A packaging structure of a power module

Abstract

The application discloses a packaging structure of a power module, and relates to the technical field of packaging structures, which comprises a packaging box, a DBC substrate and a cover plate, a substrate groove is formed in the packaging box, a DBC substrate is arranged at the bottom of the substrate groove, a power semiconductor chip is arranged on the surface of the DBC substrate, and the top of the packaging box is clamped and connected with the cover plate. The packaging structure of the power module can carry three DBC substrates with consistent structural sizes in the packaging box, facilitates the placement of the DBC substrates during the manufacturing process, solves the problem that the DBC substrates with different shapes and sizes need to be identified and placed in the right positions, thereby improving the efficiency, and can satisfy the parallel connection of six power semiconductor chips, thereby improving the current-carrying capacity.

Description

TECHNICAL FIELD

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

[0002] The existing DBC packaging structure is mainly applied to the power conversion unit in the field of automobile electronics, and is usually composed of a packaging shell, a DBC substrate and power semiconductor chips.

[0003] The existing packaging structure is usually composed of 2-3 chips in parallel, and can only be applied to occasions with small current capacity. SUMMARY

[0004] In view of the defects of the prior art, the present application provides a packaging structure of power module, which solves the problems in the background art.

[0005] To achieve the above purpose, the present application realizes the following technical scheme: a packaging structure of power module, comprising a packaging box, a DBC substrate and a cover plate, a substrate slot is formed in the inside of the packaging box, and the bottom of the substrate slot is provided with a DBC substrate, the surface of the DBC substrate is provided with a power semiconductor chip, and the top of the packaging box is connected with a cover plate.

[0006] Further, the number of power semiconductor chips is six.

[0007] Further, the power semiconductor chips are connected in parallel.

[0008] Further, the number of DBC substrates is three.

[0009] Further, the shapes and sizes of the DBC substrates are consistent.

[0010] Further, the packaging structure of the power module comprises the following steps:

[0011] Step 1: six power semiconductor chips, a driving resistor and a thermistor are welded to the DBC substrate.

[0012] Further, the packaging structure of the power module comprises the following steps:

[0013] Step 2: the six power semiconductor chips on the DBC substrate are sequentially bonded with power lines and driving lines.

[0014] Further, the packaging structure of the power module comprises the following steps:

[0015] Step 3: the bonded DBC substrate is welded to the bottom of the substrate slot, and then the glue is cured.

[0016] Further, the packaging structure of the power module comprises the following steps:

[0017] Step four: after the glue is filled and solidified, the cover plate is covered on the top of the packaging box, thereby completing the packaging through clamping.

[0018] The application provides a packaging structure of a power module, which has the following beneficial effects:

[0019] 1. The packaging structure of the power module, the inside of the packaging box can carry three DBC substrates with consistent structure sizes, facilitating the placement of the DBC substrates in the manufacturing process, solving the problem that the existing DBC substrates have different shapes and sizes, which requires identification of the shape and the placement position before placement, thereby improving the efficiency, and meeting the parallel connection of six power semiconductor chips, thereby improving the current-carrying capacity.

[0020] 2. The packaging structure of the power module, based on the monitoring of the temperature inside the packaging box by the heat sensor, the heat dissipation can be performed in three different heat dissipation efficiencies for the temperatures at different thresholds, respectively, the low or medium efficiency output of the micro motor makes the gas flow at a low flow rate to dissipate heat, the high efficiency output of the micro motor makes the gas flow at a medium flow rate to dissipate heat, and the high efficiency output of the micro motor and the cyclic meshing of the transmission gear and the semi-annular inner tooth groove make the extension distance of the elastic piston rod larger, thereby making the gas flow at a high flow rate to dissipate heat, thereby adapting to different temperature conditions to improve the heat dissipation effect.

