Ceramic airtight packaging structure for high-voltage high-power-consumption rectifier bridge

Abstract

The invention belongs to the technical field of semiconductor packaging, particularly relates to a ceramic airtight packaging structure for a high-voltage and high-power-consumption rectifier bridge, and aims to solve the problems that the existing rectifier bridge ceramic packaging generally adopts a lead bonding packaging mode, and a series chip cannot realize the miniaturization of the packaging size. The rectifier bridge diode structure comprises a heat sink cover plate, rectifier bridge diode chips, a ceramic shell and a ceramic shell leading-out end, and the diode chips connected in series are stacked, so that the area of a chip bonding area is reduced by nearly one time; the anode of the diode is directly interconnected with the ceramic shell through welding flux, and the cathode of the diode is connected to the heat sink cover plate through a high-heat-conductivity and low-resistivity bonding material, so that the interconnection conduction resistance is greatly reduced; and the heat sink cover plate and the ceramic shell are welded through eutectic solder, so that the device meets airtight packaging, and the problem of miniaturization of the packaging size of the chip is solved.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor packaging, and in particular relates to a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge. Background Art

[0002] The high-voltage and high-power rectifier bridge has the characteristics of high operating voltage, large operating current, and high power consumption. It requires the device package to have a small on-resistance, strong current carrying capacity, excellent heat dissipation performance, and a small package size.

[0003] However, the current rectifier bridge ceramic packaging usually adopts wire bonding packaging, and the serial chips cannot achieve miniaturization of the package size through the stacking process; in addition, the long bonding wire and small bonding wire diameter lead to large on-resistance and weak current carrying capacity; the chip cannot be directly connected to the external heat sink through metal or thermal conductive glue, and can only rely on the ceramic substrate for unilateral heat dissipation. The above problems will lead to the deterioration of the electrical performance and heat dissipation characteristics of the rectifier bridge device, which seriously restricts the application of rectifier bridge devices in the field of ceramic packaging. Summary of the invention

[0004] In order to solve the problem that the rectifier bridge ceramic package in the prior art usually adopts the wire bonding package form and the series chip cannot achieve the miniaturization of the package size, the present invention provides a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge, including a heat sink cover, a rectifier bridge diode chip, a ceramic housing and a ceramic housing lead-out terminal;

[0005] The heat sink cover is connected to the ceramic shell with solder, at least two rectifier bridge diode chips are provided, the anode and cathode of the rectifier bridge diode chip are respectively located on both sides thereof, the two rectifier bridge diode chips are stacked and connected in series, the stacked rectifier bridge diode chips are arranged in a packaging cavity between the heat sink cover and the ceramic shell, the anode at the bottom of the rectifier bridge diode chip is welded to the metallized area of ​​the ceramic shell, a plurality of interconnected through holes are provided in the ceramic shell, the ceramic shell lead-out terminal is provided at the bottom of the ceramic shell, and the interconnected through holes respectively connect the metallized area and the ceramic shell lead-out terminal.

[0006] According to some embodiments of the present application, a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge is provided, in which the anodes and cathodes of two rectifier bridge diode chips stacked in series are interconnected, and the two rectifier bridge diode chips stacked in series are welded by chip welding material, and the area of ​​the chip welding material is not less than 50% of the area of ​​the rectifier bridge diode chip.

[0007] According to a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge provided in some embodiments of the present application, the anode at the bottom of the rectifier bridge diode chip is welded to the metallized area of ​​the ceramic shell through the chip welding material.

[0008] According to some embodiments of the present application, a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge is provided, wherein the bottom of the heat sink cover is bonded to the cathode on the top of the rectifier bridge diode chip by a chip bonding material, and the chip bonding material is a conductive material.

[0009] According to some embodiments of the present application, a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge is provided, in which a single metallized area on the top of the ceramic shell is larger than the anode area of ​​a single rectifier bridge diode chip, and the number of interconnected through holes in a single metallized area is no less than 30.

[0010] According to a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge provided in some embodiments of the present application, the size of the heat sink cover is larger than the size range of all the stacked rectifier bridge diode chips.

[0011] According to a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge provided in some embodiments of the present application, the heat sink cover is made of copper.

[0012] According to some embodiments of the present application, a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge further includes a heat sink, the bottom of which is connected to the top of the heat sink cover.

[0013] According to some embodiments of the present application, a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge is provided, which also includes a printed circuit board, and the lead end of the ceramic shell is connected to the printed circuit board.

[0014] Beneficial effects of the present invention:

[0015] In the present invention, two series-connected rectifier bridge diode chips adopt a stacking process to achieve miniaturization of the package size, and the anode is connected to the shell by welding to ensure that the interconnection on-resistance between the anode of the rectifier bridge chip and the shell is low. The interconnection between the front and back of the shell adopts a large-area metal plane and a structure with multiple vias to ensure that the on-resistance of the internal path of the shell is low.

