Wafer film detection pick-and-place method and apparatus

Abstract

The present disclosure provides a wafer membrane detection pick-and-place method and device, belonging to the technical field of semiconductor detection. The pick-and-place method comprises: before wafer membrane detection, injecting a transparent liquid on a detection platform, and placing a wafer on the transparent liquid to form a liquid film between the back surface of the wafer and the detection platform; and after wafer membrane detection, applying liquid to the area between the edge of the wafer and the detection platform, and lifting the wafer until the wafer is separated from the detection platform. The pick-and-place device is used to perform the wafer membrane detection pick-and-place method. The pick-and-place device comprises: a detection platform for carrying a wafer; and at least two lifting mechanisms arranged on opposite sides of the detection platform and used to drive the two ends of the wafer to move up and down to place the wafer on the detection platform or lift the wafer from the detection platform.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a wafer film detection pick-and-place method and device, and belongs to the technical field of semiconductor detection. BACKGROUND

[0002] In the field of semiconductor manufacturing, the production process of wafer is extremely complex and technically difficult. In order to ensure that the final product achieves a high yield, strict wafer defect detection is required in multiple key stages of wafer production. Such detection is not limited to the inspection of the front surface of the wafer, and the back surface detection is also indispensable.

[0003] When the wafer is completed after the cutting process, the back surface needs to be detected. However, at this time, the film used to carry the wafer after cutting brings great challenges to the detection work. Due to the existence of the film, it is difficult for the camera to directly and clearly capture the image information of the back surface of the wafer. To solve this problem, the industry generally uses the method of adding water to contact the film on the back surface of the wafer. After the water contacts the film, the optical properties of the film can be changed, so that the film presents a clearer imaging effect in the camera field of view, thereby meeting the functional requirements of wafer back surface defect detection.

[0004] However, the existing water film detection technology still has many difficult problems to be solved in practical application:

[0005] Because the water forms a water film between the wafer and the detection platform, the water film makes the wafer and the detection platform tightly contact through surface tension, and it is not easy to take out. At the same time, the water film expels the air between the wafer and the detection platform, and a low pressure area is formed under the wafer, which causes the wafer to be tightly adsorbed on the film by atmospheric pressure. Under the action of this strong adsorption force, when the wafer is taken out, it will be subjected to a large pulling force and a large shearing force, thereby increasing the risk of damaging the product, which may cause the wafer to have scratches, cracks and other defects, and reduce the product yield.

[0006] In view of the many problems existing in the above-mentioned prior art, the present application proposes a pick-and-place method specially for such products, which aims to effectively solve the above-mentioned difficulties and realize high-quality detection of such products. SUMMARY

[0007] The present disclosure provides a wafer film detection pick-and-place method and device.

[0008] According to one aspect of the present disclosure, a wafer film detection pick-and-place method is provided, comprising:

[0009] Before wafer film detection, a transparent liquid is injected on the detection platform, and the wafer is placed on the transparent liquid, so that a liquid film is formed between the back surface of the wafer and the detection platform;

[0010] After the wafer is detected through the membrane, liquid is applied to the area between the wafer edge and the detection platform, and the wafer is lifted until the wafer is separated from the detection platform.

[0011] According to the technical solution of one aspect of the present disclosure, the method forms a liquid film by injecting a transparent liquid before detection, changes the optical properties of the film to meet the detection requirements; after detection, by applying liquid to the area between the wafer edge and the detection platform and lifting the wafer, the surface tension of the water film is weakened by the action of the liquid, and the low-pressure area formed below the wafer due to the discharge of air by the water film is gradually filled, thereby reducing the adsorption of atmospheric pressure on the wafer, so that the wafer can be more easily separated from the detection platform, solving the problem that the wafer is not easy to take out and is easily damaged due to the surface tension of the water film and atmospheric pressure in the prior art, reducing the risk of product damage and improving product yield.

[0012] According to the wafer membrane detection pick-and-place method of at least one embodiment of the present disclosure, after liquid is applied to the area between the wafer edge and the detection platform, and the liquid level reaches a first height, the wafer is lifted.

[0013] In the technical solution of the present embodiment, by setting the condition that the liquid reaches the first height before lifting the wafer, it can be ensured that there is enough liquid to fill below the wafer, further weakening the adsorption of atmospheric pressure on the wafer, making the wafer taking-out process more stable and reliable, and avoiding the situation that the wafer is difficult to take out or damaged due to lifting the wafer too early.

[0014] According to the wafer membrane detection pick-and-place method of at least one embodiment of the present disclosure, after the liquid level reaches the first height, the operations of lifting the wafer and applying liquid to the area between the wafer edge and the detection platform are performed synchronously.

[0015] In the technical solution of the present embodiment, the above two operations are performed synchronously, which can continuously ensure that there is liquid to fill below the wafer, maintain the weakening effect on atmospheric pressure, and make the wafer in a relatively stable stress state during the entire lifting process, further improving the success rate and safety of wafer taking-out, and reducing wafer damage caused by uneven stress.

[0016] According to the wafer membrane detection pick-and-place method of at least one embodiment of the present disclosure, after the liquid level reaches the first height, the lifting speed of the wafer is lower than the rising speed of the liquid level.

[0017] In the technical solution of the present embodiment, the lifting speed of the wafer is lower than the rising speed of the liquid level, which can ensure that the liquid can always fill the space below the wafer in time during the wafer lifting process, continuously weaken the adsorption of atmospheric pressure on the wafer, and avoid the formation of a low-pressure area below the wafer due to the liquid filling not in time, thereby ensuring the stability and reliability of wafer taking-out and reducing the possibility of wafer damage.

[0018] According to the wafer transparent membrane detection pick-and-place method of at least one embodiment of the present disclosure, after the wafer is separated from the detection platform, the liquid between the wafer and the detection platform is extracted to separate the liquid from the wafer.

