Double-sided heat dissipation power module

Abstract

The utility model discloses a double-sided heat dissipation power module, which comprises an upper packaging substrate, a lower packaging substrate and at least one power chip unit, the inner surface of the upper packaging substrate is provided with a first upper conductive part and a second upper conductive part, and the inner surface of the lower packaging substrate is provided with a first lower conductive part and a second lower conductive part. The first upper conductive part and the second lower conductive part are electrically connected through a first middle conductive piece; a first circuit board is arranged in the first lower conductive part, and a second circuit board is arranged in the second lower conductive part; the power chip unit comprises two groups of power chips, drain electrodes of the two groups of power chips are electrically connected with the first upper conductive part and the second upper conductive part respectively, source electrodes of the two groups of power chips are electrically connected with the first lower conductive part and the second lower conductive part respectively, and grid electrodes of the two groups of power chips are electrically connected with the first circuit board and the second circuit board respectively. The power module has the advantages of being good in heat dissipation performance and beneficial to achieving miniaturization.

Description

Technical Field

[0001] The utility model relates to the field of power modules; more specifically, it relates to a power module with double-sided heat dissipation. Background Art

[0002] Power modules with power chips such as IGBT (Insulated Gate Bipolar Transistor) and / or MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor) are widely used in various electronic / electrical equipment. Such power modules usually need to be provided with circuit structures having different thicknesses or current-carrying capacities, where the thicker or higher-current-carrying-capacity circuits are used to transmit large currents, and the thinner or lower-current-carrying-capacity circuits are used to transmit small currents (such as control signals / currents).

[0003] In existing power modules, the wiring spaces of different circuit structures are usually completely separated, so a large wiring area is required, which is not conducive to the miniaturization of the module. In addition, a large amount of heat is generated during the operation of the power chips, so the module is required to have better heat dissipation performance. Summary of the Utility Model

[0004] The main object of the utility model is to provide a power module with excellent heat dissipation performance and conducive to miniaturization.

[0005] To achieve the above main object, the utility model discloses a power module with double-sided heat dissipation, which includes an upper packaging substrate, a lower packaging substrate and at least one power chip unit; wherein:

[0006] A first upper conductive part and a second upper conductive part are provided on the inner surface of the upper packaging substrate, a first lower conductive part and a second lower conductive part are provided on the inner surface of the lower packaging substrate, and the first upper conductive part is electrically connected to the second lower conductive part through a first intermediate conductive member; the first lower conductive part has a first recessed area for arranging a first circuit board, and the second lower conductive part has a second recessed area for arranging a second circuit board;

[0007] The power chip unit includes two groups of power chips, the drains of the two groups of power chips are electrically connected to the first upper conductive part and the second upper conductive part respectively, the sources of the two groups of power chips are electrically connected to the first lower conductive part and the second lower conductive part respectively, and the gates of the two groups of power chips are electrically connected to the first circuit board and the second circuit board respectively.

[0008] Further, the power module further includes:

[0009] A drain pin, electrically connected to the second upper conductive part;

[0010] A source pin, electrically connected to the first lower conductive part;

[0011] A switching pin, electrically connected to the first upper conductive part and the second lower conductive part;

[0012] Wherein, the switching pin is arranged to extend from the first side of the power module, and the source pin and the drain pin are arranged to extend from the second side relative to the first side.

[0013] According to a specific embodiment of the present invention, the drain pin is welded on the third lower conductive part of the lower packaging substrate, and the third lower conductive part is electrically connected to the second upper conductive part through a second intermediate conductive member.

[0014] According to a specific embodiment of the present invention, the source pin and the switching pin are respectively welded on the first lower conductive part and the second lower conductive part.

[0015] According to a specific embodiment of the present invention, both the first circuit board and the second circuit board are connected with a plurality of auxiliary pins, and the plurality of auxiliary pins are arranged to extend from the first side of the power module.

[0016] According to a specific embodiment of the present invention, electronic components are provided on the surfaces of the first circuit board and the second circuit board facing away from the power chip, and accommodation grooves for accommodating the electronic components are provided on the bottom surfaces of the first recessed area and the second recessed area.

[0017] According to a specific embodiment of the present invention, the upper packaging substrate is a ceramic substrate, and an upper metal heat conduction layer for connecting an external radiator or directly dissipating heat is provided on its outer surface.

[0018] According to a specific embodiment of the present invention, the lower packaging substrate is a ceramic substrate, and a lower metal heat conduction layer for connecting an external radiator or directly dissipating heat is provided on its outer surface.

[0019] According to a specific embodiment of the present invention, both the first circuit board and the second circuit board are FR-4 circuit boards.

[0020] According to a specific embodiment of the present invention, a temperature sensor is provided on the upper packaging substrate and / or the lower packaging substrate.

