Light emitting device

Abstract

The present disclosure provides a light emitting device, comprising a first circuit substrate, a second circuit substrate, and a plurality of light emitting units disposed between the first circuit substrate and the second circuit substrate. The first circuit substrate comprises a first base, the second circuit substrate comprises a second base, and a difference in coefficient of thermal expansion between the first base and the second base is less than or equal to 5x10 ‑6 .

Description

Technical Field

[0001] This disclosure relates to a light-emitting device, and more particularly to a display device including thin-film transistor circuitry. Background Technology

[0002] In recent years, information devices have been widely used in daily life to provide information for people's daily lives. Light-emitting devices are one of the key components of information devices, serving as display devices or light sources to provide user information. For example, a public information display (PID) is a commonly used outdoor display device, which may be composed of multiple small display panels spliced ​​together to provide a large display area. Traditionally, the small display panels used to splice public displays may use epoxy glass fiber unclad laminate (FR4) as the substrate. The circuitry on its surface cannot be too fine, and the size is generally on the micrometer to millimeter scale. This results in complex circuit configurations and a large area ratio, requiring multiple layers of boards to be stacked, resulting in considerable thickness. Therefore, the substrate containing the circuitry has low light transmittance and high cost. Thus, the industry still needs to continuously research how to provide circuit substrates with higher light transmittance for use in light-emitting devices, while simultaneously considering the product's manufacturing cost. Summary of the Invention

[0003] One of the purposes of this disclosure is to provide a light-emitting device comprising two circuit boards with a plurality of light-emitting units disposed between the two circuit boards, thereby simplifying the manufacturing process and providing a thin and light-emitting device.

[0004] This disclosure provides a light-emitting device, including a first circuit board, a second circuit board, and a plurality of light-emitting units disposed between the first circuit board and the second circuit board. The first circuit board includes a first substrate, the second circuit board includes a second substrate, and the difference in the coefficient of thermal expansion between the first substrate and the second substrate is less than or equal to 5 x 10⁻⁶. -6 . Attached Figure Description

[0005] Figure 1 This is a partial cross-sectional schematic diagram of the first embodiment of the light-emitting device disclosed herein.

[0006] Figure 2 This is a partial cross-sectional schematic diagram of the second embodiment of the light-emitting device disclosed herein.

[0007] Figure 3 This is a partial cross-sectional schematic diagram of the third embodiment of the light-emitting device disclosed herein.

[0008] Figure 4This is a partial cross-sectional schematic diagram of the fourth embodiment of the light-emitting device disclosed herein.

[0009] Figure 5 This is a partial cross-sectional schematic diagram of the fifth embodiment of the light-emitting device disclosed herein.

[0010] Figure 6 and Figure 7 This is a cross-sectional schematic diagram of the sixth embodiment of the light-emitting device disclosed herein, wherein... Figure 6 A cross-sectional schematic diagram of the second circuit board is shown.

[0011] Figure 8 This is a cross-sectional schematic diagram of the seventh embodiment of the light-emitting device disclosed herein.

[0012] Figures 9 to 11 This is a cross-sectional schematic diagram of the eighth embodiment of the light-emitting device disclosed herein, wherein... Figure 9 A cross-sectional schematic diagram of the second circuit board is shown. Figure 10 A cross-sectional schematic diagram of the first circuit board is shown.

[0013] Explanation of reference numerals in the attached drawings: 100 - Light-emitting device; 102 - First substrate; 104, 104' - Second substrate; 1041, SB11, 1021 - Outer surface; 1042, SB12 - Inner surface; 106 - Conductor; 108, 110, 114, 116, 1161, 1162, 118, 134, 142, 144, 148, 150, 156 - Connecting pads; 112, 154 - Transistor circuit layers; 112a, 154a - Openings; 120, 120', 122, 1221, 1222, 136, 138, 146, 152 - Bonds Materials; 124, 130 - Adhesive layer; 126, 126' - Reflective layer; 128 - Driving element; 132 - Gap; 140 - Flexible circuit board; 158, 162 - Circuit board; 160 - Side conductor; ARL, ARL1, ARL2 - Arrow; CTP - Connector; ED - Electronic device; LER, LER1, LER2 - Light emission area; LEU, LEU' - Light emission unit; MD1, MD2 - Miniature driving element; SB1 - First circuit board; SB2 - Second circuit board; TH - Through hole; UT - Lamp board unit; UTS - Substrate unit; Z, X - Direction. Detailed Implementation

[0014] 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 for the sake of simplicity, many of the drawings in this disclosure depict only a portion of the electronic device, and specific components in the drawings are not drawn to scale. Furthermore, the number and dimensions of the components in the drawings are for illustrative purposes only and are not intended to limit the scope of this disclosure.

[0015] 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.

[0016] In the following description and claims, the word "comprising" is an open-ended term and should therefore be interpreted as "including but not limited to...".

[0017] The directional terms used herein, such as "up," "down," "front," "back," "left," and "right," are for illustrative purposes only and are not intended to limit this disclosure. In the accompanying drawings, the various figures illustrate general features of the methods, structures, and / or materials used in specific embodiments. However, these figures should not be construed as defining or limiting the scope or nature covered by these embodiments. For example, for clarity, the relative dimensions, thicknesses, and positions of various films, regions, and / or structures may be reduced or enlarged.

[0018] It should be understood that when an element or membrane is referred to as being "on" another element or membrane, it can be directly on that other element or membrane, or there can be an inserted element or membrane between them (indirect cases). Conversely, when an element is referred to as being "directly" on another element or membrane, there is no inserted element or membrane between them. Electrical connections can be direct electrical connections or indirect electrical connections through other elements. The terms "joining" and "connection" can also include cases where both structures are movable or both structures are fixed.

[0019] The terms "equal to" or "approximately" 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.

[0020] 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.

