Method for manufacturing a laser color converter and laser color converter structure

Abstract

The application provides a laser color converter preparation method and a laser color converter structure, which comprise a heat dissipation substrate, a fluorescent glass layer, a bonding layer and a heat dissipation cover plate; wherein the heat dissipation substrate is processed with a groove; the fluorescent glass layer is filled in the groove; the heat dissipation cover plate is located above the heat dissipation substrate and is fixed with the heat dissipation substrate through the bonding layer. The application improves the heat dissipation performance of the laser color converter by using the heat-conducting groove structure, avoids the light saturation problem and effectively improves the light brightness and thermal stability of the white laser light source; no organic adhesive material is used in the laser color converter, which avoids the failure and even carbonization of the organic adhesive material under high temperature and improves the long-term reliability of the white laser light source.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of semiconductor lighting, and relates to a laser color converter preparation method and a laser color converter structure. BACKGROUND

[0002] With the increasing global energy consumption and the increasing environmental protection pressure, the demand for energy-saving and high-efficiency lighting technology gradually becomes one of the core topics of social development. As a new light source technology, semiconductor lighting has attracted widespread attention in the lighting field due to its high efficiency, energy saving, strong directivity and other characteristics. Compared with traditional light sources, semiconductor lighting has significant advantages in energy saving, life, environmental protection, flexibility, durability and other aspects, and gradually replaces traditional incandescent lamps and fluorescent lamps to become the mainstream lighting choice. The new generation of green laser lighting is widely penetrating into many fields such as city lighting, automobile, industry, medical treatment, display and business with its high efficiency, long life, low energy consumption and strong controllability. With the continuous progress of technology, laser lighting will bring energy-saving and environmental protection, innovative design and high-quality experience solutions to more fields in the future.

[0003] With the demand for high-power and high-density lighting solutions, multi-chip packaging integrated blue light emitting diode (LED) and blue light laser diode (LD) technologies have been developed. Compared with blue light emitting diode (LED), blue light LD has the advantages of low beam divergence, long irradiation distance, no efficiency decline and high output power density.

[0004] Blue light LD can achieve high-brightness lighting by simply increasing the input power density, but the large amount of heat accumulation and light conversion loss generated by high-power density laser excitation brings new challenges to the thermal management of light color converters. The traditional resin-based phosphor (PiS) color converter has poor thermal stability and limited thermal conductivity, and has serious thermal corrosion and carbonization problems under high-power density laser excitation, which cannot meet the actual application of laser lighting. Therefore, new type of color converters with different structural configurations and material designs are urgently needed to be developed.

[0005] To address this, researchers have proposed using inorganic fluorescent conversion materials (luminescent single crystals, fluorescent ceramics, fluorescent glass, etc.) for white LED encapsulation. Fluorescent conversion materials are a crucial component of laser fluorescence technology. Unlike the organic fluorescent conversion materials commonly used in white LEDs, blue LEDs, due to their high power density and small radiation spot size, coupled with the heat generated by non-radiative transitions during fluorescence conversion, experience localized high temperatures in the laser irradiation area. Traditional organic fluorescent conversion materials have low thermal conductivity and are prone to yellowing and carbonization at high temperatures, leading to fluorescent material failure. Fluorescent glass, an inorganic composite material composed of glass and phosphor, offers advantages such as simple manufacturing processes, tunable luminescence characteristics, low cost, and ease of mass production. However, existing fluorescent glasses suffer from low thermal conductivity and poor thermal stability, making it difficult to meet the demands of high-power-density laser driving or excitation. This results in luminescence saturation problems in white LEDs, limiting the development of laser lighting and display technologies. Summary of the Invention

[0006] In view of this, the purpose of the present invention is to provide a method for preparing a laser color converter and a structure for preparing a laser color converter, so as to solve the problems mentioned in the background art.

[0007] This invention is achieved using the following scheme: A method for preparing a laser color converter, comprising the following steps:

[0008] S1. Grooves are created on the heat sink substrate by machining, laser processing or etching.

[0009] S2. Fill the groove of the heat sink substrate with excess fluorescent glass paste. The excess fluorescent glass paste that exceeds the bearing area of ​​the groove falls onto the heat sink substrate. Coat the surface of the heat sink cover with glass paste.

[0010] S3. The heat dissipation substrate filled with excess fluorescent glass paste and the heat dissipation cover plate coated with glass paste are subjected to the first high-temperature sintering together.

