CN107819064A - LED encapsulation structure - Google Patents

Abstract

The invention relates to an LED package structure, which comprises: an LED base plate (11), a first silica gel layer (12), a hemispherical lens area (13) and a second silica gel layer (14); wherein, the first silica gel The layer (12) is arranged on the LED base plate (11), the hemispherical lens area (13) is arranged on the first silica gel layer (12), and the second silica gel layer (14) is arranged on the The first silica gel layer (12) and the upper layer of the lens area (13). The LED packaging structure provided by the present invention adopts the structure of the first silica gel layer, the hemispherical lens area and the second silica gel layer; the refractive index of different types of silica gel and phosphor glue in the structure of the first silica gel layer, the hemispherical lens area and the second silica gel layer With different characteristics, lenses are formed in silica gel to improve the problem of light dispersion of LED chips, so that the light emitted by the light source can be more concentrated; at the same time, the refractive index of the first silica gel layer, the second silica gel layer and the hemispherical lens area increase sequentially; it can ensure The LED chip can be more irradiated through the packaging material.

Description

LED package structure

technical field

The invention belongs to the technical field of LED packaging, in particular to an LED packaging structure.

Background technique

At the end of the last century, the breakthrough of III-V compound semiconductors represented by GaN-based materials in the field of blue light chips brought about a revolution in lighting. The symbol of this revolution is the high-power light-emitting diode (Light-Emitting Diode, LED) Semiconductor lighting technology (Solid State Lighting, SSL) as the light source.

LED has the characteristics of long life, high luminous efficiency, good color rendering, safety and reliability, rich colors and easy maintenance. Under the background of increasingly serious environmental pollution, climate warming and increasingly tense energy sources, semiconductor lighting technology developed based on high-power LEDs has been recognized as one of the most promising high-tech fields in the 21st century. This is a great leap in the history of human lighting since gas lighting, incandescent lamps and fluorescent lamps, and has rapidly improved the lighting quality of human life.

At present, LEDs mostly use GaN-based blue wicks plus yellow fluorescent light to generate white light to achieve lighting. This method has the following problems.

1. At present, most of the chips are packaged on a thin metal heat dissipation substrate. Because the metal heat dissipation substrate is thin, has a small heat capacity, and is easy to deform, the contact between the metal heat dissipation substrate and the bottom surface of the heat sink is not close enough to affect the heat dissipation effect.

2. Since the light emitted by the LED light source is generally distributed in a divergent manner, that is, the Lambertian distribution, this causes the illumination brightness of the light source to be insufficiently concentrated, and generally requires secondary shaping through an external lens to meet the lighting needs of specific occasions, which increases production costs. .

Contents of the invention

In order to improve the performance of the LED chip, the invention provides a LED packaging structure; the technical problems to be solved in the invention are achieved through the following technical solutions:

The embodiment of the present invention provides an LED packaging structure, including: LED base plate 11, first silica gel layer 12, hemispherical lens area 13 and second silica gel layer 14; wherein, the first silica gel layer 12 is arranged on the On the LED bottom plate 11 , the hemispherical lens area 13 is disposed on the first silica gel layer 12 , and the second silica gel layer 14 is disposed on the first silica gel layer 12 and the lens area 13 .

In one embodiment of the present invention, the LED bottom plate 11 includes a heat dissipation substrate and LED chips, wherein the LED chips are disposed on the heat dissipation substrate.

In one embodiment of the present invention, the heat dissipation substrate is a heat dissipation substrate made of copper material.

In one embodiment of the present invention, the heat dissipation substrate is provided with several circular grooves; wherein, the circular grooves are along the width direction of the heat dissipation substrate and parallel to the plane of the heat dissipation substrate.

In one embodiment of the present invention, the diameter of the circular grooves is 0.3-2 mm, and the distance between the circular grooves is 0.5-10 mm.

In an embodiment of the present invention, the silica gel of the first silica gel layer 12 does not contain phosphor, and the silica gel of the second silica gel layer 14 contains phosphor.

In one embodiment of the present invention, the phosphors are red, green and blue phosphors.

In one embodiment of the present invention, the hemispherical lens region 13 includes several silica gel hemispheres distributed in a rectangular or diamond shape, wherein the silica gel of the silica gel hemispheres does not contain phosphor.

In one embodiment of the present invention, the second silica gel layer 14 is a hemispherical silica gel layer covering the entire first silica gel layer 12 and the hemispherical lens area 13 .

In one embodiment of the present invention, the LED chip is an ultraviolet LED chip.

