Wafer detection system and method

Abstract

The invention discloses a wafer detection system and method. The system comprises a motion control assembly, a probe detection platform and a control module, a wafer is arranged on the motion control assembly; the probe detection platform comprises a plurality of probes; the motion control assembly is used for driving the wafer to approach the probe detection platform under the current control instruction output by the control module so as to enable each probe to detect each chip in the wafer; and the control module is also used for determining the contact force between each chip and the corresponding probe according to the current control instruction when the wafer approaches the probe detection platform. According to the scheme, the wafer testing efficiency is improved, and meanwhile, the contact force of each chip and each probe in the wafer can be accurately detected in the testing process.

Description

Technical Field

[0001] The present invention relates to the field of wafer inspection technology, and in particular to a wafer inspection system and method. Background Technology

[0002] Chips are integrated onto wafers. To prevent defective chips from appearing in subsequent production and to improve production yield, the wafers need to be inspected before chip use. In related technologies, the wafer is placed on a slide, and the probes of the wafer testing equipment contact the wafer to perform inspection. At this inspection stage, since the chip has not yet been diced and packaged, early inspection removes unqualified bare dies, avoiding unnecessary packaging costs, improving the yield of the final product, and the test results can be quickly fed back to the front-end manufacturing process to help quickly identify and correct problems in production, optimize manufacturing processes, and ensure consistent performance.

[0003] Traditional wafer testing equipment uses probes / probe cards that are fixed on an up-and-down sliding mechanism. As the complexity of chips increases and the number of probes grows, the wire harnesses connected to the probe card may exceed hundreds, and the weight of the probe card increases. This leads to a decrease in the efficiency of probe card movement, which in turn reduces the efficiency of wafer testing. Summary of the Invention

[0004] This invention provides a wafer inspection system and method that can improve the efficiency of wafer testing and accurately detect the contact force between each chip and each probe within the wafer during the testing process.

[0005] To achieve the above objectives, in a first aspect, embodiments of the present invention provide a wafer inspection system, which includes: a motion control component, a probe inspection platform, and a control module;

[0006] The motion control component is equipped with a wafer; the probe detection platform includes multiple probes; the motion control component is used to drive the wafer closer to the probe detection platform under the current control command output by the control module so that each probe can detect each chip in the wafer.

[0007] The control module is also used to determine the contact force between each chip and the corresponding probe according to the current control command when the wafer approaches the probe detection platform.

[0008] Optionally, the control module is further configured to increase the output current command and determine the magnitude of the change in contact force between any chip and the corresponding probe after the wafer approaches the probe detection platform;

[0009] The probe is also used to determine the changing contact resistance between itself and the corresponding chip based on real-time detected electrical data when the control module increases the output current command, in order to determine the contact force-contact resistance model.

[0010] The control module determines whether the probe is dirty or whether the probe is aged based on the contact force-contact resistance model and the preset contact force-contact resistance model.

[0011] Optionally, the control module determines whether the probe is dirty or aged based on the contact force-contact resistance model and a preset contact force-contact resistance model, specifically:

[0012] When the contact resistance of the preset contact force in the contact force-contact resistance model is greater than the contact resistance of the preset contact force in the preset contact force-contact resistance model, it is determined that the probe is dirty or the probe is aged.

[0013] Optionally, the motion control component includes a magnetically levitated stator and a magnetically levitated mover.

[0014] Optionally, the control module is further configured to determine the contact force between each chip and its corresponding probe according to the current control command, specifically:

[0015] The real-time acceleration of each chip's motion is determined according to the current control command;

[0016] The contact force between each chip and its corresponding probe is determined based on the current control command, the electromagnetic force generated by the unit current, and the real-time acceleration.

[0017] Optionally, the magnetically levitated stator includes a first coil array and a first sensor circuit board for detecting the position information of the magnetically levitated mover; the magnetically levitated mover includes a permanent magnet array;

[0018] The first coil array includes at least two parallel, overlapping first coil sub-arrays, and a first magnetic field sensor array is arranged on the first sensor circuit board; the first sensor circuit board is sandwiched between the two layers of the first coil sub-arrays.

[0019] Optionally, the first coil subarray comprises coils arranged in a uniform manner.

