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

SiC packaging structure and packaging method

Technical Field

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

Background

In the field of conventional semiconductor integrated circuit production (subsequent packaging), an ultrasonic soldering process is generally used to complete the soldering of the chip. The process flow is briefly described as follows: and (3) placing the frame substrate, the chip and the bonding wires at the design positions of the frame substrate, the chip and the bonding wires for assembly, fixing the assembled product on a welding fixture, sending the fixture fixed with the product into a rail for ultrasonic welding, filling protective gas in the process, starting welding, and opening the rail to send out the product after the welding procedure is finished.

When the existing SiC packaging structure is used, a chip can move in the welding process, so that the situation of cold joint or broken joint occurs, and bubbles exist in the moving welding point of a welding gun in the packaging welding process.

Disclosure of Invention

The application aims to provide a SiC packaging structure and a packaging method, which are used for solving the defects in the prior art.

In order to achieve the above object, the present application provides the following technical solutions: the utility model provides a SiC packaging structure, includes bottom plate and curb plate, bottom plate and curb plate are L shape setting, the fixed fixture who is provided with centre gripping copper base plate in bottom plate top, first spout has been seted up on the curb plate, and first spout sliding connection has place the board, be provided with welding mechanism on placing the board, and be provided with the drive on the curb plate and place the elevating system that the board goes up and down.

Further, fixture is including placing platform and a plurality of locating piece, place platform top symmetry and seted up many sliding trays, homonymy sliding tray sliding connection has same slide bar, and a plurality of locating piece difference fixed connection is at a plurality of slide bar opposite ends, and is a plurality of slide storehouse has all been seted up to slide bar opposite ends, slide in the slide storehouse and be connected with a plurality of spacing clamp splice, a plurality of spacing clamp splice opposite ends all are provided with electric telescopic handle, a plurality of electric telescopic handle opposite ends all with locating piece fixed connection.

Further, the clamping mechanism further comprises a plurality of first positioning bolts, a plurality of second positioning bolts and a plurality of second sliding grooves, the second sliding grooves are symmetrically formed in the tops of the sliding rods, the second positioning bolts slide in different second sliding grooves respectively, the second positioning bolts are connected with the limiting clamping blocks, and the first positioning bolts penetrate through two ends of the first positioning bolts respectively and are connected with the sliding grooves.

Further, the lifting mechanism comprises a sliding column and a threaded column which are fixedly connected with the bottom plate, the threaded column is rotationally connected with the bottom plate, a threaded rod rotating machine for controlling the threaded column to rotate is arranged on the side plate, and a sliding hole which is slidingly connected with the sliding column and a threaded hole which is in threaded connection with the threaded column are formed in the placing plate.

Further, the welding mechanism comprises a first baffle and a second baffle which are fixedly connected with the side plates, a discharging device is fixedly arranged at the top of the first baffle, and a dual-purpose vacuum pump is arranged on the second baffle in a penetrating manner.

Further, welding mechanism is still including running through the inlet pipe of placing the board setting, and the inlet pipe inner wall is provided with anticorrosive coating, the inlet pipe runs through and is provided with voltage output line, and voltage output line one end and discharging device intercommunication, the voltage output line other end intercommunication has the work pipe, and work pipe and inlet pipe intercommunication, work pipe lateral wall top is provided with the protector, and the work pipe lateral wall is provided with the protection gas and acts on storehouse, and the work pipe runs through protection gas and acts on storehouse top, the work pipe is located the inside one end in protection gas and acts on storehouse and be provided with the positioning mechanism that fixes a position the chip.

Further, positioning mechanism includes the connecting block with work pipe lateral wall fixed connection, and has seted up the sliding tray on the connecting block, sliding connection has the actuating lever in the sliding tray, and the actuating lever both ends rotate respectively and be connected with head rod and second connecting rod, head rod and second connecting rod tip all rotate and are connected with the spacing ring, a plurality of spacing ring opposite ends laminating each other and coaxial rotation are connected, a plurality of spacing ring is rotationally connected with first fixed shell and bottom respectively in opposite directions, and first fixed shell and bottom fixed connection, first fixed shell and bottom all run through fixed connection with the work pipe, the bottom is a plurality of third spouts that are provided with, and equal sliding connection has splint in a plurality of third spouts.