[0011] S4. Grind the excess fluorescent glass layer produced after sintering on the heat sink substrate until the fluorescent glass just fills the groove and is flush with the surface of the heat sink substrate.

[0012] S5. Align and bond the adhesive layer formed by sintering glass paste on the heat sink cover with the fluorescent glass side of the heat sink substrate, and perform a second high-temperature sintering to form a laser color converter.

[0013] Furthermore, the thickness of the laser color converter is 1-5mm; the depth of the groove is 100μm-500μm; the area of ​​the groove is 30%-90% of the surface area of ​​the heat sink substrate; and the thickness of the adhesive layer is 30μm-350μm.

[0014] Further, the fluorescent glass paste is formed by mixing fluorescent powder, low-temperature glass powder and organic solvent, and the content of the fluorescent powder is 20-300% of the weight of the low-temperature glass powder; and the glass paste is formed by mixing low-temperature glass powder and organic solvent.

[0015] Further, the sintering temperature of the fluorescent glass paste is greater than 600 DEG C, and the glass transition temperature of the low-temperature glass powder is less than 500 DEG C.

[0016] Further, the sintering temperature of the fluorescent glass paste and the glass paste is 620 DEG C-700 DEG C, and the sintering time is 30-60 min.

[0017] Further, the heat dissipation substrate material is one or more composite materials made of ceramic, metal or glass; and the heat dissipation cover plate is made of high-thermal-conductivity heat dissipation alumina or diamond.

[0018] Further, the fluorescent glass paste is filled to 200% of the volume of the groove.

[0019] Further, during the second high-temperature sintering, pressure is applied to the surface of the heat dissipation cover plate to realize pressure sintering.

[0020] A laser color converter structure, comprising a heat dissipation substrate, a fluorescent glass layer, a bonding layer and a heat dissipation cover plate, the fluorescent glass layer is arranged on the upper surface of the heat dissipation substrate, the bonding layer covers the upper surface of the combination of the heat dissipation substrate and the fluorescent glass layer, and the heat dissipation cover plate is arranged on the bonding layer.

[0021] Further, a groove is formed on the upper surface of the heat dissipation substrate, the fluorescent glass layer is filled in the groove, and the thickness of the fluorescent glass layer is the same as the depth of the groove.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] By filling the heat dissipation substrate with excess fluorescent glass paste, the inevitable recesses in the groove caused by glass fusion and organic matter volatilization in the fluorescent paste can be effectively avoided, that is, the recess space in the groove after sintering can be avoided.

[0024] 2. The heat dissipation cover plate coated with glass paste is first sintered, instead of being directly coated on the processed heat dissipation substrate with a fluorescent glass layer, on the one hand, because the glass paste may also produce recesses due to the volatilization of organic matter during sintering, so the bonding layer after first sintering needs to be polished and trimmed; on the other hand, if the glass paste is directly coated on the processed heat dissipation substrate with a fluorescent glass layer, the recesses in the original fluorescent glass layer that may have existed will be filled with glass paste, so that the recesses in the fluorescent glass layer after secondary sintering will produce pores and other defects due to the volatilization of organic matter in the glass paste, affecting the use performance of the product, that is, solving the problems of recesses, pores and other defects in the bonding layer;

[0025] 3. The recess structure with heat conduction improves the heat dissipation performance of the laser color converter, avoids the problem of light saturation, and effectively improves the light brightness and thermal stability of the white laser light source; no organic adhesive material is used in the laser color converter, avoiding failure or even carbonization of the organic adhesive material at high temperature, and improving the long-term reliability of the white laser light source;

[0026] 4. The laser color converter is mainly applied to high-brightness fluorescent conversion white laser light sources, can withstand high-power density laser driving or excitation, so that the white laser light engine and its equipment have super-high brightness and reliability, and promote the development of laser lighting and display technology. BRIEF DESCRIPTION OF DRAWINGS

[0027] Fig. 1 The method process flow diagram for the embodiment of the application is prepared;

[0028] Fig. 2 The reflection layer diagram for the embodiment of the application is prepared;

[0029] Fig. 3 The structure diagram for the embodiment of the application is prepared.

