottom surface. This protrusion is used to increase the sealing effect during installation and reduce the risk of water leakage when installed on the cooling water channel. The top surface of the heat dissipation base plate 01 serves as the first welding surface. Furthermore, the heat dissipation fin structure 013 on the protrusion 012 is rhomboid in shape, but can also be circular, elliptical, teardrop-shaped, or other shapes. The heat dissipation fin structure 013 is used for direct water cooling, and compared to traditional plastic-encapsulated modules such as DSC and SSC, this invention has a better heat dissipation effect. In addition, preferably, the heat dissipation base plate 01 has stepped structures 014 on its four sides. After injection molding, the molding compound 10 and the heat dissipation base plate 01 engage with each other at these points, which can increase the bonding force between the two and effectively prevent the molding compound 10 and the heat dissipation base plate 01 from delaminating, thereby increasing the service life of the module. The heat dissipation base plate 01 has circular through holes at its four corners for the installation and fixing of the entire module. The bushing 09 is nested in the circular through holes by pressing. The upper surface of the molding compound 10 is also hollowed out at the corresponding points of the circular through holes and bushing 09 so that the circular through holes and bushing 09 are exposed.

[0031] like Figure 3As shown, preferably, the insulating substrate 02 is made of ceramic substrate, which has good insulation and heat dissipation performance. Of course, other materials can also be used in other embodiments. The lower surface of the ceramic substrate serves as the second welding surface 021, which is connected to the first welding surface by soldering. The upper surface of the ceramic substrate serves as the circuit pattern surface 022, which includes nine independent copper layers. These copper layers are not connected to each other and can be used as the welding areas for the chip 03, clip 04, signal control component 06, conductive block 07 (preferably made of copper, which has good conductivity and thermal conductivity), and thermistor 08, as well as the bonding areas for bonding wires 05. The drain / collector of the chip 03 is soldered to the circuit pattern surface 022 of the ceramic substrate. The source / emitter of the chip 03 is electrically connected between different chips 03 and between the chip 03 and the ceramic substrate through the clip 04 and bonding wires 05. These functional areas may be on the same copper layer, and different designs are made according to the actual circuit topology.

[0032] like Figure 4 As shown, preferably, the module signal control component 06 includes two parts: a pin holder 061 and a pin 062. The module connects to the external PCB board 12 through the pin 062 to achieve signal control. Preferably, the bottom end of the pin holder 061 is welded to the circuit pattern surface 022 of the ceramic substrate using ultrasonic welding technology, or it can be achieved using brazing technology. Before injection molding, the pin holder 061 and the pin 062 are separate; the pin 062 is inserted into the pin holder 061 after injection molding. Preferably, the pin 062 is square in shape with tapered ends for easy insertion. Of course, the pin 062 can also be round, or a fisheye pin, etc.

[0033] like Figure 6 As shown, preferably, this utility model provides a circuit pattern and chip layout for a ceramic substrate of a SiC module. Six chips are distributed on the ceramic substrate, forming a half-bridge topology. There are four chips in each of the upper and lower half-bridges, and the number of chips can be increased or decreased accordingly based on different power requirements. In the upper bridge portion of the module's circuit topology, current flows in from the DC+ terminal, passes through the three chips on the left, and flows out from the AC terminal; in the lower bridge portion, current flows in from the AC terminal, passes through the three chips on the right, and flows out from the DC- terminal. The signal control components 06 corresponding to G, D, and S are connected to the external PCB to perform electrical signal control, while T1 and T2 function as temperature sensors during operation.

[0034] Preferably, in this invention, three identical ceramic substrates are welded onto a heat dissipation base plate 01 to form a three-phase full-bridge topology (a combination of three half-bridge topologies), and a single module can achieve three-phase inverter functionality. Compared to traditional half-bridge modules such as DCM and DSC, it eliminates the need for three modules in parallel, reducing the number of modules required.

[0035] Preferably, the bottom surface of the power end copper block is brazed onto the circuit pattern surface 022, and the top surface of the copper block is exposed. In application, it is interconnected with the external busbar by laser welding.

[0036] Preferably, the thermistor 08 is soldered onto the circuit pattern surface 022 for temperature detection.