[0021] Although the terms first, second, third… can be used to describe multiple components, the components are not limited to these terms. These terms are used only to distinguish a single component from other components in the specification. The same terms may not be used in the claims, but rather replaced by first, second, third… in the order of the elements declared in the claims. Therefore, in the following description, a first component may be a second component in the claims.

[0022] 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 of this disclosure.

[0023] Please refer to Figure 1 , Figure 1 This is a partial cross-sectional schematic diagram of the first embodiment of the light-emitting device disclosed herein. The electronic device ED disclosed herein may be, for example, a light-emitting device 100. The electronic device ED may include a display device, an antenna device, a sensing device, a touch display, a curved display, or a free-shape display, but is not limited thereto. The electronic device ED may be a bendable or flexible electronic device. The electronic device ED may include, for example, liquid crystal, light-emitting diode, quantum dot (QD), fluorescence, phosphorescence, other suitable display media, or combinations of the above materials, but is not limited thereto; the light-emitting diode may include, for example, organic light-emitting diode (OLED), miniLED, micro LED, or quantum dot (QD, such as QLED, QDLED), or other suitable materials, and the materials may be arranged and combined arbitrarily, but are not limited thereto. The display device may include, for example, a splicing display device, but is not limited thereto. The antenna device may be, for example, a liquid crystal antenna, but is not limited thereto. The antenna device may include, for example, an antenna splicing device, but is not limited thereto. It should be noted that the electronic device ED can be any of the aforementioned arrangements and combinations, but is not limited thereto. The following description uses the light-emitting device 100 as an example to illustrate this disclosure. The light-emitting device 100 can display static or dynamic images or screens according to the user's needs and operations, but is not limited thereto. Furthermore, the electronic device ED can be rectangular, circular, polygonal, have curved edges, or other suitable shapes. The electronic device ED can have peripheral systems such as a drive system, control system, and light source system to support the display device, antenna device, or splicing device. The following description uses the light-emitting device 100 as an example to illustrate the content of this disclosure, but this disclosure is not limited thereto.

[0024] According to this embodiment, as Figure 1As shown, the light-emitting device 100 may include a first circuit board SB1, a second circuit board SB2, and a plurality of light-emitting units (LEUs) disposed between the first circuit board SB1 and the second circuit board SB2. The first circuit board SB1 includes a first substrate 102, and the second circuit board SB2 includes a second substrate 104. The first substrate 102 and the second substrate 104 may respectively include a flexible substrate, a rigid substrate, or a combination of the above substrates. The material of the flexible substrate may include, for example, polyimide (PI), polycarbonate (PC), polyethylene terephthalate (PET), triacetate (TAC), epoxy resin, other suitable materials, or combinations of the above materials, while the material of the rigid substrate may include, for example, glass, ceramic, quartz, sapphire, or combinations of the above materials, but is not limited thereto. The materials of the first substrate 102 and the second substrate 104 may be the same or different. It should be noted that, according to this disclosure, the difference in the coefficient of thermal expansion (CTE) between the first substrate 102 and the second substrate 104 is less than or equal to 5 x 10⁻⁶. -6 In some embodiments, such as at an ambient temperature of 20°C, the coefficient of thermal expansion of the glass may be, for example, 7.1 x 10⁻⁶. -6 The coefficient of thermal expansion of polycarbonate (PC) can be, for example, 70.2 x 10⁻⁶. -6 The coefficient of thermal expansion of polyethylene terephthalate (PET) can be, for example, 59.4 x 10⁻⁶. -6 The unit of the coefficient of thermal expansion is, for example, the reciprocal of temperature in degrees Celsius (°C). -1The coefficient of thermal expansion of each material can be referenced to the values ​​measured by measurement standards such as ASTM E831, ASTM D696, and ISO 11359. For example, in the first embodiment, the material of the first substrate 102 may be different from the material of the second substrate 104. For example, the first substrate 102 may include PI material or encapsulation material, while the second substrate 104 may include transparent material, such as glass, but is not limited thereto. In a variation embodiment, both the first substrate 102 and the second substrate 104 may include flexible materials. The first substrate SB1 may include one or more wires 106 disposed in the first substrate 102 for electrically connecting the connecting pads 110 on the surface of the first substrate SB1 and transmitting signals. For example, the wires 106 may electrically connect the connecting pads 108 located on the outer surface SB11 of the first substrate SB1 (or the outer surface of the first substrate 102), or they may electrically connect the connecting pads 110 located on the inner surface SB12 of the first substrate SB1 (or the inner surface of the first substrate 102). In some embodiments, the connecting pads 110 may be disposed in the first substrate SB1 (e.g., Figure 1 (As shown), but this disclosure is not limited thereto. The conductor 106 in the first substrate 102 may be composed of one or more conductive layers. Figure 1Only one layer is shown for illustration. The material of the wire 106 may include copper, silver, gold, aluminum, other suitable conductive materials, or combinations thereof, but is not limited thereto. The second substrate SB2 includes a transistor circuit layer 112 disposed and formed on the inner surface 1042 of the second substrate 104, wherein the transistor circuit layer 112 includes multiple material layers, such as semiconductor layers, conductive layers (e.g., but not limited to the metal materials mentioned above), and insulating layers, and may be fabricated using thin film transistor (TFT) level processes. The transistor circuit layer 112 may include multiple thin film transistors as switching elements or driving elements, and may include wires and / or other electronic components electrically connecting the thin film transistors, but this disclosure is not limited thereto. In addition, the inner side of the second circuit substrate SB2 includes multiple connection pads 114 and connection pads 118 disposed on the surface of the transistor circuit layer 112, wherein the connection pads 114 are used to electrically connect to the light-emitting unit LEU, and the connection pads 118 are used to electrically connect to the first circuit substrate SB1. In some embodiments of this disclosure, bonding material 120 can be used to bond connecting pad 110 and connecting pad 118, so that the first circuit board SB1 can be electrically connected to the second circuit board SB2. Specifically, through the connection portion CTP formed by connecting pad 118, bonding material 120 and connecting pad 110, the wires 106 in the first circuit board SB1 can be electrically connected to the transistor circuit layer 112 of the second circuit board SB2. In this embodiment, bonding material 120 is exemplified as solder, such as including metallic tin, but is not limited thereto. In some embodiments, bonding material 120 may also include other conductive materials, such as anisotropic conductive film (ACF), but this disclosure is not limited thereto.

