Plastic package unit, unit integrated power module and preparation method thereof

Abstract

The invention discloses a plastic package unit, a unit integrated power module and a preparation method thereof, and relates to the field of power electronic power modules. Comprising a conducting strip which comprises a conducting strip first area and a conducting strip second area which are arranged at an interval; the power chip set comprises a plurality of power chips, is electrically connected to the first area of the conducting strip and is electrically connected with the second area of the conducting strip through a plurality of connecting parts; the plastic package body is wrapped on the conducting strip; and the first exposed area and the second exposed area of the conducting strip are respectively exposed from the plastic package body. Specifically, the first exposed area and the second exposed area of the conducting strip are located on different surfaces of the plastic package body. Specifically, a certain height difference exists between the bottom surface of the second area of the conducting strip and the bottom surface of the first area of the conducting strip, and the height difference ranges from 0.2 mm to 10 mm. The unit integrated power module adopts a plastic package unit integration idea, the size of a plastic package body is small, the process yield is higher, and the reliability is higher.

Description

Technical Field

[0001] The present invention relates to the field of power electronic power modules, and in particular to a plastic package unit, a unit integrated power module and a preparation method thereof. Background Art

[0002] As power modules develop towards high temperature, high power and high density, new requirements are put forward for the module packaging structure. Traditional power modules usually use silicone gel encapsulation process to achieve electrical insulation, but silicone gel currently has the problem of low reliability in high temperature service. Therefore, the transfer film plastic encapsulation process came into being. The application of the transfer film plastic encapsulation process has greatly improved the high temperature service reliability of power modules.

[0003] In order to achieve a certain current output capacity, current power modules usually adopt a multi-chip parallel connection solution (8 in parallel, 10 in parallel). In theory, the more chips there are, the stronger the current capacity is, and the larger the size of the power module is. If the power module adopts the transfer film plastic sealing process, the size of the plastic seal body will be larger. Under the current technical background, the larger the size of the plastic seal body, the greater the probability of defects such as delamination and pores during the injection molding process and subsequent service process, that is, the larger the size of the plastic seal body, the lower the yield.

[0004] In addition, the current power chip technology is not yet fully mature, and dynamic and reliability screening is usually required before system application. However, the power module circuit topology is complex, and a large number of power chips are integrated internally. It is difficult to effectively screen the power chips before packaging is completed, so screening can only be done after packaging is completed. The more chips are connected in parallel in the power module, the greater the chance of defects. If one chip is defective, the module will be defective, so the cost of packaging failure remains high. Summary of the invention

[0005] In view of the above problems, the present invention provides a plastic encapsulation unit, a unit-integrated power module and a preparation method thereof, which reduce the volume of the plastic encapsulation body, improve the yield rate and perform effective screening after plastic encapsulation.

[0006] The technical solution of the present invention is: A plastic packaging unit, comprising: A conductive sheet, comprising a conductive sheet first region and a conductive sheet second region that are spaced apart; A power chipset, comprising a plurality of power chips, electrically connected to the first region of the conductive sheet, and electrically connected to the second region of the conductive sheet through a plurality of connecting components; A plastic package is wrapped around the conductive sheet; a first exposed area and a second exposed area of ​​the conductive sheet are respectively exposed from the plastic package.

[0007] Specifically, the first exposed area and the second exposed area of ​​the conductive sheet are located on different surfaces of the plastic package body.

[0008] Specifically, there is a certain height difference between the bottom surface of the second region of the conductive sheet and the bottom surface of the first region of the conductive sheet, and the height difference ranges from 0.2 mm to 10 mm.

[0009] Specifically, it also includes a third region of the conductive sheet electrically interconnected with the control electrode of the power chip, and the third exposed region of the conductive sheet is exposed from the plastic package.

[0010] Specifically, the connecting component is a bonding wire or a connecting bridge.

[0011] Specifically, the third region of the conductive sheet is spaced apart from the first region of the conductive sheet and the second region of the conductive sheet, and are electrically connected via a number of connecting components.

