CN220652012U

CN220652012U - TO-247-5L packaging structure based on DBC insulation heat dissipation

Info

Publication number: CN220652012U
Application number: CN202322345198.4U
Authority: CN
Inventors: 贾润杰; 鄢胜虎; 郑晓颖; 张耀
Original assignee: Shenzhen Shengyuan Semiconductors Co ltd
Current assignee: Shenzhen Shengyuan Semiconductors Co ltd
Priority date: 2023-08-30
Filing date: 2023-08-30
Publication date: 2024-03-22
Anticipated expiration: 2033-08-30

Abstract

The utility model discloses a TO-247-5L packaging structure based on DBC insulation heat dissipation, which comprises a shell (1), a lead frame monomer (2) packaged in the shell, a copper-clad ceramic substrate (3) and I C grains, wherein the lead frame monomer is arranged on the shell; a plurality of independent terminals (4) are arranged on the lead frame single body (2), and at least one independent terminal (4) is punched and bent to form a bending terminal so as to be fixedly connected with the copper-clad ceramic substrate (3); the copper-clad ceramic substrate (3) comprises a ceramic insulating layer, and a first copper-clad layer and a second copper-clad layer which are positioned on the upper surface and the bottom surface of the ceramic insulating layer; i C grains are fixedly connected to the first copper-clad layer; the second copper-clad layer is exposed through a window at the bottom of the shell (1) to dissipate heat. The packaging structure omits the working procedure operation of coating the heat-conducting silicone grease on the metal backboard and pasting the heat-conducting insulating sheet in the prior art, simplifies the manufacturing process, improves the production efficiency, and has better heat dissipation and insulating performance in high-power and high-current scene application.

Description

TO-247-5L packaging structure based on DBC insulation heat dissipation

Technical Field

The utility model relates TO the technical field of integrated circuit packaging, in particular TO a TO-247-5L packaging structure based on DBC insulation heat dissipation.

Background

The semiconductor industry is a strategic and fundamental industry for national economy and social development, and is the core and foundation of the electronic information industry. Semiconductor devices commonly used in high power applications, such as power transistors and power MOSFETs, provide a large heat dissipation area and low thermal resistance for the electronic package, and are well suited for high power and high temperature applications, especially TO-247 packages, which have large dimensions and metal backplanes that facilitate the mounting and dissipation of heat sinks, and which also typically have low electrical resistance and inductance that can be used TO handle higher current and power applications.

In the TO-247 package in the prior art, heat conduction silicone grease is often coated on a metal backboard, and then a heat conduction insulating sheet is attached TO the metal backboard so as TO solve the problem of insulating heat dissipation application of the I GBT. However, due TO the large package size and limited pin count of TO-247, problems can occur in certain specific application scenarios or limited space applications: the problem of overheating of I GBT in high integration, high efficiency ac motor applications, for example, has not been solved by the means of the thermally conductive silicone grease plus thermally conductive insulating sheets described above. In continuous operation, the temperature of the I GBT can be increased due to the continuously increased heat, if the heat dissipation is not timely, the I GBT reaches a certain dangerous high temperature, the performance of the I GBT can be influenced, so that the performance is reduced, even the I GBT is directly burnt out, and the operation of the whole machine is influenced. Based on the application, TO-247 packaging is urgently needed TO be an electronic packaging integrated with insulation and packaging and provided with a plurality of pins, can accommodate larger and higher-specification I GBT for packaging, has lower thermal resistance effect and good insulation performance, and improves the heat dissipation capacity of the packaging.

Disclosure of Invention

Aiming at the defects in the prior art, the utility model provides the TO-247-5L packaging structure based on DBC insulating heat dissipation, which simplifies the manufacturing process flow, improves the production efficiency and has better heat dissipation and insulation performance in high-power and high-current scene application.

