CN213816149U

CN213816149U - Silicon carbide power module structure

Info

Publication number: CN213816149U
Application number: CN202022864933.9U
Authority: CN
Inventors: 王志超
Original assignee: Huaxinwei Semiconductor Technology Beijing Co ltd
Current assignee: Huaxinwei Semiconductor Technology Beijing Co ltd
Priority date: 2020-12-03
Filing date: 2020-12-03
Publication date: 2021-07-27
Anticipated expiration: 2030-12-03

Abstract

The utility model discloses a silicon carbide power module structure, which comprises a bottom plate and a shell assembled and connected with the bottom plate; the bottom plate is provided with a copper-clad substrate, a plurality of chips are symmetrically distributed in parallel and welded on a copper-clad layer of the copper-clad substrate through a solder, and a main electrode terminal and a driving electrode terminal are welded and connected with the copper-clad layer in an ultrasonic welding mode. The multi-chip parallel symmetrical distribution mode is adopted, and the flow equalization performance is good. And meanwhile, a compact laminated busbar mode is adopted, so that the stray inductance in the whole module is reduced to about 4 nH. Meanwhile, the driving auxiliary electrode of the chip is separately led out from the surface of the chip, so that the coupling of a power loop and a driving loop is avoided, and the switching loss of a product can be reduced.

Description

Silicon carbide power module structure

Technical Field

The utility model belongs to the technical field of the semiconductor device technique and specifically relates to a carborundum power module structure is related to.

Background

Silicon carbide (SiC) is a representative of a new power semiconductor material, has the characteristics of high frequency, high temperature resistance, high voltage resistance and the like, can effectively realize high efficiency, miniaturization and light weight of a power electronic system, contributes to energy conservation of equipment and space occupation of the equipment, and has become an important choice for research on power electronic devices.

However, the stray inductance of the existing power module is usually over 10nH, and the SiC device is sensitive to the stray inductance inside the module due to its high switching speed. Higher stray inductances will affect the switching rate of the module and cause unnecessary oscillations. Adversely affecting product reliability. The auxiliary electrode for driving is directly led out from the power loop, so that the coupling problem of the driving loop and the power loop is caused, the switching loss is increased, and unnecessary oscillation is caused; and the number of parallel chips is small. In addition, the auxiliary electrode driven by the existing module is directly led out from the power loop.

The information disclosed in this background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information constitutes prior art already known to a person skilled in the art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a carborundum power module structure to solve the problem that exists among the prior art.

In order to achieve the above purpose, the utility model adopts the following technical scheme:

the utility model provides a silicon carbide power module structure, which comprises a bottom plate and a shell assembled and connected with the bottom plate; wherein the content of the first and second substances,

a copper-clad substrate is arranged on the bottom plate, a plurality of chips are symmetrically distributed in parallel and welded on a copper-clad layer of the copper-clad substrate through a solder, and a main electrode terminal and a driving electrode terminal are both connected with the copper-clad layer in a welding manner through ultrasonic welding;

the driving end grid electrodes of all the chips are electrically connected with the driving end grid electrode, the driving end source electrodes of all the chips are electrically connected with the driving end source electrode, and the driving auxiliary electrodes of all the chips are led out from the surface of the chip independently;

the drive end grid electrode and the drive end source electrode are both arranged on the copper-clad substrate, and electrode terminals of the drive end grid electrode and the drive end source electrode are both led out from the corresponding holes on the shell;

and the electrode terminals of the source electrode and the drain electrode of the silicon carbide power module structure are led out from the corresponding holes on the shell and are bent.

As a further technical scheme, 10 chips are connected in parallel on the copper-clad layer of the copper-clad substrate.

As a further technical scheme, the copper-clad substrate is connected with the bottom plate in a welding mode through welding materials.

As a further technical scheme, the chip is a SiC MOSFET chip or an IGBT chip.

As a further technical solution, the bottom plate is an aluminum silicon carbide bottom plate.

As a further technical scheme, the copper-clad substrate is an aluminum nitride substrate.

Adopt above-mentioned technical scheme, the utility model discloses following beneficial effect has:

the multi-chip parallel symmetrical distribution mode is adopted, and the flow equalization performance is good. And meanwhile, a compact laminated busbar mode is adopted, so that the stray inductance in the whole module is reduced to about 4 nH. Meanwhile, the driving auxiliary electrode of the chip is separately led out from the surface of the chip, so that the coupling of a power loop and a driving loop is avoided, and the switching loss of a product can be reduced.

Drawings

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the embodiments or the technical solutions in the prior art will be briefly described below, and it is obvious that the drawings in the following description are some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to these drawings without creative efforts.

FIG. 1 is an assembled perspective view of a silicon carbide power module structure of the present invention;

FIG. 2 is a perspective view of the bottom plate of the present invention after assembly;

FIG. 3 is an equivalent circuit diagram of a silicon carbide power module structure according to the present invention;

fig. 4 is a schematic diagram of a simulation result of stray inductance of the silicon carbide power module structure of the present invention;

FIG. 5 is a schematic view of the internal current flow of the silicon carbide power module structure of the present invention;

FIG. 6 is an equivalent circuit diagram of a prior art drive auxiliary electrode leading out of a main circuit;

fig. 7 is an equivalent circuit diagram of the present invention in which the auxiliary driving electrode is separately led out from the surface of the chip.

