CN111952292A - Light-emitting device and method of making the same - Google Patents

Abstract

The invention provides a light-emitting device and a preparation method thereof, wherein the device comprises: a flip-chip LED chip; a silica gel protective layer arranged on the surface of the light-emitting side of the flip-chip LED chip; The light emitting layer is arranged on the surface of the silica gel protective layer on the light emitting side surface, and the light emitting layer contains the light conversion material; the blocking layer is arranged on the surface of the light emitting layer to protect the light emitting layer; The light-reflecting layer contains light-reflecting particles. The light conversion material in the light emitting layer is surrounded by a silica gel protective layer, a barrier layer and a light reflection layer, which solves the problem of unstable performance during use, and at the same time improves the color gamut and brightness of the light-emitting device.

Description

Light-emitting device and method of making the same

technical field

The present invention relates to the technical field of semiconductors, in particular to a light-emitting device and a preparation method thereof.

Background technique

With the rapid development of display technology, people's demand for displays is getting higher and higher. Based on the characteristics of high light efficiency, low carbon, environmental protection, and energy saving of LEDs, most TVs and mobile phones currently use LEDs as backlight sources. In order to meet the requirements of high color gamut coverage of LED backlights, the industry has tried to introduce some new phosphor materials with narrow half-wave widths, but these materials have some reliability defects and their performance is unstable during use.

SUMMARY OF THE INVENTION

In order to overcome the above deficiencies, the present invention provides a light-emitting device and a preparation method thereof, which effectively solve the technical problem of unstable performance in the process of applying a new phosphor material with a narrow half-wave width in the prior art.

The technical scheme provided by the present invention is:

A light-emitting device, comprising:

Flip-chip LED chip;

a silicone protective layer disposed on the surface of the light-emitting side of the flip-chip LED chip;

a light emitting layer arranged on the surface of the silica gel protective layer on the light emitting side surface opposite to the electrode side surface in the flip-chip LED chip, and the light emitting layer contains a light conversion material;

a blocking layer disposed on the surface of the light emitting layer for protecting the light emitting layer; and

A light reflection layer is arranged around the flip-chip LED chip and on the side surface of the electrode, and the light reflection layer contains light reflection particles.

A method for preparing a light-emitting device, comprising:

A barrier layer is prepared on the surface of the support film;

preparing a light layer on the surface of the blocking layer, and the light output layer contains a light conversion material;

preparing a viscous silica gel protective layer on the surface of the light emitting layer, and the viscosity of the silica gel protective layer is greater than 1000mpa.s;

Arrange a plurality of flip-chip LED chips on the surface of the silica gel protective layer, and press them together; the thickness of the silica gel protective layer on the side of the flip-chip LED chip after pressing is not greater than the thickness of the flip-chip LED chip;

Curing the laminated silicone protective layer and cutting to obtain a single white light chip;

Rearrange the white light chips obtained by cutting on the surface of the support film, and fill light reflection glue between the white light chips to prepare a light reflection layer; the surface of the light reflection layer is not higher than the electrode surface;

A single light-emitting device is obtained by cutting along the light reflection layer between the white light chips.

In the light-emitting device and the preparation method thereof provided by the present invention, the film sticking process is completed by preparing a viscous silica gel protective layer on the surface of the light-emitting layer. Compared with the prior art, the light-emitting device prepared by this method has no silica gel structure or a small amount of silica gel. For the silicone structure, the brightness is increased by 1.5 to 3%. In addition, the method can simply and conveniently realize the preparation of the silica gel structure around the flip-chip LED chip. Compared with the silica gel structures formed by other structures, the preparation method is simple and easy to realize, and the light-emitting angle of the light-emitting device is increased to 150°. In addition, the light conversion material KSF or KGF or QD in the light emitting layer is surrounded by a silicone protective layer, a barrier layer and a light reflection layer, so as to solve the problem of unstable performance during use, and at the same time improve the color gamut of the light emitting device. brightness.

Description of drawings

1 is a schematic structural diagram of a light-emitting device in the present invention;

FIG. 2 is a schematic flowchart of a method for preparing a light-emitting device according to the present invention.

Description of drawings:

1- Flip chip LED chip, 2- Silicone protective layer, 3- Light emitting layer, 4- Barrier layer, 5- Light reflection layer, 6- Support film.

Detailed ways

In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the specific embodiments of the present invention will be described below with reference to the accompanying drawings. Obviously, the accompanying drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, other drawings can also be obtained from these drawings without creative efforts, and obtain other implementations.

