Power semiconductor module

Abstract

The utility model relates to the semiconductor technology, in particular to a power semiconductor module, which comprises a power module body (1), and a metal radiating surface (13) is arranged at the top of a plastic package shell (11). A creepage enhancing unit (14) is arranged on the plastic package shell (11) between the metal radiating surface (13) and the metal pin (12); and a bottom supporting boss (15) is arranged at the bottom of the plastic package shell (11). According to the utility model, the creepage distance between the electrode pin and the back electrode is increased by means of slotting the top surface and the side surface of the packaging external plastic packaging body and wrapping the electrode pin, and the risk of creepage breakdown is reduced. Meanwhile, the supporting structure designed at the bottom of the plastic package body can support the radiator to be far away from the hot surface of the PCB, the heat exchange efficiency of the radiator is improved, other circuit elements can be additionally installed in the space formed at the bottom, the size of the circuit board is reduced, and the design flexibility is improved.

Description

Technical Field

[0001] This utility model relates to semiconductor technology, and more particularly to a power semiconductor module and a plastic-encapsulated device. Background Technology

[0002] In modern electronics manufacturing, power electronic devices are evolving towards higher power density, smaller size, and lower power consumption. Following this trend, top-heat-dissipating surface mount (SMT) packaging has emerged. In this type of packaging, the circuit board that enables surface-to-surface connectivity with the semiconductor chip is placed on top of the package. This means that power modules directly mounted on the PCB surface can be directly connected to external heat sinks, ensuring maximum power dissipation and optimizing heat dissipation performance. This packaging technology provides semiconductor devices with compact size, powerful heat dissipation capabilities, and efficient mounting methods, making it widely popular.

[0003] However, to maximize the heat dissipation capacity of existing top-heat-dissipating SMT packages, the top heat dissipation surface often needs to be connected to an external heat sink via a thermal interface material. The weight of the heat sink can cause the thermal interface material to be squeezed out during the manufacturing process or use, thus affecting the module's thermal resistance. Furthermore, current processes struggle to precisely control the thickness of the thermal interface material during use. Excessively thick thermal interface material directly increases the package's thermal resistance, while excessively thin material may introduce voids and air bubbles, also affecting the overall thermal resistance of the package, leading to instability in the package's thermal resistance.

[0004] However, as package size continues to shrink, the creepage distance between the bottom pins and the back electrode also decreases further. At the same time, the increasing voltage levels and current output capabilities of power semiconductor devices further increase the probability of creepage breakdown. Therefore, the problem of excessively short creepage distance on the package surface has become a major factor limiting the application of this packaging technology.

[0005] As package sizes continue to shrink, the creepage distance between the bottom pins and the back electrode of existing top-heat-dissipated SMT packages is further reduced. In addition, the voltage levels and current output capabilities of power semiconductor devices are gradually increasing, requiring further increases in creepage distance. The reliability of the package is facing severe challenges.

[0006] To maximize heat dissipation in existing top-heat-dissipating SMT packages, the top heat dissipation surface often needs to be connected to an external heatsink via a thermal interface material. However, the weight of the heatsink can cause the thermal interface material to be squeezed out during the manufacturing process or use. Furthermore, current processes struggle to precisely control the thickness of the thermal interface material. Excessively thick material directly increases the package's thermal resistance, while insufficiently thin material may introduce voids and air bubbles, also affecting the overall thermal resistance. This results in unstable thermal resistance and makes product quality control difficult.

[0007] In top-heat SMT packages, although the heat sink is placed on top of the package, it is still too close to the PCB board. The hot surface environment of the PCB board is not conducive to the heat sink dissipating heat to the external environment.

[0008] For example, in prior art US10,658,276B2, the patent title is "Power Device with Top-Side Base Plate." During manufacturing, the top-side base plate (conventionally always facing downwards and essentially flush with the PCB) is intentionally placed on top of the power device to facilitate heat dissipation and protect the chip from damage. Simultaneously, the device's leads extend from the top and in the opposite direction to the bottom for mounting on the PCB. This packaging structure allows for the application of thermal conductive devices (such as metal clips) to a single, smaller power device to aid in heat dissipation.

[0009] Existing technologies only consider the optimization of the heat dissipation structure at the top of power devices. However, with the continuous reduction of package size and the gradual increase of voltage level and current output capability of power devices, the risk of creepage breakdown between the bottom pins and the back electrode of the device is further increased, requiring a longer creepage distance to improve the reliability of the device. Utility Model Content

[0010] This invention addresses the problem of excessively short creepage distance on the packaging surface in existing technologies by providing a power semiconductor module and a plastic-encapsulated device.

