Ejector pin structure for wafer taking

Abstract

The utility model provides an ejector pin structure for wafer reclaiming, which comprises a guide shaft, a ball sliding sleeve, a bushing, an ejector pin sleeve and an ejector pin, and the guide shaft can reciprocate along the axial direction of the guide shaft; the guide shaft is sleeved with the ball sliding sleeve, the ball sliding sleeve comprises a retainer and balls arranged on the retainer, and the balls are clamped between the outer wall of the guide shaft and the inner wall of the lining and are in rolling contact with the outer wall of the guide shaft and the inner wall of the lining so as to reduce friction; the guide shaft is sleeved with a lining, and a ball sliding sleeve is embedded in the inner wall of the lining; one end of the ejector pin cap is fixedly butted with one end of the bushing in the axial direction, and an avoiding hole is formed in the other end of the ejector pin cap; the ejector pin is fixed to one end of the guide shaft and can penetrate through the receding hole to extend out of the ejector pin cap in a protruding mode. The ejector pin structure solves the problems that an ejector pin structure in the prior art is large in gap, easy to shake, large in friction force and poor in structural stability due to dust easily generated in high-frequency operation.

Description

Technical Field

[0001] This utility model relates to the field of semiconductor manufacturing, and in particular to a pin structure for wafer picking. Background Technology

[0002] In the semiconductor manufacturing industry, ejector pins play a crucial role as key components. They are mainly used to achieve precise lifting and positioning of workpieces, and their stability and accuracy directly affect product quality and production efficiency.

[0003] Currently, most existing ejector pin structures employ a combination similar to that of an oilless bushing and a guide shaft. While this combination offered some initial design convenience, it has revealed numerous drawbacks in practical applications. Due to the limited fit precision between the oilless bushing and the guide shaft, excessive clearance exists between the ejector pin guide shaft and the ejector pin bushing. This excessive clearance causes the ejector pin to wobble during operation, which not only reduces the lifting accuracy but may also damage the workpiece.

[0004] Meanwhile, this combination method results in relatively high friction. Under long-term, high-frequency operation, this increased friction accelerates component wear and shortens the lifespan of the ejector pin structure. Furthermore, dust is easily generated during the wear process. Once this dust enters the interior of the ejector pin structure, it further affects the normal fit between components, leading to increasingly poor structural stability. As usage time increases, the dust accumulation problem becomes more severe, gradually degrading the performance of the ejector pin structure and potentially causing malfunctions, thus affecting the normal operation of the entire production line.

[0005] Furthermore, existing ejector pin structures lack sufficient flexibility and adaptability to meet diverse working conditions and workpiece requirements. The limitations of their structural design make it difficult to meet production demands in applications requiring high precision and stability. Therefore, developing a novel ejector pin structure that effectively addresses these issues is of significant practical importance. Utility Model Content

[0006] The purpose of this invention is to provide a ejector pin structure for wafer feeding, so as to solve the problems of large gaps, easy shaking, high friction, and poor structural stability caused by dust generation during high-frequency operation in the existing ejector pin structure.

[0007] To achieve the above-mentioned objectives of this utility model, one embodiment of this utility model provides a ejector pin structure for wafer pick-up, wherein the ejector pin structure includes:

[0008] The guide shaft can reciprocate along its axial direction;

[0009] A ball sleeve is fitted on the guide shaft. The ball sleeve includes a cage and balls arranged on the cage. The balls are held between the outer wall of the guide shaft and the inner wall of the bushing and roll in contact with both to reduce friction.

[0010] A bushing is fitted over the guide shaft, and a ball bearing sleeve is embedded in the inner wall of the bushing.

[0011] The ejector cap has one end fixedly connected to one end of the bushing in the axial direction, and the other end is provided with a clearance hole;

[0012] The ejector pin is fixed to one end of the guide shaft and can protrude through the clearance hole to the outside of the ejector pin cap for lifting the wafer.

[0013] As a further improvement of one embodiment of the present invention, a limiting groove is provided on the inner wall of the bushing, the limiting groove forms an annular structure around the guide shaft, and the ball bearing sleeve is embedded in the limiting groove.

