Optical device and wavelength-variable interference filter

Abstract

To provide an optical device that can be suitably diced by means of laser processing.SOLUTION: An optical device comprises a laminated structure of a first substrate and a second substrate, the first substrate having a first surface and a second surface positioned opposite to the first surface, and the second substrate having a third surface and a fourth surface positioned opposite to the third surface, wherein a wiring film is disposed on at least one of the first to fourth surfaces, the wiring film comprising a high reflectivity film and a light-transmissible film, and when a laser for dicing is applied from the first surface toward the second surface, in the wiring film at a portion where the laser is applied, the light-transmissible film is selectively disposed.SELECTED DRAWING: Figure 7

Description

[Technical Field]

[0001] The present invention relates to an optical device and a tunable interference filter. [Background technology]

[0002] There are known methods for dividing devices from a large-sized substrate, such as a wafer on which multiple devices are mounted, by laser processing. For example, Patent Document 1 discloses a method for dividing a substrate by laser processing. According to this document, a laser beam is irradiated from a focal point aligned with the interior of a semiconductor substrate, and a modified region is formed inside the substrate, thereby forming a cutting start region at a predetermined distance inward from the surface of the substrate along a planned cutting line.

[0003] The tunable interference filter device is constructed by stacking two transparent substrates, and one device is cut out from the two large-sized substrates. The device has an overhang where one side of one substrate extends beyond the other side of the substrate, and multiple connection terminals are formed on the overhang. Similar two-substrate devices are often used in optical devices such as display panels. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Application Laid-Open No. 2005-184032 Summary of the Invention [Problem to be solved by the invention]

[0005] However, when the laser processing technology of Patent Document 1 is applied to an optical device, for example, when a laser is irradiated to form a protrusion, the laser may also be irradiated onto the wiring connected to the terminal, and the reflected light may return to the laser irradiation device and cause damage. In other words, there has been a demand for an optical device that can be suitably diced by laser processing. [Means for solving the problem]

[0006] An optical device according to one embodiment of the present application is an optical device comprising a first substrate and a second substrate stacked together, wherein the first substrate has a first surface and a second surface opposite to the first surface, and the second substrate has a third surface and a fourth surface opposite to the third surface, and a wiring film is provided on any of the first surface to the fourth surface, the wiring film including a high-reflectivity film and a light-transmitting film, and when a dicing laser is irradiated in a direction from the first surface to the second surface, the light-transmitting film is selectively disposed on the wiring film in the portion where the laser is irradiated.

[0007] An optical device according to one embodiment of the present application is an optical device comprising a first substrate and a second substrate stacked together, wherein the first substrate has a first surface and a second surface opposite to the first surface, and the second substrate has a third surface and a fourth surface opposite to the third surface, and a wiring film is provided on any of the first to fourth surfaces, the wiring film including a high-reflectivity film and a low-reflectivity film, and when a dicing laser is irradiated in a direction from the first surface to the second surface, the wiring film in the portion irradiated with the laser includes the low-reflectivity film provided on the second surface and the high-reflectivity film provided on top of the low-reflectivity film.

[0008] An optical device according to one embodiment of the present application is an optical device comprising a first substrate and a second substrate stacked together, wherein the first substrate has a first surface and a second surface opposite to the first surface, and the second substrate has a third surface and a fourth surface opposite to the third surface, and a wiring film is provided on any one of the first surface to the fourth surface, the wiring film including a high-reflectivity film and a low-reflectivity film, and when a dicing laser is irradiated from the first surface to the second surface, the wiring film in the portion irradiated with the laser includes the low-reflectivity film provided on the second surface and the high-reflectivity film provided on top of the low-reflectivity film, and when the dicing laser is irradiated from the fourth surface to the third surface, the wiring film in the portion irradiated with the laser includes the low-reflectivity film provided on the third surface and the high-reflectivity film provided on top of the low-reflectivity film.

[0009] In one aspect of the tunable interference filter of the present application, the first substrate has a first reflective film, and the second substrate has a second reflective film, the first reflective film and the second reflective film are formed to face each other and have a fixed gap therebetween, the wiring film is provided on the third surface and includes a first wiring connected to the first reflective film and a second wiring connected to the second reflective film, the first wiring and the second wiring are configured to be able to detect a capacitance between the first reflective film and the second reflective film that is correlated with the gap, and the low-reflectivity film is provided on the second surface and covers the first wiring and the second wiring.

[0010] An optical device according to one aspect of the present application is an optical device comprising a first substrate and a second substrate stacked together, wherein the first substrate has a first surface and a second surface opposite the first surface, the second substrate has a third surface and a fourth surface opposite the third surface, a wiring film is provided on any of the first surface to the fourth surface, one side of the second substrate has a protruding portion that protrudes from one side of the first substrate, and a plurality of terminals are arranged on the protruding portion, the wiring film is connected to the terminals and includes a high-reflectivity film and a light-transmitting film, and the light-transmitting film is selectively arranged on the wiring film in the vicinity of one side of the first substrate that is the starting point of the protruding portion.

