A lighting device

Abstract

The application discloses a lighting device, characterized in that comprising: a lamp shell and a lamp head, the lamp shell is connected with the lamp head and forms a closed space; at least one light emitting diode filament, the light emitting diode filament is arranged in the closed space; a stem, the stem is connected to the lamp head and is in electrical conduction with the light emitting diode filament; the light emitting diode filament comprises: a chip strip structure; a light conversion unit wrapping the chip strip structure; and electrodes respectively located at both ends of the length direction of the chip strip structure and electrically connected with the chip strip structure; wherein, at least part of the electrodes is wrapped in the light conversion unit; the chip strip structure comprises a substrate, the substrate comprises a first end and a second end away from the first end, and a deposition section between the first and second ends; the deposition section comprises a plurality of deposition units, the deposition units are provided with a linking layer; and a conductor layer for electrically connecting each deposition unit.

Description

Technical Field

[0001] This application relates to the technical field of LED lighting devices, and more particularly to a lighting device. Background Technology

[0002] LED lighting has many advantages such as long lifespan, small size, and energy saving, so it is widely used in the market and is gradually replacing existing incandescent and fluorescent lamps.

[0003] As one of the earliest electric lighting devices, the tungsten filament lamp, a type of incandescent bulb, has become one of the most widely accepted forms of lighting due to its long-term and extensive use. However, due to its manufacturing process and materials, the tungsten filament lamp has low luminous efficiency, generates significant heat, and consumes a lot of energy, with an average lifespan of only 1000-3000 hours. Currently, LED lighting fixtures, also known as LED filament lamps, have emerged on the market. These lamps use LED filaments as the light-emitting element and have a shape similar to tungsten filament lamps. With their superior luminous performance, low energy consumption, long lifespan, and similar shape to tungsten filament lamps, they have been rapidly accepted by consumers and are quickly replacing tungsten filament lamps in the original lighting market.

[0004] An LED filament is a light-emitting element consisting of multiple LED chips arranged and conducting in a certain direction, and encapsulated. Common LED filaments are strip-shaped. However, in order to make the LED filament resemble a tungsten filament, it needs to be made into a thin filament with an extremely small cross-section. This shape inevitably presents challenges in terms of structural strength, especially when the LED filament is flexible and needs to be bent. The LED filament itself or its internal conductive structure is prone to breakage, resulting in the inability to conduct electricity and light up.

[0005] With the increasing prevalence of light-emitting diodes (LEDs), LED bulbs have gradually become the primary lighting option for consumers in their daily lives, compared to traditional bulbs. However, beyond their lighting function, effectively improving the applicability of LED bulbs without significantly increasing production costs is undoubtedly a crucial issue for manufacturers.

[0006] However, since LED light sources emit light in a directional manner, unlike traditional lighting fixtures which can provide wide-angle illumination, there are still technical problems that urgently need to be solved in order to apply LEDs to traditional lighting fixtures (such as tungsten bulbs), reduce damage during transportation, and improve light output, assembly efficiency, and visual effects.

[0007] In summary, given the shortcomings and defects of LED filament lamps in related technologies, how to design LED filament lamps to avoid breakage is a technical problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0008] In view of the shortcomings of the above-mentioned related technologies, the purpose of this application is to provide a lighting device, a light-emitting diode filament and a method for manufacturing the same, so as to solve the above-mentioned technical problems.

[0009] To achieve the above and other related objectives, this utility model provides a lighting device, characterized in that it includes: a lamp housing and a lamp head, the lamp housing being connected to the lamp head to form a sealed space; at least one light-emitting diode (LED) filament disposed in the sealed space; a core post connected to the lamp head and electrically connected to the LED filament; the LED filament includes: a chip strip structure; a light conversion unit enclosing the chip strip structure; and electrodes located at both ends of the chip strip structure along its length and electrically connected thereto; wherein at least a portion of the electrodes are enclosed in the light conversion unit; the chip strip structure includes a substrate, the substrate including a first end and a second end away from the first end, and a deposition section located between the first and second ends; the deposition section includes a plurality of deposition units, a connecting layer being disposed between the deposition units; and a conductor layer for electrically connecting each deposition unit.

