WO2013183421A1 - Method for manufacturing micromirror array - Google Patents

Method for manufacturing micromirror array Download PDF

Info

Publication number
WO2013183421A1
WO2013183421A1 PCT/JP2013/063774 JP2013063774W WO2013183421A1 WO 2013183421 A1 WO2013183421 A1 WO 2013183421A1 JP 2013063774 W JP2013063774 W JP 2013063774W WO 2013183421 A1 WO2013183421 A1 WO 2013183421A1
Authority
WO
WIPO (PCT)
Prior art keywords
micromirror array
substrate
unit optical
manufacturing
optical element
Prior art date
Application number
PCT/JP2013/063774
Other languages
French (fr)
Japanese (ja)
Inventor
昭子 長藤
紀行 十二
成紀 森田
Original Assignee
日東電工株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 日東電工株式会社 filed Critical 日東電工株式会社
Publication of WO2013183421A1 publication Critical patent/WO2013183421A1/en

Links

Images

Classifications

    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B29—WORKING OF PLASTICS; WORKING OF SUBSTANCES IN A PLASTIC STATE IN GENERAL
    • B29D—PRODUCING PARTICULAR ARTICLES FROM PLASTICS OR FROM SUBSTANCES IN A PLASTIC STATE
    • B29D11/00—Producing optical elements, e.g. lenses or prisms
    • B29D11/00596—Mirrors
    • G—PHYSICS
    • G02—OPTICS
    • G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
    • G02B5/00—Optical elements other than lenses
    • G02B5/08—Mirrors
    • G02B5/09—Multifaceted or polygonal mirrors, e.g. polygonal scanning mirrors; Fresnel mirrors