[0020] Optionally, the magnetically levitated mover includes a second coil array and a second sensor circuit board for detecting the position information of the magnetically levitated mover; the magnetically levitated stator includes a permanent magnet array;

[0021] The second coil array includes at least two parallel, overlapping second coil sub-arrays, and a second magnetic field sensor array is arranged on the second sensor circuit board; the second sensor circuit board is sandwiched between the two layers of the second coil sub-arrays.

[0022] Secondly, embodiments of the present invention also provide a wafer inspection method, which is applied to the wafer inspection system described in the first aspect above, comprising:

[0023] Under the current control command output by the control module, the motion control component moves the wafer closer to the probe detection platform so that each probe can detect each chip in the wafer;

[0024] As the wafer approaches the probe detection platform, the control module determines the magnitude of the contact force between each chip and the corresponding probe according to the current control command.

[0025] Optionally, the wafer inspection also includes:

[0026] After the wafer approaches the probe detection platform, the control module increases the output current command and determines the magnitude of the changing contact force between any chip and the corresponding probe.

[0027] When the control module increases the output current command, the probe determines the changing contact resistance between itself and the corresponding chip based on the real-time detected electrical data to determine the contact force-contact resistance model.

[0028] The control module determines whether the probe is dirty or aged based on the contact force-contact resistance model and a preset contact force-contact resistance model.

[0029] In this embodiment of the invention, a wafer is placed on a motion control component; under the current control command output by the control module, the motion control component moves the wafer closer to the probe detection platform so that each probe can detect each chip in the wafer; this improves the efficiency of wafer testing; at the same time, when the wafer moves closer to the probe detection platform, the control module determines the contact force between each chip and the corresponding probe according to the current control command, so that the contact force between each chip and each probe in the wafer can be accurately detected during the testing process.

[0030] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the structure of a wafer inspection system provided in an embodiment of the present invention;

[0033] Figure 2 This is a schematic diagram of the specific structure of a wafer inspection system provided in an embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the specific structure of a motion control component provided in an embodiment of the present invention;

[0035] Figure 4 This is a schematic diagram of the specific structure of another motion control component provided in an embodiment of the present invention;

[0036] Figure 5 This is a schematic flowchart of a wafer inspection method provided in an embodiment of the present invention;

[0037] Figure 6 This is a schematic flowchart of another wafer inspection method provided in an embodiment of the present invention. Detailed Implementation

[0038] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0039] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0040] Figure 1 This is a schematic diagram of the structure of a wafer inspection system provided in an embodiment of the present invention, as shown below. Figure 1 As shown, the wafer inspection system includes: a motion control component 10, a probe inspection platform 20, and a control module 30;

[0041] A wafer A is mounted on the motion control component 10; a probe detection platform 20 includes multiple probes 21; the motion control component 10 is used to drive the wafer A toward the probe detection platform 20 under the current control command output by the control module 30 so that each probe 21 can detect each chip in the wafer A; the control module 30 is also used to determine the contact force between each chip and the corresponding probe 11 according to the current control command when the wafer A moves toward the probe detection platform 10.

[0042] In this embodiment, the motion control component 10 can drive wafer A to approach the probe detection platform 10 under the current control command output by the control module 30, thereby enabling the detection of each chip within wafer A. It is understood that the motion control component 20 can be any current-driven motion component, and the motion control component 10 can be a magnetic levitation planar motor, stepper motor, etc. This embodiment does not limit the specific type of the motion control component 10. Detecting each chip within wafer A can include performing electrical performance tests on each chip within wafer A, such as leakage current detection, voltage detection, and current detection.

[0043] The probe testing platform 20 includes multiple probes 21; specifically, the multiple probes 21 are used to test each chip in the wafer; the height of the multiple probes 21 is fixed; when the wafer A approaches the probe testing platform 20, the control module 30 can accurately determine the contact force between each chip and each probe according to the current control command based on the kinematic principle, thus solving the problem in the prior art that the contact force between each chip and each probe cannot be determined during the testing of each chip in the wafer A;

[0044] In this embodiment of the invention, the motion control component 10, under the current control command output by the control module 30, drives wafer A to approach the probe detection platform 20 to detect the chips within wafer A. This improves the efficiency of chip testing, thereby increasing the efficiency of wafer detection and avoiding the problem of low testing efficiency caused by the large number of wires under each probe when the probes on the probe detection platform 20 approach each chip. When the wafer approaches the probe detection platform 20, the control module 30 determines the contact force between each chip and its corresponding probe according to the current control command. Thus, this embodiment can also accurately detect the contact force between each chip and its corresponding probe during the testing process.