[0011] An optical device according to one aspect of the present application is an optical device comprising a first substrate and a second substrate stacked together, wherein the first substrate has a first surface and a second surface opposite the first surface, the second substrate has a third surface and a fourth surface opposite the third surface, a wiring film is provided on any of the first surface to the fourth surface, one side of the second substrate has a protruding portion that protrudes from one side of the first substrate, and a plurality of terminals are arranged on the protruding portion, the wiring film is connected to the terminals and includes a high-reflectivity film and a low-reflectivity film, and the wiring film in the vicinity of the one side of the first substrate that is the starting point of the protruding portion includes the low-reflectivity film provided on the second surface. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 is a plan view of an optical device according to a first embodiment. [Figure 2] 1 is a cross-sectional view of an optical device. [Figure 3] FIG. 1 is a plan view of a tunable interference filter. [Figure 4] Cross-sectional view of a tunable interference filter. [Figure 5] FIG. 1 is a schematic diagram of a laser irradiation device. [Figure 6] FIG. 4 is an enlarged plan view of part b in FIG. 3 . [Figure 7] FIG. 7 is a cross-sectional view taken along the line cc in FIG. 6 . [Figure 8] FIG. 8 is a cross-sectional view of a comparative example of FIG. 7. [Figure 9] FIG. 7 is a cross-sectional view taken along the line dd in FIG. 6 . [Figure 10] FIG. 7 is a cross-sectional view taken along the ee section of FIG. 6. [Figure 11] A graph comparing the reflectance of wiring. DETAILED DESCRIPTION OF THE INVENTION

[0013] Embodiment 1 ***Optical Device Configuration*** 1 and 2 are plan and cross-sectional views of an optical device, respectively. The configurations of an optical device 200 and a tunable interference filter 100 according to this embodiment will be described with reference to FIGS. 1 and 2. Each figure illustrates three mutually orthogonal axes: an X axis, a Y axis, and a Z axis. In this embodiment, the direction along the long side of the rectangular optical device 200 is the X-positive direction. The direction along the X-axis is referred to as the "X-direction," the direction along the Y-axis as the "Y-direction," and the direction along the Z-axis as the "Z-direction." For example, the Y-direction refers to both the positive and negative Y-directions. The positive Z-direction is also referred to as "up," and the negative Z-direction as "down." Furthermore, in the following figures, dimensions and scales may differ from the actual dimensions for clarity.

[0014] The optical device 200 is an apparatus that extracts and emits light of a predetermined target wavelength from incident light to be inspected, and is an optical filter device that includes a housing 60 and a tunable interference filter 100 housed inside the housing 60. The optical device 200 can be suitably applied to, for example, optical modules such as colorimetric sensors, and electronic devices such as colorimetric devices and gas analyzers.

[0015] As shown in FIG. 2, the housing 60 includes a base 61 and a lid 65, and houses the tunable interference filter 100 inside. The base 61 is a ceramic substrate formed by stacking and firing thin ceramic layers. As shown in Figures 1 and 2, the base 61 has a sidewall 62 that is frame-shaped in a plan view of the filter on the surface facing the lid 65. The base 61 also has a recess 63 that is surrounded by the sidewall 62. The lid 65 is bonded to a lid bonding surface 62a, which is the surface of the sidewall 62 facing the lid 65.

[0016] The tunable interference filter 100 is configured by stacking a first substrate 11 and a second substrate 12. The first substrate 11 is also called a fixed substrate, and the second substrate 12 is also called a movable substrate. The tunable interference filter 100 has a rectangular shape that is slightly smaller than the housing 60 in plan view, and is provided with protruding portions 13 and 14 on its short sides. As shown in Fig. 2 , the protruding portion 13 is a protruding portion of the second substrate 12 that protrudes from the short side of the first substrate 11 in the negative X direction. The protruding portion 14 is a protruding portion of the first substrate 11 that protrudes from the short side of the second substrate 12 in the positive X direction. The tunable interference filter 100 is fixed to the side wall on the X positive side of the recess 63 of the base 61 by a fixing member 64. More specifically, the end of the protruding portion 14 of the tunable interference filter 100 is adhesively fixed to the side wall 62b of the recess 63 by the fixing member 64. At this time, the second substrate 12 is spaced apart from the bottom 63b of the recess 63.

[0017] A light passing hole 68 is provided in the bottom 63b of the recess 63 to pass light emitted from the wavelength tunable interference filter 100. A light-transmitting member 66, such as a glass plate, which serves as a lid, is bonded to the light passing hole 68 with a bonding agent such as low-melting-point glass. Furthermore, a sealing hole 67 is provided in the bottom 63b of the recess 63, penetrating to the outside of the housing 60. This sealing hole 67 is a hole portion for, for example, sucking out gas from inside the housing 60 or replacing it with an inert gas when manufacturing the optical device 200, and can be metal-sealed with a sealing member 67b (FIG. 2) made of, for example, Au while the inside of the housing 60 is in a vacuum or reduced pressure state.

[0018] The lid 65 has a rectangular outer shape in plan view similar to that of the base 61, and is made of light-transmitting glass. The lid 65 is bonded to the lid bonding surface 62a with the tunable interference filter 100 disposed on the base 61.

[0019] ***Configuration of tunable interference filter*** Fig. 3 is a plan view showing a schematic configuration of a wavelength tunable interference filter, and Fig. 4 is a cross-sectional view showing a schematic configuration of a wavelength tunable interference filter. The tunable interference filter 100 is configured by stacking a first substrate 11 and a second substrate 12. The first substrate 11 and the second substrate 12 are each made of, for example, various types of glass or quartz, and in this embodiment, are made of quartz glass.