Definitions

  • the present invention relates to a method of manufacturing a micromirror array in which a mirror image of a projection object is formed in a space by unit optical elements having a pair of light reflecting surfaces orthogonal to each other arranged on a substrate.
  • a unit optical that reflects light by one or more mirror surfaces is applied to a substrate (substrate) that constitutes the element surface of the optical element.
  • a micromirror array in which a plurality of elements are arranged has been developed.
  • convex unit optical elements such as a small quadrangular prism having “two mirror surfaces perpendicular to each other” (corner reflectors) arranged at an angle perpendicular to or close to the substrate are arranged in an array.
  • the arranged “corner reflector array” has recently attracted attention because of its simple structure (see Patent Document 1).
  • the convex micromirror array 20 (hereinafter, also simply referred to as “array”) includes a transparent square columnar micro-unit optical element 22 (this example) on one surface of a substrate 21 (element surface P) made of a transparent material. Then, a large number of regular cubes having a vertical, horizontal, and height ratio of approximately 1: 1: 1 are arranged in a grid of 45 ° diagonally. In the case of the array 20, at least two of the four side surfaces (side surfaces 22a and 22b) of each unit optical element 22 are formed as mirror surfaces (light reflecting surfaces).
  • the above-described conventional micromirror array manufacturing method has a problem that it is difficult to obtain a micromirror array capable of forming a bright and clear image. That is, in order to obtain bright and high-brightness imaging, it is necessary to increase the amount of reflected (transmitted) light per unit area of the micromirror array.
  • each unit optical element corner reflector
  • a method of increasing or lengthening the light reflection surface (mirror surface area) is conceivable.
  • each unit optical element such as a minute quadrangular prism [height of unit optical element (vertical length in thickness direction) / width of unit optical element (element surface
  • the above-described method using photolithography has a limitation because a deep vertical groove cannot be formed accurately and the light reflecting surface becomes rough.
  • the aspect ratio is increased, there arises a problem that it is difficult to release the array from the mold. Therefore, in these conventional manufacturing methods, it is difficult to obtain a convex micromirror array having a light reflection surface of a desired shape with a high aspect ratio and a wide light reflection area.
  • the present invention has been made in view of such circumstances, and has a high degree of freedom in designing a convex unit optical element, and can easily produce a micromirror array that connects bright and high-brightness images.
  • the purpose is to provide a manufacturing method.
  • the present invention provides a method for manufacturing a micromirror array comprising a transparent flat substrate and a plurality of convex unit optical elements formed in an array on the surface of the substrate.
  • the gist of the present invention is a method of manufacturing a micromirror array, which includes a cutting process in which straight grooves are sequentially formed on the surface in two directions orthogonal to each other with a predetermined interval therebetween.
  • the present inventors have broken down the conventional technical knowledge using photolithography and molds as a processing method for increasing the degree of freedom of processing of the convex unit optical element, and considered the use of cutting.
  • the aspect ratio of the light reflecting surface [vertical length (length in the element surface thickness direction) / width], which was only “about 1” in the conventional regular cube-shaped corner reflector (ratio of aspect ratio of about 1).
  • the ratio of (the width in the element surface direction)] was successfully formed (that is, the rectangular column was long).
  • the amount of light involved in image formation in the micromirror array is increased, and a clear image (mirror image) with high brightness can be obtained.
  • the manufacturing method of the micromirror array of the present invention is such that a flat substrate serving as a work is attached to a predetermined position of a processing stage of a cutting machine, and cutting is performed using a rotary blade on a predetermined surface of the substrate.
  • a plurality of linear grooves having a depth of 50 to 500 ⁇ m and parallel to each other are sequentially formed on the surface in two directions orthogonal to each other with a predetermined interval between them, thereby forming a substantially rectangular column-shaped minute groove.
  • a large number of convex unit optical elements are provided.
  • the convex micromirror array obtained by this manufacturing method has a high “ratio of the longitudinal length in the substrate thickness direction to the lateral width in the substrate surface direction” (aspect ratio) of the light reflecting surface (side surface) in each unit optical element. Compared with the conventional micromirror array, the area of each light reflecting surface and the amount of light reflected and transmitted through the array is increased. Therefore, the convex micromirror array obtained by the manufacturing method of the micromirror array of the present invention can form a bright mirror image of the projection object with high brightness.
  • the linear groove when at least one of the rotary blade and the processing stage intermittently moves a predetermined distance to engrave and form the linear groove, the linear groove is It can be formed quickly and accurately at a desired position at a desired depth. Therefore, the formation efficiency of the linear groove is further improved.
  • a convex micromirror array 10 comprising a transparent flat substrate 1 and a group of minute square columnar convex unit optical elements 2 is used. It is a method of manufacturing. This method uses a cutting machine such as a dicing machine (dicing saw) as shown in FIG. 1 to provide a desired depth on a predetermined surface of a workpiece W (substrate) that is mounted on a moving stage S and temporarily fixed.
  • a cutting machine such as a dicing machine (dicing saw) as shown in FIG. 1 to provide a desired depth on a predetermined surface of a workpiece W (substrate) that is mounted on a moving stage S and temporarily fixed.
  • a cutting machine used in this manufacturing method is called a dicing machine or a dicing saw or the like, and is attached to the tip of a spindle (not shown) that rotates at high speed.
  • An attached rotary blade diamond blade such as dicing blade B
  • a processing stage moving stage S
  • this moving stage Stage driving means for rotating S in the three axis (x, y, z) directions and rotating around the z axis ( ⁇ ) corresponding to the rotation and vertical movement of the blade B.
  • the dicing blade B is a substantially ring-shaped ultra-thin outer peripheral blade, and abrasive grains made of small-diameter industrial diamond are imparted to the blade portion (in some cases, the left and right side end surfaces) provided on the outer peripheral surface.
  • the blade B has a thickness (total thickness in the end face direction) of about 0.015 mm (15 ⁇ m) to 0.3 mm (300 ⁇ m), and a groove obtained by engraving using the blade B ( The groove width g of the groove) is about 0.02 mm to 0.35 mm.
  • the blade B having a flat outer peripheral surface (cutting edge surface) is used, but a blade having a triangular, circular, or elliptical cross section may be used.
  • the moving stage S for temporarily fixing the workpiece W is installed on a slider (linear motion bearing) that can move (position) freely in at least two directions of x and y as shown in FIG.
  • it is further configured to be able to move up and down (not shown) in the z-axis direction and rotate around the z-axis ( ⁇ ).
  • the stage driving means in each axial direction (around the axis) will not be described because it is the same mechanism as a general-purpose machine tool, etc., but intermittent operation and accurate position control of the moving stage S using a stepping motor, actuator, or the like , And can be programmed to run at a constant speed.
  • a plurality of sets of the spindles and blades B are arranged at or apart from each other.
  • a flat substrate (W) made of a material having a visible light transmittance of 80% or more such as an acrylic resin is prepared.
  • the substrate is attached to a predetermined position on the moving stage S using an adhesive tape or an adhesive so that the surface to be processed is up (blade B side), and is attached and fixed as a workpiece W ( (Temporary fixing) [work attachment process].
  • the workpiece W may be gripped by a chuck or a vise without using an adhesive or the like.
  • the moving stage S is moved to a machining start position, and the blade B is lowered to a position where the workpiece can be cut while rotating the blade B at a high speed.
  • the (moving stage S) is slid horizontally to cut a linear groove having a desired depth (50 to 500 ⁇ m) on the processing target surface (surface) of the workpiece W.
  • the moving stage S is moved to the machining start position of the next groove, and the workpiece W is slid in the horizontal direction at a predetermined feed rate again, Process the next groove. Then, by repeating the engraving process of this linear groove at a predetermined interval (pitch) in one direction, a plurality of linear grooves parallel to each other in a predetermined first direction (y direction at this time) are obtained. It is formed.
  • the moving stage S is subsequently rotated by 90 ° in the ⁇ direction, and a second direction orthogonal to the linear grooves in the first direction (In this example, the linear groove engraving similar to the above is repeatedly performed on the one that was previously in the x direction and turned 90 ° into the y direction (cutting step).
  • the grooves 3x and 3y (groove width g) engraved on one surface of the substrate 1 in two directions (x and y directions) perpendicular to each other are formed between the grooves 3x and 3y.
  • a micromirror array 10 in which a large number of small square columnar unit optical elements 2 having a desired high aspect ratio (element height v / element width h) are arranged.
  • the position of the moving stage S may be fixed, and the position of the spindle and blade B may be moved and rotated in the horizontal direction to cut (engrave) the linear groove similar to the above.
  • the diamond abrasive grains used in the dicing blade B are usually those having a particle size of about # 240 to # 5000, but the surface of the light reflecting surface (both side walls of the groove) after cutting is preferably rough (mirror surface). ), It is preferable that the grain size of the abrasive is # 1000 or more.
  • a flat substrate 1 and the substrate 1 (element surface P) ) Of a plurality of convex unit optical elements (cuboid rectangular quadrangular prisms) 2 formed in an array on one surface (upper surface).
  • a pair of (two) light reflecting surfaces (first side surface 2a and second side surface 2b on the side of the quadrangular prism) constituting the corner reflector are respectively “substrate surface direction
  • the ratio of the vertical length (element height v) in the substrate thickness direction to the lateral width (element width h) ”(hereinafter referred to as“ aspect ratio (v / h) ”) is usually 1.5 or more, preferably 2. 0 or more.
  • the aspect ratio is usually less than about 1.3, and often 1.1 or less. It is.
  • the convex micromirror array 10 will be described in more detail.
  • the substrate 1 and each unit optical element 2 are integrally formed as shown in the cross-sectional view of FIG. Grooves 3 (3x, 3y) carved using the blade B are formed.
  • the “depth” of the grooves 3 (3x, 3y) is the same as the “element height v” of each unit optical element 2 formed by cutting.
  • the substrate 1 is a support for arranging the unit optical elements 2 in an array, and is usually a flat plate having a constant thickness (thickness of about 0.5 to 10.0 mm), An element surface of the optical element (symbol P in the figure, one-dot chain line) is formed.
  • Each unit optical element 2 has a vertically long regular quadrangular prism shape projecting convexly from one surface of the substrate 1, and faces each side surface (first side surface 2a, second side surface 2b and the same).
  • the third side surface 2d and the fourth side surface 2e) are formed at an angle substantially perpendicular to the surface (upper surface in the drawing) of the substrate 1.
  • two side surfaces (first side surface 2a and second side surface 2b) constituting one corner are the outer surfaces (and The corresponding inner surface) is a light-reflecting mirror surface, and these constitute a corner reflector.
  • the light reflecting surfaces (side surfaces 2a and 2b) of the unit optical element 2 each have a rectangular shape with the aspect ratio (v / h) of 1.5 or more.
  • the element height v of each unit optical element 2 (that is, the “depth” of the groove 3) is usually set to 200 ⁇ m or more, preferably 250 ⁇ m or more, more preferably 300 ⁇ m or more.
  • each side surface of each unit optical element 2 in the convex micromirror array 10 is normally set to 50 to 300 ⁇ m, and the interval between adjacent unit optical elements 2 (that is, the width of the engraved groove by the blade B). g) is usually set to 10 to 200 ⁇ m.
  • a bright, high-brightness, high-aspect-ratio micromirror array can be easily manufactured with a high yield. Therefore, it contributes to the cost reduction of the micromirror array.
  • the obtained micromirror array 10 increases the area of each light reflecting surface and the amount of light reflected and transmitted through the array as compared with the conventional micromirror array. Thereby, it is possible to form a clear mirror image of the projection object with high brightness.
  • a micromirror array having a substantially square columnar convex unit optical element has been described as an example.
  • the method of manufacturing a micromirror array of the present invention has other polygonal column shapes such as a substantially triangular column shape.
  • the present invention can be applied to the manufacture of a micromirror array having unit optical elements.
  • Example 1 First, an acrylic plate serving as a substrate was prepared, and a convex micromirror array of Example 1 was produced by dicing (cutting).
  • ⁇ Acrylic plate> Acrylic resin substrate (flat plate): 50 mm x 50 mm x thickness 2 mm ⁇ Cutting machine> Automatic dicing saw DAD3350 manufactured by DISCO ⁇ Dicing conditions> ⁇ Dicing blade ⁇ DBC, NBC-Z2050> Blade thickness 25 ⁇ m ⁇
  • micromirror array> Affix the acrylic plate to an adhesive tape ⁇ Dicing tape: manufactured by Nitto Denko Corp., ELEP tape> and fix the acrylic plate fixed body on the chuck table (processing stage) of the dicing device ⁇ Disco>. did. Then, a groove having a depth of 300 ⁇ m (corresponding to the “element height v” of the square column of the unit optical element) is carved (digged) into a predetermined lattice shape under the conditions shown in the above ⁇ Dicing Condition> A convex micromirror array of Example 1 was produced.
  • FIG. 4 shows an enlarged photograph of the unit optical element of the convex micromirror array of Example 1 taken with a microscope.
  • Each unit optical element has an element height v of 300 ⁇ m, an element width h of 100 ⁇ m, and a groove width g between adjacent elements of 30 ⁇ m.
  • the aspect ratio (v / h) of (and the light reflecting surface) was 3.0.
  • the dimension measurement (photographing) of the manufactured unit optical element was performed using a microscope (manufactured by Keyence Corporation, VHX-200) and a laser microscope (manufactured by Keyence Corporation, VK-9700) (the following comparative examples are also included). The same).
  • the unit optical element (square prism) of the obtained convex micromirror array has an element height v of 170 ⁇ m, an element width h of 150 ⁇ m, and a groove width g between adjacent elements of 60 ⁇ m.
  • Each unit optical element (and light reflection) Surface) had an aspect ratio (v / h) of 1.13.
  • a quartz chromium mask in which squares with a side of 100 ⁇ m are regularly arranged is arranged, and an i-line bandpass filter is used from above, and contact exposure method (gap 0 ⁇ m) is used to measure 375 mJ / Exposure by cm 2 ultraviolet irradiation was performed. Further, a heat treatment of 65 ° C. ⁇ 2 minutes + 95 ° C. ⁇ 8 minutes was performed. Next, after developing with SU-8 Developer (manufactured by Nippon Kayaku Co., Ltd.) and washing with 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.), heat treatment at 150 ° C. for 10 minutes is performed.
  • SU-8 Developer manufactured by Nippon Kayaku Co., Ltd.
  • 2-propanol manufactured by Wako Pure Chemical Industries, Ltd.
  • a square columnar pattern including one micromirror was formed to obtain a convex micromirror array of Comparative Example 2.
  • the unit height v of the unit optical element (square column) of the obtained convex micromirror array is 125 ⁇ m
  • the element width h is 100 ⁇ m
  • the groove width g between adjacent elements is 30 ⁇ m
  • each unit optical element (and light reflection) The aspect ratio (v / h) of (surface) was 1.25.
  • Example 1 in which the unit optical element (light reflecting surface) has an aspect ratio (v / h) of 3.0 is a mirror image compared to the conventional convex micromirror array (Comparative Examples 1 and 2). It was confirmed that the brightness (luminance) and the visibility of images (characters) were improved.
  • the manufacturing method of the micro mirror array of the present invention can easily and easily manufacture a micro mirror array that has a high degree of freedom in designing a convex unit optical element and connects bright and bright images.

Landscapes

  • Physics & Mathematics (AREA)
  • Engineering & Computer Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Health & Medical Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Ophthalmology & Optometry (AREA)
  • Mechanical Engineering (AREA)
  • Optical Elements Other Than Lenses (AREA)

Abstract

A method for manufacturing a micromirror array according to the present invention comprises a cutting process wherein a plurality of mutually parallel linear grooves having a depth of 50 to 500μm is sequentially formed in two directions orthogonal to each other on the prescribed surface of a planar substrate (work W) mounted on a work stage (S) with a prescribed distance generated therebetween, by using a rotary blade (blade B) of a cutting machine. Thereby, a unit optical element having the shape of a fine quadrangular prism can be formed, which has a large ratio of 1.5 or more for the height of the element (v) in the thickness direction of the substrate to the width of the element (h) in the surface direction of the substrate (aspect ratio v/h). Further, the aforementioned manufacturing method allows for easy production of a micromirror array capable of creating a bright and highly luminous image.

