CN220208957U - Power module and electronic equipment - Google Patents

Abstract

The embodiment of the application relates to the technical field of module packaging and discloses a power module and electronic equipment. The power module comprises a substrate, a chip, a lead frame and a plastic package body, wherein the substrate comprises an insulating layer, and a first metal layer and a second metal layer which sandwich the insulating layer; the chip is arranged on the first metal layer; the lead frame comprises a first section and a second section which are connected, and the first section is arranged on the first metal layer; the plastic package body surrounds the second metal layer, extends towards the first metal layer and wraps the first section of the chip and the lead frame, and exposes the surface of the second metal layer, which is away from the insulating layer, and the length of the edge of the plastic package body, which surrounds the second metal layer, exceeding the circumferential edge of the insulating layer is greater than or equal to 0.3 millimeter. The power module and the electronic equipment provided by the embodiment of the application can ensure the heat radiation performance of the power module.

Description

Power module and electronic equipment

Technical Field

The embodiment of the application relates to the technical field of module packaging, in particular to a power module and electronic equipment.

Background

With the continuous development of electronic integration technology, more and more electronic components are integrated on a circuit board. By integrating different electronic components in the same circuit, a specific electrical function can be achieved. In order to reduce the space occupation in electronic devices, these integrated electronic components are also evolving towards smaller and smaller modular designs. The modular design is not only beneficial to installation, but also can reduce the use cost.

The power module is formed by adopting a certain packaging form, and the power device is packaged, so that the power module can play a role in protecting the periphery of the power device. However, the packaged power device generates heat during operation, and if the heat is not timely transmitted, the normal operation of the power module is affected. Therefore, how to ensure the heat dissipation performance of the power module is an important issue.

Disclosure of Invention

An object of the present embodiment is to provide a power module and an electronic device, which can ensure heat dissipation performance of the power module.

In order to solve the technical problems, embodiments of the present application provide a power module, which includes a substrate, a chip, a lead frame, and a plastic package body, where the substrate includes an insulating layer, and a first metal layer and a second metal layer sandwiching the insulating layer; the chip is arranged on the first metal layer; the lead frame comprises a first section and a second section which are connected, and the first section is arranged on the first metal layer; the plastic package body surrounds the second metal layer, extends towards the first metal layer and wraps the first section of the chip and the lead frame, and exposes the surface of the second metal layer, which is away from the insulating layer, and the length of the edge of the plastic package body, which surrounds the second metal layer, exceeding the circumferential edge of the insulating layer is greater than or equal to 0.3 millimeter.

The embodiment of the application also provides electronic equipment, which comprises the power module.

According to the power module and the electronic equipment provided by some embodiments of the application, when the plastic package body wraps the first section of the chip and the lead frame, the second metal layer is exposed from the surface of the insulating layer, so that the radiating surface of the substrate is exposed. Therefore, the heat dissipation enhancing function is exerted while the insulating state is maintained by utilizing the good heat conduction performance of the metal, and the heat dissipation performance of the power module can be ensured.

In some embodiments, the plastic package is disposed flush with the second metal layer.

In some embodiments, the first metal layer and the second metal layer are symmetrically disposed about the insulating layer.

In some embodiments, the circumferential edge of the first metal layer and the circumferential edge of the second metal layer are each spaced from the circumferential edge of the insulating layer.

In some embodiments, the first section includes a first end portion and a second end portion that are sheet-like and disposed in parallel, and an extension portion connecting the first end portion and the second end portion, the first end portion being disposed on the first metal layer, the second end portion being connected to the second section.

In some embodiments, the extension is disposed obliquely to the first metal layer.

In some embodiments, there are a plurality of lead frames, and the second section of each lead frame is disposed to extend in the same direction.

In some embodiments, the second sections of two adjacent lead frames are staggered in the extending direction of the plastic package.

In some embodiments, the power module further includes bond wires that electrically connect the chip to the first metal layer.

Drawings

One or more embodiments are illustrated by way of example and not limitation in the figures of the accompanying drawings, in which like references indicate similar elements, and in which the figures of the drawings are not to be taken in a limiting sense, unless otherwise indicated.

FIG. 1 is a schematic cross-sectional view of a power module according to some embodiments of the present application;

fig. 2 is a schematic perspective view of a power module according to some embodiments of the present disclosure;

FIG. 3 is a schematic diagram of a partial enlarged structure of a power module provided in some embodiments of the present application;

fig. 4 is another partially enlarged schematic structural view of a power module according to some embodiments of the present application.

