CN108134005B

CN108134005B - Light-emitting diode chip and preparation method thereof

Info

Publication number: CN108134005B
Application number: CN201711327268.6A
Authority: CN
Inventors: 陈亮; 王江波
Original assignee: HC Semitek Zhejiang Co Ltd
Current assignee: HC Semitek Zhejiang Co Ltd
Priority date: 2017-12-13
Filing date: 2017-12-13
Publication date: 2023-12-22
Anticipated expiration: 2037-12-13
Also published as: CN108134005A

Abstract

The invention discloses a light-emitting diode chip and a preparation method thereof, and belongs to the technical field of semiconductors. The chip comprises a chip body, a reflecting layer and a light-emitting regulating layer, wherein the reflecting layer is arranged on a first surface of the chip body, the light-emitting regulating layer is arranged on a second surface of the chip body, the second surface is a surface opposite to the first surface, and at least one of the first surface and the second surface is a non-mirror surface; the light-emitting control layer consists of an optical film, the reflectivity of the light-emitting control layer to the first incident light is smaller than or equal to a set value, and the reflectivity of the light-emitting control layer to the second incident light is larger than the set value; the first incident light and the second incident light are light rays which are emitted by the chip body and are emitted into the light emitting regulation layer, the incident angle of the first incident light rays which are emitted into the light emitting regulation layer is within a set range, and the incident angle of the second incident light rays which are emitted into the light emitting regulation layer is outside the set range. The invention is beneficial to the wide application of the LED on the backlight source.

Description

Light-emitting diode chip and preparation method thereof

Technical Field

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

Background

A light emitting diode (english: light Emitting Diode, abbreviated as LED) is a semiconductor electronic element capable of emitting light. With the continuous development of LEDs, the application fields of LEDs are also gradually expanding, and the fields for realizing applications at present include display screens, traffic signal lamps, lamps for automobiles, backlights of liquid crystal displays, decorative lights and illumination light sources. Among them, a backlight (english: back Light) is a Light source located at the Back of a liquid crystal panel, and requires Light to illuminate the liquid crystal panel from the side or Back of the liquid crystal panel to increase the brightness of the liquid crystal panel in a low Light source environment.

The LED comprises a package body and a light emitting chip positioned in the package body. Since the light emitted by the chip is emitted to all directions and the backlight source has a requirement on the light emitting angle, in the LED applied to the backlight source, one surface of the LED is usually selected as the light emitting surface of the LED, and a reflecting layer is arranged on at least the surface opposite to the light emitting surface of the LED, so that most of the light is emitted from the light emitting surface; meanwhile, an optical lens is additionally arranged on the light emitting surface of the LED, so that the light emitting angle is changed, and the requirement of a backlight source is met.

In carrying out the invention, the inventors have found that the prior art has at least the following problems:

The additional arrangement of the optical lens greatly increases the volume and weight of the LED, reduces the production efficiency, increases the application cost and is unfavorable for the application of the LED on a backlight source.

Disclosure of Invention

In order to solve the problem that the prior art is unfavorable for the application of LEDs on a backlight source, the embodiment of the invention provides a light-emitting diode chip and a preparation method thereof. The technical scheme is as follows:

in one aspect, an embodiment of the present invention provides a light emitting diode chip, where the light emitting diode chip includes a chip body and a reflective layer, where the reflective layer is disposed on a first surface of the chip body, the light emitting diode chip further includes a light emission control layer disposed on a second surface of the chip body, the second surface of the chip body is a surface opposite to the first surface of the chip body, and at least one of the first surface and the second surface of the chip body is a non-mirror surface; the light-emitting regulation layer consists of an optical film, the reflectivity of the light-emitting regulation layer to the first incident light ray is smaller than or equal to a set value, and the reflectivity of the light-emitting regulation layer to the second incident light ray is larger than the set value; the first incident light ray and the second incident light ray are light rays which are emitted by the chip body and are emitted into the light-emitting control layer, the incident angle of the first incident light ray which is emitted into the light-emitting control layer is within a set range, and the incident angle of the second incident light ray which is emitted into the light-emitting control layer is outside the set range.

Optionally, the light-emitting control layer includes a plurality of oxide films stacked in sequence, refractive indexes of materials of two adjacent oxide films are different, and thickness of each oxide film is set according to the setting range.

Preferably, the thickness of each of the oxide films is set based on the following formula:

wherein the incident angle of the light emergent regulation layer is theta ₀ The reflectivity of the light rays is the reflection coefficient of the equivalent interface of the Nth oxide film through which the light rays are injected into the light-emitting control layer, and N is the number of the plurality of oxide films;the reflection coefficient of the equivalent interface of the ith oxide film through which the light rays enter the light-emitting control layer passes, wherein i is an integer; r is (r) _i Fresnel coefficient of the ith oxide film through which light is incident into the light-emitting control layer,/th>η _i-1 And eta _i+1 To simplify the coefficients used by the fresnel formula, for the p component, +.>For s component, eta _i ＝n _i ×cosθ _i ；n _i Refractive index of material of ith oxide film passing through light-emitting control layer for light ray incidence, θ _i N is the refractive angle of the light ray when the light ray enters the light-emitting control layer and passes through the ith oxide film ₀ ×sinθ ₀ ＝n _i-1 ×sinθ _i-1 ＝n _i ×sinθ _i ＝n _i+1 ×sinθ _i+1 ，n ₀ Refractive index of the material of the chip body, θ ₀ An incident angle for light to enter the light-emitting control layer; delta _i For the phase thickness of the ith oxide film through which the light enters the light-emitting control layer,d _i the thickness of the ith oxide film through which the light enters the light-emitting control layer is measured.

Preferably, the material of the oxide film is tantalum pentoxide, titanium dioxide, silicon dioxide or hafnium dioxide.

Preferably, the setting range is 50 ° or less or 20 ° or more.

More preferably, when the set range is 50 ° or less, the light emission control layer includes a plurality of thin film units stacked in order, each of the thin film units including a first oxide thin film and a second oxide thin film stacked on the first oxide thin film, a refractive index of a material of the first oxide thin film being greater than a refractive index of a material of the second oxide thin film.

More preferably, when the set range is 20 ° or more, the light emission control layer includes (2×k+1) third oxide thin films and (2*k) fourth oxide thin films, k is a positive integer, the (2×k+1) third oxide thin films and the (2*k) fourth oxide thin films are alternately laminated, and a refractive index of a material of the third oxide thin films is smaller than a refractive index of a material of the fourth oxide thin films.

Preferably, the number of the plurality of oxide films is 30 to 70.

Optionally, the reflective layer is a distributed bragg reflective layer, a metallic reflective layer, or a total angle reflective layer.

In another aspect, an embodiment of the present invention provides a method for manufacturing a light emitting diode chip, where the method includes:

providing a chip body provided with a reflecting layer, wherein the reflecting layer is arranged on a first surface of the chip body;

forming a light-emitting regulation layer on the second surface of the chip body, wherein the light-emitting regulation layer consists of an optical film, the reflectivity of the light-emitting regulation layer to the first incident light is smaller than or equal to a set value, and the reflectivity of the light-emitting regulation layer to the second incident light is larger than the set value; the first incident light ray and the second incident light ray are light rays which are emitted by the chip body and are emitted into the light-emitting control layer, the incident angle of the first incident light ray which is emitted into the light-emitting control layer is within a set range, and the incident angle of the second incident light ray which is emitted into the light-emitting control layer is outside the set range; the second surface of the chip body is a surface opposite to the first surface of the chip body, and at least one of the first surface and the second surface of the chip body is a non-mirror surface.