The technical scheme adopted for solving the technical problems is as follows: constructing a TO-247-5L packaging structure based on DBC insulation heat dissipation, which comprises a shell, a lead frame monomer, a copper-clad ceramic substrate and I C grains, wherein the lead frame monomer, the copper-clad ceramic substrate and the I C grains are packaged in the shell; the lead frame unit is provided with a plurality of independent terminals, and at least one independent terminal is punched and bent to form a bending terminal so as to be fixedly connected with the copper-clad ceramic substrate; the independent terminals are provided with a head end and a tail end, the head end is provided with a base island for pressure welding bonding, and the tail end extends out of the shell to form an outer pin; the copper-clad ceramic substrate comprises a ceramic insulating layer, a first copper-clad layer positioned on the upper surface of the ceramic insulating layer and a second copper-clad layer positioned on the bottom surface of the ceramic insulating layer; the I C crystal grains are fixedly connected to the first copper-clad layer; the second copper-clad layer is exposed through a window at the bottom of the shell for heat dissipation.

In the TO-247-5L packaging structure based on DBC insulation heat dissipation, the area of the top surface or the bottom surface of the first copper-clad layer is smaller than the area of the upper surface of the ceramic insulation layer, and the area of the bottom surface of the ceramic insulation layer is larger than the area of the top surface or the bottom surface of the second copper-clad layer.

In the TO-247-5L packaging structure based on DBC insulation heat dissipation, the ceramic insulation layer and the second copper-clad layer are rectangular, the first copper-clad layer is concave, and a through hole is formed in the position, in which the upper edge of the concave is recessed, of the first copper-clad layer, and penetrates through the ceramic insulation layer and the second copper-clad layer; a rectangular welding area is arranged at the lower edge of the concave shape and protrudes out of the lower edge; and during assembly, the rectangular welding area and the bending terminal are sintered and assembled so as to fixedly connect the copper-clad ceramic substrate and the lead frame monomer.

In the TO-247-5L packaging structure based on DBC insulation heat dissipation, the ceramic insulation layer is a ceramic plate, and the thickness is 0.5+/-0.05 mm; the thickness of the first copper-clad layer and the second copper-clad layer is 0.3 plus or minus 0.05mm.

In the TO-247-5L packaging structure based on DBC insulating heat dissipation, a material locking hole is further formed in the position, close TO the base island, on the head end of the independent terminal, the diameter of the material locking hole is 0.3mm, and the depth of the material locking hole axially penetrates through the independent terminal.

In the TO-247-5L packaging structure based on DBC insulating heat dissipation, the shell is provided with the lock screw hole, the aperture of the lock screw hole is larger than or equal TO that of the through hole on the copper-clad ceramic substrate, and the lock screw hole and the through hole are coaxially arranged.

In the TO-247-5L packaging structure based on DBC insulating heat dissipation, an etching circuit is arranged on the first copper-clad layer, and a plurality of concave holes for enhancing packaging combination strength with the shell are formed around the etching circuit.

In the TO-247-5L packaging structure based on DBC insulation heat dissipation, on the lead frame single body, the base islands at the head ends of all independent terminals are transversely connected and fixed through the middle ribs, and all tail ends are also transversely connected and fixed through the bottom ribs.

In the TO-247-5L packaging structure based on DBC insulation heat dissipation, a plurality of positioning holes are distributed on the bottom ribs of the lead frame monomers, and the depth of the positioning holes axially penetrates through the bottom ribs.

In the TO-247-5L packaging structure based on DBC insulating heat dissipation, auricle-shaped pits are respectively arranged on two side surfaces of the shell, and part of the first copper-clad layer is exposed above the pits.

The TO-247-5L packaging structure based on DBC insulation heat dissipation has the following beneficial effects: the copper-clad ceramic substrate and the lead frame monomer are sintered and assembled together through reasonable design, the copper-clad ceramic substrate is used as a bearing substrate of I C crystal grains, larger and higher-specification I GBT can be accommodated for packaging, and meanwhile, a plurality of independent terminals on the lead frame monomer are used as mechanical supports and electric link bridges, so that the insulating and heat dissipation integration of TO-247-5L packaging components is realized, namely, a plurality of pins are provided, the heat-resistant ceramic substrate has lower heat resistance effect and better insulating property, and the heat dissipation capability is improved.

