WO2018209925A1

WO2018209925A1 - Wavelength conversion device and preparation method therefor

Info

Publication number: WO2018209925A1
Application number: PCT/CN2017/114704
Authority: WO
Inventors: 田梓峰; 许颜正
Original assignee: 深圳市光峰光电技术有限公司
Priority date: 2017-05-19
Filing date: 2017-12-06
Publication date: 2018-11-22
Also published as: CN108954039B; CN108954039A

Abstract

Disclosed are a wavelength conversion device and a preparation method therefor. The wavelength conversion device comprises a light emitting layer, a reflecting layer, a connecting layer and a thermal conductive substrate layer which are provided in sequence. The light emitting layer is an aluminum oxide eutectic light emitting layer. The reflecting layer is a silver reflecting layer formed by sintering pure silver. According to the wavelength conversion device, the reflectivity and thermal conductivity of the reflecting layer are increased, and the adhesive force to the connecting layer is also improved, thus achieving high brightness and high reliability.

Description

Wavelength conversion device and preparation method thereof

Technical field

[0001] The present invention belongs to the technical field of luminescent materials, and in particular, to a wavelength conversion device and a method for fabricating the same.

[0002]

Background technique

[0003] At present, the laser fluorescence conversion type light source develops rapidly, and as the laser power increases, the heat dissipation requirement for the wavelength conversion layer is also continuously improved. The current wavelength conversion device is formed by the reflection layer being mixed and sintered by white scattering particles and glass powder. Diffuse reflective layer, this structure has high heat resistance.

technical problem

[0004] However, the thermal conductivity of the scattering particles and the glass powder of the sintered constituent material is low, and the sintered structure is generally a porous structure in order to ensure a high reflectance, and the thermal resistance is high, which is disadvantageous in that the wavelength conversion device is high. Improvement in luminance and stability of light emission under power laser excitation. Therefore, the reflective layer of the current wavelength conversion device is a bottleneck for further increasing the brightness of the laser fluorescent display source.

[0005] Therefore, in view of the above deficiencies, it is necessary to provide a new wavelength conversion device and a preparation method thereof to solve the problems of low reflectance and high thermal resistance in the prior art.

Problem solution

Technical solution

[0006] In order to overcome the deficiencies of the prior art, the problem of low reflectivity and high thermal resistance of the prior art is solved. The invention provides a novel reflective layer with high reflectivity, low thermal resistance and high long-term reliability. The wavelength conversion device using the reflective layer has higher luminous efficiency, higher brightness and still maintains good long-term reliability. The specific plan is as follows:

[0007] The present invention provides a wavelength conversion device comprising a light-emitting layer, a reflective layer, a connection layer and a heat-conducting substrate layer, which are sequentially disposed, the light-emitting layer is an aluminum oxide eutectic light-emitting layer, and the reflective layer is sintered by pure silver. A silver reflective layer.

[0008] Preferably, the alumina eutectic light-emitting layer is a eutectic light-emitting layer formed of garnet structure (Lu, Y, Gd, Tb) 3 (Ga, Al) ₅ 0 ₁₂ : Ce 3+ and alumina. . [0009] Preferably, the molar ratio of alumina in the eutectic light-emitting layer formed by the (Lu, Y, Gd, Tb) 3 (Ga, Al) ₅ 0 _12: Ce ³ + and alumina of the garnet structure is greater than 40%.

[0010] Preferably, an aluminum oxide film layer is disposed between the light emitting layer and the reflective layer.

[0011] Preferably, the thickness of the luminescent layer is 0.005-5 mm; the thickness of the reflective layer is 1-1 um; the thickness of the connecting layer is 0.005-0.5 mm; the thickness of the thermally conductive substrate is 0.1-5 mm .

[0012] Preferably, the connecting layer has a porosity of less than 50%.

[0013] Preferably, the connection layer is formed by reflow soldering of a solder paste or a preformed solder, and the solder paste is a combination of any one or more of gold tin, silver tin, antimony tin or lead tin.

[0014] Preferably, the connecting layer is formed by sintering a low-temperature sintered silver paste.

[0015] Preferably, the heat conductive substrate is a metal substrate or a ceramic substrate, and the heat conductive substrate is provided with a protective layer

[0016] Preferably, the thermally conductive substrate is a ceramic substrate of any one or more of aluminum nitride, silicon carbide, silicon nitride or aluminum oxide, between the ceramic substrate and the nickel-gold protective layer A titanium transition layer is provided.

