A flash memory chip automated production process

Abstract

The invention relates to the technical field of flash memory chips, and in particular to an automated production process for flash memory chips, comprising the following steps: A. placing a wafer to be cut on a special cutting table of a wafer laser cutting machine, and fixing the wafer to ensure that the wafer will not be displaced during the cutting process; B. scanning the wafer to determine the cutting range, and moving the cutting head to the center point of the wafer as the cutting starting point; C. planning a cutting path, starting a wafer laser cutter, and controlling the cutting head to move according to a predetermined cutting path; D. moving the cutting head from the center to the outer circle for cutting, and stopping the cutting head before reaching the edge of the wafer to ensure that the cut scraps are connected as a whole, and then the cutting head continues to move by changing the moving direction. The purpose of the invention is to solve the problem that when picking up flash memory chips, waste materials need to be distinguished and picked up by avoiding waste materials, resulting in a more complicated picking process.

Description

Technical Field

[0001] The present invention relates to the technical field of flash memory chips, and in particular to an automated production process for flash memory chips. Background Art

[0002] Flash memory chip refers to the bare die in the flash memory chip, also known as the grain. It is a core component of the flash memory chip at the physical level. It is a basic unit with storage function formed on a silicon wafer through a series of semiconductor manufacturing processes. A flash memory chip is usually composed of one or more flash memory chips. These flash memory chips are integrated together through packaging technology to eventually form the flash memory products we commonly see, such as the flash memory chips used in USB flash drives, solid-state drives, etc.

[0003] The storage capacity of a single flash memory chip varies depending on factors such as manufacturing process and technology generation. With the continuous development of semiconductor manufacturing technology, the storage capacity of flash memory chips is also increasing. For example, early flash memory chips only had a capacity of tens of GB or even less, but now some advanced flash memory chips can reach a storage capacity level of several TB.

[0004] Multiple flash memory chips are packaged together to form a complete flash memory chip. During the packaging process, some other auxiliary components are added, such as pins for electrical connection with external devices, and heat dissipation materials to ensure that the chip can dissipate heat normally during operation and maintain stable performance.

[0005] In the production process of flash memory chips, the raw materials are first purified. Silicon dioxide is used as the raw material. After a series of processes such as electric arc furnace refining, hydrochloric acid chlorination, and distillation, polysilicon with a purity of more than 99.99% is made. The high-purity polysilicon is melted, and seed crystals are planted in the melt, and then slowly pulled out to form a cylindrical single-crystal silicon crystal rod. In this process, the silicon crystal rod is gradually generated from the seed crystal in the molten silicon raw material. This process is also called "crystal growth". The silicon crystal rod is cut, rolled, sliced, chamfered, polished and other processes to make silicon wafers with uniform thickness and smooth surface. This is the basic material for the subsequent production of flash memory chips. At present, silicon wafers are mainly used in 8-inch and 12-inch specifications.

[0006] Then a layer of photoresist is evenly coated on the surface of the silicon wafer. The photoresist will change its chemical properties after being exposed to specific light. The pre-designed circuit pattern is projected onto the photoresist on the surface of the wafer through a mask using a photolithography machine. The part of the photoresist exposed to light undergoes a chemical reaction and changes its properties. The unexposed or exposed photoresist is removed by a chemical solution, leaving a photoresist pattern corresponding to the circuit pattern on the wafer surface. This step determines the location of components such as circuit patterns and transistors on the flash memory chip.

[0007] Then, high-energy particles such as plasma are used to etch the part of the wafer surface not protected by the photoresist, removing the excess silicon material and forming the transistor grooves, electrodes and other structures. For example, when making the memory cell array of flash memory, it is necessary to form a precise groove structure on the wafer through an etching process so that the charge storage material can be filled in later.

[0008] Subsequently, a layer of thin film material, such as silicon oxide, silicon nitride and other insulating materials, is deposited on the surface of the wafer through chemical reaction to isolate transistors and storage units and prevent charge leakage.

