Bridge rectifier internal packaging structure and packaging method

Abstract

The invention relates to the related technical field of bridge rectifier packaging, and discloses a bridge rectifier internal packaging structure and packaging method.The lower layer of an aluminum alloy shell is filled with heat conduction gel, an electronic circuit and a semiconductor chip are wrapped with the heat conduction gel, then epoxy resin is filled into the upper layer for sealing, and then high-temperature curing is conducted; then, through stamping processing, a packaging shell protruding button at the bottom of the aluminum alloy packaging shell is stamped inwards to form a packaging shell sunken groove, and a packaging necking opening is stamped at an opening of the aluminum alloy packaging shell, so that the pressure of heat-conducting gel in the aluminum alloy packaging shell is increased; therefore, the first pressure power connection mechanism and the second pressure power connection mechanism are triggered, and power connection is completed.

Description

Technical Field

[0001] The present invention relates to the technical field related to bridge rectifier packaging, and in particular to an internal packaging structure and a packaging method of a bridge rectifier. Background Art

[0002] A bridge rectifier is an electronic circuit that plays a vital role in power electronic systems. Its main function is to convert alternating current into direct current. This conversion is necessary for many electronic devices because many electronic devices require a stable DC power supply to work. A bridge rectifier is usually composed of four diodes connected in a bridge shape. When alternating current passes through these four diodes, they will turn on and off in turn, thereby converting alternating current into direct current. In the manufacturing process of the bridge rectifier, the packaging structure and its packaging method are crucial to the performance, safety and reliability of the rectifier. The packaging not only protects the internal electronic circuits and semiconductor chips from interference and damage from the external environment, but also ensures that the rectifier can effectively dissipate heat when working. Effective heat dissipation is crucial to the long-term stable operation of the rectifier, because excessive temperature may cause the rectifier to degrade in performance or even damage it.

[0003] However, traditional packaging methods often have many shortcomings. First, minor defects or errors in the packaging process may cause tiny gaps and cracks in the encapsulated epoxy resin, which will affect the insulation performance of the equipment after long-term use and cause the risk of short circuits. Short circuits can cause damage to other equipment. Traditional packaging methods require separate testing of the sealing of the rectifier after packaging to ensure the integrity of the package. Secondly, minor packaging defects may not cause any impact temporarily, but there is no guarantee that minor cracks will not continue to develop and expand due to frequent thermal expansion and contraction during long-term work, resulting in unstable quality control. Once packaging failure occurs, it may cause huge losses. Summary of the invention

[0004] The object of the present invention is to provide an internal packaging structure and packaging method of a bridge rectifier, so as to solve the problem that the conventional packaging structure and packaging method mentioned in the above background technology are prone to hidden defects that are difficult to detect.

[0005] To achieve the above-mentioned object, the present invention provides the following technical solutions: an internal packaging structure of a bridge rectifier, comprising an aluminum alloy packaging shell, the upper end of the aluminum alloy packaging shell is open, a polyester holder is arranged at the bottom of the aluminum alloy packaging shell, a circular circuit board is arranged on the polyester holder, the polyester holder is used to isolate the circular circuit board from the aluminum alloy packaging shell, and power connection pins are welded on the circular circuit board, and the power connection pins include a first AC input terminal, a second AC input terminal, a first DC output terminal, and a second DC output terminal; The aluminum alloy packaging shell is provided with inner and outer packaging layers, the inner layer is an insulating heat-conducting layer, and the outer layer is a resin packaging layer; The circular circuit board includes a first fan-shaped copper plate, a second fan-shaped copper plate, a third fan-shaped copper plate, and a fourth fan-shaped copper plate. A first circular copper plate is arranged on the outer side of the first fan-shaped copper plate, and a second circular copper plate is arranged on the outer side of the fourth fan-shaped copper plate. A first semiconductor chip is arranged between the first fan-shaped copper plate and the second fan-shaped copper plate, a second semiconductor chip is arranged between the first fan-shaped copper plate and the third fan-shaped copper plate, a third semiconductor chip is arranged between the second fan-shaped copper plate and the fourth fan-shaped copper plate, and a fourth semiconductor chip is arranged between the third fan-shaped copper plate and the fourth fan-shaped copper plate. A first pressure power connection mechanism is arranged between the first fan-shaped copper plate and the first circular copper plate, and a second pressure power connection mechanism is arranged between the fourth fan-shaped copper plate and the second circular copper plate. The first pressure power connection mechanism and the second pressure power connection mechanism are disconnected when the pressure is lower than the atmospheric pressure.

