Patent Application
20230178520
This application claims the priority benefit of Taiwan application serial no. 110145768, filed on Dec. 8, 2021. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The invention relates to a light-emitting diode package and a manufacturing method thereof, and more particularly to a light-emitting diode package and a manufacturing method thereof that may avoid the issues of die shift and optical interference.
Generally, in the manufacturing method of a light-emitting diode package, one of the main techniques is the use of a pick-and-place method to perform the mass transfer of light-emitting diodes. In particular, the vacuum suction method using a vacuum suction tube is a commonly used pick-and-place method. However, since the physical limit of light-emitting diodes that may be sucked by the vacuum suction tube is 80 μm, micro light-emitting diodes (uLED) less than 50 μm may not be suitable for the vacuum suction method. Moreover, even after the mass transfer of sub-millimeter light-emitting diodes (mini LED) to a temporary substrate by vacuum suction, processes using an encapsulation gel (such as an epoxy molding compound (EMC)) may cause the mini LEDs to have die shift issues.
The invention provides a light-emitting diode package and a manufacturing method thereof that may be suitable for micro light-emitting diode packaging and may avoid the issues of chip displacement and optical interference.
A light-emitting diode package of the invention includes a redistribution layer, a light-emitting diode, a first dielectric layer, a plurality of wavelength conversion structures, and a transparent encapsulant. The light-emitting diode is disposed on and electrically connected to the redistribution layer. The light-emitting diode includes a first light-emitting diode, a second light-emitting diode, and a third light-emitting diode. The first dielectric layer is disposed on the redistribution layer and covers the light-emitting diode. The plurality of wavelength conversion structures are disposed on the second light-emitting diode and the third light-emitting diode and respectively in contact with the second light-emitting diode and the third light-emitting diode. The transparent encapsulant is disposed on the first dielectric layer and covers the plurality of wavelength conversion structures.
In an embodiment of the invention, the light-emitting diode package does not have a native epitaxy substrate.
In an embodiment of the invention, the light-emitting diode package further includes a first conductive through hole. The first conductive through hole penetrates a surface of the first dielectric layer facing the redistribution layer. The first conductive through hole is connected to the redistribution layer and the light-emitting diode.
In an embodiment of the invention, the light-emitting diode package further includes a circuit board and a conductive terminal. The circuit board has a first surface and a second surface opposite to the first surface, and the redistribution layer is disposed on the second surface of the circuit board. The conductive terminal is disposed on the second surface of the circuit board. The conductive terminal is connected to the circuit board and the redistribution layer.
In an embodiment of the invention, the light-emitting diode package further includes an electronic element. The electronic element is disposed on the first surface of the circuit board and electrically connected to the light-emitting diode.
In an embodiment of the invention, the redistribution layer includes at least one conductive layer, at least one second dielectric layer, and at least one conductive hole. The conductive layer and the second dielectric layer are sequentially stacked on the first dielectric layer. The conductive hole penetrates the second dielectric layer. The conductive hole is electrically connected to the conductive layer.
In an embodiment of the invention, the circuit board includes a core layer, a first build-up circuit structure, a second build-up circuit structure, and a second conductive through hole. The first build-up circuit structure and the second build-up circuit structure are respectively disposed at two opposite sides of the core layer. The second conductive through hole penetrates the core layer. The second conductive through hole is electrically connected to the first build-up circuit structure and the second build-up circuit structure.
A manufacturing method of a light-emitting diode package of the invention includes the following steps. First, a light-emitting diode is formed on a first temporary substrate. In particular, the light-emitting diode includes a first light-emitting diode, a second light-emitting diode, and a third light-emitting diode. Next, a first dielectric layer is formed on the first temporary substrate to cover the light-emitting diode. Next, a redistribution layer is formed on a surface of the first dielectric layer to be electrically connected to the light-emitting diode. Next, a second temporary substrate is provided, and the redistribution layer is bonded onto the second temporary substrate. Then, the first temporary substrate is removed to expose the light-emitting diode and the first dielectric layer. Next, a plurality of wavelength conversion structures are formed on the second light-emitting diode and the third light-emitting diode so that the plurality of wavelength conversion structures are respectively in contact with the second light-emitting diode and the third light-emitting diode. Then, the second temporary substrate is removed.