[0009] Finally, specific impurity ions are accelerated to a certain energy and then injected into a specific area of ​​the wafer, changing the electrical properties of the area and forming a PN junction, which is used to control the switching state of the transistor and the charge storage characteristics of the memory cell. For example, in the floating gate transistor of flash memory, the electrical characteristics of the floating gate are adjusted through ion implantation, so that it can effectively store and release charge.

[0010] Flash memory chips are cut from the wafer using a laser to form individual chips.

[0011] A flash memory chip is a cut flash memory chip fixed on a packaging substrate by gluing or welding, and using metal wires to connect the electrodes on the chip to the pins on the packaging substrate to achieve circuit conduction. Finally, the chip is packaged using plastic, ceramic and other materials to protect the chip from the external environment and provide external pins for connection to other electronic devices.

[0012] When a flash memory chip is cut from a wafer using a laser, chips and waste are formed. Image processing software is then required to analyze the image information on the wafer surface, identify the position, shape, size and other information of the chips and waste, distinguish between regularly shaped chips and irregular waste, and provide accurate data for picking up the chips and waste separately. This method requires distinguishing the waste when picking up the flash memory chip, avoiding the waste for picking up, and locating the waste one by one, which makes the picking process more complicated. Summary of the invention

[0013] The purpose of the present invention is to provide an automated production process for flash memory chips to solve the problem that when picking up flash memory chips, waste materials need to be distinguished and picked up without picking up waste materials, which makes the picking process more complicated.

[0014] To achieve the above object, the present invention provides the following technical solutions:

[0015] An automated flash memory chip production process comprises the following steps:

[0016] A. Place the wafer to be cut on the dedicated cutting table of the wafer laser cutting machine and fix the wafer to ensure that the wafer will not move during the cutting process;

[0017] B. Scan the wafer to determine the cutting range, and move the cutting head to the center of the wafer as the cutting starting point;

[0018] C. Plan the cutting path, start the wafer laser cutter, and control the cutting head to move along the predetermined cutting path;

[0019] D. The cutting head moves from the center to the outer circle for cutting, and stops before reaching the edge of the wafer to ensure that the cut scraps are connected as a whole. Then, the cutting head continues to move by changing the moving direction, and after the cutting is completed, the cut scraps and multiple flash memory chips are obtained;

[0020] E. Pick up the scraps and discard them into the waste collection tank, and transfer multiple flash memory chips to the next process.

[0021] Preferably, in step D, a track limit assembly is arranged between the motion control assembly and the cutting head of the wafer laser cutting machine, and the track limit assembly is used to limit the movement of the cutting head to the scraps, and the cutting head will stop moving when it touches the end of the track limit assembly.

[0022] Preferably, in step D, the track limiting assembly includes a longitudinal rail and a transverse rail, and both ends of the longitudinal rail and the transverse rail are provided with horizontally movable limiting plates, and when the cutting head moves and hits the limiting plate, it will stop moving further.

[0023] Preferably, in step D, each of the limit plates has a data transmission processing module, which receives the cutting range information determined after scanning the wafer, and then controls the limit plate to move to the edge of the cutting range and be outside the edge according to the cutting range information.

[0024] Preferably, in step C, a spray cooling assembly is installed on the surface of the cutting head, and while the cutting head moves along a predetermined cutting path, the spray cooling assembly is controlled to spray cooling medium to cool the cut area.

[0025] Preferably, in step D, when the cutting head changes its moving direction, the spray port of the spray cooling assembly is transferred to the rear of the moving track of the cutting head.

[0026] Preferably, in step E, a picking assembly is installed at the lower end of each of the limiting plates, and after cutting is completed, the scraps are picked up and discarded into a waste collection trough.

[0027] Preferably, in step E, an up-and-down telescopic mechanism is installed between each picking assembly and the limiting plate to drive the picking assembly to move up and down.

[0028] Compared with the prior art, the present invention has the following beneficial effects:

[0029] 1. By setting the cutting starting point from the center of the wafer and stopping before reaching the edge of the wafer, the scraps after cutting are ensured to be connected as a whole, and the scraps can be removed as a whole at one time, reducing the number and complexity of picking up, which is conducive to the subsequent processing of wafer scraps.

