Wavelength converter and preparation method thereof
Technical field
The invention belongs to luminescent material technical fields more particularly to a kind of Wavelength converter and preparation method thereof.
Background technique
Laser fluorescence conversion hysteria light source development at present is very fast, with the raising of laser power, for dissipating for wavelength conversion layer
Heat request is also continuously improved, and current Wavelength converter is reflecting layer using white scattering particles and glass powder mixed sintering shape
At diffusing reflection layer, this structure heat resistance is higher, but its be sintered composition material scattering particles and glass powder thermal conductivity
It is lower, and sintering structure, in order to guarantee higher reflectivity, usually porous structure, thermal resistance is higher, thus be unfavorable for wavelength and turn
The raising of light emission luminance and stability of the changing device under high power laser light excitation.The thus reflection of current Wavelength converter
Layer becomes the bottleneck of further improving laser fluorescence display light-source brightness.
Therefore, in view of the above deficiencies, it is really necessary to provide a kind of new Wavelength converter and preparation method thereof, to solve
Prior art reflectivity is low, the higher problem of thermal resistance.
Summary of the invention
For overcome the deficiencies in the prior art, low to solve prior art reflectivity, the higher problem of thermal resistance.The present invention mentions
For a kind of new type reflection rate high, the reflecting layer that thermal resistance is low and long-term reliability is high, using the Wavelength converter in the reflecting layer
Luminous efficiency is higher, and brightness is higher and is still able to maintain preferable long-term reliability, and concrete scheme is as follows:
The present invention provides a kind of Wavelength converter, including luminescent layer, reflecting layer, articulamentum and the heat-conducting substrate set gradually
Layer, the luminescent layer are aluminium oxide eutectic luminescent layer, and the reflecting layer is argentum reflecting layer made of fine silver sintering.
Preferably, the aluminium oxide eutectic luminescent layer is (Lu, Y, Gd, the Tb) of garnet structure3(Ga, Al)5O12:Ce3+
The eutectic luminescent layer formed with aluminium oxide.
Preferably, (Lu, Y, Gd, the Tb) of the garnet structure3(Ga, Al)5O12:Ce3+The eutectic formed with aluminium oxide
The molar ratio of aluminium oxide is greater than 40% in luminescent layer.
Preferably, aluminum oxide film layer is provided between the luminescent layer and the reflecting layer.
Preferably, the luminescent layer with a thickness of 0.005-5mm;The reflecting layer with a thickness of 1-100um;The company
Connect layer with a thickness of 0.005-0.5mm;The heat-conducting substrate with a thickness of 0.1-5mm.
Preferably, the porosity of the articulamentum is less than 50%.
Preferably, the articulamentum is that solder(ing) paste or preformed soldering reflow soldering are formed, and the solder(ing) paste is golden tin,
Yin Xi, the combination of any one or more in bismuth tin or slicker solder.
Preferably, the articulamentum is that low-temperature sintering silver paste is sintered to be formed.
Preferably, the heat-conducting substrate is metal substrate or ceramic substrate, and matcoveredn is arranged on the heat-conducting substrate.
Preferably, the heat-conducting substrate is aluminium nitride, silicon carbide, any one or more group in silicon nitride or aluminium oxide
The ceramic substrate of conjunction is provided with ti interlayer between the ceramic substrate and the nickel gold protective layer.
Preferably, the heat-conducting substrate is for slab construction or with fin structure.
The present invention also provides a kind of preparation methods of Wavelength converter, include the following steps:
Step S1: Al is provided2O3-(Lu,Y, Gd,Tb)3(Ga,Al)5O12:Ce3+Eutectic luminescent material, and to the Al2O3-
(Lu,Y, Gd,Tb)3(Ga,Al)5O12:Ce3+Eutectic luminescent material carries out pretreatment and forms eutectic luminescent layer;
Step S2: the reflection for forming fine silver is sintered after coating the mixed slurry of silver powder and organism on the eutectic luminescent layer
Layer;
Step S3: providing the heat-conducting substrate of plating nickel gold, and the reflecting layer formed step S2 is arranged on the heat-conducting substrate of plating nickel gold,
Articulamentum is formed through processing.
