Detection device and detection method for MEMS micro-motion platform

Abstract

This application discloses a detection device and method for MEMS micro-motion platforms. The detection device includes: a vibration source, which generates vibrations containing the resonant frequency of the MEMS micro-motion platform, and the vibration source can cause one or more MEMS micro-motion platforms to vibrate simultaneously; and an observation device, which observes the vibration state of the MEMS micro-motion platform. The detection device of this application, by detecting the frequency response of the MEMS micro-motion platform itself, can simultaneously detect the structural yield of all MEMS micro-motion platforms on the vibration source, effectively improving the detection efficiency and accuracy of MEMS micro-motion platforms. Furthermore, this MEMS micro-motion platform detection device is low-cost and does not leave pin marks on the MEMS micro-motion platform, thus avoiding damage to the MEMS micro-motion platform's structure.

Description

Technical Field

[0001] This application relates to the field of microelectromechanical technology, and more specifically, to a detection device and detection method for a MEMS micro-motion platform. Background Technology

[0002] MEMS (Micro-Electro-Mechanical System) micro-motion platforms can be used to achieve displacement and deflection of mounted devices in different directions. The surface of the MEMS micro-motion platform is covered with a reflective layer to form a MEMS micromirror, which is a widely used application of MEMS micro-motion platforms.

[0003] Existing MEMS micro-motion platform testing methods typically involve the MEMS driver in the MEMS micro-motion platform using a probe station to apply a certain driving voltage to one or several micro-motion platforms, measuring the motion of the MEMS micro-motion platform, and obtaining various characteristic parameters of the MEMS micro-motion platform.

[0004] Meanwhile, in existing MEMS micromirror detection technologies, a probe station is used to apply voltage to one or several MEMS micromirrors in a MEMS wafer, and the quality of the MEMS micromirror is determined based on its motion state after the voltage is applied.

[0005] The existing technologies described above for detecting MEMS micro-motion platforms or MEMS micromirrors are expensive, can only detect one or a group of MEMS micro-motion platforms or MEMS micromirrors at a time, have low detection efficiency, and are prone to leaving needle marks on the detected MEMS micro-motion platforms or MEMS micromirrors, damaging the MEMS micro-motion platforms or MEMS micromirrors. Summary of the Invention

[0006] One objective of this application is to provide a new technical solution for a detection device for a MEMS micro-motion platform, which can at least solve the problems of low detection efficiency and easy puncture marks left on the MEMS micro-motion platform or MEMS micromirror in the existing technology.

[0007] According to a first aspect of this application, a detection device for a MEMS micro-motion platform is provided, comprising: a vibration source for generating vibrations including the resonant frequency of the MEMS micro-motion platform, the vibration source being capable of causing one or more of the MEMS micro-motion platforms to vibrate simultaneously; and an observation device for observing the vibration state of the MEMS micro-motion platform.

[0008] Optionally, the MEMS wafer includes multiple MEMS micro-motion platforms, and the vibration source transmits vibration to the MEMS wafer in a physical contact manner.

[0009] Optionally, the MEMS wafer includes multiple MEMS micro-motion platforms, and the vibration source transmits vibration to the MEMS wafer in a non-contact manner.

[0010] Optionally, the vibration source is a vibration table or an oscillator.

[0011] Optionally, the vibration source is a loudspeaker capable of emitting sound waves.

[0012] Optionally, the observation device is a camera.

[0013] Optionally, the MEMS micro-motion platform has a MEMS mirror, and the observation device includes: a light source for emitting light, the light emitted by the light source being able to illuminate the MEMS mirror and form a reflection; and a light receiver for receiving the light reflected by the MEMS mirror.

[0014] Optionally, the observation device further includes a displacement stage, wherein the light source is disposed on the displacement stage and is movable relative to the displacement stage.

[0015] Optionally, the vibration source is located below the MEMS wafer, and the vibration source is used to support the MEMS wafer and transmit vibration to the MEMS wafer.

[0016] Optionally, the detection device further includes a support, through which the vibration source supports the MEMS disc.

[0017] Optionally, the vibration source is located below the MEMS wafer, and the vibration source is spaced apart from the MEMS wafer to form a gap. The vibration source transmits vibration to the MEMS wafer in the form of sound waves.

[0018] Optionally, the light source is a single LED, an LED array, a point laser, a laser array, or a surface light source, and the light receiver is an opaque flat plate, a semi-transparent flat plate, a light screen, a photosensitive device, or a camera.

[0019] According to a second aspect of this application, a detection method for a MEMS micro-motion platform is provided, applied to the detection device for the MEMS micro-motion platform described in the above embodiments. The detection method includes the following steps:

[0020] Vibrations containing the resonant frequency of the MEMS micro-motion platform are generated to drive one or more of the MEMS micro-motion platforms to vibrate simultaneously.

[0021] Observe the vibration state of the MEMS micro-motion platform;

[0022] The yield of the MEMS micro-motion platform is determined based on the vibration state of the MEMS micro-motion platform.

[0023] The MEMS micro-motion platform detection device according to an embodiment of the present invention generates vibration containing the resonant frequency of the MEMS micro-motion platform through a vibration source, causing the MEMS micro-motion platform on the vibration source to resonate. The vibration state of each MEMS micro-motion platform is observed through an observation device to identify unqualified MEMS micro-motion platforms on the vibration source. The MEMS micro-motion platform detection device of this application, by detecting the frequency response of the MEMS micro-motion platform itself, can simultaneously detect the structural yield of all MEMS micro-motion platforms on the vibration source, effectively improving the detection efficiency and accuracy of MEMS micro-motion platforms. At the same time, this MEMS micro-motion platform detection device has low cost and does not leave pin marks on the MEMS micro-motion platform, thus avoiding damage to the structure of the MEMS micro-motion platform.