[0019] In the technical solution of the present embodiment, the liquid is extracted after the wafer is separated from the detection platform to separate the wafer from the liquid, which facilitates subsequent wafer pick-up and cleaning and maintenance of the detection platform, and also avoids adverse effects of liquid residue on subsequent detection operations or other process links.

[0020] According to the wafer transparent membrane detection pick-and-place method of at least one embodiment of the present disclosure, placing the wafer on the transparent liquid includes: first contacting one end of the wafer with the transparent liquid, tilting the wafer and the transparent liquid and the detection platform, and then contacting the other end of the wafer with the transparent liquid.

[0021] In the technical solution of the present embodiment, the above-mentioned method of first tilting and placing one end and then placing the other end can expel air bubbles in the transparent liquid, so that the wafer is placed more stably on the transparent liquid, reducing problems of inaccurate detection results caused by air bubbles and uneven liquid film caused by liquid fluctuation or wafer shaking during placement, which is conducive to forming a stable liquid film, thereby improving the accuracy and reliability of detection.

[0022] According to the wafer transparent membrane detection pick-and-place method of at least one embodiment of the present disclosure, after the liquid film is formed between the back surface of the wafer and the detection platform, the excess transparent liquid outside the wafer on the detection platform is extracted.

[0023] In the technical solution of the present embodiment, extracting the excess transparent liquid can make the liquid film more uniform, thereby improving the imaging effect and detection accuracy during detection, and avoiding interference of excess liquid with the detection process, such as preventing liquid splashing onto the detection equipment or affecting the imaging effect of the camera, ensuring the cleanliness and stability of the detection environment, thereby improving the precision and quality of detection.

[0024] According to one aspect of the present disclosure, a wafer transparent membrane detection pick-and-place device is provided for performing the wafer transparent membrane detection pick-and-place method described above, the pick-and-place device comprising: a detection platform for carrying a wafer; and at least two lifting mechanisms respectively arranged on opposite sides of the detection platform and used to drive the two ends of the wafer to move up and down to place the wafer on the detection platform or lift the wafer from the detection platform.

[0025] According to the technical scheme of one aspect of the present disclosure, the taking and placing device detects the wafer carried by the platform, and uses the lifting mechanisms on both sides to realize automatic placing and lifting of the wafer, can cooperate with the taking and placing method of the wafer membrane detection to complete accurate taking and placing of the wafer in the detection process, and ensure that the wafer can form a liquid film with the detection platform before and after detection, and separate smoothly, solve the problem that the wafer is not easy to take out due to the water film in the prior art, and improve the detection efficiency and product yield.

[0026] According to the taking and placing device for wafer membrane detection of at least one embodiment of the present disclosure, the detection platform comprises: a platform body provided with a mounting port; a transparent plate fixedly arranged on the inner side of the mounting port, used to form a liquid film between the transparent liquid and the wafer; and a waterproof ring in the shape of a ring, sealingly connected to the upper surface of the platform body, the waterproof ring surrounds the transparent plate to form a water injection groove containing liquid on the upper surface of the platform body and the transparent plate. Wherein, an annular water groove is formed between the outer wall of the transparent plate and the inner wall of the mounting port, the annular water groove surrounds the transparent plate and is provided with a water injection hole and a water suction hole; an annular water outlet gap is formed between the upper surface of the transparent plate and the inner wall of the mounting port, the water outlet gap is in communication with the annular water groove, and the water outlet gap, the annular water groove and the transparent plate have a common central axis.

[0027] In the technical scheme of the present embodiment, the mounting port on the platform body is used to mount the transparent plate, and the transparent plate forms a liquid film with the wafer to meet the detection requirements; the waterproof ring forms a water injection groove for containing the injected transparent liquid, and avoids excess liquid from leaking or splashing onto other components, ensuring the cleanliness and stability of the detection environment; the design of the annular water groove and its water injection hole and water suction hole facilitates the injection and extraction of liquid, and can accurately control the amount of liquid; the water outlet gap ensures the circulation of liquid between the annular water groove and the water injection groove, so that the liquid can be evenly distributed under the wafer, which is conducive to the formation of a stable liquid film, and the cooperation of the annular water groove and the water outlet gap optimizes the liquid control precision, reduces the risk of air bubble generation, improves the accuracy and reliability of detection, and also provides convenience for wafer placing and taking out operations.

[0028] The wafer transparent film detection pick-and-place device according to at least one embodiment of the present disclosure, each lifting mechanism comprises: a wafer carrier movably arranged above the platform body and provided with an opening for placing a wafer; a lifting claw movably arranged below the wafer carrier; and a driving mechanism fixedly arranged on the platform body and connected with the lifting claw for driving the lifting claw to move up and down; wherein the two lifting claws are respectively used for supporting two opposite ends of the wafer carrier, the platform body is provided with a groove matched with the shape of the lifting claw, and when the wafer carrier is at the bottom end of the stroke, the lifting claw is at least partially sunken into the groove to make the wafer contact with the transparent plate.

[0029] In the technical scheme of the present embodiment, the wafer carrier is used for placing a wafer, the lifting claw is driven by the driving mechanism to move up and down, thereby driving the wafer carrier and the wafer to move up and down; the two lifting claws are respectively used for supporting two opposite ends of the wafer carrier, thereby ensuring the stability of the wafer during the lifting process and automatically realizing the placement mode of first placing one end of the wafer in an inclined manner and then placing the other end; the groove on the platform body is designed to make the lifting claw partially located in the groove when the wafer carrier is at the bottom end of the stroke, thereby making the wafer accurately contact with the transparent plate to form a liquid film. This structure design is accurate and reliable, which can ensure the correct position and state of the wafer during the detection process, is beneficial to improve the detection precision and efficiency, and reduces the risk of damage to the wafer during the pick-and-place process. BRIEF DESCRIPTION OF DRAWINGS

[0030] The accompanying drawings illustrate exemplary embodiments of the present disclosure and together with the general description of the disclosure given above, and the detailed description of the embodiments below, serve to explain the principles of the present disclosure.

