CN209658160U - a power module - Google Patents

Abstract

The utility model relates to electronic technology fields, disclose a kind of power module, which includes substrate, the power chip group for being set to substrate side, is set to the radiator of the substrate other side and is set to the heat dissipation bridge that power chip group deviates from substrate side；Power chip group includes at least two power chips；The bridge that radiates includes heat dissipation bridge conductive layer and heat dissipation bridge heat-conducting layer, heat dissipation bridge conductive layer is electrically connected with the electrode on each the first face of power chip, heat dissipation bridge heat-conducting layer includes the intermediate region of orthographic projection covering substrate and the fringe region that substrate is connect and stretched out with intermediate region, intermediate region is located at the side that heat dissipation bridge conductive layer deviates from power chip group, fringe region is formed with the bending structure towards plane bending where substrate, and bending structure is connect with radiator.Heat in the power module on power chip can be exported to radiator from substrate and be exported from heat dissipation bridge to radiator, can realize two-side radiation using a radiator.

Description

a power module

technical field

The utility model relates to the field of electronic technology, in particular to a power module.

Background technique

In the prior art, the structure of the power module may be as shown in FIG. 1 . Due to the large overcurrent and high heat generation of the power module, the traditional power module uses bonded aluminum wires 03 to electrically connect the power chips 02. In order to ensure the overcurrent capability, multiple aluminum wires 03 need to be welded, but this structure is efficient Low and aluminum wires have poor overcurrent capability, which will lead to an increase in stray inductance; and in order to ensure heat dissipation, traditional power modules rely on the copper-clad ceramic substrate (DBC) 01 on the back of the power chip 02 and the copper-clad ceramic substrate (DBC) 01 installed on the back of the copper-clad ceramic substrate 01 The heat sink 05 dissipates heat, but only the bottom of this structure can dissipate heat, and the heat dissipation performance of the power module is poor.

Some power modules also use a copper-clad ceramic substrate (DBC) for heat dissipation on the front side, commonly known as double-sided heat dissipation. Existing double-sided heat dissipation devices must be installed with radiators on both sides to achieve a good heat dissipation effect. This will bring a lot of trouble in application, large volume and high cost. High, too much mold pressure will damage the power chip when injection molding the package shell, otherwise the pressure is too small will cause overflow of glue on the top heat dissipation surface, resulting in poor heat dissipation.

Utility model content

The utility model provides a power module. The heat on the power chip in the above power module can be exported from the substrate to the radiator, and can also be exported from the heat dissipation bridge to the radiator. One radiator can be used to realize double-sided heat dissipation.

In order to achieve the above object, the utility model provides the following technical solutions:

A power module, comprising a substrate, a power chipset disposed on one side of the substrate, a heat sink disposed on the other side of the substrate, and a thermal bridge disposed on the side of the power chipset away from the substrate;

The power chipset includes at least two power chips;

The heat dissipation bridge includes a heat dissipation bridge conductive layer and a heat dissipation bridge heat conduction layer, the heat dissipation bridge conductive layer is electrically connected to the electrodes on the first surface of each power chip to electrically connect the power chips, the heat dissipation The bridge thermal conduction layer includes a middle area covering the substrate in an orthographic projection and an edge area connected to the middle area and protruding from the substrate, and the middle area is located on the side of the heat dissipation bridge conductive layer away from the power chipset , the edge region is formed with a bent structure bent toward the plane where the substrate is located, and the bent structure is connected to the heat sink.

The above-mentioned power module includes a substrate, a power chipset disposed on one side of the substrate, a heat sink disposed on the other side of the substrate, and a heat dissipation bridge disposed on the side of the power chipset away from the substrate; the heat dissipation bridge includes a conductive layer of the heat dissipation bridge and a heat dissipation The heat conduction layer of the bridge, the heat conduction layer of the heat dissipation bridge includes a middle area covering the substrate in an orthographic projection and an edge area connected to the middle area and protruding from the substrate. The bent structure is bent on the plane where it is located, and the bent structure is connected to the radiator. In the above-mentioned power module, since the side of the power chipset away from the substrate is provided with a heat dissipation bridge, the conductive layer of the heat dissipation bridge replaces the aluminum wire in the prior art to realize the electrical connection between the power chips, thereby ensuring the overcurrent capability of the power module. The bending structure of the heat conduction layer of the heat dissipation bridge is connected to the heat sink, and the heat on the power chip is exported to the heat sink through the heat dissipation bridge, so that the heat on the power chip can be exported from the substrate side to the heat sink, and from the heat dissipation bridge The side leads to the heat sink, thereby using a heat sink to realize double-sided heat dissipation of the power module, and the power module is small in size, simple in manufacturing process, and low in production cost.