[0006] Furthermore, the aluminum alloy packaging shell is formed by stamping, which is simple and quick, and has a significantly lower cost than traditional aluminum alloy machined shells.

[0007] Furthermore, a protruding button of the packaging shell is stamped on the bottom of the aluminum alloy packaging shell, and the protruding button of the packaging shell protrudes from the bottom surface of the aluminum alloy packaging shell. The protruding button of the packaging shell is stamped into a recessed groove of the packaging shell during packaging, thereby reducing the volume inside the aluminum alloy packaging shell and increasing the internal pressure. The opening edge of the aluminum alloy packaging shell is stamped into a packaging neck, which further reinforces the resin packaging layer and prevents damage to the resin packaging layer. At the same time, no additional upper cover is required, reducing costs.

[0008] Furthermore, the polyester holder is annular and has a groove inside. The circular circuit board is embedded in the groove to isolate the circular circuit board from the aluminum alloy packaging shell to avoid short circuit.

[0009] Furthermore, the insulating heat-conducting layer uses a heat-conducting gel, which has good thermal conductivity and can efficiently transfer heat. During the operation of the rectifier, the electronic circuit and the semiconductor chip will generate a large amount of heat. The heat-conducting gel can effectively transfer this heat from the heating element to the radiator or other heat dissipation medium, thereby ensuring that the temperature inside the rectifier is kept within a safe range. In addition, the heat-conducting gel is poured into the rectifier during the packaging process to form a certain pressure environment. When there is a problem with the packaging of the rectifier, such as aging of the packaging material, cracks or poor sealing, the heat-conducting gel will overflow and leak under the action of pressure, so that the pressure inside and outside the rectifier tends to be consistent. This change can trigger the pressure insurance mechanism inside the rectifier, disconnect the circuit, and play a protective role. The resin packaging layer uses epoxy resin. Epoxy resin is used as a packaging material, which can tightly wrap the electronic circuits and semiconductor chips inside the rectifier to form a complete packaging structure. This helps prevent the intrusion of external moisture, dust and other pollutants, and improves the packaging integrity and reliability of the rectifier. Epoxy resin has extremely high electrical insulation strength, which can effectively isolate internal components from external circuits and prevent leakage and short circuits. Epoxy resin can also withstand high operating temperatures to ensure that the packaging material does not deform or age in high temperature environments, which helps maintain the stability and reliability of the internal components of the rectifier and extend the service life of the rectifier. At the same time, epoxy resin has excellent resistance to most chemicals and can prevent corrosion and oxidation. This chemical stability helps keep the internal environment of the rectifier clean and dry, reducing failures caused by chemical corrosion.

[0010] Furthermore, the first AC input end is welded on a first circular copper plate, the second AC input end is welded on a second circular copper plate, the first DC output end is welded on a third fan-shaped copper plate, and the second DC output end is welded on a second fan-shaped copper plate.

[0011] Furthermore, the first pressure power connection mechanism includes a folding airbag, a first sealed copper sheet is fixedly connected to the bottom of the folding airbag, a second sealed copper sheet is fixedly connected to the top of the folding airbag, the folding airbag is sealed with the first sealed copper sheet and the folding airbag by glue, a thermistor is welded below the second sealed copper sheet, a movable contact is welded at the lower end of the thermistor, a connecting copper sheet is welded on the first circular copper plate, the connecting copper sheet is bent in a Z shape, the end of the connecting copper sheet is located above the folding airbag, a power connection spring is welded at the end of the connecting copper sheet, and the lower end of the power connection spring is welded to the second sealed copper sheet, the second pressure power connection mechanism has a similar structure to the first pressure power connection mechanism, so that an increase in pressure will compress the folding airbag downward, causing the movable contact to contact the first sealed copper sheet, thereby completing the connection between the first fan-shaped copper plate and the first circular copper plate. The second pressure connection mechanism has a similar structure to the first pressure connection mechanism. When pressurized, the second pressure connection mechanism connects the fourth fan-shaped copper plate and the second circular copper plate, so that the rectifier circuit can work normally.