Detailed Description

For the purposes of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the following detailed description of each embodiment of the present application will be given with reference to the accompanying drawings. However, those of ordinary skill in the art will understand that in various embodiments of the present application, numerous technical details have been set forth in order to provide a better understanding of the present application. However, the technical solutions claimed in the present application can be implemented without these technical details and with various changes and modifications based on the following embodiments. The following embodiments are divided for convenience of description, and should not be construed as limiting the specific implementation of the present application, and the embodiments may be mutually combined and referred to without contradiction.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description and claims of the present application and in the description of the figures above are intended to cover non-exclusive inclusions.

In the description of the embodiments of the present application, the technical terms "first," "second," etc. are used merely to distinguish between different objects and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated, a particular order or a primary or secondary relationship. In the description of the embodiments of the present application, the meaning of "plurality" is two or more unless explicitly defined otherwise.

In the description of the embodiments of the present application, the term "and/or" is merely an association relationship describing an association object, which means that three relationships may exist, for example, a and/or B may mean: a exists alone, A and B exist together, and B exists alone. In addition, the character "/" herein generally indicates that the front and rear associated objects are an "or" relationship.

In the description of the embodiments of the present application, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "coupled," and the like should be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally formed; or may be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the embodiments of the present application will be understood by those of ordinary skill in the art according to the specific circumstances.

In the new energy field, such as a medium and small power photovoltaic inverter, an energy storage system, an On-Board Charger (OBC), etc., the power device of the power converter generally adopts a single-tube installation mode. In the package form of the plug-in single tube, a plurality of single tubes are required to be connected in parallel, and the installation area requirement is large. Meanwhile, as no built-in insulating sheet is needed, an insulating sheet is needed to be placed between the ceramic insulating sheet and the radiator, and the upper and lower surfaces of the ceramic insulating sheet are coated with heat-conducting silicone grease, so that the installation process is complicated. And, a large thermal resistance and a limited output power are caused.

If the mounting mode of the plug-in unit and the position of the heat sink relative to the motherboard are to be maintained, and the increase of output power and the reduction of system area are satisfied, a conventional SiP (Single in-line Package) Package can be considered, which uses a lead frame as a carrier, and the chip is soldered on a metal copper carrier of the lead frame, but the insulating sheet is still required to be placed due to no insulating layer, and both sides are fully covered and encapsulated, so that the heat dissipation capability is affected due to no exposure of the heat dissipation sheet.

Some embodiments of the present application are mainly directed to a plug-in single tube for structural optimization, to improve the above-mentioned drawbacks, to simplify installation and enhance output power, and to enable use of various topologies, to simplify system design. And placing the ceramic substrate with the insulating function and copper-clad on both sides in a product, welding one end of the lead frame on a substrate circuit layer, and forming a welding terminal at the tail part of the lead frame to be combined with the system board after electric connection is formed. After the plastic package is formed by injection molding, the radiating surfaces of the two-sided copper-clad ceramic substrates are exposed, and the functions of insulation and heat radiation enhancement are exerted, so that the complicated step of traditional single-tube installation is avoided. The scheme is more suitable for the power converter system in the new energy field, and is beneficial to improving the power output.

The following describes power modules provided in some embodiments of the present application with reference to fig. 1 to 4.

As shown in fig. 1 to 4, the power module provided in some embodiments of the present application includes a substrate 11, a chip 12, a lead frame 13, and a plastic package 14. The substrate 11 includes an insulating layer 111, and a first metal layer 112 and a second metal layer 113 sandwiching the insulating layer 111. The chip 12 is disposed on the first metal layer 112. The lead frame 13 includes a first segment 131 and a second segment 132 connected, the first segment 131 being disposed on the first metal layer 112. The plastic package 14 is disposed around the second metal layer 113 and extends toward the first metal layer 112 to encapsulate the chip 12 and the first section 131 of the lead frame 13, and expose the surface of the second metal layer 113 facing away from the insulating layer 111, where the length of the plastic package 14 around the edge of the second metal layer 113 beyond the circumferential edge of the insulating layer 111 is greater than or equal to 0.3 mm.

The substrate 11 may be a functional substrate 11 having insulating, heat dissipating and patterning circuit layers such as DBC (Direct Bonded Copper, direct copper plating), DBA (Direct Bonded Aluminum, direct aluminum plating), AMB (Active Metal Brazing ), etc., copper and aluminum metals may be used as upper and lower metals, ceramics may be used as the insulating layer 111, and alumina, zirconia-added toughened alumina, aluminum nitride, silicon nitride, etc. may be used as the ceramics.

The chip 12 may be a driver chip or a control chip, and the lead frame 13 is used to electrically connect the power module with external electronic components. The lead frame 13 and the chip 12 may be bonded to the wiring layer of the copper-clad ceramic substrate 11 via a solder reflow process (or a sintering process), i.e., the lead frame 13 and the chip 12 may be bonded to the wiring layer of the substrate 11 via the solder 16.