Further, a plurality of the limiting rings all include the annular plate, and the symmetry is provided with two arc grooves on the annular plate, and is adjacent all seted up the notch between the arc groove, a plurality of splint respectively with different notch sliding connection, the annular plate lateral wall is provided with first fixed block, and fixedly connected with axis of rotation on the first fixed block, a plurality of respectively with head rod and second connecting rod rotate to be connected.

Further, the cavity has been seted up to the spacing ring, and sliding connection has the slider in the cavity, and slider and actuating lever rotate to be connected, be provided with telescopic flexible pipe in the cavity, and flexible pipe lateral wall runs through and is provided with a plurality of relief valves, and flexible pipe outside cover is equipped with the spring, spring both ends respectively with slider and spacing ring fixed connection, flexible pipe top is connected with the trachea, and trachea and vacuum pump intercommunication.

A SiC packaging method, 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.

Compared with the prior art, the SiC packaging structure and the packaging method provided by the application have the advantages that the chip can be welded through the arrangement of the welding mechanism, the chip can be positioned all the time through the arrangement of the positioning mechanism during welding, the situation that the chip can move in the welding process to cause virtual welding or broken welding is prevented, protective gas continuously enters the protective gas action bin for welding at the moment through the arrangement of the positioning mechanism, the pressure in the protective gas action bin is increased, if bubbles exist in the welding point, the bubbles are extruded and discharged due to the increase of the air pressure outside the welding point, and 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, and a plurality of clamping plates can clamp the chip at the moment, so that the stability during welding can be increased through the arrangement.

Drawings

In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments described in the present application, and other drawings may be obtained according to these drawings for a person having ordinary skill in the art.

FIG. 1 is a schematic diagram of an overall structure according to an embodiment of the present application;

fig. 2 is a schematic structural diagram of a clamping mechanism according to an embodiment of the present application;

FIG. 3 is an enlarged schematic view of the structure shown at A in FIG. 2;

FIG. 4 is a schematic diagram of a welding mechanism according to an embodiment of the present application;

FIG. 5 is a schematic diagram of a positioning mechanism according to an embodiment of the present application;

FIG. 6 is a schematic diagram of a local explosion structure of a positioning mechanism according to an embodiment of the present application;

FIG. 7 is a schematic view of a stop collar according to an embodiment of the present application;

fig. 8 is a schematic structural diagram of a connection block according to an embodiment of the present application.

Reference numerals illustrate:

1. a bottom plate; 2. a side plate; 3. a clamping mechanism; 301. a placement table; 302. a positioning block; 303. an electric telescopic rod; 304. limiting clamping blocks; 305. a slide bar; 306. a sliding groove; 307. a first positioning bolt; 308. a second positioning bolt; 309. a second chute; 4. a first baffle; 5. a discharge device; 6. a vacuum pump; 7. an air pipe; 8. a second baffle; 9. a welding mechanism; 91. a working tube; 92. a positioning mechanism; 921. a connecting block; 9211. a slide block; 9212. a telescopic tube; 9213. a spring; 9214. a pressure release valve; 922. a driving rod; 923. a first connecting rod; 924. a second connecting rod; 925. a clamping plate; 926. a first fixed housing; 927. a limiting ring; 9271. a notch; 9272. an arc-shaped groove; 9273. a rotating shaft; 9274. a first fixed block; 928. a bottom cover; 929. a third chute; 93. a protective gas action bin; 94. a protector; 95. a feed pipe; 96. a voltage output line; 97. an anti-corrosion coating; 10. a sliding column; 11. a threaded column; 12. a first chute; 13. a threaded rod rotation machine; 14. the plate is placed.

Detailed Description

In order to make the technical scheme of the present application better understood by those skilled in the art, the present application will be further described in detail with reference to the accompanying drawings.

Referring to fig. 1-8, an SiC package structure includes a bottom plate 1 and a side plate 2, where the bottom plate 1 and the side plate 2 are L-shaped, a clamping mechanism for clamping a copper substrate is fixedly arranged at the top of the bottom plate 1, the copper substrate can be prevented from moving in the welding process by the arrangement of the clamping mechanism, a first chute 12 is formed on the side plate 2, the first chute 12 is slidably connected with a placing plate 14, a welding mechanism 9 is arranged on the placing plate 14, and a lifting mechanism for driving the placing plate 14 to lift is arranged on the side plate 2, so that the welding mechanism 9 penetrating through the fixed connection on the placing plate 14 can be driven to move up and down by the lifting mechanism.

