JP2012089606A - Optical device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an optical device which suppresses deterioration due to irradiation with light in the wavelength range from ultraviolet to blue.SOLUTION: The optical device comprises a support, an optical element provided on the support, a cap, and a first adhesive layer. The cap is attached to the support to cover the optical element with a space therebetween, and has a window configuring a part of the optical path of the optical element. The first adhesive layer contains polysaccharide where maltotrioses are lined by α-1,6 bonds. The support is adhered to at least one of the optical element and the cap via the first adhesive layer.

Description

  Embodiments described herein relate generally to an optical device.

  Semiconductor light emitting and receiving devices often have a sealing layer or an adhesive layer made of a resin material.

 For example, the sealing layer is formed of epoxy, silicone, or the like provided so as to cover the optical element. When the phosphor particles are dispersed and arranged in the sealing layer, wavelength converted light having a wavelength longer than the wavelength of the emitted light can be obtained. The adhesive layer is made of epoxy or the like in which silver particles are dispersed.

  These resin materials have lower processing and heat treatment temperatures than glass materials. For this reason, deterioration of the optical element can be suppressed, and mass productivity of the optical element can be enhanced.

  However, the resin material may be deteriorated by light having a high photon energy in the ultraviolet to blue wavelength range. Due to the deterioration of the resin, for example, there is a problem that the optical properties change due to discoloration.

JP 2007-32003 A

  Provided is an optical device in which deterioration of a member due to light irradiation in an ultraviolet to blue wavelength range is suppressed.

  The optical device according to the embodiment includes a support, an optical element provided on the support, a cap, and a first adhesive layer. The cap includes a window portion that covers the optical element at a distance, is attached to the support, and forms a part of the optical path of the optical element. The first adhesive layer includes a polysaccharide in which maltotrioses are linked by α-1,6 bonds. The support is bonded to at least one of the optical element and the cap through the first adhesive layer.

  The optical device according to the embodiment includes a support, a light emitting element provided on the support, and a wavelength conversion layer. The wavelength conversion layer is a wavelength conversion layer including a polysaccharide in which maltotriose is linked by α-1,6 bonds, and phosphor particles are dispersed, and absorbs a part of light emitted from the light emitting element. And a wavelength conversion layer capable of emitting wavelength-converted light having a wavelength longer than the wavelength of the emitted light. The other part of the emitted light and the wavelength converted light emit mixed light.

1A is a schematic perspective view of a cap of the optical device according to the first embodiment, FIG. 1B is a schematic perspective view of the support, and FIG. 1C is a schematic perspective view of the optical device. is there. FIG. 2A is a schematic perspective view before bonding the condenser lens of the optical device according to the second embodiment, and FIG. 2B is a schematic perspective view thereof. It is a model perspective view of the optical apparatus concerning 3rd Embodiment. FIG. 4A is a schematic perspective view before providing the optical fiber of the optical device according to the fourth embodiment, and FIG. 4B is a schematic perspective view thereof. FIG. 5A is a schematic perspective view before the light guide of the optical device according to the fifth embodiment is provided, FIG. 5B is a schematic perspective view thereof, and FIG. 5C is a schematic cross-sectional view of a modification. . It is a model perspective view of the optical apparatus concerning 6th Embodiment. It is a partial schematic cross section of the optical apparatus concerning 7th Embodiment. It is a schematic plan view of the optical apparatus concerning 8th Embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
1A is a schematic perspective view of a cap of the optical device according to the first embodiment, FIG. 1B is a schematic perspective view of the support, and FIG. 1C is a schematic perspective view of the optical device. is there.
The optical device includes a support 20, an optical element 10 provided on the support 20, a cap 22, and an adhesive layer.

