A power device and a manufacturing method thereof

Abstract

The present invention relates to the field of semiconductor device technology, and in particular to a power device and a method for manufacturing the same. The power device includes a heat sink, an insulating substrate, a chip, pins, and a package. The heat sink has a first side surface, a mounting groove is recessed on the first side surface, a notch is recessed on one of the groove walls of the mounting groove, and the notch connects the mounting groove with the outside of the heat sink. The insulating substrate is disposed in the mounting groove, and a chip is disposed on a side of the insulating substrate away from the groove bottom of the mounting groove. A first solder pad is disposed on the chip, and pins are spaced apart on one side of the heat sink. The pins are adjacent to a side of the heat sink where the notch is disposed. The pins are connected to the first solder pads via solder wires, which pass through the notch and are spaced apart from the inner wall of the notch. The package seals the mounting groove and covers at least the first side surface. The power device of the embodiment of the present invention is small in size, thin in thickness, insulated, and has good heat dissipation effect.

Description

Technical Field

[0001] The present invention relates to the technical field of semiconductor devices, and in particular to a power device. Background Art

[0002] With the rise of third-generation semiconductors, represented by SiC, power devices are developing towards high power and high frequency. For high-power devices, the greater the power, the higher the upper limit of current and voltage will be, and the heat loss will also increase. The urgent problems to be solved for these power devices are heat dissipation and insulation.

[0003] Current power devices generally include the following two structures:

[0004] The first one, such as Figure 1 As shown, this power device includes a metal housing 1′ and metal pins 2′. The metal housing 1′ is a square cup with an open side. This metal housing 1′ serves as a heat sink for the power device. A through-hole is formed through the metal housing 1′, and one end of the metal pin 2′ passes through the through-hole and is located within the metal housing 1′. An insulating rubber ring 3′ is provided between the metal pin 2′ and the through-hole wall to prevent short circuits between the metal housing 1′ and the metal pin 2′. During assembly, a chip (not shown) is mounted on an insulating substrate (not shown) and then mounted within the metal housing 1′. Wirebonds are used to connect the chip pads to the metal pins 2′. This power device has the following defects: (1) In order to achieve insulation between the metal pin 2′ and the metal shell 1′, an insulating rubber ring 3′ must be provided. The provision of the insulating rubber ring 3′ makes the thickness of the power device thicker, and for electrical safety, the thickness is generally set to be greater than 5 mm, which makes the volume of the entire power device larger; (2) Due to the voltage resistance limit of the insulating rubber ring 3′ between the metal pin 2′ and the metal shell 1′, the power device can only be used in the medium and low power segments, and the application range is narrow; (3) The molding process of the metal shell 1′ is complicated, and the plastic packaging process can only adopt the traditional glue potting packaging method, which is low in efficiency and high in cost.

[0005] The second type, such as Figure 2 and Figure 3As shown, this power device includes a heat sink 1", an insulating ceramic sheet 2", a wafer carrier 3" and a chip 4". The chip 4" is mounted on the wafer carrier 3" to form an assembly. The wafer carrier 3" is integrally provided with a first lead pin 5", and then connected to a second lead pin 6" via an aluminum wire. This assembly is mounted on the insulating ceramic sheet 2", which is then stacked on the heat sink 1", and finally plastic-encapsulated to form a power device, so that the chip 4" is encapsulated by the plastic body 7". This power device has the following defects: (1) The heat sink 1" is separated from the wafer carrier 3", and an additional insulating ceramic sheet 2" needs to be mounted between the two, which is difficult to implement in terms of process and is prone to relative displacement; (2) There are three components in the thickness direction, which will greatly increase the thickness. Generally, the thickness of a power device can reach 5mm-6mm. Because of the increase in thickness, the internal heat transfer distance of the chip 4" increases, which is not conducive to heat dissipation. Summary of the Invention

[0006] To solve the above problems, embodiments of the present invention provide a power device and a manufacturing method thereof, which can effectively reduce the thickness of the power device and improve the heat dissipation effect.

