CN220856573U - IGBT power module packaging structure capable of protecting diode chip in lap joint mode - Google Patents

Abstract

The utility model discloses an IGBT power module packaging structure of a lap joint type protectable diode chip, which comprises a conducting strip, a diode chip, an IGBT chip and a CLIP connecting piece, wherein the conducting strip comprises a first conducting strip and a second conducting strip, a C electrode of the IGBT chip and a negative electrode of the diode chip are welded on the first conducting strip, the CLIP connecting piece comprises a first CLIP connecting piece and a second CLIP connecting piece, the first CLIP connecting piece comprises a first welding piece and an E-electrode welding piece welded on an E-electrode of the IGBT chip, the second CLIP connecting piece comprises a second welding piece and a third welding piece welded on the second conducting strip, one of the first welding piece and the second welding piece is welded on a positive electrode of the diode chip and forms a lap joint welding area, the welding area is welded on the lap joint welding area, the first CLIP connecting piece and the second CLIP connecting piece are electrically connected together, and the current of the E-electrode of the IGBT chip is sequentially connected to the second conducting strip along the first CLIP connecting piece and the second CLIP connecting piece, so that the diode positive electrode is prevented from being damaged by high current.

Description

IGBT power module packaging structure capable of protecting diode chip in lap joint mode

Technical Field

The present utility model relates to semiconductor packages, and more particularly to IGBT power module packages.

Background

IGBT (Insulated Gate Bipolar Transistor) an insulated gate bipolar Transistor is a composite fully-controlled voltage-driven power semiconductor device consisting of a (Bipolar Junction Transistor, BJT) bipolar Transistor and an insulated gate field effect Transistor (Metal Oxide Semiconductor, MOS), and has the advantages of high input impedance of a (Metal-Oxide-Semiconductor Field-Effect Transistor, MOSFET) Metal Oxide semiconductor field effect Transistor and low on-state voltage drop of a power Transistor (Giant Transistor, GTR).

The IGBT module generally includes a plurality of IGBT subunits, each IGBT subunit including an IGBT chip and a diode chip, and the package structure of the IGBT module generally includes a heat dissipation substrate, conductive sheets laid on the heat dissipation substrate, the IGBT chips and the diode chips soldered on the conductive sheets, and a bonding wire or CLIP structure electrically connected between the IGBT chips, the diode chips, and the conductive sheets.

For example, in the conventional IGBT module, the CLIP structure is used as an electrical connection structure between the IGBT chip, the diode chip, and the conductive sheet because the bonding wire is easily subjected to a cold joint, an excessive current, and a slight welding point. Referring to chinese patent CN215496708U, an IGBT device based on a CLIP structure is disclosed, in which there are two copper CLIPs, one copper CLIP electrically connects the control electrode of the IGBT chip and a control electrode pin, and the other copper CLIP electrically connects the emitter of the IGBT chip, the anode of the diode chip and three soldered points of the emitter pin together. The heights of the emitter of the IGBT chip, the anode of the diode chip and the emitter pin are difficult to be completely consistent, and the actual height is difficult to be completely matched with the copper CLIP, so that the copper CLIP is easily welded, and the problems of cold joint, unstable welding or cracking of the welding point caused by overlarge stress on the copper CLIP when the copper CLIP is used for a long time are extremely easy to occur. For this reason, in chinese patent CN116469878a, an IGBT module package structure is disclosed, in which an emitter of an IGBT chip and a positive electrode of a diode chip are electrically connected together by welding a first conductive bridge, and a positive electrode of a diode chip and a conductive sheet are electrically connected together by welding a second conductive bridge, in which an emitter of an IGBT chip and a positive electrode of a diode chip, a positive electrode of a diode chip and a conductive sheet are welded together by two conductive bridges, respectively, and the welding is performed in a segment, so that the problem that the effect of welding is poor is not easily caused by three-point welding is solved, however, a main current of an IGBT module needs to flow from a collector of an IGBT chip to an emitter of an IGBT chip to a first conductive bridge to a positive electrode of a diode chip to a second conductive bridge to a conductive sheet, a current path often flows through a large current, and a metal material used on the positive electrode of a diode chip is very thin, and a distance between the welding point of the first conductive bridge and the positive electrode of the diode chip to the welding point of the second conductive bridge is relatively long, even if the area between the two electrodes is large, the area of the welding point is easy to cause the local power of the IGBT module to be burned due to the characteristic that the current flows, and the whole power of the IGBT module is very long, and the life of the IGBT module is still very easy to be burned.

