Method of manufacturing a light emitting device

Abstract

A method of manufacturing a light emitting device includes the steps of providing a substrate, coupling a light emitting unit to the substrate, forming an insulating layer on the substrate such that at least a portion of the light emitting unit is surrounded by the insulating layer, and forming a collimator on the substrate corresponding to the light emitting unit after the insulating layer is formed.

Description

Technical Field

[0001] This disclosure relates to the manufacture of a light-emitting device, and more particularly to a method for manufacturing a light-emitting unit and a collimator that combine the light-emitting device. Background Technology

[0002] Light-emitting devices are essential components of displays and are widely used in electronic products such as mobile phones, tablets, and automotive displays. Sometimes, displays require privacy features, allowing users to view the screen only from a specific angle. This enhances privacy in personal electronic products (such as mobile phones or tablets), and in automotive displays, such as those placed in the passenger seat, it prevents obstruction of the driver's view, thus meeting safety requirements. To achieve privacy, a collimator can be integrated with the display's light-emitting element. The collimator has the function of converging or reflecting divergent light into parallel light, thereby providing privacy protection for the display screen. Summary of the Invention

[0003] This disclosure provides a method for manufacturing a light-emitting device, comprising the following steps: first, providing a substrate, then bonding a light-emitting unit onto the substrate, next forming an insulating layer on the substrate such that at least a portion of the light-emitting unit is surrounded by the insulating layer, and after the insulating layer is formed, forming a collimator corresponding to the light-emitting unit on the substrate.

[0004] The key feature of this disclosure is a method that directly integrates the light-emitting unit with a collimator during the fabrication of the light-emitting device. In this way, the light-emitting device itself in the completed display device possesses a collimator, meaning the displayed image can only be seen when viewed from a specific angle; that is, the display device itself has a privacy protection function. Traditional techniques involve applying a privacy film to the surface of the completed display device, which may result in uneven adhesion, excessive thickness, and poor light transmittance. This disclosure overcomes these problems, enabling the fabrication of a higher-quality display device with privacy protection. Attached Figure Description

[0005] Figures 1 to 4 A cross-sectional structural diagram illustrating the fabrication process of the light-emitting unit according to the first embodiment of this disclosure is shown.

[0006] Figure 5 A cross-sectional structural schematic diagram of the light-emitting unit according to the second embodiment of this disclosure is shown.

[0007] Figure 6 A cross-sectional structural schematic diagram of the light-emitting unit according to the third embodiment of this disclosure is shown.

[0008] Figure 7 A cross-sectional structural schematic diagram of the light-emitting unit according to the fourth embodiment of this disclosure is shown.

[0009] Figure 8 A cross-sectional structural schematic diagram of the light-emitting unit according to the fifth embodiment of this disclosure is shown.

[0010] Figure 9 A cross-sectional structural schematic diagram of the light-emitting unit according to the sixth embodiment of this disclosure is shown.

[0011] Figure 10 A cross-sectional structural schematic diagram of the light-emitting unit according to the seventh embodiment of this disclosure is shown.

[0012] Explanation of reference numerals in the attached figures: 10 - substrate; 12 - pixel definition layer; 12A - opening; 14 - light-emitting unit; 16 - insulating layer; 16A - insulating layer; 16B - insulating layer; 16C - insulating layer; 18 - collimator; 18A - collimator; 18B - collimator; 18B-1 - lower half; 18B-2 - upper half; 20 - insulating layer; 22 - second pixel definition layer; 22A - opening; 24 - color conversion unit; 26 - second insulating layer; 28 - filter layer; 100 - light-emitting device; 200 - light-emitting device; 300 - light-emitting device; 400 - light-emitting device; 500 - light-emitting device; 600 - light-emitting device; 700 - light-emitting device; A - cavity; w - distance; h - height; H1 - thickness; H2 - thickness. Detailed Implementation

[0013] This disclosure can be understood by referring to the following detailed description and accompanying drawings. It should be noted that, for ease of understanding and to keep the drawings concise, many of the drawings in this disclosure depict only a portion of the electronic device (i.e., the display device in this disclosure), and at least some of the specific elements in the drawings are not drawn to scale. Furthermore, the number and size of the elements in the drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0014] Throughout this specification and the appended claims, certain terms are used to refer to specific elements. Those skilled in the art will understand that electronic device manufacturers may use different names to refer to the same elements. This document is not intended to distinguish between elements that function identically but have different names. In the following specification and claims, words such as "having" and "comprising" are open-ended terms and should therefore be interpreted as "including but not limited to...".

