CN101814558B - Light-emitting diode packaging structure - Google Patents

Abstract

The invention discloses a light emitting diode packaging structure which comprises a supporting substrate, a light emitting diode chip, a glue blocking structure and fluorescent glue. The light emitting diode chip is arranged on the supporting substrate and electrically connected with the supporting substrate, and the light emitting diode chip is provided with a base material and a light emitting layer arranged on the base material. The glue blocking structure is arranged on the substrate of the light emitting diode chip and surrounds the light emitting layer, and the fluorescent glue is filled in an area formed by the glue blocking structure, the substrate and the light emitting layer.

Description

Light-emitting diode packaging structure

technical field

The invention relates to a light emitting diode packaging structure. More specifically, the present invention relates to an LED packaging structure that improves phosphor distribution.

Background technique

Due to the characteristics of high brightness and low power consumption of light-emitting diodes (LEDs), LEDs have rapidly replaced traditional light sources in applications such as lighting and displays. As a light source for lighting, high-brightness white light is often required. Therefore, the industry has invested a lot of effort in the research and development of white light LEDs.

At present, it is known that a high-brightness white light-emitting diode can be obtained by using phosphor powder in combination with a blue-light chip (for example: GaN). The blue light emitted by the chip will excite the phosphor to generate light of another wavelength (for example, yellow light). The desired color of white light can be obtained by mixing the blue light and the yellow light. Among them, the packaging of light-emitting diodes is usually carried out by means of dispensing and surface coating.

The advantage of packaging LEDs by dispensing and surface coating is that the process is simple, but during the dispensing process, due to the difficulty in controlling the amount of glue, it is easy to cause uneven chromaticity.

For example, referring to FIG. 1 , the problems of the prior art LED packaging structure will be described. In FIG. 1 , the existing light-emitting diode packaging structure 10 includes: a support substrate 11, on which a pad 13 is arranged; a substrate 15; a light-emitting layer 17; an electrode 18; a wire 20, connecting the electrode 18 to the support substrate Matching pad 13 on 11; and a fluorescent encapsulating colloid 22 containing fluorescent powder for sealing the matching pad 13, substrate 15, light-emitting layer 17, electrodes 18 and wires 20 on the supporting substrate 11.

The fluorescent encapsulant 22 containing fluorescent powder will naturally form a curved hemispherical shape during the process of dispensing and surface coating. Even if the fluorescent powder is evenly dispersed in the colloid, because the thickness of the colloid above the luminescent layer is not the same, the light emitted from different regions of the luminescent layer will pass through different amounts of phosphor powder, so that the final light color emitted by the LED will vary with the thickness of the colloid. And change.

The existing light-emitting diode packaging structure is limited by the structure and cannot effectively disperse the phosphor evenly. Therefore, an improved light-emitting diode packaging structure is required to overcome the aforementioned problems in order to achieve better color uniformity and faster manufacturing process, and higher yield.

Contents of the invention

In order to solve the aforementioned problems and the problems of the prior art, an object of the present invention is to block the overflow of fluorescent glue by forming a glue blocking structure, so that the fluorescent glue can evenly cover the light-emitting layer, so as to improve the problem of uneven light color of light-emitting diodes .

The invention proposes a light emitting diode packaging structure, which includes a supporting substrate, a light emitting diode chip, a glue blocking structure and a fluorescent glue. The light emitting diode is arranged on the supporting substrate and electrically connected with the supporting substrate, and the light emitting diode chip has a base material and a light emitting layer arranged on the base material. The glue blocking structure is arranged on the base material of the LED chip and surrounds the light emitting layer, and the fluorescent glue is filled in a region formed by the glue blocking structure, the base material and the light emitting layer.

In an embodiment of the present invention, the LED packaging structure further includes an encapsulant disposed on the supporting substrate and covering the LED chip.

In an embodiment of the present invention, the glue blocking structure includes a first metal layer and a second metal layer formed on the first metal layer.

In one embodiment of the present invention, the rubber blocking structure is selected from the following groups: gold (Au), chromium (Cr), copper (Cu), silver (Ag), platinum (Pt), titanium (Ti), aluminum ( Al), and its alloys.

In one embodiment of the present invention, the light emitting diode chip further includes a first electrode and a second electrode, the first electrode is arranged on one side of the base material of the light emitting diode chip and connected to the supporting substrate, and the second electrode is arranged on the light emitting diode chip. diode on chip.

In one embodiment of the present invention, the first electrode is electrically connected to the base material of the LED chip, and the second electrode is electrically connected to a matching pad on a supporting substrate. The second electrode is electrically connected to the matching pad on the support substrate through a wire.

