JP2017088433A - Tabular component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tabular component capable of suppressing generation of deflection or warpage, while securing rigidity in a large area, and obtaining a clear visual field in a wide range.SOLUTION: As a tabular component (10), a tabular member (11) comprising a sapphire single crystal, and having a thickness of 5 mm or less is formed. Since the thickness of the tabular member (11) comprising the sapphire single crystal is set at 5 mm or less, a crystal growth time of the sapphire single crystal can be shortened, and contamination of bubbles or a foreign matter to the inside can be prevented, and generation of deflection or warpage can be suppressed, to thereby obtain a clear visual field in a wide range.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a plate-like component.

  In the technical field of measuring instruments, there has been proposed an image measuring device that places an object to be measured on a movable stage, irradiates light from above and below, images the object to be measured using an image sensor, and generates an image. (For example, Patent Document 1). In such a conventional technique, as shown in FIG. 9, the image measuring apparatus 1 includes a movable stage 2 that can move in the x and y directions, a transmission illumination unit 3, a ring illumination unit 4, image sensors 5 and 6, and a display device 7. It has. In the measurement using the image measuring apparatus 1, a measurement object is placed on the movable stage 2, and the light from the transmission illumination unit 3 and the ring illumination unit 4 is irradiated to the measurement object, and an optical device such as a lens or a half mirror is used. The measurement result is displayed on the display device 7 by taking an image of the measurement object with the imaging elements 5 and 6 using the system.

  As shown in FIG. 9, in the image measuring apparatus 1, light is irradiated on the measurement object from the lower side of the movable stage 2 by the transmission illumination unit 3. It is necessary to use a plate-like component made of a material that can transmit illumination light satisfactorily. In addition, since the measurement object is placed on the movable stage 2 in the measurement by the image measuring apparatus 1, a hard material is used so that the surface of the movable stage 2 is not damaged by contact with the measurement object even in repeated use. It was necessary to form a plate-shaped part using

  An example of a material that satisfies the requirements of light transmittance and hardness is a sapphire single crystal substrate. Patent Document 2 proposes a sapphire single plate or a sapphire plate attached to both sides of glass, for example, as a plate-like component that is a mount for a projector. Is prevented.

  On the other hand, in measuring instrument applications, there is a demand for measurement with a wide field of view in order to measure a large measurement object, and it is hoped that the area of the movable stage and the plate-shaped part should be increased in order to mount the large measurement object. It is rare. It is necessary to secure rigidity in order to make the plate-like component stand independently as a table on which the measurement object is placed. Therefore, in order to increase the area of the plate-like component, the thickness must be increased. When a plate-like component is configured with a sapphire single plate as shown in Patent Document 2, a thick sapphire single crystal must be formed by crystal growth, and the growth time is prolonged. Inside the thick sapphire single crystal, bubbles and foreign matters are easily mixed, and there is a problem that bubbles and foreign matters are reflected in the imaging range and a clear visual field cannot be secured. Moreover, in the plate-shaped component bonded to glass and sapphire shown in Patent Document 2, the larger the area due to the mismatch in thermal expansion coefficient and lattice constant between the glass used as the base substrate and sapphire bonded to the surface. There has been a problem that bending and warping are likely to occur, the parallelism of the plate-like component is lowered, and the measurement visual field is distorted.

JP 2014-052220 A Japanese Utility Model Publication No. 60-059244

  The present invention has been made in view of the above problems, and provides a plate-like component capable of suppressing the occurrence of bending and warping while ensuring rigidity in a large area and obtaining a clear field of view over a wide range. For the purpose.

  In order to solve the above problems, the plate-like component of the present invention is made of sapphire single crystal, and the thickness of the plate-like member is 5 mm or less.

  In such a plate-shaped component of the present invention, the crystal growth time of the sapphire single crystal can be shortened by setting the thickness of the plate-shaped member made of the sapphire single crystal to 5 mm or less. It is possible to prevent foreign matter from entering. In addition, it is possible to obtain a clear visual field over a wide range by suppressing the occurrence of bending and warping.

  Moreover, in one embodiment of this invention, the parallelism of both the exposed surfaces of the said plate-shaped member is 2 'or less.

  In one embodiment of the present invention, the plane shape is substantially circular, and the diameter is 4 inches or more and 12 inches or less.

  Moreover, in one embodiment of the present invention, the planar shape is substantially rectangular, and the dimension is not less than 100 mm × 100 mm and not more than 841 mm × 1189 mm.