[0030] In the figure: 1-heat dissipation substrate; 2-fluorescent glass layer; 30-contains YAG yellow fluorescent powder; 31-glass matrix; 3-bonding layer; 4-heat dissipation cover plate; 5-recess; 6-; heat dissipation cover plate surface 7-heat dissipation substrate surface; 8-heat dissipation cover plate surface. DETAILED DESCRIPTION

[0031] The application will be further described below in conjunction with the drawings and embodiments.

[0032] It should be noted that the following detailed description is exemplary and is intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0033] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, elements, components, and / or groups thereof, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof.

[0034] As shown in FIG. 1, a method for preparing a laser color converter comprises the following steps: Figs. 1-3

[0035] S1, making a groove on a heat dissipation substrate by machining, laser processing or etching;

[0036] S2, filling excess fluorescent glass paste in the groove of the heat dissipation substrate, and the part of the excess fluorescent glass paste beyond the bearing area of the groove falls on the heat dissipation substrate, and coating glass paste on the surface of the heat dissipation cover plate;

[0037] S3, performing first high-temperature sintering on the heat dissipation substrate filled with excess fluorescent glass paste and the heat dissipation cover plate coated with glass paste;

[0038] S4, grinding the excess fluorescent glass layer generated after sintering on the heat dissipation substrate until the fluorescent glass just fills the groove and is flush with the surface of the heat dissipation substrate;

[0039] S5, aligning and adhering the adhesive layer formed by sintering the glass paste on the heat dissipation cover plate with the surface of the heat dissipation substrate with fluorescent glass, and performing second high-temperature sintering to form a laser color converter.

[0040] In this embodiment,

[0041] In this embodiment, the more specific preparation method is as follows:

[0042] Step 1, Al2O3 with a thickness of 1 mm is selected as the heat dissipation substrate, and a groove with a depth of 100 μm is machined on the heat dissipation substrate by machining. Sapphire with a thickness of 1 mm is selected as the heat dissipation cover plate;

[0043] ​Step two, mix 0.35g of pine oil alcohol and 0.017g of ethyl cellulose, and stir under ultrasonic at 80℃ until the ethyl cellulose is completely dissolved, as a bottle of organic solvent, while repeating the above operation to get another bottle of organic solvent, one bottle adds 0.8g of YAG yellow fluorescent powder and 0.5g of low temperature borosilicate glass powder, one bottle adds 0.5g of low temperature borosilicate glass powder, and finally the fluorescent glass paste and the glass paste are obtained by magnetic stirring for 15 min, and the fluorescent glass paste is formed by the glass matrix of the glass paste and the fluorescent powder combination; respectively on the heat dissipation substrate obtained in step one, the excess fluorescent glass paste is coated, the glass paste is coated on the heat dissipation cover plate, and it is placed at a temperature of 110℃ for drying for 30 min; then they are placed in a high temperature furnace and sintered at a temperature of 620℃ for 30 min, to obtain a heat dissipation substrate with a fluorescent glass layer, and a heat dissipation cover plate with a glass layer, the thickness of the fluorescent glass layer is about 200μm and the thickness of the glass layer is about 30μm ~150μm, of course the heat dissipation cover plate can be coated with excess glass paste, and then polished to the actual required size.

[0044] Step three, polish the heat dissipation substrate with the fluorescent glass layer obtained in step two, to obtain a composite structure with a fluorescent glass layer thickness of about 100μm, that is, grind the excess fluorescent glass after sintering until it just fills the groove and is flush with the surface of the heat dissipation substrate, to achieve the purpose of the thickness of the fluorescent glass being consistent with the depth of the groove.

[0045] Step four, align the bonding layer formed by the glass paste sintered on the heat dissipation cover plate with the heat dissipation substrate with the fluorescent glass, and place the entire structure in a high temperature furnace and sinter at a temperature of 620℃ for 60 min under pressure, to fix the heat dissipation substrate and the heat dissipation cover plate, and form a laser color converter.

[0046] In this embodiment, by filling the excess fluorescent glass paste into the heat dissipation substrate, the inevitable recesses in the groove caused by the fusion of glass and the volatilization of organic matter in the fluorescent paste can be effectively avoided, that is, the recess space in the groove after sintering is avoided, and the heat dissipation cover plate coated with glass paste is also sintered for the first time, rather than being directly coated on the processed heat dissipation substrate with a fluorescent glass layer, on the one hand, because the glass paste may also produce recesses due to the volatilization of organic matter during sintering, so the bonding layer sintered for the first time needs to be polished and trimmed; on the other hand, if the glass paste is directly coated on the processed heat dissipation substrate with a fluorescent glass layer, the glass paste may be filled into the recesses of the fluorescent glass layer which may have existing recesses, causing defects such as pores in the recesses of the fluorescent glass layer sintered for the second time due to the volatilization of organic matter in the glass paste, affecting the performance of the product.

