TO-252 lead frame, packaging structure and lead frame strip

Abstract

The utility model discloses a TO-252 lead frame, a packaging structure and a lead frame strip, and relates to the technical field of semiconductor packaging, the lead frame comprises a frame carrier, a semiconductor power chip, an integrated control chip, a radiating fin, a bonding wire and a plurality of connecting pins; the cooling fin and the plurality of connecting pins are oppositely arranged on the two sides of the frame carrier, the cooling fin is in direct contact with the frame carrier, and connecting gaps are formed between the plurality of connecting pins and the frame carrier; the working surface of the frame carrier is provided with a grid line silver plating area; the semiconductor power chip and the integrated control chip are attached to the area, not provided with the grid line silver plating area, of the working face of the frame carrier. The integrated control chip, the grid line silver plating area, the power chip and the connecting pins are connected with one another through bonding wires. According to the scheme, the semiconductor power chip and the integrated control chip are integrated in the same lead frame, and the problems that an existing packaging device is single in function and low in integration degree are solved.

Description

Technical Field

[0001] The utility model relates to the technical field of semiconductor packaging, in particular to a TO-252 lead frame, a packaging structure and a lead frame strip. Background Art

[0002] Semiconductor power devices rely on the properties of semiconductor materials to control the output current by utilizing the electric field effect of the input circuit. The TO-252 leadframe is a structure used to package electronic components, primarily for high-frequency, low-voltage, rectifier diodes, freewheeling diodes, and protection diodes. Its design features include heat sinks, stress relief holes, and dovetail grooves. These features strengthen the bond between the plastic encapsulant and the frame, reduce deformation during plastic shrinkage, and reduce stress bending and lateral shear forces on the chip, thereby improving device reliability and service life.

[0003] Due to the limited package size, the existing TO-252 series products generally only encapsulate a semiconductor chip with three electrodes: gate (G), source (S) and drain (D). The packaged device has a single function and does not have integrated drive, control and protection circuits. If the product functions are to be realized, drive and control circuit devices need to be installed on the PCB circuit board to work with the packaged device. Utility Model Content

[0004] The utility model provides a TO-252 lead frame, a packaging structure and a lead frame strip, which solve the problems of single function and low integration of existing packaging devices.

[0005] In order to achieve the above purpose, the utility model adopts the following technical solutions:

[0006] In a first aspect, the utility model provides a TO-252 lead frame, comprising: a frame carrier, a semiconductor power chip, an integrated control chip, a heat sink, bonding wires, and a plurality of connecting pins;

[0007] The heat sink and the plurality of connecting pins are arranged on opposite sides of the frame carrier, and the heat sink is in direct contact with the frame carrier, and a connecting gap is provided between the plurality of connecting pins and the frame carrier;

[0008] The working surface of the frame carrier is provided with a grid line silver-plated area; the semiconductor power chip and the integrated control chip are mounted on the area of ​​the working surface of the frame carrier where the grid line silver-plated area is not provided;

[0009] The integrated control chip, the grid line silver-plated area, the semiconductor power chip and the connecting pins are interconnected through the bonding wires.

[0010] In a possible implementation, a die-bonding glue layer is further included, and the die-bonding glue layer is arranged between the semiconductor power chip and the frame carrier, and between the integrated control chip and the frame carrier.

[0011] In a possible implementation, the semiconductor power chip is a gallium nitride semiconductor power chip.

[0012] In a possible implementation, the grid line silver-plated area includes a first silver-plated area and a second silver-plated area;

[0013] The first silver-plated area is arranged on a side of the working surface of the frame carrier close to the heat sink; the second silver-plated area is arranged on a side of the working surface of the frame carrier close to the plurality of pins.

[0014] In a possible implementation, the semiconductor power chip and the integrated control chip are sequentially arranged on the working surface of the frame carrier, and the semiconductor power chip and the integrated control chip are located between the first silver-plated area and the second silver-plated area.

