CN116013818B - SiC packaging structure and packaging method - Google Patents

Abstract

The application discloses a SiC packaging structure and a packaging method, which relate to the field of circuit packaging and comprise a bottom plate and side plates; according to the SiC packaging structure and the packaging method, the chip can be welded through the arrangement of the welding mechanism, the chip can be always positioned through the arrangement of the positioning mechanism, the chip is prevented from moving in the welding process, the situation of cold joint or broken welding is prevented, protective gas continuously enters the protective gas action bin through the arrangement of the positioning mechanism, the welding is performed at the moment, if bubbles exist in the welding point due to the fact that the pressure in the protective gas action bin is increased, the bubbles are extruded to be discharged due to the fact that the air pressure outside the welding point is increased, meanwhile, when one of the two limiting rings reaches the limit position, the other limiting ring can continuously rotate under the action of the connecting rod until the two limiting rings reach the limit position, a plurality of clamping plates can clamp the chip at the moment, and the stability of the welding can be improved through the arrangement.

Description

A SiC packaging structure and packaging method

Technical field

The invention relates to circuit packaging technology, and in particular to a SiC packaging structure and packaging method.

Background technique

In the field of traditional semiconductor integrated circuit production (back-end packaging), ultrasonic welding process is usually used to complete the welding of chips. The process flow is briefly described as follows: Place the frame substrate, chip, and bonding wire in their designed positions for assembly, then fix the assembled product on the welding fixture, and then send the fixture with the product fixed into the orbit for ultrasonic welding. The process Protective gas is filled into the machine, and then welding begins. After the welding process is completed, the track is opened to deliver the product.

When the existing SiC packaging structure is used, the chip will move during the welding process, resulting in virtual or broken welding. At the same time, during the package welding process, there are bubbles in the welding points due to the movement of the welding gun.

Contents of the invention

The purpose of the present invention is to provide a SiC packaging structure and packaging method to solve the above-mentioned shortcomings in the prior art.

In order to achieve the above object, the present invention provides the following technical solution: a SiC packaging structure, including a bottom plate and a side plate, the bottom plate and the side plate are arranged in an L shape, and a clamping mechanism for clamping a copper substrate is fixedly provided on the top of the bottom plate , A first chute is provided on the side plate, and the first chute is slidably connected to a placement plate. The placement plate is provided with a welding mechanism, and the side plate is provided with a lifting mechanism that drives the placement plate to rise and fall.

Further, the clamping mechanism includes a placing platform and a plurality of positioning blocks. A plurality of sliding grooves are symmetrically provided on the top of the placing platform. The sliding grooves on the same side are slidingly connected with the same sliding rod. The plurality of positioning blocks are They are respectively fixedly connected to the opposite ends of a plurality of sliding rods. Each of the opposite ends of the sliding rods is provided with a sliding compartment. A plurality of limiting clamp blocks are slidingly connected in the sliding compartment. The opposite ends of the plurality of limiting clamp blocks are They are all equipped with electric telescopic rods, and the opposite ends of the plurality of electric telescopic rods are fixedly connected to the positioning blocks.

Further, the clamping mechanism also includes a plurality of first positioning bolts, a plurality of second positioning bolts and a plurality of second chute. The plurality of second chute is symmetrically opened on the top of the sliding rod. The second positioning bolts slide in different second slide grooves respectively, and the second positioning bolts are connected to the limiting clamp blocks. The plurality of first positioning bolts respectively penetrate both ends of the first positioning bolts and are connected to the sliding grooves.

Further, the lifting mechanism includes a sliding column and a threaded column fixedly connected to the bottom plate. The threaded column is rotationally connected to the bottom plate, and a threaded rod rotating machine is provided on the side plate to control the rotation of the threaded column. There are openings on the placing plate. There are sliding holes that are slidingly connected to the sliding columns and threaded holes that are threadedly connected to the threaded columns.

Further, the welding mechanism includes a first baffle and a second baffle fixedly connected to the side plate. A discharge device is fixedly provided on the top of the first baffle, and a dual-purpose vacuum pump is provided on the second baffle. .

