Wafer testing device and testing method

Abstract

The embodiment of the invention discloses a wafer testing device and a wafer testing method. The wafer testing device comprises a testing machine, a vibration meter, a probe station and a substrate. Wherein the test machine is in communication connection with the vibration meter and the wafer to be tested, the wafer to be tested is located on the substrate, the wafer to be tested and the substrate are placed on the probe station, and the vibration meter is located above the wafer to be tested; the substrate is an unsealed substrate, and the bottom of the substrate is sealed; the testing machine is used for transmitting a first signal to a crystal grain on a wafer to be tested so as to enable a vibrating membrane of the crystal grain to vibrate; the vibration meter is used for generating a second signal when the vibrating diaphragm vibrates, and the testing machine is further used for receiving the second signal and determining the state of the wafer to be tested according to the second signal and the first signal. According to the wafer testing device and the wafer testing method provided by the embodiment of the invention, vibration testing can be realized, and the testing reliability can be ensured.

Description

Technical Field

[0001] The embodiments of the present invention relate to wafer testing technology, and more particularly to a wafer testing apparatus and testing method. Background Technology

[0002] As the substrate for chips such as silicon-based chips, wafers are a crucial component of chips. During the manufacturing process, wafers require testing to ensure their performance. Currently, existing wafer testing equipment typically performs open-circuit, short-circuit, and capacitance tests, but lacks vibration testing. Summary of the Invention

[0003] This invention provides a wafer testing apparatus and testing method to achieve vibration testing and ensure testing reliability.

[0004] In a first aspect, embodiments of the present invention provide a wafer testing apparatus, comprising: a testing machine, a vibration meter, a probe station, and a substrate;

[0005] The testing machine is communicatively connected to the vibration meter and the wafer under test. The wafer under test is located on the substrate, and the wafer under test and the substrate are placed on the probe station. The vibration meter is located above the wafer under test. The substrate is an open substrate, and the bottom of the substrate is closed.

[0006] The testing machine is used to transmit a first signal to the die on the wafer to be tested, so as to cause the diaphragm of the die to vibrate; the vibration meter is used to generate a second signal when the diaphragm vibrates; the testing machine is also used to receive the second signal and determine the state of the wafer to be tested based on the second signal and the first signal.

[0007] Optionally, the substrate is a ring structure with an internal recessed area.

[0008] Optionally, the inner circular region of the annular structure is provided with a support pillar, which is used to support the wafer to be tested.

[0009] Optionally, the tester includes a pin card for transmitting signals output by the tester to the wafer under test.

[0010] Optionally, the pin card includes probes that are electrically connected to the signal interface of the wafer under test.

[0011] Optionally, the substrate is a glass substrate.

[0012] Optionally, the vibration meter is a laser vibration meter.

[0013] Optionally, the wafer to be tested is a silicon-based chip used to fabricate a microphone.

[0014] Secondly, embodiments of the present invention provide a wafer testing method, wherein the testing method is performed by the testing machine described in the first aspect, and the testing method includes:

[0015] Receive control commands;

[0016] According to the control command, a first signal is transmitted to the wafer under test;

[0017] The second signal transmitted by the vibration meter is received, and the state of the wafer to be tested is determined based on the second signal and the first signal.

[0018] Optionally, determining the state of the wafer under test based on the second signal and the first signal includes:

[0019] When the difference between the frequency of the first signal and the frequency of the second signal corresponding to each die on the wafer under test is within a preset range, it is determined that each die on the wafer under test is qualified.

[0020] When the difference value corresponding to at least one grain on the wafer under test exceeds the preset range, it is determined that at least one grain on the wafer under test is unqualified.

