JP2012137323A - Measuring device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a measuring device capable of accurately measuring a sample with application of heat with simple structure.SOLUTION: A measuring device is arranged at a position to hold a sample A or a position facing the sample A, and comprises: a transparent member 12 having a transparent substrate 121 and a transparent conductive film 122 provided on a surface of the transparent substrate 121; an optical detector 22 for photographing the sample A; and a thermal controller 42 for controlling temperature of the transparent member 12 by controlling voltage applied to the transparent conductive film 122 of the transparent member 12.

Description

  The present invention relates to a measuring device that measures the shape of an electronic component or the like that can be deformed by a temperature change.

  Conventionally, various devices are known as devices for measuring the shape of a sample in a state where heat is applied. For example, Patent Documents 1 to 3 disclose a configuration in which a sample is placed in a sealed space and the temperature of the atmosphere in the sealed space is controlled. Such a conventional configuration requires a chamber for forming a sealed space and a means for sending hot air into the chamber. As a result, the configuration of the apparatus becomes complicated, and space saving, cost reduction, and improvement in thermal efficiency are hindered. Moreover, when measuring a small sample, there is a possibility that the sample is moved by hot air.

JP 2005-227188 A JP 2001-041718 A JP 2008-261679 A

  It is also conceivable to use an infrared lamp as a heating means instead of hot air. However, when a light source such as an infrared lamp is used as the heat source, light that is not required for measurement is emitted from the heat source when heat is generated, so the light necessary for shape measurement is affected and accurate measurement may be difficult. is there.

  Therefore, an object of the present invention is to provide a measuring apparatus capable of accurately measuring a sample under temperature control with a simple configuration.

  The measuring device disclosed in the present application is disposed at a position for holding a sample to be measured or at a position facing the sample, and includes a transparent substrate and a transparent member having a transparent conductive film provided on the surface of the transparent substrate, and the sample And a heat control unit that controls the temperature of the transparent member by controlling the voltage applied to the transparent conductive film of the transparent member.

  Thus, by applying a voltage to the transparent conductive film provided on the surface of the transparent substrate and controlling the temperature, the heating means can be realized with a simple configuration of the transparent substrate and the transparent conductive film. Furthermore, generation of light that affects measurement can be avoided. Therefore, it is possible to accurately measure the sample under temperature control with a simple configuration.

  In the measurement apparatus, the transparent member may also serve as a sample table for placing the sample. Thereby, since a heat source can be arrange | positioned in the place close | similar to a sample, thermal efficiency becomes high. In addition, since the heating means does not have to be provided as a separate member, the apparatus configuration becomes simpler.

  In the measurement apparatus, the light detection unit may be disposed below the sample table and detect light from the sample placed on the upper surface of the transparent member from the lower surface of the transparent member. . With this configuration, the sample can be held and heated by the transparent member. In addition, the sample can be photographed through the transparent member. Therefore, the configuration of the apparatus is simplified and temperature control is facilitated. In addition, thermal efficiency is improved and power consumption can be suppressed.

  The measurement apparatus further includes a light irradiation unit that irradiates the sample with light, and the transparent member is disposed between at least one of the light irradiation unit and the light detection unit and an installation position of the sample. It can be. With this configuration, since the transparent member is disposed on the optical path of light used for photographing, the apparatus can be further reduced in size and simplified.

  In the measurement apparatus, the light detection unit may detect light from the sample when the transparent member reaches a predetermined temperature by the thermal control unit. Thereby, the sample at a predetermined temperature can be measured.

  The measurement apparatus may further include a calculation unit that determines whether the sample satisfies a predetermined criterion based on an image obtained by the previous light detection unit. This allows inspection of the shape of the sample at a controlled temperature.

  According to the present disclosure, it is possible to accurately measure a sample under temperature control with a simple configuration.

The figure which shows the outline of a structure of the test | inspection apparatus concerning 1st Embodiment. Top view of transparent member in FIG. The figure which shows the structural example of the measuring device concerning 2nd Embodiment. The figure which shows the structural example of the measuring device concerning 3rd Embodiment. The figure which shows the structural example of the measuring device concerning 4th Embodiment. The figure which shows the structural example of the measuring device concerning 5th Embodiment. The figure which shows the modification of the measuring device shown in FIG. The figure which shows the other modification of the measuring device shown in FIG. The figure which shows the structural example of the inspection apparatus concerning 6th Embodiment. A diagram schematically showing the projection and shooting of the light pattern Flow chart showing an example of processing for three-dimensional measurement of a sample FIG. 12 is a graph representing the formula (1).

  Embodiments of the present invention will be specifically described below with reference to the drawings.

(First embodiment)
FIG. 1 is a diagram illustrating a configuration example of a measurement apparatus according to the first embodiment. The measurement apparatus shown in FIG. 1 includes a transparent member 12 on which the sample A is placed, a light detection unit 22 that detects light from the sample, and a heat control unit 42 that controls the temperature of the transparent member 12. The thermal control unit 42 and the light detection unit 22 are connected to the computer 1.

  The transparent member 12 includes a transparent substrate 121 and a transparent conductive film 122 provided on the surface of the transparent substrate 121. Electrodes 41 a and 41 b are formed on both ends of the transparent conductive film 122. The electrodes 41a and 41b can be formed of, for example, gold (Au) or the like. FIG. 2 is a top view of the transparent member 12 in FIG. In the example shown in FIGS. 1 and 2, the transparent member 12 has a rectangular flat plate shape. A transparent conductive film 122 is formed on the entire top surface of the transparent substrate 121. On the transparent conductive film 122, electrodes 41a and 41b are respectively provided at end portions along two opposing sides of the rectangle. The electrodes 41 a and 41 b are electrodes for applying a voltage to the transparent conductive film 122, and are formed at two locations so as to sandwich at least a part of the surface region formed by the transparent conductive film 122. Thus, when a voltage is applied between the electrodes 41a and 41b, heat is generated in the region of the transparent conductive film 122 sandwiched between the electrodes 41a and 41b. It can be said that the transparent conductive film 122 is a transparent heater.

