CN212907776U - LED flip chip and display panel - Google Patents

Abstract

The utility model provides a LED flip chip and a display panel, wherein the LED flip chip comprises a second semiconductor layer, an active layer, a first semiconductor layer, a light-transmitting substrate, a first electrode and a second electrode, wherein the second semiconductor layer, the active layer, the first semiconductor layer and the light-transmitting substrate are arranged from bottom to top in sequence; the surface of the light-transmitting substrate opposite to the first semiconductor layer is a lower surface, and the surface of the light-transmitting substrate opposite to the lower surface is an upper surface; the LED flip chip also comprises a first reflecting layer formed on the upper surface and/or a second reflecting layer formed on the lower surface, at least one reflecting layer in the first reflecting layer and the second reflecting layer is composed of a plurality of separately arranged reflecting units, and a light transmitting window is formed in the area between the adjacent reflecting units, so that the light emitting angle of the chip can be enlarged from 120 degrees to 150 degrees to 180 degrees, and the manufactured display panel is thinner, fewer devices are required to be used, the optical uniformity is better, the cost is lower, and the processing technology is simpler and more convenient.

Description

LED flip chip and display panel

Technical Field

The utility model relates to a LED (Light Emitting Diode) field especially designs a LED flip chip and display panel.

Background

The LED flip chip structure is shown in fig. 1 at present, the LED flip chip structure is respectively a transparent substrate 81, an N-type layer 82, an MQWs layer 83, a P-type layer 84, an N-type electrode layer 86 and a P-type electrode layer 85 from top to bottom, the N-type electrode layer 86 and the P-type electrode layer 85 have two functions, one is connected with an external power supply to introduce current, the other is used as a reflective layer, when the N-type electrode layer 86 and the P-type electrode layer 85 are electrified, the LED flip chip emits light from the MQWs layer 83, a part of light directly transmits to a peripheral space through the side face of the LED chip and the transparent substrate 81, the other part of light transmits to the peripheral space from the side face of the chip and the transparent substrate 81 after being reflected by the N-type electrode layer 86 and the P-type electrode layer 85. From the trend of technical application, the LED flip chip of this structure has a short board in some application fields, such as:

in the direct-type large-size thin liquid crystal display field, the display module is required to be thinner, lower in cost and better in optical uniformity. In view of the limitation of the current LED flip chip or packaging technology, the light emitting angle of the LED flip chip is only about 120 °, and the light emitting angle of the LED needs to be enlarged by adding a lens above the LED flip chip, so as to increase the optical uniformity, thereby reducing the number of LEDs.

In the application field of the future Mini/Micro LED display technology, the requirement is that the number of chips is small and the optical uniformity is good. The light emitting angle of the current LED flip chip is only 120 degrees, certain optical uniformity requirements are met in advance, the distance between chips needs to be reduced by increasing the arrangement number of the chips, but the scheme is high in cost, and the process difficulty is increased.

SUMMERY OF THE UTILITY MODEL

The utility model provides a LED flip chip and display panel solves current LED flip chip and sends out light angle little, leads to using to have with high costs, is difficult to reduce the thickness of display module and the problem of using the technology degree of difficulty.

In order to solve the above technical problem, an embodiment of the present invention provides an LED flip chip, including a second semiconductor layer, an active layer, a first semiconductor layer, a light-transmitting substrate, and a first electrode and a second electrode respectively formed on exposed regions of the first semiconductor layer and the second semiconductor layer, which are sequentially arranged from bottom to top;

the surface of the light-transmitting substrate opposite to the first semiconductor layer is a lower surface, and the surface of the light-transmitting substrate opposite to the lower surface is an upper surface; the LED flip chip further comprises a first reflecting layer formed on the upper surface and/or a second reflecting layer formed on the lower surface, at least one reflecting layer of the first reflecting layer and the second reflecting layer is composed of a plurality of separately arranged reflecting units, and a light-transmitting window is formed in an area between every two adjacent reflecting units.

Optionally, the at least one reflection unit is composed of a plurality of sequentially stacked sub-reflection layers.

