JP2018189627A - Position measurement method and component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a position measurement method that highly accurately obtains positions of a lens and like, using a position of a position reference part of a component in an image of a measurement device, and to provide the component that is suitable for the position measurement method.SOLUTION: A position measurement method according to the present invention is the position measurement method that observes a position of a position reference part on a plane surface 101 or a position of an arbitrary point thereon in an image of a measurement device equipped with an imaging optical system using a coaxial epi-illumination, and determines a position of the arbitrary point, using the position of the position reference part as a reference. The position reference part, in which at least a bottom part is columnar, is provided with an inclined surface 103 surrounding the bottom of a column. The position measurement method includes the steps of, in the image of the measurement device,: determining a position of an outer periphery of the bottom from the inclined surface surrounding the bottom and a position of a boundary of the plane surface; determining the position of the position reference part from the position of the outer periphery of the bottom; and determining the position of the arbitrary point, using the position of the position reference part as the reference.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a position measurement method based on an image of a measurement apparatus provided with an imaging optical system using coaxial epi-illumination, and a component suitable for the measurement method.

  For example, when a component having a plurality of lenses arranged on one surface and a connector having a plurality of optical fibers are coupled, the lens and the optical fiber are aligned on the corresponding surface of the component. There is a case where the position reference portion which is the provided columnar convex portion is fitted into the concave portion provided in the connector. In such a case, in order to align the individual lenses and the individual optical fibers, it is necessary to guarantee the distance between the position reference portion on the surface of the component and the individual lenses with high accuracy. Therefore, it is necessary to measure the distance between the position reference portion of the component and each lens with high accuracy. Such measurement is performed using a measuring device such as a CNC (Computer Numerical Control) image measuring machine (for example, Patent Document 1).

  In measuring the distance between the position reference portion on the surface of the component and each lens, it is necessary to accurately determine the position of the columnar position reference portion on the surface in the image of the measuring apparatus. Conventionally, since it has been difficult to identify the base part of the column of the position reference part in the image of the measuring device, the tip part of the column of the position reference part is identified, and the position of the position reference part is determined from the position of the tip part. The position is determined, and the position of the lens is determined based on the position.

  However, for example, if the column of the position reference unit is inclined with respect to the normal of the surface, the position of the base and the tip of the column of the position reference unit in the image of the measuring device acquired from the direction of the normal There is a gap between the positions. Therefore, when the position of the position reference portion is determined from the position of the tip portion and the position of the lens is determined with reference to the position, an error in distance corresponding to the above-described interval occurs.

  As described above, a position measurement method for obtaining the position of a lens or the like with high accuracy using the position of the position reference portion of the component in the image of the measurement apparatus and a component suitable for the measurement method have not been developed.

Japanese Patent Laid-Open No. 2004-4055

  Therefore, there is a need for a position measurement method for obtaining the position of a lens or the like with high accuracy using the position of the position reference portion of the component in the image of the measurement apparatus, and a component suitable for the measurement method. An object of the present invention is to provide a position measurement method for obtaining the position of a lens or the like with high accuracy using the position of a position reference portion of a component in an image of a measurement apparatus, and a component suitable for the measurement method described above. It is.

  The position measuring method according to the first aspect of the present invention observes the position of a position reference portion on a plane and the position of an arbitrary point in an image of a measuring apparatus including an imaging optical system using coaxial incident illumination, In this position measurement method, the position of the arbitrary point is determined based on the position of the position reference unit. The position reference portion has a columnar shape at least at the base and includes an inclined surface surrounding the base of the column. The position measuring method includes a step of determining a position of an outer periphery of the base from a position of an inclined surface surrounding the base and a boundary of the plane in an image of the measuring device, and a position of the position reference unit from the position of the outer periphery of the base. And a step of determining a position, and a step of determining the position of the arbitrary point on the basis of the position of the position reference portion.

  In the position measuring method of the first aspect of the present invention, in the image of the measuring apparatus, the position of the outer periphery of the base of the column is determined from the position of the boundary between the inclined surface and the plane surrounding the base of the column of the position reference unit, Since the position of the position reference portion is determined from the position of the outer periphery of the base of the column, the position measurement error can be greatly reduced as compared with the case of determining the position of the position reference portion from the position of the tip end portion of the column. .

