Tolt type lead frame adapting to ai server power supply and processing technology thereof

Abstract

The application provides a TOLT lead frame suitable for an AI server power supply and a processing technology thereof, and relates to the technical field of semiconductor packaging. The lead frame comprises a central base island, a chip mounting groove is formed in the central base island, a heat dissipation fin is integrally formed on the back surface, a drain pin is symmetrically distributed on opposite sides of the central base island and is electrically connected through a copper connecting bridge, and a source pin is distributed on the other two sides and is electrically isolated from the central base island. The processing technology adopts twice laser cutting: the first cutting forms a frame contour and a half-etching area, and the second cutting forms a pin-free isolation groove, so that the source pin is completely electrically isolated from the central base island and the drain connecting bridge remains conductive, and then, after cleaning, a micro-pit roughening treatment is performed on the heat dissipation fin by using a femtosecond laser. The application solves the problems of serious traditional chemical etching side etching and large isolation groove size deviation, improves the insulation reliability between pins and the bonding force of the heat dissipation interface, and improves the feeding efficiency and the yield of the lead frame laser processing.

Description

Technical Field

[0001] This invention relates to the field of semiconductor packaging technology, and in particular to a TOLT-type lead frame adapted to the power supply of AI servers and its processing technology. Background Technology

[0002] With the rapid development of artificial intelligence (AI) technology, AI servers, as the core of computing power, are experiencing exponential growth in power consumption. To meet the demands of massive data processing and high-load model training, AI servers place unprecedentedly stringent requirements on the power density, conversion efficiency, and thermal management capabilities of their power supply systems. Traditional discrete power supply solutions are no longer sufficient to address such high-density power integration challenges, leading to the development of TOLT-based leadframe technology. TOLT-type leadframes, by directly mounting power chips onto a central base island with a large heat dissipation path, have become an ideal choice for next-generation AI server power modules.

[0003] Currently, the industry mainly relies on traditional chemical etching or mechanical stamping processes for manufacturing TOLT leadframes. While chemical etching can create complex planar patterns, it suffers from significant lateral etching effects when processing structures like "leadless isolation trenches" that require precise control of electrical connections. This results in uneven edges and large dimensional deviations in the isolation trenches, making it difficult to reliably achieve complete electrical isolation between the central base island and the source pins, while simultaneously ensuring the mechanical strength and conductivity consistency of the bridge between the drain pins and the base island. Mechanical stamping, on the other hand, is limited by mold precision and material stress, easily generating microcracks or burrs at the pin roots, further affecting the insulation resistance and long-term reliability after packaging.

[0004] Therefore, to address the above issues, the applicant needs to design a TOLT-type lead frame and its manufacturing process that are compatible with the power supply of AI servers. Summary of the Invention