The technical scheme provided by the embodiment of the invention has the beneficial effects that:

through set up the reflection stratum on one surface of chip body, set up out the light regulation and control layer simultaneously on the opposite surface of chip body for the most light that the chip body sent is followed out the light regulation and control layer. The reflectivity of the light-emitting control layer to the incident light rays with the incident angles within the set range is smaller than or equal to a set value, and the reflection efficiency of the light-emitting control layer to the incident light rays with the incident angles outside the set range is larger than the set value. The reflecting layer reflects the light to the light-emitting control layer, and the incident angle of the light changes after being reflected by the light-emitting control layer and the reflecting layer because at least one non-mirror surface exists on the surface of the chip body, on which the reflecting layer is arranged, and the surface of the light-emitting control layer is arranged. If the incidence angle of the changed light is within the set range, the light can be emitted through the light-emitting control layer; if the incidence angle of the changed light is still within the set range, the light is reflected by the light-emitting control layer and the reflecting layer again, and the incidence angle of the light is changed in the reflecting process until the incidence angle of the changed light is within the set range and is emitted through the light-emitting control layer, so that most of the light emitted by the chip body is emitted through the light-emitting control layer at the incidence angle within the set range. Because the incident angle of the light rays emitted into the light-emitting control layer is positively correlated with the emergent angle of the light rays emitted from the light-emitting control layer, the emergent angle of the light rays emitted through the light-emitting control layer is also within a certain range, the control of the emergent angle of the light rays can be realized, and the requirement of a backlight source is met. The light-emitting control layer is composed of an optical film, has little influence on the volume and the weight of the LED, is simple and convenient to manufacture, has high production efficiency and low application cost, and is beneficial to the wide application of the LED on a backlight source.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for the description of the embodiments will be briefly described below, and it is apparent that the drawings in the following description are only some embodiments of the present invention, and other drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 is a schematic structural diagram of a light emitting diode chip according to a first embodiment of the present invention;

fig. 2 is a schematic structural diagram of a light-emitting control layer according to an embodiment of the present invention;

FIG. 3 is a schematic diagram showing multi-beam interference of a single beam of light on a single film according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of the parameters in the formula provided in the first embodiment of the present invention;

FIG. 5 is an equivalent interface of a single layer film provided in accordance with an embodiment of the present invention;

FIG. 6 is a schematic view of a multilayer film reflectivity recurrence provided in accordance with an embodiment of the present invention;

fig. 7 is a schematic structural diagram of a chip body in a light emitting diode chip with a front mounting structure and a flip-chip structure according to an embodiment of the present invention;

fig. 8a is a schematic structural diagram of a light emitting diode chip with a front-loading structure according to an embodiment of the present invention;

Fig. 8b is a schematic structural diagram of a flip-chip led chip according to an embodiment of the present invention;

fig. 9 is a schematic structural diagram of a chip body in a vertical structure led chip according to an embodiment of the present invention;

fig. 10a is a schematic structural diagram of a light emitting diode chip with a vertical structure according to a first embodiment of the present invention;

fig. 10b is a schematic structural diagram of another led chip with a vertical structure according to the first embodiment of the present invention;

fig. 11 is a schematic structural diagram of a light-emitting control layer according to a second embodiment of the present invention;

fig. 12 is a schematic diagram of reflectivity of a light-emitting control layer of a specific implementation manner provided in the second embodiment of the present invention to light emitted by a chip body under different incident angles;

fig. 13 is a schematic diagram of reflectivity of a light-emitting control layer of another embodiment of the present invention for light emitted from a chip body at different incident angles;

fig. 14 is a light path diagram of light emitted by the chip body according to the second embodiment of the present invention entering the light-emitting control layer at different incident angles;

fig. 15 is a schematic structural diagram of another light-emitting control layer according to the third embodiment of the present invention;

Fig. 16 is a schematic diagram of reflectivity of a light-emitting control layer of a third embodiment of the present invention to light emitted from a chip body under different incident angles;

fig. 17 is a light path diagram of light emitted by the chip body according to the third embodiment of the present invention entering the light-emitting control layer at different incident angles;

fig. 18 is a flowchart of a method for manufacturing a light emitting diode chip according to a fourth embodiment of the present invention;

fig. 19 is a flowchart of a method for manufacturing a light emitting diode chip according to a fifth embodiment of the present invention;

fig. 20a to 20e are schematic structural diagrams of a light emitting diode chip during execution of a manufacturing method according to a fifth embodiment of the present invention;

fig. 21 is a flowchart of a method for manufacturing a light emitting diode chip according to a sixth embodiment of the present invention;

fig. 22a to 22e are schematic structural diagrams of a light emitting diode chip during execution of the manufacturing method according to the sixth embodiment of the present invention;

fig. 23 is a flowchart of a method for manufacturing a light emitting diode chip according to a seventh embodiment of the present invention;

fig. 24a to 24f are schematic structural diagrams of a light emitting diode chip during execution of the preparation method according to the seventh embodiment of the present invention;

fig. 25 is a flowchart of a method for manufacturing a light emitting diode chip according to an eighth embodiment of the present invention;

Fig. 26a to 26f are schematic structural diagrams of a light emitting diode chip during execution of the manufacturing method according to the eighth embodiment of the present invention.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the embodiments of the present invention will be described in further detail with reference to the accompanying drawings.

Example 1

Referring to fig. 1, the light emitting diode chip includes a chip body 10, a reflective layer 20 and a light-emitting control layer 30, wherein the reflective layer 20 is disposed on a first surface of the chip body 10, and the light-emitting control layer 30 is disposed on a second surface of the chip body 10. The second surface of the chip body 10 is a surface opposite to the first surface of the chip body 10, and at least one of the first surface and the second surface of the chip body 10 is a non-mirror surface.

In this embodiment, the light-emitting control layer 30 is composed of an optical film, the reflectivity of the light-emitting control layer 30 for the first incident light is less than or equal to a set value, and the reflectivity of the light-emitting control layer 30 for the second incident light is greater than the set value. The first incident light and the second incident light are light emitted by the chip body 10 and incident into the light-emitting control layer 30, the incident angle of the first incident light incident into the light-emitting control layer 30 is within a set range, and the incident angle of the second incident light incident into the light-emitting control layer 30 is outside the set range.

According to the embodiment of the invention, the reflecting layer is arranged on one surface of the chip body, and the light-emitting regulating layer is arranged on the opposite surface of the chip body, so that most of light rays emitted by the chip body are emitted from the light-emitting regulating layer. The reflectivity of the light-emitting control layer to the incident light rays with the incident angles within the set range is smaller than or equal to a set value, and the reflection efficiency of the light-emitting control layer to the incident light rays with the incident angles outside the set range is larger than the set value. The reflecting layer reflects the light to the light-emitting control layer, and the incident angle of the light changes after being reflected by the light-emitting control layer and the reflecting layer because at least one non-mirror surface exists on the surface of the chip body, on which the reflecting layer is arranged, and the surface of the light-emitting control layer is arranged. If the incidence angle of the changed light is within the set range, the light can be emitted through the light-emitting control layer; if the incidence angle of the changed light is still within the set range, the light is reflected by the light-emitting control layer and the reflecting layer again, and the incidence angle of the light is changed in the reflecting process until the incidence angle of the changed light is within the set range and is emitted through the light-emitting control layer, so that most of the light emitted by the chip body is emitted through the light-emitting control layer at the incidence angle within the set range. Because the incident angle of the light rays emitted into the light-emitting control layer is positively correlated with the emergent angle of the light rays emitted from the light-emitting control layer, the emergent angle of the light rays emitted through the light-emitting control layer is also within a certain range, the control of the emergent angle of the light rays can be realized, and the requirement of a backlight source is met. The light-emitting control layer is composed of an optical film, has little influence on the volume and the weight of the LED, is simple and convenient to manufacture, has high production efficiency and low application cost, and is beneficial to the wide application of the LED on a backlight source.

Specifically, fig. 2 is a schematic structural diagram of the light-emitting control layer provided in this embodiment, referring to fig. 2, the light-emitting control layer 30 may include a plurality of oxide films 31 stacked in sequence, where the refractive indexes of materials of two adjacent oxide films 31 are different, and the thickness of each oxide film 31 is set according to a set range. The adjustment of the light-emitting angle by the light-emitting adjusting and controlling layer is realized through the adjustment of the thickness of the oxide film.

