A power device package structure

Abstract

The application relates to the technical field of chip packaging, and discloses a power device packaging structure, which comprises an upper pressing plate assembly, a chip layer and a heat sink assembly, the chip layer is arranged between the upper pressing plate assembly and the heat sink assembly, the upper pressing plate assembly comprises a first connecting part, the heat sink assembly comprises a second connecting part, the first connecting part comprises a plurality of first insulating microwires, and the second connecting part comprises a plurality of second insulating microwires; the first insulating microwires and the second insulating microwires are connected through static friction, the static friction connection between the first insulating microwires and the second insulating microwires is not affected by temperature, and therefore the reliability of the power device packaging structure is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of chip packaging, in particular to a power device packaging structure. BACKGROUND

[0002] The existing power device packaging structure mainly connects the chip, the substrate and the heat sink through the solder. The solder is the key interface for connecting the chip, the substrate and the heat sink. The traditional solder is prone to creep and fatigue at high temperature, which affects the reliability of the soldering layer. To solve the above problems, the existing technology usually uses high melting point solder, such as silver-based solder or eutectic solder, to improve high temperature reliability; or uses silver sintering process to form a high-strength soldering interface through pressure-assisted sintering to adapt to high temperature working environment; or introduces a flexible metal intermediate layer at the soldering interface to relieve thermal stress; or uses lead-free solder instead, such as environmentally friendly Sn-Ag-Cu solder, to improve mechanical strength and fatigue life. However, the above existing technologies have problems such as that the voids and cracks in the soldering process will exacerbate thermal resistance and fatigue failure, and that the silver sintering process has high requirements for equipment and process, increasing manufacturing cost. SUMMARY

[0003] The purpose of the present application is to provide a power device packaging structure to improve the reliability of the power device packaging structure.

[0004] To achieve the above purpose, the present application provides the following solutions.

[0005] A power device packaging structure, comprising: an upper pressing plate assembly, a chip layer and a heat sink assembly, the chip layer being arranged between the upper pressing plate assembly and the heat sink assembly, the upper pressing plate assembly comprising a first connecting part, the heat sink assembly comprising a second connecting part, the first connecting part comprising a plurality of first insulating microwires, the second connecting part comprising a plurality of second insulating microwires; the first insulating microwires and the second insulating microwires being connected by static friction.

[0006] Preferably, the diameters of the first insulating microwires and the second insulating microwires are microns, and the lengths of the first insulating microwires and the second insulating microwires are millimeters.

[0007] Preferably, the upper pressing plate assembly further comprises an upper pressing plate body, and two first connecting parts are arranged on the upper pressing plate body.

[0008] Preferably, the upper pressing plate body comprises a plate body and an integrated heat sink, and the integrated heat sink is arranged on the plate body and used for heat dissipation of the chip layer.

[0009] Preferably, the plate body is made of epoxy resin, glass fiber and / or aluminum.

[0010] Preferably, the plate body is a driving layer, and the driving layer is electrically connected with the chip layer.

[0011] Preferably, the packaging structure further comprises an interconnection layer, the interconnection layer is arranged between the upper pressing plate assembly and the chip layer, and the interconnection layer comprises a metal sheet, an upper surface of the metal sheet is in contact with a lower surface of the integrated heat sink, and a lower surface of the metal sheet is in contact with the chip layer.

[0012] Preferably, the integrated heat sink comprises, from top to bottom, an upper diamond layer, a high-thermal-conductivity metal layer and a lower diamond layer, and the lower diamond layer is in contact with the upper surface of the metal sheet.

[0013] Preferably, the packaging structure further comprises a backing plate assembly, the backing plate assembly is arranged between the chip layer and the heat spreader assembly, and the backing plate assembly comprises, from top to bottom, an upper copper layer, a diamond composite layer and a ceramic insulating backing plate, a part of the upper copper layer is in contact with a lower surface of the chip layer, another part of the upper copper layer is connected with the metal sheet through a metal buried hole on the metal sheet, and the ceramic insulating backing plate is arranged on the heat spreader assembly.