[0012] Furthermore, the foldable airbag is made of high temperature resistant rubber material, and the cross section of the side wall of the foldable airbag will not bend left and right, so the pressure can only compress the foldable airbag downward.

[0013] The present invention provides another technical solution: a bridge rectifier internal packaging method, the method comprising: S1. Component assembly: First, place the polyester holder at the bottom of the aluminum alloy packaging shell, and then place the circular circuit board with the power pins welded on it into the aluminum alloy packaging shell, with the power pins facing outward, and fit the circular circuit board into the groove of the polyester holder, so that the circular circuit board and the power pins are not in contact with the inner wall of the aluminum alloy packaging shell; S2. Protective filling: Use automatic filling equipment to fill the aluminum alloy packaging shell with thermal conductive gel so that the thermal conductive gel completely submerges the circular circuit board; S3. Resin packaging: Use automatic filling equipment to fill the aluminum alloy packaging shell with epoxy resin until it is 90% full; S4. High temperature curing: Place the filled rectifier in an oven and bake at 150°C for one hour to cure the epoxy resin; S5. Pressurized activation: Use a press machine to stamp the packaged rectifier, stamp the protruding button of the package shell at the bottom of the aluminum alloy package shell inward to form a package shell recessed groove, and stamp out a package shrinkage at the opening of the aluminum alloy package shell, so that the pressure of the thermal conductive gel inside the aluminum alloy package shell increases, thereby triggering the first pressure connection mechanism and the second pressure connection mechanism to complete the power connection; S6. Power-on test: Connect the stamped rectifier to power and perform insulation test and peak current and voltage test.

[0014] Furthermore, in S6, when performing the insulation test and the peak current and voltage test, if the device can be powered on, it proves that the package is intact and has no cracks. If the device cannot be powered on, it means that cracks appear in the resin packaging layer and the package has failed.

[0015] Compared with the prior art, the present invention has the following beneficial effects: The present invention pours heat-conducting gel into the lower layer of the aluminum alloy shell to wrap the electronic circuit and the semiconductor chip, and then pours epoxy resin into the upper layer for sealing, and then performs high-temperature curing to completely cure the epoxy resin, and then punches the protruding button of the packaging shell at the bottom of the aluminum alloy packaging shell inwardly to form a packaging shell concave groove by stamping, and punches a packaging shrinkage at the opening of the aluminum alloy packaging shell, so that the pressure of the heat-conducting gel inside the aluminum alloy packaging shell increases, thereby triggering the first pressure power connection mechanism and the second pressure power connection mechanism to complete the power connection, which has the following advantages: 1. Automatic detection of packaging quality: Through the overflow leakage mechanism of thermal conductive gel under pressure, when there is a problem with the rectifier packaging, the circuit can be automatically disconnected. In this way, after the rectifier packaging is completed, only power-on detection is required to simultaneously determine whether the packaging is qualified. There is no need to perform separate packaging quality inspection, which simplifies the packaging inspection process and improves packaging production efficiency.

[0016] 2. Safety function: During long-term use, if the epoxy resin package has problems such as aging and cracks, the thermal conductive gel will also overflow, making the pressure inside and outside the rectifier tend to be consistent, so that the first pressure connection mechanism and the second pressure connection mechanism disconnect the circuit. This design plays a role in safety insurance, effectively preventing accidents such as short circuits and fires caused by aging of the rectifier package, and improving the safety of the product.

[0017] 3. Thermal expansion and contraction protection function: The rectifier generates heat during operation and the temperature rises rapidly. At this time, the internal insulating thermal conductive layer and the resin packaging layer have different thermal expansion and contraction coefficients, which may lead to expansion and cracking problems. The folding airbag of the pressure connection mechanism can provide a certain expansion adjustment effect to reduce the impact of thermal expansion and contraction. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the appearance structure of the present invention; Figure 2 This is a schematic diagram of the cross-sectional structure of the present invention before packaging; Figure 3 This is a schematic diagram of the cross-sectional structure of the present invention after packaging; Figure 4 It is a schematic diagram of the structure of the insulating heat-conducting layer and the resin packaging layer of the present invention; Figure 5 It is an exploded view of the present invention; Figure 6 This is a schematic diagram of the electrical connection pin structure of the present invention; Figure 7 This is a schematic diagram of the circular circuit board structure of the present invention; Figure 8 It is a schematic structural diagram of the first pressure power connection mechanism of the present invention.