[0007] In a first aspect, a power device is provided, comprising:

[0008] A heat sink having a first side surface, a mounting groove being recessed in the first side surface, a notch being recessed in one wall of the mounting groove, the notch communicating with the mounting groove and the exterior of the heat sink;

[0009] an insulating substrate, the insulating substrate being disposed in the mounting groove, a chip being disposed on a side of the insulating substrate away from a groove bottom of the mounting groove, and a first pad being disposed on the chip;

[0010] Pins, the pins are arranged at intervals on one side of the heat sink, the pins are adjacent to a side of the heat sink where the notch is provided, the pins are connected to the first pads via welding wires, the welding wires pass through the notch and are spaced apart from an inner wall of the notch;

[0011] A packaging body blocks the mounting groove and at least covers the first side surface and blocks an end of the pin close to the heat sink.

[0012] The power device of the present invention has the following beneficial effects: by stacking the insulating substrate and the chip in the mounting groove of the heat sink, most or even all of the insulating substrate and the chip are located in the mounting groove of the heat sink in the thickness direction, thereby effectively reducing the thickness of the power device after plastic packaging. The reduced thickness reduces the heat conduction distance, which is conducive to rapid heat dissipation. Moreover, since the chip is partially or completely immersed in the heat sink, the heat dissipation channel of the chip during operation can be dissipated from the side where the groove bottom is located, as well as from the side where the groove wall of the mounting groove is located, thereby greatly reducing the heat accumulation inside the chip and achieving good heat dissipation effect; by arranging the insulating substrate between the chip and the heat sink, the insulating substrate can be used to insulate and isolate the chip, thereby achieving internal insulation of the power device, thereby making the heat sink non-charged and highly safe; by providing the notch, the distance from the highest point of the arc of the welding wire to the outer side surface of the package body can be ensured to be wider without increasing the thickness of the power device, thereby making the ultra-thin power device have more voltage margin and effectively avoiding the short circuit problem caused by the arc height of the welding wire being too low.

[0013] In a possible implementation manner of the present invention, the thickness of the power device is H1, and H1 is not greater than 3 mm; and / or,

[0014] The package body has a main body located on the side of the chip away from the bottom of the mounting groove, and the main body has a package outer side surface away from the mounting groove. The distance between the package outer side surface and the highest point of the arc of the welding wire is H2, and H2 is less than 0.5mm.

[0015] In a possible embodiment of the present invention, the insulating substrate includes an insulating body, a circuit layer is provided on a side of the body close to the chip, a second pad is provided on the circuit layer, and the chip is fixedly connected to the second pad.

[0016] In a possible embodiment of the present invention, there are three pins, two first pads, and a third pad is further provided on the circuit layer. The third pad is spaced apart from the chip, wherein two of the pins are respectively connected to the two first pads, and the other pin is connected to the third pad.

[0017] In a possible embodiment of the present invention, the body is a ceramic plate or an aluminum nitride plate; and / or,

[0018] The circuit layer is a copper layer electroplated or deposited on the body; and / or,

[0019] The heat sink is made of copper.

[0020] In a possible implementation manner of the present invention, a moisture-proof groove is provided on the inner wall of the installation groove surrounding the notch of the installation groove.

[0021] In a possible implementation manner of the present invention, an insulating pad is provided on the inner wall of the gap.

[0022] In a possible embodiment of the present invention, the heat sink has a second side surface opposite to the first side surface, the first side surface and the second side surface are connected by a third side surface, the packaging body extends from the first side surface to the third side surface and covers the third side surface, and extends to cover the periphery of the second side surface, and the second side surface has a heat dissipation area not covered by the packaging body.

[0023] In a possible embodiment of the present invention, the heat sink and the pins are integrally manufactured using a metal plate, and multiple heat sinks and multiple pin groups are arranged at intervals on the metal plate. One group of pin groups corresponds to one heat sink, and each group of pin groups includes at least two pins. Two adjacent heat sinks are connected by connecting ribs. The pin groups are spaced apart from the heat sinks corresponding to their positions, and two adjacent pins are connected by the connecting ribs.

