A probe station electrically conductive light baffle for a cable connection pin card

Abstract

The conductive light shield for a probe station of the present invention for cable connection pin clips includes a conductive shield body and a light-absorbing layer. The conductive shield body covers the outside of the pin clip on the probe station. The conductive shield body includes a top wall and side walls extending downwards from the edge of the top wall, with one end of the side wall away from the top wall contacting the probe station. The conductive shield body provides electrostatic shielding and optical protection, ensuring that the pin clip is protected from electrostatic discharge and stray light interference during testing, thereby improving testing accuracy and stability. Cable openings are provided on the side walls to accommodate the cable layout between the pin clip and the testing machine, ensuring that the cable can pass smoothly and maintain a normal connection with the testing system. The light-absorbing layer is disposed on the surface of the conductive shield body. The organic carbon black coating has good light absorption properties and can effectively absorb stray light from the environment, reducing interference from light reflection on the optical alignment system.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor testing technology, specifically, it relates to a conductive light shield for a probe station used in cable connection pin cards. Background Technology

[0002] In semiconductor wafer testing, the probe station is one of the core testing devices, and the pin card, as a key interface device connecting the tester and the wafer pads, directly affects testing accuracy, efficiency, and chip yield due to the stability of its operating environment. Pin cards are typically connected to the tester substrate via dense cables to transmit electrical signals. However, in actual testing environments, pin cards face two main interference factors: first, electrostatic discharge (ESD) interference, where the probe station easily accumulates static electricity during high-frequency testing, mechanical movement, or environmental friction, potentially damaging the device under test or causing misinterpretation of test signals; and second, optical interference, where stray light reflection may occur when ambient light or the device's own light source illuminates the pin card area, affecting the accuracy of the optical alignment system and introducing testing errors.

[0003] To address the aforementioned issues, various protective measures have been proposed in existing technologies. Regarding electrostatic discharge (ESD) protection, a common practice is to install independent metal grounding clamps around the probe station. One end of a wire holds the metal frame of the pin clip, while the other end connects to the probe station's grounding terminal, thus achieving ESD discharge. This structure relies on manual grounding by the operator, and the grounding wire is exposed to the external environment, making it susceptible to loosening, wear, or oxidation due to mechanical movement. This leads to unstable contact resistance, unreliable ESD discharge paths, and difficulty in guaranteeing protective effectiveness. For optical protection, conductive light shields or baffles made of non-conductive materials (such as ordinary plastic or metal plates) are typically used. These are fixed above or to the side of the probe station using brackets, magnets, or screws to surround the pin clip area and reduce stray light interference. However, the surfaces of these light-shielding structures are often not treated for light absorption, resulting in high reflectivity. Furthermore, complete sealing is difficult to achieve during installation, allowing light to still enter the pin clip area through gaps or reflections, affecting the stability of the optical alignment system. In addition, some high-end probe station equipment attempts to integrate fixed shielding structures, but such structures are mostly built-in designs at the equipment level, cannot be disassembled, are difficult to maintain, and do not have adjustable light shielding and observation functions, making it difficult to adapt to the flexible needs of different testing scenarios. Summary of the Invention

[0004] In view of the problems existing in the prior art described above, this application provides a conductive light shield for a probe station used for cable connection pin cards, which can achieve integrated anti-static and light shielding functions.

[0005] To achieve the above and other related objectives, the present invention provides a conductive light shield for a probe station of a cable connection pin clip, comprising:

[0006] A conductive cover is installed outside the probe holder of the probe station. The conductive cover includes a top wall and a side wall extending downward from the edge of the top wall. The end of the side wall away from the top wall contacts the probe station, and a cable opening is provided on the side wall for the cable to pass through.

[0007] A light-absorbing layer is disposed on the surface of the conductive cover.

[0008] Optionally, the conductive cover is a stainless steel conductive cover.

[0009] Optionally, a light-absorbing layer covers the outer and / or inner surfaces of the conductive cover, and the light-absorbing layer is an organic carbon black light-absorbing layer.

[0010] Optionally, the conductive light shield of the probe station for cable connection pin clips further includes: an observation window, which is closable and disposed on the side wall of the conductive shield, and the observation window is a transparent observation window.

[0011] Optionally, the conductive light shield of the probe station for the cable connection pin card also includes an operation window, which is disposed on the side wall adjacent to the observation window.

[0012] Optionally, one side of the viewing window is hinged to the side wall.

[0013] Optionally, the size and location of the cable openings can be matched to the cable layout of the probe station.