[0030] 2. By setting the track limit component, when the cutting head moves to the area of ​​the scrap, it will stop the cutting head from moving forward. There is no need for a lot of programming and optimization of complex motion control algorithms. Compared with controlling the motion control component to prevent the cutting head from cutting the scrap, the difficulty and complexity are less;

[0031] 3. By installing a picking component at the lower end of the limiting plate, after the cutting is completed, the picking component is located above the scraps. There is no need to position the picking component and the scraps. The scraps can be directly picked up and discarded into the waste collection tank, which is easy to operate. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of a wafer cutting path of the present invention;

[0033] Figure 2 A top view of the scrap material of the present invention;

[0034] Figure 3 It is a structural schematic diagram of the track limiting assembly of the present invention;

[0035] Figure 4 It is a structural schematic diagram of the longitudinal rail of the present invention;

[0036] Figure 5 It is a structural schematic diagram of the cross rail of the present invention;

[0037] Figure 6 It is a schematic diagram of the structure of the cutting head of the present invention;

[0038] Figure 7 It is a schematic diagram of the structure of a vertical exploded view of the spray cooling assembly of the present invention.

[0039] In the figure: 1. positioning seat; 2. connecting plate; 3. longitudinal rail; 4. transverse rail; 5. limit plate; 6. cutting head; 7. protective cover; 8. connecting pipe; 9. annular groove; 10. storage ring; 11. nozzle; 12. scrap; 13. transverse cutting path; 14. longitudinal cutting path; 15. flash memory chip; 16. center mark. DETAILED DESCRIPTION

[0040] 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 described embodiments 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 creative work are within the scope of protection of the present invention.

[0041] See also Figures 1 to 7 , the present invention provides a technical solution.

[0042] An automated flash memory chip production process comprises the following steps:

[0043] A. Place the wafer to be cut on the dedicated cutting table of the wafer laser cutting machine and fix the wafer to ensure that the wafer will not move during the cutting process;

[0044] The vacuum suction cup can be used to contact the suction cup with the back of the wafer, and the wafer can be smoothly sucked out of the storage box or transmission device, and the wafer can be slowly placed on the cutting table. During the placement process, the wafer must be kept level to avoid tilting. The wafer can be firmly adsorbed on the cutting table by starting the vacuum adsorption system. At the same time, the cutting table can be gently shaken to check whether the wafer is firmly fixed. The position and fixing status of the wafer can be observed through the observation windows set around the cutting table or the internal camera to ensure that the wafer fits completely on the cutting table and the edges are not warped or not adsorbed.

[0045] B. Scan the wafer to determine the cutting range, and move the cutting head 6 to the center of the wafer as the cutting starting point;

[0046] The scanning light of the scanning system starts from one side edge of the wafer, and moves the irradiation position of the scanning light on the wafer surface line by line according to the pre-set line spacing until the entire wafer surface is covered. During the scanning process, the light interacts with the wafer surface. According to the optical properties such as reflection, refraction or absorption of different areas on the wafer surface, the scanning system will collect the corresponding light signals and transmit the collected light signals to the matching photodetector or image sensor. The photodetector converts the light signals into electrical signals, and then collects these electrical signals through the data acquisition module and transmits them to the computer processing system. The image sensor can directly generate image data of the wafer surface, which is also transmitted to the computer processing system;

[0047] After receiving the signal from the photoelectric detector or image sensor, the computer processing system processes the data and analyzes the processed data according to preset algorithms, such as image recognition algorithms, edge detection algorithms, etc.