[0021] The wafer testing apparatus and method provided in this invention include a testing machine, a vibration meter, a probe station, and a substrate. The testing machine is communicatively connected to the vibration meter and the wafer under test. The wafer under test is located on the substrate, and the wafer and substrate are placed on the probe station. The vibration meter is positioned above the wafer under test. The substrate is not hermetically sealed, but its bottom is sealed. The testing machine transmits a first signal to the dies on the wafer under test, causing the diaphragm of the dies to vibrate. The vibration meter generates a second signal when the diaphragm vibrates. The testing machine also receives the second signal and determines the state of the wafer under test based on the second and first signals. The wafer testing apparatus and method provided in this invention determine the state of the wafer under test based on the second and first signals, thereby achieving vibration testing of the wafer under test. Furthermore, the non-hermetically sealed substrate prevents the vibration of the diaphragm of the dies from deviating from expectations due to substrate sealing, and the sealed bottom of the substrate protects the wafer under test and ensures testing reliability. Attached Figure Description

[0022] Figure 1 This is a structural block diagram of a wafer testing device provided in Embodiment 1 of the present invention;

[0023] Figure 2 This is a front view of a substrate provided in Embodiment 2 of the present invention;

[0024] Figure 3 This is a top view of a substrate provided in Embodiment 2 of the present invention;

[0025] Figure 4 This is a schematic diagram of a grain provided in Embodiment 2 of the present invention;

[0026] Figure 5 This is a schematic diagram of a fixing device provided in Embodiment 2 of the present invention;

[0027] Figure 6 This is a flowchart of a wafer testing method provided in Embodiment 3 of the present invention;

[0028] Figure 7 This is a schematic diagram of the waveform of a second signal provided in Embodiment 3 of the present invention;

[0029] Figure 8 This is a schematic diagram of the frequency of a second signal provided in Embodiment 3 of the present invention. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, and not all of the structures.

[0031] Example 1

[0032] Figure 1 This is a schematic diagram of a wafer testing device provided in Embodiment 1 of the present invention. (Reference) Figure 1 The wafer testing apparatus includes a tester 10, a vibration meter 20, a probe station 30, and a substrate 40. The tester 10 is communicatively connected to the vibration meter 20 and the wafer 50 to be tested. The wafer 50 to be tested is located on the substrate 40, and the wafer 50 and the substrate 40 are placed on the probe station 30. The vibration meter 20 is located above the wafer 50 to be tested. The substrate 40 is an open substrate, and the bottom of the substrate 40 is closed. The tester 10 is used to transmit a first signal to the die on the wafer 50 to cause the diaphragm of the die to vibrate. The vibration meter 20 is used to generate a second signal when the diaphragm vibrates. The tester 10 is also used to receive the second signal and determine the state of the wafer 50 to be tested based on the second signal and the first signal.

[0033] Specifically, when the wafer testing device tests the wafer 50 to be tested, the wafer 50 is attached to the substrate 40. The probe station's transport component 60 transports the substrate and the wafer to be tested to the testing area. The vibration meter is positioned directly above the wafer to ensure the testing effect of the vibration meter. Then, the testing machine transmits a first signal to a specific die on the wafer to be tested, such as transmitting a sine wave signal to a specific die on the wafer to be tested through a probe card set on the testing machine itself. The diaphragm of the die vibrates under the action of the sine wave signal. At this time, the vibration meter detects the vibration of the diaphragm of the die and generates a second signal. The vibration meter transmits the generated second signal to the testing machine, thereby testing each die on the wafer to be tested. The testing machine determines the state of the wafer under test based on a first signal and a second signal. For example, when the difference between the frequency of the first signal and the frequency of the second signal corresponding to each die on the wafer under test is within a preset range, all dies on the wafer under test are determined to be qualified. When the difference between the frequency of the first signal and the frequency of the second signal corresponding to at least one die on the wafer under test exceeds the preset range, at least one die on the wafer under test is determined to be unqualified. The substrate protects the die vibration film of the wafer under test. Furthermore, the substrate is not sealed to prevent the vibration of the die vibration film from deviating from expectations due to a sealed substrate. The bottom of the substrate is sealed, allowing the probe station's transport components, such as the pick-up arm, to transport the substrate and the wafer under test to the testing area without damaging the wafer.

