High-coaxiality anodic bonding clamp

Abstract

The utility model relates to the technical field of anodic bonding, in particular to a high-coaxiality anodic bonding clamp, which is characterized in that a plurality of groups of positioning columns are mounted on the peripheral side of a base, and an epitaxial wafer pressurizing sheet, an epitaxial wafer limiting sheet, a workpiece limiting disc and an upper insulating disc are sequentially inserted and sleeved on the corresponding positioning columns through a plurality of groups of positioning holes distributed on the peripheral side of the upper insulating disc; an epitaxial wafer is placed in an inner ring of an epitaxial wafer limiting piece, the bottom face of the epitaxial wafer is in contact with an epitaxial wafer pressurizing piece, then an AVG glass plate is placed in an inner ring of a workpiece limiting disc and pressed on the top face of the epitaxial wafer, a graphite pressurizing disc is placed between an upper insulating disc and the AVG glass plate, and a downward pressing guide disc is placed in the center of the upper side of the upper insulating disc. The steel ball is placed in a guide cylinder formed at the top of the downward pressing guide disc; the grounding pin penetrates through the upper insulating disc and is in contact with the graphite pressurizing disc; and the positive electrode power connection sleeve sleeves the top ends of the positioning columns. The fixture ensures the coaxiality between the AVG glass plate and the epitaxial wafer through the workpiece limiting disc and the epitaxial wafer limiting piece, and ensures the overall coaxiality of the fixture through the positioning column.

Description

Technical Field

[0001] This utility model relates to the field of anodic bonding technology, specifically to a high coaxiality anodic bonding fixture. Background Technology

[0002] The third-generation low-light image intensifier is characterized by gallium arsenide (CaAs) negative electron affinity photocathodes and microchannel plates (MCPs) with anti-ion feedback films. Compared to the second-generation low-light image intensifier, the third-generation low-light image intensifier replaces the multi-alkali photocathode with a CaAs negative electron affinity photocathode, resulting in higher detection sensitivity, lower dark emission, and more concentrated electron energy distribution.

[0003] The fabrication process for CaAs negative electron affinity photocathodes includes the preparation of CaAs substrates, growth of CaAs epitaxial layers, deposition of silicon nitride films, bonding of window materials (AVG glass) to the CaAs epitaxial wafers, selective chemical etching, and electrode evaporation. Traditional thermal bonding processes require high temperatures, which leads to several drawbacks. Firstly, the bonding surface is prone to bubbles, poor uniformity, and stress stripes affecting the performance of the micro-image intensifier, and the bonding time is long. Secondly, high temperatures have a certain impact on the CaAs negative electron affinity photocathode material. In recent years, anodic bonding has emerged, offering advantages such as low bonding temperature, short bonding time, and reliable and stable connections. This significantly reduces time and resource costs, and the integrated sensitivity of micro-image intensifiers fabricated using this method is higher than that of traditional thermal bonding processes.

[0004] During anodic bonding, pressure is applied to the bonding surfaces, requiring good parallelism among the fixture components to ensure better and more uniform contact for successful bonding. This bonding process also involves heat treatment; uneven temperature distribution on the bonding surfaces can cause epitaxial wafer warping, affecting the bonding effect. Point contact is the preferred bonding voltage method to reduce bubble formation, making high coaxiality of the fixture crucial.

[0005] Therefore, designing an anode bonding fixture with high parallelism, uniform heating temperature, and high coaxiality is crucial for the quality and yield of CaAs negative electron affinity photocathodes. Utility Model Content

[0006] (I) Technical Issues

[0007] The present invention aims to at least solve the problem in the prior art that anodic bonding requires ensuring high coaxiality of components.

[0008] (II) Technical Content

[0009] This solution provides a high coaxiality anodic bonding fixture, achieved through the following specific technical means: including...