[0048] According to the wafer design drawings or production process requirements, determine the size, shape and layout of the wafers to be cut from the wafer. This information is provided to the control system of the cutting equipment in the form of electronic documents, and the control system compares and analyzes it with the scanned data;

[0049] The center point position of the wafer is determined by using the geometric analysis algorithm in the computer processing system through the wafer surface image data obtained by scanning;

[0050] The control system sends instructions to the motion control component of the cutting head 6 according to the determined coordinates of the center point of the wafer. The motion control component drives the motor to drive the cutting head 6 to move in the X, Y, and Z axis directions through moving parts such as guide rails and sliders;

[0051] During the movement, the position feedback system of the cutting head 6, such as an encoder or a grating ruler, feeds back the current position of the cutting head 6 to the control system in real time. The control system continuously compares the current position with the target center point position, and adjusts the driving speed and direction of the motor according to the deviation until the cutting head 6 accurately moves to the center mark 16 of the center point of the wafer, at which point the point is determined as the cutting starting point;

[0052] By setting the center of the wafer as the starting point for cutting, a clear and fixed reference point can be provided for the cutting operation. As long as the termination conditions of cutting to the edge are controlled, the cutting of the entire wafer can be completed more accurately. Compared with the traditional method of starting from the outer circle, when cutting from left to right or from top to bottom, more factors need to be considered in determining the starting position. For example, wafers are usually circular. When cutting in a new line, the angle between the cutting path and the curvature of the wafer surface will change, which is relatively more difficult to control accurately.

[0053] C. Plan the cutting path, start the wafer laser cutter, and control the cutting head 6 to move along the predetermined cutting path;

[0054] Before starting the wafer laser cutter, the equipment is preheated. After the laser generating system is started, the laser source starts to generate a laser beam, which is transmitted to the cutting head 6 through the beam transmission and focusing system. At the same time, auxiliary systems such as the spray cooling component and the vacuum cleaning system are started;

[0055] Please refer to Figure 1 and Figure 2 A transverse cutting street 13 and a longitudinal cutting street 14 are preset on the wafer, and the cutting head 6 cuts along the transverse cutting street 13 and the longitudinal cutting street 14. The inner area where the transverse cutting street 13 and the longitudinal cutting street 14 intersect is cut to form a plurality of flash memory chips 15, and the outside of the transverse cutting street 13 and the longitudinal cutting street 14 forms scraps 12.

[0056] D. The cutting head 6 moves from the center of the wafer toward the outer circle to perform cutting, and stops before reaching the edge of the wafer to ensure that the cut scraps 12 are connected as a whole. Then, the cutting head 6 continues to move by changing the moving direction, and after the cutting is completed, the cut scraps 12 and a plurality of flash memory chips 15 are obtained;

[0057] The cutting head 6 starts to move from the center mark 16 along the direction of the longitudinal cutting road 14 or the transverse cutting road 13, and stops moving when reaching the end of the transverse cutting road 13 or the longitudinal cutting road 14, so as to ensure that the cut scraps 12 are connected as a whole, which is more convenient for the subsequent processing of the wafer scraps 12. When the cutting head 6 stops, the cutting is continued by changing the moving direction, and finally the scraps 12 and a plurality of flash memory chips 15 are obtained. Due to the previous operation of stopping the cutting before the edge, the scraps 12 are connected as a whole, which is convenient for subsequent processing. The flash memory chips 15 are the cut chips. After the cutting is completed, these chips need to go through a series of post-processing processes, such as cleaning, testing, packaging, etc., before they can finally become usable chips.

[0058] Specifically, taking the transverse cutting path 13 located along the central axis as an example, the cutting head 6 starts from the center of the transverse cutting path 13, first moves to the left to cut, cuts the left half of the transverse cutting path 13, and then turns to move to the right until the right half of the transverse cutting path 13 is cut;

[0059] Further, taking the transverse cutting path 13 located along the central axis as an example, the cutting head 6 starts from the center of the transverse cutting path 13, first moves to the left for preheating cutting, preheating the left half of the transverse cutting path 13, then turns to move to the right, and switches to complete cutting, completely cutting the left half of the transverse cutting path 13. When the cutting head 6 moves to the right to the center mark 16, it switches to preheating cutting, preheating the right half of the transverse cutting path 13, then turns to the left, and switches to complete cutting, completely cutting the right half of the transverse cutting path 13, and finally moves back to the center of the transverse cutting path 13. The main difference between preheating cutting and complete cutting lies in the amount of cutting energy. Preheating cutting uses lower energy. The purpose is to preheat the wafer material so that it is easier to cut in the subsequent complete cutting process. When preheating cutting is performed, the laser power is set to a lower level. When switching to complete cutting, the laser power is increased to a level that meets the complete cutting requirements.