[0047] In the embodiment, the thickness of the laser color converter is 1-5 mm; the groove depth is 100 μm-500 μm; the groove area is 30%-90% of the surface area of the heat dissipation substrate; and the thickness of the adhesive layer is 30 μm-350 μm.

[0048] In the embodiment, the fluorescent glass paste is formed by mixing fluorescent powder, low-temperature glass powder and organic solvent, and the content of the fluorescent powder is 20%-300% of the weight of the low-temperature glass powder; and the glass paste is formed by mixing low-temperature glass powder and organic solvent.

[0049] In the embodiment, specifically, the material of the heat dissipation substrate is Al2O3, the fluorescent powder is YAG yellow fluorescent powder, the thickness of the heat dissipation substrate and the heat dissipation cover plate is 1 mm, the thickness of the fluorescent glass layer is 100 μm, and the radius of the fluorescent glass layer is 5 mm.

[0050] In the embodiment, the sintering temperature of the fluorescent glass paste is greater than 600 ℃, and the glass transition temperature of the low-temperature glass powder is lower than 500 ℃.

[0051] In the embodiment, the sintering temperature of the fluorescent glass paste and the glass paste is 620 ℃-700 ℃, and the sintering time is 30-60 min.

[0052] In the embodiment, the material of the heat dissipation substrate is one or more of ceramic, metal or glass composite material; and the heat dissipation cover plate is made of high-thermal-conductivity heat dissipation alumina or diamond.

[0053] In the embodiment, the fluorescent glass paste is filled to 200% of the volume of the groove.

[0054] In the embodiment, during the second high-temperature sintering, pressure is applied to the surface of the heat dissipation cover plate to realize pressure sintering, which can better ensure the adhesion of the adhesive layer to the heat dissipation substrate and the heat dissipation cover plate.

[0055] A laser color converter structure prepared by the above preparation method, the laser color converter comprises a heat dissipation substrate, a fluorescent glass layer, an adhesive layer and a heat dissipation cover plate, the fluorescent glass layer is arranged on the upper surface of the heat dissipation substrate, the adhesive layer covers the upper surface of the combination of the heat dissipation substrate and the fluorescent glass layer, and the heat dissipation cover plate is arranged on the adhesive layer, the heat dissipation cover plate and the heat dissipation substrate are fixed by the adhesive layer and kept flat, the adhesive layer completely covers the fluorescent glass layer and the surface of the heat dissipation substrate and keeps flat.

[0056] In the embodiment, a groove is formed on the upper surface of the heat dissipation substrate, the fluorescent glass layer is filled in the groove, and the thickness of the fluorescent glass layer is the same as the groove depth.

[0057] In the embodiment, the laser color converter structure is used for high light efficiency fluorescent conversion white laser light source.

[0058] In the embodiment, the laser color converter preparation method and the laser color converter structure are disclosed, which are reflective structures. The structure comprises a heat dissipation base plate, a heat dissipation cover plate, a fluorescent glass layer and a bonding layer. The heat dissipation base plate is processed with a groove, the fluorescent glass layer is filled in the groove, and the heat dissipation cover plate is fixed with the heat dissipation base plate through the bonding layer. The material of the heat dissipation base plate is Al2O3, and the material of the heat dissipation cover plate is sapphire. Meanwhile, a preparation method of high-thermal-conductivity fluorescent glass sheet is disclosed. The laser color converter structure is mainly applied to high-brightness fluorescent conversion white laser light source, can resist high-power density laser driving or excitation, makes the white laser light engine and equipment have super high brightness and reliability, and promotes the development of laser lighting and display technology.

[0059] Any technical solution disclosed in the present application, if not otherwise stated, if a numerical range is disclosed, the disclosed numerical range is a preferred numerical range. Any person skilled in the art should understand that the preferred numerical range is only one of the many implementable values with more obvious technical effects or representative values. Since there are too many values, it is impossible to enumerate them all, therefore, the present application discloses part of the values to illustrate the technical solutions of the present application, and the above-mentioned enumerated values should not constitute a limitation on the protection scope of the present application.

