CN-116741906-B - Mini-LED chip and manufacturing method thereof

CN116741906BCN 116741906 BCN116741906 BCN 116741906BCN-116741906-B

Abstract

The invention provides a Mini-LED chip and a manufacturing method thereof, wherein the Mini-LED chip comprises a transparent substrate, a reflecting layer and a combined insulating layer, wherein the transparent substrate comprises a first surface and a second surface which are oppositely arranged, the second surface is a light-emitting surface, the reflecting layer is arranged on one side surface of the second type semiconductor layer, which is far away from an active area, and is arranged at intervals with the peripheral side wall of an epitaxial structure and the side wall of a groove, the combined insulating layer covers the exposed surfaces of the epitaxial structure, the transparent substrate and part of the reflecting layer, and comprises a DBR reflecting structure layer, so that the chip is prevented from being short-circuited by water vapor, the chip is enabled to emit light from a single side by a reflecting effect, the problem of light leakage of the side wall of the chip is solved, the light-emitting efficiency of the Mini-LED chip is further improved, and the light leakage phenomenon of the Mini-LED chip when the Mini-LED chip is used in a backlight source of a display is avoided.

Inventors

LIN ZHIWEI
CHEN KAIXUAN
HE JIAN
CAI JIANJIU
YOU CUIPING

Assignees

厦门乾照光电股份有限公司

Dates

Publication Date: 20260512
Application Date: 20230510

Claims (18)