[0005] This application provides a TOLT-type lead frame adapted to AI server power supplies, including a frame body, and the frame body includes a frame connecting plate and multiple packaging units integrally formed inside the frame body and arranged in a matrix. Each packaging unit includes a central base island, and the central base island has a chip mounting slot for carrying power chips. Each packaging unit also includes at least two drain pins, and the drain pins are symmetrically distributed on opposite sides of the central base island and electrically connected to the central base island through an integrally formed copper connecting bridge. At least two source pins are distributed on the other two sides of the central base island, and the source pins are electrically isolated from the central base island. A heat sink is integrally formed on the back of the central base island, and the heat sink is exposed outside the plastic package. The specific steps of the above-mentioned TOLT-type lead frame manufacturing process for AI server power supplies are as follows: S1. Substrate pretreatment: Select copper alloy sheet, and perform degreasing, pickling, surface cleaning and pre-plating in sequence. After pre-plating, dry for later use. S2. Precise positioning and feeding: The pre-plated copper alloy sheet is placed in the buffer bin of the feeding module. The sheet is then conveyed to the laser cutting station one by one through the lifting component and the adsorption detection module. S3, First laser cutting – forming the frame outline and semi-etched area: The first cutting is performed using a nanosecond or picosecond laser to cut out the outer outline of the packaging unit along the design trajectory, and semi-etching is performed in the corresponding area of ​​the pin to form the semi-etched steps of the pin. S4. Second laser cutting - TOLT type leadless isolation groove: switch laser parameters or coaxial secondary cutting to completely cut off the electrical connection path between the central base island and the source pin, while ensuring that the drain pin and the central base island remain connected through the reserved connection bridge, thus completing the precision cutting of the leadless isolation groove. S5. Slag Removal and Cleaning: Immerse the cut frame in a chemical cleaning solution or use ultrasonic cleaning to remove slag, oxides and oil stains generated by laser cutting. Then rinse with deionized water and dry with hot air. S6. Surface roughening and micro-dimple forming of the back heat sink: The heat sink area on the back of the central base island is scanned with a femtosecond laser to form a uniform array of micro-dimples, which increases the surface roughness and improves the bonding force with the molding compound or heat dissipation medium. S7. Quality Inspection and Frame Separation: The insulation resistance between each pin, the integrity of the isolation groove, and the morphology of the micro-pits are checked by an optical inspection system. After confirming that they are qualified, the frame body is punched and separated from the connecting plate to obtain a single TOLT type lead frame unit. S8. Rewinding and Packaging: Arrange the separated lead frames in sequence on the carrier tape, or rewind them directly onto a reel and vacuum seal them for storage.

[0006] Preferably, the laser slitting mechanism includes a base, and a feeding module is provided on one side of the base. The laser slitting mechanism also includes an adsorption detection module, a conveyor frame, and a laser. The copper alloy sheet in the feeding module enters the inner side of the laser for processing through the adsorption detection module and the conveyor frame. The integration of the feeding module, adsorption detection module, conveyor frame, and laser constitutes an automated laser slitting mechanism, realizing continuous and high-precision flow of copper alloy sheet from storage to laser processing, which significantly improves the production efficiency and processing consistency of the lead frame.

[0007] Preferably, the feeding module includes a fixed plate fixedly connected to the base, and a support frame is slidably arranged on the outside of the fixed plate. A buffer bin is fixedly arranged on the inside of the support frame, and a slider is slidably arranged on the inside of the buffer bin. Several copper alloy sheets are placed on the top surface of the slider. A lifting component is also arranged on the outside of the fixed plate, and the lifting component is used to push the slider to move. The support frame slidably arranged on the outside of the fixed plate and the buffer bin on its inside, combined with the lifting component to push the slider to move, realize the stable storage and orderly feeding of copper alloy sheets, and avoid the impact of sheet overlap or jamming on the laser cutting quality.

[0008] Preferably, a connecting block is fixedly provided on the bottom surface of the support frame, and a cylinder is provided on one side of the connecting block. The outer surface of the cylinder away from the piston end is fixedly connected to the fixed plate. By providing a connecting block on the bottom surface of the support frame and driving it to move relative to the fixed plate by the cylinder, the entry and exit position of the buffer compartment can be easily adjusted, which facilitates the batch loading of sheet materials and the maintenance and cleaning of the buffer compartment.

[0009] Preferably, the lifting assembly includes a mounting plate fixedly connected to a fixed plate, and a sliding sleeve is provided through the mounting plate. A lifting rod is slidably provided on the inner side of the sliding sleeve, and the lifting rod is used to push the slider to move. The lifting assembly composed of the mounting plate, the sliding sleeve and the lifting rod pushes the slider in a linear sliding manner, providing a stable and precise vertical feeding power for the copper alloy sheet, ensuring that each sheet can reach a consistent adsorption waiting height.