[0015] It should be understood that when an element or membrane is defined as being disposed "on" or "connected" to another element or membrane, it can be directly on or directly connected to the other element or membrane, or there may be other inserted elements or membranes (indirect contact) between them. Conversely, when an element is defined as being "directly" on or "directly connected" to another element or membrane, there are no inserted elements or membranes between them.

[0016] The terms “approximately,” “equal to,” “equivalent to,” or “substantially the same” typically mean falling within 20% of a given value or range, or within 10%, 5%, 3%, 2%, 1%, or 0.5% of a given value or range.

[0017] Furthermore, the term "within the range from the first value to the second value" means that the range includes the first value, the second value, and other values ​​in between.

[0018] Although terms such as first, second, and third can be used to describe different constituent elements, these constituent elements are not limited by these terms. These terms are only used to distinguish constituent elements in the specification from other constituent elements. Claims may not use the same terms, but may use terms such as first, second, and third to indicate the order in which the elements are defined. Therefore, in the following description, a first constituent element may be a second constituent element in a claim.

[0019] It should be understood that the technical features of several different embodiments can be replaced, reorganized, or mixed to complete other embodiments without departing from the spirit or conflict of this disclosure.

[0020] Please refer to Figures 1 to 4 , Figures 1 to 4 A cross-sectional structural diagram illustrating the fabrication process of the light-emitting unit according to the first embodiment of this disclosure is shown. Firstly, as... Figure 1As shown, a substrate 10 is provided. The substrate 10 may include a base plate and a buffer layer and a circuit layer on the base plate. The base plate material may include glass, polyimide (PI), polycarbonate (PC), polyethylene naphthalate (PEN), triacetate (TAC), polyethylene terephthalate (PET), or combinations thereof, but is not limited thereto. In this embodiment, the buffer layer and the circuit layer may be simultaneously disposed on the base plate, and the circuit layer may also be directly disposed on the base plate. The buffer layer material may include inorganic materials such as silicon nitride and silicon oxide layers; the circuit layer disposed on the base plate is, for example, a driving circuit, which may include, for example, gate lines, signal lines, thin-film transistors, etc.

[0021] Next, at least one light-emitting unit 14 is bonded to the substrate 10. For example, a pixel definition layer (PDL) 12 may be formed on the substrate 10, and the pixel definition layer 12 may have at least one opening 12A, with the light-emitting unit 14 located in the opening 12A of the pixel definition layer 12. The bonding of the light-emitting unit 14 may be achieved by eutectic bonding, flip-chip bonding, surface mount technology, or conductive adhesive bonding (ACF), etc. Figure 2 Taking a pixel defining layer 12 having multiple openings 12A, and multiple light-emitting units 14 bonded on the substrate 10, each corresponding to one opening 12A, as an example, the opening 12 can also be exemplified as a groove. The light-emitting unit 14 is, for example, a light-emitting diode, which may include organic light-emitting diodes or inorganic light-emitting diodes (e.g., quantum dot LEDs, miniLEDs, microLEDs, or nanoLEDs), and the type of light-emitting diode can be vertical or flip-chip; however, this disclosure is not limited thereto. The pixel defining layer 12 may contain suitable insulating materials, such as silicon oxide, silicon nitride, silicon oxynitride, organic insulating layers, or any other suitable insulating material or combination thereof, but is not limited thereto.