[0014] As a further improvement of one embodiment of the present invention, the retainer is configured as a retainer made of stainless steel or a retainer made of PEEK material.

[0015] As a further improvement of one embodiment of the present invention, the ball is configured as a ball made of bearing steel or a ball made of silicon nitride ceramic.

[0016] As a further improvement of one embodiment of the present utility model, one end of the ejector cap and one end of the bushing are fixedly connected in the axial direction by a snap-fit ​​connection.

[0017] As a further improvement of one embodiment of the present utility model, one end of the ejector cap and one end of the bushing are fixedly connected in the axial direction to form a receiving cavity, the receiving cavity is connected to a negative pressure system, and the end of the ejector cap away from the bushing is provided with a plurality of adsorption holes communicating with the receiving cavity.

[0018] As a further improvement of one embodiment of the present invention, the bushing is provided with air holes, and the air holes are connected to the receiving cavity through a gas flow channel located between the guide shaft and the bushing.

[0019] As a further improvement of one embodiment of the present invention, the inner wall of the bushing has an abutting portion that abuts against the guide shaft. The abutting portion is disposed away from the ejector cap and is dynamically sealed to the guide shaft through a sealing member disposed thereon. The air hole is located between the ejector cap and the abutting portion.

[0020] As a further improvement of one embodiment of the present utility model, the bushing includes a bushing body and a mounting base. One end of the bushing body is fixedly connected to the pin cap in the axial direction. The mounting base is disposed on the other end of the bushing body. The abutting part is located on the mounting base and has a mounting groove on its inner side. The mounting groove forms an annular structure around the guide shaft. The sealing element is embedded in the mounting groove.

[0021] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0022] When the guide shaft moves along its own axis, it drives the ejector pin to protrude from the outside of the ejector pin cap, thereby achieving the lifting operation of the wafer. During this process, the ball bearings are clamped between the outer wall of the guide shaft and the inner wall of the bushing, maintaining a rolling contact with both. This rolling contact effectively reduces friction. In this way, the problems of large gaps between the guide shaft and the inner wall of the bushing, easy wobbling, excessive friction, and dust generation due to friction during high-frequency operation are successfully overcome, significantly improving the stability of the entire structure and ensuring the stable and reliable operation of the ejector pin structure. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of a ejector pin structure for wafer picking according to an embodiment of the present invention;

[0024] Figure 2 for Figure 1 Top view;

[0025] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure along the AA direction;

[0026] Figure 4 for Figure 3 Front view of the middle bushing;

[0027] Figure 5 for Figure 3 A magnified view of position M in the middle.

[0028] The above description of the figures includes the following reference numerals:

[0029] 1. Guide shaft;

[0030] 2. Ball bearing sleeve;

[0031] 21. Cage;

[0032] 22. Ball bearings;

[0033] 3. Bushing;

[0034] 31. Bushing body;

[0035] 311. Limiting groove;

[0036] 312. Stomata;

[0037] 313. Gas flow channel;

[0038] 32. Install the base;

[0039] 321. Contact part;

[0040] 322. Seals;

[0041] 323. Install the groove;

[0042] 33. Receiving cavity;

[0043] 4. Thimble cap;

[0044] 41. Clearance hole;

[0045] 42. Adsorption pores;

[0046] 5. Threshold pin. Detailed Implementation

[0047] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0048] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0049] In this utility model, unless otherwise stated, directional terms such as "upper," "lower," "top," and "bottom" are generally used in relation to the direction shown in the accompanying drawings, or in relation to the vertical, perpendicular, or gravitational direction of the component itself; similarly, for ease of understanding and description, "inner" and "outer" refer to the inner and outer contours of each component itself, but the above directional terms are not used to limit this utility model.

[0050] To address the problems of large gaps, easy shaking, high friction, and poor structural stability caused by dust generation during high-frequency operation in existing ejector mechanisms that use similar oil-free bushing and guide shaft combinations, this invention provides an ejector structure for wafer picking.

[0051] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. Example

[0052] like Figure 1-5As shown, this embodiment provides a ejector pin structure for wafer picking, which typically picks up wafers from a wafer frame. The wafer frame typically consists of a metal frame and an insulating film disposed on the metal frame. The wafer is typically attached to the insulating film.