Optionally, the edge regions are formed around the middle region, or the edge regions are formed on both sides of the middle region.

Optionally, the bending structure has a planar portion flush with a side of the substrate facing away from the power chipset, and the planar portion is fixedly connected to the heat sink.

Optionally, the planar portion is fixed on the heat sink by mounting screws.

Optionally, the plane part is connected to the heat sink through thermal conductive glue.

Optionally, the heat conduction layer of the heat dissipation bridge is made of heat conduction metal, and a heat dissipation bridge insulation layer is formed between the middle area of the heat conduction layer of the heat dissipation bridge and the conductive layer of the heat dissipation bridge.

Optionally, the electrodes on the first surface of each power chip are electrically connected to the conductive layer of the heat dissipation bridge through a solder layer.

Optionally, the substrate includes a substrate conductive layer, a substrate insulating layer, and a substrate thermal conduction layer, the substrate conductive layer is electrically connected to electrodes on the second surface of each power chip, and the substrate thermal conduction layer is connected to the heat sink device contacts, the substrate insulating layer is located between the substrate conductive layer and the substrate thermal conduction layer.

Optionally, it also includes a plastic package, the plastic package is injection molded and wrapped on the substrate, the power chipset and the middle area of the thermal bridge, and the plastic package does not cover the substrate and is away from the power chip side of the group.

The utility model also provides a method for manufacturing a power module, including:

A power chipset is arranged on one side of the substrate, and the power chipset includes at least two power chips;

A heat dissipation bridge is provided on the side of the power chipset away from the substrate, wherein the heat dissipation bridge includes a heat dissipation bridge conductive layer and a heat dissipation bridge heat conduction layer, and the heat dissipation bridge conductive layer is connected to the first surface of each power chip The electrodes on the top are electrically connected to make the power chips electrically connected, and the heat conduction layer of the heat dissipation bridge includes a middle area covering the substrate in an orthographic projection and an edge area connected to the middle area and protruding from the substrate, so The middle area is located on the side of the thermal bridge conductive layer away from the power chipset;

bending the edge area of the thermal conduction layer of the heat dissipation bridge toward the plane where the substrate is located to form a bent structure;

The bending structure of the thermal conduction layer of the heat dissipation bridge is fixedly connected to a heat sink, and the heat sink is located on a side of the substrate away from the power chipset.

Optionally, setting the heat dissipation bridge on the side of the power chipset away from the substrate includes:

coating a solder layer on the first side of each of the power chips;

The thermal bridge is disposed on the solder layer, and the conductive layer of the thermal bridge is electrically connected to each of the power chips through the solder layer;

Carrying out reflow soldering treatment to the solder layer;

Flux is cleaned from the solder layer.

Optionally, after the heat dissipation bridge is provided on the side of the power chipset away from the substrate, it further includes:

A plastic package is formed, and the plastic package is injection molded and wrapped on the substrate, the power chipset, and the middle area of the thermal bridge, and the plastic package does not cover the side of the substrate away from the power chipset.

Description of drawings

FIG. 1 is a schematic structural diagram of a power module in the prior art;

Fig. 2 is a partial structural schematic diagram of a power module provided by an embodiment of the present invention;

Fig. 3 is a schematic diagram of the overall structure of a power module provided by an embodiment of the present invention;

Fig. 4 is a schematic flowchart of a method for manufacturing a power module provided by an embodiment of the present invention.

icon:

01-Copper clad ceramic substrate; 02-Power chip; 03-Aluminum wire; 04-Plastic enclosure; 05-Radiator; 06-Mounting screws;

1-substrate; 11-substrate thermal conductive layer; 12-substrate insulating layer; 13-substrate conductive layer; 2-power chip; 31-thermal bridge conductive layer; 32-thermal bridge thermal conductive layer; 321-middle area; 322-edge area ; 3221-plane part; 33-thermal bridge insulation layer; 4-radiator; 5-plastic shell; 61, 62-solder layer; 7-installation screws.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. example. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