[0024] Other features and advantages of this application will become clear from the following detailed description of exemplary embodiments with reference to the accompanying drawings. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the present application and, together with their description, serve to explain the principles of the present application.

[0026] Figure 1 This is a schematic diagram of the structure of the MEMS micro-motion platform according to an embodiment of the present invention;

[0027] Figure 2 This is a schematic diagram of the detection device in Embodiment 1 of the present invention;

[0028] Figure 3 This is a schematic diagram of the detection device in Embodiment 2 of the present invention;

[0029] Figure 4 This is a schematic diagram of the detection device in Embodiment 3 of the present invention;

[0030] Figure 5 This is a schematic diagram of the detection device in Embodiment 4 of the present invention;

[0031] Figure 6 A flowchart of the detection method according to an embodiment of the present invention.

[0032] Figure label:

[0033] Vibration source 10; loudspeaker 11; loudspeaker driver 12;

[0034] 21. Laser; 22. Screen; 23. CCD camera; 24. Photosensitive device;

[0035] 31; bracket; 32; XY dual-axis displacement stage;

[0036] MEMS discs 40;

[0037] MEMS micro-motion platform 50; substrate 51; MEMS mirror 52; fixed comb teeth 53; moving comb teeth 54. Detailed Implementation

[0038] Various exemplary embodiments of the present application will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the present application.

[0039] The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the scope of this application and its application or use.

[0040] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques, methods, and equipment should be considered part of the specification.

[0041] In all the examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values.

[0042] It should be noted that similar labels and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be discussed further in subsequent figures.

[0043] The detection device of the MEMS micro-motion platform 50 according to an embodiment of the present invention will be described in detail below with reference to the accompanying drawings.

[0044] like Figures 1 to 5 As shown, the detection device of the MEMS micro-motion platform 50 according to an embodiment of the present invention includes a vibration source 10 and an observation device.

[0045] Specifically, the vibration source 10 is used to generate vibrations containing the resonant frequency of the MEMS micro-motion platform 50, and the vibration source 10 can cause one or more MEMS micro-motion platforms 50 to vibrate simultaneously. The observation device is used to observe the vibration state of the MEMS micro-motion platform 50.

[0046] In other words, such as Figure 1 and Figure 2As shown, the detection device for the MEMS micro-motion platform 50 according to an embodiment of the present invention mainly consists of a vibration source 10 and an observation device. The vibration source 10 is used to generate vibrations containing the resonant frequency of the MEMS micro-motion platform 50. In this application, the MEMS (Micro-Electro-Mechanical System) micro-motion platform can be understood as including both a MEMS micro-motion platform 50 without a reflective layer and a MEMS micro-motion platform 50 with a reflective layer (i.e., a MEMS micromirror). The vibration source 10 can transmit vibrations to the MEMS micro-motion platform 50, causing the MEMS micro-motion platforms 50 within the vibration range of the vibration source 10 to vibrate simultaneously. When the vibration frequency transmitted by the vibration source 10 to the MEMS micro-motion platform 50 reaches the same or similar frequency as its own resonant frequency, the MEMS micro-motion platform 50 resonates, and the MEMS micro-motion platform 50 can undergo a certain angle of translation or deflection.

[0047] This application employs a physical vibration method, simultaneously inducing all MEMS micro-motion platforms 50 on the vibration source 10 to resonate. Of course, for MEMS micro-motion platforms 50 with structural defects, i.e., unqualified micro-motion platform products, their resonant frequency or resonant mode is inconsistent with that of qualified MEMS micro-motion platforms 50. Therefore, during the resonance process of qualified MEMS micro-motion platforms 50, unqualified products do not vibrate. Finally, the vibration state of the MEMS micro-motion platforms 50 can be observed using an observation device, and the MEMS micro-motion platforms 50 in a resonant state (qualified products) can be selected for packaging, greatly improving the detection efficiency of MEMS micro-motion platforms 50.

[0048] It should be noted that, in this application, the vibration frequency generated by the vibration source 10 can be a single frequency, a wide frequency range, a continuously changing scanning frequency, or a speaker 11 that can emit sound waves. In this application, as long as the vibration frequency generated by the vibration source 10 can satisfy the form of resonance of the MEMS micro-motion platform 50, it should fall within the protection scope of this application, and will not be described in detail here.

[0049] The MEMS micro-motion platform 50 testing device of this application can achieve batch testing of the yield of MEMS micro-motion platform 50 by using a vibration source 10 that can generate vibration frequency and an observation device that can observe vibration state, thereby reducing testing costs while improving testing efficiency and accuracy.

[0050] Compared to existing detection equipment, this application eliminates the need to apply voltage to each MEMS micro-motion platform 50 individually using a probe station, and then determine the qualification of the MEMS micro-motion platform 50 based on its vibration state after voltage application. Those skilled in the art will understand that a single MEMS wafer 40 contains hundreds or thousands of MEMS micro-motion platforms 50. Clearly, applying voltage to each MEMS micro-motion platform 50 using a probe is labor-intensive and impractical. Existing technologies typically probe only one or a group of MEMS micro-motion platforms 50 at a time, resulting in low detection efficiency. Furthermore, because a probe is needed to apply a driving voltage to the MEMS micro-motion platform 50, the probe is prone to leaving puncture marks, damaging the MEMS micro-motion platform 50 (e.g., damaging the MEMS electrodes).

