A fully automatic ultrasonic testing unit device

Abstract

The utility model discloses a full -automatic ultrasonic detection unit device, and this structure includes open type water tank, water tank gate, wafer tray, vacuum suction nozzle, inlet pipe, drain outlet, ultrasonic probe and mechanical arm. Open type water tank edge is equipped with the water tank gate of liftable, is equipped with the hollow drain outlet of wafer tray shape adaptation in bottom, and the drain outlet is reserved with the periphery gap of tray edge, and the vacuum suction nozzle of independent drain pipe is installed on wafer tray, and inlet pipe is distributed in tray outside, and ultrasonic probe is installed on the motion shaft without the nozzle type. When detecting, the wafer is placed through the gate passage of mechanical arm, and after the vacuum suction nozzle is fixed, the gate rises, and the inlet pipe supplies water and forms the stable water layer through the gap drainage, and the probe is immersed in the water layer and is detected. The utility model can avoid the interference of water tank and mechanical arm, eliminate the detection distance increase, bubble and waterway instability problem brought by the nozzle, improve ultrasonic imaging quality, realize full -automatic high -precision detection.

Description

Technical Field

[0001] This utility model relates to the field of wafer inspection, and in particular to a fully automatic ultrasonic inspection unit device. Background Technology

[0002] In the field of defect detection for semiconductor bonded wafers, ultrasonic testing technology is widely used because it can effectively identify defects at bonding interfaces or between layers of SOI wafers. The core principle of this technology is as follows: an ultrasonic probe is placed above the wafer to be inspected, and pure water is used as a coupling medium to fill the gap between the probe and the wafer (because ultrasonic waves cannot be transmitted in air). The probe emits ultrasonic signals, which are driven by a drive shaft to move the probe back and forth on the wafer surface. The feedback signals reflected from the interface are collected, and finally, defects are identified by analyzing abnormal signals.

[0003] Currently, ultrasonic defect inspection equipment for semiconductor bonding wafers is mainly divided into three categories: manual, semi-automatic, and fully automatic. The core component of all these types is an ultrasonic testing unit, which consists of an ultrasonic probe, a pure water coupling medium, a wafer fixing device, and a pure water storage device. The testing unit structures of different types of equipment differ significantly.

[0004] The detection unit of the manual / semi-automatic equipment uses a water tank as a pure water storage device. The wafer fixing device is a clamp installed at the bottom of the water tank. The wafer is placed and fixed in the clamp manually. The pure water level in the water tank is higher than the wafer surface. The ultrasonic probe is directly immersed in the water and is coupled with the wafer through the water layer.

[0005] The fully automated equipment's testing unit uses a drainage basin instead of a water tank. The wafer fixing device is a tray with a vacuum nozzle (installed inside the drainage basin). The bottom of the vacuum nozzle is connected to a vacuum drainage pipe to drain any small amount of water sucked in. The wafer is automatically placed on the vacuum nozzle by a robotic arm and fixed by vacuum adsorption. The ultrasonic probe is integrated into a nozzle with an internal water channel. The pure water sprayed from the end of the nozzle forms a coupling medium. The water flows over the wafer surface and is then drained away by the drainage basin.

[0006] However, the existing structure has obvious flaws:

[0007] Limitations of manual / semi-automatic inspection units: Because the fixture is installed at the bottom of the water tank, the movement of the fully automatic robotic arm will interfere with the water tank, and the water resistance makes it difficult for the robotic arm to accurately control the positioning and movement of the wafer, making it unsuitable for fully automatic equipment.

[0008] Defects of fully automated detection units:

[0009] Increased detection distance leads to blurred imaging: The structural thickness at the bottom of the nozzle (usually several millimeters) causes the distance between the ultrasonic probe and the wafer surface to exceed the optimal focusing range, resulting in attenuation of the ultrasonic signal, insufficient feedback signal, and ultimately reduced image clarity.

