An integrated three-phase full-bridge power module

Abstract

The application discloses an integrated three-phase full-bridge power module and relates to the field of semiconductor devices.The application comprises a frame, a chip, a power connecting part, a signal connecting part and a plastic sealing body.The frame and the chip are connected through welding material, the frame is connected with each part through the power connecting part and the signal connecting part, and the plastic sealing body is sealed.In the application, the cost is reduced through MOS tube integration, heat dissipation is facilitated, the power is not reduced while the volume is reduced, the reliability of the integrated MOS is higher than that of the discrete MOS, the switching loop area is small, and the anti-electromagnetic interference performance is better.The integrated MOS can improve the product competitiveness.

Description

Technical Field

[0001] This invention relates to the field of semiconductor devices, and more particularly to an integrated three-phase full-bridge power module. Background Technology

[0002] Currently, three-phase full-bridge power modules on the market are composed of six MOSFETs or three half-bridge packages, and are then used in brushless motors. Because the three-phase full-bridge power modules are composed of half-bridge packages, their size is relatively large. There are also applications using discrete MOSFETs, but these suffer from large size and poor heat dissipation.

[0003] The State Intellectual Property Office issued an authorization announcement on May 19, 2023, with announcement number CN219046290U, entitled "A Full-Bridge Power Module," which includes a lead frame divided into a first base island, a second base island, a third base island, a fourth base island, power supply pins, a GND pin, a gate pin, and output pins. MOSFETs are assembled on the first, second, third, and fourth base islands. The electrodes are connected according to a three-phase full-bridge circuit to achieve a three-phase full-bridge electrical connection. Partial half-etching is used on the second, third, and fourth base islands, the GND pin, and the gate pin. This partial half-etching, with molding compound filling and covering the half-etched portions, increases the bonding strength between the base islands, pins, and molding compound, thereby increasing the module's mechanical strength.

[0004] However, its problems are: 1. There are gaps between the second base island and the third and fourth base islands, and there are also gaps between the second base island and the first base island, resulting in a large volume; 2. The second, third, and fourth base islands have GND pins at both ends. This results in an excessively long circuit current path, causing ① excessively high packaging resistance, leading to excessive energy loss and heat generation in the device; ② high parasitic inductance; and the base islands carrying the chip are concentrated, causing heat to concentrate in the center. 3. Using PCB board circuit heat dissipation has the following drawbacks: ① poor heat dissipation ② may have thermal effects on other components on the PCB board. 4. The DS overcurrent circuit and GS control circuit of the U, V, and W phase chips share the S terminal, causing interference between the current and control signal; 5. If the soldering area between the product and the PCB is too large, it will warp and separate from the PCB under vibration and temperature shock. Summary of the Invention

[0005] To address the above problems, this invention provides an integrated three-phase full-bridge power module with a simple structure, high integration, and improved reliability.

[0006] The technical solution of the present invention is as follows: an integrated three-phase full-bridge power module, including a plastic package, a frame is provided inside the plastic package, the top surface of the frame is on the same plane as the top surface of the plastic package, and the two sides of the frame extend out of the two side edges of the plastic package; The frame includes six pin groups, a VS phase base island on one side, and a U phase base island, a V phase base island, and a W phase base island on the other side. Among them, three pin groups are located on one side of the VS phase base island, and the other three pin groups are set one-to-one with the U phase base island, V phase base island and W phase base island; The pin group includes source pins and gate pins. The frame also includes GND pins located between the U-phase base island and the V-phase base island, and between the V-phase base island and the W-phase base island. The VS phase base island is provided with three chips, and the U phase base island, V phase base island and W phase base island are each provided with one chip; The chip includes a semiconductor layer, with a source metal layer and a gate metal layer on the top and a drain metal layer on the bottom. The source metal layers of the three chips on the VS phase base island are respectively connected to the U phase base island, V phase base island and W phase base island in a one-to-one correspondence. The source metal layers of the chips on the U-phase base island and V-phase base island are respectively connected to the GND pin located between the U-phase base island and V-phase base island. The source metal layers of the chips on the V-phase base island and the W-phase base island are respectively connected to the GND pin located between the V-phase base island and the W-phase base island. The source metal layer and gate metal layer of the three chips on the VS phase base island are also connected one-to-one to the three pin groups on one side of the molding compound. The source metal layer and gate metal layer of the chip on the U-phase base island, V-phase base island and W-phase base island are also connected one-to-one to the three pin groups on the other side of the molding compound.