[0015] In a second aspect, the present invention provides a TO-252 package structure, comprising any one of the TO-252 lead frames described above, and further comprising a plastic package body;

[0016] The plastic package is wrapped around the outside of the frame carrier of the TO-252 lead frame, and the heat sink of the TO-252 lead frame is exposed outside the plastic package at one end away from the frame carrier, and multiple connecting pins of the TO-252 lead frame are exposed outside the plastic package at one end away from the frame carrier.

[0017] In a possible implementation, the heat sink is not provided on the outside of the plastic package, and gaps are provided on two sides of the connecting pins.

[0018] In a third aspect, the present invention provides a TO-252 lead frame strip, comprising any one of the TO-252 lead frames described above, and further comprising connecting ribs;

[0019] There are multiple TO-252 lead frames, which are arranged in an array and connected by the connecting ribs.

[0020] In a possible implementation, the connecting ribs include top connecting ribs, middle ribs, bottom connecting ribs, and transverse ribs that are arranged parallel to each other, and also include vertical ribs that are arranged perpendicular to the top connecting ribs.

[0021] A first loading portion is provided between the top connecting rib and the middle rib, and a second loading portion is provided between the middle rib and the bottom connecting rib; the first loading portion and the second loading portion each include a first row of lead frames and a second row of lead frames that are arranged in mirror symmetry, and the first row of lead frames and the second row of lead frames each include a plurality of TO-252 lead frames that are arranged at intervals;

[0022] The first row of lead frames and the second row of lead frames are connected by the transverse ribs;

[0023] The top edge connecting reinforcement, the middle reinforcement and the bottom edge connecting reinforcement are connected by the vertical reinforcement.

[0024] In a possible implementation, the top edge connecting rib, the first loading part, the middle rib, the second loading part and the bottom edge connecting rib are connected in sequence in a stepped manner, and the top edge connecting rib, the middle rib and the bottom edge connecting rib are located in the same plane, and the first loading part and the second loading part are located in another plane.

[0025] The TO-252 lead frame provided by the embodiment of the present invention integrates the semiconductor power chip and the integrated control chip in the same lead frame, that is, the drive, control and protection circuits of the semiconductor power chip are integrated in the same semiconductor package device, thereby improving the packaging integration of the packaged device and increasing the functions that can be achieved by the packaged device, making the semiconductor control system design simpler and the design progress faster, and the size of the packaged product is smaller, thereby improving the system-level packaging cost and packaging volume. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the structure of mounting a chip and bonding wires on a frame carrier in a TO-252 lead frame provided by an embodiment of the present utility model;

[0027] Figure 2 A schematic diagram of a portion of the structure of a TO-252 lead frame provided by an embodiment of the present utility model before a power chip and an integrated control chip are bonded thereto;

[0028] Figure 3 A schematic diagram of the overall structure of a TO-252 package structure provided by an embodiment of the present utility model;

[0029] Figure 4 A schematic structural diagram of a TO-252 lead frame strip provided in an embodiment of the present utility model;

[0030] Figure 5 A partially enlarged structural schematic diagram of a TO-252 lead frame strip provided by an embodiment of the utility model;

[0031] Figure 6 for Figure 5 A side view of a partially enlarged structural schematic diagram.

[0032] Reference numerals and descriptions:

[0033] 1. TO-252 lead frame; 11. Frame carrier; 12. Semiconductor power chip; 13. Integrated control chip; 14. Heat sink; 15. Wire bond; 16. Connecting pins; 161. Lead body; 162. Pin connector; 163. Pin header; 164. First pin; 165. Second pin; 166. Third pin; 167. Fourth pin; 168. Lead; 17. Silver-plated grid line area; 18. Glue layer for bonding; 19. Stress relief hole; 110. Stress relief dovetail groove;

[0034] 2. TO-252 package structure; 21. Plastic package; 22. Notch;

