CN112397496A

CN112397496A - Power module

Info

Publication number: CN112397496A
Application number: CN201910763448.1A
Authority: CN
Inventors: 冷中明; 谢智正
Original assignee: Niko Semiconductor Co Ltd
Current assignee: Niko Semiconductor Co Ltd
Priority date: 2019-08-19
Filing date: 2019-08-19
Publication date: 2021-02-23

Abstract

The invention discloses a power module. The carrier assembly of the power module comprises a bottom plate, a circuit board, a lead frame and a welding pad group. The circuit board is arranged on a bearing surface of the bottom plate. The circuit board comprises a component setting part and an extension part, wherein the extension part extends from one side of the component setting part. The lead frame is arranged on the bottom plate and at least comprises a first conductive part and a second conductive part which are electrically insulated with each other. The extension part of the circuit board is embedded between the first conductive part and the second conductive part, and the upper surface of the lead frame and the upper surface of the extension part are cut to be even. The bonding pad group comprises a first bonding pad, a second bonding pad and a third bonding pad. The first welding pad is arranged on the extension part, and the second welding pad and the third welding pad are respectively arranged on the first conductive part and the second conductive part. The power module further comprises at least one power element, and the power element is arranged on the carrier plate assembly through the welding pad group.

Description

Power module

Technical Field

The present invention relates to a power module, and more particularly, to a power module suitable for operating at high power.

Background

The power module can be applied to a household frequency conversion system, an electric vehicle and an industrial control system (industrial control system) to convert electric energy or control a circuit. In the conventional circuit system, a power device, a gate driving device and a control device are usually applied.

In the prior art, a specific circuit layout is formed on a circuit board in advance according to a circuit design, and then a plurality of discrete power components, control components, gate driving components and other related components are assembled on a main control circuit board to be integrated into a power module.

However, in some circuits, such as: the voltage conversion circuit and the power module can be required to operate under high-power conditions such as high voltage or large current. Therefore, the power module generates more heat energy when operating. Therefore, the power module needs to have good heat dissipation capability in addition to the requirements of high withstand voltage and large current.

Disclosure of Invention

The present invention is directed to a power module, which is suitable for operating under high voltage or large current, and has good heat dissipation capability.

In order to solve the above technical problem, one technical solution of the present invention is to provide a power module, which includes a carrier assembly and at least one power device. The carrier plate assembly comprises a bottom plate, a circuit board, a lead frame and a welding pad group. The circuit board is arranged on a bearing surface of the bottom plate. The circuit board comprises an element setting part and an extension part, wherein the extension part extends from one side of the element setting part. The lead frame is arranged on the bottom plate and at least comprises a first conductive part and a second conductive part which are electrically insulated with each other. The extension part of the circuit board is embedded between the first conductive part and the second conductive part, and the upper surface of the first conductive part, the upper surface of the second conductive part and the upper surface of the extension part are aligned. The bonding pad group comprises a first bonding pad, a second bonding pad and a third bonding pad. The first welding pad is arranged on the extension part, and the second welding pad and the third welding pad are respectively arranged on the first conductive part and the second conductive part. At least one power element is arranged on the carrier plate assembly through the welding pad group.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide a power module, which includes a carrier plate assembly and at least two power components. The carrier plate assembly comprises a bottom plate, a circuit board, a lead frame and two welding pad groups. The circuit board is arranged on a bearing surface of the base plate and comprises an element arrangement part and two extension parts. The two extending parts extend from the same side of the element arranging part. The lead frame is arranged on the bottom plate and at least comprises a first conductive part, a second conductive part and a third conductive part which are separated from each other and electrically insulated. The first conductive part and the third conductive part are respectively positioned on two opposite sides of the second conductive part. One of the extending portions is located between the first conductive portion and the second conductive portion, the other extending portion is located between the second conductive portion and the third conductive portion, and the upper surfaces of the first conductive portion, the second conductive portion, the third conductive portion and the two extending portions are aligned. Each bonding pad group comprises a first bonding pad, a second bonding pad and a third bonding pad. The first to third pads of one pad group are respectively arranged on one of the extension part, the first conductive part and the second conductive part, and the first to third pads of the other pad group are respectively arranged on the other extension part, the second conductive part and the third conductive part. One of the power elements is arranged on the first conductive part, the second conductive part and the extension part between the first conductive part and the second conductive part through one of the welding pad groups. The other power element is arranged on the second conductive part, the third conductive part and the extension part between the second conductive part and the third conductive part through the other welding pad group. And the two power elements are connected in series with each other through the second conductive part.