[0010] Preferably, a clamping frame is fixedly installed at one end of the lifting rod, and a conveyor belt is installed on the inner side of the clamping frame. A drive wheel is coupled to the inner side of the conveyor belt, and a drive motor is installed on one side of the drive wheel. A tensioning wheel is also coupled to the inner side of the conveyor belt, and a fixed seat fixedly connected to a fixed plate is rotatably installed on one side of the tensioning wheel. The drive motor drives the clamping frame to move through the drive wheel, tensioning wheel, and conveyor belt. The cooperation of the conveyor belt, drive wheel, tensioning wheel, and drive motor on the inner side of the clamping frame realizes the electric drive and precise position control of the lifting rod, ensuring the automation and repeatability of the lifting action.

[0011] Preferably, the adsorption detection module includes a mounting frame fixedly connected to a fixed plate, and a driving component is provided inside the mounting frame. A moving block is fixedly mounted on the driving component, and an electric telescopic rod is fixedly mounted on one side of the moving block. An extension plate is fixedly mounted at the output end of the electric telescopic rod, and a glass plate is fixedly mounted on the extension plate. A negative pressure adsorption head for adsorbing copper alloy sheets is fixedly mounted on the glass plate, and the negative pressure adsorption head is connected to an external adsorption machine. The driving component drives the moving block and the electric telescopic rod, so that the negative pressure adsorption head can actively move to the top of the buffer compartment to adsorb the copper alloy sheets, realizing automated gripping and transfer of the sheets and reducing the risk of contamination or damage caused by manual intervention.

[0012] Preferably, a bracket is also fixedly installed on the extension plate, and a visual inspection head is fixedly installed on the bracket. The visual inspection head is located directly above the glass plate and is connected to an external visual inspection machine. The bracket is fixed above the glass plate and the visual inspection head is installed, which can perform real-time visual inspection on the surface of the sheet while adsorbing it, realizing the synchronous integration of the feeding process and the preliminary quality inspection.

[0013] Preferably, the drive assembly includes a servo motor fixedly connected to the mounting frame, and the output end of the servo motor is provided with a rotating wheel. A drive belt is coupled to the outer side of the rotating wheel and is connected to the moving block to drive the moving block to move. An auxiliary wheel is also coupled to the inner side of the drive belt and is rotatably connected to the mounting frame. The rotating wheel driven by the servo motor and the drive belt work together as the power source of the moving block, providing a smooth and programmable linear driving force, ensuring the positioning accuracy of the adsorption head on the material picking and discharging path.

[0014] Preferably, a guide rail is fixedly provided on the inner side of the mounting frame, and a guide block is slidably provided on the outer side of the guide rail. The guide block is fixedly connected to the moving block. The guide rail provided on the inner side of the mounting frame and slidingly cooperate with the guide block form a precise guide for the movement of the moving block, thereby enhancing the rigidity and position repeatability accuracy of the adsorption detection module in high-speed reciprocating motion.

[0015] This invention provides a TOLT-type lead frame adapted to AI server power supplies and its manufacturing process, which, compared with existing technologies, offers the following advantages: This invention uses a lifting component to push copper alloy sheets one by one from the buffer compartment to the desired adsorption height. Combined with an adsorption detection module consisting of a drive component, an electric telescopic rod, and a negative pressure adsorption head, it achieves automatic loading and precise transfer of the sheets. Simultaneously, a visual inspection head is installed above the glass plate to take real-time photos of the sheet surface while adsorbing the sheets. This allows for the identification of appearance defects and baseline positioning before the sheets enter the laser cutting station, avoiding poor cutting caused by surface contamination, scratches, or stacking issues. This effectively improves the loading efficiency and yield rate of lead frame laser processing and reduces the risk of secondary damage to the sheets caused by manual intervention.