[0034] The wafer testing apparatus provided in this embodiment includes: a testing machine, a vibration meter, a probe station, and a substrate. The testing machine is communicatively connected to the vibration meter and the wafer under test. The wafer under test is located on the substrate, and the wafer and substrate are placed on the probe station. The vibration meter is located above the wafer under test. The substrate is not hermetically sealed, and its bottom is sealed. The testing machine transmits a first signal to the dies on the wafer under test to cause the dies' vibration diaphragm to vibrate. The vibration meter generates a second signal when the diaphragm vibrates. The testing machine also receives the second signal and determines the state of the wafer under test based on the second and first signals. The wafer testing apparatus provided in this embodiment achieves vibration testing of the wafer under test by determining the state of the wafer under test based on the second and first signals. Furthermore, the non-hermetically sealed substrate prevents the vibration of the die's vibration diaphragm from deviating from expectations due to substrate sealing, and the sealed bottom of the substrate protects the wafer under test and ensures testing reliability.

[0035] Example 2

[0036] This embodiment is based on Embodiment 1. Figure 2 This is a front view of a substrate provided in Embodiment 2 of the present invention. Figure 3This is a top view of a substrate provided in Embodiment 2 of the present invention. (Reference) Figure 2 and Figure 3 Optionally, the substrate 40 is a ring structure with an internal recessed area.

[0037] For example, the outer circle of the annular structure is equal to the size of a 12-inch wafer (300mm), and the inner circle is slightly larger than the size of an 8-inch wafer (200mm, the wafer to be tested is an 8-inch wafer), so that the wafer to be tested can be attached to the recessed area of ​​the substrate 40. Figure 2 In the figure, the heights h1, h2, h3, and h4 represent the distance from the bottom of the substrate to the top of the wafer, the minimum height of the substrate bottom, the height of the support pillar, and the distance from the top of the support pillar to the bottom of the wafer, respectively. The widths d1, d2, d3, and d4 represent the outer diameter of the substrate annular structure, the inner diameter of the annular structure, the outer ring size of the substrate mesh, and the width of the support pillar, respectively. For example, the heights h1, h2, h3, and h4 are 1 mm, 0.5 mm, 0.4 mm, and 0.1 mm, respectively, and the widths d1, d2, d3, and d4 are 300 mm, 210 mm, 190 mm, and 3 mm, respectively. Figure 3 The blue area in the image represents the suction arm of the probe station. Figure 3 The red area in the middle indicates the vacuum suction position of the suction arm.

[0038] refer to Figure 3 Optionally, a support pillar 41 is provided in the inner circular region of the substrate 40, which is used to support the wafer to be tested.

[0039] Specifically, on the surface of the substrate 40 near the wafer to be tested, the support pillar 41 has a transverse support pillar 42 and a longitudinal support pillar 43 to ensure that after the wafer to be tested is attached to the substrate 40, the grain vibration film of the wafer to be tested is in a partially sealed environment, preventing the vibration effect from being affected by the grain vibration film of the wafer to be tested being in a completely sealed environment, thereby affecting the test effect.

[0040] In addition, such as Figure 3 As shown, there are multiple horizontal support pillars 42 and one vertical support pillar 43. The specific number of horizontal support pillars 42 and vertical support pillars 43 can be determined according to the actual testing requirements of the wafer, and is not limited here.

[0041] refer to Figure 1 Optionally, the tester 10 includes a pin card 11, which is used to transmit the signal output by the tester 10 to the wafer under test.

[0042] Specifically, the probe card 11, also known as the probe card, is the interface between the wafer 50 to be tested and the tester 10 in wafer testing. It enables signal transmission between the tester 10 and the wafer 50 to be tested and belongs to the core semiconductor testing consumables.