[0035] 3. TO-252 lead frame strip; 31. Top edge connecting rib; 32. Middle rib; 33. Bottom edge connecting rib; 34. Horizontal rib; 35. Vertical rib; 36. First loading part; 37. Second loading part; 38. Top frame positioning hole; 39. Runner circular hole; 310. Bottom frame waist-shaped hole; 311. Bottom frame circular hole; 312. Runner waist-shaped hole; 313. Bend; 314. Vertical rib waist hole; 315. Rectangular hole. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0037] In the following, the terms "first" and "second" are used for descriptive purposes only and are not to be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present disclosure, unless otherwise specified, "multiple" means two or more. In addition, the use of "based on" or "according to" means openness and inclusiveness, because the process, steps, calculations or other actions "based on" or "according to" one or more of the conditions or values ​​may be based on additional conditions or values ​​beyond the stated in practice.

[0038] In order to solve the problems of single function and low integration of existing packaged devices, embodiments of the present invention provide a TO-252 lead frame, a package structure, and a lead frame strip.

[0039] like Figure 1 and Figure 2 As shown, in the first aspect, an embodiment of the present invention provides a TO-252 lead frame, including: a frame carrier 11, a semiconductor power chip 12, an integrated control chip 13, a heat sink 14, bonding wires 15 and a plurality of connecting pins 16.

[0040] The heat sink 14 and the plurality of connecting pins 16 are disposed oppositely on both sides of the frame carrier 11 , and the heat sink 14 is in direct contact with the frame carrier 11 , with a connection gap being provided between the plurality of connecting pins 16 and the frame carrier 11 .

[0041] The working surface of the frame carrier 11 is provided with a grid line silver-plated area 17 ; the semiconductor power chip 12 and the integrated control chip 13 are mounted on the working surface of the frame carrier 11 where the grid line silver-plated area 17 is not provided.

[0042] The integrated control chip 13 , the grid line silver-plated area 17 , the semiconductor power chip 12 and the connecting pins 16 are interconnected via bonding wires 15 .

[0043] The frame carrier 11 is the core framework supporting the packaged product. As the chip carrier of the integrated circuit, the frame carrier 11 is a key structural component that uses bonding materials (gold, aluminum, or copper wires) to achieve electrical connections between the chip's internal circuit terminals and external leads, forming an electrical circuit. It serves as a bridge connecting to external wires. Lead frames are required in most semiconductor integrated circuits and are an important foundational material in the electronic information industry.

[0044] The semiconductor power chip 12 is an important device that can control and amplify high-power current. It is made by performing processes such as dipping and wiring on semiconductor sheets. It can achieve specific functions and has the characteristics of low loss, high frequency response and high temperature operation.

[0045] An integrated control chip 13, also known as an IC chip, is an electronic component that integrates multiple control modules onto a single chip, primarily used to implement various control functions. It typically includes a processor, memory, input / output interfaces, and specific control algorithms, allowing it to autonomously run programs and perform data processing and control tasks.

[0046] The heat sink 14 can increase the heat conduction area and heat dissipation efficiency.

[0047] Each connecting pin 16 includes a lead body 161, a pin connecting rib 162, and a pin header 163. There are multiple lead bodies 161 and pin headers 163, and the number of lead bodies 161 and pin headers 163 matches. The pin connecting rib 162 is used to connect multiple lead bodies 161. The pin header 163 is arranged on the side of the lead body 161 close to the frame carrier 11. The pin header 163 is connected to the semiconductor power chip 12 or the integrated control chip 13 via a bonding wire 15.

[0048] When packaging the semiconductor power chip, the semiconductor power chip 12 and the integrated control chip 13 are pasted together on the working surface of the frame carrier 11, and the connection between the integrated control chip 13, the semiconductor power chip 12, the frame carrier 11 and the connecting pins 16 is achieved through the welding wire 15.

[0049] The main functions of the grid line silver-plated area 17 provided on the working surface of the frame carrier 11 include improving electrical conductivity, enhancing signal transmission quality, preventing oxidation corrosion, and improving product reliability and stability.