[0060] E. Pick up the scraps 12 and discard them into the waste collection tank, and transfer the multiple flash memory chips 15 to the next process;

[0061] Before picking up, the scrap 12 needs to be positioned, relying on a visual positioning system, which includes a camera and image processing software. The camera captures the wafer surface image, and the image processing software determines the position by identifying the shape and color of the scrap 12. For example, the scrap 12 is positioned by detecting the boundaries of the transverse cutting road 13 and the longitudinal cutting road 14;

[0062] Traditionally, when processing the cut chips and waste, image processing software is needed to analyze the image information of the wafer surface, identify the position, shape, size and other information of the chips and waste, distinguish between regularly shaped chips and irregular waste, and provide accurate data for the precise picking of the robot arm to prevent the chips and waste from being mixed up. The present technical method retains the complete scraps 12 during cutting, and can conveniently and directly pick up the scraps 12 and discard them into the waste collection tank.

[0063] In step D, a track limiter assembly is provided between the motion control assembly of the wafer laser cutting machine and the cutting head 6, and the track limiter assembly is used to limit the cutting head 6 from moving onto the scrap 12. When the cutting head 6 moves and hits the end of the track limiter assembly, it stops moving further.

[0064] By setting a track limit component, when the cutting head 6 moves to the area of ​​the scrap 12, the cutting head 6 will be prevented from moving forward. There is no need for a lot of programming and optimization of complex motion control algorithms. Compared with controlling the cutting head 6 to prevent the cutting head 6 from cutting the scrap 12 through motion control components, it is necessary to rely on complex software algorithms, obtain the layout information of the wafer in real time, combine the cutting path planning and the real-time position of the cutting head 6, and control the movement of the cutting head 6 through precise mathematical calculations, which involves geometric calculations, dynamic path planning and real-time position feedback adjustment. In comparison, setting a track limit component to stop the cutting head 6 from moving forward is less difficult and complicated.

[0065] In step D, the track limit assembly includes a longitudinal rail 3 and a transverse rail 4. Both ends of the longitudinal rail 3 and the transverse rail 4 are provided with a horizontally movable limit plate 5. When the cutting head 6 moves and hits the limit plate 5, it stops moving further.

[0066] For details, please refer to Figure 3 The cutting head 6 is installed on the horizontal rail 4 and moves left and right along the track of the horizontal rail 4. The horizontal rail 4 is installed on the longitudinal rail 3 and moves forward and backward along the track of the longitudinal rail 3. The movement of the horizontal rail 4 will move the cutting head 6 together. The longitudinal rail 3 and the horizontal rail 4 are perpendicular to each other, so that the cutting head 6 can move freely in the XY plane.

[0067] The cutting head 6 moves on the transverse rail 4, and the transverse rail 4 moves on the longitudinal rail 3 using a roller-guide rail structure. The cutting head 6 and the side of the transverse rail 4 are both equipped with electric rollers. The electric rollers on the cutting head 6 and the transverse rail 4 are respectively nested on the transverse rail 4 and the longitudinal rail 3, so that the cutting head 6 and the transverse rail 4 can slide horizontally along the transverse rail 4 and the longitudinal rail 3 respectively, and a screw drive method can also be adopted;

[0068] The horizontal movement of the limit plate 5 can be driven by an electric push rod or by a screw drive;

[0069] A sensing device is installed on the limit plate 5 to detect the proximity between the cutting head 6 and the limit plate 5. The sensing device can be an infrared sensor, a capacitive sensor, an inductive sensor or a pressure sensor;

[0070] The sensing device transmits the detected signal to the control system. When receiving the signal that the cutting head 6 is close to the limit plate 5, the control system will immediately issue a command to stop the cutting head 6 from moving further.