Description

マイクロミラーアレイの製法Manufacturing method of micromirror array
　本発明は、基板上に配列された、互いに直交する一対の光反射面を有する単位光学素子により、被投影物の鏡映像を空間に結像させるマイクロミラーアレイの製法に関する。 The present invention relates to a method of manufacturing a micromirror array in which a mirror image of a projection object is formed in a space by unit optical elements having a pair of light reflecting surfaces orthogonal to each other arranged on a substrate.
　３次元または２次元の物体，画像等を空間に結像する結像光学素子として、光学素子の素子面を構成する基板（基盤）に、「１つ以上の鏡面による光の反射を行う単位光学素子」を複数個配置したマイクロミラーアレイが開発されている。なかでも、この基板に垂直もしくはそれに近い角度で配置された「互いに直交する２つの鏡面」（コーナーリフレクタ）を有する微小四角柱状等の凸状単位光学素子を、この基板上に多数個アレイ状に配列した「コーナーリフレクタアレイ」は、構造が単純なことから、近年注目を集めている（特許文献１を参照）。 As an imaging optical element that forms a three-dimensional or two-dimensional object, image, etc. in space, a unit optical that reflects light by one or more mirror surfaces is applied to a substrate (substrate) that constitutes the element surface of the optical element. A micromirror array in which a plurality of elements are arranged has been developed. In particular, a large number of convex unit optical elements such as a small quadrangular prism having “two mirror surfaces perpendicular to each other” (corner reflectors) arranged at an angle perpendicular to or close to the substrate are arranged in an array. The arranged “corner reflector array” has recently attracted attention because of its simple structure (see Patent Document 1).
　上記マイクロミラーアレイの一例として、図６のようなものがあげられる。この凸型マイクロミラーアレイ２０（以下、単に「アレイ」ということもある）は、透明材料からなる基板２１（素子面Ｐ）の一表面に、透明な四角柱状の微小単位光学素子２２（この例では、縦，横，高さの比が、ほぼ１：１：１の正立方体）が、斜め４５°の碁盤目状に多数配列されて構成されている。上記アレイ２０の場合、各単位光学素子２２の４つの側面のうちの少なくとも２面（側面２２ａ，２２ｂ）が、鏡面（光反射面）に形成されている。 An example of the micromirror array is as shown in FIG. The convex micromirror array 20 (hereinafter, also simply referred to as “array”) includes a transparent square columnar micro-unit optical element 22 (this example) on one surface of a substrate 21 (element surface P) made of a transparent material. Then, a large number of regular cubes having a vertical, horizontal, and height ratio of approximately 1: 1: 1 are arranged in a grid of 45 ° diagonally. In the case of the array 20, at least two of the four side surfaces ( side surfaces 22a and 22b) of each unit optical element 22 are formed as mirror surfaces (light reflecting surfaces).
　そして、上記マイクロミラーアレイ２０の一方の面（表または裏）側から入射した光が素子面Ｐ（一点鎖線）を通過する際、この光（二点鎖線）が、図７のように、各単位光学素子２２の１つのコーナー２２ｃを挟む２つの光反射面（側面２２ａ，２２ｂ）の間で２回反射し、その２回反射後の光（通過光）が、上記アレイ２０の他方の面側の空間位置（素子面Ｐに対して面対称の位置）に、被投影物の鏡映像（鎖線で示す反転像）を結像させる。 Then, when light incident from one side (front or back) side of the micromirror array 20 passes through the element surface P (dashed line), the light (two-dot chain line) The light is reflected twice between two light reflecting surfaces ( side surfaces 22a and 22b) sandwiching one corner 22c of the unit optical element 22, and the light after the two reflections (passed light) is the other surface of the array 20. A mirror image (inverted image shown by a chain line) of the projection object is formed at a spatial position on the side (a position symmetrical with respect to the element surface P).
　従来、上記凸型マイクロミラーアレイを作製する方法としては、一般に、光反応性樹脂を用いて、フォトリソグラフィにより、微小な凸状単位光学素子を作製する方法が知られている。また、上記各凸状単位光学素子の形状に対応する多数のキャビティ（凹部）を有する金型を用いて、射出成形または熱プレス成形により、基板上に所定のピッチで多数の微小角柱を形成する方法も提案されている（特許文献２を参照）。 Conventionally, as a method for producing the convex micromirror array, a method for producing a minute convex unit optical element by photolithography using a photoreactive resin is generally known. In addition, by using a mold having a large number of cavities (concave portions) corresponding to the shape of each convex unit optical element, a large number of minute prisms are formed at a predetermined pitch on a substrate by injection molding or hot press molding. A method has also been proposed (see Patent Document 2).
国際公開第ＷＯ２００７／１１６６３９号International Publication No. WO2007 / 116639 特開２０１１－１９１４０４号公報JP 2011-191404 A
　ところで、上記従来のマイクロミラーアレイの製法では、明るく鮮明な結像を結ぶことのできるマイクロミラーアレイを得るのが難しいという問題があった。すなわち、明るく輝度の高い結像を得るためには、マイクロミラーアレイの単位面積あたりの反射（透過）光量を上げる必要があり、その解決手段として、各単位光学素子（コーナーリフレクタ）を構成する各光反射面（鏡面の面積）を大きく・長くする方法が考えられる。 By the way, the above-described conventional micromirror array manufacturing method has a problem that it is difficult to obtain a micromirror array capable of forming a bright and clear image. That is, in order to obtain bright and high-brightness imaging, it is necessary to increase the amount of reflected (transmitted) light per unit area of the micromirror array. As a means for solving the problem, each unit optical element (corner reflector) is configured. A method of increasing or lengthening the light reflection surface (mirror surface area) is conceivable.
　しかしながら、上記各光反射面を長大にするために、各微小四角柱状等の単位光学素子のアスペクト比〔単位光学素子の高さ（厚さ方向の縦長さ）／単位光学素子の幅（素子面方向の横幅）の比〕を大きくしようとしても、上記フォトリソグラフィを用いた方法では、深い垂直溝を正確に形成できず、光反射面が面荒れしてしまうため、制約がある。また、上記金型を使う従来の製法では、アスペクト比を高くすると、このアレイの、金型からの離型が困難になるという問題が生じる。そのため、これら従来の製法では、高アスペクト比でかつ光反射面積の広い、所望の形状の光反射面を有する凸型マイクロミラーアレイを得ることが、難しかった。 However, in order to make each of the light reflecting surfaces long, the aspect ratio of each unit optical element such as a minute quadrangular prism [height of unit optical element (vertical length in thickness direction) / width of unit optical element (element surface Even if an attempt is made to increase the ratio of the lateral width in the direction], the above-described method using photolithography has a limitation because a deep vertical groove cannot be formed accurately and the light reflecting surface becomes rough. Further, in the conventional manufacturing method using the above mold, when the aspect ratio is increased, there arises a problem that it is difficult to release the array from the mold. Therefore, in these conventional manufacturing methods, it is difficult to obtain a convex micromirror array having a light reflection surface of a desired shape with a high aspect ratio and a wide light reflection area.
　本発明は、このような事情に鑑みなされたもので、凸状単位光学素子の設計の自由度が高く、明るく輝度の高い結像を結ぶマイクロミラーアレイを容易に製造することのできるマイクロミラーアレイの製法の提供をその目的とする。 The present invention has been made in view of such circumstances, and has a high degree of freedom in designing a convex unit optical element, and can easily produce a micromirror array that connects bright and high-brightness images. The purpose is to provide a manufacturing method.
　上記の目的を達成するため、本発明は、透明な平板状の基板と、この基板の表面に配列状に形成された複数の凸状単位光学素子と、からなるマイクロミラーアレイを製造する方法であって、ワークとなる基板を、切削加工機の加工ステージの所定位置に取り付ける工程と、上記基板の所定の表面に、回転刃を用いて、深さ５０～５００μｍでかつ互いに平行な複数本の直線状溝を、この表面上で互いに直交する２つの方向に、それぞれ所定の間隔を空けながら順次形成する切削工程と、を備えるマイクロミラーアレイの製法を、その要旨とする。 In order to achieve the above object, the present invention provides a method for manufacturing a micromirror array comprising a transparent flat substrate and a plurality of convex unit optical elements formed in an array on the surface of the substrate. A step of attaching a substrate to be a workpiece to a predetermined position of a processing stage of a cutting machine, and a plurality of parallel blades having a depth of 50 to 500 μm using a rotary blade on a predetermined surface of the substrate. The gist of the present invention is a method of manufacturing a micromirror array, which includes a cutting process in which straight grooves are sequentially formed on the surface in two directions orthogonal to each other with a predetermined interval therebetween.
　すなわち、本発明者らは、凸状単位光学素子の加工の自由度を高める加工方法として、上記従来のフォトリソグラフィや金型を用いる技術常識を打破し、切削加工の利用を考え実施した。その結果、従来の正立方体状（縦横の比がほぼ１）のコーナーリフレクタにおいて「１程度」でしかなかった、光反射面のアスペクト比〔縦長さ（素子面厚さ方向の長さ）／横幅（素子面方向の幅）の比〕を、かなり大きく（すなわち、四角柱を長く）形成することに成功した。これにより、上記マイクロミラーアレイにおける結像に関与する光の量が増えて、輝度が高く鮮明な結像（鏡影像）が得られるようになった。 That is, the present inventors have broken down the conventional technical knowledge using photolithography and molds as a processing method for increasing the degree of freedom of processing of the convex unit optical element, and considered the use of cutting. As a result, the aspect ratio of the light reflecting surface [vertical length (length in the element surface thickness direction) / width], which was only “about 1” in the conventional regular cube-shaped corner reflector (ratio of aspect ratio of about 1). The ratio of (the width in the element surface direction)] was successfully formed (that is, the rectangular column was long). As a result, the amount of light involved in image formation in the micromirror array is increased, and a clear image (mirror image) with high brightness can be obtained.
　以上のように、本発明のマイクロミラーアレイの製法は、ワークとなる平板状の基板を、切削加工機の加工ステージの所定位置に取り付け、その基板の所定の表面に、回転刃を用いた切削加工により、深さ５０～５００μｍでかつ互いに平行な複数本の直線状溝を、この表面上で互いに直交する２つの方向に、それぞれ所定の間隔を空けながら順次形成して、略四角柱状の微小凸状単位光学素子を多数設ける。これにより、本発明のマイクロミラーアレイの製法では、従来の製法に比べ、アスペクト比の高い凸型マイクロミラーアレイを、容易にかつ低コストで製造することができる。 As described above, the manufacturing method of the micromirror array of the present invention is such that a flat substrate serving as a work is attached to a predetermined position of a processing stage of a cutting machine, and cutting is performed using a rotary blade on a predetermined surface of the substrate. By processing, a plurality of linear grooves having a depth of 50 to 500 μm and parallel to each other are sequentially formed on the surface in two directions orthogonal to each other with a predetermined interval between them, thereby forming a substantially rectangular column-shaped minute groove. A large number of convex unit optical elements are provided. Thereby, in the manufacturing method of the micromirror array of this invention, a convex micromirror array with a high aspect ratio can be manufactured easily and at low cost compared with the conventional manufacturing method.
