A packaging structure of a power module

Abstract

The application discloses a packaging structure of a power module, which comprises an insulating substrate, a plurality of base islands, a power device, a first diode, a second diode, a signal terminal, a power terminal and a plastic package body. The combination of the power device and the first diode is packaged together with the second diode, so that the stray inductance in the device is reduced, the layout and wiring are simplified, the device performance is improved, the application range of the device is wider, and the space utilization is greatly improved.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and more specifically, to a packaging structure for a power module. Background Technology

[0002] As product applications expand into various fields, including consumer electronics, frequency conversion and energy storage, as well as industrial applications and even automotive products, the performance requirements for power devices are constantly increasing.

[0003] In existing technologies, the Insulated-Gate Bipolar Transistor (IGBT) and the Fast Recovery Diode (FRD) connected in reverse parallel are usually packaged together, while the Schottky Barrier Diode (SBD) is packaged separately. This separation results in a large amount of stray inductance, which does not meet the requirements of current application scenarios.

[0004] Therefore, it is necessary to design a power module packaging structure that integrates the IGBT and the anti-parallel FRD with the SBD together, reducing stray inductance and adapting to different voltage levels and product specifications, thereby greatly improving the overall space utilization. Utility Model Content

[0005] In view of this, the purpose of this utility model is to provide a packaging structure for a power module that solves the above problems.

[0006] This utility model provides a packaging structure for a power module, comprising:

[0007] An insulating substrate, the insulating substrate including multiple base islands, the multiple base islands being located on a first surface of the insulating substrate, the multiple base islands including a first base island and a second base island;

[0008] Power device, first diode, second diode;

[0009] The signal terminals include a first signal terminal and a second signal terminal.

[0010] The power terminals include a first power terminal, a second power terminal, and a third power terminal.

[0011] A molding compound that encapsulates an insulating substrate, a base island, a power device, a first diode, a second diode, a first power terminal, a second power terminal, a third power terminal, a first signal terminal, and a second signal terminal.

[0012] The first terminal of the power device is electrically connected to the first terminal of the first diode and to the first power terminal; the second terminal of the power device and the second terminal of the first diode are located on the first base island, the first base island is led out from the side of the plastic package and connected to the second power terminal, the anode of the second diode is electrically connected to the second power terminal; the cathode of the second diode is located on the second base island, the second base island is led out from the side of the plastic package and connected to the third power terminal; the third terminal of the power device is electrically connected to the first signal terminal, and the Kelvin terminal of the power device is electrically connected to the second signal terminal.

[0013] Optionally, the power device is an insulated gate bipolar transistor (IGBT), with the first terminal of the IGBT being the emitter, the second terminal of the IGBT being the collector, and the third terminal of the IGBT being the gate. The first terminal of the first diode is the anode, the second terminal of the first diode is the cathode, the first terminal of the second diode is the anode, and the second terminal of the second diode is the cathode.

[0014] The emitter of the insulated-gate bipolar transistor (IGBT) of the power device is connected to the anode of the first diode via a bonding wire, a metal clip, or an aluminum strip to a third base island. The third base island extends from the side of the encapsulation and is connected to a first power terminal. The collector of the IGBT and the cathode of the first diode are connected via a bonding wire, a metal clip, or an aluminum strip and are both located on the first base island. The first base island extends from the side of the encapsulation and is connected to a second power terminal. The anode of the second diode is connected to the second power terminal via a bonding wire, a metal clip, or an aluminum strip. The cathode of the second diode is located on a second base island, which extends from the side of the encapsulation and is connected to a third power terminal. The gate of the IGBT is connected to a fourth base island via a bonding wire, a metal clip, or an aluminum strip. The fourth base island extends from the side of the encapsulation and is connected to a first signal terminal. The Kelvin terminal of the IGBT is connected to a fifth base island via a bonding wire, a metal clip, or an aluminum strip. The fifth base island extends from the side of the encapsulation and is connected to a second signal terminal.

[0015] Optionally, the power device is a metal-oxide-semiconductor field-effect transistor, with the first terminal of the metal-oxide-semiconductor field-effect transistor being the source, the second terminal of the metal-oxide-semiconductor field-effect transistor being the drain, and the third terminal of the metal-oxide-semiconductor field-effect transistor being the gate; the first terminal of the first diode is the anode, the second terminal of the first diode is the cathode, the first terminal of the second diode is the anode, and the second terminal of the second diode is the cathode.