Therefore, the TO-247-5L packaging structure based on DBC insulation heat dissipation avoids the working procedure operation of coating heat conduction silicone grease on a metal backboard and attaching a heat conduction insulating sheet in the prior art, simplifies the manufacturing flow, improves the production efficiency, and has better heat dissipation and insulation performance in high-power and high-current scene application.

Drawings

The utility model will be further described with reference to the accompanying drawings and examples, in which:

FIG. 1 is a schematic diagram of a TO-247-5L package structure based on DBC insulating heat dissipation in accordance with the present utility model;

FIG. 2 is a schematic diagram of the front structure of a copper-clad ceramic substrate according to the present utility model;

FIG. 3 is a schematic view of the reverse structure of a copper-clad ceramic substrate according to the present utility model;

fig. 4 is a schematic view of a lead frame according to the present utility model;

FIG. 5 is a schematic diagram of a sintered assembly of a copper-clad ceramic substrate and a leadframe according to the present utility model;

FIG. 6 is a bottom view of a TO-247-5L package structure based on DBC insulating heat dissipation in accordance with the present utility model;

FIG. 7 is a schematic diagram of the front structure of the power device of the utility model based on the TO-247-5L package structure of DBC insulating heat dissipation;

FIG. 8 is a schematic diagram of the reverse side structure of the power device of the utility model based on the TO-247-5L package structure with DBC insulating heat dissipation.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present utility model more apparent, the embodiments of the present utility model will be described in further detail with reference to the accompanying drawings.

Referring TO fig. 1, which is a schematic structural diagram of a TO-247-5L package structure based on DBC insulation heat dissipation, and referring TO fig. 6, which is a bottom view of the TO-247-5L package structure based on DBC insulation heat dissipation, the utility model provides a TO-247-5L package structure based on DBC insulation heat dissipation, which meets design standardization and has better heat dissipation performance, and meanwhile, a mode of coating heat conduction silicone grease and an insulation sheet on a metal backboard is abandoned, and heat dissipation and insulation resistance are combined TO realize integrated package. The TO-247-5L packaging structure based on DBC insulation heat dissipation specifically comprises a shell 1, a lead frame monomer 2, a copper-clad ceramic substrate 3 and I C grains, wherein the lead frame monomer 2, the copper-clad ceramic substrate 3 and the I C grains are packaged in the shell 1; a plurality of independent terminals 4 are arranged on the lead frame single body 2, and at least one independent terminal 4 is punched and bent to form a bending terminal so as to be fixedly connected with the copper-clad ceramic substrate 3; the independent terminals 4 are provided with a head end and a tail end, the head end is provided with a base island 5 for pressure welding bonding, and the tail end extends out of the shell 1 to form an outer pin; the copper-clad ceramic substrate 3 comprises a ceramic insulating layer 9, a first copper-clad layer 17 positioned on the upper surface of the ceramic insulating layer 9 and a second copper-clad layer 8 positioned on the bottom surface of the ceramic insulating layer 9; i C grains are fixedly connected to the first copper-clad layer 17; the second copper-clad layer 8 is exposed through a window at the bottom of the case 1 for heat dissipation. Preferably, the lead frame unit 2 is provided with 5 independent terminals 4, and the lead frame unit is of a standard TO-247-5L packaging structure. The head ends of the 5 independent terminals 4 are respectively provided with a base island 5 for pressure welding bonding, the base islands 5 are transversely connected and fixed by middle ribs 6 on the longitudinal spacing, and the tail ends of the base islands 5 are also transversely connected and fixed and mechanically supported by bottom ribs 7 which are transversely connected.

In the TO-247-5L packaging structure based on DBC insulation heat dissipation, the copper-clad ceramic substrate and the lead frame are sintered and assembled together through reasonable design, and the copper-clad ceramic substrate is used as a bearing substrate of I C crystal grains and can accommodate larger and higher-specification I GBT for packaging; meanwhile, a plurality of independent terminals 4 on the lead frame monomer are used as mechanical supports and electric link bridges, so that insulation and heat dissipation integration of TO-247-5L packaging components is realized, namely, the lead frame has a plurality of pins, lower thermal resistance effect and better insulation performance, and the heat dissipation capacity of packaging is improved.