　そして、この製法により得られた凸型マイクロミラーアレイは、各単位光学素子における光反射面（側面）の「基板表面方向の横幅に対する基板厚さ方向の縦長さの比」（アスペクト比）が高く、従来のマイクロミラーアレイに比べ、個々の光反射面の面積およびそれにより反射されてアレイを透過する光量が増大している。したがって、本発明のマイクロミラーアレイの製法により得られる凸型マイクロミラーアレイは、輝度が高く鮮明な被投影物の鏡映像を、結像させることができる。 The convex micromirror array obtained by this manufacturing method has a high “ratio of the longitudinal length in the substrate thickness direction to the lateral width in the substrate surface direction” (aspect ratio) of the light reflecting surface (side surface) in each unit optical element. Compared with the conventional micromirror array, the area of each light reflecting surface and the amount of light reflected and transmitted through the array is increased. Therefore, the convex micromirror array obtained by the manufacturing method of the micromirror array of the present invention can form a bright mirror image of the projection object with high brightness.
　また、本発明のマイクロミラーアレイの製法のなかでも、上記回転刃と加工ステージの少なくとも一方が、間欠的に所定距離移動して上記直線状溝を彫り込み形成する場合は、この直線状溝を、所定の位置に所望の深さで、素早くかつ正確に形成することができる。したがって、上記直線状溝の形成効率が、より向上する。 Further, in the method of manufacturing the micromirror array of the present invention, when at least one of the rotary blade and the processing stage intermittently moves a predetermined distance to engrave and form the linear groove, the linear groove is It can be formed quickly and accurately at a desired position at a desired depth. Therefore, the formation efficiency of the linear groove is further improved.
本発明の実施形態のマイクロミラーアレイの製法に用いられる切削加工機の概略構成図である。It is a schematic block diagram of the cutting machine used for the manufacturing method of the micromirror array of embodiment of this invention. 本発明の実施形態のマイクロミラーアレイの製法により得られた凸状単位光学素子の構成を説明する斜視図である。It is a perspective view explaining the structure of the convex unit optical element obtained by the manufacturing method of the micromirror array of embodiment of this invention. 上記マイクロミラーアレイの単位光学素子の形状を説明する断面図である。It is sectional drawing explaining the shape of the unit optical element of the said micromirror array. 本発明のマイクロミラーアレイの単位光学素子をマイクロスコープにより撮影した拡大写真である。It is the enlarged photograph which image | photographed the unit optical element of the micromirror array of this invention with the microscope. 本発明の実施例における鏡映像の輝度の測定方法を説明する模式図である。It is a schematic diagram explaining the measuring method of the brightness | luminance of the mirror image in the Example of this invention. 従来のマイクロミラーアレイの表面構造を示す斜視図である。It is a perspective view which shows the surface structure of the conventional micromirror array. マイクロミラーアレイによる鏡映像の結像様式を説明する模式図である。It is a schematic diagram explaining the image formation mode of the mirror image by a micromirror array.
　つぎに、本発明の実施の形態を、図面にもとづいて詳しく説明する。
　本実施形態におけるマイクロミラーアレイの製法は、図２に示すような、透明な平板状の基板１と、微小四角柱状の凸状単位光学素子２の群と、からなる凸型のマイクロミラーアレイ１０を製造する方法である。この方法は、図１に示すようなダイシングマシン（ダイシングソー）等の切削加工機を用いて、移動ステージＳ上に取り付けて仮固定したワークＷ（基板）の所定の表面に、所望の深さでかつ互いに平行な複数本の直線状溝（３）を、この表面上で互いに直交する２つの方向（ｘ，ｙ方向）に、それぞれ所定の間隔（ピッチ）で、回転刃（ブレードＢ）により切削（彫り込み）加工を行う。これが本発明のマイクロミラーアレイの製法の特徴である。 Next, embodiments of the present invention will be described in detail with reference to the drawings.
The manufacturing method of the micromirror array in the present embodiment is as follows. As shown in FIG. 2, a convex micromirror array 10 comprising a transparent flat substrate 1 and a group of minute square columnar convex unit optical elements 2 is used. It is a method of manufacturing. This method uses a cutting machine such as a dicing machine (dicing saw) as shown in FIG. 1 to provide a desired depth on a predetermined surface of a workpiece W (substrate) that is mounted on a moving stage S and temporarily fixed. And a plurality of linear grooves (3) parallel to each other by a rotary blade (blade B) at predetermined intervals (pitch) in two directions (x and y directions) orthogonal to each other on the surface. Perform cutting (carving). This is a feature of the manufacturing method of the micromirror array of the present invention.
　上記マイクロミラーアレイの製法について、より詳しく説明すると、この製法に用いられる切削加工機（図１参照）は、ダイシングマシンまたはダイシングソー等と呼ばれるもので、高速回転するスピンドル（図示省略）の先端に取り付けられた回転刃（ダイシングブレードＢ等のダイヤモンドブレード）と、加工後マイクロミラーアレイとなる基板（ワークＷ）を載置して仮固定するための加工ステージ（移動ステージＳ）と、この移動ステージＳを、上記ブレードＢの回転および上下に対応して三軸（ｘ，ｙ，ｚ）方向に移動させるとともにｚ軸周り（θ）に回転させるステージ駆動手段等と、を備える。 The manufacturing method of the micromirror array will be described in more detail. A cutting machine (see FIG. 1) used in this manufacturing method is called a dicing machine or a dicing saw or the like, and is attached to the tip of a spindle (not shown) that rotates at high speed. An attached rotary blade (diamond blade such as dicing blade B), a processing stage (moving stage S) for mounting and temporarily fixing a substrate (work W) to be a micromirror array after processing, and this moving stage Stage driving means for rotating S in the three axis (x, y, z) directions and rotating around the z axis (θ) corresponding to the rotation and vertical movement of the blade B.
　上記ダイシングブレードＢは、略リング状の極薄外周刃で、その外周面に設けられた刃部（場合によっては、左右の側端面にも）に、小径の工業用ダイヤモンドからなる砥粒が付与されている。なお、ブレードＢの厚さ（端面方向の全厚）は、約０．０１５ｍｍ（１５μｍ）～０．３ｍｍ（３００μｍ）程度のものが使用され、このブレードＢを用いた彫り込み加工により得られる溝（グルーブ）の溝幅ｇは、約０．０２ｍｍ～０．３５ｍｍ程度である。また、この例では、外周面（切刃面）がフラットなブレードＢを用いているが、上記切刃面の断面形状が三角形状，円形状，楕円状等のブレードを用いてもよい。 The dicing blade B is a substantially ring-shaped ultra-thin outer peripheral blade, and abrasive grains made of small-diameter industrial diamond are imparted to the blade portion (in some cases, the left and right side end surfaces) provided on the outer peripheral surface. Has been. The blade B has a thickness (total thickness in the end face direction) of about 0.015 mm (15 μm) to 0.3 mm (300 μm), and a groove obtained by engraving using the blade B ( The groove width g of the groove) is about 0.02 mm to 0.35 mm. In this example, the blade B having a flat outer peripheral surface (cutting edge surface) is used, but a blade having a triangular, circular, or elliptical cross section may be used.
　上記ワークＷを仮固定するための移動ステージＳは、図１のように、少なくともｘ，ｙの二軸方向に自在に位置を移動（位置決め）できるスライダ（直動軸受）の上に設置されており、この例ではさらに、ｚ軸方向の昇降（図示せず）と、このｚ軸周り（θ）の回転が可能なように構成されている。なお、各軸方向（軸周り）のステージ駆動手段は、汎用の工作機械等と同様の機構のため説明しないが、ステッピングモータやアクチュエータ等を用いて、移動ステージＳの間欠動作と正確な位置制御、および、プログラムされた定速走行ができるようになっている。また、ダイシングマシンによっては、上記スピンドルおよびブレードＢが、互いに離れた位置または近傍に、複数セット配設されているものもある。 The moving stage S for temporarily fixing the workpiece W is installed on a slider (linear motion bearing) that can move (position) freely in at least two directions of x and y as shown in FIG. In this example, it is further configured to be able to move up and down (not shown) in the z-axis direction and rotate around the z-axis (θ). The stage driving means in each axial direction (around the axis) will not be described because it is the same mechanism as a general-purpose machine tool, etc., but intermittent operation and accurate position control of the moving stage S using a stepping motor, actuator, or the like , And can be programmed to run at a constant speed. In some dicing machines, a plurality of sets of the spindles and blades B are arranged at or apart from each other.
　上記ダイシングマシンを用いたマイクロミラーアレイの作製は、まず、アレイに加工する基板として、例えばアクリル樹脂等、可視光の透過率が８０％以上の材料からなる平板状の基板（Ｗ）を準備する。 For producing a micromirror array using the dicing machine, first, as a substrate to be processed into an array, a flat substrate (W) made of a material having a visible light transmittance of 80% or more such as an acrylic resin is prepared. .
　ついで、この基板を、粘着テープまたは粘着剤等を用いて、上記移動ステージＳ上の所定位置に、加工対象面が上（ブレードＢ側）になるように貼り付け、ワークＷとして取り付けて固定（仮固定）する〔ワーク取付工程〕。なお、粘着剤等を用いず、チャックやバイス等でワークＷを把持してもよい。 Next, the substrate is attached to a predetermined position on the moving stage S using an adhesive tape or an adhesive so that the surface to be processed is up (blade B side), and is attached and fixed as a workpiece W ( (Temporary fixing) [work attachment process]. Note that the workpiece W may be gripped by a chuck or a vise without using an adhesive or the like.
　つぎに、上記移動ステージＳを加工開始位置まで移動させ、上記ブレードＢを高速で回転させながら、上記ワークを切削できる位置までこのブレードＢを下降させ、予めプログラムされた手順にしたがって、上記ワークＷ（移動ステージＳ）を水平にスライド移動させ、ワークＷの加工対象面（表面）に所望の深さ（５０～５００μｍ）の直線状溝を切削加工する。 Next, the moving stage S is moved to a machining start position, and the blade B is lowered to a position where the workpiece can be cut while rotating the blade B at a high speed. The (moving stage S) is slid horizontally to cut a linear groove having a desired depth (50 to 500 μm) on the processing target surface (surface) of the workpiece W.
　１本の直線状溝の彫り込み作業が終了すれば、上記移動ステージＳを次の溝の加工開始位置まで移動させ、再度、上記ワークＷを所定の送り速度で水平方向にスライド移動させて、上記次の溝を加工する。そして、この直線状溝の彫り込み加工を、一方向に所定の間隔（ピッチ）で繰り返すことにより、所定の第１の方向（この時点におけるｙ方向）に、互いに平行な複数本の直線状溝が形成される。 When the engraving work for one linear groove is completed, the moving stage S is moved to the machining start position of the next groove, and the workpiece W is slid in the horizontal direction at a predetermined feed rate again, Process the next groove. Then, by repeating the engraving process of this linear groove at a predetermined interval (pitch) in one direction, a plurality of linear grooves parallel to each other in a predetermined first direction (y direction at this time) are obtained. It is formed.
　上記第１の方向への全ての直線状溝の加工完了後、続いて上記移動ステージＳをθ方向に９０°回転させ、上記第１の方向への直線状溝に直交する第２の方向（この例では、先にｘ方向であったものが、９０°回転してｙ方向となったもの）に、上記と同様の直線状溝の彫り込み加工を、繰り返し行う〔切削工程〕。 After the machining of all the linear grooves in the first direction is completed, the moving stage S is subsequently rotated by 90 ° in the θ direction, and a second direction orthogonal to the linear grooves in the first direction ( In this example, the linear groove engraving similar to the above is repeatedly performed on the one that was previously in the x direction and turned 90 ° into the y direction (cutting step).
