Internal packaging structure and packaging method of a bridge rectifier

Abstract

The present invention relates to the technical field related to the packaging of bridge rectifiers, and discloses an internal packaging structure and a packaging method for a bridge rectifier. By pouring a thermal conductive gel under the aluminum alloy housing to wrap the electronic circuit and the semiconductor chip with the thermal conductive gel, and then pouring epoxy resin upward for sealing, followed by high-temperature curing to completely cure the epoxy resin, and then through stamping processing, the protruding button at the bottom of the aluminum alloy packaging shell is stamped inward to form a sunken groove of the packaging shell, and a packaging shrinkage is stamped at the opening of the aluminum alloy packaging shell, so that the pressure of the thermal conductive 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 power connection.

Description

Technical Field

[0001] The present invention relates to the technical field related to the encapsulation of bridge rectifiers, and particularly to an internal encapsulation structure and an encapsulation method for a bridge rectifier. Background Art

[0002] A bridge rectifier is an electronic circuit that plays a crucial role in power electronic systems. Its main function is to convert alternating current into direct current, which is necessary for many electronic devices because many electronic devices require a stable DC power supply to operate. A bridge rectifier is usually formed by connecting four diodes in a bridge shape. When alternating current passes through these four diodes, they will conduct and cut off in turn, thus converting alternating current into direct current. During the manufacturing process of a bridge rectifier, the encapsulation structure and its encapsulation method are crucial for the performance, safety, and reliability of the rectifier. Encapsulation not only protects the internal electronic circuit and semiconductor chip from external environmental interference and damage but also ensures that the rectifier can effectively dissipate heat during operation. Effective heat dissipation is crucial for the long-term stable operation of the rectifier because excessive temperature may cause the performance of the rectifier to decline or even be damaged.

[0003] However, traditional encapsulation methods often have many deficiencies. First, minor defects or errors during the encapsulation process may cause tiny gaps and cracks to appear in the encapsulated epoxy resin, which will affect the insulation performance of the device after long-term use and pose a risk of short circuit. A short circuit can damage other devices. Traditional encapsulation methods require a separate inspection of the sealing performance of the rectifier after encapsulation to ensure the integrity of the encapsulation. Second, minor encapsulation flaws may not have an impact temporarily, but it cannot be guaranteed that tiny cracks will not continue to develop and expand during long-term operation when frequently subjected to thermal expansion and contraction, resulting in unstable product quality control. Once encapsulation failure occurs, it may cause huge losses. Summary of the Invention

[0004] The purpose of the present invention is to provide an internal encapsulation structure and an encapsulation method for a bridge rectifier to solve the problem that the current traditional encapsulation structure and encapsulation method are prone to hidden defects that are difficult to detect as proposed in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solution: An internal encapsulation structure for a bridge rectifier, including an aluminum alloy encapsulation shell with an open upper end. A polyester holder is provided at the bottom of the aluminum alloy encapsulation shell. A circular circuit board is arranged on the polyester holder, and the polyester holder is used to isolate the circular circuit board from the aluminum alloy encapsulation shell. Connecting pins are soldered on the circular circuit board, and the connecting pins include a first AC input terminal, a second AC input terminal, a first DC output terminal, and a second DC output terminal.

[0006] An inner and an outer encapsulation layer are provided inside the aluminum alloy encapsulation case. The inner layer is an insulating and heat-conducting layer, and the outer layer is a resin encapsulation layer;

[0007] The circular circuit board includes a first sector-shaped copper plate, a second sector-shaped copper plate, a third sector-shaped copper plate, and a fourth sector-shaped copper plate. A first circular copper plate is provided outside the first sector-shaped copper plate, and a second circular copper plate is provided outside the fourth sector-shaped copper plate. A first semiconductor chip is provided between the first sector-shaped copper plate and the second sector-shaped copper plate, a second semiconductor chip is provided between the first sector-shaped copper plate and the third sector-shaped copper plate, a third semiconductor chip is provided between the second circular copper plate and the fourth sector-shaped copper plate, and a fourth semiconductor chip is provided between the third sector-shaped copper plate and the fourth sector-shaped copper plate. A first pressure electrical connection mechanism is provided between the first sector-shaped copper plate and the first circular copper plate, and a second pressure electrical connection mechanism is provided between the fourth sector-shaped copper plate and the second circular copper plate. The first pressure electrical connection mechanism and the second pressure electrical connection mechanism are disconnected when the pressure is lower than the atmospheric pressure.