  In addition, the shape of the transparent member 12 is not restricted to the example shown in FIG.1 and FIG.2. For example, the shape of the transparent member 12 can be a disk shape or a cylindrical shape. Further, the transparent conductive film 122 may be formed not on the entire top surface of the transparent substrate 121 but on a part thereof. For example, the transparent conductive film 122 can be patterned into a shape suitable for efficiently heating the sample.

  The electrodes 41a and 41b are not necessarily provided. For example, a probe for applying a voltage may be directly attached to the transparent conductive film 122. Further, an additional film can be formed on the transparent conductive film 122. For example, by forming an insulating film so as to cover the transparent conductive film 122, the user can be prevented from receiving an electric shock. Further, the insulating film can prevent current from leaking from the transparent conductive film 122 to the sample when the sample is a conductor.

  The thermal control unit 42 applies a voltage to the transparent conductive film 122 through the electrodes 41a and 41b. The heat control unit 42 can control the temperature of the transparent member 12 by controlling this voltage. Thereby, the temperature of the sample A can be controlled. The heat control unit 42 can be said to be a temperature controller.

  A thermocouple 43 can be attached to the transparent conductive film 122. The thermal control unit 42 adjusts the voltage applied to the transparent conductive film 122 based on the temperature measured by the thermocouple 43. For example, the thermal control unit 42 can control the magnitude of the voltage to the transparent conductive film 122 or ON / OFF of the voltage so as to maintain the temperature instructed by the computer 1.

  From the viewpoint of accurately controlling the temperature of the sample A, the position where the thermocouple 43 is attached is preferably a position close to the sample A, but the position of the thermocouple 43 is not limited to the example shown in FIG. For example, the thermocouple 43 can be attached to the lower surface of the transparent member 12 (the surface facing the sample A mounting surface). Thereby, the upper surface of the transparent member 12, which is the surface on which the sample A is placed, can be flattened.

[Transparent conductor film]
The material of the transparent conductive film 122 is not limited to a specific material. For example, a material mainly composed of indium oxide (for example, ITO (Indium Tin Oxide)), a material mainly composed of zinc oxide (for example, AZO (Aluminium Zinc Oxide), GZO (Gallium doped Zinc Oxide), etc.), or A material containing tin oxide as a main component can be used for the material of the transparent conductive film 122.

The transmittance of the transparent conductive film 122 is preferably 80% or more, for example. By setting the transmittance of the transparent conductive film 122 to 80% or more, it is possible to prevent light used for measurement from being disturbed by the transparent conductive film 122 and affecting the measurement result. The resistivity of the transparent conductive film 122 is preferably 10 ⁻³ [Ω · cm] or less. Note that the resistivity of the electrodes 41 a and 41 b is preferably smaller than the resistivity of the transparent conductive film 122.

  The transparent conductive film 122 can be formed on the transparent substrate 121 by, for example, sputtering, PLD (Pulsed Laser Deposition), or vacuum deposition. The surface accuracy of the transparent substrate 121 can be determined according to, for example, the resolution or measurement accuracy of the measurement device. As an example, when the measurement accuracy required by the measuring apparatus is about ± 1 μm, the surface accuracy of the transparent substrate 121 is preferably λ (inspection wavelength = 0.6328 μm) or less. Here, the surface accuracy is the difference (PV value) between the highest position (Peak) and the lowest position (valley) in the entire effective anti-surface.

  In the example shown in FIG. 1, a transparent conductive film 122 is provided on the surface of the transparent member 12 on which the sample is placed (sample placement surface). The transparent conductive film 122 may be provided on a surface facing the sample placement surface.

  The light detection unit 22 is disposed below the transparent member 12. The light detection unit 22 images the sample A placed on the upper surface of the transparent member 12 from the lower surface of the transparent member 12. The light detection unit 22 converts the light from the sample A into an electrical signal and outputs it, and includes, for example, a photosensor such as a CCD or CMOS. In the example illustrated in FIG. 1, the light detection unit 22 images the sample A and transmits an image signal or image data of the sample A to the computer 1.

  The computer 1 includes a calculation unit 50. The computing unit 50 includes, for example, a measurement control unit 51, an image processing unit 52, and a determination unit 53. For example, the measurement control unit 51 can set the temperature of the transparent member 12 by sending a signal indicating the set temperature to the temperature control unit 42. Moreover, the light from the sample at the set temperature can be detected by sending a control signal to the light detector 22 in conjunction with the temperature setting. For example, the measurement control unit 51 can detect light from the sample at an arbitrary temperature by performing a temperature setting instruction to the temperature control unit 42 and a light detection instruction to the light detection unit 22 at appropriate timing. it can.

  The computer 1 can also record in advance a program that controls temperature setting and light detection as a program that defines the operation of the measurement control unit 51. In addition, the computer 1 may include a user interface unit (not shown) that receives input of control information including a set temperature, light detection timing, and the like from the user. In this case, the measurement control unit 51 can control the operations of the heat control unit 42 and the light detection unit 22 based on the control information input from the user.

  The image processing unit 52 processes image data or an image signal obtained by light detection by the light detection unit 22. For example, the image processing unit 52 receives an image based on the light detected by the light detection unit 22 and generates 2D image data of the sample A or shape data indicating a 3D shape. For example, when the top surface of the transparent member 12 is an XY plane, the shape data is represented by a value indicating a height (for example, a distance from the top surface of the transparent member 12) at each position (x, y) on the XY plane. it can. The image processing unit 52 stores, for example, two-dimensional image data or three-dimensional shape data of the sample A generated based on the signal or image data sent from the light detection unit 22 in a memory on the computer 1, and determines the determination unit. 53 can be made accessible.

