JP6753202B2 - Fluorescent light source device - Google Patents

Description

The present invention relates to a fluorescent light source device. More specifically, the present invention relates to a reflection type fluorescence light source device including a fluorescence plate in which an excitation light incident surface and a fluorescence emitting surface are formed on the same surface.

Conventionally, as a kind of fluorescence light source device, a phosphor constituting the fluorescence layer of the fluorescence plate is excited by irradiating one surface of the fluorescence plate with laser light as excitation light, and fluorescence is emitted from the one surface. A reflective type with a structure is known.
In such a reflection type fluorescence light source device, a fluorescence plate provided with a reflection layer made of a metal such as aluminum, silver, and gold on the opposite side of the fluorescence layer on the side opposite to the excitation light incident side is used. (See, for example, Patent Document 1.).
Then, in the fluorescent light source device of Patent Document 1, in order to increase the brightness, the refractive index between the fluorescent layer and the reflective layer is smaller than that of the constituent material of the fluorescent layer, and the constituent material of the fluorescent layer is used. A total reflection film made of a material having a refractive index difference of 0.2 or more is provided in a state of being in direct contact with the fluorescent layer. The total reflection film is made of, for example, magnesium fluoride (MgF ₂ ). Further, between the fluorescent layer and the reflective layer, specifically, between the total reflective film and the reflective layer, a reflective layer made of an optical multilayer film and, if necessary, a protective film made of a metal oxide are provided. It is laminated.

On the other hand, it is known that a reflective mirror used for an optical system such as a flat panel display or a projector has a reflective layer made of metal formed on a resin substrate, and the reflective layer has a high reflectance. It is made of silver having (see, for example, Patent Document 2).

Japanese Unexamined Patent Publication No. 2015-50124 Japanese Unexamined Patent Publication No. 2008-260978

However, it has been clarified that in a fluorescence light source device in which a reflection layer is provided on a fluorescence plate, various problems occur when the reflection layer is made of silver.
More specifically, there is a problem that the reflective layer is oxidatively deteriorated and the reflectance of the reflective layer is lowered. According to the diligent research of the present inventors, such a problem is remarkable when the fluorescent plate has a constituent layer made of an oxide, particularly when the constituent layer made of an oxide is in direct contact with the reflective layer. It became clear that Further, there is also a problem that sufficient adhesion to the fluorescent layer cannot be obtained, and thus the reflective layer is peeled off.

The present invention has been made based on the above circumstances, and an object of the present invention is a fluorescent light source in which a high reflectance is obtained in the reflective layer for a long period of time and the occurrence of peeling of the reflective layer is suppressed. To provide the device.

The fluorescence light source device of the present invention is a fluorescence light source device including a fluorescence plate in which an excitation light incident surface and a fluorescence emitting surface are formed of the same surface.
In the fluorescent plate, a fluorescent layer made of polycrystalline material, a first oxide layer, and a reflective layer made of silver are laminated in this order.
A first protective layer is provided between the first oxide layer and the reflective layer.
The first protective layer is made of a translucent material made of nitride or fluoride , and is an adhesive layer that covers the first oxide layer, the first protective layer, and the reflective layer. Is provided,
The adhesive layer is provided in a state of being adhered to the fluorescent layer .

In the fluorescent light source device of the present invention, the first oxide layer is an oxide multilayer film composed of an oxide monolayer film made of alumina, a first constituent layer made of silicon dioxide, and a second constituent layer made of titania. It is preferably composed of at least one of the membranes.

The fluorescence light source device of the present invention is a fluorescence light source device including a fluorescence plate in which an excitation light incident surface and a fluorescence emitting surface are formed of the same surface.
In the fluorescent plate, a fluorescent layer, a first oxide layer, and a reflective layer made of silver are laminated in this order.
A first protective layer is provided between the first oxide layer and the reflective layer.
The second oxide layer is laminated on the surface side of the reflective layer opposite to the surface on which the fluorescent layer, the first oxide layer and the first protective layer are laminated.
A second protective layer is provided between the second oxide layer and the reflective layer.
The first protective layer is made of a translucent material made of nitride or fluoride.
The second protective layer is characterized by being composed of an oxygen atom-free material made of a material containing no oxygen atom in its molecular structure.