[0010] The base has multiple sets of positioning posts installed around its perimeter;

[0011] The epitaxial sheet pressure plate is a circular sheet structure. It is inserted into multiple sets of positioning posts through positioning holes opened on the periphery and embedded in the groove on the top surface of the base.

[0012] The epitaxial wafer limiting piece is a circular ring structure with an inner diameter that matches the outer diameter of the epitaxial wafer to be processed. It is located on the upper side of the epitaxial wafer pressure piece and is also inserted into multiple positioning posts through positioning holes on the periphery. It is also embedded in the groove on the top surface of the base.

[0013] The workpiece limiting plate is also a ring structure. It is inserted into multiple sets of positioning posts through positioning holes opened on the periphery, and is located above the epitaxial sheet limiting plate with its bottom wall in contact with the top wall of the epitaxial sheet limiting plate.

[0014] Place the epitaxial wafer to be processed into the inner ring of the epitaxial wafer limiting plate and make its bottom surface contact the epitaxial wafer pressure plate. Then place the AVG glass plate into the inner ring of the workpiece limiting plate and press it onto the top surface of the epitaxial wafer.

[0015] The upper insulating plate is located above the AVG glass plate and is also inserted into multiple sets of positioning posts through positioning holes opened on the periphery;

[0016] The graphite pressure plate is inserted into the recess at the center of the bottom side of the upper insulating plate, and the bottom wall of the graphite pressure plate is in contact with the top surface of the AVG glass plate.

[0017] The lower pressure guide plate is placed at the center of the upper insulating plate, and the lower pressure guide plate, the upper insulating plate and the graphite pressure plate are fixed together by bolts;

[0018] The steel ball is placed in the guide cylinder formed at the top of the pressing guide plate. The outer diameter of the steel ball is the same as the inner diameter of the guide cylinder, and it plays a guiding role during the pressing process.

[0019] The grounding pin passes through the upper insulating plate and contacts the graphite pressure plate;

[0020] The positive terminal sleeve is inserted into the top of a set of positioning posts;

[0021] The high-voltage wire is connected to the positive terminal of the sleeve, and the voltage is applied to the epitaxial wafer by the positioning post and the epitaxial wafer pressure plate in contact with it. In addition, the ground wire is connected to the grounding pin, and the negative terminal is connected to the AVG glass plate by the graphite pressure plate in contact with it, so that the epitaxial wafer and the AVG glass plate form a closed circuit loop.

[0022] Preferred technical solution 1: The positioning post is composed of a bottom shaft section with a diameter of 6mm and a top shaft section with a diameter of 3mm. The bottom shaft section is fully inserted into the base. The top shaft section sequentially contacts the positioning hole on the epitaxial wafer pressure plate, the epitaxial wafer limiting plate, the workpiece limiting plate, and the upper insulating plate before its top end contacts the positive electrode connecting sleeve.

[0023] Preferred technical solution 2: The graphite pressure plate is integrally composed of an upper flat disc-shaped structure and a lower hemispherical structure, and its material is graphite;

[0024] The graphite pressure plate is connected to the AVG glass plate through a hemispherical structure, thus achieving the connection between the negative electrode and the AVG glass plate.

[0025] Preferred technical solution 3: The positive electrode connecting sleeve is made of 304 stainless steel.

[0026] Preferred technical solution four: It also includes a positioning pin insulating sleeve, which is placed on the top side of the upper insulating plate. The grounding pin passes through the positioning pin insulating sleeve and then through the upper insulating plate, and its bottom end contacts the graphite pressure plate to play an insulating function.

[0027] The grounding pin is made of 304 stainless steel.

[0028] Preferred technical solution five: The upper insulating disk is made of quartz glass.

[0029] Preferred technical solution six: The workpiece limiting plate is made of quartz glass, and its inner diameter is adapted to the outer diameter of the AVG glass plate.

[0030] Preferred technical solution seven: The material of the epitaxial wafer limiting sheet is quartz glass.

[0031] Preferred technical solution eight: The material of the epitaxial wafer pressure sheet is graphite.