Referring to fig. 2 and 3, schematic diagrams of the front and back surfaces of the copper-clad ceramic substrate according to the present utility model are shown. The copper-clad ceramic substrate 3 is provided with a three-layer structure, wherein the upper surface structure and the lower surface structure are both metal layers, and the middle is an insulating layer, and specifically comprises a ceramic insulating layer 9, a first copper-clad layer 17 positioned on the upper surface of the ceramic insulating layer 9 and a second copper-clad layer 8 positioned on the bottom surface of the ceramic insulating layer 9; i C grains are fixedly connected to the first copper-clad layer 17; the second copper-clad layer 8 is exposed through a window at the bottom of the case 1 for heat dissipation. Preferably, the ceramic insulating layer 9 is a ceramic plate, the size is 18.21mm 14.33mm, the material is insulating non-conductive alumina or aluminum nitride, and the thickness is 0.5+/-0.05 mm; the thickness of the first copper-clad layer 17 and the second copper-clad layer 8 is 0.3±0.05mm, and the size of the second copper-clad layer 8 is 17mm 13.53mm.

A through hole 10 is provided at one end position of the copper-clad ceramic substrate 3, the through hole 10 penetrating the ceramic insulating layer 9 and the second copper-clad layer 8. Preferably, the pore size is 6.7.+ -. 0.1mm. The first copper-clad layer 17 is further provided with an etched circuit 11, the etched circuit 11 is used for interconnecting I C dies, the pattern of the etched circuit is designed into a rectangular area according to the type of the packaged chip, a rectangular welding area 12 is arranged at one end far away from the through hole 10, and the rectangular welding area 12 and the bending terminal 13 are sintered and assembled during assembly so as to fixedly connect the copper-clad ceramic substrate 3 and the lead frame unit 2 to be assembled.

Further, on the first copper-clad layer 17, a plurality of concave holes 14 for enhancing the packaging bonding strength with the housing 1 are formed around the etched circuit 11. Correspondingly, the housing 1 is also provided with a convex structure which is matched with the concave hole 14.

Further specifically, the ceramic insulating layer 9 and the second copper-clad layer 8 are both rectangular, the first copper-clad layer 17 is concave, the through hole 10 is arranged at the position where the upper side of the concave is concave, the through hole 10 penetrates through the ceramic insulating layer 9 and the second copper-clad layer 8, and no connection or contact with the first copper-clad layer 17 exists, namely, the through hole 10 is separated from the first copper-clad layer 17. The rectangular welding area 12 is arranged at the lower side of the concave shape and protrudes from the lower side; during assembly, the rectangular welding area 12 and the bending terminal 13 on the lead frame unit 2 are sintered and assembled so as to fixedly connect the copper-clad ceramic substrate 3 and the lead frame unit 2.

Fig. 4 is a schematic view of the structure of the lead frame according to the present utility model. The lead frame comprises a plurality of lead frame monomers which are sequentially arranged in parallel. A plurality of independent terminals 4 are arranged on the lead frame single body 2, and at least one independent terminal 4 is punched and bent to form a bending terminal so as to be fixedly connected with the copper-clad ceramic substrate 3; the independent terminals 4 are provided with a head end and a tail end, the head end is provided with a base island 5 for pressure welding bonding, and the tail end extends out of the shell 1 to form an outer pin.

For each lead frame unit 2, the islands 5 of all the independent terminals 4 are transversely connected and fixed through the middle ribs 6, and all the tail ends are also transversely connected and fixed through the bottom ribs 7. Then, for the lead frame composed of a plurality of lead frame units which are arranged in parallel in sequence, the islands 5 of all the independent terminals 4 are also transversely connected and fixed through the middle ribs 6, and all the tail ends are also transversely connected and fixed through the bottom ribs 7.

A material locking hole 15 is further formed in the lead frame unit 2 at a position close to the base island 5 on the head end of the independent terminal 4, and preferably, the diameter of the material locking hole 15 is 0.3mm, and the depth of the material locking hole axially penetrates through the independent terminal 4. These locking holes 15 are used to strengthen the bonding strength between the package rear case 1 and the lead frame unit 2 and to eliminate excessive stress inside the packaging process.