One of the benefits of the present invention is that the power module and the carrier assembly thereof provided by the present invention can operate under high voltage and high current and have good heat dissipation capability through the technical schemes of "the extending portion of the circuit board is embedded between the first conductive portion and the second conductive portion" and "the upper surface of the lead frame and the upper surface of the extending portion are aligned".

For a better understanding of the features and technical content of the present invention, reference should be made to the following detailed description of the invention and accompanying drawings, which are provided for purposes of illustration and description only and are not intended to limit the invention.

Drawings

Fig. 1 is a perspective view of a power module according to a first embodiment of the invention.

Fig. 2 is a partially exploded perspective view of a power module according to a first embodiment of the invention.

Fig. 3 is a partially exploded perspective view of the power module according to the first embodiment of the invention at another angle.

Fig. 4 is a schematic perspective view of the power module without a heat sink and a packaging adhesive layer according to the first embodiment of the invention.

Fig. 5 is a top view schematic diagram of the power module of fig. 4.

Fig. 6 is a schematic sectional view along line VI-VI in fig. 1.

Fig. 7 is a partially enlarged schematic view of a region VII in fig. 6.

Fig. 8 is a schematic perspective view of a power module without a heat sink and a packaging adhesive layer according to a second embodiment of the invention.

Fig. 9 is a top view schematic diagram of the power module of fig. 8.

[ notation ] to show

M1 power module

1 Carrier plate Assembly

10 base plate

10a bearing surface

10b bottom surface

Slotting for 10h

W1 Slot Width

11. 11' circuit board

110 element setting part

111 extension

Upper surface of 111s extension

P1 first pad

12. 12' lead frame

120 first conductive part

120s upper surface

121 a second conductive part

Upper surface of 121s

122 third conductive part

122s upper surface

12h strip-shaped opening

W2 Bar opening Width

P2 second pad

P3 third pad

2 power element

2a assembly side

2b back side

21 grid electrode

22 source electrode

23 drain electrode

C1 control element

3 Heat sink

4 packaging adhesive layer

5 input/output pin

6 diode element

Detailed Description

The following is a description of the embodiments of the present disclosure related to "power module" by specific embodiments, and those skilled in the art can understand the advantages and effects of the present disclosure from the disclosure of the present disclosure. The invention is capable of other and different embodiments and its several details are capable of modification and various other changes, which can be made in various details within the specification and without departing from the spirit and scope of the invention. The drawings of the present invention are for illustrative purposes only and are not intended to be drawn to scale. The following embodiments will further explain the related art of the present invention in detail, but the disclosure is not intended to limit the scope of the present invention.

It will be understood that, although the terms first, second, third, etc. may be used herein to describe various elements or signals, these elements or signals should not be limited by these terms. These terms are used primarily to distinguish one element from another element or from one signal to another signal. In addition, the term "or" as used herein should be taken to include any one or combination of more of the associated listed items as the case may be.

Please refer to fig. 1 to 4. Fig. 1 is a perspective view of a power module according to a first embodiment of the invention. Fig. 2 is a partially exploded perspective view of a power module according to a first embodiment of the invention. Fig. 3 is a partially exploded perspective view of the power module according to the first embodiment of the invention at another angle. Fig. 4 is a schematic perspective view of the power module without a heat sink and a packaging adhesive layer according to the first embodiment of the invention.

As shown in fig. 1, the power module M1 includes a carrier assembly 1, at least one power device 2 (fig. 1 shows a plurality of examples), a heat spreader 3, a plurality of input/output pins 5, and an encapsulant layer 4.