Optionally, in the multiple sub-reflective layers sequentially stacked, materials of different sub-reflective layers are different;

or, in the multiple sub-reflecting layers which are sequentially overlapped, the materials of the adjacent sub-reflecting layers are different, and the materials of the two sub-reflecting layers which are positioned on the upper surface and the lower surface of the same sub-reflecting layer are the same.

Optionally, in the plurality of sequentially stacked sub-reflective layers, the thicknesses of different sub-reflective layers are different.

Optionally, the refractive indexes of the plurality of sequentially stacked sub-reflecting layers decrease sequentially in a direction away from the light-transmitting substrate.

Optionally, at least one of the upper surface and the lower surface of at least one of the reflection units is a rough surface.

Optionally, the LED flip chip further includes a third reflective layer filled in the light-transmissive window and having a light-transmissive characteristic.

Optionally, the LED flip chip comprises a first reflective layer formed on the upper surface, and a second reflective layer formed on the lower surface, the first and second reflective layers each being formed of a plurality of separately disposed reflective units;

the positions of the plurality of reflection units of the first reflection layer on the upper surface are distributed and correspond to the positions of the plurality of reflection units of the second reflection layer on the lower surface in a one-to-one manner;

or the like, or, alternatively,

the positions of the reflection units of the second reflection layer on the lower surface correspond to the positions of the light transmission windows formed on the upper surface by the plurality of reflection units of the first reflection layer.

Optionally, at least one of the first and second reflective layers is an opaque reflective layer.

In order to solve the above problem, the embodiment of the utility model provides a display panel is still provided, display panel is including showing the backplate and many as above LED flip chip, many LED flip chip set up in show on the backplate.

Advantageous effects

The utility model provides a LED flip chip, which comprises a second semiconductor layer, an active layer, a first semiconductor layer, a light-transmitting substrate, a first electrode and a second electrode, wherein the second semiconductor layer, the active layer, the first semiconductor layer and the light-transmitting substrate are sequentially arranged from bottom to top; the surface of the light-transmitting substrate opposite to the first semiconductor layer is a lower surface, and the surface of the light-transmitting substrate opposite to the lower surface is an upper surface; the LED flip chip also comprises a first reflecting layer formed on the upper surface and/or a second reflecting layer formed on the lower surface, at least one reflecting layer of the first reflecting layer and the second reflecting layer is composed of a plurality of separately arranged reflecting units, and a light-transmitting window is formed in an area between the adjacent reflecting units, and the LED flip chip at least has the following advantages:

a part of light emitted by the LED flip chip from the active layer can be emitted from the side surface of the LED flip chip after being reflected by the reflecting units in the first reflecting layer and/or the second reflecting layer with light transmission property, so that the light emitting quantity of the chip in different directions is changed, the light emitting quantity of the front surface of the LED flip chip is reduced, the light emitting quantity of the side surface of the LED flip chip is increased, the light emitting angle of the LED flip chip is enlarged, and the light emitting angle can be enlarged from 120 degrees to 150 degrees to 180 degrees;

the LED flip chip is simple in structure and manufacture, only the upper surface and/or the lower surface of the light-transmitting substrate needs to be additionally provided to form the reflecting unit, the universality is good, the manufacturing efficiency is high, and the manufacturing cost is low;

in the application process of the LED flip chip, the probability of additionally arranging the lens can be greatly reduced, and the number of used LED flip chips can be reduced, so that the display panel manufactured by using the LED flip chip is thinner, fewer devices needing to be used are needed, the optical uniformity is better, the cost is lower, and the processing technology is simpler and more convenient.

