A small light-emitting module and laser white light device

Abstract

The present invention discloses a small light-emitting module and a laser white light device, which belong to the field of lighting and display technology. The light-emitting module includes: a wavelength conversion unit, two copper electrodes and an LD chip; the LD chip is fixed between the two copper electrodes and electrically connected to the two copper electrodes, and the wavelength conversion unit is arranged on the two copper electrodes, and there is a gap between the LD chip; the two copper electrodes are used to supply power to the LD chip after being powered on, so that the LD chip emits a blue laser; the wavelength conversion unit is used to provide fluorescent conversion materials for the LD chip to excite and convert, emit yellow light, and mix with the blue laser to form white light. A white light device based on the above-mentioned light-emitting module is also provided. The present invention solves the problems of excessive temperature of fluorescent conversion materials and excitation chips, and the large size and difficulty of integration of traditional semiconductor white light sources, and has the advantages of miniaturization, high power, high brightness, good heat dissipation and low light loss.

Description

Technical Field

[0001] The present invention belongs to the field of lighting and display technology, and more specifically, relates to a small light-emitting module and a laser white light device. Background Art

[0002] With the continuous improvement of semiconductor manufacturing technology and the reduction of production costs, people's demand for high-brightness lighting equipment is increasing. Semiconductor lighting is developing towards high current, high power density, lightweight and small size. Laser white light source has emerged as a new generation of high-brightness solid-state light source.

[0003] Laser white light sources (white light LD) often use laser fluorescence technology, that is, the blue light LD chip excites the yellow fluorescent layer (YAG:Ce). Due to the high light power density and small radiation spot of the blue light LD, the fluorescent layer must withstand high laser radiation energy and fluorescence conversion heat, which puts higher requirements on the heat resistance of the fluorescent conversion material.

[0004] In the prior art, highly thermally stable inorganic fluorescent conversion materials (luminescent single crystals, fluorescent ceramics and fluorescent glass) are used to replace traditional organic fluorescent conversion materials, and a corresponding "laser + inorganic fluorescent conversion material" white light source system is constructed. However, the existing white light LD simply uses a blue laser (or a laser combined with a related optical lens) as an excitation source to excite the fluorescent conversion material, which makes the white light LD bulky and complex. As a result, it is difficult for the white light LD to achieve small-size device-level packaging like white light LEDs, which limits the miniaturization and integrated application of white light LDs.

[0005] In addition, the thermal dissipation of the fluorescent conversion material in the white light LD is an issue that cannot be ignored. It determines the interaction between the laser beam and the fluorescent conversion material. The thermal dissipation will seriously affect the luminescence performance of the white light LD. Summary of the invention

[0006] In view of the defects of the prior art and the need for improvement, the present invention provides a small laser white light device, which aims to reduce the volume of the white light source, realize the miniaturization of the white light source, and at the same time disperse the high energy generated by the interaction between the fluorescent conversion material and the excitation chip.

[0007] To achieve the above object, according to one aspect of the present invention, there is provided a small light emitting module, characterized in that it comprises: a wavelength conversion unit, two copper electrodes and an LD chip; the LD chip is fixed between the two copper electrodes and electrically connected to the two copper electrodes, and the wavelength conversion unit is arranged on the two copper electrodes and has a gap between the LD chip;

[0008] The two copper electrodes are used to supply power to the LD chip after being powered on, so that the LD chip emits blue laser; the wavelength conversion unit is used to provide fluorescent conversion material for the LD chip to excite and convert, emit yellow light, and mix with the blue laser to form white light.

[0009] Furthermore, a microlens array or a concave lens is arranged in the gap between the wavelength conversion unit and the LD chip.

[0010] Furthermore, it also includes an adhesive layer arranged between the wavelength conversion unit and the copper electrode, and the adhesive layer is made of a high thermal conductivity material, and the thermal conductivity coefficient is greater than 30 W / (m·K).

[0011] Furthermore, the wavelength conversion unit is fluorescent glass, fluorescent ceramic or fluorescent single crystal.