A plurality of power components 2 are arranged on the carrier board assembly 1. The plurality of power elements 2 are, for example, Insulated Gate Bipolar Transistors (IGBTs), Metal-Oxide-Semiconductor Field Effect transistors (MOSFETs), or any combination thereof. The material of the power element 2 is, for example, silicon carbide, silicon or gallium nitride. In another embodiment, the power module M1 further includes a diode element connected in parallel with the power element, such as: fast forward diodes (FRD) or power diodes.

It should be noted that, in the embodiment of the present invention, the carrier board assembly 1 is used to carry the plurality of power devices 2, and also can be used as an electrical transmission structure for the plurality of power devices 2. Accordingly, the power devices 2 can be electrically connected to each other through the carrier assembly 1. The detailed structure of the carrier plate assembly 1 will be further described later.

It should be noted that the number of the power devices 2 and the electrical connection relationship thereof can be adjusted according to actual requirements, and the invention is not limited thereto. In one embodiment, when the power module M1 is applied to a voltage conversion circuit, three power elements 2 in the same row are connected in parallel. In addition, the two power devices 2 in the same row are connected in series, that is, in the two power devices in the same row, the drain of one power device is electrically connected to the source of the other power device 2 through the carrier assembly 1.

In addition, in the present embodiment, the power module M1 may further include other electronic components according to actual requirements, such as: master control elements, passive elements, protection elements, etc. The electronic components and the power components can be disposed on the carrier assembly 1 together, and are electrically connected to the power components through the carrier assembly 1 to form a part of the standardized circuit.

The heat dissipation plate 3 is disposed on the power devices 2 for dissipating heat generated by the power devices 2 during operation. In an embodiment, the heat dissipation plate 3 is, for example, a Copper-clad ceramic substrate (DBC) or a Direct Plated Copper ceramic substrate (DPC), but the invention is not limited thereto.

A plurality of i/o pins 5 are disposed on one side of the carrier assembly 1, so that the power module M1 can be electrically connected to another external circuit. A plurality of input/output pins 5 may be defined for outputting a variety of different signals.

The encapsulant layer 4 covers the carrier assembly 1 and the plurality of power devices 2. However, the connecting portions (not numbered) of the lead frame 12 and the plurality of input/output pins 5 are exposed outside the encapsulant layer 4. That is, when the power module M1 is disposed on another main control circuit board (not shown), the power devices 2 and other electronic devices in the power module M1 can be electrically connected to the system circuit of the main control circuit board by disposing the input/output pins 5 of the power module M1 and the connecting portion of the lead frame 12 corresponding to a specific position on the main control circuit board.

The detailed structure of the carrier board assembly 1 and the electrical connection relationship between the carrier board assembly 1 and the plurality of power devices 2 according to the embodiment of the invention are further described below. In the present embodiment, a part of the circuit forming the voltage conversion system circuit is taken as an example for explanation.

Referring to fig. 2 and fig. 3, the carrier assembly 1 includes a bottom plate 10, a circuit board 11, a lead frame 12, and at least one pad set (a plurality of pads are shown).

The base plate 10 has a supporting surface 10a and a bottom surface 10b opposite to the supporting surface 10 a. In one embodiment, the base plate 10 is actually a circuit board, and a plurality of circuits (not shown) are disposed on the surface (the carrying surface 10a or the bottom surface 10b) and inside the base plate 10.

Accordingly, other components may be provided on the board 10 depending on the actual circuit. Referring to fig. 3, in the present embodiment, the power module M1 further includes a control element C1, and the control element C1 is disposed on the bottom surface 10b of the bottom plate 10.

In addition, the bottom plate 10 has at least one slot 10h (two slots are shown as an example). As shown in fig. 2, the slot 10h extends from one side of the base plate 10 toward the other side. The slot 10h of the present embodiment has an open end (not numbered) and a closed end (not numbered).

It is worth noting that the bottom plate 10 having the slot 10h can provide the power module M1 with a high voltage withstanding capability. In one embodiment, the power module M1 has a withstand voltage of at least 600V by providing the slot 10h in the base plate 10.