　これにより、図２のように、基板１の一面に彫り込まれた、互いに直交する２つの方向（ｘ，ｙ方向）の溝３ｘ，３ｙ（溝幅ｇ）により、これらの溝３ｘ，３ｙの間に、所望の高アスペクト比（素子高さｖ／素子幅ｈ）の微小四角柱状単位光学素子２が多数並んで形成されたマイクロミラーアレイ１０を、得ることができる。 As a result, as shown in FIG. 2, the grooves 3x and 3y (groove width g) engraved on one surface of the substrate 1 in two directions (x and y directions) perpendicular to each other are formed between the grooves 3x and 3y. In addition, it is possible to obtain a micromirror array 10 in which a large number of small square columnar unit optical elements 2 having a desired high aspect ratio (element height v / element width h) are arranged.
　なお、上記移動ステージＳの位置を固定し、スピンドルとブレードＢの位置を水平方向に移動・回転させて、上記と同様の直線状溝を切削する（彫り込む）ようにしてもよい。また、ダイシングブレードＢに用いられているダイヤモンド砥粒は、通常、粒径＃２４０～＃５０００程度のものであるが、切削後の光反射面（溝の両側壁）の表面荒れ（鏡面が望ましい）を考慮すると、砥粒の粒径＃１０００以上のものが、好ましい。 The position of the moving stage S may be fixed, and the position of the spindle and blade B may be moved and rotated in the horizontal direction to cut (engrave) the linear groove similar to the above. The diamond abrasive grains used in the dicing blade B are usually those having a particle size of about # 240 to # 5000, but the surface of the light reflecting surface (both side walls of the groove) after cutting is preferably rough (mirror surface). ), It is preferable that the grain size of the abrasive is # 1000 or more.
　つぎに、上記本発明のマイクロミラーアレイの製法により得られたマイクロミラーアレイ１０は、その構造を詳しく見ると、図２に示すように、平板状の基板１と、この基板１（素子面Ｐ）の一方の表面（上面）に配列状に形成された複数の凸状単位光学素子（直方体状の微小四角柱）２とからなる。そして、上記各単位光学素子２においてコーナーリフレクタを構成する一対（２つ）の光反射面（四角柱の側方の第１の側面２ａ，第２の側面２ｂ）は、それぞれ、「基板表面方向の横幅（素子幅ｈ）に対する基板厚さ方向の縦長さ（素子高さｖ）の比」〔以下、「アスペクト比（ｖ／ｈ）」という〕が、通常１．５以上、好ましくは２．０以上になっている。ちなみに、従来のフォトリソグラフィ法または金型を用いたインジェクション法，インプリント法により作製された凸型マイクロミラーアレイであれば、通常、上記アスペクト比は約１．３未満、多くは１．１以下である。 Next, when the structure of the micromirror array 10 obtained by the method of manufacturing a micromirror array of the present invention is examined in detail, as shown in FIG. 2, a flat substrate 1 and the substrate 1 (element surface P) ) Of a plurality of convex unit optical elements (cuboid rectangular quadrangular prisms) 2 formed in an array on one surface (upper surface). In each of the unit optical elements 2, a pair of (two) light reflecting surfaces (first side surface 2a and second side surface 2b on the side of the quadrangular prism) constituting the corner reflector are respectively “substrate surface direction The ratio of the vertical length (element height v) in the substrate thickness direction to the lateral width (element width h) ”(hereinafter referred to as“ aspect ratio (v / h) ”) is usually 1.5 or more, preferably 2. 0 or more. Incidentally, in the case of a convex micromirror array manufactured by a conventional photolithography method, an injection method using a mold, or an imprint method, the aspect ratio is usually less than about 1.3, and often 1.1 or less. It is.
　上記凸型マイクロミラーアレイ１０について、より詳しく説明すると、基板１と各単位光学素子２とは、図３の断面図のように、一体に成形されており、各単位光学素子２の間に、上記ブレードＢを用いて彫り込まれた溝３（３ｘ，３ｙ）が形成されている。なお、これらの溝３（３ｘ，３ｙ）の「深さ」は、切削形成された上記各単位光学素子２の「素子高さｖ」と同じである。 The convex micromirror array 10 will be described in more detail. The substrate 1 and each unit optical element 2 are integrally formed as shown in the cross-sectional view of FIG. Grooves 3 (3x, 3y) carved using the blade B are formed. The “depth” of the grooves 3 (3x, 3y) is the same as the “element height v” of each unit optical element 2 formed by cutting.
　上記基板１は、上記各単位光学素子２をアレイ状に配置するための支持体であり、通常、一定の厚みを有する平坦な板状（厚さ０．５～１０．０ｍｍ程度）であり、光学素子の素子面（図中では符号Ｐ、一点鎖線）を構成する。 The substrate 1 is a support for arranging the unit optical elements 2 in an array, and is usually a flat plate having a constant thickness (thickness of about 0.5 to 10.0 mm), An element surface of the optical element (symbol P in the figure, one-dot chain line) is formed.
　上記各単位光学素子２は、上記基板１の一方の表面から凸状に突出する、縦に長い正四角柱状で、その各側面（第１の側面２ａ，第２の側面２ｂおよびこれに対向する第３の側面２ｄ，第４の側面２ｅ）は、上記基板１の表面（図では上面）からほぼ垂直な角度に形成されている。また、この単位光学素子２の各側面のうち、１つの角部（図中のコーナー２ｃ）を構成する２つの側面（第１の側面２ａおよび第２の側面２ｂ）は、その外側表面（および対応する内側面）が、光反射性の鏡面になっており、これらが、コーナーリフレクタを構成している。 Each unit optical element 2 has a vertically long regular quadrangular prism shape projecting convexly from one surface of the substrate 1, and faces each side surface (first side surface 2a, second side surface 2b and the same). The third side surface 2d and the fourth side surface 2e) are formed at an angle substantially perpendicular to the surface (upper surface in the drawing) of the substrate 1. Of the side surfaces of the unit optical element 2, two side surfaces (first side surface 2a and second side surface 2b) constituting one corner (corner 2c in the figure) are the outer surfaces (and The corresponding inner surface) is a light-reflecting mirror surface, and these constitute a corner reflector.
　また、先に述べたように、上記単位光学素子２の各光反射面（側面２ａ，２ｂ）は、それぞれ、上記アスペクト比（ｖ／ｈ）が１．５以上の長方形になっている。さらに、これら各単位光学素子２の素子高さｖ（すなわち、上記溝３の「深さ」）は、通常２００μｍ以上、好ましくは２５０μｍ以上、さらに好ましくは３００μｍ以上に設定されており、上記各光反射面（側面２ａ，２ｂ）の面積が長大になることによって、このアレイ１０に下面または上面から入射する光を、より多く反射して反対側に反射（透過）させることができるようになっている。 Further, as described above, the light reflecting surfaces (side surfaces 2a and 2b) of the unit optical element 2 each have a rectangular shape with the aspect ratio (v / h) of 1.5 or more. Further, the element height v of each unit optical element 2 (that is, the “depth” of the groove 3) is usually set to 200 μm or more, preferably 250 μm or more, more preferably 300 μm or more. By increasing the area of the reflecting surface ( side surfaces 2a, 2b), more light incident on the array 10 from the lower surface or the upper surface can be reflected and reflected (transmitted) to the opposite side. Yes.
　また、上記凸型マイクロミラーアレイ１０における各単位光学素子２の各側面の素子幅ｈは、通常５０～３００μｍに設定され、隣接する単位光学素子２どうしの間隔（すなわち、ブレードＢによる彫り込み溝幅ｇ）は、通常１０～２００μｍに設定される。 The element width h of each side surface of each unit optical element 2 in the convex micromirror array 10 is normally set to 50 to 300 μm, and the interval between adjacent unit optical elements 2 (that is, the width of the engraved groove by the blade B). g) is usually set to 10 to 200 μm.
　上記のように、本発明のマイクロミラーアレイの製法によれば、明るく輝度の高い、高アスペクト比のマイクロミラーアレイを、容易に、かつ、高い歩留りで作製することができる。したがって、マイクロミラーアレイのコスト低減に寄与する。 As described above, according to the method of manufacturing a micromirror array of the present invention, a bright, high-brightness, high-aspect-ratio micromirror array can be easily manufactured with a high yield. Therefore, it contributes to the cost reduction of the micromirror array.
　また、得られたマイクロミラーアレイ１０は、従来のマイクロミラーアレイに比べ、各光反射面の面積、および、それにより反射されてアレイを透過する光量が増大する。これにより、輝度が高く鮮明な被投影物の鏡映像を、結像させることができる。 Also, the obtained micromirror array 10 increases the area of each light reflecting surface and the amount of light reflected and transmitted through the array as compared with the conventional micromirror array. Thereby, it is possible to form a clear mirror image of the projection object with high brightness.
　なお、上記実施形態においては、略四角柱状の凸状単位光学素子を有するマイクロミラーアレイを例に説明したが、本発明のマイクロミラーアレイの製法は、略三角柱状等、その他の多角柱形状の単位光学素子を備えるマイクロミラーアレイの製造に適用でき得ることは勿論である。 In the above embodiment, a micromirror array having a substantially square columnar convex unit optical element has been described as an example. However, the method of manufacturing a micromirror array of the present invention has other polygonal column shapes such as a substantially triangular column shape. Of course, the present invention can be applied to the manufacture of a micromirror array having unit optical elements.
　つぎに、上記凸型マイクロミラーアレイを作製した実施例について、比較例と併せて説明する。ただし、本発明は、以下の実施例に限定されるものではない。 Next, an example in which the convex micromirror array was produced will be described together with a comparative example. However, the present invention is not limited to the following examples.
　以下の実施例では、上記ダイシングマシン（回転刃）を用いた切削加工により凸状単位光学素子を形成した「実施例１」の凸型マイクロミラーアレイ（発明品）と、多数のキャビティ（凹部）を有する金型を用いた射出成形により凸状単位光学素子を形成した「比較例１」の凸型マイクロミラーアレイ（従来品）と、光反応性樹脂を用いてフォトリソグラフィにより凸状単位光学素子を形成した「比較例２」の凸型マイクロミラーアレイと、を用いて、液晶ディスプレイ（ＬＣＤ）に表示された所定の画像を投影した場合の鏡映像（空間画像）の「明るさ（輝度）」と、画像の「鮮明さ（視認性）」を比較した。 In the following examples, a convex micromirror array (invention) of “Example 1” in which convex unit optical elements are formed by cutting using the dicing machine (rotating blade) and a large number of cavities (recesses). Convex unit optical element of “Comparative Example 1” in which a convex unit optical element is formed by injection molding using a metal mold having a mold, and a convex unit optical element by photolithography using a photoreactive resin The “brightness (luminance)” of the mirror image (spatial image) when a predetermined image displayed on a liquid crystal display (LCD) is projected using the convex micromirror array of “Comparative Example 2” formed with "And" clearness (visibility) "of the image.
［実施例１］
　まず、基板となるアクリル板を準備して、ダイシング（切削）により、実施例１の凸型マイクロミラーアレイを作製した。
〈アクリル板〉
　アクリル樹脂製基板（平板）：５０ｍｍ×５０ｍｍ×厚さ２ｍｍ
〈切削加工機〉
　ディスコ社製　オートマチックダイシングソー　ＤＡＤ３３５０
〈ダイシング条件〉
・ダイシングブレード〈ディスコ社製，ＮＢＣ－Ｚ２０５０〉ブレード厚さ２５μｍ
・スピンドル回転数：３００００ｒｐｍ
・テーブル送り速度：３．０ｍｍ／ｓｅｃ
・冷却：シャワークーラー（水）１Ｌ／ｍｉｎ，シャワーノズル（水）０．５Ｌ／ｍｉｎ [Example 1]
First, an acrylic plate serving as a substrate was prepared, and a convex micromirror array of Example 1 was produced by dicing (cutting).
<Acrylic plate>
Acrylic resin substrate (flat plate): 50 mm x 50 mm x thickness 2 mm
<Cutting machine>
Automatic dicing saw DAD3350 manufactured by DISCO
<Dicing conditions>
・ Dicing blade <DBC, NBC-Z2050> Blade thickness 25μm
・ Spindle speed: 30000rpm
・ Table feed speed: 3.0mm / sec