  The determination unit 53 uses the shape data or image data of the sample A calculated by the image processing unit 52 to determine whether the sample satisfies a predetermined standard. For example, the determination unit 53 determines whether the height information of the sample A calculated by the image processing unit 52 satisfies a predetermined standard. Alternatively, the determination unit 53 can determine whether the shape of the sample is within a predetermined range, whether it is not deviated from the reference shape, or the like. As a result, the shape of the sample can be inspected. Further, the determination result of the sample may be recorded or output in association with the set temperature at the time of acquiring the sample image. The determination process and determination criteria are not limited to specific ones.

  The computer 1 includes at least a processor such as a CPU and storage means such as a memory. The functions of the functional units (measurement control unit 51, image processing unit 52, and determination unit 53) of the calculation unit 50 can be realized by the processor executing a predetermined program recorded in the memory. From the viewpoint of executing processing at high speed, for example, the function of the image processing unit 103 may be realized by hardware dedicated to image data processing (image processing board) provided separately from the general-purpose processor of the computer 1. . Examples of such hardware include a GPU (Graphics Processing Unit), a VPU (Visual Processing Unit), a geometry engine, and other ASIC (Application Specific Integrated Circuit). Further, the thermal control unit 42 may be configured by an electronic circuit or chip on a board provided separately from the computer 1, or may be realized as a function of the calculation unit 1 of the computer 1. Alternatively, for example, the heat control unit 42 may be mounted on the transparent substrate 121 by a COG (Chip On Glass) technique or the like.

  As described above, in the measurement apparatus shown in FIG. 1, the transparent member 12 having the transparent conductive film 122 is disposed on the optical path connecting the sample A and the light detection unit 22. Therefore, a heating element for adjusting the temperature of the sample A can be arranged near the sample A. As a result, thermal efficiency and space utilization efficiency can be improved. Moreover, in the example shown in FIG. 1, since the transparent member 12 serves as both the means for holding the sample A and the means for heating the sample A, it is possible to further improve the thermal efficiency and simplify the apparatus.

  In addition, since the light from the sample A placed on the upper surface of the transparent member 12 is detected via the transparent member 12, the shape of the sample can be measured using the upper surface of the transparent member 12 as a reference. Here, the transparent member 12 is also a heat source having a transparent conductive film 122 as a heating means. That is, the sample is measured with reference to the upper surface of the heat source. Therefore, for example, the deformation of the sample due to heat can be detected more significantly.

  Further, for example, when the temperature is adjusted by heating the atmosphere of the sample as in the prior art, an additional member such as a chamber for sealing the space of the sample A is required. On the other hand, in this embodiment, since the table holding the sample A is a heat source, the sample can be efficiently heated and the apparatus structure can be simplified.

  In the present embodiment, since the sample A is heated by applying a voltage to the transparent conductive film 122 to generate heat, the shape measurement can be performed while the transparent member 12 serving as a heating means is kept transparent. Is possible. That is, since the heating unit itself can be configured not to emit light unnecessary for image processing, adverse effects on measurement by the heating unit can be suppressed. For example, when an infrared lamp or the like is used as the heating means, the infrared lamp emits light including visible light during heat generation, which may adversely affect the measurement. On the other hand, in this embodiment, since the heat source is a transparent member and does not emit visible light, such a countermeasure is unnecessary.

(Second Embodiment)
FIG. 3A is a diagram illustrating a configuration example of a measurement apparatus according to the second embodiment. The measurement apparatus illustrated in FIG. 3 includes two light detection units 22-1 and 22-2 that photograph the sample A placed on the transparent member 12 from different directions. The transparent member 12 includes a transparent substrate 121 and a transparent conductive film 122 as in the first embodiment. The light detection units 22-1 and 22-2 are disposed below the transparent member 12. The light detection units 22-1 and 22-2 photograph the sample A from the lower surface of the transparent member 12 through the transparent member 12.

  FIG. 3B is a diagram illustrating a modified example of the measurement apparatus according to the second embodiment. In the example shown in FIG. 3B, the transparent member 12-1 is provided with the table 12-2 on which the sample A is installed at the top and the space for the sample interposed therebetween. The transparent member 12-1 is disposed so that the surface of the transparent member 12-1 on which the transparent conductive film 122 is formed faces the table 12-2, that is, the sample. The light detection units 22-1 and 22-2 are disposed further above the transparent member 12-1. That is, the transparent member 12-1 is disposed between the table 12-2 and the light detection units 22-1 and 22-2. The light detection units 22-1 and 22-2 can photograph the sample through the transparent member 12-1. The table 12-2 does not necessarily need to be transparent.

  Also with the configuration shown in FIG. 3B, the heat source can be arranged near the sample A, so that the thermal efficiency can be improved and the measuring device can be simplified. Moreover, in FIG.3 (b), since it is the structure which pinches | interposes the space of the sample A with the table 12-2 and the transparent member 12-1, heat dissipation is suppressed.

  FIG. 3C is a diagram illustrating another modified example of the measuring apparatus according to the second embodiment. In the example shown in FIG. 3C, the transparent conductive film 122 is formed on the surface of the transparent member 12 that faces the sample placement surface. In this configuration, since the transparent conductive film 122 is formed on the lower surface of the transparent member 12, it is possible to reduce the degree of risk of electric shock when the user touches the transparent conductive film 122 during voltage application. Further, when the sample touches the transparent conductive film 122, it is possible to prevent a situation in which an electric current flows through the sample placed on the transparent member 12 for measurement.

  3A, 3B, and 3C, the temperature of the electrodes 41a and 41b and the transparent member 12 provided at both ends on the transparent conductive film 122 is measured as in FIG. There may be provided the thermocouple 43, the heat control unit 42 that controls the voltage between the electrodes 41a and 41b, and the computer 1 that controls the heat control unit 42 and the light detection units 22-1 and 22-2.

