Discrete device based on aluminum strip bonding

Abstract

The utility model provides a discrete device based on aluminum strip bonding, which relates to the technical field of semiconductor power device packaging, and comprises a heat dissipation frame, a plurality of power chips welded on the top of the heat dissipation frame, and a plurality of LED chips welded on the top of the heat dissipation frame. The power chips are electrically connected through aluminum strip bonding, and the surfaces of the power chips and the pins of the heat dissipation frame are electrically connected through aluminum strip bonding. The heat dissipation frame and the power chips are packaged in the shell, and the bottom of the heat dissipation frame and the pins are exposed out of the shell. The beneficial effects are that the power chips are electrically connected through aluminum tape bonding, and the surfaces of the power chips and the pins of the heat dissipation frame are electrically connected through aluminum tape bonding; and an ultrasonic welding technology and a bonding aluminum strip are used, so that the reliability and the overcurrent capability are greatly improved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor power device packaging, in particular to a discrete device based on aluminum ribbon bonding. Background Art

[0002] As discrete devices are increasingly used in inverters, welding, photovoltaic inverters, wind inverters and automotive fields, the requirements for current levels, output efficiency, heat dissipation and reliability of discrete devices are becoming more and more stringent.

[0003] In general discrete device packaging processes, aluminum wire bonding or copper wire bonding is generally used. Discrete devices are used in power electronic circuits and have a series of voltage and current levels to adapt to different occasions or industry applications. Aluminum wire bonding and copper wire bonding cannot meet the current carrying capacity of large currents, and the thermal expansion coefficient of semiconductor chips and the thermal expansion coefficient of bonding wires are quite different. The most common failure of discrete devices during long-term use is the separation of the bonding point from the chip surface. Therefore, in order to improve its current carrying capacity, reliability and reduce losses, some companies have used aluminum ribbon bonding in discrete devices. Utility Model Content

[0004] In view of the problems existing in the prior art, the utility model provides a discrete device based on aluminum ribbon bonding, comprising:

[0005] A heat dissipation frame, wherein a plurality of power chips are welded on the top of the heat dissipation frame, and the power chips and the surfaces of the power chips and the pins of the heat dissipation frame are electrically connected by aluminum ribbon bonding;

[0006] The shell, the heat dissipation frame and the chips are packaged inside the shell, and the bottom of the heat dissipation frame and the pins are exposed from the shell.

[0007] Preferably, the heat dissipation frame comprises:

[0008] A metal heat sink, one end of which is provided with a plurality of the pins.

[0009] Preferably, the bottom of the metal heat sink is exposed from the bottom of the housing and is flush with the bottom of the housing;

[0010] Each of the pins is exposed from one side of the housing.

[0011] Preferably, the power chip includes an insulated gate bipolar transistor chip and a diode chip;

[0012] The insulated gate bipolar transistor chip and the diode chip are welded on the top of the heat dissipation frame;

[0013] The surface of the insulated gate bipolar transistor chip and the surface of the diode chip are electrically connected via the aluminum ribbon bonding;

[0014] The surface of the insulated gate bipolar transistor chip and the surface of the diode chip are electrically connected to the pins through aluminum ribbon bonding.

[0015] Preferably, the aluminum strip is a soft aluminum strip.

[0016] Preferably, the interval between the highest point of the aluminum strip and the top of the housing is 2-5 mm.

[0017] The above technical solution has the following advantages or beneficial effects: the power chips and the surface of the power chip and the pins of the heat dissipation frame are electrically connected by aluminum ribbon bonding; and the ultrasonic welding technology is used to greatly improve the reliability and overcurrent capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a discrete device based on aluminum ribbon bonding in a preferred embodiment of the utility model;

[0019] Figure 2 It is a front view schematic diagram of a discrete device based on aluminum ribbon bonding without a housing in a preferred embodiment of the utility model;

[0020] Figure 3 This is a front schematic diagram of a discrete device with a housing based on aluminum ribbon bonding in a preferred embodiment of the present invention. DETAILED DESCRIPTION

[0021] The present invention is described in detail below in conjunction with the accompanying drawings and specific embodiments. The present invention is not limited to the implementation mode, and other implementation modes may also fall within the scope of the present invention as long as they meet the purpose of the present invention.

[0022] In a preferred embodiment of the present utility model, based on the above problems existing in the prior art, a discrete device based on aluminum ribbon bonding is provided, such as Figure 1 , Figure 2 and Figure 3 As shown, including:

[0023] A heat dissipation frame 1, a plurality of power chips 2 are welded on the top of the heat dissipation frame 1, and the power chips 2 and the surfaces of the power chips 2 and the pins 11 of the heat dissipation frame 1 are electrically connected by bonding with aluminum strips 4;

[0024] The housing 3 , the heat dissipation frame 1 and the power chips 2 are packaged inside the housing 3 , and the bottom of the heat dissipation frame 1 and the pins 11 are exposed from the housing 3 .

