WO2016165570A1

WO2016165570A1 - Method for preparing diffuse reflective layer and wavelength conversion device

Info

Publication number: WO2016165570A1
Application number: PCT/CN2016/078441
Authority: WO
Inventors: 田梓峰; 陈雨叁; 许颜正
Original assignee: 深圳市光峰光电技术有限公司
Priority date: 2015-04-16
Filing date: 2016-04-05
Publication date: 2016-10-20
Also published as: CN106154365B; CN106154365A

Abstract

A method for preparing a diffuse reflective layer, comprising the following steps: preparing a mixed solution comprising a binder (12) and scattering particles (11), applying the mixed solution on a substrate (2), and then sintering the substrate at a first temperature so as to form a diffuse reflective layer with pores on the substrate; preparing a sol liquid with auxiliary particles suspended therein; immersing the substrate attached with the diffuse reflective layer into the sol liquid for a preset time so that the auxiliary particles are infiltrated into the pores of the diffuse reflective layer, and then taking out and drying same; subsequently performing another immersion and drying, and repeating at least twice; and finally sintering same into a final diffuse reflective layer. The prepared diffuse reflective layer has a high density, a high content of reflecting particles and a high reflectivity. A wavelength conversion device, comprising a diffuse reflective layer prepared by the method.

Description

Method for preparing diffuse reflection layer and wavelength conversion device

Technical field

The invention relates to the field of fabrication of a reflective wavelength conversion device, and in particular to a method for preparing a diffuse reflection layer and a wavelength conversion device.

Background technique

With the development of display and lighting technology, the original halogen bulb as a light source is increasingly unable to meet the high power and high brightness requirements of display and illumination. Use solid state light sources such as LD ( Laser Diode The laser emits excitation light to excite the wavelength conversion material to obtain visible light of various colors, and this technology is increasingly used in illumination and display. This technology has the advantages of high efficiency, low energy consumption, low cost and long life, and is an ideal alternative to existing white or monochromatic light sources.

Since the reflective wavelength conversion device is highly efficient, it is widely used in illumination display devices, and includes a light-emitting layer, a reflective layer, and a thermally conductive substrate. It is mainly divided into two structures: one is that the organic silica phosphor layer is directly cured and bonded to the mirror aluminum metal substrate, the mirror aluminum acts as both a reflective and a heat conductive substrate, and the second is directly cured on the heat conductive substrate. / The diffuse reflective layer and the fluorescent layer are sintered. The diffuse reflection layer structure generally consists of scattering particles and glass powder. The thermal stability of the reflectivity is much higher than that of the specular reflection metal film layer, which can fundamentally overcome the high temperature oxidation problem of the metal film and become the choice of high power laser light source.

technical problem

However, since the reflection in the diffuse reflection layer is mainly scattering particles, in order to achieve sufficient reflectivity of the diffuse reflection layer, there are generally two ways: first, increase the percentage content of the scattering particles; second, improve the diffuse reflection layer. Thickness; in the first way, the percentage of the glass powder is reduced. Since the glass powder acts as a binder, this not only causes the adhesion of the diffuse reflection layer to the substrate to decrease, but also the diffuse reflection layer itself is difficult to be sintered tightly, resulting in A large number of pores appear, the existence of pores will form the thermal resistance of the pore interface, and the increase of the thermal resistance will lead to the decrease of its reliability. In the second way, increasing the thickness of the diffuse reflection layer will increase its thermal resistance, especially for the presence of pores. The diffuse reflection layer, the increase of the thickness makes the increase of the thermal resistance more obvious, and the increase of the thermal resistance leads to the decrease of the reliability.

Technical solution

The present application provides a method of preparing a diffuse reflection layer having sufficient reflectivity and reliability, and a wavelength conversion device having sufficient reflectance and reliability.