[0014] Optionally, the cable opening is a rectangular opening, with a length between 100 mm and 140 mm and a width between 100 mm and 140 mm.

[0015] Optionally, the conductive cover can be rectangular or cylindrical.

[0016] Optionally, the conductive light shield of the probe station for cable connection pins also includes a handle disposed on the top wall of the conductive shield.

[0017] As described above, the conductive light shield for the probe station of the present invention for cable connection pin clips has at least the following beneficial technical effects:

[0018] The conductive light-shielding cover for a probe station used for cable connection pin clips of the present invention includes a conductive cover body and a light-absorbing layer. The conductive cover body is disposed over the pin clip of the probe station. The conductive cover body includes a top wall and side walls extending downward from the edge of the top wall, with the end of the side wall away from the top wall contacting the probe station. The conductive cover body provides electrostatic shielding and optical protection, ensuring that the pin clip is protected from electrostatic discharge and stray light interference during testing, thereby improving testing accuracy and stability. Cable openings are provided on the side walls to accommodate the cable layout between the pin clip and the testing machine, ensuring that the cable can pass through smoothly and maintain a normal connection with the testing system. The light-absorbing layer is disposed on the surface of the conductive cover body. The organic carbon black coating has good light absorption properties, effectively absorbing stray light from the environment and reducing interference from light reflection on the optical alignment system. Simultaneously, the organic carbon black coating is tightly bonded to the conductive cover body, without affecting the conductivity and overall structural strength of the conductive cover body. The conductive light shield of the probe station for cable connection pin clips of the present invention integrates anti-static, light shielding, automatic grounding and operability into one, forming a pin clip protection device with simple structure, integrated functions and convenient installation. Attached Figure Description

[0019] Figure 1 The diagram shown is a structural schematic of a conductive light shield for a probe station used for cable connection pin cards, provided in an embodiment of the present invention.

[0020] Figure 2 The illustration provided is for an embodiment of the present invention. Figure 1 A structural diagram from another perspective.

[0021] Figure 3 The image shows a square wave signal observed by an oscilloscope when the probe station provided in this embodiment of the invention is not fitted with a conductive light shield.

[0022] Figure 4 The image shows the square wave signal observed by an oscilloscope when a conductive light shield is added to the probe station provided in this embodiment of the invention.

[0023] Figure Labels

[0024] 1. Conductive light shield; 11. Conductive cover body; 111. Top wall; 1111. Handle; 112. Side wall; 1121. Cable opening; 1122. Observation window; 1123. Operation window; 1124. Auxiliary wire threading hole. Detailed Implementation

[0025] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention.

[0026] It should be noted that the illustrations provided in this embodiment are only schematic representations of the basic concept of the present invention. Although the illustrations only show components related to the present invention and are not drawn according to the actual number, shape and size of the components, the shape, quantity, positional relationship and proportion of each component can be arbitrarily changed under the premise of realizing the technical solution of this invention, and the layout of the components may also be more complex.

[0027] This embodiment provides a conductive light shield 1 for a probe station used in cable connection pin clips, see reference. Figure 1 and Figure 2 The conductive light shield 1 includes a conductive cover body 11 and a light-absorbing layer. The conductive light shield 1 is used to cover the probe card of the probe station to provide electrostatic shielding and optical protection functions, ensuring that the probe card is protected from electrostatic discharge and ambient stray light interference during testing, thereby improving testing accuracy and stability.

[0028] Specifically, the conductive cover 11 is installed over the probe holder of the probe station. In this embodiment, the conductive cover 11 is made of stainless steel, which has good conductivity and mechanical strength, and can effectively shield against external electromagnetic interference and electrostatic discharge. The shape of the conductive cover 11 can be designed as a rectangle or a cylinder according to actual application requirements, and is not limited here.

[0029] The conductive cover 11 includes a top wall 111 and a side wall 112 extending downward from the edge of the top wall 111. The end of the side wall 112 away from the top wall 111 contacts the probe station, thereby achieving automatic grounding during installation without the need for additional wiring. Specifically, the conductive cover 11 is hollow inside, closed at the top and open at the bottom, facilitating snap-fit ​​installation. Preferably, conductive foam or elastic contacts are provided in the contact area between the side wall 112 and the probe station to improve grounding reliability. A cable opening 1121 is provided on the side wall 112 for cables to pass through, adapting to the cable layout between the pin clip and the testing machine, ensuring that cables can pass through smoothly and maintain normal connection with the testing system.