[0043] In addition, pin cards include cantilever pin cards, vertical pin cards, and MEMS pin cards. Among them, cantilever pin cards have lower cost, but their signal transmission is usually below 400Mbps. They have larger pin marks and are suitable for low-speed analog chip testing. Their probe diameter is relatively large, and the spacing cannot be too small, and the number of pins cannot be too high. They are mainly used for chips with large solder pads or bumps. Vertical pin cards have more precise probe tip contact and have advantages such as small size, small probe diameter, and easy replacement. They can meet the requirements of high pin count and short pin spacing, and are suitable for high-density bump testing. They are mainly used for high-end packaged chips with small solder pads or bumps. MEMS pin cards use MEMS technology, and the probe diameter can be as small as below 25.4μm. They have advantages in batch processing, good probe structure consistency, and high array planarity. They can simultaneously meet the testing requirements of fine pitch, flexible testing range, high pin count, and high density, and are widely used in the field of high-end wafer testing. The pin card in this embodiment can be a microelectromechanical system (MEMS) pin card. The type of pin card used in actual wafer testing can be determined according to the actual testing requirements of the wafer, and is not limited here.

[0044] Figure 4 This is a schematic diagram of a grain provided in Embodiment 2 of the present invention. (Reference) Figure 1 and Figure 4 Optionally, the pin card 11 includes a probe 12, which is electrically connected to the signal interface V of the wafer 50 to be tested.

[0045] Specifically, the signal interface V of the wafer under test 50 is the signal interface of the die on the wafer under test 50, and each die on the wafer under test 50 has its own signal interface. For example... Figure 4 As shown, the die has a hollow structure, with a diaphragm in the middle and a fixed axis around it. The ground interface G and signal interface V of the die are located on the fixed axis. Probe 12 is a tiny tip electrically connected to the signal interface V of the wafer under test 50. It is usually made of tungsten or beryllium copper alloy and is used to transmit the first signal output by the tester 10 to the signal interface of the wafer under test 50, so that the diaphragm of the die under test 50 vibrates.

[0046] Furthermore, the performance of probe 12 (such as conductivity, hardness, accuracy, and stability) affects the accuracy of the test results. The design and material of probe 12 need to be precisely matched according to the application scenario. The types of probe 12 mainly include semiconductor test probes and medical probes, as well as electronic circuit probes, industrial probes, etc. Probe 12 in this embodiment belongs to semiconductor test probes. Semiconductor test probes are key components for semiconductor wafer testing and finished chip testing. They need to achieve stable electrical connections at the micron level to transmit test signals. According to their structure and application, probes can be divided into cantilever probes, vertical probes, microelectromechanical system probes, and radio frequency probes. Among them, cantilever probes are cantilever beam-shaped (one end is fixed, and the other end is suspended and contacts the chip). The tip diameter is usually 50-100μm. Cantilever probes have low cost, are simple to process, and are suitable for low-pin-count testing and low-speed analog chip testing. Vertical probes are arranged vertically and achieve contact buffering through springs or elastic structures. The tip diameter is 20-50μm, the signal transmission is stable (supporting 1-10Gbps), and they are easy to replace. The microelectromechanical system (MEMS) probe utilizes MEMS technology. Probe diameters can be as small as 10-25 μm, offering excellent batch processing consistency and extremely high probe density (supporting tens of thousands of probes). Integrated impedance matching structures (such as 50Ω characteristic impedance) reduce high-frequency signal loss and support high-frequency signal transmission (up to 110 GHz). The probe type in this embodiment can be determined based on the actual testing requirements of the wafer and is not limited here.

