Power module structure, power module package and method for manufacturing the package

Abstract

The present application is directed to the field of power device packaging technology, and specifically relates to a power module structure, a power module package, and a method for manufacturing the package. The power module structure includes: a lead frame, a first chip is welded on the lead frame; a second chip, the second chip is arranged on the first chip, and is coupled and connected to the first chip through a conductive adhesive. The package includes a substrate, a positioning hole is provided on the substrate, and the power module structure as described in the first aspect of the present application is arranged in the positioning hole; a metal wire is provided on the substrate around the positioning hole, and the lead end of the power module structure is connected to the metal wire; a lower heat sink, the lower heat sink is arranged under the substrate, and is used to dissipate heat from the power module structure. The present application provides a power module structure and a package thereof, which can improve the response speed of the device while reducing the size of the device.

Description

Technical Field

[0001] The present application relates to the field of power device packaging technology, and specifically to a power module structure, a power module package, and a method for manufacturing the package. Background Art

[0002] Intelligent Power Module (IPM) is a power-driven semiconductor packaging structure that combines power electronics and integrated circuit technology. The packaging structure of IPM includes: driver chip, power device, module packaging, MCU, frequency conversion solution and control programming software.

[0003] In the current related technology, each functional chip is usually packaged and then mounted on a substrate individually, and the functional chip includes a triode, a diode, an IC control chip or an insulated gate bipolar transistor (IGBT) chip, etc. In this way, the final product structure is large in size and high in cost.

[0004] Another IPM packaging structure is to integrate the above-mentioned various functional chips into the same package, but the basic dual in-line package technology (DIP) packaging is thick and has poor heat dissipation, which does not meet the current demand for thin and light products. In addition, the internal chip arrangement is unreasonable. In order to meet the packaging requirements, traditional IPM can only use rectangular IGBT devices, which greatly affects the response speed of the device and the uniformity of the cell performance. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, the present application provides a power module structure, a power module package and a method for manufacturing the package, which can improve the device response speed while reducing the device size.

[0006] According to the technical solution provided by the present application, as a first aspect of the present application, a power module structure is provided, the power module structure comprising:

[0007] A lead frame, on which a first chip is welded;

[0008] a second chip, the second chip being disposed on the first chip and coupled to the first chip via an adhesive structure; a contact area between the adhesive structure and the first chip being one half of a cross-sectional area of ​​the first chip;

[0009] A third chip is arranged around the first chip.

[0010] Optionally, a straight-line distance between the center of the third chip and the center of the first chip is 200um-1mm.

[0011] Optionally, the first chip is an IGBT chip, the second chip is a control chip, and the third chip is a transistor chip.

[0012] Optionally, the second chip and the first chip are coated with epoxy resin and are packaged on the lead frame by the epoxy resin.

[0013] Optionally, the epoxy resin contains 3% to 5% aluminum nitride.

[0014] As a second aspect of the present application, a power module package is provided, comprising:

[0015] A lower substrate, wherein the positioning hole is formed on the lower substrate, and the edge of the lower substrate extends outward to form a connecting outer edge;

[0016] An upper substrate, wherein the upper substrate covers the positioning hole, an edge of the upper substrate is coupled with the lower substrate, and a metal wire is disposed on the upper substrate;

[0017] The power module structure described in the first aspect of the present invention is arranged in the positioning hole, the lead frame of the power module structure is installed on the lower surface of the upper substrate, the lead end of the power module structure is connected to the metal wire; an electrical path is formed between the lead end of the power module structure, the upper substrate and the lower substrate;

[0018] A lower heat sink is disposed under the lower substrate and is used to dissipate heat from the power module structure.

[0019] Optionally, a first silicone rubber layer is provided between the lower substrate and the lower heat dissipation plate, and the first silicone rubber layer is in contact with the power module structure.