[0037] Preferably, the molding compound 10 in this invention is used to cover the upper surface and sides of the heat dissipation base plate 01, the ceramic substrate, the chip 03, the clip 04, the bonding wire 05, the signal control component 06, the conductive block 07, the thermistor 08, and the bushing 09. After covering, the upper surface of the pin seat 061, the heat dissipation surface 011 of the heat dissipation base plate 01, the upper surface of the bushing 09, and the upper surface of the copper block are all exposed outside the molding compound 10. The upper surfaces of the pin seat 061 and the copper block are slightly lower than the upper surface of the molding compound 10, which can effectively prevent glue overflow during injection molding.

[0038] like Figure 5 As shown, preferably, the upper surface of the molding compound 10 has four strip-shaped protrusions 101 on both sides. During use, these protrusions support the PCB board 12, preventing it from tilting during installation and affecting the reliability of the connection between the signal control component 06 and the PCB board 12. A through groove 102 is provided on the upper surface of the molding compound 10 along the short side of the module to alleviate stress during manufacturing and reduce the risk of cracking due to excessive stress. The upper surface of the molding compound 10 also has an isolation groove 103 to enhance creepage distance, increasing the creepage distance between the power terminal copper blocks and reducing safety risks during use.

[0039] Furthermore, preferably, in the copper block welding area (corresponding to the DC+, DC- and AC ports) of the circuit pattern surface 022 of the ceramic substrate, the molding compound 10 has through holes at the corresponding positions. The lower surface of the copper block is welded to the circuit pattern surface 022 of the ceramic substrate, the upper surface is exposed, and the rest is wrapped by the molding compound 10. In use, the upper surface of the copper block is connected to the external busbar through laser welding technology, which has better reliability than traditional brazing technology.

[0040] Preferably, the dimensions of this utility model module are 116mm*64mm*9mm, and its volume is approximately one-third that of a potted HPD module (approximately 152*97*17mm). It is suitable for applications with power not exceeding 400KW, serving as a replacement for potted power modules with the same circuit topology. Compared to potted HPD modules, this utility model module offers superior moisture resistance, salt spray resistance, and corrosion resistance. Depending on power requirements, products in different sizes ranging from 90mm to 152mm in length and 50mm to 100mm in width can be produced to meet diverse market application needs.

[0041] Example 2 Figures 7 to 9 Another embodiment of the plastic-encapsulated power semiconductor module of this utility model is shown: like Figure 7 As shown, the heat dissipation pin structure 013 is removed from the heat dissipation surface 011 of the heat dissipation base plate 01. The heat dissipation base plate 01 is a metal plate. Except for the removal of the structure of the heat dissipation surface 011, the rest is consistent with that in Example 1. When in use, the module is pressed onto the heat sink. Thermal grease is applied between the module heat dissipation surface 011 and the heat sink to improve the heat conduction efficiency.

[0042] The module signal control component 06 is entirely implemented by the pin 062. The lower end of the pin 062 is soldered to the ceramic substrate by a brazing process, and the upper end is exposed outside the plastic package 10. The electrical interconnection between chips 10 and between chips 10 and the ceramic substrate is entirely implemented by the bonding wire 05. Compared with Example 1, the soldering process of the clip 04 is reduced, and it is easier to implement in terms of process.

[0043] In addition, such as Figure 8 As shown, Embodiment 2 provides a circuit pattern plane 022 and chip 03 layout for an IGBT (Insulated Gate Bipolar Transistor) module on a ceramic substrate. The module also uses three identical ceramic substrates, with four chips distributed on each substrate: two IGBT chips, two FRD (Fast Recovery Diode) chips, and one IGBT and one FRD combined into a switch. The four chips together form a half-bridge topology. In the upper bridge section of the circuit topology corresponding to the IGBT module, current flows in from the DC+ terminal, passes through the left IGBT chip, and flows out from the AC terminal; in the lower bridge section of the circuit topology, current flows in from the AC terminal, passes through the right IGBT chip, and flows out from the DC- terminal. The two FRD chips in the circuit topology also function as reverse recovery. The signal control components (06) corresponding to G, C, and E are connected to the external PCB to perform electrical signal control, among which T1 and T2 function as temperature detection during operation.

