CN220963348U - IGBT power module packaging structure - Google Patents

Abstract

The utility model discloses an IGBT power module packaging structure, which comprises a conducting plate, an IGBT chip, a diode chip and a CLIP connecting piece, wherein the conducting plate is paved on a radiating plate, the conducting plate comprises a first conducting plate and a second conducting plate, a C electrode of the IGBT chip and a negative electrode of the diode chip are welded on the first conducting plate, the CLIP connecting piece comprises a first CLIP connecting piece welded between an E electrode of the IGBT chip and a positive electrode of the diode chip, a second CLIP connecting piece welded between the positive electrode of the diode chip and the second conducting plate, a large welding area with a notch and a small welding area matched with the notch are formed on the positive electrode of the diode chip, the small welding area is positioned in the notch, the first CLIP connecting piece comprises a large welding tab corresponding to the large welding area and welded, the second CLIP connecting piece comprises a small welding tab corresponding to the small welding area and welded, and the small welding tab is surrounded by side edges of at least two directions of the large welding tab. The utility model can prevent the anode of the diode chip from being burnt and has long service life.

Description

IGBT power module packaging structure

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. Therefore, 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 an anode of the diode chip and a conductive sheet are electrically connected together by welding a second conductive bridge.

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, which reduces the resistance and heat generated when the metal of the positive electrode of a diode chip is used as a main current conducting sheet, effectively protects the metal layer of the positive electrode of the diode chip and prevents the metal layer from being damaged.

In order to achieve the above object, the present utility model discloses an IGBT power module packaging structure, comprising a heat dissipating plate, at least one IGBT unit mounted on the heat dissipating plate, each of the IGBT units comprising a conductive sheet laid on the heat dissipating plate, an IGBT chip, a diode chip, and a CLIP connection member, the conductive sheet comprising a first conductive sheet and 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 welded between an E electrode of the IGBT chip and a positive electrode of the diode chip, a second CLIP connection member welded between the positive electrode of the diode chip and the second conductive sheet, the positive electrode of the diode chip being formed with a large welding area having a notch and a small welding area matched with the notch, the notch of the large welding area being oriented to one side of the positive electrode of the diode chip adjacent to the second conductive sheet, the small welding area being positioned in the notch, the first CLIP connection member comprising a small welding area being welded to the large welding area and the small welding area being welded to the small welding area from the large welding area and the small welding area.

Preferably, the notch is located at a corner of the large bonding area or in the middle of the front side of the large bonding area.

Preferably, at least part of the area between the large welding sheet and the small welding sheet is provided with a gap, namely the small welding sheet is in clearance fit with the notch.

Preferably, the large welding area is a square welding area with a notch, the notch is square, and the small welding area is a square welding area.

Preferably, the first CLIP connector includes a large bonding pad welded on the large bonding area, an E-pole bonding pad welded on an E-pole of the IGBT chip, and a first connecting pad connecting the large bonding pad and the E-pole bonding pad, and the first connecting pad is straight and higher than the large bonding pad and the E-pole bonding pad.

Specifically, the E-pole welding sheet 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 connecting tab has a width wider than the large welding tab and the E-pole welding tab.

Specifically, two opposite side edges of the first connecting sheet outwards form at least two positioning protruding points with opposite positions respectively.

Preferably, the CLIP connecting piece includes the welding part that is located both ends and connects the connection piece that the welding part at both ends is in the same place, the height of connection piece is higher than both ends the height of welding part, just the connection piece is the straight piece, and its opposite side outwards forms at least two location bump that the position is relative respectively, the welding part includes big welding piece and little welding piece.

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.

According to the utility model, the current is transmitted from the E pole of the IGBT chip to the positive electrode of the diode chip through the first CLIP connecting piece and the second CLIP connecting piece respectively, and when the current flows from the metal surface of the positive electrode of the diode chip to the second conducting strip through the second CLIP connecting piece and is welded respectively through the two connecting pieces, compared with the prior art, the small welding piece of the second CLIP connecting piece of the utility model stretches into the large welding piece of the first CLIP connecting piece, so that at least two groups of side edges between the small welding piece and the large welding piece are opposite, the width of the positive electrode of the diode chip between the small welding piece and the large welding piece is increased while the length of the positive electrode of the diode chip between the small welding piece and the large welding piece is reduced, and when the current flows from the C pole to the E pole, the metal piece bearing capacity of the positive electrode of the diode chip is more, and the metal piece of the positive electrode is not easy to be damaged due to heat.

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 top view of the IGBT power module package of the utility model.