[0019] Numbers in the figure: 1, aluminum alloy package shell; 101, package shell protruding button; 102, package shell recessed groove; 103, package shrinkage; 2, polyester retainer; 3, round circuit board; 301, first fan-shaped copper plate; 302, second fan-shaped copper plate; 303, third fan-shaped copper plate; 304, fourth fan-shaped copper plate; 305, first round copper plate; 306, second round copper plate; 307, first semiconductor chip; 308, second semiconductor chip; 309, third semiconductor chip; 31 0. Fourth semiconductor chip; 4. Power connection pin; 401. First AC input terminal; 402. Second AC input terminal; 403. First DC output terminal; 404. Second DC output terminal; 5. Insulating thermal conductive layer; 6. Resin packaging layer; 7. First pressure power connection mechanism; 701. Folding airbag; 702. First sealed copper sheet; 703. Second sealed copper sheet; 704. Thermistor spring; 705. Movable contact; 706. Connecting copper sheet; 707. Power connection spring; 8. Second pressure power connection mechanism. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0021] In order to further understand the content of the present invention, the present invention is described in detail in conjunction with the accompanying drawings.

[0022] See also Figure 1 - Figure 8 A bridge rectifier internal packaging structure includes an aluminum alloy packaging shell 1, which is formed by stamping. The upper end of the aluminum alloy packaging shell 1 is open, and the stamping process is simple and fast. Compared with the traditional aluminum alloy machined shell, the cost is greatly reduced. The bottom of the aluminum alloy packaging shell 1 is stamped with a packaging shell protruding button 101, and the packaging shell protruding button 101 protrudes from the bottom surface of the aluminum alloy packaging shell 1. The packaging shell protruding button 101 is stamped into a packaging shell concave groove 102 during packaging, thereby reducing the volume inside the aluminum alloy packaging shell 1, thereby increasing the internal pressure. The opening edge of the aluminum alloy packaging shell 1 is stamped into a packaging shrinkage 103, which further reinforces the resin packaging layer 6 to prevent damage to the resin packaging layer 6. At the same time, no additional upper cover is required, which reduces the cost.

[0023] A polyester holder 2 is provided at the bottom of the aluminum alloy packaging shell 1. The polyester holder 2 is annular and has a groove inside. The circular circuit board 3 is embedded in the groove to isolate the circular circuit board 3 and the aluminum alloy packaging shell 1 to avoid short circuit.

[0024] A circular circuit board 3 is arranged on the polyester retaining frame 2, and the polyester retaining frame 2 is used to isolate the circular circuit board 3 and the aluminum alloy packaging shell 1. Power connection pins 4 are welded on the circular circuit board 3, and the power connection pins 4 include a first AC input terminal 401, a second AC input terminal 402, a first DC output terminal 403 and a second DC output terminal 404.

[0025] The aluminum alloy packaging shell 1 is provided with an inner and outer packaging layer, the inner layer is an insulating heat-conducting layer 5, and the outer layer is a resin packaging layer 6. The insulating heat-conducting layer 5 is made of a thermally conductive gel, which has good thermal conductivity and can efficiently transfer heat. During the operation of the rectifier, the electronic circuit and the semiconductor chip will generate a large amount of heat. The thermally conductive gel can effectively transfer this heat from the heating element to the radiator or other heat dissipation medium, thereby ensuring that the temperature inside the rectifier is kept within a safe range and avoiding performance degradation or damage caused by overheating. In addition, the thermally conductive gel is poured into the rectifier during the packaging process to form a certain pressure environment. When there is a problem with the packaging of the rectifier, such as aging, cracks or poor sealing of the packaging material, the thermally conductive gel will overflow and leak under the action of pressure, so that the pressure inside and outside the rectifier tends to be consistent. This change can trigger the pressure insurance mechanism inside the rectifier, disconnect the circuit, and play a protective role.

[0026] The resin encapsulation layer 6 is made of epoxy resin. As an encapsulation material, epoxy resin can tightly wrap the electronic circuits and semiconductor chips inside the rectifier to form a complete encapsulation structure. This helps to prevent the intrusion of external moisture, dust and other pollutants, and improve the encapsulation integrity and reliability of the rectifier. Epoxy resin has extremely high electrical insulation strength, which can effectively isolate internal components from external circuits and prevent leakage and short circuit. Epoxy resin can also withstand high operating temperatures to ensure that the encapsulation material does not deform or age in a high temperature environment, which helps to maintain the stability and reliability of the internal components of the rectifier and extend the service life of the rectifier. At the same time, epoxy resin has excellent resistance to most chemical substances and can prevent corrosion and oxidation. Such chemical stability helps to keep the internal environment of the rectifier clean and dry, and reduce failures caused by chemical corrosion.