[0045] Optional, continue to refer to Figure 1The control module 30 is also used to gradually increase the output current command and determine the magnitude of the changing contact force between any chip and the corresponding probe after the wafer A approaches the probe detection platform 20; the probe 11 is also used to determine the changing contact resistance between itself and the corresponding chip based on the real-time detected electrical data when the control module 30 increases the output current command, so as to determine the contact force-contact resistance model.

[0046] The control module 30 determines whether the probe is dirty or aged based on the contact force-contact resistance model and the preset contact force-contact resistance model.

[0047] The preset contact force-contact resistance model is a model in which the contact resistance between any chip and its corresponding probe (without contaminants or aging) decreases according to a certain rule as the contact force increases after the wafer approaches the probe detection platform 20. In this embodiment, after the wafer approaches the probe detection platform 20, the output current command is gradually increased and the magnitude of the changing contact force between any chip and its corresponding probe is determined, with the magnitude of the changing contact force gradually increasing. When the control module 30 increases the output current command, the probe 11 determines the changing contact resistance with the corresponding chip based on the real-time detected voltage and current data, thereby determining the contact force-contact resistance model. If the contact force-contact resistance model does not match the preset contact force-contact resistance model, it can be determined that there is contamination on the probe or the probe is aged. If the contact force-contact resistance model matches the preset contact force-contact resistance model, it means that there is no contamination on the probe or the probe is not aged.

[0048] Optional, continue to refer to Figure 1 The control module 30 determines whether the probe is dirty or aged based on the contact force-contact resistance model and the preset contact force-contact resistance model. Specifically, when the contact resistance of the preset contact force in the contact force-contact resistance model is greater than the contact resistance of the preset contact force in the preset contact force-contact resistance model, it is determined that the probe is dirty or aged.

[0049] Alternatively, in some embodiments, the control module 30 can determine that the probe is dirty or the probe is aging when the contact force of the preset contact resistance on the contact force-contact resistance model is greater than the contact force of the preset contact resistance on the preset contact force-contact resistance model.

[0050] Optional, Figure 2 This is a schematic diagram of a specific structure of a wafer inspection system provided in an embodiment of the present invention; as shown below. Figure 2As shown, the motion control component 10 includes a magnetically levitated stator 11 and a magnetically levitated mover 12. In this embodiment, the current control command output by the control module 30 is sent to the magnetically levitated stator 11. The interaction force between the magnetically levitated stator 11 and the magnetically levitated mover 12 can be used to move wafer A closer to the probe detection platform 20 so that each probe 21 can detect each chip in wafer A.

[0051] Optional, continue to refer to Figure 2 The control module 30 is also used to determine the contact force between each chip and its corresponding probe 11 according to the current control command. Specifically, it determines the real-time acceleration of each chip's movement according to the current control command and determines the contact force between each chip and its corresponding probe according to the current control command, the electromagnetic force generated by the unit current, and the real-time acceleration.

[0052] Specifically, the real-time acceleration az(t) of each chip's motion is determined according to the current control command; az(t) can be obtained by performing a second differential operation on the real-time position signal z(t); z(t) can be determined according to the current control command.

[0053] The contact force of each probe on each chip is determined based on the current control command, the electromagnetic force generated by the unit current, and the real-time acceleration. Specifically:

[0054] The sum of the contact forces between each chip and each probe:

[0055] F(t)=Kf(z)*Iz(t)-Mtotal*g-Mtotal*az(t);

[0056] Wherein, Kf(z)*Iz(t) represents the total electromagnetic driving force driving the vertical movement of the magnetic levitation mover 12; Iz(t) represents the real-time driving current corresponding to the vertical movement of the magnetic levitation mover 12, which is the current control command; Kf(z) represents the force-current coefficient; this coefficient is not a constant value, but a function related to the vertical position z(t) of the magnetic levitation mover 12, which represents the electromagnetic force that a unit current can generate at different working heights; Mtotal*g represents the total gravity of the system (magnetic levitation mover 12 and crystal A); Mtotal*az(t) represents the dynamic inertial force of the system. It can be understood that the contact force of each chip corresponding to each probe is determined by averaging F(t) according to the number of corresponding chips.