を満たす。 In the position measurement method according to the first embodiment of the first aspect of the present invention, θ is an aperture angle of the imaging optical system, φ is an acute angle formed by an inclined surface surrounding the root and the plane, and θ is

Meet.

  When the above relationship is satisfied, the light beam reflected by the inclined surface does not reach the measuring device. Therefore, in the image by the measuring apparatus, the area of the inclined surface is not brightened, and the boundary between the planar area and the inclined surface area becomes clear.

を満たす。 In the position measurement method according to the second embodiment of the first aspect of the present invention, the aperture angle of the imaging optical system is φ, the acute angle between the inclined surface surrounding the root and the plane is θ, and the unit of the angle is degree. As θ is

Meet.

  When the above relationship is satisfied, the light beam reflected by the plane does not reach the measuring device after being reflected by the inclined surface. Therefore, in the image by the measuring apparatus, the area of the inclined surface is not brightened, and the boundary between the planar area and the inclined surface area becomes clear.

  In the position measurement method according to the third embodiment of the first aspect of the present invention, the inclined surface that surrounds the root connects the plane and the side surface of the column, or the plane and another plane parallel to the plane. It is formed to connect.

を満たす。 In the position measurement method according to the fourth embodiment of the first aspect of the present invention, the inclined surface surrounding the base has an opening angle of φ and the column when the plane and the side surface of the column are connected. X is the width in the direction perpendicular to the central axis of the inclined surface in the cross section including the central axis, and L is the length of the column.

Meet.

  According to the present embodiment, in the vicinity of the boundary between the inclined surface and the plane, a substantial part of the light rays that are incident on and reflected by the plane at an angle of φ or less are reflected after being reflected on the side surface of the column. Reach the device. Accordingly, in the image obtained by the measuring apparatus, the planar area becomes sufficiently bright, and the boundary between the planar area and the inclined surface area becomes clear.

  In the position measurement method according to the fifth embodiment of the first aspect of the present invention, the position of the arbitrary point is the position of the optical element.

  According to the present embodiment, the position of the optical element can be determined with high accuracy using the position of the position reference portion as a reference.

  The component according to the second aspect of the present invention is a component including at least two position reference portions and an optical element, which are installed on one plane or a plurality of planes parallel to each other, and each position reference portion. Has a columnar shape at least at the base, and includes an inclined surface surrounding the base of the column, and an angle θ of the inclined surface with respect to a plane on which each position reference portion is installed is in the range of 20 degrees to 70 degrees.

  The component according to this aspect is suitable for measuring the position of the optical element with high accuracy based on the position of the position reference unit based on the image of a measurement apparatus including an imaging optical system using coaxial incident illumination. .

  In the component of the first embodiment of the second aspect of the present invention, the inclined surface surrounding the root connects the plane and the side surface of the column or connects the plane and another plane parallel to the plane. It is formed as follows.

It is a figure which shows the components provided with the position reference part of one Embodiment of this invention. It is a figure which shows the cross section containing the central axis of the position reference part of the conventional components. It is a figure which shows the measuring apparatus which uses the coaxial epi-illumination used in the measuring method of this invention. It is a figure which shows the path | route of the illumination light of the coaxial epi-illumination of said measuring apparatus, and the reflected light for imaging. It is a figure which shows the cross section containing the central axis of the position reference part of the components of the 1st Embodiment of this invention. It is a figure which shows the path | route of the light ray which advances perpendicularly | vertically to a plane among the lights for illumination, and the image by the light ray. It is a figure which shows the path | route of the light ray which advances at an angle of the predetermined range with respect to a plane among the lights for illumination, and the image by the light ray. It is a figure which shows the path | route of the light ray of the light for illumination, and the image by the light ray. It is a figure for demonstrating the relationship between angle (theta) with respect to a plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between angle (theta) with respect to a plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between angle (theta) with respect to a plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between angle (theta) with respect to a plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between the length X and the length L of the perpendicular | vertical direction and the central axis of the inclined surface in the cross section containing the central axis of a pillar. It is a figure which shows the cross section containing the central axis of the position reference part of the components of the 2nd Embodiment of this invention. It is a figure which shows the path | route of the light ray which advances perpendicularly | vertically to a plane among the lights for illumination, and the image by the light ray. It is a figure which shows the path | route of the light ray which progresses with the angle of the predetermined range with respect to a plane among the lights for illumination, and the image by the light ray. It is a figure which shows the path | route of the light ray of the light for illumination, and the image by the light ray. It is a figure for demonstrating the relationship between angle (theta) with respect to the plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between angle (theta) with respect to the plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between angle (theta) with respect to the plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between angle (theta) with respect to the plane of an inclined surface, and opening angle (phi) of the imaging optical system of a measuring device. It is a figure for demonstrating the relationship between the width W of a groove | channel, and the length L of a pillar. It is a flowchart for demonstrating the measuring method of one Embodiment of this invention. It is a figure which shows the relationship between the measuring method shown to the flowchart of FIG. 19, and the boundary E and E '. It is a figure which shows the deviation of the reference | standard position with respect to the inclination angle of a pillar about the conventional components and the components of this invention. It is a figure which shows the components provided with the position reference part of other embodiment of this invention.