  Moreover, in one embodiment of this invention, surface roughness Ra of the plane which the said plate-shaped member exposed is 20 nm or less.

  In one embodiment of the present invention, the plate-like member does not contain cracks.

  According to the present invention, it is possible to provide a plate-like component capable of obtaining a clear field of view over a wide range while suppressing the occurrence of bending and warping while ensuring rigidity in a large area.

It is a figure which shows the plate-shaped component which concerns on 1st Embodiment, (a) is a schematic plan view, (b) is when the plate-shaped component shown to Fig.1 (a) is seen from an AA cutting line direction. It is a schematic cross section. It is a schematic block diagram which shows the manufacturing apparatus of the sapphire single crystal by EFG method. It is process drawing shown about the manufacturing method until it obtains a plate-shaped component from a sapphire single crystal. It is the partial enlarged photograph which shows the external appearance defect of a plate-shaped component, and is the partial enlarged photograph which shows the defect of a crack. It is the partial enlarged photograph which shows the external appearance defect of a plate-shaped component, and is the partial enlarged photograph which shows the defect of a bubble. It is the partial enlarged photograph which shows the external appearance defect of a plate-shaped component, and is the partial enlarged photograph which shows the defect of a foreign material. It is the partial enlarged photograph which shows the external appearance defect of a plate-shaped component, and is the partial enlarged photograph which shows the defect of a crack. It is a figure which shows the plate-shaped component which concerns on 2nd Embodiment, (a) is a schematic plan view, (b) is when the plate-shaped component shown to Fig.8 (a) is seen from a BB cutting line direction. It is a schematic cross section. 1 is a schematic cross-sectional view illustrating an image measurement apparatus that captures an image of a measurement object using an image sensor and generates an image.

(First embodiment)

  Hereinafter, a first embodiment of the present invention will be described in detail with reference to the drawings. FIG. 1 is a view showing a plate-like component according to the first embodiment of the present invention, FIG. 1 (a) is a schematic plan view, and FIG. 1 (b) is a schematic sectional view.

  As shown in FIG. 1, the plate-like component 10 of this embodiment is composed of a single sapphire single crystal substrate 11. The sapphire single crystal substrate 11 has a substantially rectangular planar shape. Here, the substantially rectangular shape includes a state in which the four corners of the rectangle are chamfered, and it is preferable that the outer shape is appropriately processed according to the specification of the measuring instrument using the plate-like component 10. As a specific rectangular dimension, a size of 100 mm × 100 mm or more and 841 mm × 1189 mm or less is preferable, and within this range, rigidity can be secured while obtaining a wide visual field range, and the plate-like component 10 can be held independently. Become.

  The sapphire single crystal substrate 11 is a plate-like member made of a single crystal of sapphire using a known single crystal substrate growth method, and is grown and grown by, for example, an EFG (Edge-defined Film-fed. Growth) method described later in detail. Use the same thing. The crystal plane orientation of the sapphire single crystal substrate 11 is, for example, that having a c-plane surface, but is not limited to the c-plane, and a desired crystal plane such as an r-plane, a-plane, or m-plane may be used as the surface.

  It has been found that by setting the thickness of the sapphire single crystal substrate 11 to 5 mm or less, a desired thickness can be achieved and rigidity can be ensured while shortening the time required for crystal growth. In addition, if the sapphire single crystal substrate 11 is formed with a thickness of 5 mm or less, the possibility of bubbles or foreign matters occurring inside the sapphire single crystal substrate 11 can be reduced, and even when the plate-like component 10 is used in a measuring machine. It has been found that a clear measurement field can be obtained. Moreover, by setting the thickness of the sapphire single crystal substrate 11 to 5 mm or less, it is possible to suppress the occurrence of bending and warping and improve the parallelism of the plate-like component 10.

  The parallelism between the exposed surface 11a and the exposed surface 11b of the sapphire single crystal substrate 11 is 2 '(min) or less, and the amount of warpage is 10 μm or less. By setting the parallelism to 2 ′ or less and the warping amount to 10 μm or less, when the plate-like component 10 is used for a measuring instrument, distortion is reduced over a wide visual field range, and a clear visual field can be obtained. Further, the exposed surfaces 11a and 11b are each polished, and for example, it is preferable to polish until the surface roughness Ra becomes 20 nm or less. By setting the surface roughness Ra to 20 nm or less, a clearer visual field can be obtained when the plate-like component 10 is used in a measuring instrument.