[0010] In one embodiment of this invention, the plurality of deposition units are arranged along the length of the substrate, wherein adjacent deposition units are electrically connected through the conductor layer formed by the deposition process, so that the plurality of deposition units form a continuous strip structure on the substrate.

[0011] In one embodiment of this utility model, the electrode is a filament electrode disposed at the first end and / or the second end of the substrate, for electrically connecting to a deposition unit adjacent to the first end and / or the second end of the substrate.

[0012] In one embodiment of this utility model, the substrate is made of a transparent or opaque material.

[0013] In one embodiment of this utility model, the substrate is a sapphire substrate, a silicon substrate, a silicon carbide substrate, a glass substrate, a metal substrate, a fiberglass substrate, a PCB, or a flexible substrate.

[0014] In one embodiment of this utility model, the thickness of the substrate is 70μm-700μm.

[0015] In one embodiment of the present invention, the connecting layer formed between adjacent deposition units on the substrate enables the plurality of deposition units to form a continuous strip structure on the substrate.

[0016] In one embodiment of this invention, the ratio of the height of the connecting layer to the height of the deposition unit is 0.80-1.20.

[0017] In one embodiment of this utility model, the ratio of the first length of the connecting layer along the length direction of the substrate to the second length of each deposition unit along the length direction of the substrate is 0.05-0.30.

[0018] In one embodiment of this utility model, the first width of the connecting layer along the width direction of the substrate is equal to the second width of each deposition unit along the width direction of the substrate.

[0019] In one embodiment of this utility model, the first length of the connecting layer along the length direction of the substrate is 0.03 mm to 0.30 mm.

[0020] In one embodiment of this invention, adjacent deposition units are electrically connected to the bonding layer by a formed conductor layer covering the bonding layer.

[0021] In one embodiment of the present invention, the deposition unit includes: a first semiconductor layer formed on the substrate; a light-emitting layer formed on the first semiconductor layer; a second semiconductor layer formed on the light-emitting layer; a first electrode formed on the first semiconductor layer and spaced apart from the light-emitting layer; and a second electrode formed on the second semiconductor layer.

[0022] In one embodiment of this invention, the deposition unit adjacent to the first end and / or the second end of the substrate is electrically connected to the filament electrode of the substrate by wire bonding formed by wire bonding process.

[0023] In one embodiment of this invention, the deposition units adjacent to the first end and / or the second end of the substrate respectively form electrode extension ends through the conductor layer formed by the deposition process to electrically connect to the filament electrode.

[0024] In one embodiment of the present invention, the deposition area of ​​the electrode extension end on the substrate accounts for more than 70% of the deposition area of ​​the deposition unit adjacent to the first end and / or the second end of the substrate on the substrate.

[0025] In one embodiment of the present invention, the optical conversion unit includes a first optical conversion layer and a second optical conversion layer. The second optical conversion layer covers the chip strip structure and is located between the first optical conversion layer and the conductor layer. The first optical conversion layer wraps around the outside of the second optical conversion layer and covers at least a portion of the second optical conversion layer.

[0026] In one embodiment of this invention, the second light conversion layer includes K2SiF6∶Mn4+(KSF) red phosphor.

[0027] In one embodiment of the present invention, a coating layer is further included, which completely covers the first light conversion layer and has a different color from the first light conversion layer when the light-emitting diode filament is not working.

[0028] In one embodiment of this utility model, the conductor layer and the first and second electrodes of each deposition unit are formed by a single deposition process, and the first and second electrodes are made of the same material.