[0025] The light-emitting unit (LEU) is disposed on the inner surface 1042 of the second circuit substrate SB2 and includes connection pads 116. Each connection pad 116 corresponds to a connection pad 114 on the surface of a transistor circuit layer 112, and the connection pads 114 and 116 are electrically connected by a bonding material 122. This allows the LEU to be electrically connected to the transistor circuit layer 112 of the second circuit substrate SB2, and the thin-film transistors in the second circuit substrate SB2 can drive the corresponding electrically connected LEU. The connection pads 116 can be electrodes of the LEU; for example, the connection pads 116 on both sides can be the cathode and anode of the LEU, respectively. In some embodiments, the LEU can be a flip-chip LED, with the cathode and anode located on the same side of the LEU, but this is not a limitation. The LEU may include a light-emitting diode (LED). Light-emitting diodes (LEDs) may include, for example, organic light-emitting diodes (OLEDs), inorganic light-emitting diodes (LEDs), mini-light-emitting diodes (mini LEDs), mini-meter-sized LEDs, micro-light-emitting diodes (micro-LEDs), quantum dot (QDs) LEDs (e.g., QLEDs, QDLEDs), other suitable LEDs, or any combination thereof, but are not limited thereto. The light-emitting unit (LEU) may be in chip form, but is not limited thereto. Figure 1 In the illustrated embodiment, the light-emitting device 100 is a top-emitting device, with the outer surface 1041 of the second circuit board SB2 serving as the light-emitting side or display side of the light-emitting device 100. That is, the user is located on the side of the second circuit board SB2 opposite to the first circuit board SB1, so as to receive light or view images from the outer surface 1041 of the second circuit board SB2. Figure 1As shown, the light-emitting unit (LEU) can emit light upwards, that is, towards the outer surface 1041 of the second circuit board SB2, with its light path as shown by arrow ARL. In this embodiment, the light-emitting unit (LEU) can also be a six-sided light-emitting device, but this disclosure is not limited thereto. It should be noted that in some embodiments, the transistor circuit layer 112 may include a plurality of openings 112a, at least one of which corresponds to the position between the two connecting pads 116 of the light-emitting unit (LEU). The openings 112a allow light to pass through. For example, the transistor circuit layer 112 at least partially does not have an opaque material layer at the opening 112a position. The opaque material layer is, for example, a metal layer or a metal wire. In this embodiment, the transistor circuit layer 112 located outside the two connecting pads 116 may also include a plurality of openings (not shown), that is, the light emitted by the light-emitting unit (LEU) can also pass through the outer position of the two connecting pads 116, but this disclosure is not limited thereto. In other embodiments, the outer surface 1041 may be surface treated and / or an optical film layer may be selectively provided. For example, the outer surface 1041 may be atomized or have its surface roughness increased, or a diffusion film or light-collecting film may be provided, which may change the optical properties such as surface reflection, refraction or optical viewing angle, but this disclosure is not limited thereto.

[0026] Furthermore, the light-emitting device 100 may include an adhesive layer 124 located between the first circuit board SB1 and the second circuit board SB2. In some embodiments, the adhesive layer 124 may completely fill the space between the first circuit board SB1 and the second circuit board SB2. Therefore, there will be an adhesive layer 124 between the light-emitting unit LEU and the first circuit board SB1, and between the light-emitting unit LEU and the second circuit board SB2. The adhesive layer 124 can be used to assemble the first circuit board SB1 and the second circuit board SB2, and fix the relative positions of the first circuit board SB1, the second circuit board SB2, and the light-emitting unit LEU. The adhesive layer 124 may include any suitable adhesive material, such as (but not limited to) optical adhesive or thermoplastic. Figure 1 The embodiment shown uses a light-emitting diode encapsulating adhesive (e.g., epoxy resin) as the adhesive layer 124, but is not limited thereto.

[0027] Furthermore, the first circuit board SB1 may optionally include a reflective layer 126, located on the inner surface SB12 of the first circuit board SB1, or located within the first circuit board SB1. The reflective layer 126 may be a patterned coating covering the entire surface. For example, the patterned reflective layer 126 may be positioned corresponding to the position of the light-emitting unit (LEU). The area of ​​each pattern may be slightly larger than the area of ​​the light-emitting unit (LEU). In this design, light emitted from the light-emitting unit (LEU) can be reflected upward by the reflective layer 126, increasing the probability of light escaping from the outer surface 1041 of the second substrate 104, thereby improving light utilization. The reflective layer 126 may include, for example, a metal layer, silver paste, white paint, or other materials with high reflectivity, such as materials with a reflectivity of 90% or higher. When the reflective layer 126 includes a metal material, the light-emitting unit (LEU) may have a distance D1 between itself and the reflective layer 126, and this distance D1 is greater than 0. The distance D1 refers to the shortest distance along the direction Z, and the direction Z is parallel to the normal direction of the inner surface SB12 of the first substrate SB1. In a variation embodiment, the first circuit substrate SB1 may not have a reflective layer 126; in another variation embodiment, the reflective layer 126 may be a cup shape with a higher periphery and a lower center, which can have the effect of light collection and other optical properties to improve light utilization. On the other hand, the wires 106 in the first circuit substrate SB1 may be electrically connected to the connecting pads 108 through the vias TH in the first substrate 102, and the driving element 128 may be disposed on the connecting pads 108 and electrically connected to the wires 106 through the connecting pads 108. The driving element 128 includes, but is not limited to, an integrated circuit chip. Arrow ARS indicates the input direction of the signal / voltage. For example, when the driving element 128 is disposed on the outer surface SB11 of the first circuit substrate SB11, the signal / voltage may be input to the driving element 128, thereby providing the operating voltage of the light-emitting device 100 or controlling the operation of the light-emitting device 100. In other embodiments, the driving element 128 may be, for example, a flexible printed circuit (FPC), a chip on film (COF), etc., but this disclosure is not limited thereto.