In fluorescence light source device of the present invention, an oxygen atom-free material constituting the second protective layer is magnesium fluoride, silicon nitride, aluminum nitride, aluminum, is preferably made of any material of chromium and nickel.

In the fluorescent light source device of the present invention, since the first oxide layer and the first protective layer are provided between the fluorescent layer and the reflective layer in the fluorescent plate, the reflective layer is made of silver. However, high adhesion can be obtained between the fluorescent layer and the reflective layer. Further, since the first protective layer is disposed between the first oxide layer and the reflective layer, and the first protective layer is made of a translucent material made of nitride or fluoride, Even if the fluorescent plate has a first oxide layer, it is possible to prevent oxidative deterioration of the reflective layer due to the provision of the first oxide layer.
Further, since the fluorescent layer is composed of polycrystals, the thermal conductivity of the fluorescent layer can be improved.
Further, since the adhesive layer provided so as to cover each of the first oxide layer, the first protective layer, and the reflective layer is adhered to the fluorescent layer, the first oxide layer and the first protective layer The reflective layer can be sealed together with the fluorescent layer and the adhesive layer, and the occurrence of oxidative deterioration and peeling of the reflective layer can be further suppressed.
Therefore, according to the fluorescent light source device of the present invention, a high reflectance can be obtained in the reflective layer for a long period of time, and the occurrence of peeling of the reflective layer is suppressed.

In the fluorescent light source device of the present invention, the first oxide layer is an oxide monolayer film made of alumina, and an oxide multilayer film composed of a first constituent layer made of silicon oxide and a second constituent layer made of titania. The fluorescent plate has more excellent properties when it is composed of at least one of the above.

In the fluorescent light source device of the present invention, the second oxide layer and the oxygen atom-free material are placed on the surface side of the reflective layer opposite to the surface on which the fluorescent layer, the first oxide layer and the first protective layer are laminated. By providing the second protective layer composed of the above in this order, even if the fluorescent plate has the second oxide layer, the reflective layer is caused by the provision of the second oxide layer. It is possible to prevent oxidative deterioration of.

It is explanatory drawing which shows the outline of an example of the structure of the fluorescent light source device of this invention. It is explanatory drawing which shows the specific structure of the fluorescence light emitting member in the fluorescence light source apparatus of FIG. It is a graph which shows the result of the linear reflectance measurement obtained in Experimental Example 1.

Hereinafter, embodiments of the fluorescent light source device of the present invention will be described.
FIG. 1 is an explanatory view showing an outline of an example of the configuration of the fluorescence light source device of the present invention, and FIG. 2 is an explanatory exploded view showing a specific configuration of the fluorescence light emitting member in the fluorescence light source device of FIG. ..
As shown in FIG. 1, the fluorescence light source device 10 includes, for example, an excitation light source 11 made of a semiconductor laser and a fluorescence light emitting member 20 having a fluorescence plate 21 that emits fluorescence by excitation light from the excitation light source 11. Are arranged apart from each other.
In the example of this figure, the fluorescence light emitting member 20 is arranged in an inclined posture with respect to the optical axis of the excitation light source 11 so as to face the excitation light source 11.

The fluorescence light emitting member 20 has a flat plate-shaped fluorescent plate 21 arranged on the surface (upper surface in FIG. 1) of the flat plate-shaped heat radiating substrate 24, and is located between the heat radiating substrate 24 and the fluorescent plate 21. , A rectangular flat plate-shaped joint member layer 28 is formed. That is, the fluorescent plate 21 and the heat radiating substrate 24 are joined by the joining member layer 28. Further, the fluorescence light emitting member 20 is arranged so that the surface of the fluorescence plate 21 (upper surface in FIG. 1) faces the excitation light source 11, and the surface of the fluorescence plate 21 is an excitation light incident surface. It is also used as a fluorescent emission surface. That is, in the fluorescence plate 21, the excitation light incident surface and the fluorescence emitting surface are formed by the same surface.