FIG. 1 is a schematic structural diagram of the light-emitting device provided by the present invention. As can be seen from the figure, the light-emitting device includes: a flip-chip LED chip 1 ; a silica gel protective layer 2 disposed on the surface of the light-emitting side of the flip-chip LED chip 1 ; a light emitting layer 3 arranged on the surface of the silica gel protective layer 2 on the surface of the light emitting side opposite to the electrode side surface in the flip-chip LED chip 1, and the light emitting layer 3 contains a light conversion material; the barrier layer 4 arranged on the surface of the light emitting layer 3, The light reflective layer 5 is used to protect the light emitting layer 3 ; and the light reflective layer 5 arranged around the flip-chip LED chip 1 and on the side surface of the electrode, and the light reflective layer 5 contains light reflective particles.

In the light-emitting device, the thickness of the silicone protection layer 2 around the flip-chip LED chip 1 is not greater than that of the flip-chip LED chip 1 , that is, the silicone protection layer 2 will not overflow to the electrode side surface of the chip 1 . The surface of the light reflection layer 5 is not higher than the surface of the electrode. In an example, as shown in FIG. 1 , the surface of the light reflection layer 5 is flush with the surface of the electrode of the chip 1 .

The light conversion material in the light emitting layer 3 is KSF or KGF or QD, wherein KSF/KGF (S in KSF specifically refers to Si element, and G in KGF refers to Ge element) means that it contains A ₂ (MF ₆ ) : Abbreviation of a type of compound of Mn4+ structural formula, wherein A is one of Li, Na, K, Rb, Cs or _NH4 , and M is one or more of Ge, Si, Sn, Ti or Zr elements A combination of elements; QD quantum dots are a new type of nanomaterial with a grain diameter of 2-20 nanometers. After excitation, they can emit concentrated, very pure, high-quality red and green monochromatic light. In practical applications, the thickness of the light emitting layer is 70-100 μm, and the corresponding light conversion material is doped into the silica gel for use. The barrier layer 4 is made of silicon dioxide or titanium dioxide, and the mass ratio of silica gel to silicon dioxide/titanium dioxide is 1% to 100%, and the thickness is 40 μm to 100 μm.

The present invention also provides a method for preparing a light-emitting device, as shown in FIG. 2 , comprising:

1.1 The barrier layer 4 is prepared on the surface of the support film 6 and baked to form, as shown in Figure 2(a). Specifically, the barrier layer 4 is made of silicon dioxide or titanium dioxide, and the mass ratio of silica gel to silicon dioxide/titanium dioxide is 1% to 100%, and the thickness is 40 μm to 100 μm.

1.2 Prepare the light layer 3 on the surface of the barrier layer 4 and bake it, as shown in Figure 2(b). Specifically, the light emitting layer 3 includes KSF or KGF or QD light conversion material, wherein KSF/KGF (S in KSF specifically refers to Si element, and G in KGF refers to Ge element) refers to containing A ₂ (MF ₆ ) : Abbreviation of a type of compound of Mn4+ structural formula, wherein A is one of Li, Na, K, Rb, Cs or _NH4 , and M is one or more of Ge, Si, Sn, Ti or Zr elements A combination of elements; QD quantum dots are a new type of nanomaterial with a grain diameter of 2-20 nanometers. After excitation, they can emit concentrated, very pure, high-quality red and green monochromatic light. In practical applications, the thickness of the light emitting layer is 70-100 μm, and the corresponding light conversion material is doped into the silica gel for use. The barrier layer 4 is made of silicon dioxide or titanium dioxide, and the mass ratio of silica gel to silicon dioxide/titanium dioxide is 1% to 100%, and the thickness is 40 μm to 100 μm.

1.3 Prepare an adhesive silica gel protective layer 2 on the surface of the light-emitting layer 3, as shown in Figure 2(c). Here, having viscosity specifically means that the silicone protective layer 2 is in an incompletely cured state, that is, a state in which solid and liquid coexist and cannot flow. It can be baked between 50°C and 120°C to obtain a silicone protective layer 2 that is not fully cured and has the ability to stick to chips (the viscosity should be greater than 1000mpa.s).