Further, the welding mechanism also includes a feed pipe that runs through the placing plate, and the inner wall of the feed pipe is provided with an anti-corrosion coating. The feed pipe is provided with a voltage output line, and one end of the voltage output line is connected to the discharge device. , the other end of the voltage output line is connected to a working pipe, and the working pipe is connected to the feed pipe, a protector is provided on the top of the side wall of the working pipe, and a protective gas chamber is provided on the side wall of the working pipe, and the working pipe runs through On the top of the protective gas chamber, one end of the working tube located inside the protective gas chamber is provided with a positioning mechanism for positioning the chip.

Further, the positioning mechanism includes a connecting block fixedly connected to the side wall of the working pipe, and a sliding groove is provided on the connecting block. A driving rod is slidably connected in the sliding groove, and the two ends of the driving rod are respectively rotatably connected to the first The connecting rod and the second connecting rod, the ends of the first connecting rod and the second connecting rod are rotationally connected to the limiting rings, the opposite ends of the plurality of limiting rings fit each other and are coaxially rotatably connected, and the plurality of limiting rings are The opposite ends of the limiting ring are respectively rotatably connected to a first fixed shell and a bottom cover, and the first fixed shell and the bottom cover are fixedly connected. Both the first fixed shell and the bottom cover are fixedly connected to the working pipe, and the first fixed shell and the bottom cover are fixedly connected to the working pipe. The bottom cover is provided with a plurality of third slide grooves in a cross shape, and the plurality of third slide grooves are all slidably connected with splints.

Further, each of the plurality of limiting rings includes an annular plate, and two arc-shaped grooves are symmetrically provided on the annular plate, and notches are provided between adjacent arc-shaped grooves. The plurality of clamping plates are respectively connected with Different slots are slidingly connected. The side wall of the annular plate is provided with a first fixed block, and a rotating shaft is fixedly connected to the first fixed block. A plurality of the first fixed blocks are respectively connected to the first connecting rod and the second connecting rod in a rotational manner.

Further, the limiting ring has a cavity, and a slider is slidably connected in the cavity, and the slider and the driving rod are rotationally connected. A telescopic tube is provided in the cavity, and the side wall of the telescopic tube A plurality of pressure relief valves are provided throughout, and a spring is set on the outside of the telescopic tube. Both ends of the spring are fixedly connected to the slider and the limit ring respectively. A trachea is connected to the top of the telescopic tube, and the trachea is connected to the vacuum pump.

A SiC packaging method including:

S1. Solder paste printing and chip mounting. First, ultrasonically clean the copper substrate in the order of 5% dilute hydrochloric acid, deionized water, and absolute ethanol to remove oxides and oil stains on the copper surface, and then mix the uniformly stirred nano-silver solder paste. Print on the top of the substrate through the stencil, and then use a high-precision placement machine to place the chip on top of the solder paste;

S2. The nano-silver solder paste is sintered at low temperature, and the substrate with the chip attached in step 1 is placed into a vacuum furnace for soldering;

S3, secondary welding, fix the copper base plate, SAC305 solder tab and DBC substrate through the clamp, and then put the device into the ATV vacuum sintering furnace to continue welding;

S4. Shell installation, install and fix the plastic shell to the copper base plate through four rivets, and then apply polymer resin evenly in the gap between the shell and the base plate;

S5. Wire bonding. Fix the module cured in the previous step on the workbench. Set the position of each lead and the ultrasonic bonding parameters through the computer. After the settings are completed, the bonding equipment can automatically complete the wire bonding process;

S6. Glue sealing, add the prepared silicone gel into the above module, use a vacuum device to remove air bubbles in the sealant, and wait for the sealant to solidify.

Compared with the existing technology, the SiC packaging structure and packaging method provided by the present invention can weld the chip through the setting of the welding mechanism, and the positioning mechanism can always position the chip during welding to prevent the chip from being welded. Movement will occur during the welding process, resulting in virtual welding or broken welding. The setting of the positioning mechanism allows the protective gas to continuously enter the protective gas action chamber. At this time, welding will occur. Due to the increase in pressure in the protective gas action chamber, if There are bubbles in the welding point. Due to the increase in air pressure outside the welding point, the bubbles are squeezed and discharged. At the same time, when one of the two limit rings reaches the extreme position, the other can continue to rotate under the action of the connecting rod until both Each limit ring reaches the extreme position. At this time, multiple splints can clamp the chip. This setting can increase the stability during welding.

