MOSFET chip packaging structure

Abstract

The utility model discloses an MOSFET chip packaging structure, comprising an upper housing and a lower housing, the center of the lower housing is provided with a square groove, the square groove is internally provided with a frame, the frame is provided with a packaging assembly, the packaging assembly comprises a carrier fixedly connected on the frame, two ends of the outer surface of the carrier are provided with pins, and the pins are connected with the carrier. A chip body is fixedly connected to the top end of the carrier, chip back metal is fixedly connected to the bottom end of the chip body, a metal coating is fixedly connected to the top end of the carrier, an eutectic soldering lug is arranged between the metal coating and the chip back metal, the carrier is heated to reach the temperature suitable for working of the eutectic soldering lug, and at the moment, the eutectic soldering lug is connected with the chip body. The eutectic soldering lug forms a eutectic body, so that bonding between the chip body and the carrier is realized, the bonding mode enables the lower surface of the chip body to be completely bonded on the carrier, and a gap between the chip body and the carrier can be effectively prevented from appearing, so that the packaging effect of the chip is not influenced.

Description

Technical Field

[0001] The utility model relates to MOSFET chip packaging, in particular to a MOSFET chip packaging structure. Background Art

[0002] The packaging of MOSFET chips includes a variety of packaging forms. In traditional packaging, the MOSFET chip is basically fixed on the base island with an adhesive material (conductive glue or solder paste) so that the drain of the MOSFET chip is connected to the base island; then a bonding machine is used to perform bonding operations, and the source area of ​​the MOSFET chip is connected to the source pin through bonding wires, and the gate area of ​​the MOSFET chip is connected to the gate pin, and then the plastic encapsulation, electroplating and singulation processes are performed to form a single package structure.

[0003] At present, the conventional MOSFET chip packaging is fixed by means of adhesive materials. However, the adhesive materials only connect the MOSFET chip to the base island at the periphery, so that the MOSFET chip and the center of the base island cannot be bonded, which leads to poor MOSFET chip packaging performance.

[0004] Currently, no effective solution has been proposed for the problems in the related technologies. Utility Model Content

[0005] In view of the problems in the related technology, the utility model proposes a MOSFET chip packaging structure to overcome the above technical problems existing in the existing related technology.

[0006] To this end, the specific technical solutions adopted by the utility model are as follows:

[0007] A MOSFET chip packaging structure comprises an upper shell and a lower shell, wherein the upper shell is connected to the lower shell by fastening bolts, a square groove is provided at the center of the lower shell, a frame is provided in the square groove, a packaging component is provided on the frame, the packaging component comprises a carrier fixedly connected to the frame, pins are provided at both ends of the outer surface of the carrier, a chip body is fixedly connected to the top end of the carrier, a chip back gold is fixedly connected to the bottom end of the chip body, a metal plating is fixedly connected to the top end of the carrier, a eutectic welding piece is provided between the metal plating and the chip back gold, grooves are provided at both ends of the outer surface of the lower shell, one end of the pin away from the carrier passes through the groove and extends to the outside of the lower shell, T-slots are provided at both ends of the inner surface of the groove, protrusions are welded at both ends of the outer surface of the upper shell, T-blocks are welded at both ends of the outer surface of the protruding piece, the T-blocks and the T-slots are clamped with each other, and a fixing mechanism is provided between the square groove and the frame.

[0008] Furthermore, in order to fix the frame in the square groove, the fixing mechanism includes a limiting round rod symmetrically welded on the bottom end of the frame, a limiting hole is provided on the outer surface of the limiting round rod, and a limiting round groove matched with the limiting round rod is symmetrically provided on the bottom end of the square groove, a limiting groove is provided on the inner surface of the limiting round groove, a limiting block is slidably connected in the limiting groove, and one end of the limiting block is fixedly connected to the inner wall of the limiting groove through a spring.

[0009] Furthermore, in order to make the limiting block slide stably in the limiting groove, sliding grooves are opened on the top and bottom ends of the limiting groove, and sliding blocks are welded on the top and bottom ends of the limiting block, and the sliding blocks are slidably connected to the sliding grooves.

[0010] Furthermore, in order to fix the limiting round rod in the limiting round groove, the limiting block matches the limiting hole.