[0020] Optionally, an upper heat dissipation plate is provided on the upper substrate, and an outer edge of the upper heat dissipation plate extends outwardly from an edge of the upper substrate;

[0021] A second silicone rubber layer is provided between the outer edge of the upper heat dissipation plate and the lower substrate, and the second silicone rubber layer surrounds the outer periphery of the upper substrate.

[0022] Optionally, the second silicone rubber layer is annular, and a second gap is formed between the inner edge of the second silicone rubber layer and the outer edge of the upper substrate;

[0023] An upper heat dissipation hole is provided in the upper heat dissipation plate located at the second gap position;

[0024] The aperture of the upper heat dissipation hole does not exceed the width of the second gap, and is not less than half of the width of the second gap. A first gap is formed between the inner edge of the lower substrate and the outer edge of the power module structure;

[0025] A lower heat dissipation hole is provided in the lower heat dissipation plate located at the first gap position;

[0026] The aperture of the lower heat dissipation hole does not exceed the width of the first gap and is not less than half of the width of the first gap.

[0027] As a third aspect of the present invention, a method for manufacturing a power module package is provided, comprising the following steps:

[0028] Providing a lower substrate, and defining a positioning hole in the middle of the lower substrate;

[0029] An upper substrate is arranged on the positioning hole, and an edge of the upper substrate is coupled to a lower substrate located around the positioning hole;

[0030] Providing a power module structure according to the first aspect of the present invention, the power module structure is arranged in the positioning hole, a lead frame of the power module structure is coupled to the lower surface of the upper substrate, and a first gap is formed between the inner edge of the lower substrate and the outer edge of the power module structure;

[0031] Filling the first gap with a first material, wherein the thermal expansion coefficient of the first material is consistent with the thermal expansion coefficient of the lower substrate;

[0032] A first silicone rubber layer is disposed on the lower surface of the lower substrate, and a lower heat sink is disposed on the lower surface of the first silicone rubber layer;

[0033] A lower heat dissipation hole is formed in the lower heat dissipation plate at the position of the first gap;

[0034] Disposing a second silicone rubber layer on the lower substrate around the upper substrate, wherein a second gap is formed between an inner edge of the second silicone rubber layer and an outer edge of the upper substrate;

[0035] Filling the second gap with a second material, wherein the thermal expansion coefficient of the second material is consistent with the thermal expansion coefficient of the upper substrate;

[0036] An upper heat sink is provided, wherein the upper heat sink is provided on the upper substrate, and an outer edge of the upper heat sink extends outward to cover an upper surface of the second silicone rubber layer;

[0037] An upper heat dissipation hole is opened in the upper heat dissipation plate located at the second gap position.

[0038] Optionally, the upper heat sink, the base plate and the lower heat sink are connected by fasteners.

[0039] From the above, it can be seen that the power module structure and its package provided by the present application have the following advantages compared with the prior art: the power module structure and its package provided by the present application have better thermal characteristics, can simplify the assembly process and provide higher reliability. In addition, the small and ultra-thin package makes the application circuit more compact, greatly reduces parasitic effects, and improves energy efficiency. The volume is 50% smaller than that of traditional IPM modules, which means that the packaging cost can be reduced by 50%. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 This is the main view of the first aspect of this application.

[0041] Figure 2 This is a cross-sectional view of the second aspect of the present application.

[0042] 100. power module structure, 110. lead frame, 120. first chip, 130. second chip, 140. epoxy resin, 150. lead end, 210. positioning hole, 220. metal wire, 230. lower heat sink, 231. lower heat sink, 241. lower substrate, 2410. connecting outer edge, 242. upper substrate, 250. first silicone rubber layer, 260. second silicone rubber layer, 270. upper heat sink, 271. upper heat dissipation hole, 280. fastener, 290. solder ball, 300. third chip. DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below in combination with specific embodiments and with reference to the accompanying drawings. The same parts are represented by the same figure numerals. It should be noted that the words "front", "rear", "left", "right", "up" and "down" used in the following description refer to the directions in the accompanying drawings. The words "inside" and "outside" used refer to the direction toward or away from the geometric center of a specific component, respectively.