[0047] In addition, the tips of probe 12 are mostly made of tungsten or beryllium copper alloy (high hardness and strong wear resistance). Some high-end probes are plated with gold or palladium to reduce contact resistance. The probe body can be made of phosphor bronze (good elasticity) or stainless steel (high strength). The conductivity, hardness and wear resistance, accuracy, elasticity and fatigue life of probe 12 affect its performance. Conductivity: The contact resistance of probe 12 needs to be extremely low, usually less than 50mΩ, to avoid signal attenuation or distortion. The resistivity of the material (e.g., copper alloy resistivity less than 1.7×10) is also important. -8The hardness (Ω·m) and surface coating (such as the thickness of the gold plating layer) are key; hardness and wear resistance: probe 12 needs to repeatedly contact the signal interface of the wafer, so the hardness of probe 12 needs to be relatively high, such as not less than Hv 300 (the hardness of tungsten is about Hv 400-500). Poor wear resistance of probe 12 will lead to tip wear, affecting the stability of the test; accuracy: including the tip size accuracy, positional accuracy (the spacing tolerance of the probe array can be ±2μm), and flatness (the flatness of the probe array can be ±1μm), which affect the accuracy of the test; elasticity and fatigue life: probe 12 will produce small deformations when it contacts the signal interface of the wafer, so it needs to have good elasticity (such as the elastic modulus of beryllium copper alloy is about 130GPa) and a large fatigue life to avoid frequent replacement. Before testing the wafer, the probe card can be installed above the probe station and aligned with the signal interface on the wafer through the optical system. When testing the wafer, the probe station can move the wafer upward, and the probe tip of the probe card lightly presses the signal interface of the wafer to form a stable electrical connection. The first signal output by the tester is transmitted to the signal interface of the wafer through the probe of the probe card, realizing signal transmission.

[0048] Optionally, the substrate is a glass substrate.

[0049] Specifically, the glass substrate is made of glass, which is easy to process and has high hardness, making it resistant to deformation. The ease of processing glass is mainly reflected in two stages: molten forming and precision cold working. This is primarily due to its amorphous structure (no fixed melting point, softening gradually with increasing temperature). Molten forming (thermoforming): At high temperatures (ordinary soda-lime glass softens at approximately 700-800℃, while special glasses such as quartz glass require above 1600℃), glass is in a viscous fluid state and can be formed into complex shapes such as flat plates, curved surfaces, vessels, and optical fibers through processes like blowing, pressing, float glass, and drawing. Cold working (precision forming): At room temperature, fine processing can be achieved through cutting, grinding, polishing, drilling, and etching. For example, diamond tools can be used to cut to specific dimensions, and chemical mechanical polishing can achieve nanoscale surface smoothness. The processing difficulty of glass is positively correlated with its composition and hardness. The higher the hardness of the glass, the higher the precision requirements for tools and equipment during cold working, and the higher the processing cost; while processing ordinary soda-lime glass is relatively simple. The hardness of glass is typically assessed using Mohs hardness (measuring scratch resistance) and Vickers hardness (measuring crush resistance), with its hardness level primarily determined by its composition. Ordinary glass (soda-lime glass): Mohs hardness is approximately 5-6, easily scratched by keys (Mohs hardness 5.5) and silica sand (Mohs hardness 7), its hardness only meeting basic protection needs. Mid-to-high-end glass (aluminosilicate glass, microcrystalline glass): Mohs hardness can be increased to 6.5-7.5, and Vickers hardness can reach 600-850 HV, capable of resisting scratches from most everyday items. Ultra-high hardness glass (sapphire glass, high-entropy glass): Mohs hardness reaches 9 (only lower than diamond's 10), Vickers hardness exceeds 1000 HV, extremely strong scratch resistance, suitable for scenarios requiring extremely high hardness. The resistance to deformation of glass is essentially a manifestation of its low coefficient of thermal expansion and high rigidity, which stems from the stability of its atomic arrangement (amorphous structures have no risk of lattice distortion). Thermal stability (resistance to thermal deformation): Most glasses have a low coefficient of thermal expansion (e.g., quartz glass has a coefficient of thermal expansion of only 0.5 × 10⁻⁶). -6 / ℃, ordinary soda-lime glass is about 9×10 -6 / ℃ means that when the temperature changes (such as ambient temperature fluctuations, hot and cold cycles during processing), the size change is minimal, and the size deviation is in the micrometer range, which can be met by ordinary glass; mechanical rigidity (resistance to external deformation): the elastic modulus of glass is high (about 70-80GPa for ordinary glass, and more than 400GPa for sapphire glass), and it is not easy to undergo plastic deformation (i.e., deformation that cannot be recovered after the external force is removed) under the action of external force (such as daily pressing, supporting weight), and only a small elastic deformation will be produced (returning to the original shape after the external force disappears).