[0071] As needed, a buffer device is provided on the surface of the limit plate 5. When the cutting head 6 collides with the limit plate 5, the buffer device undergoes elastic deformation to absorb the impact force generated by the collision and protect the structural integrity of the limit plate 5 and the cutting head 6.

[0072] In step D, each limiting plate 5 has a data transmission processing module, which receives the cutting range information determined after scanning the wafer, and then controls the limiting plate 5 to move to the edge of the cutting range and to be outside the edge according to the cutting range information;

[0073] A positioning seat 1 is fixedly installed at the top middle position of the longitudinal rail 3, and a connecting plate 2 is fixedly installed at the top of the positioning seat 1. The longitudinal rail 3 is connected to the motion control component through the connecting plate 2. When the motion control component is controlled, it drives the positioning seat 1, the connecting plate 2, the longitudinal rail 3, the transverse rail 4, and the cutting head 6 to move as a whole. At the beginning of cutting, the transverse rail 4 also moves to the center position of the longitudinal rail 3, and the cutting head 6 also moves to the center position of the transverse rail 4. When the motion control component controls the cutting head 6 to move to the center mark 16, the positioning seat 1 and the connecting plate 2 are both above the center mark 16, and the longitudinal rail 3 is above the center axis of the wafer. At this time, taking the cutting along the path of the transverse cutting path 13 as an example, the transverse rail 4 is moved along the track of the longitudinal rail 3. Move to the top of one of the transverse cutting roads 13, then, the cutting range information after scanning the wafer is sent by the scanning system, the cutting range information includes an array of a series of coordinate points, these coordinate points describe the boundary shape of the cutting range, such as the coordinates of each vertex of the polygon, the limit plate 5 on the transverse rail 4 moves to the two end positions of the transverse cutting road 13 according to the information, and the limit plate 5 on the longitudinal rail 3 moves to the surface of the transverse cutting road 13 at the edge, so that the limit plate 5 on the transverse rail 4 will block the area of ​​the scrap 12 where the cutting head 6 will not move, and the limit plate 5 on the longitudinal rail 3 will block the area where the transverse rail 4 will not move to the scrap 12, indirectly blocking the area where the cutting head 6 will not move to the scrap 12;

[0074] When cutting along the path of the longitudinal cutting path 14 , first rotate the longitudinal rail 3 and the transverse rail 4 so that the longitudinal rail 3 faces the transverse cutting path 13 and the transverse rail 4 faces the longitudinal cutting path 14 , and then move the transverse rail 4 so that it moves above the longitudinal cutting path 14 .

[0075] In step E, a picking assembly is installed at the lower end of each limiting plate 5, and after the cutting is completed, the scraps 12 are picked up and discarded into the waste collection tank;

[0076] The picking component may adopt a vacuum suction cup, and a vacuum generating device connected to the vacuum suction cup may adopt a vacuum pump or a vacuum generator;

[0077] Since the limit plate 5 is outside the edge of the cutting range, the limit plate 5 is above the scrap 12 after the cutting is completed. By setting the picking component at the lower end of the limit plate 5 and the size of the picking component is smaller than the size of the limit plate 5, it is ensured that the picking component is also above the scrap 12 after the cutting is completed, and there is no need to perform positioning operations on the picking component and the scrap 12.

[0078] In step E, an up-and-down telescopic mechanism is installed between each picking assembly and the limiting plate 5 to drive the picking assembly to move up and down.

[0079] In step C, a spray cooling assembly is installed on the surface of the cutting head 6. While the cutting head 6 moves along a predetermined cutting path, the spray cooling assembly is controlled to spray a cooling medium to cool the cut area;

[0080] The spray cooling assembly is mainly composed of a cooling medium storage container, a nozzle 11, a delivery pipeline and a control valve. The cooling medium storage container is used to store cooling medium, such as nitrogen. The nozzle 11 is used to spray the cooling medium. The delivery pipeline connects the cooling medium storage container and the nozzle 11. The control valve is used to control the flow rate and spraying time of the cooling medium.

[0081] When the cutting head 6 starts cutting, the control system will open the control valve to start the cooling medium spraying.