  FIG. 1 is a diagram illustrating a component 100 including a position reference unit 110 according to an embodiment of the present invention. On one surface 101 of the component 100, two position reference portions 110 and a plurality of lenses 150 are installed. The two position reference parts 110 are substantially cylindrical. The component 100 including the plurality of lenses 150 is connected to, for example, a connector including a plurality of optical fibers. The two position reference parts 110 are used for connecting the component 100 and the connector. For example, the connector may include two concave portions corresponding to the two columnar position reference portions 110, and the two position reference portions may be accommodated in the two concave portions of the connector. At that time, it is necessary to align the plurality of lenses 150 and the plurality of optical fibers with high accuracy. For this reason, in order to guarantee alignment with high accuracy, it is necessary to accurately measure the positions of the plurality of lenses 150 with reference to the two position reference units 110.

  FIG. 2 is a view showing a cross section including the central axis of the position reference portion 110 ′ of the conventional component.

  Here, the measurement of the positions of the plurality of lenses 150 is performed using a measuring device such as a CNC (Computer Numerical Control) image measuring machine. In an image acquired by a measuring apparatus such as an image measuring machine, it is difficult to distinguish the base portion of the pillar of the position reference portion 110 ′ of the conventional component from the surrounding plane. In view of this, the position of the position reference unit 110 ′ is determined by observing the tip end portion of the column surrounded by a circle in FIG. 2 in an image acquired by a measuring apparatus such as an image measuring machine.

  FIG. 3 is a diagram showing a measuring apparatus using coaxial epi-illumination used in the conventional measuring method and the measuring method of the present invention. The measuring device may be a CNC image measuring machine. The measurement apparatus includes a light source 301, a field lens 303, a half mirror 304, a condenser lens 305, an imaging lens 307, and an image acquisition unit 309. The light source 301, the field lens 303, the half mirror 304, and the condenser lens 305 form an illumination optical system of the measurement apparatus. The condenser lens 305, the half mirror 304, and the imaging lens 307 form an imaging optical system of the measuring device. A surface of the component 100 including the position reference unit 110 is denoted by 101. The light from the light source 301 forms an image of the light source at the pupil position 3051 of the condenser lens 305 through the field lens 303 and the half mirror 304. Illumination of the surface 101 of the component 100 is performed via the condenser lens 305 using the image of the light source as a light source. The light reflected by the surface 101 of the component 100 passes through the condenser lens 305, passes through the half mirror 304 and the imaging lens 307, and reaches the image acquisition unit 309.

  FIG. 4 is a diagram illustrating a path of illumination light and reflected light for imaging of the coaxial epi-illumination of the measurement apparatus. The above path is determined by the aperture angle of the imaging optical system of the measurement apparatus, that is, the aperture angle of the condenser lens 305. In FIG. 4, a principal ray that coincides with a perpendicular line drawn from the center position of the pupil of the condenser lens 305 to the plane 101 is denoted by L1, and a principal ray that reaches the point farthest from the point where the principal ray L1 reaches the plane 101 is represented. Represented by L2. The principal rays L1 and L2 can be regarded as being substantially parallel, and the aperture angle with respect to the principal ray L1 and the aperture angle with respect to L2 are substantially the same. This opening angle is represented by φ. Of the reflected light, a light beam whose angle with the normal of the plane 101 exceeds the opening angle φ is not taken into the measuring device.