[0011] To solve the above-mentioned technical problems, the present invention provides a solution through the following technical method:

[0012] A power semiconductor module includes a power module body, which comprises a plastic-encapsulated housing and metal leads extending from the housing. A metal heat dissipation surface is provided on the top of the plastic-encapsulated housing. Creepage enhancement units are provided on the plastic-encapsulated housing between the metal heat dissipation surface and the metal leads. A bottom support boss is provided on the bottom of the plastic-encapsulated housing. The support structure designed at the bottom of the plastic-encapsulated housing can support the heat sink away from the hotter PCB board surface, improving the heat exchange efficiency of the heat sink. Simultaneously, the space formed at the bottom can be used to install other circuit components, helping to reduce the board size and improve design flexibility.

[0013] Preferably, the top surface of the plastic-encapsulated housing is provided with a top support boss. The support structure designed on the top of the plastic-encapsulated housing can ensure the minimum thickness of the metal solder, which helps to fully utilize the heat dissipation at the top and ensures the uniformity and stability of the module's thermal resistance.

[0014] Preferably, the thickness of the top support boss is equal to the thickness of the metal solder. The thickness of the metal solder can be controlled by setting the thickness of the top support boss.

[0015] Preferably, the creepage enhancement unit includes at least one set of top-slotted units in a plastic-encapsulated housing.

[0016] Preferably, the creepage enhancement unit includes a side-grooved unit in a plastic-encapsulated housing.

[0017] Preferably, the top periphery of the molded housing has a sealing ring groove for placing a sealing ring. A sealing ring gasket is placed within the sealing ring groove, and the minimum thickness of the thermal interface material, such as thermal grease, is controlled by the sealing ring gasket. This helps to fully utilize top heat dissipation and ensures uniform and stable thermal resistance of the module.

[0018] Preferably, the side protrusion unit of the plastic-encapsulated housing is an inverted triangular protrusion unit.

[0019] Preferably, the side protrusions of the molding compound are triangular in shape. Multiple top slotted units can be arranged on the hypotenuse of the triangle, reducing the amount of molding compound used while further increasing the creepage distance.

[0020] This utility model, by adopting the above technical solution, has the following significant technical effects:

[0021] The power module of this practical design optimizes the structural shape of the molded package. By slotting the top and sides and wrapping the electrode leads, the creepage distance between the electrode leads and the back electrode is effectively increased, thereby improving the creepage breakdown voltage and reliability of the packaged device.

[0022] The support structure designed on the top of the molded body in this invention can ensure the minimum thickness of thermal interface materials such as thermal grease, which helps to fully utilize the heat dissipation at the top and ensures the uniformity and stability of the module's thermal resistance.

[0023] The support structure designed at the bottom of the molded enclosure in this invention can support the heat sink away from the hotter PCB surface, improving the heat exchange efficiency of the heat sink. At the same time, the space formed at the bottom can be used to install other circuit components, which helps to reduce the size of the circuit board and improve design flexibility. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the power module body structure of Embodiment 1 of this utility model;

[0025] Figure 2This is a front view of the power module structure of Embodiment 1 of this utility model;

[0026] Figure 3 This is a schematic diagram of the power module structure of the top support boss of this utility model;

[0027] Figure 4 This is a schematic diagram of the power module structure of the array slotted unit of this utility model;

[0028] Figure 5 This is a schematic diagram of the power module structure in which the side protrusion unit is triangular in shape.

[0029] Figure 6 This is a schematic diagram of the power module structure with the reserved sealing ring groove in this utility model;

[0030] The parts referred to by the numbers in the attached diagram are as follows: 1—Power module body, 11—Plastic housing, 12—Metal pins, 13—Metal heat dissipation surface, 131—Sealing ring groove, 14—Creepfastness enhancement unit, 142—Top slotted unit, 143—Side slotted unit, 15—Bottom support boss, 16—Top support boss. Detailed Implementation

[0031] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0032] Example 1

[0033] A power semiconductor module, Figure 1 , Figure 2 The device includes a power module body 1, which includes a plastic encapsulated housing 11 and metal pins 12 extending from the plastic encapsulated housing 11; a metal heat dissipation surface 13 is provided on the top of the plastic encapsulated housing 11; a sealing ring groove 131 is provided on the outer periphery of the top surface of the plastic encapsulated housing 11 for placing a sealing ring; a creepage enhancement unit 14 is provided on the plastic encapsulated housing 11 between the metal heat dissipation surface 13 and the metal pins 12, including a top surface slotting unit 142 and a side slotting unit 143 of the plastic encapsulated housing 11; and a bottom support boss 15 is provided at the bottom of the plastic encapsulated housing 11.