[0051] When faced with pressure from testing costs and tight deadlines, existing testing solutions for MEMS micro-motion platforms 50 are expensive and inefficient. Furthermore, long-term testing experience shows that electrical performance failures of MEMS micro-motion platforms 50 typically account for a relatively low proportion of overall resonant MEMS micro-motion platform 50 failures; device (MEMS micro-motion platform 50) failures often stem from structural defects. This application addresses these shortcomings by providing a testing device for MEMS micro-motion platforms 50, primarily composed of a vibration source 10 and an observation device. By employing physical vibration and detecting the frequency response of the MEMS micro-motion platform 50 itself, high testing efficiency and accuracy can be achieved.

[0052] Therefore, the detection device for the MEMS micro-motion platform 50 according to an embodiment of the present invention generates vibrations containing the resonant frequency of the MEMS micro-motion platform 50 through the vibration source 10, causing the MEMS micro-motion platforms 50 on the vibration source 10 to resonate. The vibration state of each MEMS micro-motion platform 50 is observed through an observation device, and unqualified MEMS micro-motion platforms 50 on the vibration source 10 are identified. The detection device for the MEMS micro-motion platform 50 of this application, by detecting the frequency response of the MEMS micro-motion platform 50 itself, can simultaneously detect the structural yield of all MEMS micro-motion platforms 50 on the vibration source 10, effectively improving the detection efficiency and accuracy of the MEMS micro-motion platforms 50. At the same time, this detection device for the MEMS micro-motion platform 50 has low cost and does not leave pin marks on the MEMS micro-motion platform 50, thus avoiding damage to the structure of the MEMS micro-motion platform 50.

[0053] According to one embodiment of the present invention, the MEMS wafer 40 includes a plurality of MEMS micro-motion platforms 50, and the vibration source 10 transmits vibration to the MEMS wafer 40 in a physical contact manner.

[0054] In another embodiment of this application, the MEMS wafer 40 includes a plurality of MEMS micro-motion platforms 50, and the vibration source 10 transmits vibration to the MEMS wafer 40 in a non-contact manner.

[0055] In other words, such as Figures 3 to 5 As shown, before dicing, the MEMS wafer 40 has multiple MEMS micro-motion platforms 50. The number of MEMS micro-motion platforms 50 in a single MEMS wafer 40 can typically reach hundreds, thousands, or more. The MEMS micro-motion platforms 50 can transmit vibration to the vibration source 10 through contact or non-contact methods. Single or multiple MEMS micro-motion platforms 50 can be directly attached to the surface of the vibration source 10, or the MEMS wafer 40 can be directly attached to the surface of the vibration source 10 (see [reference]). Figure 2 This enables direct or indirect contact between the MEMS micro-motion platform 50 in the MEMS wafer 40 and the vibration source 10.

[0056] This application may also include a clamp for fixing the entire MEMS disc 40, so that the MEMS disc 40 makes direct or indirect contact with the vibration source 10 (see [link]). Figure 3 and Figure 4 Alternatively, the MEMS disc 40 may not contact the vibration source 10, and the vibration may be transmitted to the MEMS micro-motion platform 50 in the form of sound waves (see...). Figure 5 ).

[0057] This application transmits vibration to the MEMS wafer 40 through physical contact or non-contact methods using a vibration source 10, ensuring that all MEMS micro-motion platforms 50 within the MEMS wafer 40 can resonate simultaneously. The vibration state of each MEMS micro-motion platform 50 within the MEMS wafer 40 is observed using an observation device. Since the resonant frequency or mode of a defective micro-motion platform product is inconsistent with that of a qualified MEMS micro-motion platform 50, defective products do not vibrate during the resonance process of qualified MEMS micro-motion platforms 50. Finally, the vibration state of the MEMS micro-motion platforms 50 can be observed using the observation device to identify defective MEMS micro-motion platforms 50 on the vibration source 10. This facilitates the selection of MEMS micro-motion platforms 50 in a resonant state (qualified products) for packaging, significantly improving the testing efficiency of the MEMS micro-motion platforms 50 and achieving low-cost, high-efficiency, and non-destructive wafer-level testing.

[0058] The detection device for the MEMS micro-motion platform 50 of this application can detect the structural yield of all MEMS micro-motion platforms 50 on the vibration source 10 at one time by detecting the frequency response of the MEMS micro-motion platform 50 itself, effectively improving the detection efficiency and accuracy of the MEMS micro-motion platform 50.

[0059] In some specific embodiments of the present invention, the vibration source 10 is a vibration table or an oscillator.

[0060] In one embodiment of this application, the vibration source 10 is a loudspeaker 11 capable of emitting sound waves.

[0061] In other words, the vibration source 10 can be a vibration table or an oscillator. The vibration source 10 can also be a loudspeaker 11 capable of emitting sound waves. The vibration frequency generated by the vibration source 10 can be a single frequency, a wide frequency range, a continuously changing scanning frequency, or a loudspeaker 11 capable of emitting sound waves. In this application, the specific type of vibration source 10 includes, but is not limited to, a vibration table, an oscillator, or a loudspeaker 11 capable of emitting sound waves; the applicant can specify the appropriate type according to actual needs.

[0062] See Figures 2 to 4 Taking vibration source 10 as a vibration table as an example, the MEMS micro-motion platform 50 can transmit vibration to the vibration table through contact or non-contact methods. See [link / reference] Figure 2 The MEMS disc 40 can be directly attached to the surface of the vibration table. Alternatively, the MEMS disc 40 can be directly or indirectly contacted with the vibration table via a custom fixture, such as a bracket 31 (see [link to fixture]). Figure 3 and Figure 4 Taking the vibration source 10 as the speaker 11 as an example, the MEMS disc 40 may not be in contact with the speaker 11. See [link / reference]. Figure 5 The speaker 11 transmits vibrations to the MEMS micro-motion platform 50 in the form of sound waves, enabling low-cost, high-efficiency, and non-destructive wafer-level testing.

