CN106340511A - LED chip and its packaging method - Google Patents

Abstract

The invention provides an LED chip and its packaging method wherein the LED chip comprises an LED chip unit with at least one lighting face; and a half transparent packaging structure, the opening at one side of which forms holding space for the LED chip unit. The half transparent packaging structure contains phosphor, and at least a portion of the outgoing light of the at least one lighting face is emitted from the semiconductor packaging structure. The LED chip and the packaging method increase the performance of an LED chip product.

Description

A kind of LED chip and packaging method thereof

technical field

The invention belongs to the technical field of optoelectronics, and in particular relates to an LED chip and a packaging method thereof.

Background technique

Light Emitting Diode (LED) is known as the most promising green lighting source in the 21st century because of its high brightness, low heat, and long life. It is used in various applications including light sources, lighting equipment, smart terminal etc. Today, as smart terminals become thinner and lighter, and wearable electronics attract much attention, the integration of package size and functions of LED chips has become increasingly important.

As a new packaging technology, chip scale package (CSP) technology has attracted the attention of the industry in the application of next-generation discrete power LEDs, and has a large room for improvement. With the improvement of flip chip yield rate and the expansion of production capacity, its price advantage will be more obvious. Today, CSP has not only stayed in the research and development room, but has been mass-produced in some applications, and has shown its advantages and value. At present, the CSP technology of most flip-chip LED chips generally goes through five manufacturing steps: flip-chip bonding, phosphor spraying, lens molding, cutting, and testing and sorting.

The above-mentioned existing CSP technology is to directly smear phosphor powder on the light-emitting surface of the LED chip. Not only is the process complicated, but the phosphor layer is prone to uneven thickness and irregular shape, which will lead to uneven emission spots of the LED chip and greatly affect the product performance of LED chips.

Contents of the invention

In view of this, the present invention proposes an LED chip and a packaging method thereof, so as to improve the product performance of the LED chip.

In a first aspect, an embodiment of the present invention provides an LED chip, which includes:

LED chip unit, including at least one light-emitting surface;

A translucent encapsulation structure, one side of which is opened to form an accommodating space, the LED chip unit is arranged in the accommodating space, the translucent encapsulation structure contains fluorescent powder, and at least part of the emitted light from the at least one light-emitting surface passes through The semiconductor package structure is issued.

Optionally, all outgoing light from the light-emitting surface is emitted through the semiconductor package structure.

Optionally, the LED chip unit includes a substrate, and a light emitting structure formed on the substrate;

The light-emitting surface is the back and side surfaces of the substrate.

Optionally, a layer of transparent organic colloidal material is disposed between the translucent encapsulation structure and the light emitting surface of the LED chip unit.

Optionally, the translucent encapsulation structure is an integral molding structure.

Optionally, the translucent encapsulation structure is glass containing phosphor powder or a colloidal film containing phosphor powder.

Optionally, the translucent encapsulation structure has a plurality of periodic concave-convex patterns on the bottom surface facing away from the containing space.

Optionally, the periodic concave-convex pattern is conical and/or semicircular.

In a second aspect, an embodiment of the present invention provides a packaging method for an LED chip, the method comprising:

Place a plurality of LED chip units in a translucent packaging structure with one side opening to form a plurality of accommodation spaces, the translucent packaging structure contains fluorescent powder, and at least part of the emitted light from the at least one light-emitting surface passes through the Semiconductor package structure issued;

The translucent package structure is cut to form individual discrete LED chips.

Optionally, before placing a plurality of LED chip units into a translucent packaging structure with one side opening forming a plurality of accommodation spaces, the method further includes:

Coating a layer of transparent organic colloid material on the surface of the accommodation space of the translucent packaging structure;

Before cutting the translucent packaging structure to form a single discrete LED chip, it also includes:

Bake the translucent encapsulation structure to cure the organic colloid material.

An embodiment of the present invention provides an LED chip and a packaging method thereof. By arranging the LED chip unit in the accommodation space of the translucent packaging structure, the translucent packaging structure contains fluorescent powder, and at least part of the emitted light from at least one light-emitting surface is transmitted. issued through the semiconductor package structure. The whole process is simple, the cost is low, the light-emitting device has many light-emitting surfaces, the process method is simple, and the electrical performance is stable.