The circuit board 11 and the lead frame 12 are disposed on the carrying surface 10a of the base plate 10. In the present embodiment, the shape of the circuit board 11 and the shape of the lead frame 12 are matched to each other to be commonly disposed on the base plate 10. It should be noted that the circuit board 11 is a multilayer board including a plurality of insulating layers and wiring layers stacked alternately. In addition, each circuit layer of the circuit board 11 may be laid out according to an actual circuit, and the present invention is not limited thereto.

As shown in fig. 2 and fig. 3, in the present embodiment, the circuit board 11 includes a device installation portion 110 and at least one extension portion 111. The component placement portion 110 can be used to place one or more other electronic components, such as a control component, a protection component, or a passive component. Therefore, the pattern of the wiring layer located inside or on the surface of the circuit board 11 can be changed according to the electronic component to be disposed.

Thus, the power module M1 according to the embodiment of the present invention can be applied to form various normalized circuits, and has a larger expansion (expansion) of components. In another embodiment, the control component C1 may be disposed on the component disposing part 110 of the circuit board 11 instead of on the bottom surface 10b of the base plate 10. In yet another embodiment, the control component C1 is disposed on the bottom surface 10b of the base plate 10, and the protection component or the passive component can be disposed on the component disposing part 110.

When the circuit board 11 is disposed on the base plate 10, the component arrangement portion 110 is disposed on the base plate 10 adjacent to the closed end of the slot 10h, but does not overlap the slot 10 h. That is, the element setting portion 110 does not shield the slot 10 h.

As shown in fig. 2 and 3, the circuit board 11 further includes two extending portions 111. The two extending portions 111 extend from the same side of the element-disposing portion 110 in substantially the same direction. In the present embodiment, each of the extending portions 111 extends from the closed end of the slot 10h toward the open end.

In addition, when the circuit board 11 is disposed on the carrying surface 10a, the two extending portions 111 are disposed adjacent to the two slots 10h of the base plate 10, respectively. It is noted that, in one embodiment, the position of each extension 111 is offset from the position of the slot 10 h.

The lead frame 12 has a shape corresponding to the shape of the circuit board 11 and includes a plurality of conductive portions separated from each other and electrically insulated from each other. In detail, as shown in fig. 2 and 3, the lead frame 12 includes a first conductive portion 120, a second conductive portion 121 and a third conductive portion 122 separated from each other, and the second conductive portion 121 is located between the first conductive portion 120 and the third conductive portion 122.

In the present embodiment, one of the extending portions 111 of the circuit board 11 is embedded between the first conductive portion 120 and the second conductive portion 121, and the other of the extending portions 111 is embedded between the second conductive portion 121 and the third conductive portion 122.

Referring to fig. 2 to 5, further, the first conductive portion 120 and the second conductive portion 121 are separated from each other to define a bar-shaped opening 12 h. The second conductive portion 121 and the third conductive portion 122 are separated from each other to define another strip-shaped opening 12 h. In addition, the two extending portions 111 are substantially in the shape of a long bar in a plan view, and are respectively located in the two bar-shaped openings 12h defined by the first conductive portion 120, the second conductive portion 121, and the third conductive portion 122.

In the present embodiment, the width W2 of each strip-shaped opening 12h is greater than the width W1 of each slot 10 h. In addition, when the lead frame 12 is disposed on the bottom plate 10, each of the strip-shaped openings 12h overlaps the slot 10h up and down and communicates with each other.

As shown in fig. 5, the extension 111 of the circuit board 11 is located in the strip-shaped opening 12h, and the extension 111 is disposed on the bottom plate 10 substantially parallel to one side of the slot 10 h. In other words, the extension 111 does not cover the slot 10h, so that the power module M1 can have a higher withstand voltage. In one embodiment, the width W2 of the strip-shaped opening 12h is greater than the sum of the width of the extension 111 and the width W1 of the slot 10h, so as to prevent the slot 10h from being covered by the extension 111 or the lead frame 12.