[0008] Furthermore, the aluminum alloy encapsulation case is formed by stamping. Stamping is simple and fast, and the cost is greatly reduced compared with the traditional machined aluminum alloy shell.

[0009] Furthermore, an encapsulation case protruding button is stamped at the bottom of the aluminum alloy encapsulation case. The encapsulation case protruding button protrudes from the bottom surface of the aluminum alloy encapsulation case. The encapsulation case protruding button is stamped into an encapsulation case recessed groove during encapsulation, so as to reduce the volume inside the aluminum alloy encapsulation case, thereby increasing the internal pressure. The opening edge of the aluminum alloy encapsulation case is stamped into an encapsulation necking, which further strengthens the resin encapsulation layer, prevents the resin encapsulation layer from being damaged, and at the same time eliminates the need for an additional upper cover, reducing the cost.

[0010] Furthermore, the polyester cage is annular, and a groove is provided inside the polyester cage. The circular circuit board is embedded in the groove to isolate the circular circuit board from the aluminum alloy encapsulation case and avoid short circuits.

[0011] Furthermore, the insulating and heat-conducting layer is made of heat-conducting gel, which has good heat-conducting performance and can transfer heat efficiently. During the operation of the rectifier, a large amount of heat is generated by the electronic circuit and the semiconductor chip. The heat-conducting gel can effectively conduct this heat from the heating element to the radiator or other heat-dissipating media, thus ensuring that the temperature inside the rectifier remains within a safe range. In addition, the heat-conducting gel is poured into the rectifier during the encapsulation process to form a certain pressure environment. When there are problems with the encapsulation of the rectifier, such as aging, cracks or loose sealing of the encapsulation material, 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 the same. This change can trigger the pressure insurance mechanism inside the rectifier to disconnect the circuit and play a protective role. The resin encapsulation layer is made of epoxy resin. As an encapsulation material, epoxy resin can tightly wrap the electronic circuit and semiconductor chip inside the rectifier to form a complete encapsulation structure. This helps to prevent the intrusion of external moisture, dust and other pollutants, improve the encapsulation integrity and reliability of the rectifier. Epoxy resin has extremely high electrical insulation strength, can effectively isolate the internal components from the external circuit, and prevent the occurrence of electric leakage and short-circuit phenomena. Epoxy resin can also withstand a relatively high working temperature, ensure that the encapsulation material does not deform or age under high-temperature environment, help 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 problems such as corrosion and oxidation. This chemical stability helps to keep the internal environment of the rectifier clean and dry and reduce the failures caused by chemical substance erosion.

[0012] Furthermore, the first AC input terminal is welded to the first circular copper plate, the second AC input terminal is welded to the second circular copper plate, the first DC output terminal is welded to the third sector-shaped copper plate, and the second DC output terminal is welded to the second sector-shaped copper plate.

[0013] Further, the first pressure power connection mechanism includes a folding airbag. The bottom of the folding airbag is fixedly connected with a first sealed copper sheet, and the top of the folding airbag is fixedly connected with a second sealed copper sheet. The folding airbag is adhesively sealed with the first sealed copper sheet, and the second sealed copper sheet is welded with a thermal spring below. The lower end of the thermal spring is welded with a movable contact. A connecting copper sheet is welded on the first circular copper plate. The connecting copper sheet is bent in a Z shape, and the end of the connecting copper sheet is located above the folding airbag. The end of the connecting copper sheet is welded with a power connection spring, and the lower end of the power connection spring is welded together with the second sealed copper sheet. The second pressure power connection mechanism is similar in structure to the first pressure power connection mechanism. Therefore, when the pressure increases, the folding airbag is compressed downward, causing the movable contact to contact the first sealed copper sheet, completing the connection between the first sector-shaped copper plate and the first circular copper plate. The second pressure power connection mechanism is similar in structure to the first pressure power connection mechanism. When pressurized, the second pressure power connection mechanism connects the fourth sector-shaped copper plate and the second circular copper plate, enabling the rectifier circuit to work properly.

