JP2007127605A - Probe-driving type displacement measuring instrument - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-sized probe-driving type displacement measuring instrument, with reduced variations in measurement accuracy among individual pieces. <P>SOLUTION: This probe-driving type displacement measuring instrument is structured by being equipped with a substrate 1 and a movable part 2, formed displaceably with respect to the substrate 1. The movable part 2 is integrally formed out of a probe 4 for copying the surface of an object under detection, a first sensor 6 for detecting the displacement amount of the probe 4, and a first electrode for driving the probe 4. The movable part 2 is formed integrally out of a second sensor 9, at a position confronting the first sensor and a second electrode 8, at a position facing the first electrode 5. In addition, the first and second sensors 6 and 9 constitute an encoder for detecting the displacement amount of the probe 4, while the first and second electrodes 5 and 8 constitute an actuator that drives the probe 4. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a probe-driven displacement measuring apparatus that detects the surface shape of an object to be measured.

  With the recent development of microfabrication technology, highly accurate shape measurement that detects a fine surface profile of an object to be measured is required.

For this shape measurement, an actuator such as a piezo element that serves as a driving force is installed in the probe body, the probe body is caused to follow the surface of the object to be measured by the driving force of the actuator, and the amount of change in the driving force caused by this A probe-driven displacement measuring device that detects the surface shape of an object to be measured by measuring the above is known (Patent Document 1).
Japanese Patent Laid-Open No. 2002-39799, FIG.

  However, such a conventional probe-driven displacement measuring device has a large overall structure because an actuator such as a piezo element is added to the probe body later. In addition, since there are large individual differences between the probe body and the piezo elements, the probe-driven displacement measuring device with a piezo element added to the probe body has different characteristics depending on the individual produced, and has a stable measurement accuracy. There is a problem that it is difficult to manufacture a measuring device.

  The present invention has been made in view of these points, and is a probe-driven displacement that is capable of measuring the profile of the surface of an object to be measured with a stable characteristic with a certain characteristic between individuals, with the entire apparatus being small. It aims at providing a measuring device.

  A probe-driven displacement measuring device according to the present invention includes a substrate, and a movable part including a probe that is supported by an elastic support member so as to be displaceable in the measurement axis direction with respect to the substrate and that contacts a measurement object The movable part has a first electrode part and a first sensor part, and the substrate has a second electrode part facing the first electrode part and a second sensor facing the first sensor part. The first electrode part and the second electrode part constitute an electrostatic actuator that drives the probe to be displaced, and the first sensor part and the second sensor part determine the displacement amount of the probe. An encoder to be detected is configured, and the substrate and the movable portion are integrally formed by a fine processing technique.

  According to the present invention, the probe main body, the first electrode part constituting the actuator, and the first sensor part constituting the displacement detection sensor part are integrally formed on the movable part connected to the substrate via the elastic support member. The probe-driven displacement measuring device can be reduced in size by integrally forming the second electrode part constituting the actuator and the second sensor part constituting the displacement detection sensor part on the substrate. In addition, since the probe main body and the actuator can be integrally formed from the same member, an effect of reducing variations in probe measurement accuracy among individuals can be expected.

  Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.

  FIG. 1 is a plan view of a probe-driven displacement measuring apparatus according to the first embodiment of the present invention, and FIG. 2 is a cross-sectional view taken along line A-A ′ of FIG. 1. FIG. 3 is an enlarged perspective view of the main part of the apparatus.

  This probe-driven displacement measuring device is connected to a substrate 1 by a substrate 1 and an anchor 7 included in the substrate 1 and includes a parallel leaf spring 3 to be described later so as to be movable with respect to the substrate 1. 2. The movable portion 2 is formed on a probe 4 that imitates the surface of the object to be detected, a parallel leaf spring 3 that absorbs the stress applied when the probe 4 imitates the object to be detected by elastic deformation, and a member constituting the probe 4. A comb-shaped first sensor 6 that detects a displacement that occurs when copying the surface of the object to be detected, and a pair of comb-shaped first electrodes 5 that are installed at both ends in the displacement direction of the probe 4 to drive the probe. And is configured. The substrate 1 includes a pair of comb-shaped second sensors 9 disposed so as to face each other so as to sandwich the first sensor 6, and the first sensor 6 and the second sensor 9 include the first sensor 6 and the second sensor 9. A capacitance type encoder that detects the displacement of the probe 4 by measuring the amount of change in capacitance due to the relative displacement between the first sensor 6 and the second sensor 9 is configured. Here, as the encoder, a photoelectric encoder, a magnetic encoder, an electromagnetic induction encoder, or the like may be used. The substrate 1 is provided with a capacitance-type second electrode so as to face the first electrode 5, and the first electrode 5 and the second electrode 8 are applied with a voltage to at least one of them. A capacitive actuator that drives the probe 4 is configured. The external locking member 10 is formed in a shape protruding from the upper surface of the substrate 1 and is a locking member with an external component such as a cover glass (not shown).