[0027] The circular circuit board 3 includes a first fan-shaped copper plate 301, a second fan-shaped copper plate 302, a third fan-shaped copper plate 303, and a fourth fan-shaped copper plate 304. A first circular copper plate 305 is arranged outside the first fan-shaped copper plate 301, a second circular copper plate 306 is arranged outside the fourth fan-shaped copper plate 304, a first semiconductor chip 307 is arranged between the first fan-shaped copper plate 301 and the second fan-shaped copper plate 302, and a second semiconductor chip 308 is arranged between the first fan-shaped copper plate 301 and the third fan-shaped copper plate 303. A third semiconductor chip 309 is arranged between the second circular copper plate 306 and the fourth fan-shaped copper plate 304, a fourth semiconductor chip 310 is arranged between the third fan-shaped copper plate 303 and the fourth fan-shaped copper plate 304, a first pressure connection mechanism 7 is arranged between the first fan-shaped copper plate 301 and the first circular copper plate 305, a second pressure connection mechanism 8 is arranged between the fourth fan-shaped copper plate 304 and the second circular copper plate 306, and the first pressure connection mechanism 7 and the second pressure connection mechanism 8 are disconnected when the pressure is lower than the atmospheric pressure. The first AC input terminal 401 is welded on the first circular copper plate 305, the second AC input terminal 402 is welded on the second circular copper plate 306, the first DC output terminal 403 is welded on the third fan-shaped copper plate 303, and the second DC output terminal 404 is welded on the second fan-shaped copper plate 302, thereby forming a complete rectifier circuit.

[0028] The first pressure power connection mechanism 7 includes a folding airbag 701, a first sealed copper sheet 702 is fixedly connected to the bottom of the folding airbag 701, a second sealed copper sheet 703 is fixedly connected to the top of the folding airbag 701, the folding airbag 701 is sealed with the first sealed copper sheet 702 and the folding airbag 701 by glue, a thermistor spring 704 is welded below the second sealed copper sheet 703, a movable contact 705 is welded to the lower end of the thermistor spring 704, a connecting copper sheet 706 is welded to the first circular copper plate 305, the connecting copper sheet 706 is bent in a Z shape, the end of the connecting copper sheet 706 is located above the folding airbag 701, a power connection spring 707 is welded to the end of the connecting copper sheet 706, and the lower end of the power connection spring 707 is welded to the second sealed copper sheet 703. In this way, when the protruding button 101 of the encapsulation shell at the bottom of the aluminum alloy encapsulation shell 1 is punched into the encapsulation shell recessed groove 102, the volume inside the encapsulation shell recessed groove 102 decreases, and the pressure of the thermal conductive gel increases. The folding airbag 701 is made of high-temperature resistant rubber material, and the side wall section of the folding airbag 701 will not bend left and right. Therefore, the pressure increase will compress the folding airbag 701 downward, so that the movable contact 705 contacts the first sealing copper sheet 702, completing the connection between the first fan-shaped copper plate 301 and the first circular copper plate 305. The second pressure connection mechanism 8 has a similar structure to the first pressure connection mechanism 7. When pressurized, the second pressure connection mechanism 8 connects the fourth fan-shaped copper plate 304 and the second circular copper plate 306, so that the rectifier circuit can work normally.

[0029] It should be noted that the movable contact 705 of the folded airbag 701 maintains a small gap with the first sealed copper sheet 702 under normal pressure, and when the folded airbag 701 is compressed, the movable contact 705 can quickly contact the first sealed copper sheet 702. In addition, the thermal spring 704 deforms with temperature, and when the temperature exceeds 170 degrees Celsius, the thermal spring 704 will overheat and change phase, resulting in shortening, thereby cutting off the circuit for protection, playing the role of over-temperature insurance.