Description of drawings

The exemplary embodiments of the present invention or prior art will be described in detail below with reference to the accompanying drawings, so that those of ordinary skill in the art will be more aware of the above-mentioned and other features and advantages of the present invention. In the accompanying drawings:

Fig. 1 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention;

Fig. 2 is a cross-sectional view of an LED chip unit provided by Embodiment 1 of the present invention;

Fig. 3 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention;

Fig. 4 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention;

Fig. 5 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention;

6 is a flow chart of a method for preparing an LED chip provided by Embodiment 2 of the present invention;

7a-7b are cross-sectional views corresponding to each step of an LED chip manufacturing method provided in Embodiment 2 of the present invention;

FIG. 8 is a flow chart of a method for preparing an LED chip provided by Embodiment 2 of the present invention;

9a-9o are cross-sectional views corresponding to each step of an LED chip manufacturing method provided by Embodiment 2 of the present invention.

detailed description

The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the present invention, but not to limit the present invention. In addition, it should be noted that, for the convenience of description, only some structures related to the present invention are shown in the drawings but not all structures.

FIG. 1 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention. Fig. 2 is a cross-sectional view of an LED chip unit provided by Embodiment 1 of the present invention. FIG. 3 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention. FIG. 4 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention. FIG. 5 is a cross-sectional view of an LED chip provided by Embodiment 1 of the present invention.

Referring to FIG. 1 , the present invention provides an LED chip, which includes: an LED chip unit 10 including at least one light emitting surface. The translucent encapsulation structure 20 has an opening on one side to form an accommodating space 30, and the LED chip unit 10 is arranged in the accommodating space 30. In the area inside the dotted line frame in the figure, the translucent encapsulation structure 20 contains phosphor powder, and the at least one light-emitting surface At least part of the emitted light is emitted through the semiconductor package structure 20 .

An embodiment of the present invention provides an LED chip. By arranging the LED chip unit in the accommodation space of the translucent package structure, the translucent package structure contains fluorescent powder, and at least part of the emitted light from at least one light-emitting surface passes through the semiconductor package structure. issue. The whole process is simple, the cost is low, the light-emitting device has many light-emitting surfaces, and the electrical performance is stable. In the embodiment of the present invention, the LED chip is made to emit light by using a translucent packaging structure containing phosphor, wherein the light-emitting surface is greater than or equal to one, which increases the chance of emitting light and improves the luminous efficiency.

Optionally, in the above technical solution, all outgoing light from the light emitting surface is emitted through the semiconductor package structure 20 .

Optionally, referring to FIG. 2 , in the above technical solution, the LED chip unit 10 includes a substrate 110 and a light emitting structure formed on the substrate 110 . The light-emitting surfaces are the back surface 1100 of the substrate 110 and the four side surfaces 1101 of the LED chip unit, that is, there are five light-emitting surfaces, which greatly improves the luminous efficiency of the LED chip unit 10 .

Exemplarily, referring to FIG. 2 , in the above technical solution, the LED chip unit 10 includes a substrate 110 , and the light-emitting structure on the substrate 110 is: an N-type III-nitride semiconductor layer 111 located above the substrate 110 . On top of the N-type Group III nitride semiconductor layer 111 is a multi-quantum well active layer 112 . Above the MQW active layer 112 is a P-type Group III nitride semiconductor layer 113 . Above the P-type III-nitride semiconductor layer 113 is a first electrode layer 114 directly connected to the P-type III-nitride semiconductor layer 113 . On the surface of the first electrode layer 114 there is a first groove 115 reaching the N-type Group III nitride semiconductor layer 111 . An insulating layer 116 is formed on the surface of the first electrode layer 114 and the surface of the first groove 115 . The surface of the insulating layer 116 has a second groove 117 reaching the first electrode layer 114 . On the surface of the insulating layer 116 and in the second groove 117 is a second electrode layer 118 , and the second electrode layer 118 is electrically connected to the first electrode layer 114 . On the surface of the insulating layer 116 and in the first groove 115 is a third electrode layer 119, the third electrode layer 119 is electrically connected to the N-type Group III nitride semiconductor layer 111, and the second electrode layer 118 is not connected to the third electrode layer 119. connect. Wherein, the insulating layer 116 is a multilayer dielectric film layer with low light absorption rate and high optical reflectivity, such as silicon dioxide, silicon nitride, aluminum oxide, gallium oxide, etc., but not limited to the above materials. It has a multi-period Bragg structure with high reflectivity, such as a multi-period silicon dioxide/titania dielectric film. The transmission of light emitted by the LED chip unit is reduced, and the external quantum efficiency is increased. Thin film layer The first electrode layer 114 is one of a metal oxide transparent conductive layer and a highly optical reflective metal layer. For example, Ag, Au, Al, Pt, and Rh can be used for the metal film layer. The material of the metal oxide transparent conductive layer may include but not limited to the following materials: indium tin oxide, gallium-doped zinc oxide, aluminum-doped zinc oxide, graphene and other materials with high light transmittance and high conductivity. A good ohmic contact is formed between the first electrode layer 114 and the P-type group III nitride semiconductor layer 113 .