[0030] The size and position of the cable opening 1121 match the cable layout of the probe station. Optionally, the cable opening 1121 can be designed as a U-shaped, rectangular, or circular opening depending on the cable harness diameter and layout; there is no limitation thereto. Optionally, the cable opening 1121 is a rectangular opening, with a length between 100 mm and 140 mm and a width between 100 mm and 140 mm. This size range can accommodate the cable layout requirements of most probe stations on the market, ensuring that the cable can pass through smoothly without causing cable compression due to an excessively small opening or affecting the light-shielding effect due to an excessively large via. In an optional embodiment of this first embodiment, the length of the cable opening 1121 is 120 mm, and the width of the cable opening 1121 is 120 mm. Preferably, the edge of the cable opening 1121 is provided with a flange or flexible sheath to prevent the cable from being damaged by sharp edges during passage.

[0031] A light-absorbing layer is disposed on the surface of the conductive cover 11. In this embodiment, the light-absorbing layer is an organic carbon black light-absorbing layer, coated on the outer and / or inner surfaces of the conductive cover 11. The organic carbon black coating has good light absorption properties, effectively absorbing stray light from the environment and reducing interference from light reflection on the optical alignment system. In an optional embodiment of this invention, the thickness of the organic carbon black coating is between 20 μm and 50 μm, ensuring that the absorption rate of visible and near-infrared light is not less than 95%. The coating surface can be further processed into a matte texture to avoid specular reflection. At the same time, the organic carbon black coating is tightly bonded to the conductive cover 11, without affecting the conductivity and overall structural strength of the conductive cover 11.

[0032] Preferably, the conductive light shield 1 of the probe station for cable connection pin cards in this embodiment further includes an observation window 1122, which is closably disposed on the side wall 112 of the conductive shield 11. The observation window 1122 is a transparent observation window made of transparent material, such as transparent glass or transparent plastic, so that operators can directly observe the working status and testing process of the pin card without disassembling the conductive light shield 1. In this embodiment, the thickness of the observation window 1122 is between 2 mm and 4 mm, embedded in the side wall of the conductive shield 11, and has conductive sealing strips around it to ensure optical observation function without destroying the continuity of electromagnetic shielding. Optionally, one side of the observation window 1122 is closably connected to the side wall 112 via a hinge, and the other side is provided with a buckle or magnetic attraction to achieve locking when closed. The transparent part of the observation window 1122 can be made of electromagnetic shielding glass to maintain electrostatic shielding effect while ensuring observation function. The opening and closing design of the observation window 1122 can also be used to open it for replacement, debugging or other maintenance operations of the pin card.

[0033] Preferably, the conductive light shield 1 of this embodiment further includes a handle 1111, which is disposed on the top wall 111 of the conductive shield body 11. The handle 1111 facilitates the operator's gripping and handling of the conductive light shield 1, and facilitates installation, disassembly and maintenance operations. In an optional embodiment of this embodiment, the handle 1111 is made of insulating material or has an insulating layer on its surface to avoid the risk of introducing static electricity during operation.

[0034] Optionally, the conductive light shield 1 in this embodiment also includes an operation window 1123, which is disposed adjacent to the observation window 1122 on the side wall 112. The operation window 1123 is also closable on the side wall 112 and can be used by operators to perform needle card replacement, adjustment, or other maintenance operations. The opening and closing structure of the operation window 1123 can be achieved by means of hinges, slide rails, or snap-fit ​​mechanisms. When closed, it should ensure a tight fit with the side wall 112 to prevent light leakage or electrostatic shielding failure. The adjacent arrangement of the operation window 1123 and the observation window 1122 facilitates simultaneous observation and operation by the operator, improving work efficiency.

[0035] Overall, the conductive light shield 1 of this embodiment has good versatility and adaptability, and can be applied to various models of pin clips. Since different models of pin clips differ in structural layout, interface position, and size, traditional protective devices often need to be designed separately for specific models, making universality difficult to achieve. However, this conductive light shield 1, through its openable observation window 1122 and operation window 1123, provides convenience for quick pin clip replacement. In actual use, the operator can first confirm the current pin clip model and working status through the observation window 1122. If it is necessary to replace it with another model of pin clip, there is no need to disassemble the entire conductive light shield 1; simply open the operation window 1123 or the observation window 1122 to directly replace or adjust the pin clip. After replacement, closing the operation window 1123 or the observation window 1122 restores the protective function. The entire process is simple and quick, significantly improving the switching efficiency of the equipment between different testing tasks. Meanwhile, the size of the cable opening 1121 can be customized or adjusted according to the cable layout corresponding to different pin cards, further enhancing the compatibility of the conductive light shield 1 with different types of pin cards. This design makes the conductive light shield 1 not only suitable for a single test platform, but also widely applicable to a variety of probe station devices, possessing good scalability and market adaptability.