Compared with the prior art, the present invention has the following beneficial effects:

1. The LED packaging structure provided by the present invention adopts a heat dissipation substrate provided with a circular groove, which reduces the cost of the heat dissipation substrate while increasing the heat dissipation effect of the heat convection of the air while the strength hardly changes.

2. The LED packaging structure provided by the present invention adopts the structure of the first silica gel layer, the hemispherical lens area and the second silica gel layer; using different types of silica gel and phosphor glue in the structure of the first silica gel layer, the hemispherical lens area and the second silica gel layer Due to the different refractive index, a lens is formed in the silica gel, which improves the problem of light dispersion of the LED chip and makes the light emitted by the light source more concentrated; at the same time, the refractive index of the first silica gel layer, the second silica gel layer, and the hemispherical lens area increases sequentially; It can ensure that more of the LED chip can be irradiated through the packaging material.

3. The silica gel hemispheres provided by the present invention can be evenly arranged in a rectangle, or arranged in a rhombus. It can ensure that the light of the light source is evenly distributed in the concentrated area.

Description of drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following will briefly introduce the accompanying drawings that need to be used in the description of the embodiments. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For Those of ordinary skill in the art can also obtain other drawings based on these drawings without making creative efforts.

Other aspects and features of the present invention will become apparent from the following detailed description with reference to the accompanying drawings. It should be understood, however, that the drawings are designed for purposes of illustration only and not as a limitation of the scope of the invention since reference should be made to the appended claims. It should also be understood that, unless otherwise indicated, the drawings are not necessarily drawn to scale and are merely intended to conceptually illustrate the structures and processes described herein.

Fig. 1 is a schematic diagram of the LED package structure provided by an embodiment of the present invention;

2 is a schematic diagram of a heat dissipation substrate of an LED package provided by an embodiment of the present invention;

FIG. 3 is a flow chart of an LED packaging method provided by another embodiment of the present invention;

Figure 4a-Figure 4b is a schematic diagram of the distribution of hemispherical lenses provided by another embodiment of the present invention;

Fig. 5 is a schematic structural diagram of a highly light-transmitting LED package provided by yet another embodiment of the present invention;

FIG. 6 is a schematic structural diagram of an ultraviolet LED chip provided by yet another embodiment of the present invention.

Detailed ways

The present invention will be described in further detail below in conjunction with specific examples, but the embodiments of the present invention are not limited thereto.

Embodiment one

Please refer to FIG. 1. FIG. 1 is a schematic diagram of an LED package structure provided by an embodiment of the present invention, including: an LED base plate 11, a first silica gel layer 12, a hemispherical lens area 13, and a second silica gel layer 14; wherein, the first The silica gel layer 12 is disposed on the LED base plate 11, the hemispherical lens area 13 is disposed on the first silica gel layer 12, and the second silica gel layer 14 is disposed on the first silica gel layer 12 and the lens District 13 Upper.

Specifically, the refractive index of silica gel in the first silica gel layer 12 , the second silica gel layer 14 and the hemispherical lens area 13 increases sequentially.

Specifically, the LED bottom plate 11 includes a heat dissipation substrate and LED chips, wherein the LED chips are disposed on the heat dissipation substrate.

Preferably, the heat dissipation substrate is a copper material heat dissipation substrate.

Further, please refer to FIG. 2 , which is a schematic diagram of a heat dissipation substrate of an LED package provided by an embodiment of the present invention. The heat dissipation substrate is provided with several circular grooves; wherein, the circular grooves are along the width direction of the heat dissipation substrate and are aligned with The planes of the heat dissipation substrates are parallel.

Preferably, the diameter of the circular grooves is 0.3-2 mm, and the distance between the circular grooves is 0.5-10 mm.

Specifically, the silica gel of the first silica gel layer 12 does not contain phosphor, and the silica gel of the second silica gel layer 14 contains phosphor.

Specifically, the phosphors are red, green and blue phosphors.

Preferably, the hemispherical lens area 13 includes several silica gel hemispheres distributed in a rectangular or diamond shape, wherein the silica gel of the silica gel hemispheres does not contain phosphor.

Specifically, the second silica gel layer 14 is a hemispherical silica gel layer covering the entire first silica gel layer 12 and the hemispherical lens area 13 .

Wherein, the LED chip is an ultraviolet LED chip.

The LED packaging structure provided in this embodiment adopts the process of separating the phosphor powder from the LED chip, which solves the problem of the decrease in the quantum efficiency of the phosphor powder caused by high temperature; the silica gel in contact with the LED chip is high temperature resistant silica gel, which solves the problem of aging and yellowing of the silica gel At the same time, at the same time, the refractive index of the first silica gel layer, the second silica gel layer and the lens area increase sequentially; it can ensure that more light from the LED chip can be irradiated through the packaging material.