[0028] In a variation of the first embodiment, if the light-emitting device 100 is designed as a double-sided light-emitting device, the reflective layer 126 can be omitted, and the through hole TH and the connecting pad 108 can be set corresponding to the connecting portion CTP. That is, in the direction Z, the through hole TH and the connecting pad 108 are at least partially overlapped with the connecting portion CTP, and the driving element 128 can be set perpendicular to the outer surface SB11 of the first circuit board SB1, that is, set along the direction Z. That is, the driving element 128 does not overlap with the light-emitting unit LEU in the direction Z (for example, parallel to the normal direction of the inner surface SB12 of the first board SB1).

[0029] according to Figure 1 In the illustrated embodiment, the method for fabricating the disclosed light-emitting device 100 may include providing a second circuit board SB2, wherein the second circuit board SB2 includes a second substrate 104, on which a transistor circuit layer 112 and connection pads 114 and 118 have been formed. Then, a light-emitting unit (LEU) is bonded to the surface of the second circuit board SB2 using a bonding material 122, such that the connection pad 116 of the light-emitting unit LEU is electrically connected to the connection pad 114 on the surface of the second circuit board SB2 through the bonding material 122. Furthermore, a bonding material 120 may be provided on the connection pad 118. Next, an adhesive layer 124 is formed on the second circuit board SB2, wherein the adhesive layer 124 completely covers the light-emitting unit LEU, for example, covering the surface of the light-emitting unit LEU opposite to the surface of the second circuit board SB2, and the adhesive layer 124 exposes at least a portion of the bonding material 120, for example, the adhesive layer 124 does not cover the surface of the bonding material 120 opposite to the surface of the second circuit board SB2. The adhesive layer 124 may be formed by a coating method, but is not limited thereto. On the other hand, the method for manufacturing the light-emitting device 100 disclosed herein also includes providing a first circuit board SB1, wherein the first circuit board SB1 includes a first substrate 102, a conductor 106 is provided in the first substrate 102, and a connecting pad 110, a connecting pad 108, and a selective reflective layer 126 are provided on the surface of the first substrate 102. Then, the inner surface SB12 of the first circuit board SB1 is aligned with the inner surface 1042 of the second substrate 104 and the light-emitting unit LEU, and the first circuit board SB1 and the second circuit board SB2 are assembled. Then, reflow soldering can be performed to electrically connect the bonding material 120 to the connecting pad 110, while simultaneously curing the adhesive layer 124. In some embodiments, the above-mentioned curing of the adhesive layer 124 can also be selectively accomplished by hot pressing or ultraviolet light irradiation, and this disclosure is not limited thereto. After the assembly is completed, the driving element 128 can be bonded to the connecting pad 108 to complete the fabrication of the light-emitting device 100.

[0030] According to this disclosure, the difference in the coefficients of thermal expansion between the first substrate 102 and the second substrate 104 is less than or equal to 5 x 10⁻⁶. -6This design reduces the probability of substrate warping or breakage after assembly. Under the above conditions, the light-emitting device 100 can use different materials for the first substrate 102 and the second substrate 104, or design different structures and processes, as needed, while still providing good product reliability. The condition of the difference in the coefficient of thermal expansion between the first substrate 102 and the second substrate 104 can be applied to the various embodiments and variations disclosed herein, and will not be repeated below. Furthermore, the light-emitting device 100 uses the second substrate 104 as the light-emitting side. The second substrate 104 can be made of a highly transparent material, such as (but not limited to) the aforementioned glass, sapphire, etc., which can improve light extraction efficiency and brightness. In addition, the aforementioned material of the second substrate 104 is suitable for use in thin-film transistor-level processes to fabricate a transistor circuit layer 112 containing thin-film transistors. Thin-film transistor-level processes can improve process accuracy. On the other hand, this disclosure places the main driving elements (e.g., thin-film transistors) and wires (e.g., data lines or scan lines) on the light-emitting side substrate (second circuit substrate). This design can reduce the thickness of the back-side substrate (first circuit substrate) and / or save on manufacturing costs. Furthermore, according to this disclosure, the light-emitting unit can be disposed together on the light-emitting side substrate, allowing the light-emitting unit to be directly electrically connected to the driving elements and wires, thereby improving performance and light extraction efficiency.

[0031] The electronic device and light-emitting device disclosed herein are not limited to the embodiments described above, and may have other embodiments or variations as described below. Without departing from the spirit of this disclosure, technical features in different embodiments can be replaced, recombined, or mixed to complete other embodiments. For the sake of simple comparison between the embodiments and variations, the differences between different embodiments or variations will be described below, while features that are identical will not be repeated.