In practical application, the light-emitting control layer capable of controlling the light-emitting angle can be realized by sequentially stacking oxide films made of different materials; the material and thickness of the oxide film which are sequentially laminated can be comprehensively selected, so that the light-emitting regulation layer capable of regulating the light-emitting angle is realized. Since the light-emitting control layer is realized by selecting the thickness of the oxide film most simply and conveniently, the embodiment is specifically described in a manner of realizing the light-emitting control layer by selecting the thickness of the oxide film, but is not limited to a manner of realizing the light-emitting control layer by selecting the thickness of the oxide film.

In a specific implementation, the thickness of each oxide film 31 may be set based on the following formula:

wherein, the incident angle of the light emergent regulating layer is theta ₀ The reflectivity of the light rays is the reflectivity of the equivalent interface of the Nth oxide film through which the light rays are emitted into and out of the light regulation layer, and N is the number of the plurality of oxide films;the reflection coefficient of the equivalent interface of the ith oxide film through which the light rays enter and exit the light regulating layer passes, wherein i is an integer; r is (r) _i Fresnel coefficient of ith oxide film through which light is incident/outgoing light-adjusting layer passes,/>η _i-1 And eta _i+1 To simplify the coefficients used by the fresnel formula, for the p component, +.>For s component, eta _i ＝n _i ×cosθ _i ；n _i Refractive index, θ, of the material of the ith oxide thin film through which light is incident/exiting the light modulating layer _i For light incident on or exiting from the light-regulating layer through the ith oxide filmRefractive angle, n ₀ ×sinθ ₀ ＝n _i-1 ×sinθ _i-1 ＝n _i ×sinθ _i ＝n _i+1 ×sinθ _i+1 ，n ₀ Refractive index of material of chip body, θ ₀ The incident angle of the light entering and exiting the light regulating layer is the incident angle of the light; delta _i The phase thickness of the ith oxide film through which the light is incident/exiting the light control layer,/I>d _i The thickness of the ith oxide film through which light enters and exits the light regulating layer.

Based on the above, the reflectance of the light-emitting control layer for incident light is the reflectance of the equivalent interface of the nth oxide thin film through which the light enters the light-emitting control layer, and the reflectance of the equivalent interface of the nth oxide thin film is related to the reflectance of the equivalent interface of the N-1 th oxide thin film, the reflectance of the equivalent interface of the N-1 th oxide thin film is related to the reflectance of the equivalent interface of the N-2 nd oxide thin film, … …, and the reflectance of the equivalent interface of the 2 nd oxide thin film is related to the reflectance of the equivalent interface of the 1 st oxide thin film, so the reflectance of the light-emitting control layer for incident light is related to the reflectance of the equivalent interfaces of all oxide thin films. While the reflection coefficient of the equivalent interface of each oxide film is related to the respective fresnel coefficient and the phase thickness, the fresnel coefficient of each oxide film is related to the respective refractive index of the material and the refractive angle of the light, and the phase thickness of each oxide film is related to the respective thickness, the refractive index of the material and the refractive angle of the light, so the reflectivity of the light-exiting regulating layer to the incident light is substantially related to the incident angle of the light, and the thicknesses of all the oxide films and the refractive indexes of the materials.

In particular, the range of the incident angle and the corresponding reflectivity is determined, and according to the above, after the materials and the number of the oxide films are selected, the thickness of each oxide film can be obtained, so that the function of the light-emitting control layer is realized, that is, the incident light with the incident angle within the set range is transmitted, and the incident light with the incident angle outside the set range is reflected.

The origin of the above formula is further described below:

starting first with a relatively simple single layer film, fig. 3 is a schematic diagram of multi-beam interference of a beam of light on the single layer film, see fig. 3, where the light enters the single layer film from a certain medium, passes through the single layer film and exits to another medium, where the light is reflected and refracted at a first interface entering the single layer film and at a second interface exiting the single layer film simultaneously, thereby producing a set of reflected beams 1, 2, 3, 4, … … and a set of transmitted beams 1', 2', 3', 4', … ….

If the amplitude of the incident light is E ₀ The amplitudes of the respective reflected beams are sequentially as follows:

……

wherein E is ₁ 、E ₂ 、E ₃ 、E ₄ The … … amplitudes of the reflected beams 1, 2, 3, 4, … … in turn; fig. 4 is a schematic diagram of the parameters in the above equation, see fig. 4, Transmittance for light to enter the monolayer at the first interface, +.>Reflection coefficient for light to enter the monolayer film at the first interface, +.>For the reflection coefficient of the light rays emerging from the monolayer film at the first interface, +.>For the transmission coefficient of the light rays emerging from the monolayer film at the first interface, < >>For the transmission coefficient of the light rays emerging from the monolayer at the second interface, < >>Reflection coefficient for light to enter the monolayer at the second interface, +.>For the reflection coefficient of the light rays emitted from the single-layer film at the second interface, +.>The transmission coefficient of the light rays entering the single-layer film at the second interface; delta is the phase thickness of the monolayer film,as shown in fig. 3, d is the thickness of the single-layer film, n is the refractive index of the material of the single-layer film, θ is the refractive angle in the single-layer film, i.e., the phase difference between two adjacent light beams is 2×δ.

From Stokes' law, r ⁺ ＝-r ^- ，(r ⁺ ) ² +t ⁺ ×t ⁺ ＝1。

Thus the combined amplitude E of the reflected light _R The following are provided:

the reflection coefficient r of the single-layer film was as follows:

it follows that the reflectance of a single film is a complex number, which can be written as follows:

wherein,for the phase shift of the reflected light, this indicates that the phase of the reflected light is behind the value of the incident light,

the reflectance R of the single layer film can therefore be as follows:

FIG. 5 is an equivalent interface of a single layer film, see FIG. 5, using an equivalent interface instead of two interfaces of a single layer film, assuming that the refractive index of the single layer film is n _i The refractive index of the incident medium is n _i-1 The refractive index of the emergent medium is n _i+1 The phase thickness of the film is delta _i The reflection coefficient of the interface of the light rays entering the single-layer film is r _i-1 The reflection coefficient of the interface of the light rays emitted from the single-layer film is r _i The reflection coefficient of this equivalent interface may be as follows:

with reference to such a process, calculation of the reflectance of a single-layer film is generalized to a multilayer film. FIG. 6 is a multilayer film reflectivity passPush-up schematic, see FIG. 6, first starting with film 1 where light is incident, two interfaces (r ₀ And r ₁ ) Equivalent to an interface (reflection coefficient is) This equivalent interface (reflection coefficient is +.>) And the interface (r) not equivalent to that of the 2 nd film ₂ ) Equivalent to an interface (reflection coefficient is +.>) This equivalent interface (reflection coefficient is then +.>) And the interface (r) not equivalent to that before the 3 rd film ₃ ) Equivalent to an interface (reflection coefficient is) This is sequentially repeated in the order of light incidence until the equivalent interface (reflection coefficient is +.>) And the interface (r) not equivalent to that before the Nth film _N ) Equivalent to an interface (reflection coefficient is +.>) The following formula can be obtained:

……

i.e., the above formula for setting the thickness of each oxide film.

Alternatively, the material of the oxide film 31 may be tantalum pentoxide, titanium dioxide, silicon dioxide or hafnium dioxide, which is low in implementation cost.

For example, the light emission control layer is formed by alternately laminating oxide films of two materials, wherein the material of the oxide film of one material is titanium dioxide and the material of the oxide film of the other material is silicon dioxide.

In practical application, the setting range can be below 50 degrees (such as 0-25 degrees) or above 20 degrees (such as 35-80 degrees). When the setting range is below 50 degrees, more concentrated forward light can be provided, so that the light-emitting diode chip is applied to a backlight source for irradiating the liquid crystal screen from the back of the liquid crystal screen; when the setting range is more than 20 degrees, lateral light with wider coverage can be provided, so that the light-emitting diode chip is applied to a backlight source for irradiating the liquid crystal screen from the side surface of the liquid crystal screen.

Alternatively, the number of the plurality of oxide films 31 may be 30 to 70. Under the condition of accurately regulating and controlling the light emitting angle, the complex process caused by excessive quantity of oxide films is avoided as much as possible, and the manufacturing cost is increased.