[0012] According to another aspect of the present invention, there is provided a laser white light device, comprising a ceramic substrate, a dam arranged on the ceramic substrate, a transparent cover plate arranged opposite to the ceramic substrate, and one or more light-emitting modules as described in any one of the first aspects; the ceramic substrate, the dam and the transparent cover plate form a cavity, and the light-emitting module is arranged on the ceramic substrate.

[0013] Furthermore, a metal layer is arranged between the light emitting module and the ceramic substrate, and a conductive through hole is arranged on the ceramic substrate for the metal layer to be connected to an external power source.

[0014] Furthermore, the metal layer is electrically connected to the copper electrode.

[0015] Furthermore, the inner surface of the dam has a diffuse reflection layer or a specular reflection layer.

[0016] Furthermore, a welding layer is provided between the dam and the transparent cover plate.

[0017] Furthermore, the metal layer is made of an alloy of copper, gold and tin; the ceramic substrate is made of aluminum nitride; and the transparent cover is made of sapphire, diamond or glass.

[0018] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects:

[0019] (1) The present invention uses an LD chip as a blue light source and integrates the LD chip with a wavelength conversion unit, thereby reducing the volume of the light-emitting module and realizing miniaturization and integration of white light sources. At the same time, the LD chip and the wavelength conversion unit are directly in contact with the copper electrode, so that the high energy generated by the LD chip and the wavelength conversion unit can be dispersed through the heat conduction of the copper electrode, solving the problem in the prior art that the interaction between the laser beam and the fluorescent conversion material causes the fluorescent material to be subjected to high heat.

[0020] (2) Preferably, a microlens array or a concave lens is provided between the wavelength conversion unit and the LD chip, so as to diverge the linear laser emitted by the LD chip and make the light beam more uniform.

[0021] (3) Preferably, the adhesive layer provided between the wavelength conversion unit and the copper electrode is also made of a high thermal conductivity material, which can not only fix the wavelength conversion unit and the copper electrode, but also effectively conduct the heat generated by the wavelength conversion unit under high-power blue light excitation to the copper electrode.

[0022] (4) Preferably, the metal layer disposed between the copper electrode and the ceramic substrate can not only provide a conductive path for the copper electrode, but also further disperse the heat conducted from the wavelength conversion unit and the LD chip to the copper electrode. Meanwhile, the ceramic substrate also has good thermal conductivity properties, further reducing heat concentration.

[0023] (5) Preferably, the inner surface of the dam has a reflective property, which can reduce light loss and improve the performance and reliability of the white light source. The LD chip used has a higher brightness than the existing LED chip.

[0024] In summary, the present invention solves the problems of excessively high temperatures of fluorescent conversion materials and excitation chips, and the large size and difficulty in integration of traditional semiconductor white light sources, and improves the performance and reliability of miniaturized semiconductor white light source packaging. It has the advantages of miniaturization, high power, high brightness, good heat dissipation and low light loss, and can meet various application requirements of small and high-brightness semiconductor white light sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 It is a structural schematic diagram of the light-emitting module and the laser white light device of the present invention;

[0026] Figure 2 It is a schematic diagram of arranging a microlens array between the wavelength conversion unit and the LD chip in the present invention;

[0027] Figure 3 Schematic diagram of a concave lens disposed between the wavelength conversion unit and the LD chip in the present invention. In all the drawings, the same reference numerals are used to represent the same elements or structures, wherein:

[0028] 1-wavelength conversion unit, 2-adhesive layer, 3-copper electrode, 4-LD chip, 5-metal layer, 6-ceramic substrate, 7-dam, 8-welding layer, 9-transparent cover, 101-microlens array, 301-concave lens. DETAILED DESCRIPTION

[0029] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0030] like Figure 1 As shown, the light-emitting module of the present invention mainly includes: a wavelength conversion unit 1, two copper electrodes 3 and an LD chip 4; the LD chip 4 is fixed between the two copper electrodes 3 and electrically connected to the two copper electrodes 3, and the wavelength conversion unit 1 is arranged on the two copper electrodes 3, and there is a gap between the wavelength conversion unit 1 and the LD chip 4; after the two copper electrodes 3 are energized, power is supplied to the LD chip 4, so that the LD chip 4 emits a blue laser, which excites the wavelength conversion unit 1 to emit yellow light, and mixes with the blue light to form white light.