[0031] Figure 1 is a structural schematic diagram of a wafer transparent film detection pick-and-place device according to an embodiment of the present disclosure.

[0032] Figure 2 is a top view of a wafer transparent film detection pick-and-place device according to an embodiment of the present disclosure.

[0033] Figure 3 is a side view of a wafer transparent film detection pick-and-place device according to an embodiment of the present disclosure.

[0034] Figure 4 is a bottom perspective view of a wafer transparent film detection pick-and-place device according to an embodiment of the present disclosure.

[0035] Figure 5is a bottom view of a wafer film detection pick-and-place device according to one embodiment of the present disclosure.

[0036] Figure 6 is Figure 5 is a sectional view of the A section in the middle.

[0037] Figure 7 is Figure 6 is an enlarged schematic view of the B area in the middle.

[0038] Figure 8 is a step flow chart of a wafer film detection pick-and-place method according to one embodiment of the present disclosure.

[0039] The reference numerals in the drawings are specifically as follows:

[0040] 100, detection platform

[0041] 110, platform body

[0042] 111, mounting port

[0043] 112, groove

[0044] 113, mounting plate

[0045] 120, transparent plate

[0046] 121, glass platform

[0047] 130, waterproof ring

[0048] 131, water injection groove

[0049] 140, annular water groove

[0050] 141, water injection hole

[0051] 142, water suction hole

[0052] 150, water outlet gap

[0053] 200, lifting mechanism

[0054] 210, wafer carrier

[0055] 211, opening

[0056] 220, lifting claw

[0057] 230, driving mechanism

[0058] 231, servo motor

[0059] 232, eccentric wheel

[0060] 233, roller

[0061] 234, lifting plate

[0062] 235, guide rail assembly

[0063] 236, return spring

[0064] 237, position detection switch

[0065] 300, robot

[0066] 400, wafer DETAILED DESCRIPTION

[0067] The present disclosure will be further described in detail with reference to the drawings and embodiments. It can be understood that the specific embodiments described herein are only intended to explain the related content, and not to limit the present disclosure. In addition, it should be noted that only parts related to the present disclosure are shown in the drawings for ease of description.

[0068] It should be noted that the embodiments in the present disclosure and the features in the embodiments can be combined with each other without conflict. The technical solutions of the present disclosure will be described in detail below with reference to the drawings and in combination with the embodiments.

[0069] Unless otherwise specified, the exemplary embodiments shown will be understood to provide exemplary features of various details that can implement the technical concepts of the present disclosure in practice. Therefore, unless otherwise specified, the features of various embodiments can be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of the present disclosure.

[0070] The existing water-added membrane detection technology still has many difficult problems to be solved in practical application: first, because water forms a water film between the wafer and the detection platform, the water film makes the wafer and the detection platform tightly contact through surface tension, and it is not easy to take out. At the same time, the water film discharges the interface air between the wafer and the detection platform, and a low pressure area will be formed under the wafer, causing the wafer to be tightly adsorbed on the film by atmospheric pressure. Under the action of this strong adsorption force, when the wafer is taken out, it will be subjected to a huge pulling force and shearing force, thereby increasing the risk of damaging the product, which may cause the wafer to have scratches, cracks and other defects, and reduce the product yield. Second, air bubbles are easily generated during the contact of the membrane with water. These air bubbles will interfere with the imaging of the camera on the back of the wafer, causing the acquired image to appear blurred, distorted, and other situations, which seriously affects the accuracy and reliability of defect detection. Third, the thickness of the water at the bottom of the membrane is difficult to ensure uniform. The uneven water thickness will cause the light to refract and scatter to different degrees when passing through the membrane and the water layer, resulting in uneven imaging quality, which further affects the accurate judgment of the defects on the back of the wafer.

[0071] In order to solve the above technical problems, the present disclosure provides a wafer membrane detection taking and placing device and method.

[0072] The wafer membrane detection pick-and-place device of the present disclosure, hereinafter referred to as the pick-and-place device, is designed for the pick-and-place method of wafer membrane detection. The core of the pick-and-place device is to achieve precise control of liquid and automatic and stable pick-and-place of wafers through structural design, thereby overcoming the problems of adsorption, bubbles, and uneven water film thickness caused by water film surface tension and low pressure area in the background technology.

[0073] Figure 1 is a structural schematic diagram of a wafer membrane detection pick-and-place device according to an embodiment of the present disclosure, Figure 2 is a top view of a wafer membrane detection pick-and-place device according to an embodiment of the present disclosure.

[0074] As shown in Figure 1 and Figure 2 , the pick-and-place device comprises a detection platform 100 and at least two lifting mechanisms 200. In this embodiment, two lifting mechanisms are described.

[0075] The detection platform 100 is the basic load-bearing component of the pick-and-place device, which is used to contain transparent liquid and form a uniform liquid film with the wafer 400 to support membrane detection.

[0076] Figure 3 is a side view of a wafer membrane detection pick-and-place device according to an embodiment of the present disclosure, Figure 4 is a bottom perspective view of a wafer membrane detection pick-and-place device according to an embodiment of the present disclosure, Figure 5 is a bottom view of a wafer membrane detection pick-and-place device according to an embodiment of the present disclosure.

[0077] As shown in Figures 3 to 5 , in an embodiment, the detection platform 100 comprises a platform body 110, a transparent plate 120, and a waterproof ring 130. The structure is designed to optimize the liquid flow path, reduce bubble generation, and maintain pressure balance to solve the above technical problems.