In one implementation of this embodiment, the reflective layer 20 may be a distributed Bragg reflective layer (English: distributed Bragg Reflection, DBR for short).

Specifically, the DBR may include a plurality of periods of oxide films, the plurality of periods of oxide films being sequentially laminated, each period of oxide film including at least two kinds of oxide films, the refractive indices of the oxide films of different materials being different, the at least two kinds of oxide films being sequentially laminated, the order of lamination of the at least two kinds of oxide films in the oxide films of different periods being the same.

More specifically, the thickness of the oxide film per cycle may be equal to 1/4 of the wavelength of light emitted from the chip body.

Alternatively, the number of cycles of the oxide film may be 20 to 60. The reflective film has the advantages that the reflective effect is achieved, the number of oxide films is reduced as much as possible, the complex processing technology is avoided, and the production cost is high.

Further, the oxide film of one cycle may include oxide films of two or three materials to reduce process complexity as much as possible while securing a reflection effect.

Specifically, the oxide film in the DBR may be made of tantalum pentoxide, hafnium dioxide, titanium dioxide, or silicon dioxide.

For example, the oxide film of one cycle includes an oxide film of two materials, the material of the oxide film of one material is titanium dioxide, and the material of the oxide film of the other material is silicon dioxide.

As described above for the thickness of the oxide film in the light emission control layer, the reflection effect of the same oxide film (same material) on light is different at different thicknesses. Therefore, even if the material of the oxide film in the DBR is the same as that of the oxide film in the light-emission control layer, the thickness of the oxide film in the DBR and the thickness of the oxide film in the light-emission control layer are different, and thus, the respective different functions can be realized.

In another implementation of this embodiment, the reflective layer 20 may be a metallic reflective layer.

Specifically, the material of the metal reflecting layer can be silver or aluminum, and the reflecting effect is good.

In yet another implementation of this embodiment, the reflective layer 20 may be a total angle reflective layer (english: omni Directional Reflector, abbreviated: ODR), that is, the reflective layer includes a DBR and a metal reflective layer laminated in order. The reflective effect is optimized by combining the reflective capabilities of the DBR and the metal reflective layer.

Specifically, the light emitting diode chip may be a front-loading structure, a flip-chip structure, or a vertical structure.

Alternatively, fig. 7 is a schematic structural diagram of a chip body in a light emitting diode chip with a forward mounting structure and a flip chip structure according to the present embodiment, referring to fig. 7, the chip body 10 may include a substrate 11, an N-type semiconductor layer 12, a light emitting layer 13, a P-type semiconductor layer 14, a P-type electrode 15, and an N-type electrode 16, where the N-type semiconductor layer 12, the light emitting layer 13, and the P-type semiconductor layer 14 are sequentially stacked on the substrate 11, a groove extending to the N-type semiconductor layer 12 is formed on the P-type semiconductor layer 14, the N-type electrode 16 is disposed on the N-type semiconductor layer 12 in the groove, and the P-type electrode 15 is disposed on the P-type semiconductor layer 14.

Specifically, the substrate 11 may be a sapphire substrate, the N-type semiconductor layer 12 may be an N-type GaN layer, and the P-type semiconductor layer 14 may be a P-type GaN layer; the light emitting layer 13 includes a plurality of quantum wells and a plurality of quantum barriers, which are alternately stacked, and the quantum wells may be InGaN layers and the quantum barriers may be GaN layers; the N-type electrode 16 and the P-type electrode 15 may be formed using a metal material.

Fig. 8a is a schematic structural diagram of a light emitting diode chip with a front-loading structure according to the present embodiment, and referring to fig. 8a, when the light emitting diode chip is in a front-loading structure, the reflective layer 20 is disposed on the substrate 11, and the light emission regulating layer 30 is disposed on the P-type semiconductor layer 14 except for the region where the P-type electrode 15 is disposed.

Further, as shown in fig. 8a, the light emitting diode chip may further include a passivation layer 40, and the passivation layer 40 is disposed on the light emission control layer 30, the sidewall of the groove, and other regions of the N-type semiconductor layer 12 within the groove except for the disposed region of the N-type electrode 16. Specifically, the material of the passivation layer 40 may be silicon dioxide.

Fig. 8b is a schematic structural diagram of a light emitting diode chip with a flip-chip structure according to the present embodiment, and referring to fig. 8b, when the light emitting diode chip is in a flip-chip structure, the light emitting control layer 30 is disposed on the substrate 11, and the reflective layer 20 is disposed at least on other areas of the P-type semiconductor layer 14 except for the disposed area of the P-type electrode 15.

It should be noted that, if the reflective layer 20 is implemented by a metal reflective layer, the reflective layer 20 may also be disposed between the P-type semiconductor layer 14 and the P-type electrode 15, i.e., the reflective layer 20 is first laid on the entire P-type semiconductor layer 14, and then the P-type electrode 15 is disposed on the reflective layer 20.

Further, if the reflective layer 20 and the P-type electrode 15 are formed of the same metal material, it is also possible to directly lay the metal material on the entire P-type semiconductor layer 14 while functioning as the reflective layer 20 and the P-type electrode 15.

Preferably, as shown in fig. 8b, the light emitting diode chip may further include a passivation layer 40, the passivation layer 40 being disposed on the reflective layer 20, the sidewalls of the recess, and other regions of the N-type semiconductor layer 12 within the recess except for the region where the N-type electrode 16 is disposed. Specifically, the material of the passivation layer 40 may be silicon dioxide.

Further, the chip body 10 may further include a transparent conductive layer (not shown in the drawing) disposed on the P-type semiconductor layer. Specifically, indium tin oxide may be used as a material of the transparent conductive layer.

Still further, the chip body 10 may further include a current blocking layer (not shown) disposed between the P-type electrode and the P-type semiconductor layer. Specifically, the material of the current blocking layer may be silicon dioxide.

Alternatively, fig. 9 is a schematic structural diagram of a chip body in the light emitting diode chip with a vertical structure provided in this embodiment, referring to fig. 9, the chip body 10 may include an N-type semiconductor layer 12, a light emitting layer 13, a P-type semiconductor layer 14, a P-type electrode 15 and an N-type electrode 16, where the N-type semiconductor layer 12, the light emitting layer 13 and the P-type semiconductor layer 14 are sequentially stacked, the P-type electrode 15 is disposed on the P-type semiconductor layer 14, and the N-type electrode 16 is disposed on the N-type semiconductor layer 12.

Specifically, the N-type semiconductor layer 12 may be an N-type GaN layer, and the P-type semiconductor layer 14 may be a P-type GaN layer; the light emitting layer 13 includes a plurality of quantum wells and a plurality of quantum barriers, which are alternately stacked, and the quantum wells may be InGaN layers and the quantum barriers may be GaN layers; the N-type electrode 16 and the P-type electrode 15 may be formed using a metal material. Alternatively, the N-type semiconductor layer 12 may be an N-type AlInP layer, and the P-type semiconductor layer 14 may be a P-type AlInP layer; the light emitting layer 13 includes a plurality of quantum wells and a plurality of quantum barriers, which are alternately stacked, and the quantum wells and the quantum barriers may be AlGaInP layers having different Al compositions; the N-type electrode 16 and the P-type electrode 15 may be formed using a metal material.

Fig. 10a is a schematic structural diagram of a light emitting diode chip according to the present embodiment, referring to fig. 10a, the reflective layer 20 is disposed at least on the other regions of the N-type semiconductor layer 12 except for the region where the N-type electrode 16 is disposed, and the light emission controlling layer 30 is disposed on the other regions of the P-type semiconductor layer 14 except for the region where the P-type electrode 15 is disposed.

It should be noted that, if the reflective layer 20 is implemented by a metal reflective layer, the reflective layer 20 may also be disposed between the N-type semiconductor layer 12 and the N-type electrode 16, that is, the reflective layer 20 is first laid on the entire N-type semiconductor layer 12, and then the N-type electrode 16 is disposed on the reflective layer 20.