  The image processing unit 52 of the computer 1 can calculate the three-dimensional shape of the sample A from the images of the sample A taken by the plurality of light detection units 22-1 and 22-2 using, for example, the stereo method. . The image processing unit 52 specifies the corresponding points of the stereo images obtained from the plurality of light detection units 22-1 and 22-2 by matching processing, and analyzes the matched stereo images to analyze the three-dimensional sample A. The shape can be measured. In other words, the image processing unit 52 associates pixels among the plurality of images acquired by the plurality of light detection units 22-1 and 22-2, the pixel on the associated one image, and the other image By applying the principle of triangulation to the positional difference (parallax) with the upper pixel, the distance from the light detection unit 22-1 or the light detection unit 22-2 to the point on the sample corresponding to the pixel is calculated. It can be measured.

  The measurement apparatus according to the present embodiment is an example of a passive shape measurement apparatus using a plurality of cameras (an example of a light detection unit). Note that the number of light detection units is not limited to two and may be three or more. Further, the method for obtaining the distance (height information) or the three-dimensional shape to the sample using the sample image acquired by the light detection unit is not limited to the stereo method. For example, a focus method such as a (DFD (Depth from Defocus) method, a lens focus method, or the like can be used. When the focus method is used, only one light detection unit may be used.

(Third embodiment)
FIG. 4 is a diagram illustrating a configuration example of a measurement device according to the third embodiment. The measurement apparatus shown in FIG. 4 includes a laser displacement meter 22 a that irradiates a sample A placed on the transparent member 12 with a laser and detects the laser reflected by the sample A. The transparent member 12 includes a transparent substrate 121 and a transparent conductive film 122 as in the first embodiment. The laser displacement meter 22 a is disposed below the transparent member 12. The laser displacement meter 22 a irradiates the sample A with laser through the transparent member 12 and detects light from the sample A through the transparent member 12. That is, the transparent member 12 is provided on the optical path between the laser displacement meter 22a and the sample A. The laser displacement meter 22a has functions of a light irradiation unit and a light detection unit.

  It should be noted that the thickness of the transparent member 12 is preferably constant from the viewpoint of suppressing the influence of laser refraction on the measurement result. That is, the transparent member 12 is preferably a transparent parallel plate in which the laser incident surface and the emission surface of the transparent member 12 are parallel.

  Also, in FIG. 4, although not shown, as in FIG. 1, between the electrodes 41a and 41b provided at both ends on the transparent conductive film 122 and the thermocouple 43 for measuring the temperature of the transparent member 12, and between the electrodes 41a and 41b. There may be provided a thermal control unit 42 for controlling the voltage of the computer 1 and a computer 1 for controlling the thermal control unit 42 and the laser displacement meter 22a.

  As shown in FIG. 4, by irradiating the laser from the lower side of the transparent member 12 holding the sample A, the shape of the lower surface of the sample A can be accurately measured. Moreover, since the surface on which the sample A is placed generates heat, the laser displacement meter 22a can detect the displacement of the portion in which the displacement due to heating appears remarkably.

(Fourth embodiment)
FIGS. 5A and 5B are diagrams illustrating a configuration example of the measurement apparatus according to the fourth embodiment. 5A and 5B includes a transparent member 12 on which the sample A is placed, a light irradiation unit 21 that irradiates the sample A with light, and light that detects light from the sample A. It is provided with a detector 22.

  In the example shown in FIG. 5A, the light irradiation unit 21 is provided on the surface side of the transparent member 12 facing the sample mounting surface, and irradiates the sample A with light through the transparent member 12. The light detection unit 22 is provided on the sample mounting surface side of the transparent member 12 and detects light that has passed through the transparent member 12 and the sample A in order from the light irradiation unit 21. The light detection unit 22 can acquire a fluoroscopic image of the sample A.

  In the example illustrated in FIG. 5B, the light irradiation unit 21 is provided on the sample placement surface side of the transparent member 12 and directly irradiates the sample A with light. The light detection unit 22 is provided on the surface side of the transparent member 12 that faces the sample placement surface, and detects light that has exited from the light irradiation unit 21 and sequentially transmitted through the sample A and the transparent member 12.

  Although not shown in FIGS. 5A and 5B, the temperatures of the electrodes 41a and 41b and the transparent member 12 provided at both ends on the transparent conductive film 122 are measured as in FIG. The thermocouple 43, the heat control unit 42 that controls the voltage between the electrodes 41a and 41b, and the computer 1 that controls the heat control unit 42 and the light detection unit 22 may be provided.

  The present embodiment is an example in which the light irradiation unit 21 and the light detection unit 22 are arranged to face each other with the transparent member 12 interposed therebetween. As in this embodiment, by disposing a transparent member between at least one of the light irradiation unit or the light detection unit and the sample, it is possible to improve heat transfer efficiency and simplify the apparatus. .

(Fifth embodiment)
FIG. 6A is a diagram illustrating a configuration example of a measurement apparatus according to the fifth embodiment. The measurement apparatus shown in FIG. 6A includes a light irradiation unit 21 that irradiates light to the sample A placed on the transparent member 12, and light that photographs the sample A by detecting light from the sample A. And a detector 22. The transparent member 12 includes a transparent substrate 121 and a transparent conductive film 122, as in the first embodiment.

  The light irradiation unit 21 and the light detection unit 22 are disposed on the side of the transparent member 12 that faces the mounting surface of the sample A. Therefore, the irradiation light of the light irradiation unit 21 reaches the sample A through the transparent member 12. The light scattered by the sample A reaches the light detection unit 22 through the transparent member 12 and is detected. In this way, the configuration of the apparatus is simplified by irradiating light through the transparent member 12 holding the sample A and having the heat generating means, and detecting the light from the sample A through the transparent member 12. The Further, since the heat source can be arranged near the sample A, the conversion efficiency to heat is improved, and the power consumption can be suppressed.