1.4 Arrange multiple flip-chip LED chips 1 on the surface of the silicone protective layer 2, and perform vacuum lamination under the press equipment to embed the chips into the silicone protective layer 2, as shown in Figure 2(d) and Figure 2(e) . Here, in order to ensure that the transparent silica gel will not overflow to the electrode side surface of the flip-chip LED chip 1 after the chip emits light and is pressed, the thickness of the silica gel protective layer 2 can be limited according to the actual situation, so as to ensure the surrounding area of the flip-chip LED chip 1 after pressing. The thickness of the transparent silicone is not greater than the thickness of the chip. For flip-chip LED chips, the general thickness is 150-250 μm. For this purpose, the thickness of the silicone protective layer can be limited to be smaller than that of the flip-chip LED chip. For example, when the thickness of the flip-chip LED chip is 200 μm, the silicone protective layer is limited. The thickness is not more than 50 μm (the thickness can be limited to between 10 and 50 μm). It should be clear that the height of the silicone protective layer after lamination is not only limited by its own thickness, but also limited by factors such as the area of the support film and the number of flip-chip LED chips, so its thickness is not specifically limited here. , and can achieve the purpose of the invention in practical applications.

1.5 Curing the laminated silicone protective layer 2 and cutting to obtain a single white light chip, as shown in Figure 2(f).

1.6 Rearrange the cut white light chips on the surface of the support film 6, and fill light reflective glue between the white light chips to prepare a light reflective layer 5, as shown in FIG. 2(g). Specifically, the light-reflecting glue is doped with reflective particles such as titanium dioxide, so that the reflectivity thereof is greater than 95%. In order to make the surface of the light reflection layer 5 not higher than the surface of the electrode, if necessary, the chip is subjected to a grinding operation, as shown in FIG. 2(h).

1.7 Cut, spot and sort along the light reflection layer 5 between the white light chips to obtain a single light-emitting device as shown in FIG. 1 .

It should be noted that the above embodiments can be freely combined as required. The above are only the preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, without departing from the principles of the present invention, several improvements and modifications can be made. It should be regarded as the protection scope of the present invention.

Claims (10)

1. A light-emitting device, characterized in that, comprising: Flip-chip LED chip; a silicone protective layer disposed on the surface of the light-emitting side of the flip-chip LED chip; a light emitting layer arranged on the surface of the silica gel protective layer on the light emitting side surface opposite to the electrode side surface in the flip-chip LED chip, and the light emitting layer contains a light conversion material; a blocking layer disposed on the surface of the light emitting layer for protecting the light emitting layer; and A light reflection layer is arranged around the flip-chip LED chip and on the side surface of the electrode, and the light reflection layer contains light reflection particles. 2 . The light-emitting device according to claim 1 , wherein the light conversion material in the light emitting layer is KSF, KGF or QD; and/or the thickness of the light emitting layer is 70-100 μm. 3 . 3. The light-emitting device of claim 1 or 2, wherein the blocking layer comprises silicon dioxide or titanium dioxide. 4 . The light-emitting device according to claim 1 , wherein the barrier layer has a thickness of 40 μm˜100 μm. 5 . 5 . The light-emitting device according to claim 1 or 2 , wherein the thickness of the silicone protective layer on the side of the flip-chip LED chip is not greater than that of the flip-chip LED chip, and the surface of the light reflection layer is not greater than the thickness of the flip-chip LED chip. 6 . electrode surface. 6. A method for preparing a light-emitting device, comprising: A barrier layer is prepared on the surface of the support film; preparing a light layer on the surface of the blocking layer, and the light output layer contains a light conversion material; preparing a viscous silica gel protective layer on the surface of the light emitting layer, and the viscosity of the silica gel protective layer is greater than 1000mpa.s; Arrange a plurality of flip-chip LED chips on the surface of the silica gel protective layer, and press them together; the thickness of the silica gel protective layer on the side of the flip-chip LED chip after pressing is not greater than the thickness of the flip-chip LED chip; Curing the laminated silicone protective layer and cutting to obtain a single white light chip; Rearrange the white light chips obtained by cutting on the surface of the support film, and fill light reflection glue between the white light chips to prepare a light reflection layer; the surface of the light reflection layer is not higher than the electrode surface; A single light-emitting device is obtained by cutting along the light reflection layer between the white light chips. 7 . The method of claim 6 , wherein the light conversion material in the light emitting layer is KSF, KGF or QD. 8 . 8 . The light emitting device according to claim 6 , wherein the thickness of the light emitting layer is 70-100 μm. 9 . 9. The light-emitting device of claim 6 or 7, wherein the blocking layer comprises silicon dioxide or titanium dioxide. 10 . The light-emitting device according to claim 6 , wherein the barrier layer has a thickness of 40 μm˜100 μm. 11 .

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