[0053] The ejector pin structure in this embodiment specifically includes a guide shaft 1, a ball bearing sleeve 2, a bushing 3, an ejector pin cap 4, and an ejector pin 5.

[0054] The guide shaft 1 can reciprocate along its axial direction; the ball sleeve 2 is sleeved on the guide shaft 1, and the ball sleeve 2 includes a retainer 21 and balls 22 arranged on the retainer 21.

[0055] Understandably, the retainer 21 in this invention is configured as a ring structure. The retainer 21 is sleeved on the guide shaft 1. The ball bearing 22 is clamped between the outer wall of the guide shaft 1 and the inner wall of the bushing 3 and rolls in contact with both to reduce friction. The bushing 3 is sleeved on the outside of the guide shaft 1, and the ball bearing sleeve 2 is embedded in the inner wall of the bushing 3. One end of the ejector cap 4 is fixedly connected to one end of the bushing 3 in the axial direction, and the other end is provided with a clearance hole 41. The ejector pin 5 is fixed to one end of the guide shaft 1 and can protrude through the clearance hole 41 to the outside of the ejector cap 4 for lifting the wafer.

[0056] With the above configuration, when the guide shaft 1 moves along its own axial direction, it can drive the ejector pin 5 to protrude out of the ejector pin cap 4 to lift the wafer. During this process, the ball bearing 22 is clamped between the outer wall of the guide shaft 1 and the inner wall of the bushing 3 and rolls in contact with both to reduce friction. This solves the problems of large gap between the guide shaft 1 and the inner wall of the bushing 3, easy shaking, high friction, and high frequency operation that easily generates dust, resulting in poor structural stability.

[0057] Furthermore, a limiting groove 311 is provided on the inner wall of the bushing 3. The limiting groove 311 forms an annular structure around the circumference of the guide shaft 1, and the ball sleeve 2 is embedded in the limiting groove 311. This structural design can effectively limit the position of the ball sleeve 2 in the axial direction, making it run more stably within the bushing 3.

[0058] In practical applications, the limiting groove 311 can also precisely restrict the radial movement of the ball sleeve 2 on the guide shaft 1, preventing it from shifting during operation, thereby further ensuring the fitting accuracy between the guide shaft 1 and the bushing 3. Simultaneously, this limiting structure also provides a fixed running track for the ball sleeve 2, allowing the balls 22 to roll more smoothly between the outer wall of the guide shaft 1 and the inner wall of the bushing 3, further reducing friction, effectively improving the operational stability and service life of the ejector pin structure, and better solving the problems existing in the prior art.

[0059] Optionally, the cage 21 is made of stainless steel or PEEK. When a stainless steel cage is used, stainless steel possesses good strength and corrosion resistance, maintaining stable performance in various harsh working environments. Its high strength ensures that the cage 21 is not easily deformed when subjected to the rolling pressure of the balls 22 and the interaction force between the guide shaft 1 and the bushing 3, thus guaranteeing the normal rolling and guiding accuracy of the balls 22. When a PEEK cage is chosen, PEEK material has excellent self-lubricating properties, wear resistance, and chemical corrosion resistance. Its self-lubricating properties further reduce friction between the balls 22 and the cage 21, reducing energy loss; its wear resistance makes the cage 21 less prone to wear during long-term use, extending the service life of the ejector pin structure; and its chemical corrosion resistance ensures that the cage 21 can operate normally in working environments with corrosive gases or liquids, providing a reliable guarantee for the stable operation of the ejector pin structure.

[0060] Preferably, the ball bearing 22 is made of bearing steel or silicon nitride ceramic. If bearing steel is used, it possesses high hardness, high wear resistance, and good contact fatigue strength. Its high hardness prevents the ball bearing 22 from being flattened or deformed when subjected to pressure between the guide shaft 1 and the bushing 3, thus ensuring smooth rolling; its high wear resistance extends the service life of the ball bearing 22 and reduces replacement frequency. When silicon nitride ceramic is used, it possesses excellent self-lubricating properties, high-temperature resistance, and corrosion resistance. Self-lubricating properties reduce the coefficient of friction between the ball bearing 22 and the outer wall of the guide shaft 1 and the inner wall of the bushing 3, further improving operating efficiency; high-temperature resistance allows it to work stably in high-temperature environments; and corrosion resistance ensures good performance even in corrosive environments, guaranteeing long-term stable operation of the ejector pin structure.