[0044] As a first aspect of this application, refer to Figure 1 , providing a power module structure, which can make the device thinner and lighter and improve the response speed of the device by changing the structure of the power module structure and the structure of the package.

[0045] The technical solution of the present invention will be clearly and completely described below through specific embodiments. Obviously, the described embodiments are only embodiments of a part of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0046] Embodiment 1, as a first aspect of the present invention, provides a power module structure 100 .

[0047] The power module structure 100 comprises:

[0048] A lead frame 110 , on which a first chip 120 is welded.

[0049] The second chip 130 is arranged on the first chip 120 and is coupled to the first chip 120 through an adhesive structure; the contact area between the adhesive structure and the first chip 120 is half of the cross-sectional area of ​​the first chip 120, thereby ensuring a reliable connection, preventing adjacent adhesive structures from sticking together, and reducing the use of colloid to ensure good heat dissipation.

[0050] The third chip 300 is disposed around the first chip.

[0051] The straight-line distance between the center of the third chip 300 and the center of the first chip is 200um-1mm, so that while ensuring the functional reliability of the chips, the distance between the third chip 300 and the first chip is as short as possible to achieve the fastest possible signal transmission and ensure that the final package is as small as possible.

[0052] The first chip is an IGBT chip, the second chip is a control chip, and the third chip 300 is a transistor chip.

[0053] It should be explained that the second chip 130 includes a control chip integrating a triode, a diode or other power tubes, and the control chip can be an unpackaged product with the functional surface facing upward, or a packaged product with the functional surface facing downward. The conductive adhesive includes a silica gel containing conductive particles.

[0054] It is understandable that by stacking the second chip 130 on the first chip 120 , the distance between the second chip 130 and the first chip 120 can be reduced, so that there is no need to consider the package size during packaging, and the response speed between the second chip 130 and the first chip 120 can be improved.

[0055] Example 2

[0056] In this embodiment, based on the embodiment 1, an epoxy resin layer 140 is coated around the second chip 130 and the first chip 120, and the epoxy resin layer 140 is encapsulated on the lead frame 110. The epoxy resin layer 140 coated around the second chip 130 and the first chip 120 can protect the connection between the chips and isolate the chips from the external environment, so as to ensure that the chips can work normally in environments such as vibration and high humidity.

[0057] Optionally, the epoxy resin layer 140 contains 3% to 5% aluminum nitride.

[0058] It should be explained that the power module structure 100 is also provided with a lead-out terminal 150 . Before being packaged by the epoxy resin layer 140 , the lead-out terminal 150 is connected to each chip via a lead wire.

[0059] As a second aspect of the present invention, referring to Figure 2 , a power module package is provided, which encapsulates the power module structure 100 described in the first aspect of the present invention so as to improve the heat dissipation performance of the power module structure 100 when in use.

[0060] The technical solution of the present invention will be clearly and completely described below through specific embodiments. Obviously, the described embodiments are only embodiments of a part of the present invention, rather than all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0061] Embodiment 3, as the second aspect of the present invention, provides a power module package.

[0062] The power module package includes a substrate, and the substrate includes an upper substrate 242 and a lower substrate 241 ; the power module structure 100 described in the first aspect of the present invention is packaged on the substrate.

[0063] Specifically, the positioning hole 210 is opened on the lower substrate 241, and the edge of the lower substrate extends outward to form a connecting outer edge 2410; the upper substrate 242 is covered on the positioning hole 210, and the edge of the upper substrate 242 is coupled with the solder ball 290 formed by welding of the lower substrate 241, and the metal wire 220 is set on the upper substrate 242.

[0064] The power module structure is arranged in the positioning hole 210, the lead frame 110 of the power module structure is installed on the lower surface of the upper substrate 242, and the lead end 150 of the power module structure is connected to the metal wire 220; an electrical path is formed between the lead end 150 of the power module structure, the upper substrate 242 and the lower substrate 241.