[0024] In a possible implementation manner of the present invention, the width of the notch is not greater than the width of the mounting groove; and / or,

[0025] The depth of the notch is no greater than the depth of the mounting groove.

[0026] In a second aspect, a method for manufacturing a power device is provided, comprising:

[0027] Step S10: providing a heat sink, pins, a chip and an insulating substrate;

[0028] Step S20: soldering the chip onto the insulating substrate to form an assembly;

[0029] Step S30: placing the component in the mounting groove of the heat sink;

[0030] Step S40: Connecting the chip to the pins through bonding wires, and passing the bonding wires through the notches on the heat sink;

[0031] Step S50: encapsulating the heat sink to seal the mounting groove and fix the pins.

[0032] In a possible implementation manner of the present invention, the step S10 includes: step S11, a manufacturing process of the heat sink and the pins;

[0033] A metal plate is provided, on which a plurality of heat sinks and a plurality of pin groups are formed, wherein two adjacent heat sinks are connected by connecting ribs, and the opposite pin groups and heat sinks are spaced apart, and the pin groups are arranged on a side of the heat sink where a notch is provided, and each pin group includes at least two spaced apart pins, and two adjacent pins are connected by the connecting ribs.

[0034] In a possible implementation manner of the present invention, step S60 is further provided after step S50 , in which the connecting ribs on the metal plate are punched out to separate the packaged power device from the metal plate.

[0035] In a possible implementation manner of the present invention, the metal plate is a copper plate, and after the heat sink and the pins are processed on the copper plate, a protective layer is provided on the surface of the copper plate.

[0036] In a possible implementation manner of the present invention, the protective layer is one or more of a tin layer, a nickel layer, and a nickel-tin alloy layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the following briefly introduces the drawings required for use in the embodiments or related technology descriptions. Obviously, the drawings described below are only simplified schematic diagrams of some embodiments of the present invention or related technologies. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0038] Figure 1 It is a schematic diagram of the structure of the metal shell and metal pins of the existing first power device after assembly.

[0039] Figure 2 It is a structural diagram of the second existing power device.

[0040] Figure 3 This is a schematic diagram of the second type of existing power device.

[0041] Figure 4 Schematic diagram of a front view of a power device according to an embodiment of the present invention.

[0042] Figure 5 Schematic diagram of a rear view of a power device according to an embodiment of the present invention.

[0043] Figure 6 3D is a schematic perspective view of a power device according to an embodiment of the present invention.

[0044] Figure 7 Schematic diagram of an exploded view of a power device according to an embodiment of the present invention.

[0045] Figure 8 for Figure 7 A magnified schematic diagram of .

[0046] Figure 9 Schematic diagram of the structure of a power device according to an embodiment of the present invention (the package is not shown).

[0047] Figure 10 FIG. 4 is a schematic diagram of heat dissipation of a power device according to an embodiment of the present invention.

[0048] Figure 11 Schematic diagram of the structure of a metal plate according to an embodiment of the present invention.

[0049] Figure 1 middle:

[0050] 1′, metal shell; 2′, metal pin; 3′, insulating rubber ring.

[0051] Figure 2 and 3 middle:

[0052] 1", heat sink; 2", insulating ceramic sheet; 3", wafer carrier; 4", chip; 5", first lead pin; 6", second lead pin; 7", plastic package.

[0053] Figures 4 to 11 middle:

[0054] 1. Heat sink; 11. First side; 12. Mounting groove; 121. Groove bottom; 122. Groove wall; 13. Notch; 14. Groove; 15. Second side; 16. Third side; 17. Reinforcement groove; 2. Insulating substrate; 21. Main body; 22. Circuit layer; 221. Second solder pad; 222. Third solder pad; 3. Chip; 31. First solder pad; 4. Pin; 5. Solder wire; 6. Package body; 61. Main body; 62. Package outer side; 7. Metal plate; 71. Connecting rib. DETAILED DESCRIPTION

[0055] The following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0056] In the description of the embodiments of the present invention, unless otherwise expressly specified or limited, the terms "connected," "connected," and "fixed" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and they may refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention in specific contexts.