[0063] According to one embodiment of the present invention, the observation device is a camera. That is, the observation device can also be a camera, which can be an integration of a light source and a light receiver. For example, the camera can be a CCD camera 23, which projects light onto the MEMS micro-motion platform 50 and uses the change in reflected light to determine whether the MEMS micro-motion platform 50 vibrates.

[0064] According to one embodiment of the present invention, the MEMS micro-motion platform 50 has a MEMS mirror 52, and the observation device includes a light source and a light receiver.

[0065] Specifically, a light source is used to emit light, which can illuminate the MEMS mirror 52 and be reflected. A light receiver receives the light reflected by the MEMS mirror 52.

[0066] In other words, see Figure 1The MEMS micro-motion platform 50 can be covered with a reflective layer, which forms a MEMS mirror 52. The MEMS micro-motion platform 50 covered with a reflective layer can be called a MEMS micromirror. In this application, the MEMS micro-motion platform 50 mainly consists of a substrate 51, a MEMS mirror 52, movable comb teeth 54, and fixed comb teeth 53. The substrate 51 is used to fix and support the overall structure. The MEMS mirror 52 is the micro-motion platform, connected to the movable comb teeth 54, and the fixed comb teeth 53 is connected to the substrate 51. There is a gap between the fixed comb teeth 53 and the movable comb teeth 54. When the MEMS micro-motion platform 50 is in a resonant state, the MEMS mirror 52 undergoes translational or deflection motion along the direction of the comb tooth gap (the direction of motion of the MEMS mirror 52 is as follows). Figure 1 (As indicated by the middle arrow). At this time, the light illuminating the MEMS mirror 52 in the resonant state can cause the light spot reflected by the MEMS mirror 52 to expand, for example, into a bright line, a ring line, or other types of shapes. The specific shape of the expanded light spot reflected by the MEMS mirror 52 varies depending on the movement mode of the MEMS micro-motion platform 50. Of course, for those skilled in the art, the specific structure, shape, and working principle of the MEMS micro-motion platform 50 are understandable and achievable, and will not be described in detail in this application.

[0067] The observation device mainly consists of a light source and a light receiver. The light source emits light; optionally, the light source in this application includes, but is not limited to, a single LED (Light-Emitting Diode), an LED array, a point laser 21, an array of laser 21, or a surface light source. Any light-emitting device capable of generating light should fall within the protection scope of this application. The light emitted by the light source can illuminate the MEMS mirror 52 and form reflected light on the MEMS mirror 52. The light receiver receives the light reflected by the MEMS mirror 52. Optionally, the light receiver includes, but is not limited to, an opaque plate, a semi-transparent plate, a light screen 22, a photosensitive device 24, or a camera.

[0068] The photosensitive device 24 can be a CMOS (Complementary Metal Oxide Semiconductor) or CCD (Photocoupler) camera, and the camera can be a CCD camera 23. The CCD camera 23 can act as a light receiver to directly take pictures and observe whether the MEMS micro-motion platform 50 vibrates. The CCD camera 23 can also be an integrated light source and light receiver, projecting light onto the MEMS micro-motion platform 50 and using changes in reflected light to determine whether the MEMS micro-motion platform 50 vibrates.

[0069] When the testing device for the MEMS micro-motion platform 50 is working, the vibration source 10 vibrates, causing the MEMS micro-motion platform 50 of the MEMS wafer 40 to resonate. Light emitted from the light source can then illuminate the MEMS mirror 52, forming reflected light on the mirror 52. The light receiver receives the light reflected from the MEMS mirror 52. A qualified MEMS micro-motion platform 50 resonates, and the light spot illuminating the MEMS mirror 52 is spread into a bright line on the light receiver. A defective MEMS micro-motion platform 50 remains almost motionless when the vibration source 10 vibrates, and the light reflected onto the light receiver is still just a single light spot. Testing personnel can determine whether the MEMS micro-motion platform 50 in the MEMS wafer 40 is qualified based on the shape of the light spot displayed on the light receiver. This facilitates the process of selecting qualified MEMS micromirrors for packaging after dicing the MEMS wafer 40, reducing testing costs and improving testing efficiency.

[0070] In this application, the vibration source 10 can be a vibration table capable of generating a single frequency, and the observation device can be a point laser as the light source and a screen 22 as the light receiver. The laser 21 can be a point laser with a wavelength of 650nm, emitting continuous red light. The MEMS disc 40 can be directly fixed to the vibration table, with direct physical contact between the MEMS disc 40 and the vibration table. The red light from the laser 21 is incident on the MEMS mirror 52 of the MEMS disc 40, and the MEMS mirror 52 reflects the red light onto the screen 22. When the MEMS mirror 52 is stationary, it appears as a red spot on the screen 22. Since the vibration table is a single-frequency source, when the output single frequency matches the resonant frequency of the MEMS micromirror (MEMS micro-motion platform 50), the MEMS micromirror resonates, causing the light spot to spread into a bright line on the screen 22.

[0071] When the vibration frequency of the vibration table and the resonance frequency of the MEMS micromirror are not the same, the MEMS micromirror will not resonate, the MEMS mirror 52 will remain almost stationary, and the light screen 22 will still receive a dotted light spot. Simultaneously, when the vibration frequency of the vibration table varies within a certain range (including the resonance frequency of the MEMS micromirror), the light spot received by the light screen 22 will continuously switch between dotted and linear states. Therefore, whether the MEMS micromirror chip is functioning normally (i.e., whether the MEMS micro-motion platform 50 is qualified) can be accurately determined by the naked eye or by photosensitive devices (e.g., light receiving devices such as the light screen 22). This facilitates the selection of MEMS micro-motion platforms 50 in a resonant state (qualified products) for packaging, greatly improving the testing efficiency of the MEMS micro-motion platform 50 and achieving low-cost, high-efficiency, and non-destructive wafer-level testing.