[0065] In order to ensure that the power module structure 100 is light and thin when it is packaged on the substrate, the size of the positioning hole 210 is larger than the power module structure, that is, a first gap is formed between the inner edge of the lower substrate 241 and the outer edge of the power module structure, so that the power module structure 100 is arranged in the positioning hole 210. Preferably, the size of the positioning hole 210 is larger than 20%-30% of the size of the power module structure. Due to the large difference in CTE (coefficient of expansion) and mismatch, if the combination is tight or the space reserved is too small, cracks may be generated, affecting the working efficiency of the module and seriously shortening the working life of the module; therefore, the positioning hole 210 of the above size can also ensure heat dissipation and prevent the accumulation of heat generated by the module when it is working.

[0066] The lower heat sink 230 is disposed under the substrate and is used to dissipate heat for the power module structure 100 .

[0067] The connecting outer edge 2410 is connected by wires, so that the signal on the chip can be led out (not shown in the figure), which can facilitate the interconnection and coupling of the power module package with other structures.

[0068] It is understandable that the positioning hole 210 is provided on the substrate to facilitate the placement of the power module structure 100, which can reduce the size of the device and make the device thinner and lighter. The lead-out end 150 of the power module structure 100 is connected to the metal wire 220 to ensure that the device can work reliably. The lower heat sink 230 can achieve heat dissipation of the device.

[0069] Example 4

[0070] On the basis of the above embodiments, the present embodiment provides a first silicone rubber layer 250 between the substrate and the lower heat sink 230 , and the first silicone rubber layer 250 is in contact with the power module structure 100 .

[0071] An upper heat dissipation plate 270 is disposed on the upper substrate 242, and an outer edge of the upper heat dissipation plate 270 extends outward from the edge of the upper substrate 242;

[0072] A second silicone rubber layer 260 is disposed between the outer edge of the upper heat dissipation plate 270 and the lower substrate 241 , and the second silicone rubber layer 260 surrounds the outer periphery of the upper substrate 242 .

[0073] The second silicone rubber layer 260 is annular, and a second gap is formed between the inner edge of the second silicone rubber layer 260 and the outer edge of the upper substrate 242;

[0074] An upper heat dissipation hole 271 is provided in the upper heat dissipation plate 270 located at the second gap position;

[0075] The aperture of the upper heat dissipation hole 271 is not larger than the width of the second gap, and is not smaller than half of the width of the second gap;

[0076] A first gap is formed between the inner edge of the lower substrate 241 and the outer edge of the power module structure.

[0077] A lower heat dissipation hole 231 is provided in the lower heat dissipation plate 230 located at the first gap position;

[0078] The diameter of the lower heat dissipation hole 231 is not greater than the width of the first gap, and is not less than half of the width of the first gap.

[0079] The upper heat sink 270 , the base plate and the lower heat sink 230 are connected via fasteners 280 .

[0080] The first silicone rubber layer 250 and the second silicone rubber layer 260 can provide good protection for the power module structure 100, so that the power module structure 100 is isolated from the external environment, thereby ensuring that the chip can work normally in an environment of vibration, high humidity, etc. The upper heat dissipation holes 271 on the upper heat dissipation plate 270 and the lower heat dissipation holes 231 opened in the lower heat dissipation plate 230 are more conducive to heat dissipation.

[0081] From the above, it can be seen that the power module structure 100 and its package provided by the present application have better thermal characteristics, can simplify the assembly process and provide higher reliability. In addition, the small and ultra-thin package makes the application circuit more compact, greatly reduces parasitic effects, improves energy efficiency, and is 50% smaller than the traditional IPM module, which means that the packaging cost can be reduced by 50%.