[0016] The source of the metal-oxide-semiconductor field-effect transistor (MOSFET) of the power device is connected to the anode of the first diode via a bonding wire, a metal clip, or an aluminum strip to a third base island. The third base island extends from the side of the molding compound and is connected to a first power terminal. The drain of the MOSFET and the cathode of the first diode are connected via a bonding wire, a metal clip, or an aluminum strip and are both located on the first base island. The first base island extends from the side of the molding compound and is connected to a second power terminal. The anode of the second diode is connected to the second power terminal via a bonding wire, a metal clip, or an aluminum strip. The cathode of the second diode is located on a second base island, which extends from the side of the molding compound and is connected to a third power terminal. The gate of the MOSFET is connected to a fourth base island via a bonding wire, a metal clip, or an aluminum strip. The fourth base island extends from the side of the molding compound and is connected to a first signal terminal. The Kelvin terminal of the MOSFET is connected to a fifth base island via a bonding wire, a metal clip, or an aluminum strip. The fifth base island extends from the side of the molding compound and is connected to a second signal terminal.

[0017] Optionally, the power device is connected to the corresponding base island via lead-tin solder, conductive adhesive, solder paste, or sintered silver bonding material.

[0018] Optionally, the power terminals and signal terminals are connected to the corresponding base islands via lead-tin solder, conductive adhesive, solder paste, or sintered silver bonding material.

[0019] Optionally, the first diode is either a silicon-based fast recovery diode or a silicon carbide Schottky barrier diode.

[0020] Optionally, the second diode is either a silicon-based fast recovery diode or a silicon carbide Schottky barrier diode.

[0021] Optionally, the insulating substrate includes, but is not limited to, directly bonded copper ceramic substrates, active metal brazed ceramic substrates, and directly plated copper ceramic substrates.

[0022] Optionally, shallow etched lines are provided on the portions of the power terminals and signal terminals inside the plastic package.

[0023] Optionally, the encapsulation between the power terminals has a recessed structure.

[0024] Optionally, the power terminal is wider than the signal terminal.

[0025] Optionally, the spacing between two adjacent power terminals is greater than the spacing between two adjacent signal terminals.

[0026] Optionally, the molding compound covers some of the protrusions of the signal terminals and power terminals.

[0027] Optionally, the portions of the signal terminals and power terminals encapsulated in the plastic casing may be bent.

[0028] Optionally, the encapsulation covering the power terminals and the encapsulation encapsulating the power device are not on the same horizontal plane.

[0029] The power module packaging structure provided in this application encapsulates the power device, the first diode, and the second diode in the same plastic package. The second end of the power device and the second end of the second diode are located on the first base island, and the cathode of the first diode is located on the second base island. The first base island and the second base island are set separately, which avoids stray inductance between the power device and the first diode. At the same time, it simplifies the internal wiring of the packaging structure, making the circuit board layout more reasonable, flexible, and simple, with higher integration, and can meet a variety of different needs.

[0030] Furthermore, the third base island is electrically connected to the first power terminal, the fourth base island is electrically connected to the first signal terminal, and the fifth base island is electrically connected to the second signal terminal, which avoids interference between signals and improves the performance of the power module.

[0031] Furthermore, the encapsulation between the power terminals has grooves, and the spacing between the power terminals is greater than the spacing between the signal terminals, which increases the creepage distance of the power module, enhances its withstand voltage, and increases the bonding force of the encapsulation, making the device more robust.

[0032] Furthermore, the protrusions of the signal terminals and power terminals are encapsulated in the molding compound, and the encapsulated portions of the signal terminals and power terminals are bent.

[0033] Furthermore, the plastic casing for the power terminals is not on the same horizontal plane as the plastic casing encapsulating the power devices, which increases the electrical clearance of the devices and the creepage distance, thereby enhancing the voltage withstand capability of the power modules, improving their resistance to environmental interference, and expanding their application areas. Attached Figure Description

[0034] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly introduced below. Obviously, the drawings in the following description only involve some embodiments of this disclosure, and are not intended to limit this disclosure.

