JP6476805B2 - Inspection system - Google Patents

Description

  The present invention relates to an inspection system.

  A micro electro mechanical system (MEMS) mirror product (element) needs to perform a pass / fail judgment by inspecting a plurality of different characteristics. Conventionally, in order to inspect a biaxial MEMS mirror product, a plurality of inspection apparatuses have been used to inspect a plurality of different characteristics.

  For example, Patent Document 1 discloses a method for measuring the resonance frequency and the maximum optical swing angle of a MEMS mirror element.

  However, several different characteristics in the 2-axis MEMS mirror product had to be inspected by different instruments. Therefore, it is necessary to perform the movement (conveyance by the user), connection, inspection setting, and the like for each measuring instrument, and there is a problem in that the time for performing all inspections cannot be shortened.

  This invention is made | formed in view of the above, Comprising: It aims at providing the inspection system which can test | inspect a biaxial MEMS mirror efficiently.

In order to solve the above-described problems and achieve the object, the present invention provides an inspection stage in which a biaxial MEMS mirror to be inspected can be detachably installed, and an object to be inspected installed on the inspection stage. An irradiation unit that irradiates a laser beam to the sensor, a sensor that receives the laser beam reflected by the inspection target and outputs a signal, and a distance between the inspection target installed on the inspection stage and the sensor together changed, the direction of the object to be inspected placed on the inspection stage to change depending on the direction of the two-axis MEMS mirrors, have a, a driving portion for moving the inspection stage, wherein the sensor , At least one of two light receiving elements and a wobble sensor which are installed apart from each other at a predetermined interval .

  According to the present invention, there is an effect that the biaxial MEMS mirror can be efficiently inspected.

FIG. 1 is a diagram showing an inspection environment of a conventional two-axis MEMS mirror product. FIG. 2 is a diagram illustrating an outline of a configuration of the inspection system according to the embodiment. FIG. 3 is a diagram illustrating a positional relationship between the MEMS installed on the second stage and the sensor. FIG. 4 is a flowchart illustrating an operation example of the inspection system. FIG. 5 is a diagram illustrating an outline of a configuration of an inspection system according to the second embodiment. FIG. 6 is a diagram illustrating the movement position of the PM. FIG. 7-1 is a flowchart illustrating an operation example in which the inspection system inspects the MEMS installed in the second stage. FIG. 7B is a flowchart illustrating an operation example in which the inspection system inspects the MEMS installed in the second stage.

(background)
First, the background that led to the present invention will be described. FIG. 1 is a diagram showing an inspection environment of a conventional two-axis MEMS mirror product. As shown in FIG. 1A, the PZT characteristic of a biaxial MEMS mirror product (hereinafter simply referred to as MEMS) is measured using an LCR meter 1, for example.

  Next, the MEMS was moved by the user to the X-axis dedicated device shown in FIG. 1B and connected and set, and then the deflection angle of reflected light on the X-axis was measured. Further, the MEMS is moved by the user to the Y-axis dedicated device shown in FIG. 1C and connected and set, and then the deflection angle of the reflected light of the Y-axis is measured.

  As described above, conventionally, in order to inspect (measure) a plurality of characteristics of the MEMS, it is necessary to connect and set a dedicated measuring instrument or the like according to the measurement item, and it has been difficult to increase the measurement throughput. It was. In some cases, the reflectance of the MEMS is measured using a power meter before the PZT characteristic is measured.

(First embodiment)
Next, the inspection system 10 according to the first embodiment will be described. FIG. 2 is a diagram illustrating an outline of a configuration of the inspection system 10 according to the first embodiment. As shown in FIG. 2, the inspection system 10 includes an input unit 12, a CPU board 14, a control program 16, a laser diode (LD) control unit 20, a laser irradiation unit 22, an LCR meter 24, a waveform generation unit 26, and a first stage. 30, a first motor control unit 32, a second stage (inspection stage) 34, and a second motor control unit 36. The inspection system 10 also includes a first photo detector (PD) 40, a second photo detector (PD) 42, a wobble sensor 44, and a PSD (Position Sensitive Detector) 46 as sensors, and a sensor control unit 48 that controls these sensors. Is provided. The inspection system 10 is also provided with a power button for switching on / off of the power, a start button for receiving an operation start instruction, and the like.

  The input unit 12 includes a keyboard and a monitor, a touch panel, or the like, and accepts user operation input. The input unit 12 may be a PC (Personal Computer) or the like. The CPU board 14 includes a CPU, a memory, peripherals, and the like, and controls each part constituting the inspection system 10. The control program 16 is executed by the CPU included in the CPU board 14 and performs processing for controlling each unit constituting the inspection system 10.