Referring to fig. 4 and 5, the upper surface of the lead frame 12 and the upper surface of the extension portion 111 are aligned. Specifically, the upper surface 120s of the first conductive portion 120, the upper surface 121s of the second conductive portion 121, and the upper surface 122s of the third conductive portion 122 are coplanar with the upper surfaces 111s of the two extending portions 111.

Referring to fig. 2 and 3, at least one pad set (a plurality of pad sets are shown as an example) is disposed on the circuit board 11 and the lead frame 12. Further, the number of pad groups may be set according to the number of elements (power elements 2 or diode elements) to be set.

In addition, each pad group may include a plurality of pads. The number of the bonding pads may be determined according to the type of the device to be disposed on the carrier assembly 1. In one embodiment, the device to be disposed on the carrier assembly 1 is a power device, and thus the pad set includes a first pad P1, a second pad P2 and a third pad P3. In another embodiment, when the device to be disposed on the carrier assembly 1 is a diode device, the bonding pad set may include only an anode bonding pad and a cathode bonding pad. The aforementioned diode element is, for example, a fast forward diode (FRD) or a power diode.

In addition, the position of each pad group defines the position where each power element 2 is to be disposed. Referring to fig. 2, a first pad P1 of one (left) pad set is disposed on the extension portion 111 of the circuit board 11, and a second pad P2 and a third pad P3 are disposed on the first conductive portion 120 and the second conductive portion 121, respectively. The first pad P1 of the other (right-side) pad set is disposed on the other extension portion 111 of the circuit board 11, and the second pad P2 and the third pad P3 are disposed on the second conductive portion 121 and the third conductive portion 122, respectively.

Referring to fig. 3, in the present embodiment, each power device 2 has an assembly side 2a and a back side 2b opposite to the assembly side 2 a. Each power device 2 further has a gate 21, a drain 23 and a source 22 on the assembly side 2 a. The gate 21 is located between the drain 23 and the source 22.

Please refer to fig. 6 and fig. 7. Fig. 6 is a schematic sectional view taken along line VI-VI in fig. 1, and fig. 7 is a partially enlarged schematic view of region VII in fig. 6. When the power device 2 is disposed on the carrier assembly 1, the assembly side 2a faces the lead frame 12 and the circuit board 11. Accordingly, the gate 21, the source 22 and the drain 23 are connected to the first pad P1, the second pad P2 and the third pad P3, respectively.

That is, the gate 21 of the power device 2 can be electrically connected to the chassis 10 or the control device C1 on the circuit board 11 through the circuit board 11. The power element 2 can be controlled to be turned on or off by the control element C1.

In addition, the source 22 and the drain 23 of one of the power devices 2 are electrically connected to the first conductive portion 120 and the second conductive portion 121 (or the second conductive portion 121 and the third conductive portion 122) of the leadframe 12, respectively. Accordingly, when the power device 2 is turned on and a voltage difference is applied to the first conductive part 120 and the second conductive part 121, most of the current can flow from the first conductive part 120 to the second conductive part 121 through the power device 2.

In addition, in the present embodiment, the lead frame 12 and the circuit board 11 are disposed such that a plurality of power devices 2 (3 power devices shown in fig. 2) disposed along the same extension portion 111 are connected in parallel. In addition, the two power devices 2 electrically connected to the two extending portions 111 are connected in series.

As shown in fig. 6, the drain 23 of one (left) power device 2 is connected to the third pad P3 on the second conductive part 121, and the source 22 of the other (right) power device 2 is also connected to the second pad P2 on the second conductive part 121. That is, one (left side) power element 2 is disposed on the first conductive part 120, the second conductive part 121 and the extension part 111 between the first conductive part 120 and the second conductive part 121 through one pad set.

The other (right side) power element 2 is disposed on the second conductive part 121, the third conductive part 122 and the extension part 111 between the second conductive part 121 and the third conductive part 122 through another pad group. Accordingly, the drain 23 of one of the power devices 2 can be electrically connected to the source 22 of the other power device 2 through the second conductive portion 121, so that the left and right power devices 2 are connected in series.