[0035] Figure 1 A circuit diagram of the packaging structure of this utility model is shown;

[0036] Figure 2 A schematic diagram of the packaging structure of this utility model is shown;

[0037] Figure 3 The three-dimensional packaging structure of this utility model is shown. Detailed Implementation

[0038] Various embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. In the various drawings, the same elements are indicated by the same or similar reference numerals. For clarity, the various parts in the drawings are not drawn to scale.

[0039] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0040] Figure 1 The circuit diagram shows the encapsulated power module structure provided by this utility model. Taking the power device 301 as an insulated gate bipolar transistor (IGBT) as an example, the circuit diagram includes a first diode 302, a second diode 303, a first power terminal 401, a second power terminal 402, a third power terminal 403, a first signal terminal 501, and a second signal terminal 502. The first signal terminal 501 is connected to the gate of the IGBT 301, the second signal terminal 502 is connected to the Kelvin terminal of the IGBT 301, the first power terminal 401 is connected to the emitter of the IGBT 301 and the anode of the first diode 302, the second power terminal is connected to the collector of the IGBT 301, the cathode of the first diode 302, and the anode of the second diode 303, and the third power terminal 403 is connected to the cathode of the second diode 303.

[0041] In this circuit, the first diode 302 is connected in reverse parallel with the insulated gate bipolar transistor 301 to provide protection and prevent the insulated gate bipolar transistor 301 from being broken down by reverse withstand voltage. The collector of the insulated gate bipolar transistor 301, the cathode of the first diode 302 are connected, and the anode of the second diode 303 share the second power terminal 402, which reduces stray inductance and simplifies the wiring structure.

[0042] In this package structure, the power device 301 can also be a metal-oxide-semiconductor field-effect transistor (MOSFET). The first diode 302 and the second diode 303 can both be either silicon-based fast recovery diodes or silicon carbide Schottky barrier diodes. Their circuit connection is consistent with that of an insulated-gate bipolar transistor (IGBT). The collector of the IGBT is replaced with the drain of the MOSFET, the emitter of the IGBT is replaced with the source of the MOSFET, and the gate of the IGBT is replaced with the gate of the MOSFET.

[0043] Figure 2A schematic diagram of the power module packaging structure of this utility model is shown. To better illustrate the connection and positional relationship of each part in the encapsulation structure, the encapsulation body 100 of the encapsulation structure is shown through a perspective effect. The packaging structure includes an encapsulation body 100, an insulating substrate 200, a first base island 201, a second base island 202, a third base island 203, a fourth base island 204, a fifth base island 205, a power device 301, a first diode 302, a second diode 303, a first power terminal 401, a second power terminal 402, a third power terminal 403, a first signal terminal 501, a second signal terminal 502, and the first base island 201, the second base island 202, the third base island 203, the fourth base island 204, and the fifth base island 205 located on the first surface of the insulating substrate 200.

[0044] The first terminal of power device 301 is electrically connected to the first terminal of first diode 302 at a first power terminal 401; the second terminal of power device 301 and the second terminal of first diode 302 are located together at a first base island 201, the first base island 201 is led out from the side of the encapsulation and connected to the second power terminal 402, the anode of second diode 303 is electrically connected to the second power terminal; the cathode of second diode 303 is located at the second base island 202, the second base island 202 is led out from the side of encapsulation 100 and connected to the third power terminal 403; the third terminal of power device 301 is electrically connected to a first signal terminal 501, and the Kelvin terminal of power device 301 is electrically connected to the second signal terminal 502.

[0045] Furthermore, the power device 301 is an insulated-gate bipolar transistor (IGBT). Its emitter is connected to the anode of the first diode 302 via a bonding wire, a metal clip, or an aluminum strip to a third base island 203. The third base island 203 extends from the side of the molding compound 100 and is connected to the first power terminal 401. The collector of the IGBT is connected to the cathode of the first diode 302 via a bonding wire, a metal clip, or an aluminum strip, and both are located on the first base island 201. The first base island 201 extends from the side of the molding compound 100 and is connected to the second power terminal 402. The anode of the second diode 303 is connected via a bonding wire, a metal clip, or an aluminum strip. The second power terminal 402 is connected in one way; the cathode 302 of the second diode is located on the second base island 202, and the second base island is led out from the side of the molding compound 100 and connected to the third power terminal 403; the gate of the insulated gate bipolar transistor is connected to the fourth base island 204 through one of the following: bonding wire, metal clip, and aluminum strip; the fourth base island 204 is led out from the side of the molding compound 100 and connected to the first signal terminal 501; the Kelvin terminal of the insulated gate bipolar transistor is connected to the fifth base island 205 through one of the following: bonding wire, metal clip, and aluminum strip; the fifth base island 205 is led out from the side of the molding compound 100 and connected to the second signal terminal 502.