[0014] Further, the folding airbag is made of high-temperature resistant rubber material, and the cross-section of the side wall of the folding airbag will not bend left and right. Therefore, the pressure can only compress the folding airbag downward.

[0015] The present invention provides another technical solution: a method for internal encapsulation of a bridge rectifier, and the method includes:

[0016] S1. Component assembly: First, place the polyester cage at the bottom of the aluminum alloy encapsulation shell, and then put the circular circuit board welded with power connection pins into the aluminum alloy encapsulation shell, making the power connection pins face outward, and making the circular circuit board snap into the groove of the polyester cage, so that the circular circuit board and the power connection pins have no contact with the inner wall of the aluminum alloy encapsulation shell;

[0017] S2. Protective filling: Use an automatic filling device to pour heat-conducting gel into the aluminum alloy encapsulation shell, so that the heat-conducting gel completely submerges the circular circuit board;

[0018] S3. Resin encapsulation: Use an automatic filling device to pour epoxy resin into the aluminum alloy encapsulation shell until it is 90% full;

[0019] S4. High-temperature curing: Place the filled rectifier into an oven and bake it at 150 °C for one hour until the epoxy resin cures;

[0020] S5. Pressurization activation: Use a press to stamp the encapsulated rectifier, stamp the protruding button at the bottom of the aluminum alloy encapsulation shell inward to form a sunken groove of the encapsulation shell, and stamp a shrinkage opening at the opening of the aluminum alloy encapsulation shell, so that the pressure of the heat-conducting gel inside the aluminum alloy encapsulation shell increases, thereby triggering the first pressure power connection mechanism and the second pressure power connection mechanism to complete the power connection;

[0021] S6. Power-on test: Power on the rectifier after stamping and conduct insulation test and peak current voltage test.

[0022] Furthermore, in S6, when conducting insulation test and peak current voltage test, if power can be connected, it proves that the encapsulation is intact without cracks; if power cannot be connected, it indicates that there are cracks in the resin encapsulation layer and the encapsulation fails.

[0023] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0024] In the present invention, a heat-conducting gel is poured into the lower layer of the aluminum alloy housing to wrap the electronic circuit and semiconductor chip with the heat-conducting gel, and then epoxy resin is poured into the upper layer for sealing. After that, high-temperature curing is carried out to make the epoxy resin completely cured. Then, through stamping processing, the protruding button at the bottom of the aluminum alloy encapsulation shell is stamped inward to form a recessed groove of the encapsulation shell, and an encapsulation shrinkage opening is stamped at the opening of the aluminum alloy encapsulation shell, so that the pressure of the heat-conducting gel inside the aluminum alloy encapsulation shell increases, thereby triggering the first pressure power-on mechanism and the second pressure power-on mechanism to complete power-on, having the following many advantages:

[0025] 1. Automatically detect the encapsulation quality: Through the overflow and leakage mechanism of the heat-conducting gel under pressure, when there is a problem with the encapsulation of the rectifier, the circuit can be automatically disconnected. In this way, after the encapsulation of the rectifier is completed, only power-on detection is required to synchronously determine whether the encapsulation is qualified, and there is no need for separate encapsulation quality detection, simplifying the encapsulation detection process and improving the encapsulation production efficiency.

[0026] 2. Safety insurance function: During long-term use, if problems such as aging and cracks occur in the epoxy resin encapsulation, the heat-conducting gel will also overflow, making the pressure inside and outside the rectifier tend to be the same, so that the first pressure power-on mechanism and the second pressure power-on mechanism disconnect the circuit. This design plays a role of safety insurance, effectively preventing accidents such as short circuits and fires caused by the aging of the rectifier encapsulation and improving the safety of the product.