In the fluorescent plate 21, as shown in FIG. 2, a flat plate-shaped fluorescent layer 22, a flat plate-shaped first oxide layer 33, and a thin-film reflective layer 31 made of silver are laminated in this order. It was provided. In the fluorescent plate 21, the surface of the fluorescent layer 22 (upper surface in FIG. 2) constitutes the surface of the fluorescent plate 21, that is, the excitation light incident surface and the fluorescent emitting surface of the fluorescent plate 21, and the back surface of the fluorescent layer 22. The first oxide layer 33 and the reflective layer 31 are provided in this order on the (lower surface in FIG. 2) side.
In the example of this figure, the fluorescent plate 21 has a first oxide layer 33 and a reflective layer 31 on the back surface side of the fluorescent layer 22, and a first protective layer 32A, a second protective layer 32B and a second oxide described later. An adhesive layer 42 and a sealing layer 41 are provided so as to cover the layer 37. Specifically, on the back surface of the fluorescent layer 22, a laminated body in which the first oxide layer 33, the first protective layer 32A, the reflective layer 31, the second protective layer 32B, and the second oxide layer 37 are laminated in this order ( Hereinafter, it is also referred to as “reflective laminate”), and the sealing layer 41 is adhered to the reflective laminate and the fluorescent layer 22 by the adhesive layer 42 so as to cover the reflective laminate. It is provided in a state. That is, the fluorescent layer 22, the adhesive layer 42, and the sealing layer 41 form a sealing structure of the reflective laminate.
Further, on the back surface of the sealing layer 41 (lower surface in FIG. 2), a stress relaxation layer 43, a gold layer 45, a diffusion prevention layer 46, and a solder wet film layer 47 are provided in this order. The stress relaxation layer 43 is made of a multilayer film having a titanium layer 43A and a platinum layer 43B.

The fluorescent layer 22 is made of a polycrystal containing a phosphor, specifically, a mixed sintered body of a phosphor and a metal oxide such as alumina (Al ₂ O ₃ ).
Since the fluorescent layer 22 is made of a polycrystalline material, the fluorescent layer 22 has high thermal conductivity.

Specific examples of the polycrystals constituting the fluorescent layer 22 include Al ₂ O ₃ / YAG: Ce, Al ₂ O ₃ / YAG: Pr, Al ₂ O ₃ / YAG: Sm, Al ₂ O ₃ / LuAG: Ce. And so on. In these polycrystalline phosphors, the doping amount of the rare earth element (activator) is about 0.5 mol%.
In the example of this figure, the fluorescent layer 22 is made of a mixed sintered body (polycrystal) of a YAG-based phosphor and alumina.

The polycrystals constituting the fluorescent layer 22 can be obtained, for example, by the following method.
First, raw materials (specifically, base material, activator, firing aid and metal oxide (specifically, for example, alumina (Al ₂ O ₃ )) are pulverized by using a ball mill or the like to sub-process. A raw material fine powder of micron or less is obtained. Then, the obtained raw material fine powder and an organic solvent are used to prepare a slurry in which the raw material fine powder is uniformly dispersed in the organic solvent.
Next, a green sheet having a predetermined thickness is produced from the obtained slurry by the doctor blade method, and the green sheet is fired to obtain a sintered body. Then, by subjecting the obtained sintered body to hot isotropic pressure processing, a polycrystal having a porosity of 0.5% or less can be obtained.

The thickness of the fluorescent layer 22 is preferably 0.05 to 2.0 mm from the viewpoint of effective use of excitation light and heat dissipation.
In the example of this figure, the thickness of the fluorescent layer 22 is 0.10 mm.

The first oxide layer 33 has a first configuration made of an oxide single layer film (hereinafter, also referred to as “specific single layer film”) 34 made of alumina (Al ₂ O ₃ ) and silicon dioxide (SiO ₂ ). It is preferably composed of at least one of an oxide multilayer film (hereinafter, also referred to as “specific multilayer film”) 35 composed of a second constituent layer 35B composed of layer 35A and titania (TiO ₂ ).
By forming the first oxide layer 33 with at least one of the specific single layer film 34 and the specific multilayer film 35, the fluorescent plate 21 has more excellent characteristics.
Specifically, according to the fact that the first oxide layer 33 has the specific single layer film 34, the specific single layer film 34 has excellent weather resistance, so that the surface of the reflective layer 31 (Upper surface in FIG. 2) is exposed to moisture that has penetrated into the inside of the fluorescent plate 21 via the constituent layers (specifically, the specific multilayer film 35 and the fluorescent layer 22) laminated on the surface side of the reflective layer 31. It can be prevented or sufficiently suppressed.
On the other hand, according to the fact that the first oxide layer 33 has the specific multilayer film 35, the specific multilayer film 35 acts as a hyperreflective film, so that the reflectance of the fluorescent plate 21 (specifically, fluorescence). Since the reflectance on the back surface of the layer 22) can be increased, the fluorescent plate 21 has even more excellent high reflection performance.
In the example of this figure, the first oxide layer 33 is composed of a specific single layer film 34 and a specific multilayer film 35, and the specific single layer film 34 is arranged on the reflective layer 31 side (lower side in FIG. 2). The specific multilayer film 35 is provided on the fluorescent layer 22 side (upper side in FIG. 2).

