CN115172570A - Transparent fluorescent ceramic and LED packaging structure - Google Patents

Abstract

The invention provides a transparent fluorescent ceramic and an LED packaging structure, wherein the transparent fluorescent ceramic comprises a fluorescent ceramic body, a first LED chip and a second LED chip, wherein the fluorescent ceramic body is in a cuboid shape and comprises a first surface and a second surface which are opposite; a recess on the first surface having a central region thereof, the recess for receiving an LED chip; there is also a first annular groove on the first surface surrounding the recess; the first annular groove is filled with first light cut-off resin; the second surface is provided with a conical concave surface which is arranged corresponding to the groove; and a second light-cutting resin is arranged on the conical concave surface. Therefore, white light with yellow or yellow-green light emitted from the top surface of the transparent fluorescent ceramic can be obtained.

Description

A kind of transparent fluorescent ceramic and LED packaging structure

technical field

The invention relates to the field of LED package lighting, in particular to a transparent fluorescent ceramic and an LED package structure.

Background technique

Currently, white light-emitting diodes (WLEDs) are widely used in indoor lighting and most greenhouses as an artificial light device because of their advantages of high energy conversion and long lifetime. The market-oriented white LED packaging method is to mix Ce:YAG phosphor powder with epoxy resin or silica gel uniformly. After Ce3+ is excited by blue light, it emits yellow light through spontaneous radiation, and yellow light is combined with blue light to produce white light. However, the deterioration of polymers (epoxy resin and silicone), packaged chips and phosphors have some problems in the practical application of WLED, such as: degradation of lighting efficiency, change of luminous color, and reduction of lifespan, etc., which will reduce human eyesight. of comfort. Therefore, the emergence of inorganic transparent ceramic materials (such as fluorescent transparent ceramics, glass, glass ceramics) can improve the thermal stability of materials. However, the lack of red part of YAG fluorescent transparent ceramics results in a low color rendering index. Therefore, the supplement of red components is a key to the application of YAG fluorescent transparent ceramics. For this reason, it is of great significance to prepare fluorescent transparent ceramics with high color rendering.

In addition, since the YAG fluorescent transparent ceramic is excited by the blue light emitted by the blue LED to emit yellow light, and then mixed to form white light, due to the uneven excitation, and the blue LED chip itself has high-energy short-wave blue light, its damage to the eyes is inevitable. How to solve the mixed light and prevent blue light damage is the problem to be solved by the present invention.

SUMMARY OF THE INVENTION

Based on solving the above problems, the present invention provides a transparent fluorescent ceramic, comprising:

a fluorescent ceramic body, which is in the shape of a rectangular parallelepiped and includes opposite first and second surfaces;

There is a groove in the middle area on the first surface, the groove is used for accommodating the LED chip;

There is also a first annular groove surrounding the groove on the first surface, and the depth of the first annular groove is more than 50% of the thickness of the body;

The first annular groove is filled with a first light-cutting resin;

There is a conical concave surface corresponding to the groove on the second surface;

A second light-cutting resin is provided on the conical concave surface;

Wherein, the material of the fluorescent ceramic body is Cr/Ce:YAG transparent fluorescent ceramics.

Further, the second surface further has a second annular groove outside the first annular groove, and the second annular groove is filled with a luminescent material.

Further, the depth of the first annular groove is not lower than the depth of the second annular groove.

Further, the first light-cutting resin and the second light-cutting resin are made of the same material, which cut short-wavelength blue light.

Further, the first light-cutting resin and the second light-cutting resin are EVA materials.

Further, the chemical formula of Cr/Ce:YAG is Y _3-x Al _5-y C _y O ₁₂ :Ce _x , wherein x is 0.001-0.06, and y is 0-4.

Further, the body is formed by pressing and sintering raw materials of Y ₂ O ₃ , Al ₂ O ₃ , CeO ₂ and Cr ₂ O ₃ using a suitable mold.

The present invention also provides an LED packaging structure, comprising the above-mentioned transparent fluorescent ceramic, a blue LED chip and a circuit board, wherein the blue LED chip is bonded to the circuit board, and the transparent fluorescent ceramic covers the blue LED A chip, the blue LED chip is accommodated in the groove.

The beneficial effects of the present invention are:

The transparent fluorescent ceramic of the present invention is in the shape of a cuboid, and has a light-cutting resin on its top surface and around the LED chip, and the light-cutting resin can block short-wavelength high-energy blue light, which can prevent damage to the eyes;

There is also a ring-shaped reflective layer around the LED chip. The reflective layer is located outside the ring-shaped optical medium resin. The top surface of the transparent fluorescent ceramic has a conical concave surface, which can reflect a part of the direct light, and this part of the reflected light first passes through The light is cut off by the resin, and then reflected by the reflective layer, so that the light emitted from the top surface of the transparent fluorescent ceramic is yellowish or yellowish-green white light.