[0027] 3. Thermal expansion and contraction protection function: When the rectifier is working and generating heat, the temperature will rise rapidly. At this time, the thermal expansion and contraction coefficients of the internal insulation and heat-conducting layer and the resin encapsulation layer are different, which may cause cracking problems. The folding airbag of the pressure power-on mechanism can provide a certain expansion adjustment effect to reduce the impact caused by thermal expansion and contraction. Brief Description of the Drawings

[0028] Figure 1 is a schematic diagram of the external structure of the present invention;

[0029] Figure 2 is a schematic cross-sectional view of the structure before encapsulation of the present invention;

[0030] Figure 3Schematic cross-sectional structure diagram after encapsulation of the present invention;

[0031] Figure 4 Schematic structure diagram of the insulating and heat-conducting layer and resin encapsulation layer of the present invention;

[0032] Figure 5 Exploded view of the present invention;

[0033] Figure 6 Schematic structure diagram of the power connection pin of the present invention;

[0034] Figure 7 Schematic structure diagram of the circular circuit board of the present invention;

[0035] Figure 8 Schematic structure diagram of the first pressure power connection mechanism of the present invention.

[0036] Reference numerals in the figure: 1, aluminum alloy encapsulation shell; 101, protruding button of the encapsulation shell; 102, recessed groove of the encapsulation shell; 103, encapsulation necking; 2, polyester cage; 3, circular circuit board; 301, first sector-shaped copper sheet; 302, second sector-shaped copper sheet; 303, third sector-shaped copper sheet; 304, fourth sector-shaped copper sheet; 305, first circular copper sheet; 306, second circular copper sheet; 307, first semiconductor chip; 308, second semiconductor chip; 309, third semiconductor chip; 310, 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 and heat-conducting layer; 6, resin encapsulation layer; 7, first pressure power connection mechanism; 701, folding airbag; 702, first sealing copper sheet; 703, second sealing copper sheet; 704, thermal spring; 705, movable contact; 706, connecting copper sheet; 707, power connection spring; 8, second pressure power connection mechanism. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] To further understand the content of the present invention, the present invention will be described in detail in conjunction with the accompanying drawings.

[0039] Please refer to Figure 1 - Figure 8, An internal packaging structure of a bridge rectifier, including an aluminum alloy packaging shell 1. The aluminum alloy packaging shell 1 is formed by stamping. The upper end of the aluminum alloy packaging shell 1 is open. The stamping process is simple and fast, and the cost is greatly reduced compared with the traditional machined aluminum alloy shell. At the bottom of the aluminum alloy packaging shell 1, a packaging shell protruding button 101 is stamped. The packaging shell protruding button 101 protrudes from the bottom surface of the aluminum alloy packaging shell 1. When packaging, the packaging shell protruding button 101 is stamped into a packaging shell concave groove 102, so as to reduce 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 necking 103 to further reinforce the resin packaging layer 6 and prevent the resin packaging layer 6 from being damaged. At the same time, no additional upper cover is required, reducing the cost.

[0040] A polyester cage 2 is arranged at the bottom of the aluminum alloy packaging shell 1. The polyester cage 2 is annular, and a groove is arranged inside the polyester cage 2. The circular circuit board 3 is embedded in the groove to isolate the circular circuit board 3 from the aluminum alloy packaging shell 1 and prevent short circuit.

[0041] The circular circuit board 3 is arranged on the polyester cage 2. The polyester cage 2 is used to isolate the circular circuit board 3 from the aluminum alloy packaging shell 1. Electric connection pins 4 are welded on the circular circuit board 3. The electric 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.

[0042] There are two layers of packaging layers inside the aluminum alloy packaging shell 1. The inner layer is an insulating and heat-conducting layer 5, and the outer layer is a resin packaging layer 6. The insulating and heat-conducting layer 5 uses a heat-conducting gel. The heat-conducting gel has good heat-conducting performance and can transfer heat efficiently. During the operation of the rectifier, a large amount of heat is generated by the electronic circuit and the semiconductor chip. The heat-conducting gel can effectively conduct this heat from the heating element to the radiator or other heat-dissipating media, so as to ensure that the temperature inside the rectifier remains within a safe range and avoid performance degradation or damage caused by overheating. 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, cracks or poor sealing of the packaging material, the heat-conducting gel will overflow and leak under the action of pressure, so that the internal and external pressures of the rectifier tend to be the same. This change can trigger the pressure insurance mechanism inside the rectifier to disconnect the circuit and play a protective role.