The clamping mechanism 3 comprises a placing table 301 and a plurality of positioning blocks 302, wherein a plurality of sliding grooves 306 are symmetrically formed in the top of the placing table 301, the same sliding rod 305 is slidably connected with the same sliding groove 306, the sliding rods 305 can be slidably connected with the same sliding rod 305 in the sliding grooves 306, the plurality of positioning blocks 302 are respectively and fixedly connected with opposite ends of the plurality of sliding rods 305, sliding bins are respectively formed in opposite ends of the plurality of sliding rods 305, a plurality of limiting clamping blocks 304 are slidably connected with the sliding bins, the limiting clamping blocks 304 on the same side can be mutually close to each other, so that a copper substrate placed between the adjacent limiting clamping blocks 304 on the same side can be clamped, the opposite ends of the limiting clamping blocks 304 are respectively provided with an electric telescopic rod 303, the opposite ends of the electric telescopic rods 303 are fixedly connected with the positioning blocks 302, the positions of the adjacent limiting clamping blocks 304 on the same side can be changed by controlling the telescopic rods 303 to be telescopic, and the aims of being set.

The clamping mechanism 3 further comprises a plurality of first positioning bolts 307, a plurality of second positioning bolts 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 bolts 308 slide in different second sliding grooves 309 respectively, the second positioning bolts 308 are connected with the limiting clamp blocks 304, the first positioning bolts 307 penetrate through two ends of the first positioning bolts 307 respectively and are connected with the sliding grooves 306, the purpose of the arrangement is that the clamping mechanism is convenient to fix through the first positioning bolts 307 when the position of the sliding rod 305 is determined, and the clamping mechanism can be ensured not to shake when the clamping mechanism 3 clamps a copper substrate through the second positioning bolts 308 when the position of the limiting clamp blocks 304 is determined.

The elevating system includes slip post 10 and screw thread post 11 with bottom plate 1 fixed connection, screw thread post 11 rotates with bottom plate 1 to be connected, and be provided with the threaded rod rotating machine 13 of control screw thread post 11 pivoted on the curb plate 2, set up on the board 14 with slip post 10 sliding connection's sliding hole and with screw thread post 11 threaded connection's screw hole, the purpose of setting like this is, when threaded rod rotating machine 13 drive screw thread post 11 rotate, screw thread post 11 can drive and place board 14 up-and-down motion, can change the direction of motion of placing board 14 through changing the direction of rotation of screw thread post 11.

The welding mechanism 9 comprises a first baffle 4 and a second baffle 8 which are fixedly connected with the side plate 2, a discharging device 5 is fixedly arranged at the top of the first baffle 4, the discharging device 5 is arranged for supplying power to a working tube 91 in the welding device, and a dual-purpose vacuum pump 6 is arranged on the second baffle 8 in a penetrating manner, wherein the dual-purpose vacuum pump 6 can be used for inflation operation and air extraction operation.

The welding mechanism 9 further comprises a feeding pipe 95 penetrating through the placing plate 14, and an anti-corrosion coating 97 is arranged on the inner wall of the feeding pipe 95, the purpose of the arrangement is to prevent corrosion of the inner wall of the feeding pipe 95, the feeding pipe 95 penetrates through a voltage output line 96, one end of the voltage output line 96 is communicated with the discharging device 5, the other end of the voltage output line 96 is communicated with a working pipe 91, the discharging device 5 and the working pipe 91 are communicated through the voltage output line 96, the working pipe 91 and the feeding pipe 95 are communicated, welding materials can flow into the working pipe 91 through the feeding pipe 95, a protector 94 is arranged on the top of the side wall of the working pipe 91, the protector 94 stabilizes output voltage and current of the voltage output line 96, so that all directions of the welding system have high-temperature gas flowing to a chip, the side wall of the working pipe 91 is provided with a protective gas action bin 93, the working pipe 91 penetrates through the top of the protective gas action bin 93, one end of the working pipe 91, and the working pipe 91 is positioned at the inner end of the protective gas action bin 93 is provided with a positioning mechanism for positioning the chip, and the positioning mechanism can always position the chip when welding, so that the chip is prevented from moving in the welding process, and the chip is prevented from being broken or broken.