[0021] According to a specific embodiment of the present invention, the power chip is an IGBT chip.

[0022] The technical solution of the present invention has the following beneficial effects:

[0023] In the present utility model, the power chip is encapsulated between the upper encapsulation substrate and the lower encapsulation substrate, and is dissipating heat on both sides through the upper encapsulation substrate and the lower encapsulation substrate to achieve excellent heat dissipation performance; meanwhile, the circuit board for transmitting small current is integrally arranged in the conductive part of the lower encapsulation substrate, which not only helps to reduce the conductive wiring area of the whole module, thereby simplifying the structure of the module and realizing the miniaturization of the module, but also helps to reduce the current loop area of the power chip, thereby reducing the circuit parasitic effect.

[0024] To more clearly illustrate the purpose, technical solutions and advantages of the present utility model, the present utility model will be further described in detail below in conjunction with the drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 is the overall structural schematic diagram of the encapsulation module in the embodiment;

[0026] Figure 2 is the exploded structural schematic diagram of the encapsulation module in the embodiment;

[0027] Figure 3 is the top view of the encapsulation module after removing the upper encapsulation substrate in the embodiment;

[0028] Figure 4 is the cross-sectional structural schematic diagram of the encapsulation module in the embodiment;

[0029] Figure 5 is the structural schematic diagram of the lower encapsulation substrate in the embodiment;

[0030] Figure 6 is the structural schematic diagram of the circuit board in the embodiment. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] Many specific details are set forth in the following description in order to provide a thorough understanding of the present utility model, but the present utility model may be practiced in other ways different from those described herein. Therefore, the scope of protection of the present utility model is not limited to the limitations of the specific embodiments disclosed below.

[0032] As Figures 1 to 4 shown, the power module of the present utility model includes an upper encapsulation substrate 10, a lower encapsulation substrate 20 and a power chip unit, and the power chip unit is encapsulated between the upper encapsulation substrate 10 and the lower encapsulation substrate 20. In the present utility model, the number of power chip units may be one or more, which can be specifically set according to needs. In the embodiment, an example with one power chip unit is used for illustration. The power chip unit includes two groups of power chips 30, namely the first group of power chips 30a and the second group of power chips 30b, and both groups of power chips 30 include a plurality of (for example, 10) parallel-connected power chips 30.

[0033] In the present utility model, corresponding to each power chip unit, a first upper conductive part 12a and a second upper conductive part 12b for transmitting large current are provided on the inner surface of the upper encapsulation substrate 10, and the first upper conductive part 12a and the second upper conductive part 12b are arranged independently of each other; a first lower conductive part 22a and a second lower conductive part 22b for transmitting large current are provided on the inner surface of the lower encapsulation substrate 20, and the first lower conductive part 22a and the second lower conductive part 22b are arranged independently of each other. The first upper conductive part 12a is electrically connected to the second lower conductive part 22b through a first intermediate conductive member 251. The first intermediate conductive member 251 is preferably a copper bar, and its upper and lower surfaces can be welded to the first upper conductive part 12a and the second lower conductive part 22b respectively.

[0034] In the embodiment, the upper encapsulation substrate 10 can use a ceramic substrate with double-sided copper cladding, for example, a double-sided copper-clad ceramic substrate fabricated by AMB (active metal brazing) technology can be adopted. Specifically, the upper encapsulation substrate 10 includes a first ceramic core board 11, an outer copper foil 13 as an example of the upper metal heat dissipation layer, and an inner copper foil having the first upper conductive part 12a and the second upper conductive part 12b. Among them, the outer copper foil 13 as the upper metal heat dissipation layer can be connected to an external radiator or directly dissipate heat.

[0035] The lower encapsulation substrate 20 can also use a ceramic substrate with double-sided copper cladding. Specifically, in combination with Figure 4 and Figure 5 as shown, the lower encapsulation substrate 20 includes a second ceramic core board 21, an outer copper foil 23 as an example of the lower metal heat dissipation layer, and an inner copper foil having the first lower conductive part 22a and the second lower conductive part 22b. Among them, the outer copper foil 13 as the lower metal heat dissipation layer can be connected to an external radiator or directly dissipate heat.

[0036] In the embodiment, both the upper encapsulation substrate 10 and the lower encapsulation substrate 20 adopt ceramic substrates with excellent thermal conductivity, which is beneficial to promoting double-sided heat dissipation of the power chip 30. Specifically, the materials of the first ceramic core board 11 and the second ceramic core board 21 can be ceramics such as aluminum nitride, silicon carbide, and silicon oxide. Their thicknesses are preferably 0.2 mm to 1.5 mm, and the thicknesses of the inner copper foil and the outer copper foil are preferably 0.5 mm to 2.0 mm, but are not limited thereto.