[0043] The resin encapsulation layer 6 uses epoxy resin. As an encapsulation material, the epoxy resin can tightly wrap the electronic circuits and semiconductor chips inside the rectifier to form a complete encapsulation structure. This helps prevent the intrusion of external moisture, dust, and other contaminants, improving the encapsulation integrity and reliability of the rectifier. The epoxy resin has extremely high electrical insulation strength, which can effectively isolate the internal components from the external circuit, preventing leakage and short-circuit phenomena. The epoxy resin can also withstand relatively high working temperatures, ensuring that the encapsulation material does not deform or age under high-temperature environments, helping to maintain the stability and reliability of the internal components of the rectifier and extending the service life of the rectifier. At the same time, the epoxy resin has excellent resistance to most chemical substances, preventing problems such as corrosion and oxidation. This chemical stability helps keep the internal environment of the rectifier clean and dry, reducing failures caused by chemical substance erosion.

[0044] The circular circuit board 3 includes a first sector-shaped copper plate 301, a second sector-shaped copper plate 302, a third sector-shaped copper plate 303, and a fourth sector-shaped copper plate 304. A first circular copper plate 305 is provided outside the first sector-shaped copper plate 301, and a second circular copper plate 306 is provided outside the fourth sector-shaped copper plate 304. A first semiconductor chip 307 is provided between the first sector-shaped copper plate 301 and the second sector-shaped copper plate 302, a second semiconductor chip 308 is provided between the first sector-shaped copper plate 301 and the third sector-shaped copper plate 303, a third semiconductor chip 309 is provided between the second circular copper plate 306 and the fourth sector-shaped copper plate 304, and a fourth semiconductor chip 310 is provided between the third sector-shaped copper plate 303 and the fourth sector-shaped copper plate 304. A first pressure electrical connection mechanism 7 is provided between the first sector-shaped copper plate 301 and the first circular copper plate 305, and a second pressure electrical connection mechanism 8 is provided between the fourth sector-shaped copper plate 304 and the second circular copper plate 306. The first pressure electrical connection mechanism 7 and the second pressure electrical connection mechanism 8 are disconnected when the pressure is lower than the atmospheric pressure. The first AC input terminal 401 is welded to the first circular copper plate 305, the second AC input terminal 402 is welded to the second circular copper plate 306, the first DC output terminal 403 is welded to the third sector-shaped copper plate 303, and the second DC output terminal 404 is welded to the second sector-shaped copper plate 302, thus forming a complete rectification circuit.

[0045] 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 adhesively sealed with the first sealed copper sheet 702. A thermal spring 704 is welded below the second sealed copper sheet 703. A movable contact 705 is welded to the lower end of the thermal 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. 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 at the bottom of the aluminum alloy encapsulation shell 1 is pressed into the encapsulation shell recess 102, the volume inside the encapsulation shell recess 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 cross-section of the folding airbag 701 will not bend left and right. Therefore, when the pressure increases, the folding airbag 701 will be compressed downward, causing the movable contact 705 to contact the first sealed copper sheet 702, completing the connection between the first sector-shaped copper plate 301 and the first circular copper plate 305. The second pressure power connection mechanism 8 has the same structure as the first pressure power connection mechanism 7. When pressurized, the second pressure power connection mechanism 8 connects the fourth sector-shaped copper plate 304 and the second circular copper plate 306, enabling the rectifier circuit to work properly.

[0046] It should be noted that there is a small gap between the movable contact 705 and the first sealed copper sheet 702 of the folding airbag 701 under normal pressure. When the folding 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. When the temperature exceeds 170 degrees Celsius, the thermal spring 704 will undergo a phase change due to overheating and shorten, thereby cutting off the circuit for protection, playing the role of an over-temperature fuse.