[0014] Preferably, the chip layer comprises a substrate and a power chip, a first molybdenum sheet and a second molybdenum sheet arranged on the substrate, an upper surface and a lower surface of the power chip are respectively provided with the first molybdenum sheet and the second molybdenum sheet, an upper surface of the first molybdenum sheet is in contact with a lower surface of the metal sheet, a lower surface of the second molybdenum sheet is in contact with an upper surface of the upper copper layer, and a gate of the power chip is connected with the driving layer through a copper buried hole.

[0015] According to the above-mentioned scheme, the following technical effects are disclosed:

[0016] The application provides a power device packaging structure, comprising an upper pressing plate assembly, a chip layer and a heat spreader assembly, the chip layer is arranged between the upper pressing plate assembly and the heat spreader assembly, the upper pressing plate assembly comprises a first connecting part, the heat spreader assembly comprises a second connecting part, the first connecting part comprises a plurality of first insulating microwires, and the second connecting part comprises a plurality of second insulating microwires; the first insulating microwires and the second insulating microwires are connected through static friction. The chip layer is packaged inside the upper pressing plate assembly and the heat spreader assembly through the static friction connection between the first insulating microwires and the second insulating microwires, compared with the power device packaging structure of the prior art which mainly connects the chip, the substrate and the heat spreader through solder, the problem that the traditional solder is prone to creep and fatigue under high temperature and affects the reliability of the soldering layer can be solved, the static friction connection between the first insulating microwires and the second insulating microwires is not affected by temperature, thereby the reliability of the power device packaging structure is improved. BRIEF DESCRIPTION OF DRAWINGS

[0017] In order to make the technical solutions in the embodiments of the present application or the prior art clearer, the accompanying drawings needed in the embodiments will be briefly introduced below. Obviously, the accompanying drawings in the following description only need to be some embodiments of the present application, and for those skilled in the art, other drawings can be obtained without creative labor on the basis of these drawings.

[0018] Figure 1 The shaft measurement schematic diagram of the power device packaging structure is provided for the embodiments of the present application.

[0019] Figure 2 The cross-sectional schematic diagram of the power device packaging structure is provided for the embodiments of the present application.

[0020] Figure 3 The partial enlarged view in the embodiment of the present application is provided. Figure 2

[0021] Figure 4 The specific structure schematic diagram of the first connecting part is provided for the embodiments of the present application.

[0022] Figure 5 The interconnection layer shaft measurement diagram is provided for the embodiments of the present application.

[0023] Figure 6 The metal sheet side view schematic diagram is provided for the embodiments of the present application.

[0024] Figure 7 The chip layer top view schematic diagram is provided for the embodiments of the present application.

[0025] Figure 8 The lining plate assembly explosion diagram is provided for the embodiments of the present application.

[0026] In the present application, 10 is the upper pressing plate body, 11 is the integrated heat sink, 12 is the first connecting part, 121 is the first insulating micron wire, 20 is the interconnection layer, 21 is the base material, 22 is the metal sheet, 221 is the metal buried hole, 30 is the chip layer, 31 is the first molybdenum sheet, 32 is the gate, 40 is the lining plate assembly, 41 is the upper copper layer, 42 is the diamond composite layer, 43 is the ceramic insulating lining plate, 50 is the heat sink assembly, and 51 is the second connecting part. DETAILED DESCRIPTION

[0027] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the protection scope of the present application.

[0028] As Figures 1-4 ​As shown, the embodiment of the present application provides a power device packaging structure, comprising: an upper pressing plate assembly, a chip layer 30 and a heat sink assembly 50, the chip layer 30 is arranged between the upper pressing plate assembly and the heat sink assembly 50, the upper pressing plate assembly comprises a first connecting part 12, the heat sink assembly 50 comprises a second connecting part 51, the first connecting part 12 comprises a plurality of first insulating microwires 121, and the second connecting part 51 comprises a plurality of second insulating microwires; the first insulating microwires 121 and the second insulating microwires are connected by static friction. The static friction connection between the first insulating microwires 121 and the second insulating microwires is not affected by temperature, compared with the prior art power device packaging structure which mainly connects the chip, the substrate and the heat sink through solder, the problem that the traditional solder is prone to creep and fatigue under high temperature, affecting the reliability of the soldering layer can be solved, and the reliability of the power device packaging structure is improved.

