JP6400980B2 - Cover member for optical device and optical device - Google Patents

Description

  The present invention relates to a cover member used in an optical apparatus having an optical element such as a mirror device used in a projector or the like.

  In general, for example, in an optical device having an optical element such as a mirror device, high airtightness is required to stably operate a minute mirror, and a glass member is directly bonded to a metal frame. A cover member for an optical device having a structure may be used (see, for example, Patent Document 1).

JP 2003-282754 A

  However, in the case of the above structure, a compressive stress is applied to the glass member in order to keep the airtightness stably, and the stress tends to remain inside the glass member. Further, for example, when the metal frame is deformed by sealing by seam weld bonding or the like, stress is directly applied to the glass member, and the stress tends to remain inside the glass member. And in the part to which the stress was added, the phenomenon of birefringence in which the refractive index deviates from the refractive index of the original glass member tends to occur. As described above, when birefringence occurs in the glass member, the diffraction angle of the image transmitted through the glass member differs depending on the part, and thus there is a problem that distortion is likely to occur in the projected image.

  The present invention has been made in view of the above-described problems, and an object of the present invention is to provide an optical element in which stress is not easily applied to a glass member by bonding the glass member to the frame-shaped member having a stepped portion via the glass bonding material. It is to propose a device cover member and an optical device.

A cover member for an optical element according to one aspect of the present invention has a first opening that penetrates in the thickness direction, and the first opening is surrounded by a frame-shaped portion, and is a rectangular metal in plan view. The frame has a second opening that is provided in the frame-shaped portion of the metal frame and corresponds to the first opening, and is surrounded by sidewalls on all sides. A frame-shaped member made of a ceramic material that is rectangular in plan view, having a stepped portion that is notched over the wall surface, and the outside of the lower main surface so as to close the first opening and the second opening. A peripheral edge and a side surface are provided with a glass member bonded to the step portion via a glass bonding material, and the second opening of the frame-shaped member is more than the first opening of the metal frame. It is located inside .

  An optical device according to one aspect of the present invention includes an optical device cover member according to the present invention, an optical device substrate having an optical element mounting region closed by the optical device cover member, and the mounting region. And an optical element provided, wherein the metal frame is bonded to the optical device base.

  According to the cover member for an optical device of the present invention, it is possible to make it difficult for stress to be applied to the glass member by bonding the glass member to the frame-shaped member having the stepped portion via the glass bonding material.

(A) is a top view of the optical apparatus in embodiment of this invention, (b) is a longitudinal cross-sectional view in AA of the optical apparatus shown to (a). FIG. 2 is an enlarged view of a portion indicated by reference numeral B in the optical device shown in FIG. (A) is the top view except the metal frame of the cover member for optical devices in the optical apparatus shown in FIG. 1, (b) is the back view which looked at the cover member for optical devices shown in (a) from the back surface. . FIG. 3A is an enlarged view of a portion indicated by reference numeral C in the optical device cover member shown in FIG. 3A, and FIG. 3B is an optical device cover member shown in FIG. It is an enlarged view of the part shown. (A) And (b) is sectional drawing which shows the other example of the optical apparatus shown in FIG. It is sectional drawing which shows the other example of the optical apparatus shown in FIG. (A) is a plan view of the optical device shown in FIG. 1 excluding the metal frame of the other optical device cover member, and (b) is a back view of the optical device cover member shown in (a) as seen from the back side. Show. FIG. 7A is an enlarged view of a portion indicated by reference numeral E in the optical device cover member shown in FIG. 7A, and FIG. 7B is an optical device cover member shown in FIG. It is an enlarged view of the part shown. It is an enlarged view of the part shown by the code | symbol B of the optical apparatus of the other example in the optical apparatus shown in FIG. It is an enlarged view of the part shown by the code | symbol B of the optical apparatus of the other example in the optical apparatus shown in FIG. (A)-(c) is sectional drawing which shows the other example of the optical apparatus shown in FIG. 1, respectively.

  Hereinafter, exemplary embodiments of the present invention will be described with reference to the drawings. Note that the drawings used in the following description are schematic, and the dimensional ratios and the like on the drawings do not necessarily match the actual ones. For convenience of explanation, the optical device defines an orthogonal coordinate system xyz and uses the word “upper surface (front surface)” or “lower surface” with the positive side in the z direction as the upper side.

  In the description of the embodiments and the like, the same or similar configurations as those already described may be denoted by the same reference numerals and description thereof may be omitted.

<Embodiment 1>
An optical device cover member and an optical device according to a first embodiment (referred to as Embodiment 1) of the present invention will be described below with reference to FIGS.

  As shown in FIG. 1, the optical device cover member 3 according to Embodiment 1 of the present invention has a first opening 31a penetrating in the thickness direction, and the first opening 31a is a frame-shaped portion 31b. The second metal frame 31 is surrounded by a rectangular metal frame 31 and the first opening 31a provided in the frame-shaped portion 31b of the metal frame 31 and surrounded by side walls. A rectangular frame member 32 in plan view, a first opening portion 31a, and a second opening portion 32a that have an opening portion 32a and a step portion 32b that is notched on the side wall 32c from the upper surface to the inner wall surface. So that the outer peripheral edge portion and the side surface of the lower main surface are joined to the step portion 32b via the glass joining material 34.

The optical device includes an optical device substrate 1, an optical element 2 mounted on the optical device substrate 1, and an optical device cover member 3 bonded to the optical device substrate 1. In the following description, the optical device substrate 1 may be referred to as the substrate 1, and the optical device cover member 3 may be referred to as the cover member 3.

  The base 1 includes an insulator 11, a wiring conductor (not shown) provided on the upper surface, the lower surface or inside of the insulator 11, and a bonding metal ring 12 provided on the upper surface of the insulator 11. .

The insulator 11 is made of, for example, a ceramic material, and has a concave portion 11a in a central region. The concave portion 11a serves as a mounting region for the optical element 2. For example, when the insulator 11 is made of a ceramic material, it is integrally formed by firing. As shown in FIG. 1, the optical element 2 is mounted on the bottom of the recess 11a and mounted on the base 11 using a wire bonding method. Moreover, although the insulator 11 has provided the mounting area | region in the recessed part 11a, it is not restricted to this. The insulator 11 may be provided with a mounting region in a flat portion in the central region without forming a recess.