[0012] A unit-integrated power module includes the above-mentioned plastic-encapsulated unit, and further includes: A system insulating substrate, wherein at least one of the plastic encapsulation units is electrically connected to the system insulating substrate and forms a preset circuit topology by connecting with the system insulating substrate; Specifically, the system insulating substrate includes a first conductive layer, an insulating layer, and a second conductive layer connected in sequence from top to bottom; The first exposed area of ​​the conductive sheet of the plastic encapsulation unit is electrically connected to the first conductive layer; The second exposed area of ​​the conductive sheet of the plastic encapsulation unit is electrically connected to the first conductive layer through a system connection component; Specifically, the third exposed area of ​​the conductive sheet of the plastic packaging unit is fixedly connected with a driving electrode; A method for preparing a unit-integrated power module comprises the following steps: Step 1: Sintering or welding the power chip; Fixing and connecting a plurality of power chips on the lead frame by sintering or welding; Step 2: Chip bonding or bridge connection; Step 3: Plastic sealing and cutting tendons; Using epoxy resin and an injection molding press, the unit obtained by completing the above steps is plastic-encapsulated, and a rib cutting device is used to cut off the connection portion between the lead frame and the conductive sheet to obtain a plastic-encapsulated unit; Step 4: welding or sintering the plastic sealing unit; Select appropriate types and quantities of plastic-encapsulated units and fix them on the system insulation substrate by welding or sintering; Step 5: System connection The plastic encapsulation unit is connected to the system insulating substrate through the system connection components to form a preset circuit topology; Step 5: Encapsulation or insulation material coating; Step 6: electrode welding; The electrodes and the driving electrodes are fixedly connected at corresponding positions by ultrasonic welding or laser welding process; Step 7: Glue filling and curing or insulation spraying.

[0013] Beneficial effects of the present invention: The plastic package unit of the present invention integrates a small amount of power chips and innovatively exposes the conductive area electrically connected to each pole of the power chip directly to the plastic package body, which brings the following beneficial effects: 1. The plastic encapsulation unit integrates a small number of power chips, the volume of the plastic encapsulation body is small, the residual stress generated by the plastic encapsulation is small, and the reliability is high; 2. Eliminate the pins and electrodes of traditional discrete devices / T-Pak packages, and the size of the plastic package unit is smaller at the same power. Compared with the T-Pak package at the same power, the volume is reduced by more than 2 / 3. When multiple devices are connected in parallel, the overall size is smaller, and the system size is smaller, that is, the system power density is greater; 3. The two polarities of the power chip with high voltage are electrically connected through the conductive sheet and exposed on a different surface from the plastic package, making it easier to meet the requirements for electrical safety clearance and creepage in high voltage applications; 4. Eliminate the DBC substrate and use the lead frame as the conductive carrier, which reduces costs and makes mass production easier; The unit-integrated power module of the present invention adopts the concept of unit integration, and has the following beneficial effects: 1. When power chip technology is not yet fully mature, a small number of chips are packaged into plastic-sealed units and screened, and then the appropriate topology and quantity are selected for integration according to the system application requirements. On the one hand, the failure rate and failure cost of the integrated power module are greatly reduced, and on the other hand, users can connect different quantities in parallel according to different power requirements, making the application more flexible; 2. There are two methods for manufacturing the unit integrated power module of the present invention: glue filling and insulation spraying; Glue pouring scheme: The unit-integrated power module glue pouring scheme of the present invention has better reliability than the traditional frame-type module glue pouring scheme. In more and more application scenarios, the temperature of the power chip exceeds 175°C. In the traditional frame-type module glue pouring scheme, the silicone gel is in direct contact with the power chip. The temperature of the silicone gel in the contact area is consistent with the temperature of the power chip, and changes rapidly with the temperature of the power chip. The reliability of the silicone gel at this peak temperature and alternating temperature is low. The unit-integrated power module glue pouring scheme of the present invention is different from this. The power chip is not directly in contact with the silicone gel in the plastic encapsulation unit, but with the plastic encapsulation material. The high temperature reliability of the plastic encapsulation material is much higher than that of silicone gel. Therefore, the unit-integrated power module glue pouring scheme of the present invention has better reliability. Insulation spraying solution: Compared with the glue filling solution, the shell and silicone gel are eliminated, the process is reduced and the overall cost is reduced; compared with the plastic sealing solution, the unit integrated power module of the present invention adopts the plastic sealing unit integration concept, the plastic sealing body is small in size, the process yield is higher, and the reliability is higher. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 1 is a schematic diagram of the three-dimensional structure of the plastic sealing unit 1; Figure 2 yes Figure 1 Schematic diagram of the top structure; Figure 3 yes Figure 1 Bottom structure diagram; Figure 4 yes Figure 1 Side structural diagram; Figure 5 yes Figure 1 Internal schematic diagram; Figure 6 yes Figure 1 Schematic diagram of the side structure; Figure 7 yes Figure 1 Schematic diagram of the internal three-dimensional structure; Figure 8 It is a schematic diagram of the three-dimensional structure of the plastic sealing unit 2; Fig. 9 yes Figure 8 Schematic diagram of the top structure; Fig.10 yes Figure 8 Schematic diagram of the bottom structure; Fig.11 yes Figure 8 Schematic diagram of the internal structure; Fig.12 It is a schematic diagram of the three top surface structures of the plastic sealing unit; Fig.13 yes Fig.12 Bottom structure diagram Fig.14 yes Fig.12 Internal diagram Fig.15 yes Fig.12 Schematic diagram of the side structure Fig.16 This is a schematic diagram of the four structures of the plastic sealing unit. Fig.17 It is a schematic diagram of the system insulation substrate structure; Fig.18 It is a structural schematic diagram of a unit integrated power module; Fig.19 It is a schematic diagram of a three-dimensional structure of a unit integrated power module; Fig. 20 It is a schematic diagram of the structure of one side of the unit integrated power module; Fig.21 It is a schematic diagram of the structure of the unit integrated power module II; Fig. 22 It is a schematic diagram of the three structures of the unit integrated power module; Fig.23 It is a three-dimensional structural schematic diagram of the connection state of the unit integrated power module and the enclosure; Fig.24 It is a three-dimensional structural schematic diagram of the connection state of the unit integrated power module and the upper cover; Fig.25 It is a structural schematic diagram when the unit integrated power module is a half-bridge circuit; Fig.26 It is a three-dimensional structural schematic diagram when the unit integrated power module is a half-bridge circuit; Fig. 27 It is a schematic diagram of the insulating substrate structure of a unit integrated power module system; Fig.28 It is a schematic diagram of the insulating material coating position of the insulating substrate of the unit integrated power module system; Fig.29 It is a schematic diagram of the application of unit integrated power module; Fig.30 is a schematic diagram of the lead frame structure; In the figure, 100-plastic encapsulation unit, 10-plastic encapsulation body, 101-first surface of plastic encapsulation body, 102-second surface of plastic encapsulation body, 20-conductive sheet, 201-first exposed area, 201A-first area of ​​conductive sheet, 202-second exposed area, 202A-second area of ​​conductive sheet, 203-third exposed area, 203A-third area of ​​conductive sheet, 204-fourth exposed area, 204A-fourth area of ​​conductive sheet, 30-power chip, 40-connecting component, 401-connecting bridge, 402-bonding wire, 403-system connection Connection component one, 404-system connection component two, 50-system insulating substrate, 50A-system insulating substrate two, 501-first conductive layer, 502-insulating layer, 503-second conductive layer, 501A-positive connection area, 501B-output connection area, 501C-negative area, 601-negative electrode, 602-positive electrode, 603-output electrode, 604-driving electrode, 70-thermistor, 80-housing, 90-upper cover, 110-insulating material coating area, 120-heat sink, 130-lead frame. DETAILED DESCRIPTION