Therefore, there is an urgent need for an IGBT power module package structure that can solve the above-mentioned problems.

Disclosure of utility model

The utility model aims to provide an IGBT power module packaging structure capable of protecting a diode chip in a lap joint mode, wherein an E pole of the IGBT chip, a positive electrode of the diode chip and a conducting plate are welded sequentially through two CLIP connectors, and one adjacent ends of the two CLIP connectors are lap-jointed together, so that current output by the E pole of the IGBT chip can be directly transmitted to the conducting plate without passing through the positive electrode of the diode chip, and the metal damage of the positive electrode of the diode chip is prevented.

In order to achieve the above object, the present utility model discloses an IGBT power module packaging structure of a lap-joint protectable diode chip, comprising one or more IGBT units, each of the IGBT units comprising a conductive sheet, a diode chip, an IGBT chip, and a CLIP connection member, the conductive sheet comprising a first conductive sheet, a second conductive sheet, a C electrode of the IGBT chip and a negative electrode of the diode chip being welded to the first conductive sheet, the CLIP connection member comprising a first CLIP connection member and a second CLIP connection member, the first CLIP connection member comprising a first welding sheet and a E-electrode welding sheet welded to an E-electrode of the IGBT chip, the second CLIP connection member comprising a second welding sheet and a third welding sheet welded to the second conductive sheet, one of the first welding sheet and the second welding sheet being welded to a positive electrode of the diode chip and forming a lap-joint region, the other of the first welding sheet and the second welding sheet being carried by and welded to one of the first CLIP connection member and the second CLIP connection member, the second CLIP connection member being connected to the second CLIP connection member in sequence along the lap-joint.

Preferably, the first welding sheet is larger than the second welding sheet, the first welding sheet is matched with the positive electrode of the diode chip in shape and size and welded on the positive electrode of the diode chip, and the second welding sheet is welded on one corner or the middle of one side, close to the second conductive sheet, of the first welding sheet in a bearing manner. When the IGBT is turned off, the follow current flows from the E pole of the IGBT chip to the positive electrode of the diode chip, so that the first welding tab and the positive electrode of the diode chip are directly welded together, and continuous current transmission is facilitated. Because the IGBT chip generates heat more, the width of the first CLIP connection sheet can be set wider, heat dissipation is facilitated, and the first welding sheet is matched with the positive electrode of the diode chip in shape and size, so that the positive electrode of the diode chip is also effectively protected.

Preferably, the first welding piece is smaller than the second welding piece, the second welding piece is matched with the positive electrode of the diode chip in shape and size and welded on the positive electrode of the diode chip, and the first welding piece is welded on one corner or the middle of one side, close to the IGBT chip, of the second welding piece in a bearing mode. Since the diode chip is generally slightly higher than the IGBT chip, which is higher than the conductive sheet, the diode chip will

Preferably, the lap welding area is provided with a first soldering tin hole penetrating through, and the first welding sheet or the second welding sheet welded on the lap welding area is provided with a second soldering tin hole communicated with or staggered from the first soldering tin hole.

Preferably, the first welding tab and the second welding tab are square.

Preferably, the first CLIP connector further comprises a first connecting piece connecting the first welding piece and the E-pole welding piece, and the first connecting piece is vertically higher than the first welding piece and the E-pole welding piece.