[0082] Embodiment 5:

[0083] In this embodiment, based on Embodiment 5, a first material is filled into the first gap, and the thermal expansion coefficient of the first material is consistent with the thermal expansion coefficient of the lower substrate 241; that is, a material consistent with the thermal expansion coefficient of the lower substrate 241 is filled in the positioning holes 210 around the epoxy resin layer 140, and preferably, a resin layer is filled in the positioning holes 210 around the epoxy resin layer 140.

[0084] Filling the second gap with a second material, wherein the thermal expansion coefficient of the second material is consistent with the thermal expansion coefficient of the upper substrate 242;

[0085] As a third aspect of the present invention, a method for manufacturing a power module package is provided, comprising the following steps:

[0086] Providing a lower substrate 241, and defining a positioning hole 210 in the middle of the lower substrate 241;

[0087] An upper substrate 242 is disposed on the positioning hole 210, and an edge of the upper substrate 242 is coupled to a lower substrate 241 located around the positioning hole 210;

[0088] The power module structure according to the first aspect of the present invention is provided, the power module structure is arranged in the positioning hole 210, the lead frame 110 of the power module structure is coupled to the lower surface of the upper substrate 242, and a first gap is formed between the inner edge of the lower substrate 241 and the outer edge of the power module structure;

[0089] Filling the first gap with a first material, wherein the thermal expansion coefficient of the first material is consistent with the thermal expansion coefficient of the lower substrate 241;

[0090] A first silicone rubber layer 250 is disposed on the lower surface of the lower substrate 241, and a lower heat sink 230 is disposed on the lower surface of the first silicone rubber layer 250;

[0091] A lower heat dissipation hole 231 is provided in the lower heat dissipation plate 230 located at the first gap position;

[0092] A second silicone rubber layer 260 is disposed on the lower substrate 241 around the upper substrate 242, and a second gap is formed between the inner edge of the second silicone rubber layer 260 and the outer edge of the upper substrate 242;

[0093] Filling the second gap with a second material, wherein the thermal expansion coefficient of the second material is consistent with the thermal expansion coefficient of the upper substrate 242;

[0094] An upper heat dissipation plate 270 is provided, wherein the upper heat dissipation plate 270 is provided on the upper substrate 242 , and an outer edge of the upper heat dissipation plate 270 extends outward to cover an upper surface of the second silicone rubber layer 260 ;

[0095] An upper heat dissipation hole 271 is opened in the upper heat dissipation plate 270 located at the second gap position.

[0096] A person skilled in the art should understand that the above description is only a specific embodiment of the present application and is not intended to limit the present application. Any modifications, equivalent substitutions, improvements, etc. made within the scope of the present application should be included in the protection scope of the present application.

Claims

1. A power module package, characterized in that: include: A lower base plate, wherein a positioning hole is formed on the lower base plate, and an edge of the lower base plate extends outward to form a connecting outer edge; An upper substrate, the upper substrate is covered on the positioning hole, the edge of the upper substrate is coupled with the lower substrate, and the metal wire is arranged on the upper substrate; A power module structure is arranged in the positioning hole, and the power module structure includes: A lead frame, on which a first chip is welded; a second chip, the second chip being disposed on the first chip and connected to the first chip via an adhesive structure, wherein a contact area between the adhesive structure and the first chip is one half of a cross-sectional area of ​​the first chip, and the adhesive structure comprises a conductive adhesive; a third chip, the third chip being arranged around the first chip; The lead frame of the power module structure is installed on the lower surface of the upper substrate, and the lead end of the power module structure is connected to the metal wire; an electrical path is formed between the lead end of the power module structure, the upper substrate and the lower substrate; A lower heat sink, which is disposed under the lower substrate and is used to dissipate heat from the power module structure; An upper heat sink is disposed on the upper substrate, and an outer edge of the upper heat sink extends outwardly from an edge of the upper substrate; A second silicone rubber layer is provided between the outer edge of the upper heat dissipation plate and the lower substrate, and the second silicone rubber layer surrounds the outer periphery of the upper substrate; The second silicone rubber layer is annular, and a second gap is formed between the inner edge of the second silicone rubber layer and the outer edge of the upper substrate; An upper heat dissipation hole is provided in the upper heat dissipation plate located at the second gap position; The diameter of the upper heat dissipation hole is no larger than the width of the second gap and no smaller than one half of the width of the second gap; A first gap is formed between the inner edge of the lower substrate and the outer edge of the power module structure; A lower heat dissipation hole is provided in the lower heat dissipation plate located at the first gap position; The aperture of the lower heat dissipation hole does not exceed the width of the first gap and is not less than half of the width of the first gap.