[0016] This invention employs a two-stage laser cutting process: first, the frame outline and semi-etched area are cut, and then a TOLT-type leadless isolation trench is specifically cut. Combined with the high precision and low thermal impact characteristics of nanosecond or picosecond lasers, the electrical connection path between the central base island and the source pins can be completely severed, while ensuring that the connection bridge between the drain pin and the central base island remains fully conductive. This effectively avoids problems such as uneven isolation trench edges and large dimensional deviations caused by the side etching effect in traditional chemical etching processes. As a result, precise electrical isolation between the central base island and the source pins is stably achieved, and the mechanical strength and conductivity consistency of the drain connection bridge are guaranteed. This improves the insulation resistance and long-term reliability of the lead frame in high power density applications of AI servers. Attached Figure Description

[0017] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the three-dimensional structure of the frame body according to an embodiment of the present invention; Figure 2 This is a three-dimensional structural diagram of the packaging unit according to an embodiment of the present invention; Figure 3 This is a three-dimensional structural diagram of the laser slitting mechanism according to an embodiment of the present invention; Figure 4 This is a schematic diagram of the connection structure between the feeding module and the adsorption detection module in an embodiment of the present invention; Figure 5 This is a three-dimensional structural diagram of the feeding module according to an embodiment of the present invention; Figure 6 This is a three-dimensional structural diagram of the lifting component according to an embodiment of the present invention; Figure 7 This is a three-dimensional structural diagram of the adsorption detection module according to an embodiment of the present invention; Figure 8 This is a three-dimensional structural diagram of the driving component according to an embodiment of the present invention.

[0019] icon: 1. Frame body; 2. Laser slitting mechanism; 3. Feeding module; 4. Adsorption detection module; 11. Frame connecting plate; 12. Packaging unit; 21. Base; 22. Conveyor frame; 23. Laser; 31. Fixing plate; 32. Support frame; 33. Buffer bin; 34. Connecting block; 35. Cylinder; 36. Lifting assembly; 37. Slider; 41. Mounting frame; 42. Drive assembly; 43. Moving block; 44. Electric telescopic rod; 45. Glass plate; 46. Negative pressure adsorption head; 47. Bracket; 4 8. Vision inspection head; 49. Extension board; 121. Central base island; 122. Drain pin; 123. Chip mounting slot; 124. Source pin; 361. Mounting plate; 362. Sliding sleeve; 363. Lifting rod; 364. Clamping frame; 365. Conveyor belt; 366. Drive wheel; 367. Drive motor; 368. Tensioning wheel; 369. Fixing base; 421. Servo motor; 422. Rotating wheel; 423. Drive belt; 424. Auxiliary wheel; 425. Guide rail; 426. Guide block. Detailed Implementation

[0020] The following detailed description of some embodiments of the present invention is provided in conjunction with the accompanying drawings. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0021] Please refer to Figure 1 and Figure 2 This invention provides a TOLT-type lead frame adapted to an AI server power supply, comprising a frame body 1, which includes a frame connecting plate 11 and multiple packaging units 12 integrally formed inside the frame body 1 and arranged in a matrix. The frame connecting plate 11 is used to support and connect the packaging units 12 during processing, and is then separated during the final process.

[0022] Each packaging unit 12 includes a central base island 121. A chip mounting slot 123 is formed in the center of the lower surface of the central base island 121. The chip mounting slot 123 is used to position and support power chips, such as MOSFET chips used in AI server power supplies. A heat sink is integrally formed on the back of the central base island 121. The heat sink is exposed outside the molded package in the subsequent molding process so that it can directly contact the external heat sink or heat dissipation medium to improve heat dissipation efficiency.

[0023] The packaging unit 12 also includes at least two drain pins 122, which are symmetrically distributed on opposite sides of the central base island 121 and electrically connected to the central base island 121 via an integrally formed copper connecting bridge. At least two source pins 124 are distributed on the other two sides of the central base island 121. Electrical isolation between the source pins 124 and the central base island 121 is achieved through leadless isolation grooves formed by laser cutting. The central base island 121 also serves as an electrical extension of the drain. The chip's drain can be connected to the central base island 121 via conductive adhesive or soldering, thus establishing conductivity with the drain pins 122. The chip's source is connected to the source pins 124 via bonding wires or clips, forming a complete power loop. The heat sink, being integral with the central base island 121, also serves to dissipate heat from the back of the chip.