  The support 20 includes a metal block-shaped first electrode 20a, a metal block-shaped second electrode 20b, and an insulator 20c that insulates the two metal blocks. The support 20 may have a submount 12. The optical element 10 has a conductive portion on the surface and is provided on the surface of the submount 12 made of AlN or the like. The electrode on the lower surface of the optical element 10 is connected to the first electrode 20 a via the conductive portion of the submount 12. Further, the electrode on the upper surface of the optical element 10 is connected to the second electrode 20 b by the bonding wire 14. The support 20 may include an insulating material and first and second electrodes provided on the upper surface thereof.

  The cap 22 made of glass or the like can be provided with a recess 22a, for example. The cap 22 has a window portion constituting a part of the optical path of the optical element 10 on the side surface 22b. When the cap 22 is made of a transparent material, the entire cap 22 becomes a window portion. Or it can also be set as the cap which makes a window part a transparent material, and makes another part light-shielding material.

The adhesive layer includes pullulan. Pullulan is a polysaccharide that is a polymer in which maltotriose is linked by α-1,6 bonds, and the compositional formula thereof is represented by (C ₆ H ₁₀ O ₅ ) _n (n: number of polymerizations). Pullulan includes a water-soluble type using water as a solvent and a type using organic substances such as alcohol, acetone and hexane as a solvent. All pullulans are highly adhesive.

  The support 20 is bonded to at least one of the optical element 10 and the cap 22 via the first adhesive layer 30. In FIG. 1, the cap 22 and the support 20 are bonded via a first adhesive layer 30. In this case, the optical element 10 is provided in the recess 22a so as to be separated from the inner wall of the recess 22a. The optical element 10 and the submount 12 may be further bonded with an adhesive layer made of pullulan.

  If the optical element 10 is a light emitting element, the emitted light is emitted outside from the window. The light emitting element 10 may be either a side light emitting type or a top light emitting type. In FIG. 1C, it is assumed that the light emitting element 10 is an LD (Laser Diode) and emits laser light from the side surface. The laser light has an optical path represented by G1, and the spread of the optical path G1 can be reduced such that the full width at half maximum in the vertical direction is 30 degrees, the full width at half maximum in the horizontal direction is 10 degrees, and the like. In the case of an LD, the laser light emission end face needs to have a predetermined reflectance. For this reason, the space between the cap 22 and the light emitting element 10 is often filled with air or an inert gas.

FIG. 2A is a schematic perspective view before bonding the condenser lens of the optical device according to the second embodiment, and FIG. 2B is a schematic perspective view thereof.
A second adhesive layer 32 is provided on the side surface 22 b of the cap 22. The second adhesive layer 32 includes pullulan like the first adhesive layer 30. The optical member 37 made of a condensing lens is bonded to the cap 22 via the second adhesive layer 32. When the optical element 10 is an LD, for example, a laser beam that diverges from a light emitting point can be used as an optical path G1 close to parallel light by a condenser lens. The optical member 37 may be an optical fiber or a light guide.

  The adhesive layers 30 and 32 in the first and second embodiments will be described in detail. Pullulan dissolves easily in water and organic solvents. A pullulan solution is applied to a desired location, an optical member and a chip are placed, and heated at a temperature at which the solvent evaporates. When a solvent having a vaporization point of 100 ° C. or lower is used, the inorganic material such as glass and ceramic, or between the inorganic material and a metal material such as a copper-based alloy, an iron-based alloy, and kovar is firmly formed even at a temperature of 100 ° C. Can be glued. If a support made of metal and a cap made of glass are bonded with solder, frit glass, or the like, an adhesion temperature higher than 100 ° C. is required, and the optical element 10 may be deteriorated.

  On the other hand, when pullulan is used as the adhesive layer, it can be bonded at a lower temperature. Moreover, since the thermosetting temperature of resin, such as an epoxy, a silicone, and an acryl, is the range of 130-170 degreeC, for example, when pullulan is used, it can adhere | attach at temperature lower than this. As a result, the bonding process becomes easy and high bonding strength can be obtained.