When the insulator 11 is made of, for example, a ceramic material, an example thereof is an aluminum oxide (alumina: Al ₂ O ₃ ) sintered body or an aluminum nitride (AlN) sintered body. On the insulator 11, the above-described wiring conductor, bonding metallization layer, and the like are formed.

If the insulator 11 is made of, for example, an aluminum oxide sintered body, first, raw material powder of alumina (Al ₂ O ₃ ) and silica (SiO ₂ ), calcia (CaO), magnesia (MgO), or the like. A suitable organic solvent and solvent are added and mixed to form a slurry, which is then formed into a sheet using a well-known doctor blade method or calendar roll method to obtain a ceramic green sheet (hereinafter also referred to as a green sheet). .

  Next, a conductor paste layer to be a wiring conductor and a bonding metallization layer is formed to a thickness of about 10 (μm) to 20 (μm) at a predetermined position of the green sheet using a screen printing method or the like.

  The conductive paste is produced by kneading a metal powder having a high melting point such as tungsten (W), molybdenum (Mo), or molybdenum-manganese (Mo-Mn) alloy with an appropriate resin binder and solvent.

  Next, a through-hole that becomes the recess 11a is formed at a predetermined position of the green sheet by using an appropriate punching process, and if necessary, these green sheets are stacked and pressure-bonded to produce a laminated body. Is fired at a high temperature of about 1600 (° C.) to produce a mother substrate in a multi-piece state.

  Next, in the above-described mother substrate, a plating layer is provided on the metallized layer as necessary. Note that the plating layer is formed of a metal material such as nickel, for example. For example, a brazing material using, for example, a silver-copper eutectic alloy is provided in a predetermined shape on the metallization layer for bonding using an assembly jig. For example, a connecting metal ring 12 is disposed on the brazing material of the silver-copper eutectic alloy. Further, the connecting metal ring 12 is produced, for example, by forming a FeNi29Co17 alloy into a predetermined shape using a known press working method or the like. The connection metal ring 12 is used for seam weld bonding to the metal frame 31 of the cover member 3 for the optical device, whereby the optical device has the substrate 1 for the optical device and the cover member 3 for the optical device. Bonded and hermetically sealed. By maintaining the temperature exceeding the melting point of the brazing material in a reducing atmosphere, the joining metallized layer on the insulator 11 and the joining metal ring 12 are joined via the brazing material. If necessary, a nickel plating layer or a gold plating layer is formed on the connection metal ring 12 or the like by using a plating method, and is divided into individual pieces, whereby the substrate 1 is obtained.

  When the insulator 11 is made of an aluminum oxide sintered body, since the insulator 11 has high mechanical strength, warping or the like hardly occurs, and it has an appropriate thermal conductivity. It becomes easy to dissipate the heat generated by 2 to the outside. Thus, when the insulator 11 is an aluminum oxide sintered body, it is preferable in terms of mechanical strength, thermal conductivity, or cost.

  The optical element 2 is, for example, a mirror device. For example, the optical element 2 reflects light incident on the mirror device to project an image or the like on a screen. The optical element 2 may be a light emitting element such as a light emitting diode.

  As shown in FIG. 1, the cover member 3 includes a metal frame 31, a frame-like member 32 provided on the metal frame 31, and a glass member 33 joined to the frame-like member 32. The metal frame 31 and the frame-like member 32 are joined via a joining material 35.

  The metal frame 31 has a first opening 31a penetrating the upper surface (one main surface) and the lower surface (the other main surface), and the first opening 31a is surrounded by a frame-shaped portion 31b. Yes. Thus, the metal frame 31 has a rectangular shape in plan view, penetrates in the thickness direction, the first opening 31a is provided in the central portion, and the first opening 31a is the frame-shaped portion 31b. being surrounded. The first opening 31a has, for example, a rectangular shape. The metal frame 31 has a side length of, for example, 10 (mm) to 30 (mm), and the first opening 31a has a side length of, for example, 5 (mm) to It is opened at 20 (mm).

  The metal frame 31 preferably has a thermal expansion coefficient similar to that of the frame member 32, the glass member 33, and the insulator 11 joined to the upper surface of the frame portion 31b. As the insulator 11, a ceramic material such as an aluminum nitride sintered body or an alumina sintered body is excellent in heat conductivity and is preferable in terms of heat dissipation. Therefore, the metal frame 31 is made of an aluminum nitride sintered body. Or what has a thermal expansion coefficient similar to the thermal expansion coefficient of an alumina sintered compact is preferable.

For example, 42 alloy (thermal expansion coefficient is about 5.0 (× 10 ⁻⁶ / ° C.)) or FeNi29Co17 alloy (thermal expansion coefficient is about 4.8 (× 10 ⁻⁶ / ° C.)) is an aluminum nitride sintered body. Thermal expansion coefficient (linear thermal expansion coefficient is about 4.6 (× 10 ⁻⁶ / ° C.)) or thermal expansion coefficient of alumina sintered body (linear thermal expansion coefficient is about 7.2 (× 10 ⁻⁶ / ° C.) The metal frame 31 is preferably made of 42 alloy or FeNi29Co17 alloy.

  Moreover, the metal frame 31 can have the 1st opening part 31a in the area | region including a center part by using the conventionally well-known etching method or press work method.

  As shown in FIG. 1, the frame-shaped member 32 is surrounded by four side walls 32 c and has a second opening 32 a corresponding to the first opening 31 a of the metal frame 31. It is rectangular in plan view. Further, the frame-like member 32 has a step portion 32b that is notched from the upper surface (upper part) to the inner wall surface on the side wall 32c over the entire circumference. That is, the stepped portion 32b is formed in the side wall 32c from the upper surface (upper portion) to the inner wall surface, and the stepped portion 32b is formed in the side wall 32c. It is provided inside the side wall 32c over the circumference. The frame member 32 is made of a material having higher rigidity than the glass member 33, for example, the same ceramic material as the insulator 11. The frame-like member 32 has a side length of, for example, 8 (mm) to 27 (mm) in plan view.