[0050] Furthermore, the ease of processing, high hardness, and resistance to deformation of glass are the result of both the inherent properties of the material and optimized processing techniques. The reason why glass can simultaneously achieve ease of processing, high hardness, and resistance to deformation is essentially the result of the combined effect of the plasticity of its amorphous structure and the performance enhancement through compositional regulation (such as the addition of alumina and zirconium oxide): processing flexibility comes from the plasticity of the molten state and the precise controllability of cold processing, but the higher the hardness, the greater the processing difficulty; achieving the required hardness depends on compositional optimization (such as using aluminum and zirconium elements to increase hardness), and the appropriate material must be selected to match the needs of the application scenario; resistance to deformation stems from the low coefficient of thermal expansion and high rigidity.

[0051] It should be noted that the type of glass used for the glass substrate in this embodiment is determined according to the actual testing requirements of the wafer, and is not limited here.

[0052] Optionally, the vibration meter is a laser vibration meter.

[0053] Specifically, a laser vibrometer is an instrument that uses laser technology to measure the vibration parameters of the grain vibration film of an object, such as the wafer under test in this embodiment. The laser vibrometer primarily operates based on the laser Doppler effect and laser interferometry. When the laser beam irradiates the surface of the grain vibration film of the wafer under test, the reflected light interferes with the reference light, generating a Doppler frequency shift. By measuring this frequency shift, the vibration velocity and frequency of the grain vibration film of the wafer under test can be obtained. The laser vibrometer features non-contact measurement, eliminating the need for direct contact with the wafer under test or its grain vibration film, thus avoiding the influence of mass loading on the measurement results. It also boasts high precision and high resolution, featuring a digitally integrated structure capable of accurately measuring minute vibrations. Furthermore, the laser vibrometer can perform long-distance measurements, as the laser beam can be transmitted over long distances, making it widely applicable. Laser vibrometers can be categorized into different types, such as single-point laser vibrometers, full-field scanning laser vibrometers, and microscopic laser vibrometers, to meet various measurement needs. For example, the handheld laser vibration meter is based on the Doppler principle and uses photonic chip technology. It has two vibration measurement modes: handheld and fixed. It can obtain vibration time domain and spectrum analysis data in a few seconds. It also has advanced anti-shake and noise reduction algorithms and can support a test distance of ten meters.

[0054] Furthermore, Figure 5 This is a schematic diagram of a fixing device provided in Embodiment 2 of the present invention. (Reference) Figure 5 Laser vibration meter Figure 5 The fixing device 70 shown is fixed, and the laser vibrometer is located inside the fixing device 70. It should be noted that the specific type of laser vibrometer in this embodiment can be determined according to the actual testing requirements of the wafer, and is not limited here.

[0055] Optionally, the wafer to be tested is a silicon-based chip used to fabricate a microphone.

[0056] Specifically, the wafer, as the substrate for chip manufacturing, is an essential component of silicon-based chips. Silicon-based chips use silicon as the core semiconductor material, and by building transistors, circuits, and interconnect structures on a silicon substrate, they are miniaturized electronic devices that enable information processing, storage, and transmission. The silicon-based chip for a microphone, simply called a silicon microphone chip, requires wafers for fabrication, which are tested by the testing device described in this embodiment to ensure wafer performance.

[0057] It should be noted that the values ​​of each parameter in this embodiment are only illustrative and can be determined according to the actual testing requirements of the wafer, and are not limited here.

