A power package structure with high efficiency heat dissipation and pressure-resistant insulation film

Abstract

This invention provides a high-efficiency heat dissipation power packaging structure with a pressure-resistant insulating film, belonging to the field of semiconductor technology. The high-efficiency heat dissipation power packaging structure with a pressure-resistant insulating film includes a thermally conductive carrier plate and a molding compound, with a chip disposed on the thermally conductive carrier plate. An insulating film formed by sputtering is disposed on the side of the thermally conductive carrier plate opposite to the chip, and the molding compound covers the periphery of the thermally conductive carrier plate. This structure can reduce the manufacturing difficulty of power components and improve the heat dissipation efficiency of power components by utilizing the sputtered insulating film; furthermore, the insulating film allows for a smaller and thinner overall packaging structure.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor technology, and in particular to a power packaging structure with a high-efficiency heat dissipation and a pressure-resistant insulating film. Background Technology

[0002] In the semiconductor field, power component packaging technology is crucial, directly affecting the component's performance, lifespan, and reliability. (See also...) Figure 1 Traditional power components, such as TO-247 and TO-220 packages, typically use ceramic insulating sheets (such as Al2O3 or AlN ceramic plates) attached between the chip and the metal heat sink to achieve electrical isolation and heat conduction. However, this traditional packaging structure has certain drawbacks.

[0003] First, this traditional packaging structure struggles to balance thinness and insulation. High-power chips generate significant amounts of instantaneous heat during dynamic conduction. The high thermal resistance of traditional packaging structures can easily lead to junction temperature spikes, impacting component lifespan and reliability. Second, because the ceramic substrate is not thin-film, it cannot be integrated with current wafer-level processes or vacuum sputtering systems. This severely limits the automation of the packaging process and the development of low-cost, high-volume processes. Furthermore, the relatively large thickness and high thermal resistance of insulating ceramics, coupled with the need for mechanical bonding during encapsulation, prevent automation. Ultimately, this results in thick, large packaging structures with high manufacturing costs, especially given the high price of high thermal conductivity ceramic materials, which further increases packaging costs.

[0004] Therefore, it is necessary to improve the structure of existing power components to overcome the shortcomings of existing technologies. Utility Model Content

[0005] To overcome the problems existing in related technologies, one of the objectives of this utility model is to provide a power packaging structure with a high-efficiency heat dissipation with a pressure-resistant insulating film. This structure can reduce the manufacturing difficulty of power components and improve the heat dissipation efficiency of power components by utilizing the insulating film formed by sputtering; and the insulating film can make the entire heat packaging structure smaller and thinner.

[0006] A power package structure with a high-efficiency heat dissipation feature and a pressure-resistant insulating film, comprising:

[0007] A thermally conductive carrier plate on which a chip is disposed; an insulating film formed by sputtering is disposed on the side of the thermally conductive carrier plate opposite to the chip;

[0008] A molding compound that covers the periphery of the thermally conductive carrier plate.

[0009] In a preferred embodiment of this invention, the outer wall of the encapsulated body is provided with a heat dissipation component, which corresponds to the insulating film.

[0010] In a preferred embodiment of this invention, the thickness of the insulating film is 0.2 μm to 5 μm, and the thermal conductivity of the insulating film is not less than 100 W / m·K.

[0011] In a preferred embodiment of this invention, the encapsulating body comprises glass-filled epoxy resin, wherein the glass transition temperature is between 175°C and 235°C.

[0012] In a preferred embodiment of this invention, the thickness of the encapsulated body is 3.8mm-4.5mm.

[0013] In a preferred embodiment of this invention, a heat transfer element is provided in the encapsulation body, one end of which is connected to the insulating film, and the other end of which abuts against the heat dissipation element.

[0014] In a preferred embodiment of this invention, a pin is provided on one side of the thermally conductive carrier plate, the pin penetrates the plastic package and is exposed outside the plastic package, and the chip is electrically connected to the pin via a gold wire.

[0015] In a preferred embodiment of this invention, the insulating film is made of aluminum nitride and is sputtered onto the side of the thermally conductive carrier plate away from the chip and at least one side.