Please refer to FIG. 2 and FIG. 3, the utility model provides a power module, including a substrate 1, a power chipset set on one side of the substrate 1, a heat sink 4 set on the other side of the substrate 1, and a power chip set Set the heat dissipation bridge on the side away from the substrate 1;

The power chipset includes at least two power chips 2;

The heat dissipation bridge includes a heat dissipation bridge conductive layer 31 and a heat dissipation bridge heat conduction layer 32. The heat dissipation bridge conductive layer 31 is electrically connected to the electrodes on the first surface of each power chip 2 so as to electrically connect the power chips 2. The heat dissipation bridge heat conduction layer 32 includes Orthographic projection covers the middle area 321 of the substrate 1 and the edge area 322 connected to the middle area 321 and protruding from the substrate 1. The middle area 321 is located on the side of the heat dissipation bridge conductive layer 31 away from the power chip 2 group, and the edge area 322 is formed to face the substrate. 1 is a bent structure bent on the plane, and the bent structure is connected to the radiator 4 .

The power module provided by the above-mentioned utility model embodiment includes a base plate 1, a power chipset set on one side of the base plate 1, a heat sink 4 set on the other side of the base plate 1, and a heat sink set on the side away from the base plate 1 of the power chipset. Bridge; thermal bridge includes conductive layer 31 of thermal bridge and thermal conductive layer 32 of thermal bridge, thermal conductive layer 32 of thermal bridge includes middle area 321 of orthographic projection covering substrate 1 and edge area 322 connected with middle area 321 and extending out of substrate 1, middle area 321 is located on the side of the thermal bridge conductive layer 31 facing away from the power chipset, and the edge region 322 is formed with a bent structure bent toward the plane where the substrate 1 is located, and the bent structure is connected to the heat sink 4 . In the above-mentioned power module, since the side of the power chipset away from the substrate 1 is provided with a heat dissipation bridge, the conductive layer 31 of the heat dissipation bridge replaces the aluminum wire in the prior art to realize the electrical connection between the power chips 2, thereby ensuring the overcurrent of the power module. capability, and the bending structure of the heat conduction layer 32 of the heat dissipation bridge is connected to the heat sink 4, and the heat on the power chip 2 is exported to the heat sink 4 through the heat dissipation bridge, so that the heat on the power chip 2 can be derived from the side of the substrate 1 To the radiator 4, it can be led to the radiator 4 from the side of the heat dissipation bridge, so that a radiator 4 can be used to realize double-sided heat dissipation of the power module, and the power module is small in size, simple in manufacturing process, and low in production cost.

In the power module provided by the above-mentioned utility model embodiment, edge areas 322 are provided around the middle area 321 of the thermal conduction layer 32 of the heat dissipation bridge, or edge areas 322 are set on both sides of the middle area 321, and the bends on the edge areas 322 The structure is connected with the radiator 4, and the heat on the power chip 2 can be exported to the radiator 4 through the thermal bridge. In the prior art, as shown in Figure 1, the plastic casing 04 is fixed on the heat sink 05 through the mounting screws 07 to realize the assembly and fixation of the overall structure of the power module. The assembly and fixation of the overall structure of the power module is realized, the structure is simple, the manufacture is convenient, and the way of assembling and fixing the power module is improved.

Specifically, the bent structure has a plane part 3221 that is flush with the side of the substrate 1 facing away from the power chip 2 group, and the plane part 3221 is fixedly connected to the heat sink 4, so that the assembly and fixation of the overall structure of the power module can be realized.

Specifically, the plane part 3221 can be fixed on the heat sink 4 through the mounting screws 7, which has a simple structure and saves cost.

Specifically, the plane portion 3221 and the heat sink 4 can also be connected by thermally conductive glue, which can realize the fixing of the power module and the good thermal conductivity of the heat dissipation bridge.