[0037] Furthermore, in combination with Figure 5As shown, the first lower conductive part 22a has a first recessed area 221a, and a first circuit board 24a for transmitting a small current (such as a control signal) is provided in the first recessed area 221a; the second lower conductive part 22b has a second recessed area 221b, and a second circuit board 24b for transmitting a small current is provided in the second recessed area 221b. The first circuit board 24a and the second circuit board 24b are preferably flush with the surfaces of the first lower conductive part 22a and the second lower conductive part 22b to facilitate the soldering of the power chip 30. The first circuit board 24a and the second circuit board 24b are preferably FR-4 circuit boards, but are not limited thereto.

[0038] In the embodiment, the first circuit board 24a and the second circuit board 24b are two independent circuit boards. As a variation of the embodiment, the first circuit board 24a and the second circuit board 24b can also be two different parts of the same circuit board, that is, the first circuit board 24a and the second circuit board 24b can constitute an entire circuit board. The part of the entire circuit board located in the first recessed area 221a is the first circuit board 24a, and the part located in the second recessed area 221b is the second circuit board 24b.

[0039] The power chip 30 can specifically be an IGBT chip, such as a SiC IGBT chip; a drain D is provided on the upper surface of the power chip 30, and a source S and a gate G are provided on the lower surface of the power chip 30. In the embodiment, the drains D of the two groups of power chips 30 are respectively soldered to the first upper conductive part 12a and the second upper conductive part 12b to be electrically connected thereto, the sources S of the two groups of power chips 30 are respectively soldered to the first lower conductive part 22a and the second lower conductive part 2b to be electrically connected thereto, and the gates G of the two groups of power chips 30 are respectively soldered to the first circuit board 24a and the second circuit board 24b to be electrically connected thereto.

[0040] Specifically, as Figure 4 shown, the drain D of the first group of power chips 30a is electrically connected to the first upper conductive part 12a, the source S is electrically connected to the first lower conductive part 22a, and the gate G is electrically connected to the first circuit board 24a. The drain D of the second group of power chips 30b is electrically connected to the second upper conductive part 12b, the source S is electrically connected to the second lower conductive part 22b, and the gate G is electrically connected to the second circuit board 24b.

[0041] As Figure 6 shown, electronic components 241 such as Rg resistors (gate resistors) are provided on the surfaces of the first circuit board 24a and the second circuit board 24b facing away from the power chip 30, and accommodation grooves 222 for accommodating the electronic components 241 are provided on the bottom surfaces of the first recessed area 221a and the second recessed area 221b. In the embodiment, the design of the accommodation grooves 222 enables electronic components to be installed on the back surfaces of the first circuit board 24a and the second circuit board 24b, which is beneficial to improving the packaging integration degree and the miniaturization of the module.

[0042] Furthermore, the power module has a switching pin 413 protruding from its first side, and a source pin 412 and a drain pin 411 protruding from a second side opposite to the first side. Among them, the drain pin 411 is electrically connected to the second upper conductive part 12b (i.e., electrically connected to the drain D of the second group of power chips 30b), the source pin 412 is electrically connected to the first lower conductive part 22a (i.e., electrically connected to the source S of the first group of power chips 30a), and the switching pin 413 is electrically connected to both the first upper conductive part 12a and the second lower conductive part 22b (i.e., electrically connected to the drain D of the first group of power chips 30a and the source S of the second group of power chips 30b).

[0043] Specifically, the source pin 412 is welded to and electrically connected to the first lower conductive part 22a; the switching pin 413 is welded to and electrically connected to the second lower conductive part 22b. Since the first upper conductive part 12a and the second lower conductive part 22b are electrically connected through the first intermediate conductive member 251, the switching pin 413 is electrically connected to both the first upper conductive part 12a and the second lower conductive part 22b. The drain pin 411 is welded to the third lower conductive part 22c of the lower package substrate 20. The third lower conductive part 22c is independently arranged relative to the first lower conductive part 22a and the second lower conductive part 22b, and a second intermediate conductive member 252 (such as a copper bar) is provided between the third lower conductive part 22c and the second upper conductive part 12b. The upper and lower surfaces of the second intermediate conductive member 252 can be welded to the second upper conductive part 12b and the third lower conductive part 22c respectively, so that the drain pin 411 can be electrically connected to the second upper conductive part 12b.

[0044] In the embodiment, the switching pin 413, the source pin 412, and the drain pin 411 are all welded to the corresponding conductive parts of the lower package substrate 20, which is beneficial to simplifying the manufacturing process and reducing the production cost. As a variation of the embodiment, the drain pin 411 can also be welded to the second upper conductive part 12b of the upper package substrate 10 to be directly electrically connected to the second upper conductive part 12b.