[0011] Furthermore, in order to fix the carrier and the chip to each other, the material of the eutectic solder sheet is Au80Sn20.

[0012] Furthermore, in order to prevent the protruding piece from damaging the pin, a rubber gasket is fixedly connected to the bottom end of the protruding piece.

[0013] Furthermore, in order to facilitate the discharge of heat from the shell, heat dissipation fins are welded at equal distances on the top of the upper shell.

[0014] The beneficial effects of the utility model are:

[0015] 1. The lower surface of the chip body is plated with chip back gold, the upper surface of the carrier is plated with a metal coating, and a eutectic soldering piece is placed between the metal coating and the chip back gold. The carrier is heated to a temperature suitable for the eutectic soldering piece to work. At this time, the eutectic soldering piece forms a eutectic, thereby achieving bonding between the chip body and the carrier. This bonding method makes the lower surface of the chip body completely bonded to the carrier, which can effectively avoid the appearance of a gap between the two, thereby affecting the chip packaging effect.

[0016] 2. By aligning the limiting round rod on the frame with the limiting round groove and moving the limiting round rod into the limiting round groove, during the movement of the limiting round rod, the bottom end of the limiting round rod contacts the limiting block and causes the limiting block to slide into the limiting groove, so that the spring is in a compressed state. If the bottom end of the limiting round rod contacts the bottom end of the limiting round groove, the limiting hole and the limiting groove are in a flush state. At this time, the spring is in a loose state, driving the limiting block to move into the limiting hole, so that the limiting round rod is fixed in the limiting round groove and the frame is fixed in the square groove. If the frame is fixed in the square groove, the pins on the carrier are placed in the grooves on the lower shell body, and the T-block on the protruding piece is clamped with the T-slot on the groove, so that the upper shell body is fixed on the lower shell body. By twisting the fastening bolts, the tightness between the upper shell body and the lower shell body is improved, thereby improving the fixation of the chip body in the shell body. The setting of the rubber gasket effectively prevents the protruding piece from damaging the pins. The setting of the fixing mechanism facilitates the fixing of the chip body in the shell. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0018] Figure 1 It is a structural schematic diagram of a MOSFET chip packaging structure according to an embodiment of the utility model;

[0019] Figure 2 It is a structural schematic diagram of an upper housing in a MOSFET chip packaging structure according to an embodiment of the utility model;

[0020] Figure 3 It is a structural schematic diagram of a lower housing in a MOSFET chip packaging structure according to an embodiment of the utility model;

[0021] Figure 4 It is a partial cross-sectional view of a lower housing in a MOSFET chip packaging structure according to an embodiment of the utility model;

[0022] Figure 5 yes Figure 4 Enlarged view of point A in the middle;

[0023] Figure 6 It is a structural schematic diagram of a frame in a MOSFET chip packaging structure according to an embodiment of the utility model.

[0024] In the figure:

[0025] 1. Upper shell; 2. Lower shell; 3. Fastening bolts; 4. Square groove; 5. Limiting circular groove; 6. Limiting groove; 7. Sliding groove; 8. Limiting block; 9. Sliding block; 10. Spring; 11. Frame; 12. Limiting round rod; 13. Limiting hole; 14. Carrier; 15. Metal plating; 16. Eutectic solder pad; 17. Chip body; 18. Chip back gold; 19. Pin; 20. Groove; 21. T-slot; 22. Protrusion; 23. T-block; 24. Rubber gasket; 25. Heat sink fin. DETAILED DESCRIPTION

[0026] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0027] According to an embodiment of the utility model, a MOSFET chip packaging structure is provided.

[0028] Embodiment 1;