[0016] The beneficial effects of this utility model are as follows:

[0017] This invention provides a high-efficiency heat dissipation power packaging structure with a pressure-resistant insulating film. The power packaging structure includes a thermally conductive carrier plate and a molding compound. A chip is disposed on the thermally conductive carrier plate. An insulating film, formed by sputtering, is disposed on the side of the thermally conductive carrier plate opposite to the chip. The molding compound covers the periphery of the thermally conductive carrier plate. During the manufacturing process, the insulating film is directly sputtered onto the back of the thermally conductive carrier plate, eliminating the need for additional mechanical bonding processes. This avoids the interfacial thermal resistance between the ceramic sheet and the metal heat sink in traditional packaging, while also reducing the package size. The direct sputtering deposition process of the insulating film results in high material utilization and significantly reduces manufacturing costs compared to the traditional high thermal conductivity ceramic sheet structure. Furthermore, the insulating film structure significantly shortens the heat conduction path, reducing heat loss. This helps optimize the heat dissipation path, control the chip junction temperature, and extend the component's lifespan. Attached Figure Description

[0018] Figure 1 This is an exploded view of an existing high-efficiency heat dissipation power package structure with a pressure-resistant insulating film and ceramic insulating sheet provided in an embodiment of this utility model.

[0019] Figure 2This is a schematic diagram showing the insulating film provided in an embodiment of the present invention being disposed on a thermally conductive carrier plate.

[0020] Figure label:

[0021] 1. Molded enclosure; 2. Thermal carrier plate; 21. Chip; 22. Pin; 3. Ceramic insulating sheet; 4. Heat sink; 5. Insulating film. Detailed Implementation

[0022] Preferred embodiments of the present invention will now be described in more detail with reference to the accompanying drawings. While preferred embodiments of the present invention are shown in the drawings, it should be understood that the present invention may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present invention will be thorough and complete, and will fully convey the scope of the present invention to those skilled in the art.

[0023] In the semiconductor field, power component packaging technology is crucial, directly affecting the component's performance, lifespan, and reliability. (See also...) Figure 1 Traditional power components, such as TO-247 and TO-220 packages, typically use ceramic insulating sheets (such as Al2O3 or AlN ceramic plates) attached between the chip and the metal heat sink to achieve electrical isolation and heat conduction. However, this traditional packaging structure has certain drawbacks.

[0024] First, this traditional packaging structure struggles to balance thinness and insulation. High-power chips generate significant amounts of instantaneous heat during dynamic conduction. The high thermal resistance of traditional packaging structures can easily lead to junction temperature spikes, impacting component lifespan and reliability. Second, because the ceramic substrate is not thin-film, it cannot be integrated with current wafer-level processes or vacuum sputtering systems. This severely limits the automation of the packaging process and the development of low-cost, high-volume processes. Furthermore, the relatively large thickness and high thermal resistance of insulating ceramics, coupled with the need for mechanical bonding during encapsulation, prevent automation. Ultimately, this results in thick, large packaging structures with high manufacturing costs, especially given the high price of high thermal conductivity ceramic materials, which further increases packaging costs.

[0025] Based on this, this application provides a power packaging structure with a high-efficiency heat dissipation and a pressure-resistant insulating film.

[0026] Example 1

[0027] like Figure 2 As shown, this embodiment provides a high-efficiency heat dissipation power package structure with a pressure-resistant insulating film, comprising:

[0028] A thermally conductive carrier plate 2 is provided with a chip 21; an insulating film 5 formed by sputtering is provided on the side of the thermally conductive carrier plate 2 away from the chip 21; the thermally conductive carrier plate 2 of this application can be made of a thick nickel-plated copper substrate.

[0029] A molding compound 1, which covers the periphery of the thermally conductive carrier plate 2.

[0030] An insulating film 5, consisting of a 2μm thick aluminum nitride (AlN) film, is deposited on the side of the thermally conductive carrier 2 opposite to the chip 21 using radio frequency magnetron sputtering technology. The AlN film has a thermal conductivity of 130 W / m·K and an insulation withstand voltage of 2.8 kV. After molding, a 1μm aluminum film (PVD) is deposited on the surface of the molded body 1. The measured thermal resistance decreased from 2.8 K / W to 2.1 K / W, and the overall package thickness decreased from 4.8 mm to 4.2 mm.