[0031] The wavelength conversion unit 1 is an inorganic phosphor for blue light excitation, which is used to provide fluorescent conversion material for the LD chip 4 to excite and convert, emit yellow light, and mix with the blue light emitted by the blue laser chip to form white light. Specifically, it can be fluorescent glass, fluorescent ceramics or fluorescent single crystals, with a visible light transmittance of not less than 60%. In this embodiment, the material is fluorescent ceramics or glass containing YAG yellow phosphor, and the visible light transmittance is 75%.

[0032] The copper electrode 3 is also used for heat conduction, which conducts the heat generated by the wavelength conversion unit 1 and the LD chip 4 to the copper electrode 3, and disperses the high heat generated when the blue laser emitted by the LD chip interacts with the wavelength conversion unit 1.

[0033] The LD chip 4 is a blue laser chip.

[0034] The light-emitting module provided by the present invention uses the LD chip 4 to emit blue laser light, and integrates the wavelength conversion unit 1 with the LD chip 4, thereby greatly reducing the volume of the light-emitting module.

[0035] At the same time, the LD chip and the wavelength conversion are directly in contact with the copper electrode. The copper electrode 3 can conduct the heat generated by the wavelength conversion unit 1 and the LD chip 4, and dissipate the high heat generated when the blue laser emitted by the LD chip interacts with the wavelength conversion unit 1.

[0036] As a preference, Figure 2 and Figure 3 As shown, a microlens array 101 or a concave lens 301 is provided between the wavelength conversion unit 1 and the LD chip 4 to diverge the laser light emitted by the LD chip 4 and make the light beam more uniform. Specifically, the microlens array 101 is located on the incident surface of the blue laser light incident on the wavelength conversion unit.

[0037] When a concave lens 301 is provided between the wavelength conversion unit 1 and the LD chip 4 , a groove is provided at one end of the two copper electrodes 3 close to the wavelength conversion unit, and the concave lens 301 is placed in the groove and is located between the wavelength conversion unit 1 and the LD chip 4 .

[0038] It also includes an adhesive layer 2 disposed between the wavelength conversion unit 1 and the copper electrode 3, which is made of a high thermal conductivity material with a thermal conductivity greater than 30W / (m·K), and is used to fix the wavelength conversion unit 1 and the copper electrode 3, and can effectively conduct the heat generated by the wavelength conversion unit under high-power blue light excitation to the copper electrode 3 while meeting the requirements of bonding strength. In this embodiment, the adhesive layer 2 is made of a high thermal conductivity glue with a thermal conductivity of 35W / (m·K).

[0039] Based on the above-mentioned light-emitting module, the present invention also provides a small laser white light device, comprising a ceramic substrate 6, a dam 7 arranged around the ceramic substrate 6, a transparent cover plate 9 arranged opposite to the ceramic substrate 6, and the above-mentioned one or more light-emitting modules, the ceramic substrate 6, the dam 7 and the transparent cover plate 9 are welded to form a cavity, and the one or more light-emitting modules are arranged on the ceramic substrate 6. Among them, the ceramic substrate 6 also has thermal conductivity, which can disperse and conduct the heat generated by the wavelength conversion unit 1 and the LD chip 4. The transparent cover plate is used for light transmission.

[0040] Preferably, a metal layer 5 is disposed between the light emitting module and the ceramic substrate 6, and a conductive through hole is disposed on the ceramic substrate 6 for the metal layer 5 to pass through the ceramic substrate 6 to connect to an external power source, and the metal layer 5 is electrically connected to the copper electrode 3, so as to energize the copper electrode 3 through the external power source of the metal layer 5. Preferably, the copper electrode is fixed to the ceramic substrate by welding through the metal layer.