[0007] Steps are provided on the VS phase base island, U phase base island, V phase base island and W phase base island respectively.

[0008] The source metal layers of the three chips on the VS phase base island are connected one-to-one to the U phase base island, V phase base island and W phase base island by aluminum wires. The source metal layers of the chips on the U-phase base island, V-phase base island, and W-phase base island are connected to the corresponding GND pins via aluminum wires.

[0009] The source metal layers of the three chips on the VS phase base island are connected one-to-one to the U phase base island, V phase base island and W phase base island respectively by aluminum strips; The source metal layers of the chips on the U-phase base island, V-phase base island, and W-phase base island are connected to the corresponding GND pins via aluminum strips.

[0010] The source metal layers of the three chips on the VS phase base island are connected one-to-one to the U phase base island, V phase base island and W phase base island respectively through copper sheets; The source metal layers of the chips on the U-phase base island, V-phase base island, and W-phase base island are connected to the corresponding GND pins via copper sheets.

[0011] The source metal layer and gate metal layer of the three chips on the VS phase base island are also connected to several pins on one side of the plastic package through aluminum wires. The source metal layer and gate metal layer of the chip on the U-phase base island, V-phase base island and W-phase base island are also connected to several pins on the other side of the plastic package through aluminum wires.

[0012] The portion of the frame extending out of the plastic seal is provided with a tin-plated layer, the thickness of which is 8-20 μm.

[0013] The VS phase base island includes three VS phase base island pins extending out of the molding compound. The U-phase base island includes U-phase base island pins extending out of the molding compound. The V-phase base island includes V-phase base island pins extending out of the molding compound. The W-phase island includes W-phase island pins extending out of the molding compound.

[0014] The source pin, gate pin, GND pin, VS phase base island pin, U phase base island pin, V phase base island pin, and W phase base island pin are all gull-shaped pins.

[0015] In operation, this invention reduces costs and facilitates heat dissipation through MOSFET integration, while maintaining power output despite a smaller size. Compared to discrete MOSFETs, integrated MOSFETs offer higher reliability, a smaller switching loop area, and better electromagnetic interference immunity. Using integrated MOSFETs can enhance product competitiveness. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the entire invention. Figure 1 ; Figure 2 This is a front view of the framework of the present invention; Figure 3 This is a schematic diagram of the back of the frame of the present invention; Figure 4 This is a schematic diagram of the chip of the present invention; Figure 5 This is a circuit diagram of the chip of the present invention; Figure 6 This is an assembly diagram of the present invention. Figure 1 ; Figure 7 This is an assembly diagram of the present invention. Figure 2 ; Figure 8 This is an assembly diagram of the present invention. Figure 3 ; Figure 9 This is a schematic diagram of the entire invention. Figure 2 ; In the diagram: 1. Frame; 101. VS phase base island; 102. U phase base island; 103. V phase base island; 104. W phase base island; 105. GHU pin; 106. SHU pin; 107. GHV pin; 108. SHV pin; 109. GHW pin; 110. SHW pin; 111. SLU pin; 112. GLU pin; 113. SLV pin; 114. GLV pin; 115. SLW pin; 116. GLW pin; 117. GND pin; 118. Step; 2. Chip; 201. Semiconductor layer; 202. Source metal layer; 203. Gate metal layer; 204. Drain metal layer; 3. Power connection part; 301. Two-phase power connection part; 302. Grounding power connection part; 4. Signal connection section; 401. Gate signal connection section; 402. Source signal connection section; 5. Plastic sealant. Detailed Implementation

[0017] Embodiments of the present invention are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and should not be construed as limiting the present invention.