The frame member 32 is made of, for example, an aluminum oxide (alumina: Al ₂ O ₃ , alumina Young's modulus: 370 (Gpa)) sintered body or aluminum nitride (AlN, aluminum nitride Young's modulus: 320 (Gpa)). A sintered body or the like, and thus the glass member 33 (D26
If a material having higher rigidity than Young's modulus of 3 glass: 72 (Gpa)) is used, the glass member 33
It is preferable because the stress applied to the film can be reduced.

  Further, the frame-shaped member 32 may be formed by stacking and punching in the same manner as the base body 1 to form the outer shape and the stepped portion 32b, and the outer shape and the stepped portion 32b may be formed by powder press molding using a mold. May be formed. Then, it can be set as the frame-shaped member 32 which consists of ceramic materials by baking similarly to the base | substrate 1. FIG.

  In the frame-shaped member 32, the lower surface of the side wall 32 c is joined to the frame-shaped portion 31 b of the metal frame 31. That is, the frame-shaped member 32 is joined to the frame-shaped portion 31 b on the upper surface of the metal frame 31 so that the second opening 32 a corresponds to the first opening 31 a of the metal frame 31.

  The glass member 33 has a rectangular parallelepiped shape (plate shape), and is provided so as to close the first opening portion 31a and the second opening portion 32a as shown in FIGS. 1 and 2. The outer peripheral edge portion and the side surface are joined to the step portion 32 b of the frame-like member 32 through the glass joining material 34. Thereby, compared with the case where the glass member 33 is joined to the frame-shaped member 32 only on the lower main surface, the applied stress is dispersed, so that the stress is hardly applied. Therefore, the cover member 3 for optical devices can suppress the stress applied to the glass member 33.

The glass member 33, the frame-shaped member 32, the metal frame 31, and the insulator 11 are preferably made of materials having similar thermal expansion coefficients. Further, the glass member 33 has a thermal expansion coefficient of, for example, 4 (× 10 ⁻⁶ / ° C.) in order to reduce the possibility of birefringence or breakage and to improve the reliability of the temperature cycle and the like. It is preferable to use a glass material having about ˜8 (× 10 ⁻⁶ / ° C.).

The glass member 33 is, for example, BK7 (manufactured by HOYA, linear thermal expansion coefficient is approximately 7.5 (× 10 ⁻⁶ / ° C.)) or D263 (manufactured by Schott, linear thermal expansion coefficient is approximately 7.2 (× 10 Using a glass material such as ⁻⁶ / ° C.), a conventionally known dicing method or laser cutting method can be used to form a rectangular shape.

  In addition, the glass member 33 has a shape in which chamfering of each cuboid ridge line is not performed in the figure, but by chamfering each cuboid ridge line on the C surface or the R surface, for example, When the glass member 33 is formed into a predetermined shape by processing the glass member 33, it is possible to reduce cracks from microcracks.

  Here, the cover member 3 for optical devices and the manufacturing method of an optical device are demonstrated.

  As shown in FIGS. 1 and 2, the frame-shaped member 32 is bonded onto the metal frame 31 via the bonding material 35 with the second opening 32 a corresponding to the first opening 31 a of the metal frame 31. Is done. Note that the bonding material 35 is, for example, an active metal brazing material.

  When the bonding material 35 is an active metal brazing material, the paste is a silver brazing material composed of silver and copper powder, silver-copper alloy powder, or a mixed powder thereof (for example, silver: 72% by mass) Copper: 28 mass (%)) powder, active metal such as titanium, hafnium, zirconium or hydride thereof is added to and mixed with silver brazing filler in an amount of 2-5 mass (%). It is manufactured by adding and mixing a solvent and a solvent and kneading.

When joining the metal frame 31 and the frame-shaped member 32 with the joining material 35 of the active metal brazing material,
An active metal brazing material paste is printed and applied in a predetermined pattern with a thickness of, for example, 30 (μm) to 50 (μm) using at least one of the joining surfaces of each member using a known screen printing or the like.

  Then, after placing the metal frame 31 on the frame-like member 32 so as to have a predetermined structure, the metal frame 31 is loaded in a non-oxidizing atmosphere such as a hydrogen gas atmosphere or a nitrogen gas atmosphere while applying a load. By heating for 780 (° C.) to 900 (° C.), 10 (min) to 120 (min), changing the organic solvent, solvent, and dispersant of the brazing material paste into a gas and releasing the brazing material Joining is performed. Moreover, since the metal frame 31 can suppress corrosion by providing a plated layer of nickel or the like, for example, it is preferable to provide a nickel layer or the like using a plating method after joining with the frame-like member 32.

  As shown in FIGS. 1 and 2, the glass member 33 is bonded to the stepped portion 32 b of the frame-shaped member 32 to which the metal frame 31 is bonded using a glass bonding material 34. Thus, the cover member 3 including the metal frame 31, the frame-shaped member 32, and the glass member 33 is obtained. As the glass bonding material 34, for example, low melting point glass or the like can be used.

  The glass bonding material 34 is preferably a material having a thermal expansion coefficient comparable to that of the frame-shaped member 32 or the glass member 33. For example, when a low melting glass is used as the glass bonding material 34, the low melting glass preferably has a thermal expansion coefficient comparable to that of the frame-shaped member 32 or the glass member 33. Thereby, the stress applied to the glass member 33 is suppressed, and the glass member 33 is bonded to the step portion 32b of the frame-shaped member 32 with high bonding strength.

When the low-melting glass has a large thermal expansion coefficient, the glass bonding material 34 is obtained by adding a low thermal expansion material such as a cordierite-based compound as a filler to a thermal expansion coefficient of 4 to 8 (× 10 ^{− By controlling the} temperature to about ⁶ / ° C. or less, the stress applied to the glass member 33 can be suppressed and the bonding strength can be improved.

  The low-melting glass may be, for example, a conventionally known lead-based low-melting glass, but is preferably made of lead-free glass because of its influence on the environment. The low melting point glass is preferably made of, for example, bismuth-based lead-free glass that can be bonded at a low temperature of about 450 (° C.) or vanadium pentoxide-based lead-free glass that can be bonded at a low temperature of about 400 (° C.).

  When low melting glass is used as the glass bonding material 34, a paste that becomes low melting glass is formed by screen printing over the outer peripheral edge of the lower main surface of the glass member 33 and the entire periphery of the side surface. Then, after the paste is heated to evaporate the solvent, the glass member 33 is placed on the stepped portion 32b of the frame-like member 32 to which the metal frame 31 is bonded, and maintained at a temperature equal to or higher than the melting point of the low-melting glass. And what is necessary is just to melt-bond. Thus, the cover member 3 of the present invention including the metal frame 31, the frame-shaped member 32, and the glass member 33 is obtained.