[0050] The TO-252 lead frame provided by the embodiment of the present invention integrates the semiconductor power chip 12 and the integrated control chip 13 in the same lead frame, that is, the driving, control and protection circuits of the semiconductor power chip 12 are integrated in the same semiconductor package device, thereby improving the packaging integration of the packaged device and increasing the functions that can be achieved by the packaged device, making the semiconductor control system design simpler and the design progress faster, and the size of the packaged product is smaller, thereby improving the system-level packaging cost and packaging volume.

[0051] In this embodiment, stress relief holes 19 and stress relief dovetail grooves 110 are further provided at the connection between the heat sink 14 and the frame carrier 11. The design of stress relief holes 19 and stress relief dovetail grooves 110 strengthens the bonding force between the encapsulation material and the frame carrier 11 during the subsequent encapsulation process, reduces deformation of the encapsulation material during shrinkage, and thereby reduces stress bending and lateral shear forces on the semiconductor power chip 12 and the integrated control chip 13. Furthermore, when the encapsulated device is soldered to the PCB board, stress relief holes 19 and stress relief dovetail grooves 110 effectively prevent stress caused by solder shrinkage from damaging the semiconductor power chip 12 and the integrated control chip 13, thereby improving the reliability and service life of the encapsulated device.

[0052] Furthermore, the TO-252 lead frame 1 further includes a die-bonding glue layer 18 , which is disposed between the semiconductor power chip 12 and the frame carrier 11 , and between the integrated control chip 13 and the frame carrier 11 .

[0053] The die-bonding glue layer 18 is used to bond the semiconductor power chip 12 and the integrated control chip 13 to the working surface of the frame carrier 11 .

[0054] Die-bonding adhesive is a type of adhesive used to bond electronic components to substrates, primarily in surface mount technology. Die-bonding adhesive plays a crucial role in electronics assembly, ensuring a secure bond between components and substrates, preventing them from falling off or shifting during subsequent processing and long-term use.

[0055] Furthermore, the semiconductor power chip 12 is a gallium nitride semiconductor power chip.

[0056] A GaN semiconductor power chip is a semiconductor device made of gallium nitride (GaN) material. GaN is a wide-bandgap semiconductor material with high electron mobility and high electron saturation drift velocity. This enables GaN power chips to operate at high frequencies and high powers with low resistance and energy loss.

[0057] In this solution, the gallium nitride power chip and the integrated control chip 13 are packaged in the same product, which not only improves the packaging integration of the packaged device and increases the functions that can be achieved by the packaged device; it also improves the power density of the power device and improves the heat dissipation conditions.

[0058] In order to facilitate circuit connection between the semiconductor power chip 12 and the integrated control chip 13 and the frame carrier 11 , the grid line silver-plated area 17 further includes a first silver-plated area and a second silver-plated area.

[0059] The first silver-plated area is disposed on a side of the working surface of the frame carrier 11 close to the heat sink 14 ; the second silver-plated area is disposed on a side of the working surface of the frame carrier 11 close to the plurality of pins.

[0060] Furthermore, the semiconductor power chip 12 and the integrated control chip 13 are sequentially arranged on the working surface of the frame carrier 11 , and the semiconductor power chip 12 and the integrated control chip 13 are located between the first silver-plated area and the second silver-plated area.

[0061] In an embodiment of the present invention, the back surfaces of the gallium nitride semiconductor power chip and the integrated control chip 13 are bonded to the working surface of the frame carrier 11 by adhesive glue, and the gallium nitride semiconductor power chip is located on the left side of the center of the working surface of the frame carrier 11, and the integrated control chip 13 is located on the right side of the center of the working surface of the frame carrier 11.

[0062] The front surface of the gallium nitride semiconductor power chip and the front surface of the integrated control chip 13, the front surface of the gallium nitride semiconductor power chip and the grid line silver-plated area 17, the front surface of the integrated control chip 13 and the grid line silver-plated area 17, and the front surfaces of the gallium nitride semiconductor power chip and the integrated control chip 13 and the connecting pins 16 are all connected by bonding wires 15.