[0020] 4, the first substrate 11 and the second substrate 12 are integrally formed by being bonded together by a bonding film 53. More specifically, a first bonding portion 53a of the first substrate 11 and a second bonding portion 53b of the second substrate 12 are bonded together by the bonding film 53 made of, for example, a plasma polymerized film containing siloxane as a main component. The surface on the positive Z side of first substrate 11 is referred to as first surface 11a, and the back surface of first substrate 11 is referred to as second surface 11b. The surface on the positive Z side of second substrate 12 is referred to as third surface 12a, and the surface on the negative Z side of second substrate 12 is referred to as fourth surface 12b. The second surface 11b of first substrate 11 and the third surface 12a of second substrate 12 face each other. In other words, first substrate 11 has first surface 11a and second surface 11b, which is the surface opposite first surface 11a. Second substrate 12 has third surface 12a and fourth surface 12b, which is the surface opposite third surface 12a.

[0021] A first reflective film 21 is provided approximately in the center of the second surface 11b of the first substrate 11. A second reflective film 22 is provided on the third surface 12a of the second substrate 12 at a position overlapping the first reflective film 21. The first reflective film 21 and the second reflective film 22 are disposed opposite each other with a gap G interposed therebetween. In other words, the first reflective film 21 and the second reflective film 22 are formed to face each other and have a fixed gap G therebetween.

[0022] The first substrate 11 has a circular electrode placement groove 81 that surrounds a cylindrical mounting base 80 on which the first reflective film 21 is disposed. A circular fixed electrode 56a is provided in the electrode placement groove 81. The second substrate 12 has a movable electrode 56b that pairs with the fixed electrode 56a, and the fixed electrode 56a and the movable electrode 56b form an electrostatic actuator 56. The electrostatic actuator 56 adjusts the gap G between the first reflective film 21 and the second reflective film 22 by an electrostatic attractive force that corresponds to a drive voltage applied between the fixed electrode 56a and the movable electrode 56b. The first substrate 11 is formed thicker than the second substrate 12 and has sufficient rigidity to prevent bending even when an electrostatic attractive force is generated by the electrostatic actuator 56. A ring-shaped adjustment electrode (not shown) is provided on the outer periphery of the movable electrode 56b to surround the movable electrode 56b. Opposite the adjustment electrode is the fixed electrode 56a at GND potential, and the adjustment electrode is used to suppress vibration of the second reflection film 22 caused by driving the electrostatic actuator 56.

[0023] The first reflective film 21 may be, for example, a metal film such as Ag or an alloy film such as an Ag alloy. Alternatively, a dielectric multilayer film with a high refractive index layer made of TiO2 and a low refractive index layer made of SiO2 may be used. Furthermore, a reflective film in which a metal film (or alloy film) is laminated on a dielectric multilayer film, a reflective film in which a dielectric multilayer film is laminated on a metal film (or alloy film), or a reflective film in which a single refractive layer (such as TiO2 or SiO2) and a metal film (or alloy film) are laminated may be used. Furthermore, an anti-reflection film may be formed on the first surface 11a, which is the light incident surface of the first substrate 11, at a position corresponding to the first reflective film 21. This anti-reflection film can be formed by alternately laminating low-refractive-index films and high-refractive-index films, and reduces the reflectance of visible light on the surface of the first substrate 11 and increases the transmittance.

[0024] A circular groove 90 is formed on the fourth surface 12b of the second substrate 12 at a position surrounding the second reflective film 22. The circular portion whose thickness is reduced by the groove 90 is called a support portion 91. The portion inside the support portion 91 that includes the second reflective film 22 is called a movable portion 92. The support portion 91 is an elastic and deformable diaphragm, and the electrostatic attractive force of the electrostatic actuator 56 allows the movable portion 92 to move forward and backward relative to the first substrate 11. At this time, since the movable portion 92 is thicker and more rigid than the support portion 91, even if the support portion 91 is pulled toward the first substrate 11 by the electrostatic attractive force, the shape of the movable portion 92 does not change, and therefore the second reflective film 22 does not bend, and it is possible to always maintain the first reflective film 21 and the second reflective film 22 in a parallel state. As with the first substrate 11, an anti-reflection film may also be formed on the fourth surface 12b of the second substrate 12 at a position corresponding to the second reflective film 22.

[0025] ***Connection of terminals at the protruding part*** As shown in FIG. 3, the extension portion 13 is provided with a plurality of terminals 8a to 8g. The terminal 8a is connected to a wire 1. The wire 1 is electrically connected to an adjustment electrode (not shown) that surrounds the movable electrode 56b. The terminal 8b is connected to the wiring 2. The wiring 2 is electrically connected to the movable electrode 56b. The terminal 8c is connected to the wiring 3. The wiring 3 is electrically connected to the fixed electrode 56a. More specifically, the wiring 3 is electrically connected to the wiring 23 on the first substrate 11 side by the conductive bump 85 from the second substrate 12 side, and the wiring 23 is electrically connected to the fixed electrode 56a.