Cooling: Shower cooler (water) 1 L / min, shower nozzle (water) 0.5 L / min
〈マイクロミラーアレイの作製〉
　上記アクリル板を粘着テープ〈ダイシングテープ：日東電工社製，エレップテープ〉に貼り付けて固定し、その状態で、上記アクリル板固定体をダイシング装置〈ディスコ社製〉のチャックテーブル（加工ステージ）にセットした。そして、上記〈ダイシング条件〉に示す条件で、深さ３００μｍの溝（単位光学素子の四角柱の「素子高さｖ」に相当）を、所定の格子状に彫り込み（掘り込み）、図２のような、実施例１の凸型マイクロミラーアレイを作製した。 <Production of micromirror array>
Affix the acrylic plate to an adhesive tape <Dicing tape: manufactured by Nitto Denko Corp., ELEP tape> and fix the acrylic plate fixed body on the chuck table (processing stage) of the dicing device <Disco>. did. Then, a groove having a depth of 300 μm (corresponding to the “element height v” of the square column of the unit optical element) is carved (digged) into a predetermined lattice shape under the conditions shown in the above <Dicing Condition> A convex micromirror array of Example 1 was produced.
　上記実施例１の凸型マイクロミラーアレイの単位光学素子を、マイクロスコープにより撮影した拡大写真を図４に示す。この図（写真）に示す凸型マイクロミラーアレイの単位光学素子（四角柱）の素子高さｖは３００μｍ、素子幅ｈは１００μｍ、隣接する素子間の溝幅ｇは３０μｍで、各単位光学素子（および光反射面）のアスペクト比（ｖ／ｈ）は、３．０であった。なお、作製された単位光学素子の寸法測定（撮影）は、マイクロスコープ〈キーエンス社製，ＶＨＸ－２００〉およびレーザー顕微鏡〈キーエンス社製，ＶＫ－９７００〉を用いて行った（以下の比較例も同様）。 FIG. 4 shows an enlarged photograph of the unit optical element of the convex micromirror array of Example 1 taken with a microscope. Each unit optical element has an element height v of 300 μm, an element width h of 100 μm, and a groove width g between adjacent elements of 30 μm. The aspect ratio (v / h) of (and the light reflecting surface) was 3.0. In addition, the dimension measurement (photographing) of the manufactured unit optical element was performed using a microscope (manufactured by Keyence Corporation, VHX-200) and a laser microscope (manufactured by Keyence Corporation, VK-9700) (the following comparative examples are also included). The same).
［比較例１］
　所定形状のキャビティ（凹部）を有する金型（スタンパ）と平坦な金型とを準備し、これらを密着させた状態で、アクリル樹脂を２００℃（樹脂の軟化温度以上）に加熱し、金型のゲート部より、溶融した樹脂を金型内に高圧にて充填する。金型を密着させたまま、樹脂の軟化温度以下まで冷却し、固化した樹脂（アレイ）を、金型とともにスタンパから脱型する。そして、ゲート部により形成された樹脂部分（ばり）を切り落として、比較例１の凸型マイクロミラーアレイを得た（特許文献２を参照）。得られた凸型マイクロミラーアレイの単位光学素子（四角柱）の素子高さｖは１７０μｍ、素子幅ｈは１５０μｍ、隣接する素子間の溝幅ｇは６０μｍで、各単位光学素子（および光反射面）のアスペクト比（ｖ／ｈ）は、１．１３であった。 [Comparative Example 1]
A mold (stamper) having a cavity (concave portion) of a predetermined shape and a flat mold are prepared, and in a state where these molds are in close contact with each other, the acrylic resin is heated to 200 ° C. (above the softening temperature of the resin). The molten resin is filled into the mold at a high pressure from the gate portion. While the mold is kept in close contact, the resin is cooled to below the softening temperature of the resin, and the solidified resin (array) is removed from the stamper together with the mold. And the resin part (flash) formed by the gate part was cut off, and the convex type micromirror array of the comparative example 1 was obtained (refer patent document 2). The unit optical element (square prism) of the obtained convex micromirror array has an element height v of 170 μm, an element width h of 150 μm, and a groove width g between adjacent elements of 60 μm. Each unit optical element (and light reflection) Surface) had an aspect ratio (v / h) of 1.13.
［比較例２］
　ソーダガラス（５０ｍｍ×５０ｍｍ×厚さ１．１ｍｍ）を準備し、このガラスの表面にＨＭＤＳ（ヘキサメチルジシラザン、ａｌｄｒｉｃｈ社製、プライマーとして使用）を塗布した後、室温にて乾燥させた。ついで、上記表面に、ＳＵ－８　３０５０（日本化薬社製）をスピンコーターにより塗布した後、６５℃×２分間＋９５℃×６０分間の加熱処理を行った。続いて、一辺１００μｍの正方形が規則的に配列された石英系のクロムマスク（フォトマスク）を配置し、その上方からｉ線バンドパスフィルターを使用し、コンタクト露光法（ギャップ０μｍ）にて３７５ｍＪ／ｃｍ2の紫外線照射による露光を行った。さらに、６５℃×２分間＋９５℃×８分間の加熱処理を行った。つぎに、ＳＵ－８　Ｄｅｖｅｌｏｐｅｒ（日本化薬社製）を用いて現像、２－プロパノール（和光純薬社製）を用いて洗浄した後、１５０℃×１０分間の加熱処理を行うことにより、２枚のマイクロミラーを含む四角柱状のパターンを形成し、比較例２の凸型マイクロミラーアレイを得た。得られた凸型マイクロミラーアレイの単位光学素子（四角柱）の素子高さｖは１２５μｍ、素子幅ｈは１００μｍ、隣接する素子間の溝幅ｇは３０μｍで、各単位光学素子（および光反射面）のアスペクト比（ｖ／ｈ）は、１．２５であった。 [Comparative Example 2]
Soda glass (50 mm × 50 mm × 1.1 mm in thickness) was prepared, and HMDS (hexamethyldisilazane, manufactured by aldrich, used as a primer) was applied to the surface of the glass, and then dried at room temperature. Next, SU-8 3050 (manufactured by Nippon Kayaku Co., Ltd.) was applied to the surface using a spin coater, and then heat treatment was performed at 65 ° C. × 2 minutes + 95 ° C. × 60 minutes. Subsequently, a quartz chromium mask (photomask) in which squares with a side of 100 μm are regularly arranged is arranged, and an i-line bandpass filter is used from above, and contact exposure method (gap 0 μm) is used to measure 375 mJ / Exposure by cm 2 ultraviolet irradiation was performed. Further, a heat treatment of 65 ° C. × 2 minutes + 95 ° C. × 8 minutes was performed. Next, after developing with SU-8 Developer (manufactured by Nippon Kayaku Co., Ltd.) and washing with 2-propanol (manufactured by Wako Pure Chemical Industries, Ltd.), heat treatment at 150 ° C. for 10 minutes is performed. A square columnar pattern including one micromirror was formed to obtain a convex micromirror array of Comparative Example 2. The unit height v of the unit optical element (square column) of the obtained convex micromirror array is 125 μm, the element width h is 100 μm, the groove width g between adjacent elements is 30 μm, and each unit optical element (and light reflection) The aspect ratio (v / h) of (surface) was 1.25.
〈鏡映像（空間像）の明るさ測定〉
　得られた実施例１および比較例１，２の凸型マイクロミラーアレイ（１０）を、図５のように、その単位光学素子を下に向けて水平にセットし、その下側の所定位置に、ＬＣＤを４５°傾けた状態で配置した。そして、上記ＬＣＤに所定の輝度の評価用画像（１ｃｍ×１ｃｍ角の白色）を表示させ、素子面Ｐで面対称となる空間位置に投影される鏡映像（図中に点線で表示）の明るさ（輝度）を、鏡映像から５０ｃｍ離れた上方から、鏡映像に正対する下向き４５°で計測した。なお、上記鏡映像の明るさの測定は、暗室中で行った。また、鏡映像の明るさの測定には、輝度計Ｍ〈トプコン社製，ＢＭ－９〉を用いた。 <Brightness measurement of mirror image (aerial image)>
The obtained convex micromirror array (10) of Example 1 and Comparative Examples 1 and 2 was set horizontally with its unit optical elements facing downward, as shown in FIG. The LCD was placed at an angle of 45 °. Then, an image for evaluation (1 cm × 1 cm square white) having a predetermined luminance is displayed on the LCD, and the brightness of a mirror image (displayed by a dotted line in the figure) projected onto a spatial position that is plane-symmetrical on the element plane P The brightness (brightness) was measured at an angle of 45 ° facing the mirror image from the top 50 cm away from the mirror image. Note that the brightness of the mirror image was measured in a dark room. For measuring the brightness of the mirror image, a luminance meter M <Topcon BM-9> was used.
〈鏡映像（文字）の視認性評価〉
　上記「鏡映像の明るさ測定」に続いて、同様の配置（図５参照）で、上記ＬＣＤに所定の輝度の評価用画像（白色の背景に、１文字２ｍｍ×２ｍｍ角の黒色の文字「日東電工」明朝体）を表示させ、素子面Ｐで面対称となる空間位置に投影される鏡映像（図中に点線で表示）を、鏡映像から５０ｃｍ離れた上方から、鏡映像に正対する下向き４５°で目視により観察した。なお、上記鏡映像の視認性評価は、室内蛍光灯下（３００ルクス以上）で行った。また、評価は、文字として視認できるものを「良」、視認できないものを「不良」として表した。上記測定の結果を以下に示す。 <Visibility evaluation of mirror image (text)>
Subsequent to the above “brightness measurement of mirror image”, in the same arrangement (see FIG. 5), an image for evaluation with a predetermined brightness is displayed on the LCD (a black character “2 mm × 2 mm square on a white background” NITTO DENKO “Mincho” is displayed, and the mirror image projected in a spatial position that is plane-symmetrical on the element plane P (displayed by a dotted line in the figure) is displayed on the mirror image from the top 50 cm away from the mirror image. In contrast, it was visually observed at 45 ° downward. The visibility evaluation of the mirror image was performed under an indoor fluorescent lamp (300 lux or more). In the evaluation, those that can be visually recognized as characters are indicated as “good”, and those that cannot be visually recognized are indicated as “bad”. The results of the measurement are shown below.
　　　　　　　明るさ（輝度）　　　視認性　　　アスペクト比（ｖ／ｈ）
　実施例１　　１．６　ｃｄ／ｍ2　　良　　　　　　３．０
　比較例１　　０．２　ｃｄ／ｍ2　　不良　　　　　１．１３
　比較例２　　０．２　ｃｄ／ｍ2　　不良　　　　　１．２５ Brightness (luminance) Visibility Aspect ratio (v / h)
Example 1 1.6 cd / m 2 Good 3.0
Comparative Example 1 0.2 cd / m 2 failure 1.13
Comparative Example 2 0.2 cd / m 2 failure 1.25
　上記結果より、単位光学素子（光反射面）のアスペクト比（ｖ／ｈ）が３．０の実施例１は、従来の凸型マイクロミラーアレイ（比較例１，２）に比べ、鏡映像の明るさ（輝度）および画像（文字）の視認性が向上していることが確認された。 From the above results, Example 1 in which the unit optical element (light reflecting surface) has an aspect ratio (v / h) of 3.0 is a mirror image compared to the conventional convex micromirror array (Comparative Examples 1 and 2). It was confirmed that the brightness (luminance) and the visibility of images (characters) were improved.
　上記実施例においては、本発明における具体的な形態について示したが、上記実施例は単なる例示にすぎず、限定的に解釈されるものではない。当業者に明らかな様々な変形は、本発明の範囲内であることが企図されている。 In the above embodiments, specific forms in the present invention have been described. However, the above embodiments are merely examples and are not construed as limiting. Various modifications apparent to those skilled in the art are contemplated to be within the scope of this invention.
　本発明のマイクロミラーアレイの製法は、凸状単位光学素子の設計の自由度が高く、明るく輝度の高い結像を結ぶマイクロミラーアレイを、容易かつ簡単に製造することができる。 The manufacturing method of the micro mirror array of the present invention can easily and easily manufacture a micro mirror array that has a high degree of freedom in designing a convex unit optical element and connects bright and bright images.
　１　基板
　２　単位光学素子
　２ａ，２ｂ　側面
　２ｃ　コーナー
　２ｄ，２ｅ　側面
　３　溝
　３ｘ，３ｙ　溝
　１０　マイクロミラーアレイ
　２０　マイクロミラーアレイ
　２１　基板
　２２　単位光学素子
　２２ａ，２２ｂ　側面
　２２ｃ　コーナー
　Ｐ　素子面
　Ｂ　ブレード
　Ｓ　移動ステージ
　Ｗ　ワーク（基板）
　Ｍ　輝度計 DESCRIPTION OF SYMBOLS 1 Substrate 2 Unit optical element 2a, 2b Side surface 2c Corner 2d, 2e Side surface 3 Groove 3x, 3y Groove 10 Micro mirror array 20 Micro mirror array 21 Substrate 22 Unit optical element 22a, 22b Side surface 22c Corner P Element surface B Blade S Moving stage W Workpiece (substrate)
M Luminance meter