[0031] Specifically, a pin 22 is provided on one side of the thermally conductive carrier plate 2. The pin 22 passes through the molding compound 1 and is exposed outside the molding compound 1. The chip 21 is electrically connected to the pin 22 through a gold wire.

[0032] After molding, a 1μm aluminum film (PVD) was applied to the surface of the molded body 1. The measured thermal resistance decreased from 2.8K / W to 2.1K / W, and the overall package thickness decreased from 4.8mm to 4.2mm.

[0033] More preferably, a heat sink 4 is provided on the outer wall of the molding compound 1, and the heat sink 4 corresponds to the insulating film 5. At the position on the outer wall of the molding compound 1 corresponding to the insulating film 5, a 1μm thick aluminum metal coating (thermal conductivity 237W / m·K) is formed by physical vapor deposition (PVD), and the area matches that of the insulating film 5.

[0034] Specifically, the insulating film 5 in this application is an AlN film, which directly covers the back of the thermally conductive carrier plate 2, rapidly dissipating the heat conducted by the chip 21 through the substrate and reducing thermal resistance. Compared with the traditional ceramic insulating sheet 3 (thickness > 0.5 mm, high thermal resistance), the 2 μm thin-film structure significantly shortens the heat conduction distance and reduces heat loss. In a specific embodiment, the thickness of the insulating film 5 is 0.2 μm to 5 μm, and the thermal conductivity of the insulating film 5 is not less than 100 W / m·K.

[0035] The aluminum heat sink 4 on the outer wall of the molding compound 1 corresponds to the insulating film 5, forming a heat conduction chain of "insulating film 5 - molding compound 1 - heat sink 4". The high thermal conductivity of aluminum accelerates the diffusion of heat to the environment, significantly reducing the measured thermal resistance and improving the junction temperature control capability of chip 21.

[0036] The 2μm AlN film can achieve a withstand voltage of 2.8kV, which is superior to the performance of traditional ceramic sheets of the same thickness. Moreover, the thin-film design avoids the thickness limitations of traditional ceramic sheets, reducing the overall package thickness to 4.2mm, meeting the requirements for thinness. The insulating film 5 is directly sputtered onto the substrate without additional mechanical bonding processes, reducing the package volume. The heat sink 4 is integrated onto the surface of the molding compound 1 through PVD without adding extra space, realizing the thin-film integration of "insulation-heat dissipation" functions.

[0037] Furthermore, the molding compound 1 comprises a glass-filled epoxy resin, wherein the glass transition temperature is between 175°C and 235°C.

[0038] The molding compound 1 of this application uses a glass-filled epoxy resin with a glass transition temperature (Tg) between 175°C and 235°C, so that the molding compound 1 material is still in the glass state when the chip 21 is working, maintaining structural rigidity and avoiding material softening or deformation due to temperature approaching Tg (traditional low Tg materials are prone to molding compound 1 collapse at high temperatures, affecting the internal structural stability).

[0039] Furthermore, the coefficient of thermal expansion (CTE) of glass-filled epoxy resin can be adjusted by changing the glass filler ratio, similar to that of AlN film (CTE≈4.1×10⁻⁶). -6 / ℃), copper-based substrate (CTE≈17×10) -6 / ℃) to form a better match. When Tg is higher than the operating temperature, the material is in a low expansion state during thermal cycling, reducing film-substrate interface delamination or molding compound 1 cracking caused by CTE mismatch.

[0040] Furthermore, the thickness of the molding compound 1 is 3.8mm-4.5mm. Controlling the thickness of the molding compound 1 to 3.8mm-4.5mm allows for a thinner packaging structure.

[0041] Example 3

[0042] A heat transfer element is provided in the molding compound 1. One end of the heat transfer element is connected to the insulating film 5, and the other end abuts against the heat sink 4. The insulating film 5 is made of aluminum nitride and is sputtered on the side of the thermally conductive carrier plate 2 away from the chip 21 and at least one side.

[0043] The heat transfer components in this application can be heat transfer components disposed in the encapsulation 1, mainly including heat dissipation carriers, heat dissipation blocks, thermally conductive metal sheets, insulating thermally conductive adhesives, etc.