Optionally, referring to FIG. 3 , a layer of transparent organic colloidal material 40 is provided between the translucent encapsulation structure 20 and the light-emitting surface of the LED chip unit. Exemplarily, the transparent organic colloid material may be an organic material such as epoxy resin.

Optionally, referring to FIG. 4 , the translucent encapsulation structure 20 is an integrally formed structure. Wherein, the integrally formed structure means that the translucent structure is not completed by splicing or bonding multiple parts of the substance during the manufacturing process. The one-piece molding structure ensures sufficient uniformity of the phosphor powder to ensure uniformity of the light spot.

Optionally, the translucent encapsulation structure 20 is glass containing phosphor powder or a colloidal film containing phosphor powder. Because of the phosphor, after the light emitted by the LED passes through the light-emitting surface, a part of the phosphor is excited to emit light of the corresponding color, and the light emitted by the phosphor can be coupled with the light emitted by the diode to obtain the desired spot.

Optionally, in the above technical solution, the translucent encapsulation structure 20 has a plurality of periodic concave-convex patterns on the bottom surface facing away from the accommodating space. It should be noted that the shape of the pattern is not limited.

Optionally, the periodic concave-convex pattern is conical and/or semicircular.

Referring to FIG. 3 and FIG. 4 , the periodic concave-convex pattern is tapered 200 . Referring to FIG. 5 , the periodic concave-convex pattern is a semicircle 201 . The periodic concave-convex pattern can also include both cones and semicircles. Such a periodic concavo-convex pattern is to increase luminous efficiency.

Embodiment two

FIG. 6 is a flow chart of a method for manufacturing an LED chip provided by Embodiment 2 of the present invention. 7a-7b are cross-sectional views corresponding to each step of an LED chip manufacturing method provided in Embodiment 2 of the present invention. FIG. 8 is a flow chart of a method for manufacturing an LED chip provided by Embodiment 2 of the present invention. 9a-9o are cross-sectional views corresponding to each step of an LED chip manufacturing method provided by Embodiment 2 of the present invention.

On the basis of the first embodiment above, the second embodiment of the present invention provides an LED chip packaging method. It should be noted that the LED chip involved in the above embodiment can be packaged through the LED chip packaging method provided in this embodiment Completed. Referring to Figure 6, the method steps are as follows:

Step 110, placing a plurality of LED chip units into a translucent package structure with one side opening forming multiple accommodation spaces, the translucent package structure contains phosphor, and at least part of the emitted light from at least one light-emitting surface passes through the semiconductor package structure issue.

Referring to Fig. 7a, a plurality of LED chip units 10 are placed in a translucent encapsulation structure 20 having one side opening to form a plurality of accommodating spaces 30, the translucent encapsulation structure 20 contains phosphor, and at least part of at least one light-emitting surface emits light emitted through the semiconductor package structure. That is, the light emitted by the LED chip unit passes through the translucent encapsulation structure 20 as a light emitting surface. It should be noted that as the degree of transparency increases, the proportion of emitted light from the LED chip unit increases. For the same translucent encapsulation structure 20 , the higher the degree of transparency, the relatively less phosphor content. The addition of phosphor should have a preferred content range. On the one hand, a sufficient proportion of light is transmitted to increase the external quantum efficiency. On the other hand, the light from the LED chip unit irradiates the phosphor to excite the phosphor to emit light, and the two kinds of light can be coupled together to form a desired light spot.

Step 120, cutting the translucent packaging structure to form individual discrete LED chips.

Referring to Fig. 7b, the translucent packaging structure 20 is cut longitudinally to form a single discrete LED chip.