[0022] The light-emitting unit 14 described in this disclosure can be combined with other components (such as control circuits) in subsequent processes to form a self-emissive display device, while the pixel definition layer 12 is used to define the position of each pixel on the display device. In this embodiment, the pixel definition layer 12 may be made of transparent photoresist, gray photoresist, white photoresist, or black photoresist, but this disclosure is not limited to these. These technologies are prior art in this field and will not be described in detail here.

[0023] Then as Figure 2 As shown, an insulating layer 16 is formed on the substrate 10, such that the light-emitting unit 14 is surrounded or covered by the insulating layer 16. The insulating layer 16 can be made of transparent or translucent materials, such as acrylic (PMMA), polycarbonate, silicone resin, epoxy resin, or mixtures thereof. The insulating layer 16 can also be a single-layer structure or a composite layer structure (not shown in the diagram), but this disclosure is not limited to these. Furthermore, the phrase "the light-emitting unit 14 is surrounded by the insulating layer 16" may mean that the light-emitting unit 14 is completely covered by the insulating layer 16, or that the light-emitting unit 14 is partially surrounded by the insulating layer 16 (e.g., the insulating layer 16 surrounds the lower half or sides of the light-emitting unit 14). In another embodiment, if the thickness H1 of the insulating layer 16 is smaller than the thickness H2 of the light-emitting unit 14, it means that a portion of the light-emitting unit 14 is surrounded by the insulating layer 16; if the thickness H1 of the insulating layer 16 is larger than the thickness H2 of the light-emitting unit 14, it means that all the light-emitting units 14 are surrounded by the insulating layer 16. If the light-emitting unit 14 is an organic light-emitting diode (OLED), its thickness H2 includes an anode layer, an organic light-emitting layer, and a cathode layer. If it is an inorganic light-emitting diode (OLED), its thickness H2 may include, for example, an electrode, a P-semiconductor layer, an N-semiconductor layer, and a quantum well light-emitting layer. That is, if the light-emitting unit 14 is partially surrounded by the insulating layer 16, the electrode, P-semiconductor layer, or N-semiconductor layer of the light-emitting unit 14 may be exposed, and a portion of the inorganic light-emitting diode may be covered by the insulating layer 16. If the light-emitting unit 14 is surrounded by or includes the insulating layer 16, it should meet the definition of "surrounded" as described in this disclosure.

[0024] In this disclosure, forming an insulating layer 16 on or around the light-emitting unit 14 has the following advantages, such as protecting the light-emitting unit 14, fixing the position of the light-emitting unit 14 to maintain structural stability, or forming a relatively flat surface on the light-emitting unit 14 to facilitate the formation of other components (e.g., collimators).

[0025] Next, as Figure 3As shown, a plurality of collimators 18 are formed on the surface of the insulating layer 16. The collimators 18 are made of materials such as metal (e.g., aluminum, silver, titanium, or their alloys); non-transparent resin, such as photoresist of different colors (e.g., black, white, gray) or ink of different colors; or transparent resin, such as materials with a refractive index between 1.5 and 2.0, such as acrylic (PMMA), polycarbonate, silicone resin, epoxy resin, or mixtures thereof, but this disclosure is not limited to these. In some embodiments of this disclosure, the collimators 18 can form a cavity A with light-gathering function corresponding to the light-emitting unit 14. Furthermore, in another embodiment, depending on product requirements, this cavity A can be filled with materials that can concentrate the light pattern, increase color purity, increase brightness, or no material can be filled. That is, the positions of the collimators 18 correspond to the light-emitting units 14. In more detail, from the cross-sectional view, the light-emitting unit 14 in this disclosure is preferably disposed between two adjacent collimators 18, or the collimator 18 can be aligned with the pixel definition layer 12 along the vertical direction (e.g., aligned with the top edge of the opening 12A of the pixel definition layer 12). In some embodiments of this disclosure, from the top view (not shown), the collimator 18 can be a plurality of parallel strip structures, and the light-emitting unit 14 is disposed between adjacent strip structures; or in other embodiments, from the top view (not shown), the collimator 18 can be a grid structure, and the light-emitting unit 14 is disposed within the grid structure. In this disclosure, the divergent light emitted from the light-emitting unit 14 is reflected by the collimator 18, causing the divergent light to converge into parallel light traveling almost vertically. Therefore, different degrees of privacy protection can be achieved through different shape designs of the collimator 18. For example, the measured light pattern of the light reflected and converged through the collimator 18 will be more concentrated than the measured light pattern of the light emitted by the light-emitting unit 140.