Further, if the reflective layer 20 and the N-type electrode 16 are formed of the same metal material, it is also possible to directly lay the metal material on the entire N-type semiconductor layer 12 while functioning as the reflective layer 20 and the N-type electrode 16.

Fig. 10b is a schematic structural diagram of another led chip provided in this embodiment, referring to fig. 10b, the light-emitting control layer 30 is disposed on the other area of the N-type semiconductor layer 12 except for the area where the N-type electrode 16 is disposed, and the reflective layer 20 is disposed at least on the other area of the P-type semiconductor layer 14 except for the area where the P-type electrode 15 is disposed.

Example two

The embodiment of the invention provides a light-emitting diode chip, which is a specific implementation of the light-emitting diode chip provided by the second embodiment, and is suitable for a backlight source for illuminating a liquid crystal screen from the back of the liquid crystal screen.

Fig. 11 is a schematic structural view of a light-emission control layer provided in this embodiment, and referring to fig. 11, the light-emission control layer 30 includes a plurality of thin film units sequentially stacked, each of the thin film units including a first oxide thin film 31a and a second oxide thin film 31b stacked on the first oxide thin film 31a, and a refractive index of a material of the first oxide thin film 31a is greater than a refractive index of a material of the second oxide thin film 31 b.

In a specific implementation manner of this embodiment, the light emission control layer 30 includes 16 thin film units stacked in order, the material of the first oxide thin film 31a is titanium dioxide (refractive index is 2.35), and the material of the second oxide thin film 31b is silicon dioxide (refractive index is 1.46).

The thickness of each oxide film in the order of lamination of the light emission control layers is shown in the following table one:

list one

FIG. 12 shows the reflectance of the light-emitting control layer to the chip body at different incident angles, referring to FIG. 12, in the process that the incident angle of the light emitted from the chip body to the light-emitting control layer increases from 0 ° to 20 °, the reflectance of the light by the light-emitting control layer is maintained at about 35% all the time; in the process that the incident angle of the light emitted by the chip body and entering the light emitting and controlling layer is increased from 20 degrees to 35 degrees, the reflectivity of the light emitting and controlling layer to the light is increased from 35 percent to the maximum 90 percent; in the process that the incident angle of light emitted by the chip body and injected into the light-emitting regulation layer is increased from 35 degrees to 50 degrees, the reflectivity of the light-emitting regulation layer to the light is basically maintained at about 90 percent all the time; in the process that the incident angle of the light emitted by the chip body and incident into the light-emitting regulation layer is increased from 50 degrees to 90 degrees, the reflectivity of the light-emitting regulation layer to the light is reduced from 90 percent to 0 percent. When the incident angle of the light emitted by the chip body to the light emitting and controlling layer is between 25 and 80 degrees, the reflectivity of the light emitting and controlling layer to the light is more than 50 percent; when the incident angle of the light emitted by the chip body to the light emitting and controlling layer is between 0 and 25 degrees or between 80 and 90 degrees, the reflectivity of the light emitting and controlling layer to the light is below 50 percent.

In another specific implementation manner of this embodiment, the light emission control layer 30 includes 24 thin film units stacked in sequence, the material of the first oxide thin film 31a is titanium dioxide (refractive index is 2.35), and the material of the second oxide thin film 31b is silicon dioxide (refractive index is 1.46).

The thickness of each oxide film in the order of lamination of the light emission control layers is shown in the following table two:

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FIG. 13 shows the reflectance of the light-emitting control layer to the chip body at different incident angles, see FIG. 13, in which the reflectance of the light-emitting control layer to the light is maintained at about 0% substantially all the time during the process of increasing the incident angle of the light emitted from the chip body into the light-emitting control layer from 0 ° to 20 °; in the process that the incident angle of the light emitted by the chip body and entering the light emitting and controlling layer is increased from 20 degrees to 50 degrees, the reflectivity of the light emitting and controlling layer to the light is increased from 0% to the maximum 90%; in the process that the incident angle of the light emitted by the chip body and incident into the light-emitting regulation layer is increased from 50 degrees to 90 degrees, the reflectivity of the light-emitting regulation layer to the light is reduced from 90 percent to 0 percent. When the incident angle of the light emitted by the chip body to the light emitting and controlling layer is between 35 and 80 degrees, the reflectivity of the light emitting and controlling layer to the light is more than 50 percent; when the incident angle of the light emitted by the chip body to the light emitting and controlling layer is between 0 and 35 degrees or between 80 and 90 degrees, the reflectivity of the light emitting and controlling layer to the light is below 50 percent.

Therefore, the reflectivity of the light-emitting control layer to the light emitted by the chip body is smaller when the incident angle is smaller, and is larger when the incident angle is larger.

Fig. 14 is a light path diagram of light emitted by the chip body and entering the light-emitting control layer at different incident angles, referring to fig. 14, light a emitted by the chip body 10 from the O-point enters the light-emitting control layer 30 at an incident angle a, the reflectivity of the light-emitting control layer 30 to the light a is smaller, and the light a is directly emitted through the light-emitting control layer 30.

The light ray B emitted from the O point of the chip body 10 is first incident into the light-emitting control layer 30 at an incident angle B1 (greater than the incident angle a), the reflectivity of the light-emitting control layer 30 to the light ray B is greater, the light ray B is reflected to the reflective layer 20 by the light-emitting control layer 30, and then the light ray B is reflected to the light-emitting control layer 30 by the reflective layer 20. Since at least one of the interface between the chip body 10 and the light-emitting reflective layer 30 and the interface between the chip body 10 and the reflective layer 20 is a non-mirror surface, the light B is incident into the light-emitting control layer 30 for the second time at an incident angle B2 (smaller than the incident angle B1) different from the incident angle B1, and the light-emitting control layer 30 has a smaller reflectivity to the light B, and the light B is emitted through the light-emitting control layer 30.

The light ray C emitted from the O point of the chip body 10 is first incident into the light-emitting control layer 30 at an incident angle C1 (greater than the incident angle b 1), the reflectivity of the light-emitting control layer 30 to the light ray C is greater, the light-emitting control layer 30 reflects the light ray C to the reflective layer 20 for the first time, and then the reflective layer 20 reflects the light ray C to the light-emitting control layer 30 for the first time. The light ray C is incident to the light-emitting control layer 30 for the second time at an incident angle C2 (smaller than the incident angle C1) different from the incident angle C1, the reflectivity of the light-emitting control layer 30 to the light ray C is still larger, the light-emitting control layer 30 reflects the light ray C to the reflective layer 20 for the second time, and then the reflective layer 20 reflects the light ray C to the light-emitting control layer 30 for the second time. The light ray C enters the light-emitting control layer 30 for the third time at an incident angle C3 (smaller than the incident angle C2) different from the incident angle C2, the reflectivity of the light-emitting control layer 30 to the light ray C is smaller, and the light ray C is emitted through the light-emitting control layer 30.

As can be seen from fig. 14, although the incident angles of the light a, the light B and the light C entering the light-emitting control layer 30 are greatly different, under the combined action of the light-emitting control layer 30 and the reflective layer 20, the light a, the light B and the light C finally exit from the light-emitting control layer 30 at a small exit angle, so as to meet the requirement of the backlight source for illuminating the liquid crystal screen from the back side of the liquid crystal screen.

Example III

The embodiment of the invention provides a light-emitting diode chip, which is another specific implementation of the light-emitting diode chip provided by the second embodiment, and is suitable for a backlight source for illuminating a liquid crystal screen from the side surface of the liquid crystal screen.

Fig. 15 is a schematic structural diagram of a light-emitting control layer provided in this embodiment, referring to fig. 15, the light-emitting control layer 30 includes (2×k+1) third oxide films 31c and (2*k) fourth oxide films 31d, k is a positive integer, (2×k+1) third oxide films 31c and (2*k) fourth oxide films 31d are alternately stacked, and the refractive index of the material of the third oxide film 31c is smaller than that of the material of the fourth oxide film 31 d.