Description of the drawings

In order to more clearly explain the embodiments of the present application or the technical solutions in the prior art, the drawings needed to be used in the embodiments will be briefly introduced below. Obviously, the drawings in the following description only describe the present invention. For some embodiments, those of ordinary skill in the art can also obtain other drawings based on these drawings.

Figure 1 is a schematic diagram of the overall structure provided by an embodiment of the present invention;

Figure 2 is a schematic structural diagram of a clamping mechanism provided by an embodiment of the present invention;

Figure 3 is an enlarged schematic diagram of the structure at A in Figure 2;

Figure 4 is a schematic structural diagram of a welding mechanism provided by an embodiment of the present invention;

Figure 5 is a schematic structural diagram of a positioning mechanism provided by an embodiment of the present invention;

Figure 6 is a schematic diagram of the partial explosion structure of the positioning mechanism provided by the embodiment of the present invention;

Figure 7 is a schematic structural diagram of a limiting ring provided by an embodiment of the present invention;

Figure 8 is a schematic structural diagram of a connection block provided by an embodiment of the present invention.

Explanation of reference symbols:

1. Bottom plate; 2. Side plate; 3. Clamping mechanism; 301. Placement table; 302. Positioning block; 303. Electric telescopic rod; 304. Limit clamp block; 305. Sliding rod; 306. Sliding groove; 307. First positioning bolt; 308, second positioning bolt; 309, second chute; 4, first baffle; 5, discharge device; 6, vacuum pump; 7, air pipe; 8, second baffle; 9, welding mechanism ; 91. Working pipe; 92. Positioning mechanism; 921. Connecting block; 9211. Slider; 9212. Telescopic tube; 9213. Spring; 9214. Pressure relief valve; 922. Driving rod; 923. First connecting rod; 924. Second connecting rod; 925, splint; 926, first fixed shell; 927, limit ring; 9271, notch; 9272, arc groove; 9273, rotating shaft; 9274, first fixed block; 928, bottom cover; 929. Third chute; 93. Protective gas chamber; 94. Protector; 95. Feed pipe; 96. Voltage output line; 97. Anti-corrosion coating; 10. Sliding column; 11. Threaded column; 12. No. A chute; 13. Threaded rod rotating machine; 14. Placing plate.

Detailed ways

In order to enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be introduced in further detail below in conjunction with the accompanying drawings.

Please refer to Figure 1-8. A SiC packaging structure includes a bottom plate 1 and a side plate 2. The bottom plate 1 and the side plate 2 are arranged in an L shape. The top of the bottom plate 1 is fixed with a clamping mechanism for clamping the copper substrate. By clamping The setting of the mechanism can prevent the copper substrate from moving during the welding process. A first chute 12 is provided on the side plate 2, and the first chute 12 is slidably connected to a placement plate 14, and a welding mechanism 9 is provided on the placement plate 14. And the side plate 2 is provided with a lifting mechanism that drives the placement plate 14 to rise and fall. In this way, the lifting mechanism can drive the welding mechanism 9 that is fixedly connected to the placement plate 14 to move up and down.

The clamping mechanism 3 includes a placement platform 301 and a plurality of positioning blocks 302. A plurality of sliding grooves 306 are symmetrically provided on the top of the placement platform 301. The sliding grooves 306 on the same side are slidingly connected with the same sliding rod 305. In this way, the sliding rod 305 can be slid Sliding in the groove 306, a plurality of positioning blocks 302 are respectively fixedly connected to the opposite ends of a plurality of sliding rods 305. The opposite ends of the plurality of sliding rods 305 are provided with sliding bins, and a plurality of limiting clamp blocks 304 are slidably connected in the sliding bins, so that The setting can be made by approaching each other with the limit clamp blocks 304 on the same side, so as to clamp the copper substrate placed between the adjacent limit clamp blocks 304 on the same side. The opposite ends of the multiple limit clamp blocks 304 are equipped with electric telescopic devices. Rod 303, the opposite ends of multiple electric telescopic rods 303 are all fixedly connected to the positioning block 302. The purpose of this arrangement is to change the position of the adjacent limiting clamp block 304 on the same side by controlling the expansion and contraction of the electric telescopic rod 303, so that The purpose of setting is that when the copper substrate is placed between the adjacent limiting clamp blocks 304 on the same side, the electric telescopic rod 303 is activated, and the positions of the adjacent limiting clamp blocks 304 on the same side are close to each other, so that the adjacent limiting clamp blocks 304 on the same side are positioned closer to each other. The copper substrate is clamped between adjacent limiting clamping blocks 304 .