[0029] In summary, the lighting device, LED filament, and fabrication method provided in this application form a conductive layer electrically connecting multiple deposition units during the deposition process, thereby creating a continuous strip structure on the substrate. Compared to the traditional wire bonding process, which results in thicker leads and a higher risk of wire breakage or detachment, the LED filament of this application has a more stable electrical connection. Furthermore, the conductive layer formed by the deposition process in this application allows for a shorter spacing between deposition units, enabling more deposition units to be set within the same unit length, thus increasing the lumen output per unit length of the filament. Attached Figure Description

[0030] The specific features involved in this application are shown in the appended claims. The features and advantages of the utility model involved in this application can be better understood by referring to the exemplary embodiments and drawings described in detail below. A brief description of the drawings is as follows:

[0031] Figure 1a The diagram shown is a schematic representation of the arrangement of the light-emitting diode filaments in one embodiment of this application.

[0032] Figure 1b The diagram shown is a schematic representation of the arrangement of the light-emitting diode filaments in another embodiment of this application.

[0033] Figure 2 The diagram shown is a schematic representation of the arrangement of the light-emitting diode filaments in another embodiment of this application.

[0034] Figure 3 The diagram shows the arrangement of the light-emitting diode filaments in another embodiment of this application;

[0035] Figure 4 The diagram shows the arrangement of the light-emitting diode filaments in yet another embodiment of this application;

[0036] Figure 5 The diagram shown is a schematic representation of the arrangement of the light-emitting diode filaments in a further embodiment of this application;

[0037] Figure 6The diagram shown is a side view of a light-emitting diode filament structure in one embodiment of this application.

[0038] Figure 7a The diagram shown is a schematic representation of the deposition unit in one embodiment of this application.

[0039] Figure 7b This is a schematic diagram of the deposition unit in another embodiment of this application;

[0040] Figure 8 This is a schematic diagram showing a bonding layer formed between adjacent deposition units of a substrate in one embodiment of this application;

[0041] Figure 9 The diagram shown is a side view of a light-emitting diode filament structure in another embodiment of this application.

[0042] Figure 10 Displayed as Figure 8 The enlarged schematic diagram shown at point A in the middle;

[0043] Figure 11a The diagram shown is a schematic diagram of the formation of a conductor layer and electrodes in one embodiment of this application;

[0044] Figure 11b This is a schematic diagram illustrating the formation of a conductor layer and electrodes in another embodiment of this application;

[0045] Figure 12 The diagram shown is a side view of the light-emitting diode filament structure in yet another embodiment of this application.

[0046] Figure 13 Displayed as Figure 12 Schematic diagram of the BB section;

[0047] Figure 14 The diagram shown is a schematic representation of a light-emitting diode filament package in one embodiment of this application.

[0048] Figure 15a The diagram shown is a schematic diagram of a deposition unit electrically connected to a filament electrode via leads in one embodiment of this application;

[0049] Figure 15b This is a schematic diagram showing the deposition unit electrically connected to the filament electrode via leads in another embodiment of this application;

[0050] Figure 16 The diagram shown is a schematic diagram of the connection between the filament electrode and the electrode extension end in one embodiment of this application;

[0051] Figure 17 The diagram shown is a side view of a chip strip structure having a second light conversion layer formed on it in one embodiment of this application.

[0052] Figure 18 The diagram shown is a side view of a chip strip structure in another embodiment of this application, in which a second light conversion layer is formed on the chip strip structure.

[0053] Figure 19 The diagram shown is a side view of a chip strip structure in another embodiment of this application, in which a second light conversion layer is formed on the chip strip structure.

[0054] Figure 20 The diagram shown is a side view of a light-emitting diode filament having a covering layer in one embodiment of this application.

[0055] Figure 21a The diagram shows a heat dissipation path with different particle sizes of the filling material particles in one embodiment of this application.

[0056] Figure 21b This is a schematic diagram showing a heat dissipation path with the same particle size of the filling material particles in another embodiment of this application;

[0057] Figure 21c shows a schematic diagram of the heat dissipation path in the chip strip of this application;

[0058] Figure 22 The diagram shows a schematic representation of the cladding structure of a light-emitting diode filament according to some embodiments of this application.