  FIG. 5 is a diagram showing a cross section including the central axis of the position reference portion 110A of the component 100A according to the first embodiment of the present invention. The column 115 of the position reference portion 110A is a cylinder, and is formed on the plane 101 of the component 100A so that the central axis of the cylinder is perpendicular to the plane 101. The component 100A according to the embodiment of the present invention is different from the conventional component in that an inclined surface 103 is provided around the base of the column 115 of the position reference unit 110A. The inclined surface 103 connects the flat surface 101 and the side surface of the column 115 of the position reference portion 110A. The boundary line between the inclined surface 103 and the plane 101 is a circle, and the center of the circle is the intersection of the center axis and the plane 101. 5 is a diagram showing a cross section including the central axis of the inclined surface 103. The roughness of the flat surface 101 is preferably finished to 30 nm or less. The plane 101 is preferably formed so as to form the same plane as the plane on which the lens 150 is disposed.

  In FIG. 5, the axis AX is perpendicular to the plane 101, and the direction thereof is the direction of the principal ray shown in FIG.

  In FIG. 5, the corner indicated by A is preferably formed so that the cross section does not have a so-called R portion on the arc.

  FIG. 6 is a diagram illustrating a path of a light beam that travels perpendicular to the plane 101 of the illumination light and an image of the light beam. The reflected light of the light ray that enters the plane 101 perpendicularly travels perpendicularly to the plane 101 and reaches the image acquisition unit 309. On the other hand, when the light beam traveling perpendicular to the plane 101 is reflected by the inclined surface 103, it does not reach the image acquisition unit 309. Therefore, in the image acquired by the image acquisition unit 309, the area of the plane 101 becomes bright and the area of the inclined surface 103 becomes dark. As a result, in the above image, the boundary E between the region of the plane 101 and the region of the inclined surface 103 is clearly shown.

  FIG. 7 is a diagram showing a path of light rays traveling at an angle within a predetermined range with respect to the plane 101 in the illumination light and an image by the light rays. The reflected light of the light beam incident on the plane 101 at an angle within the predetermined range is reflected by the plane 101 and the side surfaces of the pillar 115 and then reaches the image acquisition unit 309. On the other hand, light rays traveling at an angle within the predetermined range with respect to the plane 101 are reflected by the inclined surface 103 and do not reach the image acquisition unit 309. Therefore, in the reflection image obtained by the light beam reflected by the side surface of the pillar 115 acquired by the image acquisition unit 309, the area of the plane 101 becomes bright and the area of the inclined surface 103 becomes dark. As a result, in the above image, the boundary E ′ between the reflected image in the area of the plane 101 and the reflected image in the area of the inclined surface 103 is clearly shown.

  FIG. 8 is a diagram showing a path of a light beam for illumination and an image by the light beam. FIG. 8 is a combination of FIGS. 6 and 7. In FIG. 8, the boundary E ′ is an image of the boundary E between the region of the plane 101 and the region of the inclined surface 103 due to reflection on the side surface of the column 115. Therefore, the midpoint of the line segment connecting the point on the boundary E and the corresponding point on the boundary E ′ corresponds to the position of the point on the outer periphery of the column 115 on the plane 101. In this manner, the position of the outer periphery of the column 115 on the plane 101 can be obtained from the image shown in FIG. A method for obtaining the position of the outer periphery of the column 115 on the plane 101 will be described in detail later.

  Hereinafter, the angle of the inclined surface 103 with respect to the plane 101 will be described. In this specification, the unit of angle is degrees.

の関係を満たす。この場合に、平面１０１に反射された光線が傾斜面１０３に反射された後、画像取得部３０９に到達することはない。したがって、測定装置による画像において、傾斜面１０３の領域が明るくなることはなく平面１０１の領域と傾斜面１０３の領域との境界Ｅ’が明確になる。 FIG. 9A is a diagram for explaining the relationship between the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measurement apparatus. In FIG. 9A,

Satisfy the relationship. In this case, the light beam reflected by the plane 101 does not reach the image acquisition unit 309 after being reflected by the inclined surface 103. Therefore, in the image by the measuring apparatus, the area of the inclined surface 103 does not become bright, and the boundary E ′ between the area of the plane 101 and the area of the inclined surface 103 becomes clear.