  The LD control unit 20 controls the laser irradiation unit 22 according to the control of the CPU board 14. The laser irradiation unit 22 irradiates the MEMS installed on the second stage 34 with laser light according to the control of the LD control unit 20. The LCR meter 24 measures a leak value between pins, a capacitance, an inductance, and the like as a PZT characteristic of the MEMS installed on the second stage 34. The waveform generator 26 generates a predetermined arbitrary waveform (a drive signal having a predetermined duty ratio, drive frequency, and voltage), and outputs the generated waveform to the MEMS installed on the second stage 34.

  The first stage 30 is driven by the first motor control unit 32 to move the PSD 46 in the horizontal direction toward the upper side of the second stage 34. The first motor control unit 32 is a PSD (optical position sensor) driving unit that moves the PSD 46 in the horizontal direction toward the laser beam reflected by the MEMS installed on the second stage 34.

  The second stage 34 is configured such that the MEMS to be inspected can be detachably installed. The second stage 34 is driven by the second motor control unit 36, so that the direction of the installed MEMS (installation angle with respect to the laser beam) and Move to change the height (vertical position). The second motor control unit 36 is a drive unit that moves the second stage 34 so as to change the direction and height of the second stage 34.

  The first PD 40 and the second PD 42 are light receiving elements that are separated from each other at a predetermined interval and are disposed above the second stage 34, and the laser beams reflected by the MEMS installed on the second stage 34 are in different positions. Detect with. That is, the first PD 40 and the second PD 42 are sensors that receive a laser beam reflected by the inspection target and output a signal.

  The wobble sensor 44 is disposed above the second stage 34. The wobble sensor 44 is, for example, a triangular slit type capable of changing the pulse width over time. When the second stage 34 moves upward, the pulse width of the output signal (wobble signal) becomes longer, and the second stage 34 moves downward. The pulse width time of the output signal is shortened when moved to. That is, the wobble sensor 44 is also a sensor that receives the laser beam reflected by the object to be inspected and outputs a signal.

  The PSD 46 moves to the upper side of the second stage 34 by being installed on the first stage 30, and obtains the position of the “center of gravity” of the light quantity of the spot of the laser beam reflected by the MEMS installed on the second stage 34. It is an optical position sensor capable of That is, the PSD 46 is also a sensor that receives the laser beam reflected by the object to be inspected and outputs a signal.

  The sensor control unit 48 is a multi-channel time measuring device and also has a function as a TIA (Time Interval Analyzer) board that measures the time of signals output from the first PD 40, the second PD 42, and the wobble sensor 44.

  Next, the positional relationship between the MEMS installed on the second stage 34 and the first PD 40, the second PD 42, the wobble sensor 44, and the PSD 46 will be described in detail. FIG. 3 is a diagram showing a positional relationship between the MEMS installed on the second stage 34 and the first PD 40, the second PD 42, the wobble sensor 44, and the PSD 46. As shown in FIG.

  The MEMS is installed on the second stage 34 at the time of inspection. As described above, the second stage 34 moves in the vertical direction by being driven by the second motor control unit 36. The wobble sensor 44 is disposed substantially directly above the second stage 34. Further, the first PD 40 and the second PD 42 are disposed above the second stage 34 with a predetermined interval therebetween, for example, with the wobble sensor 44 interposed therebetween.

  That is, the second motor control unit 36 is a distance conversion unit that converts (changes) the distance between the MEMS and the first PD 40, the second PD 42, and the wobble sensor 44 by moving the second stage 34 in the vertical direction. Yes. In addition, the second motor control unit 36 converts (changes) the direction (angle) of the second stage 34 with respect to the laser light emitted by the laser irradiation unit 22 by 90 ° according to the direction of the two axes of the MEMS. It is a conversion means.

  Therefore, the inspection system 10 performs distance conversion and angle conversion on the object to be inspected (MEMS), which is a biaxial MEMS mirror product, so that the reflection range of the X-axis laser light and the reflection range of the Y-axis laser light. , And a wobble signal can be detected without moving (attaching / detaching or transporting) the MEMS.

  Further, in the inspection system 10, the first stage 30 driven by the first motor control unit 32 moves the PSD 46 directly above the MEMS (the reflected light range of the laser light) installed on the second stage 34. It has been made possible. That is, the first motor control unit 32 is a position changing unit that changes the position of the PSD 46 in the horizontal direction. Therefore, the inspection system 10 can measure the linearity of the MEMS without moving the MEMS (attaching / detaching or transporting by the user).