[0078] The platform body 110 is the basic structure of the entire detection platform 100, on which the mounting hole 111 is arranged. The platform body 110 can be made of high-strength and corrosion-resistant materials, such as stainless steel or marble, to ensure its stability and durability during use. The position and size of the mounting hole 111 are designed according to actual needs to ensure that the transparent plate 120 can be accurately installed and meet the overall layout requirements of wafer membrane detection. The edge of the mounting hole 111 is finely processed to ensure the installation precision with the transparent plate 120, avoiding liquid leakage and other problems. In alternative embodiments, the platform body 110 can be made of non-metallic materials, such as engineering plastics, to reduce the weight of the device and lower the cost, but the strength and stability of the platform body 110 must meet the use requirements.

[0079] Figure 6 yes Figure 5 Sectional view of section A.

[0080] like Figure 6 As shown, a transparent plate 120 is fixedly disposed inside the mounting opening 111 to form a liquid film between the transparent liquid and the wafer 400. The material of the transparent plate 120 must have good optical transparency; for example, optical glass or high-quality plexiglass can be used. The thickness of the transparent plate 120 is selected according to the detection requirements; too thin may affect its strength, while too thick may affect the light transmission effect. In some specific embodiments, the transparent plate 120 is a glass platform 121, which is fixed inside the mounting opening 111 with sealant to ensure a seamless connection between it and the platform body 110, preventing liquid leakage. The transparent plate 120 can also be made of other materials with good optical properties, such as certain special optical crystals, selected according to different detection wavelengths and accuracy requirements.

[0081] like Figure 1 As shown, the waterproof ring 130 is annular and sealed to the upper surface of the platform body 110. The waterproof ring 130 surrounds the transparent plate 120, forming a liquid-retaining injection groove 131 on the upper surfaces of the platform body 110 and the transparent plate 120. The waterproof ring 130 can be made of materials with good elasticity and sealing properties, such as rubber. Its function is to prevent the injected transparent liquid from leaking or splashing onto other components, ensuring a clean and stable testing environment. For example, when injecting transparent liquid, the waterproof ring 130 can effectively prevent liquid overflow, preventing damage to electronic components or mechanical structures around the testing platform 100. Besides rubber, the waterproof ring 130 can also be made of materials such as silicone.

[0082] Figure 7 yes Figure 6 Enlarged schematic diagram of region B in the middle.

[0083] like Figure 6 and Figure 7 As shown, an annular water tank 140 is formed between the outer wall of the transparent plate 120 and the inner wall of the mounting port 111. This annular water tank 140 surrounds the transparent plate 120 and is provided with an injection hole 141 and a suction hole 142. The design of the annular water tank 140 facilitates liquid injection and extraction operations, enabling precise control of the liquid volume. The diameter and position of the injection hole 141 and suction hole 142 are designed according to actual flow requirements and device structure. For example, the injection hole 141 can be located on one side of the annular water tank 140 for easy connection to a water injection pipe; the suction hole 142 can be located on the other side for easy liquid discharge. In some embodiments, connectors and valves are provided at the injection hole 141 and suction hole 142 to control the liquid flow rate and opening / closing status.

[0084] like Figure 7 As shown, an annular water outlet gap 150 is formed between the upper surface of the transparent plate 120 and the inner wall of the mounting port 111. This water outlet gap 150 communicates with the annular water tank 140 and shares a common central axis with both the annular water tank 140 and the transparent plate 120. The water outlet gap 150 ensures the flow of liquid between the annular water tank 140 and the water injection tank 131, allowing the liquid to be evenly distributed below the wafer 400, which is beneficial for forming a stable liquid film. For example, when transparent liquid is injected into the annular water tank 140 through the water injection hole 141, the liquid slowly flows into the water injection tank 131 through the water outlet gap 150 and flows evenly from all around the wafer 400 to the wafer 400, forming a uniform liquid film below the wafer 400. This reduces the risk of bubble formation and makes the liquid film thickness more uniform, improving the accuracy and reliability of the detection.

[0085] like Figure 1 and Figure 2 As shown, the lifting mechanism 200 is responsible for driving the placement and lifting operations of the wafer 400. The pick-and-place device includes at least two lifting mechanisms 200, respectively disposed on opposite sides of the inspection platform 100, such as on the left and right sides of the inspection platform 100, to achieve independent or synchronous control of both ends of the wafer 400. Each lifting mechanism 200 includes a wafer carrier 210, a lifting claw 220, and a drive mechanism 230 to support the tilting placement and precise lifting of the wafer 400.

[0086] The wafer carrier 210 is movably disposed above the platform body 110 and has an opening 211 for placing the wafer 400. The wafer carrier 210 can be made of lightweight, high-strength materials, such as steel and aluminum alloy. The size of the opening 211 is designed according to the specifications of the wafer 400 to ensure accurate placement and prevent wobbling during lifting and lowering. For example, in some embodiments, the edge of the opening 211 of the wafer carrier 210 is provided with a flexible pad, such as a rubber pad, to prevent the wafer 400 from being scratched or damaged during placement and lifting. The edge of the opening 211 of the wafer carrier 210 can also be designed to be slightly inclined to assist in the tilting placement step.