[0082] In step D, when the cutting head 6 changes its moving direction, the spray port of the spray cooling assembly is moved to the rear of the moving track of the cutting head 6;

[0083] Specifically, a protective cover 7 is coaxially sleeved on the surface of the cutting head 6, and a storage ring 10 is coaxially rotatably connected to the bottom end of the protective cover 7. The storage ring 10 can be rotated by an electric roller, or by a motor plus gear transmission. An annular groove 9 for the storage ring 10 to rotate is provided at the bottom end of the protective cover 7. A connecting pipe 8 connected to the conveying pipeline is installed at the top of the protective cover 7. A nozzle 11 is installed at the bottom end of the storage ring 10. The connecting pipe 8, the storage ring 10, and the nozzle 11 are interconnected. When the cutting head 6 turns, the nozzle 11 can be driven to rotate by rotating the storage ring 10, and the position of the nozzle 11 can be adjusted to move the nozzle 11 to the rear of the moving trajectory of the cutting head 6. The connecting pipe 8 and the protective cover 7 do not move, and do not affect the layout of the conveying pipeline.

[0084] Preheating the wafer before cutting is helpful to reduce the temperature change gradient of the wafer during the cutting process. For example, after the wafer is preheated to a certain temperature, the temperature rise of the material after absorbing laser energy during cutting will be relatively small.

[0085] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A flash memory chip automated production process, characterized in that: The following steps are involved: A. Place the wafer to be cut on the dedicated cutting table of the wafer laser cutting machine and fix the wafer to ensure that the wafer will not move during the cutting process; B. Scan the wafer to determine the cutting range, and move the cutting head to the center of the wafer as the cutting starting point; C. Plan the cutting path, start the wafer laser cutter, and control the cutting head to move along the predetermined cutting path; D. The cutting head moves from the center to the outer circle for cutting, and stops before reaching the edge of the wafer to ensure that the cut scraps are connected as a whole. Then, the cutting head continues to move by changing the moving direction, and after the cutting is completed, the cut scraps and multiple flash memory chips are obtained; E. Pick up the scraps and discard them into the waste collection tank, and transfer the multiple flash memory chips to the next process; In step C, a spray cooling assembly is installed on the surface of the cutting head. While the cutting head moves along a predetermined cutting path, the spray cooling assembly is controlled to spray cooling medium to cool the cut area. In step D, when the cutting head changes its moving direction, the spray port of the spray cooling assembly is moved to the rear of the moving track of the cutting head; A track limit assembly is arranged between the motion control assembly and the cutting head of the wafer laser cutting machine, and the track limit assembly includes a longitudinal rail and a transverse rail, and both ends of the longitudinal rail and the transverse rail are provided with a limit plate that can be moved horizontally. When the cutting head touches the limit plate during movement, it will stop moving further. Each of the limit plates has a data transmission processing module, and the data transmission processing module receives the cutting range information determined after scanning the wafer, and then controls the limit plate to move to the edge of the cutting range and be outside the edge according to the cutting range information; There are preset transverse cutting streets and longitudinal cutting streets on the wafer. The cutting head starts from the center of the transverse cutting street, moves to the left to preheat and cut the left half of the transverse cutting street, and then turns to the right to completely cut the left half of the transverse cutting street. When the cutting head moves to the right to the center of the transverse cutting street, it is converted to preheat cutting, preheat cutting the right half of the transverse cutting street, then turns to the left and converts to completely cut the right half of the transverse cutting street, and finally moves back to the center of the transverse cutting street.

2. The flash memory wafer automated production process according to claim 1, characterized in that: In step D, the track limit assembly is used to limit the cutting head from moving onto the scraps, and the cutting head will stop moving when it hits the end of the track limit assembly.

3. The flash memory wafer automated production process according to claim 1, characterized in that: In step E, a picking assembly is installed at the lower end of each of the limiting plates, and after cutting is completed, the scraps are picked up and discarded into a waste collection trough.

4. The flash memory wafer automated production process according to claim 3, characterized in that: In step E, an up-and-down telescopic mechanism is installed between each picking component and the limiting plate to drive the picking component to move up and down.

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