の関係を満たす。この場合に、平面１０１に反射された光線の一部が傾斜面１０３に反射された後、画像取得部３０９に到達する。したがって、測定装置による画像において、傾斜面１０３の領域が明るくなり平面１０１の領域と傾斜面１０３の領域との境界Ｅ’が明確でなくなる。 FIG. 9B is a diagram for explaining the relationship between the angle θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus. In FIG. 9B,

Satisfy the relationship. In this case, a part of the light beam reflected by the plane 101 is reflected by the inclined surface 103 and then reaches the image acquisition unit 309. Therefore, in the image by the measuring apparatus, the area of the inclined surface 103 becomes brighter and the boundary E ′ between the area of the flat surface 101 and the area of the inclined surface 103 becomes unclear.

の関係を満たす。この場合に、傾斜面１０３で反射された光線は、測定装置に到達しない。したがって、測定装置による画像において、傾斜面１０３の領域が明るくなることはなく平面１０１の領域と傾斜面１０３の領域との境界Ｅが明確になる。 FIG. 10A is a diagram for explaining the relationship between the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus. In FIG. 10A,

Satisfy the relationship. In this case, the light beam reflected by the inclined surface 103 does not reach the measuring device. Therefore, in the image by the measuring apparatus, the area of the inclined surface 103 does not become bright, and the boundary E between the area of the plane 101 and the area of the inclined surface 103 becomes clear.

の関係を満たす。この場合に、傾斜面１０３で反射された光線は測定装置に到達する。この場合に、測定装置による画像において、傾斜面１０３の領域が明るくなり平面１０１の領域と傾斜面１０３の領域との境界Ｅが明確でなくなる。したがって、この状態は、画像による測定の観点から好ましくない。 FIG. 10B is a diagram for explaining the relationship between the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus. In FIG. 10B,

Satisfy the relationship. In this case, the light beam reflected by the inclined surface 103 reaches the measuring device. In this case, in the image by the measuring apparatus, the area of the inclined surface 103 becomes bright and the boundary E between the area of the plane 101 and the area of the inclined surface 103 becomes unclear. Therefore, this state is not preferable from the viewpoint of measurement by an image.

なお、測定装置の撮像光学系の開口角φは、一般的に10度から20度の範囲である。したがって、平面１０１に対する傾斜面１０３の角度は、20度から70度であるのが好ましい。 Therefore, the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus preferably satisfy the following relationship.

Note that the aperture angle φ of the imaging optical system of the measuring apparatus is generally in the range of 10 degrees to 20 degrees. Therefore, the angle of the inclined surface 103 with respect to the plane 101 is preferably 20 degrees to 70 degrees.

また、長さＸは、鮮明な画像を得るには０．０１ｍｍ以上であるのが望ましい。他方、測定装置の解像限界dは、測定光学系のエフナンバーをf_n0として以下の式で表せる。
d = 2.44×λ×f_n0
λ= 0.55μm、f_n0=0.4 としてd = 0.537um である。図８に示すように、測定装置の画像において、直接観察される傾斜面の像と反射によって観察される傾斜面の像とが存在する。そこで、解像限界ｄのみから考察すると、長さＸは、ｄ/２より大きくなければならない。 FIG. 11 is a diagram for explaining the relationship between the length X of the column 115 and the length X in the direction perpendicular to the center axis of the inclined surface 103 in the cross section including the center axis of the column 115. In order for a considerable part of the light beam reflected at the point on the boundary between the plane 101 and the inclined surface 103 to be reflected by the side surface of the column 115 and reach the measuring device, the aperture angle of the imaging optical system of the measuring device It is desirable that the following relationship is satisfied, where φ is φ.

The length X is preferably 0.01 mm or more in order to obtain a clear image. On the other hand, the resolution limit d of the measuring device can be expressed by the following equation where the f-number of the measuring optical system is f _n0 .
d = 2.44 × λ × f _n0
Assuming that λ = 0.55 μm and f _n0 = 0.4, d = 0.537 um. As shown in FIG. 8, in the image of the measuring apparatus, there are an image of an inclined surface observed directly and an image of an inclined surface observed by reflection. Therefore, considering only from the resolution limit d, the length X must be larger than d / 2.