  Next, an operation example of the inspection system 10 will be described. FIG. 4 is a flowchart illustrating an operation example in which the inspection system 10 inspects the MEMS installed on the second stage 34. As shown in FIG. 4, in step 100 (S100), the input unit 12 accepts input of measurement conditions by the user. For example, the input unit 12 receives a pass / fail judgment standard (test specification) for the MEMS.

  In step 102 (S102), the inspection system 10 accepts operations such as initial setting by the user and power-on of each part.

  In step 104 (S104), the inspection system 10 accepts pressing of the start button by the user.

  In step 106 (S106), the inspection system 10 measures the PZT characteristics (leak current value between pins, capacitance, inductance, etc.) of the MEMS using the LCR meter 24, and makes a pass / fail judgment. The inspection system 10 proceeds to the process of S128 when the result of the pass / fail determination is not good (when the result of the pass / fail determination is negative), and proceeds to the next step (S108) when the result of the pass / fail determination is good. Similarly, the inspection system 10 proceeds to the process of S128 when the result of the quality determination is not good, and proceeds to the next step when the result of the quality determination is good.

  In step 108 (S108), the inspection system 10 uses the first PD 40 and the second PD 42 to measure, for example, the deflection angle of the laser beam in the X-axis direction, and determines pass / fail.

  In step 110 (S110), the inspection system 10 uses the first PD 40 and the second PD 42 to measure, for example, jitter in the X-axis direction, and performs pass / fail determination.

  In step 112 (S112), the inspection system 10 performs a wobble measurement that detects a wobble signal in the X-axis direction by using the wobble sensor 44, and performs pass / fail determination.

  In step 114 (S114), the inspection system 10 moves the second stage 34 backward (moves downward) by driving the second motor control unit 36. At the same time (in parallel), the inspection system 10 rotates the second stage 34 by 90 ° by driving the second motor control unit 36. Here, the second motor control unit 36 is not limited to simultaneously moving the second stage 34 downward and rotating 90 °.

  In step 116 (S116), the inspection system 10 uses the first PD 40 and the second PD 42 to measure, for example, the deflection angle of the laser beam in the Y-axis direction, and performs pass / fail determination.

  In step 118 (S118), the inspection system 10 uses the first PD 40 and the second PD 42 to measure, for example, jitter in the Y-axis direction, and performs pass / fail determination.

  In step 120 (S120), the inspection system 10 performs a wobble measurement by using the wobble sensor 44 to detect a wobble signal in the Y-axis direction, and determines pass / fail.

  In step 122 (S122), the inspection system 10 moves the first stage 30 on which the PSD 46 is installed to the second stage 34 side on which the MEMS is installed by driving the first motor control unit 32. That is, the inspection system 10 moves the first stage 30 to a position (set side) where the linearity of the MEMS can be measured using the PSD 46 (PSD set).

  In step 124 (S124), the inspection system 10 measures the linearity of the MEMS using the PSD 46, and makes a pass / fail determination.

  In step 126 (S126), the inspection system 10 causes the display unit (or the input unit 12 or the like) to display that the MEMS is a good product (good product display).

  In step 128 (S128), the inspection system 10 causes the display unit (or the input unit 12 or the like) to display that the MEMS is not good (defective product display).

  In step 130 (S130), the inspection system 10 causes the first motor control unit 32 and the second motor control unit 36 to move the first stage 30 and the second stage 34 to the initial positions.

(Second Embodiment)
Next, the inspection system 10a according to the second embodiment will be described. FIG. 5 is a diagram showing an outline of the configuration of the inspection system 10a according to the second embodiment. As shown in FIG. 5, the inspection system 10a includes an input unit 12, a CPU board 14, a control program 16, a laser diode (LD) control unit 20, a laser irradiation unit 22, an LCR meter 24, a waveform generation unit 26, and a first stage. 30, a first motor control unit 32, a second stage (inspection stage) 34, a second motor control unit 36, a third stage 37, and a third motor control unit 38.

  In addition, the inspection system 10a includes a first photo detector (PD) 40, a second photo detector (PD) 42, a wobble sensor 44, a PSD 46, and a PM (power meter: sensor) 49 as sensors, and sensors that control these sensors. A control unit 48 is provided. The inspection system 10a is also provided with a power button for switching on / off of the power, a start button for receiving an operation start instruction, and the like. Note that among the components of the inspection system 10a shown in FIG. 5, the components substantially the same as the components shown in the inspection system 10 (FIG. 2) are denoted by the same reference numerals.

  The third stage 37 is moved by the third motor control unit 38 to move the PM 49. The third motor control unit 38 moves the PM 49 sequentially and accurately to a position facing the laser irradiation unit 22 and a position for receiving the laser light reflected by the MEMS installed on the second stage 34.