[0021] 3. The packaging structure of the power module, the rubber piston part of the elastic piston rod divides the gas-liquid pipe into a cooling liquid chamber and a gas extraction chamber, the piston movement of the elastic piston rod makes the gas flow for air cooling heat dissipation, and at the same time, the cooling liquid circulates through the interlayer chamber to pre-cool the gas in the gas extraction chamber, thereby further improving the heat dissipation effect of the air cooling heat dissipation on the basis of the three heat dissipation efficiencies, and the cooling liquid chamber is provided with a refrigeration fin at the bottom to re-cool the cooling liquid circulating through the cooling liquid chamber, thereby prolonging the use time of the cooling liquid and avoiding excessive heat absorption of the cooling liquid to make the heat absorption pre-cooling effect lost. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a schematic diagram of the internal structure of the substrate groove of the packaging structure of the power module of the application;

[0023] Figure 2 It is a schematic diagram of the structure of the packaging box of the packaging structure of the power module of the application after the cover is sealed;

[0024] Figure 3 It is a schematic diagram of the top view of the substrate groove of the packaging structure of the power module of the application;

[0025] Figure 4This is a top view cross-sectional diagram of the gas-liquid pipe structure of the packaging structure of a power module according to the present invention.

[0026] Figure 5 This is a three-dimensional structural diagram of the left side of the gas-liquid pipe of the packaging structure of a power module according to the present invention;

[0027] Figure 6 This is a schematic cross-sectional view of the right side of the gas-liquid pipe of the packaging structure of a power module according to the present invention.

[0028] Figure 7 This is a schematic diagram of the packaging structure of a power module of the present invention after the turntable is separated;

[0029] Figure 8 This is a schematic diagram of the bottom view of the packaging structure of a power module of the present invention after the turntable is separated.

[0030] In the diagram: 1. Packaging box; 2. Substrate groove; 3. DBC substrate; 4. Power semiconductor chip; 5. Cover plate; 6. Sealed chamber; 7. Heat dissipation assembly; 701. Gas-liquid pipe; 702. Jacketed pipe; 703. Jacketed chamber; 704. First one-way valve; 705. Air inlet pipe; 706. Second one-way valve; 707. Air distribution channel; 708. Third one-way valve; 709. Fourth one-way valve; 710. Elastic piston rod; 711. Wire rope; 712. Steering wheel; 713. Movable shaft; 714. Turntable; 715. Transmission gear; 716. Micro motor; 717. Electromagnet; 718. Semi-tooth ring box. Detailed Implementation

[0031] The embodiments of the present invention will be described in further detail below with reference to the accompanying drawings and examples. The following examples are for illustrative purposes only and should not be construed as limiting the scope of the invention.

[0032] like Figures 1-2 As shown, the present invention provides a technical solution: a power module packaging structure, including a packaging box 1, a DBC substrate 3 and a cover plate 5. The packaging box 1 has a substrate groove 2 inside, and the DBC substrate 3 is placed at the bottom of the substrate groove 2. A power semiconductor chip 4 is disposed on the surface of the DBC substrate 3, and the cover plate 5 is snapped to the top of the packaging box 1. The number of power semiconductor chips 4 is six, and the power semiconductor chips 4 are connected in parallel. The number of DBC substrates 3 is three, and the DBC substrates 3 have the same shape and size.

[0033] The packaging structure of the power module includes the following steps:

[0034] Step 1: Solder the six power semiconductor chips 4, the drive resistor, and the thermistor onto the DBC substrate 3;

[0035] Step 2: Bond power lines and drive lines sequentially to six power semiconductor chips 4 on the DBC substrate 3;

[0036] Step 3: Weld the bonded DBC substrate 3 to the bottom of the substrate groove 2, and then perform potting and curing.

[0037] Step 4: After the potting adhesive has cured, place the cover plate 5 on top of the encapsulation box 1, thereby completing the encapsulation through locking.

[0038] Based on the above description, the packaging box 1 of the present invention can carry three DBC substrates 3 with the same structural size, which facilitates the placement of DBC substrates 3 during the manufacturing process. This solves the problem that the shape and placement position of existing DBC substrates 3 are different in shape and size, which requires identification of their shape and placement position before placement, thereby improving efficiency. Moreover, it can meet the requirements of six power semiconductor chips 4 connected in parallel, thereby improving the current carrying capacity.

