A power semiconductor package structure

Abstract

The utility model provides a kind of power semiconductor packaging structure, it is related to the field of semiconductor packaging, comprising: backing plate;Power chip, the power chip includes the drain of back and the source of front, the back of the power chip is sintered connection with the front of the backing plate;Connecting piece, including first, second connecting part and intermediate part, the first connecting part is sintered connection with the source of the power chip, the second connecting part is sintered connection with the backing plate, the first connecting part and second connecting part are the component of metal, the opposite side of the first, second connecting part is respectively provided with connecting hole, the intermediate part has flexible conductive structure, two ends of the intermediate part are respectively inserted in the connecting hole of first, second connecting part, the application retains the advantage of wire bonding, so that packaging structure is more flexible, increase the connection area of source in power chip again, can effectively realize complex function and high-speed data transmission.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor packaging, and in particular to a power semiconductor packaging structure. Background Technology

[0002] In traditional power module packaging processes, the connection between the chip's front electrode and the substrate surface typically employs wire bonding technology, primarily using thick aluminum wires. However, aluminum wires themselves have inherent limitations such as high resistivity and low yield strength, making this connection method a bottleneck restricting the reliability of power devices. Furthermore, for power chips such as silicon carbide MOSFETs, the available bonding area on the front side is limited, restricting the number of aluminum wires that can be accommodated, thus limiting the chip's current carrying capacity. Therefore, there is an urgent need to explore novel connection methods. Utility Model Content

[0003] This invention provides a power semiconductor packaging structure, the purpose of which is to solve the problems of single bonding method and difficulty in multi-aluminum wire bonding in the existing power module packaging technology.

[0004] To achieve the above objectives, embodiments of this utility model provide a power semiconductor packaging structure, comprising:

[0005] Liner;

[0006] A power chip, the power chip including a drain on the back and a source on the front, the back of the power chip being sintered and connected to the front of the substrate;

[0007] The connector includes a first connecting part, a second connecting part, and an intermediate part connecting the first connecting part and the second connecting part. The first connecting part is sintered to the source electrode of the power chip, and the second connecting part is sintered to the substrate. The first connecting part and the second connecting part are metal components. The opposite sides of the first connecting part and the second connecting part are respectively provided with connecting holes. The intermediate part has a flexible conductive structure, and the two ends of the intermediate part are respectively inserted into the connecting holes of the first connecting part and the second connecting part.

[0008] Preferably, the intermediate portion includes two ends for inserting into the connecting hole and a middle portion for connecting the ends, wherein the first connecting portion, the second connecting portion and the ends are made of MoCu30 material, and the middle portion is a metal lead or a metal lead wrapped with insulating material.

[0009] Preferably, the end is inserted into the connecting hole and generates a frictional force that prevents the two from separating.

[0010] Preferably, the diameter of the end is smaller than the diameter of the connecting hole, and the surface of the end is roughened; the machining accuracy of the end and the connecting hole is less than ±25µm.

[0011] Preferably, the power chip and the substrate, the first connection portion and the source electrode of the power chip, and the second connection portion and the substrate are sintered together using silver.

[0012] Preferably, at least one power chip is provided. When two or more power chips are provided, a plurality of power chips are arranged in a line on the substrate, and the first connection portion is connected to the source of the power chip respectively.

[0013] The above-mentioned solution of this utility model has the following beneficial effects:

[0014] The power semiconductor packaging structure provided in this application retains the advantages of wire bonding, making the packaging structure more flexible, and increases the connection area of ​​the source in the power chip, which can effectively realize complex functions and high-speed data transmission. At the same time, multi-wire bonding can also play an auxiliary role in heat dissipation. Combined with the heat dissipation effect of the first connection part and the second connection part, the packaging structure can have a good working condition.

[0015] Other features and advantages of this invention will be described in detail in the following detailed description section. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the first embodiment of the present invention;

[0017] Figure 2 This is an exploded view of the connector;

[0018] Figure 3 This is a side view of the connector;

[0019] Figure 4 This is a schematic diagram of a power chip;

[0020] Figure 5 This is the intent of the second embodiment of the present invention.