[0016] The welding area of ​​the shell is larger than the anode area of ​​the chip, which can improve the current conduction capability.

[0017] An exposed heat sink is directly connected to the surface of the rectifier bridge chip, so that the heat of the device is directly and effectively exported to the top of the package, which significantly reduces the thermal resistance of the device and greatly reduces the operating temperature of the chip by relying on the heat sink.

[0018] The exposed heat sink is connected to the shell through solder to ensure the airtightness of the device.

[0019] The welding airtight structure is adopted, no bonding space is required, and the serial chips are stacked, etc., which reduces the package size of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Other features, objects and advantages of the present application will become more apparent by reading the detailed description of non-limiting embodiments made with reference to the following drawings:

[0021] Figure 1 are cross-sectional schematic diagrams of some embodiments of the present application;

[0022] Figure 2 is a top view of some embodiments of the present application before heat sink bonding;

[0023] Figure 3 This is a schematic diagram of the internal wiring of the housing of some embodiments of the present application.

[0024] In the figure: 1. Radiator; 2. Heat sink cover bonding material; 3. Heat sink cover; 4. Chip bonding material; 5. Rectifier bridge diode chip; 6. Chip welding material; 7. Ceramic shell welding material; 8. Ceramic shell; 9. Interconnection through hole; 10. Ceramic shell lead end; 11. Printed circuit board; 12. Metallized area. DETAILED DESCRIPTION

[0025] The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

[0026] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] like Figure 1-3 As shown, the present invention provides a ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge, comprising a heat sink cover plate 3, a rectifier bridge diode chip 5, a ceramic housing 8 and a ceramic housing lead-out terminal 10;

[0028] The heat sink cover 3 is connected to the ceramic shell 8 by solder, and at least two rectifier bridge diode chips 5 are provided. The anode and cathode of the rectifier bridge diode chip 5 are respectively located on both sides thereof, and the two rectifier bridge diode chips 5 are stacked and connected in series. The stacked rectifier bridge diode chips 5 are arranged in the packaging cavity between the heat sink cover 3 and the ceramic shell 8, and the anode at the bottom of the rectifier bridge diode chip 5 is welded to the metallized area 12 of the ceramic shell 8. A plurality of interconnected through holes 9 are arranged in the ceramic shell 8, and a ceramic shell lead-out terminal 10 is arranged at the bottom of the ceramic shell 8. The interconnected through holes 9 respectively connect the metallized area 12 and the ceramic shell lead-out terminal 10, and also include a radiator 1. The bottom of the radiator 1 is connected to the top of the heat sink cover 3 by a heat sink cover adhesive material 2, wherein the heat sink cover adhesive material 2 can also play a good thermal conductive role.

[0029] In specific implementation, the heat sink cover plate 3 and the ceramic shell 8 are fixedly connected by the ceramic shell welding material 7, which ensures the air tightness of the device. A packaging cavity is formed between the heat sink cover plate 3 and the ceramic shell 8, and the rectifier bridge diode chip 5 can be arranged in the packaging cavity. The two series-connected rectifier bridge diode chips 5 adopt a stacking process to achieve miniaturization of the packaging size, reduce the area expansion caused by the flat structure and do not require a bonding space, thereby reducing the overall size of the device. The rectifier bridge diode chip anode is connected to the ceramic shell 8 to ensure that the interconnection on-resistance between the rectifier bridge diode chip 5 anode and the ceramic shell 8 is low, which can significantly reduce the on-resistance from the rectifier bridge to the shell; the interconnection between the welding area on the front of the ceramic shell 8 and the ceramic shell lead-out terminal 10 adopts a large-area metal plane and a multi-via arrangement structure to ensure that the internal path on-resistance of the ceramic shell 8 is low; the exposed heat sink cover plate 3 is directly connected to the cathode of the rectifier bridge diode chip 5, so that the heat of the device is directly and effectively exported to the top of the package, significantly reducing the thermal resistance of the device, and relying on the fins of the heat sink 1 to dissipate the heat to the external environment in time, reducing the operating temperature of the rectifier bridge diode chip 5.

[0030] In some embodiments, the anodes and cathodes of two rectifier bridge diode chips 5 stacked in series are interconnected, and the two rectifier bridge diode chips 5 stacked in series are fixed by welding by setting chip welding material 6.

[0031] In specific implementation, as a preferred embodiment, the area of ​​the chip welding material 6 is not less than 50% of the area of ​​the rectifier bridge diode chip 5 .

[0032] In some embodiments, the anode at the bottom of the rectifier bridge diode chip 5 is welded to the metallized area 12 of the ceramic housing 8 through the chip welding material 6 .

[0033] During specific implementation, the anode of the rectifier bridge diode chip 5 and the ceramic shell 8 are directly interconnected through the chip welding material 6. This structure has a large conduction interface and a short conduction length, which can significantly reduce the conduction resistance from the rectifier bridge to the shell; the interconnection between the front welding area of ​​the ceramic shell 8 and the lead-out terminal 10 of the ceramic shell adopts a large-area metal plane and a multi-via arrangement structure to ensure that the internal path of the ceramic shell 8 has a low conduction resistance.