[0057] In the embodiments of the present invention, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first and second features being in direct contact, or may include the first and second features being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0058] See attached Figure 4 To the attached Figure 10 The power device of an embodiment of the present invention includes a heat sink 1, an insulating substrate 2, a chip 3, pins 4 and a package 6, wherein the heat sink 1 has a first side surface 11, the first side surface 11 is recessed with a mounting groove 12, one of the groove walls 122 of the mounting groove 12 is recessed with a notch 13, the notch 13 connects the mounting groove 12 with the outside of the heat sink 1, the insulating substrate 2 is arranged in the mounting groove 12, the chip 3 is arranged on a side of the insulating substrate 2 away from the groove bottom 121 of the mounting groove 12, a first soldering pad 31 is provided on the chip 3, the pins 4 are arranged at intervals on one side of the heat sink 1, the pins 4 are adjacent to the side of the heat sink 1 with the notch 13, the pins 4 are connected to the first soldering pad 31 through a soldering wire 5, the soldering wire 5 passes through the notch 13 and is spaced apart from the inner wall of the notch 13, and the package 6 blocks the mounting groove 12 and covers at least the first side surface 11.

[0059] In this embodiment, the width of the notch 13 is no greater than the width of the mounting groove 12, and the depth of the notch 13 is no greater than the depth of the mounting groove 12. When both the width and depth of the notch 13 are no greater than the width and depth of the mounting groove 12, the path for moisture from outside the power device to enter the power device is extended, effectively improving the reliability of the power device.

[0060] The power device of the embodiment of the present invention is formed by stacking the insulating substrate 2 and the chip 3 in the mounting groove 12 of the heat sink 1, so that most or even all of the insulating substrate 2 and the chip 3 are located in the mounting groove 12 of the heat sink 1 in the thickness direction, thereby effectively reducing the thickness of the power device after plastic packaging. Moreover, since the chip 3 is partially or completely immersed in the heat sink 1, the heat dissipation channel of the chip 3 during operation can be dissipated from not only the side where the groove bottom 121 of the mounting groove 12 is located, but also from all sides of the chip 3, that is, from the side where the groove wall 122 of the mounting groove 12 is located (such as Figure 10 As shown), the heat accumulation inside the chip 3 is greatly reduced, and the heat dissipation effect is good; by arranging an insulating substrate 2 between the chip 3 and the heat sink 1, the insulating substrate 2 can be used to insulate and isolate the chip 3, thereby realizing internal insulation of the power device, thereby making the heat sink 1 non-charged and highly safe; by providing the notch 13, the distance from the highest point of the arc of the welding wire 5 to the outer side surface 62 of the package 6 can be ensured to be wider without increasing the thickness of the power device, thereby making the ultra-thin power device have more voltage resistance margin, and effectively avoiding the short circuit problem caused by the arc height of the welding wire 5 (that is, the distance from the highest point of the arc of the welding wire 5 to the outer side surface 62 of the package 6) being too low.

[0061] Preferably, the insulating substrate 2 and the chip 3 are all located in the mounting groove 12 of the heat sink 1 in the thickness direction. At this time, the size of the highest point of the arc of the welding wire 5 can be minimized, that is, the distance between the highest point of the arc of the welding wire 5 and the bottom 121 of the mounting groove 12 can be minimized, so that the thickness of the power device after plastic encapsulation can be minimized.

[0062] In this embodiment, the heat sink 1 has a rectangular plate-like structure, the mounting slot 12 defined in the heat sink 1 is a rectangular slot, and the chip 3 has a rectangular plate-like structure. Each edge of the chip 3 faces a slot wall 122 of the mounting slot 12, and each edge of the chip 3 is equidistant from the slot wall 122. Chips 3 are generally rectangular in structure. Therefore, configuring the heat sink 1 as a rectangular plate-like structure and the mounting slot 12 as a rectangular slot ensures that heat dissipated from the chip 3 is evenly distributed from all sides.