[0032] Figure 2 This is a partial cross-sectional schematic diagram of the second embodiment of the light-emitting device disclosed herein. The main difference between the light-emitting device of the second embodiment and the first embodiment lies in the design of the adhesive layer. Please refer to... Figure 2In the second embodiment, the adhesive layer 130 of the light-emitting device 100 is partially filled or partially disposed between the first circuit board SB1 and the second circuit board SB2. For example, the adhesive layer 130 may be located between adjacent light-emitting units (LEUs) or between a light-emitting unit (LEU) and a connecting portion (CTP), and there is a gap 132 between the adhesive layer 130 and the light-emitting unit (LEU), that is, there is a gap between the adhesive layer 130 and the adjacent light-emitting unit (LEU). The adhesive layer 130 may include any suitable adhesive material. In some embodiments, the adhesive layer 130 may include a reworkable adhesive material. Since the adhesive layer 130 is only disposed at certain locations between the first circuit board SB1 and the second circuit board SB2, it is easier to untie or rework the adhesive layer 130, which is beneficial for the rework of the light-emitting device 100. The adhesive layer 130 can be debonded by means of, but not limited to, heating or light exposure. Alternatively, a desoldering process can be performed on the bonding materials 120 and 122 to separate the first circuit board SB1 and the second circuit board SB2, allowing for repair or rework of the light-emitting unit (LEU) and circuitry. In some embodiments, the adhesive layer 130 can be a spacer, such as a spacer ball, providing support between the first circuit board SB1 and the second circuit board SB2, maintaining a fixed spacing between the two boards. The cross-sectional shape of the adhesive layer 130 as a spacer is not limited to... Figure 2 As shown, it can be spherical or other shapes. In some embodiments, the adhesive layer 130 can also provide a sealing function to prevent water and oxygen from intruding between the first circuit board SB1 and the second circuit board SB2. In some embodiments, depending on various display requirements, the adhesive layer 130 can also have optical effects that affect the light path, such as reflection, light guiding, diffusion, and / or light absorption, which can improve the light emission efficiency of the light-emitting device 100. The fabrication method of the light-emitting device 100 in this embodiment is generally similar to that in the first embodiment, the main difference being that the adhesive layer 130 can be fabricated by dispensing, screen printing, or spraying. In this embodiment, the area between adjacent adhesive layers 130 can be defined as the light-emitting region LER, for example, the light-emitting region LER can be defined by the edge of the adhesive layer 130 closest to the adjacent light-emitting unit LEU, but it is not limited to this.

[0033] Please refer to Figure 3 , Figure 3 This is a partial cross-sectional schematic diagram of the third embodiment of the light-emitting device disclosed herein. The main differences between this embodiment and the second embodiment include the light-emitting design, the input position and connection method of the external signal, and the design of the connection part. Figure 3The light-emitting device 100 shown is a double-sided light-emitting device, or it can also be used as a transparent display device. The light-emitting unit (LEU) can be a six-sided light-emitting unit, such as a six-sided light-emitting diode, and the LEU can emit light upwards, downwards, and sideways. Therefore, the transparent areas of the corresponding light-emitting units (LEU) in the first circuit board SB1 and the second circuit board SB2 can allow light from the LEU to pass through. The first circuit board SB1 includes a first substrate 102 and a transistor circuit layer 154, wherein the transistor circuit layer 154 can be similar to the transistor circuit layer 112 of the second circuit board SB2, including thin-film transistors, wires, and / or other electronic components fabricated using thin-film transistor-level processes, which will not be described in detail here. The first substrate 102 and the second substrate 104 can include the same or different transparent materials, for example, both can include glass or both can include transparent flexible materials, but are not limited thereto. The transistor circuit layers 154 and 112, fabricated using thin-film transistor-level processes, are thinner and have higher transmittance. Combined with the highly transparent first substrate 102 and second substrate 104 materials, they can provide double-sided light emission. As in the first embodiment, the transistor circuit layer 112 may include multiple openings 112a, for example, at least one opening 112a between two connecting pads 116, allowing light emitted by the light-emitting unit (LEU) to pass through the opening 112a. The transistor circuit layer 112 located outside the two connecting pads 116 may also include multiple openings (not shown), meaning light emitted by the LEU can also pass through the outer positions of the two connecting pads 116, as shown by arrow ARL1, forming a light-emitting region LER1. However, this disclosure is not limited to this. On the other hand, the transistor circuit layer 154 may include multiple openings 154a, each corresponding to a light-emitting unit (LEU), allowing light emitted by the LEU to pass through the opening 154a, as shown by arrow ARL2, forming a light-emitting region LER2. In other embodiments, the light-emitting region LER2 may include multiple openings 154a, but this disclosure is not limited thereto. In this embodiment, the light-emitting region LER1 or LER2 may be defined, for example, by two adhesive layers 130 adjacent to the light-emitting unit LEU, i.e., by the edge of the adhesive layer 130 closest to the light-emitting unit LEU; or, the light-emitting region LER1 or LER2 may be defined by the edge of the adhesive layer 130 closest to the light-emitting unit LEU and the edge of the connecting pad 142 closest to the light-emitting unit LEU. The outer surface 1021 of the first substrate 102 and the outer surface 1041 of the second substrate 104 may serve as the light-emitting surfaces of the light-emitting device 100.

[0034] Furthermore, in this embodiment, the external signal or voltage input position is located at the edge of the light-emitting device 100, as indicated by arrow ARS. The external signal or voltage is input from the side of the light-emitting device 100, and is transmitted via the flexible circuit board 140. It can be electrically connected to the second circuit board SB2 via connecting pad 144, bonding material 146, and connecting pad 142, and can also be electrically connected to the first circuit board SB1 via connecting pad 150, bonding material 152, and connecting pad 148. The flexible circuit board 140 may include, for example, PI material, but is not limited thereto. In some embodiments, an integrated circuit chip may also be disposed on the flexible circuit board 140, but this disclosure is not limited thereto. In this embodiment, the signal / voltage input position is located at the edge of the device, rather than on the outer surface of the back plate (first circuit board SB1), so it does not obstruct the light path. Therefore, the outer surface 1021 of the back plate can also serve as the display side.