[0024] like Figures 3-8 As shown, this embodiment also provides a process for processing the aforementioned TOLT type lead frame and a laser slitting mechanism 2 for implementing this process. The laser slitting mechanism 2 includes a base 21, a feeding module 3 on one side of the base 21, and also includes an adsorption detection module 4, a conveyor frame 22, and a laser 23. The copper alloy sheet in the feeding module 3 enters the laser 23 through the adsorption detection module 4 and the conveyor frame 22 for laser cutting.

[0025] S1, Substrate Pretreatment Uniformly thick copper alloy sheets are selected and subjected to a series of processes including degreasing (using an alkaline degreasing solution), pickling (removing the oxide layer with a dilute sulfuric acid solution), surface cleaning, and pre-plating. The pre-plating layer can be nickel, palladium, gold, etc., to improve subsequent welding performance and oxidation resistance. After pre-plating, the sheets are dried for later use.

[0026] S2, Precise positioning and feeding like Figure 5 and Figure 6 As shown, the feeding module 3 includes a fixed plate 31 fixedly connected to the base 21. A support frame 32 is slidably arranged on the outer side of the fixed plate 31, and a buffer chamber 33 is fixedly arranged on the inner side of the support frame 32. A slider 37 is slidably arranged on the inner side of the buffer chamber 33, and several pre-treated copper alloy sheets are stacked on the top surface of the slider 37. A connecting block 34 is fixedly arranged on the bottom surface of the support frame 32, and a cylinder 35 is arranged on one side of the connecting block 34. The outer surface of the cylinder 35 away from the piston end is fixedly connected to the fixed plate 31. When the cylinder 35 extends or retracts, it can drive the support frame 32 and the buffer chamber 33 to move relative to the fixed plate 31, which facilitates the replenishment of sheets into the buffer chamber 33 or maintenance.

[0027] A lifting assembly 36 is also provided on the outer side of the fixed plate 31 to push the slider 37 upward within the buffer chamber 33. Specifically, the lifting assembly 36 includes a mounting plate 361 fixedly connected to the fixed plate 31. A sliding sleeve 362 is provided through the mounting plate 361. A lifting rod 363 is slidably provided inside the sliding sleeve 362, with the upper end of the lifting rod 363 facing the bottom of the slider 37. A clamping frame 364 is fixedly provided at the lower end of the lifting rod 363. A conveyor belt 365 is provided inside the clamping frame 364. A drive wheel 366 and a tension wheel 368 are coupled inside the conveyor belt 365. A drive motor 367 is provided on one side of the drive wheel 366, and a fixed seat 369 fixedly connected to the fixed plate 31 is rotatably provided on one side of the tension wheel 368. When the drive motor 367 is working, it drives the conveyor belt 365 to rotate via the drive wheel 366 and tension wheel 368. The conveyor belt 365 is connected to the clamping frame 364, thereby driving the clamping frame 364 and the lifting rod 363 to move up and down along the sliding sleeve 362. When the lifting rod 363 rises, its top pushes the slider 37 to rise, sending the uppermost copper alloy sheet to the set picking height.

[0028] The adsorption detection module 4 is used to pick up copper alloy sheets one by one from the top of the buffer bin 33 and transfer them to the conveyor rack 22. For example... Figure 7 and Figure 8 As shown, the adsorption detection module 4 includes a mounting frame 41 fixedly connected to the fixed plate 31, and a drive assembly 42 is provided inside the mounting frame 41. The drive assembly 42 includes a servo motor 421 fixedly connected to the mounting frame 41, a rotating wheel 422 at the output end of the servo motor 421, a drive belt 423 coupled to the outer side of the rotating wheel 422, and an auxiliary wheel 424 coupled to the inner side of the drive belt 423. The auxiliary wheel 424 is rotatably connected to the mounting frame 41. The drive belt 423 is fixedly connected to the moving block 43, and an electric telescopic rod 44 is fixedly provided on one side of the moving block 43. When the servo motor 421 rotates, the drive belt 423 drives the moving block 43 to move horizontally. A guide rail 425 is also fixedly provided inside the mounting frame 41, and a guide block 426 is slidably provided on the outer side of the guide rail 425. The guide block 426 is fixedly connected to the moving block 43 to ensure the straightness of the horizontal movement of the moving block 43.