In an embodiment of the present invention, the LED chip further includes a first electrode and a second electrode, and the first electrode and the second electrode are disposed on the light emitting layer of the LED chip opposite to each other. The first electrode and the second electrode are respectively electrically connected to a matching pad on a supporting substrate through a wire.

In an embodiment of the present invention, the fluorescent glue includes at least one kind of fluorescent powder.

Description of drawings

FIG. 1 is a schematic structural diagram of a light emitting diode package in the prior art;

2 is a schematic cross-sectional view of a light emitting diode packaging structure according to an embodiment of the present invention;

FIG. 3 is a schematic cross-sectional view of a light emitting diode package structure according to another embodiment of the present invention.

[Description of main component symbols]

10 LED packaging structure

11 Support substrate

13 matching cushion

15 Substrate

17 luminous layer

18 electrodes

20 wires

22 Fluorescent encapsulation colloid

110 support substrate

120 first electrode

130 with cushion

132 with cushion

150 substrate

170 luminous layers

180 second electrode

190 rubber blocking structure

192 first metal layer

194 second metal layer

200 wires

202 wire

210 fluorescent glue

212 colloid

214 phosphor

220 encapsulation colloid

Detailed ways

While the present invention will be described in terms of a number of preferred embodiments, other embodiments (including embodiments that do not provide all of the advantages and features set forth herein) known to those of ordinary skill in the art also fall within the scope of the present invention. within the scope of the present invention. Accordingly, the scope of the present invention is defined only with reference to the appended claims and their equivalents.

The purpose, functions, features, and advantages of the present invention can be further understood from the following preferred embodiments of the present invention with the accompanying drawings.

Please refer to FIG. 2 , which is a schematic cross-sectional view of an LED packaging structure according to an embodiment of the present invention. The LED packaging structure of the present invention includes a supporting substrate 110 , a LED chip and a fluorescent glue 210 , and the fluorescent glue 210 is formed by mixing at least one fluorescent powder 214 and a glue 212 .

In detail, the light emitting diode chip is disposed on the support substrate 110 and is electrically connected to the support substrate 110. The light emitting diode chip has a base material 150, a light emitting layer 170 and a glue blocking structure 190, wherein the light emitting layer 170 is disposed on the base material 150 , the light emitting layer is, for example, a compound containing indium or a nitride containing aluminum, and different compounds are used according to the color of light emission. The luminescent layer 170 emits light with a specific wavelength, and the emitted light excites the fluorescent glue 210 to generate light with another wavelength, and the desired light color is obtained by mixing the two kinds of light.

It is worth noting that, in the light emitting diode packaging structure of the present invention, a glue blocking structure 190 is formed on the base material 150 of the light emitting diode chip and surrounded by the light emitting layer 170. The glue blocking structure 190 includes a first metal layer 192 and a layer formed on the second A second metal layer 194 on the first metal layer 192 . It should be noted that since the electroplating method can increase the film thickness relatively quickly, the glue blocking structure 190 is first formed on the first metal layer 192 by evaporation, and then the thickness is increased by electroplating to form the second metal layer 194 , so that the time required for the process can be effectively reduced. In this embodiment, the thickness of the first metal layer 192 is 0.3 μm to 2 μm, and the thickness of the second metal layer 194 is 200 μm to 300 μm. In addition, the rubber blocking structure 190 is selected from the group consisting of gold (Au), chromium (Cr), copper (Cu), silver (Ag), platinum (Pt), titanium (Ti), aluminum (Al) and alloys thereof .

Since the light-emitting diode packaging structure of the present invention has the glue blocking structure 190, therefore, in the process of filling the fluorescent glue 210, the glue blocking structure 190 formed around the light-emitting layer 170 will block the overflow of the fluorescent glue 210, so that the fluorescent glue 210 Evenly covering the light-emitting layer 170 to improve the problem of uneven light color of the light-emitting diode.

In addition, in an embodiment of the present invention, the LED packaging structure further includes an encapsulant 220 disposed on the supporting substrate 110 and covering the LED chip.

The light emitting diode packaging structure of the present invention has a first electrode 120 and a second electrode 180 , and the first electrode 120 and the second electrode 180 have different positions. In one embodiment, the first electrode 120 is formed on one side of the base material 150 of the LED and connected to the support substrate 110, and the second electrode 180 is formed on the light emitting layer 180 of the LED chip to form a vertical conduction type. LED packaging structure. The first electrode 120 is electrically connected to the substrate 150 of the LED, and the second electrode 180 is electrically connected to the matching pad 130 on the supporting substrate through a wire 200 . Certainly, the first electrode 120 and the second electrode 180 can be disposed on the light-emitting layer of the light-emitting diode chip at the same time, as shown in FIG. The mating pads 132, 130 are connected.