1. A Mini-LED chip, comprising: The transparent substrate comprises a first surface and a second surface which are oppositely arranged, and the second surface is a light-emitting surface; An epitaxial structure laminated on the first surface, wherein the epitaxial structure comprises a first type semiconductor layer, an active region and a second type semiconductor layer which are sequentially laminated along a first direction, the upper surface of the second type semiconductor layer is provided with a groove extending towards the first type semiconductor layer, part of the first type semiconductor layer is exposed, and the first direction is perpendicular to the transparent substrate and is directed to the epitaxial structure by the transparent substrate; The reflecting layer is arranged on the surface of one side of the second type semiconductor layer, which is away from the active region, and is arranged at intervals with the peripheral side wall of the epitaxial structure and the side wall of the groove; the insulation layer covers the epitaxial structure, the transparent substrate and part of the exposed surface of the reflecting layer and exposes the bottom of the groove, and the insulation layer comprises a DBR reflecting structure layer; The first electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and extends to the exposed part of the groove to be connected with the first type semiconductor layer; The second electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and is connected with the second type semiconductor layer through a second electrode conductive through hole, and the first electrode and the second electrode are arranged at intervals.
2. The Mini-LED chip of claim 1, wherein the reflecting layer is an insulating reflecting layer or a metal reflecting layer, the insulating reflecting layer comprises a laminated structure of any one or more of a titanium dioxide layer, a silicon nitride layer, a silicon dioxide layer, a magnesium fluoride layer and a magnesium oxide layer, and the metal reflecting layer comprises a laminated structure of any one or more of Ag, al and Au.
3. The Mini-LED chip of claim 2, wherein the second electrode conductive via penetrates the insulating layer and the insulating reflective layer exposing a portion of the second semiconductor layer, the second electrode extending through the second electrode conductive via to the second semiconductor layer to form an electrical connection.
4. The Mini-LED chip of claim 2, wherein the metal reflective layer covers the second type semiconductor layer, the second electrode conductive via penetrates the insulating layer, a portion of the metal reflective layer is exposed, and the second electrode extends to the metal reflective layer through the second electrode conductive via to form an electrical connection with the second type semiconductor layer.
5. The Mini-LED chip of claim 2, wherein the metal reflecting layer is arranged at intervals with the peripheral side wall of the epitaxial structure through an isolating layer, the isolating layer covers the peripheral side wall of the epitaxial structure and the peripheral side wall of the transparent substrate, and the metal reflecting layer extends to the surface of one side of the isolating layer, which is away from the epitaxial structure; Or, the metal reflecting layer is arranged at intervals with the peripheral side wall of the epitaxial structure and the side wall of the groove through an isolating layer, the isolating layer covers the peripheral side wall of the epitaxial structure, the peripheral side wall of the transparent substrate and the side wall of the groove, and the metal reflecting layer extends to the surface of one side of the isolating layer, which is away from the epitaxial structure.
6. The Mini-LED chip of claim 2, wherein a barrier layer is arranged between the metal reflecting layer and the insulating layer, the barrier layer covers the metal reflecting layer, the second electrode conductive through hole penetrates through the insulating layer to expose part of the barrier layer, the second electrode extends to the barrier layer through the second electrode conductive through hole to form electric connection with the second type semiconductor layer, and the barrier layer is made of a metal material which is not easy to oxidize.
7. The Mini-LED chip of claim 1, wherein the peripheral side wall of the epitaxial structure and the peripheral side wall of the transparent substrate are both sloped side walls.
8. The Mini-LED chip of claim 1, wherein the angle between the peripheral side wall of the epitaxial structure and the first surface is a first angle, the angle between the peripheral side wall of the transparent substrate and the second surface is a second angle, and the angles of the first angle and the second angle are all smaller than 80 degrees.
9. The Mini-LED chip of claim 1, wherein the separation distance between the first electrode and the second electrode is greater than 20um.
10. The Mini-LED chip of claim 1, wherein the active region is located within a reflective range of the insulating layer and the reflective layer.
11. The manufacturing method of the Mini-LED chip is characterized by comprising the following steps of: step S1, providing a transparent substrate and a temporary carrier plate, wherein the transparent substrate comprises a first surface; s2, epitaxially forming a stacked structure on the first surface; Step S3, etching along the upper surface of the stacked structure by ICP (inductively coupled plasma), exposing part of the transparent substrate to form a first cutting channel, dividing the stacked structure into a plurality of independent epitaxial structures by the first cutting channel, wherein each epitaxial structure comprises a first type semiconductor layer, an active region and a second type semiconductor layer which are stacked in sequence along the growth direction; Simultaneously, etching along the upper surface of the second type semiconductor layer to expose part of the first type semiconductor layer and form a groove; s4, thinning the transparent substrate by adopting a grinding process, and exposing the second surface; S5, transferring an epitaxial structure to the temporary carrier plate through the transparent substrate, wherein a second surface B is connected with the temporary carrier plate, and penetrates through the second surface along the first cutting path by adopting a laser cutting process to expose the temporary carrier plate and the peripheral side wall of the transparent substrate, the second surface is opposite to the first surface, and the second surface is a light emitting surface; step S6, a reflecting layer is grown, and the reflecting layer is arranged on the surface of one side of the second type semiconductor layer, which is away from the active region, and is arranged at intervals with the peripheral side wall of the epitaxial structure and the side wall of the groove; Step S7, growing an insulating layer which covers the epitaxial structure, the transparent substrate and part of the exposed surface of the reflecting layer and exposes the bottom of the groove, wherein the insulating layer comprises a DBR reflecting structure layer; S8, manufacturing a first electrode and a second electrode; the first electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and extends to the exposed part of the groove to be connected with the first type semiconductor layer; The second electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and is connected with the second semiconductor layer through a second electrode conductive through hole, and the first electrode and the second electrode are arranged at intervals; and S9, stripping the temporary carrier plate to form a plurality of independent Mini-LED chips.
12. The manufacturing method of the Mini-LED chip is characterized by comprising the following steps of: step A1, providing a transparent substrate, wherein the transparent substrate comprises a first surface; a2, epitaxially forming a stacked structure on the first surface; A3, cutting along the upper surface of the stacked structure by using a cutting knife, exposing part of the transparent substrate to form a second cutting channel, exposing the peripheral side wall of the transparent substrate by the second cutting channel, and dividing the stacked structure into a plurality of independent epitaxial structures by the second cutting channel, wherein each epitaxial structure comprises a first semiconductor layer, an active region and a second semiconductor layer which are stacked in turn along the growth direction; Step A4, etching along the upper surface of the second type semiconductor layer to expose part of the first type semiconductor layer and form a groove; A5, growing a reflecting layer, which is arranged on the surface of one side of the second type semiconductor layer, which is away from the active region, and is arranged at intervals with the peripheral side wall of the epitaxial structure and the side wall of the groove; A6, growing an insulating layer which covers the epitaxial structure, the transparent substrate and part of the exposed surface of the reflecting layer and exposes the bottom of the groove, wherein the insulating layer comprises a DBR reflecting structure layer; a7, manufacturing a first electrode and a second electrode; the first electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and extends to the exposed part of the groove to be connected with the first type semiconductor layer; The second electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and is connected with the second semiconductor layer through a second electrode conductive through hole, and the first electrode and the second electrode are arranged at intervals; And A8, thinning the transparent substrate by adopting a grinding process, exposing a second surface, and simultaneously separating to form a plurality of independent Mini-LED chips, wherein the second surface is opposite to the first surface, and the second surface is a light emitting surface.
13. The method of manufacturing a Mini-LED chip according to claim 11 or 12, wherein the reflective layer is an insulating reflective layer or a metal reflective layer, the insulating reflective layer comprises a laminated structure of any one or more of a titanium dioxide layer, a silicon nitride layer, a silicon dioxide layer, a magnesium fluoride layer and a magnesium oxide layer, and the metal reflective layer comprises a laminated structure of any one or more of Ag, al and Au.
14. The method of manufacturing a Mini-LED chip according to claim 13, wherein the metal reflective layer covers the second type semiconductor layer, the second electrode conductive via penetrates through the insulating layer to expose a portion of the metal reflective layer, and the second electrode extends to the metal reflective layer through the second electrode conductive via to form electrical connection with the second type semiconductor layer.
15. The method of manufacturing the Mini-LED chip of claim 13, wherein the metal reflecting layer is arranged at intervals with the peripheral side wall of the epitaxial structure through an isolation layer, the isolation layer covers the peripheral side wall of the epitaxial structure and the peripheral side wall of the transparent substrate, and the metal reflecting layer extends to the surface of one side of the isolation layer, which is away from the epitaxial structure; Or, the metal reflecting layer is arranged at intervals with the peripheral side wall of the epitaxial structure and the side wall of the groove through an isolating layer, the isolating layer covers the peripheral side wall of the epitaxial structure, the peripheral side wall of the transparent substrate and the side wall of the groove, and the metal reflecting layer extends to the surface of one side of the isolating layer, which is away from the epitaxial structure.
16. The method of manufacturing a Mini-LED chip according to claim 13, wherein a barrier layer is arranged between the metal reflecting layer and the insulating layer, the barrier layer covers the metal reflecting layer, the second electrode conductive through hole penetrates through the insulating layer to expose part of the barrier layer, the second electrode extends to the barrier layer through the second electrode conductive through hole to form electrical connection with the second type semiconductor layer, and the barrier layer is made of a metal material which is not easy to oxidize.
17. The method of manufacturing a Mini-LED chip according to claim 11 or 12, wherein the peripheral side wall of the epitaxial structure and the peripheral side wall of the transparent substrate are both inclined side walls.
18. The method of manufacturing a Mini-LED chip according to claim 11 or 12, wherein an included angle between the peripheral side wall of the epitaxial structure and the first surface is a first included angle, an included angle between the peripheral side wall of the transparent substrate and the second surface is a second included angle, and the angles of the first included angle and the second included angle are both smaller than 80 degrees.

