Discussion on the Design of Automated Production of Monocrystalline Silicon Wafer

Design ideas

Each cutting material of the silicon wafer is a material number containing the model identification information of the material. One cutting material is about 3,200 pieces, and 4 carrier jigs carry it. Specific types of silicon wafers need to be cleaned in the corresponding cleaning machine equipment. Equipment action process: the feeding manipulator grabs the empty carrier jig of the washing machine and places it on the return line body of the empty jig. The full-loaded silicon wafer jigs are transported to the washing machine station through the conveyor line (conveyor line with water) to stop for identification. The manipulator grabs at the conveying position, and again determines to confirm that the silicon wafer of the carrier jig meets the cleaning model setting conditions. The loading manipulator is preferentially placed at the empty loading position of the washing machine (double loading station). If there is material at the loading station of the cleaning machine, place the buffer material box. The whole process ensures that the washing machine does not stop and wait for materials.

The two parts of the silicon wafer carrier fixture and the loading and unloading manipulator function and run through the conveying, buffering, cleaning and slicing, and empty fixture return conveying systems, which are important design elements.

Silicon wafer jig carrier design, from wafer packaging, information recording, conveying, robotic grasping, cleaning machine slicing, and empty jig reflow as the carrier. In the design, first ensure the positioning and inclination function of the cleaning segment. The load-bearing capacity of the jig meets the capacity and load of about 800 pieces of material per cut. Design and install RFID chip to record tool number information, and the design conforms to the interface of conveying stop and block function. The design fixture carrier has the gripping position of the loading and unloading manipulator gripper.

The manipulator design realizes the transfer function of connecting the upper and lower parts from the conveying of the silicon wafer full-load jig, buffering, the loading of the cleaning slicing position, and the reflow of the empty jig. The manipulator design traverse stroke covers the area of each functional module, and the vertical lifting and lowering meet the requirements of various heights. The manipulator is designed with a full load fixture bearing capacity of 20Kg, and the structure is stable and reliable. Servo motor with brake is used for vertical lifting. The traverse stroke covers the return line of the empty fixture, the full-load conveyor line, the buffer line, and the area of the material level on the cleaning slice. The manipulator runs smoothly, without climbing or jitter. The traverse adopts profile steel processing and installation guide rail, servo motor with reducer drive, belt pulley drive. Ensure that the jig is not deformed during grasping and cannot cause damage to the product twice. In the grasping process, it is determined whether the material information meets the cleaning target requirements. The conveying line body with full load of jigs, jig buffer device, and empty jig return conveying line are designed to be highly unified, which is convenient for programming and debugging.

Institutional design

The loading and unloading manipulator functions and runs through the conveying, buffering, cleaning and slicing, and empty jig return conveying systems to complete the loading and unloading sequence of the silicon wafer jigs of each functional module. The top view is shown in Figure 1:

The single silicon wafer is very thin, hard, and brittle, and the environmental jigs that are immersed in water quality under consideration of the working conditions should be deformed little. Jig material adopts hard PVC materialFlame retardant, high hardness, good toughness, low moisture absorption. The inner frame limit is designed according to the size of the 8-inch silicon wafer, and the gap is 4mm on one side. The carrying capacity is800The silicon chip is designed for fixture height and bearing capacity, and threaded steel sleeve is embedded in the threaded bottom hole of the mounting plate. The bottom plate is designed to clean the positioning hole of the slicer, and the entrance hole is chamfered for easy guidance. The four corners of the bottom plate are designed with inner arc corners, which are used to partition the front and rear jigs when they follow up. The left and right side plates are designed with limit guides before the robot grasps. When the robot descends, it automatically guides the fixture and then grasps it in place. The design angle of the inclined plate conforms to the angle of the cleaning segment. The gripper design meets both manual and robotic handling. The back plate is designed to be hollowed out to facilitate manual placement of silicon wafers. The rear panel is also designed with RFID chip installation positions.

Figure IISchematic diagram of silicon wafer carrier fixture

1. Bottom plate 2. Side plate 3. Incline plate 4. Grab plate 5. Rear plate

The manipulator system is composed of pneumatic control components, junction boxes, three-color light alarms, LED displays, rack frames, manipulator truss components, touch screen control components, protective covers, control electrical boxes, and fixture buffer water tanks. As shown in Figure 3. Pneumatic control components and junction boxes facilitate energy access. The three-color light alarm dynamically displays the status of the equipment from time to time, which is convenient for maintenance. The LED display mainly displays the material number information of the equipment. The rack frame design meets the installation and load-bearing of the manipulator truss components and the jig buffer tank. The support height of the frame takes into account the requirements of full-loaded fixture conveying, fixture buffering water tank, cleaning and segmentation position, and empty fixture backflow conveying function requirements. The design of the manipulator truss assembly meets the requirements for the conveying, buffering, cleaning of the wafer full-loaded jigs, the loading of the slicing position, the flow lateral movement of the empty jigs, and the load and stroke of the loading and unloading. The touch screen control components are designed with automatic and manual modes, which are convenient for debugging, maintenance and management. The protective cover protects the mechanical movement mechanism to prevent accidents. The design of the jig buffer water tank prevents all the cutting materials from being collected, causing traffic jam in the conveying line body as a buffer. When the number of materials in the buffer is less than 2 pieces, the material preparation time of the intermediate link is considered when the material is started.