[0046] Furthermore, the power device 301 can also be a metal-oxide-semiconductor field-effect transistor, and the first diode 302 and the second diode 303 can both be one of silicon-based fast recovery diodes or silicon carbide Schottky barrier diodes, and their connection method is consistent with that of insulated gate bipolar transistors.

[0047] Furthermore, the encapsulation 100 covers the distribution of the first power terminal 401, the second power terminal 402, the third power terminal 403, and the first signal terminal 501 and the second signal terminal 502. The encapsulation 100 between the power terminals is provided with grooves 601, which can increase the bonding force of the encapsulation 100 and increase the creepage distance.

[0048] Furthermore, the widths of the first power terminal 401, the second power terminal 402, and the third power terminal 403 are greater than the widths of the first signal terminal 501 and the second signal terminal 502; the spacing D2 between the first power terminal 401, the second power terminal 402, and the third power terminal 403 is greater than the spacing D1 between the first signal terminal 501 and the second signal terminal 502, which allows for the passage of large currents and increases the withstand voltage capability of the device.

[0049] Furthermore, the area of ​​the molding compound 100 covering the first power terminal 401, the second power terminal 402, the third power terminal 403, and the first signal terminal 501 and the second signal terminal 502 is provided with protrusions, and the first power terminal 401, the second power terminal 402, the third power terminal 403, and the first signal terminal 501 and the second signal terminal 502 are bent in this area, which improves the electrical clearance of the device, increases the creepage distance, and makes the product more resistant to voltage, safer, and more reliable.

[0050] Furthermore, the insulating substrate 200 includes, but is not limited to, directly bonded copper ceramic substrates, active metal brazed ceramic substrates, and directly plated copper ceramic substrates; power terminals and corresponding base islands, and signal terminals and corresponding base islands are connected by adhesive materials such as lead-tin solder, conductive adhesive, solder paste, and sintered silver, so that the device can be applied to more fields.

[0051] Furthermore, shallow engravings 701 are provided on the portions of the power terminals and signal terminals inside the plastic package.

[0052] Figure 3 This is a front view of the packaging structure of the power module provided in this application.

[0053] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0054] As described above, these embodiments of the present invention do not exhaustively cover all details, nor do they limit the invention to the specific embodiments described. Clearly, many modifications and variations can be made based on the above description. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to effectively utilize the present invention and its modifications. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A packaging structure for a power module, characterized in that, include: An insulating substrate, the insulating substrate comprising a plurality of base islands located on a first surface of the insulating substrate, the plurality of base islands including a first base island and a second base island; Power device, first diode, second diode; The signal terminal includes a first signal terminal and a second signal terminal; The power terminals include a first power terminal, a second power terminal, and a third power terminal; A molding compound that encapsulates portions of the insulating substrate, the base island, the power device, the first diode, the second diode, the first power terminal, the second power terminal, the third power terminal, the first signal terminal, and the second signal terminal. The first terminal of the power device is electrically connected to the first terminal of the first diode at a first power terminal; the second terminal of the power device and the second terminal of the first diode are located on the first base island, the first base island extends from the side of the encapsulation and is connected to the second power terminal, and the anode of the second diode is electrically connected to the second power terminal; the cathode of the second diode is located on the second base island, the second base island extends from the side of the encapsulation and is connected to the third power terminal; the third terminal of the power device is electrically connected to a first signal terminal, and the Kelvin terminal of the power device is electrically connected to a second signal terminal.