[0025] Specifically, discrete devices are inherently small in size, but because they need to be applied in different fields and as the chip current level increases, thick aluminum wire bonding technology is no longer the only option. Aluminum ribbon bonding breaks through the limitations of package size and achieves the strength and performance advantages of the bonding process in the package of small power devices. Aluminum ribbon bonding provides a nearly perfect technical alternative and is more attractive than existing technologies. In terms of bonding quality, process capabilities, and design requirements, bonding aluminum ribbons are superior to traditional bonding aluminum wires. In this embodiment, the power chips and the surface of the power chip and the pins of the heat dissipation frame are electrically connected by aluminum ribbon bonding; and ultrasonic welding technology and bonding aluminum ribbon are used to greatly improve reliability and overcurrent capability; an aluminum ribbon with a width-to-length ratio of 10:1 can replace 8 aluminum wires or 6 copper wires with a wire diameter equivalent to its thickness.

[0026] In a preferred embodiment of the present invention, Figure 2 As shown, the heat dissipation frame 1 includes:

[0027] The metal heat sink 12 has a plurality of pins 11 at one end thereof.

[0028] In a preferred embodiment of the present invention, Figure 2 As shown, the bottom of the metal heat sink 12 is exposed from the bottom of the housing 3 and is flush with the bottom of the housing 3;

[0029] Each pin 11 is exposed from one side of the housing 3 .

[0030] Specifically, the metal heat sink 12 in this embodiment is exposed from the bottom of the shell 3, and can directly contact the air or other heat dissipation devices to improve the heat dissipation effect, and is flush with the bottom of the shell 3 and will not exceed the shell 3 to increase the overall volume and affect the installation.

[0031] In a preferred embodiment of the present invention, Figure 2 As shown, the power chip 2 includes an insulated gate bipolar transistor chip 21 and a diode chip 22;

[0032] The insulated gate bipolar transistor chip 21 and the diode chip 22 are welded on the top of the heat dissipation frame 1;

[0033] The surface of the insulated gate bipolar transistor chip 21 and the surface of the diode chip 22 are electrically connected by bonding with an aluminum ribbon 4;

[0034] The surface of the IGBT chip 21 and the surface of the diode chip 22 are electrically connected to the lead 11 by bonding with the aluminum ribbon 4 .

[0035] In a preferred embodiment of the present invention, the aluminum strip 4 is a soft aluminum strip, and the interval between the highest point of the aluminum strip 4 and the top of the shell is 2-5 mm.

[0036] Specifically, in this embodiment, the aluminum strip 4 is a soft aluminum strip prepared by a casting process or other suitable processes, and a certain distance is provided between the highest point of the aluminum strip 4 and the top of the housing 3 to avoid affecting the electrical connection effect and the heat dissipation effect.

[0037] The above are only preferred embodiments of the present invention, and are not intended to limit the implementation methods and protection scope of the present invention. Those skilled in the art should be aware that all solutions obtained by equivalent substitutions and obvious changes made using the contents of this specification and illustrations should be included in the protection scope of the present invention.

Claims

1. A discrete device based on aluminum ribbon bonding, It is characterized in that include: A heat dissipation frame, wherein a plurality of power chips are welded on the top of the heat dissipation frame, and the power chips and the surfaces of the power chips and the pins of the heat dissipation frame are electrically connected by aluminum ribbon bonding; The heat dissipation frame and the power chips are packaged inside the shell, and the bottom of the heat dissipation frame and the pins are exposed from the shell.

2. The discrete device according to claim 1, It is characterized in that The heat dissipation frame comprises: A metal heat sink, one end of which is provided with a plurality of the pins.

3. The discrete device according to claim 2, It is characterized in that The bottom of the metal heat sink is exposed from the bottom of the housing and is flush with the bottom of the housing; Each of the pins is exposed from one side of the housing.

4. The discrete device according to claim 1, It is characterized in that The power chip includes an insulated gate bipolar transistor chip and a diode chip; The insulated gate bipolar transistor chip and the diode chip are welded on the top of the heat dissipation frame; The surface of the insulated gate bipolar transistor chip and the surface of the diode chip are electrically connected via the aluminum ribbon bonding; The surface of the insulated gate bipolar transistor chip and the surface of the diode chip are electrically connected to the pins through aluminum ribbon bonding.

5. The discrete device according to claim 1, It is characterized in that The aluminum strip is a soft aluminum strip.

6. The discrete device according to claim 1, It is characterized in that The spacing between the highest point of the aluminum strip and the top of the housing is 2-5 mm.

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