The positioning mechanism comprises a connecting block 921 fixedly connected with the side wall of the working tube 91, a sliding groove is arranged on the connecting block 921, a driving rod 922 is connected in the sliding groove in a sliding way, a cavity is arranged on the limiting ring 927, a sliding block 9211 is connected in the cavity in a sliding way, the sliding block 9211 slides in the cavity, the sliding block 9211 is rotationally connected with the driving rod 922, a telescopic pipe 9212 is arranged in the cavity, a plurality of pressure relief valves 9214 are penetrated through the side wall of the telescopic pipe 9212, pressure relief can be carried out only when the pressure relief valve 9214 reaches a certain pressure, a spring 9213 is sleeved on the outer side of the telescopic pipe 9212, two ends of the spring 9213 are fixedly connected with the sliding block 9211 and the limiting ring 927 respectively, the top of the telescopic pipe 9212 is connected with the air pipe 7, and the air pipe 7 is communicated with the vacuum pump 6, the purpose of the arrangement is that when the vacuum pump 6 is used for introducing air into the telescopic pipe 9212 through the air pipe 7, the telescopic pipe 9212 stretches to drive the sliding block 9211 to slide downwards, when the sliding block 9211 does not slide downwards any more, the air pressure in the air pipe 7 is continuously increased, when the air pressure in the air pipe 7 exceeds the threshold value of the pressure relief valve 9214, air is discharged through the pressure relief valve 9214, meanwhile, the discharged air continuously enters the protective air action bin 93, welding is performed at the moment, due to the fact that the pressure in the protective air action bin 93 is increased, at the moment, if air bubbles exist in the welding point, the air bubbles are extruded and discharged due to the fact that the air pressure outside the welding point is increased.

The actuating lever 922 both ends rotate respectively and are connected with head rod 923 and second connecting rod 924, head rod 923 and second connecting rod 924 tip all rotate and are connected with spacing ring 927, a plurality of spacing rings 927 opposite ends mutually laminate and coaxial rotation are connected, a plurality of spacing rings 927 are rotated respectively and are connected with first fixed shell 926 and bottom 928 in opposite directions, and first fixed shell 926 and bottom 928 fixed connection, first fixed shell 926 and bottom 928 all run through fixed connection with work tube 91, bottom 928 is cross-shaped and is provided with a plurality of third spouts 929, and a plurality of third spouts 929 in all sliding connection have splint 925 a plurality of spacing rings 927 all include the annular slab, and the symmetry is provided with two arc grooves 9272 on the annular slab, notch 9271 has all been seted up between the adjacent arc groove 9272, a plurality of splint 9271 sliding connection with different notch 9271 respectively, the annular slab lateral wall is provided with first fixed block 9274, and fixed connection has axis of rotation 9273 on the first fixed block 9274, a plurality of 9273 respectively with first connecting rod 923 and second connecting rod rotate and be connected with head rod 91 runs through fixed connection, bottom 923 is like this and is that a plurality of limit rings 9212, can reach two limit rings 927 rotation limit position through two limit rings 927 and one of other end limit rings 927, can reach two limit expansion pipe positions through another limit ring 927, can rotate beyond the limit position, and two limit ring 927, can reach one of limit expansion pipe 927, and two limit expansion pipe position rotation limit position is reached.

A SiC packaging method, 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.

Working principle: when the device is used, firstly, a copper substrate is ultrasonically cleaned according to the sequence of 5% dilute hydrochloric acid, deionized water and absolute ethyl alcohol to remove oxides and greasy dirt on the copper surface, then, nano silver soldering paste which is uniformly stirred is printed above the substrate through a steel screen, then, a chip is pasted above the soldering paste by using a high-precision chip mounter, the substrate on which the chip is pasted in the step 1 is placed into a vacuum furnace to be welded, a copper bottom plate, a SAC305 soldering lug and a DBC substrate are fixed through a clamp, then, the device is placed into an ATV vacuum sintering furnace to be continuously welded, a plastic shell is fixedly arranged on the copper bottom plate through four rivets, then, polymer resin is uniformly coated at the gap between the shell and the bottom plate, a module after the solidification in the previous step is fixed on a workbench, the position and ultrasonic bonding parameters of each lead are set through a computer, after the setting is completed, the bonding process of the lead bonding equipment can be automatically completed, the prepared silicone gel is added into the module, the bubbles in the sealing glue are removed by using a vacuumizing device, and the sealing colloid is waited to be solidified.

While certain exemplary embodiments of the present application have been described above by way of illustration only, it will be apparent to those of ordinary skill in the art that modifications may be made to the described embodiments in various different ways without departing from the spirit and scope of the application. Accordingly, the drawings and description are to be regarded as illustrative in nature and not as restrictive of the scope of the application, which is defined by the appended claims.

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.