[0015] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0016] In the description of the present invention, it should be understood that the terms "upper", "lower", "left", "right", "vertical", "horizontal" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

[0017] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0018] Reference below Figure 1-30 describe the invention; A plastic packaging unit, comprising: The conductive sheet 20 comprises a conductive sheet first region 201A and a conductive sheet second region 202A which are arranged at intervals; The conductive sheet 20 is composed of two or more independent regions. To facilitate mass production, the conductive sheet 20 is usually formed by cutting the lead frame 130. In this case, the conductive sheet 20 is made of a metal material with weldability, and copper is preferably used as the conductive sheet material.

[0019] A power chipset, comprising a plurality of power chips 30, electrically connected to the first region 201A of the conductive sheet, and electrically connected to the second region 202A of the conductive sheet via a plurality of connecting components 40; Specifically, the first electrode of the power chip 30 is connected to the first region 201A of the conductive sheet by welding or sintering, and the second electrodes of the power chips 30 are connected to the second region 202A of the conductive sheet by the connecting component 40; The plastic package 10 is wrapped on the conductive sheet 20; the first exposed area 201 and the second exposed area 202 of the conductive sheet are respectively exposed from the plastic package 10. The plastic package 10 of the present embodiment is preferably made of epoxy resin.

[0020] Specifically, the first exposed area 201 and the second exposed area 202 of the conductive sheet are located on different surfaces of the plastic package 10. The first exposed area 201 and the second exposed area 202 are usually local areas of the first area 201A and the second area 202A of the conductive sheet, respectively. The first area 201A and the second area 202A of the conductive sheet are electrically connected to the first electrode and the second electrode of the power chip 30, respectively. In application, there is usually a high voltage between the first electrode and the second electrode of the power chip 30, and sufficient electrical clearance and creepage distance need to be reserved. The present invention arranges the first exposed area 201 and the second exposed area 202 on different surfaces of the plastic package, so that the electrical clearance and creepage distance are larger, and the safety requirements are better met.

[0021] Specifically, there is a certain height difference between the bottom surface of the second region 202A of the conductive sheet and the bottom surface of the first region 201A of the conductive sheet, and the height difference ranges from 0.2mm to 10mm. After the plastic packaging is completed, the bottom surface of the second region 202A of the conductive sheet or the bottom surface of the first region 201A of the conductive sheet is completely wrapped by the plastic packaging body 10 to meet the electrical insulation requirements of the two regions.

[0022] The power chip connection method is further described: The power chip 30 includes one or more of an IGBT chip, a MOSFET chip, a thyristor chip, an FRD chip, and an SBD chip. The power chip in a plastic encapsulation unit may be the same type or may be a combination of several types. For example, the plastic encapsulation unit in the first embodiment only contains a MOSFET chip, and the plastic encapsulation unit in the fourth embodiment contains both an IGBT chip and an FRD chip.