[0063] The front side of the GaN semiconductor power chip and the front side of the integrated control chip 13 are both the sides where electrodes or solder joints are set.

[0064] There are four connecting pins 16 , including a first pin 164 , a second pin 165 , a third pin 166 and a fourth pin 167 , which are arranged sequentially from left to right.

[0065] First pin 164 serves as the electrode lead for the GaN semiconductor power chip, while frame carrier 11 serves as the common electrode lead for the GaN semiconductor power chip and integrated control chip 13. Second pin 165, third pin 166, and fourth pin 167 serve as electrode lead terminals for the integrated control chip 13, providing an electrical path for the device and enabling the encapsulation of the GaN semiconductor power chip and integrated control chip 13 within a TO-252 form factor.

[0066] Specifically, one end of the bonding wire connecting the gallium nitride semiconductor power chip and the connecting pin 16 is bonded to the surface solder joint of the gallium nitride semiconductor power chip, and the other end is bonded to the pin head 163 of the first pin 164; one end of the bonding wire connecting the integrated control chip 13 and the connecting pin 16 is bonded to the surface solder joint of the integrated control chip 13, and the other end is bonded to the pin heads 163 of the second pin 165, the third pin 166, and the fourth pin 167, respectively.

[0067] Compared with the prior art, the TO-252 lead frame of the present invention can improve the packaging integration of the device under the same TO-252 package shape, and simultaneously improve the packaging integration and packaging power density of the device.

[0068] like Figure 3 As shown, in a second aspect, an embodiment of the present invention provides a TO-252 packaging structure, including any of the TO-252 lead frames 1 described above, and also including a plastic package body 21 .

[0069] Among them, the plastic package 21 is wrapped around the outside of the frame carrier 11 of the TO-252 lead frame 1, and the end of the heat sink 14 of the TO-252 lead frame 1 away from the frame carrier 11 is exposed outside the plastic package 21, and the end of multiple connecting pins 16 of the TO-252 lead frame 1 away from the frame carrier 11 is exposed outside the plastic package 21.

[0070] Specifically, such as Figure 2 and Figure 3 As shown, the inside of the bonding area of ​​the TO-252 lead frame 1 is filled and encapsulated with a plastic encapsulation material to obtain a plastic encapsulation body 21. In this embodiment, the plastic encapsulation material is a resin filler.

[0071] Furthermore, notches 22 are provided on opposite sides of the plastic package body 21 where the heat sink 14 and the connecting pins 16 are not provided.

[0072] like Figures 1 to 3 As shown, the TO-252 package structure of the present invention seals the semiconductor power chip 12 and the integrated control chip 13 together, and can integrate modular functions such as driving, circuit control and circuit protection functions using the appearance of a single tube of an ordinary power device.

[0073] The TO-252 packaging structure of the present invention seals the semiconductor power chip 12 and the integrated control chip 13 together, and can also reduce the number of external components and reduce system costs.

[0074] like Figure 4 As shown, in a third aspect, an embodiment of the present invention provides a TO-252 lead frame strip, comprising any one of the above-mentioned TO-252 lead frames, and further comprising connecting ribs.

[0075] There are multiple TO-252 lead frames 1 , which are arranged in an array and connected by connecting ribs.

[0076] In the embodiment of the present invention, the TO-252 lead frame strip is composed of 4 rows and 28 columns of TO-252 lead frames 1 arranged in an array, wherein the first row and the second row are arranged in a mirror image, and the third row and the fourth row are arranged in a mirror image.

[0077] Further, such as Figure 6 As shown, the connecting ribs include top connecting ribs 31 , middle ribs 32 , bottom connecting ribs 33 and transverse ribs 34 that are arranged parallel to each other, and also include vertical ribs 35 that are arranged perpendicular to the top connecting ribs 31 .

[0078] A first loading portion 36 is provided between the top connecting rib 31 and the middle rib 32 , and a second loading portion 37 is provided between the middle rib 32 and the bottom connecting rib 33 .