Specifically, the E-pole welding piece is U-shaped, and is provided with two U-shaped arms, the tail ends of the two U-shaped arms extend to one end of the E-pole of the IGBT chip, which is far away from the diode chip, and the front end of the U-shaped arm extends to the middle of the IGBT chip so as to form a clearance groove exposing the G pole of the IGBT chip between the two U-shaped arms.

Specifically, the first connection tab has a width wider than the first welding tab and the E-pole welding tab.

Preferably, the CLIP connecting piece includes a welding part at two ends and a connecting piece connecting the welding parts at two ends together, the connecting piece is higher than the welding parts at two ends, and the connecting piece is a flat piece, and two opposite sides of the connecting piece respectively form at least two positioning protruding points with opposite positions outwards.

Preferably, the conductive sheet further comprises a third conductive sheet, and the CLIP connector further comprises a third CLIP connector welded between the G-pole of the IGBT chip and the third conductive sheet.

Preferably, the CLIP connector further comprises a plurality of unit connection bridges, and the first conductive sheet of one IGBT unit and the second conductive sheet of the other IGBT unit are electrically connected together through one or more unit connection bridges.

Compared with the prior art, the E pole of the IGBT chip, the positive electrode of the diode chip and the conducting strip are welded sequentially through the two CLIP connectors, and one ends, close to the two CLIP connectors, of the E pole of the IGBT chip are lapped together, so that the current output by the E pole of the IGBT chip can be directly transmitted to the conducting strip without passing through the positive electrode of the diode chip, and the metal damage of the positive electrode of the diode chip is prevented.

Drawings

Fig. 1 is a structural diagram of an IGBT power module package of the utility model.

Fig. 2 is an enlarged view of the portion a in fig. 1.

Fig. 3 is a partial cross-sectional view of an IGBT power module package of the utility model.

Fig. 4 is an enlarged view of the portion b in fig. 3.

Fig. 5 is an enlarged partial cross-sectional view of an IGBT power module package in a preferred embodiment.

Fig. 6 is a partial cross-sectional view of an IGBT power module package in another preferred embodiment.

Detailed Description

In order to describe the technical content, the constructional features, the achieved objects and effects of the present utility model in detail, the following description is made in connection with the embodiments and the accompanying drawings.

Referring to fig. 1 to 3, the present utility model discloses an IGBT power module package structure 100 including a heat dissipation plate 10, at least one IGBT unit mounted on the heat dissipation plate 10, each of the IGBT unit including a conductive sheet laid on the heat dissipation plate, an IGBT chip 200 and a diode chip 300 welded on the conductive sheet, and a CLIP connection electrically connecting an electrode of the IGBT chip 200 and an electrode of the diode chip 300, the conductive sheet including a first conductive sheet 21 and a second conductive sheet 22, a C electrode of the IGBT chip 200 and a negative electrode of the diode chip 300 being welded on the first conductive sheet 21, the CLIP connection including a first CLIP connection 31 welded between an E electrode of the IGBT chip 200 and an electrode of the diode chip 300, and a second CLIP connection 32 welded between a positive electrode of the diode chip 300 and the second conductive sheet 22.

Referring to fig. 1 to 4, the first CLIP connector 31 includes a first bonding pad 311 and an E-electrode bonding pad 312 bonded to the E-electrode of the IGBT chip, the second CLIP connector 32 includes a second bonding pad 321 and a third bonding pad 322 bonded to the second conductive pad 32, the first bonding pad 311 is bonded to the positive electrode of the diode chip and forms a bonding pad, the second bonding pad 312 is bonded to the bonding pad of the first bonding pad 311, the first CLIP connector 31 and the second CLIP connector 32 are electrically connected together, and the current of the E-electrode of the IGBT chip 200 sequentially flows along the first CLIP connector 31 and the second CLIP connector 32 to the second conductive pad 22, so that the current flowing between the C-electrode and the E-electrode on the IGBT chip can quickly and smoothly bypass the metal layer of the positive electrode of the diode chip 300 to the second conductive pad 22.