[0026] A wiring 4 is connected to the terminal 8d. The wiring 4 is electrically connected to the first reflective film 21. More specifically, the wiring 4 is electrically connected to the wiring 24 on the first substrate 11 side by a conductive bump 85 from the second substrate 12 side, and the wiring 24 is electrically connected to the first reflective film 21. The wiring 4 corresponds to the first wiring. The terminal 8e is connected to the wiring 5. The wiring 5 is electrically connected to the second reflective film 22. The wiring 5 corresponds to the second wiring. The terminal 8f is connected to the wiring 6. The wiring 6 is electrically connected to the movable electrode 56b. The wiring 6 and the wiring 2 are electrically at the same potential. A wire 7 is connected to the terminal 8g. The wire 7 is electrically connected to an adjustment electrode (not shown) that surrounds the movable electrode 56b. The wire 7 is electrically at the same potential as the wire 1. The multiple terminals 8a to 8g are collectively referred to as terminal 8. The wires 1 to 7 are also included in the wiring film of this embodiment.

[0027] The wiring 4 and the wiring 5 are wirings for detecting the capacitance between the first reflective film 21 and the second reflective film 22, and the gap G is measured from the detected capacitance. In other words, the wiring film is provided on the third surface 12a and includes wiring 4 as a first wiring connected to the first reflective film 21 and wiring 5 as a second wiring connected to the second reflective film 22, and the wiring 4 and wiring 5 are configured so as to be able to detect the capacitance between the first reflective film 21 and the second reflective film 22, which is correlated with the gap G.

[0028] Return to Figure 1. 1, a plurality of base terminals 9 corresponding to the plurality of terminals 8 of the protruding portion 13 are provided on the bottom 63b of the recess 63 of the base 61. As shown in FIG. 2, the terminals 8 and the corresponding base terminals 9 are electrically connected by bonding wires 82. The base terminals 9 are electrically connected to corresponding external terminals 83 formed on the outside of the base 61 by wiring (not shown). The external terminals 83 also serve as mounting terminals for the optical device 200.

[0029] ***Laser processing method*** FIG. 5 is a schematic diagram of a laser irradiation device. 5 is a laser processing device that performs dicing by irradiating a large-sized substrate 110 on which a plurality of tunable interference filters 100 are mounted. The laser irradiation device 50 is composed of a laser oscillator 41, a transmission optical system 42, an irradiation unit 43, a processing table 45, a control device 47, etc. For example, a YAG laser can be used as the laser oscillator 41. Any device can be used as long as it is capable of emitting laser light with a wavelength of approximately 1064 nm, which is suitable for dicing, and for example, a CO2 laser or a fiber laser can also be used. The transmission optical system 42 is an optical path that transmits the laser light generated by the laser oscillator 41 to the irradiation unit 43, and is configured to include a plurality of reflecting mirrors.

[0030] The irradiation unit 43 is an irradiation nozzle that condenses laser light and irradiates the object to be processed, and includes a condenser lens. The processing table 45 is an XY table, and moves the placed object in a plane according to the scanning path pattern of the laser irradiation in accordance with instructions from the control device 47. Note that the irradiation unit 43 may also move in a plane. The control device 47 is a controller for the laser irradiation device 50, and is configured to include one or more processors, and controls the overall operation of each part. The control device 47 is equipped with a storage unit 48 including a non-volatile memory. The storage unit 48 stores a control program for controlling the operation of the laser irradiation device 50, a dicing program, various data, and the like. The dicing program specifies the order and content of dicing the large-format substrate 110, and the various data stores irradiation conditions and path pattern data for the planned cutting lines, and the like. The irradiation conditions include parameters such as output frequency, scanning speed, laser output, and scanning path pitch.

[0031] 5 shows the laser irradiation on the surface of the large-sized substrate 110 on the side of the first substrate 11, but the laser irradiation is also performed on the back surface on the side of the second substrate 12. More specifically, as shown in FIG. 4, the laser irradiation is performed along the outline of the wavelength tunable interference filter 100. In FIG. 4, four laser irradiation lines in the short-side direction of the wavelength tunable interference filter 100 are indicated by white arrows. Similarly, the laser irradiation is performed from the front and back surfaces of the large-sized substrate 110 along the outline of the wavelength tunable interference filter 100 in the long-side direction as well. After a cutting starting point region is formed a predetermined distance inward from the surface of the substrate along a predetermined cutting line by irradiating the laser, external forces such as expanding and breaking are applied to the large-sized substrate 110 to extend the crack and separate it into individual wavelength-tunable interference filters 100.

[0032] ***Wiring details*** Fig. 6 is an enlarged plan view of part b in Fig. 3. Fig. 7 is a cross-sectional view of cross-section cc in Fig. 6, that is, a cross-sectional view of a laser irradiated region of wiring 1. Fig. 8 is a cross-sectional view of a comparative example of Fig. 7. As shown in FIG. 7, the wiring 1 is composed of a wiring 1a extending from the terminal 8a and a wiring 1b connecting to the wiring 1a and extending in the X-positive direction. The wiring 1a is a two-layer wiring consisting of a first layer 31 made of TiW, which is a low-reflectivity film, and a second layer 32 made of Au, which is a high-reflectivity film. The wiring 1b is a wiring drawn out from an adjustment electrode (not shown) surrounding the movable electrode 56b, and is an ITO wiring made of a light-transmitting film. As shown in FIG. 7, the wiring 1b is provided in the area irradiated by the dicing laser irradiation Lb.

[0033] As shown in the comparative diagram of Figure 8, when the wiring 1a of the wiring 1 is located in the irradiation area of ​​the dicing laser irradiation Lb indicated by the white arrow, the laser light is reflected by the wiring 1a, which is a high-reflectivity film, and becomes reflected light RL, which may affect the laser irradiation device 50. 7, in the present embodiment, wiring 1b made of a light-transmitting film of wiring 1 is selectively arranged in the irradiated portion of laser irradiation Lb. As will be described in detail later, most of the laser light incident on wiring 1b is transmitted and is hardly reflected, so that the laser irradiation device 50 is not affected.