  FIG. 12 is a diagram illustrating a cross section including the central axis of the position reference portion 110B of the component 100B according to the second embodiment of the present invention. The column 115 of the position reference portion 110B is a cylinder, and is formed on the plane 101 of the component 100B so that the central axis of the cylinder is perpendicular to the plane 101. The figure surrounded by the circle in FIG. 12 is a diagram showing a cross section including the central axis of the cylinder near the base of the cylinder. The plane 101 is surrounded by an annular inclined surface 103, and the inclined surface 103 connects the plane 101 and a plane 105 parallel to the plane 101 and having a distance D from the plane 101. The boundary line between the inclined surface 103 and the plane 101 is a circle, and the center of the circle is the intersection of the center axis and the plane 101. In the present embodiment, the flat surface 101 and the inclined surface 103 form a groove around the pillar 115. In the cross section, the width of the plane 101 in the direction perpendicular to the central axis, that is, the width of the groove is W. The plane 101 preferably forms the same plane as the plane on which the lens 150 is disposed.

  In FIG. 12, the corner indicated by A is preferably formed so that the cross section does not have a so-called R portion.

  FIG. 13 is a diagram illustrating a path of a light beam that travels perpendicular to the plane 101 of the illumination light and an image of the light beam. The reflected light of the light ray that enters the plane 101 perpendicularly travels perpendicularly to the plane 101 and reaches the image acquisition unit 309. Similarly, reflected light that enters the plane 105 perpendicularly also reaches the image acquisition unit 309. On the other hand, when the light beam traveling perpendicular to the plane 101 is reflected by the inclined surface 103, it is further reflected by the side surface of the column 115 and does not reach the image acquisition unit 309. Therefore, in the image acquired by the image acquisition unit 309, the areas of the plane 101 and the plane 105 become bright, and the area of the inclined surface 103 becomes dark. As a result, in the above image, the boundary E between the region of the plane 101 and the region of the inclined surface 103 is clearly shown.

  FIG. 14 is a diagram illustrating a path of light rays that travel at an angle within a predetermined range with respect to the plane 101 in the illumination light, and an image of the light rays. The reflected light of the light beam incident on the plane 101 at an angle within the predetermined range is reflected by the plane 101 and the side surfaces of the pillar 115 and then reaches the image acquisition unit 309. Similarly, the reflected light that enters the plane 105 also reaches the image acquisition unit 309. On the other hand, even if the light ray traveling at an angle within the predetermined range with respect to the plane 101 is reflected by the inclined surface 103, it is further reflected by the side surface of the column 115 and does not reach the image acquisition unit 309. Therefore, in the reflected image obtained by the light beam reflected by the side surface of the column 115 acquired by the image acquisition unit 309, the areas of the plane 101 and the plane 105 become bright and the area of the inclined plane 103 becomes dark. As a result, in the above image, the boundary E ′ between the reflected image in the area of the plane 101 and the reflected image in the area of the inclined surface 103 is clearly shown.

  FIG. 15 is a diagram illustrating a path of a light beam for illumination and an image by the light beam. FIG. 15 is a combination of FIGS. 13 and 14. In FIG. 15, a boundary E ′ is an image obtained by reflection on the side surface of the column 115 of the boundary E between the region of the plane 101 and the region of the inclined surface 103. Therefore, the midpoint of the line segment connecting the point on the boundary E and the corresponding point on the boundary E ′ corresponds to the position of the point on the outer periphery of the column 115 on the plane 101. In this manner, the position of the outer periphery of the base of the pillar 115 can be obtained from the image shown in FIG. A method for obtaining the position of the outer periphery of the column 115 on the plane 101 will be described in detail later.

  Hereinafter, the angle of the inclined surface 103 with respect to the plane 101 will be described. In this specification, the unit of angle is degrees.

の関係を満たす。この場合に、照射される光線の大部分は、平面１０１に到達する。 FIG. 16A is a diagram for explaining the relationship between the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus. In FIG. 16A,

Satisfy the relationship. In this case, most of the irradiated light rays reach the plane 101.