In one aspect, an embodiment provides a method for preparing a diffuse reflection layer, including the following steps:

Preparing a mixed solution containing a binder and scattering particles, applying the mixed solution to the substrate, and sintering the substrate at a first temperature to form a substrate with a diffuse reflection layer with pores, the adhesive being a transparent powder. And the melting point is lower than the scattering particles, and the scattering particles are particles having reflective properties;

Preparing a sol solution suspended with auxiliary particles, the auxiliary particles being particles having reflective properties;

Immersing the substrate with the diffuse reflection layer in the sol solution, soaking for a preset time, so that the auxiliary particles penetrate into the pores of the diffuse reflection layer, and then take it out and dry; then soak it in the sol solution, and then take it out and dry, so Repeated at least 2 times; finally sintered at a second temperature to form a final diffuse reflection layer;

The drying temperature is 50 to 200 ° C, and the second temperature is 500 to 1000 ° C.

Further, each of the scattering particles and the auxiliary particles is one or more of alumina, titania, boron nitride, zinc oxide, zirconium oxide, magnesium oxide, barium sulfate, silicon oxide, and water glass.

Further, the particle diameter of the scattering particles and the auxiliary particles is 0.5 times the wavelength of the scattered light.

Further, the binder is silicate glass powder or borosilicate glass powder.

Further, the mixed liquid further includes an organic vehicle for homogeneous mixing, and the organic vehicle is a mixture of ethyl cellulose, terpineol and butyl carbitol or silicone oil.

Further, the mixed solution is applied to the substrate by screen printing, blade coating or spray coating.

Further, the first temperature is greater than or equal to the melting point temperature of the binder and less than the melting point temperature of the scattering particles.

Further, each drying time is 0.5 to 3 hours, and the second temperature sintering time is 0.5 to 2 hours.

Further, the soaking time is 1 to 24 hours.

In other embodiments, the sol solution is heated while soaking.

In another aspect, an embodiment provides a wavelength conversion device comprising the diffuse reflection layer prepared by the above preparation method.

Beneficial effect

A method for preparing a diffuse reflection layer and a wavelength conversion device according to the above embodiment, the preparation method is capable of ensuring a diffuse reflection layer and a substrate because the percentage of the scattering particles is not increased when the diffuse reflection layer having pores is initially prepared Adhesion, after sintering, the auxiliary particles are infiltrated into the gap of the diffuse reflection layer, the penetration of the auxiliary particles is increased, the density of the diffuse reflection layer is improved, and the content of the particles having reflection properties is improved, thereby improving the reflection layer. The reflective capability does not increase the thickness of the outline structure and does not increase the thermal resistance. The diffuse reflection layer in the wavelength conversion device is fabricated according to the above-described preparation method, and has a higher reflection ability.

DRAWINGS

1 is a flow chart of a method for preparing a diffuse reflection layer;

2 is a schematic structural view of a preliminary prepared diffuse reflection layer;

Figure 3 is a schematic view showing the structure of the finally formed diffuse reflection layer;

Figure 4 is a schematic view of the structure of the wavelength replacement device.

BEST MODE FOR CARRYING OUT THE INVENTION

The present invention will be further described in detail below with reference to the accompanying drawings.

Embodiment 1:

In the present embodiment, the preparation of the diffuse reflection layer in the wavelength conversion device will be described as an example.

As shown in FIG. 1, the preparation method of the diffuse reflection layer includes the following steps:

(a) preparing a mixed solution, applying the mixed solution to the substrate, and then sintering the substrate at a first temperature to form a substrate to which the diffuse reflective layer with pores is attached;

The mixed solution is prepared by uniformly mixing an adhesive, scattering particles, and an organic vehicle. The binder is a silicate glass powder or a borosilicate glass powder having high physicochemical stability. The scattering particles are one or more of alumina, titania, boron nitride, zinc oxide, zirconium oxide, magnesium oxide, barium sulfate, silicon oxide, and water glass. The organic vehicle is a mixture of ethyl cellulose, terpineol and butyl carbitol or a silicone oil. The substrate is a heat conductive substrate made of a heat conductive material, and the mixed solution is applied to the heat conductive substrate by screen printing, blade coating or spraying. The first temperature is above the melting point temperature of the binder.