[0018] In the description of this invention, it should be understood that the terms "upper," "lower," "left," "right," "vertical," and "horizontal," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the invention 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, and therefore should not be construed as a limitation of the invention. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0019] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; 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; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0020] The present invention is as follows Figure 1-8 As shown, an integrated three-phase full-bridge power module includes a frame 1, a chip 2, a power connection part 3, a signal connection part 4, and a plastic package 5. The top surface of the frame and the top surface of the plastic package are located on the same plane, so heat dissipation is achieved through the exposed metal at the top. Figure 9 As shown; The frame extends beyond the two sides of the encapsulated body; The frame includes six pin groups, a VS phase base island on one side, and a U phase base island, a V phase base island, and a W phase base island on the other side. Among them, three pin groups are located on one side of the VS phase base island, and the other three pin groups are set one-to-one with the U phase base island, V phase base island and W phase base island; The pin group includes source pins and gate pins. There is only one gap between the VS phase base island and the U, V, and W phase base islands. This invention uses a stamped frame, which ensures the overall stability of the frame and greatly reduces costs compared to etched frames or substrates (currently, the cost of etched frames is more than 5 times that of stamped frames, and the cost of substrates is more than 10 times that of stamped frames). By providing a gap, the structure is compact and costs are reduced.

[0021] Specifically, frame 1 includes VS phase base island 101, U phase base island 102, V phase base island 103, W phase base island 104, GHU pin 105, SHU pin 106, GHV pin 107, SHV pin 108, GHW pin 109, SHW pin 110, SLU pin 111, GLU pin 112, SLV pin 113, GLV pin 114, SLW pin 115, GLW pin 116, GND pin 117, and step 118. Two GND pins 117 are located between the U-phase base island and the V-phase base island, and between the V-phase base island and the W-phase base island, to avoid heat concentration. The base island is used to carry the chip and connect to the external circuit through the pins, which are used to connect the circuit.

[0022] Step 118 is used to enhance the sealing effect of the plastic sealant and improve product reliability. Conventional frames have all parts on one plane, resulting in poor reliability.

[0023] Specifically, chip 2 includes a semiconductor layer 201, a source metal layer 202, a gate metal layer 203, and a drain metal layer 204. The semiconductor layer has a source metal layer and a gate metal layer on top and a drain metal layer on the bottom. Wherein, source: S, drain: D, gate: G.

[0024] In this invention, the chips on the VS phase base island, as well as the chips on the U, V, and W phase base islands, have two S-terminals connected to the outside, so that the signal switches of GS and the current paths of DS do not interfere with each other.

[0025] The working principle of a MOSFET is to change the conduction of the device by controlling the control signal between the gate and source (GS). By applying a voltage between GS (without current flowing, only voltage as a signal), the state between the source and drain (DS) changes from a state where almost no current can flow under no voltage to a state where a large current can flow (the magnitude of the voltage affects the current carrying capacity). If the current path and the voltage signal path share the same source (S) terminal, the voltage signal and the magnitude of the overcurrent will interfere with each other, making it difficult to control.

[0026] like Figure 6-8 As shown, specifically, the power connection part 3 includes a two-phase power connection part 301 and a ground power connection part 302, and the power connection parts are connected by aluminum wire.

[0027] The two-phase power connection section 301 connects the source metal layer 202 of the three chips on the VS phase base island to the U phase base island 102, V phase base island 103, and W phase base island 104, respectively.

[0028] The grounding power connection section connects the source metal layer 202 of the chips on the U-phase base island 102, V-phase base island 103, and W-phase base island 104 to the corresponding GND pin 117.

[0029] The source metal layers of the chips on the U-phase base island and V-phase base island are respectively connected to the GND pin located between the U-phase base island and V-phase base island. The source metal layers of the chips on the V-phase base island and the W-phase base island are respectively connected to the GND pin located between the V-phase base island and the W-phase base island.