[0023] The collector, drain or anode of the power chip 30 is electrically connected to the first region 201A of the conductive sheet by welding or sintering; The emitter, source or cathode of the power chip 30 is electrically connected to the second region 202A of the conductive sheet through a plurality of connecting components 40 ; If the power chip set includes an IGBT chip, a MOSFET chip or a thyristor chip, the conductive sheet further includes a conductive sheet third region 203A spaced apart from the conductive sheet first region 201A and the conductive sheet second region 202A, and the conductive sheet third region 203A is electrically connected to the conductive sheet first region 201A and the conductive sheet second region 202A respectively through the power chip 30 and a plurality of connecting components 40; The gate or control electrode of the IGBT chip, MOSFET chip or thyristor chip is electrically connected to the third region 203A of the conductive sheet through a plurality of connecting components 40. For the convenience of the following description, the gate or control electrode of the power chip is collectively described as the control electrode.

[0024] Specifically, the third exposed area 203 of the conductive sheet is usually a partial area of ​​the third area 203A of the conductive sheet, and the third exposed area 203 of the conductive sheet is exposed from the plastic package 10. The connecting component 40 is a bonding wire 402 or a connecting bridge 401. The bonding wire 402 is made of aluminum, copper or gold, and the connecting bridge 401 is made of copper, molybdenum, tungsten, molybdenum-copper alloy, tungsten-copper alloy, copper-molybdenum-copper composite material or aluminum-silicon-carbon (AlSiC). The bonding wire 402 is connected by ultrasonic bonding, and the connecting bridge 401 is connected by welding or sintering.

[0025] Embodiment 1 like Figure 1-7 As shown, the plastic encapsulation unit-power chip 30 adopts a MOSFET chip, and the MOSFET chip contains a control electrode for controlling its opening and closing in addition to the source and drain electrodes. In practical applications, the system realizes the opening and closing of the MOSFET chip by adjusting the voltage between the control electrode and the source electrode. In this embodiment, the conductive sheet 20 includes a conductive sheet first region 201A, a conductive sheet second region 202A, a conductive sheet third region 203A and a conductive sheet fourth region 204A arranged at intervals. The drain electrodes of the two MOSFET chips are electrically connected to the conductive sheet first region 201A by sintering, and the source electrodes of the two MOSFET chips are connected to the conductive sheet second region 202A by a connecting bridge 401, and the connection method is welding or sintering. In this embodiment, a pair of conductive sheet fourth region 204A is provided, and the conductive sheet third region 203A is located between a pair of conductive sheet fourth regions 204A. The source electrodes of the two MOSFET chips are also connected to the fourth region 204A of one of the conductive sheets by means of bonding wires 402 to achieve Kelvin connection, and the gate electrodes of the two MOSFET chips are connected to the bonding gate resistor on the third region 203A of the conductive sheet by means of bonding wires 402, and the bonding gate resistor is electrically connected to the third region 203A of the conductive sheet by means of welding or sintering. This layout can reduce the parasitic inductance between the control electrode and the source electrode, and can achieve separate control of the two MOSFET chips. The function of the bond and gate resistor is to reduce the uneven current phenomenon of the two MOSFET chips during the switching process.

[0026] The second region 202A, the third region 203A and the fourth region 204A of the conductive sheet are in a step shape as a whole. The bottom region of the step is electrically connected to the MOSFET chip through the connecting component 40, and the top of the step is respectively the second exposed region 202, the third exposed region 203 and the fourth exposed region 204. The bottom region and the top region are set as planes to facilitate the connection of the connecting component 40 and the connection of the second exposed region 202, the third exposed region 203 and the fourth exposed region 204 with the outside. The first region 201 of the conductive sheet has platform regions extending upward on both sides, and the extension direction is the same as that of the third region 203 and the fourth region 204 of the conductive sheet, such as Figure 5 As shown. The platform area is connected to the lead frame 130 to achieve overall symmetry of the lead frame, which is more convenient for the actual production process. The height of the platform area is lower than the third exposed area 203 and the fourth exposed area 204. After the plastic packaging is completed, the platform is completely wrapped in the plastic packaging body 10. In this embodiment, the bottom surface of the second area 202A of the conductive sheet is higher than the bottom surface of the first area 201A of the conductive sheet, as shown in FIG. Figure 6 After the plastic packaging is completed, the bottom surface of the second area 202A of the conductive sheet is completely wrapped in the plastic packaging body 10, so as to achieve a safe electrical gap and creepage distance with the first area 201A of the conductive sheet.