[0035] On the other hand, such as Figure 3 As shown, the light-emitting device 100 of the third embodiment includes two minidrivers, MD1 and MD2, which can be electrically connected to each other or in series. Minidriver MD1 is electrically connected to a connecting pad 118 via a bonding material 136, and then electrically connected to a second circuit board SB2. Minidriver MD2 is electrically connected to a connecting pad 134 via a bonding material 138, and then electrically connected to a first circuit board SB1. The first circuit board SB1 is electrically connected to the second circuit board SB2. Minidrivers MD1 and MD2 can each be thin-film transistor integrated circuit chips (TFT ICs) and can be used to drive multiple light-emitting units (LEUs). Minidrivers MD1 and MD2 can each include a miniature transparent substrate (e.g., but not limited to a miniature glass substrate) or a miniature non-transparent (e.g., white) substrate and circuits, thin-film transistors, and / or electronic components formed thereon, wherein these electronic components can be fabricated using thin-film transistor-level processes. Because minidrivers MD1 and MD2 can be designed with transparent elements, they can be applied to double-sided light-emitting devices or transparent displays. In a variation embodiment, the micro-driving elements MD1 and MD2 in the connector CTP may also include conventional integrated circuit chips. It should be noted that the number of micro-driving elements included in the connector CTP is not limited to... Figure 3As shown, the CTP connector may include one or more micro-driving elements, wherein the electrical connection of the multiple micro-driving elements may be soldered or connected with conductive adhesive, but is not limited thereto. In this embodiment, the micro-driving elements are disposed between the first substrate 102 and the second substrate 104, and external signals are transmitted to the micro-driving elements through the transistor circuit layer 112 and the transistor circuit layer 154, thus eliminating the need to design additional lines that penetrate the first substrate 102, thereby improving the process yield.

[0036] Please refer to Figure 4 , Figure 4 This is a partial cross-sectional schematic diagram of the fourth embodiment of the light-emitting device disclosed herein. The main differences between this embodiment and the third embodiment lie in the light-emitting design, the signal input terminal design, and the design of the CTP connector. Figure 4 The light-emitting device 100 shown is a single-sided light-emitting device, with the outer surface 1041 of the second substrate 104 serving as the light-emitting surface. The surface of the first circuit board SB1 may include a reflective layer 126', the pattern of which corresponds to each light-emitting unit (LEU). The reflective layer 126' may be formed on the surface of the first substrate 102. The flexible circuit board 140 can be electrically connected to the transistor circuit layer 112 via connecting pads 144, bonding material 146, and connecting pads 142, and further electrically connected to the micro-driving element MD1. In this embodiment, the first circuit board SB1 exposes the second circuit board SB2 at the signal input position. For example, the size of the first circuit board SB1 is slightly smaller than that of the second circuit board SB2, so the flexible circuit board 140 can be bent along a direction perpendicular to the substrate surface, that is, it can be bent along the sidewall of the first substrate 102. This design can save the installation space of the flexible circuit board 140 or save the bezel area to achieve a narrow bezel or bezel-less setting, but it is not limited thereto. In addition, Figure 4 The light-emitting device 100 may not have a connection portion CTP for electrically connecting the first circuit board SB1 and the second circuit board SB2. The micro-driving element MD1 is electrically connected to the second circuit board SB2 via bonding material 136 and connecting pad 118, but is not directly electrically connected to the first circuit board SB1 from the bottom. In a variant embodiment, the transistor circuit layer 154 of the first circuit board SB1 may be omitted, but this is not a limitation.

[0037] In one variation of this disclosure, parts of the designs of the aforementioned second, third, and fourth embodiments can be combined to provide a light-emitting device with an alternative structure. For example, using... Figure 3 or Figure 4 The first circuit board SB1 and the second circuit board SB2 shown have a CTP connection structure as follows: Figure 2 As shown, the signal / voltage input terminal design is as follows: Figure 4As shown, a flexible circuit board 140 provides signal / voltage input. In this embodiment, the transistor circuit layer 112 and transistor circuit layer 154 in the first circuit board SB1 and the second circuit board SB2 can be transistor circuit layers including a flexible substrate, that is, transistor circuit layer 112 and transistor circuit layer 154 can respectively include a flexible circuit board and a switching element or a driving element disposed thereon. In this embodiment, a portion of transistor circuit layer 112 can serve as... Figure 4 The flexible circuit board in, i.e. Figure 4 The flexible circuit board 140 and the transistor circuit layer 112 have the same structure, eliminating the need for connection pads 142, 144, and bonding material 146. When provided... Figure 3 When the first circuit board SB1 shown is provided, a double-sided light-emitting device can be fabricated. Figure 4 When the first circuit board SB1 is shown, a single-sided light-emitting device can be fabricated. In another variation, the flexible circuit board for input signals / voltages can also be a chip-on-film (COF) circuit board with an integrated circuit chip disposed thereon, but is not limited thereto. In yet another variation, the two circuit boards can have the same size, and an adhesive layer 130 is still provided at the edge of the substrate with the flip-chip circuit board to provide fixation and sealing between the substrates.