[0072] According to one embodiment of the present invention, the observation device further includes a displacement stage.

[0073] Specifically, the light source is located on the displacement stage, and the light source can move relative to the displacement stage.

[0074] In other words, such as Figures 2 to 4 As shown, the observation device may also include a displacement stage. A light source can be mounted on the displacement stage via a connector 32, and the light source is movable relative to the displacement stage. The displacement stage can be an XY dual-axis displacement stage 33, which can achieve movement in both the X and Y axes. The movement direction of the light source (e.g., laser 21) in the XY dual-axis displacement stage 33 is as follows: Figure 2 As shown by the XY arrows, the XY direction represents two mutually perpendicular directions in a one-dimensional plane. Figure 3 and Figure 4 The laser 21 moves in the same direction as the XY dual-axis displacement stage 33. Figure 2 The directions of movement are the same.

[0075] The vibration source 10 can be a vibration table capable of generating a single frequency, and the observation device can use a point laser as the light source and a screen 22 as the light receiver. The vibration table continuously outputs vibration, and the XY dual-axis displacement stage 33 is rapidly moved according to the size and spacing of the MEMS micromirrors to ensure that the light spot of the laser 21 hits a specific MEMS mirror surface 52 of the MEMS wafer 40 each time. The screen 22 displays the spread state of the light spot for each MEMS micromirror. A bright line indicating a spread state indicates a qualified product, while a blank spread state indicates a defective product. A CP map is used to record the state of all MEMS micromirrors during the test. The CP map (Circuit Probing, CP) is a wafer testing diagram, which is understandable to those skilled in the art and will not be described in detail in this application.

[0076] After the MEMS wafers are diced at 40mm, only the qualified MEMS micromirrors are selected for packaging, thereby reducing testing costs and improving testing efficiency. Furthermore, because no probes are needed, the quality of each micromirror can be determined without leaving any testing traces.

[0077] Therefore, compared to existing technologies, the testing device of this application does not require the purchase of expensive testing equipment. The yield of the resonant MEMS micro-motion platform 50 can be tested using only the weak vibrations generated by the vibration table. Furthermore, this invention can simultaneously test the yield of the entire MEMS wafer 40, which is more efficient than existing technologies that can only test one or a few devices per measurement. In addition, the testing device of this application does not need to contact the device surface during the testing process, thus preventing damage to the devices.

[0078] In some specific embodiments of the present invention, the vibration source 10 is located below the MEMS disc 40, and the vibration source 10 is used to support the MEMS disc 40 and transmit vibration to the MEMS disc 40.

[0079] In other words, such as Figure 2 As shown, the vibration source 10 is positioned below the MEMS disc 40, supporting the MEMS disc 40. Physical contact is formed between the vibration source 10 and the MEMS disc 40, allowing the vibration source 10 to directly transmit vibrations to the MEMS disc 40. The light source and the light receiver are located on opposite sides of the vibration source 10, facilitating the reflection of incident light received by the MEMS mirror 52 onto the light receiver.

[0080] According to one embodiment of the present invention, such as Figure 3 and Figure 4 As shown, the detection device also includes a support 31, through which the vibration source 10 supports the MEMS wafer 40. The vibration generated by the vibration source 10 can be indirectly transmitted to the MEMS wafer 40 through the support 31. Of course, the specific structure, shape, and arrangement of the support 31 can be specifically defined according to actual needs, and will not be described in detail in this application.

[0081] In some specific embodiments of the present invention, the vibration source 10 is located below the MEMS wafer 40, and the vibration source 10 and the MEMS wafer 40 are spaced apart to form a gap. The vibration source 10 transmits vibration to the MEMS wafer 40 in the form of sound waves.

[0082] In other words, such as Figure 5 As shown, the vibration source 10 is positioned below the MEMS disc 40. The vibration source 10 and the MEMS disc 40 can be spaced apart to form a gap, ensuring that the vibration source 10 and the MEMS disc 40 do not contact each other. The vibration source 10 can be a speaker 11, which has a speaker driver 12. The speaker driver 12 can drive the speaker 11 to generate sound waves. The speaker 11 transmits vibrations to the MEMS disc 40 in the form of sound waves using air as the propagation medium.

[0083] See also in this application Figure 5Taking a MEMS wafer 40 with a resonant frequency of 2000Hz as an example, the resonant frequency range of the MEMS micromirrors on the entire MEMS wafer 40 is 2000±50Hz. The speaker driver 12 can be set to a sweep speed of 500ms, a return speed of 500ms, a sweep start frequency of 1800Hz, and a sweep end frequency of 2200Hz. Clicking "Start Output Sweep Signal" will cause the speaker 11 to continuously output a sweep signal with a vibration frequency of 1800-2200Hz. When the vibration frequency reaches the resonant frequency of the MEMS micromirror (2000Hz), the MEMS micromirror resonates, driving the MEMS mirror surface 52, which can be easily captured by the naked eye or a light receiver (e.g., CCD camera 23). The CCD camera 23 records whether each MEMS micromirror unfolds and resonates, thus determining the quality of each micromirror without using probes or leaving any test traces. The CP map is used to record the state of MEMS micromirrors during testing. After the MEMS wafer is diced 40 times, only the qualified micromirrors need to be selected for packaging, thereby reducing testing costs and improving testing efficiency.