[0059] Figure 23 The diagram shows a side view of a chip strip structure having a second light conversion layer and a coating layer formed on it in one embodiment.

[0060] Figure 24 The diagram shows a side view of a chip strip structure in another embodiment, in which a second light conversion layer and a coating layer are formed on the chip strip structure.

[0061] Figure 25 The image shown is a side view of a filament in one embodiment of this application, in which an ITO thin film or layer is used as a conductive layer.

[0062] Figure 26 The image shown is a side view of a filament in another embodiment of this application, in which an ITO thin film or layer is used as a conductive layer.

[0063] Figure 27 The diagram shown is a structural schematic of the lighting device of this application in one embodiment;

[0064] Figure 28a The diagram shown is a structural schematic of the lighting device of this application in another embodiment;

[0065] Figure 28b The diagram shown is a structural schematic of the lighting device of this application in another embodiment;

[0066] Figure 29The flowchart shown is a preparation method of this application in one embodiment;

[0067] Figure 30 The flowchart shown is a preparation method of this application in another embodiment;

[0068] Figure 31 The image shown is a side view of a light-emitting diode filament according to yet another embodiment of this application.

[0069] Reference numerals: 100, LED filament; 101, chip strip structure; 110, substrate; 110a, first end; 110b, second end; 110c, deposition section; 120, first row; 121, deposition unit; S1, first semiconductor layer; S2, second semiconductor layer; E1, first electrode; E2, second electrode; LE, light-emitting layer; P1, first length; P2, second length; 122, connecting layer; 123, conductor layer; 130, filament electrode; 140, light conversion unit; 141 1411 First light conversion layer; 1412 Top layer; 1413 Base layer; 142 Second light conversion layer; 150D Electrode connection layer; 150W Lead wire (conductor); 160 Coating layer; 1601 Filler particles; 1062 Largest particle size; 1063 Medium particle size; 1064 Smallest particle size; 200 Lighting device; 210 Lamp housing; 300 Lighting device; 310 Lamp housing; 320 Core column; 330 Lamp holder; 340 Conductive support; 220 Second row group; Detailed Implementation

[0070] The following specific embodiments illustrate the implementation of this application. Those skilled in the art can easily understand other advantages and effects of this application / disclosure from the content disclosed in this specification. The following descriptions of various embodiments of this application presented herein are for illustrative and exemplary purposes only and are not intended to be exclusive or limited to the exact forms disclosed. These exemplary embodiments are merely examples, and many implementations and variations are possible without requiring the details provided herein. It should also be emphasized that this disclosure provides details of alternative examples, but these alternative arrangements are not exclusive. Moreover, any consistency of details between various examples should be understood as necessary, since it is impractical to arrange every possible variation for every feature described herein.

[0071] In the accompanying drawings, the dimensions and relative dimensions of the components may be enlarged for clarity. Throughout the drawings, the same reference numerals refer to the same components.

[0072] The technical terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the scope of this application. In the terminology used herein, the singular forms “a” or “an” are intended to include the plural forms as well, unless the context clearly indicates otherwise. In the terminology used herein, the terms “and / or” and “and / or” include any one or more of the associated listed terms and all combinations thereof, and may be abbreviated as “ / ”.

[0073] It should be understood that although the terms first, second, third, etc., may be used herein to describe various components, elements, regions, layers, or steps, these components, elements, regions, layers, and / or steps should not be limited by these terms. Unless the context otherwise indicates, these terms are used only to distinguish one component, element, region, layer, or step from another, for example, as a naming convention. Therefore, without departing from the teachings of this application, a first component, element, region, layer, or step discussed in one section of the specification below may be named a second component, element, region, layer, or step in another section of the specification or in the claims. Furthermore, in some cases, even if descriptive terms such as "first" or "second" are not used in the specification, the term may still be referred to as "first" or "second" in the claims to distinguish the different components described from one another.