[0034] In other words, the wiring 1 as a wiring film includes wiring 1a having the second layer 32, which is a high-reflectivity film, as its surface and wiring 1b made of a light-transmitting film, and when a dicing laser is irradiated from the first surface 11a to the second surface 11b, wiring 1b made of a light-transmitting film is selectively arranged in the wiring 1 in the laser-irradiated portion Lb. Also, a plurality of terminals 8 are arranged on a protruding portion 13 where one side of the second substrate 12 protrudes from one side of the first substrate 11, and the wiring 1 as a wiring film is connected to the terminals 8 and includes wiring 1a having the second layer 32, which is a high-reflectivity film, as its surface and wiring 1b made of a light-transmitting film, and wiring 1b made of a light-transmitting film is selectively arranged in the wiring 1 near the side of the first substrate 11 that is the starting point of the protruding portion 13. As with the wiring 1, the wiring 2, wiring 6, and wiring 7 are selectively arranged in the laser irradiated Lb portion as wirings made of a light-transmitting film.

[0035] FIG. 9 is a cross-sectional view taken along the line dd in FIG. 6, showing the laser irradiated region of the wiring 4. In FIG. 9, the wiring 4 provided on the third surface 12a is the first wiring, and is a wiring having a two-layer configuration consisting of a first layer 31 made of TiW, which is a low-reflectivity film, and a second layer 32 made of Au, which is a high-reflectivity film. The wiring 4 is drawn out from the terminal 8d and extends to the conductive bump 85. The wiring 24 on the second surface is a wiring that is electrically connected to the first reflective film 21, and is a two-layer wiring consisting of a first layer 31 made of TiW, which is a low-reflectivity film, and a second layer 32 made of Au, which is a high-reflectivity film. As mentioned above, the wiring 4 is a wiring for detecting capacitance between the first reflective film 21 and the second reflective film 22, and low-resistance wiring is preferable for high-precision detection, so the wiring is a two-layer wiring including a lower-resistance Au layer rather than an ITO film. The same is true for the wiring 24. 6, after being connected to the conductive bump 85, the wiring 24 extends toward the protruding portion 13 to form a rectangular light-shielding portion 24b. Note that in FIG. 6, a portion of the light-shielding portion 24b that straddles an adjacent device in the state of the large-sized substrate 110 before dicing is shown by a dotted line.

[0036] The light-shielding portion 24b is provided to cover the wiring 4 on the third surface, and the outermost layer on the laser light incident side is the first layer 31 of the low reflectance film. As a result, for example, if the light-shielding portion 24b is not provided, there is a risk that the incident laser light will be reflected by the second layer 32 of the wiring 4 on the second surface, resulting in reflected light (Figure 8).However, according to this embodiment, the first layer 31 of the low-reflectivity film is provided, so the reflected light is reduced and does not affect the laser irradiation device 50. In other words, the wiring 24 as a wiring film includes a second layer 32 which is a high-reflectivity film and a first layer 31 which is a low-reflectivity film, and when a dicing laser is irradiated in the direction from the first surface 11a to the second surface 11b, the wiring 24 in the laser-irradiated portion Lb includes the first layer 31 which is made of a low-reflectivity film provided on the second surface 11b, and the second layer 32 which is made of a high-reflectivity film provided on top of the first layer 31. In addition, a plurality of terminals 8 are arranged on the protruding portion 13 where one side of the second substrate 12 protrudes from one side of the first substrate 11, and wiring 24 as a wiring film is connected to the terminal 8d and includes a second layer 32 which is a high-reflectivity film and a first layer 31 which is a low-reflectivity film, and the wiring 24 near one side of the first substrate 11 which is the starting point of the protruding portion 13 includes the first layer 31 of the low-reflectivity film provided on the second surface 11b.

[0037] The wiring 24 is provided for connection to the first reflective film 21, and therefore it is easy to form the light-shielding portion 24b by extending this wiring to the side of the protruding portion 13, and the configuration can be simplified. As shown in FIG. 6, the wiring 23 is similar to the wiring 24, and the wiring 23 connected to the fixed electrode 56a is extended to the side of the protruding portion 13 to provide a rectangular light-shielding portion 23b.

[0038] FIG. 10 is a cross-sectional view taken along the ee line of FIG. 6, showing the laser irradiated region of the wiring 5. In FIG. 10, the wiring 5 provided on the third surface 12a is the second wiring, and is a wiring having a two-layer structure consisting of a first layer 31 made of TiW, which is a low-reflectivity film, and a second layer 32 made of Au, which is a high-reflectivity film. Like the wiring 4, the wiring 5 is a wiring for detecting capacitance between the first reflective film 21 and the second reflective film 22, and a low-resistance wiring is preferable for high-precision detection, so the wiring is a two-layer structure including a lower-resistance Au layer rather than an ITO film. The second surface is provided with a rectangular light-shielding portion 25 similar to the light-shielding portion 23b. The light-shielding portion 25 is composed of a first layer 31 made of TiW, which is a low-reflectivity film, and a second layer 32 made of Au, which is a high-reflectivity film. The light-shielding portion 25 is a floating terminal formed in the same manufacturing process as the wirings 23 and 24.