In the power module provided by the above utility model embodiment, the material of the heat conduction layer 32 of the heat dissipation bridge can be a heat conduction metal, and a heat dissipation bridge insulating layer 33 is formed between the middle area 321 of the heat conduction layer 32 of the heat dissipation bridge and the conductive layer 31 of the heat dissipation bridge, which is used for insulating The thermal bridge conductive layer 31 and the thermal bridge thermal conductive layer 32 are opened. Optionally, the material of the thermal conduction layer 32 of the heat dissipation bridge may also be an insulating material capable of dissipating heat, and the heat conduction layer 32 of the heat dissipation bridge is directly connected to the conductive layer 31 of the heat dissipation bridge.

In the power module provided by the above utility model embodiments, the electrodes on the first surface of each power chip 2 are electrically connected to the thermal bridge conductive layer 31 through the solder layer 61 . The solder layer 61 can fix the power chip 2 in the power module and realize the electrical connection between the power chip 2 and the conductive layer 31 of the heat dissipation bridge. The material of the solder layer 61 may be solder paste.

In the power module provided by the above utility model embodiment, the substrate 1 may specifically include a substrate conductive layer 13, a substrate insulating layer 12, and a substrate thermally conductive layer 11, and the substrate conductive layer 13 is electrically connected to the electrodes on the second surface of each power chip 2, The substrate heat conduction layer 11 is in contact with the heat sink 4 , and the substrate insulation layer 12 is located between the substrate conductive layer 13 and the substrate heat conduction layer 11 , so that the heat on the power chip 2 can be conducted from the substrate 1 to the heat sink 4 . Specifically, the substrate 1 may be a copper-clad ceramic substrate, the upper conductive copper layer of the copper-clad ceramic substrate is the substrate conductive layer 13 , the ceramic substrate is the substrate insulating layer 12 , and the lower copper layer is the substrate thermal conduction layer 11 .

Specifically, the electrodes on the second surface of each power chip 2 are electrically connected to the conductive layer 13 of the substrate through the solder layer 62 to realize the electrical connection between the power chips 2 .

The power module provided by the above-mentioned utility model embodiment also includes a plastic package 5, which is injection-molded and wrapped on the substrate 1, the power chipset, and the middle area 321 of the heat dissipation bridge, and the plastic package 5 does not cover the substrate 1 and is away from the power chipset. On one side, the plastic package 5 is used to provide physical protection and electrical protection for the power chip 2, and the side of the substrate 1 away from the power chip set is exposed to the outside, which can realize good heat dissipation. Specifically, the material of the plastic package 5 may be epoxy resin.

Based on the power module provided by the above-mentioned embodiment of the utility model, the utility model also provides a manufacturing method of the power module, as shown in FIG. 4 , including the following steps:

S401: setting a power chipset on one side of the substrate, where the power chipset includes at least two power chips;

S402: Install a heat dissipation bridge on the side of the power chipset away from the substrate, wherein the heat dissipation bridge includes a heat dissipation bridge conductive layer and a heat dissipation bridge heat conduction layer, and the heat dissipation bridge conductive layer is electrically connected to the electrodes on the first surface of each power chip to make the power The chips are electrically connected, and the thermal conduction layer of the heat dissipation bridge includes a middle area covering the substrate in an orthographic projection and an edge area connected to the middle area and protruding from the substrate. The middle area is located on the side of the conduction layer of the heat dissipation bridge away from the power chipset;

S403: Bending the edge area of the thermal conduction layer of the heat dissipation bridge toward the plane where the substrate is located to form a bent structure;

S404: Fix and connect the bent structure of the thermal conduction layer of the heat dissipation bridge to the heat sink, and the heat sink is located on the side of the substrate away from the power chipset.

In the manufacturing method of the power module provided by the above utility model embodiment, a heat dissipation bridge is provided on the side of the power chipset away from the substrate, and the conductive layer of the heat dissipation bridge is electrically connected to the electrodes on the first surface of each power chip so that the power chips are electrically connected to each other. connection, the conductive layer of the heat dissipation bridge replaces the aluminum wire in the prior art to realize the electrical connection between the power chips, which ensures the overcurrent capability of the power module, and the bending structure of the heat conduction layer of the heat dissipation bridge is connected to the radiator to connect the power chip The heat is exported to the radiator through the thermal bridge, so that the heat on the power chip can be exported from the substrate to the radiator, and can be exported from the thermal bridge to the radiator, so that the double-sided heat dissipation of the power module can be realized by using a radiator , and the power module is small in size, simple in manufacturing process and low in production cost.