An embodiment of the present invention provides a LED chip packaging method. By arranging the LED chip unit in the accommodation space of the translucent packaging structure, the translucent packaging structure contains fluorescent powder, and at least part of the emitted light from at least one light-emitting surface passes through the semiconductor. Encapsulation structure emitted. The whole process is simple, the cost is low, the light-emitting device has many light-emitting surfaces, the process method is simple, and the electrical performance is stable.

Exemplarily, referring to FIG. 8, the preparation method of the LED chip unit 10 mentioned in the first embodiment above is as follows:

Step 210, providing a substrate.

Referring to Fig. 9a, the substrate 110 may be, for example, a sapphire substrate, a silicon carbide substrate or other insulating and transparent substrates.

Step 211 , forming an N-type Group III nitride semiconductor layer on the substrate.

Step 212, forming a multi-quantum well active layer on the N-type semiconductor layer.

Step 213 , forming a P-type Group III nitride semiconductor layer on the multi-quantum well active layer.

Referring to FIGS. 9 b to 9 d , an N-type III-nitride semiconductor layer 111 , a multi-quantum well active layer 112 and a P-type III-nitride semiconductor layer 113 are sequentially formed above the substrate 110 .

Step 214 , forming a first electrode layer directly connected to the P-type III-nitride semiconductor layer above the P-type III-nitride semiconductor layer.

Referring to FIG. 9 e , the first electrode layer 114 directly connected to the P-type III-nitride semiconductor layer 113 is formed over the P-type III-nitride semiconductor layer 113 . Exemplarily, the thin-film first electrode layer 114 may include one of a metal oxide transparent conductive layer and a highly optically reflective metal layer.

Step 215 , performing trench etching on the surface of the first electrode layer to form a first groove reaching the N-type III-nitride semiconductor layer.

Referring to FIG. 9f , trench etching is performed on the surface of the first electrode layer 114 to form a first groove 115 reaching the N-type Group III nitride semiconductor layer. The etching method may be, for example, dry etching or wet etching.

Step 216 , forming an insulating layer on the surface of the first electrode layer and the surface of the first groove.

Referring to FIG. 9 g , an insulating layer 116 is formed on the surface of the first electrode layer 114 and the surface of the first groove 115 . Exemplarily, the insulating layer 116 may be insulating materials such as SiO ₂ and SiN. The production method can be, for example, an oxidation or deposition process.

Step 217 , etching the insulating layer on the bottom surface of the first groove to expose the N-type Group III nitride semiconductor layer. Groove etching is performed on the insulating layer to form a second groove reaching the first electrode layer.

Referring to FIG. 9 h , the insulating layer 116 on the bottom surface of the first groove 115 is etched to expose the N-type Group III nitride semiconductor layer 111 . At the same time, a second groove 117 is formed on the surface of the insulating layer 116 , and the depth of the second groove 117 extends to the first electrode layer 114 .

Step 218, forming a second electrode layer on the surface of the insulating layer and in the second groove, the second electrode layer is electrically connected to the first electrode layer; forming a third electrode layer on the surface of the insulating layer and in the second groove, the third electrode layer The layer is electrically connected to the N-type Group III nitride semiconductor layer, and the second electrode layer is not connected to the third electrode layer.

Referring to FIG. 9 i , the second electrode layer 118 is formed on the surface of the insulating layer 116 and in the second groove 117 . The third electrode 119 directly contacts the N-type Group III nitride semiconductor layer 111 . Another part extends above the insulating layer 116 . Exemplarily, the second electrode layer 118 and the third electrode 119 may be made of one or more of Au, Al, Cu, Ag, Fe, Ti, Cr, Pt, Ni. The process method can be, for example, a magnetron sputtering process.

It should be noted that, the above steps are for the convenience of description, and a single discrete LED chip is taken as an example of the packaging method introduced. But in fact, in the production process, there are repeated LED chip unit areas on the entire wafer, so it needs to be divided into multiple discrete LED chip units, and the discrete LED chip units include the second electrode layer 118 and the third electrode. layer 119 and all materials in the vertical direction of the second electrode layer 118 and the third electrode layer 119 . And after the whole wafer is divided into individual LED chip units, they need to be sorted, and the chips with similar photoelectric parameters are gathered together.

Step 219: Obtain a translucent encapsulation structure by mixing a certain amount of fluorescent powder and a translucent substance.

Exemplarily, referring to FIG. 9 j , the surface of the translucent encapsulation structure 20 has a plurality of directional pits arranged periodically in a square, that is, accommodating spaces 30 . The length and width of the square pit are slightly larger than the length and width of the LED chip unit, and the height of the pit is slightly smaller than the height of the LED chip unit. The minimum distance between the dimples is about twice the material thickness of the lower surface of the dimples (the side facing away from the dimples).