[0017] Preferably, the thermally conductive substrate is a flat plate structure or a fin structure.

[0018] The present invention also provides a method for preparing a wavelength conversion device, comprising the following steps:

[0019] Step S1: providing Al ₂ 0 ₃ -(Lu, Y, Gd, Tb) ₃ (Ga, Al) ₅ 0 ₁₂ : Ce ³⁺

a eutectic luminescent material, and pretreating the Al ₂ 0 ₃ -(Lu, Y, Gd, Tb) ₃ (Ga, Al) ₅ 0 ₁₂ : Ce ^{3 +} eutectic luminescent material to form a eutectic luminescent layer;

[0020] Step S2: coating a mixed slurry of silver powder and an organic body on the eutectic light-emitting layer, and then sintering to form a reflective layer of pure silver;

[0021] Step S3: providing a nickel-plated gold-plated thermally conductive substrate, and the reflective layer formed in step S2 is disposed on the nickel-plated gold-plated thermally conductive substrate, and is processed to form a connection layer.

[0022] Preferably, the step of pre-S 1 comprises _{_{Al 2 0 3 - (Lu,}} Y, Gd, Tb) 3 (Ga, Al) 5 0 12: Ce 3+ luminescent material duplex eutectic abrasive polishing, One side is coated with an antireflection film or the surface is roughened.

[0023] Preferably, the particle size of the silver powder used in the step S2 is 0.01-20 um.

[0024] Preferably, the step S2 includes:

[0025] Step S21: pre-baking the eutectic light-emitting layer coated with the mixed slurry at 60-150 ° C to form a silver reflective layer preform layer; [0026] Step S22: The silver reflective layer preform layer obtained in step S21 is sintered in a high temperature furnace at 500-1000 ° C to form a silver reflective layer.

[0027] Preferably, the processing method of forming the connection layer in the step S3 is to apply a solder paste or a pre-formed soldering piece on the heat-conducting substrate, and place the reflective layer thereon, and reflow at 280-320 ° C. Welding forms a tie layer.

[0028] Preferably, the step S3 forms a connection layer by applying a nano silver paste on the heat conductive substrate, and placing the reflective layer thereon to perform sintering at 200-300 ° C.

Advantageous effects of the invention

Beneficial effect

[0029] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0030] Compared with the current porous diffuse reflection structure, the present invention adopts a silver reflective layer formed by sintering pure silver, improves the reflectivity of the reflective layer and the thermal conductivity, and oxidizes the alumina eutectic light-emitting layer by using the silver reflective layer. The high adhesion of the aluminum single crystal also solves the problem of adhesion between the silver reflective layer and the alumina eutectic light-emitting layer.

[0031] The alumina eutectic light-emitting layer used in the present invention has higher thermal conductivity and higher mechanical strength, and has higher reflectivity and higher thermal conductivity of the pure silver reflective layer, and the connection layer The adhesion is good, and thus the wavelength conversion device of this structure can achieve high efficiency and high brightness and high reliability.

The present invention will be further described with reference to the accompanying drawings and embodiments.

Brief description of the drawing

DRAWINGS

1 is a schematic structural view of a wavelength conversion device according to a first embodiment of the present invention;

2 is a flow chart showing a method of fabricating a wavelength conversion device according to a first embodiment of the present invention;

3 is a schematic structural view of a wavelength conversion device according to a second embodiment of the present invention.

Embodiments of the invention

The present invention provides a novel wavelength conversion device and a method for fabricating the same to solve the problems of low reflectance and high thermal resistance in the prior art.

[0037] Embodiment 1 [0038] Referring to FIG. 1, the wavelength conversion device provided by the present invention includes a light-emitting layer 1-1, a reflective layer 1-2, a connection layer 1-3, and a heat-conductive substrate layer 1-4 which are sequentially stacked.

[0039] wherein the light-emitting layer 1-1 is an aluminum oxide eutectic light-emitting layer, specifically in the embodiment, it is a garnet structure.

(Lu, Y, Gd, Tb) 3 (Ga, Al) ₅ 0 _12: a eutectic light-emitting layer of Ce ³ + with alumina. The molar ratio of alumina in the eutectic light-emitting layer of (L, Y, Gd, Tb) 3 (Ga, Al) ₅ 0 _12: Ce ³⁺ and alumina is more than 40%. The thickness of the light-emitting layer is 0.005 to 5 mm, preferably 0.05 to 0.5 mm. Further, an anti-reflection film may be disposed on the surface of the light-emitting layer or a surface roughening treatment may be performed to improve light extraction efficiency.