Drawings

FIG. 1 is a schematic diagram of a conventional LED flip chip structure;

fig. 2 is a schematic view of a structure of an LED flip chip according to an embodiment of the present invention;

fig. 3 is a schematic diagram of a structure of an LED flip chip according to an embodiment of the present invention;

fig. 4 is a schematic diagram of a third structural diagram of an LED flip chip according to an embodiment of the present invention;

fig. 5 is a schematic diagram of a structure of an LED flip chip according to an embodiment of the present invention;

fig. 6 is a schematic diagram of a structure of an LED flip chip according to an embodiment of the present invention;

fig. 7 is a schematic diagram six of a structure of an LED flip chip according to an embodiment of the present invention;

fig. 8 is a seventh schematic structural diagram of an LED flip chip according to an embodiment of the present invention;

fig. 9 is an eighth schematic structural diagram of an LED flip chip provided in an embodiment of the present invention;

fig. 10 is a first schematic structural diagram of a reflection unit according to an embodiment of the present invention;

fig. 11 is a schematic structural diagram of a second reflection unit according to an embodiment of the present invention;

fig. 12 is a schematic structural diagram of a reflection unit provided in the embodiment of the present invention;

fig. 13 is a schematic structural diagram of a sub-reflective layer according to an embodiment of the present invention;

fig. 14 is a schematic structural diagram of a sub-reflective layer according to an embodiment of the present invention;

fig. 15 is a schematic structural diagram of a sub-reflective layer according to an embodiment of the present invention;

FIG. 16 is a schematic view of the light-emitting angle of the LED flip chip shown in FIG. 1;

fig. 17 is a schematic view of a light-emitting angle of an LED flip chip according to an embodiment of the present invention.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more clearly understood, the embodiments of the present invention are described in further detail below with reference to the accompanying drawings by way of specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The LED flip chip provided in this embodiment can be used for, but is not limited to, manufacturing COB lighting devices (e.g., COB light bar, COB light, etc.) or display screen light source devices (e.g., backlight light source, or direct display screen light source device); compared with the LED flip chip shown in the figure 1, the LED flip chip at least has the advantages of larger light-emitting angle, more uniform light-emitting, lower application cost, simpler processing technology during application, better universality and more convenience for popularization and application of the miniature flip LED chip.

For ease of understanding, the structure of the LED flip chip is illustrated below in the present embodiment.

The LED flip chip in this embodiment may be a common-sized LED chip, or may be a Micro LED chip, where the Micro LED chip may be, but is not limited to, a mini LED flip chip or a Micro LED flip chip. The LED flip chip comprises an epitaxial layer, wherein the epitaxial layer comprises but is not limited to a light-transmitting substrate, a first semiconductor layer, an active layer and a second semiconductor layer which are sequentially arranged from top to bottom, and the LED flip chip further comprises a first electrode and a second electrode which are respectively formed on the first semiconductor layer and the second semiconductor layer;

the surface of the transparent substrate opposite to the first semiconductor layer is a lower surface (namely, the lower surface of the transparent substrate), and the surface of the transparent substrate opposite to the lower surface is an upper surface (namely, the upper surface of the transparent substrate); the LED flip chip further comprises a first reflecting layer formed on the upper surface of the light-transmitting substrate and/or a second reflecting layer formed on the lower surface of the light-transmitting substrate, at least one reflecting layer of the first reflecting layer and the second reflecting layer is formed by a plurality of reflecting units which are separately arranged, and a light-transmitting window is formed in an area between every two adjacent reflecting units so that light emitted into the light-transmitting window can be directly emitted.

It should be understood that the transparent substrate in this embodiment may be a transparent substrate, or a translucent substrate may be selected according to the application scenario.

It should be understood that, in this embodiment, the epitaxial layer structure of the LED flip chip is not limited, and other layer structures, such as a passivation layer or a protection layer, may be added according to application scenarios besides the light-transmitting substrate, the first semiconductor layer, the active layer (which may include but is not limited to a quantum well layer), and the second semiconductor layer, which are exemplified above. In this embodiment, the first semiconductor layer may be an N-type layer and the second semiconductor layer may be a P-type layer, or the first semiconductor layer may be a P-type layer and the second semiconductor layer may be an N-type layer.

In this embodiment, the material and shape of the first electrode and the second electrode are not limited, for example, in an example, the material of at least one of the first electrode and the second electrode may include but is not limited to at least one of Cr, Ni, Al, Ti, Au, Pt, W, Pb, Rh, Sn, Cu, and Ag. It should be understood that the materials of the first electrode and the second electrode in this embodiment may be the same, or may be different according to the requirement.