It should be noted that since the lead frame 12 is electrically connected to the drain 23 and the source 22 of the power device 2 in the power module M1 of the present invention, the power module M1 can withstand a large surge current. In one embodiment, the power module M1 may withstand a current of at least 300 amps.

In the conventional power module, the power element is disposed only on the circuit board, and thus the conventional power module can withstand only 50 to 70 amperes of current. In contrast, in the carrier board assembly 1 of the power module M1 provided in the embodiment of the invention, the lead frame 12 is combined with the circuit board 11 to allow a larger current to pass through in cooperation with the operation of the power device 2. In addition, the lead frame 12 may further dissipate heat generated by the power module M1 during operation.

In another embodiment, the power module M1 may also include at least one diode device, and the anode and the cathode of the diode device respectively replace one of the power devices 2 with a diode device, so that the power device 2 and the diode device may be electrically connected through the lead frame 12.

Please refer to fig. 8 and fig. 9. Fig. 8 is a schematic perspective view of a power module without a heat sink and a packaging adhesive layer according to a second embodiment of the invention. Fig. 9 is a top view schematic diagram of the power module of fig. 8.

In the embodiment of fig. 8, the circuit board 11 'may have only one extending portion 111, and the lead frame 12' has only the first conductive portion 120 and the second conductive portion 121 separated from each other. That is, the number of the extending portions 111 is not limited in the present invention as long as the shape of the lead frame 12 and the shape of the extending portion 111 of the circuit board 11 can be matched, and the upper surface of the lead frame 12 (including the upper surface 120s of the first conductive portion 120 and the upper surface 121s of the second conductive portion 121) and the upper surface of the extending portion 111 are coplanar or aligned.

In addition, in the embodiment, the power module M1 further includes a diode element 6, and two electrodes of the diode element 6 are electrically connected to the first conductive part 120 and the second conductive part 121, respectively. Accordingly, the two electrodes of the diode element 6 can be electrically connected to the drain 23 and the source 22 of the power element 2 through the first conductive part 120 and the second conductive part 121, respectively. It should be noted that, in the present embodiment, the diode element 6 does not need to be electrically connected to the pad disposed on the extension portion 111.

[ advantageous effects of the embodiments ]

One of the advantages of the power module and the carrier board assembly thereof provided by the present invention is that the power module M1 can satisfy the requirements of high voltage resistance and large current and has good heat dissipation capability through the technical scheme that the extension portion 111 of the circuit board 11, 11 'is embedded between the first conductive portion 120 and the second conductive portion 121 (or the second conductive portion 121 and the third conductive portion 122) and the technical scheme that the upper surfaces of the lead frames 12, 12' and the upper surface 111s of the extension portion 111 are cut and aligned.

Furthermore, in the carrier assembly 1 according to the embodiment of the invention, the circuit boards 11 and 11 ' are combined with the lead frames 12 and 12 ', wherein the lead frames 12 and 12 ' can increase the current passing path, allow large current to pass through, and have good heat dissipation capability. In addition, the slot 10h of the bottom plate 10 is overlapped with the strip-shaped opening 12h of the lead frame 12, 12', so that the voltage resistance of the power module M1 can be increased.

On the other hand, the bottom surface 10b of the base plate 10 and the component mounting portion 110 of the circuit boards 11 and 11 'can be used for mounting other electronic components such as control components, protection components, passive components, etc. according to actual requirements, and the circuit layers in the base plate 10 and the circuit boards 11 and 11' can also be changed according to the components to be mounted. In this way, the component expandability of the power module M1 can be increased.

It should be noted that in the carrier assembly 1 of the present embodiment, the upper surface 111s of the extension portion 111 is aligned with the upper surfaces of the lead frames 12 and 12'. Therefore, the power device 2 or the diode device 6 can be directly soldered on the carrier assembly 1 by Surface Mount Technology (SMT) without a wire bonding process, thereby further reducing the manufacturing complexity.