[0087] like Figure 1As shown, the lifting gripper 220 is movably arranged on the platform body 110 and below the wafer carrier 210. The shape of the lifting gripper 220 is designed according to the structure of the wafer carrier 210 to ensure that the wafer carrier 210 can be stably supported. For example, the lifting gripper 220 can adopt a fork-shaped structure, and the two ends of the fork-shaped structure are inserted into the support positions below the wafer carrier 210. At the same time, the lifting gripper 220 can also be provided with a flexible material, and the flexible material is in contact with the wafer carrier 210 to reduce the abrasion and bruise between the wafer carrier 210 and the lifting gripper 220. The material of the lifting gripper 220 needs to have sufficient strength and rigidity, such as stainless steel, to bear the weight of the wafer 400 and the wafer carrier 210. The platform body 110 is provided with a groove 112 matched with the shape of the lifting gripper 220. When the wafer carrier 210 is located at the bottom end of the stroke, the lifting gripper 220 at least partially sinks into the groove 112 to make the wafer 400 accurately contact the transparent plate 120. The depth and width of the groove 112 are designed according to the size of the lifting gripper 220 to ensure that the lifting gripper 220 can smoothly enter the groove 112 during the descending process, so that the wafer carrier 210 stably descends, and the wafer 400 and the transparent plate 120 form a uniform liquid film.

[0088] As shown in Figure 3 and Figure 5 , the driving mechanism 230 is fixedly arranged on the platform body 110 and connected with the lifting gripper 220 for driving the lifting gripper 220 to move up and down. The driving mechanism 230 can adopt various forms, such as a servo driving mechanism, an electric push rod, an air cylinder, etc. In some embodiments, the driving mechanism 230 adopts a servo driving mechanism, which has the advantages of high control precision and stable operation. The electric push rod is fixed on the platform body 110 by bolts, and the output end of the electric push rod is connected with the lifting gripper 220. The lifting and descending movement of the lifting gripper 220 is realized by controlling the extension and retraction of the electric push rod. In addition to the electric push rod and the air cylinder, the driving mechanism 230 of the lifting mechanism 200 can also adopt a hydraulic cylinder, which is suitable for occasions with high lifting force requirements.

[0089] Exemplarily, the driving mechanism 230 comprises a servo motor 231, an eccentric wheel 232, a roller 233, a lifting plate 234, a guide rail assembly 235, and a position detection switch 237. The servo motor 231 is mounted on the mounting plate 113 of the platform body 110, and the output shaft of the servo motor 231 is connected to the eccentric wheel 232 to form a rigid transmission. The roller 233 is mounted on the lifting plate 234, and the outer circle of the roller 233 is in contact with the outer edge of the eccentric wheel 232 to form a cam-follower mechanism. The lifting plate 234 is mounted on the side of the platform body 110 through the guide rail assembly 235. The guide rail assembly 235 comprises linear guide rails and matched sliders mounted on the platform body 110 and the lifting plate 234 respectively, for guiding the lifting movement. One end of the reset spring 236 is connected to the platform body 110, and the other end of the reset spring 236 is connected to the lifting plate 234, for resetting the platform body 110 after the lifting. The position detection switch 237 is mounted on the platform body 110 and located on the moving path of the lifting plate 234. When the lifting plate 234 moves to a preset position (such as a first height or a wafer taking height), the position detection switch 237 is triggered. The switch converts the mechanical displacement into an electrical signal, which is fed back to the control system to realize functions such as movement stopping, reversing or alarming, so as to ensure the safety and precision of the system. In operation, the servo motor 231 drives the eccentric wheel 232 to rotate, the roller 233 converts the rotary motion into reciprocating motion, the lifting plate 234 moves linearly along the guide rail assembly 235, the reset spring 236 assists in resetting, and the position detection switch 237 monitors the position in real time and feeds back signals to form a closed-loop control. The driving mechanism 230 can realize precise and efficient linear driving and position control, so that the lifting of the lifting claws 220 is more accurate and reliable.

[0090] The pick-and-place device realizes the automation of the pick-and-place operation through the cooperation of the detection platform 100 and the lifting mechanism 200. In operation, the water injection groove 131 of the detection platform 100 contains transparent liquid, and the annular water groove 140 and the water outlet gap 150 ensure the uniformity of the liquid film; the lifting mechanism 200 drives the wafer carrier 210 to complete the placing, detecting and taking out.

[0091] In the wafer placing stage, the lifting mechanism 200 lowers the wafer carrier 210 to the bottom end of the stroke, the lifting claws 220 are embedded in the grooves 112, and the wafer 400 lightly touches the transparent plate 120; the annular water groove 140 is injected with water, and the liquid forms a liquid film through the water outlet gap 150. In the detecting stage, the waterproof ring 130 seals the water injection groove 131, and the camera captures the image of the back of the wafer 400 through the transparent plate 120. In the wafer taking-out stage, the annular water groove 140 injects water to the edge area, and the lifting mechanism 200 synchronously lifts the wafer carrier 210.

[0092] The cooperation of the waterproof ring 130 and the annular water tank 140 of the above technical solution significantly reduces bubble generation and improves detection image quality; differential control of the lifting mechanism 200 reduces shear force, and is particularly suitable for thin wafers; and the overall modular design of the taking and placing device simplifies maintenance, prolongs the service life of the equipment, and indirectly improves product yield.

[0093] In some embodiments, the taking and placing device further comprises a mechanical hand 300 for placing the wafer 400 and the wafer carrier on the lifting claw 220 or taking them out from the lifting claw 220.

[0094] The working process of the taking and placing device for wafer film detection is as follows:

[0095] First, after the mechanical hand 300 takes the wafer product and the wafer carrier, it places them on the lifting claw 220 and then withdraws, at the same time, the stage starts to inject a certain amount of water on the glass platform 121. The two lifting claws 220 are controlled by two independent servo motors. The lifting claw on one side is lowered first, and the lifting claw on the other side is lowered later, so that the wafer can be placed on the glass platform 121 while contacting the glass platform 121 and then slowly placed obliquely downward. In this way, the water on the glass platform 121 can be pushed to one side, thereby avoiding the formation of bubbles between the wafer film and the water.