For ease of understanding, the following description is made in conjunction with the three examples shown in fig. 2-4.

An application example is shown in fig. 2, and the LED flip chip can be, but is not limited to, a mini LED flip chip or a Micro LED flip chip. The light-transmitting substrate comprises, but is not limited to, a light-transmitting substrate 1, a first semiconductor layer 2, an active layer 3, a second semiconductor layer 4, a first electrode 21 and a second electrode 41, wherein the light-transmitting substrate, the first semiconductor layer 2, the active layer 3 and the second semiconductor layer 4 are sequentially arranged from top to bottom; it further includes a first reflective layer 5 formed on the upper surface of the light-transmitting substrate 1, the first reflective layer 5 including a plurality of separately disposed reflective units 51. It should be understood that the forming process of the reflecting unit 51 of the first reflecting layer 5 in this embodiment is not limited in this embodiment, and for example, but not limited to, an electroplating process, a spraying process, an electron gun evaporation deposition coating film; in this example, at least one of the reflection units 51 may be made of a transparent or translucent material, or may be made of an opaque material. In the example, the distances between adjacent reflection units 51 may be the same, or may be different according to requirements.

As another application example, referring to fig. 3, the LED flip chip also includes, but is not limited to, a light-transmitting substrate 1, a first semiconductor layer 2, an active layer 3, a second semiconductor layer 4, a first electrode 21 and a second electrode 41 respectively formed on the first semiconductor layer 2 and the second semiconductor layer 4; it further comprises a second reflective layer 6 formed on the lower surface of the light-transmissive substrate 1. The second reflective layer 6 includes a plurality of separately provided reflective units 61. It should be understood that the forming process of the reflection unit 61 of the second reflection layer 6 in the present embodiment is not limited in this example, and for example, but not limited to, an electroplating process, a spraying process, an electron gun evaporation deposition coating film; in this example, at least one of the reflection units 61 may be made of a transparent or translucent material, or may be made of an opaque material. In the example, the distances between adjacent reflection units 61 may be the same, or may be different according to the requirement.

As shown in fig. 4, the LED flip chip also includes, but is not limited to, a light-transmitting substrate 1, a first semiconductor layer 2, an active layer 3, a second semiconductor layer 4, a first electrode 21 and a second electrode 41 formed on the first semiconductor layer 2 and the second semiconductor layer 4 respectively; it further comprises a second reflective layer 6 formed on the lower surface of the light-transmissive substrate 1, and a first reflective layer 5 formed on the upper surface of the light-transmissive substrate 1, both the second reflective layer 6 and the first reflective layer 5 being formed of a plurality of separately disposed reflective elements in this example.

It should be understood that, in the present embodiment, when the first reflective layer 5 and the second reflective layer 6 are both formed by a plurality of reflective units separately disposed, the reflective units of both reflective layers are made of opaque material, or the reflective unit of one of the reflective layers is made of opaque material, and the transparent unit of the other reflective layer is made of transparent or semi-transparent material.

It should be understood that, in the present embodiment, when the first reflective layer 5 and the second reflective layer 6 are both composed of a plurality of separately disposed reflective units, the position distribution of the reflective units of the two reflective layers can be flexibly set, for example:

in one example, the plurality of reflection units of the first reflection layer may be distributed at positions on the upper surface, and the plurality of reflection units of the second reflection layer may be distributed at positions on the lower surface in a one-to-one correspondence;

for another example, in another example, the positions of the reflection units of the second reflection layer on the lower surface correspond to the positions of the light transmission windows formed on the upper surface by the plurality of reflection units of the first reflection layer. Referring to fig. 4, the positions of the reflective units 61 on the lower surface of the transparent substrate 1 correspond to the positions of the transparent windows between the adjacent reflective units 61 on the upper surface of the transparent substrate 1, such arrangement can make the light reflection more sufficient and improve the uniformity of the emitted light.