[0021] [Explanation of Labels in the Attached Image]

[0022] 100. Lining plate;

[0023] 200, Power chip; 210, Drain; 220, Source; 230, Gate;

[0024] 300, Connector; 310, First connecting part; 320, Second connecting part; 330, Connecting hole; 340, Middle part; 341, End; 342, Middle part. Detailed Implementation

[0025] To make the technical problems, technical solutions and advantages of this utility model clearer, a detailed description will be given below in conjunction with the accompanying drawings and specific embodiments.

[0026] like Figures 1-5 As shown, an embodiment of this utility model provides a power semiconductor packaging structure, including a substrate 100 and a power chip 200. The power chip 200 includes a drain 210 on the back side and a source 220 and a gate 230 on the front side. The back side of the power chip 200 is sintered and connected to the front side of the substrate 100, that is, the drain 210 of the power chip 200 is electrically connected to the substrate 100. A connector 300 is also connected to the substrate 100 and the power chip 200. The connector 300 includes a first connecting portion 310, a second connecting portion 320, and an intermediate portion 340. The first connecting portion 310 is sintered and connected to the source 220 of the power chip 200, the second connecting portion 320 is sintered and connected to the substrate 100, and the intermediate portion 340 connects the first connecting portion 310 and the second connecting portion 320, thereby maintaining the electrical connection between the first connecting portion 310 and the second connecting portion 320. Both the first connecting part 310 and the second connecting part 320 are metal components, thus providing a good electrical connection. The middle part 340 has a flexible conductive structure, allowing it to be bent into any shape. Connecting holes 330 are also provided on the opposite sides of the first connecting part 310 and the second connecting part 320, and the two ends of the middle part 340 are connected to the connecting holes 330 of the first connecting part 310 and the second connecting part 320 by insertion.

[0027] Compared to the existing technology that uses a gate-shaped metal component to connect the power chip 200 and the substrate 100, this application increases the connection area of ​​the source 220 by using the first connection portion 310. At the same time, the first connection portion 310 and the second connection portion 320 are still bonded by wire (i.e., the middle portion 340). The shape of the connector 300, the position of the middle portion 340, and the length can be designed according to different processes. This retains the advantage of wire bonding for easy connection while ensuring that the density between the wires is not too dense. Each wire has an auxiliary heat dissipation effect. Combined with the main heat dissipation effect of the first connection portion 310 and the second connection portion 320, the package structure can be kept in a good operating temperature environment.

[0028] Furthermore, the aforementioned intermediate portion 340 includes an end portion 341 and a middle portion 342, wherein the end portion 341 is used to insert into the connection hole 330 of the first connecting portion 310 and the second connecting portion 320, and the middle portion 342 is used to connect the two end portions 341. Specifically, the intermediate portion 340 has a flexible conductive structure, as mentioned above, meaning the middle portion 342 is a metal lead or a metal lead wrapped with insulating material. It is understood that the metal lead can be bent into any shape, thus possessing flexibility. The first connecting portion 310, the second connecting portion 320, and the end portion 341 are all made of MoCu30, which has good conductivity, enabling the intermediate portion 340 to electrically connect the first connecting portion 310 and the second connecting portion 320.

[0029] It is understood that metal wires with insulating material are mainly used in encapsulation structures with / without plastic sealing, while those without insulating material are used in encapsulation structures. Preferably, in this embodiment, the middle portion 340 uses metal leads wrapped with insulating material, and the middle portion 340 is in the form of a ribbon cable, that is, multiple metal leads are arranged between insulating materials and spaced apart from each other by the insulating material.

[0030] Furthermore, the end portion 341, inserted into the connecting hole 330, can generate a frictional force that prevents the end portion 341 from disengaging from the connecting hole 330. This application not only breaks away from the traditional solid-state welding (hot pressing, ultrasonic, or thermo-ultrasonic) method of wire bonding by using an insertion method, but also facilitates the replacement of the middle portion 340, and the connection process becomes more convenient, eliminating the need for bonding equipment.

[0031] In this embodiment, to generate friction between the end portion 341 and the connecting hole 330 to prevent them from disengaging, the diameter of the end portion 341 is smaller than the diameter of the connecting hole 330, and the surface of the end portion 341 is roughened. When the end portion 341 is inserted into the connecting hole 330, the rough surface of the end portion 341 rubs against the wall of the connecting hole 330, thereby preventing the end portion 341 from disengaging from the connecting hole 330. Preferably, the machining accuracy of the end portion 341 and the connecting hole 330 is less than ±25µm.