The substrate may be selected from one of an aluminum nitride substrate, an alumina substrate, a boron nitride substrate, a silicon nitride substrate, a silicon carbide substrate, a yttrium oxide substrate, or a composite substrate of the above ceramic and metal (such as aluminum), or a metal. Substrate.

As shown in Fig. 2, the scattering particles 11 in the initially formed diffuse reflection layer are bonded together by the adhesive 12 to form a stable structure with pores.

(b) preparing a sol solution in which auxiliary particles are suspended;

The auxiliary particles are suspended in the sol solution, and the auxiliary particles are one or more of alumina, titania, boron nitride, zinc oxide, zirconium oxide, magnesium oxide, barium sulfate, silicon oxide, and water glass.

The particle diameter of the scattering particles and the auxiliary particles is preferably 0.5 times the wavelength of the scattered light, and the particle diameter of the ratio has the best scattering effect. It can be understood that since the light used in the life is light having a certain wavelength range, the particle size range of the scattering particles and the auxiliary particles is in accordance with the present invention as long as it falls within 0.5 times of the wavelength in the wavelength range of the scattered light. Design ideas. For example, for a scattering visible wavelength of 400 to 800 nm, the particle diameter of the scattering particles and the auxiliary particles is preferably 0.2 to 0.5 um.

(c) The substrate to which the diffuse reflection layer is attached is immersed in the sol solution, taken out and dried, and then sintered at a second temperature to form a final diffuse reflection layer.

Specifically, the heat-dissipating substrate to which the diffuse reflection layer is attached is immersed in the sol solution, taken out after being immersed for several hours, and then dried at a low temperature, and then continuously immersed in the sol solution, and then taken out and dried, thus repeated at least 2 times; Finally, it is sintered to a final diffuse reflection layer at a second temperature. The soaking time is determined according to the specific conditions, generally 1~12 hours; the drying temperature is 50~200°C, the drying time is 0.5~3 hours; the second temperature is 500~1000°C, and the sintering time is 0.5~ 2 hours; the number of times of immersion drying depends on the product demand.

As shown in FIG. 3, after several times of immersion drying of the diffuse reflection layer, the auxiliary particles 13 penetrate into the gap between the scattering particles, so that the diffuse reflection layer is more dense and the content of the reflective particles is increased.

In other embodiments, the sol solution is heated while immersing, accelerating the penetration of the auxiliary particles into the slot of the diffuse reflection layer to shorten the soaking time.

The steps (a) and (b) in the above preparation method may be reversed or may be carried out simultaneously.

In a specific embodiment of the present embodiment, the scattering particles are alumina particles, and the alumina is uniformly mixed with the glass powder and the organic carrier as a binder, and then brushed on the aluminum nitride substrate. The slurry of alumina, glass frit and organic carrier is sintered together with the aluminum nitride substrate at a first temperature of about 700 ° C to decompose and volatilize the organic carrier to obtain alumina and glass powder adhered to the aluminum nitride substrate. A porous diffuse reflective layer.

To prepare an aqueous sol of alumina, the aluminum nitride substrate to which the porous diffuse reflection layer of alumina is adhered is immersed in an alumina hydrosol for 1 hour, taken out and dried at 120 ° C for 2 hours, and thus repeated twice, diffuse reflection The quality of the layer is significantly increased. The aluminum nitride substrate to which the diffuse reflection layer is attached is sintered at 600 ° C to finally obtain a dense alumina diffuse reflection layer. The aluminum oxide diffuse reflection layer is attached to the aluminum nitride substrate, and the aluminum nitride substrate surface is easily oxidized to produce an aluminum oxide layer, and the aluminum oxide layer has better bonding characteristics with the aluminum oxide diffuse reflection layer, so the technical solution is obtained. The diffuse reflection layer has higher structural stability.

In the method for preparing the diffuse reflection layer of the present embodiment, since the percentage of the scattering particles is not increased when the diffuse reflection layer with pores is initially prepared, the adhesion of the diffuse reflection layer to the substrate can be ensured, and after sintering, The auxiliary particles are infiltrated into the gap of the diffuse reflection layer, the penetration of the auxiliary particles is increased, the density of the diffuse reflection layer is improved, the content of the particles having the reflection performance is improved, thereby improving the reflection ability of the reflection layer, and the shape structure is not increased. Thickness and no increase in thermal resistance.