[0079] The first loading portion 36 and the second loading portion 37 both include a first row of lead frames and a second row of lead frames that are arranged in mirror symmetry. The first row of lead frames and the second row of lead frames both include a plurality of TO-252 lead frames 1 that are arranged at intervals.

[0080] The first row of lead frames and the second row of lead frames are connected by transverse ribs 34 .

[0081] The top edge connecting reinforcement 31 , the middle reinforcement 32 and the bottom edge connecting reinforcement 33 are connected by vertical reinforcement 35 .

[0082] Specifically, a rectangular hole 315 is provided between the heat sinks 14 of the TO-252 lead frames 1 in the first row of lead frames and the second row of lead frames that are opposite to each other.

[0083] A circular hole is provided on the vertical rib 35 at a position corresponding to the rectangular hole 315 ; vertical rib waist holes 314 are provided on opposite sides of each circular hole on the vertical rib 35 .

[0084] A top frame positioning hole 38 is provided on the top edge connecting rib 31 corresponding to each row of TO-252 lead frames 1. A flow channel waist-shaped hole 312 is provided corresponding to the flow channel between two adjacent rows of TO-252 lead frames 1.

[0085] A flow channel circular hole 39 is provided on the center rib 32 corresponding to the flow channel waist-shaped hole 312 .

[0086] The bottom edge connecting rib 33 is further provided with a bottom frame circular hole 311 corresponding to each row of TO-252 lead frames 1 , and a bottom frame waist-shaped hole 310 is provided every two bottom frame circular holes 311 .

[0087] The lead 168 is arranged in the same plane as the top edge connecting rib 31 and is connected to the top edge connecting rib 31 through the lead connecting rib 162 .

[0088] In the first loading portion 36 and the second loading portion 37 , the TO-252 lead frames 1 in each column are connected in mirror symmetry via heat sinks 14 , and the heat sinks 14 between adjacent columns are connected via transverse ribs 34 to increase the strength of the frame.

[0089] In this embodiment, two channel waist-shaped holes 312 are vertically symmetrically provided at the flow channel positions between two adjacent rows of TO-252 lead frames 1 on the center rib 32 , and the channel circular hole 39 is located between the two channel waist-shaped holes 312 .

[0090] Two channel waist-shaped holes 312 are vertically symmetrically provided at the flow channel positions between two adjacent rows of TO-252 lead frames 1 on the top edge connecting rib 31 .

[0091] A waist-shaped flow channel hole 312 and a circular flow channel hole 39 are vertically provided at the flow channel position between two adjacent rows of TO-252 lead frames 1 on the bottom edge connecting rib 33 .

[0092] Further, such as Figure 6 As shown, the top edge connecting rib 31, the first loading portion 36, the middle rib 32, the second loading portion 37 and the bottom edge connecting rib 33 are connected in sequence in a stepped manner, and the top edge connecting rib 31, the middle rib 32 and the bottom edge connecting rib 33 are located in the same plane, and the first loading portion 36 and the second loading portion 37 are located in another plane.

[0093] Specifically, the stepped shape among the top side connecting rib 31 , the first loading portion 36 , the middle rib 32 , the second loading portion 37 and the bottom side connecting rib 33 is achieved by a bend 313 provided on the vertical rib 35 .

[0094] The TO-252 lead frame, packaging structure and lead frame strip of the utility model can realize the TO-252 series appearance products for semiconductor power chip packaging. The product can be widely used in the fields of chargers for mobile phones and laptops below 500W, TV power supplies, solid-state lighting power supplies, etc.

[0095] The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited to this. Any changes or replacements within the technical scope disclosed in this utility model should be included in the scope of protection of the present utility model. Therefore, the scope of protection of the present utility model should be based on the scope of protection of the claims.