[0084] It should be noted that the CCD camera 23 can be used as a light receiving device alone, or it can be used as both a light source and a light receiving device simultaneously. The specific structure and working principle of the CCD camera 23 are understandable and achievable by those skilled in the art, and will not be described in detail in this application.

[0085] The working process of the detection device of the MEMS micro-motion platform 50 of this application is described below with reference to the accompanying drawings and specific embodiments.

[0086] Example 1

[0087] See Figure 2 The vibration source 10 is a vibration table with a single frequency. The light source in the observation device is a point laser, and the light receiver is a screen 22. The laser 21 can be one of several light sources, such as a point laser with a wavelength of 650nm that emits continuous red light. The laser 21 is fixed to the XY dual-axis displacement stage 33 via a connector 32, allowing movement in both the X and Y axes. The MEMS disc 40 is directly fixed to the vibration table. The red light from the laser 21 is incident on the MEMS mirror 52 of the MEMS disc 40, and the MEMS mirror 52 reflects the red light onto the screen 22. When the MEMS mirror 52 is stationary, it appears as a red spot on the screen 22. The incident and reflected light rays are as follows... Figure 2As indicated by the middle arrow, the vibration table is a single-frequency vibration source. When the output single frequency is the same as the resonant frequency of the MEMS micromirror, the MEMS mirror 52 resonates, causing the light spot to spread into a bright line on the screen 22. When the vibration frequency of the vibration table and the resonance frequency of the MEMS micromirror are not the same, the MEMS micromirror will not resonate, the MEMS mirror 52 remains almost stationary, and the screen 22 still receives a dotted light spot.

[0088] When the driving frequency of the vibration table varies within a certain range (including the resonant frequency of the MEMS micromirrors), the light spot received by the screen 22 will continuously switch between two states: a dot and a line. Therefore, it is possible to accurately determine whether the MEMS micromirror is working properly with the naked eye or a photosensitive device. The vibration table continuously outputs vibration, and the XY dual-axis displacement stage 33 moves rapidly according to the size and spacing of the MEMS micromirrors, ensuring that the light spot of the laser 21 hits a specific MEMS mirror surface 52 of the MEMS wafer 40 each time. The screen 22 displays the spread state of the light spot of each MEMS micromirror. Then, a CP map is used to record the state of all MEMS micromirrors during the test. After the MEMS wafer 40 is diced, only the qualified MEMS micromirrors are selected for packaging, thereby reducing testing costs and improving testing efficiency. At the same time, because no probes are needed, the quality of each MEMS micromirror can be determined without leaving any test marks.

[0089] Example 2

[0090] like Figure 3 As shown, the vibration source 10 is a vibration table capable of outputting a sweep frequency signal. The observation device is a combination of a surface laser (light source) and a photosensitive device 24 (light receiver). The laser 21 is a surface light source that can cover the entire MEMS wafer 40 with light at once. The MEMS wafer 40 has multiple MEMS micromirrors, each MEMS mirror 52 reflecting a light spot, which is projected onto the photosensitive device 24 (the incident and reflected light are like...). Figure 3 As indicated by the middle arrow, the MEMS wafer 40 is indirectly fixed to the vibration table via a bracket 31. The vibration table is a frequency-sweeping source that outputs a frequency-sweeping drive signal within a certain range (including the resonant frequency of the MEMS micromirrors). The light spot received by the photosensitive device 24 will continuously switch between two states: a dot and a bright line. This physical contact detection device can determine the condition of all MEMS micromirrors in the MEMS wafer 40 in one go, selecting, packaging, and testing only the qualified MEMS micromirrors, thus achieving true mass production.

[0091] Example 3

[0092] See Figure 4The vibration source 10 is a vibration source device (vibration table) capable of outputting broadband signals. The observation device is a combination of an array laser (light source) and a CCD camera 23 (light receiver). The laser 21 is an array laser, with the array spacing matching the spacing of the MEMS micromirrors. The array laser can cover the entire MEMS disc 40 with light at once. The MEMS disc 40 has multiple MEMS micromirrors, each of which reflects a light spot 52, which is projected onto the CCD camera 23. The CCD camera 23 has the function of detecting reflected light and can determine the motion state of the MEMS micromirrors (incident and reflected light, such as...). Figure 4 (As indicated by the middle arrow). This detection device can determine the condition of all MEMS micromirrors in the MEMS wafer 40 in one go, mark defective MEMS micromirrors, generate a CP map, and select and package only qualified MEMS micromirrors, which greatly improves testing efficiency, saves testing costs, and enables mass production.

[0093] Example 4

[0094] like Figure 5 As shown, the vibration source 10 is a loudspeaker 11 that can output sound waves. The observation device is a CCD camera 23 (which is a combination of a light source and a light receiver) that can take pictures and observe the dynamics of the micromirror.

[0095] The bracket 31 supports the MEMS disc 40, which is placed above the speaker 11 without contacting it. The speaker driver 12 outputs a drive signal with a certain bandwidth to the speaker 11, or the speaker driver 12 sweeps the frequency within a certain range and outputs the sweep signal to the speaker 11. The frequency range of the wideband or sweep signal includes the resonant frequency of the MEMS micromirror. The speaker 11 uses air as a propagation medium to transfer energy to the MEMS disc 40, causing it to vibrate. The MEMS micromirror resonates near its resonant frequency. When the vibration frequency is not near the resonant frequency of the MEMS micromirror, the MEMS micromirror will not resonate, and the MEMS mirror 52 will remain almost stationary. The speaker driver 12 continuously outputs audio vibrations, and the light spot received by the CCD camera 23 is either a bright line or remains stationary (the incident and reflected light are as follows). Figure 5 As indicated by the dashed arrow in the middle, the CCD camera 23, which continuously switches between these two states, can take pictures to observe the dynamics of the MEMS micromirror and accurately determine whether the MEMS micromirror can work normally.