In a specific implementation manner of this embodiment, the light emission control layer 30 includes 25 third oxide films 31c and 24 fourth oxide films 31d stacked in order, where the material of the third oxide film 31c adopts silicon dioxide (refractive index 1.46), and the material of the fourth oxide film 31d adopts titanium dioxide (refractive index 2.35).

The thickness of each oxide film in the order of lamination of the light emission control layers is shown in the following table three:

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FIG. 16 shows the reflectance of the light-emitting control layer to the chip body at different incident angles, and referring to FIG. 16, the reflectance of the light-emitting control layer to the light is maintained at about 80% substantially all the time during the process that the incident angle of the light emitted from the chip body into the light-emitting control layer increases from 0 ° to 10 °. In the process that the incident angle of the light emitted by the chip body and incident into the light-emitting regulation layer is increased from 10 degrees to 90 degrees, the reflectivity of the light-emitting regulation layer to the light is reduced from 80% to 0% along with the increase. When the incidence angle of the light emitted by the chip body to the light emitting and controlling layer is between 0 and 25 degrees, the reflectivity of the light emitting and controlling layer to the light is more than 50 percent; when the incident angle of the light emitted by the chip body to the light emitting and controlling layer is between 25 and 90 degrees, the reflectivity of the light emitting and controlling layer to the light is below 50 percent.

Therefore, the reflectivity of the light-emitting control layer to the light emitted by the chip body is larger when the incident angle is smaller, and is smaller when the incident angle is larger.

Fig. 17 is a light path diagram of light emitted by the chip body and entering the light-emitting control layer at different incident angles, referring to fig. 17, light D emitted by the chip body 10 from the O-point enters the light-emitting control layer 30 at an incident angle D, the reflectivity of the light-emitting control layer 30 to the light D is smaller, and the light D is directly emitted through the light-emitting control layer 30.

The light ray E emitted from the O-point of the chip body 10 is first incident into the light-emitting control layer 30 at an incident angle E1 (smaller than an incident angle d), the reflectivity of the light-emitting control layer 30 to the light ray E is larger, the light ray E is reflected to the reflective layer 20 by the light-emitting control layer 30, and then the light ray E is reflected to the light-emitting control layer 30 by the reflective layer 20. Since at least one of the interface between the chip body 10 and the light-emitting reflective layer 30 and the interface between the chip body 10 and the reflective layer 20 is a non-mirror surface, the light E is incident into the light-emitting control layer 30 for the second time at an incident angle E2 (greater than the incident angle E1) different from the incident angle E1, the reflectivity of the light E by the light-emitting control layer 30 is smaller, and the light E is emitted through the light-emitting control layer 30.

The light ray F emitted from the O point of the chip body 10 is first emitted into the light-emitting control layer 30 at an incident angle F1 (smaller than the incident angle e 1), the reflectivity of the light-emitting control layer 30 to the light ray F is larger, the light-emitting control layer 30 reflects the light ray F to the reflective layer 20 for the first time, and then the reflective layer 20 reflects the light ray F to the light-emitting control layer 30 for the first time. The light ray F is incident into the light-emitting control layer 30 for the second time at an incident angle F2 (greater than the incident angle F1) different from the incident angle F1, the reflectivity of the light ray F by the light-emitting control layer 30 is still greater, the light ray F is reflected to the reflective layer 20 for the second time by the light-emitting control layer 30, and then the light ray F is reflected to the light-emitting control layer 30 for the second time by the reflective layer 20. The light ray F enters the light-emitting control layer 30 for the third time at an incident angle F3 (greater than the incident angle F2) different from the incident angle F2, the reflectivity of the light-emitting control layer 30 to the light ray F is smaller, and the light ray F is emitted through the light-emitting control layer 30 at the moment.

As can be seen from fig. 17, although the incident angles of the light D, the light E and the light F entering the light-emitting control layer 30 are greatly different, under the combined action of the light-emitting control layer 30 and the reflective layer 20, the light D, the light E and the light F finally exit from the light-emitting control layer 30 at a great exit angle, thereby meeting the requirement of the backlight source for illuminating the liquid crystal screen from the side surface of the liquid crystal screen.

Example IV

The embodiment of the invention provides a preparation method of a light-emitting diode chip, which is suitable for preparing the light-emitting diode chips provided in the first embodiment, the second embodiment and the third embodiment. Fig. 18 is a flowchart of a preparation method provided in this embodiment, referring to fig. 18, the preparation method includes:

step 101: a chip body provided with a reflecting layer is provided, and the reflecting layer is arranged on a first surface of the chip body.

Step 102: and forming a light-emitting control layer on the second surface of the chip body.

In this embodiment, the light-emitting control layer is composed of an optical film, the reflectivity of the light-emitting control layer to the first incident light is smaller than or equal to a set value, and the reflectivity of the light-emitting control layer to the second incident light is larger than the set value. The first incident light and the second incident light are light rays emitted by the chip body and emitted into the light-emitting control layer, the incident angle of the first incident light emitted into the light-emitting control layer is within a set range, and the incident angle of the second incident light emitted into the light-emitting control layer is outside the set range. The second surface of the chip body is a surface opposite to the first surface of the chip body, and at least one of the first surface and the second surface of the chip body is a non-mirror surface.

Specifically, this step 202 may include:

and forming a light emitting control layer on the second surface of the chip body by adopting a magnetron sputtering method, an evaporation deposition method or a chemical vapor deposition method.

Example five

The embodiment of the invention provides a preparation method of a light-emitting diode chip, which is a specific implementation of the preparation method provided by the fourth embodiment, and is suitable for preparing the light-emitting diode chip with a positive-mounting structure. Fig. 19 is a flowchart of a preparation method provided in this embodiment, referring to fig. 19, the preparation method includes:

step 201: an N-type semiconductor layer, a light emitting layer and a P-type semiconductor layer are sequentially grown on a substrate.

Fig. 20a is a schematic structural diagram of the led chip after the execution of step 201. Wherein 11 is a substrate, 12 is an N-type semiconductor layer, 13 is a light emitting layer, and 14 is a P-type semiconductor layer. As shown in fig. 20a, an N-type semiconductor layer 12, a light emitting layer 13, and a P-type semiconductor layer 14 are sequentially stacked on a substrate 11.

Specifically, this step 201 may include:

an N-type semiconductor layer, a multiple quantum well layer and a P-type semiconductor layer are sequentially grown on a substrate by adopting a metal organic chemical vapor deposition (English: metal organic Chemical Vapor Deposition, MOCVD for short) technology.

Step 202: a groove extending to the N-type semiconductor layer is formed on the P-type semiconductor layer.

Fig. 20b is a schematic structural diagram of the led chip after the execution of step 202. As shown in fig. 20b, the recess extends from the P-type semiconductor layer 14 to the N-type semiconductor layer 12.

Specifically, this step 202 may include:

forming photoresist of a first pattern on the P-type semiconductor layer by adopting a photoetching technology;

under the protection of photoresist, dry etching the P-type semiconductor layer and the light-emitting layer to form a groove extending from the P-type semiconductor layer to the N-type semiconductor layer;

the photoresist is removed.

Step 203: and forming a light-emitting control layer on the P-type semiconductor layer.

Fig. 20c is a schematic structural diagram of the led chip after the execution of step 203. Wherein 30 is a light-emitting control layer. As shown in fig. 20c, the light extraction regulating layer 30 is disposed on the P-type semiconductor layer 14.

In this embodiment, the light-emitting control layer is composed of an optical film, the reflectivity of the light-emitting control layer to the first incident light is smaller than or equal to a set value, and the reflectivity of the light-emitting control layer to the second incident light is larger than the set value. The first incident light and the second incident light are light emitted by the light-emitting layer and emitted into the light-emitting regulation layer, the incident angle of the first incident light emitted into the light-emitting regulation layer is within a set range, and the incident angle of the second incident light emitted into the light-emitting regulation layer is outside the set range.

Specifically, this step 203 may include:

forming a light-emitting control layer in the groove and on the P-type semiconductor layer;

forming a photoresist of a second pattern on the light-emitting control layer by adopting a photoetching technology;

under the protection of photoresist, wet etching the light-emitting control layer to remove the light-emitting control layer in the groove and on the P-type electrode arrangement area;

the photoresist is removed.