[0039] The light-shielding portion 25 is provided to cover the wiring 5 on the third surface, and the outermost layer on the laser light incident side is a first layer 31 of a low reflectance film. As a result, for example, if the light-shielding portion 25 were not provided, incident laser light would be reflected by the second layer 32 of the wiring 5 on the second surface, causing reflected light ( FIG. 8 ). However, according to this embodiment, the first layer 31 of the low-reflectivity film is provided, thereby reducing reflected light and preventing it from affecting the laser irradiation device 50. Thus, even if there is no wiring with a low-reflectivity film on the second surface, providing the floating light-shielding portion 25 can reduce reflected light. The potential of the light-shielding portion 25 may be set to a power supply potential such as a GND potential. In other words, the wiring film is provided on the third surface 12a and includes wiring 4 as a first wiring connected to the first reflective film 21 and wiring 5 as a second wiring connected to the second reflective film 22. The wiring 4 and wiring 5 are provided so that the capacitance between the first reflective film 21 and the second reflective film 22, which is correlated with the gap G, can be detected. The second surface 11b is provided with the light-shielding portion 24b and the light-shielding portion 25, each having a low-reflectivity film covering the wiring 4 and wiring 5 as its outermost layer. The wiring film including the above-mentioned wirings 1 to 7, wiring 24, and light-shielding portion 25 can be formed by forming a film using a known film-forming method such as sputtering, vapor deposition, or CVD, and then patterning it using a photolithography method.

[0040] While the above describes the wiring pattern in the laser irradiation line at the start point of the protruding portion 13, the same wiring pattern applies to the other lines to be cut. Specifically, the same wiring pattern applies to the wiring in the short-side direction indicated by the white arrows in FIG. 4 , including the wiring in the laser irradiation line of the protruding portion 14, and the wiring corresponding to the laser irradiation line in the long-side direction of the wavelength-tunable interference filter 100. In other words, the same wiring pattern applies to the wiring corresponding to all of the laser irradiation lines that form the outline of the wavelength-tunable interference filter 100. For example, when a dicing laser is irradiated in the direction from the fourth surface 12b to the third surface 12a, the wiring film in the portion irradiated with the laser includes a TiW layer as a low-reflectivity film provided on the third surface 12a and an Au layer as a high-reflectivity film superimposed on the TiW layer.

[0041] ***Reflectivity of wiring*** FIG. 11 is a graph comparing the reflectance of wiring, with the horizontal axis representing the wavelength of light (nm) and the vertical axis representing the reflectance (%). Graph 71 in Fig. 11 shows the reflectance of the light-transmitting film. The reflectance was measured by forming an ITO film on the second surface 11b of only the first substrate 11 in Fig. 8 and irradiating light from the first surface 11a. As shown in Graph 71, it can be seen that the ITO film has high light transmittance and therefore low reflectance. In particular, the reflectance at a wavelength of approximately 1064 nm, which is the central wavelength of the laser irradiation during dicing, was approximately 3.15%. Note that the light-transmitting film is not limited to the ITO film, and any conductive film with equivalent light transmittance and reflectance will suffice.

[0042] Graph 72 shows the reflectance of the low-reflectance film. The reflectance was measured by irradiating light from the first surface 11a with the same configuration as wiring 24 in FIG. 9, in which a TiW film is formed on the second surface 11b of only the first substrate 11 and an Au film is formed on top of the TiW film. As shown in graph 72, it can be seen that the TiW film has a lower reflectance than the Au film shown in graph 73. The reflectance at a wavelength of approximately 1064 nm, which is the central wavelength of the laser irradiation during dicing, was approximately 49.5%. Note that the low reflectance film is not limited to the TiW film, and any conductive film with a similar reflectance will suffice.

[0043] Graph 73 shows the reflectance of the high-reflectance film. The reflectance was measured by irradiating light from the first surface 11a on the structure in which only the first substrate 11 is used, with an Au film formed on the second surface 11b and a TiW film formed on top of the Au film, as shown in FIG. As shown in Graph 73, the reflectance of the Au film increases sharply when the wavelength exceeds approximately 500 nm. The reflectance at a wavelength of approximately 1064 nm, which is the central wavelength of the laser irradiation during dicing, was approximately 89.9%.

[0044] ***Verification results, modifications*** According to the results of verification by the inventors, a large-sized substrate 110 with a plurality of the above-described wavelength tunable interference filters 100 mounted thereon was created, and diced using a laser irradiation device 50. As a result, the separated chips had no external defects such as chipping, all of them were good in terms of external dimensions, and the process capability was also good. In the conventional scribe-break method, in which grooves are mechanically formed and then the substrate is separated starting from the grooves, chipping such as chips, breaks, and cracks occurs, which requires external inspection. However, according to the configuration of this embodiment, chipping due to laser separation is rare, which not only improves yield but also enables rationalization by eliminating or eliminating the external inspection process. In the above, the wavelength tunable interference filter 100 has been described as being rectangular, but this is not limited to a rectangle, and the chip can be divided into a variety of shapes, such as curves, acute angles, and obtuse angles, thereby increasing the degree of freedom in design. Furthermore, the application is not limited to the wavelength tunable interference filter 100, but can be suitably applied to optical devices with a two-substrate configuration, such as liquid crystal panels and organic EL displays.