In contrast, the diffuse reflection layer of the same composition as the present invention is obtained by directly sintering the raw materials after mixing, and since the amount of the binder is too small, it cannot form an effective coating of the scattering particles after being uniformly dispersed, and The internal adhesion of the diffuse reflection layer is insufficient, and it is prone to breakage.

Embodiment 2:

As shown in FIG. 4, the present embodiment provides a wavelength conversion device. On the basis of the above embodiment 1, the diffuse reflection layer 1 is formed on the heat conductive substrate 2, and the fluorescent layer 3 is added, and the fluorescent layer 3 is covered on the diffuse reflection layer 1. on.

The fluorescent layer 3 is prepared by uniformly mixing the phosphor particles, the binder, and the organic vehicle, by screen printing, blade coating or spraying onto the diffuse reflection layer 1, and then sintering at a high temperature to form the fluorescent layer 3. The binder and the organic vehicle used in this step may be the same binder and organic carrier as in the method of Example 1 to improve the consistency of the wavelength conversion device.

The heat conductive substrate 2 is a ceramic substrate, and may be selected from one of an aluminum nitride substrate, an alumina substrate, a boron nitride substrate, a silicon nitride substrate, a silicon carbide substrate, a yttria substrate, or the above ceramics and metals (such as aluminum). Composite substrate, or metal substrate.

The wavelength conversion device provided in this embodiment includes the diffuse reflection layer 1 made by the method of the first embodiment, so that the wavelength conversion device has higher reflection capability.

The invention has been described above with reference to specific examples, which are merely intended to aid the understanding of the invention and are not intended to limit the invention. For the person skilled in the art to which the invention pertains, several simple derivations, variations or substitutions can be made in accordance with the inventive concept.

Claims

A method for preparing a diffuse reflection layer, comprising the steps of:

Preparing a mixed solution comprising a binder and scattering particles, applying the mixture to a substrate, and sintering the substrate at a first temperature to form a substrate to which a diffuse reflective layer having pores is attached, the adhesive being a transparent powder having a melting point lower than the scattering particles, the scattering particles being particles having reflective properties;

Immersing the substrate to which the diffuse reflection layer is attached into the sol solution, soaking for a predetermined time, so that the auxiliary particles penetrate into the pores of the diffuse reflection layer, and then take out and dry; then immersing it in the sol solution Then, take out the drying, and then repeat at least 2 times; finally, sintering at the second temperature to form a final diffuse reflection layer; wherein the drying temperature is 50 to 200 ° C, and the second temperature is 500 to 1000 ° C.

2. The preparation method according to claim 1, wherein each of the scattering particles and the auxiliary particles is alumina, titania, boron nitride, zinc oxide, zirconium oxide, magnesium oxide, barium sulfate, silicon oxide, and water glass. One or more of them.

3. The method according to claim 2, wherein the scattering particles and the auxiliary particles have a particle diameter of 0.5 times the wavelength of the scattered light.

4. The method according to claim 1, wherein the binder is silicate glass powder or borosilicate glass powder.

5. The preparation method according to any one of claims 1 to 2, wherein the mixed liquid further comprises an organic vehicle for uniform mixing, and the organic carrier is ethyl cellulose, terpineol and butyl. A mixture of carbitol or silicone oil.

6. The preparation method according to claim 5, wherein the mixed solution is applied to the substrate by screen printing, blade coating or spray coating.

7. The method according to claim 1, wherein the first temperature is greater than or equal to a melting point temperature of the binder and less than a melting point temperature of the scattering particles.

8. The preparation method according to claim 1, wherein the drying time is 0.5 to 3 hours, and the second temperature sintering time is 0.5 to 2 hours.

9. The preparation method according to claim 8, wherein the soaking time is 1 to 24 hours.

10. The preparation method according to claim 9, wherein the sol solution is heated while the immersion is performed.

A wavelength conversion device comprising the diffuse reflection layer prepared by the production method according to any one of claims 1 to 10.