The plastic enclosure 14 defines the main appearance of the entire power module and may be formed by injection molding with epoxy. The plastic package 14 can protect the internal chip 12 and prolong the service life of the power module.

In the power module provided in some embodiments of the present application, when the plastic package 14 wraps the chip 12 and the first section 131 of the lead frame 13, the second metal layer 113 is exposed away from the surface of the insulating layer 111, so that the heat dissipation surface of the substrate 11 is exposed. Therefore, the heat dissipation enhancing function is exerted while the insulating state is maintained by utilizing the good heat conduction performance of the metal, and the heat dissipation performance of the power module can be ensured.

In addition, by making the length of the plastic sealing body 14 (the length in the direction indicated by the double-headed arrow a in fig. 3 and 4) around the edge of the second metal layer 113 beyond the circumferential edge of the insulating layer 111 be greater than or equal to 0.3 mm, a sufficient space can be reserved outside the circumferential edge of the insulating layer 111 to form a sufficient plastic sealing material. The bonding force between the plastic package 14 and the substrate 11 and the overall insulating capability of the power module product are ensured. The peripheral edges of the molding compound 14 may be designed according to this design rule. In practical applications, the length of the plastic package 14 around the edge of the second metal layer 113 beyond the circumferential edge of the insulating layer 111 may be 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, or 0.9 mm.

As shown in fig. 2, the plastic package 14 may be disposed flush with the second metal layer 113.

That is, the surface of the whole power module, which plays a role in heat dissipation, is a flat surface. The surface of the second metal layer 113 facing away from the insulating layer 111 and the annular surface of the plastic package 14 connected with the surface are both flat surfaces, and are located on the same plane. In this way, the rugged state is not formed at the position of the power module, which plays a role in heat conduction, so that the connection of the power module and the radiator is facilitated, and the heat generated during the operation of the power module is smoothly conducted to the outside through the surface of the second metal layer 113, which is away from the insulating layer 111. In practical situations, the surface of the second metal layer 113 facing away from the insulating layer 111 may also exceed the annular surface connected with the surface in the plastic package body 14 by a certain distance, so that the area of the heat dissipation surface at the bottom of the power module may be increased, which is beneficial to improving the heat dissipation performance.

In some embodiments of the present application, the first metal layer 112 and the second metal layer 113 may be symmetrically disposed with respect to the insulating layer 111.

Through the symmetry setting, can make the heat that the device during operation that generates heat such as chip 12 conveyed to on the first metal layer 112 effectively transmit to on the second metal layer 113, avoid leading to the unable effective conduction of heat of part position department to go out because of there is the phenomenon of staggering between first metal layer 112 and the second metal layer 113, and then avoid the inside heat concentration phenomenon that appears of power module.

In addition, the circumferential edges of the first metal layer 112 and the circumferential edges of the second metal layer 113 may each have a space from the circumferential edges of the insulating layer 111.

In this way, it is possible to advantageously ensure the insulation of the insulating layer 111, avoiding the occurrence of electrical communication or creepage phenomena between the first metal layer 112 and the second metal layer 113.

As shown in fig. 1, in some embodiments of the present application, the first section 131 of the lead frame 13 may include a first end 1311 and a second end 1312 disposed in parallel in a sheet shape, and an extension 1313 connecting the first end 1311 and the second end 1312, the first end 1311 being disposed on the first metal layer 112, the second end 1312 being connected with the second section 132.

The first segment 131 of the lead frame 13 is wrapped inside the plastic package 14 when packaged, one of two ends of the first segment 131 is welded on the circuit layer of the substrate 11, and the other of two ends of the first segment 131 is located at the critical edge portion of the plastic package 14. The entire lead frame 13 may be in a sheet shape, or may be in a sheet shape at end positions and a columnar shape at a middle position. The sheet shape is advantageous in ensuring the bonding strength at the time of soldering, and the columnar shape is advantageous in ensuring the structural strength of the lead frame 13 itself.

The two ends of the first section 131 are disposed in parallel, that is, the direction of the second section 132 may be parallel to the plane of the substrate 11, and the second section may be led out from the plastic package 14 around the edge of the substrate 11, so as to maintain a laterally-protruded state.

In addition, the first segment 131 may be provided in a bent shape to ensure the stability when connected with the plastic package 14. That is, the extension 1313 may be disposed obliquely to the first metal layer 112.

The inclination angle of the extension portion 1313 may be determined according to the side-out position of the lead frame 13, and by providing the extension portion 1313 obliquely with respect to the first metal layer 112, a bent shape may be formed in the molding compound 14.