[0096] Then, when the product is completely placed, a water film is formed between the glass platform 121 and the wafer. At this time, the glass platform 121 is pumped by the water hole 142 and vacuumized, so that the water film thickness is uniform and the vacuum of the product is established. The support of the glass platform 121 also ensures the flatness of the product. After the film contacts the water, it becomes highly transparent, and the detection of the product begins. The lens group detects through the glass below the glass platform 121.

[0097] After the product detection is completed, the vacuumization is finished, and the stage water injection hole 141 starts to inject water. It should be noted that the wafer and the glass platform 121 are in complete contact and are affected by water at the time of detection. If the wafer is lifted directly, the film will be pulled by the water, causing the film to deform under external force, which may cause the risk of wafer loss. When the water is injected to the first height, the lifting claw 220 is also lifted slowly and synchronously controlled by the servo motor. The lifting speed and height can be matched with the water injection speed. Due to the filling of water and the lifting action, the wafer film is separated from the glass platform 121. After complete separation, the water injection hole 141 is closed, and the water hole 142 is opened. At this time, the water level naturally decreases, and the wafer is supported by the lifting claw 220, thereby realizing the separation of the wafer film and the water.

[0098] Finally, when the lifting claw 220 rises to the discharge position, the mechanical hand 300 takes the wafer away for subsequent action process.

[0099] Figure 8 is a step flow chart of a wafer membrane detection pick-and-place method according to an embodiment of the present disclosure.

[0100] As shown in Figure 8 , a wafer membrane detection pick-and-place method of the present disclosure forms a liquid film by injecting a transparent liquid before detection to change the optical properties of the film to meet the detection requirements; after detection, the wafer is separated from the detection platform 100 by applying liquid between the wafer edge and the detection platform 100 and lifting the wafer, using the action of the liquid to weaken the surface tension of the water film, and gradually filling the low-pressure area formed below the wafer due to the water film discharging air, thereby reducing the adsorption effect of atmospheric pressure on the wafer, so that the wafer can be more easily separated from the detection platform 100.

[0101] The wafer membrane detection pick-and-place method of the present disclosure includes two main steps: placing the wafer and picking up the wafer, as follows:

[0102] Placing the wafer is a prerequisite for membrane detection, and a uniform liquid film needs to be formed to improve the optical properties of the film so that the camera can clearly capture the image of the back of the wafer. This stage focuses on solving the problems of imaging distortion caused by air bubbles and damage caused by impact.

[0103] Before wafer membrane detection, first inject a transparent liquid into the water injection groove 131 of the detection platform 100. When injecting the transparent liquid, inject water through the water injection hole 141 of the annular water groove 140, and the liquid slowly flows into the water injection groove 131 through the water outlet gap 150 until the amount of liquid reaches the appropriate level. The injected transparent liquid is deionized water, which needs to meet the detection requirements in terms of purity to avoid impurities affecting the detection results. The injection process can be carried out in stages, first injecting at a low speed to form an initial cover, and then injecting at a high speed to complete the filling, in order to balance the water injection speed and reduce the generation of air bubbles.

[0104] Then, place the wafer on the transparent liquid: use an inclined method to avoid air bubbles being rolled in directly by placing it flat. The specific steps are: first contact one end of the wafer with the transparent liquid, and tilt the wafer with the transparent liquid and the detection platform 100; then contact the other end of the wafer with the transparent liquid.

[0105] This placement method can expel air bubbles in the transparent liquid, allowing the wafer to be placed more stably on the transparent liquid, reducing the problem of inaccurate detection results caused by air bubbles and the problem of uneven liquid film caused by liquid fluctuations or wafer shaking during the placement process. For example, when placing the wafer, the lifting mechanism 200 controls the wafer carrier 210 to tilt and slowly descend, allowing one end of the wafer to first contact the transparent liquid, then continue to slowly descend and adjust the angle, allowing the other end to also smoothly contact the liquid, and finally allowing the wafer to be placed stably on the transparent liquid, forming a liquid film between the back of the wafer and the transparent plate 120 of the detection platform 100.

[0106] In alternative embodiments, the bubble can also be removed in other ways when the wafer is placed obliquely, such as using a vacuum pump to perform vacuum treatment on the water injection tank 131, so that the bubble is removed under the action of negative pressure, and then the wafer is placed on the transparent liquid. The oblique angle can be dynamically optimized, that is, the initial contact point is detected by the vision system, and then the angle is adjusted in real time, so that the bubble is minimized. Bubble reduction directly improves detection accuracy, avoids the problem of image distortion affecting the accuracy of detection results, reduces buffer, reduces mechanical impact, and prevents thin wafers from breaking, especially suitable for processing of ultra-thin wafers.

[0107] Then, after the liquid film is formed between the back of the wafer and the detection platform 100, the excess transparent liquid outside the wafer of the detection platform 100 is extracted. By starting the suction operation through the water extraction hole 142 of the annular water tank 140, the liquid outside the wafer edge in the water injection tank 131 is removed. The water extraction process lasts for a period of time to ensure that only the necessary liquid film under the wafer is retained. In alternative embodiments, water extraction can be performed in regions, first sucking the annular region outside the wafer, and then sucking the more peripheral region, to avoid disturbance of the liquid film; or combined with the water injection hole 141 fine adjustment, to maintain the constant thickness of the liquid film. The beneficial effects of this step are: the uniformity of the liquid film is improved, the contrast of the detection imaging is enhanced; the excess liquid is prevented from splashing onto the detection equipment, ensuring the stability of the detection environment; and the complexity of liquid management during subsequent wafer taking is reduced, indirectly improving the operation reliability.