Specifically, the heat dissipation bridge is arranged on the side of the power chipset away from the substrate, which specifically includes the following steps: first, coating a solder layer on the first surface of each power chip; then, disposing the heat dissipation bridge on the solder layer, and the heat dissipation bridge The conductive layer is electrically connected to each power chip through the solder layer; then, the solder layer is reflowed; finally, the flux in the solder layer is cleaned. Wherein, the material of the solder layer may be solder paste. The solder layer can fix the power chip in the power module and realize the electrical connection between the power chip and the conductive layer of the heat dissipation plate.

Specifically, setting a power chipset on one side of the substrate includes the following steps:

Firstly, a solder layer is coated on the substrate; then, the power chips in the power chip group are placed on the substrate, and each power chip is electrically connected to the substrate through the solder layer to realize the electrical connection between the power chips. The solder layer can fix the power chip in the power module and realize the electrical connection between the power chip and the substrate.

Specifically, after the heat dissipation bridge is provided on the side of the power chipset away from the substrate, it also includes: forming a plastic package, the plastic package is injection molded and wrapped on the substrate, the power chipset, and the middle area of the heat dissipation bridge, and the plastic package does not cover the substrate. side of the chipset.

The plastic package is used to provide physical protection and electrical protection for the power chips, and the side of the substrate facing away from the power chipset is exposed to the outside, which can achieve good heat dissipation. Specifically, the material of the plastic casing may be epoxy resin.

Apparently, those skilled in the art can make various changes and modifications to the embodiments of the utility model without departing from the spirit and scope of the utility model. In this way, if these modifications and variations of the utility model fall within the scope of the claims of the utility model and equivalent technologies thereof, the utility model is also intended to include these modifications and variations.

Claims (9)

1. a kind of power module, which is characterized in that including substrate, the power chip group that is set to the substrate side, be set to The radiator of the substrate other side and be set to the power chip group deviate from the substrate side heat dissipation bridge；

The power chip group includes at least two power chips；

The heat dissipation bridge includes heat dissipation bridge conductive layer and heat dissipation bridge heat-conducting layer, the heat dissipation bridge conductive layer and each power Electrode in chip first side is electrically connected so as to be electrically connected between the power chip, and the heat dissipation bridge heat-conducting layer includes orthographic projection It covers the intermediate region of the substrate and the fringe region of the substrate, the centre is connect and stretched out with the intermediate region Region is located at the side that the heat dissipation bridge conductive layer deviates from the power chip group, and the fringe region is formed with towards the base The bending structure of plane bending, the bending structure are connect with the radiator where plate.

2. power module according to claim 1, which is characterized in that the surrounding of the intermediate region is each formed with the side Edge region, alternatively, the two sides of the intermediate region are formed with the fringe region.

3. power module according to claim 2, which is characterized in that the bending structure, which has, deviates from institute with the substrate The concordant planar portions in the side of power chip group are stated, the planar portions are fixedly connected with the radiator.

4. power module according to claim 3, which is characterized in that the planar portions are fixed on described by mounting screw On radiator.

5. power module according to claim 3 or 4, which is characterized in that lead between the planar portions and the radiator Cross thermally conductive glue connection.

6. power module according to claim 1, which is characterized in that the material of the heat dissipation bridge heat-conducting layer is thermally conductive gold Belong to, heat dissipation bridge insulating layer is formed between the heat dissipation bridge heat-conducting layer intermediate region and the heat dissipation bridge conductive layer.

7. power module according to claim 1, which is characterized in that the electrode on each first face of power chip is logical Solder layer is crossed to be electrically connected with the heat dissipation bridge conductive layer.

8. power module according to claim 1, which is characterized in that the substrate includes substrate conductive layer, substrate insulation Layer and substrate heat-conducting layer, the substrate conductive layer are electrically connected with the electrode on each second face of power chip, the base Plate heat-conducting layer is contacted with the radiator, the substrate insulating layer be located at the substrate conductive layer and the substrate heat-conducting layer it Between.

9. power module according to claim 1, which is characterized in that it further include plastic shell, the plastic shell injection molding Molding is wrapped on the substrate, the power chip group and the heat dissipation bridge intermediate region, and the plastic shell does not cover Cover the side that the substrate deviates from the power chip group.