[0032] In actual production, the diameter of end 341 is slightly smaller than the diameter of connecting hole 330.

[0033] The aforementioned power chip 200 and substrate 100, the first connection part 310 and source electrode 220 of power chip 200, and the second connection part 320 and substrate 100 are sintered together using silver.

[0034] Depending on different production needs, power semiconductor packaging structures may include one or more power chips 200.

[0035] Reference Figure 5As shown, when there are two or more power chips 200, the multiple power chips 200 are arranged in a line on the substrate 100. The first connecting part 310 and the second connecting part 320 extend along the arrangement direction of the power chips 200, and the first connecting part 310 is sintered and connected to the source electrode 220 of different power chips 200 respectively.

[0036] This application also provides a power semiconductor packaging method for fabricating the aforementioned power semiconductor packaging structure, comprising the following steps:

[0037] Step 1. Using an automatic chip mounter, dip the bottom of the first connector 310 into a silver film, attach the first connector 310 to the source 220 of the power chip 200, and perform a pre-sintering process to achieve initial fixation of the first connector 310 and the power chip 200.

[0038] The second connecting part 320 is initially fixed to the liner 100 and the power chip 200 is initially fixed to the liner 100 in the same manner.

[0039] Step 2: Place the initially fixed first connecting part 310, second connecting part 320, power chip 200 and substrate 100 into the sintering equipment for sintering. Under preset pressure and temperature, the silver film forms a sintered layer to connect the corresponding components. For example, the silver film between the first connecting part 310 and the source electrode 220 forms a sintered layer to connect the first connecting part 310 and the source electrode 220.

[0040] Step 3: After sintering, remove the first connecting part 310, the second connecting part 320, the power chip 200 and the substrate 100. At this time, the first connecting part 310, the second connecting part 320, the power chip 200 and the substrate 100 have been solidified into a whole. Insert the two ends of the middle part 340 into the connecting holes 330 of the first connecting part 310 and the second connecting part 320 respectively to realize the electrical connection between the source electrode 220 and the substrate 100.

[0041] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. A power semiconductor packaging structure, characterized in that, include: Liner plate (100); A power chip (200) includes a drain (210) on the back side and a source (220) on the front side, and the back side of the power chip (200) is sintered and connected to the front side of the substrate (100). The connector (300) includes a first connecting part (310), a second connecting part (320), and an intermediate part (340) connecting the first connecting part (310) and the second connecting part (320). The first connecting part (310) is sintered to the source electrode (220) of the power chip (200), and the second connecting part (320) is sintered to the substrate (100). The first connecting part (310) and the second connecting part (320) are metal components. The opposite sides of the first connecting part (310) and the second connecting part (320) are respectively provided with connecting holes (330). The intermediate part (340) has a flexible conductive structure, and the two ends of the intermediate part (340) are respectively inserted into the connecting holes (330) of the first connecting part (310) and the second connecting part (320).

2. The power semiconductor packaging structure according to claim 1, characterized in that: The intermediate portion (340) includes two ends (341) for inserting into the connecting hole (330) and a middle portion (342) for connecting the ends (341). The first connecting portion (310), the second connecting portion (320) and the ends (341) are made of MoCu30 material, and the middle portion (342) is a metal lead or a metal lead wrapped with insulating material.

3. The power semiconductor packaging structure according to claim 2, characterized in that: The end (341) is inserted into the connecting hole (330) and generates a frictional force that prevents the two from separating.

4. The power semiconductor packaging structure according to claim 3, characterized in that: The diameter of the end (341) is smaller than the diameter of the connecting hole (330), and the surface of the end (341) is roughened; the machining accuracy of the end (341) and the connecting hole (330) is less than ±25um.

5. The power semiconductor packaging structure according to claim 1, characterized in that: The power chip (200) and the substrate (100), the first connection part (310) and the source electrode (220) of the power chip (200), and the second connection part (320) and the substrate (100) are sintered together with silver.

6. The power semiconductor packaging structure according to claim 1, characterized in that: At least one power chip (200) is provided. When two or more power chips (200) are provided, a plurality of power chips (200) are arranged in a line on the substrate (100), and the first connection part (310) is connected to the source (220) of the power chip (200) respectively.

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