The clamping mechanism 3 also includes a plurality of first positioning pegs 307, a plurality of second positioning pegs 308 and a plurality of second chute 309. The plurality of second chute 309 is symmetrically opened on the top of the sliding rod 305. The bolts 308 slide in different second slide grooves 309 respectively, and the second positioning bolts 308 are connected to the limiting clamps 304. A plurality of first positioning bolts 307 respectively penetrate both ends of the first positioning bolts 307 and are connected to the sliding grooves 306, so that The purpose of the setting is to facilitate fixation through the first positioning bolt 307 when the position of the sliding rod 305 is determined. When the position of the limit clamp 304 is determined, it can be fixed through the second positioning bolt 308. This setting can ensure that the clamping mechanism 3 There will be no shaking when clamping the copper substrate.

The lifting mechanism includes a sliding column 10 and a threaded column 11 fixedly connected to the base plate 1. The threaded column 11 is rotationally connected to the base plate 1, and a threaded rod rotating machine 13 is provided on the side plate 2 to control the rotation of the threaded column 11. There are openings on the placement plate 14. There is a sliding hole slidably connected with the sliding column 10 and a threaded hole threadedly connected with the threaded column 11. The purpose of this arrangement is that when the threaded rod rotating machine 13 drives the threaded column 11 to rotate, the threaded column 11 will drive the placement plate 14 to move up and down. , the movement direction of the placement plate 14 can be changed by changing the rotation direction of the threaded column 11.

The welding mechanism 9 includes a first baffle 4 and a second baffle 8 fixedly connected to the side plate 2. A discharge device 5 is fixedly installed on the top of the first baffle 4. The discharge device 5 is provided to supply power to the working pipe 91 in the welding device. , and a dual-purpose vacuum pump 6 is provided through the second baffle 8, wherein the dual-purpose vacuum pump 6 can not only perform an inflation operation, but also a degassing operation.

The welding mechanism 9 also includes a feed pipe 95 that runs through the placing plate 14, and the inner wall of the feed pipe 95 is provided with an anti-corrosion coating 97. The purpose of this arrangement is to prevent corrosion of the inner wall of the feed pipe 95. The feed pipe 95 is provided with a The voltage output line 96 is connected to the discharge device 5 at one end, and the working tube 91 is connected to the other end of the voltage output line 96. The purpose of this arrangement is to connect the discharge device 5 and the working tube 91 through the voltage output line 96. , and the working pipe 91 is connected with the feed pipe 95, so that the welding material can flow into the working pipe 91 through the feeding pipe 95. A protector 94 is provided on the top of the side wall of the working pipe 91, and the protector 94 stabilizes the voltage output line 96. Output voltage and current, so that high-temperature gas flows to the chip in all directions of the welding system, and a protective gas chamber 93 is provided on the side wall of the working tube 91, and the working tube 91 penetrates the top of the protective gas chamber 93, and the working tube 91 is located at the protective One end of the inside of the gas chamber 93 is provided with a positioning mechanism for positioning the chip. The setting of the positioning mechanism can always position the chip during welding to prevent the chip from moving during the welding process, resulting in false soldering or broken soldering. situation occurs.