  The inventors have found that the adhesive layer made of pullulan transmits light in the ultraviolet to blue wavelength range, and the deterioration due to light irradiation is smaller than the deterioration in the resin. Further, according to experiments by the inventors, it has been found that the maximum operating temperature of the optical element can be 85 ° C. or higher.

  If a resin containing siloxane is used for the cap, the support, the adhesive layer, the sealing layer, etc., the photochemical reaction is accelerated by irradiation with ultraviolet to blue light. For this reason, siloxane having a Si—O—Si bond is decomposed, and foreign matter containing Si may be deposited in the vicinity of the light emitting point. When the optical element 10 is an LD that emits ultraviolet to blue light, the photochemical reaction is more likely to occur because the energy is high. On the other hand, since pullulan does not contain siloxane, generation | occurrence | production of a foreign material can be suppressed.

FIG. 3 is a schematic perspective view of an optical device according to the third embodiment.
The optical device includes a support 20, a light receiving element 11 provided on the support 20, a cap 22, an optical member 37, and a second adhesive layer 32 made of pullulan.

  The support 20 includes a first electrode 20a, a second electrode 20b, and an insulator 20c. Further, the support 20 may have a submount 12. The light receiving element 11 may be provided via a submount 12 made of AlN or the like. The light receiving element 11 can be, for example, a photodiode made of Si, a light receiving IC, or the like. That is, the optical device can be used as an optical sensor or the like.

  An optical member 37 made of a condensing lens is provided on the surface 22c of the cap 22 serving as a window portion with the second adhesive layer 32 interposed therebetween. An optical path R1 of emitted light from an optical fiber or the like is collected by the optical member 37 and enters the light receiving surface of the light receiving element 11. The optical member 37 is firmly bonded to the surface 22 c of the cap 22. Further, the second adhesive layer 32 is suppressed from being deteriorated with respect to the emitted light.

FIG. 4A is a schematic perspective view before providing the optical fiber of the optical device according to the fourth embodiment, and FIG. 4B is a schematic perspective view thereof.
The optical device is provided with an adhesive layer 32 provided on the side surface 22b of the cap 22, an optical fiber (optical member) 42 serving as an optical member that guides emitted light, and one end surface thereof is adhered to the adhesive layer 32, and a V-groove. And a pedestal 44 formed thereon. The optical fiber 42 is fixed to the V groove. The optical fiber 42 includes a cylindrical core 42a and a clad 42b having a refractive index lower than that of the core 42a and provided on the outer edge of the core 42a.

  The optical fiber 42 may also include a core 42a made of cylindrical glass, and a clad 42b made of pullulan having a refractive index lower than that of the core 42a and provided on the outer edge of the core 42a. Good. Alternatively, the optical fiber 42 may include a clad 42b made of a transparent resin and the like, and a core 42a made of pullulan having a refractive index higher than that of the clad 42b and provided inside the clad 42b. Good.

  The light emitted from the light emitting element 10 is introduced from one end face of the optical fiber 42, travels along the first direction 60 while being reflected at the interface between the core and the clad, and is emitted from the other end face of the optical fiber 42. (G3).

FIG. 5A is a schematic perspective view before the light guide of the optical device according to the fifth embodiment is provided, FIG. 5B is a schematic perspective view thereof, and FIG. 5C is a schematic cross-sectional view of a modification. .
The optical device can guide emitted light and is provided in contact with a light guide (optical member) 40 extending in a direction intersecting the side surface 22 b of the cap 22 and an outer edge of the light guide 40. And a wavelength conversion layer 34 made of pullulan in which phosphor particles are dispersed and arranged as a filler.

  If the phosphor particles are applied to the glass using the slurry method, it is necessary to perform heat treatment at 600 ° C. or higher. Silicate phosphor particles have low heat resistance, and there is a problem that wavelength conversion efficiency is lowered by such high temperature treatment. In the slurry method, the adhesive strength is low. For this reason, especially when the phosphor layer is thick, it tends to be peeled off, and unlike the fluorescent lamp or CCFL (Cold Cathode Fluorescent Lamp), there is little possibility of direct contact with the outside. It is difficult to use.