  FIG. 6B is a diagram illustrating a modification of the present embodiment. In the example shown in FIG. 6B, the transparent member 12-1 is provided with the table 12-2 on which the sample A is installed at the top and the space for the sample. The transparent member 12-1 is disposed so that the surface of the transparent member 12-1 on which the transparent conductive film 122 is formed faces the table 12-2, that is, the sample. The light irradiation unit 21 and the light detection unit 22 are disposed further above the transparent member 12-1. That is, the transparent member 12-1 having the transparent conductive film 122 is disposed between the table 12-2 and the light irradiation unit 21 and the light detection unit 22. The light irradiation unit 21 irradiates the sample with light through the transparent member 12-1, and the light detection unit 22 can photograph the sample through the transparent member 12-1. Also with the configuration shown in FIG. 6B, the heat source can be brought close to the sample A to improve the heat transfer efficiency, and the measuring device can be simplified. Moreover, in FIG.6 (b), since it is the structure which pinches | interposes the space of the sample A with the table 12-2 and the transparent member 12-1, the divergence of the heat from the sample A periphery is suppressed. Note that the table 12-1 on which the sample A is placed does not have to be transparent.

  The measuring apparatus shown in FIG. 6C has a configuration in which a transparent member 12-1 that covers the space above the sample A is further provided in the configuration shown in FIG. A transparent conductive film 122 is formed on the surface of the transparent member 12-1 on the sample side. With this configuration, the heat source can be arranged on both the surface holding the sample A and the surface covering the space above the sample A. Thereby, the sample A can be heated rapidly. In addition, since the upper and lower sides of the sample A are sandwiched between heating elements, it is possible to suppress the heat from being diffused from the space around the sample A. In addition, the transparent member 12-1 provided on a sample does not necessarily need to be transparent.

  Although not shown in FIGS. 6A to 6C, as in FIG. 1, thermocouples that measure the temperatures of the electrodes 41a and 41b and the transparent member 12 provided at both ends of the transparent conductive film 122 are used. 43, the heat control part 42 which controls the voltage between the electrodes 41a and 41b, and the computer 1 which controls the heat control part 42, the light irradiation part 21, and the light detection part 22 may be provided.

  6 (a) to 6 (c), the light irradiating unit 21 has a periodic intensity of light from the lower surface of the transparent member 12 with respect to the sample A placed on the upper surface of the transparent member 12. Can be irradiated with a light pattern that changes with time. In this case, the light detection unit 22 photographs the sample A irradiated with the light pattern from the lower surface of the transparent member 12. The image processing unit 52 of the computer 1 processes the image of the sample A photographed by the light detection unit 22 and generates surface shape data representing the three-dimensional shape of the surface of the sample. For example, the light irradiation unit 21 can irradiate the sample A with a light pattern such as a sine curve while shifting the phase, and the light detection unit 22 can take an image of the light pattern with the phase shifted multiple times. The image processing unit 52 can calculate the three-dimensional shape of the sample A using the phase shift method based on a plurality of images of the sample irradiated with the light pattern having a shifted phase. A specific example of the three-dimensional measurement using the phase shift method will be described later in the sixth embodiment.

  The present embodiment can be suitably used for a three-dimensional measurement apparatus using an active method in which a distance is measured by irradiating a sample with a laser or a pattern and observing light from the sample. For example, the measuring apparatus shown in FIGS. 6A and 6C arranges a sample on the upper surface of a transparent member provided with a transparent conductive film, irradiates light from the lower surface of the transparent member, and reflects light reflected by the sample on the lower surface. It is a configuration to observe with. Thus, the distance from the sample placement surface (heat generation surface) can be measured with high accuracy, and the sample temperature can be controlled with a simple configuration.

  Examples of measurement methods using the active method include the above-described pattern projection method, laser beam cutting method, laser time-of-flight (TOF) method, confocal method, and illuminance difference stereo method. Can be mentioned. In addition to the phase shift method, the pattern projection method includes, for example, a lattice pattern projection method, a spatial encoding method, a random pattern projection method, a moire method, and an interference method. Any of these can be applied to the present embodiment.

(Modification)
FIG. 7 is a view showing a modification of the measuring apparatus shown in FIG. In the example shown in FIG. 7, in the transparent member 12, a transparent conductive film 122 is formed on a part of the upper surface of the transparent substrate 121 instead of the whole. Specifically, the transparent conductive film 122 is formed in a region other than the region where the sample A is placed. As described above, by removing the transparent conductive film 122 in the region where the sample A is placed, it is possible to avoid the sample A from coming into direct contact with the transparent conductive film 122 that is a heating element. For example, the configuration shown in FIG. 7 is effective when the sample A is a resin or the like and may be dissolved when the transparent conductive film 122 that generates heat is touched.

  The patterning of the transparent conductive film 122 can be performed, for example, by forming a transparent conductive film on the entire top surface of the transparent substrate 121 and then forming a pattern by etching using a photoresist. Further, the pattern of the transparent electrode film 122 is not limited to the example shown in FIG. For example, in order to heat only the region of the sample A, the transparent conductive film 122 can be formed only in the mounting region of the sample A and its periphery. Thereby, the power consumption used for a heating can be reduced.

  FIG. 8 is a diagram illustrating another modification of the measurement apparatus illustrated in FIG. In the example shown in FIG. 8, a cover 61 for sealing a space including the sample A is provided. Thereby, thermal efficiency can be improved. In addition, the temperature of the sample A can be prevented from becoming unstable due to the influence of outside air.

  Note that the modification examples shown in FIGS. 7 and 8 can also be applied to the first to fourth embodiments and the sixth embodiment described below.

(Sixth embodiment)
FIG. 9 is a diagram illustrating a configuration example of an inspection apparatus according to the sixth embodiment. It is detailed embodiment at the time of applying the measuring apparatus in the said 5th Embodiment to an inspection apparatus.