[0030] A bridge rectifier internal packaging method, the method comprising: 1. Component assembly: First, place the polyester holder 2 into the bottom of the aluminum alloy packaging shell 1, and then place the circular circuit board 3 with the power connection pins 4 welded on it into the aluminum alloy packaging shell 1, so that the power connection pins 4 face outward, and the circular circuit board 3 is inserted into the groove of the polyester holder 2, so that the circular circuit board 3 and the power connection pins 4 are not in contact with the inner wall of the aluminum alloy packaging shell 1.

[0031] 2. Protective filling: Use automatic filling equipment to fill the aluminum alloy packaging shell 1 with thermal conductive gel so that the thermal conductive gel completely submerges the circular circuit board 3. After filling, wait for the thermal conductive gel to fully flow into all gaps to ensure that no bubbles are generated.

[0032] 3. Resin packaging: Use automatic filling equipment to fill the aluminum alloy packaging shell 1 with epoxy resin until it is 90% full to avoid bubbles.

[0033] 4. High temperature curing: Place the filled rectifier into an oven and bake it at 150°C for one hour until the epoxy resin is cured.

[0034] 5. Pressurized activation: Use a press machine to stamp the packaged rectifier, stamp the protruding button 101 at the bottom of the aluminum alloy packaging shell 1 inward to form a packaging shell recessed groove 102, and stamp a packaging shrinkage 103 at the opening of the aluminum alloy packaging shell 1, so that the pressure of the thermal conductive gel inside the aluminum alloy packaging shell 1 increases, thereby triggering the first pressure power connection mechanism 7 and the second pressure power connection mechanism 8 to complete the power connection.

[0035] 6. Power connection test: Connect the stamped rectifier to power and perform insulation test and peak current and voltage test. When performing insulation test and peak current and voltage test, if power can be connected, it proves that the package is intact and has no cracks. Failure to connect power indicates that cracks appear in the resin packaging layer 6 and the package fails.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A bridge rectifier internal packaging structure, comprising an aluminum alloy packaging shell (1), characterized in that: The upper end of the aluminum alloy packaging shell (1) is open, a polyester retaining frame (2) is arranged at the bottom of the aluminum alloy packaging shell (1), a circular circuit board (3) is arranged on the polyester retaining frame (2), the polyester retaining frame (2) is used to isolate the circular circuit board (3) and the aluminum alloy packaging shell (1), and the aluminum alloy packaging shell (1) is provided with inner and outer packaging layers, the inner layer is an insulating heat-conducting layer (5), and the outer layer is a resin packaging layer (6); The bottom of the aluminum alloy packaging shell (1) is punched with a packaging shell protruding button (101), the packaging shell protruding button (101) protrudes from the bottom surface of the aluminum alloy packaging shell (1), the packaging shell protruding button (101) is punched into a packaging shell recessed groove (102) during packaging, the packaging shell recessed groove (102) is used to increase the internal pressure of the aluminum alloy packaging shell (1) after packaging is completed, and the opening edge of the aluminum alloy packaging shell (1) is punched into a packaging shrinkage (103); The circular circuit board (3) is provided with a first pressure power connection mechanism (7) and a second pressure power connection mechanism (8), and the first pressure power connection mechanism (7) and the second pressure power connection mechanism (8) are energized when the pressure is greater than the atmospheric pressure.

2. The internal packaging structure of a bridge rectifier according to claim 1, characterized in that: The circular circuit board (3) is welded with a power connection pin (4), the power connection pin (4) comprising a first AC input terminal (401), a second AC input terminal (402), a first DC output terminal (403) and a second DC output terminal (404); the circular circuit board (3) comprises a first fan-shaped copper plate (301), a second fan-shaped copper plate (302), a third fan-shaped copper plate (303) and a fourth fan-shaped copper plate (304); a first circular copper plate (305) is arranged outside the first fan-shaped copper plate (301); a second circular copper plate (306) is arranged outside the fourth fan-shaped copper plate (304); the first fan-shaped copper plate (301) and the second fan-shaped copper plate (302) are A first semiconductor chip (307) is arranged between the first sector-shaped copper plate (301) and the third sector-shaped copper plate (303), a second semiconductor chip (308) is arranged between the first sector-shaped copper plate (301) and the third sector-shaped copper plate (303), a third semiconductor chip (309) is arranged between the second circular copper plate (306) and the fourth sector-shaped copper plate (304), a fourth semiconductor chip (310) is arranged between the third sector-shaped copper plate (303) and the fourth sector-shaped copper plate (304), the first pressure connection mechanism (7) is arranged between the first sector-shaped copper plate (301) and the first circular copper plate (305), and the second pressure connection mechanism (8) is arranged between the fourth sector-shaped copper plate (304) and the second circular copper plate (306).