[0045] Furthermore, a plurality of first auxiliary pins 42a are connected to the first circuit board 24a, and a plurality of second auxiliary pins 42b are connected to the second circuit board 24b. The first auxiliary pins 42a and the second auxiliary pins 42b are both arranged to protrude from the first side of the power module. The specific setting of the auxiliary pins can refer to the prior art and will not be elaborated here.

[0046] A temperature sensor 50 can be provided on the upper package substrate 10 and / or the lower package substrate 20, and the number of the temperature sensors 50 can be one or more. In the embodiment, such as Figure 2 、 Figure 3 and Figure 5As shown, the inner copper foil of the lower encapsulation substrate 20 may be provided with a pad 22d for mounting the temperature sensor 50, and the temperature measurement pin 43 electrically connected to the pad 22d and the temperature sensor 50 also extends from the first side of the encapsulation module.

[0047] In the present utility model, the gap between the upper encapsulation substrate 10 and the lower encapsulation substrate 20 may be filled with a resin encapsulation material (not shown in the figure). Additionally, a resin encapsulation body may also be used to integrally encapsulate the power module. For example, except for the pins, the upper metal heat dissipation layer, and the lower metal heat dissipation layer that are exposed from the resin encapsulation body, other parts of the power module are encapsulated inside the resin encapsulation body; optionally, multiple power modules may be encapsulated in an overall resin encapsulation body.

[0048] Although the present utility model has been depicted through the embodiments above, it should be understood that the above embodiments are only used to exemplarily describe the feasible implementation schemes of the present utility model and should not be construed as limiting the protection scope of the present utility model. Any equivalent changes made by those skilled in the art in accordance with the present utility model should also be covered by the protection scope of the claims of the present utility model.

Claims

1. A double-sided heat dissipation power module, comprising an upper packaging substrate, a lower packaging substrate and at least one power chip unit; characterized in that: The inner surface of the upper package substrate is provided with a first upper conductive portion and a second upper conductive portion, and the inner surface of the lower package substrate is provided with a first lower conductive portion and a second lower conductive portion, the first upper conductive portion and the second lower conductive portion are electrically connected via a first intermediate conductive member; the first lower conductive portion has a first recessed area for arranging a first circuit board, and the second lower conductive portion has a second recessed area for arranging a second circuit board; The power chip unit includes two groups of power chips, the drain electrodes of the two groups of power chips are electrically connected to the first upper conductive part and the second upper conductive part respectively, the source electrodes of the two groups of power chips are electrically connected to the first lower conductive part and the second lower conductive part respectively, and the gate electrodes of the two groups of power chips are electrically connected to the first circuit board and the second circuit board respectively.

2. The double-sided heat dissipation power module according to claim 1, characterized in that Also includes: a drain pin electrically connected to the second upper conductive portion; A source pin electrically connected to the first lower conductive portion; a switching pin, electrically connected to the first upper conductive portion and the second lower conductive portion; The switching pin is configured to extend from a first side of the power module, and the source pin and the drain pin are configured to extend from a second side relative to the first side.

3. The double-sided heat dissipation power module according to claim 2, characterized in that: The drain pin is welded on the third lower conductive portion of the lower package substrate, and the third lower conductive portion is electrically connected to the second upper conductive portion via a second intermediate conductive member.

4. The double-sided heat dissipation power module according to claim 2, characterized in that: The source pin and the switch pin are respectively welded on the first lower conductive portion and the second lower conductive portion.

5. The double-sided heat dissipation power module according to claim 2, characterized in that: The first circuit board and the second circuit board are both connected to a plurality of auxiliary pins, and the plurality of auxiliary pins are arranged to extend from a first side of the power module.

6. The double-sided heat dissipation power module according to claim 1, characterized in that: Electronic components are arranged on the surfaces of the first circuit board and the second circuit board facing away from the power chip, and accommodating grooves for accommodating the electronic components are arranged on the bottom surfaces of the first recessed area and the second recessed area.

7. The double-sided heat dissipation power module according to claim 1, characterized in that: The upper packaging substrate is a ceramic substrate, and its outer surface is provided with an upper metal thermal conductive layer for connecting to an external radiator or directly dissipating heat; the lower packaging substrate is a ceramic substrate, and its outer surface is provided with a lower metal thermal conductive layer for connecting to an external radiator or directly dissipating heat.

8. The double-sided heat dissipation power module according to claim 1, characterized in that: The first circuit board and the second circuit board are both FR-4 circuit boards.

9. The double-sided heat dissipation power module according to claim 1, characterized in that: A temperature sensor is disposed on the upper packaging substrate and / or the lower packaging substrate.

10. The double-sided heat dissipation power module according to claim 1, characterized in that: The power chip is an IGBT chip.

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