[0040] The reflective layer 1-2 is a silver reflective layer formed by coating a mixed slurry of pure silver silver powder and an organic carrier on an alumina eutectic light-emitting layer at a high temperature. The organic carrier in which the slurry is mixed is a volatile or decomposable substance, which is removed during high-temperature sintering, and the formed reflective layer 1-2 is a sintered pure silver structure. The thickness of the reflective layer is from 1 to 100 μm, preferably from 2 to 50 μm, and still more preferably from 5 to 20 μm. Wherein, the particle size of the silver powder in the mixed slurry is 0.01-20 μm, because the silver powder having a particle diameter smaller than O.Olum is not easily dispersed, and the surface roughness of the silver paste prepared by the silver powder having a particle diameter larger than 20 μm is not easily controlled, and The silver powder with larger particle size is less likely to be sintered densely on the eutectic luminescent layer, and the adhesion is deteriorated. Therefore, the size of the sintered particles is an important factor affecting the sintering activity. The smaller the particle size of the silver powder, the easier it is to oxidize. A dense silver reflective layer is formed on the aluminum eutectic light-emitting layer. Therefore, the preferred particle size range of the silver powder of the present embodiment can achieve both surface flatness and sintering compactness.

[0041] The particle shape of the silver powder is preferably spherical or flake-shaped, and the two shape particles are favorable for forming a close-packed structure, and the sintered silver reflective layer is denser; further, the silver powder may be mixed with metal powder of platinum or palladium, such that It can improve the high-temperature migration characteristics of silver, in which the content of palladium powder and platinum powder does not exceed 30%, otherwise the reflectance will be affected. The particle diameter selected in the present embodiment is most likely to form a reflective layer having a high reflectance.

[0042] The connection layer 1-3 is specifically a metal solder layer, mainly serves as a connection between the reflective layer 1-2 and the heat conductive substrate 1-4, and may specifically be solder paste such as gold tin, silver tin, antimony tin, lead tin or the like. The preformed soldering piece is formed by reflow soldering, and may also be formed by sintering a low-temperature sintered silver paste. The thickness of the connecting layer is 0.005 to 0.5 mm, and the porosity is less than 50%. Preferably, the porosity is less than 30%, and further less than 10%.

[0043] The heat conductive substrate 1-4 may be a metal substrate or a ceramic substrate, and the thickness of the heat conductive substrate is 0.1 to 5 mm. Further, a protective layer is provided on the heat conductive substrate. The protective layer is a nickel-plated gold protective layer. Metal base The plate is preferably a copper metal substrate. The ceramic substrate may be any one or a combination of a ceramic substrate such as aluminum nitride, silicon carbide, silicon nitride or aluminum oxide. When the heat conductive substrate 1-4 is a ceramic substrate, the surface of the ceramic substrate is plated with a Ti transition layer. (Titanium transition layer), and then a nickel-gold protective layer is plated, and the ceramic substrate is fixed by a Ti transition layer and a nickel-gold protective layer. The heat conductive substrate 1-4 may be a flat plate structure as shown in FIG. 1 or a fin structure, and may be implemented.

[0044] As described above, the reflective layer 1-2 is a silver reflective layer formed by coating a mixed slurry of silver powder and an organic carrier of pure silver on the alumina eutectic light-emitting layer at a high temperature, and the reflective layer of the germanium is not only very The high reflectivity also increases the adhesion to the metal solder layer because the high purity silver layer easily forms a metal oxide with the metal in the solder paste or the metal solder layer of the preform. The metal oxide can further form a reliable weld to increase the adhesion between the reflective layer and the tie layer.

[0045] Further, the reflective layer 1-2 can increase the adhesion to the light-emitting layer, since the reflective layer is sintered by pure silver, and the light-emitting layer is garnet structure (Lu, Y, Gd). , Tb) 3 (Ga, Al) ₅ 0 _12: Ce ³ + eutectic light-emitting layer formed with alumina, wherein the crystal structures of silver and aluminum oxide are hexagonal crystal structures, and the same crystal structure makes silver powder of pure silver and The mixed slurry of the organic carrier is coated on the alumina eutectic luminescent layer to form a higher temperature sintering enthalpy, which will form a tighter adhesion, and the adhesion between the reflective layer and the luminescent layer can be further improved.