Figure threeSchematic diagram of manipulator system

1. Pneumatic control assembly 2. Junction box 3. Tri-color light alarm 4. LED display 5. Rack frame 6. Manipulator truss assembly 7. Touch screen control assembly 8. Protective cover 9. Control electric box 10 Fixture buffer water tank

(1) Design of truss manipulator components

The truss manipulator is composed of a horizontal transplanting module, a vertical transplanting module, a manipulator assembly, a drag chain assembly, and a junction box. As shown in Figure 4. The stroke of the horizontal transplanting module meets the on-site layout. The horizontal shift of transplanting involves the transportation of full-loaded fixtures, the storage tank of the fixtures, the cleaning segmentation position, and the precise position of the empty fixture's return transportation. It is driven by a servo motor. The zero point, the limit position on the left and right sides, and the acceleration/deceleration induction position are set in the middle of the transfer stroke range. The beam adopts a profile steel structure, and the guide rail is installed in a T-shaped installation method. The installation surface is welded to maintain parallelism and perpendicularity. The transplanting limit position is designed with mechanical hard limit position. The traction method adopts belt.

Figure FourSchematic diagram of truss manipulator

1. Horizontal transplanting module 2. Vertical transplanting module 3. Manipulator assembly 4. Drag chain assembly 5. Junction box

The height stroke of the vertical transplanting module involves the conveying of full-loaded fixtures, the buffering water tank for fixtures, the cleaning of the sliced upper material level, and the return conveying system of empty fixtures. Except for the height of the material level on the cleaning segment, the other heights are designed to be consistent. The height of the stroke has a margin of 50mm at the lowest point. Due to the different heights, the vertical lifting is driven by a brake servo motor. The lifting mechanism is designed as a guide rail slider and ball screw method. The zero point, the upper and lower limit positions, and the acceleration/deceleration induction position are set in the middle of the transfer travel range.

(2) Design of fixture buffer water tank

The jig buffer water tank is placed and fixed in the manipulator traverse frame. As shown in Figure 5. The center position of the line body of the buffer tank coincides with the center position of the manipulator transfer. The manipulator buffers the full-loaded fixtures of the conveyor line body in the water tank. The jig buffer water tank is composed of a water tank body, an underwater conveying line body, a material detection and interception mechanism.

Figure 5 Schematic diagram of the installation position of the cache water tank

The water tank material is made of stainless steel sheet metal, which is spliced and welded to form a seal and cannot leak. The water tank is designed with a water inlet and a drain to facilitate regular water replacement and is equipped with a liquid level sensor. There is a mounting plate fixed to the frame outside the water tank. A conveying line body is installed in the water tank for conveying fixtures. The material level on the water tank is designed with material sensor, and the sensor starts to convey when there is material. In the water tank, 4 fixture positions and 1 discharge position can be buffered to meet the size space of 5 fixture positions. Each position has material induction to prevent full material discharge or stacking. The front end of the conveyor is designed with a stop mechanism. When the jig reaches the loading and grasping position, the stop mechanism will start to block the jig immediately behind to prevent the grasping and lifting.

Figure SixSchematic diagram of the structure of the buffer tank

1. Water tank body 2. Underwater conveying line body 3. Fixture 4. Conveying drive 5. Material detection 6. Intercepting mechanism fixture

Promote the prospects and conclusions

A silicon wafer carrier jig automatic feeding manipulator designed in this paper, after the implementation of 13 cleaning lines in the overall workshop, the silicon wafer degumming and the pre-cleaning sub-assembly, handling, distribution, and feeding links are realized only in the silicon wafer degumming Afterwards, it requires manual work to pack silicon wafers into the jig, which greatly reduces the labor intensity. Different types of silicon wafer cleaning corresponding to different cleaning equipment can realize automatic separation and shuffle in the production line. Realize early warning before cleaning the shard lack of material, prepare for material preparation to avoid equipment downtime and increase production capacity. Under the status quo of the mass-produced photovoltaic industry, automated production is an inevitable trend. The loading and unloading manipulator of the cleaning machine improves the working environment of employees, increases the product qualification rate and increases the productivity. On the basis of the operation of the original equipment, 20 sets of this feeding manipulator were installed before the new washing machine equipment, so it has industry promotion significance in the appeal process.