[0063] Of course, the heat sink 1 is not limited to being a rectangle, and can also be a circular, elliptical, triangular, pentagonal, or other structure. Similarly, the shape of the mounting groove 12 is not limited to being a rectangle, and can also be a circular groove, an elliptical groove, or the like.

[0064] Preferably, the side of the chip 3 away from the insulating substrate 2 is lower than the slot of the mounting slot 12. This design allows the chip 3 to be completely inside the mounting slot 12, so as to more reasonably utilize the slot wall 122 of the mounting slot 12 for heat dissipation and improve the heat dissipation effect.

[0065] In this embodiment, the thickness of the power device is H1, which is no greater than 3 mm. This thickness allows for high power due to its improved structure, ensuring heat dissipation and safety. Preferably, the power device can achieve a power of 1200 V / 100 A.

[0066] Package body 6 includes a main portion 61 located on the side of chip 3 away from groove bottom 121 of mounting groove 12. Main portion 61 has a package outer side surface 62 facing away from mounting groove 12. The distance between package outer side surface 62 and the highest point of the arc of bond wire 5 is H2, which is less than 0.5 mm. This design significantly shortens the heat transfer distance between chip 3 and the outside. Because package body 6 does not dissipate heat as effectively as heat sink 1, the thickness of package body 6 at this location is designed to be less than 0.5 mm to ensure rapid heat dissipation on the side of chip 3 closest to heat sink 1.

[0067] In one embodiment, the insulating substrate 2 includes an insulating body 21. A circuit layer 22 is disposed on a side of the body 21 proximate to the chip 3. A second bonding pad 221 is disposed on the circuit layer 22, and the chip 3 is fixedly connected to the second bonding pad 221. The insulating substrate 2 is designed with the circuit layer 22 disposed on the insulating body 21 to reduce the overall thickness of the chip 3 after being fixed to the insulating substrate 2, thereby achieving an extremely thin power device.

[0068] Preferably, the circuit layer 22 is a copper layer electroplated or deposited on the body 21 .

[0069] In order to ensure the insulation of the insulating substrate 2, the body 21 is a ceramic plate or an aluminum nitride plate. Of course, the body 21 is not limited to the above two materials, as long as it can ensure the insulation and safety of the power device under high power.

[0070] Specifically, this power device has three pins 4, two first pads 31, and a third pad 222 is provided on the circuit layer 22. The third pad 222 is spaced apart from the chip 3, wherein two pins 4 are respectively connected to the two first pads 31, and the other pin 4 is connected to the third pad 222.

[0071] In one embodiment, if Figure 8 As shown (see attached Figure 4 To the attached Figure 7 ), the inner wall of the mounting groove 12 is provided with a moisture-proof groove 14 around the notch of the mounting groove 12. By providing this groove 14, the compactness of the power device can be improved, and moisture can be prevented from entering the mounting groove 12 and damaging the power device, thereby improving the reliability of the power device.

[0072] In this embodiment, the groove 14 is interrupted at the position of the notch 13. When the power device is in use, the notch 13 is located below the heat sink 1 of the power device. Therefore, even if the groove 14 is not provided at the position of the notch 13, moisture can be completely prevented from invading the interior of the mounting groove 12. In other words, the groove 14 can be omitted at this position, reducing processing difficulty and improving production efficiency.

[0073] An insulating pad (not shown) is provided on the inner wall of the notch 13. The insulating pad isolates the bonding wire 5 from the metal heat sink 1, providing insulation protection. Therefore, when the bonding wire 5 passes through the notch 13, the bonding wire 5 is as close as possible to the inner wall of the notch 13 near the bottom 121 of the mounting groove 12, further reducing the arc height of the bonding wire 5 and, in turn, the thickness of the entire power device.

[0074] In this embodiment, the insulating pad is arranged on the inner wall of the notch 13. Optionally, the insulating pad can be arranged on the inner wall of the notch 13 by spraying, painting or bonding.