[0046] As shown in FIG. 2, the method for fabricating the wavelength conversion device as described above includes the following steps:

[0047] Step S1: providing Al ₂ 0 ₃ -(Lu, Y, Gd, Tb) ₃ (Ga, Al) ₅ 0 ₁₂ : Ce ³⁺ eutectic luminescent material, and for A1 ₂ 0 3-(Lu, Y , Gd, Tb) ₃ (Ga, Al) ₅ 0 ₁₂ : Ce ³⁺ eutectic luminescent material is subjected to double-side grinding and polishing, and an antireflection coating or surface roughening pretreatment is performed on one side to form a eutectic luminescent layer;

[0048] Step S2: coating a mixed layer of silver powder and an organic body on the eutectic light-emitting layer, and then sintering to form a reflective layer of pure silver, specifically comprising:

[0049] Step S21: pre-baking the eutectic light-emitting layer coated with the mixed slurry at 60-150 ° C to form a silver reflective layer preform layer;

[0050] Step S22: The silver reflective layer preform layer obtained in step S21 is placed in a high temperature furnace at 500-1000 ° C to form a silver reflective layer.

[0051] Step S3: providing a nickel-plated gold-plated thermally conductive substrate, specifically in the embodiment, a copper substrate, applying a solder paste or a preformed soldering piece on the copper substrate, and placing one side of the light-emitting layer sintered with the silver reflective layer on the solder Paste above, on 2 Reflow soldering at 80~320 °C to form a metal solder layer.

In other optional embodiments, step S3 may also be: coating a copper substrate with a nano silver paste at 20 to 300 ° C to form a connection layer. Preferably, sintering can be carried out under pressure to lOMpa, which increases the density.

[0053] The silver powder used in the step S2 is pure silver, the particle size ranges from 0.01 to 20 um, the particles are spherical or flake, the organism is selected to be volatile or decomposable at a high temperature, and the drying in step S21 and the step S22 are performed. During the sintering process, the organism is removed to form a silver reflective layer.

Further, in the silver powder, a palladium or platinum metal powder having a content of not more than 30% may be used for improving the high-temperature migration property of silver.

[0055]

[0056] Embodiment 2

[0057] As shown in FIG. 3, the present embodiment is basically the same as the first embodiment, and the wavelength conversion device includes a light-emitting layer 2-1, a reflective layer 2-2, a connection layer 2-3, and a heat conductive substrate layer 2 4. The difference is that an aluminum oxide film layer 2-5 is further provided between the light-emitting layer 2-1 and the reflective layer 2-2.

As described above, since the crystal structures of the alumina and the silver layer are both hexagonal crystal structures, an additional arrangement of the aluminum oxide film layer can form a close adhesion with the silver reflective layer. At the same time, the aluminum oxide film layer and the aluminum oxide eutectic light-emitting layer can also form good adhesion. Therefore, compared with the first embodiment, the aluminum oxide film layer 2-5 in the present embodiment can be used to further improve the adhesion between the fluorescent layer and the silver reflective layer, and to enhance the adhesion between the light-emitting layer and the reflective layer.

Since the particle size of the silver particles is smaller, the sintering activity is high; therefore, by providing the aluminum oxide film 2-5, the particle diameter of the silver particles can be further reduced, and the sintering activity can be improved.

[0060] Compared with the prior art, the beneficial effects of the present invention are as follows:

Compared with the current porous diffuse reflection structure, the present invention adopts a silver reflective layer formed by sintering pure silver, improves the reflectivity of the reflective layer and the thermal conductivity, and oxidizes the alumina eutectic light-emitting layer by using the silver reflective layer. The high adhesion of the aluminum single crystal also solves the problem of adhesion between the silver reflective layer and the alumina eutectic light-emitting layer.

The alumina eutectic light-emitting layer used in the invention has higher thermal conductivity and higher mechanical strength, and has higher reflectivity and higher thermal conductivity of the pure silver reflective layer, and the connection layer Good adhesion, so this structure The wavelength conversion device can achieve high efficiency and high brightness and high reliability.

The above embodiments are merely preferred embodiments of the present invention, and the scope of the present invention is not limited thereto, and any insubstantial changes and substitutions made by those skilled in the art based on the present invention belong to the present invention. The scope of the claim.