The thickness of the first oxide layer 33 is appropriately determined by the configuration of the first oxide layer 33.
Specifically, for example, when the first oxide layer 33 is composed of the specific single layer film 34, the thickness is 5 to 15 nm, and the first oxide layer 33 is composed of the specific multilayer film 35. When it becomes, it is set to 80 to 100 nm. Further, when the first oxide layer 33 is composed of the specific single layer film 34 and the specific multilayer film 35, the thickness is 85 to 115 nm.
In the example of this figure, the thickness of the first oxide layer 33 is 85 to 115 nm. That is, the thickness of the specific monolayer film 34 is 5 to 15 nm, and the thickness of the specific multilayer film 35 is 80 to 100 nm. In the specific multilayer film 35, the thickness of the first constituent layer 35A is 10 nm, and the thickness of the second constituent layer 35B is 40 nm.

The reflective layer 31 is made of silver. Specifically, it is composed of a silver reflective film or a silver alloy reflective film mainly composed of silver.
Since the reflective layer 31 is made of silver, silver has high reflection characteristics, so that the fluorescent plate 21 (specifically, the back surface of the fluorescent layer 22) has high reflection performance. To.

The thickness of the reflective layer 31 is, for example, 110 to 350 nm.
Further, the area of the front surface of the reflective layer 31 is preferably equal to or less than the area of the back surface of the fluorescent layer 22 from the viewpoint of effective utilization of excitation light and fluorescence.
In the example of this figure, the thickness of the reflective layer 31 is 130 nm. Further, the front surface of the reflective layer 31 has a dimension slightly smaller than the dimension of the back surface of the fluorescent layer 22, and the entire surface thereof faces the central portion of the back surface of the fluorescent layer 22.

The fluorescent plate 21 is provided with a thin-film first protective layer 32A between the first oxide layer 33 and the reflective layer 31 together with the fluorescent layer 22, the first oxide layer 33, and the reflective layer 31. ing. The first protective layer 32A is made of a translucent material made of nitride or fluoride, and has translucency to excitation light and fluorescence. The first protective layer 32A has a function of protecting the reflective layer 31 from oxidation. Specifically, it does not allow oxygen to permeate and does not release oxygen.
By providing the first protective layer 32A, in the reflective layer 31 made of silver (specifically, the surface of the reflective layer 31), compounds such as silver sulfide, silver oxide and silver hydroxide can be used. Generation can be prevented. Therefore, it is possible to suppress a decrease in the reflectance of the reflective layer 31. Therefore, even if the fluorescent plate 21 has an oxide layer (specifically, the first oxide layer 33), the surface of the reflection layer 31 is oxygen released from the oxide layer and is reflected. It is not exposed to oxygen that has entered the inside of the fluorescent plate 21 via the constituent layers (specifically, the fluorescent layer 22 and the first oxide layer 33) laminated on the surface side of the layer 31. As a result, oxidative deterioration of the reflective layer 31 can be prevented.
Here, since the first protective layer 32A is composed of a translucent material made of nitride or fluoride, the compound such as silver sulfide, silver oxide and silver hydroxide in the reflective layer 31 The reason why the generation can be prevented will be explained. The translucent material constituting the first protective layer 32A is preferably a material other than an oxide and is not amorphous (amorphous) but crystalline. According to the fact that the translucent material is other than the oxide, oxygen is not released from the first protective layer 32A, and the oxygen partial pressure during the film formation of the reflective film can be reduced. Oxidation of the reflective layer 31 can be prevented. Further, according to the fact that the translucent material is crystalline, since the first protective layer 32A is dense, the first protective layer 32A does not contain water, and oxygen and sulfur from the outside are not contained. , Water and the like, and oxygen from the first oxide layer 33, particularly diffusion of water in silicon dioxide (SiO ₂ ) constituting the first constituent layer 35A to the reflecting layer 31 can be further prevented. It becomes a thing. Therefore, by forming the first protective layer 32A with a translucent material made of nitride or fluoride, which is not an oxide and is crystalline, the silver constituting the reflective layer 31 is oxygen and sulfur. , Can be prevented from reacting with water.