[0032] Preferred technical solution nine: The base material is quartz glass.

[0033] (III) Technical Effects

[0034] The above structure gives this solution the following advantages:

[0035] 1. The overall fixture adopts a stacked component structure. The positioning posts and positioning slots between the components provide coaxial constraint on the axis of the fixture. This structure ensures the uniformity of ion diffusion during the bonding process.

[0036] 2. Furthermore, the continuous application of voltage to the workpiece during the bonding process is ensured through the mutual contact of each conductive component;

[0037] 3. By using quartz glass as the insulating material in the parts, the safety of equipment and personnel during operation is ensured, and the voltage is guaranteed not to short-circuit due to contact with the equipment;

[0038] 4. Compared with high-temperature, continuous-pressure bonding methods, this bonding fixture, combined with low-temperature bonding technology, effectively reduces the generation of stress lines on the workpiece and effectively improves the bonding success rate. Attached Figure Description

[0039] The accompanying drawings are provided to further illustrate the present invention and form part of the specification. They are used together with the embodiments of the present invention to explain the present invention, but do not constitute a limitation thereof. In the drawings:

[0040] Figure 1 This is a schematic diagram of the overall structure of this solution;

[0041] Figure 2 This is an exploded view of the plan;

[0042] Figure 3 This is a side view of the design.

[0043] Figure 4 This is a sectional view of the proposed solution.

[0044] Among them, 1. base, 2. positioning post, 3. epitaxial wafer pressure plate, 4. epitaxial wafer limiting plate, 5. workpiece limiting plate, 6. epitaxial wafer, 7. AVG glass plate, 8. upper insulating plate, 9. graphite pressure plate, 10. lower pressure guide plate, 11. guide cylinder, 12. steel ball, 13. grounding pin, 14. positive terminal connection sleeve, 15. bolt, 16. positioning pin insulating sleeve. Detailed Implementation

[0045] 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.

[0046] Please see Figures 1-4 A high coaxiality anodic bonding fixture includes a base 1, an epitaxial wafer pressure plate 3, an epitaxial wafer limiting plate 4, a workpiece limiting plate 5, an epitaxial wafer 6, an AVG glass plate 7, an upper insulating plate 8, a graphite pressure plate 9, a lower pressure guide plate 10, steel balls 12, a grounding pin 13, a positioning pin insulating sleeve 16, and a positive terminal connection sleeve 14, wherein:

[0047] Multiple sets of positioning posts 2 are installed around the base 1. The number of positioning posts 2 is two or more sets, preferably no more than six sets.

[0048] The epitaxial wafer pressure plate 3, the epitaxial wafer limiting plate 4, the workpiece limiting plate 5, and the upper insulating plate 8 are sequentially inserted into the corresponding positioning post 2 through multiple sets of positioning holes distributed on their periphery;

[0049] The epitaxial wafer limiting plate 4 and the workpiece limiting plate 5 are ring-shaped. When in use, the epitaxial wafer 6 is placed in the inner ring of the epitaxial wafer limiting plate 4 and its bottom surface is in contact with the epitaxial wafer pressure plate 3. Then, the AVG glass plate 7 is placed in the inner ring of the workpiece limiting plate 5 and pressed on the top surface of the epitaxial wafer 6.

[0050] The graphite pressure plate 9 is placed between the upper insulating plate 8 and the AVG glass plate 7. The lower pressure guide plate 10 is placed at the center of the upper side of the upper insulating plate 8. The lower pressure guide plate 10, the upper insulating plate 8 and the graphite pressure plate 9 are fixed together by bolts 15. That is, after the bolts 15 pass through the lower pressure guide plate 10, the upper insulating plate 8 and the graphite pressure plate 9, the bottom end is tightened with a nut.

[0051] The steel ball 12 is placed in the guide cylinder 11 formed on the top of the pressing guide plate 10. The outer diameter of the steel ball 12 is the same as the inner diameter of the guide cylinder 11, and it plays a guiding role during the pressing process.