The disclosure is only a preferred embodiment of the invention and should not be taken as limiting the scope of the invention, so that the invention is not limited by the disclosure of the invention.

Claims

1. A power module, characterized in that the power module comprises:

a carrier assembly, comprising:

a base plate;

the circuit board is arranged on a bearing surface of the bottom plate and comprises an element arranging part and an extending part, wherein the extending part extends from one side of the element arranging part;

the lead frame is arranged on the bottom plate and at least comprises a first conductive part and a second conductive part which are electrically insulated with each other, wherein the extension part of the circuit board is embedded between the first conductive part and the second conductive part, and the upper surface of the lead frame and the upper surface of the extension part are cut to be even; and

a pad set including a first pad, a second pad and a third pad, wherein the first pad is disposed on the extension portion, and the second pad and the third pad are disposed on the first conductive portion and the second conductive portion, respectively; and

and the power element is arranged on the carrier plate assembly through the welding pad group.

2. The power module of claim 1, wherein the first conductive portion and the second conductive portion are separated from each other to define a strip-shaped opening, and the extension portion is located in the strip-shaped opening.

3. The power module of claim 2 wherein said base plate has at least one slot, said slot having a width less than a width of said strip opening, said strip opening overlapping said slot, and said extension being offset from said slot.

4. The power module of claim 1, wherein at least one of the power devices has an assembly side, and a gate, a drain and a source disposed on the assembly side, the power device is disposed on the carrier assembly with the assembly side facing the leadframe and the circuit board, and the gate, the source and the drain are respectively connected to the first pad, the second pad and the third pad.

5. The power module of claim 1, wherein the power module further comprises: and the heat dissipation plate is arranged on at least one power element.

6. The power module of claim 1, wherein the power module further comprises: and the control element is arranged on the element arranging part or on one bottom surface of the bottom plate, wherein the control element is electrically connected with at least one power element through the circuit board.

7. The power module of claim 1, wherein the power module further comprises: and the diode element is arranged on the carrier plate assembly and is electrically connected with at least one power element through the first conductive part and the second conductive part.

8. A power module, characterized in that the power module comprises:

a carrier assembly, comprising:

a base plate;

the circuit board is arranged on a bearing surface of the bottom plate and comprises an element arranging part and two extending parts, and the two extending parts extend from the same side of the element arranging part;

the lead frame is arranged on the bottom plate and at least comprises a first conductive part, a second conductive part and a third conductive part which are separated from each other and electrically insulated, wherein the first conductive part and the third conductive part are respectively positioned at two opposite sides of the second conductive part;

one of the extension portions is located between the first conductive portion and the second conductive portion, the other extension portion is located between the second conductive portion and the third conductive portion, and the upper surface of the lead frame and the upper surfaces of the two extension portions are aligned; and

two pad groups, each pad group including a first pad, a second pad and a third pad, wherein the first to third pads of one pad group are respectively disposed on one of the extension portion, the first conductive portion and the second conductive portion, and the first to third pads of the other pad group are respectively disposed on the other of the extension portion, the second conductive portion and the third conductive portion; and

at least two power elements, wherein one of the power elements is disposed on the first conductive part, the second conductive part and the extension part between the first conductive part and the second conductive part through one of the pad sets, and the other of the power elements is disposed on the second conductive part, the third conductive part and the extension part between the second conductive part and the third conductive part through the other pad set, and at least two of the power elements are connected in series with each other through the second conductive part.

9. The power module of claim 8, wherein the first conductive portion, the second conductive portion, and the third conductive portion of the leadframe are separated from each other to define two strip-shaped openings, and the two extending portions are respectively located in the two strip-shaped openings.

10. The power module of claim 8 wherein said base plate has at least two slots, each of said slots having a width less than a width of a corresponding said strip opening, said strip openings overlapping said slots one another, and said extensions being offset from said slots.

11. The power module of claim 8, wherein the power module further comprises: and the control element is arranged on the element arranging part or on one bottom surface of the bottom plate, wherein the control element is electrically connected with at least one power element through the circuit board.