Step 204: and a P-type electrode is arranged on the P-type semiconductor layer, and an N-type electrode is arranged on the N-type semiconductor layer in the groove.

Fig. 20d is a schematic diagram of the led chip after the execution of step 204. Wherein 15 is a P-type electrode and 16 is an N-type electrode. As shown in fig. 20d, the P-type electrode 15 is disposed on the P-type semiconductor layer 14, and the N-type electrode 16 is disposed on the N-type semiconductor layer 12.

Specifically, this step 204 may include:

forming photoresist of a third pattern on the light-emitting control layer and other areas except the N-type electrode setting area on the N-type semiconductor layer in the groove by adopting a photoetching technology;

forming an electrode on the photoresist, the P-type semiconductor layer and the N-type semiconductor layer;

and removing the photoresist, wherein the electrode on the P-type semiconductor layer becomes a P-type electrode, and the electrode on the N-type semiconductor layer becomes an N-type electrode.

Step 205: a reflective layer is formed on a substrate.

Fig. 20e is a schematic diagram of the structure of the led chip after the execution of step 205. Wherein 20 is a reflective layer. As shown in fig. 20e, the reflective layer 20 is disposed on the substrate 11.

Example six

The embodiment of the invention provides a preparation method of a light-emitting diode chip, which is another specific implementation of the preparation method provided by the fourth embodiment, and is suitable for preparing the light-emitting diode chip with a flip-chip structure. Fig. 21 is a flowchart of a preparation method provided in this embodiment, and referring to fig. 21, the preparation method includes:

step 301: an N-type semiconductor layer, a light emitting layer and a P-type semiconductor layer are sequentially grown on a substrate.

Fig. 22a is a schematic structural diagram of the led chip after the execution of step 301. Wherein 11 is a substrate, 12 is an N-type semiconductor layer, 13 is a light emitting layer, and 14 is a P-type semiconductor layer. As shown in fig. 22a, an N-type semiconductor layer 12, a light emitting layer 13, and a P-type semiconductor layer 14 are sequentially stacked on a substrate 11.

Specifically, this step 301 may be the same as step 201 in embodiment five, and will not be described in detail here.

Step 302: a groove extending to the N-type semiconductor layer is formed on the P-type semiconductor layer.

Fig. 22b is a schematic structural diagram of the led chip after the execution of step 302. As shown in fig. 22b, the recess extends from the P-type semiconductor layer 14 to the N-type semiconductor layer 12.

Specifically, this step 302 may be the same as step 202 in embodiment five, and will not be described in detail here.

Step 303: a reflective layer is formed on the P-type semiconductor layer.

Fig. 22c is a schematic structural diagram of the led chip after the execution of step 303. Wherein 20 is a reflective layer. As shown in fig. 22c, the reflective layer 20 is disposed on the P-type semiconductor layer 14.

Specifically, this step 303 may be similar to step 203 in embodiment five, and will not be described in detail herein.

Step 304: and a P-type electrode is arranged on the P-type semiconductor layer, and an N-type electrode is arranged on the N-type semiconductor layer in the groove.

Fig. 22d is a schematic structural diagram of the led chip after the execution of step 304. Wherein 15 is a P-type electrode and 16 is an N-type electrode. As shown in fig. 22d, the P-type electrode 15 is disposed on the P-type semiconductor layer 14, and the N-type electrode 16 is disposed on the N-type semiconductor layer 12.

Specifically, the step 304 may be the same as the step 204 in the fifth embodiment, and will not be described in detail herein.

Step 305: forming a light-emitting control layer on the substrate.

Fig. 22e is a schematic diagram of the led chip after the execution of step 305. Wherein 30 is a light-emitting control layer. As shown in fig. 22e, the light extraction regulating layer 30 is provided on the substrate 11.

Example seven

The embodiment of the invention provides a preparation method of a light-emitting diode chip, which is a specific implementation of the preparation method provided by the fourth embodiment, and is suitable for preparing a light-emitting diode chip with a vertical structure. Fig. 23 is a flowchart of a preparation method provided in this embodiment, referring to fig. 23, the preparation method includes:

step 401: an N-type semiconductor layer, a light emitting layer and a P-type semiconductor layer are sequentially grown on a substrate.

Fig. 24a is a schematic structural diagram of the led chip after the execution of step 401. Wherein 11 is a substrate, 12 is an N-type semiconductor layer, 13 is a light emitting layer, and 14 is a P-type semiconductor layer. As shown in fig. 24a, an N-type semiconductor layer 12, a light emitting layer 13, and a P-type semiconductor layer 14 are sequentially stacked on a substrate 11.

Specifically, this step 401 may be the same as step 201 in embodiment five, and will not be described in detail here.

Step 402: a reflective layer is formed on the P-type semiconductor layer.

Fig. 24b is a schematic structural diagram of the led chip after the execution of step 402. Wherein 20 is a reflective layer. As shown in fig. 24b, the reflective layer 20 is disposed on the P-type semiconductor layer 14.

Specifically, this step 402 may include:

forming a reflective layer on the P-type semiconductor layer;

forming photoresist with a set pattern on the reflecting layer by adopting a photoetching technology;

under the protection of photoresist, wet etching the reflecting layer to remove the reflecting layer on the P-type electrode setting area;

the photoresist is removed.

Step 403: a P-type electrode is disposed on the P-type semiconductor layer.

Fig. 24c is a schematic structural diagram of the led chip after the execution of step 403. Wherein 15 is a P-type electrode. As shown in fig. 24b, the P-type electrode 15 is disposed on the P-type semiconductor layer 14.

Specifically, this step 403 may be similar to step 204 in embodiment five, and will not be described in detail herein.

Step 404: the substrate is removed.

Fig. 24d is a schematic diagram of the led chip after the execution of step 404. As shown in fig. 24d, the substrate 11 has been removed from the light emitting diode chip.

Specifically, this step 404 may include:

the substrate is removed using laser techniques or wet etching techniques.

Step 405: and forming a light-emitting control layer on the N-type semiconductor layer.

Fig. 24e is a schematic diagram of the led chip after the execution of step 405. Wherein 30 is a light-emitting control layer. As shown in fig. 24e, the light extraction regulating layer 30 is provided on the N-type semiconductor layer 12.

Specifically, this step 405 may be similar to step 402 and will not be described in detail herein.

Step 406: an N-type electrode is disposed on the N-type semiconductor layer.

Fig. 24f is a schematic structural diagram of the led chip after the execution of step 406. Wherein 16 is an N-type electrode. As shown in fig. 24f, the N-type electrode 16 is disposed on the N-type semiconductor layer 12.

Specifically, this step 406 may be similar to step 204 in embodiment five, and will not be described in detail herein.

In practical application, steps 402 to 403 and steps 404 to 406 are not sequential.

Example eight

The embodiment of the invention provides a preparation method of a light-emitting diode chip, which is a specific implementation of the preparation method provided by the fourth embodiment, and is suitable for preparing a light-emitting diode chip with another vertical structure. Fig. 25 is a flowchart of a preparation method provided in this embodiment, referring to fig. 25, the preparation method includes:

step 501: an N-type semiconductor layer, a light emitting layer and a P-type semiconductor layer are sequentially grown on a substrate.

Fig. 26a is a schematic structural diagram of the led chip after the execution of step 501. Wherein 11 is a substrate, 12 is an N-type semiconductor layer, 13 is a light emitting layer, and 14 is a P-type semiconductor layer. As shown in fig. 26a, an N-type semiconductor layer 12, a light-emitting layer 13, and a P-type semiconductor layer 14 are sequentially stacked on a substrate 11.

Specifically, this step 501 may be the same as step 201 in embodiment five, and will not be described in detail here.

Step 502: and forming a light-emitting control layer on the P-type semiconductor layer.

Fig. 26b is a schematic structural diagram of the led chip after the execution of step 502. Wherein 30 is a light-emitting control layer. As shown in fig. 26b, the light extraction regulating layer 30 is disposed on the P-type semiconductor layer 14.