[0061] Furthermore, one end of the ejector cap 4 and one end of the bushing 3 are fixedly connected axially via a snap-fit ​​connection. This snap-fit ​​connection method is simple in structure and easy to operate, enabling quick fixation of the ejector cap 4 and the bushing 3. During assembly, simply engaging the snap-fit ​​structure of the ejector cap 4 with the corresponding slot of the bushing 3 completes the connection without requiring additional tools or complex procedures. Simultaneously, the snap-fit ​​connection also provides a certain degree of connection strength, ensuring that the ejector cap 4 and the bushing 3 will not easily separate during operation, thus ensuring the stability and reliability of the ejector structure.

[0062] Further, refer to Figure 3As shown, one end of the ejector cap 4 and one end of the bushing 3 are fixedly connected in the axial direction to form a receiving cavity 33. The receiving cavity 33 is connected to a negative pressure system. The end of the ejector cap 4 away from the bushing 3 is provided with multiple adsorption holes 42 communicating with the receiving cavity 33. In actual operation, after the negative pressure system is activated, a negative pressure environment is formed inside the receiving cavity 33. Since the adsorption holes 42 are connected to the receiving cavity 33, outside air is drawn into the receiving cavity 33 through the adsorption holes 42, thereby generating an adsorption force at the adsorption holes 42. This adsorption force can firmly adsorb the insulating film of the wafer frame, ensuring the stability of the insulating film during operation. Then, the drive guide shaft moves along its axial direction, causing the ejector pin 5 to protrude beyond the receiving cavity 33, thereby lifting the wafer on the insulating film, achieving precise wafer positioning and lifting operations, and facilitating subsequent processing or handling procedures.

[0063] Still for reference Figure 3 As shown, the bushing 3 is provided with an air hole 312, which is connected to the receiving cavity 33 through a gas flow channel 313 located between the guide shaft 1 and the bushing 3. In actual working scenarios, the air hole 312 plays a crucial role. On one hand, the air hole 312 can be connected to a negative pressure system. When it is necessary to adsorb the insulating film of the wafer frame, the negative pressure system extracts air from the receiving cavity 33 through the air hole 312, creating a negative pressure environment that allows the insulating film to adhere tightly to the ejector cap 4. On the other hand, when it is necessary to release the insulating film, air can be injected into the receiving cavity 33 through the air hole 312. External gas enters the receiving cavity 33 through the gas flow channel 313, balancing the negative pressure and allowing the insulating film to detach smoothly from the ejector cap 4. This design makes the ejector structure more flexible and efficient in adsorbing and releasing the insulating film, improving overall working performance and stability.

[0064] Further, refer to Figure 3 and Figure 5As shown, the inner wall of the bushing 3 has an abutment portion 321 that abuts against the guide shaft 1. The abutment portion 321 is located away from the ejector cap 4 and is dynamically sealed to the guide shaft 1 through a sealing member 322 disposed thereon. The vent 312 is located between the ejector cap 4 and the abutment portion 321. The abutment portion 321 abuts against the guide shaft 1, providing a stable mounting base for the sealing member 322 and ensuring that the sealing member 322 can function effectively. The dynamic sealing connection between the sealing member 322 and the guide shaft 1 prevents gas leakage from the abutment portion 321 during the movement of the guide shaft 1, maintaining stable air pressure in the receiving cavity 33. The vent 312 is located between the ejector cap 4 and the abutment portion 321, a layout that facilitates connection to a negative pressure system or inflation operations. In practical operation, when air is drawn or filled through the vent 312 to control adsorption and release, the seal 322 can reliably seal, ensuring that the adsorption and release of the insulating film of the wafer frame by the pin structure is accurate and reliable, thus improving the working performance of the device.