[0027] After completing the above connections, the plastic sealing process is carried out. After the plastic sealing is completed, the structural diagram of the plastic sealing unit is as follows Figure 1-4 As shown. The first exposed area 201 of the conductive sheet is exposed on the first surface 101 of the plastic package, and the surfaces of the second exposed area 202, the third exposed area 203 and the fourth exposed area 204 of the conductive sheet are exposed on the second surface 102 of the plastic package. There is high voltage in the first exposed area 201 and the second exposed area 202 in application. By exposing the two sides to different surfaces of the plastic package 10, the electrical clearance and creepage distance are effectively increased to better meet the safety requirements. The exposed area of ​​the conductive sheet can facilitate the electrical connection of a certain pole of the power chip electrically connected thereto with the system insulating substrate 50 or with the driving electrode 604 through welding or sintering or system connection component one or system connection component two, so as to realize a unit integrated power module of a preset circuit.

[0028] Embodiment 2 like Figure 8-11 As shown, the power chip 30 is an SBD chip, and the SBD chip only contains a cathode and an anode. Therefore, in the present embodiment, the conductive sheet 20 only contains a first conductive sheet region 201A and a second conductive sheet region 202A that are spaced apart. The cathodes of the two SBD chips are electrically connected to the first conductive sheet region 201A by sintering, and the anodes of the two SBD chips are connected to the second conductive sheet region 202A by a connecting component 40, and the connection method is welding or sintering. The second conductive sheet region 202A is in a step-like shape as a whole, and the bottom area of ​​the step is electrically connected to the SBD chip by a connecting component 40, and the top of the step is the second exposed area 202. The bottom area and the top area are set as planes to facilitate the connection of the connecting component 40 and the connection of the second exposed area 202 with the outside. Platform areas extend upward on both sides of the first conductive sheet region 201, and the extension direction is away from the second conductive sheet region 202, so as to facilitate the connection with the lead frame 130. After the plastic encapsulation is completed, the platform area is completely wrapped in the plastic encapsulation body 10. The schematic diagram of the plastic encapsulation unit structure after the plastic encapsulation is completed is shown as follows. Figure 8-10As shown. The first exposed area 201 of the conductive sheet is exposed on the first surface 101 of the plastic package, and the second exposed area 202 of the conductive sheet is exposed on the second surface 102 of the plastic package. The first exposed area 201 and the second exposed area 202 have high voltage in application. By exposing the two surfaces on different surfaces of the plastic package 10, the electrical clearance and creepage distance are effectively increased, and the safety requirements are better met.

[0029] Embodiment 3 like Figure 12-15 As shown, as in the second embodiment, the power chip 30 is an SBD chip, and the conductive sheet 20 also only includes a conductive sheet first region 201A and a conductive sheet second region 202A that are spaced apart. The cathodes of the two SBD chips are electrically connected to the conductive sheet first region 201A by sintering, and the anodes of the two SBD chips are connected to the conductive sheet second region 202A by connecting components 40, and the connection method is welding or sintering. Different from the second embodiment, the conductive sheet second region 202A is a plane as a whole, and the bottom surface of the conductive sheet second region 202A is lower than the bottom surface of the conductive sheet first region 201A. After the plastic packaging is completed, the conductive sheet first region 201A is completely wrapped in the plastic packaging body 10.

[0030] After the plastic sealing is completed, the structural diagram of the plastic sealing unit is as follows Figure 12-13 As shown, different from the second embodiment, the first exposed area 201 of the conductive sheet is exposed on the second surface 102 of the plastic package body, and the second exposed area 202 of the conductive sheet is exposed on the first surface 101 of the plastic package body.

[0031] Embodiment 4 like Fig.16As shown, the power chipset includes an IGBT chip 302 and an FRD chip 301. The conductive sheet 20 includes a first conductive sheet region 201A, a second conductive sheet region 202A, a third conductive sheet region 203A, and a fourth conductive sheet region 204A, which are arranged at intervals. The collectors of the two IGBT chips are electrically connected to the first conductive sheet region 201A by sintering or welding, and the cathodes of the two FRD chips are electrically connected to the first conductive sheet region 201A by sintering or welding; the emitters of the two IGBT chips and the anodes of the two FRD chips are electrically connected to the second conductive sheet region 202A and the fourth conductive sheet region 204A by a number of connecting components 40; the control electrodes of the two IGBT chips are electrically connected to the third conductive sheet region 203A by connecting components 40. In this embodiment, one conductive sheet region 203A and one conductive sheet region 204A are provided, and are placed adjacent to each other. The first area 201A of the conductive sheet is planar, and the back side is exposed in the plastic packaging body 10 after the plastic packaging is completed; the second area 202A of the conductive sheet, the third area 203A of the conductive sheet and the fourth area 204A of the conductive sheet are all step-shaped, and the second exposed area 202, the third exposed area 203 and the fourth exposed area 204 are exposed in the plastic packaging body 10 after the plastic packaging is completed.