The positioning mechanism includes a connecting block 921 fixedly connected to the side wall of the working tube 91, and a sliding groove is provided on the connecting block 921. A driving rod 922 is slidably connected in the sliding groove, and a limiting ring 927 is provided with a cavity, and the cavity slides A slider 9211 is connected. This arrangement allows the slider 9211 to slide in the cavity, and the slider 9211 and the drive rod 922 are rotationally connected. A telescopic telescopic tube 9212 is provided in the cavity, and the side wall of the telescopic tube 9212 is provided through There are multiple pressure relief valves 9214, of which the pressure will be relieved only when the pressure relief valve 9214 reaches a certain pressure, and a spring 9213 is set on the outside of the telescopic tube 9212, and the two ends of the spring 9213 are connected to the slider 9211 and the limit ring 927 respectively. Fixed connection, the top of the telescopic tube 9212 is connected to the trachea 7, and the trachea 7 is connected with the vacuum pump 6. The purpose of this arrangement is that when the vacuum pump 6 passes gas into the telescopic tube 9212 through the trachea 7, the telescopic tube 9212 will extend, driving the The slider 9211 slides downward. When the slider 9211 no longer slides downward, the gas pressure in the trachea 7 continues to increase. When the gas pressure in the trachea 7 exceeds the threshold of the pressure relief valve 9214, the gas is discharged through the pressure relief valve 9214. At the same time, the discharged gas continuously enters the protective gas action chamber 93. At this time, welding is performed. Since the pressure in the protective gas action chamber 93 increases during welding, if there are bubbles in the welding point, the bubbles will be squeezed due to the increase in air pressure outside the welding point. Exhaust.

A first connecting rod 923 and a second connecting rod 924 are respectively rotatably connected to both ends of the driving rod 922. The ends of the first connecting rod 923 and the second connecting rod 924 are both rotatably connected to a limiting ring 927. The opposite ends of a plurality of limiting rings 927 Fitting each other and coaxially rotating, the opposite ends of the plurality of limiting rings 927 are respectively rotatably connected to a first fixed shell 926 and a bottom cover 928, and the first fixed shell 926 and the bottom cover 928 are fixedly connected. The first fixed shell 926 The bottom cover 928 and the bottom cover 928 are all fixedly connected to the working pipe 91. The bottom cover 928 is provided with a plurality of third chute 929 in a cross shape, and the plurality of third chute 929 are all slidingly connected with a splint 925 and a plurality of limiting rings 927. Both include an annular plate, and two arc-shaped grooves 9272 are symmetrically arranged on the annular plate. Notches 9271 are provided between adjacent arc-shaped grooves 9272. Multiple splints 925 are slidingly connected to different notches 9271. The side of the annular plate The wall is provided with a first fixed block 9274, and a rotating shaft 9273 is fixedly connected to the first fixed block 9274. The plurality of 9273 are respectively rotatably connected to the first connecting rod 923 and the second connecting rod 924. The purpose of this arrangement is to ensure that when the gas passes through The trachea 7 is injected into the telescopic tube 9212. The telescopic tube 9212 drives the slider 9211 to move downward. The two ends of the driving rod 922 push one limit ring 927 to rotate clockwise and the other outward through the first connecting rod 923 and the second connecting rod 924. The limit ring 927 rotates counterclockwise, and when one of the two limit rings 927 reaches the limit position, the other one can continue to rotate under the action of the connecting rod until both limit rings 927 reach the limit position. At this time Multiple clamping plates 925 can clamp the chip.

A SiC packaging method including:

S1. Solder paste printing and chip mounting. First, ultrasonically clean the copper substrate in the order of 5% dilute hydrochloric acid, deionized water, and absolute ethanol to remove oxides and oil stains on the copper surface, and then mix the uniformly stirred nano-silver solder paste. Print on the top of the substrate through the stencil, and then use a high-precision placement machine to place the chip on top of the solder paste;

S2. The nano-silver solder paste is sintered at low temperature, and the substrate with the chip attached in step 1 is placed into a vacuum furnace for soldering;

S3, secondary welding, fix the copper base plate, SAC305 solder tab and DBC substrate through the clamp, and then put the device into the ATV vacuum sintering furnace to continue welding;

S4. Shell installation, install and fix the plastic shell to the copper base plate through four rivets, and then apply polymer resin evenly in the gap between the shell and the base plate;

S5. Wire bonding. Fix the module cured in the previous step on the workbench. Set the position of each lead and the ultrasonic bonding parameters through the computer. After the settings are completed, the bonding equipment can automatically complete the wire bonding process;

S6. Glue sealing, add the prepared silicone gel into the above module, use a vacuum device to remove air bubbles in the sealant, and wait for the sealant to solidify.