[0074] It should also be understood that when the terms “comprising” or “including” are used in the specification, these terms enumerate the presence of the described features, areas, integers, steps, operations, components and / or elements, but do not exclude the presence or addition of one or more other features, areas, integers, steps, operations, components and / or elements.

[0075] It should be understood that when a component is referred to as "connected" or "coupled" to another component or to another component, the component may be directly connected or coupled to the other component or to another component, or there may be an intermediate component. Conversely, when a component is referred to as "directly connected" or "directly coupled" to another component, there is no intermediate component. Other terms used to describe relationships between components should be interpreted in a similar manner (e.g., "between" vs. "directly between," "adjacent" vs. "directly adjacent," etc.). However, the term "contact" as used herein refers to direct contact (i.e., touching), unless the context otherwise indicates. "Electrically connected" as used in this application refers to a connection in an electrical sense that enables the conduction and transmission of electrical signals.

[0076] The embodiments described herein will be described with reference to ideal schematic diagrams, plan views, and / or sectional views. Therefore, exemplary views may be modified depending on manufacturing techniques and / or tolerances. Consequently, the disclosed embodiments are not limited to those shown in the views, but include variations of configurations formed based on manufacturing processes. Therefore, the areas illustrated in the figures may be schematic in nature, and the shapes of the areas shown in the figures may exemplify the shapes of areas of components, but aspects of this application are not limited thereto.

[0077] This document uses spatial relative terms such as “below,” “under,” “down,” “above,” “up,” etc., to describe the relationship between one component or feature shown in the accompanying figures and another component or feature. However, it should be understood that, in addition to the orientations depicted in the accompanying figures, spatial relative terms are intended to cover different orientations of the device in use or operation. For example, if the device in the figures is flipped, then a component or feature described as “below” or “under” other components or features will be oriented “above” other components or features. Therefore, the term “below” can cover both above and below orientations. The device may be oriented in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein should be interpreted accordingly.

[0078] The terms “identical,” “equal,” “planar,” or “coplanar” used in this document when referring to orientation, layout, location, shape, size, quantity, or other measures do not necessarily mean exactly identical orientation, layout, location, shape, size, quantity, or other measures, but are intended to cover substantially identical orientation, layout, location, shape, size, quantity, or other measures within an acceptable range of variation, for example, that may be caused by manufacturing processes. The term “substantially” may be used in this document to reflect this meaning.

[0079] Terms such as “about” or “approximately” can reflect changes in size, orientation, or layout that are only relatively small and / or do not significantly alter the operation, function, or structure of certain components. For example, a range from “about 0.1 to about 1” can cover, for example, deviations of 0% to 5% near 0.1 and deviations of 0% to 5% near 1, especially if such deviations have the same effect as the listed ranges.

[0080] Unless otherwise defined, all terms used herein (including technical and scientific terms) have the same meaning as commonly understood by one of ordinary skill in the art described in this disclosure. It should also be understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning consistent with their meaning in the relevant field and / or the context of this application, and should not be interpreted in an idealized or overly formal sense unless expressly defined herein.

[0081] To enable LED filaments to be used in lighting devices such as bulbs and achieve 360° omnidirectional illumination, flexible LED filaments are required. Current flexible LED filament structures employ either conventional chip packaging or flip-chip packaging. Conventional chip packaging filaments are prone to wire bonding detachment or breakage during the production and transportation of lighting devices; while flip-chip packaging is more expensive, has a thicker overall filament, and a more complex packaging process. Furthermore, current chips are typically connected by wire bonding, requiring a large gap between LED chips. The wire bonding process also necessitates the placement of pads at corresponding positions on the chips, which not only hinders chip light emission but also limits the lumen output per unit length of the filament. Moreover, the wire bonding process inevitably results in curved wires, leading to a larger overall filament thickness. Therefore, this application provides a lighting device, a light-emitting diode filament and a method for manufacturing the same, in order to solve the problems that the metal wire bonding of the filament in the standard chip package is prone to fall off or break during the production and transportation of the lighting device, the luminous value that the filament can provide per unit length is limited, and the overall thickness of the filament is relatively thick.