Preferably, the pretreatment of step S1 includes by Al2O3-(Lu,Y, Gd,Tb)3(Ga,Al)5O12:Ce3+Eutectic shines
Material two-side grinding and polishing plates anti-reflection film or roughing in surface on one side.
Preferably, the particle size range of the silver powder used in step S2 is 0.01-20um.
Preferably, the step S2 includes:
Step S21: by the eutectic luminescent layer for coating mixed slurry, prebake forms argentum reflecting layer preformed layer at 60-150 DEG C;
Step S22: the argentum reflecting layer preformed layer that step S21 is obtained is placed in 500-1000 DEG C of sintering in high temperature furnace and forms silver instead
Penetrate layer.
Preferably, it is to coat solder(ing) paste on the heat-conducting substrate or set that the step S3, which forms the processing method of articulamentum,
Preformed soldering is set, reflecting layer is placed on it, and reflow soldering forms articulamentum at 280-320 DEG C.
Preferably, it is the coated with nano silver paste on the heat-conducting substrate that the step S3, which forms the processing method of articulamentum,
It is sintered at 200-300 DEG C by reflecting layer is placed on it.
Compared with the existing technology, beneficial effects of the present invention are as follows:
Relative to current porous diffusing reflection structure, the present invention is sintered the argentum reflecting layer to be formed using fine silver, and it is anti-to improve reflecting layer
While penetrating rate and thermal conductivity, using argentum reflecting layer to the higher adhesive force of alumina single crystal in aluminium oxide eutectic luminescent layer, from
And also solves the adhesion problem of argentum reflecting layer Yu aluminium oxide eutectic luminescent layer together.
The thermal conductivity for the aluminium oxide eutectic luminescent layer that the present invention uses is higher, and mechanical strength is also higher, while fine silver is anti-
The reflectivity for penetrating layer is high, and thermal conductivity is also higher, good with the adhesive force of articulamentum, thus the Wavelength converter energy of this structure
Enough realize it is efficient simultaneously, realize high brightness and high reliability.
Present invention will be further explained below with reference to the attached drawings and examples.
Detailed description of the invention
Fig. 1 is the structural schematic diagram of the Wavelength converter of the first embodiment of the invention;
Fig. 2 is the preparation method flow chart of the Wavelength converter of the first embodiment of the invention;
Fig. 3 is the structural schematic diagram of the Wavelength converter of second of embodiment of the invention.
Specific embodiment
The present invention provides a kind of new Wavelength converter and preparation method thereof, heat low to solve prior art reflectivity
Hinder higher problem.
Embodiment one
Shown in referring to Fig.1, Wavelength converter provided by the invention includes the luminescent layer 1-1 being cascading, reflecting layer 1-
2, articulamentum 1-3 and heat-conducting substrate layer 1-4.
Wherein luminescent layer 1-1 be aluminium oxide eutectic luminescent layer, specifically in the present embodiment, be garnet structure (Lu,
Y, Gd, Tb)3(Ga, Al)5O12:Ce3+The eutectic luminescent layer formed with aluminium oxide.Wherein, garnet structure (Lu, Y, Gd,
Tb)3(Ga, Al)5O12:Ce3+The molar ratio of aluminium oxide is greater than 40% or more in the eutectic luminescent layer formed with aluminium oxide.It is described
Luminescent layer with a thickness of 0.005 ~ 5mm, it is preferred that be 0.05 ~ 0.5mm.Further, increasing can also be set in luminous layer surface
Permeable membrane carries out surface roughening treatment to improve light extraction efficiency.