[0108] The above wafer taking is the core innovation of the method, which directly solves the problem of wafer taking damage caused by the above-mentioned suction force. The whole step weakens the surface tension and atmospheric pressure suction by applying liquid to the edge of the wafer and controlling the lifting process. Specifically as follows:

[0109] After the wafer is detected by the membrane, liquid is applied to the area between the edge of the wafer and the detection platform 100. The specific operation is: through the water injection hole 141 of the annular water tank 140, the liquid is injected into the water outlet gap 150 at a controllable flow rate. The liquid flows into the water outlet gap 150 and fills the small gap under the wafer. The working principle of this step is: the newly injected liquid offsets the surface tension of the water film, reduces the suction force by increasing the interfacial energy, and balances the low pressure area, and the liquid filling reduces the pressure difference.

[0110] Then, after the liquid level reaches the first height, the wafer is lifted. The specific value of the first height is determined according to factors such as the size of the wafer, the properties of the film, and the properties of the liquid. For example, for a wafer with a diameter of 300 mm, the first height can be set to 5-10 mm. The working principle of this step is that when the liquid level reaches the first height, the liquid has fully penetrated the edge gap, effectively neutralizing the surface tension and balancing the air pressure, avoiding sudden changes in adsorption force at the initial lifting stage. In specific implementations, the water level can be detected by a liquid level sensor, and the sensor signal triggers the controller to start lifting after a delay, ensuring that the liquid is stable. In alternative embodiments, the first height can be dynamically adjusted: if the wafer curvature anomaly is detected, the height is automatically increased; or the height threshold is optimized in combination with the wafer material. The beneficial effects of this step are: avoiding the phenomenon of sticking caused by premature lifting, improving the success rate of wafer picking; reducing sudden stress and reducing the risk of wafer edge micro-cracks.

[0111] Further, after the liquid level reaches the first height, the wafer is lifted and the liquid is applied to the area between the wafer edge and the detection platform 100 simultaneously. The specific process is: the controller starts the lifting mechanism 200 to lift the wafer, while continuously injecting water; lifting and water injection are synchronized by the same clock signal, ensuring that the time error is within a controllable range. Synchronous operation maintains continuous replenishment of the edge liquid film, filling the space below in real time and continuously weakening the adsorption force. For example, the newly injected liquid compensates for the volume increase caused by lifting during the lifting process, preventing vacuum regeneration.

[0112] For example, the synchronization mechanism can be divided into primary synchronization and real-time synchronization. Primary synchronization: fixed lifting speed and constant water injection flow rate; Real-time synchronization: detect the lifting force of the wafer through a force sensor, and dynamically adjust based on force sensor feedback - if the lifting force suddenly increases, automatically increase the water injection flow rate.

[0113] For example, after the liquid level reaches the first height, the lifting speed of the wafer is lower than the rising speed of the liquid level. The slower lifting speed ensures that the liquid fills the space below in time, maintains dynamic balance of pressure, and avoids the regeneration of low-pressure areas. In alternative embodiments, the speed ratio can be self-adaptive: if the liquid level sensor detects that the liquid level rises behind schedule, the lifting speed is automatically reduced; or a non-linear speed curve is used to match the changes in adsorption force.

[0114] The control of the wafer lifting speed and the liquid level rising speed can also use an intermittent control method, i.e., the wafer is lifted for a certain distance and then stopped, and after the liquid fills to a certain height, the lifting continues. This method can eliminate microscopic stress concentration and reduce hidden damage; improve the stability of wafer picking, reduce the failure rate of operation, and indirectly improve the utilization rate of equipment.

[0115] After the wafer is separated from the detection platform 100, the liquid between the wafer and the detection platform 100 is extracted to separate the liquid from the wafer. When the lifting mechanism 200 is lifted to the preset height, the water extraction operation is triggered to remove the residual liquid. After the wafer is separated from the detection platform 100, the liquid is extracted to separate the wafer from the liquid, which facilitates subsequent wafer removal and detection platform 100 cleaning and maintenance, and also avoids the adverse effects of liquid residue on subsequent detection operations or other process steps.

[0116] In summary, the complete flow of the pick-and-place method is as follows: injecting transparent liquid, tilting the wafer, extracting excess liquid, detection, injecting edge liquid, liquid level reaching the first height, synchronous lifting and water injection, and water extraction after separation. The whole process is automated, reasonable in time consumption, and ensures detection efficiency.

[0117] Optionally, after the liquid is separated from the wafer, the wafer is removed by the mechanical hand 300, such as grabbing the wafer carrier to the outside of the detection platform 100.

[0118] As can be seen, the above embodiments are all around the core inventive concept: systematic weakening of the adsorption force through the synergy of liquid application and lifting control. Realization: surface tension weakening, newly injected liquid increasing interfacial energy, reducing adsorption force; low pressure balance, liquid filling eliminating pressure difference, avoiding atmospheric pressure adsorption; force distribution optimization, synchronous operation and speed control making the stress uniform, reducing shear force peak. These mechanisms are used to solve the above technical problems, reduce the risk of product damage, and improve the product yield in the detection link.

[0119] In summary, a pick-and-place method for wafer membrane detection includes:

[0120] Step S100: Before wafer membrane detection, water is injected on the detection platform, one end of the wafer is first contacted with the water, the wafer and the water are tilted, and the other end of the wafer is contacted with the water to form a water film between the back of the wafer and the detection platform.

[0121] Step S200: After the water film is formed between the back of the wafer and the detection platform, the excess water outside the wafer on the detection platform is extracted.

[0122] Step S300: After wafer membrane detection, water is injected into the area between the edge of the wafer and the detection platform, and the wafer is lifted until the wafer is separated from the detection platform.

[0123] Step S400: After the wafer is separated from the detection platform, the liquid between the wafer and the detection platform is extracted to separate the wafer from the water.

[0124] Step S500: When the lifting claw is lifted to the discharge position height, the mechanical hand removes the wafer.