[0047] A method for internal encapsulation of a bridge rectifier, the method includes:

[0048] I. Component assembly: First, place the polyester cage 2 at the bottom of the aluminum alloy encapsulation shell 1. Then, put the circular circuit board 3 with the power connection pins 4 welded thereon into the aluminum alloy encapsulation shell 1, with the power connection pins 4 facing outward, and make the circular circuit board 3 snap into the groove of the polyester cage 2, so that the circular circuit board 3 and the power connection pins 4 have no contact with the inner wall of the aluminum alloy encapsulation shell 1.

[0049] II. Protective filling: Use an automatic filling device to pour thermal conductive gel into the aluminum alloy encapsulation shell 1 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 the gaps to ensure that no bubbles are generated.

[0050] III. Resin Encapsulation: Use an automatic filling device to pour epoxy resin into the aluminum alloy encapsulation shell 1 until it is 90% full, avoiding the generation of air bubbles.

[0051] IV. High - temperature Curing: Place the filled rectifier into an oven and bake it at 150 °C for one hour until the epoxy resin cures.

[0052] V. Pressurization Activation: Use a press to stamp the encapsulated rectifier. Stamp the encapsulation shell protrusion button 101 at the bottom of the aluminum alloy encapsulation shell 1 inward to form an encapsulation shell recessed groove 102, and stamp an encapsulation necking 103 at the opening of the aluminum alloy encapsulation shell 1, so that the pressure of the thermal gel inside the aluminum alloy encapsulation shell 1 increases, thereby triggering the first pressure - powered electrical mechanism 7 and the second pressure - powered electrical mechanism 8 to complete the electrical connection.

[0053] VI. Electrical Connection Test: Connect the stamped rectifier for electrical connection and conduct insulation testing and peak current - voltage testing. When conducting insulation testing and peak current - voltage testing, if it can be electrically connected, it proves that the encapsulation is intact without cracks; if there is no electrical connection, it indicates that there are cracks in the resin encapsulation layer 6 and the encapsulation fails.

[0054] Although the embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention. 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), and the polyester retaining frame (2) is used to isolate the circular circuit board (3) and the aluminum alloy packaging shell (1); The bottom of the aluminum alloy packaging shell (1) is punched to form 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 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; The aluminum alloy packaging shell (1) is provided with two inner and outer packaging layers, the inner layer being an insulating heat-conducting layer (5), the insulating heat-conducting layer (5) using a heat-conducting gel, and the outer layer being a resin packaging layer (6), the resin packaging layer (6) using an epoxy resin; The first pressure-connecting mechanism (7) and the second pressure-connecting mechanism (8) respectively comprise a folding airbag (701); a first sealing copper sheet (702) is fixedly connected to the bottom of the folding airbag (701); a second sealing copper sheet (703) is fixedly connected to the top of the folding airbag (701); the folding airbag (701) is bonded and sealed to the first sealing copper sheet (702) and the folding airbag (701) by glue; a thermal spring (704) is welded below the second sealing copper sheet (703); and a movable contact (705) is welded to the lower end of the thermal spring (704).

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 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).

6. The internal packaging structure of a bridge rectifier according to claim 5, characterized in that: The first pressure power connection mechanism (7) and the second pressure power connection mechanism (8) respectively comprise a connecting copper sheet (706), the connecting copper sheet (706) being bent in a Z-shape, one end of the connecting copper sheet (706) being located above the folding airbag (701), the other end of the connecting copper sheet (706) in the first pressure power connection mechanism (7) being welded to the first circular copper plate (305), the other end of the connecting copper sheet (706) in the second pressure power connection mechanism (8) being welded to the second circular copper plate (306), one end of the connecting copper sheet (706) being welded to a power connection spring (707), the lower end of the power connection spring (707) being welded to the second sealing copper sheet (703).

7. The internal packaging structure of a bridge rectifier according to claim 6, 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.

8. A packaging method for the internal packaging structure of a bridge rectifier according to any one of claims 1 to 7, 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.

9. The packaging method of the internal packaging structure of a bridge rectifier according to claim 8, 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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