[0058] The wafer testing apparatus provided in this embodiment includes: a testing machine, a vibration meter, a probe station, and a substrate; wherein, the testing machine is communicatively connected to the vibration meter and the wafer under test, the wafer under test is located on the substrate, the wafer under test and the substrate are placed on the probe station, and the vibration meter is located above the wafer under test; the substrate is an open substrate, and the bottom of the substrate is closed; the testing machine is used to transmit a first signal to the die on the wafer under test to cause the diaphragm of the die to vibrate; the vibration meter is used to generate a second signal when the diaphragm vibrates, and the testing machine is also used to receive the second signal and determine the state of the wafer under test based on the second signal and the first signal; the substrate is a ring structure with an internal concave area, and a support pillar is provided in the inner circular area of ​​the ring structure to support the wafer under test; the testing machine includes a probe card, which is used to transmit the signal output by the testing machine to the wafer under test; the probe card includes a probe, which is electrically connected to the signal interface of the wafer under test; the substrate is a glass substrate; the vibration meter is a laser vibration meter; the wafer under test is a silicon-based chip wafer used to fabricate a microphone. The wafer testing apparatus provided in this embodiment determines the state of the wafer under test based on the second signal and the first signal, thereby realizing the vibration test of the wafer under test. Furthermore, the substrate is an open substrate to prevent the vibration of the grain vibration film of the wafer under test from being inconsistent with expectations due to the sealing of the substrate. The bottom of the substrate is sealed to protect the wafer under test and ensure the reliability of the test.

[0059] Example 3

[0060] Figure 6 This is a flowchart of a wafer testing method provided in Embodiment 3 of the present invention. This embodiment is applicable to testing wafers such as silicon-based chip wafers, etc. The method can be executed by a testing machine in a wafer testing device, and the method specifically includes the following steps:

[0061] Step 210: Receive control commands.

[0062] The control commands can be input from an external source to the test machine, and the control commands can include information about the wafer to be tested.

[0063] Step 220: According to the control command, transmit the first signal to the die on the wafer to be tested.

[0064] For example, the first signal is a 1kHz sine wave signal with an amplitude of ±5V.

[0065] Step 230: Receive the second signal transmitted by the vibration meter, and determine the state of the wafer to be tested based on the second signal and the first signal.

[0066] The frequency of the second signal is the frequency of the oscillation film of the die on the wafer under test. Specifically, when the difference between the frequency of the first signal and the frequency of the second signal corresponding to each die on the wafer under test is within a preset range, it is determined that each die on the wafer under test is qualified; when the difference between the frequency of the first signal and the frequency of the second signal corresponding to at least one die on the wafer under test exceeds the preset range, it is determined that at least one die on the wafer under test is unqualified.

[0067] For example, Figure 7 This is a schematic diagram of the waveform of a second signal provided in Embodiment 3 of the present invention. Figure 8 This is a schematic diagram illustrating the frequency of a second signal according to Embodiment 3 of the present invention. (Reference) Figure 7 and Figure 8 The amplitude of the second signal is within a certain range. Figure 8 The frequency of the second signal shown is f, such as f = 999.7559 Hz. Alternatively, the tester can output the first signal and receive the second signal, then change the frequency of the first signal and output the first signal again, then receive the second signal, and so on, changing the frequency of the first signal multiple times to perform multiple tests based on signals of different frequencies. For example, the frequencies of the first signal output multiple times could be 10 Hz, 500 Hz, 1 kHz, 10 kHz, and 50 kHz.

[0068] It should be noted that the specific size of the preset range in this embodiment can be determined according to the actual testing requirements of the wafer, and is not limited here.

[0069] The wafer testing method provided in this embodiment includes: receiving a control command; transmitting a first signal to the dies on the wafer to be tested according to the control command; receiving a second signal transmitted by a vibration meter; and determining the state of the wafer to be tested based on the second signal and the first signal. The wafer testing method provided in this embodiment determines the state of the wafer to be tested based on the second signal and the first signal. If the difference between the frequency of the first signal and the frequency of the second signal corresponding to each die on the wafer to be tested is within a preset range, it is determined that each die on the wafer to be tested is qualified. If the difference between the frequency of the first signal and the frequency of the second signal corresponding to at least one die on the wafer to be tested exceeds the preset range, it is determined that at least one die on the wafer to be tested is unqualified, thereby achieving wafer testing.

[0070] Example 4

[0071] Embodiment 4 of the present invention provides a computer-readable storage medium storing a computer program thereon. When executed by a test machine, the program implements the wafer testing method provided in the embodiments of the present invention, the method comprising:

[0072] Receive control commands;

[0073] According to the control command, the first signal is transmitted to the die on the wafer to be tested;

[0074] The system receives the second signal transmitted by the vibration meter and determines the state of the wafer to be tested based on the second signal and the first signal.