Embodiment two

Please refer to FIG. 3 . FIG. 3 is a flow chart of an LED packaging method provided by another embodiment of the present invention. On the basis of the above-mentioned embodiments, this embodiment describes in detail the packaging method of the LED packaging structure of the present invention as follows. Specifically, include the following steps:

S21, selecting a heat dissipation substrate;

S22, selecting LED chips;

S23. Welding the LED chip to the heat dissipation substrate;

S24, coating the first silica gel on the LED chip to form a first silica gel layer;

S25. Prepare a hemispherical lens area above the first silica gel layer;

S26, configuring fluorescent powder glue;

S27. Apply phosphor glue on the first silica gel layer and the hemispherical lens region to form a second silica gel layer; to complete the LED package.

Specifically, step S21 may include:

S211, selecting a heat dissipation substrate and a support;

S212, cleaning the heat dissipation substrate and the support;

S213, drying the heat dissipation substrate and the support by baking.

Preferably, the heat dissipation substrate is made of copper material, the thickness is greater than 0.5 mm and less than 10 mm, and a circular groove is formed in the heat dissipation substrate along the width direction, and the circular groove is parallel to the plane of the heat dissipation substrate along the width direction in the heat dissipation substrate; The diameter of the circular groove is 0.3-2 millimeters, and the distance between the circular holes is 0.5-10 millimeters.

Among them, the use of the heat dissipation substrate provided with circular grooves reduces the cost of the heat dissipation substrate while the strength hardly changes, increases the channels for air circulation, and increases the heat dissipation effect by utilizing the heat convection of the air.

Preferably, the LED chip is an ultraviolet LED chip.

Specifically, step S23 may include:

S231, printing solder and inspecting the crystal bonding of the solder:

S232. Using a reflow soldering process, solder the LED chip to the heat dissipation substrate, and mount the heat dissipation substrate to the bracket.

Specifically, step S24 may include:

S241, coating the first silica gel on the LED chip;

S242, at a temperature of 90-125°C, bake with a mold for 15-60 minutes;

S243. After the baking is completed, the mold is removed to form the first silica gel layer.

Preferably, step S25 may include:

S251. Applying second silica gel on the first silica gel layer to form a third silica gel layer;

S252. Using several hemispherical molds to form several silica gel hemispheres on the third silica gel layer;

S253. After baking with the mold, the mold is removed to form a hemispherical lens area.

Specifically, step S26 may include:

S261, selecting fluorescent powder and silica gel;

S262. Mix the phosphor powder and the silica gel to form phosphor powder glue;

S263. Perform a color test on the phosphor glue;

S264. Baking the phosphor glue.

Further, the phosphors are red, green, and blue phosphors; that is, the phosphor glue contains red, green, and blue phosphors;

Among them, the fluorescent powder glue can continuously adjust the color of light by changing the content of red, green, and blue phosphors. In addition to white light, it can also be changed into any color, and the color temperature of the light source can also be adjusted.

Preferably, step S27 may include:

S271. Apply the phosphor glue on the first silica gel layer and the hemispherical lens area;

S272, using a hemispherical mold to form a second silica gel layer on the phosphor glue;

S273, remove the mold after baking;

S274. Baking at a temperature of 100-150° C. for 4-12 hours to complete the LED package.

Specifically, please refer to Figure 4a-Figure 4b, Figure 4a-Figure 4b is a schematic diagram of the distribution of hemispherical lenses provided by another embodiment of the present invention, the hemispherical lenses in Figure 4a are evenly distributed in the first silica gel layer in a rectangular shape and between the second silica gel layer; in FIG. 4 b , the hemispherical lenses are rhombus-shaped and evenly distributed between the first silica gel layer and the second silica gel layer.

Among them, the silica gel hemispheres can be evenly arranged in a rectangular shape, or in a rhombus staggered arrangement; it can ensure that the light of the light source is evenly distributed in the concentration area.

Further, the silica gel balls have a diameter of 10-200 microns and a spacing of 10-200 microns;

Specifically, after step S27, it also includes: inspecting and packaging the LED packaging structure.

Embodiment Three

Further, please refer to FIG. 5 . FIG. 5 is a schematic diagram of a highly transparent LED package structure provided by another embodiment of the present invention. The LED package structure provided by this embodiment is prepared by the method provided by the above-mentioned embodiment. Specifically, the LED packaging structure includes: a heat dissipation substrate 31 , an LED chip 32 , a first silicone layer 33 , a hemispherical lens area 34 and a second silicone layer 35 from bottom to top.