[0030] In operation, this invention reduces costs and facilitates heat dissipation through MOSFET integration, achieving a reduction in size without sacrificing power. Compared to discrete MOSFETs, integrated MOSFETs offer higher reliability, a smaller switching loop area, and better electromagnetic interference immunity. The smaller loop area results in lower parasitic inductance and improved circuit performance.

[0031] Preferably, the power connection can be connected using an aluminum strip. The aluminum strip connection has a larger contact area with the source metal layer 202 and the frame, resulting in lower resistance and reducing the formation of hot spots.

[0032] Preferably, the power connection part can be connected with copper sheet. Compared with aluminum strip connection, copper sheet connection has a larger contact surface, better conductivity and heat dissipation of material, significantly reduced resistance, improved heat dissipation performance, and greatly improved hot spot problem.

[0033] Specifically, the signal connection part 4 includes a gate signal connection part 401 and a source signal connection part 402. The signal connection parts are connected by aluminum wire. The gate signal connection part 401 is used to connect the gate metal layer 203 of each chip to the corresponding pin, and the source signal connection part 402 is used to connect the source metal layer 202 of each chip to the corresponding pin.

[0034] The source metal layer and gate metal layer of the three chips on the VS phase base island are also connected one-to-one to three pin groups on one side of the molding compound (i.e., GHU pin 105 and SHU pin 106 correspond to one chip, GHV pin 107 and SHV pin 108 correspond to one chip, and GHW pin 109 and SHW pin 110 correspond to one chip); the source pin and gate pin in the pin group are the pins of two connected chips (such as GHU pin 105 and SHU pin 106), and so on.

[0035] The source metal layer and gate metal layer of the chips on the U-phase base island, V-phase base island and W-phase base island are also connected one-to-one to three pin groups on the other side of the molding compound (i.e., SLU pin 111 and GLU pin 112 correspond to one chip, SLV pin 113 and GLV pin 114 correspond to one chip, and SLW pin 115 and GLW pin 116 correspond to one chip).

[0036] By setting up the molding compound 5, the module is prevented from failing due to environmental factors.

[0037] The portion of frame 1 not encapsulated by the plastic encapsulation has a tin plating layer with a thickness of 8-20um. This protects the frame from oxidation and also facilitates soldering it onto the printed circuit board using solder paste.

[0038] The VS phase base island includes three VS phase base island pins extending out of the molding compound, with one side pin group located between adjacent VS phase base island pins.

[0039] The U-phase base island includes U-phase base island pins extending out of the molding compound. The V-phase base island includes V-phase base island pins extending out of the molding compound. The W-phase island includes W-phase island pins extending out of the molding compound.

[0040] The other three pin groups are located one-to-one at one end of the U-phase base island pin, V-phase base island pin, and W-phase base island pin.

[0041] The source pin, gate pin, GND pin, VS phase base island pin, U phase base island pin, V phase base island pin, and W phase base island pin are all gull-shaped pins.

[0042] This invention uses seagull feet to connect to the PCB board, which can absorb stress by bending the pins, maintain good stability under temperature changes, and also have good shock resistance.

[0043] This invention dissipates a small portion of the heat through the pins on the PCB board, while most of the heat is dissipated through the top air, resulting in good heat dissipation and minimal thermal impact on other components on the PCB board.

[0044] The present invention has a compact structure with the connection lines as short as possible, reducing parasitic parameters (i.e., package resistance and inductance), resulting in low resistance and inductance of the entire module's current path. Low resistance leads to less heat generation and energy loss, while low inductance reduces interference to the circuit. This also results in low resistance of the control signal path and fast switching speed, which is highly advantageous in high-frequency circuits.

[0045] Regarding the information disclosed in this case, the following points need to be clarified: (1) The accompanying drawings of the embodiments disclosed in this case only involve the structures involved in the embodiments disclosed in this case. Other structures can refer to the general design. (2) Where there is no conflict, the embodiments and features disclosed in this case can be combined with each other to obtain new embodiments; The above are merely specific embodiments disclosed in this case, but the scope of protection of this disclosure is not limited thereto. The scope of protection disclosed in this case shall be determined by the scope of protection of the claims.