[Configuration of inspection system]
An inspection apparatus 100 illustrated in FIG. 9 includes a measurement unit 5 that measures the shape of a sample, a control unit 4 that controls the measurement unit 5, and a computer 1 that is connected to the measurement unit 5 and the control unit 4. A monitor 2 and an input device 3 (a mouse 3a and a keyboard 3b) are connected to the computer 1. An inspection apparatus 100 shown in FIG. 9 is an apparatus that measures the shape of a sample and determines the quality of the shape. The measurement unit 5 is controlled by the control unit 4 to measure the surface shape of the sample (inspection object), the computer 1 determines the quality of the sample shape based on the measurement data, and stores or outputs the result (inspection result) To do. As in the first embodiment, the computer 1 includes a calculation unit 50 including a measurement control unit 51, an image processing unit 52, and a determination unit 53 (see FIG. 1). For example, the inspection apparatus 100 can be used to determine the quality of a completed electronic component in an electronic component production line. Hereinafter, although the case where the inspection apparatus 100 is used for shape determination of an electronic component will be described, the sample of the inspection apparatus 100 is not limited to the electronic component.

  As shown in FIG. 9, the measurement unit 5 includes a projection projector 21 (an example of a light irradiation unit), a light detection unit 22, a table 12, a drive unit 13 that moves the table 12, and a temperature control unit that controls the temperature of the table 12. 41 is provided. The table 12 can be configured in the same manner as the transparent member 12 in the first embodiment. That is, the table 12 includes a transparent substrate 121 that is a transparent glass plate, a transparent conductive film 122 formed on an upper surface thereof, and electrodes 41 a and 41 b formed on both ends of the transparent conductive film 122. The table 12 is provided on the upper surface of the housing of the measurement unit 5. A sample A is placed on the upper surface of the table 12. Under the table 12, a projection projector 21 and a light detection unit 22 are provided. The projection projector 21 irradiates the sample A with a striped light pattern from the lower surface of the table 12. The light detection unit 22 images the light pattern projected on the sample A from the lower surface of the table 12.

  The inspection apparatus 100 shown in FIG. 9 uses a grid projection method classified as triangulation for obtaining a three-dimensional shape. When the striped light pattern is projected onto the sample A, the striped pattern is deformed in accordance with the shape of the sample A. Therefore, the shape can be measured by measuring the amount of deformation of the striped pattern in the image of the sample A. it can. Hereinafter, each part of the inspection apparatus 100 will be described in detail. The upper surface of the table 12 is a surface on which the sample A is placed (hereinafter referred to as a sample surface 12a). Here, the axes orthogonal to each other in the sample surface 12a are defined as the XY axes, and the axis perpendicular to the sample surface 12a is defined as the Z axis. The drive unit 13 may include an XY drive unit 13 that moves the table 12 in the X-axis direction and the Y-axis direction, and a Z drive unit 13 that moves the table 12 in the Z-axis direction. Moreover, it can also be set as the structure which moves the projection project 21 and the light detection part 22 instead of the structure to which the table 12 is moved. Further, the temperature of the table 12 is controlled by the temperature control unit 42 so as to be a temperature designated by the computer 1.

  The projection projector 21 is a unit that irradiates a sample A on the other side of the sample surface 12a with a striped light pattern in which the intensity of light periodically changes. Therefore, in the projection projector 21, for example, the light source 6, the condensing lens 7, the grid 8, and the telecentric lenses 9, 10 are arranged in order.

  For the light source 6, for example, an LED is preferably used from the viewpoint of cost. In addition, a halogen lamp, a laser light source, or the like can be used as the light source 6. The condensing lens 7 condenses the light from the light source 6 and brings it close to parallel light. The grid 8 turns the light close to the parallel light into striped light whose intensity changes periodically.

  The grid 8 includes a film having a sine wave or cosine wave pattern, for example. As the film, for example, a sine wave pattern lattice film having a wavelength of about 50 μm to 500 μm can be used.

  In addition, the grid pattern of the grid may be a grid pattern in which two types of intensity of light and dark appear alternately, or has a light intensity corresponding to a cosine wave or a sine wave in the change from light to dark and from dark to light. It may be a pattern. By projecting light having a cosine wave or sine wave intensity change onto the sample A in this way, height analysis can be performed on all the pixels photographed by the light detection unit 22. The light pattern may be a multiple ring pattern or a checkered pattern.

  The means for generating the light pattern is not limited to the above film. For example, a striped light pattern whose intensity periodically changes can be generated using a liquid crystal panel.

  Further, by providing a stepping motor on the grid 8, the position of the stripe of the light pattern can be moved (shifted). The driving of the grid 8 by the stepping motor is controlled by a signal from the control unit 4, for example. For example, the control unit 4 or the measurement unit 5 can be provided with a microstepping driver that drives a microstepping motor. By using the microstepping driver, it is possible to shift the optical pattern with high resolution. The computer 1 can set the driving conditions of the grid 8 for the control unit 4.

  The striped light pattern passing through the grid 8 passes through the telecentric lens unit 11 and is irradiated onto the sample A on the sample surface 12a. The telecentric lens unit 11 forms a telecentric optical system by the telecentric lenses 9 and 10. The telecentric optical system formed by the telecentric lenses 9 and 10 can be an image side telecentric optical system, an object side telecentric optical system, or a both side telecentric optical system. For example, in the case of a bilateral telecentric optical system, the telecentric lenses 9 and 10 are arranged so that the main intersection line is parallel to the lens optical axis K on both the object side and the image side.

  In the image by the light exiting the telecentric lens unit 11, the subject size hardly changes within the depth of field. That is, the stripe interval in the light emitted from the telecentric lens unit 11 hardly changes in the light traveling direction. This eliminates the need for processing for correcting the change in the stripe interval in the subsequent processing of the image of the sample A irradiated with the light pattern.

  The light detection unit 22 includes a CCD camera 15 and a telecentric lens unit 17. The telecentric lens unit 17 includes telecentric lenses 16 and 18. The CCD camera 15 photographs the sample A irradiated with the striped light pattern. Note that the imaging apparatus is not limited to the CCD camera 15, and for example, a CMOS sensor, a line sensor, or the like can be used. Since the CCD camera 15 captures an image by light passing through the telecentric lens unit 17, an image that does not require correction of the fringe interval can be obtained.