Working principle: When using, first ultrasonically clean the copper substrate in the order of 5% dilute hydrochloric acid, deionized water, and absolute ethanol to remove oxides and oil stains on the copper surface, and then print the uniformly stirred nano-silver solder paste through the stencil to the top of the substrate, and then use a high-precision placement machine to place the chip on top of the solder paste. Put the substrate with the chip attached in step 1 into a vacuum furnace for welding, and fix the copper base plate, SAC305 solder tab and DBC through the clamp base plate, and then put the device into the ATV vacuum sintering furnace to continue welding. Install and fix the plastic shell to the copper base plate through four rivets. Then apply the polymer resin evenly in the gap between the outer shell and the base plate, and solidify it in the previous step. The final module is fixed on the workbench, and the position of each lead and the ultrasonic bonding parameters are set through the computer. After the settings are completed, the bonding equipment can automatically complete the wire bonding process, and the prepared silicone gel is added to the above module. Inside, use a vacuum device to remove air bubbles in the sealant and wait for the sealant to solidify.

Certain exemplary embodiments of the present invention have been described above only by way of illustration. It goes without saying that those skilled in the art can implement various embodiments in various ways without departing from the spirit and scope of the present invention. The described embodiments are modified. Therefore, the above drawings and descriptions are illustrative in nature and should not be construed as limiting the scope of the claims of the present invention.

Claims (5)

1. The utility model provides a SiC packaging structure, includes bottom plate (1) and curb plate (2), its characterized in that, bottom plate (1) and curb plate (2) are L shape setting, bottom plate (1) top is fixed to be provided with the fixture of centre gripping copper substrate, first spout (12) have been seted up on curb plate (2), and first spout (12) sliding connection has place board (14), be provided with welding mechanism (9) on placing board (14), and be provided with the elevating system that drives to place board (14) on curb plate (2);

the welding mechanism (9) comprises a first baffle (4) and a second baffle (8) which are fixedly connected with the side plate (2), a discharge device (5) is fixedly arranged at the top of the first baffle (4), and a dual-purpose vacuum pump (6) is arranged on the second baffle (8) in a penetrating manner;

the welding mechanism (9) further comprises a feeding pipe (95) which is arranged through the placing plate (14), an anti-corrosion coating (97) is arranged on the inner wall of the feeding pipe (95), a voltage output wire (96) is arranged through the feeding pipe (95), one end of the voltage output wire (96) is communicated with the discharging device (5), the other end of the voltage output wire (96) is communicated with a working pipe (91), the working pipe (91) is communicated with the feeding pipe (95), a protector (94) is arranged at the top of the side wall of the working pipe (91), a protective gas action bin (93) is arranged at the side wall of the working pipe (91), the working pipe (91) penetrates through the top of the protective gas action bin (93), and a positioning mechanism (92) for positioning the chip is arranged at one end of the working pipe (91) inside the protective gas action bin (93).

The positioning mechanism (92) comprises a connecting block (921) fixedly connected with the side wall of the working tube (91), a sliding groove is formed in the connecting block (921), a driving rod (922) is connected in the sliding groove in a sliding mode, a first connecting rod (923) and a second connecting rod (924) are respectively connected at two ends of the driving rod (922) in a rotating mode, limiting rings (927) are respectively connected at the ends of the first connecting rod (923) and the second connecting rod (924) in a rotating mode, opposite ends of the limiting rings (927) are mutually attached and coaxially connected in a rotating mode, a first fixing shell (926) and a bottom cover (928) are respectively connected at opposite ends of the limiting rings (927) in a rotating mode, the first fixing shell (926) and the bottom cover (928) are fixedly connected with the working tube (91) in a penetrating mode, and a plurality of third sliding grooves (929) are formed in the bottom cover (928) in a cross mode, and clamping plates (925) are respectively connected in the third sliding grooves (929) in a sliding mode;