[0026] In this embodiment, the horizontal distance between the surfaces of two adjacent collimators 18 is defined as distance w, and the vertical height of any collimator 18 is defined as height h, where height h is the vertical distance from the surface of the insulating layer 16 to the top surface of the collimator 18. In some embodiments, distance w and height h may satisfy the condition h>(w / 2), but this disclosure is not limited thereto.

[0027] Next, as Figure 4As shown, another insulating layer 20 is formed on the insulating layer 16 to complete the light-emitting device 100 of this embodiment. The material of the insulating layer 20 can be the same as that of the insulating layer 16, and can include transparent or translucent materials, such as acrylic (PMMA), polycarbonate, silicone resin, epoxy resin, or mixtures thereof, but this disclosure is not limited to these. The insulating layer 20 is formed between the collimators 18, which can fix the collimators 18 and improve the structural stability. In this embodiment, the top surface of the insulating layer 20 is slightly lower than the top surface of the collimator 18, that is, a portion of the top surface of the collimator 18 is not covered by the insulating layer 20, but this disclosure is not limited to this.

[0028] Therefore, in the first embodiment described above, a method for combining a light-emitting unit and a collimator of a light-emitting device is provided. During the fabrication of the light-emitting device, the collimator is directly formed above the light-emitting unit and positioned corresponding to the light-emitting unit (here, "correspondingly positioned" means that the light-emitting unit is located between two adjacent collimators or that the collimator is positioned on both sides of the light-emitting unit adjacent to it). Thus, a light-emitting device containing a collimator can be fabricated. Subsequently, the light-emitting device having these light-emitting units can be further fabricated into a display device, thereby forming a display device with privacy protection functionality. The thickness of the display device formed by the method described in this disclosure can be reduced.

[0029] The following will describe different embodiments of the manufacturing method of the light-emitting device disclosed herein. For the sake of simplicity, the following description will focus on the differences between the embodiments and will not repeat the same points. In addition, the same elements in the embodiments of this disclosure are identified by the same reference numerals to facilitate comparison between the embodiments.

[0030] In different embodiments disclosed herein, insulating layers 16 of different shapes can be formed by adjusting process parameters. For example, such as Figure 5 As shown, where Figure 5 A cross-sectional structural diagram of the light-emitting unit according to the second embodiment of this disclosure is shown. In this embodiment, the insulating layer 16A of the light-emitting device 200 has a similar material and function to the insulating layer 16 described in the first embodiment. However, the insulating layer 16A does not completely cover the light-emitting unit 14, but rather surrounds or encircles the lower half of the light-emitting unit 14, while the upper half of the light-emitting unit 14 is exposed (and subsequently covered by the insulating layer 20). In this embodiment, the collimator 18 can be, for example, formed on the pixel definition layer 12. The remaining components are the same as in the first embodiment and will not be described in detail here.

[0031] In other embodiments disclosed herein, such as Figure 6 As shown, Figure 6A cross-sectional structural diagram of the light-emitting unit according to the third embodiment of this disclosure is shown. In this embodiment, the insulating layer 16B of the light-emitting device 300 is similar in material and function to the insulating layer 16 described in the first embodiment. However, the insulating layer 16B covers the light-emitting unit 14 and the pixel definition layer 12, and forms a corresponding convex surface above the light-emitting unit 14. The convex insulating layer 16B can provide a light-focusing function. The structure described in this embodiment is also within the scope of this disclosure. The remaining components are the same as in the first embodiment and will not be described in detail here.