Further, as shown in FIG. 2, according to the provision of the first protective layer 32A in a state of being in direct contact with the reflective layer 31, the reflective layer 31 is high as is clear from the experimental examples described later. The reflectance is obtained.

Examples of the nitride used as the translucent material constituting the first protective layer 32A include metal nitrides such as aluminum nitride (AlN) and silicon nitride (Si ₃ N ₄ ).
Further, examples of the fluoride used as the translucent material constituting the first protective layer 32A include metal fluorides such as magnesium fluoride (MgF ₂ ).
As described above, the translucent material constituting the first protective layer 32A includes magnesium fluoride (MgF ₂ ) and silicon nitride from the viewpoint of preventing oxygen release and infiltration of oxygen, sulfur, water and the like. (Si ₃ N ₄ ) and aluminum nitride (AlN) are preferable.
In the example of this figure, the first protective layer 32A is composed of magnesium fluoride (MgF ₂ ).

The thickness of the first protective layer 32A is preferably 1 to 80 nm. More preferably, it is 40 to 80 nm. When the thickness of the first protective layer 32A is 40 to 80 nm, it is possible to prevent the silver constituting the reflective layer 31 from reacting with oxygen, sulfur, water and the like.
Further, the area of the back surface (lower surface in FIG. 2) of the first protective layer 32A is preferably the same as the area of the front surface of the reflective layer 31 from the viewpoint of protecting the reflective layer 31.
In the example of this figure, the thickness of the first protective layer 32A is 40 nm. Further, the back surface of the first protective layer 32A has the same dimensions as the surface of the reflective layer 31, and the first protective layer 32A covers the entire surface of the reflective layer 31.

Further, as shown in FIG. 2, the fluorescent plate 21 has a reflective layer 31 on the opposite side of the surface on which the first protective layer 32A, the first oxide layer 33 and the fluorescent layer 22 are laminated, that is, reflection. A second oxide layer 37 is laminated on the back surface side (lower surface side in FIG. 2) of the layer 31, and a second protective layer 32B is provided between the second oxide layer 37 and the reflective layer 31. It is preferable to have. That is, in the fluorescent plate 21, when the second oxide layer 37 is provided on the back surface side of the reflective layer 31, the second protective layer 32B is interposed between the second oxide layer 37 and the reflective layer 31. Is preferable. The second protective layer 32B is made of an oxygen atom-free material made of a material that does not contain oxygen atoms in its molecular structure, and has a function of protecting the reflective layer 31 from oxidation. Specifically, it does not allow oxygen to permeate and does not release oxygen.
According to the provision of the second protective layer 32B, even if the fluorescent plate 21 has an oxide layer (specifically, the second oxide layer 37), the back surface of the reflective layer 31 is formed. It is not exposed to oxygen released from the oxide layer. As a result, oxidative deterioration of the reflective layer 31 can be prevented.

The second protective layer 32B may be transparent to excitation light and fluorescence, or may be non-transparent.

The oxygen atom-free material constituting the second protective layer 32B is preferably made of fluoride, nitride or metal.
Specifically, the oxygen atom-free material is any one of magnesium fluoride (MgF2), silicon nitride (Si3 N4), aluminum nitride (AlN), aluminum (Al), chromium (Cr) and nickel (Ni). It is preferably made of a material .
Oxygen-free material, magnesium fluoride (MgF2), silicon nitride (Si3 N4), aluminum nitride (AlN), aluminum (Al), by made of any material of chromium (Cr) and nickel (Ni) , The reflective layer 31 (specifically, the back surface of the reflective layer 31) is not exposed to oxygen released from the oxide layer (specifically, the second oxide layer 37).
In the example of this figure, the second protective layer 32B is composed of magnesium fluoride (MgF2).

The thickness of the second protective layer 32B is preferably 1 to 30 nm.
Further, the area of the front surface (upper surface in FIG. 2) of the second protective layer 32B is preferably the same as the area of the back surface of the reflective layer 31 from the viewpoint of protecting the reflective layer 31.
In the example of this figure, the front surface of the second protective layer 32B has the same dimensions as the back surface of the reflective layer 31, and the second protective layer 32B covers the entire back surface of the reflective layer 31. There is.