[0010] Bubbles causing black lines in imaging: The bends in the water path inside the nozzle can easily cause turbulent water flow, generating bubbles, and the incoming water itself may also carry bubbles. When these bubbles enter the coupling area between the probe and the wafer, they cause unstable ultrasonic signal transmission and signal loss, which manifests as black lines in the imaging, leading to missed or false defects. Patent document CN216696166U uses an ultrasonic vibrator to eliminate bubbles on the sample surface and break up false interlayer connections before using an ultrasonic probe to detect defects, undoubtedly increasing the complexity of the device.

[0011] Unstable water path causes black lines in imaging: During the detection process, the nozzle moves back and forth with the probe, and the inertia generated by acceleration and deceleration causes the water path between the probe and the wafer to shake or even break. The coupling medium is discontinuous, which also causes signal loss and black lines in imaging, affecting the accuracy of detection.

[0012] Compatibility limitations of vacuum nozzles and water tanks: Vacuum nozzles have limited drainage capacity and cannot be submerged in water in a closed water tank, which prevents fully automatic equipment from using a water tank structure and limits the stability of the coupling medium.

[0013] Therefore, existing ultrasonic testing units struggle to balance robotic arm compatibility, coupling medium stability, and testing accuracy in fully automated testing, necessitating a structural design that can circumvent these shortcomings. Utility Model Content

[0014] The purpose of this invention is to achieve fully automated ultrasonic defect detection of semiconductor wafers while avoiding interference from water tanks and fixtures on the robotic arm, thus achieving fully automated detection. It also avoids the use of nozzles, thereby preventing problems such as increased detection distance, unstable water flow, and air bubbles associated with nozzles. By effectively reducing the distance between the ultrasonic probe and the wafer surface, the ultrasonic signal is improved, and a suitable focusing distance is achieved, ensuring a stable and bubble-free water layer between the ultrasonic probe and the wafer surface, thereby improving the quality of ultrasonic imaging.

[0015] This utility model provides a fully automatic ultrasonic testing unit device, comprising:

[0016] An open water tank with a drain outlet is configured to store pure water in a flowing manner.

[0017] A wafer tray is positioned above the drain outlet;

[0018] Several water inlet pipes are distributed on the outside of the wafer tray;

[0019] Several vacuum nozzles are disposed on a wafer tray and configured to pick up wafers;

[0020] A drain pipe, located below the vacuum nozzle, is configured to drain water entering from the vacuum nozzle; and

[0021] Ultrasonic probes are used to inspect wafers.

[0022] In one embodiment of this utility model, the wafer tray and the drain outlet are shaped to match each other and have a gap.

[0023] In one embodiment of this utility model, the flow rate of the inlet pipe is greater than the flow rate of the outlet pipe.

[0024] In one embodiment of this utility model, the wafer tray is a horizontal adjustment mechanism configured to adjust the horizontal state of the wafer.

[0025] In one embodiment of this utility model, a robotic arm is also included, configured to realize automatic loading and unloading of wafers.

[0026] In one embodiment of this utility model, a water tank gate is also included. When the water tank gate is lowered, it provides a channel for the robotic arm to place or retrieve wafers. When it is raised, it allows the open water tank to form a water storage space.

[0027] In one embodiment of this utility model, the bottom height of the open water tank is close to or lower than the height of the wafer surface, so as to form a stable water layer on the wafer surface.

[0028] In one embodiment of this invention, the ultrasonic probe is directly immersed in the water layer on the wafer surface.

[0029] This utility model has the following beneficial effects:

[0030] (1) The combination structure of water tank gate and open water tank is adopted. During the wafer placement stage, the gate descends to provide an unobstructed passage for the robotic arm, avoiding the movement interference between the traditional closed water tank and the robotic arm. After the wafer is fixed, the gate rises to form a water storage space, which not only meets the requirements of fully automatic loading and unloading, but also solves the problem that semi-automatic equipment cannot be adapted to the robotic arm, and realizes the efficient compatibility between the detection unit and the fully automatic equipment.

[0031] (2) The vacuum nozzle is not submerged in water and the small amount of water sucked in is discharged in time through an independent drain pipe. This not only preserves the stable fixation ability of vacuum adsorption, but also breaks through the limitation that the vacuum nozzle in traditional fully automatic equipment cannot use a water tank due to its limited drainage capacity, thus ensuring the smooth operation of the fully automatic detection process.