[0034] Figure 6 When the power module and the external heat sink are connected using a thermal interface material such as thermal grease, a sealing ring can be inserted into the sealing ring groove 131 reserved around the metal heat sink 13. The part of the sealing ring that protrudes from the heat sink surface can precisely control the minimum thickness of the thermal grease, which helps to fully utilize the top heat dissipation and ensures the uniformity and stability of the module's thermal resistance.

[0035] The bottom support boss 15 designed at the bottom of the molding compound can support the heat sink away from the hotter PCB surface, improving the heat exchange efficiency of the heat sink. At the same time, the space formed at the bottom can be used to install other circuit components, which helps to reduce the board size and improve design flexibility.

[0036] The bottom of the plastic-encapsulated housing 11 is provided with a bottom support boss 15. The size and number of bosses can be flexibly adjusted according to the size of the bottom components, further reducing the size of the circuit board and improving design flexibility.

[0037] Example 2

[0038] Based on the above embodiments, the difference from Embodiment 1 is that the installation of the sealing gasket is omitted in this embodiment. For example... Figure 1 As shown, if the power module and the top heat sink are to be connected using metal sintering, such as silver sintering, the sealing ring can be omitted, allowing the sintering pressure to be fully conducted to the top heat dissipation surface. Furthermore, this solution is also compatible with brazing processes.

[0039] Example 3

[0040] Based on Example 1, Figure 3 In this embodiment, the plastic-encapsulated housing 11 has a top support boss on its top. There are four top support bosses 16 on its top; the thickness of each top support boss 16 is equal to the thickness of the metal solder. By setting the thickness of the top support bosses, the thickness of the metal solder is controlled, which helps to fully utilize top heat dissipation and ensures uniform and stable thermal resistance of the module.

[0041] Example 4

[0042] Based on the above embodiments, the creepage enhancement unit 14 in this embodiment includes at least one set of top slotted units 142 of the plastic-encapsulated housing 11. Figure 4 In the process, an array of slotted units is provided on the top of the plastic-encapsulated housing 11; a longer creepage distance is obtained by arranging multiple smaller creepage enhancement slotted units.

[0043] Example 5

[0044] Based on the above embodiments, the side protrusion unit of the plastic-encapsulated housing 11 in this embodiment can be configured as an inverted triangular shape, such as... Figure 3 As shown.

[0045] Example 6

[0046] Based on the above embodiments, Figure 5 In this embodiment, the side protrusion unit of the encapsulated housing 11 can be configured as a triangular shape. The side of the encapsulated housing 11 can be configured as a triangle, and multiple top slotted units can be arranged on the hypotenuse of the triangle, which reduces the amount of encapsulating material used while further increasing the creepage distance.

[0047] Example 7

[0048] Based on the above embodiments, this embodiment is a plastic-encapsulated device including a power semiconductor module.

Claims

1. A power semiconductor module, comprising a power module body (1), characterized in that, The power module body (1) includes a plastic encapsulated housing (11) and metal pins (12) extending from the plastic encapsulated housing (11); a metal heat dissipation surface (13) is provided on the top of the plastic encapsulated housing (11); a creepage enhancement unit (14) is provided on the plastic encapsulated housing (11) between the metal heat dissipation surface (13) and the metal pins (12); a bottom support boss (15) is provided at the bottom of the plastic encapsulated housing (11); a top support boss (16) is provided on the metal heat dissipation surface (13); the thickness of the top support boss (16) is equal to the thickness of the metal solder.

2. The power semiconductor module according to claim 1, characterized in that, The creepage enhancement unit (14) includes at least one set of top slotted units (142) on the top surface of the plastic-encapsulated housing (11).

3. A power semiconductor module according to claim 1, characterized in that, The creepage enhancement unit (14) includes a side slotted unit (143) of a plastic-encapsulated housing (11).

4. A power semiconductor module according to claim 1, characterized in that, The power module body (1) has a sealing ring groove (131) on the plastic shell (11) around the metal heat dissipation surface (13) for placing the sealing ring.

5. A power semiconductor module according to claim 1, characterized in that, The side protrusion unit of the plastic-encapsulated housing (11) is an inverted triangular protrusion unit.

6. A power semiconductor module according to claim 1, characterized in that, The side protrusion unit of the plastic-encapsulated housing (11) is a triangular protrusion unit.

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