  On the other hand, as shown in FIG. 2, the substrate 1 includes a bonding metallization layer 13 provided on the insulator 11 and a bonding metal ring 12 bonded to the bonding metallization layer 13 by a brazing material 14. Yes. For example, a brazing material 14 made of, for example, a silver-copper eutectic alloy is disposed on the joining metallization layer 13 using an assembly jig, and a joining metal ring 12 is disposed on the brazing material 14. The metallization layer 13 for joining and the metal ring 12 for joining are joined by hold | maintaining at the temperature exceeding 14 melting | fusing point.

Thereafter, after the optical element 2 is mounted on the optical device substrate 1, for example, the optical element 2 is electrically connected to the wiring conductor by a bonding wire using a wire bonding method. Then, the outer edge of the entire circumference of the metal frame 31 of the cover member 3 and the bonding metal ring 12 of the base 1 are bonded by seam weld bonding. The optical device base 1 and the optical device lid 3 may be bonded using direct seam bonding or electron beam bonding without using the bonding metal ring 12. Thus, the optical device includes the optical device substrate 1, the optical element 2 mounted on the optical device substrate 1, and the optical device cover member 3 bonded to the optical device substrate 1. It becomes.

  In the cover member 3 for an optical device according to the present embodiment, the glass member 33 is a frame-shaped member having an outer peripheral edge portion and a side surface of the lower main surface through a glass bonding material 34 as shown in FIGS. The frame-shaped member 32 is provided between the metal frame 31 and the glass member 33. Therefore, in the cover member 3 for an optical device, the stress applied to the metal frame 31 is suppressed by the highly rigid frame-like member 32, and the stress applied to the glass member 33 is suppressed. The birefringence phenomenon that occurs is less likely to occur. Birefringence refers to a phenomenon in which the refractive index deviates from the original refractive index of the glass member 33.

  Further, for example, when the metal frame 31 is seam welded to the optical device substrate 1, stress is easily generated because heat is locally applied, but the optical device cover member 3 is stress applied to the metal frame 31. Is suppressed by the highly rigid frame-shaped member 32, stress is applied to the glass member 33 in a distributed manner. As a result, the stress applied to the glass member 33 is dispersed in the optical device cover member 3, so that the glass member 33 is prevented from being damaged and the optical device is highly reliable with improved airtightness of the optical element 2. Can be. Moreover, since the stress applied to the glass member 33 is suppressed, birefringence is suppressed. Therefore, the optical device cover member 3 can make the optical device high in image quality and high in reliability.

  In the optical device according to the present embodiment, for example, the distortion of the metal frame 31 in the seam weld bonding is suppressed by the frame-shaped member 32 made of a material having a higher Young's modulus than the glass member 33, thereby It is difficult to transmit stress to the glass member, breakage of the glass member 33 is suppressed, and airtightness can be improved.

  Further, the glass bonding material 34 is provided between the frame-shaped member 32 and the glass member 33, and in order to improve the bonding strength between the frame-shaped member 32 and the glass member 33, FIG. As shown in FIG. 4, the glass member 33 is provided on the lower main surface of the glass member 33 so that the inner peripheral edge of the glass bonding material 34 is located inside the second opening 32 a of the frame-like member 32 in plan view. In other words, the glass member 33 is bonded to the stepped portion 32b of the frame-shaped member 32 through the glass bonding material 34 so that the inner peripheral edge of the glass bonding material 34 is located on the inner side of the inner peripheral edge of the frame-shaped member 32 in plan view. Has been. In FIG. 3A, the position of the second opening 32a of the frame-shaped member 32 is indicated by a broken line. 3 and 4, the glass bonding material 34 is hatched. In FIG. 3A and FIG. 4A, the glass bonding material 34 is provided in plan perspective for convenience of explanation. The hatched area is hatched.

  Moreover, as shown in FIG. 4, the distance L between the inner periphery of the frame-shaped member 32 and the inner periphery of the glass bonding material 34 in a plan view is, for example, 0.1 (mm) to 0.5 (mm). .

  The present invention is not limited to the first embodiment described above, and various modifications and improvements can be made without departing from the scope of the present invention. Hereinafter, other embodiments will be described. Of the optical device or the optical device cover member according to the other embodiments, the same parts as those of the optical device or the optical device cover member according to the first embodiment are denoted by the same reference numerals. The description will be omitted as appropriate.

<Embodiment 2>
Optical device cover members 3A and 3B according to a second embodiment (referred to as a second embodiment) of the present invention will be described below with reference to FIGS. 5 (a) and 5 (b).

  In the cover member 3A for an optical device according to the second embodiment of the present invention, the lower main surface of the glass member 33 is joined to the step portion 32b while being inclined with respect to the horizontal direction. The frame-shaped member 32 has a rectangular shape in a plan view, and is surrounded by side walls 32c on four sides. The frame-shaped member 32 includes two opposing side walls 32c.

  As shown in FIG. 5A, in the optical device cover member 3A, the frame-shaped member 32 has a pair of side walls 32c facing each other such that the lower main surface of the glass member 33 is inclined with respect to the horizontal direction. The heights of 32c are different from each other. As described above, the frame-shaped member 32 has a pair of opposing side walls 32c parallel to the x direction, and the height of the side walls 32c gradually increases toward the positive direction of the x direction, and is parallel to the y direction. In the pair of opposing side walls 32, the heights of the side walls 32c are different from each other. As shown in FIG. 5A, in the side view from the y direction, the frame-shaped member 32 has an inclination such that the right side wall 32c is high.

  That is, in the frame-shaped member 32, the height of the side wall 32c is different from each other in one set of the opposing side walls 32c of the two sets of opposing side walls 32c. Thus, by making the height of the side wall 32c of the frame-shaped member 32 different, the glass member 33 has a main surface (lower main surface or upper main surface) inclined with respect to the horizontal direction. It joins to level difference part 32b. As shown in FIG. 5A, the glass member 33 is inclined at an angle α with respect to the horizontal direction, and the angle α is, for example, 5 (degrees) to 30 (degrees).