[0075] In one embodiment, the heat sink 1 has a second side surface 15 opposite the first side surface 11. The first side surface 11 and the second side surface 15 are connected by a third side surface 16. The encapsulation body 6 extends from the first side surface 11 to the third side surface 16 and covers the third side surface 16. When the encapsulation body 6 encapsulates the heat sink 1, if the third side surface 16 is also covered, the bonding strength between the encapsulation body 6 and the heat sink 1 can be increased, effectively preventing the encapsulation body 6 from peeling off from the heat sink 1. In addition, the extension of the encapsulation body 6 from the slotted first side surface 11 to the third side surface 16 can enhance the sealing effect of the mounting groove 12, effectively preventing damage to components in the mounting groove 12, and thus improving the reliability of the power device.

[0076] Preferably, the package body 6 extends from the third side 16 to the second side 15, and the package body 6 covers the periphery of the second side 15. The second side 15 has a heat dissipation area not covered by the package body 6. By extending the package body 6 to the second side 15, the sealing of the power device is further improved. In the reserved heat dissipation area, the metal of the heat sink 1 in this area is not covered by the package body 6, which can ensure the heat dissipation effect.

[0077] Preferably, if Figure 8 As shown (refer to Figure 7 ), a reinforcement groove 17 is provided on both the first side 11 and the second side 15. The reinforcement groove 17 can increase the bonding strength between the package body 6 and the heat sink 1 when the package body 6 is packaged on the heat sink 1. More preferably, the reinforcement groove 17 on the first side 11 and the second side 15 extends to the third side 16.

[0078] Preferably, all pins 4 are arranged in the same plane, and pins 4 are located in the middle of the thickness direction of the entire power device. This design can ensure that the force exerted by the package body 6 on the pins 4 is consistent on both sides of the thickness direction of the power device, effectively preventing the package body 6 from deforming or breaking at the pins 4.

[0079] In one embodiment, if Figure 11 As shown (see attached Figure 4 To the attached Figure 10 ) The heat sink 1 and the pins 4 are integrally manufactured using a metal plate 7. Multiple heat sinks 1 and multiple pin groups are spaced apart on the metal plate 7. One pin group corresponds to one heat sink 1. Each pin group includes at least two pins 4. Two adjacent heat sinks 1 are connected by a connecting rib 71. The pin groups and the heat sinks 1 corresponding to their positions are spaced apart, and two adjacent pins 4 are connected by a connecting rib 71. The integrated metal plate 7 is used to manufacture several heat sinks 1 and pins 4. When assembling power devices, there is no need to locate the positions of the heat sink 1 and pins 4, nor is there any need to assemble the pins 4 one by one. This can reduce the difficulty of manufacturing the heat sink 1 and pins 4 and improve production efficiency. Moreover, when producing power devices, multiple power devices can be produced directly on the metal plate 7 at a time, and automated production can be achieved, greatly improving production efficiency.

[0080] The present invention also discloses a method for manufacturing a power device, which is used to manufacture the power device of any of the above embodiments, comprising:

[0081] Step S10, providing a heat sink 1, pins 4, a chip 3 and an insulating substrate 2;

[0082] Step S20: soldering the chip 3 onto the insulating substrate 2 to form a component;

[0083] Step S30: placing the component in the mounting groove 12 of the heat sink 1;

[0084] Step S40: Connect the chip 3 to the pin 4 through the bonding wire 5, and pass the bonding wire 5 through the notch 13 on the heat sink 1;

[0085] Step S50 , encapsulating the heat sink 1 to seal the mounting groove 12 and the fixing pin 4 .

[0086] The above-mentioned manufacturing method is simple to operate and can quickly assemble the power device. The assembled power device is thin and can meet the high-power design requirements.

[0087] Preferably, step S10 includes: step S11, a manufacturing process of the heat sink 1 and the pins 4;

[0088] A metal plate 7 is provided, on which a plurality of heat sinks 1 and a plurality of pin groups are formed. Adjacent heat sinks 1 are connected by connecting ribs 71, and opposing pin groups are spaced apart from each other. The pin groups are arranged on the side of the heat sink 1 where the notch 13 is provided. Each pin group includes at least two spaced apart pins 4, and adjacent pins 4 are connected by connecting ribs 71. By integrally forming the plurality of heat sinks 1 and pins 4 on the metal plate 7, not only is the processing difficulty of the heat sinks 1 and pins 4 reduced, but also, during the assembly of the power device, the positioning and assembly processes of the heat sinks 1 and pins 4 can be eliminated, effectively improving the assembly accuracy and efficiency of the power device.