[0096] In this application, for example, a MEMS wafer 40 is designed with a resonant frequency of 2000Hz. The resonant frequency range of the MEMS micromirrors on the entire MEMS wafer 40 is 2000±50Hz. The sweep frequency speed is set to 500ms, the return speed to 500ms, the sweep start frequency to 1800Hz, and the sweep end frequency to 2200Hz. Clicking to enable the output sweep frequency signal causes the speaker 11 to continuously output a sweep frequency signal with a vibration frequency of 1800-2200Hz. When the vibration frequency reaches the resonant frequency of the MEMS micromirror, 2000Hz, the MEMS micromirror resonates, driving the MEMS mirror surface 52, which can be easily captured by the naked eye or a light receiver (e.g., CCD camera 23). The CCD camera 23 records whether each MEMS micromirror unfolds and resonates, thus determining the quality of each micromirror without using probes or leaving any test traces. The CP map is used to record the state of MEMS micromirrors during testing. After the MEMS wafer is diced 40 times, only the qualified micromirrors need to be selected for packaging, thereby reducing testing costs and improving testing efficiency.

[0097] Compared to existing technologies, the embodiments described above do not require the purchase of expensive testing equipment. The yield of the resonant MEMS micro-motion platform 50 can be detected using weak vibrations generated by a vibration table or a broadband vibration source. Furthermore, this invention can simultaneously detect the device yield of the entire MEMS wafer 40, which is more efficient than existing technologies that can only test one or a few devices per measurement. In addition, the testing device of this application does not need to contact the device surface during testing, thus preventing damage to the device.

[0098] The specific structures of the vibration source 10 and the observation device in the above embodiments of this application can be combined according to actual needs. This application does not limit them. As long as the combination can meet the yield detection of the MEMS micro-motion platform 50, it should fall within the protection scope of this application.

[0099] In summary, the detection device for the MEMS micro-motion platform 50 according to embodiments of the present invention generates vibrations containing the resonant frequency of the MEMS micro-motion platform 50 through the vibration source 10, causing the MEMS micro-motion platforms 50 on the vibration source 10 to resonate. The vibration state of each MEMS micro-motion platform 50 is observed through an observation device to determine the defective MEMS micro-motion platforms 50 on the vibration source 10. The detection device for the MEMS micro-motion platform 50 of this application, by detecting the frequency response of the MEMS micro-motion platform 50 itself, can simultaneously detect the structural yield of all MEMS micro-motion platforms 50 on the vibration source 10, effectively improving the detection efficiency and accuracy of the MEMS micro-motion platforms 50. Furthermore, this detection device for the MEMS micro-motion platform 50 has low cost and does not leave pin marks on the MEMS micro-motion platform 50, thus avoiding damage to the structure of the MEMS micro-motion platform 50.

[0100] like Figure 6 As shown, in a second aspect of this application, a detection method for a MEMS micro-motion platform 50 is provided, applied to the detection device for the MEMS micro-motion platform 50 in the above embodiments. The detection method includes the following steps:

[0101] S1. Generate vibrations containing the resonant frequency of the MEMS micro-motion platform 50 to drive one or more MEMS micro-motion platforms 50 to vibrate simultaneously.

[0102] S2. Observe the vibration state of the MEMS micro-motion platform 50;

[0103] S3. Determine the yield of MEMS micro-motion platform 50 based on the vibration state of MEMS micro-motion platform 50.

[0104] Specifically, see Figure 6 In the detection method of the MEMS micro-motion platform 50 in this embodiment of the invention, firstly, vibrations containing the resonant frequency of the MEMS micro-motion platform 50 can be generated by the vibration source 10. The vibration source 10 can transmit the vibrations to the MEMS micro-motion platform 50, causing the MEMS micro-motion platforms 50 within the vibration range of the vibration source 10 to vibrate simultaneously. Then, the vibration state of the MEMS micro-motion platform 50 is observed. When the vibration frequency transmitted by the vibration source 10 to the MEMS micro-motion platform 50 reaches the same or similar frequency as its own resonant frequency, the MEMS micro-motion platform 50 resonates, and the MEMS micro-motion platform 50 can undergo a certain angle of translation or deflection. By simultaneously initiating vibrations on all MEMS micro-motion platforms 50 on the vibration source 10, the MEMS micro-motion platforms 50 resonate. Of course, for MEMS micro-motion platforms 50 with structural problems, i.e., unqualified micro-motion platform products, their resonant frequency or resonant mode is inconsistent with that of qualified MEMS micro-motion platforms 50. Therefore, during the process of qualified MEMS micro-motion platforms 50 resonating, unqualified products do not vibrate. Finally, the vibration state of the MEMS micro-motion platform 50 can be observed through the observation device to determine the yield of the MEMS micro-motion platform 50, and the MEMS micro-motion platform 50 in the resonant state (qualified product) can be selected for packaging, which greatly improves the detection efficiency of the MEMS micro-motion platform 50.

[0105] See also in this application Figure 5 and Figure 6The vibration source 10 is exemplified by a speaker 11 capable of outputting sound waves. The observation device is exemplified by a CCD camera 23 capable of taking pictures and observing the dynamics of the micromirror. A bracket 31 supports the MEMS disc 40, which is placed above the speaker 11 without contacting it. The speaker driver 12 outputs a drive signal of a certain bandwidth to the speaker 11, or the speaker driver 12 sweeps a frequency within a certain frequency range and outputs the swept signal to the speaker 11. The frequency range of both the wideband and swept signals includes the resonant frequency of the MEMS micromirror. The speaker 11 uses air as a propagation medium to transfer energy to the MEMS disc 40, causing it to vibrate. The MEMS micromirror resonates near its resonant frequency. When the vibration frequency is not near the resonant frequency of the MEMS micromirror, the MEMS micromirror will not resonate, and the MEMS mirror surface 52 will remain almost stationary. The speaker driver 12 continuously outputs audio vibrations, and the light spot received by the CCD camera 23 is either a bright line or remains stationary. It continuously switches between these two states, and the CCD camera 23, which can take pictures to observe the dynamics of the MEMS micromirror, can accurately determine whether the MEMS micromirror is working properly.