Step 220 , placing the backside of the substrate of the discrete light-emitting chip in the accommodation space of the translucent packaging structure. A layer of translucent encapsulation structure containing fluorescent powder is formed on the back and sides of the substrate. Cut along the translucent encapsulation structure containing phosphor powder perpendicular to the discrete light-emitting chips to form individual discrete light-emitting devices.

Optionally, before placing a plurality of LED chip units into the translucent packaging structure with one side opening forming a plurality of accommodation spaces, the method further includes:

Referring to FIG. 9k , a layer of transparent organic colloidal material 40 is coated on the surface of the accommodation space of the translucent packaging structure 20 .

Before cutting the translucent packaging structure to form a single discrete LED chip, it also includes:

Bake the translucent encapsulation structure to cure the organic colloidal material. It should be noted that the temperature of the oven is in the range of 100° C. to 200° C., and the baking time is 20 minutes to 60 minutes.

Exemplarily, the translucent encapsulation structure 20 has a plurality of periodic concave-convex patterns on the bottom surface facing away from the accommodating space. It should be noted that the shape of the pattern is not limited.

Referring to FIG. 9l, the periodic concave-convex pattern may be in the shape of a cone 200 . Referring to FIG. 9m , the periodic concave-convex pattern may be a semicircle 201 . The periodic concave-convex pattern can also include both cones and semicircles. Such a periodic concavo-convex pattern is to increase luminous efficiency. FIG. 9n shows the corresponding discrete LED chip after cutting, and its periodic concave-convex pattern can be tapered. Fig. 9o shows the corresponding discrete LED chip after cutting, and its periodic concave-convex pattern can be a semicircle.

Note that the above are only preferred embodiments of the present invention and applied technical principles. Those skilled in the art will understand that the present invention is not limited to the specific embodiments described herein, and that various obvious changes, readjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present invention. Therefore, although the present invention has been described in detail through the above embodiments, the present invention is not limited to the above embodiments, and can also include more other equivalent embodiments without departing from the concept of the present invention, and the present invention The scope is determined by the scope of the appended claims.

Claims (10)

1. A LED chip, characterized in that, comprising: LED chip unit, including at least one light-emitting surface; A translucent encapsulation structure, one side of which is opened to form an accommodating space, the LED chip unit is arranged in the accommodating space, the translucent encapsulation structure contains fluorescent powder, and at least part of the emitted light from the at least one light-emitting surface passes through The semiconductor package structure is issued. 2. The LED chip according to claim 1, characterized in that, All the outgoing light from the light-emitting surface is emitted through the semiconductor package structure. 3. The LED chip according to claim 1, characterized in that, The LED chip unit includes a substrate, and a light emitting structure formed on the substrate; The light-emitting surface is the back and side surfaces of the substrate. 4. The LED chip according to claim 1, comprising: A layer of transparent organic colloidal material is arranged between the translucent encapsulation structure and the light-emitting surface of the LED chip unit. 5. The LED chip according to claim 1, comprising: The translucent encapsulation structure is an integral molding structure. 6. The LED chip according to claim 1, comprising: The translucent encapsulation structure is glass containing fluorescent powder or a colloidal film containing fluorescent powder. 7. The LED chip according to claim 1, wherein the translucent encapsulation structure has a plurality of periodic concave-convex patterns on the bottom surface facing away from the containing space. 8. The LED chip according to claim 7, comprising: The periodic concave-convex pattern is cone-shaped and/or semi-circular. 9. A packaging method for an LED chip, comprising: Place a plurality of LED chip units in a translucent packaging structure with one side opening to form a plurality of accommodation spaces, the translucent packaging structure contains fluorescent powder, and at least part of the emitted light from the at least one light-emitting surface passes through the Semiconductor package structure issued; The translucent package structure is cut to form individual discrete LED chips. 10. The LED chip packaging method according to claim 9, characterized in that before placing a plurality of LED chip units into a translucent packaging structure with one side opening forming a plurality of accommodation spaces, it further comprises: Coating a layer of transparent organic colloid material on the surface of the accommodation space of the translucent packaging structure; Before cutting the translucent packaging structure to form a single discrete LED chip, it also includes: Bake the translucent encapsulation structure to cure the organic colloid material.