[0032] (3) By removing the traditional nozzle structure, the ultrasonic probe is directly immersed in the water layer on the wafer surface, eliminating the influence of the thickness of the nozzle bottom structure on the detection distance, making the distance between the probe and the wafer surface closer to the optimal focusing range, significantly enhancing the intensity and feedback efficiency of the ultrasonic signal, and improving the imaging clarity.

[0033] (4) An open water tank and slow-flow water inlet design are adopted (e.g., the bottom of the water tank is lower than the wafer surface, and a water layer is formed by overflow). The water flow covers the wafer surface smoothly, avoiding the turbulence and bubble problems when spraying water with traditional nozzles. At the same time, the water path does not move with the probe, reducing the water path shaking or discontinuity caused by inertia. A stable, bubble-free coupling water layer is formed between the probe and the wafer, ensuring stable ultrasonic signal transmission, effectively eliminating imaging black lines, and reducing the probability of missed or false defects.

[0034] (5) The dynamic balance between the inlet water flow and the drainage flow of the water tank gap ensures that the wafer surface is always covered with a sufficient coupling water layer, while avoiding interference from excessively thick water layers or water accumulation. This provides a continuous and stable medium environment for ultrasonic testing and further improves the reliability of the test results.

[0035] (6) The wafer tray serves as a leveling mechanism, working in conjunction with the precise adsorption of the vacuum nozzle to ensure that the wafer maintains a stable posture during the inspection process, thus avoiding the impact of wafer displacement on inspection accuracy. Attached Figure Description

[0036] Figure 1 A schematic diagram of the structure of a fully automatic ultrasonic testing unit device according to an embodiment of the present invention is shown; and

[0037] Figure 2 The diagram shows a front view of the fully automatic ultrasonic testing unit device according to one embodiment of the present invention. Detailed Implementation

[0038] In the following description, the present invention is described with reference to various embodiments. However, those skilled in the art will recognize that the embodiments may be practiced without one or more specific details or with other alternatives and / or additional methods, materials, or components. In other instances, well-known structures, materials, or operations are not shown or described in detail so as not to obscure the inventive aspects of the present invention. Similarly, for illustrative purposes, specific quantities, materials, and configurations are set forth to provide a comprehensive understanding of embodiments of the present invention. However, the present invention is not limited to these specific details.

[0039] In this utility model, the various embodiments are merely intended to illustrate the solution of this utility model and should not be construed as limiting.

[0040] In this specification, references to "an embodiment" or "this embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing throughout this specification does not necessarily refer to all of the same embodiment.

[0041] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0042] Figure 1 A schematic diagram of the structure of a fully automatic ultrasonic testing unit device according to an embodiment of the present invention is shown;

[0043] Figure 2 The diagram shows a front view of the fully automatic ultrasonic testing unit device according to one embodiment of the present invention.

[0044] like Figure 1 and Figure 2 As shown, in one embodiment of this utility model, the fully automatic ultrasonic testing unit device includes:

[0045] The open-type water tank 5 features an open design, with its bottom height adjustable to be below or near the surface of the wafer 9 (two options available). The bottom has a perforated drain outlet 1 that conforms to the shape of the wafer tray 4. A continuous peripheral gap is left between the drain outlet 1 and the edge of the wafer tray 4 as the main drainage channel. The edge is equipped with a water tank gate 6 that can be raised / lowered. As a flowing storage medium for pure water, the flow rate of water entering through the inlet pipe 7 and draining through the gap in the drain outlet 1 is balanced, forming a stable water layer on the surface of the wafer 9. The open design, combined with the gate, enables unobstructed operation of the robotic arm and water storage during testing, solving the interference problem of traditional closed water tanks.

[0046] The water tank gate 6 is configured as a rotatable or translatable plate structure, installed on the edge of the open water tank, and switches between "lowering / flattening" and "raising / standing" states through a drive mechanism. During the wafer placement stage, it lowers / flattens to provide an entry and exit channel for the robotic arm; during the inspection stage, it raises / stands to close the water tank opening to store water and ensure that a water layer forms on the wafer surface.