[0106] Taking a MEMS wafer 40 with a resonant frequency of 2000Hz as an example, the resonant frequency range of the MEMS micromirrors on the entire MEMS wafer 40 is 2000±50Hz. The speaker driver 12 can be set to a sweep speed of 500ms, a return speed of 500ms, a sweep start frequency of 1800Hz, and a sweep end frequency of 2200Hz. Clicking to enable the output sweep signal causes the speaker 11 to continuously output a sweep signal with a vibration frequency of 1800-2200Hz. When the vibration frequency reaches the resonant frequency of the MEMS micromirror (2000Hz), the MEMS micromirror resonates, driving the MEMS mirror surface 52, which can be easily detected by the naked eye or a light receiver (e.g., a CCD camera 23). The CCD camera 23 records whether each MEMS micromirror unfolds and resonates, thus determining the quality of each micromirror without using probes or leaving any test traces. The CP map is used to record the state of MEMS micromirrors during testing. After the MEMS wafer is diced 40 times, only the qualified micromirrors need to be selected for packaging, thereby reducing testing costs and improving testing efficiency.

[0107] In summary, the MEMS micro-motion platform 50 detection method according to embodiments of the present invention generates vibrations containing the resonant frequency of the MEMS micro-motion platform 50 through a vibration source 10, causing the MEMS micro-motion platforms 50 on the vibration source 10 to resonate. The vibration state of each MEMS micro-motion platform 50 is observed through an observation device to determine the defective MEMS micro-motion platforms 50 on the vibration source 10. The MEMS micro-motion platform 50 detection method of this application, by detecting the frequency response of the MEMS micro-motion platform 50 itself, can simultaneously detect the structural yield of all MEMS micro-motion platforms 50 on the vibration source 10, effectively improving the detection efficiency and accuracy of the MEMS micro-motion platforms 50. Furthermore, this MEMS micro-motion platform 50 detection method is low-cost and does not leave pin marks on the MEMS micro-motion platforms 50, thus avoiding damage to the structure of the MEMS micro-motion platforms 50.

[0108] While specific embodiments of this application have been described in detail by way of examples, those skilled in the art should understand that the above examples are for illustrative purposes only and are not intended to limit the scope of this application. Those skilled in the art should understand that modifications can be made to the above embodiments without departing from the scope and spirit of this application. The scope of this application is defined by the appended claims.

Claims

1. A detection device for a MEMS micro-motion platform, characterized in that, include: A vibration source is used to generate vibrations containing the resonant frequency of the MEMS micro-motion platform. The MEMS wafer includes multiple MEMS micro-motion platforms. The vibration source is a loudspeaker capable of emitting sound waves. The loudspeaker is located below the MEMS wafer and is spaced apart from the MEMS wafer to form a gap. The loudspeaker transmits vibrations to the MEMS wafer in the form of sound waves. Based on the resonant frequency of the MEMS micromirror, the sweep start frequency and sweep end frequency of the loudspeaker driver are set. The loudspeaker continuously outputs a sweep signal with a vibration frequency of 1800Hz to 2200Hz. The sweep start frequency is less than the resonant frequency of the MEMS micromirror, and the sweep end frequency is greater than the resonant frequency of the MEMS micromirror, so that qualified MEMS micro-motion platforms disposed on the MEMS wafer can vibrate, and unqualified MEMS micro-motion platforms cannot vibrate. An observation device is used to observe the vibration state of the MEMS micro-motion platform; The MEMS micro-motion platform has a MEMS mirror, and the observation device includes: Light source and light receiver; Among them, the light emitted by the light source can shine on the MEMS mirror surface and form reflected light on the MEMS mirror surface; The optical receiver receives light reflected from the MEMS mirror. A qualified MEMS micro-motion platform resonates and spreads the light spot on the MEMS mirror into a bright line on the optical receiver. A defective MEMS micro-motion platform reflects only a light spot onto the optical receiver when the vibration source vibrates. The shape of the light spot displayed on the optical receiver determines whether the MEMS micro-motion platform in the MEMS wafer is qualified.

2. The detection device for the MEMS micro-motion platform according to claim 1, characterized in that, The observation device is a camera.

3. The detection device for the MEMS micro-motion platform according to claim 1, characterized in that, The observation device also includes: A displacement stage is provided, and the light source is disposed on the displacement stage and is movable relative to the displacement stage.

4. The detection device for the MEMS micro-motion platform according to claim 1, characterized in that, The light source is a single LED, an LED array, a point laser, a laser array, or a surface light source, and the light receiver is an opaque flat plate, a semi-transparent flat plate, a light screen, a photosensitive device, or a camera.

5. A detection method for a MEMS micro-motion platform, applied to the detection device for the MEMS micro-motion platform according to any one of claims 1-4, characterized in that, The detection method includes the following steps: Vibrations containing the resonant frequency of the MEMS micro-motion platform are generated to drive one or more of the MEMS micro-motion platforms to vibrate simultaneously. Observe the vibration state of the MEMS micro-motion platform; The yield of the MEMS micro-motion platform is determined based on the vibration state of the MEMS micro-motion platform.

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