Specifically, this step 502 may be similar to step 402 in embodiment seven, and will not be described in detail herein.

Step 503: a P-type electrode is disposed on the P-type semiconductor layer.

Fig. 26c is a schematic diagram of the structure of the led chip after the execution of step 503. Wherein 15 is a P-type electrode. As shown in fig. 26c, the P-type electrode 15 is disposed on the P-type semiconductor layer 14.

Specifically, this step 503 may be similar to step 204 in embodiment five, and will not be described in detail herein.

Step 504: the substrate is removed.

Fig. 26d is a schematic structural diagram of the led chip after the execution of step 504. As shown in fig. 26d, the substrate 11 has been removed from the light emitting diode chip.

Specifically, the step 504 may be the same as the step 404 in the seventh embodiment, and will not be described in detail herein.

Step 505: a reflective layer is formed on the N-type semiconductor layer.

Fig. 26e is a schematic diagram of the structure of the led chip after the execution of step 505. Wherein 20 is a reflective layer. As shown in fig. 26e, the reflective layer 20 is disposed on the N-type semiconductor layer 12.

In particular, this step 505 may be similar to step 405 and will not be described in detail herein.

Step 506: an N-type electrode is disposed on the N-type semiconductor layer.

Fig. 26f is a schematic structural diagram of the led chip after the execution of step 506. Wherein 16 is an N-type electrode. As shown in fig. 26f, the N-type electrode 16 is disposed on the N-type semiconductor layer 12.

Specifically, this step 506 may be similar to step 204 in embodiment five, and will not be described in detail herein.

The foregoing embodiment numbers of the present invention are merely for the purpose of description, and do not represent the advantages or disadvantages of the embodiments.

The foregoing description of the preferred embodiments of the invention is not intended to limit the invention to the precise form disclosed, and any such modifications, equivalents, and alternatives falling within the spirit and scope of the invention are intended to be included within the scope of the invention.

Claims

1. The light-emitting diode chip comprises a chip body and a reflecting layer, wherein the reflecting layer is arranged on a first surface of the chip body, and the light-emitting diode chip is characterized by further comprising a light-emitting regulation layer which is arranged on a second surface of the chip body, the second surface of the chip body is a surface opposite to the first surface of the chip body, and at least one of the first surface and the second surface of the chip body is a non-mirror surface; the light-emitting regulation layer consists of an optical film, the reflectivity of the light-emitting regulation layer to the first incident light ray is smaller than or equal to a set value, and the reflectivity of the light-emitting regulation layer to the second incident light ray is larger than the set value; the first incident light ray and the second incident light ray are light rays which are emitted by the chip body and are emitted into the light-emitting control layer, the incident angle of the first incident light ray which is emitted into the light-emitting control layer is within a set range, and the incident angle of the second incident light ray which is emitted into the light-emitting control layer is outside the set range;

the light-emitting control layer comprises a plurality of oxide films which are sequentially laminated, and the thickness of each oxide film is set based on the following formula:

Wherein the incident angle of the light emergent regulation layer is theta ₀ The reflectivity of the light rays is the reflection coefficient of the equivalent interface of the Nth oxide film through which the light rays are injected into the light-emitting control layer, and N is the number of the plurality of oxide films;the reflection coefficient of the equivalent interface of the ith oxide film through which the light rays enter the light-emitting control layer passes, wherein i is an integer; r is (r) _i For controlling the light incident into the light emergentFresnel coefficient of the ith oxide film through which the layer passes, < >>η _i-1 And eta _i+1 To simplify the coefficients used by the fresnel formula, for the p component, +.>For s component, eta _i ＝n _i ×cosθ _i ；n _i Refractive index of material of ith oxide film passing through light-emitting control layer for light ray incidence, θ _i N is the refractive angle of the light ray when the light ray enters the light-emitting control layer and passes through the ith oxide film ₀ ×sinθ ₀ ＝n _i-1 ×sinθ _i-1 ＝n _i ×sinθ _i ＝n _i+1 ×sinθ _i+1 ，n ₀ Refractive index of the material of the chip body, θ ₀ An incident angle for light to enter the light-emitting control layer; delta _i The phase thickness of the ith oxide film passing through the light-emitting control layer for light rays is +.>d _i The thickness of the ith oxide film through which the light enters the light-emitting control layer is measured.

2. The light-emitting diode chip according to claim 1, wherein refractive indices of materials of adjacent two of the oxide films are different.

3. The light-emitting diode chip according to claim 2, wherein the material of the oxide thin film is tantalum pentoxide, titanium dioxide, silicon dioxide, or hafnium dioxide.

4. A light emitting diode chip as claimed in any one of claims 1 to 3, wherein the set range is 50 ° or less or 20 ° or more.

5. The light-emitting diode chip according to claim 4, wherein when the set range is 50 ° or less, the light-emission control layer includes a plurality of thin film units stacked in this order, each of the thin film units including a first oxide thin film and a second oxide thin film stacked on the first oxide thin film, a refractive index of a material of the first oxide thin film being larger than a refractive index of a material of the second oxide thin film.

6. The light-emitting diode chip according to claim 4, wherein when the set range is 20 ° or more, the light-emission control layer includes (2×k+1) third oxide thin films and (2*k) fourth oxide thin films, k is a positive integer, the (2×k+1) third oxide thin films and the (2*k) fourth oxide thin films are alternately stacked, and a refractive index of a material of the third oxide thin films is smaller than a refractive index of a material of the fourth oxide thin films.

7. A light emitting diode chip as claimed in any one of claims 1 to 3, wherein the number of the plurality of oxide films is 30 to 70.

8. A light emitting diode chip as claimed in any one of claims 1 to 3, wherein the reflective layer is a distributed bragg reflective layer, a metallic reflective layer or a total angle reflective layer.

9. A method for manufacturing a light emitting diode chip, the method comprising:

forming a light-emitting control layer on the second surface of the chip body, wherein the light-emitting control layer is composed of optical films, the light-emitting control layer comprises a plurality of oxide films which are sequentially laminated, and the thickness of each oxide film is set based on the following formula:

wherein the incident angle of the light emergent regulation layer is theta ₀ The reflectivity of the light rays is the reflection coefficient of the equivalent interface of the Nth oxide film through which the light rays are injected into the light-emitting control layer, and N is the number of the plurality of oxide films;the reflection coefficient of the equivalent interface of the ith oxide film through which the light rays enter the light-emitting control layer passes, wherein i is an integer; r is (r) _i Fresnel coefficient of the ith oxide film through which light is incident into the light-emitting control layer,/th>η _i-1 And eta _i+1 To simplify the coefficients used by the fresnel formula, for the p component, +.>For s component, eta _i ＝n _i ×cosθ _i ；n _i Refractive index of material of ith oxide film passing through light-emitting control layer for light ray incidence, θ _i N is the refractive angle of the light ray when the light ray enters the light-emitting control layer and passes through the ith oxide film ₀ ×sinθ ₀ ＝n _i-1 ×sinθ _i-1 ＝n _i ×sinθ _i ＝n _i+1 ×sinθ _i+1 ，n ₀ Refractive index of the material of the chip body, θ ₀ An incident angle for light to enter the light-emitting control layer; delta _i An ith oxide film through which light is incident on the light-emission control layerThickness of phase>d _i The thickness of the ith oxide film through which the light enters the light-emitting control layer is the thickness, the reflectivity of the light-emitting control layer to the first incident light is smaller than or equal to a set value, and the reflectivity of the light-emitting control layer to the second incident light is larger than the set value; the first incident light ray and the second incident light ray are light rays which are emitted by the chip body and are emitted into the light-emitting control layer, the incident angle of the first incident light ray which is emitted into the light-emitting control layer is within a set range, and the incident angle of the second incident light ray which is emitted into the light-emitting control layer is outside the set range; the second surface of the chip body is a surface opposite to the first surface of the chip body, and at least one of the first surface and the second surface of the chip body is a non-mirror surface.