3. The internal packaging structure of a bridge rectifier according to claim 1, characterized in that: The aluminum alloy packaging shell (1) is formed by stamping.

4. The internal packaging structure of a bridge rectifier according to claim 1, characterized in that: The polyester retaining frame (2) is annular, and a groove is provided inside the polyester retaining frame (2), and the circular circuit board (3) is embedded in the groove.

5. The internal packaging structure of a bridge rectifier according to claim 1, characterized in that: The insulating heat-conducting layer (5) is made of heat-conducting gel, and the resin packaging layer (6) is made of epoxy resin.

6. The internal packaging structure of a bridge rectifier according to claim 2, characterized in that: The first AC input terminal (401) is welded to a first circular copper plate (305), the second AC input terminal (402) is welded to a second circular copper plate (306), the first DC output terminal (403) is welded to a third fan-shaped copper plate (303), and the second DC output terminal (404) is welded to the second fan-shaped copper plate (302).

7. The internal packaging structure of a bridge rectifier according to claim 6, characterized in that: The first pressure connection mechanism (7) comprises a folding airbag (701), a first sealing copper sheet (702) being fixedly connected to the bottom of the folding airbag (701), a second sealing copper sheet (703) being fixedly connected to the top of the folding airbag (701), the folding airbag (701) being bonded and sealed with glue to the first sealing copper sheet (702) and the folding airbag (701), a thermal spring (704) being welded below the second sealing copper sheet (703), and the lower end of the thermal spring (704) being welded to the There is a movable contact (705), a connecting copper sheet (706) is welded on the first circular copper plate (305), the connecting copper sheet (706) is bent in a Z shape, the end of the connecting copper sheet (706) is located above the folding airbag (701), a power connection spring (707) is welded to the end of the connecting copper sheet (706), the lower end of the power connection spring (707) is welded to the second sealing copper sheet (703), and the second pressure power connection mechanism (8) is similar in structure to the first pressure power connection mechanism (7).

8. The internal packaging structure of a bridge rectifier according to claim 7, characterized in that: The folding airbag (701) is made of high temperature resistant rubber material, and the side wall cross section of the folding airbag (701) will not bend left or right.

9. A packaging method for the internal packaging structure of a bridge rectifier according to any one of claims 1 to 8, characterized in that: The method comprises: S1. Component assembly: first, place the polyester holder (2) into the bottom of the aluminum alloy packaging shell (1), then place the circular circuit board (3) with the power connection pins (4) welded thereto into the aluminum alloy packaging shell (1), with the power connection pins (4) facing outward, and fit the circular circuit board (3) into the groove of the polyester holder (2), so that the circular circuit board (3) and the power connection pins (4) are not in contact with the inner wall of the aluminum alloy packaging shell (1); S2. Protective filling: Use automatic filling equipment to fill the aluminum alloy packaging shell (1) with thermal conductive gel so that the thermal conductive gel completely submerges the circular circuit board (3); S3. Resin encapsulation: Use automatic filling equipment to fill the aluminum alloy encapsulation shell (1) with epoxy resin until it is 90% full; S4. High temperature curing: Place the filled rectifier in an oven and bake at 150°C for one hour to cure the epoxy resin; S5. Pressurized activation: using a press machine to stamp the packaged rectifier, stamping the package shell protruding button (101) at the bottom of the aluminum alloy package shell (1) inwardly to form a package shell concave groove (102), and stamping a package shrinkage (103) at the opening of the aluminum alloy package shell (1), so that the pressure of the thermal conductive gel inside the aluminum alloy package shell (1) increases, thereby triggering the first pressure power connection mechanism (7) and the second pressure power connection mechanism (8), and completing the power connection; S6. Power-on test: Connect the stamped rectifier to power and perform insulation test and peak current and voltage test.

10. The packaging method of the internal packaging structure of a bridge rectifier according to claim 9, characterized in that: In the above S6, when the insulation test and the peak current and voltage test are performed, if the power can be connected, it proves that the package is intact and has no cracks. If the power cannot be connected, it means that cracks appear in the resin packaging layer (6) and the package fails.

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