[0089] More preferably, after step S50, step S60 is further provided to punch out the connecting ribs 71 on the metal plate 7 to separate the encapsulated power device from the metal plate 7. After the encapsulation is completed, the connecting ribs 71 are cut off to separate the power device from the metal plate 7 to form a single finished product, which can realize automatic production line and improve production efficiency and precision.

[0090] The metal plate 7 is a copper plate. After the heat sink 1 and pins 4 are machined on the copper plate, a protective layer is applied to the surface of the copper plate. Copper plates have high heat dissipation efficiency, but copper is easily oxidized, and the oxide layer on the copper surface affects welding. Therefore, the protective layer can prevent the copper plate from being oxidized and ensure the welding effect.

[0091] Specifically, the protective layer is one or more of a tin layer, a nickel layer and a nickel-tin alloy layer.

[0092] The functional device of the present invention and Figure 1 Metal shell packaging, Figure 2 and Figure 3 Compared with the common internal insulation design package, based on the premise that the external heat dissipation conditions are consistent with the chip and the heating conditions are consistent, the thermodynamic analysis results using ANSYS Workbench (finite element software platform) are as follows:

[0093] Assuming the chip is operating in a steady state at full load current, based on the same chip and heat sink, the same heat dissipation boundary conditions are set: natural convection of air: 5W / m 2 K; forced convection of water: 2000W / m 2 K (based on full load current, water cooling mode is selected).

[0094] Figure 1 The thermodynamic analysis results of the metal shell package are as follows: According to the simulation analysis of ANSYS Workbench, the highest core temperature is 147.14℃.

[0095] Figure 2 and Figure 3The thermodynamic analysis results of the ordinary internal insulation design are as follows: According to the simulation analysis of ANSYS Workbench, the highest core temperature is 130.16℃.

[0096] Figures 4 to 7 The thermodynamic analysis results of the power device of the present invention are as follows: According to the simulation analysis of ANSYS Workbench, the core temperature thereof is at most 126.68°C.

[0097] Through the simulation results, it can be seen that under the same conditions, the power device of the present invention is based on the design of the mounting groove 12 and the notch 13 of the heat sink 1, so that the chip 3 has a shorter distance in the thickness direction of heat transmission, while having the dual advantages of good heat dissipation and good insulation. Its heat dissipation effect is better than that of the metal shell structure ( Figure 1 The junction temperature of chip 3 is reduced by 16.98℃; compared with the common internal insulation structure ( Figure 2 and Figure 3 The junction temperature of chip 3 is reduced by 3.48°C. Based on industry experience that lifespan doubles for every 10°C temperature reduction, the lifespan of the power device of the present invention is nearly three times longer than that of a metal housing structure and approximately 0.5 times longer than that of a conventional internal insulation structure. The temperature resistance of SiC power devices means that the power device of the present invention can accommodate a higher-power chip 3, allowing for a higher power density while maintaining product stability.

[0098] Throughout this specification, references to terms such as "one embodiment" or "example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0099] The technical principles of the present invention have been described above with reference to specific embodiments. These descriptions are intended solely to illustrate the principles of the present invention and are not to be construed in any way as limiting the scope of protection of the present invention. Based on the explanations herein, those skilled in the art will readily conceive of other specific embodiments of the present invention without inventive effort, and such embodiments will fall within the scope of protection of the present invention.