  The PM 49 has a size of, for example, 30 mm × 18 mm, and measures the mirror characteristics of the MEMS. Specifically, the PM 49 measures the power of the laser beam irradiated by the laser irradiation unit 22. Next, the PM 49 measures the power of the laser beam reflected by the MEMS. And PM49 measures the reflectance of MEMS, for example using the power of two measured laser beams.

  FIG. 6 is a diagram illustrating the movement position of the PM 49. 6A shows the position of the PM 49 at the horizontal axis viewpoint, and FIG. 6B shows the position of the PM 49 at the vertical axis viewpoint. First, PM49 is arrange | positioned in the position of A shown in FIG. 6 in a measurement standby state. Next, the PM 49 is moved to the position B shown in FIG. 6 so as to face the laser irradiation unit 22, and measures the power of the laser beam irradiated by the laser irradiation unit 22. The PM 49 is moved between the MEMS and the PSD 46, receives the laser beam reflected by the MEMS, and measures the reflectance of the MEMS.

  FIG. 7A and FIG. 7B are flowcharts illustrating an operation example in which the inspection system 10 a inspects the MEMS installed on the second stage 34. Of the processes in the operation example of the inspection system 10a shown in FIGS. 7-1 and 7-2, the same reference numerals are used for the processes that are substantially the same as those in the operation example of the inspection system 10 shown in FIG. Is attached. In step 200 (S200), the inspection system 10a moves the PM 49 installed on the third stage 37 to the position B (FIG. 6).

  In step 202 (S202), the PM 49 measures the power of the laser beam irradiated by the laser irradiation unit 22 and determines whether it is good or bad. The inspection system 10a proceeds to the process of S128 when the result of the quality determination is not good (when the result of the quality determination is NO), and proceeds to the next step (S204) when the result of the quality determination is good. Similarly, the inspection system 10a proceeds to the process of S128 when the result of the quality determination is not good, and proceeds to the next step when the result of the quality determination is good.

  In step 204 (S204), the inspection system 10a moves the PM 49 installed on the third stage 37 to the position C (FIG. 6).

  In step 206 (S206), the PM 49 measures the power of the laser light reflected by the MEMS, measures the reflectivity of the MEMS in comparison with the power of the laser light irradiated by the laser irradiation unit 22, and determines whether it is acceptable. Do.

  In step 208 (S208), the inspection system 10a returns the PM 49 installed on the third stage 37 to the position A (FIG. 6).

  As described above, the inspection system 10 and the inspection system 10 a include the control program 16, change the distance between the inspection target installed on the second stage 34 and the sensor, and the inspection target installed on the second stage 34. Since the second stage 34 is moved so as to change the direction of the object according to the direction of the two axes of the MEMS, a plurality of inspection items for the MEMS to be inspected can be inspected (measured).

DESCRIPTION OF SYMBOLS 10 Inspection system 12 Input part 14 CPU board 16 Control program 20 LD control part 22 Laser irradiation part 24 LCR meter 26 Waveform generation part 30 1st stage 32 1st motor control part 34 2nd stage 36 2nd motor control part 37 3rd Stage 38 Third motor control unit 40 First PD
42 2nd PD
44 Wobble sensor 46 PSD
48 Sensor controller 49 PM

JP 2009-109305 A

Claims (4)

An inspection stage capable of detachably installing a biaxial MEMS mirror to be inspected;
An irradiating unit for irradiating a laser beam to an object to be inspected installed on the inspection stage;
A sensor that receives a laser beam reflected by the inspection target and outputs a signal;
While changing the distance between the inspection target installed on the inspection stage and the sensor, the direction of the inspection target installed on the inspection stage is changed according to the direction of the two-axis MEMS mirror , A drive unit for moving the inspection stage;
I have a,
The sensor is
It is at least one of two light receiving elements installed at a predetermined interval and a wobble sensor,
Inspection system characterized by that. An optical position sensor capable of detecting the position of the center of gravity of the amount of laser light spot;
An optical position sensor driving unit that moves the optical position sensor toward the laser beam reflected by the inspection target installed on the inspection stage;
The inspection system according to claim 1 , further comprising: An LCR meter for measuring a PZT characteristic of an inspection target installed on the inspection stage;
A waveform generating unit that generates a signal having an arbitrary predetermined waveform and outputs the signal to an inspection target installed on the inspection stage;
Inspection system according to claim 1 or 2, characterized in that it further comprises a. The sensor is
And the power of the laser beam the irradiation unit irradiates, according to any one of claims 1 to 3, further comprising a power meter for measuring the power of the laser beam to be inspected was reflected Inspection system.

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