In each example, the area between adjacent reflection units forms a light-transmitting window, and light can be emitted more uniformly through the cooperation of the light-transmitting window and the reflection units.

Optionally, in some examples of this embodiment, the LED flip chip may further include a third reflective layer filled in the light-transmissive window and having a light-transmissive characteristic. For example, referring to fig. 5, an example is shown, based on the LED flip chip shown in fig. 2, a third reflective layer 10 is disposed in a light-transmitting window between adjacent reflective units 51, and the third reflective layer 10 and the reflective units 51 cooperate to make the light reflection direction richer, and further improve the light-emitting uniformity. For another example, as shown in fig. 6, on the basis of the LED flip chip shown in fig. 3, a third reflective layer 10 is disposed in the light-transmitting window between the adjacent reflective units 61. For another example, referring to fig. 7, in still another example, based on the LED flip chip shown in fig. 4, the third reflective layer 10 is disposed in the light transmission window between the adjacent reflective units 61 and the light transmission window between the adjacent reflective units 51.

Alternatively, in the present embodiment, when the second reflective layer 6 is formed on the lower surface of the transparent substrate 1 and the first reflective layer 5 is formed on the upper surface of the transparent substrate 1, one of the reflective layers may be formed of a plurality of reflective units and the other reflective layer may have light transmittance and be a continuous integral layer. For example, referring to fig. 8, a second reflective layer 6 is formed on the lower surface of a transparent substrate 1 and is composed of a plurality of separated reflective units 61, and a first reflective layer 5 is formed on the upper surface of the transparent substrate 1, wherein the first reflective layer 5 has light transmittance and is a continuous integral layer. For another example, referring to fig. 9, a second reflective layer 6 is formed on the lower surface of the transparent substrate 1, the second reflective layer 6 is a continuous and integral layer having light transmittance, a first reflective layer 5 is formed on the upper surface of the transparent substrate 1, and the first reflective layer 5 is composed of a plurality of separated reflective units 51.

Optionally, in this embodiment, in each of the above examples, at least one of the reflection units in the first reflection layer 5 and the second reflection layer 6 may be a single-layer structure, or may be a multi-layer structure, and may be flexibly configured according to specific application requirements. For example, in the above-described example shown in fig. 2, the reflection unit 51 of the first reflection layer 5 may have a single-layer structure, or may be provided as a multi-layer structure as needed, that is, the reflection unit 51 may be composed of a plurality of sub-reflection layers stacked in sequence. Accordingly, in the above-described example shown in fig. 3, the reflection unit 61 of the second reflection layer 6 may also be a single-layer structure, or may be a multi-layer structure as required, that is, the reflection unit 61 may also be composed of a plurality of sub-reflection layers stacked in sequence. In the above-described example shown in fig. 4, the reflection unit 61 may also be a single-layer structure or a multi-layer structure as needed, and the reflection unit 51 may also be a single-layer structure or a multi-layer structure as needed; for example, the reflection unit 51 and the reflection unit 61 may be both provided in a single-layer structure, or a multi-layer structure, or the reflection unit 51 may be provided in a single-layer structure and the reflection unit 61 may be provided in a multi-layer structure, or the reflection unit 51 may be provided in a multi-layer structure and the reflection unit 61 may be provided in a single-layer structure.

That is, in each of the above examples, at least one of the reflection units 51 and 61 may be composed of a plurality of sub-reflection layers sequentially stacked.

Alternatively, in some examples of the present embodiment, when at least one of the reflection units 51 and 61 may be formed by a plurality of sub-reflection layers stacked in sequence, the materials of different sub-reflection layers may also be flexibly set in the plurality of sub-reflection layers stacked in sequence. For example, in some application examples, the materials of the different sub-reflective layers may be the same. In still other application examples, the material of different sub-reflective layers may be different.