The second oxide layer 37 is preferably made of a metal oxide.
Specifically, the second oxide layer 37 is preferably composed of a metal oxide monolayer film (specific monolayer film) made of alumina (Al ₂ O ₃ ).
Since the second oxide layer 37 is composed of the specific monolayer film, the specific monolayer film has excellent weather resistance, so that the back surface of the reflective layer 31 is exposed to moisture. Can be prevented or sufficiently suppressed.
In the example of this figure, the second oxide layer 37 is composed of a metal oxide single layer film made of alumina (Al ₂ O ₃ ).

The thickness of the second oxide layer 37 is appropriately determined depending on the material of the second oxide layer 37.
Specifically, for example, when the second oxide layer 37 is composed of a metal oxide single layer film, that is, when the material of the second oxide layer 37 is alumina, the thickness is 5 to 30 nm. ..
In the example of this figure, the thickness of the second oxide layer 37 is 20 nm.

The heat radiating substrate 24 has a function of exhausting heat generated in the fluorescent plate 21 (fluorescent layer 22).
The heat radiating substrate 24 is preferably made of a material having high thermal conductivity and having a small difference in thermal expansion coefficient from the fluorescent plate 21 (constituent material (polycrystal) of the fluorescent layer 22).

As a constituent material of the heat radiating substrate 24, a metal such as copper (Cu) and an alloy of molybdenum and copper (Mo—Cu) is used.
Here, the coefficient of thermal expansion of copper used as a constituent material of the heat dissipation substrate 24 is 16.5 × 10 ^-6 [1 / K], and the alloy of molybdenum and copper (copper (Cu) content ratio 30% by mass). ) Has a coefficient of thermal expansion of 8.6 × 10 ^-6 [1 / K]. On the other hand, the coefficient of thermal expansion of YAG used as a constituent material of the fluorescent layer 22 is 8.6 × 10 ^-6 [1 / K].
In the example of the figure, the heat radiating substrate 24 is made of copper.

The thickness of the heat radiating substrate 24 may be appropriately determined in consideration of the heat radiating characteristics, and is, for example, 0.5 to 5.0 mm.
Further, as shown in FIGS. 1 and 2, the area of the front surface of the heat radiating substrate 24 is preferably larger than the area of the back surface of the fluorescent plate 21 from the viewpoint of heat dissipation and the like.
Further, the heat radiating substrate 24 may also have a function of heat radiating fins.
In the example of this figure, the thickness of the heat radiating substrate 24 is 0.5 to 4 mm.

Further, on the heat radiating substrate 24, as shown in FIG. 2, a protective film layer 25 and a solder wet film layer 26 are formed on the surface of the heat radiating substrate 24 from the viewpoint of bondability with the bonding member layer 28. It is preferable that metal films laminated in order are formed.
In the example of this figure, the heat radiating substrate 24 is formed by covering the entire outer surface (front surface, back surface, and peripheral side surface) with a metal film composed of a protective film layer 25 and a solder wet film layer 26. The thickness of each layer constituting this metal film is 2.5 μm for the protective film layer 25 and 0.03 μm for the solder wet film layer 26.

As the joining member constituting the joining member layer 28, it is preferable to use tin-containing solder from the viewpoint of heat exhaust property and low stress property.
Specific examples of tin-containing solder used as a joining member include, for example, a gold-tin alloy (AuSn, tin (Sn) content ratio of 20% by mass, thermal conductivity 250 W / mk) and a tin-silver-copper alloy (Sn). -3Ag-0.5Cu (silver (Ag) content 3% by mass, copper (Cu) content 0.5% by mass, tin (Sn) content 96.5% by mass), thermal conductivity 55W / mk) and the like.
The thickness of the joining member layer 28 is, for example, 30 μm.
In the example of this figure, as a method of joining the fluorescent plate 21 and the heat radiating substrate 24 by the joining member, for example, a reflow furnace is used, and a flux-free solder sheet (joining member) is placed between the fluorescent plate 21 and the heat radiating board 24. A reflow method is used in which sandwiching and heating are performed in an atmosphere of formic acid gas or hydrogen gas. As described above, according to the bonding method in which the surface oxide film of the flux-free solder sheet is removed by utilizing the reducing force of formic acid or hydrogen and reflow is performed, voids do not occur in the formed bonding member layer 28. Good thermal conductivity can be obtained.