  Further, according to the inclination of the glass member 33 with respect to the horizontal direction, the frame-shaped member 32 is provided with a stepped portion 32b cut out on the side wall 32c from the upper surface (upper part) to the inner wall surface. That is, the frame-shaped member 32 is appropriately set according to the inclination of the glass member 33 with respect to the horizontal direction of the notch of the stepped portion 32c.

  For example, when the glass member 33 is provided so that the lower main surface is parallel to the upper surface of the frame-shaped portion 31 b of the metal frame 31, as a result, the glass member 33 is disposed parallel to the upper main surface of the optical element 2. become. For example, light that has entered the optical element 2 through the glass member 33 from the outside is reflected by the optical element 2 and emitted toward, for example, a lens disposed outside the glass member 33. When the glass member 33 and the optical element 2 are arranged in parallel, a part of the emitted light is reflected toward the optical element 2 by the surface (lower main surface or upper main surface) of the glass member 33. It will be. And the reflected light on the surface of this glass member 33 becomes easy to inject into the area | region of the vicinity of the incident area | region of the light which initially entered into the optical element 2 from the outside.

  In the case where the optical element 2 is a mirror device and, for example, reflects light incident on the mirror device and projects an image or the like on a screen or the like, the optical element 2 and the glass member 33 are provided in parallel. In this case, the reflected light reflected by the surface of the glass member 33 is likely to be incident on the mirror device in the region near the incident region where the incident light from the outside is first incident. Therefore, the light incident on the mirror device is reflected again by the mirror device, and the image by the reflected light is projected on the screen so as to overlap the image that is originally projected, and the image is displayed in multiple on the screen. A phenomenon (so-called ghost phenomenon) is likely to occur.

  In addition, when the mirror device handles an optical signal, the same phenomenon becomes a time lag of the signal and is likely to be generated as noise.

However, as shown in FIG. 5A, in the optical device cover member 3 </ b> A, the main surface (lower main surface or upper main surface) of the glass member 33 is relative to the upper surface of the frame-shaped portion 31 b of the metal frame 31. Tilted. By adopting such a configuration, incident light transmitted through the glass member 32 from the outside and reflected by the optical element 2 is reflected on the surface of the glass member 33 (lower main surface or upper main surface). The reflected light reflected by the surface of the glass member 33 changes in the reflection direction according to the inclination of the glass member 33 because the glass member 33 is inclined with respect to the optical element 2. It becomes difficult to enter the area near the optical element 2 where the incident light is incident. That is, the reflected light on the surface of the glass member 33 is less likely to be incident on a region near the incident region where the incident light from the outside is first incident.

  Therefore, when the optical element 2 is a mirror device, for example, when the incident light is reflected to project an image or the like, the optical element 2 and the glass member 33 are provided inclined, The reflected light reflected on the surface of the glass member 33 is less likely to enter the mirror device in a region near the incident region where the incident light from the outside is first incident, and is due to the reflected light reflected on the surface of the glass member 33. Since the image is suppressed from being projected on the screen by overlapping the image that is originally projected, the phenomenon that the image is reflected on the screen (so-called ghost) is less likely to occur, and a higher quality image is projected. Can do. Further, even when the mirror device handles an optical signal, the same phenomenon is less likely to occur as signal noise, so that signal noise can be further reduced.

  Further, in FIG. 5A, the frame-shaped member 32 has a side wall 32c having a height different from that of the pair of side walls 32c facing each other, and the step portion 32b is formed in a side wall so as to have a shape corresponding to the inclination of the glass member 33. 32c. Moreover, the metal frame 31 has the 1st opening part 31a similarly to Embodiment 1. FIG.

  5A, in the optical device cover member 3A, the metal frame 31 and the frame-shaped member 32 are bonded via the bonding material 35, and the glass member 33 is attached to the side wall 32c of the frame-shaped member 32. It is joined to the step part 32 b on the upper surface via a glass joining material 34. Further, the height of the side wall 32c is different from each other in the pair of corresponding side walls 32c. In order to form the frame-shaped member 32 having such a shape, the stepped portion 32b of the frame-shaped member 32 is formed. What is necessary is just to shape | mold by the conventionally well-known press processing method using the metal mold | die according to the shape of inclination, and to bake.

  As shown in FIG. 5B, in the optical device cover member 3B, the frame-shaped member 32 has a pair of side walls 32c facing each other such that the lower main surface of the glass member 33 is inclined with respect to the horizontal direction. The heights of 32c are different from each other. As described above, the frame-shaped member 32 has a pair of opposing side walls 32c parallel to the x direction, and the height of the side walls 32c gradually increases toward the positive direction of the x direction, and is parallel to the y direction. In the pair of opposing side walls 32, the heights of the side walls 32c are different from each other. As shown in FIG. 5B, in the side view from the y direction, the frame-shaped member 32 has an inclination such that the right side wall 32c is high.

  That is, in the frame-shaped member 32, the height of the side wall 32c is different from each other in one set of the opposing side walls 32c of the two sets of opposing side walls 32c. Thus, by making the height of the side wall 32c of the frame-shaped member 32, the main surface (lower main surface or upper main surface) of the glass member 33 is inclined with respect to the horizontal direction. Further, the outer peripheral edge of the glass member 33 is bonded to the upper surface of the frame-shaped member 32 via the glass bonding material 34 so as to close the first opening 31a and the second opening 32a. In the glass member 33, it is preferable that the outer peripheral edge and the side surface of the lower main surface are bonded to the upper surface of the frame-shaped member 32 via the glass bonding material 34. The frame-shaped member 32 is inclined in accordance with the inclination of the glass member 33. As shown in FIG. 5B, the glass member 33 is inclined at an angle β with respect to the horizontal direction, and the angle β is, for example, 5 (degrees) to 30 (degrees).

Thus, the frame member 32 has the upper surface (upper part) of the side wall 32c inclined according to the inclination of the glass member 33 with respect to the horizontal direction, and the inclination of the upper surface of the side wall 32c is the inclination of the glass member 33 with respect to the horizontal direction. Accordingly, the inclination is appropriately set.