Specifically, the LED chip is an ultraviolet LED chip; please refer to FIG. 6, which is a schematic structural diagram of an ultraviolet LED chip provided by another embodiment of the present invention, and the ultraviolet LED chip includes a sapphire substrate 301 from bottom to top. , N-type AlGaN layer 302, Al _x Ga _1-x N/ _Aly Ga _1-y N multi-quantum well structure 303, P-type AlGaN barrier layer 304, P-type GaN layer 305; and, set on the P-type GaN The positive electrode 306 on the surface of the layer 305 and the negative electrode 307 on the surface of the N-type AlGaN layer 302 .

Specifically, the first silica gel layer 32 is silica gel that does not contain phosphor, and the second silica gel layer 35 is silica gel containing phosphor, so that the phosphor is separated from the LED chip 32, and the problem of the quantum efficiency of the phosphor caused by high temperature is reduced. .

Specifically, the refractive index of the silica gel in the first silica gel layer 33 , the second silica gel layer 35 and the hemispherical lens area 34 increases sequentially.

Preferably, the thickness of the first silica gel layer 32 is 10 μm˜110 μm, and the thickness of the second silica gel layer 34 is 50 μm˜500 μm.

Preferably, the radius R of the silicone hemisphere in the hemispherical lens area 34 is greater than 10 microns, the distance L between the silicone hemisphere and the LED chip 32 is greater than 3 microns, and the distance A between the silicone hemispheres is 5-10 microns.

Further, in the LED packaging structure, the first silica gel layer 33 can be made of modified epoxy resin, organic silicon material, etc.; the hemispherical lens area 34 is made of polycarbonate, polymethyl methacrylate, glass and other materials; the second The silica gel layer 35 is preferably made of methyl silicone rubber with a refractive index of 1.41, phenyl silicone rubber with a high refractive index (eg, 1.54), or the like.

The LED packaging structure provided in this embodiment adopts a three-layer design of the first silica gel layer, the hemispherical lens area and the second silica gel layer, and the refractive index of the silica gel in the first silica gel layer, the second silica gel layer, and the hemispherical lens area increases sequentially , can effectively suppress total reflection, and at the same time ensure that the light source of the LED chip can be irradiated more through the packaging material.

In summary, the principles and implementation methods of the present invention have been described using specific examples in this paper, and the descriptions of the above embodiments are only used to help understand the present invention and its core ideas; meanwhile, for those of ordinary skill in the art, According to the idea of the present invention, there will be changes in the specific implementation and scope of application. In summary, the content of this specification should not be construed as limiting the present invention, and the scope of protection of the present invention should be defined by the appended claims. prevail.

Claims (10)

1. A kind of 1. LED encapsulation structure, it is characterised in that including：LED bottom plates (11), the first layer of silica gel (12), hemispherical lens area And the second layer of silica gel (14) (13)；Wherein, first layer of silica gel (12) is arranged on the LED bottom plates (11), and described half Sphere lenses area (13) is arranged on first layer of silica gel (12), and second layer of silica gel (14) is arranged at first silica gel On layer (12) and the lens region (13).
2. 2. encapsulating structure according to claim 1, it is characterised in that the LED bottom plates (11) include heat-radiating substrate and LED Chip, wherein, the LED chip is arranged on the heat-radiating substrate.
3. 3. encapsulating structure according to claim 2, it is characterised in that the heat-radiating substrate is copper product heat-radiating substrate.
4. 4. encapsulating structure according to claim 3, it is characterised in that the heat-radiating substrate is provided with some circular grooves；Wherein, The circular groove is along the heat-radiating substrate width and parallel with the heat-radiating substrate plane.
5. 5. encapsulating structure according to claim 4, it is characterised in that a diameter of 0.3--2 millimeters of the circular groove, described Spacing is 0.5-10 millimeters between circular groove.
6. 6. encapsulating structure according to claim 1, it is characterised in that the silica gel of first layer of silica gel (12) is free of fluorescence Powder, the silica gel of second layer of silica gel (14) contain fluorescent material.
7. 7. encapsulating structure according to claim 6, it is characterised in that the fluorescent material is glimmering for red, green, three kinds of blueness Light powder.
8. 8. encapsulating structure according to claim 1, it is characterised in that the packaged lens area (13) is in square including several Shape or the silica gel hemisphere of rhombus distribution, wherein, the silica gel of the silica gel hemisphere is free of fluorescent material.
9. 9. encapsulating structure according to claim 1, it is characterised in that second layer of silica gel (14) is covering described first Layer of silica gel (12) and the hemisphere layer of silica gel in the hemispherical lens area (13).
10. 10. encapsulating structure according to claim 1, it is characterised in that the LED chip is UV LED chip.