[0125] The scheme effectively solves the wafer adsorption problem caused by water film surface tension and low pressure area in the background technology by applying liquid to the area between the wafer edge and the detection platform when the wafer is taken out and synchronously lifting the wafer. The specific working principle is as follows: in the placement stage, a transparent liquid is injected to form a uniform liquid film, the water is in contact with the film on the back of the wafer to improve the optical properties, and the detection is facilitated; in the taking-out stage, the liquid is applied to the edge area to fill the small gap between the wafer and the detection platform, offset the surface tension effect, and balance the air pressure below the wafer to avoid the formation of a low pressure area. This significantly reduces the adsorption force, reduces the pulling force and shear force in the lifting process, thereby preventing the wafer from being scratched or broken during the wafer taking operation.

[0126] In the embodiment, the operations of lifting the wafer and applying the liquid are performed synchronously, which can continuously ensure that there is liquid filling below the wafer, maintain the weakening effect of atmospheric pressure, and enable the wafer to be in a relatively stable stress state during the entire lifting process. Controlling the wafer lifting speed to be lower than the liquid surface rising speed can ensure that the liquid can always fill the space below the wafer in a timely manner during the wafer lifting process, and continuously weaken the adsorption effect of atmospheric pressure on the wafer.

[0127] The implementation of the scheme significantly reduces the pulling force and shear force that the wafer receives during the wafer taking operation, reduces the risk of product damage, and improves the product yield. By placing the wafer in an inclined manner, the distortion of the detection image caused by air bubbles is effectively avoided, and the accuracy of backside defect detection is improved. By pumping out the excess transparent liquid, the liquid film is more uniform, and the imaging effect and detection accuracy during detection are improved.

[0128] In the description of the present specification, the description of the terms "one embodiment / way", "some embodiments / ways", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments / ways or examples. In addition, the skilled person in the art can combine and combine the features of different embodiments / ways or examples described in the present specification without contradiction.

[0129] Those skilled in the art should understand that the above embodiments are only for clearly illustrating the present disclosure, and are not intended to limit the scope of the present disclosure. Based on the above disclosure, other changes or modifications can also be made by those skilled in the art, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A wafer transillumination film inspection device, characterized in that, The application relates to a wafer detection device. The device comprises: a detection platform for carrying a wafer; at least two lifting mechanisms arranged on opposite sides of the detection platform and used for driving two ends of the wafer to move up and down so as to place the wafer on the detection platform or lift the wafer from the detection platform, wherein the detection platform comprises a platform body provided with a mounting opening, a transparent plate fixedly arranged on the inner side of the mounting opening and used for forming a liquid film between the transparent liquid and the wafer, and a waterproof ring in the shape of a ring and sealingly connected to the upper surface of the platform body, the waterproof ring being arranged around the transparent plate to form a water injection groove on the upper surface of the platform body and the transparent plate, wherein an annular water groove is formed between the outer wall of the transparent plate and the inner wall of the mounting opening, the annular water groove is arranged around the transparent plate and is provided with a water injection hole and a water suction hole, an annular water outlet gap is formed between the upper surface of the transparent plate and the inner wall of the mounting opening, the water outlet gap is communicated with the annular water groove, and the water outlet gap, the annular water groove and the transparent plate have a common central axis.

2. The pick-and-place device for wafer through membrane inspection according to claim 1, wherein, Each of the lifting mechanisms comprises: a wafer carrier movably arranged above the platform body and provided with an opening for placing the wafer, a lifting claw movably arranged on the platform body and located below the wafer carrier, and a driving mechanism fixedly arranged on the platform body and connected with the lifting claw and used for driving the lifting claw to move up and down, wherein the two lifting claws are respectively used for supporting two ends of the wafer carrier in opposite positions, the platform body is provided with a groove matched with the shape of the lifting claw, and when the wafer carrier is located at the bottom end of the stroke, the lifting claw is at least partially sunk into the groove so that the wafer is in contact with the transparent plate.

3. A pick-and-place method for wafer through film inspection, for use in the pick-and-place apparatus for wafer through film inspection according to claim 1 or 2, characterized by, The method comprises the following steps: placing the wafer: before wafer film detection, transparent liquid is injected on the detection platform, and the wafer is placed on the transparent liquid to form a liquid film between the back of the wafer and the detection platform; taking out the wafer: after wafer film detection, liquid is applied to the area between the edge of the wafer and the detection platform, and the wafer is lifted until the wafer is separated from the detection platform.

4. The pick-and-place method for wafer through membrane inspection according to claim 3, wherein, The wafer is lifted after liquid is applied to the area between the edge of the wafer and the detection platform and the liquid level reaches a first height.

5. The pick-and-place method for wafer through membrane inspection according to claim 4, wherein, The wafer is lifted and liquid is applied to the area between the edge of the wafer and the detection platform simultaneously after the liquid level reaches the first height.

6. The pick-and-place method for wafer through membrane inspection according to claim 5, wherein, The lifting speed of the wafer is lower than the rising speed of the liquid level after the liquid level reaches the first height.

7. The pick-and-place method for wafer through membrane inspection according to claim 3, wherein, After the wafer is separated from the detection platform, the liquid between the wafer and the detection platform is pumped out so that the liquid is separated from the wafer.

8. The pick-and-place method for wafer through membrane inspection according to claim 3, wherein, The wafer is placed on the transparent liquid by the following steps: one end of the wafer is first in contact with the transparent liquid, the wafer and the transparent liquid and the detection platform are inclined, and then the other end of the wafer is in contact with the transparent liquid.

9. The pick-and-place method for wafer through membrane inspection according to claim 3, wherein, After the liquid film is formed between the back of the wafer and the detection platform, the excess transparent liquid outside the wafer is pumped out of the detection platform.

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