Or in other application examples, a plurality of sub-reflection layers which are sequentially stacked may be further provided, the material of adjacent sub-reflection layers is different, and the material of two sub-reflection layers which are located on the upper and lower surfaces of the same sub-reflection layer is the same. For example, if a sub-reflective layer a, a sub-reflective layer B, a sub-reflective layer C, and a sub-reflective layer D are sequentially stacked, the sub-reflective layer a and the sub-reflective layer B are made of different materials, the sub-reflective layer a and the sub-reflective layer C are made of different materials, the sub-reflective layer B and the sub-reflective layer C are made of different materials, and the sub-reflective layer B and the sub-reflective layer D are made of the same material, so that the reflective layers made of different materials are alternately arranged to improve the reflective effect and the uniformity of the emitted light.

That is, in this embodiment, when one of the reflection units is composed of a plurality of sub-reflection layers, the sub-reflection layers may be made of the same material, for example, organic materials (including but not limited to silica gel, resin, and the like) or inorganic materials (including but not limited to silica, silicon, titanium dioxide, gold, silver, chromium, and nickel) may be used. When a certain reflection unit is composed of a plurality of sub-reflection layers, the sub-reflection layers may be different in material, or may be partially the same, or partially different, for example, each sub-reflection layer may be made of an organic material, but the specifically-adopted organic material may be different, or each sub-reflection layer may be made of an inorganic material, but the specifically-adopted inorganic material may be different, or some sub-reflection layers may be made of an inorganic material, some sub-reflection layers may be made of an organic material, and may be flexibly set according to an application scene.

Optionally, in some examples of this embodiment, in order to further improve the reflection efficiency and the uniformity of the emitted light, the reflection unit 51 and the reflection unit 61 may be further disposed, at least one of the upper surface and the lower surface of at least one reflection unit is a rough surface, and a manner of forming the rough surface may be flexibly selected, for example, but not limited to, a manner of roughening the mist surface.

For example, referring to fig. 10, in at least one of the reflection unit 51 and the reflection unit 61, an upper surface thereof may be a rough surface 91, and a lower surface thereof may be a relatively smooth surface. As another application example, referring to fig. 11, in at least one of the reflection unit 51 and the reflection unit 61, an upper surface thereof may be a relatively smooth surface, and a lower surface thereof is a rough surface 92. Referring to fig. 11, in another application example, in at least one of the reflection unit 51 and the reflection unit 61, an upper surface thereof may be a rough surface 91, and a lower surface thereof may also be a rough surface 92. When the reflection unit is composed of a plurality of sub reflection layers, the upper surface and the lower surface of each sub reflection layer may also be rough surfaces as exemplified in the above examples, or rough surfaces may be formed only on the upper surface and/or the lower surface of the uppermost and/or lowermost sub reflection layer, which may be flexibly selected according to application requirements. Through the arrangement of the rough surface, the reflection direction of light can be more fully changed, and the reflection efficiency and the light emitting uniformity are improved.

Optionally, in this embodiment, when a certain reflection unit is composed of a plurality of sub-reflection layers, the thicknesses of the sub-reflection layers may also be flexibly set according to requirements, for example, the thicknesses of the sub-reflection layers may be set to be the same, the thicknesses of the sub-reflection layers may also be set to be different, or the thicknesses of some sub-reflection layers are set to be the same, and the thicknesses of some sub-reflection layers are different. And particularly, the method can be flexibly set according to application scenes.

For example, as shown in fig. 13, when at least one of the reflective layers of the reflective unit 51 and the reflective unit 61 may be formed by a plurality of sequentially stacked sub-reflective layers, the at least one of the reflective layers may include a first sub-reflective layer 71, a second sub-reflective layer 72, and a third sub-reflective layer 73, which are sequentially stacked from bottom to top, in this application example, the thicknesses of the first sub-reflective layer 71, the second sub-reflective layer 72, and the third sub-reflective layer 73 are the same.