  As described above, the measurement unit 5 of the present embodiment is configured by combining the projection projector 21 including the light source 6, the grid 8, and the telecentric lens unit 11 with the light detection unit 22 including the CCD camera 15 and the telecentric lens unit 17. It becomes possible to acquire high-resolution three-dimensional information having a horizontal resolution and a height resolution of several microns. For this reason, the measurement unit 5 can obtain, for example, three-dimensional shape data (surface shape data) suitable for evaluation of terminals of electronic components. In addition, the structure of the measurement part 5 is not restricted to the structure shown in FIG. For example, it may be configured to include a plurality of projection projectors that irradiate light patterns from different directions. The light detection unit 22 does not necessarily need to use a telecentric optical system. For example, the light detection unit 22 can take a wide projection surface by irradiating a light pattern whose width increases in the light traveling direction. In addition, the light detection unit 22 may be configured to perform the tilt projection that projects the light pattern without tilting the grid with respect to the projection plane.

[Surface shape data calculation example]
Next, a method for calculating the surface shape data of the sample A using the lattice projection method will be described. FIG. 10 is a diagram schematically illustrating the state of projection and photographing of a striped light pattern onto the sample A in the measurement unit 5. As shown in FIG. 10A, the projection projector 21 irradiates the sample A with a striped light pattern whose intensity periodically changes in the arrow D direction. FIG. 3B is a diagram illustrating an example of a striped pattern. On the sample surface, a striped pattern whose intensity changes periodically in the Y-axis direction is projected. On the surface of the sample A, the striped pattern is deformed according to the surface shape of the sample A. FIG. 3C is a diagram illustrating an example of an image captured by the light detection unit 22. A state in which the stripe pattern is deformed in accordance with the surface shape of the sample A appears in the image. The relationship between the deformation amount x of the striped pattern and the height h of the sample A is calculated by h = x / tan α where α represents each projection of light onto the sample surface 12a (FIG. 3 (d)).

  Here, in order to perform measurement with higher accuracy, a phase shift method can be applied to the phase analysis. In the measurement by the phase shift method, the fringe pattern projected by the projection projector 21 is shifted by ¼ period, and four fringe images are taken to perform phase analysis.

  FIG. 11 is a flowchart illustrating an example of processing in which the inspection apparatus 100 illustrated in FIG. 9 performs three-dimensional measurement of the sample A using the phase shift method. In the example shown in FIG. 9, when the sample A is set on the sample surface 12a (S1), the temperature control unit 42 adjusts the temperature of the table 12 to the temperature set by the computer 1 (S2). When the temperature of the table 12 reaches the set temperature, the temperature control unit 42 sends a signal to that effect to the computer 1. When the computer 1 receives a notification that the temperature of the table 12 has reached the set temperature, it issues a measurement start instruction to the control unit 4. The control unit 4 controls the measurement unit 5 to start measurement.

  First, in the measurement unit 5, the sample A is irradiated with light having a striped pattern (lattice pattern) from under the table 12. Thereby, the lattice pattern is projected onto the sample A. An image of the sample A onto which the lattice pattern is projected is taken from the lower surface of the table 12 by the light detection unit 22 (S3). Here, the case where the light of the striped pattern which shows the change equivalent to a cosine wave is irradiated is demonstrated. In this photographed image, a striped pattern deformed according to the surface shape of the sample A is shown. The projection projector 21 projects light obtained by shifting the cosine wave stripe pattern by ¼ period, respectively, and the light detection unit 22 displays an image of the stripe pattern in which four phases are shifted by ¼ period. Take a picture. Here, image data captured by the measurement unit 5 is sent to an image processing unit (described later) of the computer 1. The image processing unit 52 of the computer 1 performs phase analysis by processing the image data (S4). In the phase analysis, the phase θ of the light pattern projected at the position (coordinates (x, y)) of each pixel in the image is calculated. The brightness at the position (x, y) is represented by the following formula (1).

a is a coefficient indicating the amplitude of the brightness of the stripes at that position, and b is a coefficient indicating the brightness offset amount b at that position. FIG. 12 is a graph showing the above formula (1). As shown in FIG. 12, the brightness at the same position (x, y) on the four images is represented by the following formula (2): I ₀ , I ₁ , I ₂ , I ₃

  Therefore, the phase θ at (x, y) can be calculated by the following equation (3).

  The phase θ shown in the above equation (3) does not depend on the coefficients a and b. Thus, since the amplitude a term of the brightness of the fringe and the offset amount b term of the brightness are canceled in the calculation formula, it is difficult to be influenced by disturbance light, and highly accurate measurement is possible. Therefore, by using the phase shift method, it is possible to perform measurement with accuracy suitable for fine inspection such as shape inspection of terminals of electronic components.

  In this way, the phase θ of each position (x, y) is calculated. On the line (equal phase line) obtained by connecting the points having the same phase θ, the variation corresponding to the shape of the sample A appears as in the striped pattern shown in FIG. Therefore, the deformation amount (phase difference) of the phase θ at each position is calculated (S5 in FIG. 11), and this phase difference is converted into a height unit (S6), thereby indicating the height of the sample A at each position. A value is obtained. That is, data indicating the three-dimensional shape of the surface of the sample A is obtained.

  In the process S5, when calculating the phase difference indicating how much the phase θ of each position changes depending on the sample A, the reference phase data recorded in advance in the computer 1 is used. For example, an image when a striped pattern of the same cosine wave is projected on the sample surface 12a on which the sample A is not placed is taken in advance, and data indicating the phase θ of each position on the sample surface 12a is calculated, and the reference phase data Can be recorded as The computer 1 calculates the phase difference by calculating the difference between the reference phase data representing the phase θ at each position on the sample surface 12a and the data representing the phase θ at each position when the sample A is placed. be able to. Since the phase difference at each position is a value corresponding to the distance (height) between the surface of the sample A and the sample surface 12a, it can be converted into data indicating the height (S6).