[0065] Furthermore, the bushing 3 includes a bushing body 31 and a mounting base 32. One end of the bushing body 31 is fixedly connected to the ejector cap 4 in the axial direction. The mounting base 32 is disposed on the other end of the bushing body 31. The abutment portion 321 is located on the mounting base 32 and has a mounting groove 323 on its inner side. The mounting groove 323 forms an annular structure around the guide shaft, and the seal 322 is embedded in the mounting groove. This structural design makes the installation of the seal 322 more stable. The annular structure of the mounting groove 323 can well fit the seal 322, ensuring its dynamic sealing effect with the guide shaft 1. The mounting base 32 provides stable support for the abutment portion 321, ensuring that the abutment portion 321 reliably abuts against the guide shaft 1. When the ejector structure is working, the seal 322 can effectively prevent gas leakage, ensure stable gas pressure in the receiving cavity 33, and thus ensure that the ejector structure can accurately and stably perform the adsorption and release operation of the insulating film of the wafer frame.

[0066] In summary, the embodiments of this utility model achieve the following technical effects:

[0067] When the guide shaft 1 moves along its own axis, it drives the ejector pin 5 to protrude from the ejector pin cap 4, thereby achieving the lifting operation of the wafer. During this process, the ball bearing 22 is clamped between the outer wall of the guide shaft 1 and the inner wall of the bushing 3, and maintains a rolling contact with both, which effectively reduces friction. In this way, the problems of large gap between the guide shaft 1 and the inner wall of the bushing 3, easy wobbling, excessive friction, and dust generation due to friction during high-frequency operation are successfully overcome, significantly improving the stability of the entire structure and ensuring that the ejector pin structure can operate stably and reliably.

[0068] Obviously, the embodiments described above are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort should fall within the protection scope of this utility model.

[0069] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0070] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0071] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A ejector pin structure for wafer feeding, characterized in that, include: The guide shaft can reciprocate along its axial direction; A ball sleeve is fitted on the guide shaft. The ball sleeve includes a cage and a plurality of balls embedded in the cage. The plurality of balls are held between the outer wall of the guide shaft and the inner wall of the bushing and roll in contact with both to reduce friction. A bushing is fitted over the guide shaft, and a ball bearing sleeve is embedded in the inner wall of the bushing. The ejector cap has one end fixedly connected to one end of the bushing in the axial direction, and the other end is provided with a clearance hole; The ejector pin is fixed to one end of the guide shaft and can protrude through the clearance hole to the outside of the ejector pin cap for lifting the wafer.

2. The ejector pin structure for wafer feeding according to claim 1, characterized in that, The bushing has a limiting groove on its inner wall, and the limiting groove forms an annular structure around the guide shaft. The ball bearing sleeve is embedded in the limiting groove.

3. The ejector pin structure for wafer feeding according to claim 1, characterized in that, The cage is made of stainless steel or PEEK material.

4. The ejector pin structure for wafer feeding according to claim 3, characterized in that, The balls are made of bearing steel or silicon nitride ceramic.

5. The ejector pin structure for wafer feeding according to claim 1, characterized in that, One end of the pin cap and one end of the bushing are fixedly connected in the axial direction by a snap-fit ​​connection.

6. The ejector pin structure for wafer feeding according to claim 1, characterized in that, One end of the ejector cap and one end of the bushing are fixedly connected in the axial direction to form a receiving cavity. The receiving cavity is connected to a negative pressure system. The end of the ejector cap away from the bushing is provided with a plurality of adsorption holes that communicate with the receiving cavity.

7. The ejector pin structure for wafer feeding according to claim 6, characterized in that, The bushing is provided with air holes, which are connected to the receiving cavity through a gas flow channel located between the guide shaft and the bushing.

8. The ejector pin structure for wafer feeding according to claim 7, characterized in that, The inner wall of the bushing has an abutment portion that abuts against the guide shaft. The abutment portion is located away from the ejector cap and is dynamically sealed to the guide shaft through a seal provided thereon. The vent is located between the ejector cap and the abutment portion.

9. The ejector pin structure for wafer feeding according to claim 8, characterized in that, The bushing includes a bushing body and a mounting base. One end of the bushing body is fixedly connected to the ejector cap in the axial direction. The mounting base is disposed on the other end of the bushing body. The abutment portion is located on the mounting base and has a mounting groove on its inner side. The mounting groove forms an annular structure around the guide shaft. The seal is embedded in the mounting groove.

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