Referring to fig. 1 to 4, in the present embodiment, the first bonding pad 311 is larger than the second bonding pad 321, the first bonding pad 311 is matched with the shape and size of the positive electrode of the diode chip 300 and is welded to the positive electrode of the diode chip 300, and the second bonding pad 321 is welded to a corner of one side of the first bonding pad 311 adjacent to the second conductive pad 22. Of course, the second bonding pad 321 may be welded to the middle of the side of the first bonding pad 311 adjacent to the second conductive pad 22.

In this embodiment, the first bonding pad 311 and the second bonding pad 321 are both square, however, the first bonding pad 311 and the second bonding pad 321 may be other shapes, and the shapes of the first bonding pad 311 and the second bonding pad 321 may be the same or different.

Referring to fig. 4, a first bonding pad 311 is bonded to the positive electrode of the diode chip 300 through the solder paste layer 302, and a second bonding pad 311 is bonded to the first bonding pad 311 through the solder paste layer 303.

Preferably, referring to fig. 5, the first bonding pad 311 is provided with a first solder hole 304 penetrating through the bonding pad, the second bonding pad 321 welded on the bonding pad is provided with a second solder hole 305 communicating with or staggered from the first solder hole 304, when the first bonding pad 311 is welded on the positive electrode of the diode chip 300 through the solder paste layer 302, part of the solder fills the first solder hole 304, when the second bonding pad 321 is welded on the first bonding pad 311 through the solder paste layer 303, part of the solder fills the second solder hole 305, so that the solder paste layer 302 and the solder paste layer 303 are connected into a whole through the first solder hole 304 at this time, the structure is stable, and the second bonding pad 321 and the first bonding pad 311 are firmly connected through the solder filled in the second bonding hole 305. In this embodiment, the second welding holes 305 are round holes, square holes or bar-shaped holes, and one or more second welding holes 305 may be provided, and a plurality of second welding holes 305 are uniformly provided on the second welding tab 321. The first welding holes 304 may be circular holes, square holes, or bar-shaped holes, and the second welding holes 304 may be one or more, and the plurality of first welding holes 304 may be uniformly provided throughout the first welding tab 311.

Referring to fig. 1 and 2, the first CLIP connection member 31 includes a first bonding pad 311 bonded to the diode chip 300, an E-pole bonding pad 312 bonded to the E-pole of the IGBT chip 200, and a first connection pad 313 connecting the first bonding pad 311 and the E-pole bonding pad 312, the first connection pad 313 being vertically higher than the first bonding pad 311 and the E-pole bonding pad 312.

Referring to fig. 1 and 2, the E-pole soldering tab 312 has two U-shaped arms, the ends of the two U-shaped arms extend to the end of the E-pole of the IGBT chip 200 away from the diode chip 300, and the front end of the U-shaped arm extends to the middle of the IGBT chip 200 to form a void-avoidance groove 314 exposing the G-pole of the IGBT chip 200 between the two U-shaped arms. Specifically, the width of the first connecting piece 313 is wider than the width of the first welding piece 311 and the width of the E-pole welding piece 312, so that the first connecting piece can be conveniently grasped and positioned.

Referring to fig. 2 and fig. 4, two opposite side edges of the first connecting piece 313 form at least two positioning protruding points 301 with opposite positions outwards, and the two positioning protruding points 301 are not only convenient for positioning when the first CLIP connecting piece 31 is punched, but also convenient for a corresponding manipulator to accurately position the first CLIP connecting piece 31 when the first CLIP connecting piece 31 is welded, so that the positioning accuracy of the first CLIP connecting piece 31 is ensured, and the welding effect is increased.

Referring to fig. 2 and 4, the second CLIP connection member 32 includes a second bonding pad 321 bonded to the positive electrode of the diode chip 300, a first bonding pad 322 bonded to the second conductive pad 22, and a second connection pad 323 connecting the second bonding pad 321 and the first bonding pad 322. Wherein two opposite side edges of the second connecting piece 323 are formed with at least two positioning protruding points 301 opposite to each other.

