A graphite fixture for horizontally loading silicon wafers

Abstract

The utility model discloses a kind of graphite clamps of horizontal loading silicon wafer, belong to silicon wafer processing technical field, including clamp, sliding slot, positioning pin and stepper motor, gas groove is opened in clamp inside, gas groove inside is opened and has gas hole, clamp is adhered with drum sac through gas hole, sliding slot is clamped in the back of clamp by connecting plate, the sliding slot inside is slidably connected with slide post, the slide post is fixedly installed with rack, the rack is engaged with gear wheel.The utility model drives gear rack by stepper motor, makes slide post drive clamping plate to move, cooperate positioning pin to realize the four-end fixing of silicon wafer, avoid high temperature warping and coating, and the problems such as edge collapse, etc.;Drum sac, torsion spring etc. are simultaneously utilized, trigger alarm through gas groove sealing condition, detect silicon wafer tiny damage, prevent subsequent high temperature breakage influence work, to solve the problem that the existing clamp positioning is insufficient and causes silicon wafer high temperature warping, cannot detect tiny crack.

Description

Technical Field

[0001] This utility model relates to the field of silicon wafer processing technology, and in particular to a graphite jig for horizontally loading silicon wafers. Background Technology

[0002] In the silicon wafer coating production process, graphite fixtures are core tooling equipment for ensuring the quality of silicon wafer processing. Their core function is to achieve stable fixation and precise positioning of the silicon wafers. However, currently widely used graphite fixtures still suffer from two major technical pain points in practical applications, which seriously restrict production efficiency and product yield:

[0003] Insufficient positioning stability: Existing fixtures have limited positioning constraint strength for silicon wafers, especially in high-temperature coating environments, where silicon wafers are prone to warping and deformation due to thermal stress. This deformation directly leads to defects such as wrap-around coating (film layer not covering the edge or back of the silicon wafer as intended) and edge chipping (fracture of the silicon wafer edge) during the film deposition process. In extreme cases, it can even cause short circuits, significantly reducing the product yield.

[0004] Lack of Microcrack Detection: Traditional fixtures often employ rigid structural designs, lacking the ability to predict potential damage to silicon wafers. When microcracks, invisible to the naked eye, exist on the silicon wafer, they cannot be detected and warned of in time before coating. These damaged wafers, once introduced into subsequent high-temperature processes, will experience rapid crack propagation and breakage, not only resulting in the scrapping of a single wafer but also potentially causing batch product quality issues due to fragment contamination, increasing production costs and risks.

[0005] To address the aforementioned issues, existing technologies have attempted improvements: some solutions enhance stability by adding multiple supports or introducing elastic structures to alleviate warping; others add sensors to the fixture to indirectly detect cracks by monitoring stress or temperature changes on the silicon wafer. However, these improvements have significant limitations: they are either functionally limited (only solving one problem of fixation or detection), lack sufficient detection accuracy (difficult to identify micron-level microcracks), or have complex structures leading to poor adaptability (incompatible with different specifications of silicon wafers or coating equipment). They ultimately fail to achieve the integrated requirement of "stable fixation - accurate detection - coating quality assurance."

[0006] Therefore, developing a novel graphite fixture with a reasonable structural design, reliable positioning constraints, and the ability to detect minute damage to silicon wafers in real time has become a key breakthrough in meeting the high-quality and high-reliability requirements of silicon wafer coating processes.

[0007] Therefore, a graphite jig for horizontally loading silicon wafers is proposed. Utility Model Content

[0008] The purpose of this invention is to solve the problems in the prior art where silicon wafers are prone to warping at high temperatures due to the lack of locating pins at the inlet, leading to coating wrapping, edge chipping, and the inability to detect tiny cracks, resulting in high-temperature breakage of damaged silicon wafers and affecting operation. Therefore, a graphite jig for horizontally loading silicon wafers is proposed.

[0009] To achieve the above objectives, the present invention adopts the following technical solution:

[0010] A graphite jig for horizontally loading silicon wafers includes a jig, a slide groove, a positioning pin, and a stepper motor. The jig has an internal air groove with an air outlet. A bulge is attached to the jig through the air outlet. The slide groove is secured to the back of the jig via a connecting plate. A sliding column is slidably connected inside the slide groove. A rack is fixedly mounted on the sliding column, and the rack meshes with a gear. The gear is fixedly connected to the output end of the stepper motor via the connecting plate. A rotating plate is fixedly connected to one end of both the sliding column and the bulge.