[0032] A unit-integrated power module, comprising Plastic sealing unit 100; A system insulating substrate 50, wherein at least one of the plastic encapsulation units 100 is electrically connected to the system insulating substrate 50, and is electrically connected to the first conductive layer 501 of the system insulating substrate 50 to form a preset circuit topology; Specifically, the preset circuit topology includes single tube, half bridge, boost, chopper, full bridge, three-phase full bridge or rectification.

[0033] The electrodes include a positive electrode 602 respectively fixedly connected to the first conductive layer 501 , a plurality of negative electrodes 601 , a plurality of output electrodes 603 , and a plurality of driving electrodes 604 fixedly connected to the plastic packaging unit.

[0034] The system insulating substrate 50 is further described: The system insulating substrate 50 includes a first conductive layer 501, an insulating layer 502 and a second conductive layer 503 connected in sequence from top to bottom. Fig.16 As shown; Specifically, the material of the first conductive layer 501 is preferably copper, the material of the second conductive layer 503 is aluminum-based, copper-based or stainless steel-based; the material of the insulating layer 502 is aluminum oxide, aluminum nitride, Si 3 N 4 or ceramic polymer composites; The first exposed area (201) of the conductive sheet of the plastic encapsulation unit is electrically connected to the first conductive layer (501); the connection method is welding or sintering.

[0035] The second exposed area (202) of the conductive sheet of the plastic encapsulation unit is electrically connected to the first conductive layer (501) through a system connection component; the system connection component is a bonding wire 402, a connection bridge 401 or a flexible circuit board, the bonding wire 402 is made of aluminum, copper or gold, and the connection bridge 401 is made of copper, molybdenum, tungsten, molybdenum-copper alloy, tungsten-copper alloy, copper-molybdenum-copper composite material or aluminum silicon carbon (AlSiC). The bonding wire 402 is connected by ultrasonic bonding, and the connection bridge 401 and the flexible circuit board are connected by welding or sintering. In this case, the system connection component is preferably a connection bridge, the material is preferably copper, and the connection method is preferably laser welding.

[0036] The third exposed area (203) of the conductive sheet of the plastic-encapsulated unit is fixedly connected with a driving electrode; the driving electrode is a metal electrode or a flexible circuit board, and the connection method is welding or sintering. In this case, the driving electrode is preferably a copper electrode, and the material method is preferably ultrasonic welding.

[0037] Embodiment 5 An embodiment of a unit-integrated power module: like Figure 17-20 As shown, the unit integrated power module is composed of two plastic encapsulated units to form a half-bridge circuit, specifically: The system insulating substrate 50 adopts the AMB substrate commonly used in the industry, and from top to bottom are the first conductive layer 501, the insulating layer 502 and the second conductive layer 503, wherein the first conductive layer 501 and the second conductive layer 502 are both made of copper, and the insulating layer material is Si3N4 ceramic. The first conductive layer 501 includes a positive electrode connection area 501A, a negative electrode connection area 501C, and an output electrode connection area 501B arranged at intervals; Specifically, the first exposed area 201 of the conductive sheet of a plastic-encapsulated unit is electrically connected to the positive electrode connection area 501A of the first conductive layer of the system insulating substrate by welding or sintering, the second exposed area 202 of the conductive sheet is electrically connected to the output electrode connection area by the system connecting component 403, and the third exposed area 203 and the fourth exposed area 204 of the conductive sheet are connected to the driving electrode 604 by welding connection.

[0038] The first exposed area 201 of the conductive sheet of another plastic-encapsulated unit is electrically connected to the output electrode connection area 501B of the first conductive layer of the system insulating substrate by welding or sintering, the second exposed area 202 of the conductive sheet is electrically connected to the negative electrode connection area by the system connecting component 404, and the third exposed area 203 and the fourth exposed area 204 of the conductive sheet are connected to the driving electrode 604 by welding respectively; the positive electrode 602 is fixedly connected to the positive electrode connection area 501A by sintering / welding, the two negative electrodes 601 are fixedly connected to the negative electrode connection area 501C by sintering or welding, the two output electrodes 603 are fixedly connected to the output electrode connection area 501B by sintering or welding, and the driving electrode 604 is fixedly connected to the surface of the third exposed area 203 and the fourth exposed area 204 of the conductive sheet by welding / sintering. In actual use, the system usually has the requirement to monitor the temperature of the power chip, so a system insulating substrate 2 50A is fixedly connected to the first conductive layer of the system insulating substrate by welding or sintering, and then a thermistor 70 is fixedly connected to its surface by welding to detect the temperature of the power chip.

[0039] Embodiment 6 Second embodiment of the unit integrated power module: like Fig.21 As shown, the unit integrated power module is composed of two plastic encapsulated units to form a boost circuit, and the structure of one plastic encapsulated unit is Figure 8-11 The plastic encapsulation unit shown in the figure has two SBD chips as power chips, which are temporarily called plastic encapsulation unit A for easy distinction. The structure of the other plastic encapsulation unit is as follows: Figure 1-7 The plastic encapsulation unit shown has two MOSFET chips as power chips, which are temporarily referred to as plastic encapsulation unit B.