In an embodiment of the invention, the manufacturing method of the light-emitting diode package further includes: forming a first conductive through hole penetrating the surface of the first dielectric layer and connected to the redistribution layer and the light-emitting diode.
In an embodiment of the invention, the manufacturing method of the light-emitting diode package further includes: providing a circuit board, and bonding the redistribution layer onto the circuit board. In particular, the circuit board has a first surface and a second surface opposite to the first surface. The redistribution layer is disposed on the second surface of the circuit board. The light-emitting diode and the first dielectric layer are disposed on the redistribution layer; and a conductive terminal is formed to be connected to the circuit board and the redistribution layer.
In an embodiment of the invention, the manufacturing method of the light-emitting diode package further includes: disposing an electronic element on the first surface of the circuit board to be electrically connected to the light-emitting diode.
In an embodiment of the invention, a method of forming the light-emitting diode is an epitaxy growth method.
Based on the above, in the light-emitting diode package and the manufacturing method thereof of the present embodiment, the light-emitting diode is formed on the first temporary substrate first by, for example, an epitaxy growth method, and the first dielectric layer and the redistribution layer are directly manufactured on the light-emitting diode. As a result, mass transfer and encapsulation gel processes may be omitted, so that the light-emitting diode package and the manufacturing method thereof of the present embodiment may be applied to the micro light-emitting diode package. In addition, since the redistribution layer is manufactured from the light-emitting diode end, the issue of die shift caused by the current use of pick-and-place may be avoided, and therefore the process may be simplified. Moreover, the step of removing the first temporary substrate may avoid the issue of optical interference in the subsequently formed light-emitting diode package due to the light guiding characteristics of sapphire.
In order to make the aforementioned features and advantages of the disclosure more comprehensible, embodiments accompanied with figures are described in detail below.
The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
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In the present embodiment, the redistribution layer 140 may include the conductive layer 141, the second dielectric layer 142, the conductive layer 143, the second dielectric layer 145, and the conductive hole 144. In particular, the conductive layers 141 and 143 and the second dielectric layers 142 and 145 are sequentially stacked on the first dielectric layer 120, the conductive hole 144 penetrates the second dielectric layer 145, and the conductive hole 144 is electrically connected to the conductive layer 141 and the conductive layer 143. In particular, the spacing between two adjacent pads in the conductive layer 143 is greater than the spacing between two adjacent pads in the conductive layer 141, and the spacing between two adjacent pads in the conductive layer 141 is greater than the spacing between two adjacent light-emitting diodes 110 (that is, the spacing between the first light-emitting diode 111 and the second light-emitting diode 112, or the spacing between the second light-emitting diode 112 and the third light-emitting diode 113). Moreover, although the redistribution layer 140 of the present embodiment may include two conductive layers and two dielectric layers, the invention does not limit the number of conductive layers and dielectric layers in the redistribution layer.
It should be mentioned that, in the present embodiment, after the light-emitting diode 110 is formed on the first temporary substrate 210, by directly manufacturing the first dielectric layer 120 and the redistribution layer 140 on the resulting light-emitting diode 110, mass transfer and encapsulation gel processes may be omitted. As a result, the manufacturing method of the present embodiment may be applicable to micro light-emitting diode packaging and the issue of die shift may be avoided (mainly since the micro light-emitting diode GaN epitaxy thin film itself is still bonded to sapphire in a monocrystalline manner at this time, and therefore this strong bonding substantially does not have any nano-level die shift). Therefore, the effect of simplifying the process is achieved.
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Specifically, the circuit board 180 may include a core layer 183, a first build-up circuit structure 184, a second build-up circuit structure 185, a second conductive through hole 186, and solder masks 187 and 188. The first build-up circuit structure 184 and the second build-up circuit structure 185 are respectively disposed at two opposite sides of the core layer 183. The second conductive through hole 186 penetrates the core layer 183. The second conductive through hole 186 is electrically connected to the first build-up circuit structure 184 and the second build-up circuit structure 185.