Claims (2)

  1. 　透明な平板状の基板と、この基板の表面に配列状に形成された複数の凸状単位光学素子と、からなるマイクロミラーアレイを製造する方法であって、ワークとなる基板を、切削加工機の加工ステージの所定位置に取り付ける工程と、上記基板の所定の表面に、回転刃を用いて、深さ５０～５００μｍでかつ互いに平行な複数本の直線状溝を、この表面上で互いに直交する２つの方向に、それぞれ所定の間隔を空けながら順次形成する切削工程と、を備えることを特徴とするマイクロミラーアレイの製法。 A method of manufacturing a micromirror array comprising a transparent flat substrate and a plurality of convex unit optical elements formed in an array on the surface of the substrate, the substrate serving as a workpiece being cut by a cutting machine And a plurality of linear grooves having a depth of 50 to 500 μm and parallel to each other on a predetermined surface of the substrate using a rotary blade perpendicular to each other on the surface. A method of manufacturing a micromirror array, comprising: a cutting step of sequentially forming in two directions at predetermined intervals.
  2. 　上記回転刃と加工ステージの少なくとも一方が、間欠的に所定距離移動して上記直線状溝を彫り込み形成する請求項１記載のマイクロミラーアレイの製法。 The method of manufacturing a micromirror array according to claim 1, wherein at least one of the rotary blade and the processing stage intermittently moves a predetermined distance to engrave and form the linear groove.
PCT/JP2013/063774 2012-06-08 2013-05-17 Method for manufacturing micromirror array WO2013183421A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2012-130709 2012-06-08
JP2012130709A JP2013254145A (en) 2012-06-08 2012-06-08 Method for manufacturing micromirror array