Referring to fig. 14, when at least one of the reflective layers of the reflective unit 51 and the reflective unit 61 may be formed by a plurality of sequentially stacked sub-reflective layers, the at least one of the reflective layers may also include a first sub-reflective layer 71, a second sub-reflective layer 72, and a third sub-reflective layer 73, which are sequentially stacked from bottom to top, in this application example, the thicknesses of the first sub-reflective layer 71, the second sub-reflective layer 72, and the third sub-reflective layer 73 are different from each other, and the thicknesses of the first sub-reflective layer 71, the second sub-reflective layer 72, and the third sub-reflective layer 73 are sequentially increased. In another application example, please refer to fig. 15, which is different from fig. 14 mainly in that the thicknesses of the first sub-reflective layer 71, the second sub-reflective layer 72, and the third sub-reflective layer 73 are sequentially decreased.

Of course, the thickness relationship of each sub-reflective layer is not limited to that shown in the above examples, and can be flexibly set according to application requirements, and is not described herein again.

Optionally, in some examples of this embodiment, in order to further improve the reflection efficiency and the uniformity of the emitted light, when at least one of the reflection units 51 and 61 may be composed of a plurality of sub-reflection layers stacked in sequence, the refractive indexes of the plurality of sub-reflection layers stacked in sequence may be set to decrease in sequence in a direction away from the transparent substrate 1, and when light is emitted from the active layer 3 and enters the transparent substrate 1 through the second reflection layer 6, since the refractive indexes of the reflection units 51 of the first reflection layer 5 and the second reflection layer 6 and the sub-reflection layers of the reflection units 61 decrease in sequence in a direction away from the transparent substrate 1, more light is emitted from the side of the transparent substrate 1 after being totally reflected between the sub-reflection layers, thereby improving the side light-emitting efficiency of the flip chip. For example, referring to the application examples shown in fig. 13 to fig. 15, the refractive indexes of the first sub-reflective layer 71, the second sub-reflective layer 72, and the third sub-reflective layer 73 in at least one application example may be sequentially decreased, and the difference between the refractive indexes of the adjacent sub-reflective layers may be the same or different.

In addition, it should be understood that the thicknesses of the reflection unit 51 and the reflection unit 61 in the present embodiment can also be flexibly set according to the requirement, for example, in an example, the reflection unit 51 and the reflection unit 61 can be set to be, but not limited to, 0.05um-5um, and specifically can be set to be 0.05um, 0.1um, 0.2um, 0.3um, 0.4um, 0.5um, and the like according to the requirement. Accordingly, when the reflection unit is composed of a plurality of sub-reflection layers, the thickness of each sub-reflection layer can be flexibly set based on the total thickness of the reflection layer, for example, but not limited to, 0.01um-3um, and specifically, can be set to 0.01um, 0.02um, 0.03um, 0.05um, 0.1um, 0.15um, 0.2um, etc. according to the requirement.

Optionally, in this embodiment, when the second reflective layer 6 is formed on the lower surface of the transparent substrate 1, and the first reflective layer 5 is formed on the upper surface of the transparent substrate 1, and both the second reflective layer 6 and the first reflective layer 5 are formed by a plurality of reflective units, the thicknesses and the materials of the reflective units 51 and the reflective units 61 may be the same, or at least one of the thicknesses and the materials of the reflective units 51 and the reflective units 61 may be different.

For example, in one example, the reflective unit 51 and the reflective unit 61 may have different thicknesses and the same material. In another example, the thicknesses of the reflection unit 51 and the reflection unit 61 may be the same, and the materials may be different (the difference in the materials necessarily results in a difference in the layer structures in the reflection unit 51 and the reflection unit 61), or in yet another example, the thicknesses of the reflection unit 51 and the reflection unit 61 may be different, and the materials may also be different.

It can be seen that, in the LED flip chip provided in this embodiment, a part of light emitted from the active layer may be reflected by the reflective unit in the first reflective layer and/or the second reflective layer having light transmittance, and then emitted from the side surface of the LED flip chip, so that the light emitting angle may be enlarged from 120 ° to 150 ° -180 °. For example, as shown in fig. 16, it is tested that the light emitting angle of the LED flip chip shown in fig. 1 is 120 °, and the light emitting angle of an application example using the LED flip chip in the above example of the present embodiment is 160 °, as shown in fig. 17. And the structure and the simple manufacture of the LED flip chip that this embodiment provided only need increase the first reflection stratum that has the light transmissivity that forms on the printing opacity basement upper surface, and/or, in the second reflection stratum that has the light transmissivity that forms on the printing opacity basement lower surface, the commonality is good, and the preparation is efficient, and the cost of manufacture is low.