[0039] like Figures 1-8 As shown, a sealed chamber 6 is formed inside the substrate groove 2 on one side of the encapsulation box 1. The heat dissipation assembly 7 includes a gas-liquid pipe 701 disposed inside the sealed chamber 6, and a jacketed pipe 702 is sleeved on the outer wall of the gas-liquid pipe 701. A jacketed chamber 703 is provided between the outer wall of one end of the gas-liquid pipe 701 and the jacketed pipe 702. An air inlet pipe 705 is connected to one end face of the gas-liquid pipe 701 through a first one-way valve 704, and an air inlet pipe 705 is connected to one side of the gas-liquid pipe 701 through a second one-way valve 706. A gas distribution channel 707 is located at the bottom of the substrate groove 2 and below the DBC substrate 3. One end of the gas distribution channel 707, away from the second one-way valve 706, connects to the outside of the packaging box 1. The other end of the gas-liquid pipe 701 is connected to the interlayer chamber 703 via a third one-way valve 708 and a conduit. The side of the interlayer chamber 703 away from the third one-way valve 708 is connected to the gas-liquid pipe 701 via another conduit and a fourth one-way valve 709. The fourth one-way valve 709... Opposite to the third one-way valve 708, a flexible piston rod 710 runs through the gas-liquid pipe 701. The flexible piston rod 710 divides the gas-liquid pipe 701 into two spaces. Coolant is provided in the space near the fourth one-way valve 709 and the third one-way valve 708 and in the interlayer chamber 703. A cooling plate is provided at the bottom of this space, and the heat dissipation surface of the cooling plate is exposed at the bottom of the package 1. The end of the flexible piston rod 710 is connected by a rope 711 and a steering wheel 71. 2 is connected to a movable shaft 713, with turntables 714 rotatably connected to both ends of the movable shaft 713, forming an eccentric wheel with the turntables 714. A transmission gear 715 is fixed at the bottom of the movable shaft 713, a micro motor 716 is connected to the top of the eccentric wheel, and an electromagnet 717 is rotatably connected to the bottom of the eccentric wheel. The transmission gear 715 is located above the electromagnet 717, and a semi-toothed ring box 718 is provided below the electromagnet 717, and the semi-toothed ring box 718 is slidably connected to the encapsulation box 1.

[0040] The specific operation is as follows, considering that the six power semiconductor chips 4 will generate heat when working, the eccentric wheel is driven to rotate by the micro motor 716, so that the wire rope 711 carries the elastic piston rod 710 to make piston movement inside the gas-liquid pipe 701, when the elastic piston rod 710 is away from the first one-way valve 704, the first one-way valve 704 is opened and the second one-way valve 706 is closed, at this time, external air is introduced through the air inlet pipe 705, and when the elastic piston rod 710 is close to the first one-way valve 704, the first one-way valve 704 is closed and the second one-way valve 706 is opened, so that the air inside the gas-liquid pipe 701 is injected into the air distribution channel 707 and passes under the DBC substrate 3, thereby using the gas flow to take out the heat from the bottom of the DBC substrate 3 to achieve the heat dissipation effect;

[0041] When it is necessary to improve the gas flow rate to improve the heat dissipation effect, not only can the output efficiency of the micro motor 716 be improved to increase the piston frequency of the elastic piston rod 710, but also the electromagnet 717 can be energized to attract the half-tooth ring box 718 to slide upward, so that the inner tooth groove is flush with the transmission gear 715, and when the movable shaft 713 rotates with the rotating disc 714, the transmission gear 715 will mesh with the half-ring-shaped inner tooth groove, so that the transmission gear 715 rotates, and in the process of rotating, the transmission gear 715 will wind the wire rope 711, so that the elastic piston rod 710 obtains a greater stroke when it is retracted, thereby increasing the gas suction amount, and when the transmission gear 715 leaves the half-ring-shaped inner tooth groove, the wire rope 711 is released under the elastic action of the elastic piston rod 710, so that the extension distance of the elastic piston rod 710 is matched with the retraction distance, thereby increasing the gas discharge amount, thereby further increasing the gas intake amount inside the air distribution channel 707;

[0042] Based on the above description, the present application monitors the temperature inside the packaging box 1 based on the heat sensor, and can dissipate heat in three heat dissipation efficiencies for temperatures at different thresholds, respectively, the micro motor 716 is in low or medium efficiency output, so that the gas flows at low flow rate to dissipate heat, the micro motor 716 is in high efficiency output, so that the gas flows at medium flow rate to dissipate heat, and the micro motor 716 is in high efficiency output and the transmission gear 715 is cyclically meshed with the half-ring-shaped inner tooth groove, so that the extension and retraction stroke of the elastic piston rod 710 is increased, thereby making the gas flow at high flow rate to dissipate heat, thereby adapting to different temperature conditions to improve the heat dissipation effect;