In the fluorescence light source device 10 having such a configuration, the excitation light emitted from the excitation light source 11 irradiates the surface (excitation light incident surface) of the fluorescence plate 21 in the fluorescence light emitting member 20 and is incident on the fluorescence plate 21. .. Then, in the fluorescent plate 21, the phosphor constituting the fluorescent layer 22 is excited. As a result, fluorescence is emitted from the phosphor in the fluorescent layer 22. This fluorescence is emitted to the outside from the surface (fluorescence emission surface) of the fluorescence plate 21 together with the excitation light reflected by the reflection layer 31 on the back surface of the fluorescence layer 22 without being absorbed by the phosphor, and is emitted to the outside of the fluorescence light source device 10. It is emitted.

Therefore, in the fluorescence light source device 10, the first oxide layer 33 and the first protective layer 32A are provided between the fluorescence layer 22 and the reflection layer 31 in the fluorescence plate 21, so that the fluorescence light source device 10 is concerned. Even if the reflective layer 31 is made of silver having low adhesion to the fluorescent layer 22, high adhesion can be obtained between the fluorescent layer 22 and the reflective layer 31. Further, the first protective layer 32A is disposed between the first oxide layer 33 and the reflective layer 31, and the first protective layer 32A is made of a translucent material made of nitride or fluoride. Since the fluorescent plate 21 does not permeate oxygen and does not release oxygen, even if the fluorescent plate 21 has the first oxide layer 33, it is caused by the provision of the first oxide layer 33. , Oxidative deterioration of the reflective layer 31 can be prevented.
Therefore, according to the fluorescent light source device 10, high reflectance can be obtained in the reflective layer 31 for a long period of time, and the occurrence of peeling of the reflective layer 31 is suppressed.

Further, in the fluorescence light source device 10, since the first oxide layer 33 is composed of the specific single layer film 34 and the specific multilayer film 35, it is possible to prevent the surface of the reflective layer 31 from being exposed to moisture. Alternatively, it can be sufficiently suppressed, and the fluorescent plate 21 has even more excellent high reflection performance.

Further, in the fluorescent light source device 10, the fluorescent plate 21 is provided with the second oxide layer 37 and the second protective layer 32B between the second oxide layer 37 and the reflection layer 31. It is possible to prevent oxidative deterioration of the reflective layer 31 due to the provision of the second oxide layer 37.

In the above, the fluorescent light source device of the present invention has been described with reference to specific examples, but the fluorescent light source device of the present invention is not limited thereto.
For example, the fluorescent plate may have a periodic structure in which a plurality of convex portions are periodically arranged on the surface of the fluorescent plate. Here, the periodic structure of the surface of the fluorescent plate is, for example, a structure in which convex portions having a substantially conical shape (specifically, a conical shape or a frustum shape) are densely arranged in a two-dimensional periodic manner. When the fluorescent plate has a periodic structure on its surface, the fluorescent plate has a periodic structure layer having light transmission to excitation light and fluorescence on the surface of the fluorescent layer from the viewpoint of ease of manufacture. Is preferably laminated.

Further, the structure of the entire fluorescent light source device is not limited to that shown in FIG. 1, and various configurations can be adopted. For example, in the fluorescence light source device according to FIG. 1, the light of one excitation light source (for example, a semiconductor laser) is used, but there are a plurality of excitation light sources, and a condenser lens is arranged in front of the fluorescence light emitting member to collect light. It may be in the form of irradiating the fluorescent light emitting member with light. Further, the excitation light is not limited to the light emitted by the semiconductor laser, and as long as it can excite the phosphor in the fluorescent plate, the light emitted by the LED may be condensed, and mercury, xenone, etc. may be used. It may be light from an enclosed lamp. When a light source having a width in the radiation wavelength such as a lamp or an LED is used, the wavelength of the excitation light is in the region of the main radiation wavelength. However, the present invention is not limited to this.

Hereinafter, experimental examples of the present invention will be described.