  In the plate-like component 10, a central region 14 and a peripheral region 15 are set as shown in FIG. The central region 14 is a region set at a substantially central position of the plate-like component 10, and when the plate-like component 10 is used as a mounting table for a measuring instrument as shown in FIG. 9, a measurement object is placed thereon. This is the area where an image is captured. The peripheral region 15 is a region set from the periphery of the central region 14 to the vicinity of the outer shape of the plate-like component 10, and is a region that can be an imaging range when the measurement object is imaged. Since the central area 14 is an area on which a measurement object is placed and imaged, it is preferable to set an allowable size and number more strictly than the peripheral area 15 for defects such as bubbles, foreign matter, and scratches. A measurement visual field can be obtained.

  Next, crystal growth of the sapphire single crystal substrate 11 will be described. As shown in FIG. 2, the sapphire single crystal manufacturing apparatus 21 includes a growth container 23 for growing a sapphire single crystal 22 and a pulling container 24 for pulling up the grown sapphire single crystal 22. Grow 22 and grow.

  The growth container 23 includes a crucible 25, a crucible drive unit 26, a heater 27, an electrode 28, a die 29, and a heat insulating material 30. The crucible 25 melts the aluminum oxide raw material. The crucible drive unit 26 rotates the crucible 25 around the vertical direction. The heater 27 heats the crucible 25. The electrode 28 energizes the heater 27. The die 29 is installed in the crucible 25 and determines the liquid surface shape of the aluminum oxide melt (hereinafter simply referred to as “melt” as necessary) when pulling up the sapphire single crystal 22. The heat insulating material 30 surrounds the crucible 25, the heater 27, and the die 29.

  Further, the growth container 23 includes an atmospheric gas inlet 31 and an exhaust port 32. The atmosphere gas inlet 31 is an inlet for introducing, for example, argon gas into the growth vessel 23 as the atmosphere gas. On the other hand, the exhaust port 32 is provided for exhausting the inside of the growth vessel 23.

  The pulling container 24 includes a shaft 33, a shaft driving unit 34, a gate valve 35, and a substrate inlet / outlet 36, and pulls up a plurality of flat plate-shaped sapphire single crystals 22 grown from a seed crystal 37. The shaft 33 holds a seed crystal 37. Further, the shaft drive unit 34 moves the shaft 33 up and down toward the crucible 25 and rotates the shaft 33 around the lifting direction. The gate valve 35 partitions the growth container 23 and the pulling container 24. Further, the substrate inlet / outlet 36 takes in and out the seed crystal 37.

  The manufacturing apparatus 21 also has a control unit (not shown), and the rotation of the crucible drive unit 26 and the shaft drive unit 34 is controlled by this control unit.

  The aluminum oxide raw material charged into the crucible 25 is melted (raw material melt) to become a melt. A part of this melt enters the slit of the die 29, rises in the slit based on the capillary phenomenon and is exposed from the opening, and an aluminum oxide melt pool is formed.

  Next, a method for manufacturing the sapphire single crystal 22 using the manufacturing apparatus 21 will be described. First, a predetermined amount of granulated aluminum oxide raw material powder (99.99% aluminum oxide), which is a sapphire raw material, is charged into a crucible 25 in which a die 29 is housed. The aluminum oxide raw material powder may contain compounds and elements other than aluminum oxide depending on the purity or composition of the sapphire single crystal to be produced.

  Subsequently, the inside of the growth vessel 23 is replaced with argon gas, and the oxygen concentration is set to a predetermined value or less.

  Next, the crucible 25 is heated with the heater 27 to melt the aluminum oxide raw material powder, thereby preparing an aluminum oxide melt. Further, a part of the melt rises through the slit of the die 29 by capillary action and reaches the surface of the die 29, and a melt pool is formed in the upper part of the slit.

  Next, after bringing the seed crystal 37 into contact with the melt surface, the pulling up of the seed crystal 37 is started, and the flat sapphire single crystal 22 is grown. Thereafter, the obtained sapphire single crystal 22 is taken out from the substrate entrance 36. For details, see, for example, Japanese Patent No. 4245856.

  Next, a manufacturing method until the plate-like component 10 is obtained from the obtained sapphire single crystal 22 will be described with reference to the process diagram of FIG.