[0029] like Figure 1-Figure 3 and Figure 6As shown, according to the MOSFET chip packaging structure of the embodiment of the utility model, it includes an upper shell 1 and a lower shell 2, the upper shell 1 is connected to the lower shell 2 by fastening bolts 3, and heat dissipation fins 25 are welded at equal distances on the top of the upper shell 1, a square groove 4 is opened at the center of the lower shell 2, a frame 11 is arranged in the square groove 4, and a packaging component is arranged on the frame 11, and the packaging component includes a carrier 14 fixedly connected to the frame 11, pins 19 are arranged on both ends of the outer surface of the carrier 14, a chip body 17 is fixedly connected to the top of the carrier 14, the lower surface of the chip body 17 is plated with chip back gold 18, the lower surface of the carrier 14 is plated with a metal coating 15, and a eutectic welding piece 16 is arranged between the metal coating 15 and the chip back gold 18, and the material of the eutectic welding piece 16 is Au80Sn20, grooves 20 are opened on both ends of the outer surface of the lower shell 2, and the end of the pin 19 away from the carrier 14 passes through the groove 20 and extends to the outside of the lower shell 2, in order to avoid damage to the pin 19 by the groove 20, the groove A gasket is fixedly connected to the bottom end of the inner part 20, and the material of the gasket is rubber. T-slots 21 are provided on both ends of the inner surface of the groove 20. Both ends of the outer surface of the upper shell 1 are welded with protruding pieces 22, and both ends of the outer surface of the protruding pieces 22 are welded with T-blocks 23. The T-blocks 23 and the T-slots 21 are mutually engaged. In order to prevent the protruding pieces 22 from damaging the pins 19, a rubber gasket 24 is fixedly connected to the bottom end of the protruding pieces 22. The chip body 17 is plated with a chip back gold 18 on the lower surface. The upper surface of the carrier 14 is plated with a metal coating 15, and a eutectic soldering sheet 16 is placed between the metal coating 15 and the chip back gold 18. The carrier 14 is heated to a temperature suitable for the operation of the eutectic soldering sheet 16. At this time, the eutectic soldering sheet 16 forms a eutectic, thereby achieving bonding between the chip body 17 and the carrier 14. This bonding method allows the lower surface of the chip body 17 to be completely bonded to the carrier 14, which can effectively avoid the formation of a gap between the two, thereby affecting the chip packaging effect.

[0030] Embodiment 2:

[0031] See also Figure 1-Figure 2 and Figure 4-Figure 6In order to facilitate the fixing of the chip body 17 in the shell, a fixing mechanism is provided between the square groove 4 and the frame 11, and the fixing mechanism includes a limiting round rod 12 symmetrically welded on the bottom end of the frame 11, and a limiting hole 13 is provided on the outer surface of the limiting round rod 12. A limiting round groove 5 matching the limiting round rod 12 is symmetrically provided on the bottom end of the square groove 4, and a limiting groove 6 is provided on the inner surface of the limiting round groove 5. A limiting block 8 is slidably connected in the limiting groove 6, and the limiting block 8 matches the limiting hole 13. In order to make the limiting block 8 The limiting block 8 is welded with a sliding block 9 on the top and bottom ends of the limiting groove 6, and the sliding block 9 is slidably connected with the sliding groove 7. One end of the limiting block 8 is fixedly connected with the inner wall of the limiting groove 6 by a spring 10. The spring 10 has a certain elasticity. By aligning the limiting round rod 12 on the frame 11 with the limiting round groove 5 and moving the limiting round rod 12 into the limiting round groove 5, the limiting round rod 12 is aligned with the limiting round groove 5 during the movement of the limiting round rod 12. The limit block 8 contacts the limit block 8, and the limit block 8 slides into the limit groove 6, so that the spring 10 is in a compressed state. If the bottom end of the limit round rod 12 contacts the bottom end of the limit round groove 5, the limit hole 13 and the limit groove 6 are in a flush state. At this time, the spring 10 is in a loose state, driving the limit block 8 to move into the limit hole 13, so that the limit round rod 12 is fixed in the limit round groove 5, and the frame 11 is fixed in the square groove 4. If the frame 11 is fixed in the square groove 4, the pin 19 on the carrier 14 is placed at the bottom The upper shell 1 is fixed to the lower shell 2 by clamping the T-block 23 on the protruding piece 22 into the T-slot 21 on the groove 20. By twisting the fastening bolts 3, the tightness between the upper shell 1 and the lower shell 2 is improved, and the fixation of the chip body 17 in the shell is improved. The setting of the rubber gasket 24 and the gasket can effectively avoid damage to the pin 19. The setting of the fixing mechanism makes it easy to fix the chip body 17 in the shell.

[0032] In order to facilitate understanding of the above technical solution of the present invention, the working principle or operation method of the present invention in the actual process is described in detail below.