Claims

1. A TO-252 lead frame, characterized in that: include: A frame carrier (11), a semiconductor power chip (12), an integrated control chip (13), a heat sink (14), welding wires (15), and a plurality of connecting pins (16); The heat sink (14) and the plurality of connecting pins (16) are arranged on two sides of the frame carrier (11) opposite to each other, the heat sink (14) is in direct contact with the frame carrier (11), and a connecting gap is provided between the plurality of connecting pins (16) and the frame carrier (11); The working surface of the frame carrier (11) is provided with a grid line silver-plated area (17); the semiconductor power chip (12) and the integrated control chip (13) are mounted on an area of ​​the working surface of the frame carrier (11) where the grid line silver-plated area (17) is not provided; The integrated control chip (13), the grid line silver-plated area (17), the semiconductor power chip (12) and the connecting pin (16) are interconnected via the welding wire (15).

2. The TO-252 lead frame according to claim 1, characterized in that: It also comprises a chip adhesive layer (18), wherein the chip adhesive layer (18) is arranged between the semiconductor power chip (12) and the frame carrier (11), and between the integrated control chip (13) and the frame carrier (11).

3. The TO-252 lead frame according to claim 1, characterized in that: The semiconductor power chip (12) is a gallium nitride semiconductor power chip.

4. The TO-252 lead frame according to claim 1, characterized in that: The grid line silver-plated area (17) comprises a first silver-plated area and a second silver-plated area; The first silver-plated area is arranged on a side of the working surface of the frame carrier (11) close to the heat sink (14); and the second silver-plated area is arranged on a side of the working surface of the frame carrier (11) close to the plurality of pins.

5. The TO-252 lead frame according to claim 4, characterized in that: The semiconductor power chip (12) and the integrated control chip (13) are arranged in sequence on a working surface of the frame carrier (11), and the semiconductor power chip (12) and the integrated control chip (13) are located between the first silver-plated area and the second silver-plated area.

6. A TO-252 packaging structure, characterized in that: A TO-252 lead frame (1) according to any one of claims 1 to 5, further comprising a plastic package (21); The plastic package (21) is wrapped around the outside of the frame carrier (11) of the TO-252 lead frame (1), and one end of the heat sink (14) of the TO-252 lead frame (1) away from the frame carrier (11) is exposed outside the plastic package (21), and one end of a plurality of connecting pins (16) of the TO-252 lead frame (1) away from the frame carrier (11) is exposed outside the plastic package (21).

7. The TO-252 package structure according to claim 6, characterized in that: The exterior of the plastic package body (21) is not provided with the heat sink (14) and has notches (22) on two sides of the connecting pins (16) facing each other.

8. A TO-252 lead frame strip, characterized in that: The TO-252 lead frame (1) according to any one of claims 1 to 5, further comprising connecting ribs; There are a plurality of TO-252 lead frames (1), which are arranged in an array and connected via the connecting ribs.

9. The TO-252 lead frame strip according to claim 8, characterized in that The connecting ribs include top connecting ribs (31), middle ribs (32), bottom connecting ribs (33) and transverse ribs (34) arranged parallel to each other, and also include vertical ribs (35) arranged perpendicular to the top connecting ribs (31); A first loading portion (36) is provided between the top edge connecting rib (31) and the middle rib (32), and a second loading portion (37) is provided between the middle rib (32) and the bottom edge connecting rib (33); the first loading portion (36) and the second loading portion (37) both comprise a first row of lead frames and a second row of lead frames arranged in mirror symmetry, and the first row of lead frames and the second row of lead frames both comprise a plurality of TO-252 lead frames (1) arranged at intervals; The first row of lead frames and the second row of lead frames are connected via the transverse ribs (34); The top edge connecting reinforcement (31), the middle reinforcement (32), and the bottom edge connecting reinforcement (33) are connected via the vertical reinforcement (35).

10. The TO-252 lead frame strip according to claim 9, wherein: The top edge connecting rib (31), the first loading portion (36), the middle rib (32), the second loading portion (37) and the bottom edge connecting rib (33) are sequentially connected in a stepped manner, and the top edge connecting rib (31), the middle rib (32) and the bottom edge connecting rib (33) are located in the same plane, and the first loading portion (36) and the second loading portion (37) are located in another plane.

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