<Experimental Example 1>
An experimental reflective laminate (hereinafter, also referred to as "reflective laminate A") in which a metal oxide layer made of alumina (Al ₂ O ₃ ) was formed on each of the front surface and the back surface of the reflective film made of silver was prepared. ..
Further, in the reflective laminate A, except that a metal fluoride layer made of magnesium fluoride (MgF ₂ ) was prepared instead of the metal oxide layer made of alumina (Al ₂ O ₃ ). An experimental reflective laminate having the same configuration as that of the above (hereinafter, also referred to as “reflective laminate B”) was produced. That is, the reflective laminate B has a magnesium fluoride (MgF ₂ ) metal fluoride layer formed on each of the front surface and the back surface of the reflective film made of silver.
Then, linear reflectance was measured by irradiating each of the produced reflective laminate A and reflective laminate B with light under light irradiation conditions at a light incident angle of 5 °, and the spectral reflectance was measured. Results are shown in FIG. In FIG. 3, the spectral reflectance of the reflective laminate A is shown by a broken line, and the spectral reflectance of the reflective laminate B is shown by a solid line.

From the results shown in FIG. 3, the average reflectance of light having a wavelength of 435 to 660 nm of the reflective laminate A is 96.8%, while the average reflectance of light having a wavelength of 435 to 660 nm of the reflective laminate B is average. The value was 97.7%, and it was confirmed that the reflectance of the reflective laminate B was about 1% higher than the reflectance of the reflective laminate A.
From this result, by providing a protective layer that does not allow oxygen to permeate and does not release oxygen on each of the front and back surfaces of the reflection layer made of silver instead of the oxide layer, the fluorescence power from the fluorescence plate with respect to the excitation power can be obtained. It was revealed that the external quantum efficiency, which is a ratio, increased from 65% to 68.3% and became 3.3% brighter.
Further, it was found that in the configuration of the reflective laminate B, which is the configuration of the present invention, high reflectance can be maintained for a long period of time without peeling of the reflective layer made of silver.

10 Fluorescent light source device 11 Excitation light source 20 Fluorescent light emitting member 21 Fluorescent plate 22 Fluorescent layer 24 Heat dissipation substrate 25 Protective film layer 26 Solder wet film layer 28 Bonding member layer 31 Reflective layer 32A First protective layer 32B Second protective layer 33 First oxidation Material layer 34 Oxide monolayer film (specific monolayer film)
35 Oxide multilayer film (specific multilayer film)
35A 1st constituent layer 35B 2nd constituent layer 37 2nd oxide layer 41 Sealing layer 42 Adhesive layer 43 Stress relaxation layer 43A Titanium layer 43B Platinum layer 45 Gold layer 46 Diffusion prevention layer 47 Solder wet film layer

Claims (4)

In a fluorescence light source device including a fluorescence plate in which an excitation light incident surface and a fluorescence emitting surface are formed on the same surface.
In the fluorescent plate, a fluorescent layer made of polycrystalline material, a first oxide layer, and a reflective layer made of silver are laminated in this order.
A first protective layer is provided between the first oxide layer and the reflective layer.
The first protective layer is made of a translucent material made of nitride or fluoride , and is an adhesive layer that covers the first oxide layer, the first protective layer, and the reflective layer. Is provided,
A fluorescent light source device characterized in that the adhesive layer is provided in a state of being adhered to the fluorescent layer . The first oxide layer is composed of at least one of an oxide single layer film made of alumina and an oxide multilayer film made of a first constituent layer made of silicon dioxide and a second constituent layer made of titania. The fluorescent light source device according to claim 1. In a fluorescence light source device including a fluorescence plate in which an excitation light incident surface and a fluorescence emitting surface are formed on the same surface.
In the fluorescent plate, a fluorescent layer, a first oxide layer, and a reflective layer made of silver are laminated in this order.
A first protective layer is provided between the first oxide layer and the reflective layer.
The second oxide layer is laminated on the surface side of the reflective layer opposite to the surface on which the fluorescent layer, the first oxide layer and the first protective layer are laminated.
A second protective layer is provided between the second oxide layer and the reflective layer.
The first protective layer is made of a translucent material made of nitride or fluoride.
The second protective layer is a fluorescence light source device characterized in that it is made of an oxygen atom-free material made of a material that does not contain oxygen atoms in its molecular structure. The fluorescent light source according to claim 3, wherein the oxygen atom-free material constituting the second protective layer is made of any compound of magnesium fluoride, silicon nitride, aluminum nitride, aluminum, chromium and nickel. apparatus.

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