[0082] The first aspect of this application provides a light-emitting diode filament, comprising: a chip strip structure; a light conversion unit enclosing the chip strip structure; and electrodes located at both ends of the chip strip structure along its length and electrically connected thereto; wherein at least a portion of the electrodes is enclosing the light conversion unit.

[0083] In one embodiment, the chip strip structure includes: a substrate; a plurality of deposition units formed on a deposition section of the substrate; a connecting layer located on the substrate and disposed between the plurality of deposition units; and a conductor layer for electrically connecting each deposition unit. Adjacent deposition units on the substrate are electrically connected via the conductor layer, thereby shortening the spacing between the light-emitting diodes (LEDs) fabricated from the deposition units. This allows for a greater number of deposition units to be disposed per unit length of the LED filament, thereby increasing the lumen value per unit length of the LED filament. In some embodiments, the LED filament can be configured in LED lighting devices of different shapes, specifications, or power levels, such as bulbs, tube lights, panel lights, flat panel lights, pendant lights, recessed lights, recessed lights, and ceiling lights. In the embodiments described below, the application of the LED filament to a tube light is used as an example, but it should be understood that this is not a limitation. In subsequent embodiments, the LED filament may also be referred to as an LED filament.

[0084] In some embodiments, a light-emitting diode (LED) filament is provided, wherein adjacent deposition units are electrically connected by a conductor layer, thereby shortening the spacing between LEDs and allowing for more deposition units to be disposed per unit length of the LED filament, thus increasing the lumen output per unit length of the LED filament. This disclosure also provides another type of LED filament. In this filament, the LEDs extend uninterruptedly from one end of the substrate to the other, meaning that the vast majority of the substrate surface is covered by LEDs, allowing the LED filament to have a larger light-emitting area.

[0085] In some embodiments, the plurality of deposition units deposited on the substrate are arranged in rows or columns, for example, in one embodiment, the plurality of deposition units on the substrate are arranged in a row, and the plurality of deposition units are electrically connected in series through the conductor layer. Please refer to Figure 1a The figure shows a schematic diagram of the arrangement of the light-emitting diode filament in one embodiment of the present application. As shown, in the light-emitting diode filament 100, a plurality of deposition units 121 on the substrate 110 encapsulated by the first light conversion layer 141 are arranged in a row. Adjacent deposition units 121 are electrically connected through a conductor layer 123, which is disposed between or above adjacent deposition units 121. The first end and the second end of the substrate 110 are respectively provided with filament electrodes 130 (it can be said that the filament electrodes 130 are formed at the end of the substrate 110). The deposition units 121 on both sides are electrically connected through an electrode connection layer 150D (i.e., the electrode extension 150D in the following embodiment). The first light conversion layer 141 covers at least a portion of the substrate 110, the deposition units 121, and the conductor layer 123, while the conductor layer 123 covers at least a portion of the deposition units 121, or the uppermost portion.

[0086] In this application, the conductor layer may also be referred to as the conductive layer, which refers to a conductor that enables electrical signal conduction / transmission between two deposition units and between the deposition unit and the filament electrode.