The first build-up circuit structure 184 may include a conductive layer 1841, a dielectric layer 1842, and a conductive hole 1843. In particular, the conductive layer 1841 and the dielectric layer 1842 are sequentially stacked on one side of the core layer 183, the conductive hole 1843 penetrates the dielectric layer 1842, and the conductive hole 1843 is electrically connected to the conductive layer 1841. The second build-up circuit structure 185 may include a conductive layer 1851, a dielectric layer 1852, and a conductive hole 1853. In particular, the conductive layer 1851 and the dielectric layer 1852 are sequentially stacked on another side of the core layer 183, the conductive hole 1853 penetrates the dielectric layer 1852, and the conductive hole 1853 is electrically connected to the conductive layer 1851.
The solder mask 187 is disposed on the first build-up circuit structure 184 to cover the outermost dielectric layer 1842 (that is, the dielectric layer 1842 in the first build-up circuit structure 184 farthest from the core layer 183) and expose a portion of the outermost conductive layer 1841 (that is, the conductive layer 1841 in the first build-up circuit structure 184 farthest from the core layer 183). The solder mask 188 is disposed on the second build-up circuit structure 185 to cover the outermost dielectric layer 1852 (that is, the dielectric layer 1852 in the second build-up circuit structure 185 farthest from the core layer 183) and expose a portion of the outermost conductive layer 1851 (that is, the conductive layer 1851 in the second build-up circuit structure 185 farthest from the core layer 183). In particular, the conductive terminal 170 may be in contact with a portion of the outermost conductive layer 1851 exposed by the solder mask 188.
Next, an electronic element 190 is disposed on the first surface 181 of the circuit board 180 so that the electronic element 190 may be electrically connected to the light-emitting diode 110 via the circuit board 180, the conductive terminal 170, the redistribution layer 140, and the first conductive through hole 130. In particular, the electronic element 190 may be in contact with a portion of the outermost conductive layer 1841 exposed by the solder mask 187. The electronic element 190 may be, for example, a driver IC, but the invention is not limited thereto. At this point, the light-emitting diode package 100 of the present embodiment is substantially completed.
In short, the light-emitting diode package 100 of the present embodiment may include the circuit board 180, the redistribution layer 140, the light-emitting diode 110, the first dielectric layer 120, and the plurality of wavelength conversion structures 150 and 151. The circuit board 180 has the first surface 181 and the second surface 182 opposite to the first surface 181. The redistribution layer 140 is disposed on the second surface 182 of the circuit board 180. The light-emitting diode 110 is disposed on the redistribution layer 140 and includes the first light-emitting diode 111, the second light-emitting diode 112, and the third light-emitting diode 113. The first dielectric layer 120 is disposed on the redistribution layer 140 and covers the light-emitting diode 110. The plurality of wavelength conversion structures 150 and 151 are disposed on the first dielectric layer 120 and respectively in contact with the second light-emitting diode 112 and the third light-emitting diode 113.
Based on the above, in the light-emitting diode package and the manufacturing method thereof of the present embodiment, by directly manufacturing the first dielectric layer and the redistribution layer on the resulting light-emitting diode, mass transfer and encapsulation gel processes may be omitted. Therefore, the light-emitting diode package and the manufacturing method thereof of the present embodiment may be applied to micro light-emitting diode packaging, and the issue of die shift may be avoided, thereby achieving the effect of simplifying the process. Moreover, the step of removing the first temporary substrate may avoid the issue of optical interference in the subsequently formed light-emitting diode package due to the light guiding characteristics of sapphire.
Moreover, the wavelength conversion structures are formed on the epitaxy thin film of the light-emitting diode (for example, a micro light-emitting diode), and the final light-emitting diode package (as shown in
Although the invention has been described with reference to the above embodiments, it will be apparent to one of ordinary skill in the art that modifications to the described embodiments may be made without departing from the spirit of the disclosure. Accordingly, the scope of the disclosure is defined by the attached claims not by the above detailed descriptions.
| Number | Date | Country | Kind |
|---|---|---|---|
| 110145768 | Dec 2021 | TW | national |