Detailed Description

The technical solution of the present invention will be described clearly and completely with reference to the accompanying drawings, and obviously, the described embodiments are some, but not all embodiments of the present invention. Based on the embodiments in the present invention, all other embodiments obtained by a person skilled in the art without creative work belong to the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and are only for convenience of description and simplification of description, but do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus, should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it is to be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present invention can be understood according to specific situations by those skilled in the art.

The following detailed description of the embodiments of the present invention will be made with reference to the accompanying drawings. It is to be understood that the description of the embodiments herein is for purposes of illustration and explanation only and is not intended to limit the invention.

As shown in fig. 1-3, the present embodiment provides a silicon carbide power module structure, which includes a bottom plate 1 and a housing 2 assembled and connected to the bottom plate 1; wherein the content of the first and second substances,

a copper-clad substrate 3 is arranged on the bottom plate 1, a plurality of chips 4 are symmetrically distributed in parallel and welded on a copper-clad layer of the copper-clad substrate through a solder, and a main electrode terminal and a driving electrode terminal are welded and connected with the copper-clad layer in an ultrasonic welding mode;

the grid electrodes of the driving ends of all the chips 4 are electrically connected with the grid electrode 5 of the driving end, the source electrodes of the driving ends of all the chips 4 are electrically connected with the source electrode 6 of the driving end, and the driving auxiliary electrodes of all the chips 4 are separately led out from the surfaces of the chips;

the drive end grid electrode 5 and the drive end source electrode 6 are both arranged on the copper-clad substrate 3, and electrode terminals of the drive end grid electrode and the drive end source electrode are both led out from the corresponding holes on the shell;

and the source electrode terminal 7 and the drain electrode terminal 8 of the silicon carbide power module structure are led out from the corresponding holes on the shell and are bent.

In this embodiment, as a further technical solution, 10 chips are connected in parallel on the copper-clad layer of the copper-clad substrate.

In this embodiment, as a further technical solution, the copper-clad substrate is connected to the base plate by soldering.

In this embodiment, as a further technical solution, the chip is a SiC MOSFET chip or an IGBT chip.

In this embodiment, as a further technical solution, the bottom plate is an aluminum silicon carbide bottom plate.

In this embodiment, as a further technical solution, the copper-clad substrate is an aluminum nitride substrate.

As shown in fig. 4, the stray inductance of the module of this embodiment is about 4 nH.

As shown in fig. 5, the 10 chips are uniformly and symmetrically distributed, the dotted line indicates the current flowing out from the drain terminal, and the solid line indicates the current flowing into the source terminal. It can be seen that the directions of current flowing out and current flowing in are exactly parallel and opposite, and the distances are close, and the electric fields generated by the current flowing out and current flowing in are offset to the maximum extent, so that the stray inductance inside the module is very low, and as can be seen from the simulation result in fig. 4, the stray inductance of the module in the scheme is about 4nH, which is much lower than the designed stray inductance of the current power module (generally over 10 nH).

Referring to fig. 6, in the conventional power module design, the auxiliary electrode terminal of the driving terminal is led out from the main circuit and connected to the terminal of the housing by wire bonding. Such a lead-out manner may cause the coupling L1 of the common inductance between the driving loop and the power loop (L1 in fig. 6 is a parasitic inductance common to both loops), and further cause the oscillation and loss of the driving loop to increase.

As shown in fig. 7, the present application adopts a structure form in which the driving auxiliary electrode of the chip is separately led out from the surface of the chip, so that the coupling between the power and the driving loop is avoided, and the switching loss of the module is reduced.

The main process of the application is as follows:

chip and substrate welding → wire bonding → electrode terminal ultrasonic welding → shell assembly → silicone gel encapsulation → electrode bending.

In summary, the technical scheme of the application has the following advantages:

1. the chip in the scheme can be a SiC MOSFET chip or an IGBT chip;

2. the module stray inductance of the scheme is lower, about 4 nH;

3. in the scheme, the chips are symmetrically distributed in parallel, the number of the chips in parallel is as large as 10, and high-current and high-power are formed;

4. in the scheme, the driving auxiliary electrode of the chip is led out from the surface of the chip independently, so that the coupling of a power loop and a driving loop is avoided, and the switching loss of a module can be reduced;

5. the electrode terminal of the product is welded in an ultrasonic mode, which is not a traditional welding flux welding mode, so that the reliability is higher;

6. this scheme bottom plate adopts aluminium carborundum bottom plate, and ceramic substrate adopts aluminium nitride base board, and both thermal expansion coefficient is close, and the welding face thermal stress can, and the reliability is higher.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; although the present invention has been described in detail with reference to the foregoing embodiments, it should be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; such modifications and substitutions do not depart from the spirit and scope of the present invention.

Claims

1. A silicon carbide power module structure is characterized by comprising a bottom plate and a shell assembled and connected with the bottom plate; wherein the content of the first and second substances,

2. The silicon carbide power module structure of claim 1, wherein the copper-clad layer of the copper-clad substrate is connected in parallel with 10 chips.

3. The silicon carbide power module structure of claim 1, wherein the copper-clad substrate is solder bonded to the base plate.

4. The silicon carbide power module structure of claim 1, wherein the chips are SiC MOSFET chips or IGBT chips.

5. The silicon carbide power module structure of claim 1, wherein the backplane is an aluminum silicon carbide backplane.

6. The silicon carbide power module structure of claim 1, wherein the copper-clad substrate is an aluminum nitride substrate.