Referring to fig. 1 to 4, the conductive sheet further includes a third conductive sheet 23, and the CLIP connection further includes a third CLIP connection 33 welded between the G-pole of the IGBT chip 200 and the third conductive sheet 23. The third CLIP connection member 33 includes a G-pole bonding pad 331 electrically connected to the G-pole of the IGBT chip 200, a second bonding pad 332 bonded to the third conductive pad 23, and a third connection pad 333 connecting the G-pole bonding pad 331 and the second bonding pad 332 together, the third connection pad 333 having a height higher than the G-pole bonding pad 331 and the second bonding pad 332, and two opposite side edges of the third connection pad 333 forming at least two positioning bumps 301 facing each other.

Referring to fig. 1 and 3, the CLIP connection further includes a cell connection bridge 34, and a plurality of IGBT cells, and among two of the IGBT cells, a first conductive tab 21 of one IGBT cell and a second conductive tab 22 of the other IGBT cell are electrically connected together by one or more cell connection bridges 34. When the first conductive sheet 21 of one IGBT cell and the second conductive sheet 22 of the other IGBT cell are electrically connected together by a plurality of cell connection bridges 34, the plurality of cell connection bridges 34 are arranged at intervals.

Referring to fig. 1 and 3, the CLIP connector further includes a terminal connection bridge 35, the conductive sheet includes a signal conductive sheet 24 to which a signal terminal is soldered, and the terminal connection bridge 35 is soldered between the signal conductive sheet 24 and a corresponding conductive sheet.

The CLIP connectors in this embodiment all include a welding portion at two ends and a connecting piece connecting the welding portions at the two ends together, the connecting piece is higher than the welding portions at the two ends, and the connecting piece is a flat piece, and two opposite sides of the connecting piece respectively form at least two positioning protruding points 301 with opposite positions outwards.

Referring to fig. 6, in another embodiment, unlike the above embodiment, the second bonding pad 312a is bonded to the positive electrode of the diode chip 300 and forms a bonding pad, and the first bonding pad 311a is bonded to the bonding pad of the second bonding pad 312, so that the first CLIP connector 31 and the second CLIP connector 32 are electrically connected together, and the current of the E-electrode of the IGBT chip 200 sequentially flows along the first CLIP connector 31 and the second CLIP connector 32 to the second conductive sheet 22, so that the current passing through the path between the C-electrode and the E-electrode on the IGBT chip can quickly and smoothly bypass the metal layer of the positive electrode of the diode chip 300 to reach the second conductive sheet 22. The first bonding pad 311a is smaller than the second bonding pad 321a, the second bonding pad 321a is matched with the positive electrode of the diode chip 300 in shape and size and is bonded to the positive electrode of the diode chip 300, and the first bonding pad 311a is welded to a corner or the middle of one side, adjacent to the IGBT chip 200, of the second bonding pad 321a in a bearing manner.

The first bonding pad 311 is soldered to the positive electrode of the diode chip 300 through a solder paste layer, and the second bonding pad 311 is soldered to the first bonding pad 311 through a solder paste layer.

Preferably, the second soldering tab 321a has a first solder hole penetrating through the bonding pad, the first soldering tab 311 soldered to the bonding pad has a second solder hole communicating with or staggered from the first solder hole, when the second soldering tab 321a is soldered to the positive electrode of the diode chip 300 through the solder paste layer, a part of the solder fills the first solder hole, and when the first soldering tab 311 is soldered to the second soldering tab 321a through the solder paste layer, a part of the solder fills the second solder hole, so that the second soldering tab 321a is firmly connected to the first soldering tab 311 a. In this embodiment, the second welding hole may be a round hole, a square hole or a bar hole, and one or more second welding holes may be provided. The first welding hole is a round hole, a square hole or a strip hole, and the second welding hole can be one or more.