[0011] Preferably, a torsion spring is fixedly connected between the two rotating plates, and an alarm and a button are fixedly installed around the outer periphery of the slide through a connecting plate.

[0012] Preferably, a fixing block is fixedly installed on the side of the card plate facing the clamp, and the three positioning pins are distributed on the three outer peripheries of the clamp away from the card plate.

[0013] Preferably, the gear is sized to fit the rack, and the slide column is sized to fit the groove.

[0014] Preferably, the torque of the torsion spring is directed toward the button.

[0015] Preferably, the two rotating plates are rotatably connected by a rotating shaft inside a torsion spring.

[0016] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0017] 1. Before placing the silicon wafer, start the stepper motor to drive the gears, causing the sliding column to slide and the clamping plate to move away from the fixture, facilitating the placement of the silicon wafer. After the silicon wafer is placed, it is initially positioned by the three locating pins below the fixture. Then, the stepper motor reverses, driving the sliding column and clamping plate closer to the fixture. The locating pins on the clamping plate lock the top of the silicon wafer, securing it at all four ends. This prevents the silicon wafer from warping at high temperatures due to the lack of locating pins at the entry point, thus preventing problems such as coating wrapping, edge chipping, and short circuits, ensuring a stable and reliable processing procedure.

[0018] 2. When the sliding column moves the clamping plate away from the fixture, the rotating plate below it squeezes the bulge to expel air. After the silicon wafer is fixed, the rotating plate moves with the sliding column, stretching the bulge. If the silicon wafer is intact, it covers the air groove, preventing the bulge from drawing in air and creating negative pressure. This causes the torsion spring to rotate, moving the rotating plate away from the button to avoid an alarm. If the silicon wafer has a tiny crack, the damage prevents it from completely covering the air groove, causing the bulge to draw in air and inflate. The torsion spring is no longer pulled by the negative pressure and uses its own torque to make the rotating plate press the button to trigger an alarm, thus detecting silicon wafer damage and preventing subsequent breakage at high temperatures from affecting the work. When preparing for coating, remove the auxiliary detection equipment clipped to the back of the fixture and use a plug (ceramic material) to block the air vent before starting the subsequent high-temperature work. Attached Figure Description

[0019] Figure 1 A three-dimensional structural diagram of a graphite clamp for horizontally loading silicon wafers proposed in this utility model. Figure 1 ;

[0020] Figure 2 A three-dimensional structural diagram of a graphite clamp for horizontally loading silicon wafers proposed in this utility model. Figure 2 ;

[0021] Figure 3 This utility model Figure 2 Enlarged schematic diagram of the structure at point A;

[0022] Figure 4 This is a cross-sectional view of the structure of a graphite clamp for horizontally loading silicon wafers proposed in this utility model;

[0023] Figure 5 This utility model Figure 4 Enlarged schematic diagram of the structure at point B;

[0024] Figure 6 This utility model Figure 4 An enlarged schematic diagram of the structure at point C.

[0025] In the diagram: 1. Card plate; 2. Stepper motor; 3. Gear; 4. Rack; 5. Slide groove; 6. Clamp; 7. Air outlet; 8. Air groove; 9. Positioning pin; 10. Alarm; 11. Bulb; 12. Slide column; 13. Button; 14. Torsion spring; 15. Rotating plate. Detailed Implementation

[0026] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present utility model. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present utility model without creative effort are within the protection scope of the present utility model.

[0027] Reference Figures 1-6 A graphite jig for horizontally loading silicon wafers includes a jig 6, a slide groove 5, a positioning pin 9, and a stepper motor 2. The jig 6 has an air groove 8 inside, and an air outlet 7 inside the air groove 8. The jig 6 is fixedly connected to a bulge 11 through the air outlet 7. The slide groove 5 is fixedly connected to the back of the jig 6 through a connecting plate. A slide column 12 is slidably connected inside the slide groove 5. A rack 4 is fixedly installed on the slide column 12. The rack 4 meshes with a gear 3. The gear 3 is fixedly connected to the output end of the stepper motor 2 through the connecting plate. A rotating plate 15 is fixedly connected to one end of both the slide column 12 and the bulge 11.