[0029] An extension plate 49 is fixedly installed at the output end of the electric telescopic rod 44. A glass plate 45 is fixedly installed on the extension plate 49. Multiple negative pressure adsorption heads 46 are fixedly installed on the glass plate 45, and the negative pressure adsorption heads 46 are connected to an external vacuum adsorption machine. A bracket 47 is also fixedly installed on the extension plate 49. A visual inspection head 48 is fixedly installed on the bracket 47. The visual inspection head 48 is located directly above the glass plate 45 and is connected to an external visual inspection machine.

[0030] The working process is as follows: The drive motor 367 drives the lifting rod 363 to rise, pushing the top copper alloy sheet to the desired adsorption height. The servo motor 421 drives the moving block 43 to move horizontally, so that the negative pressure adsorption head 46 faces the top of the sheet. Then, the electric telescopic rod 44 extends, so that the negative pressure adsorption head 46 contacts the upper surface of the sheet, and the negative pressure adsorption machine starts, adsorbing the sheet. The electric telescopic rod 44 retracts, lifting the sheet. At this time, the vision inspection head 48 takes pictures of the surface of the sheet through the glass plate 45 to detect whether there are obvious defects, and at the same time, it can identify the reference points of the sheet for positioning compensation in subsequent laser cutting. After passing the inspection, the servo motor 421 drives the moving block 43 to move to the entrance of the conveyor frame 22 again, the electric telescopic rod 44 extends, the negative pressure adsorption head 46 releases the sheet, and the sheet is placed steadily on the conveyor frame 22.

[0031] S3, First laser cutting – forming the frame outline and semi-etched area The conveyor 22 feeds the sheet material into the processing area of ​​the laser 23. In this embodiment, the laser 23 is a nanosecond or picosecond laser. During the first cut, the laser beam cuts along the outer contour of the packaging unit according to the preset CAD cutting trajectory, and simultaneously performs a semi-etching (thinning) process in the area corresponding to each pin, forming a semi-etched step of the pin. This step can increase the bonding area between the molding compound and the pin during subsequent molding and prevent delamination. After the first cut is completed, the outer contour of each packaging unit 12 of the frame is basically formed, but the central base island 121 and the source pin 124 are not completely cut off, and a micro-connecting strip is still retained to ensure the integrity of the entire frame in subsequent processing.

[0032] S4, Second Laser Cutting – TOLT Type Leadless Isolation Groove By switching laser parameters (e.g., increasing laser power or decreasing scanning speed) or employing coaxial secondary cutting (i.e., scanning the same trajectory again), the electrical connection path between the central base island 121 and the source pin 124 is completely severed, forming a pinless isolation trench. Simultaneously, the drain pin 122 and the central base island 121 are kept conductive through a pre-designed copper bridge. This second laser cutting utilizes the characteristics of lasers—no mechanical stress and a minimal heat-affected zone—avoiding the side-etching effect of traditional chemical etching. This results in a clean, precisely sized isolation trench with neat edges, ensuring stable and complete electrical isolation between the central base island and the source pin, while maintaining the mechanical strength and conductivity consistency of the drain bridge.

[0033] S5. Slag Removal and Cleaning After laser cutting, a small amount of slag, oxides, and oil may remain on the frame surface. The entire cut frame should be immersed in a chemical cleaning solution or cleaned using an ultrasonic cleaning tank to remove these contaminants. It should then be rinsed thoroughly with deionized water and dried with hot air.