  Step S1 is a crystal growth step, which is a step of obtaining the sapphire single crystal 22 by the above-described EFG method or the like. Next, step S2 is an outer shape cutting step, which is a step of obtaining the outer shape of the substantially rectangular sapphire single crystal substrate 11 by cutting the neck portion of the sapphire single crystal 22 obtained in step S1. Next, step S3 is an outer shape forming process, which is a process of grinding the chamfered portions of the side surfaces and the four corners of the sapphire single crystal substrate 11. The planar shape of the sapphire single crystal substrate 11 becomes the same as the planar shape of the plate-like component 10 by the outer shape forming step.

  Next, step S4 is a double-sided lapping process, and both surfaces of the sapphire single crystal substrate 11 obtained in step S3 are lapped with a polishing machine, and the sapphire single crystal substrate 11 is adjusted to a desired thickness.

  Next, step S5 is a double-side polishing process, in which both surfaces of the sapphire single crystal substrate 11 are mirror-polished by a polishing machine. As the double-side polishing step, it is preferable to perform a plurality of types of polishing by changing the material, load, rotation speed, etc. of the slurry that is the polishing liquid, and the surface roughness Ra of the sapphire single crystal substrate 11 after the double-side polishing step is finished. Processing until the thickness is 20 nm or less. Next, step S6 is a cleaning process, and the surface of the sapphire single crystal substrate 11 is cleaned with an organic solvent or pure water in order to remove the slurry used for polishing in step S5 and obtain a clean surface. Further, if necessary, a desired region of the sapphire single crystal substrate 11 may be subjected to laser marking and further cleaned.

  By setting the thickness of the plate-like member 10 to 5 mm or less, it is possible to suppress the warpage, and to make the parallelism of both exposed surfaces (11a, 11b) 2 'or less, and the parallelism of the sapphire single crystal substrate 11 Is 2 ′ or less, and the plate-like component 10 is obtained.

  Next, step S7 is an inspection process, in which the plate-like component 10 is inspected by visual inspection or the like, and undesired defective products are selected for use in measuring instruments. For example, with respect to the exposed surfaces 11a and 11b which are the front and back surfaces of the plate-shaped component 10, the parallelism is measured by measuring four points with a digital indicator in the central φ60 mm range. And Further, the transmittance is measured with a spectrophotometer, and for example, the transmittance in the wavelength range of 400 to 800 nm is less than a predetermined value (for example, less than 80%) as a defective product. Further, the amount of warpage is measured using a flat tester, and if the amount of warpage is larger than a predetermined value, it is determined as a defective product.

  4 to 7 are partially enlarged photographs showing appearance defects in the plate-like component 10. In the selection of defective products, visible light (for example, green light) is irradiated from the side of the plate-like component 10, and the number of items that are reflected at the defective portions and viewed as bright spots are counted.

  FIG. 4 shows a defective chip, and is a state where a part of the sapphire single crystal substrate 11 is missing from the outer edge portion of the plate-like component 10. Since this chipping defect is outside the peripheral region 15, if the size is small, the influence on the image pickup is small, but if it is large, there is a problem in the rigidity and durability of the plate-like component 10. If any chipping occurs, the product will be defective. Similarly, even when a crack is generated in the entire region of the sapphire single crystal substrate 11, a problem occurs in the rigidity and durability of the plate-like component 10, so that it is a defective product, and the sapphire single crystal substrate 11 includes a crack. Not to be. Since the sapphire single crystal substrate 11 has a high Vickers hardness, generation of cracks can be prevented, and the strength of the plate-like component 10 and a clear measurement field of view can be obtained.

  FIG. 5 shows a bubble defect, and FIG. 6 shows a foreign object defect. Bubbles and foreign substances may be mixed during the crystal growth of the sapphire single crystal substrate 11 and are visible because small luminescent spots are generated as shown in the photograph. When the plate-like component 10 is used as a measuring instrument and an image of the measurement object is picked up, light is emitted from the front side or the back side of the plate-like component 10, so that imaging is performed when bubbles or foreign objects exist around the measurement object. It is not preferable because it is reflected in the image. Therefore, the size of bubbles and foreign matters allowed in the central area 14 where the measurement object is placed is set smaller than that in the peripheral area 15. In addition, if bubbles and foreign matter are concentrated in a narrow area, the above-mentioned reflection in the image becomes noticeable. Therefore, the number of bubbles and foreign matters allowed within a predetermined range is set. If the number is more than that, it will be defective. For example, it is preferable to set up to four bubbles or foreign substances within the range of φ10 mm as the allowable range, and it is even more preferable to set up to two bubbles or foreign substances within the range of φ10 mm as the allowable range.