[0032] In other embodiments disclosed herein, such as Figure 7 As shown, Figure 7 A cross-sectional structural diagram of the light-emitting unit according to the fourth embodiment of this disclosure is shown. The insulating layer 16C of the light-emitting device 400 in this embodiment has a similar material and function to the insulating layer 16 described in the first embodiment. However, the insulating layer 16C covers the light-emitting unit 14 and forms a corresponding convex surface above the light-emitting unit 14. Furthermore, the insulating layer 16C in this embodiment is not a single layer, but is divided into multiple insulating layers 16C by the pixel definition layer 12. It can be considered that the insulating layer 16C is formed in the opening 12A of the pixel definition layer 12 and does not cover the top surface of the pixel definition layer 12. The structure described in this embodiment is also within the scope of this disclosure. The remaining components are the same as in the first embodiment and will not be described in detail here.

[0033] In other embodiments disclosed herein, such as Figure 8 As shown, Figure 8 A cross-sectional structural schematic diagram of the light-emitting unit according to the fifth embodiment of this disclosure is shown. In this embodiment, the collimator 18A of the light-emitting device 500 has a color different from that of the collimator 18 described in the first embodiment, such as black, white, or gray. This disclosure does not limit the color or material of the collimator. The structure described in this embodiment is also within the scope of this disclosure. The remaining components are the same as those in the first embodiment described above, and will not be repeated here.

[0034] In other embodiments disclosed herein, such as Figure 9 As shown, Figure 9A cross-sectional structural schematic diagram of the light-emitting unit according to the sixth embodiment of this disclosure is shown. In this embodiment, the collimator of the light-emitting device 600 can be manufactured in different shapes. For example, the collimator 18B is formed by two photolithography processes (photolithography) to create the lower half 18B-1 and the upper half 18B-2, with the upper half 18B-2 located above the lower half 18B-1. In some cases, the height-to-width ratio of the collimator 18 is large (i.e., the height / width value is large), which makes manufacturing difficult and the structure prone to collapse. Therefore, in this embodiment, the collimator 18B is divided into upper and lower parts and manufactured in segments. This reduces the manufacturing difficulty and the probability of structural collapse. The remaining components are the same as in the first embodiment described above, and will not be described in detail here.

[0035] Besides the collimator formed by photolithography (photolithography) as mentioned above, collimators can also be formed by other methods, such as printing, inkjet printing, embossing, and screen printing. Since these processes are well-known in the art, they will not be elaborated upon here.

[0036] In other embodiments disclosed herein, other types of light-emitting units and collimators can be combined to fabricate the light-emitting device. Please refer to... Figure 10 , Figure 10 A cross-sectional structural schematic diagram of the light-emitting unit according to the seventh embodiment of this disclosure is shown. In this embodiment, a quantum dot light-emitting diode (QD LED) is used as an example, and it is fabricated into a light-emitting device 700 by being combined with a collimator. Figure 10As shown, this embodiment differs from the first embodiment in that, after the insulating layer 16 is completed and before the collimator 18 is formed, a second pixel definition layer 22 and a plurality of color conversion units 24 are first formed above the insulating layer 16. The second pixel definition layer 22 has an opening 22A, and the position of the opening 22A of the second pixel definition layer 22 can correspond to the opening 12A of the pixel definition layer 12. Each color conversion unit 24 is respectively disposed in one opening 22A and corresponds to each light-emitting unit 14. That is, the position of the second pixel definition layer 22 is aligned with the pixel definition layer 12 in the vertical direction, but is not limited thereto. The position of each color conversion unit 24 is also aligned with each light-emitting unit 14 in the vertical direction, but is not limited thereto. The alignment mentioned above means that the light emitted by the light-emitting unit 14 can pass through the corresponding color conversion unit 24. Therefore, the light emitted from the light-emitting unit 14 will sequentially pass through the insulating layer 16 and the color conversion units 24. Next, a relatively flat second insulating layer 26 is formed on the second pixel definition layer 22 and the color conversion unit 24, followed by the collimator 18 and insulating layer 20 mentioned in the aforementioned embodiments. In addition, a filter layer 28 can be formed on top of the insulating layer 20. Alternatively, in some other embodiments, a filter layer can replace part of the insulating layer 20 (not shown), meaning that the insulating layer 20 is not formed above the second insulating layer 26, and the filter layer 28 is formed directly, which is also within the scope of this disclosure. However, this disclosure is not limited to this.