Publications (1)

Publication Number Publication Date
WO2013183421A1 true WO2013183421A1 (en) 2013-12-12

Family

ID=49711821

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2013/063774 WO2013183421A1 (en) 2012-06-08 2013-05-17 Method for manufacturing micromirror array

Country Status (3)

Country Link
JP (1) JP2013254145A (en)
TW (1) TW201403141A (en)
WO (1) WO2013183421A1 (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2015166845A (en) * 2014-02-13 2015-09-24 日本電気硝子株式会社 Optical image forming element and method of manufacturing the same
JP2016114733A (en) * 2014-12-15 2016-06-23 コニカミノルタ株式会社 Method for manufacturing optical element

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09218304A (en) * 1995-12-08 1997-08-19 Victor Co Of Japan Ltd Manufacture of micromirror
JP2003500684A (en) * 1999-05-20 2003-01-07 ツムトーベル シュタッフ ゲゼルシャフト ミット ベシュレンクテル ハフツング Optical element for reflecting light rays and method of manufacturing the same
JP2010256840A (en) * 2009-03-29 2010-11-11 Utsunomiya Univ Polarizer, method for manufacturing the same, and optical module
WO2011052588A1 (en) * 2009-10-28 2011-05-05 シャープ株式会社 Optical system
JP2011191404A (en) * 2010-03-12 2011-09-29 Stanley Electric Co Ltd Two-face corner reflector array optical element and display device using the same
JP2012027172A (en) * 2010-07-22 2012-02-09 Mitsubishi Rayon Co Ltd Molded article and manufacturing method of the same

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH09218304A (en) * 1995-12-08 1997-08-19 Victor Co Of Japan Ltd Manufacture of micromirror
JP2003500684A (en) * 1999-05-20 2003-01-07 ツムトーベル シュタッフ ゲゼルシャフト ミット ベシュレンクテル ハフツング Optical element for reflecting light rays and method of manufacturing the same
JP2010256840A (en) * 2009-03-29 2010-11-11 Utsunomiya Univ Polarizer, method for manufacturing the same, and optical module
WO2011052588A1 (en) * 2009-10-28 2011-05-05 シャープ株式会社 Optical system
JP2011191404A (en) * 2010-03-12 2011-09-29 Stanley Electric Co Ltd Two-face corner reflector array optical element and display device using the same
JP2012027172A (en) * 2010-07-22 2012-02-09 Mitsubishi Rayon Co Ltd Molded article and manufacturing method of the same

Also Published As

Publication number Publication date
TW201403141A (en) 2014-01-16
JP2013254145A (en) 2013-12-19

Similar Documents

Publication Publication Date Title
WO2014010538A1 (en) Micromirror array, manufacturing method for micromirror array, and optical elements used in micromirror array
TWI601986B (en) Optical element, method of manufacturing optical element, and optical device
US20070177116A1 (en) Method and apparatus for manufacturing microstructure and device manufactured thereby
EP3255492B1 (en) Transmission-type screen and head-up-display device using same
JP2008545996A (en) Hybrid microlens manufacturing method
JP2006171753A (en) Microlens array sheet using micro machining and method for manufacturing same
JP2013219230A (en) Nanoimprint method and nanoimprint device
JP2015057632A (en) Optical element and projection device
WO2013183421A1 (en) Method for manufacturing micromirror array
KR20080012005A (en) Light guide plate having a prism and hologram pattern and method for manufacturing thereof
JP2005121916A (en) Method for manufacturing base plate with recessed part for lenticular lens, base plate with recessed part for lenticular lens, lenticular lens base plate, transmission type screen and rear type projector
WO2014014197A1 (en) Light guide panel, manufacturing method therefor, backlight unit including same, and liquid crystal display including same
WO2013129043A1 (en) Dihedral corner reflector array
JP6547283B2 (en) Method of manufacturing structure on substrate
JPH02149837A (en) Projecting type image display device
JP4918768B2 (en) Optical screen, projection screen using the same, and method of manufacturing the optical screen
JP2009151257A (en) Inclined exposure lithography system
CN101149560A (en) Micro structure mold core and its manufacture method
JP4918769B2 (en) Optical screen, projection screen using the same, and method of manufacturing the optical screen
KR100819539B1 (en) Mold for manufacturing light guide plate having a prism and hologram pattern and method for manufacturing thereof
JP2011232446A (en) Optic lens film and display device
TWI377112B (en) Method of polishing
JP2004258423A (en) Method for manufacturing triangular groove and optical element
JP6195121B2 (en) Molded body, mold manufacturing method, mold and optical element
CN102929098A (en) V-structured mold cavity and manufacturing method thereof, and manufacturing method of light-guide plate

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 13800936

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 13800936

Country of ref document: EP

Kind code of ref document: A1