Claims

1. An integrated three-phase full-bridge power module, comprising a plastic encapsulation, characterized in that, The molding compound has a frame inside, the top surface of the frame is on the same plane as the top surface of the molding compound, and the two sides of the frame extend beyond the two side edges of the molding compound. The frame includes six pin groups, a VS phase base island on one side, and a U phase base island, a V phase base island, and a W phase base island on the other side. Among them, three pin groups are located on one side of the VS phase base island, and the other three pin groups are set one-to-one with the U phase base island, V phase base island and W phase base island; The pin group includes source pins and gate pins. The frame also includes GND pins located between the U-phase base island and the V-phase base island, and between the V-phase base island and the W-phase base island. The VS phase base island is provided with three chips, and the U phase base island, V phase base island and W phase base island are each provided with one chip; The chip includes a semiconductor layer, with a source metal layer and a gate metal layer on the top and a drain metal layer on the bottom. The source metal layers of the three chips on the VS phase base island are respectively connected to the U phase base island, V phase base island and W phase base island in a one-to-one correspondence. The source metal layers of the chips on the U-phase base island and V-phase base island are respectively connected to the GND pin located between the U-phase base island and V-phase base island. The source metal layers of the chips on the V-phase base island and the W-phase base island are respectively connected to the GND pin located between the V-phase base island and the W-phase base island. The source metal layer and gate metal layer of the three chips on the VS phase base island are also connected one-to-one to the three pin groups on one side of the molding compound. The source metal layer and gate metal layer of the chip on the U-phase base island, V-phase base island and W-phase base island are also connected one-to-one to the three pin groups on the other side of the molding compound.

2. The integrated three-phase full-bridge power module according to claim 1, characterized in that, Steps are provided on the VS phase base island, U phase base island, V phase base island and W phase base island respectively.

3. The integrated three-phase full-bridge power module according to claim 1, characterized in that, The source metal layers of the three chips on the VS phase base island are connected one-to-one to the U phase base island, V phase base island and W phase base island by aluminum wires. The source metal layers of the chips on the U-phase base island, V-phase base island, and W-phase base island are connected to the corresponding GND pins via aluminum wires.

4. An integrated three-phase full-bridge power module according to claim 1, characterized in that, The source metal layers of the three chips on the VS phase base island are connected one-to-one to the U phase base island, V phase base island and W phase base island respectively by aluminum strips; The source metal layers of the chips on the U-phase base island, V-phase base island, and W-phase base island are connected to the corresponding GND pins via aluminum strips.

5. An integrated three-phase full-bridge power module according to claim 1, characterized in that, The source metal layers of the three chips on the VS phase base island are connected one-to-one to the U phase base island, V phase base island and W phase base island respectively through copper sheets; The source metal layers of the chips on the U-phase base island, V-phase base island, and W-phase base island are connected to the corresponding GND pins via copper sheets.

6. An integrated three-phase full-bridge power module according to any one of claims 1-5, characterized in that, The source metal layer and gate metal layer of the three chips on the VS phase base island are also connected to several pins on one side of the plastic package through aluminum wires. The source metal layer and gate metal layer of the chip on the U-phase base island, V-phase base island and W-phase base island are also connected to several pins on the other side of the plastic package through aluminum wires.

7. An integrated three-phase full-bridge power module according to claim 1, characterized in that, The portion of the frame extending out of the plastic seal is provided with a tin-plated layer, the thickness of which is 8-20 μm.

8. An integrated three-phase full-bridge power module according to claim 1, characterized in that, The VS phase base island includes three VS phase base island pins extending out of the molding compound. The U-phase base island includes U-phase base island pins extending out of the molding compound. The V-phase base island includes V-phase base island pins extending out of the molding compound. The W-phase island includes W-phase island pins extending out of the molding compound.

9. An integrated three-phase full-bridge power module according to claim 8, characterized in that, The source pin, gate pin, GND pin, VS phase base island pin, U phase base island pin, V phase base island pin, and W phase base island pin are all gull-shaped pins.

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