の関係を満たす。この場合に、照射される光線の一部は、平面１０５によるケラレによって平面１０１に到達することができない。したがって、この状態は照射の効率の観点から好ましくない。 FIG. 16B is a diagram for explaining the relationship between the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus. In FIG. 16B,

Satisfy the relationship. In this case, some of the irradiated light beams cannot reach the plane 101 due to vignetting by the plane 105. Therefore, this state is not preferable from the viewpoint of the efficiency of irradiation.

の関係を満たす。この場合に、傾斜面１０３で反射された光線は、測定装置に到達しない。したがって、測定装置による画像において、傾斜面１０３の領域が明るくなることはなく平面１０１の領域と傾斜面１０３の領域との境界Ｅが明確になる。 FIG. 17A is a diagram for explaining the relationship between the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus. In FIG. 17A,

Satisfy the relationship. In this case, the light beam reflected by the inclined surface 103 does not reach the measuring device. Therefore, in the image by the measuring apparatus, the area of the inclined surface 103 does not become bright, and the boundary E between the area of the plane 101 and the area of the inclined surface 103 becomes clear.

の関係を満たす。この場合に、傾斜面１０３で反射された光線の一部は、測定装置に到達する。この場合に、測定装置による画像において、傾斜面１０３の領域が明るくなり平面１０１の領域と傾斜面１０３の領域との境界Ｅが明確でなくなる。したがって、この状態は、画像による測定の観点から好ましくない。 FIG. 17B is a diagram for explaining the relationship between the angle (acute angle) θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus. In FIG. 17B,

Satisfy the relationship. In this case, a part of the light beam reflected by the inclined surface 103 reaches the measuring device. In this case, in the image by the measuring apparatus, the area of the inclined surface 103 becomes bright and the boundary E between the area of the plane 101 and the area of the inclined surface 103 becomes unclear. Therefore, this state is not preferable from the viewpoint of measurement by an image.

なお、測定装置の撮像光学系の開口角φは、一般的に10度から20度の範囲である。したがって、平面１０１に対する傾斜面１０３の角度は、20度から70度であるのが好ましい。 Therefore, the angle θ of the inclined surface 103 with respect to the plane 101 and the aperture angle φ of the imaging optical system of the measuring apparatus preferably satisfy the following relationship.

Note that the aperture angle φ of the imaging optical system of the measuring apparatus is generally in the range of 10 degrees to 20 degrees. Therefore, the angle of the inclined surface 103 with respect to the plane 101 is preferably 20 degrees to 70 degrees.

また、幅Ｗは、鮮明な画像を得るには０．０１ｍｍ以上であるのが望ましい。 FIG. 18 is a diagram for explaining the relationship between the width W of the groove and the length L of the pillar 115. In order for a considerable part of the light beam reflected at the point on the boundary between the plane 101 and the inclined surface 103 to be reflected by the side surface of the column 115 and reach the measuring device, the aperture angle of the imaging optical system of the measuring device It is desirable that the following relationship is satisfied, where φ is φ.

The width W is desirably 0.01 mm or more in order to obtain a clear image.

  FIG. 19 is a flowchart for explaining a measurement method according to an embodiment of the present invention.

  FIG. 20 is a diagram showing the relationship between the measurement method shown in the flowchart of FIG. 19 and the boundaries E and E ′.

  In step S1010 of FIG. 19, a circle forming the boundary E is determined from three points on the boundary E in the image of the measuring apparatus.

  In step S1020 of FIG. 19, an axis A passing through the center of the circle is determined. Here, the axis A is the horizontal direction.

  In step S1030 of FIG. 19, on the right side of the circle, intersections of the axis A, the boundary E, and the boundary E ′ are defined as A1 and A1 ′. As described above, the boundary E ′ is an image of the boundary E due to reflection on the side surface of the column 115.

  In step S1040 of FIG. 19, the midpoint of the line segment connecting point A1 and point A1 'is AC1.

  In step S1050 of FIG. 19, on the left side of the circle, intersections of the axis A, the boundary E, and the boundary E ′ are defined as A2 and A2 ′.

  In step S1060 in FIG. 19, the midpoint of the line segment connecting point A2 and point A2 'is AC2.

  In step S1070 in FIG. 19, the midpoint of the line segment connecting the points AC1 and AC2 is defined as AC.