2. The packaging structure of the power module according to claim 1, characterized in that, The power device is an insulated-gate bipolar transistor (IGBT), with the first terminal of the IGBT being the emitter, the second terminal of the IGBT being the collector, and the third terminal of the IGBT being the gate. The first terminal of the first diode is the anode, the second terminal of the first diode is the cathode, the first terminal of the second diode is the anode, and the second terminal of the second diode is the cathode. The emitter of the insulated-gate bipolar transistor (IGBT) is connected to the anode of the first diode via a bonding wire, a metal clip, or an aluminum strip to a third base island. The third base island extends from the side of the encapsulation and is connected to the first power terminal. The collector of the IGBT is connected to the cathode of the first diode via a bonding wire, a metal clip, or an aluminum strip and is located on the first base island. The first base island extends from the side of the encapsulation and is connected to the second power terminal. The anode of the second diode is connected to the second power terminal via a bonding wire, a metal clip, or an aluminum strip. The cathode of the second diode is located on the second base island, which extends from the side of the encapsulation and is connected to the third power terminal. The gate of the IGBT is connected to a fourth base island via a bonding wire, a metal clip, or an aluminum strip. The fourth base island extends from the side of the encapsulation and is connected to the first signal terminal. The Kelvin terminal of the IGBT is connected to a fifth base island via a bonding wire, a metal clip, or an aluminum strip. The fifth base island extends from the side of the encapsulation and is connected to the second signal terminal.

3. The packaging structure of the power module according to claim 1, characterized in that, The power device is a metal-oxide-semiconductor field-effect transistor (MOSFET). The first terminal of the MOSFET is the source, the second terminal is the drain, and the third terminal is the gate. The first terminal of the first diode is the anode, the second terminal is the cathode, the first terminal of the second diode is the anode, and the second terminal of the second diode is the cathode. The source of the metal-oxide-semiconductor field-effect transistor (MOSFET) is connected to the anode of the first diode via a bonding wire, a metal clip, or an aluminum strip to a third base island. The third base island extends from the side of the molding compound and is connected to the first power terminal. The drain of the MOSFET is connected to the cathode of the first diode via a bonding wire, a metal clip, or an aluminum strip and is located on the first base island. The first base island extends from the side of the molding compound and is connected to the second power terminal. The anode of the second diode is connected to the second power terminal via a bonding wire, a metal clip, or an aluminum strip. The cathode of the second diode is located on the second base island, which extends from the side of the molding compound and is connected to the third power terminal. The gate of the MOSFET is connected to a fourth base island via a bonding wire, a metal clip, or an aluminum strip. The fourth base island extends from the side of the molding compound and is connected to the first signal terminal. The Kelvin terminal of the MOSFET is connected to a fifth base island via a bonding wire, a metal clip, or an aluminum strip. The fifth base island extends from the side of the molding compound and is connected to the second signal terminal.

4. The packaging structure of the power module according to claim 1, characterized in that, The power devices are connected to the corresponding base islands via lead-tin solder, conductive adhesive, solder paste, and sintered silver bonding material.

5. The packaging structure of the power module according to claim 1, characterized in that, The power terminals and signal terminals are connected to the corresponding base islands via lead-tin solder, conductive adhesive, solder paste, and sintered silver bonding material.

6. The packaging structure of the power module according to claim 1, characterized in that, The first diode is one of a silicon-based fast recovery diode or a silicon carbide Schottky barrier diode.

7. The packaging structure of the power module according to claim 1, characterized in that, The second diode is one of a silicon-based fast recovery diode or a silicon carbide Schottky barrier diode.

8. The packaging structure of the power module according to claim 1, characterized in that, The insulating substrate includes, but is not limited to, directly bonded copper ceramic substrates, active metal brazed ceramic substrates, and directly plated copper ceramic substrates.

9. The packaging structure of the power module according to claim 1, characterized in that, The power terminals and signal terminals have shallow engravings inside the plastic package.

10. The packaging structure of the power module according to claim 1, characterized in that, The encapsulation between the power terminals has a groove structure.

11. The packaging structure of the power module according to claim 1, characterized in that, The power terminal is wider than the signal terminal.

12. The packaging structure of the power module according to claim 1, characterized in that, The spacing between two adjacent power terminals is greater than the spacing between two adjacent signal terminals.

13. The packaging structure of the power module according to claim 1, characterized in that, The encapsulation covers a portion of the protrusions of the signal terminal and the power terminal.

14. The packaging structure of the power module according to claim 1, characterized in that, The portions of the signal terminals and power terminals encapsulated by the plastic casing are bent.

15. The packaging structure of the power module according to claim 14, characterized in that, The encapsulation covering the power terminals is not on the same horizontal plane as the encapsulation encapsulating the power device.

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