[0052] The grounding pin 13 passes through the upper insulating plate 8 and contacts the graphite pressure plate 9;

[0053] The positioning pin insulating sleeve 16 is placed on the top side of the upper insulating plate 8 for the grounding pin 13 to be inserted and protrude;

[0054] The positive terminal connecting sleeve 14 is inserted into the top of a set of positioning posts 2;

[0055] The high-voltage connection is made to the positive terminal of the sleeve 14, and the voltage is applied to the epitaxial sheet 6 by the positioning post 2 and the epitaxial sheet pressure plate 3 in contact with it; in addition, the ground wire is connected to the grounding pin 13, and the negative terminal is connected to the AVG glass plate 7 by the graphite pressure plate 9 in contact with it, so that the epitaxial sheet 6 and the AVG glass plate 7 form a closed circuit loop.

[0056] To ensure uniform ion diffusion between the epitaxial wafer 6 and the AVG during the pressurization and heating process, the fixture ensures the coaxiality between the AVG glass plate 7 and the epitaxial wafer 6 through the workpiece limiting plate 5 and the epitaxial wafer limiting plate 4, and ensures the overall coaxiality of the fixture through the positioning post 2 and the positioning holes on each component.

[0057] Furthermore, the fixture uses 304 stainless steel and graphite as the internal conductive parts, and quartz glass as the overall insulating material.

[0058] In one embodiment: Please refer to Figure 2The positioning post 2 has a stepped structure and is made of 304 stainless steel. It consists of a bottom shaft section with a diameter of 6mm and a top shaft section with a diameter of 3mm. The bottom shaft section is fully inserted into the base 1. The top end face of the bottom shaft section contacts the bottom wall of the pressure plate 3 of the epitaxial sheet 6. The top shaft section contacts the positioning holes on the epitaxial sheet pressure plate 3, the epitaxial sheet limiting plate 4, the workpiece limiting plate 5, and the upper insulating plate 8 in sequence, and then the top end contacts the positive electrode connecting sleeve 14. The positioning post 2 serves to guide the positive electrode voltage to the epitaxial sheet 6.

[0059] In one embodiment: Please refer to Figure 2 , Figure 3 , Figure 4 The graphite pressure plate 9 is composed of an upper flat disc-shaped structure and a lower hemispherical structure. Its material is graphite. At the same time, there are 6 positioning holes distributed on the outer periphery of the graphite pressure plate 9.

[0060] The graphite pressure plate 9 contacts the AVG glass plate 7 through a hemispherical structure to achieve the connection between the negative electrode and the AVG glass plate 7. The positioning hole on the graphite pressure plate 9 allows the positioning post 2 to pass through and contact to ensure the overall coaxiality of the graphite pressure plate 9 relative to the fixture.

[0061] In one embodiment: Please refer to Figure 1 , Figure 2 , Figure 4 The positive electrode connecting sleeve 14 is a cylindrical structure made of 304 stainless steel. It has a 3.2mm hole on the bottom end face. The flat end face of the top of the positive electrode connecting sleeve 14 is welded to the positive electrode guide, and the side with the hole is matched with the positioning post 2.

[0062] In one embodiment: Please refer to Figure 4 The positioning pin insulating sleeve 16 has a cylindrical structure and is made of quartz glass. It has a countersunk hole and a through hole. The grounding pin 13 enters the countersunk hole, passes through the through hole, and then passes through the upper insulating plate 8. Its bottom end contacts the graphite pressure plate 9. The positioning pin insulating sleeve 16 has an insulating effect.

[0063] The grounding pin 13 is a flat-headed cylindrical pin made of 304 stainless steel. The top flat-headed side is welded to the ground wire, and the bottom end is connected to the graphite pressure plate 9.