Description of drawings

1 is a schematic diagram of an LED package of the present invention;

2 is a schematic diagram of a single LED package of the present invention;

FIG. 3 is a schematic diagram of an optical path of a single LED package of the present invention.

Detailed ways

In order to make the purposes, technical solutions and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are some, but not all, embodiments of the present disclosure. Based on the described embodiments of the present disclosure, all other embodiments obtained by those of ordinary skill in the art without creative efforts fall within the protection scope of the present disclosure.

Unless otherwise defined, technical or scientific terms used in this disclosure shall have the ordinary meaning as understood by one of ordinary skill in the art to which this disclosure belongs. As used in this disclosure, "first," "second," and similar words do not denote any order, quantity, or importance, but are merely used to distinguish the various components. "Comprising" or "comprising" and similar words mean that the elements or things appearing before the word encompass the elements or things recited after the word and their equivalents, but do not exclude other elements or things. Words like "connected" or "connected" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "Down", "Left", "Right", etc. are only used to represent the relative positional relationship, and when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

The transparent fluorescent ceramic of the present invention and the LED packaging structure using the same will be described below with reference to FIGS. 1-3 .

The LED package structure of the present invention includes a plurality of LED chips 20 on the circuit board 40 , and the plurality of LED chips 20 are blue LED chips. A plurality of LED chips 20 are arranged on the circuit board 40 in an array, and the plurality of LED chips 20 are electrically connected to the circuit board 40 and form a series or parallel structure through the circuits in the circuit board 40 .

Each LED chip 20 is covered with a transparent fluorescent ceramic 10 , and the transparent fluorescent ceramic 10 includes a transparent fluorescent ceramic body 30 . The transparent fluorescent ceramic body 30 has a rectangular parallelepiped structure, and has a groove 31 on its lower surface. The groove 31 is bowl-shaped, or has a stepped structure inside. The groove 31 is used for accommodating the LED chip 20 and is disposed in the middle area of the lower surface of the transparent fluorescent ceramic body 30 .

The fluorescent ceramic body 30 is made of Cr/Ce:YAG transparent fluorescent ceramics, and the chemical formula of Cr/Ce:YAG is Y _3-x Al _5-y C _y O ₁₂ :Ce _x , where x is 0.001-0.06 , y is 0-4. It can convert blue light into yellow light, and the fluorescent ceramic body 30 is formed by sintering raw materials Y ₂ O ₃ , Al ₂ O ₃ , CeO ₂ and Cr ₂ O ₃ at high temperature. During the forming process, the fluorescent ceramic body 30 is made by using a mold, so that its upper and lower surfaces have specific structures. Specifically, in addition to the above-mentioned groove 31 for accommodating the LED chip 20 , the lower surface of the fluorescent ceramic body 30 also has two annular grooves, namely a first annular groove 34 closer to the middle area and a second annular groove 34 away from the middle area. Two annular grooves 35 . The first annular groove 34 and the second annular groove 35 surround the groove 31, and the distance between the two can be relatively close. Specifically, the distance between the two can be less than 2 mm.

The first annular groove 34 is filled with a first light-cutting resin 36, and the first light-cutting resin 36 is used to cut off light waves below 420 nm. Specifically, the material of the first light-cutting resin 36 is selected as ethylene-vinyl acetate (EVA) material doped with fluorescent nanoparticles, which also includes other additives such as stabilizers, coupling agents, and antioxidants. The fluorescent nanoparticles can be at least one of titanium oxide, zirconium oxide, and niobium oxide, which have thermal curing properties and can be cured after being filled into the first annular groove 34 .

Further, the second annular groove 35 is also filled with a reflective material 37, and the reflective material 37 may be a metal material such as aluminum or silver. The height of the first light-cutting resin 36 in the first annular groove 34 should not be lower than the height of the reflective material 37 in the second annular groove 35, so that the light first enters the fluorescent ceramic body 30 and is then at least partially converted into yellow light Mix the light, then pass through the first light-cutting resin 36, filter out the high-energy blue light with small wavelengths, and finally exit through the reflection of the reflective material 37 to form the white light output on the upper surface. It is yellowish or yellowish-green white light.

In addition, the upper surface of the fluorescent ceramic body 30 also has a conical concave surface 32 corresponding to the groove 31 , and the concave surface 32 is used to reflect part of the outgoing light. A second light-cutting resin 33 is disposed on the concave surface 32 . The first light-cutting resin 36 and the second light-cutting resin 32 are made of the same material and cut off blue light of lower wavelengths. The first light-cutting resin 36 and the second light-cutting resin 32 are made of EVA material, and the second light-cutting resin 32 is a thin layer, which cuts off short-wavelength blue light from direct light.