  Therefore, the optical device cover member 3B has the same effect as the optical device cover member 3A, and the reflected light reflected by the surface of the glass member 33 is inclined with respect to the optical element 2 by the glass member 33. Therefore, the reflection direction changes according to the inclination of the glass member 33, and it becomes difficult to enter the region near the optical element 2 where the first incident light is incident. That is, the reflected light on the surface of the glass member 33 is less likely to be incident on a region near the incident region where the incident light from the outside is first incident.

  In FIG. 5B, the frame member 32 has an upper surface of the side wall 32c such that the height of the side wall 32c is different between the pair of opposing side walls 32c, and has a shape corresponding to the inclination of the glass member 33. Is provided with an inclination. Moreover, the metal frame 31 has the 1st opening part 31a similarly to Embodiment 1. FIG.

  5B, in the optical device cover member 3B, the metal frame 31 and the frame-shaped member 32 are bonded via the bonding material 35, and the glass member 33 is attached to the side wall 32c of the frame-shaped member 32. It is bonded to the upper surface via a glass bonding material 34. Further, the height of the side wall 32c of the pair of corresponding side walls 32c is different from each other, and in order to form the frame-shaped member 32 having such a shape, the upper surface of the side wall 32c of the frame-shaped member 32 is used. What is necessary is just to shape | mold by the conventionally well-known press processing method using the metal mold | die according to the shape, and to bake.

<Embodiment 3>
An optical device cover member 3C according to a third embodiment (referred to as Embodiment 3) of the present invention will be described below with reference to FIG.

  In the cover member 3C for an optical device according to the third embodiment of the present invention, the lower main surface of the glass member 33 is joined to the step portion 32b so as to be inclined with respect to the horizontal direction.

  As shown in FIG. 6, in the optical device cover member 3 </ b> C, the metal frame 31 is formed at a pair of opposing side portions of the frame-shaped portion 31 b so that the lower main surface of the glass member 33 is inclined with respect to the horizontal direction. The heights of the frame portions 31b are different from each other. As described above, the frame-shaped member 32 is gradually increased in the pair of opposing side portions of the frame-shaped portion 31b parallel to the x direction as the height of the frame-shaped portion 31b moves in the positive direction of the x direction. Moreover, the height of the frame-shaped part 31b differs in a pair of side part which the frame-shaped part 31b parallel to ay direction opposes. As shown in FIG. 6, the metal frame 31 has an inclination such that the right-side frame-like portion 31 b becomes higher in a side view from the y direction. As shown in FIG. 6, the glass member 33 is inclined at an angle γ with respect to the horizontal direction, and the angle γ is, for example, 5 (degrees) to 30 (degrees).

  That is, in the metal frame 31, the height of the frame-shaped portion 31b is different from the side of the pair of opposed frame-shaped portions 31b of the two pairs of opposed frame-shaped portions 31b. Thus, the main surface (lower main surface or upper main surface) of the glass member 33 is set in the horizontal direction by making the height of the frame-shaped portion 31b of the metal frame 31 different from each other at the pair of opposing side portions. It leans against it. The metal frame 31 has a thickness of, for example, 0.05 (mm) to 0.2 (mm).

As with the optical device cover members 3A and 3B of the second embodiment, the optical device cover member 3C has the main surface (lower main surface or upper main surface) of the glass member 33 with respect to the upper surface of the optical element 2. Leaning. By adopting such a configuration, incident light that has entered through the glass member 32 from the outside is reflected by the surface of the optical element 2, and the reflected light is reflected on the surface (lower main surface or upper main surface of the glass member 33). ), The reflected light reflected on the surface of the glass member 33 changes its reflection direction according to the inclination of the glass member 33 because the glass member 33 is inclined with respect to the optical element 2. It becomes difficult to enter the area near the optical element 2 where the incident light is incident. That is, the reflected light on the surface of the glass member 33 is less likely to be incident on a region near the incident region where the incident light from the outside is first incident.

  Accordingly, the optical device cover member 3C has the same effect as the optical device cover members 3A and 3B. The optical device is, for example, a mirror device in which the optical element 2 is used in a projector or communication. Can be prevented from occurring in a multiple manner (so-called ghost) or signal noise.

  In FIG. 6, in the optical device cover member 3 </ b> C, the inclined metal frame 31 and the frame-shaped member 32 are bonded via the bonding material 35, and the glass member 33 is the frame-shaped member 32. A glass bonding material 34 is bonded to the stepped portion 32b on the upper surface of the side wall 32c. In the metal frame 31, the height of the frame-shaped part 31b is different between a pair of opposite sides of the frame-shaped part 31b. To form the metal frame 31 having such a shape, the shape of the inclination of the metal frame 31 is used. What is necessary is just to shape | mold by the conventionally well-known press processing method using the metal mold | die according to.

  Further, in the optical device cover member 3C, the glass member 33 is inclined with respect to the horizontal direction using the metal frame 31, and the thickness of the metal frame 31 can be reduced to reduce the weight. Therefore, the optical device cover member 3C is more preferable in terms of reducing the weight of the optical device.

  In FIG. 6, the metal frame 31 is made higher by bending a part of the right frame portion 31 b in order to make the height of the frame portion 31 b different. For example, FIG. As in the side wall 32c of the frame-shaped member 32, the entire right-side frame-shaped portion 31b may be made higher.

<Embodiment 4>
An optical device cover member 3D according to a fourth embodiment (referred to as a fourth embodiment) of the present invention will be described below with reference to FIGS. In FIG. 7A and FIG. 8A, for convenience of explanation, a region where the glass bonding material 34 is provided in a plan view is hatched.

  In the optical device cover member 3D according to the fourth embodiment of the present invention, the radius of curvature R of the corner portion of the second opening 32a of the frame-shaped member 32 is larger than that of the optical device cover member 3 according to the first embodiment. ing. The technical contents of the fourth embodiment can also be applied to the second and third embodiments.

  The frame-shaped member 32 has a rectangular shape, and stress is easily applied to the corners (four corners), and the stress is easily applied to the glass member 33 through the glass bonding material 34. That is, the glass member 33 is likely to be stressed via the glass bonding material 34 in accordance with the stress applied to each part of the frame-shaped member 32 from the metal frame 31, and in particular, in the corner portion, in the x and y directions. Since stress is applied from both directions, the stress applied to the corner tends to increase. As a result, the glass member 33 is likely to generate birefringence in the corner region joined to the frame member 32. That is, the glass member 33 tends to easily generate birefringence in the corner region.