[0064] In one embodiment: Please refer to Figure 2 , Figure 4 The upper insulating disk 8 has a flat disk-shaped structure and is made of quartz glass. The upper end surface is flat, and the lower end surface has a circular positioning groove to form a recess. In addition, the upper insulating disk 8 has 6 positioning holes distributed on the outer periphery and 3 connecting holes distributed on the inner periphery.

[0065] The outer positioning hole is used for the positioning post 2 to pass through, so as to achieve coaxial positioning of the entire fixture. The circular positioning groove on the lower end face is adapted to the flat disk structure of the graphite pressure plate 9 to achieve coaxial positioning constraint. Two of the three connecting holes on the inner side are used for the bolt 15 to pass through and fix the lower pressure guide plate 10, the upper insulating plate 8 and the graphite pressure plate 9. The other hole is used for the grounding pin 13 to pass through and make contact.

[0066] In one embodiment: Please refer to Figure 2 , Figure 4 The workpiece limiting disk 5 is a flat disk-shaped structure made of quartz glass. There is a stepped through hole structure in the center of the workpiece limiting disk 5 to ensure the coaxiality of the AVG glass plate 7.

[0067] The workpiece limiting plate 5 has 6 positioning holes distributed on the outer side of the circumference, which are used for the positioning pin 2 to pass through and contact each other, so as to achieve coaxial positioning of the entire fixture.

[0068] In one embodiment: Please refer to Figure 2 , Figure 4 The epitaxial wafer limiting plate 4 is a flat disk-shaped structure made of quartz glass. Six positioning holes are distributed around the periphery of the epitaxial wafer limiting plate 4, allowing different positioning pins 2 to pass through and contact each other, so as to achieve coaxial positioning of the entire fixture.

[0069] In one embodiment: Please refer to Figure 2 , Figure 4 The epitaxial wafer 6 and the pressure wafer 3 have a flat disk-shaped structure and are made of graphite.

[0070] The top surface of the epitaxial wafer pressure plate 3 contacts the epitaxial wafer 6 for applying pressure, and the bottom surface contacts the base 1;

[0071] Six positioning holes are distributed on the outer side of the epitaxial wafer pressure plate 3, allowing different positioning pins 2 to pass through and contact each other, so as to achieve coaxial positioning of the entire fixture.

[0072] In one embodiment: Please refer to Figure 2 , Figure 4 The base 1 is a stepped cylindrical structure made of quartz glass. A circular positioning groove is opened on the top end face to form a recess, and there are 6 positioning countersunk holes on the bottom wall of the circular positioning groove. The inner end face of the positioning hole is a flat circular surface. The bottom shaft section of the positioning post 2 is inserted into the corresponding positioning countersunk hole.

[0073] The base 1 provides coaxial constraint to the epitaxial wafer pressure plate 3 via a circular positioning groove.

[0074] In one embodiment: Please refer to Figure 2 , Figure 4 Steel ball 12 is a stainless steel ball with a diameter of 10mm, which plays a guiding role during the downward pressing process.

[0075] During use, this solution requires daily maintenance of each component according to the established maintenance plan to ensure its working condition.

[0076] The parts not disclosed in this utility model are all prior art, and their specific structures and working principles will not be described in detail.