As shown in fig. 2, in some embodiments of the present application, there may be a plurality of lead frames 13, and the second section 132 of each lead frame 13 is disposed to extend in the same direction.

Each lead frame 13 may provide a different interface function, and at the same time, the second sections 132 of the plurality of lead frames 13 are arranged to extend in the same direction, which may facilitate the installation of the power module.

In addition, the second sections 132 of the adjacent two lead frames 13 may be disposed offset in the extending direction of the plastic package 14.

Thus, when the distance between the lead frames 13 is short, the second sections 132 are staggered in the extending direction of the plastic package 14, so that the electrical contact phenomenon between the second sections 132 of two adjacent lead frames 13 can be avoided.

As shown in fig. 1, the power module may further include bond wires 15, the bond wires 15 electrically connecting the die 12 to the first metal layer 112.

The bonding wire 15 may be a conductive tape, a sheet, such as an aluminum tape, a copper sheet, or the like, and the purpose of electrical connection may be achieved through the bonding wire 15, so as to achieve electrical connection between the chip 12 and the circuit layer of the substrate 11.

In the manufacturing process of the power module provided by some embodiments of the present application, different modes may be adopted, which are specifically as follows:

in the first case, a solder plus aluminum wire bonding scheme can be used, and the complete steps include: printing an insulating ceramic plate solder, assembling a chip, assembling a lead frame, reflow soldering, cleaning a soldering flux, bonding and interconnecting aluminum wires (aluminum strips), plastic packaging and curing, electroplating tin on the lead frame, laser coding, cutting ribs for forming, testing functions, and packaging and shipping.

In the second case, a solder plus copper bonding scheme can be adopted, and the whole steps comprise: printing an insulating ceramic plate solder, assembling a chip, assembling a copper sheet, assembling a lead frame, reflow soldering, cleaning a soldering flux, plastic packaging and curing, electroplating tin on the lead frame, laser coding, cutting ribs for forming, testing functions, and packaging and shipping.

In the third case, a bonding scheme of sintering and copper sheet can be adopted, and the whole steps comprise: printing an insulating ceramic plate sintering material, assembling a chip, sintering, coating solder, assembling a lead frame and a copper sheet, reflowing, cleaning soldering flux, plastic packaging and curing, electroplating tin on the lead frame, laser coding, cutting ribs for forming, testing functions, and packaging and shipping.

Some embodiments of the present application further provide an electronic device, where the electronic device includes the power module described above.

The power module has the heat dissipation performance, so that an insulating sheet is not required to be placed between the power module and the radiator during installation of the system end, and a layer of heat conduction silicone grease can be reduced. Meanwhile, the functional substrate with the insulating, heat dissipation and patterned circuit layers is arranged inside the plastic package body, so that the bonding force between the plastic package body and the substrate and the insulating capability of the product can be ensured.

It will be understood by those of ordinary skill in the art that the foregoing embodiments are specific examples of implementing the present application and that various changes in form and details may be made therein without departing from the spirit and scope of the present application.

Claims (10)

1. A power module, comprising:

a substrate including an insulating layer, a first metal layer and a second metal layer sandwiching the insulating layer;

the chip is arranged on the first metal layer;

the lead frame comprises a first section and a second section which are connected, and the first section is arranged on the first metal layer;

the plastic package body is arranged around the second metal layer and extends towards the first metal layer to wrap the chip and the first section of the lead frame in the first section, the surface of the second metal layer, which is away from the insulating layer, is exposed, and the length of the edge of the plastic package body, which surrounds the second metal layer, exceeding the circumferential edge of the insulating layer is greater than or equal to 0.3 millimeter.

2. The power module of claim 1, wherein the plastic package is disposed flush with the second metal layer.

3. The power module of claim 1 or 2, wherein the first metal layer and the second metal layer are symmetrically disposed about the insulating layer.

4. A power module according to claim 3, wherein the circumferential edges of the first metal layer and the second metal layer are each spaced from the circumferential edge of the insulating layer.

5. The power module of claim 1, wherein the first section includes a first end portion and a second end portion that are sheet-like and disposed in parallel, and an extension portion connecting the first end portion and the second end portion, the first end portion being disposed on the first metal layer, the second end portion being connected to the second section.

6. The power module of claim 5, wherein the extension is disposed obliquely to the first metal layer.

7. The power module of claim 1 wherein there are a plurality of said lead frames, said second section of each said lead frame extending in the same direction.

8. The power module of claim 7, wherein the second segments of adjacent two of the lead frames are staggered in the direction of extension of the plastic package.

9. The power module of claim 1 further comprising bond wires electrically connecting the chip to the first metal layer.

10. An electronic device comprising the power module of any one of claims 1 to 9.