[0057] Optional, Figure 3 This is a schematic diagram of a specific structure of a motion control component provided in an embodiment of the present invention; as shown below. Figure 3As shown, in some embodiments, the magnetically levitated stator 11 includes a first coil array 111 and a first sensor circuit board 112 for detecting the position information of the magnetically levitated mover 12; the magnetically levitated mover 12 includes a permanent magnet array; the first coil array 111 includes at least two layers of parallel, overlapping first coil sub-arrays 1111; a first magnetic field sensor array 113 is arranged on the first sensor circuit board 112; the first sensor circuit board 112 is sandwiched between the two layers of first coil sub-arrays 1111. In this embodiment, the motion control component 10 uses a moving magnet type magnetically levitated mover 12, and the motion control component 10 can drive the wafer A to move closer to the probe detection platform 20 via the control module 30.

[0058] Optional, continue to refer to Figure 3 The first coil subarray 1111 includes uniformly arranged coils. The coils can be circular or rectangular; this embodiment does not limit the shape of the coils.

[0059] Optional, Figure 4 This is a schematic diagram of the specific structure of another motion control component provided in an embodiment of the present invention; as shown below. Figure 4 As shown, in some embodiments, the magnetically levitated mover 12 includes a second coil array 121 and a second sensor circuit board 122 for detecting the position information of the magnetically levitated mover 12; the magnetically levitated stator 11 includes a permanent magnet array; the second coil array 121 includes at least two layers of parallel, overlapping second coil sub-arrays 1211, and a second magnetic field sensor array 123 is arranged on the second sensor circuit board 122; the second sensor circuit board 122 is sandwiched between the two layers of second coil sub-arrays 1211. In this embodiment, the motion control component 10 uses a moving coil type magnetically levitated mover 12, and the motion control component 10 can drive the wafer A to move closer to the probe detection platform 20 via the control module 30.

[0060] Based on the same inventive concept, this invention also provides a wafer inspection method, which is applied to the wafer inspection system described above. Figure 5 This is a schematic flowchart of a wafer inspection method provided in an embodiment of the present invention, as shown below. Figure 5 As shown, the wafer inspection method includes:

[0061] S110. Under the current control command output by the control module, the motion control component drives the wafer to approach the probe detection platform to detect the chips inside the wafer.

[0062] S120. When the wafer approaches the probe detection platform, the control module determines the contact force between each chip and each probe according to the current control command.

[0063] In this embodiment of the invention, the motion control component, under the current control command output by the control module, moves the wafer closer to the probe detection platform to detect the chips within the wafer. This improves the testing efficiency of each chip, thereby increasing the overall testing efficiency of the wafer and avoiding the problem of low testing efficiency caused by probes on the probe detection platform moving closer to each chip. When the control module moves the wafer closer to the probe detection platform, it determines the contact force between each chip and each probe according to the current control command. This also enables accurate detection of the contact force between each chip and its corresponding probe during the testing process.

[0064] Optionally, based on the above embodiments, further optimizations can be made. Figure 6 This is a schematic flowchart of another wafer inspection method provided in an embodiment of the present invention; as shown. Figure 6 As shown, the wafer inspection method includes:

[0065] S210. Under the current control command output by the control module, the motion control component drives the wafer to move closer to the probe detection platform to detect the chips inside the wafer.

[0066] S220. When the wafer approaches the probe detection platform, the control module determines the contact force between each chip and each probe according to the current control command.

[0067] S230. After the wafer approaches the probe detection platform, the control module increases the output current command and determines the magnitude of the changing contact force. When the control module increases the output current command, the probe determines the changing contact resistance between itself and the corresponding chip based on the real-time detected electrical data to determine the contact force-contact resistance model. The control module determines whether there is dirt or aging on the probe based on the contact force-contact resistance model and the preset contact force-contact resistance model.