[0029] In use, the upper pressing plate assembly is pressed, the first insulating microwires 121 are inserted into the gap between the second insulating microwires, static friction connection is formed, and thus the chip layer 30 is fixed inside the upper pressing plate assembly and the heat sink assembly 50.

[0030] The diameters of the first insulating microwires 121 and the second insulating microwires are preferably microns, and the specific diameters can be set according to actual needs; the lengths of the first insulating microwires 121 and the second insulating microwires are preferably millimeters, and the specific lengths can be set according to actual needs.

[0031] The upper pressing plate assembly further comprises an upper pressing plate body 10, the upper pressing plate body 10 is used for pressing the chip layer 30 from the top, and two first connecting parts 12 are arranged on the upper pressing plate body 10 and are connected with the heat sink assembly 50 by static friction from both sides of the upper pressing plate body 10, so that the connection strength of the upper pressing plate assembly and the heat sink assembly 50 is improved.

[0032] The upper pressing plate body 10 comprises a plate body and an integrated heat sink 11, the integrated heat sink 11 is arranged on the plate body and is used for heat dissipation of the chip layer 30, and the arrangement of the integrated heat sink 11 enables the chip layer 30 to be heat dissipated from the top, so that the chip layer 30 is heat dissipated from the top and the bottom, and the heat dissipation effect is improved.

[0033] The plate body is preferably made of epoxy resin, glass fiber and / or aluminum, and other commonly used plate body manufacturing materials in the chip packaging field can also be used.

[0034] The plate body is a driving layer, the driving layer is electrically connected with the chip layer 30, the driving layer is integrated into the chip packaging structure, compared with the external driving assembly in the prior art, the external circuit is reduced, the parasitic noise is reduced, the integration degree of the chip packaging structure is improved, and the electromagnetic interference is reduced.

[0035] As Figure 5As shown, the packaging structure further comprises an interconnection layer 20 arranged between the upper pressing plate assembly and the chip layer 30, the interconnection layer 20 comprises a metal sheet 22, the upper surface of the metal sheet 22 is in contact with the lower surface of the integrated heat sink 11, the lower surface of the metal sheet 22 is in contact with the chip layer 30, the metal sheet 22 is used to transfer the heat generated by the chip layer 30 to the integrated heat sink 11 for heat dissipation, and the metal sheet 22 is preferably a copper sheet. The interconnection layer 20 further comprises a substrate 21, and the metal sheet 22 is embedded on the substrate 21, and the substrate 21 can be selected from a PCB insulating material such as FR4.

[0036] The integrated heat sink 11 comprises an upper diamond layer, a high thermal conductivity metal layer and a lower diamond layer arranged in sequence from top to bottom, the lower diamond layer is in contact with the upper surface of the metal sheet 22, and the high thermal conductivity metal layer is preferably a copper layer. The upper diamond layer and the lower diamond layer can be connected to the high thermal conductivity metal layer in two ways: pre-connection by pressure-assisted sintering; or tightly attached through a whole compression interconnection structure.

[0037] As shown in Figure 8 The packaging structure further comprises a backing plate assembly 40 arranged between the chip layer 30 and the heat sink assembly 50, the backing plate assembly 40 comprises an upper copper layer 41, a diamond composite layer 42 and a ceramic insulating backing plate 43 arranged in sequence from top to bottom, as shown in Figure 6 A part of the upper copper layer 41 is in contact with the lower surface of the chip layer 30; another part of the upper copper layer 41 is connected to the metal sheet 22 through a metal buried hole 221 on the metal sheet 22; the metal sheet 22 is preferably a copper sheet, and the ceramic insulating backing plate 43 is arranged on the heat sink assembly 50. The thermal resistance of the double-sided heat dissipation insulating backing plate of the prior art is large, and the upper copper layer 41 is arranged to replace the heat dissipation insulating backing plate of the prior art, which is conducive to reducing the backing plate thermal resistance. At the same time, the arrangement of the diamond composite layer 42 is conducive to reducing the thickness of the insulating backing plate, and at the same time, high-efficiency lateral heat diffusion is realized to improve the chip heat dissipation efficiency. The ceramic insulating backing plate 43 is combined with the diamond composite layer 42 and the upper copper layer 41 to form a composite substrate by pressing and high-temperature sintering, and the upper copper layer 41 can be etched according to the corresponding pattern of the circuit design.