[0040] Specifically, the first exposed area 201 of the conductive sheet of the plastic encapsulation unit A is electrically connected to the positive electrode connection area 501A of the first conductive layer of the system insulating substrate by welding or sintering, the second exposed area 202 of the conductive sheet is electrically connected to the output electrode connection area by the system connecting component 403, the first exposed area 201 of the conductive sheet of the plastic encapsulation unit B is electrically connected to the output electrode connection area 501B of the first conductive layer of the system insulating substrate by welding or sintering, the second exposed area 202 of the conductive sheet is electrically connected to the negative electrode connection area by the system connecting component 404, and the third exposed area 203 and the fourth exposed area 204 of the conductive sheet are connected to the driving electrode 604 by welding; the positive electrode 602 is fixedly connected to the positive electrode connection area 501A by sintering / welding, the two negative electrodes 601 are fixedly connected to the negative electrode connection area 501C by sintering or welding, and the two output electrodes 603 are fixedly connected to the output electrode connection area 501B by sintering or welding.

[0041] Embodiment 7 The third embodiment of the unit integrated power module: like Fig. 22 As shown, the unit integrated power module is composed of 6 plastic encapsulated units to form a three-phase full-bridge circuit. The structure of the plastic encapsulated unit is as follows: Figure 1-7 The plastic encapsulated unit shown has two MOSFET chips as the power chips. The insulating substrate of the system in this embodiment adopts an insulated metal substrate (IMS), which includes a first conductive layer 501, an insulating layer 502, and a second conductive layer 503 from top to bottom, wherein the first conductive layer 501 and the second conductive layer 502 are both made of copper, and the insulating layer material is a ceramic polymer composite material. Since the thermal conductivity of the IMS thermal conductive layer is relatively good, material cost savings can be achieved by reducing the required material thickness (for heat dissipation) and reducing the demand for a heat dissipation system. The specific implementation is similar to the above and will not be repeated here.

[0042] In the above unit integrated power module embodiment, further, as Fig.23 and Fig.24 As shown, the system insulating substrate 50 is connected to the housing 80 through a sealant; Silicon gel or epoxy resin is filled between the system insulating substrate 50 and the shell 80; a cover plate 90 is added on top of the shell 80, and the cover plate is connected to the shell by bonding or snapping. An opening is set in the middle of the cover plate and at the position of the driving electrode of the plastic-encapsulated unit module, and the size of the opening is slightly larger than the electrode size; after the cover plate is assembled, the positive electrode 602, the negative electrode 601, the output electrode 603 and the power electrode 604 all extend out of the shell or cover plate. The shell material in this case is PBT, PPS, or PA.

[0043] Embodiment 8 like Fig.25 and Fig.26 As shown. In high-power application scenarios, multiple plastic-encapsulated units are required to be used in parallel. The unit integrated power module is a half-bridge circuit. To achieve higher output power, the upper and lower half bridges use three plastic-encapsulated units in parallel. The specific implementation is similar to the above and will not be repeated here. The insulating material coating area 110 on the surface of the first conductive layer 501 of the insulating substrate of the unit integrated power module system is coated with a layer of insulating material of a certain thickness, and the thickness of the insulating material is greater than the thickness of the first conductive layer 501. Fig.28 As shown. After the plurality of plastic encapsulation units 100 are electrically connected to the first conductive layer 501 to form a preset circuit topology, an insulating material of a specific thickness is sprayed on the surface through an insulating spraying technique to achieve electrical insulation. Different from the above-mentioned embodiment, this embodiment does not require a housing and silicone gel filling, further reducing costs. In actual application, three half-bridges are usually sintered or welded on the same heat sink 120 to achieve a three-phase full-bridge circuit topology structure, such as Fig.25 shown.

[0044] A method for preparing a unit-integrated power module comprises the following steps: Step 1: Sintering or welding the power chip; A plurality of power chips 30 are fixedly connected to the lead frame 130 by sintering or welding; Step 2: Chip bonding or bridge connection; For IGBT chips, MOSFET chips or thyristor chips, the gate / control electrode, emitter / source / cathode of the power chip are connected to the corresponding area of ​​the conductive sheet by bonding, bridge sintering or welding; for FRD chips / SBD chips, the anode of the power chip is connected to the corresponding area of ​​the conductive sheet by bonding or bridge sintering or welding; Step 3: Plastic sealing and cutting tendons; Using epoxy resin and an injection molding press, the unit obtained by completing the above steps is plastic-encapsulated, and a rib cutting device is used to cut off the connection portion between the lead frame and the conductive sheet to obtain a plastic-encapsulated unit; Step 4: welding or sintering the plastic sealing unit; Select plastic encapsulation units of appropriate specifications, and fix a specific number of plastic encapsulation units to corresponding positions on the system insulation substrate by welding or sintering; Step 5: System connection; The plastic encapsulation unit is connected to the system insulating substrate through the system connection components to form a preset circuit topology; Step 6: Encapsulation or insulation material coating; Encapsulation: Use sealant to connect the system insulation substrate to the housing; Insulation material coating: coating a certain thickness of insulation material on a specific area on the surface of the first conductive layer of the system insulation substrate; Step 7: electrode welding; The electrodes and the driving electrodes are fixedly connected at corresponding positions by ultrasonic welding or laser welding process; Step 7: Glue filling and curing or insulation spraying; If the encapsulation process in step 6 is adopted, silicone gel is poured inside the shell, vacuum degassed and cured; If the insulating material coating process in step six is ​​adopted, the insulating layer is sprayed by insulating spraying technology.