  On the other hand, in this embodiment, the wavelength conversion layer 34 in which the phosphor particles are dispersedly arranged is thinly and uniformly provided on the cylindrical light guide 40 made of glass while maintaining high adhesive strength. The light emitted from the light emitting element 10 is introduced into the end face of the light guide 40, and the inside of the light guide 40 is repeatedly reflected along a first direction 60 extending in a direction orthogonal to the side face 22b. Continue on. A part of the emitted light travels along the first direction 60 and emits the wavelength-converted light and the other part of the emitted light in a direction orthogonal to the first direction 60. If the emitted light is blue light and the wavelength-converted light is yellow light, pseudo white light G4 can be obtained as mixed light. Further, according to experiments by the inventors, it has been found that the wavelength conversion layer made of pullulan is less deteriorated by light irradiation than that of the resin, and the maximum operating temperature can be 85 ° C. or higher.

  As shown in FIG. 5C, when the reflecting surface is provided by the reflector 45 on the pedestal 44 side in the outer edge of the wavelength conversion layer 34, the pseudo white light G <b> 4 is reflected, and in a direction orthogonal to the first direction 60. Pseudo white light G4 having high emission intensity can be emitted. The reflector 45 can be easily provided by applying a pullulan solution in which a white reflector such as barium sulfate is mixed to the outer edge on the lower side of the wavelength conversion layer 34 made of pullulan. The phosphor particles may emit green light, red light, or the like. The wavelength of the emitted light can be in the wavelength range of ultraviolet to blue light.

  The cross section of the light guide 40 is not limited to a circle, and may be a rectangle or a polygon. Moreover, if it is set as a plate-shaped light guide, it can be set as a surface light source. Further, the emission intensity may be controlled by patterning or the like without providing the phosphor particles uniformly.

FIG. 6 is a schematic perspective view of an optical device according to the sixth embodiment.
The optical device includes a light emitting element 10 and a package (support) 70. In this figure, the light emitting element 10 is assumed to be an LED (Light Emitting Diode). The support 70 includes an insulator such as ceramic or a metal. The electrode is exposed on the bottom surface of the recess 70 a provided in the support 70. The light emitting element 10 can be adhered on the electrode through a first adhesive layer made of pullulan.

  In addition, the wavelength conversion layer 34 may be provided in the recess 70 a so as to cover the light emitting element 10. In this case, in the wavelength conversion layer 34, the phosphor particles 50 are dispersedly arranged as fillers in the pullulan. When the support body 70 provided with the recess 70a contains an inorganic material such as ceramic, the adhesion between the pullulan and the ceramic is high, and no gap is generated between the ceramic and the wavelength conversion layer 34. For this reason, a change in optical characteristics, disconnection of the bonding wire, and the like are suppressed, and reliability can be improved. Even if the light emitting element 10 emits high-luminance ultraviolet to blue light, it is easy to suppress the pullulan deterioration.

  The optical device can be bonded to the conductive portions 72 and 73 provided on the mounting substrate 76 via the adhesive layer 35. The adhesive layer 35 is assumed that fillers having high conductivity and thermal conductivity are dispersed and arranged in the pullulan. For example, Ag particles can be used as the filler. Such a component bonding method is not limited to an optical device, but can also be applied to mounting of other semiconductor devices.

FIG. 7 is a partial schematic cross-sectional view of an optical device according to a seventh embodiment.
The optical device can be used as a light bulb that can emit pseudo white light. The optical device includes a support including the substrate 80 and the base 82, the light emitting element 10 provided on the substrate 80, a bulb 84, and the wavelength conversion layer 34. The bulb 84 is attached to the support so that the light emitting element 10 and the bulb 84 are separated from each other. On the inner surface 84a of the bulb 84, for example, a yellow phosphor is dispersedly arranged, and a wavelength conversion layer 34 made of pullulan is provided.