[0045] As described above, the wavelength tunable interference filter 100 and the optical device 200 of this embodiment can provide the following effects. The optical device 200 comprises a tunable interference filter 100 configured by stacking a first substrate 11 and a second substrate 12, the first substrate 11 having a first surface 11a and a second surface 11b opposite the first surface 11a, the second substrate 12 having a third surface 12a and a fourth surface 12b opposite the third surface 12a, the wiring 1 as a wiring film including wiring 1a having a second layer 32 which is a high-reflectivity film on its surface and wiring 1b made of a light-transmitting film, and when a dicing laser is irradiated in the direction from the first surface 11a to the second surface 11b, the wiring 1 in the laser-irradiated portion Lb is selectively arranged with wiring 1b made of the light-transmitting film.

[0046] According to this, even if the dicing laser is irradiated, the irradiated portion of the wiring 1 is the wiring 1b made of a light-transmitting film, so that almost no reflected light occurs and the laser irradiation device 50 is not affected. Therefore, it is possible to provide the tunable interference filter 100 and the optical device 200 that can be suitably diced by laser processing.

[0047] The optical device 200 comprises a tunable interference filter 100 configured by stacking a first substrate 11 and a second substrate 12, wherein the first substrate 11 has a first surface 11a and a second surface 11b opposite the first surface 11a, the second substrate 12 has a third surface 12a and a fourth surface 12b opposite the third surface 12a, and the wiring 24 as a wiring film includes a second layer 32 which is a high-reflectivity film and a first layer 31 which is a low-reflectivity film, and when a dicing laser is irradiated in the direction from the first surface 11a to the second surface 11b, the wiring 24 in the laser-irradiated portion Lb includes the first layer 31 made of a low-reflectivity film provided on the second surface 11b, and the second layer 32 made of a high-reflectivity film provided on top of the first layer 31.

[0048] According to this, even if the dicing laser is irradiated, the wiring film in the irradiated portion is the first layer 31 of the low reflectivity film, so that reflected light is reduced and the laser irradiation device 50 is not affected. Therefore, it is possible to provide the tunable interference filter 100 and the optical device 200 that can be suitably diced by laser processing.

[0049] The optical device 200 includes a tunable interference filter 100 configured by stacking a first substrate 11 and a second substrate 12, the first substrate 11 having a first surface 11a and a second surface 11b opposite to the first surface 11a, the second substrate 12 having a third surface 12a and a fourth surface 12b opposite to the third surface 12a, the wiring 24 as a wiring film including a second layer 32 which is a high-reflectivity film and a first layer 31 which is a low-reflectivity film, and a dicing laser is applied in the direction from the first surface 11a to the second surface 11b. When the dicing laser is irradiated, the wiring 24 in the laser irradiated portion Lb includes a first layer 31 consisting of a low-reflectivity film provided on the second surface 11b, and a second layer 32 consisting of a high-reflectivity film provided on top of the first layer 31. When the dicing laser is irradiated in the direction from the fourth surface 12b to the third surface 12a, the wiring film in the portion irradiated with the laser includes a TiW layer as a low-reflectivity film provided on the third surface 12a, and an Au layer as a high-reflectivity film provided on top of the TiW layer.

[0050] According to this, even if the dicing laser is irradiated, the wiring film in the irradiated portion is the first layer 31 of the low reflectivity film, so that reflected light is reduced and the laser irradiation device 50 is not affected. Therefore, it is possible to provide the tunable interference filter 100 and the optical device 200 that can be suitably diced by laser processing.

[0051] In addition, the wiring film is provided on the third surface 12a and includes wiring 4 as a first wiring connected to the first reflective film 21 and wiring 5 as a second wiring connected to the second reflective film 22, and is configured so that the wiring 4 and wiring 5 can detect the capacitance between the first reflective film 21 and the second reflective film 22, which is correlated with the gap G, and on the second surface 11b, light-shielding portions 24b and 25 are provided, with a low-reflectivity film covering the wiring 4 and wiring 5 as the outermost layer. According to this, even when a dicing laser is irradiated, the wiring film in the irradiated area is made of light-shielding sections 24b and 25, which have a low-reflectivity film as the outermost layer, so reflected light is reduced and does not affect the laser irradiation device 50.

[0052] In addition, a plurality of terminals 8 are arranged on a protruding portion 13 where one side of the second substrate 12 protrudes from one side of the first substrate 11, and the wiring 1 as a wiring film is connected to the terminals 8 and includes wiring 1a whose surface is the second layer 32 which is a high-reflectivity film, and wiring 1b made of a translucent film, and the wiring 1 near one side of the first substrate 11 which is the starting point of the protruding portion 13 is selectively arranged with wiring 1b made of a translucent film. According to this, even if the dicing laser is irradiated, the irradiated portion of the wiring 1 is the wiring 1b made of a light-transmitting film, so that almost no reflected light occurs and the laser irradiation device 50 is not affected. Therefore, it is possible to provide the tunable interference filter 100 and the optical device 200 that can be suitably diced by laser processing.