Claims

Claim

A wavelength conversion device comprising a light-emitting layer, a reflective layer, a connection layer and a heat-conducting substrate layer, which are sequentially disposed, wherein the light-emitting layer is an aluminum oxide eutectic light-emitting layer, and the reflective layer is sintered by pure silver. A silver reflective layer.

The wavelength conversion device according to claim 1, wherein the alumina eutectic light-emitting layer is garnet-structured (Lu, Y, Gd, Tb) 3 (Ga, Al) ₅ 0 _12: Ce ³⁺ emission layer formed of a eutectic alumina.

3. The wavelength conversion device according to claim 2, wherein the garnet structure of (Lu, Y, Gd, Tb) 3 (Ga, Al) ₅ 0 _12: Ce ³⁺ is formed with alumina The molar ratio of alumina in the eutectic light-emitting layer is greater than 40%.

The wavelength conversion device according to claim 2, wherein an aluminum oxide film layer is provided between the light-emitting layer and the reflective layer.

The wavelength conversion device according to claim 2 or 4, wherein the light-emitting layer has a thickness of 0.005 to 5 mm; the reflective layer has a thickness of 1 - 100 μm; and the connection layer has a thickness of 0.005 - 0.5 mm; The heat conductive substrate has a thickness of 0.1 to 5 mm.

The wavelength conversion device according to claim 5, wherein the connection layer has a porosity of less than 50 < 3⁄4.

The wavelength conversion device according to claim 6, wherein the connection layer is formed by reflow soldering of a solder paste or a preform solder, and the solder paste is gold tin, silver tin, antimony tin or lead tin. Any combination of one or more.

The wavelength conversion device according to claim 6, wherein the connection layer is formed by sintering a low-temperature sintered silver paste.

The wavelength conversion device according to claim 6, wherein the heat conductive substrate is a metal substrate or a ceramic substrate, and a nickel gold protective layer is provided on the heat conductive substrate.

The wavelength conversion device according to claim 9, wherein the heat conductive substrate is a ceramic substrate of any one or more of aluminum nitride, silicon carbide, silicon nitride or aluminum oxide, A titanium transition layer is disposed between the ceramic substrate and the nickel gold protective layer.

The wavelength conversion device according to claim 8, wherein the heat conductive substrate It is a flat structure or a fin structure.

12. A method of preparing a wavelength conversion device, comprising the steps of: Step S1: providing Al ₂ 0 ₃ -(Lu, Y, Gd, Tb) ₃ (Ga, Al) ₅ 0 ₁₂ : Ce ³⁺ a eutectic luminescent material, and pretreating the Al ₂ 0 ₃ -(Lu, Y, Gd, Tb) ₃ (Ga, Al) ₅ 0 ₁₂ : Ce ^{3 +} eutectic luminescent material to form a eutectic luminescent layer;

Step S2: coating a mixed slurry of silver powder and an organic body on the eutectic light-emitting layer, and then sintering a reflective layer forming pure silver;

Step S3: providing a nickel-plated gold-plated heat-conducting substrate, and the reflective layer formed in step S2 is disposed on the nickel-plated gold-plated heat-conductive substrate, and is processed to form a connecting layer.

The method of manufacturing a wavelength conversion device according to claim 12, wherein the pre-processing of step S1 comprises: Al ₂ 0 ₃ -(Lu, Y, Gd, Tb) ₃ (Ga, Al) ₅ 0 ₁₂ : Ce ³⁺ eutectic luminescent material is polished on both sides by double-sided polishing or surface roughening.

The method of preparing a wavelength conversion device according to claim 12, wherein the particle size of the silver powder used in the step S2 is 0.01-20 um.

The method for preparing a wavelength conversion device according to claim 14, wherein the step S2 comprises:

Step S21: pre-baking the eutectic light-emitting layer coated with the mixed slurry at 60-150 ° C to form a silver reflective layer preform layer;

Step S22: placing the silver reflective layer preform layer obtained in step S21 in a high temperature furnace 500-1000

The sintering at °C forms a silver reflective layer.

The method of manufacturing the wavelength conversion device according to claim 12, wherein the step of forming the connection layer in the step S3 is to apply a solder paste or a pre-formed soldering piece on the thermally conductive substrate, and to reflect A layer was placed thereon and reflow soldered at 280-320 ° C to form a tie layer.

The method of manufacturing a wavelength conversion device according to claim 12, wherein the step S3 forms a connection layer by applying a nano silver paste on the thermally conductive substrate, and placing a reflective layer thereon. Sintering is carried out at 200-300 °C.