[0037] In this embodiment, the color conversion unit 24 may include quantum dots, phosphorescent materials, fluorescent materials, pigments, dyes, scattering particles, or filter layers, but is not limited to these. Quantum dots may be composed of semiconductor nanocrystal structures, such as CdSe, CdS, CdTe, ZnSe, ZnTe, ZnS, HgTe, InAs, Cd1-xZnxSe1-ySy, CdSe / ZnS, InP, and GaAs, but are not limited to these. The main function of the color conversion unit 24 is to convert light of a specific color (e.g., blue light) into light of other colors (e.g., green light or red light). If the light-emitting unit 14 in this embodiment is, for example, a blue light-emitting diode, and works with the color conversion unit 24 to convert blue light into light of other colors, the light-emitting device 100 can emit light of red, blue, green, and other colors. The material of the second insulating layer 26 may be the same as or different from that of the insulating layer 16, for example, acrylic (PMMA), polycarbonate, silicone resin, epoxy resin, or mixtures thereof, but this disclosure is not limited thereto. The second insulating layer 26 can also achieve the functions of planarization and protection of the underlying components. The light filter layer 28 is, for example, a blue light filter layer used to filter out incompletely converted blue light, but this disclosure is not limited thereto. The light filter layer 28 may also filter out other colors of light, or in some other embodiments, the light filter layer 28 may be omitted, and these structures are also within the scope of this disclosure. This embodiment combines a quantum dot light-emitting diode with a collimator, and the remaining details of the quantum dot light-emitting diode are well known in the art and will not be described in detail here.

[0038] In summary, the key feature of this disclosure is that it provides a method for directly integrating the light-emitting unit with a collimator during the fabrication of the light-emitting device. In this way, the light-emitting device itself in the subsequently completed display device possesses a collimator, meaning that the displayed image can only be seen when the user views the display device from a specific angle; that is, the display device itself has a privacy protection function. In conventional techniques, applying a privacy film to the surface of the completed display device may result in problems such as uneven adhesion, excessive thickness, and poor light transmittance. This disclosure overcomes these problems, enabling the fabrication of a higher-quality display device with privacy protection functionality.

[0039] The above description is merely an embodiment of this disclosure and is not intended to limit the scope of this disclosure. Various modifications and variations can be made to this disclosure by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.

Claims

1. A method for manufacturing a light-emitting device, characterized in that, Includes the following steps: Provide a base; A pixel definition layer is formed, wherein the pixel definition layer has at least one opening; A light-emitting unit is attached to the substrate, wherein the light-emitting unit is located in at least one opening of the pixel definition layer; An insulating layer is formed on the substrate such that at least a portion of the light-emitting unit is surrounded by the insulating layer, and the insulating layer fills the at least one opening of the pixel definition layer; as well as After the insulating layer is formed, a collimator corresponding to the light-emitting unit is formed on the substrate, wherein the substrate is retained and not removed after the collimator is formed.

2. The method according to claim 1, characterized in that, The collimator is formed by a printing process.

3. The method according to claim 1, characterized in that, The collimator is formed by a photolithography process.

4. The method according to claim 1, characterized in that, The collimator is formed by an imprinting process.

5. The method according to claim 1, characterized in that, The collimator is formed by a screen printing process.

6. The method according to claim 1, characterized in that, Further includes: After the insulating layer is formed, a color conversion unit corresponding to the light-emitting unit is formed.

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