Description

Mini-LED chip and manufacturing method thereof Technical Field The invention relates to the technical field of light emitting diodes, in particular to a Mini-LED chip and a manufacturing method thereof. Background With the rapid development of light emitting diodes, the application of LEDs (LIGHT EMITTING diode) is more and more varied, and particularly, LEDs are developing in display technology. As the resolution of LED displays is increased, the size and pitch of the opposing LED chips is reduced. Compared with the existing LCD and OLED display devices, the Mini-LED device has the advantages of quick response, high color gamut, high PPI, low energy consumption and the like. At present, a Mini-LED is mostly applied to a display screen by combining a transparent substrate with a flip-chip welding structure as a backlight source, and in order to avoid light leakage, the conventional design is to use a package encapsulation body at the encapsulation end to avoid light leakage. However, the package end uses a non-transparent material to wrap the periphery of the package body, so that although most of the light leakage can be avoided, a small amount of light leakage still exists, and the display effect cannot reach the optimal effect. Disclosure of Invention In view of this, the present invention provides a Mini-LED chip and a method for manufacturing the same, which solves the problems of light leakage from the side wall of the chip in the prior art. In order to achieve the above purpose, the technical scheme adopted by the invention is as follows: a Mini-LED chip, comprising: The transparent substrate comprises a first surface and a second surface which are oppositely arranged, and the second surface is a light-emitting surface; An epitaxial structure laminated on the first surface, wherein the epitaxial structure comprises a first type semiconductor layer, an active region and a second type semiconductor layer which are sequentially laminated along a first direction, the upper surface of the second type semiconductor layer is provided with a groove extending towards the first type semiconductor layer, part of the first type semiconductor layer is exposed, and the first direction is perpendicular to the transparent substrate and is directed to the epitaxial structure by the transparent substrate; The reflecting layer is arranged on the surface of one side of the second type semiconductor layer, which is away from the active region, and is arranged at intervals with the peripheral side wall of the epitaxial structure and the side wall of the groove; the insulation layer covers the epitaxial structure, the transparent substrate and part of the exposed surface of the reflecting layer and exposes the bottom of the groove, and the insulation layer comprises a DBR reflecting structure layer; The first electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and extends to the exposed part of the groove to be connected with the first type semiconductor layer; The second electrode is arranged on one side surface of the insulating layer, which is away from the reflecting layer, and is connected with the second type semiconductor layer through a second electrode conductive through hole, and the first electrode and the second electrode are arranged at intervals. Preferably, the reflecting layer is an insulating reflecting layer or a metal reflecting layer, the insulating reflecting layer comprises a laminated structure of any one or more of a titanium dioxide layer, a silicon nitride layer, a silicon dioxide layer, a magnesium fluoride layer and a magnesium oxide layer, and the metal reflecting layer comprises a laminated structure of any one or more of Ag, al and Au. Preferably, the second electrode conductive via penetrates through the insulating layer and the insulating reflective layer, exposing a portion of the second type semiconductor layer, and the second electrode extends to the second type semiconductor layer through the second electrode conductive via to form an electrical connection. Preferably, the second type semiconductor layer is covered by the metal reflecting layer, the second electrode conductive through hole penetrates through the insulating layer, part of the metal reflecting layer is exposed, and the second electrode extends to the metal reflecting layer through the second electrode conductive through hole to form electric connection with the second type semiconductor layer. Preferably, the metal reflecting layer is arranged at intervals with the peripheral side wall of the epitaxial structure through an isolating layer, the isolating layer covers the peripheral side wall of the epitaxial structure and the peripheral side wall of the transparent substrate, and the metal reflecting layer extends to the surface of one side of the isolating layer, which is away from the epitaxial structure; Or, the metal reflecting layer is arranged at intervals with