[0045] Finally, the upper cover of the unit integrated power module is installed. This step is not required if the insulation spraying technology is used.

[0046] Regarding the contents disclosed in this case, there are a few points that need to be explained: (1) The 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) In the absence of conflict, the embodiments and features of the embodiments disclosed in this case may be combined with each other to obtain new embodiments; The above are only specific implementation methods disclosed in this case, but the protection scope of the present disclosure is not limited thereto. The protection scope disclosed in this case should be based on the protection scope of the claims.

Claims

1. A plastic sealing unit, characterized in that: include: A conductive sheet (20), comprising a conductive sheet first region (201A) and a conductive sheet second region (202A) arranged at intervals; A power chipset, comprising a plurality of power chips (30), which are electrically connected to the first region (201A) of the conductive sheet and electrically connected to the second region (202A) of the conductive sheet via a plurality of connecting components (40); The plastic package body (10) is wrapped on the conductive sheet (20); the first exposed area (201) and the second exposed area (202) of the conductive sheet are respectively exposed from the plastic package body (10).

2. A plastic sealing unit according to claim 1, characterized in that: The first exposed area (201) and the second exposed area (202) of the conductive sheet are located on different surfaces of the plastic package (10).

3. A plastic sealing unit according to claim 1, characterized in that: There is a certain height difference between the bottom surface of the second area (202A) of the conductive sheet and the bottom surface of the first area (201A) of the conductive sheet, and the height difference ranges from 0.2 mm to 10 mm.

4. A plastic encapsulation unit according to claim 1, characterized in that: It also comprises a third region (203A) of the conductive sheet electrically interconnected with the control electrode of the power chip (30), and the third exposed region (203) of the conductive sheet (20) is exposed from the plastic package (10).

5. The plastic sealing unit according to claim 1, characterized in that: The connecting component (40) is a bonding wire (402) or a connecting bridge (401).

6. A plastic encapsulation unit according to claim 4, characterized in that: The third region (203A) of the conductive sheet is spaced apart from the first region (201A) of the conductive sheet and the second region (202A) of the conductive sheet, and is electrically connected via a plurality of connecting components (40).

7. A unit-integrated power module, comprising a plastic-encapsulated unit according to claim 1, characterized in that: Also includes: A system insulating substrate (50), wherein at least one of the plastic encapsulation units (100) is electrically connected to the system insulating substrate (50), and forms a preset circuit topology by being connected to the system insulating substrate (50).

8. The unit-integrated power module according to claim 7, characterized in that: The system insulating substrate (50) comprises a first conductive layer (501), an insulating layer (502) and a second conductive layer (503) which are connected in sequence from top to bottom; The first exposed area (201) is electrically connected to the first conductive layer (501); The second exposed area (202) is electrically connected to the first conductive layer (501) via a system connection component.

9. The unit-integrated power module according to claim 7, characterized in that: The third exposed area (203) is fixedly connected to the driving electrode.

10. A method for preparing a unit-integrated power module, the unit-integrated power module according to claim 7, characterized in that: The following steps are involved: Step 1: sintering or welding the power chip; Fixing a plurality of power chips (30) on a lead frame (130) by sintering or welding; Step 2: Chip bonding or bridge connection; Step 3: Plastic sealing and cutting tendons; Using epoxy resin and an injection molding press, the unit obtained by completing the above steps is plastic-encapsulated, and a rib cutting device is used to cut off the connection portion between the lead frame and the conductive sheet to obtain a plastic-encapsulated unit; Step 4: welding or sintering the plastic sealing unit; Select appropriate types and quantities of plastic-encapsulated units and fix them on the system insulation substrate by welding or sintering; Step 5: System connection; The plastic encapsulation unit is connected to the system insulating substrate through the system connection components to form a preset circuit topology; Step 6: Encapsulation or insulation material coating; Step 7: electrode welding; The electrodes and the driving electrodes are fixedly connected at corresponding positions by ultrasonic welding or laser welding process; Step 8: Glue filling and curing or insulation spraying.

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