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

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 4, the present utility model discloses an IGBT power module package structure 100, comprising a heat dissipation plate 10, at least one IGBT unit 11 mounted on the heat dissipation plate 10, each IGBT unit 11 comprising 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 member electrically connecting the electrode of the IGBT chip 200 and the electrode of the diode chip 300, the conductive sheet comprising a first conductive sheet 21 and a second conductive sheet 22, the C electrode of the IGBT chip 200 and the negative electrode of the diode chip 300 being welded on the first conductive sheet 21, the CLIP connection member comprising a first CLIP connection member 31 welded between the E electrode of the IGBT chip 200 and the electrode of the diode chip 300, and a second CLIP connection member 32 welded between the positive electrode of the diode chip 300 and the second conductive sheet 22, a large welding area having a notch and a small welding area matching the notch 321 being formed on the positive electrode of the diode chip 300, the large welding area 321 being positioned on the small welding area 311 and the small welding area 311 being welded on the small welding area 311, and the small welding area being welded on the small welding area 311.

In this embodiment, at least two edges of the large bonding area are opposite to at least two edges of the small bonding area, and of course, the large bonding area may be directly connected to the small bonding area. In this embodiment, the matching between the small welding area and the notch is specifically: the shape of the small welding area is the same as that of the notch, and the size of the small welding area is in clearance fit with the notch. After the small welding piece 321 is welded on the small welding area, the small welding piece 321 can be adjacent to the large welding piece 311 in a gap manner, or can be connected with part of the edge of the large welding piece 311. The soldering tin on the large soldering area and the small soldering area can be connected together or separated from each other.

In this embodiment, the notch is located at a corner of the large bonding area, and of course, the notch may be located in the middle of the front side (the side adjacent to the second conductive sheet 22) of the large bonding area.

The large welding area is a square welding area with a notch, the notch is square, and the small welding area is a square welding area. Of course, the large welding area, the notch and the small welding area may have other shapes, and are not limited to square, and the shapes of the large welding area and the notch may be the same or different. The large bonding area and the small bonding area are respectively areas where the corresponding bonding pads of the first CLIP connector 31 and the second CLIP connector 32 on the positive electrode of the diode chip 300 are bonded, and the solder paste printing patterns are related to the areas and are not completely consistent, and a plurality of solder paste strips or other solder paste printing patterns arranged in parallel gaps can be directly printed on the large bonding area and the small bonding area respectively.

Wherein the first CLIP connection member 31 includes a large bonding pad 311 bonded on the large bonding region, an E-pole bonding pad 312 bonded on the E-pole of the IGBT chip 200, and a first connection pad 313 connecting the large bonding pad 311 and the E-pole bonding pad 312, the first connection pad 313 being straight and higher than the large bonding pad 311 and the E-pole bonding pad 312.

Specifically, 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-free 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 large welding piece 311 and the E-pole welding piece 312, so that the first connecting piece is convenient to grasp and position.

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 small welding tab 321 welded to the positive electrode of the diode chip 300, a first welding tab 322 welded to the second conductive tab, and a second connection tab 323 connecting the small welding tab 321 and the first welding tab 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 the IGBT cells 11, and among the two IGBT cells 11, the first conductive sheet 21 of one IGBT cell 11 and the second conductive sheet 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 11 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.

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 an IGBT power module packaging structure, includes the heating panel, installs at least one IGBT unit on the heating panel, every IGBT unit is including laying conducting strip, IGBT chip, diode chip and the CLIP connecting piece on the heating panel, the conducting strip includes first conducting strip and 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 including weld in first CLIP connecting piece between the E pole of IGBT chip and the positive electrode of diode chip, weld in second CLIP connecting piece between the positive electrode of diode chip and the second conducting strip, its characterized in that: the positive electrode of the diode chip is provided with a large welding area with a notch and a small welding area matched with the notch, the notch of the large welding area faces to one side, close to the second conducting strip, of the positive electrode of the diode chip, the small welding area is located in the notch, the first CLIP connecting piece comprises a large welding sheet matched with the large welding area in shape and size and welded on the large welding area, the second CLIP connecting piece comprises a small welding sheet matched with the small welding area in shape and size and welded on the small welding area, and the small welding sheet is surrounded by the large welding sheet from at least two directions.

2. The IGBT power module package of claim 1 wherein: the notch is positioned at one corner of the large welding area or in the middle of the front side of the large welding area.

3. The IGBT power module package of claim 1 wherein: at least part of the area between the large welding sheet and the small welding sheet is provided with a gap.

4. The IGBT power module package of claim 1 wherein: the large welding area is a square welding area with a notch, the notch is square, and the small welding area is a square welding area.

5. The IGBT power module package of claim 1 wherein: the first CLIP connecting piece comprises a large welding sheet welded on the large welding area, an E-pole welding sheet welded on an E pole of the IGBT chip and a first connecting sheet connected with the large welding sheet and the E-pole welding sheet, and the first connecting sheet is straight and higher than the large welding sheet and the E-pole welding sheet.

6. The IGBT power module package of claim 5 wherein: the E-pole welding sheet 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 large 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, the height of each connecting piece is higher than that of each welding part at two ends, each connecting piece is a flat piece, two opposite sides of each connecting piece respectively form at least two positioning protruding points with opposite positions outwards, and each welding part comprises a large welding piece and a small welding piece.

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.