[0028] With the above technical solution, before placing the silicon wafer into the fixture 6, the stepper motor 2 needs to be started in advance. The operation of the stepper motor 2 drives the gear 3 to rotate, which in turn drives the slide column 12 to slide in the slide groove 5, causing the clamping plate 1 to move away from the fixture 6, creating sufficient space for the silicon wafer to be placed. After the silicon wafer is placed, it will be precisely locked by the three positioning pins 9 under the fixture 6, achieving initial positioning. Subsequently, the stepper motor 2 is reversed, and the meshing relationship between the gear 3 and the rack 4 acts in the opposite direction, driving the slide column 12 to slide closer to the fixture 6, causing the clamping plate 1 to move synchronously. At this time, the fixing block on the side of the clamping plate 1 facing the fixture 6 will contact the top of the silicon wafer and lock it in place. In this way, all four ends of the silicon wafer are firmly fixed, effectively avoiding the problem of warping of the silicon wafer in a high-temperature environment due to the lack of fixing block constraint at the entrance where the silicon wafer is placed. This not only prevents coating wrapping during the coating process (such as the film layer accidentally wrapping around to the back of the silicon wafer), but also eliminates a series of defects such as edge chipping and short circuits caused by warping, ensuring the stability and reliability of the silicon wafer processing process.

[0029] Specifically, a torsion spring 14 is fixedly connected between the two rotating plates 15, an alarm 10 and a button 13 are fixedly installed on the periphery of the slide 5 through a connecting plate, a fixing block is fixedly installed on the side of the clamping plate 1 facing the clamp 6, and three positioning pins 9 are distributed on the three periphery of the clamp 6 away from the clamping plate 1.

[0030] Through the above technical solution, when the sliding column 12, driven by the stepper motor 2, moves the clamping plate 1 away from the fixture 6, the rotating plate 15 fixedly connected below the sliding column 12 will squeeze the bulge 11 between the fixture 6 and the lower rotating plate 15, expelling the air inside the bulge 11. When the silicon wafer is placed into the fixture 6 and the stepper motor 2 reverses, causing the sliding column 12 to slide and the positioning pin 9 above the clamping plate 1 to complete the fixing of the silicon wafer, the rotating plate 15 will move together with the sliding column 12, forming a stretching effect on the bulge 11. Since the intact silicon wafer can completely cover the air groove 8 inside the fixture 6, the bulge 11 cannot draw in air through the air outlet 7 in the air groove 8 to restore its bulging state, thus forming a negative pressure environment inside the bulge 11. This negative pressure will cause the torsion spring 14 to rotate, causing the lower rotating plate 15 to move in the opposite direction of the torsion of the torsion spring 14, preventing the button 13 from being accidentally pressed and triggering the alarm 10. If the silicon wafer has tiny cracks that are difficult to detect with the naked eye, these cracks will prevent it from completely covering the air groove 8. In this case, the bulge 11 can draw in air through the air outlet 7 in the air groove 8, and the internal and external pressures will reach equilibrium, causing the bulge 11 to inflate. Since the bulge 11 no longer exerts negative pressure on the torsion spring 14, the torsion spring 14 uses its own torque to drive the rotating plate 15 to move towards the button 13, ultimately pressing the button 13 and causing the alarm 10 to sound. This process can accurately detect whether there is damage to the silicon wafer, thereby effectively preventing the damaged silicon wafer from breaking under subsequent high-temperature conditions and avoiding adverse effects on normal operation.

[0031] Specifically, the gear 3 is sized to fit the rack 4, the slide column 12 is sized to fit the slide groove 5, the torque direction of the torsion spring 14 is towards the button 13, and the two rotating plates 15 are rotatably connected by a rotating shaft inside the torsion spring 14.

[0032] It should be noted that, through the above technical solution, the positioning pins 9, the clamping plate 1 and other components that come into contact with the silicon wafer or graphite boat are all made of ceramic material. The stepper motor 2 and the metal transmission components such as gears 3 and racks 4 only participate in the positioning and installation process of the silicon wafer. After all the actions of fixing the four ends of the silicon wafer are completed, they can be separated from the clamps 6 through the quick disassembly structure, so as to avoid the metal components from affecting the subsequent coating process from the root.

[0033] Using the above technical solution, before entering the coating process, the fixture 6 needs to undergo targeted pretreatment to ensure stability and safety under high-temperature coating conditions. Specifically, the auxiliary detection components (including the stepper motor 2, the transmission mechanism composed of gears 3 and racks 4, the alarm 10, and related connecting parts) installed on the back of the fixture 6 via a snap-fit ​​structure need to be completely disassembled and removed (the auxiliary detection components will not contact the internal silicon wafer when snapped onto the fixture 6). The core purpose of this operation is to prevent the metal transmission components and sensors from being degraded by high temperatures during the high-temperature coating process, and to prevent them from releasing impurities that contaminate the coating environment, thus ensuring the purity of the film deposition.