[0075] The computer storage medium of this invention can be any combination of one or more computer-readable media. A computer-readable medium can be a computer-readable signal medium or a computer-readable storage medium. A computer-readable storage medium can be, for example,—but not limited to—an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of computer-readable storage media (a non-exhaustive list) include: an electrical connection having one or more wires, a portable computer disk, a hard disk, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage device, magnetic storage device, or any suitable combination thereof. In this document, a computer-readable storage medium can be any tangible medium that contains or stores a program that can be used by or in conjunction with an instruction execution system, apparatus, or device.

[0076] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying computer-readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. Computer-readable signal media may also be any computer-readable medium other than computer-readable storage media, capable of sending, propagating, or transmitting programs for use by or in connection with an instruction execution system, apparatus, or device.

[0077] Program code contained on a computer-readable medium may be transmitted using any suitable medium, including—but not limited to—wireless, wire, optical fiber, RF, etc., or any suitable combination thereof.

[0078] Computer program code for performing the operations of this invention can be written in one or more programming languages ​​or a combination thereof, including object-oriented programming languages ​​such as Java, Smalltalk, and C++, as well as conventional procedural programming languages ​​such as "C" or similar programming languages. The program code can be executed entirely on the user's computer, partially on the user's computer, as a standalone software package, partially on the user's computer and partially on a remote computer, or entirely on a remote computer or terminal. In cases involving remote computers, the remote computer can be connected to the user's computer via any type of network—including a local area network (LAN) or a wide area network (WAN)—or can be connected to an external computer (e.g., via the Internet using an Internet service provider).

[0079] 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, rearrangements, combinations, 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 testing apparatus, characterized in that, include: Test machine, vibration meter, probe station and substrate; The testing machine is communicatively connected to the vibration meter and the wafer under test. The wafer under test is located on the substrate, and the wafer under test and the substrate are placed on the probe station. The vibration meter is located above the wafer under test. The substrate is an open substrate, and the bottom of the substrate is closed. The testing machine is used to transmit a first signal to the die on the wafer to be tested, so as to cause the diaphragm of the die to vibrate; the vibration meter is used to generate a second signal when the diaphragm vibrates; the testing machine is also used to receive the second signal and determine the state of the wafer to be tested based on the second signal and the first signal.

2. The wafer testing apparatus according to claim 1, characterized in that, The substrate is a ring structure with internal recesses.

3. The wafer testing apparatus according to claim 2, characterized in that, The inner circular region of the annular structure is provided with a support pillar, which is used to support the wafer to be tested.

4. The wafer testing apparatus according to claim 1, characterized in that, The tester includes a pin card, which is used to transmit the signal output by the tester to the wafer under test.

5. The wafer testing apparatus according to claim 4, characterized in that, The pin card includes probes, which are electrically connected to the signal interface of the wafer under test.

6. The wafer testing apparatus according to claim 1, characterized in that, The substrate is a glass substrate.

7. The wafer testing apparatus according to claim 1, characterized in that, The vibration meter is a laser vibration meter.

8. The wafer testing apparatus according to claim 1, characterized in that, The wafer to be tested is a silicon-based chip used to manufacture microphones.

9. A method for testing a wafer, characterized in that, The test method is performed by the test machine according to any one of claims 1-8, and the test method includes: Receive control commands; According to the control command, a first signal is transmitted to the die on the wafer to be tested; The second signal transmitted by the vibration meter is received, and the state of the wafer to be tested is determined based on the second signal and the first signal.

10. The wafer testing method according to claim 9, characterized in that, Determining the state of the wafer under test based on the second signal and the first signal includes: When the difference between the frequency of the first signal and the frequency of the second signal corresponding to each die on the wafer under test is within a preset range, it is determined that each die on the wafer under test is qualified. When the difference value corresponding to at least one grain on the wafer under test exceeds the preset range, it is determined that at least one grain on the wafer under test is unqualified.

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