[0043] When the elastic piston rod 710 is away from the first one-way valve 704 and close to the third one-way valve 708, the third one-way valve 708 is opened and the fourth one-way valve 709 is closed, the cooling liquid is pushed by the elastic piston rod 710 and injected into the interlayer chamber 703, and when the elastic piston rod 710 is close to the first one-way valve 704 and away from the third one-way valve 708, the third one-way valve 708 is closed and the fourth one-way valve 709 is opened, so that the cooling liquid in the interlayer chamber 703 returns to the gas-liquid pipe 701, and the cooling liquid circulates through the interlayer chamber 703 with the piston movement of the elastic piston rod 710, thereby being able to pre-cool the gas in the gas extraction part inside the gas-liquid pipe 701;

[0044] Based on the above description, the present application uses the elastic piston rod 710 to divide the gas-liquid pipe 701 into a cooling liquid chamber and an air extraction chamber, and with the piston movement of the elastic piston rod 710, the gas flow is cooled and radiated, and the cooling liquid is circulated through the interlayer chamber 703 to pre-cool the gas in the air extraction chamber, thereby further improving the heat dissipation effect of the gas cooling on the basis of the three heat dissipation efficiencies, and the bottom of the cooling liquid chamber is provided with a refrigeration fin to re-cool the cooling liquid circulating through the cooling liquid chamber, thereby prolonging the use time of the cooling liquid and avoiding excessive heat absorption to make the heat absorption pre-cooling effect lost.

[0045] In summary, the packaging structure of the power module, when in use, first, three DBC substrates 3 with consistent structure size can be carried in the packaging box 1, and the packaging box 1 can satisfy the parallel connection of six power semiconductor chips 4, thereby improving the current-carrying capacity;

[0046] Considering that the six power semiconductor chips 4 will generate heat when working, the micro motor 716 drives the eccentric wheel to rotate to make the wire rope 711 carry the elastic piston rod 710 to make piston movement inside the gas-liquid pipe 701, when the elastic piston rod 710 is away from the first one-way valve 704, the first one-way valve 704 is opened and the second one-way valve 706 is closed, at this time, external air is introduced through the air inlet pipe 705, and when the elastic piston rod 710 is close to the first one-way valve 704, the first one-way valve 704 is closed and the second one-way valve 706 is opened, so that the air inside the gas-liquid pipe 701 is injected into the air distribution channel 707 and passes below the DBC substrate 3, thereby using the gas flow to take out heat from below the DBC substrate 3 to achieve the heat dissipation effect;

[0047] When the gas flow rate needs to be increased to improve the heat dissipation effect, not only can the piston frequency of the elastic piston rod 710 be increased by increasing the output efficiency of the micro motor 716, but also the electromagnet 717 can be energized to attract the half-tooth ring box 718 to make it slide upwards, so that its inner tooth groove is flush with the transmission gear 715. When the movable shaft 713 rotates with the rotating disc 714, the transmission gear 715 will mesh with the half-ring inner tooth groove, so that the transmission gear 715 rotates. During the rotation of the transmission gear 715, it will wind the wire rope 711, so that a greater stroke is obtained when the elastic piston rod 710 contracts, thereby increasing the gas suction amount. When the transmission gear 715 leaves the half-ring inner tooth groove, the wire rope 711 is released under the elastic action of the elastic piston rod 710, so that the extension distance of the elastic piston rod 710 is matched with the contraction distance, thereby increasing the gas discharge amount, thereby further increasing the gas inlet amount in the gas distribution channel 707.

[0048] While the three heat dissipation efficiencies can be achieved, as the elastic piston rod 710 moves away from the first one-way valve 704 and approaches the third one-way valve 708, the third one-way valve 708 is opened and the fourth one-way valve 709 is closed. The cooling liquid is pushed by the elastic piston rod 710 and injected into the interlayer chamber 703. When the elastic piston rod 710 approaches the first one-way valve 704 and moves away from the third one-way valve 708, the third one-way valve 708 is closed and the fourth one-way valve 709 is opened, so that the cooling liquid in the interlayer chamber 703 returns to the gas-liquid pipe 701. The cooling liquid circulates through the interlayer chamber 703 with the piston movement of the elastic piston rod 710, thereby being able to pre-cool the gas in the gas extraction part inside the gas-liquid pipe 701. On the basis of the three heat dissipation efficiencies, the heat dissipation effect of the gas cooling heat dissipation is further improved.