[0034] After disassembling the auxiliary testing equipment, the vent 7 on the fixture 6 needs to be sealed. A ceramic plug precisely matched to the size of the vent 7 should be used to seal it tightly. The ceramic plug is chosen because ceramics have excellent high-temperature resistance (able to withstand the high-temperature environments common in silicon wafer coating processes), strong chemical stability (will not react with coating gases), and a coefficient of thermal expansion similar to graphite (avoiding gaps or stress damage to the fixture 6 due to temperature changes).

[0035] After sealing is completed, fixture 6 enters the coating-ready state. At this time, the silicon wafer is firmly fixed by the positioning pin 9. The entire fixture 6 structure retains only the graphite body and ceramic positioning / sealing components, which is fully adapted to the environmental requirements of high-temperature coating processes. This ensures the stable progress of subsequent coating processes and effectively avoids the risks of impurity interference and structural deformation.

[0036] Working principle:

[0037] When using this invention, the stepper motor 2 is first started to drive the gear 3 to rotate. The gear 3 meshes with the rack 4 to make the slide column 12 slide in the slide groove 5, which causes the clamping plate 1 to move away from the fixture 6 and place the silicon wafer. After the silicon wafer is placed, it is initially positioned by the three positioning pins 9 below the fixture 6. Then the stepper motor 2 reverses, which drives the slide column 12 and the clamping plate 1 to move closer to the fixture 6. The fixing block on the clamping plate 1 clamps the top of the silicon wafer, thereby fixing the silicon wafer at all four ends and avoiding warping and related adverse effects under high temperature. Simultaneously, when the sliding column 12 moves the clamping plate 1 away from the fixture 6, the rotating plate 15 below it squeezes the bulge 11 to expel air. After the silicon wafer is fixed, the rotating plate 15 moves with the sliding column 12 to stretch the bulge 11. The intact silicon wafer covers the air groove 8, preventing the bulge 11 from drawing in air and forming a negative pressure. This causes the torsion spring 14 to rotate, moving the rotating plate 15 away from the button 13 to avoid alarm. If the silicon wafer has a tiny crack, it may break under high temperature, causing it to not completely cover the air groove 8. The bulge 11 will draw in air and bulge. The torsion spring 14 will use its own torque to make the rotating plate 15 press the button 13 to trigger an alarm, thus realizing silicon wafer damage detection and preventing subsequent breakage under high temperature from affecting the work.

[0038] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A graphite jig for horizontally loading silicon wafers, comprising a jig (6), a slide (5), a clamping plate (1), a positioning pin (9), and a stepper motor (2), characterized in that, The clamp (6) has an air groove (8) inside, and an air outlet (7) inside the air groove (8). The clamp (6) has a bulge (11) attached to it through the air outlet (7). The slide groove (5) is attached to the back of the clamp (6) through a connecting plate. The slide groove (5) has a sliding column (12) slidably connected inside. The slide column (12) has a rack (4) fixedly installed on it. The rack (4) meshes with a gear (3). The gear (3) is fixedly connected to the output end of the stepper motor (2) through a connecting plate. A rotating plate (15) is fixedly connected to one end of both the slide column (12) and the bulge (11).

2. The graphite jig for horizontally loading silicon wafers according to claim 1, characterized in that, A torsion spring (14) is fixedly connected between the two rotating plates (15), and an alarm (10) and a button (13) are fixedly installed on the periphery of the slide (5) through a connecting plate.

3. The graphite jig for horizontally loading silicon wafers according to claim 1, characterized in that, A fixing block is fixedly installed on the side of the card plate (1) facing the clamp (6), and three positioning pins (9) are distributed on the three outer sides of the clamp (6) away from the card plate (1).

4. A graphite jig for horizontally loading silicon wafers according to claim 1, characterized in that, The gear (3) is sized to fit the rack (4), and the slide column (12) is sized to fit the groove (5).

5. A graphite jig for horizontally loading silicon wafers according to claim 2, characterized in that, The torque direction of the torsion spring (14) is toward the button (13).

6. A graphite jig for horizontally loading silicon wafers according to claim 1, characterized in that, The two rotating plates (15) are rotatably connected by a rotating shaft inside a torsion spring (14).

Images