Claims

1. A power device, characterized in that: include: A heat sink having a first side surface, a mounting groove being recessed in the first side surface, a notch being recessed in one wall of the mounting groove, the notch communicating with the mounting groove and the exterior of the heat sink; an insulating substrate, the insulating substrate being disposed in the mounting groove, a chip being disposed on a side of the insulating substrate away from a groove bottom of the mounting groove, and a first pad being disposed on the chip; Pins, the pins are arranged at intervals on one side of the heat sink, the pins are adjacent to a side of the heat sink where the notch is provided, the pins are connected to the first pads via welding wires, the welding wires pass through the notch and are spaced apart from an inner wall of the notch; a packaging body, the packaging body sealing the mounting groove and at least covering the first side surface and sealing an end of the pin close to the heat sink; The inner wall of the installation groove is provided with a moisture-proof groove surrounding the notch of the installation groove; The heat sink has a second side surface opposite to the first side surface, the first side surface and the second side surface are connected by a third side surface, the packaging body extends from the first side surface to the third side surface and covers the third side surface, and extends to cover the periphery of the second side surface, and the second side surface has a heat dissipation area not covered by the packaging body; The width of the notch is no greater than the width of the mounting slot; and / or, The depth of the notch is no greater than the depth of the mounting groove.

2. The power device according to claim 1, wherein: The thickness of the power device is H1, which is not greater than 3 mm; and / or, The package body has a main body located on the side of the chip away from the bottom of the mounting groove, and the main body has a package outer side surface away from the mounting groove. The distance between the package outer side surface and the highest point of the arc of the welding wire is H2, and H2 is less than 0.5mm.

3. The power device according to claim 1, wherein: The insulating substrate includes an insulating body. A circuit layer is provided on a side of the body close to the chip. A second pad is provided on the circuit layer. The chip is fixedly connected to the second pad.

4. The power device according to claim 3, wherein: There are three pins and two first pads. A third pad is also provided on the circuit layer. The third pad is spaced apart from the chip. Two of the pins are respectively connected to the two first pads, and the other pin is connected to the third pad.

5. The power device according to claim 3, wherein: The body is a ceramic plate or an aluminum nitride plate; and / or, The circuit layer is a copper layer electroplated or deposited on the body; and / or, The heat sink is made of copper.

6. The power device according to any one of claims 1 to 5, characterized in that: An insulating pad is provided on the inner wall of the notch.

7. The power device according to any one of claims 1 to 5, characterized in that: The heat sink and the pins are integrally manufactured using a metal plate, and multiple heat sinks and multiple pin groups are arranged at intervals on the metal plate. One group of pin groups corresponds to one heat sink, and each group of pin groups includes at least two pins. Two adjacent heat sinks are connected by connecting ribs. The pin groups are spaced apart from the heat sinks corresponding to their positions, and two adjacent pins are connected by the connecting ribs.

8. A method for manufacturing a power device, characterized in that: For manufacturing the power device according to any one of claims 1 to 7, comprising: Step S10: providing a heat sink, pins, a chip and an insulating substrate; Step S20: soldering the chip onto the insulating substrate to form an assembly; Step S30: placing the component in the mounting groove of the heat sink; Step S40: Connecting the chip to the pins through bonding wires, and passing the bonding wires through the notches on the heat sink; Step S50: encapsulating the heat sink to seal the mounting groove and fix the pins.

9. The method for manufacturing a power device according to claim 8, wherein: The step S10 includes: step S11, a manufacturing process of the heat sink and the pins; A metal plate is provided, on which a plurality of heat sinks and a plurality of pin groups are formed, wherein two adjacent heat sinks are connected by connecting ribs, and the opposite pin groups and heat sinks are spaced apart, and the pin groups are arranged on a side of the heat sink where a notch is provided, and each pin group includes at least two spaced apart pins, and two adjacent pins are connected by the connecting ribs.

10. The method for manufacturing a power device according to claim 9, wherein: After step S50 , step S60 is further provided to punch out the connecting ribs on the metal plate to separate the packaged power device from the metal plate.

11. The method for manufacturing a power device according to claim 9, wherein: The metal plate is a copper plate. After the heat sink and the pins are processed on the copper plate, a protective layer is provided on the surface of the copper plate.

12. The method for manufacturing a power device according to claim 11, wherein: The protective layer is one or more of a tin layer, a nickel layer and a nickel-tin alloy layer.

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