  FIG. 7 shows a defect of scratches, and it is possible to visually observe a flaw in which bright spots similar to bubbles and foreign matters are continuously linear. If scratches are present around the measurement object, it will be reflected in the captured image, which is not preferable. Therefore, the width of the flaw allowed in the central region 14 where the measurement object is placed is set smaller than that in the peripheral region 15.

  As described above, the plate-like component 10 of the present embodiment can reduce and suppress defects such as bubbles and foreign matters generated in the sapphire single crystal substrate 11 by setting the thickness to 5 mm or less. Even when used in a measuring instrument, a good measurement visual field can be obtained even in a wide visual field range.

  Hereinafter, a second embodiment of the present invention will be described in detail with reference to the drawings. The description overlapping with the first embodiment is omitted. FIG. 8 is a view showing a plate-like component according to the second embodiment of the present invention, FIG. 8A is a schematic plan view, and FIG. 8B is a schematic cross-sectional view.

  As shown in FIG. 8, the plate-like component 60 of the present embodiment is composed of a sapphire single crystal substrate 61, and the thickness is set to 5 mm or less. Here, the substantially circular shape includes a state in which an orientation flat is formed by chamfering a part of a circle as shown in FIG. 8A, according to the specification of a measuring instrument using the plate-like component 60. It is preferable to process the outer shape as appropriate. The specific circular dimension is preferably 4 inches or more and 12 inches or less (1 inch is 25.4 mm), and within this range, rigidity can be secured while obtaining a wide field of view, and a plate-like component. 60 can be held independently.

  As a method for growing the substantially circular sapphire single crystal substrate 61, the Kilopros method, the Chocraslky method, the Bernoulli method, the vertical Bridgman method, etc. can be used in addition to the EFG method.

  61a and 61b are exposed surfaces. As shown in FIG. 8A, the plate-like component 60 has a central area 64 and a peripheral area 65 in plan view. The central area 64 is an area set at a substantially central position of the plate-like component 60. When the plate-like component 60 is used for the mounting table of the measuring instrument as shown in FIG. This is the area where an image is captured. The peripheral area 65 is an area set from the periphery of the central area 64 to the vicinity of the outer shape of the plate-like component 60, and is an area that can be an imaging range when the measurement object is imaged. Since the central area 64 is an area on which a measurement object is placed and imaged, it is preferable to set a stricter size and number than the peripheral area 65 for defects such as bubbles, foreign matter, and scratches. A measurement visual field can be obtained.

  Also in the present embodiment, the plate-like component 60 has a large area and secures rigidity, but the occurrence of bending and warpage is suppressed, the parallelism is good, and defects such as bubbles, foreign matter, and scratches can be reduced. A good measurement field can be obtained in a wide field of view even when used in a measuring instrument.

DESCRIPTION OF SYMBOLS 1 ... Image measuring apparatus 2 ... Movable stage 3 ... Transmission illumination unit 4 ... Ring illumination unit 5, 6 ... Imaging device 7 ... Display apparatus 10, 60 ... Plate-shaped component 11, 61 ... Sapphire single crystal substrate 11a, 11b, 61a, 61b ... exposed surface 14,64 ... central region 15,65 ... peripheral region

Claims (6)

  A plate-like component comprising a sapphire single crystal and a plate-like member having a thickness of 5 mm or less.   The plate-like component according to claim 1, wherein the parallelism of both surfaces of the exposed surface is 2 'or less.   3. The plate-like component according to claim 1, wherein the planar shape is substantially circular, and the diameter thereof is 4 inches or more and 12 inches or less.   3. The plate-like component according to claim 1, wherein the planar shape is a substantially rectangular shape, and the dimension is 100 mm × 100 mm size or more and 841 mm × 1189 mm size or less.   It is a plate-shaped component as described in any one of Claims 1-4, Comprising: Surface roughness Ra of the exposed plane is 20 nm or less, The plate-shaped component characterized by the above-mentioned.   It is a plate-shaped component as described in any one of Claims 1-5, Comprising: A crack is not contained, The plate-shaped component characterized by the above-mentioned.