  Part of the light emitted from the light emitting element 10 such as a blue LED is absorbed by the yellow phosphor and emits yellow light. On the other hand, the other part of the emitted light is emitted without being absorbed by the yellow phosphor. As a result, the pseudo white light G5 can be emitted toward the outside of the bulb 84. In this case, the pullulan can be firmly bonded to the inner surface 84a of the valve 84 only by drying. For this reason, the process is simple and high mass productivity is possible.

FIG. 8 is a schematic plan view of an optical device according to the eighth embodiment.
The optical device includes the light emitting element 10, the mirror 90, and the screen 92, and can be used as a display device. The light emitting element 10 is a blue-violet LD. The mirror 90 has, for example, a MEMS (Micro Electro Mechanical Systems) structure, and can scan the beam-like emitted light G6 from the light emitting element 10 on the screen 92.

  The screen 92 is provided with an RGBW pixel pattern 94, which is sequentially irradiated with the scanned beam. For example, a pullulan solution containing an RGBW phosphor as a filler is sequentially applied to a glass sheet-like surface made of an inorganic material using a mask printing method. Each pixel pattern 94a, 94b, 94c, 94d is firmly adhered to the glass surface and hardly peeled off by only the step of drying at a temperature of 100 ° C. or lower. For this reason, the screen 92 in which deterioration is suppressed with respect to ultraviolet to blue light can be produced with high productivity. This display device can also display TV images.

  As described above, according to the first to eighth embodiments, an optical device in which deterioration of a member due to light irradiation in the ultraviolet to blue wavelength range is suppressed is provided. Such an optical device has high productivity and can be widely used for a lamp, a lighting device, a display device, a traffic light, an optical sensor, and the like.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the invention described in the claims and the equivalents thereof.

DESCRIPTION OF SYMBOLS 10 Optical element (light emitting element), 11 Light receiving element, 20, 70 Support body, 22 Cap, 30 1st contact bonding layer, 32 2nd contact bonding layer, 34 Wavelength conversion layer, 37 Optical member, 40 Light guide, 50 Phosphor particles, 84 bulb, G1, G2, G3 optical path

Claims (6)

A support;
An optical element provided on the support;
A cap having a window portion that covers and separates the optical element, is attached to the support, and forms a part of an optical path of the optical element;
A first adhesive layer comprising a polysaccharide in which maltotriose is linked by α-1,6 bonds;
With
The optical device is characterized in that the support is bonded to at least one of the optical element and the cap via the first adhesive layer. An optical member capable of controlling the spread of the optical path;
A second adhesive layer comprising a polysaccharide in which maltotriose is linked by α-1,6 bonds, and capable of adhering the optical member and the cap;
The optical device according to claim 1, further comprising: A support;
A light emitting device provided on the support;
A wavelength conversion layer in which maltotriose includes a polysaccharide linked by α-1,6 bonds, and phosphor particles are dispersedly arranged, and absorbs a part of the emitted light from the light emitting element, and the wavelength of the emitted light. A wavelength conversion layer capable of emitting wavelength-converted light having a longer wavelength,
With
An optical device characterized in that a mixed light of the other part of the emitted light and the wavelength-converted light can be emitted. Further comprising a bulb attached to the support so as to cover the light emitting element;
The optical device according to claim 3, wherein the wavelength conversion layer is provided on an inner surface of the bulb so as to be separated from the light emitting element. A cap that is spaced apart from the light emitting element, is attached to the support, and is capable of transmitting the emitted light;
A light guide capable of guiding the emitted light and extending in a side surface direction of the cap;
Further comprising
The wavelength conversion layer is provided in contact with the light guide,
The optical device according to claim 3, wherein the mixed light can be emitted in a direction orthogonal to a direction in which the light guide body extends. The support has a recess;
The light emitting element is provided on the bottom surface of the recess,
The optical device according to claim 3, wherein the wavelength conversion layer is provided in the recess so as to cover the light emitting element.

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