Through the novel structure in the light emitting diode packaging structure of the present invention, since the glue blocking structure 190 is arranged on the light emitting diode chip, it can effectively block and avoid the phenomenon of overflow generated when adding the fluorescent glue 210, so that the fluorescent glue 210 And the phosphor powder 214 contained therein can be evenly distributed on the surface of the light emitting layer 170 . Through this, when the blue light emitted by the light-emitting layer 170 as the active layer passes through the fluorescent glue 210, since the thickness of the irradiated fluorescent glue 210 is very uniform, the amount of the excited phosphor powder 214 is also uniformly distributed, and the obtained The white light color is also quite uniform.

The color of white light can be measured by a commercially available spectrometer and displayed on the C.I.E. (Commission Internationale de l’clairage) color coordinate diagram. C.I.E. is an international organization dedicated to setting standards for photometry and color. The C.I.E color coordinate diagram is a diagram representing light color on the xy plane coordinates. Taking white light as an example, the position of its color coordinate is about CIE(x, y)=(0.3,0.3).

In an exemplary embodiment, the CIEx at the central position of the light-emitting diode of the present invention is about 0.30, and the CIEx at the edge position is about 0.32, compared with the CIEx at the center position of the light-emitting diode in the prior art is about 0.30, and the CIEx at the edge position is about 0.30. It is about 0.38, that is to say, the light-emitting diode of the present invention exhibits a significantly improved color uniformity distribution. CIEy also has a similar effect.

It should be understood that for the sake of convenience and clear expression, the spatial terms such as "above", "below", "upper" and "lower" used in this specification as contrasting figures are relative words. These terms are not limiting and absolute.

Furthermore, it should be understood that any suitable alternative to the substrate of the present invention may be used, for example, SiC, carbide, or metal, etc. may be used. Depending on needs, the base material of the present invention may also be selectively connected with a heat sink or a bonding layer. Such substitutions and equivalent variations will be apparent to those skilled in the art.

Although the present invention has been disclosed in detail using the above-mentioned preferred examples, it is not intended to limit the present invention. Those who are familiar with this invention can make various changes and modifications without departing from the spirit and scope of the present invention. Therefore, the protection scope of the present invention should be regarded as defined by the scope of the appended patent application.

Claims (10)

1. package structure for LED is characterized in that comprising:

One supporting substrate;

One light-emitting diode chip for backlight unit is arranged on this supporting substrate and electrically connects with this supporting substrate, and this light-emitting diode chip for backlight unit has a base material and and is arranged at the luminescent layer on this base material;

One glue-guard structure is arranged on the base material of this light-emitting diode chip for backlight unit and ring is established this luminescent layer; And

One fluorescent glue, filling is in the formed zone of this glue-guard structure, this base material and this luminescent layer.

2. package structure for LED as claimed in claim 1 is characterized in that, also comprises a packing colloid, is disposed on this supporting substrate, and covers this light-emitting diode chip for backlight unit.

3. package structure for LED as claimed in claim 1 is characterized in that, this glue-guard structure comprises that a first metal layer and is formed at second metal level on this first metal layer.

4. package structure for LED as claimed in claim 3 is characterized in that, this glue-guard structure is to be selected from the group that comprises following person: golden Au, chromium Cr, copper Cu, silver-colored Ag, platinum Pt, titanium Ti, aluminium Al and alloy thereof.

5. package structure for LED as claimed in claim 1; It is characterized in that; This light-emitting diode chip for backlight unit also comprises one first electrode and one second electrode; This first electrode be arranged at this light-emitting diode chip for backlight unit base material a side and be connected with this supporting substrate, and this second electrode is arranged at the luminescent layer upside of this light-emitting diode chip for backlight unit.

6. package structure for LED as claimed in claim 5 is characterized in that, the base material of this first electrode and this light-emitting diode chip for backlight unit electrically connects, and the pad of joining on this second electrode and this supporting substrate electrically connects.

7. package structure for LED as claimed in claim 6 is characterized in that, this second electrode electrically connects through the pad of joining on a lead and this supporting substrate.

8. package structure for LED as claimed in claim 1 is characterized in that, this light-emitting diode chip for backlight unit also comprises one first electrode and one second electrode, and this first electrode and this second electrode are relatively arranged on the luminescent layer of this light-emitting diode chip for backlight unit.

9. package structure for LED as claimed in claim 8 is characterized in that, this first electrode and this second electrode electrically connect through the pad of joining on a lead and this supporting substrate respectively.

10. package structure for LED as claimed in claim 1 is characterized in that, this fluorescent glue comprises at least a fluorescent material and a kind of colloid.

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