However, as shown in FIGS. 7 and 8, the frame-shaped member 32 has a large radius of curvature R at the corner of the second opening 32 a, so that the second opening 32 a of the frame-shaped member 32 has a larger radius of curvature. In plan view, the glass bonding material 34 has a second inner peripheral edge in the corner region in plan view.
In the region other than the corners, the inner peripheral edge is provided so as to be located inside the second opening 32a. 7 and 8, the position of the second opening 32a of the frame-like member 32 is indicated by a broken line.

  That is, in the plan view, the glass bonding material 34 is provided so that the inner peripheral edge extends to the inside of the second opening 32a in a region other than the corner portion, and the inner peripheral edge is formed in the corner portion region. It is provided so as to be retracted outside the second opening 32a. Thus, since the inner peripheral edge of the glass bonding material 34 does not extend to the inside of the second opening 32a in the corner region, it is possible to suppress an increase in stress applied to the glass member 33 in the corner region. can do.

  Thus, the optical device cover member 3D is provided in advance such that the glass bonding material 34 is positioned outside the second opening 32a in the corner region. Therefore, even if the birefringence occurs in the corner region of the glass member 33, the optical device cover member 3D has the glass bonding material 34 located outside the second opening 32a. Even if the area of the birefringence generated at the corner portion of the member 33 is the same, the region where the birefringence occurs in the glass member 33 can be positioned outside the second opening 32 a of the frame-shaped member 32. Therefore, it is preferable. In other words, since the region where birefringence occurs is located outside the second opening 32a, the optical device cover member 3C is double-coated with respect to the glass member 33 located in the second opening 32a. The influence of refraction becomes difficult. Therefore, the optical device cover member 3D can prevent the diffraction angle of the image transmitted through the glass member 33 from being different depending on the part, and can prevent the projected image from being distorted.

  Further, the frame member 32 can increase the proportion of the frame member 32 in the corner region by increasing the radius of curvature R of the corner portion of the second opening 32a. That is, by increasing the radius of curvature R of the frame-shaped member 32, the proportion of the ceramic material having high rigidity in the corner region increases. Accordingly, the frame member 32 has increased rigidity in the corner region and can suppress the stress applied to the glass member 33, so that the region where the birefringence occurs in the glass member 33 is reduced. Moreover, the curvature radius R of a corner | angular part is 2 (mm)-8 (mm), for example.

  Therefore, the frame-shaped member 32 increases the radius of curvature R of the corner portion of the second opening 32a, and the glass bonding material 34 is formed in the corner portion region in plan view as shown in FIGS. The peripheral edge is positioned outside the second opening 32a (outside the inner peripheral edge of the frame-shaped member 32), and the inner peripheral edge is positioned inside the second opening 32a (the frame-shaped member in a region other than the corner). By providing so that it may be located in the inner peripheral edge of 32, the area | region where birefringence does not generate | occur | produce in the glass member 33 can be expanded.

<Embodiment 5>
An optical device cover member 3E according to a fifth embodiment (referred to as a fifth embodiment) of the present invention will be described below with reference to FIG. The technical contents of the fifth embodiment can also be applied to the second to fourth embodiments.

  As shown in FIG. 9, the optical device cover member 3 </ b> E according to Embodiment 5 of the present invention is provided with a copper plate 36 between the metal frame 31 and the frame-shaped member 32, and the metal frame 31 has the copper plate 36. It is joined to the frame-shaped member 32 with a gap therebetween. The frame-shaped member 32 is bonded to the copper plate 36 via a bonding material 35 made of an active brazing material containing an active metal, and the copper plate 36 is bonded to the metal frame 31 via a brazing material 37. . In addition, the brazing material 37 is comprised by the composition remove | excluding the active metal from the composition of the above-mentioned joining material 35, for example.

Further, the copper plate 36 has an opening 36a corresponding to the second opening 32a, and the outer shape is formed corresponding to the outer shape of the frame-like member 32, and is made to correspond to the second opening 32a. The frame member 32 is joined. At least the outer peripheral edge of the copper plate 36 is joined to the inner peripheral edge of the metal frame 31 over the entire periphery via the brazing material 37.

  For example, compared with the case where the metal frame 31 made of 42 alloy or FeNi29Co17 alloy and the frame-like member 32 made of a ceramic material are joined by the joining material 35 containing the active metal, the cover member 3E for the optical device has the copper plate 36 and Since the frame-shaped member 32 made of a ceramic material is bonded via a bonding material 35 containing an active metal, the active metal component of the bonding material 35 forms a dense layer on the surface of the ceramic material. The bonding strength between the ceramic material of the member 32 and the bonding material 35 is increased. In this manner, the optical device cover member 3E can have a higher bonding strength than when the metal frame 31 is directly bonded to the frame-shaped member 32 via the bonding material 35 made of an active brazing material. Moreover, since the copper plate 36 is soft and can relieve stress, the optical device cover member 3E has high reliability with respect to a temperature cycle or the like.

  Accordingly, in the optical device cover member 3E, the metal frame 31 is joined to the frame-shaped member 32 with the copper plate 36 interposed therebetween. Therefore, the stress is relieved by the copper plate 36, and the frame-shaped member 32 and the metal frame 31 are also relieved. And the connection reliability between the frame-shaped member 32 and the metal frame 31 is increased. Thus, the optical device using the optical device cover member 3E has high airtightness and high reliability.

<Embodiment 6>
An optical device cover member 3F according to a sixth embodiment (referred to as Embodiment 6) of the present invention will be described below with reference to FIG. The technical contents of the sixth embodiment can also be applied to the second to fourth embodiments.

  As shown in FIG. 10, in the optical device cover member 3F according to the sixth embodiment of the present invention, the metal frame 31 is provided with a copper layer 38 mainly composed of copper on the upper surface. It is joined to the frame-shaped member 32 with a gap therebetween. As described above, the frame-shaped member 32 is bonded to the copper layer 38 on the upper surface of the metal frame 31 through the bonding material 35 made of the active brazing material containing the active metal. The copper layer 38 is mainly composed of copper, and is, for example, oxygen-free copper or tough pitch copper. Further, the copper layer 38 is formed on the upper surface of a metal material to be the metal frame 31 by using a cladding process or a plating method, for example. Then, by using a conventionally known etching method or press working method, the metal frame 31 is provided with a first opening 31a in a region including the central portion, and on the upper surface of the frame-shaped portion 31b. A copper layer 38 is provided. For example, the copper layer 38 has a thickness of 10 (μm) to 50 (μm).