[0060] If the words such as "first", "second" are used to limit the parts in the present application, those skilled in the art should know that: the use of "first", "second" is only for the convenience of describing the parts to be distinguished, and the above-mentioned words have no special meaning unless otherwise stated.

[0061] If the present application discloses or involves parts or structural members fixedly connected with each other, unless otherwise stated, the fixed connection can be understood as: detachable fixed connection (for example, connected by using bolts or screws), and can also be understood as: non-detachable fixed connection (for example, riveting, welding), of course, the mutually fixed connection can also be replaced by an integral structure (for example, integrally formed by using casting process) (obviously, except for the integral forming process).

[0062] In addition, the terms used to indicate the position relationship, such as "vertical", "horizontal", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. in any of the technical solutions disclosed in the present application are based on the position relationship shown in the drawings, and are only used for the convenience of describing the present patent, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present patent, and the terms used to indicate the shape in any of the technical solutions disclosed in the present application include shapes similar, similar or close to the shape unless otherwise stated.

[0063] Any component provided by the present application can be assembled from a plurality of individual components or manufactured as a single component by an integral molding process.

[0064] Finally, it should be noted that: the above examples are only used to illustrate the technical solutions of the present application and not to limit them; although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the specific embodiments of the present application can be modified or some technical features can be replaced by equivalents; without departing from the spirit of the technical solutions of the present application, they should be included in the technical solution range of the present application claimed.

Claims

1. A method of making a laser color converter, the method comprising: The method comprises the following steps: ​ S1, making a groove on a heat dissipation substrate by machining, laser processing or etching; S2, filling excess fluorescent glass paste in the groove of the heat dissipation substrate, and the part of the excess fluorescent glass paste beyond the bearing area of the groove falls on the heat dissipation substrate, and glass paste is coated on the surface of the heat dissipation cover plate; S3, performing first high-temperature sintering on the heat dissipation substrate filled with excess fluorescent glass paste and the heat dissipation cover plate with the surface coated with glass paste; S4, grinding the excess fluorescent glass layer generated after sintering on the heat dissipation substrate until the fluorescent glass just fills the groove and is flush with the surface of the heat dissipation substrate; S5, aligning and adhering the adhesive layer formed by sintering the glass paste on the heat dissipation cover plate with the surface of the heat dissipation substrate with the fluorescent glass, and performing second high-temperature sintering to form a laser color converter; The thickness of the laser color converter is 1-5mm; the groove depth is 100μm-500μm; the groove area is 30%-90% of the surface area of the heat dissipation substrate; and the adhesive layer thickness is 30μm-350μm; The fluorescent glass paste is formed by mixing fluorescent powder, low-temperature glass powder and organic solvent, and the content of the fluorescent powder is 20%-300% of the weight of the low-temperature glass powder; and the glass paste is formed by mixing low-temperature glass powder and organic solvent; The sintering temperature of the fluorescent glass paste is greater than 600℃, and the glass transition temperature of the low-temperature glass powder is lower than 500℃; The sintering temperature of the fluorescent glass paste and the glass paste is 620℃-700℃, and the sintering time is 30-60min.

2. The method of claim 1, wherein; The heat dissipation substrate material is one or more composite materials of ceramic, metal or glass; and the heat dissipation cover plate is made of high-thermal-conductivity heat dissipation alumina or diamond.

3. The method of claim 1, wherein; The filling of the fluorescent glass paste is 200% of the volume of the groove.

4. The method of claim 1, wherein; During the second high-temperature sintering, pressure is applied to the surface of the heat dissipation cover plate to realize pressure sintering.

5. A laser color converter structure made using the method of claim 1, wherein: The laser color converter comprises a heat dissipation substrate, a fluorescent glass layer, an adhesive layer and a heat dissipation cover plate, the fluorescent glass layer is arranged on the upper surface of the heat dissipation substrate, the adhesive layer covers the upper surface of the combination of the heat dissipation substrate and the fluorescent glass layer, and the heat dissipation cover plate is arranged on the adhesive layer.

6. The laser color converter structure of claim 5, wherein; The groove is arranged on the upper surface of the heat dissipation substrate, the fluorescent glass layer is filled in the groove, and the thickness of the fluorescent glass layer is the same as the groove depth.

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