[0041] The metal layer 5 is a vertical interconnection structure, that is, the metal layer 5 is provided on the upper and lower surfaces of the ceramic substrate 6, and the two metal layers 5 are vertically interconnected through the conductive through holes on the ceramic substrate 6. The metal layer 5 is also used for heat conduction, and the heat conducted from the wavelength conversion unit 1 and the LD chip 4 to the copper electrode 3 is further conducted to the metal layer 5.

[0042] Preferably, the metal layer 5 is made of an alloy of copper, gold and tin. The ceramic substrate 6 is made of aluminum nitride.

[0043] The inner surface of the dam 7 has a reflective property, which can reduce light loss, and can be a diffuse reflection layer or a specular reflection layer, and its reflectivity is greater than 90%. In this embodiment, the reflectivity is 95%.

[0044] Preferably, a welding layer 8 is provided between the dam 7 and the transparent cover plate 9 for welding the dam 7 and the transparent cover plate 9. The welding layer 8 is made of metal solder; the transparent cover plate 9 is made of sapphire, diamond or glass, and its transmittance is greater than 90%. In this embodiment, it is sapphire or glass, and its transmittance is 95%.

[0045] The present invention adopts an integrated approach to simultaneously solve the heat dissipation problem of the excitation chip and the fluorescent conversion material and realizes the miniaturization of the white light source, thereby improving the luminous performance of the chip and the luminous efficiency of the fluorescent conversion material, and can meet various application requirements of small high-brightness laser white light devices.

[0046] It will be easily understood by those skilled in the art that the above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A small light emitting module, characterized in that: include: A wavelength conversion unit (1), two copper electrodes (3), an LD chip (4), a metal layer (5) and a ceramic substrate (6); the LD chip (4) is fixed between the two copper electrodes (3) and electrically connected to the two copper electrodes (3); the wavelength conversion unit (1) is arranged on the two copper electrodes (3) and has a gap between the LD chip (4); the upper and lower surfaces of the ceramic substrate (6) are both provided with the metal layer (5), and the two layers of the metal layer (5) are vertically interconnected through conductive through holes on the ceramic substrate (6); the metal layer (5) is used for an external power supply, and the metal layer (5) is electrically connected to the copper electrodes (3); The two copper electrodes (3) are used to supply power to the LD chip (4) after being energized, so that the LD chip (4) emits blue laser light; the wavelength conversion unit (1) is used to provide fluorescent conversion material for the LD chip (4) to excite and convert, emit yellow light, and mix with the blue laser light to form white light; It also includes an adhesive layer (2) arranged between the wavelength conversion unit (1) and the copper electrode (3).

2. The light emitting module according to claim 1, characterized in that: A microlens array (101) or a concave lens (301) is arranged in the gap between the wavelength conversion unit (1) and the LD chip (4).

3. The light emitting module according to claim 2, characterized in that: The adhesive layer (2) is made of a high thermal conductivity material, and the thermal conductivity coefficient is greater than 30 W / (m·K).

4. The light emitting module according to claim 3, characterized in that: The wavelength conversion unit is fluorescent glass, fluorescent ceramic or fluorescent single crystal.

5. A laser white light device, characterized in that: The invention comprises a dam (7) arranged on the ceramic substrate (6), a transparent cover plate (9) arranged opposite to the ceramic substrate (6), and one or more light-emitting modules according to any one of claims 1 to 4; the ceramic substrate (6), the dam (7) and the transparent cover plate (9) form a cavity, and the light-emitting module is arranged on the ceramic substrate (6).

6. The device according to claim 5, characterized in that The inner surface of the dam (7) has a diffuse reflection layer or a specular reflection layer.

7. The device according to claim 6, characterized in that A welding layer (8) is provided between the dam (7) and the transparent cover plate (9).

8. The device according to claim 7, characterized in that The material of the metal layer (5) is an alloy of copper, gold and tin; the material of the ceramic substrate (6) is aluminum nitride; and the material of the transparent cover plate (9) is sapphire, diamond or glass.

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