[0036] Optionally, refer to Figure 2The conductive light shield 1 also includes an auxiliary wire-passing hole 1124, which is disposed on the side wall 112 of the conductive shield 11. The auxiliary wire-passing hole 1124 is relatively small. In an optional embodiment of this example, the auxiliary wire-passing hole 1124 is 10 mm × 10 mm in size, and is used for the auxiliary signal line, grounding line, or sensor cable of the probe card to pass through individually. The auxiliary wire-passing hole 1124 can be used in conjunction with the main cable opening 1121 to avoid the problem of compression or insufficient light shielding caused by multiple cables sharing a single opening. Optionally, the edge of the auxiliary wire-passing hole 1124 can be provided with conductive brushes or anti-static cloth to maintain the continuity of electromagnetic shielding while ensuring the passage of cables.

[0037] When installing the conductive light shield 1, the operator lifts the conductive shield 11 using handle 1111, aligns it with the top of the probe clip, and drops it vertically, ensuring the lower end of the side wall contacts the grounding surface of the probe station, forming a reliable grounding circuit. After the cable passes through the cable opening 1121, its position can be adjusted to avoid compression. Disassembly can be completed simply by lifting handle 1111; the entire process requires no tools and is quick.

[0038] To verify the protective performance of the conductive light shield 1 in this embodiment, the test signals before and after the conductive light shield 1 was installed were compared and analyzed. The results are as follows:

[0039] Reference Figure 3 When the conductive shield 1 is not installed on the probe station, the square wave signal observed by the oscilloscope exhibits obvious high-frequency oscillation and overshoot on the rising edge, and forms non-ideal spikes or ringing at the peak. This is because the environment around the probe station, especially fluorescent lamps and LED lights, is not only a light source but also a broadband source of electromagnetic noise. These devices generate high-frequency electromagnetic fields during operation. Without the conductive shield 1, this external electromagnetic noise couples to the exposed Device Under Test (DUT) and high-impedance probes and transmission lines via radiated coupling, and is ultimately captured by the oscilloscope, manifesting as jitter on the rising edge and spikes at the peak.

[0040] Reference Figure 4When a conductive light shield 1 (usually lined with absorbing material) is installed on the probe station and properly grounded, the aforementioned high-frequency noise components are significantly reduced, the overshoot amplitude decreases, the transient response of the waveform becomes smoother, and signal integrity is improved. This phenomenon is mainly attributed to the shielding effect of electromagnetic interference (EMI). Specifically, the conductive light shield 1 installed in this embodiment has a conductive layer or absorbing material (such as conductive paint, ferrite, etc.) coated on its inner wall. When this conductive shield is properly grounded, a simple Faraday cage is formed. It can effectively reflect incident external electromagnetic waves, absorb some electromagnetic energy and convert it into heat energy loss. It provides a low-impedance discharge path to ground for the coupling current. Therefore, after installing and grounding the conductive light shield 1 in this embodiment, the interference of external environmental noise on the sensitive measurement circuit is greatly reduced, resulting in a lower noise floor observed on the oscilloscope and improved waveform quality. This phenomenon is a typical example of how adding shielding measures effectively reduces the radiative coupling interference of environmental electromagnetic noise on high-sensitivity measurement systems, thereby improving the signal-to-noise ratio (SNR) and signal integrity.

[0041] Furthermore, taking wafer testing with a probe card as an example, during the testing process, when the probe station is not equipped with a conductive light shield 1, the machine vision system of the probe station often experiences a decrease in image signal-to-noise ratio (SNR) due to ambient light interference when performing pre-alignment or edge search procedures, which in turn causes alignment algorithm failure or positioning drift. Specifically, without the conductive light shield 1, broadband stray light in the environment (such as fluorescent lamps and LED lighting) will directly or through reflection enter the optical system, producing the following negative effects. First, it reduces contrast, as stray light "dilutes" the grayscale difference between wafer surface features (such as edges and etching marks) and the background, resulting in a decrease in image contrast. It also introduces noise; the instability of ambient light (such as flicker and intensity fluctuations) is converted into random noise in the image, interfering with the judgment of the edge detection algorithm. In addition, glare can occur. The metal or smooth dielectric layer on the wafer surface produces specular reflection of ambient light, forming glare or spots in the image and obscuring key alignment features.