The probe-driven displacement measuring apparatus configured as described above is, for example, a Si—SiO ₂ —Si bonded substrate in which a sacrificial layer of SiO ₂ is formed on a base substrate made of a Si substrate and the Si substrate is further installed. The substrate 1 and the movable part 2 can be manufactured as a single unit by performing fine processing such as photolithography and etching on the substrate.

  The effect of the probe-driven displacement measuring device configured as described above will be described.

  A second electrode 8 and a second sensor 9 are integrally formed on the substrate 1, and the first electrode 5 and the first sensor 6 are integrally formed on the movable part 2 provided with the probe 4 at positions facing these, respectively. Since it is formed, there is no need to install a retrofit sensor or actuator. In addition, since the sensor and the actuator are integrally formed, it is possible to provide a probe-driven displacement measuring device that has small individual differences between devices to be manufactured and has stable accuracy.

  FIG. 4 is a partially enlarged perspective view of a probe-type displacement measuring apparatus according to the second embodiment of the present invention. FIG. 5 is a B-B ′ cross-sectional view of FIG. 4.

  In the first embodiment, the capacitive encoder that detects the displacement of the probe 4 includes a first sensor installed on an extension of a member constituting the probe 4 and a second sensor 9 that sandwiches the first sensor from the planar direction. In the second embodiment, for example, a second sensor 9 ′ is disposed on the lower surface of the upper cover member 11 such as a cover glass, and the second sensor 9 ′ and a member constituting the probe 4. The first sensor 6 installed on the extension of the encoder constitutes an encoder.

  Next, the control method of this probe drive type displacement measuring apparatus will be described.

  Generally, in a displacement measuring device using a probe, a tapping method in which the probe is vibrated by an actuator and intermittently contacts the object to be measured, and a contact that follows the surface of the object to be measured while contacting the surface of the object to be measured. There is a method. In both the tapping method and the contact method, the amount of displacement of the probe is measured by detecting the amount of displacement of the probe with an encoder, and an actuator is used so that the amount of displacement of the probe body relative to the substrate is always constant. At the same time as controlling the position of the probe with respect to the fixed part, the relative position between the object to be measured and the probe body is controlled to be constant by driving the displacement measuring device with a voice coil or a piezo element (not shown) according to this control amount. There is a method of measuring the amount of displacement of the object to be measured from the control amount at the time. In the tapping method and the contact method, a measurement method in which the surface of the object to be measured is a position where the probe approaches the object to be measured and the electrostatic attractive force becomes a constant value without actually contacting the probe and the object to be measured. Is widely used. The present invention can be carried out using any control method such as a tapping type or a contact type.

It is a top view of the probe concerning the embodiment of the present invention. It is A-A 'sectional drawing of FIG. It is a partial enlarged view of the same probe drive type displacement measuring device. It is a top view of the probe drive type displacement measuring device concerning other embodiments. FIG. 5 is a B-B ′ cross-sectional view of FIG. 4.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Board | substrate, 2 ... Movable part, 3 ... Parallel leaf spring, 4 ... Probe, 5 ... 1st electrode, 6 ... 1st sensor, 7 ... Anchor, 8 ... 2nd electrode, 9 ... 2nd sensor, 10 ... External Locking part, 11 ... cover glass.

Claims (2)

A substrate,
A movable part including a probe that is supported by an elastic support member so as to be displaceable in the measurement axis direction with respect to the substrate and that contacts a measurement object
The movable part has a first electrode part and a first sensor part,
The substrate has a second electrode portion facing the first electrode portion, and a second sensor portion facing the first sensor portion,
The first electrode portion and the second electrode portion constitute an electrostatic actuator that drives the probe to be displaced,
The first sensor unit and the second sensor unit constitute an encoder that detects a displacement amount of the probe;
The probe-driven displacement measuring apparatus, wherein the substrate and the movable part are integrally formed by a fine processing technique.   2. The probe according to claim 1, wherein the first sensor unit and the second sensor unit constitute one of an encoder of a capacitive encoder, a photoelectric encoder, a magnetic encoder, and an electromagnetic induction encoder. Drive type displacement measuring device.

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