Further, a plurality of positioning holes which are convenient to fix during assembly are distributed on the bottom rib 7 of the lead frame monomer 2, the distance between the adjacent positioning holes 18 is 17.5mm, the diameter of the positioning holes 18 is 2.0 plus or minus 0.1mm, and the depth of the positioning holes is axially penetrated through the bottom rib 7.

Fig. 5 is a schematic diagram showing a sintering assembly structure of a copper-clad ceramic substrate and a lead frame according to the present utility model. Preferably, on the lead frame element 2, the total area of the lower surfaces of the bent terminals 13 is smaller than the rectangular lands 12. That is, the area of the bending terminal 13 on the lead frame unit 2 which is integrally contacted with the copper-clad ceramic substrate 3 is smaller than the rectangular welding area 12 reserved at the tail end of the first copper-clad layer 17 on the top of the copper-clad ceramic substrate 3, and the bending terminal 13 and the rectangular welding area 12 are supported by sintering connection through a medium bonding material.

The utility model relates TO a TO-247-5L packaging structure based on DBC insulation heat dissipation, which comprises the following specific steps:

A1. the copper-clad ceramic substrate 3 is arranged in a substrate carrier for position fixing, and a preset steel mesh window is coated with solder paste medium, so that solder paste is uniformly distributed on the surface of the copper-clad ceramic substrate 3;

a2, placing the substrate carrier which is printed with solder paste and carries the copper-clad ceramic substrate 3 into a die bonder, and carrying out die bonding on the surface of the copper-clad ceramic substrate 3 coated with the solder paste to complete die bonding operation;

A3. placing the lead frame into a frame carrier, aligning and assembling pins below the frame carrier and pin holes on a substrate carrier, enabling a bending terminal 13 on a lead frame monomer 2 to be attached to a rectangular welding area 12 at the tail end of the surface of a copper-clad ceramic substrate 3 through solder paste, and welding and combining the lead frame monomer 2 and the copper-clad ceramic substrate 3 together through melting of solder reflow;

A4. carrying out plasma cleaning on the combined lead frame single body 2-copper-clad ceramic substrate 3, carrying out appearance dimension measurement and reliability inspection after cleaning, and carrying out the next step of wire bonding operation on qualified products;

A5. and (3) performing wire bonding operation and electric binding of bonding wires, molding and packaging in a packaging process, performing surface treatment in an electroplating process and forming of cutting ribs (cutting the middle ribs 6, the bottom ribs 7 and the like), and finally packaging the complete power device formed by the upper shell 1, wherein qualified products after electric testing can be prepared for shipment.

Referring TO fig. 7 and 8, schematic diagrams of the front and back surface structures of the power device with the TO-247-5L package structure based on DBC insulation heat dissipation according TO the present utility model are shown. The shell 1 is provided with a lock screw hole 16, the aperture of the lock screw hole 16 is larger than or equal to the through hole 10 on the copper-clad ceramic substrate 3, and the lock screw hole 16 and the through hole 10 are coaxially arranged and used for mounting, fixing and radiating of the whole component.

Further, auricle-shaped pits 19 are distributed on two sides of the shell 1, and a plurality of ventilation holes are arranged above the pits 19 to expose part of the first copper-clad layer 17, so that heat dissipation is enhanced.

In summary, the TO-247-5L packaging structure based on DBC insulation heat dissipation avoids the working procedure operation of coating heat conduction silicone grease on a metal backboard and attaching a heat conduction insulating sheet in the prior art, simplifies the manufacturing process, improves the production efficiency, ensures that heat generated in the working of a device can be effectively released from a packaging body through the design and assembly of a lead frame monomer and a copper-clad ceramic substrate, avoids performance reduction or burnout caused by sudden I GBT temperature rise and untimely heat dissipation in the packaging body when the device continuously works, and ensures that the heat can be safely dissipated around heating equipment or in the environment of the whole device, thereby realizing the application requirements of multi-pin and insulation heat dissipation, namely having better heat dissipation and insulation performance in high-power and high-current scene application.