[0033] In actual application, the lower surface of the chip body 17 is plated with chip back gold 18, the upper surface of the carrier 14 is plated with metal coating 15, and a eutectic soldering sheet 16 is placed between the metal coating 15 and the chip back gold 18. The carrier 14 is heated to a temperature suitable for the operation of the eutectic soldering sheet 16. At this time, the eutectic soldering sheet 16 forms a eutectic, thereby achieving bonding between the chip body 17 and the carrier 14. If the bonded chip body 17 is fixed in the shell, first, the limiting round rod 12 on the frame 11 is aligned with the limiting circular groove 5, and then the limiting round rod 12 is moved into the limiting circular groove 5. During the movement of the limiting round rod 12, the bottom end of the limiting round rod 12 contacts the limiting block 8, and the limiting block 8 Slide into the limit groove 6 to compress the spring 10. If the bottom end of the limit rod 12 contacts the bottom end of the limit groove 5, the limit hole 13 is flush with the limit groove 6. At this time, the spring 10 is in a loosened state, driving the limit block 8 to move into the limit hole 13, so that the limit rod 12 is fixed in the limit groove 5, and the frame 11 is fixed in the square groove 4. Then, the T-block 23 on the protrusion 22 is engaged with the T-slot 21 on the groove 20, so that the upper shell 1 is fixed on the lower shell 2. Finally, the fastening bolt 3 is twisted to improve the tightness between the upper shell 1 and the lower shell 2, thereby improving the fixation of the chip body 17 in the shell, so that the chip body 17 is firmly installed in the shell.

[0034] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A MOSFET chip packaging structure, comprising an upper housing (1) and a lower housing (2), characterized in that: The upper shell (1) is connected to the lower shell (2) by means of fastening bolts (3); a square groove (4) is provided at the center of the lower shell (2); a frame (11) is provided in the square groove (4); a packaging component is provided on the frame (11); the packaging component comprises a carrier (14) fixedly connected to the frame (11); pins (19) are provided at both ends of the outer surface of the carrier (14); a chip body (17) is fixedly connected to the top end of the carrier (14); a chip backing (18) is fixedly connected to the bottom end of the chip body (17); a metal plating (15) is fixedly connected to the top end of the carrier (14); the metal plating (15) ) and the chip back gold (18), a eutectic solder sheet (16) is provided between the two ends of the outer surface of the lower shell (2), a groove (20) is provided on both ends of the outer surface of the lower shell (2), an end of the pin (19) away from the carrier (14) passes through the groove (20) and extends to the outside of the lower shell (2), a T-slot (21) is provided on both ends of the inner surface of the groove (20), a protrusion (22) is welded on both ends of the outer surface of the upper shell (1), a T-block (23) is welded on both ends of the outer surface of the protrusion (22), the T-block (23) and the T-slot (21) are mutually clamped, and a fixing mechanism is provided between the square groove (4) and the frame (11).

2. A MOSFET chip packaging structure according to claim 1, characterized in that: The fixing mechanism comprises a limiting round rod (12) symmetrically welded on the bottom end of the frame (11); a limiting hole (13) is provided on the outer surface of the limiting round rod (12); a limiting round groove (5) matched with the limiting round rod (12) is symmetrically provided on the bottom end of the square groove (4); a limiting groove (6) is provided on the inner surface of the limiting round groove (5); a limiting block (8) is slidably connected in the limiting groove (6); one end of the limiting block (8) is fixedly connected to the inner wall of the limiting groove (6) through a spring (10).

3. A MOSFET chip packaging structure according to claim 2, characterized in that: The top and bottom ends of the limiting groove (6) are provided with sliding grooves (7), the top and bottom ends of the limiting block (8) are welded with sliding blocks (9), and the sliding blocks (9) are slidably connected to the sliding grooves (7).

4. A MOSFET chip packaging structure according to claim 3, characterized in that: The limiting block (8) matches the limiting hole (13).

5. A MOSFET chip packaging structure according to claim 1, characterized in that: The material of the eutectic solder sheet (16) is Au80Sn20.

6. A MOSFET chip packaging structure according to claim 1, characterized in that: A rubber gasket (24) is fixedly connected to the bottom end of the protruding piece (22).

7. A MOSFET chip packaging structure according to claim 1, characterized in that: Heat dissipation fins (25) are welded at equal distances on the top of the upper shell (1).

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