  In the present embodiment, since the light pattern is projected and photographed in a state where the sample A is placed on the upper surface of the table 12, the floating amount from the upper surface of the table 12 can be obtained as height information. Therefore, for example, assuming that the upper surface of the table 12 is the mounting substrate, it is possible to determine the floating amount when mounting the electronic component. Furthermore, since the table 12 includes the transparent conductive film 122, the temperature of the mounting surface can be arbitrarily set. Therefore, the mounting surface side of the electronic component can be measured in substantially the same state as when it is actually mounted. Thereby, it is possible to perform measurement in consideration of the balance at the time of mounting the electronic component and the temperature assumed at the time of mounting.

  As described above, in the phase shift method, the phase of intensity change in the light pattern irradiated to the sample A is made different, and data of a plurality of images corresponding to each phase is acquired. Using the brightness at the same position (x, y) of the plurality of images, the phase θ of the light pattern projected at the position (x, y) is obtained, and the principle of triangulation is used based on the phase θ. To calculate the height.

  Note that the method for acquiring height information using the phase shift method is not limited to the above example. For example, the number of images to be captured is not limited to four. If three images are taken, the phase θ can be calculated, and four or more images can be taken to improve accuracy. The above formulas (1) to (3) used for calculating the phase θ are also examples, and the phase θ can be calculated using other formulas.

  The computer 1 processes the data indicating the three-dimensional shape of the surface of the sample A obtained by using the phase shift method in this manner, whereby the inspection of the sample A is executed by the determination unit 52 (S7). . For example, as described above, the image processing unit 52 calculates the position (height information) of the protrusion of the sample A with respect to the sample surface 12a, and the determination unit 53 determines whether or not the position is within a predetermined range. By determining, the quality of the sample having the protrusion can be determined.

  The inspection apparatus 100 can inspect a sample including a plurality of protrusions arranged in at least one direction, such as an IC chip. When an IC chip is mounted on a substrate, it is required that a plurality of legs (projections) of the IC chip are securely connected to the substrate. Therefore, the inspection apparatus 100 measures the position of each protrusion with respect to the sample surface 12a of the table 12 in a state where the IC chip placed on the sample surface 12a of the table 12 is heated to a specific temperature. It can be determined whether or not it is within a predetermined range. Thereby, it is possible to inspect whether or not the IC chip can be mounted on the substrate under a specific temperature.

  The inspection apparatus 100 controls the temperature of the sample A in a state where the sample A is placed on the table 12 having the transparent conductive film 122 formed on the surface, and further irradiates the light pattern from the lower surface of the sample A and the sample A. Can be taken. The shape can be inspected at a specific temperature only by placing the sample A on the table 12. Thus, according to the present embodiment, it is possible to simplify the installation work of the sample A and the configuration of the apparatus, and it is possible to measure the shape of the sample at high speed under temperature control. Further, when measuring an electronic component mounted on a ceramic substrate, a flexible substrate, or the like, it is possible to measure in substantially the same state as the mounting state with the upper surface of the table 12 as the mounting surface. That is, the state of the sample at the time of mounting can be simulated.

  That is, the combination of the table 12 using the transparent member having the transparent conductive film 122 and the three-dimensional shape measuring instrument using the pattern projection method as described above enables three-dimensional measurement suitable for the inspection of the terminals of the electronic component. Become. For example, it becomes possible to quickly inspect the heat resistance of a large number of electronic components. Furthermore, by using the phase shift, the height information can be processed efficiently and quickly, and a highly accurate analysis result can be obtained. As described above, according to the present embodiment, for example, a measuring instrument having a structure suitable for inspection in a production line of electronic equipment and a calculation process are provided.

  The application range of the present invention is not limited to the above embodiment. For example, the sample is not limited to an electronic component. Moreover, although the case where the three-dimensional shape measuring device using the lattice projection method was used as the measuring device has been described in the above embodiment, the measuring device is, for example, a pattern projection method other than the above (for example, a gray scale pattern). Or a method of projecting a color pattern, etc.), a moire, a focus method, a stereo method, or other methods may be used.

  As described above, the measurement device or the inspection device in the first to sixth embodiments uses the transparent conductive film as the heating device. Therefore, the apparatus configuration is simplified as compared with the conventional apparatus. Also, temperature control can be easily performed. Furthermore, since the conversion efficiency into heat is good, power consumption can also be suppressed.

DESCRIPTION OF SYMBOLS 1 Computer 2 Monitor 3 Input device 4 Control part 5 Measurement part 6 Light source 7 Condensing lens 8 Grid 9 Telecentric lens 10 Image processing part 11 Telecentric lens unit 12 Transparent member (table)
12a Sample surface 121 Transparent substrate 122 Transparent conductive film 13 Drive unit 15 Camera 16 Telecentric lens 17 Telecentric lens unit 21 Light irradiation unit (projection projector)
22 Photodetector 30 Electronic component 31 Main body 32a-32e Terminal 50 Calculation unit 51 Measurement control unit 52
52 Image Processing Unit 53 Determination Unit 100 Inspection Device

Claims (6)

A transparent member having a transparent substrate and a transparent conductive film provided on the surface of the transparent substrate, which is disposed at a position holding the sample to be measured or at a position facing the sample;
A light detection unit for detecting light from the sample;
A measurement apparatus comprising: a thermal control unit that controls a temperature of the transparent member by controlling a voltage applied to the transparent conductive film of the transparent member.   The measuring apparatus according to claim 1, wherein the transparent member also serves as a sample table on which the sample is placed.   The measurement device according to claim 2, wherein the light detection unit is disposed below the sample table and detects light from the sample placed on the upper surface of the transparent member from the lower surface of the transparent member. A light irradiation unit for irradiating the sample with light;
The measuring device according to claim 1, wherein the transparent member is disposed between at least one of the light irradiation unit and the light detection unit and an installation position of the sample.   The measuring device according to claim 1, wherein the light detection unit detects light from the sample when the transparent member reaches a predetermined temperature by the thermal control unit.   The measurement apparatus according to claim 1, further comprising a calculation unit that determines whether the sample satisfies a predetermined criterion based on an image obtained by the light detection unit.

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