[0034] S6, Roughened and micro-dimpled surface of the rear heatsink To improve the adhesion between the heatsink on the back of the central base island 121 and the subsequent molding compound or external heat dissipation medium, a femtosecond laser is used to scan the heatsink area on the back of the central base island 121. The femtosecond laser has an extremely short pulse width, produces almost no molten layer, and can form a uniform array of micro-pits on the copper surface, increasing surface roughness.

[0035] S7, Quality Inspection and Frame Separation The insulation resistance between each pin is checked using an optical inspection system (including a high-resolution camera and image processing software) (visually inspecting whether the isolation groove is completely connected), the integrity of the isolation groove (whether there are any residual connections), and whether the micro-dimple morphology meets the requirements. After confirming that it is qualified, the frame body 1 is punched and separated from the frame connecting plate 11 using a punching die to obtain a single TOLT type lead frame unit.

[0036] S8. Winding and Packaging Arrange the separated lead frames in sequence on the carrier tape, or directly wind them into a reel, place them in a moisture-proof bag, vacuum seal them, and store them in the warehouse for later use.

[0037] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various modifications and variations. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A TOLT-type lead frame adapted to AI server power supplies, characterized in that: The package includes a frame body (1), which includes a frame connecting plate (11) and multiple packaging units (12) integrally formed inside the frame body (1) and arranged in a matrix. The packaging unit (12) includes a central base island (121), and the central base island (121) is provided with a chip mounting slot (123) for carrying power chips. The packaging unit (12) also includes at least two drain pins (122), and the drain pins (122) are symmetrically distributed on opposite sides of the central base island (121) and electrically connected to the central base island (121) through an integrally formed copper connecting bridge. At least two source pins (124) are distributed on the other two sides of the central base island (121), and the source pins (124) are electrically isolated from the central base island (121). A heat sink is integrally formed on the back of the central base island (121), and the heat sink is exposed outside the plastic package. The specific steps of the above-mentioned TOLT-type lead frame manufacturing process for AI server power supplies are as follows: S1. Substrate pretreatment: Select copper alloy sheet, and perform degreasing, pickling, surface cleaning and pre-plating in sequence. After pre-plating, dry for later use. S2. Precise positioning and feeding: The pre-plated copper alloy sheet is placed in the buffer bin of the feeding module. The sheet is then conveyed to the laser cutting station one by one through the lifting component and the adsorption detection module. S3, First laser cutting – forming the frame outline and semi-etched area: The first cutting is performed using a nanosecond or picosecond laser to cut out the outer outline of the packaging unit along the design trajectory, and semi-etching (thinning) is performed in the corresponding area of ​​the pin to form the semi-etched steps of the pin. S4. Second laser cutting - TOLT type leadless isolation groove: switch laser parameters or coaxial secondary cutting to completely cut off the electrical connection path between the central base island and the source pin, while ensuring that the drain pin and the central base island remain connected through the reserved connection bridge, thus completing the precision cutting of the leadless isolation groove. S5. Slag Removal and Cleaning: Immerse the cut frame in a chemical cleaning solution or use ultrasonic cleaning to remove slag, oxides and oil stains generated by laser cutting. Then rinse with deionized water and dry with hot air. S6. Surface roughening and micro-dimple forming of the back heat sink: The heat sink area on the back of the central base island is scanned with a femtosecond laser to form a uniform array of micro-dimples, which increases the surface roughness and improves the bonding force with the molding compound or heat dissipation medium. S7. Quality Inspection and Frame Separation: The insulation resistance between each pin, the integrity of the isolation groove, and the morphology of the micro-pits are checked by an optical inspection system. After confirming that they are qualified, the frame body is punched and separated from the connecting plate to obtain a single TOLT type lead frame unit. S8. Rewinding and Packaging: Arrange the separated lead frames in sequence on the carrier tape, or rewind them directly onto a reel and vacuum seal them for storage.

2. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 1, characterized in that: The laser slitting mechanism (2) includes a base (21), and a feeding module (3) is provided on one side of the base (21). The laser slitting mechanism (2) also includes an adsorption detection module (4), a conveyor (22) and a laser (23). The copper alloy sheet in the feeding module (3) enters the inside of the laser (23) for processing through the adsorption detection module (4) and the conveyor (22).

3. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 2, characterized in that: The feeding module (3) includes a fixed plate (31) fixedly connected to the base (21), and a support frame (32) is slidably arranged on the outside of the fixed plate (31). A buffer chamber (33) is fixedly arranged on the inside of the support frame (32). A slider (37) is slidably arranged on the inside of the buffer chamber (33). Several copper alloy sheets are placed on the top surface of the slider (37). A lifting component (36) is also arranged on the outside of the fixed plate (31), and the lifting component (36) is used to push the slider (37) to move.

4. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 3, characterized in that: A connecting block (34) is fixedly provided on the bottom surface of the support frame (32), and a cylinder (35) is provided on one side of the connecting block (34), and the outer surface of the cylinder (35) away from the piston end is fixedly connected to the fixing plate (31).

5. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 3, characterized in that: The lifting assembly (36) includes a mounting plate (361) fixedly connected to the fixing plate (31), and a sliding sleeve (362) is provided through the mounting plate (361). A lifting rod (363) is slidably provided on the inner side of the sliding sleeve (362), and the lifting rod (363) is used to push the slider (37) to move.

6. The TOLT-type lead frame processing technology for adapting AI server power supplies according to claim 5, characterized in that: One end of the lifting rod (363) is fixedly provided with a clamping frame (364), and a conveyor belt (365) is provided on the inner side of the clamping frame (364). A drive wheel (366) is coupled to the inner side of the conveyor belt (365), and a drive motor (367) is provided on one side of the drive wheel (366). A tension wheel (368) is also coupled to the inner side of the conveyor belt (365), and a fixed seat (369) is rotatably provided on one side of the tension wheel (368) and fixedly connected to the fixed plate (31). The drive motor (367) drives the clamping frame (364) to move through the drive wheel (366), the tension wheel (368) and the conveyor belt (365).

7. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 3, characterized in that: The adsorption detection module (4) includes a mounting bracket (41) fixedly connected to the fixed plate (31), and a drive assembly (42) is provided inside the mounting bracket (41). A moving block (43) is fixedly provided on the drive assembly (42), and an electric telescopic rod (44) is fixedly provided on one side of the moving block (43). An extension plate (49) is fixedly provided at the output end of the electric telescopic rod (44), and a glass plate (45) is fixedly provided on the extension plate (49). A negative pressure adsorption head (46) for adsorbing copper alloy sheets is fixedly provided on the glass plate (45), and the negative pressure adsorption head (46) is connected to an external adsorption machine.

8. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 7, characterized in that: A bracket (47) is also fixedly installed on the extension plate (49), and a visual inspection head (48) is fixedly installed on the bracket (47). The visual inspection head (48) is located directly above the glass plate (45) and is connected to an external visual inspection machine.

9. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 7, characterized in that: The drive assembly (42) includes a servo motor (421) fixedly connected to the mounting bracket (41), and the output end of the servo motor (421) is provided with a rotating wheel (422). The outer side of the rotating wheel (422) is coupled with a drive belt (423), and the drive belt (423) is connected to the moving block (43) for driving the moving block (43) to move. The inner side of the drive belt (423) is also coupled with an auxiliary wheel (424), and the auxiliary wheel (424) is rotatably connected to the mounting bracket (41).

10. The TOLT-type lead frame processing technology for adapting to AI server power supplies according to claim 9, characterized in that: The mounting bracket (41) is fixedly provided with a guide rail (425) on its inner side, and a guide block (426) is slidably provided on the outer side of the guide rail (425), and the guide block (426) is fixedly connected to the moving block (43).

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