Reflecting layer 1-2 is that the mixed slurry of the silver powder of fine silver and organic carrier is coated on to height on aluminium oxide eutectic luminescent layer
The argentum reflecting layer that temperature sintering is formed.Wherein the organic carrier of mixed slurry is volatilizable or decomposable substance, in high temperature sintering mistake
It is removed in journey, is fine silver structure made of sintering in the reflecting layer 1-2 of formation.Reflecting layer with a thickness of 1 ~ 100um, preferably
2 ~ 50um is still more preferably 5 ~ 20um.Wherein, the particle size range of the silver powder in mixed slurry is 0.01 ~ 20um, this be by
It is not easy to disperse in silver powder of the partial size less than 0.01um, silver paste surface smoothness prepared by silver powder of the partial size greater than 20um is not easy
Control, and the biggish silver powder of partial size is less susceptible to the densified sintering product on aluminium oxide eutectic luminescent layer, and adhesive force is deteriorated, so burning
The size of knot particle is to influence a key factor of sintering activity, and the partial size of silver powder is smaller, easier to send out in aluminium oxide eutectic
Fine and close argentum reflecting layer is formed on photosphere.Therefore the preferred silver powder particle size range of present embodiment can take into account profile pattern and
Densified sintering product.
The grain shape of silver powder preferred spherical or sheet, both shaped particles advantageously form close-packed structure, burn
The argentum reflecting layer of knot is finer and close;Further, it can also be mixed with the metal powder of platinum or palladium in silver powder, the height of silver can be improved in this way
Warm migration characteristic, wherein palladium powder, platinum powder content be no more than 30%, otherwise will affect reflectivity.The grain of present embodiment selection
Diameter is easiest to form the high reflecting layer of reflectivity.
Articulamentum 1-3 is specially metallic solder layer, primarily serves the connection function of reflecting layer 1-2 Yu heat-conducting substrate 1-4, tool
Body can be formed by golden tin, Yin Xi, bismuth tin, the soldering paste such as slicker solder or preformed soldering reflow soldering, be also possible to low-temperature sintering
Silver paste is sintered to be formed.Articulamentum with a thickness of 0.005 ~ 0.5mm, and porosity is lower than 50%, it is preferred that porosity is lower than
30%, further below 10%.
Heat-conducting substrate 1-4 can may be ceramic substrate for metal substrate, heat-conducting substrate with a thickness of 0.1 ~ 5mm,
Further, matcoveredn is set on heat-conducting substrate.Wherein protective layer is plating nickel gold protective layer.Metal substrate is preferably copper gold
Belong to substrate.Ceramic substrate can be aluminium nitride, silicon carbide, silicon nitride, the ceramic substrates such as aluminium oxide any one or or it is a variety of
Combination, when heat-conducting substrate 1-4 is ceramic substrate, ceramic base plate surface is coated with Ti transition zone (ti interlayer), then plates again
If nickel gold protective layer, ceramic substrate is fixed by Ti transition zone and nickel gold protective layer.Heat-conducting substrate 1-4 can be as shown in Figure 1
Slab construction, be also possible to band fin structure, can be implemented.
Reflecting layer 1-2 as described above is to be coated on aluminium oxide eutectic by the silver powder of fine silver and the mixed slurry of organic carrier
The argentum reflecting layer that high temperature sintering is formed on luminescent layer, not only there is very high reflectivity in reflecting layer at this time, also will increase and metal
Adhesive force between welding layer is, which is because, the silver layer of high-purity is easy to the metal welding with solder(ing) paste or preformed soldering
The metal connect in layer forms metal oxide, which can be further formed a reliable weld seam, to increase reflecting layer
Adhesive force between articulamentum.
Further, reflecting layer 1-2 can increase the caking property between luminescent layer, since the reflecting layer is burnt using fine silver
It ties, and the luminescent layer is (Lu, Y, Gd, the Tb) of garnet structure3(Ga, Al)5O12:Ce3+The eutectic formed with aluminium oxide
Luminescent layer, wherein the crystal structure of silver and aluminium oxide is all hexagonal crystallographic texture, same crystal structure makes the silver powder of fine silver
When being coated on high temperature sintering on aluminium oxide eutectic luminescent layer with the mixed slurry of organic carrier, closer attachment will form, it can
Further increase the adhesive force between reflecting layer and luminescent layer.