The present embodiment further provides a display panel, which includes a display backplane and a plurality of LED flip chips as shown in the above examples, where the plurality of LED flip chips are disposed on the display backplane. The display panel can be applied to various electronic display devices. Due to the adoption of the LED flip chip with the light-emitting angle, additional lenses are not needed, and the number of used LED flip chips can be reduced, so that the display panel is thinner, fewer devices are needed to be used, the optical uniformity is better, the cost is lower, and the processing process is simpler and more convenient.

The foregoing is a more detailed description of embodiments of the present invention, and the specific embodiments are not to be considered in a limiting sense. To the utility model belongs to the technical field of ordinary technical personnel, do not deviate from the utility model discloses under the prerequisite of design, can also make a plurality of simple deductions or replacement, all should regard as belonging to the utility model discloses a protection scope.

Claims (10)

1. An LED flip chip is characterized by comprising a second semiconductor layer, an active layer, a first semiconductor layer, a light-transmitting substrate, a first electrode and a second electrode, wherein the second semiconductor layer, the active layer, the first semiconductor layer and the light-transmitting substrate are sequentially arranged from bottom to top;

the surface of the light-transmitting substrate opposite to the first semiconductor layer is a lower surface, and the surface of the light-transmitting substrate opposite to the lower surface is an upper surface; the LED flip chip further comprises a first reflecting layer formed on the upper surface and/or a second reflecting layer formed on the lower surface, at least one reflecting layer of the first reflecting layer and the second reflecting layer is composed of a plurality of separately arranged reflecting units, and a light-transmitting window is formed in an area between every two adjacent reflecting units.

2. The LED flip chip of claim 1, wherein said at least one of said reflective elements is comprised of a plurality of sequentially stacked sub-reflective layers.

3. The LED flip chip of claim 2, wherein different sub-reflective layers of the plurality of sequentially stacked sub-reflective layers are of different materials;

or, in the multiple sub-reflecting layers which are sequentially overlapped, the materials of the adjacent sub-reflecting layers are different, and the materials of the two sub-reflecting layers which are positioned on the upper surface and the lower surface of the same sub-reflecting layer are the same.

4. The LED flip chip of claim 2, wherein the plurality of sequentially stacked sub-reflective layers differ in thickness from sub-reflective layer to sub-reflective layer.

5. The LED flip chip according to any one of claims 2 to 4 wherein the refractive indices of the plurality of sequentially stacked sub-reflective layers decrease sequentially in a direction away from the light transmissive substrate.

6. The LED flip chip according to any one of claims 1 to 4, wherein at least one of the upper surface and the lower surface of at least one of the reflecting units is a roughened surface.

7. The LED flip chip according to any one of claims 1 to 4, further comprising a third reflective layer filled in the light transmissive window and having light transmissive properties.

8. The LED flip chip according to any one of claims 1 to 4, wherein the LED flip chip comprises a first reflective layer formed on the upper surface, and a second reflective layer formed on the lower surface, both the first reflective layer and the second reflective layer being comprised of a plurality of separately disposed reflective elements;

the positions of the plurality of reflection units of the first reflection layer on the upper surface are distributed and correspond to the positions of the plurality of reflection units of the second reflection layer on the lower surface in a one-to-one manner;

or the like, or, alternatively,

the positions of the reflection units of the second reflection layer on the lower surface correspond to the positions of the light transmission windows formed on the upper surface by the plurality of reflection units of the first reflection layer.

9. The LED flip chip of any of claims 1-4 wherein at least one of the first and second reflective layers is an opaque reflective layer.

10. A display panel comprising a display backplane and a plurality of LED flip chips according to any one of claims 1 to 9, the plurality of LED flip chips being disposed on the display backplane.

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