According to the above description, the transparent fluorescent ceramic of the present invention includes:

a fluorescent ceramic body, which is in the shape of a rectangular parallelepiped and includes opposite first and second surfaces;

There is a groove in the middle area on the first surface, the groove is used for accommodating the LED chip;

There is also a first annular groove surrounding the groove on the first surface, and the depth of the first annular groove is more than 50% of the thickness of the body;

The first annular groove is filled with a first light-cutting resin;

There is a conical concave surface corresponding to the groove on the second surface;

A second light-cutting resin is provided on the conical concave surface;

Wherein, the material of the fluorescent ceramic body is Cr/Ce:YAG transparent fluorescent ceramics.

Wherein, the second surface further has a second annular groove outside the first annular groove, and the second annular groove is filled with luminescent material.

Wherein, the depth of the first annular groove is not lower than the depth of the second annular groove.

Wherein, the first light-cutting resin and the second light-cutting resin are made of the same material, which cut off blue light with a shorter wavelength.

Wherein, the first light-cutting resin and the second light-cutting resin are EVA materials.

Wherein, the chemical formula of Cr/Ce:YAG is Y _3-x Al _5-y C _y O ₁₂ :Ce _x , wherein x is 0.001-0.06, and y is 0-4.

Wherein, the body is formed by pressing and sintering raw materials of Y ₂ O ₃ , Al ₂ O ₃ , CeO ₂ and Cr ₂ O ₃ using a suitable die.

The present invention also provides an LED package structure, comprising the above-mentioned transparent fluorescent ceramic, a blue LED chip and a circuit board, wherein the blue LED chip is bonded to the circuit board, and the transparent fluorescent ceramic covers the blue light LED chips, the blue LED chips are accommodated in the grooves.

The expressions "exemplary embodiment," "exemplary," etc. used in this disclosure do not refer to the same embodiment, but are instead provided to highlight different specific features. However, the above-described examples and exemplary embodiments do not exclude their realization in combination with features of other examples. For example, even if a description of a particular example is not provided in another example, the description may be construed as an explanation in relation to the other example unless otherwise stated or contrary to the description in the other example.

The terms used in the present invention are only used to illustrate examples, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise.

While example embodiments have been shown and described above, it will be apparent to those skilled in the art that modifications and changes can be made without departing from the scope of the invention as defined by the claims.

Claims (8)

1. A transparent fluorescent ceramic, comprising: a fluorescent ceramic body, which is in the shape of a rectangular parallelepiped and includes opposite first and second surfaces; There is a groove in the middle area on the first surface, the groove is used for accommodating the LED chip; There is also a first annular groove surrounding the groove on the first surface, and the depth of the first annular groove is more than 50% of the thickness of the body; The first annular groove is filled with a first light-cutting resin; There is a conical concave surface corresponding to the groove on the second surface; A second light-cutting resin is provided on the conical concave surface; Wherein, the material of the fluorescent ceramic body is Cr/Ce:YAG transparent fluorescent ceramics. 2 . The transparent fluorescent ceramic according to claim 1 , wherein the second surface further has a second annular groove outside the first annular groove, and the second annular groove is filled with a luminescent material. 3 . 3 . The transparent fluorescent ceramic according to claim 2 , wherein the depth of the first annular groove is not lower than the depth of the second annular groove. 4 . 4 . The transparent fluorescent ceramic according to claim 1 , wherein the first light-cutting resin and the second light-cutting resin are made of the same material, which cut off blue light with a shorter wavelength. 5 . 5 . The transparent fluorescent ceramic according to claim 4 , wherein the first light-cutting resin and the second light-cutting resin are EVA materials. 6 . 6. The transparent fluorescent ceramic according to claim 1, wherein the chemical formula of the Cr/Ce:YAG is Y _{3- x} Al _5-y C _y O ₁₂ :Ce _x , wherein x is 0.001-0.06, y is 0-4. 7 . The transparent fluorescent ceramic according to claim 6 , wherein the body is formed by pressing and sintering raw materials of Y ₂ O ₃ , Al ₂ O ₃ , CeO ₂ and Cr ₂ O ₃ using a suitable mold. 8 . 8. An LED package structure, comprising the transparent fluorescent ceramic according to any one of claims 1-7, a blue LED chip and a circuit board, wherein the blue LED chip is bonded to the circuit board, and the transparent fluorescent The ceramic covers the blue LED chip, and the blue LED chip is accommodated in the groove.

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