[0044] For example, in one specific embodiment, the heat transfer element is a 0.2mm thick copper metal sheet (thermal conductivity 401W / m·K) with a size of 12mm×4mm. One end of the heat transfer element is fixed to the AlN film on the side of the heat-conducting carrier plate 2 by silver paste welding, and the other end extends to the outer wall of the encapsulation body 1 and abuts against the aluminum metal heat sink 4.

[0045] The AlN film on the side of this packaging structure forms a "side insulation-metal thermal conduction" channel with the copper heat transfer component, directly conducting heat to the heat sink 4 on the outer wall of the molded body 1. The measured thermal resistance is effectively reduced, solving the problem of insufficient side heat dissipation in traditional packaging. The copper metal heat transfer component (thermal conductivity 401 W / m·K) acts as a solid-state thermal bridge, directly connecting the side AlN film and the external heat sink 4, reducing interfacial thermal resistance in heat conduction (traditional molded body 1 relies on epoxy resin for heat conduction, with a thermal conductivity of only 1.5-2.0 W / m·K), forming a highly efficient heat conduction chain of "chip 21-substrate-AlN-heat transfer component-heat sink 4".

[0046] Example 4

[0047] This embodiment uses a 1200V-rated IGBT chip 21 as the high-voltage application test object. A 3μm AlN insulating film is formed on the bare die using RF sputtering, and then covered with copper-based wires and molded. The outside of the package is treated with a 1μm aluminum coating and surface laser-etched microstructures are added to improve heat dissipation and convection efficiency. According to actual measurements, the thermal resistance of the package structure in this embodiment is reduced from 3.5K / W to 2.6K / W, the withstand voltage exceeds 3.2kV, and the overall package thickness is controlled within 4.5mm.

[0048] Unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps described in these embodiments do not limit the scope of this application. It should also be understood that, for ease of description, the dimensions of the various parts shown in the drawings are not drawn to actual scale. Techniques, methods, and devices known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and devices should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that similar reference numerals and letters in the following drawings denote similar items; therefore, once an item is defined in one drawing, it need not be further discussed in subsequent drawings. In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0049] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0050] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, these terms have no special meaning and therefore should not be construed as limiting the scope of protection of this application. The above description is only a preferred embodiment of this utility model and is not intended to limit this utility model. For those skilled in the art, this utility model can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. A power package structure with high efficiency heat dissipation and pressure-resistant insulation film, characterized in that, include: A thermally conductive carrier plate on which a chip is disposed; an insulating film formed by sputtering is disposed on the side of the thermally conductive carrier plate opposite to the chip; A molding compound that covers the periphery of the thermally conductive carrier plate.

2. The power packaging structure with high-efficiency heat dissipation and a pressure-resistant insulating film according to claim 1, characterized in that: The outer wall of the encapsulation is provided with a heat dissipation component, which corresponds to the insulating film.

3. The power packaging structure with high-efficiency heat dissipation and a pressure-resistant insulating film according to claim 2, characterized in that: The thickness of the insulating film is 0.2 μm to 5 μm, and the thermal conductivity of the insulating film is not less than 100 W / m·K.

4. The power packaging structure with high-efficiency heat dissipation and a pressure-resistant insulating film according to any one of claims 1-3, characterized in that: The encapsulation comprises a glass-filled epoxy resin, wherein the glass transition temperature is between 175°C and 235°C.

5. The power packaging structure with high-efficiency heat dissipation and a pressure-resistant insulating film according to claim 4, characterized in that: The thickness of the encapsulation is 3.8mm-4.5mm.

6. The power packaging structure with high-efficiency heat dissipation and a pressure-resistant insulating film according to claim 3, characterized in that: The encapsulation body is provided with a heat transfer element, one end of which is connected to the insulating film, and the other end of which abuts against the heat dissipation element.

7. The power packaging structure with high-efficiency heat dissipation and a pressure-resistant insulating film according to claim 6, characterized in that: The thermally conductive carrier plate has pins on one side, which penetrate the plastic package and are exposed outside the plastic package. The chip is electrically connected to the pins via gold wires.

8. The power packaging structure with high-efficiency heat dissipation and a pressure-resistant insulating film according to claim 6, characterized in that: The insulating film is made of aluminum nitride and is sputtered on the side of the thermally conductive carrier plate away from the chip and at least one side.

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