In the present utility model, unless explicitly specified and limited otherwise, the terms "connected," "stacked," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present utility model can be understood by those of ordinary skill in the art according to the specific circumstances.

The foregoing is only illustrative of the present utility model and is not to be construed as limiting the scope of the utility model, and all equivalent structures or equivalent flow modifications which may be made by the teachings of the present utility model and the accompanying drawings or which may be directly or indirectly employed in other related art are within the scope of the utility model.

Claims

1. A TO-247-5L packaging structure based on DBC insulation heat dissipation comprises a shell (1), a lead frame monomer (2), a copper-clad ceramic substrate (3) and an IC crystal grain, wherein the lead frame monomer (2), the copper-clad ceramic substrate (3) and the IC crystal grain are packaged in the shell (1),

a plurality of independent terminals (4) are arranged on the lead frame single body (2), and at least one independent terminal (4) is punched and bent to form a bending terminal so as to be fixedly connected with the copper-clad ceramic substrate (3); the independent terminals (4) are provided with a head end and a tail end, the head end is provided with a base island (5) for pressure welding bonding, and the tail end extends out of the shell (1) to form an outer pin;

the copper-clad ceramic substrate (3) comprises a ceramic insulating layer (9), a first copper-clad layer (17) positioned on the upper surface of the ceramic insulating layer (9) and a second copper-clad layer (8) positioned on the bottom surface of the ceramic insulating layer (9); the first copper-clad layer (17) is fixedly connected with the IC crystal grain; the second copper-clad layer (8) is exposed through a window at the bottom of the shell (1) for heat dissipation.

2. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 1, wherein the top or bottom surface area of the first copper clad layer (17) is smaller than the upper surface area of the ceramic insulating layer (9), and the bottom surface area of the ceramic insulating layer (9) is larger than the top or bottom surface area of the second copper clad layer (8).

3. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 1, wherein the ceramic insulating layer (9) and the second copper-clad layer (8) are rectangular;

the first copper-clad layer (17) is concave, a through hole (10) is arranged at the position of the concave upper edge, and the through hole (10) penetrates through the ceramic insulating layer (9) and the second copper-clad layer (8); a rectangular welding area (12) is arranged at the lower edge of the concave shape and protrudes out of the lower edge; and during assembly, the rectangular welding area (12) and the bending terminal (13) are sintered and assembled so as to fixedly connect the copper-clad ceramic substrate (3) and the lead frame unit (2).

4. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 1, wherein the ceramic insulating layer (9) is a ceramic sheet with a thickness of 0.5±0.05mm; the thickness of the first copper-clad layer (17) and the second copper-clad layer (8) is 0.3 + -0.05 mm.

5. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 1, wherein a material locking hole (15) is further arranged at a position close TO the base island (5) on the head end of the independent terminal (4), and the material locking hole (15) has a diameter of 0.3mm and a depth of axially penetrating the independent terminal (4).

6. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 3, wherein a lock screw hole (16) is formed in the case (1), the hole diameter of the lock screw hole (16) is larger than or equal TO the through hole (10) in the copper-clad ceramic substrate (3), and the lock screw hole (16) and the through hole (10) are coaxially arranged.

7. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 1, wherein an etched circuit is arranged on the first copper-clad layer (17), and a plurality of concave holes (14) for enhancing package bonding strength with the housing (1) are circumferentially arranged around the etched circuit.

8. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 1, wherein on the lead frame unit (2), the islands (5) on the head ends of all the individual terminals (4) are laterally connected and fixed by the middle ribs (6), and all the tail ends are also laterally connected and fixed by the bottom ribs (7).

9. The TO-247-5L packaging structure based on DBC insulation heat dissipation according TO claim 8, wherein a plurality of positioning holes (18) are distributed on the bottom ribs (7) of the lead frame single body (2), and the depth of the positioning holes penetrates through the bottom ribs (7) axially.

10. The TO-247-5L package structure based on DBC insulating heat dissipation according TO claim 1, wherein two sides of the case (1) are respectively provided with a auricle-shaped pit (19), and a part of the first copper-clad layer is exposed above the pit (19).