  In step S1080 in FIG. 19, an axis B orthogonal to the axis A is determined.

  In step S1090 of FIG. 19, for the axis B, the points BC1, BC2, and BC are obtained according to the procedure from step S1030 to step S1070.

  In step S1100 of FIG. 19, the position of the position reference unit 110 is determined from the point AC and the point BC. In the present embodiment, since the main part of the position reference unit 110 is a cylinder, a point having the coordinates of the point AC in the axis A direction and the point BC in the axis B direction is the center of the cross section perpendicular to the cylinder axis. By setting the position, the position of the position reference unit 110 can be determined.

  As described with reference to FIG. 2, in the conventional part, the measurement is performed based on the position of the tip portion of the column of the position reference unit 110 ′. For this reason, the deviation of the reference position is caused by the inclination angle of the column.

Table 1 is a table showing the deviation of the reference position with respect to the inclination angle of the column for the conventional part and the part of the present invention. The tilt angle of the column is an angle of the axis in the longitudinal direction of the column with respect to the normal line of the plane 101. The unit of length in Table 1 is millimeter. The column length is 2.67 millimeters.

  FIG. 21 is a diagram showing the deviation of the reference position with respect to the inclination angle of the column for the conventional part and the part of the present invention. In FIG. 21, the deviation of the conventional part is indicated by a broken line, and the deviation of the part of the present invention is indicated by a solid line. Compared with the conventional part, in the part of the present invention, the deviation of the reference position due to the inclination angle of the column is greatly reduced. According to the present invention, as an example, a tolerance of lens position ± 3 micrometers can be realized.

  Further, even if the position of the outer periphery of the column of the position reference portion 110 and the position of the outer periphery of the groove are not formed concentrically, according to the measurement method shown in FIGS. It is possible to reduce an error caused by the position of the peripheral edge.

  FIG. 22 is a diagram illustrating a component 100C including a position reference unit 110C according to another embodiment of the present invention. The two position reference portions 110C have a quadrangular prism shape. In general, the cross section perpendicular to the longitudinal direction of the column of the position reference portion may be circular or polygonal. Even if the cross section of the column of the position reference portion is polygonal, the position of the position reference portion can be determined by a measurement method similar to the measurement method shown in FIG.

Claims (8)

In an image of a measuring apparatus equipped with an imaging optical system that uses coaxial epi-illumination, the position of a position reference part on a plane and the position of an arbitrary point are observed. A position measuring method for determining a position, wherein the position reference part has a columnar shape at least at the base, and includes an inclined surface surrounding the base of the pillar,
Determining the position of the outer periphery of the base from the position of the inclined surface surrounding the base and the boundary of the plane in the image of the measuring device;
Determining the position of the position reference portion from the position of the outer periphery of the root;
Determining a position of the arbitrary point on the basis of the position of the position reference unit. Assuming that the aperture angle of the imaging optical system is φ, the acute angle formed between the inclined surface surrounding the root and the plane is θ, θ is

The position measuring method according to claim 1, wherein: The aperture angle of the imaging optical system is φ, the acute angle between the inclined surface surrounding the base and the plane is θ, the unit of angle is degrees, and θ is

The position measuring method according to claim 1 or 2, satisfying   The position according to any one of claims 1 to 3, wherein the inclined surface surrounding the base is formed so as to connect the plane and a side surface of the column or connect the plane and another plane parallel to the plane. Measuring method. The inclined surface that surrounds the root is the width of the inclined surface perpendicular to the central axis in the cross section including the central axis of the column when the opening angle of the microscope is φ and the plane is connected to the side surface of the column. Is X and the length of the pillar is L,

The position measurement method according to claim 4, wherein:   The position measuring method according to claim 1, wherein the position of the arbitrary point is a position of an optical element.   A component having at least two position reference portions and an optical element, which are installed on one plane or a plurality of planes parallel to each other, each of the position reference portions is columnar at least at the base, A part having an inclined surface surrounding the base of the column, and an angle θ of the inclined surface with respect to a plane on which each position reference portion is installed is in the range of 20 degrees to 70 degrees.   The inclined surface surrounding the base connects the plane on which each position reference portion is installed and the side surface of the column, or connects the plane on which each position reference portion is installed and another plane parallel to the plane. The component according to claim 7, formed in

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