[0038] Please refer to Figure 5 , Figure 5 This is a partial cross-sectional schematic diagram of the fifth embodiment of the light-emitting device disclosed herein. The main difference between this embodiment and the second embodiment is that... Figure 5 The light-emitting device 100 includes a vertical type light-emitting unit LEU'. Connecting pads 1161 and 1162 are located on opposite sides of the light-emitting unit LEU', and can serve as the cathode or anode of the light-emitting unit LEU', respectively. The light-emitting unit LEU' is electrically connected upward to the second circuit board SB2 via connecting pad 1161, bonding material 1221, and connecting pad 114, and electrically connected downward to the first circuit board SB1 via connecting pad 1162, bonding material 1222, and connecting pad 156. In other words, the light-emitting unit LEU' is electrically connected to the first circuit board SB1 and the second circuit board SB2 by connecting pads 1162 and 1161 on opposite sides, respectively. Furthermore, Figure 5The light-emitting device 100 is a single-sided light-emitting device. A reflective layer 126' may be selectively disposed on the surface of the first circuit board SB1, corresponding to the light-emitting unit LEU', or at least disposed around the light-emitting unit LEU'. In other embodiments, the reflective layer 126' may be selected to contact or not contact the bonding material 1222 according to design requirements. The transistor circuit layer 112 of the second circuit board SB2 may include a plurality of openings 112a disposed on one side of the light-emitting unit LEU' or adjacent to the connection pad 1161. Figure 5 The location of the opening 112a is merely an example and is not limited to the disclosed content. According to this embodiment, for example, at least one opening 112a is provided between the two adhesive layers 130, so that the light emitted by the light-emitting unit LEU' can pass through the opening 112a. Alternatively, multiple openings (not shown) can be provided between the connecting pad 1161 and the adhesive layer 130, that is, the light emitted by the light-emitting unit LEU' can also pass through both sides of the connecting pad 1161, as shown by arrow ARL, forming the light-emitting area LER, but this disclosure is not limited thereto.

[0039] The method for manufacturing the light-emitting device 100 according to the fifth embodiment of this disclosure includes first providing a second circuit board SB2, wherein the second circuit board SB2 includes a second substrate 104, on which a transistor circuit layer 112 and connection pads 114 and 118 have been formed. Then, a light-emitting unit LEU' can be bonded to the surface of the second circuit board SB2 using a bonding material 1221, so that the connection pad 1161 of the light-emitting unit LEU' is electrically connected to the connection pad 114 on the surface of the second circuit board SB2 through the bonding material 1221. In addition, a bonding material 120 can be provided on the surface of the connection pad 118, and a bonding material 1222 can be provided on the surface of the connection pad 1162. Next, an adhesive layer 130 is formed on the second circuit board SB2. The adhesive layer 130 can be located between adjacent light-emitting units LEU' and / or around the connection portion CTP, wherein the adhesive layer 130 can be manufactured by dispensing, screen printing, or spraying, but is not limited thereto. On the other hand, the method for manufacturing the light-emitting device 100 disclosed herein also includes providing a first circuit board SB1, wherein the first circuit board SB1 includes a first substrate 102, in which conductive wires 106 are provided, and the surface of the first substrate 102 is provided with connecting pads 110, 156, 108 and a selectively disposed reflective layer 126'. Then, the inner surface of the first circuit board SB1 (e.g., the surface where connecting pads 110 and 156 are provided) is faced with the inner surface 1042 of the second substrate 104 and the light-emitting unit LEU', and the first circuit board SB1 and the second circuit board SB2 are assembled. Then, reflow soldering can be performed to electrically connect the bonding material 120 to the connecting pad 110 and the bonding material 1222 to the connecting pad 156, while simultaneously curing the adhesive layer 130. In some embodiments, the above steps can also be selectively performed by hot pressing or ultraviolet light irradiation. After the assembly is completed, the driving element 128 can be bonded to the connecting pad 108 to complete the fabrication of the light-emitting device 100.

[0040] Please refer to Figure 6 and Figure 7 , Figure 6 and Figure 7 This is a cross-sectional schematic diagram of the sixth embodiment of the light-emitting device disclosed herein, wherein... Figure 6 The components on one side of the second circuit board SB2 are shown. For example... Figure 6As shown, the light-emitting device of the sixth embodiment may include several lamp board units UT, which are mainly composed of a second circuit board SB2 and components on its surface, as described below. The second circuit board SB2 may include a second substrate 104 and a transistor circuit layer 112 disposed on the surface of the second substrate 104. The material of the second substrate 104 may be the same as or similar to the second substrate material of the previous embodiment, and therefore will not be described again here. The transistor circuit layer 112 may include electronic components, such as transistors and wires, fabricated using thin-film transistor-level processes. A plurality of light-emitting units LEU may be disposed on the surface of the second substrate 104, which are electrically connected to the transistor circuit layer 112 via connecting pads and bonding materials. For the sake of simplicity, Figure 6 The connecting pads and bonding materials are omitted, and the same applies to subsequent figures and embodiments, so they will not be described again. The transistor circuit layer 112 can be electrically connected to a circuit board 158 disposed on another surface of the second substrate 104 via side conductors 160 located on the sidewall of the second substrate 104. The side conductors 160 may include a metallic conductive material or anisotropic conductive adhesive, and may be manufactured by side bonding or side printing processes, but are not limited thereto. The circuit board 158 may be, for example, a flexible circuit board, a non-flexible circuit board, a flip-chip thin-film circuit board, or a combination thereof, but is not limited thereto. When the circuit board 158 is a flip-chip thin-film circuit board, its surface may be provided with driving elements 128. Please also refer to... Figure 6 and Figure 7 Multiple small-sized lamp board units UT with their light-emitting units LEU facing inward are bonded to a large-sized first circuit board SB1 to create a light-emitting device 100. Figure 6 Multiple lamp board units UT are assembled by bonding one side of the light-emitting unit LEU to the first circuit board SB1. A bonding material 120' can be used to electrically connect the transistor circuit layer 112 of the second circuit board SB2 and the transistor circuit layer 154 of the first circuit board SB1 (connection pads omitted in the figure), thus creating a connection CTP between each lamp board unit UT and the first circuit board SB1. In some embodiments, the bonding material 120' may be the same as or similar to the bonding material 120 in the aforementioned embodiments, and will not be described again here. Furthermore, an adhesive layer 130 can be formed between the first circuit board SB1 and the second circuit board SB2 to fix and assemble the circuit boards. The first circuit board SB1 includes a first substrate 102 and a transistor circuit layer 154 disposed on the surface of the first substrate 102. The first substrate 102 may include materials that are the same as or similar to the first substrate material in the aforementioned embodiments, and will not be described again here. The transistor circuit layer 154 may include electronic components fabricated using thin-film transistor-level processes, such as, but not limited to, transistors and wires. Figure 7As shown, the light-emitting device 100 disclosed herein can be a large-sized electronic device ED, wherein the size of the first circuit board SB1 is substantially the same as that of the entire light-emitting device 100, while the size of the second circuit board SB1 is smaller than that of the first circuit board SB1, and it can be assembled with the first circuit board SB1 by multiple lamp board units UT arranged side by side. The light-emitting device 100 of this embodiment can be applied to various products that require large-sized light sources or display panels, such as public displays, but is not limited thereto. The following... Figures 8 to 11 The illustrated embodiments can also be applied in the same way, and will not be described in detail here.