As shown in Fig. 2, the preparation method of Wavelength converter as described above includes the following steps:
Step S1: Al is provided2O3-(Lu,Y, Gd,Tb)3(Ga,Al)5O12:Ce3+Eutectic luminescent material, and to Al2O3-(Lu,Y,
Gd,Tb)3(Ga,Al)5O12:Ce3+Eutectic luminescent material carries out Two sides milling and polishing, plates anti-reflection film or roughing in surface on one side
Pretreatment is to form eutectic luminescent layer;
Step S2: the reflecting layer for forming fine silver, tool are sintered after coating the mixed slurry of silver powder and organism on eutectic luminescent layer
Body includes:
Step S21: by the eutectic luminescent layer for coating mixed slurry, prebake forms argentum reflecting layer preformed layer at 60-150 DEG C;
Step S22: the argentum reflecting layer preformed layer that step S21 is obtained is placed in 500-1000 DEG C of sintering in high temperature furnace and forms silver instead
Penetrate layer.
Step S3: providing the heat-conducting substrate of plating nickel gold, is specifically copper base in present embodiment, weldering is coated on copper base
Luminescent layer sintering is had being placed in above solder(ing) paste on one side for argentum reflecting layer, flowed back at 280 ~ 320 DEG C by tin cream or preformed soldering
Welding forms metallic solder layer.
In selectable other embodiments, step S3 may be: on copper base coated with nano silver paste 200 ~
Sintering forms articulamentum at 300 DEG C.Preferably, it can be to be forced under 10Mpa to be sintered, consistency can be improved in this way.
The silver powder used in step S2 is fine silver, and particle size range is 0.01 ~ 20um, and particle is spherical or sheet, organic
Body selects volatilizable or decomposable substance under high temperature, in the drying of step S21 and the sintering process of step S22, organism
It is removed, to form argentum reflecting layer.
Further, 30% palladium can be no more than with doping content in silver powder or the metal powder of platinum is used to improve the height of silver
Warm migration characteristic.
Embodiment two
As shown in figure 3, present embodiment and the first embodiment are essentially identical, Wavelength converter includes luminescent layer 2-
1, reflecting layer 2-2, articulamentum 2-3 and heat-conducting substrate layer 2-4, difference are, also set between luminescent layer 2-1 and reflecting layer 2-2
It is equipped with aluminum oxide film layer 2-5.
As noted previously, as the crystal structure of aluminium oxide and silver layer is all hexagonal crystallographic texture, therefore additional setting oxidation
Aluminum membranous layer can form closely attachment between argentum reflecting layer.Meanwhile aluminum oxide film layer and aluminium oxide eutectic luminescent layer can also
To form good adhesion.Therefore compare embodiment one, the aluminum oxide film layer 2-5 in present embodiment can be used for more into
One step improves the caking property between fluorescence coating and argentum reflecting layer, enhances the adhesive force between luminescent layer and reflecting layer.
Since the partial size of Argent grain is smaller, sintering activity is high;Therefore setting pellumina 2-5, can further decrease silver
The partial size of particle improves sintering activity.
Compared with the existing technology, beneficial effects of the present invention are as follows:
Relative to current porous diffusing reflection structure, the present invention is sintered the argentum reflecting layer to be formed using fine silver, and it is anti-to improve reflecting layer
While penetrating rate and thermal conductivity, using argentum reflecting layer to the higher adhesive force of alumina single crystal in aluminium oxide eutectic luminescent layer, from
And also solves the adhesion problem of argentum reflecting layer Yu aluminium oxide eutectic luminescent layer together.
The thermal conductivity for the aluminium oxide eutectic luminescent layer that the present invention uses is higher, and mechanical strength is also higher, while fine silver is anti-
The reflectivity for penetrating layer is high, and thermal conductivity is also higher, good with the adhesive force of articulamentum, thus the Wavelength converter energy of this structure
Enough realize it is efficient simultaneously, realize high brightness and high reliability.
The above embodiment is only the preferred embodiment of the present invention, and the scope of protection of the present invention is not limited thereto,
The variation and replacement for any unsubstantiality that those skilled in the art is done on the basis of the present invention belong to institute of the present invention
Claimed range.