The foregoing description of the preferred embodiments of the present utility model is not intended to limit the scope of the claims, which follow, as defined in the claims.

Claims (10)

1. The utility model provides a but overlap joint formula protection diode chip's IGBT power module packaging structure, includes one or more IGBT unit, each IGBT unit includes conducting strip, diode chip, IGBT chip and CLIP connecting piece, the conducting strip includes first conducting strip, second conducting strip, the C electrode of IGBT chip and the negative electrode welding of diode chip are in on the first conducting strip, the CLIP connecting piece includes first CLIP connecting piece and second CLIP connecting piece, its characterized in that: the first CLIP connecting piece comprises a first welding piece and an E-pole welding piece welded on an E pole of the IGBT chip, the second CLIP connecting piece comprises a second welding piece and a third welding piece welded on the second conducting piece, one of the first welding piece and the second welding piece is welded on a positive electrode of the diode chip and forms a lap joint welding area, the other of the first welding piece and the second welding piece is carried and welded on the lap joint welding area, so that the first CLIP connecting piece and the second CLIP connecting piece are electrically connected together, and current of the E pole of the IGBT chip sequentially flows along the first CLIP connecting piece and the second CLIP connecting piece to the second conducting piece.

2. The IGBT power module package of claim 1 wherein: the first welding sheet is larger than the second welding sheet, the first welding sheet is matched with the positive electrode of the diode chip in shape and size and welded on the positive electrode of the diode chip, and the second welding sheet is welded at one corner or the middle of one side, close to the second conductive sheet, of the first welding sheet in a bearing manner; or alternatively

The first welding sheet is smaller than the second welding sheet, the second welding sheet is matched with the positive electrode of the diode chip in shape and size and welded on the positive electrode of the diode chip, and the first welding sheet is welded on one corner or the middle of one side, close to the IGBT chip, of the second welding sheet in a bearing mode.

3. The IGBT power module package of claim 1 wherein: the lap joint welding area is provided with a first soldering tin hole which penetrates through the lap joint welding area, and the first welding sheet or the second welding sheet welded on the lap joint welding area is provided with a second soldering tin hole which is communicated with or staggered with the first soldering tin hole.

4. The IGBT power module package of claim 1 wherein: the first welding tab and the second welding tab are square.

5. The IGBT power module package of claim 1 wherein: the first CLIP connector further comprises a first connecting piece connected with the first welding piece and the E-pole welding piece, and the first connecting piece is vertically higher than the first welding piece and the E-pole welding piece.

6. The IGBT power module package of claim 5 wherein: the E-pole welding piece is U-shaped and is provided with two U-shaped arms, the tail ends of the two U-shaped arms extend to one end of the E-pole of the IGBT chip, which is far away from the diode chip, and the front end of the U-shaped arm extends to the middle of the IGBT chip so as to form a clearance groove exposing the G pole of the IGBT chip between the two U-shaped arms.

7. The IGBT power module package of claim 5 wherein: the first connecting piece is wider than the first welding piece and the E-pole welding piece.

8. The IGBT power module package of claim 1 wherein: the CLIP connecting piece comprises welding parts at two ends and connecting pieces for connecting the welding parts at two ends together, wherein the connecting pieces are higher than the welding parts at two ends, and are flat pieces, and two opposite sides of the connecting pieces respectively form at least two positioning protruding points with opposite positions outwards.

9. The IGBT power module package of claim 1 wherein: the conductive sheet further comprises a third conductive sheet, and the CLIP connector further comprises a third CLIP connector welded between the G pole of the IGBT chip and the third conductive sheet.

10. The IGBT power module package of claim 1 wherein: the CLIP connector further comprises a plurality of unit connection bridges, and the first conductive sheet of one IGBT unit and the second conductive sheet of the other IGBT unit are electrically connected together through one or more unit connection bridges in two IGBT units.