[0068] In this embodiment of the invention, based on the above embodiments, it is further determined whether there is dirt or aging on the probe according to the contact force-contact resistance model and the preset contact force-contact resistance model.

[0069] Note that the above description is merely a preferred embodiment of the present invention and the technical principles employed. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and various obvious changes, readjustments, and substitutions can be made without departing from the scope of protection of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and may include many other equivalent embodiments without departing from the concept of the present invention, the scope of which is determined by the scope of the appended claims.

Claims

1. A wafer inspection system, characterized in that, include: Motion control components, probe detection platform and control module; The motion control component is equipped with a wafer; the probe detection platform includes multiple probes; the motion control component is used to drive the wafer closer to the probe detection platform under the current control command output by the control module so that each probe can detect each chip in the wafer. The control module is further configured to determine the magnitude of the contact force between each chip and the corresponding probe according to the current control command when the wafer approaches the probe detection platform.

2. The wafer inspection system according to claim 1, characterized in that, The control module is also used to increase the output current command and determine the magnitude of the change in contact force between any chip and the corresponding probe after the wafer approaches the probe detection platform; The probe is also used to determine the changing contact resistance between itself and the corresponding chip based on real-time detected electrical data when the control module increases the output current command, in order to determine the contact force-contact resistance model. The control module determines whether the probe is dirty or whether the probe is aged based on the contact force-contact resistance model and the preset contact force-contact resistance model.

3. The wafer inspection system according to claim 2, characterized in that, The control module determines whether the probe is dirty or aged based on the contact force-contact resistance model and a preset contact force-contact resistance model. Specifically: When the contact resistance of the preset contact force in the contact force-contact resistance model is greater than the contact resistance of the preset contact force in the preset contact force-contact resistance model, it is determined that the probe is dirty or the probe is aged.

4. The wafer inspection system according to claim 1, characterized in that, The motion control component includes a magnetically levitated stator and a magnetically levitated mover.

5. The wafer inspection system according to claim 4, characterized in that, The control module is further configured to determine the contact force between each chip and its corresponding probe according to the current control command, specifically: The real-time acceleration of each chip's motion is determined according to the current control command; The contact force between each chip and its corresponding probe is determined based on the current control command, the electromagnetic force generated by the unit current, and the real-time acceleration.

6. The wafer inspection system according to claim 4, characterized in that, The magnetically levitated stator includes a first coil array and a first sensor circuit board for detecting the position information of the magnetically levitated mover; the magnetically levitated mover includes a permanent magnet array; The first coil array includes at least two parallel, overlapping first coil sub-arrays, and a first magnetic field sensor array is arranged on the first sensor circuit board; the first sensor circuit board is sandwiched between the two layers of the first coil sub-arrays.

7. The wafer inspection system according to claim 6, characterized in that, The first coil subarray comprises coils arranged in a uniform manner.

8. The wafer inspection system according to claim 4, characterized in that, The magnetically levitated mover includes a second coil array and a second sensor circuit board for detecting the position information of the magnetically levitated mover; the magnetically levitated stator includes a permanent magnet array. The second coil array includes at least two parallel, overlapping second coil sub-arrays, and a second magnetic field sensor array is arranged on the second sensor circuit board; the second sensor circuit board is sandwiched between the two layers of the second coil sub-arrays.

9. A wafer inspection method, characterized in that, The wafer inspection system according to any one of claims 1-8 comprises: Under the current control command output by the control module, the motion control component moves the wafer closer to the probe detection platform so that each probe can detect each chip in the wafer; As the wafer approaches the probe detection platform, the control module determines the magnitude of the contact force between each chip and the corresponding probe according to the current control command.

10. The wafer inspection method according to claim 9, characterized in that, Also includes: After the wafer approaches the probe detection platform, the control module increases the output current command and determines the magnitude of the changing contact force between any chip and the corresponding probe. When the control module increases the output current command, the probe determines the changing contact resistance between itself and the corresponding chip based on the real-time detected electrical data to determine the contact force-contact resistance model. The control module determines whether the probe is dirty or whether the probe is aged based on the contact force-contact resistance model and the preset contact force-contact resistance model.

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