[0053] In addition, a plurality of terminals 8 are arranged on the protruding portion 13 where one side of the second substrate 12 protrudes from one side of the first substrate 11, and wiring 24 as a wiring film is connected to the terminal 8d and includes a second layer 32 which is a high-reflectivity film and a first layer 31 which is a low-reflectivity film, and the wiring 24 near one side of the first substrate 11 which is the starting point of the protruding portion 13 includes the first layer 31 of the low-reflectivity film provided on the second surface 11b. According to this, even if the dicing laser is irradiated, the wiring film in the irradiated portion is the first layer 31 of the low reflectivity film, so that reflected light is reduced and the laser irradiation device 50 is not affected. Therefore, it is possible to provide the tunable interference filter 100 and the optical device 200 that can be suitably diced by laser processing. [Explanation of symbols]

[0054] 1...wiring, 1a...wiring, 1b...wiring, 2 to 7...wiring, 8...terminal, 8a to 8g...terminal, 9...base terminal, 11...first substrate, 11a...first surface, 11b...second surface, 12...second substrate, 12a...third surface, 12b...fourth surface, 13...extending portion, 14...extending portion, 21...first reflective film, 22...second reflective film, 23...wiring, 23b...light-shielding portion, 24...wiring, 24b...light-shielding portion, 25...light-shielding portion, 31...first layer, 32...second layer, 41...laser oscillator, 42...transmission optical system, 43...irradiation unit, 45...processing table, 47...control device, 48...storage unit, 50...laser irradiation device, 53...bonding film, 53a... First bonding portion, 53b...second bonding portion, 56...electrostatic actuator, 56a...fixed electrode, 56b...movable electrode, 60...housing, 61...base, 62...side wall portion, 62a...lid bonding surface, 63...recess, 63b...bottom, 64...fixing member, 65...lid, 66...light-transmitting member, 67...sealing hole, 67b...sealing member, 68...light transmission hole, 71-73...graph, 80...mounting base portion, 81...electrode placement groove, 82...bonding wire, 83...external terminal, 85...conductive bump, 90...groove portion, 91...support portion, 92...movable portion, 100...tunable interference filter, 110...large-format substrate, 200...optical device.

Claims

1. An optical device in which a first substrate and a second substrate are superimposed, the first substrate has a first surface and a second surface opposite to the first surface; the second substrate has a third surface and a fourth surface opposite to the third surface, a wiring film is provided on any one of the first surface to the fourth surface, the wiring film includes a high-reflectivity film and a light-transmitting film; When a dicing laser is irradiated in a direction from the first surface to the second surface, the light-transmitting film is selectively disposed on the wiring film in the portion irradiated with the laser; Optical devices.

2. An optical device in which a first substrate and a second substrate are superimposed, the first substrate has a first surface and a second surface opposite to the first surface; the second substrate has a third surface and a fourth surface opposite to the third surface, a wiring film is provided on any one of the first surface to the fourth surface, the wiring film includes a high-reflectivity film and a low-reflectivity film; When a dicing laser is irradiated in a direction from the first surface to the second surface, The wiring film in the portion irradiated with the laser is the low-reflectivity film provided on the second surface; and the high-reflectivity film provided on top of the low-reflectivity film, Optical devices.

3. An optical device in which a first substrate and a second substrate are superimposed, the first substrate has a first surface and a second surface opposite to the first surface; the second substrate has a third surface and a fourth surface opposite to the third surface, a wiring film is provided on any one of the first surface to the fourth surface, the wiring film includes a high-reflectivity film and a low-reflectivity film; When a dicing laser is irradiated in a direction from the first surface to the second surface, The wiring film in the portion irradiated with the laser is the low-reflectivity film provided on the second surface, and the high-reflectivity film provided over the low-reflectivity film, When the dicing laser is irradiated in a direction from the fourth surface to the third surface, The wiring film in the portion irradiated with the laser is the low-reflectivity film provided on the third surface; and the high-reflectivity film provided on the low-reflectivity film, Optical devices.

4. 3. The optical device according to claim 2, the optical device is a tunable interference filter; the first substrate has a first reflective film; the second substrate has a second reflective film; the first reflective film and the second reflective film are formed to face each other and have a constant gap therebetween, the wiring film is provided on the third surface and includes a first wiring connected to the first reflective film and a second wiring connected to the second reflective film; the first wiring and the second wiring are provided so as to be able to detect a capacitance between the first reflective film and the second reflective film, which is correlated with the gap; the low-reflectivity film is provided on the second surface to cover the first wiring and the second wiring; Tunable interference filters.

5. An optical device in which a first substrate and a second substrate are superimposed, the first substrate has a first surface and a second surface opposite to the first surface; the second substrate has a third surface and a fourth surface opposite to the third surface, a wiring film is provided on any one of the first surface to the fourth surface, a protruding portion is provided on one side of the second substrate, the protruding portion protruding from one side of the first substrate, and a plurality of terminals are arranged on the protruding portion; the wiring film is connected to the terminal and includes a high-reflectivity film and a light-transmitting film; the wiring film in the vicinity of one side of the first substrate, which is a starting point of the protrusion, is selectively provided with the transparent film; Optical devices.

6. An optical device in which a first substrate and a second substrate are superimposed, the first substrate has a first surface and a second surface opposite to the first surface; the second substrate has a third surface and a fourth surface opposite to the third surface, a wiring film is provided on any one of the first surface to the fourth surface, a protruding portion is provided on one side of the second substrate, the protruding portion protruding from one side of the first substrate, and a plurality of terminals are arranged on the protruding portion; the wiring film is connected to the terminal and includes a high-reflectivity film and a low-reflectivity film; the wiring film in the vicinity of one side of the first substrate, which is the starting point of the protruding portion, includes the low-reflectivity film provided on the second surface; Optical devices.

Images