[0038] As shown in Figure 7 The chip layer 30 comprises a substrate 21 and a power chip, a first molybdenum sheet 31 and a second molybdenum sheet arranged on the substrate 21, the upper surface and the lower surface of the power chip are respectively provided with the first molybdenum sheet 31 and the second molybdenum sheet, the upper surface of the first molybdenum sheet 31 is in contact with the lower surface of the metal sheet 22, and is used to transfer the heat generated by the power chip upward to realize heat dissipation; the lower surface of the second molybdenum sheet is in contact with the upper surface of the upper copper layer 41, and is used to pour the heat into the backing plate assembly 40, and the gate 32 of the power chip is connected to the driving layer through a copper buried hole, so as to control the switching of the power chip.

[0039] The various embodiments described in this specification are presented for the purpose of illustrating the principles of the present application and its best mode of operation. Each of the embodiments described in this specification has been provided for the purpose of illustration only and the various embodiments are not intended to limit the present application in any way unless otherwise specifically indicated. The same parts and / or features of the various embodiments described in this specification can be referenced using the same reference numerals for the ease of understanding of the present application.

[0040] The principles and implementations of the present application have been described in the above embodiments, which are only used to help understand the method of the present application and its core idea. Meanwhile, for those skilled in the art, the specific implementation and application range of the present application can be changed according to the idea of the present application. In summary, the content of the specification should not be understood as a limitation of the present application.

Claims

1. A power device packaging structure, characterized in that: include: An upper pressing plate assembly, a chip layer, and a heat sink assembly, wherein the chip layer is disposed between the upper pressing plate assembly and the heat sink assembly, the upper pressing plate assembly includes a first connecting portion, the heat sink assembly includes a second connecting portion, the first connecting portion includes a plurality of first insulating micron-wires, and the second connecting portion includes a plurality of second insulating micron-wires; the first insulating micron-wires and the second insulating micron-wires are connected by static friction; The upper pressing plate assembly further includes an upper pressing plate body; the upper pressing plate body includes a plate body and an integrated heat sink, the integrated heat sink being arranged on the plate body for dissipating heat from the chip layer; The heat sink assembly further includes an interconnection layer, the interconnection layer being disposed between the upper pressure plate assembly and the chip layer, the interconnection layer including a metal sheet, the upper surface of the metal sheet being in contact with the lower surface of the integrated heat sink, and the lower surface of the metal sheet being in contact with the chip layer; the interconnection layer further includes a substrate, the metal sheet being embedded in the substrate; The plate body is made of epoxy resin, glass fiber and / or aluminum; the plate body is a driving layer, and the driving layer is electrically connected to the chip layer; the integrated heat sink includes an upper diamond layer, a high thermal conductivity metal layer and a lower diamond layer arranged in sequence from top to bottom, and the lower diamond layer is in contact with the upper surface of the metal sheet.

2. The power device packaging structure according to claim 1, wherein: The diameters of the first insulating micro-wire and the second insulating micro-wire are in the micrometer order, and the lengths of the first insulating micro-wire and the second insulating micro-wire are in the millimeter order.

3. The power device packaging structure according to claim 1, wherein: Two first connecting parts are provided on the upper pressing plate body.

4. The power device packaging structure according to claim 1, wherein: It also includes a liner assembly, which is arranged between the chip layer and the radiator assembly. The liner assembly includes an upper copper layer, a diamond composite layer and a ceramic insulating liner arranged in sequence from top to bottom. A portion of the upper copper layer is in contact with the lower surface of the chip layer; another portion of the upper copper layer is connected to the metal sheet through the metal buried vias on the metal sheet; the ceramic insulating liner is arranged on the radiator assembly.

5. The power device packaging structure according to claim 4, characterized in that: The chip layer includes a substrate and a power chip, a first molybdenum sheet and a second molybdenum sheet arranged on the substrate. The first molybdenum sheet and the second molybdenum sheet are respectively provided on the upper surface and the lower surface of the power chip. The upper surface of the first molybdenum sheet contacts the lower surface of the metal sheet, and the lower surface of the second molybdenum sheet contacts the upper surface of the upper copper layer. The gate of the power chip is connected to the driving layer through a copper buried via.

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