[0042] After adding the conductive light shield 1, the contrast and stability of visual imaging are significantly improved by eliminating interference from ambient stray light. This allows the feature extraction algorithm based on image processing to accurately identify wafer edges or alignment marks, thereby greatly improving alignment accuracy and repeatability. Specifically, the conductive light shield 1 creates a controllable optical environment. After adding the conductive light shield (usually with its inner wall coated with light-absorbing material), a closed optical darkroom is constructed. This achieves the following key optimizations: First, it eliminates background interference, physically isolating external stray light and ensuring that the camera only receives imaging light from the probe station's built-in light source. Second, it improves the signal-to-noise ratio; stable, high-contrast images allow the image processing unit to more accurately calculate feature center coordinates, reducing grayscale sampling errors and feature point matching errors. Third, it ensures illumination consistency, guaranteeing that the optical path is not affected by external interference, whether in bright or dark field illumination, thus achieving reliable non-contact real-time dynamic calibration. Adding a conductive light shield physically blocks ambient light interference, optimizing the imaging quality of the machine vision system, thereby solving the alignment failure problem caused by light noise and improving the alignment yield in semiconductor testing.

[0043] The conductive light shield 1 of the probe station for cable connection pin clips in this embodiment provides electrostatic shielding and optical protection, ensuring that the pin clips are protected from electrostatic discharge and stray light interference during testing, thereby improving testing accuracy and stability. A cable opening 1121 is provided on the side wall 112 of the conductive shield 11 for the cable to pass through, adapting to the cable layout between the pin clip and the testing machine, ensuring that the cable can pass smoothly and maintain normal connection with the testing system. A light-absorbing layer is disposed on the surface of the conductive shield. The organic carbon black coating has good light absorption properties, effectively absorbing stray light from the environment and reducing interference from light reflection on the optical alignment system. Simultaneously, the organic carbon black coating is tightly bonded to the conductive shield 11, without affecting the conductivity and overall structural strength of the conductive shield 11. The conductive light shield 1 of the probe station for cable connection pin clips in this embodiment integrates antistatic properties, light shielding, automatic grounding, and operability into one device, forming a simple, functionally integrated, and easily installed pin clip protection device.

[0044] The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in the present invention should still be covered by the claims of the present invention.

Claims

1. A conductive light shield for a probe station used in cable connection pin clips, characterized in that, include: A conductive cover is provided on the outside of the probe holder of the probe station. The conductive cover includes a top wall and a side wall extending downward from the edge of the top wall. The end of the side wall away from the top wall contacts the probe station. A cable opening is provided on the side wall for the cable to pass through. A light-absorbing layer is disposed on the surface of the conductive cover.

2. The conductive light shield for the probe station of the cable connection pin clip according to claim 1, characterized in that, The conductive cover is a stainless steel conductive cover.

3. The conductive light shield for the probe station of the cable connection pin clip according to claim 1, characterized in that, The light-absorbing layer covers the outer surface and / or inner surface of the conductive cover, and the light-absorbing layer is an organic carbon black light-absorbing layer.

4. The conductive light shield for the probe station of the cable connection pin clip according to claim 1, characterized in that, Also includes: An observation window is closable and is disposed on the side wall of the conductive cover; the observation window is a transparent observation window.

5. The conductive light shield for the probe station of the cable connection pin clip according to claim 4, characterized in that, Also includes: An operation window is disposed on the side wall adjacent to the observation window.

6. The conductive light shield for the probe station of the cable connection pin clip according to claim 4, characterized in that, One side of the observation window is connected to the side wall in an openable and closable manner via a hinge.

7. The conductive light shield for the probe station of the cable connection pin clip according to claim 1, characterized in that, The size and location of the cable openings are matched to the cable layout of the probe station.

8. The conductive light shield for the probe station of the cable connection pin clip according to claim 7, characterized in that, The cable opening is rectangular, with a length between 100 mm and 140 mm and a width between 100 mm and 140 mm.

9. The conductive light shield for the probe station of the cable connection pin clip according to claim 1, characterized in that, The conductive cover is rectangular or cylindrical in shape.

10. The conductive light shield for the probe station of the cable connection pin clip according to claim 1, characterized in that, Also includes: A handle is provided on the top wall of the conductive cover.

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