[0049] Embodiments of the present application are given for the purpose of illustration and description, and are not intended to be exhaustive or to limit the application to the disclosed form. Many modifications and variations will be apparent to those of ordinary skill in the art. Embodiments are chosen and described in order to best explain the principles of the application and its practical application, and to enable others skilled in the art to understand the application for various embodiments with various modifications as are suited to the particular use contemplated.

Claims

1. A power module packaging structure, comprising a packaging box (1), a DBC substrate (3), and a cover plate (5), characterized in that: The encapsulation box (1) has a substrate groove (2) inside, and a DBC substrate (3) is placed at the bottom of the substrate groove (2). A power semiconductor chip (4) is disposed on the surface of the DBC substrate (3), and a cover plate (5) is snapped onto the top of the encapsulation box (1). A sealed chamber (6) is formed inside the substrate groove (2) of the encapsulation box (1). The heat dissipation assembly (7) includes a gas-liquid pipe (701) disposed inside the sealed chamber (6), and a jacketed pipe (702) is sleeved on the outer wall of the gas-liquid pipe (701). A jacketed chamber (702) is provided between the outer wall of one end of the gas-liquid pipe (701) and the jacketed pipe (702). 03), and one end of the gas-liquid pipe (701) is connected to an air inlet pipe (705) via a first one-way valve (704). One side of the gas-liquid pipe (701) is connected to a gas distribution channel (707) via a second one-way valve (706). The gas distribution channel (707) is located at the bottom of the substrate groove (2) and below the DBC substrate (3). The end of the gas distribution channel (707) away from the second one-way valve (706) is connected to the outside of the packaging box (1). The other side of the gas-liquid pipe (701) is connected to the interlayer chamber (703) via a third one-way valve (708) and a pipe. The interlayer chamber (703) is away from the third one-way valve. One side of the valve (708) is connected to the gas-liquid pipe (701) through another pipe and the fourth check valve (709). The fourth check valve (709) is arranged opposite to the third check valve (708). An elastic piston rod (710) runs through the inside of the gas-liquid pipe (701). The elastic piston rod (710) divides the inside of the gas-liquid pipe (701) into two spaces. Coolant is provided in the space near the fourth check valve (709) and the third check valve (708) and in the interlayer chamber (703). A cooling plate is provided at the bottom of the space, and the heat dissipation surface of the cooling plate is exposed at the bottom of the encapsulation box (1). The elastic piston rod (710) is connected to the gas-liquid pipe (701) through another pipe and the fourth check valve (709) and the third check valve (708). The end of 10) is connected to a movable shaft (713) via a rope (711) and a steering wheel (712). The movable shaft (713) is rotatably connected to a turntable (714) at both ends, and forms an eccentric wheel with the turntable (714). A transmission gear (715) is fixed at the bottom of the movable shaft (713). A micro motor (716) is connected to the top of the eccentric wheel. An electromagnet (717) is rotatably connected to the bottom of the eccentric wheel. The transmission gear (715) is located above the electromagnet (717). A semi-tooth ring box (718) is provided below the electromagnet (717), and the semi-tooth ring box (718) is slidably connected to the encapsulation box (1).

2. The packaging structure of a power module according to claim 1, characterized in that: The number of power semiconductor chips (4) is six.

3. The packaging structure of a power module according to claim 2, characterized in that: The power semiconductor chips (4) are connected in parallel.

4. The packaging structure of a power module according to claim 1, characterized in that: The number of DBC substrates (3) is three.

5. The packaging structure of a power module according to claim 4, characterized in that: The DBC substrate (3) has a consistent shape and size.

6. The packaging structure of a power module according to claim 1, characterized in that: The packaging structure of the power module includes the following steps: Step 1: Solder six power semiconductor chips (4), driving resistors, and thermistors onto the DBC substrate (3).

7. The packaging structure of a power module according to claim 6, characterized in that: The packaging structure of the power module includes the following steps: Step 2: Bond the power lines and drive lines of the six power semiconductor chips (4) sequentially on the DBC substrate (3).

8. The packaging structure of a power module according to claim 7, characterized in that: The packaging structure of the power module includes the following steps: Step 3: Weld the bonded DBC substrate (3) to the bottom of the substrate groove (2), and then perform potting and curing.

9. The packaging structure of a power module according to claim 1, characterized in that: The packaging structure of the power module includes the following steps: Step 4: After the glue has cured, place the cover plate (5) on top of the encapsulation box (1) to complete the encapsulation by snapping it together.

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