[0034] The bottom of the heat sink cover plate 3 is bonded to the cathode on the top of the rectifier bridge diode chip 5 through a chip bonding material 4, and the chip bonding material 4 is a conductive material.

[0035] During specific implementation, the exposed heat sink cover 3 is directly connected to the cathode of the rectifier bridge diode chip 5, so that the heat of the device is directly and effectively conducted to the top of the package, significantly reducing the thermal resistance of the device, and relying on the heat sink 1 to dissipate the heat to the external environment in time, thereby reducing the operating temperature of the rectifier bridge diode chip 5. The chip bonding material 4 is a conductive material, ensuring that the cathodes of the stacked rectifier bridge diode chips 5 are at the same potential and connected to the lead-out terminal 10 of the ceramic shell.

[0036] In some embodiments, a single metallized area 12 on the top of the ceramic housing 8 is larger than the anode area of ​​a single rectifier bridge diode chip 5 , and the number of interconnection through holes 9 in the single metallized area 12 is no less than 30.

[0037] In specific implementation, a large-area metal plane and a structure with multiple vias are used to ensure that the on-resistance of the internal path of the ceramic housing 8 is relatively low.

[0038] In some embodiments, the size of the heat sink cover plate 3 is larger than the size range of all stacked rectifier bridge diode chips 5 .

[0039] In specific implementation, it is ensured that the rectifier bridge diode chip 5 can be packaged between the heat sink cover 3 and the ceramic housing 8, no bonding space is required and the series chips adopt a stacking process, etc., which reduces the packaging size of the device.

[0040] In some embodiments, the heat sink cover plate 3 is made of copper.

[0041] In specific implementation, copper (Cu) material is used because of its good thermal conductivity.

[0042] In some embodiments, a printed circuit board 11 is further included, and the ceramic housing lead-out terminal 10 is connected to the printed circuit board 11 .

[0043] In the description of the present invention, the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0044] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] The term "comprise" or any other similar term is intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus / device that includes a list of elements includes not only those elements but also other elements not expressly listed, or also includes elements inherent to such process, method, article, or apparatus / device.

[0046] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. A ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge, characterized in that: It comprises a heat sink cover plate (3), a rectifier bridge diode chip (5), a ceramic housing (8) and a ceramic housing lead-out terminal (10); The heat sink cover plate (3) is connected to the ceramic shell (8) by soldering, at least two rectifier bridge diode chips (5) are provided, the anode and cathode of the rectifier bridge diode chip (5) are respectively located on both sides thereof, the two rectifier bridge diode chips (5) are stacked and connected in series, the stacked rectifier bridge diode chips (5) are arranged in a packaging cavity between the heat sink cover plate (3) and the ceramic shell (8), the anode at the bottom of the rectifier bridge diode chip (5) is welded to the metallized area (12) of the ceramic shell (8), a plurality of interconnected through holes (9) are provided in the ceramic shell (8), the bottom of the ceramic shell (8) is provided with the ceramic shell lead-out terminal (10), and the interconnected through holes (9) respectively connect the metallized area (12) and the ceramic shell lead-out terminal (10).

2. A ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 1, characterized in that: The anodes and cathodes of the two rectifier bridge diode chips (5) stacked in series are interconnected, and the two rectifier bridge diode chips (5) stacked in series are welded by chip welding material (6), and the area of ​​the chip welding material (6) is not less than 50% of the area of ​​the rectifier bridge diode chip (5).

3. A ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 2, characterized in that: The anode at the bottom of the rectifier bridge diode chip (5) is welded to the metallized area (12) of the ceramic housing (8) via the chip welding material (6).

4. The ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 1, characterized in that: The bottom of the heat sink cover plate (3) is bonded to the cathode on the top of the rectifier bridge diode chip (5) via a chip bonding material (4), and the chip bonding material (4) is a conductive material.

5. The ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 1, characterized in that: A single metallized area (12) on the top of the ceramic housing (8) is larger than the anode area of ​​a single rectifier bridge diode chip (5), and the number of interconnected through holes (9) in a single metallized area (12) is not less than 30.

6. The ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 1, characterized in that: The size of the heat sink cover plate (3) is larger than the size range of all the stacked rectifier bridge diode chips (5).

7. The ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 1, characterized in that: The heat sink cover plate (3) is made of copper.

8. The ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 1, characterized in that: It also comprises a radiator (1), the bottom of the radiator (1) being connected to the top of the heat sink cover plate (3).

9. The ceramic airtight packaging structure for a high-voltage and high-power rectifier bridge according to claim 1, characterized in that: It also comprises a printed circuit board (11), and the ceramic housing lead end (10) is connected to the printed circuit board (11).

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