[0044] Preferably, in Embodiment 1, the copper block is replaced by a nut 11, which serves as the power interface of the module. The upper surface of the nut 11 is flush with or slightly higher than the upper surface of the molding compound 10. The lower surface of the nut 11 is directly soldered to the circuit pattern surface 022 of the ceramic substrate. Compared to the traditional method of embedding the nut 11 in the plastic shell of the potted module, the stray inductance of the product is lower because there is no copper busbar inside the plastic shell. In application, the module power terminal is mounted to the PCB board 12 with bolts 13, such as... Figure 9 As shown, while ensuring electrical connection, the module and PCB board 12 can be locked together, making it more convenient to use.

[0045] Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make many possible variations and modifications to the present invention, or modify it into equivalent embodiments, without departing from the scope of the present invention. Therefore, any simple modifications, equivalent changes, and modifications made to the above embodiments based on the technical essence of the present invention, without departing from the content of the present invention, should fall within the protection scope of the present invention.

Claims

1. A plastic-encapsulated power semiconductor module, characterized in that: The device includes a heat dissipation base plate (01), an insulating substrate (02), a chip (03), a signal control component (06), a power terminal, and a molding compound (10) made of epoxy resin. One side of the heat dissipation base plate (01) is a heat dissipation surface (011), and the opposite side has multiple first welding surfaces. One side of the insulating substrate (02) is a second welding surface (021), and the opposite side is a circuit pattern surface (022). Each first welding surface is welded to a second welding surface (021) of the insulating substrate (02). The chip (03), the signal control component (06), and the power terminal are located on the circuit pattern surface (011). 22), the circuit pattern surface (022) is provided with clips (04) and / or bonding lines (05) for realizing the connection between the chips (03) and between the chips (03) and the circuit pattern surface (022). The molding compound (10) covers each of the first welding surfaces, the insulating substrate (02), the chips (03), the clips (04), the bonding lines (05), the signal control component (06) and the power terminal. The top surface of the molding compound (10) is hollowed out at the location corresponding to the signal control component (06) and the power terminal. The signal control component (06) passes through the hollowed-out structure.

2. The plastic-encapsulated power semiconductor module according to claim 1, characterized in that: The heat dissipation surface (011) is provided with a boss (012), and the boss (012) is provided with a heat dissipation fin structure (013).

3. The plastic-encapsulated power semiconductor module according to claim 1, characterized in that: Each side of the heat dissipation base plate (01) is provided with a stepped structure (014), and the plastic sealant (10) engages with the stepped structure (014).

4. The plastic-encapsulated power semiconductor module according to claim 1, characterized in that: The signal control component (06) includes a pin holder (061) and a pin (062). The bottom surface of the pin holder (061) is welded to the circuit pattern surface (022), and the top surface is exposed through the hollow structure. The height of the top surface of the pin holder (061) is less than the height of the top surface of the hollow structure. The lower end of the pin (062) is inserted into the pin holder (061), and the upper end penetrates through the hollow structure. Alternatively, the signal control component (06) includes a pin (062), the lower end of which is welded to the circuit pattern surface (022), and the upper end penetrates through the hollow structure.

5. The plastic-encapsulated power semiconductor module according to claim 1, characterized in that: The power end is a conductive block (07), and the height of the top surface of the conductive block (07) is less than the height of the top surface of the hollow structure; or the power end is a nut (11), and the height of the top surface of the nut (11) is not less than the height of the top surface of the hollow structure.

6. The plastic-encapsulated power semiconductor module according to claim 5, characterized in that: The conductive block (07) is a copper block, and the clip (04) is a copper clip.

7. The plastic-encapsulated power semiconductor module according to claim 1, characterized in that: The circuit pattern surface (022) is also provided with a thermistor (08) for detecting temperature, the thermistor (08) being located inside the encapsulation (10).

8. The plastic-encapsulated power semiconductor module according to any one of claims 1 to 7, characterized in that: The top surface of the molding compound (10) has strip-shaped protrusions (101) on both sides opposite to each other for supporting the PCB board (12).

9. The plastic-encapsulated power semiconductor module according to any one of claims 1 to 7, characterized in that: The top surface of the molding compound (10) is provided with a through groove (102) along the short side of the module to relieve stress.

10. The plastic-encapsulated power semiconductor module according to any one of claims 1 to 7, characterized in that: The top surface of the plastic seal (10) is also provided with an isolation groove (103) for increasing the creepage distance.

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