the limiting rings (927) comprise annular plates, two arc grooves (9272) are symmetrically formed in the annular plates, notches (9271) are formed between the adjacent arc grooves (9272), the clamping plates (925) are respectively connected with different notches (9271) in a sliding mode, first fixing blocks (9274) are arranged on the side walls of the annular plates, rotating shafts (9273) are fixedly connected to the first fixing blocks (9274), and the rotating shafts (9273) are respectively connected with the first connecting rods (923) and the second connecting rods (924) in a rotating mode;

the utility model discloses a vacuum pump, including spacing ring (927), including flexible pipe (9212), vacuum pump (6), air pipe (9212), air pipe (9213), spacing ring (927) has seted up the cavity, and sliding connection has slider (9211), and slider (9211) and actuating lever (922) rotate to be connected, be provided with telescopic flexible pipe (9212) in the cavity, and flexible pipe (9212) lateral wall runs through and is provided with a plurality of relief valves (9214), and flexible pipe (9212) outside cover is equipped with spring (9213), spring (9213) both ends respectively with slider (9211) and spacing ring (927) fixed connection, flexible pipe (9212) top is connected with trachea (7), and trachea (7) and vacuum pump (6) intercommunication.

2. The SiC package structure according to claim 1, wherein the clamping mechanism (3) includes a placement table (301) and a plurality of positioning blocks (302), a plurality of sliding grooves (306) are symmetrically formed in the top of the placement table (301), the same sliding rod (305) is slidably connected to the sliding grooves (306) on the same side, the positioning blocks (302) are fixedly connected to opposite ends of the sliding rods (305), sliding bins are formed in opposite ends of the sliding rods (305), a plurality of limiting clamping blocks (304) are slidably connected to the sliding bins, electric telescopic rods (303) are arranged at opposite ends of the limiting clamping blocks (304), and the opposite ends of the electric telescopic rods (303) are fixedly connected to the positioning blocks (302).

3. The SiC packaging structure according to claim 2, wherein the clamping mechanism (3) further includes a plurality of first positioning pins (307), a plurality of second positioning pins (308) and a plurality of second sliding grooves (309), the second sliding grooves (309) are symmetrically formed in the top of the sliding rod (305), the second positioning pins (308) slide in different second sliding grooves (309), the second positioning pins (308) are connected with the limiting clamping blocks (304), and the first positioning pins (307) penetrate through two ends of the first positioning pins (307) and are connected with the sliding grooves (306).

4. The SiC packaging structure according to claim 1, characterized in that the lifting mechanism comprises a sliding column (10) fixedly connected with the bottom plate (1) and a threaded column (11), the threaded column (11) is rotationally connected with the bottom plate (1), a threaded rod rotating machine (13) for controlling the threaded column (11) to rotate is arranged on the side plate (2), and a sliding hole slidingly connected with the sliding column (10) and a threaded hole in threaded connection with the threaded column (11) are formed in the placing plate (14).

5. A SiC packaging method suitable for the SiC packaging structure of any one of claims 1 to 4, comprising:

s1, printing soldering paste and attaching a chip, namely firstly ultrasonically cleaning a copper substrate according to the sequence of 5% dilute hydrochloric acid, deionized water and absolute ethyl alcohol to remove oxides and greasy dirt on the surface of copper, then printing the uniformly stirred nano silver soldering paste onto the substrate through a steel screen, and then attaching the chip onto the soldering paste by using a high-precision chip mounter;

s2, sintering the nano silver soldering paste at a low temperature, and placing the substrate with the chip attached in the step 1 into a vacuum furnace for welding;

s3, secondary welding, namely fixing a copper bottom plate, a SAC305 soldering lug and a DBC substrate through a clamp, and then placing the device into an ATV vacuum sintering furnace for continuous welding;

s4, mounting the shell, namely mounting and fixing the plastic shell on the copper bottom plate through four rivets, and uniformly coating high polymer resin at the gap between the shell and the bottom plate;

s5, wire bonding, namely fixing the module cured in the previous step on a workbench, setting the position and ultrasonic bonding parameters of each wire through a computer, and automatically completing the wire bonding process by bonding equipment after setting;

s6, filling and sealing, namely adding the prepared silicone gel into the module, removing bubbles in the sealing gel by using a vacuumizing device, and waiting for curing of the sealing gel.