[0041] Please refer to Figure 8 , Figure 8 This is a cross-sectional schematic diagram of the seventh embodiment of the light-emitting device disclosed herein. Figure 8 The main difference between the light-emitting device 100 shown and the sixth embodiment is that the second circuit board SB2 includes a second substrate 104' and a transistor circuit layer 112, wherein the transistor circuit layer 112 may contain micro-driving elements. The micro-driving elements may include wires, driving elements, and other electronic components. These components can be fabricated together with other thin-film transistors, wires, or other electronic components in the transistor circuit layer 112, and the transistor circuit layer 112 is formed together by a thin-film transistor-level process. Furthermore, the circuit board 162 in this embodiment can be a flexible or non-flexible circuit board. Signals / voltages can be supplied to the circuit board 162 externally (as indicated by arrow ARS), and then transmitted to the transistor circuit layer 112 via the circuit board 162 and the side wires 160.

[0042] Please refer to Figures 9 to 11 , Figures 9 to 11 This is a cross-sectional schematic diagram of the eighth embodiment of the light-emitting device disclosed herein, wherein... Figure 9 The components on one side of the second circuit board SB2 are shown in the diagram, while Figure 10 The components on one side of the first circuit board SB1 are shown. This embodiment is similar to... Figure 8 The main difference in the illustrated embodiment lies in the placement of the light-emitting unit (LEU). Please refer to... Figure 9 The diagram illustrates multiple substrate units (UTS), each UTS including a small-sized second circuit board SB2. The second circuit board SB2 includes a second substrate 104' and a transistor circuit layer 112. The transistor circuit layer 112 is electrically connected via side conductors 160 to a circuit board 162 on the other side of the second substrate 104', wherein the circuit board 162 can be a flexible or non-flexible circuit board. Please refer to... Figure 10 The first circuit board SB1 includes a first substrate 102 and a transistor circuit layer 154 disposed on the surface of the first substrate 102. A plurality of light-emitting units (LEUs) are disposed on the inner surface SB12 of the first circuit board SB1 and electrically connected to the transistor circuit layer 154. Please refer to [further details omitted]. Figure 11 ,Will Figure 9 The multiple substrate units UTS shown Figure 10 The first circuit board SB1 assembly shown is electrically connected to the second circuit board SB2 using bonding material 120', and the substrate position is fixed by adhesive layer 130 to fabricate the light-emitting device 100. Specifically, the light-emitting device 100 is fabricated by... Figure 9 The surface of the transistor circuit layer 112 is oriented towards Figure 10 Multiple light-emitting units (LEUs) are then assembled to create a light-emitting device 100.

[0043] According to this disclosure, at least the second circuit substrate is fabricated using a thin-film transistor-level process for transistor circuit layers, which simplifies the process and reduces the overall thickness of the substrate made of FR4 material in conventional devices. Furthermore, when both circuit substrates have wires or circuit layers, connections can be made between the substrates using solder or other bonding materials, reducing the need for substrate drilling and lowering process complexity and difficulty. Moreover, the second circuit substrate on the light-emitting side can provide component protection, such as preventing the light-emitting unit from being impacted by external forces, eliminating the need for an additional cover plate. On the other hand, the light-emitting device disclosed herein uses two circuit substrates, with the light-emitting unit positioned between them. When both circuit substrates include a transparent substrate, it can function as a transparent light-emitting device or a transparent display device, for example, it can be applied to glass building materials. In alternative embodiments, the surface of the light-emitting side circuit substrate can also be additionally provided with sensing elements or touch elements, providing convenience for adding other functions.

[0044] 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 light-emitting device, characterized in that, include: A first circuit board; A second circuit board; Multiple light-emitting units are disposed between the first circuit board and the second circuit board; as well as A thin-film transistor integrated circuit chip is disposed between the first circuit substrate and the second circuit substrate, wherein the thin-film transistor integrated circuit chip is electrically connected to the second circuit substrate and is used to drive the plurality of light-emitting units. The first circuit board includes a first substrate, and the second circuit board includes a second substrate. The difference in the coefficient of thermal expansion between the first substrate and the second substrate is less than or equal to 5 x 10⁻⁶. -6 .

2. The light-emitting device according to claim 1, characterized in that, The first circuit board is electrically connected to the second circuit board.

3. The light-emitting device according to claim 1, characterized in that, The multiple light-emitting units are electrically connected to the second circuit board.

4. The light-emitting device according to claim 3, characterized in that, The second circuit board includes multiple thin-film transistors for driving the multiple light-emitting units.

5. The light-emitting device according to claim 1, characterized in that, It also includes an adhesive layer that completely fills the space between the first circuit board and the second circuit board.

6. The light-emitting device according to claim 1, characterized in that, It also includes an adhesive layer that partially fills the space between the first circuit board and the second circuit board.

7. The light-emitting device according to claim 1, characterized in that, The first circuit board also includes a reflective layer, which is disposed corresponding to the plurality of light-emitting units.

8. The light-emitting device according to claim 1, characterized in that, The plurality of light-emitting units are electrically connected to the first circuit board and the second circuit board.

9. The light-emitting device according to claim 1, characterized in that, The material of the first substrate is different from the material of the second substrate.

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