[0077] Unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0078] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A high coaxiality anodic bonding fixture, comprising an epitaxial wafer (6) and an AVG glass plate (7), characterized in that: Also includes A base (1) is provided with multiple sets of positioning posts (2) installed around its periphery; The epitaxial wafer pressure plate (3) is placed on multiple sets of positioning posts (2); The epitaxial wafer limiting piece (4) has an inner diameter of an annular structure that is adapted to the outer diameter of the epitaxial wafer (6). The epitaxial wafer limiting piece (4) is located on the upper side of the epitaxial wafer pressure piece (3) and is also placed on multiple sets of positioning posts (2). The bottom surface of the epitaxial wafer (6) is placed in the inner ring of the epitaxial wafer limiting piece (4) and contacts the epitaxial wafer pressure piece (3). The workpiece limiting disk (5) is also a ring structure. Its inner diameter is adapted to the outer diameter of the AVG glass plate (7). It is also placed on multiple sets of positioning posts (2) and contacts the upper side of the epitaxial sheet limiting plate (4). The AVG glass plate (7) is placed in the inner ring of the workpiece limiting disk (5) and pressed on the top surface of the epitaxial sheet (6). The upper insulating disk (8) is located above the AVG glass plate (7) and is also fitted onto multiple sets of positioning posts (2); A graphite pressure plate (9) is placed between the bottom of the upper insulating plate (8) and the AVG glass plate (7), and the graphite pressure plate (9) connects the negative electrode to the AVG glass plate (7). The pressure guide plate (10) is placed at the center of the upper side of the upper insulating plate (8), and the pressure guide plate (10), the upper insulating plate (8) and the graphite pressure plate (9) are fixed together by bolts (15); A steel ball (12) is placed in a guide cylinder (11) formed on the top of the downward guide plate (10), and the outer diameter of the steel ball (12) is the same as the inner diameter of the guide cylinder (11). The grounding pin (13) passes through the upper insulating disk (8) and contacts the graphite pressure disk (9), forming an external grounding wire; The positive electrode sleeve (14) is inserted into the top of a set of positioning posts (2) and connected to the high voltage positive electrode.

2. The high coaxiality anodic bonding fixture according to claim 1, characterized in that: It also includes a quartz glass positioning pin insulating sleeve (16) placed on the top side of the upper insulating plate (8). The grounding pin (13) is placed in the positioning pin insulating sleeve (16) and passes through the positioning pin insulating sleeve (16) to contact the graphite pressure plate (9). The positioning pin insulating sleeve (16) plays an insulating role.

3. The high coaxiality anodic bonding fixture according to claim 1, characterized in that: The positioning post (2) is a stepped structure made of stainless steel, specifically composed of a large-diameter bottom shaft section and a small-diameter top shaft section. The bottom shaft section is inserted into the base (1), and the top end face of the bottom shaft section contacts the bottom wall of the epitaxial sheet pressure plate (3). The top shaft section sequentially contacts the positioning holes on the epitaxial sheet pressure plate (3), the epitaxial sheet limiting plate (4), the workpiece limiting plate (5), and the upper insulating plate (8), and then the top end contacts the positive electrode connecting sleeve (14).

4. The high coaxiality anodic bonding fixture according to claim 1, characterized in that: The graphite pressure plate (9) is made of graphite and is composed of an upper flat disc-shaped structure and a lower hemispherical structure. The graphite pressure plate (9) is connected to the AVG glass plate (7) through a semi-spherical structure.

5. A high coaxiality anode bonding fixture according to claim 2, characterized in that: The positive electrode sleeve (14) is a stainless steel cylinder.

6. The high coaxiality anodic bonding fixture according to claim 1, characterized in that: The grounding pin (13) is a stainless steel pin.

7. A high coaxiality anodic bonding fixture according to claim 1, characterized in that: The workpiece limiting plate (5), the upper insulating plate (8), and the epitaxial wafer limiting plate (4) are all made of quartz.

8. A high coaxiality anodic bonding fixture according to claim 4, characterized in that: The lower end face of the upper insulating disk (8) has a circular positioning groove, the inner diameter of which is adapted to the outer diameter of the flat disk-shaped structure on the top of the graphite pressure disk (9).

9. A high coaxiality anode bonding fixture according to claim 1, characterized in that: The epitaxial wafer pressure plate (3) is made of graphite.

10. A high coaxiality anodic bonding fixture according to claim 8, characterized in that: The center of the epitaxial wafer (6), the center of the AVG glass plate (7), the center of the flat disk structure of the graphite pressure plate (9), and the steel ball (12) are all located on the extended line of the inner ring central axis of the epitaxial wafer limiting plate (4).

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