2. The power module package according to claim 1, wherein: The straight-line distance between the center of the third chip and the center of the first chip is 200 μm-1 mm.

3. The power module package according to claim 1, wherein: The first chip is an IGBT chip, the second chip is a control chip, and the third chip is a transistor chip.

4. The power module package according to claim 1, wherein: The second chip and the first chip are coated with an epoxy resin layer, and are packaged on the lead frame through the epoxy resin layer.

5. The power module package according to claim 4, characterized in that: The epoxy resin layer contains 3% to 5% of aluminum nitride, and the conductive adhesive includes silica gel containing conductive particles.

6. The power module package according to claim 1, wherein: A first silicone rubber layer is disposed between the lower substrate and the lower heat dissipation plate, and the first silicone rubber layer is in contact with the power module structure.

7. A method for manufacturing a power module package according to any one of claims 1 to 6, characterized in that: The following steps are involved: Providing a lower substrate, and defining a positioning hole in the middle of the lower substrate; An upper substrate is arranged on the positioning hole, and an edge of the upper substrate is coupled to a lower substrate located around the positioning hole; A power module structure is provided, and the power module structure is arranged in the positioning hole, a lead frame of the power module structure is coupled to the lower surface of the upper substrate, and a first gap is formed between the inner edge of the lower substrate and the outer edge of the power module structure, wherein the power module structure comprises: a lead frame, on which a first chip is welded; a second chip, which is arranged on the first chip and connected to the first chip through a bonding structure, and a contact area between the bonding structure and the first chip is one-half of a cross-sectional area of ​​the first chip; and a third chip, which is arranged around the first chip; Filling the first gap with a first material, wherein the thermal expansion coefficient of the first material is consistent with the thermal expansion coefficient of the lower substrate; A first silicone rubber layer is disposed on the lower surface of the lower substrate, and a lower heat sink is disposed on the lower surface of the first silicone rubber layer; A lower heat dissipation hole is formed in the lower heat dissipation plate at the position of the first gap; Disposing a second silicone rubber layer on the lower substrate around the upper substrate, wherein a second gap is formed between an inner edge of the second silicone rubber layer and an outer edge of the upper substrate; Filling the second gap with a second material, wherein the thermal expansion coefficient of the second material is consistent with the thermal expansion coefficient of the upper substrate; An upper heat sink is provided, wherein the upper heat sink is provided on the upper substrate, and an outer edge of the upper heat sink extends outward to cover an upper surface of the second silicone rubber layer; An upper heat dissipation hole is opened in the upper heat dissipation plate located at the second gap position.

8. The method for manufacturing a power module package according to claim 7, wherein: The straight-line distance between the center of the third chip and the center of the first chip is 200 μm-1 mm.

9. The method for manufacturing a power module package according to claim 7, wherein: The first chip is an IGBT chip, the second chip is a control chip, and the third chip is a transistor chip.

10. The method for manufacturing a power module package according to claim 7, wherein: The second chip and the first chip are coated with an epoxy resin layer, and are packaged on the lead frame through the epoxy resin layer.

11. The method for manufacturing a power module package according to claim 10, wherein: The epoxy resin layer contains 3% to 5% aluminum nitride; the bonding structure includes conductive glue, and the conductive glue includes silica gel containing conductive particles.

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