[0047] The wafer tray 4 integrates a leveling mechanism and has multiple vacuum nozzle mounting holes evenly distributed on its surface. Its overall shape is adapted to the drain outlet 1 at the bottom of the open water tank 5. It is configured to support the vacuum nozzles and adjust the level of the wafer 9; its shape matches the drain outlet to ensure stable installation and not obstruct drainage.

[0048] The vacuum nozzle 2, cylindrical or disc-shaped, has a top adsorption plane (contacting the back of the wafer) and is mounted on the wafer tray 4. The bottom of the vacuum nozzle 2 is connected to an independent drain pipe 3 via a sealed interface, and it contains an internal vacuum channel. The wafer 9 is fixed in place by vacuum adsorption to prevent displacement during testing; the bottom drain pipe 3 promptly removes any water absorbed, ensuring the nozzle is always in a non-immersed state (only a water layer on the wafer surface), thus solving the compatibility problem between traditional vacuum nozzles and water tanks.

[0049] Water inlet pipes 7, one or more, are distributed on the outside of the wafer tray, with the pipe openings facing the bottom of the water tank, supplying water to the water tank and providing a stable water layer on the wafer surface.

[0050] Drainage outlet 1 is a hollowed-out area adapted to the shape of the wafer tray, located at the bottom or edge of the open water tank, with a peripheral gap reserved between the hollowed-out area and the edge of the tray. Controllable drainage is achieved through the gap, forming a dynamic balance with the flow rate of the water inlet pipe 7 to maintain the thickness of the water layer on the wafer surface; the gap-type drainage reduces the impact of water flow, ensures the stability of the water layer, and improves the ultrasonic coupling effect.

[0051] The ultrasonic probe 8 features a nozzle-less design, directly mounted on the motion axis, with the bottom serving as the detection surface. It can be raised, lowered, and reciprocated horizontally via a drive mechanism. During detection, it descends and immerses itself in the water layer on the wafer 9 surface, emitting and receiving ultrasonic signals. The nozzle-less structure eliminates thickness interference, shortens the distance to the wafer, and enhances signal strength and focusing accuracy.

[0052] The robotic arm automatically completes the loading and unloading of wafers, and its operation is synchronized with the gate to ensure precise and interference-free operation.

[0053] Although various embodiments of the present invention have been described above, it should be understood that they are presented by way of example only and not as limitations. It will be apparent to those skilled in the art that various combinations, modifications, and alterations can be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should be defined solely by the appended claims and their equivalents.

Claims

1. A fully automatic ultrasonic testing unit device, characterized in that, include: An open water tank with a drain outlet is configured to store pure water in a flowing manner. A wafer tray is positioned above the drain outlet; Several water inlet pipes are distributed on the outside of the wafer tray; Several vacuum nozzles are disposed on a wafer tray and configured to pick up wafers; A drain pipe, located below the vacuum nozzle, is configured to drain water that enters from the vacuum nozzle; as well as Ultrasonic probes are used to inspect wafers.

2. The fully automatic ultrasonic testing unit device according to claim 1, characterized in that, The wafer tray and the drain outlet are shaped to fit together, with a gap between them.

3. The fully automatic ultrasonic testing unit device according to claim 2, characterized in that, The flow rate of the inlet pipe is greater than the flow rate of the outlet pipe.

4. The fully automatic ultrasonic testing unit device according to claim 1, characterized in that, The wafer tray is a leveling mechanism configured to adjust the horizontal state of the wafer.

5. The fully automatic ultrasonic testing unit device according to claim 1, characterized in that, It also includes robotic arms, configured to automate the loading and unloading of wafers.

6. The fully automatic ultrasonic testing unit device according to claim 5, characterized in that, It also includes a water tank gate, which provides a channel for the robotic arm to place or retrieve wafers when it descends, and creates a water storage space in the open water tank when it rises.

7. The fully automatic ultrasonic testing unit device according to claim 1, characterized in that, The bottom height of the open water tank is close to or lower than the height of the wafer surface, so as to form a stable water layer on the wafer surface.

8. The fully automatic ultrasonic testing unit device according to claim 7, characterized in that, The ultrasonic probe is directly immersed in the water layer on the wafer surface.

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