  For example, compared with a case where a metal frame 31 made of 42 alloy or FeNi29Co17 alloy and a frame-like member 32 made of a ceramic material are joined by a joining material 35 containing an active metal, the cover member 3F for an optical device has a copper layer. The metal frame 31 formed on the upper surface 38 and the frame-shaped member 32 are joined via a joining material 35 containing an active metal, and the active metal component of the joining material 35 is densely layered on the surface of the ceramic material. Therefore, the bonding strength between the ceramic material of the frame-shaped member 32 and the bonding material 35 is increased. As described above, the optical device cover member 3F can have higher bonding strength than the case where the metal frame 31 is directly bonded to the frame-shaped member 32 via the bonding material 35 made of the active brazing material.

Accordingly, in the optical device cover member 3F, the metal frame 31 is joined to the frame-shaped member 32 with the copper layer 38 interposed therebetween. Therefore, the stress is relieved by the copper layer 38, and the frame-shaped member 32 and the metal The bonding strength with the frame 31 is increased, and the connection reliability between the frame-shaped member 32 and the metal frame 31 is increased. As described above, the optical device using the optical device cover member 3F has high airtightness and high reliability.

  The present invention is not particularly limited to Embodiments 1 to 6 described above, and various modifications and improvements can be made within the scope of the present invention.

  In the example shown in FIG. 11A, the frame-shaped member 32 is joined to the lower surface of the frame-shaped portion 31b. With such a configuration, a part of the surface of the metal frame 31 and the bonding metal ring 12 is covered with the frame-shaped member 32, so that the optical device base 1 of the surfaces of the metal frame 31 and the bonding metal ring 12 is covered. The portion exposed to the internal space is reduced. Therefore, unnecessary reflected light on the inner surfaces of the metal frame 31 and the bonding metal ring 12 is reduced, and the ceramic frame-shaped member 32 absorbs unnecessary light, so that noise is reduced and image quality is improved. Further, the height of the entire apparatus can be suppressed as compared with the case where the frame-shaped member 32 is joined to the upper surface of the metal frame 31.

  In the example shown in FIG. 11B, the frame-shaped member 32 has a stepped portion 32d that is notched from the lower surface (lower portion) to the outer wall surface on the side wall 32c over the entire circumference. Further, the upper surface of the metal frame 31 is joined to the step portion 32d. With such a configuration, it is possible to reduce the dimension of the cover member 3 projecting on the optical device substrate 1 while ensuring the rigidity of the frame-shaped member 32. Further, in the internal space of the optical device substrate 1, the inner end portion of the metal frame 31 is partially shielded by the step portion 32 d, so that the influence of unnecessary reflected light on the inner surfaces of the metal frame 31 and the bonding metal ring 12 is affected. Can be reduced.

  In the example shown in FIG. 11C, the frame-shaped member 32 has a stepped portion 32d that is notched from the upper surface (upper part) to the outer wall surface on the side wall 32c. The lower surface of the metal frame 31 is joined to the step portion 32d. With such a configuration, the unnecessary reflected light can be greatly reduced as described above, and the thickness of the optical device substrate 1 can be reduced while securing the volume in the cavity, so that the rigidity of the optical device substrate 1 is reduced. It is possible to suppress the stress applied to the glass member 33 and to further improve the airtight reliability.

DESCRIPTION OF SYMBOLS 1 Optical apparatus base | substrate 11 Insulator 12 Joining metal ring 2 Optical element 3, 3A, 3B, 3C, 3D, 3E, 3F Optical apparatus cover member 31 Metal frame 31a 1st opening part 31b Frame-shaped part 32 Frame shape Member 32a Second opening 32b Stepped portion 32c Side wall 32d Stepped portion 33 Glass member 34 Glass bonding material 35 Bonding material 36 Copper plate 37 Brazing material 38 Copper layer

Claims (8)

A metal frame having a rectangular shape in plan view, having a first opening penetrating in the thickness direction, the first opening being surrounded by a frame-shaped portion;
Corresponding to the first opening provided in the frame-shaped portion of the metal frame, the second opening is surrounded by side walls on all sides, and the side wall is cut from the upper surface to the inner wall surface. A frame-like member made of a ceramic material having a rectangular shape in plan view, having a stepped portion that is lacking;
Wherein as first close the opening and the second opening, and a glass member in which the outer peripheral edge portion and the side surface of the lower principal surface is bonded to the stepped portion through the glass bonding material ,
The cover member for an optical device , wherein the second opening of the frame-shaped member is located inside the first opening of the metal frame .   2. The cover member for an optical device according to claim 1, wherein the frame-shaped member has a pair of opposing side walls whose heights of the side walls are different from each other.   The optical device cover member according to claim 1, wherein the metal frame has a pair of side portions opposed to each other at different heights.   The cover member for an optical device according to any one of claims 1 to 3, wherein the lower main surface of the glass member is inclined with respect to a horizontal direction.   The optical apparatus cover member according to claim 1, wherein a copper plate is provided between the metal frame and the frame-shaped member.   The cover member for an optical device according to any one of claims 1 to 4, wherein the metal frame is provided with a copper layer mainly composed of copper on an upper surface. A metal frame having a rectangular shape in plan view, having a first opening penetrating in the thickness direction, the first opening being surrounded by a frame-shaped portion;
Corresponding to the first opening provided in the frame-shaped part of the metal frame, and having a second opening surrounded on the four sides by a side wall, made of a rectangular ceramic material in plan view A frame-shaped member;
A glass member in which an outer peripheral edge of the lower main surface is joined to the frame-like member via a glass joining material so as to close the first opening and the second opening;
The frame-shaped members have different heights from each other in a pair of opposing side walls ,
The cover member for an optical device , wherein the second opening of the frame-shaped member is located inside the first opening of the metal frame . A cover member for an optical device according to any one of claims 1 to 7,
A base for an optical device having a mounting region of an optical element blocked by the cover member for the optical device;
An optical element provided in the mounting area,
An optical device, wherein the metal frame is bonded to the optical device substrate.

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