[0087] To improve the current density between deposition units in a light-emitting diode (LED) filament, in one embodiment, the current density can be reduced by shaping the deposition units and the conductive layer, while simultaneously improving luminous flux and enhancing the overall heat dissipation performance of the filament within a desired range. Please refer to [link / reference]. Figure 1bThe figure shows a schematic diagram of the arrangement of the light-emitting diode filament in another embodiment of the present application. As shown, a plurality of deposition units 121 on the substrate 110 encapsulated by the first light conversion layer 141 in the light-emitting diode filament 100 are arranged in a row along the length direction of the substrate 110. Adjacent deposition units 121 are electrically connected through a conductor layer 123. Filament electrodes 130 are respectively provided at the first end and the second end of the substrate 110, which are electrically connected to the deposition units 121 on the adjacent sides through electrode extensions 150D. In this embodiment, the projection shape of each deposition unit 121 on the substrate 110 is approximately rectangular. Its two opposite short sides (or width sides) are parallel to the length direction of the substrate 110, while its other two opposite long sides (or length sides) are perpendicular to the length direction of the substrate 110. The electrodes (N-electrode and P-electrode) of the deposition unit 121 are formed on the long sides of the deposition unit 121. Correspondingly, the conductor layer 123 is formed between adjacent deposition units 121 and is electrically connected to the electrodes (N-electrode or P-electrode) on the long sides of the two deposition units 121, respectively, thus providing a wider conductive path. Figure 1b As shown, the conductor layer 123 between the deposition units 121 has a larger cross-sectional area along the radial direction of the filament (or along the width direction of the substrate) or a wider conductive path / channel, thereby reducing the current density flowing through the conductor layer 123, reducing the heat generation of the LED filament, and meeting the heat dissipation requirements of the LED filament to a certain extent.

[0088] In another embodiment, the plurality of deposition units are arranged in multiple rows to increase the lumen output per unit length of the filament. For example, when the LED filament comprises two LED arrays, the lumen output per unit length of the filament is twice that of a single LED array. In an embodiment with two rows, for instance, the plurality of deposition units includes a first row and a second row parallel to the first row. In some cases, the first row may also be referred to as a first LED array, and the second row may also be referred to as a second LED array.

[0089] In one example of this embodiment, the first and second rows of the plurality of deposition units are connected in series through the conductor layer. For example, the first and second rows are connected in series at one end of the substrate through an electrical connection of the conductor layer, so that the two rows are distributed in a U-shape on the substrate; please refer to Figure 2The figure shows a schematic diagram of the arrangement of the light-emitting diode filament in another embodiment of the present application. As shown, in the light-emitting diode filament 100, multiple deposition units 121 on the substrate 110 encapsulated by the first light conversion layer 141 are arranged in two rows. Adjacent deposition units 121 are electrically connected through a conductor layer 123. The first row group located in the upper part of the figure and the second row group located in the lower part of the figure are connected in series through the electrical connection of the conductor layer 123. The first row group 120 and the second row group 220 are arranged in a transverse U-shaped distribution (or an inverted C-shaped distribution) on the substrate 110. Two filament electrodes 130 are arranged on the same side of the substrate 110 to electrically connect the deposition units 121 in the first row group 120 and the second row group 220 respectively through the electrode connection layer 150D.

[0090] Please see Figure 3 The figure shows a schematic diagram of the arrangement of the light-emitting diode filament in another embodiment of this application. As shown in the figure, in this light-emitting diode filament, in Figure 3 In the illustrated embodiment, to ensure uniform heat distribution during operation of the LED filament 100, the deposition units 121 in the first row 120 and the second row 220 on the substrate 110 encapsulated by the first light conversion layer 141 are staggered along the length of the substrate 110. This allows for uniform heat dissipation of the filament and provides more design space for the filament width. In this embodiment, the first row 120 and the second row 220 are arranged in a transverse U-shape on the substrate 110. Adjacent deposition units 121 are electrically connected through a conductor layer 123. Two filament electrodes 130 are disposed on the same side of the substrate 110 and are electrically connected to the deposition units 121 in the first row 120 and the second row 220 respectively through an electrode connection layer 150D.

[0091] In another example of this embodiment, the first and second rows of multiple deposition units are connected in parallel via a conductor layer. For instance, the first and second rows are electrically connected at both ends of the substrate via conductor layers to achieve parallel connection, and can share a filament electrode at both ends. Please refer to [link to relevant documentation]. Figure 4 The figure shows a schematic diagram of the arrangement of the light-emitting diode filament in another embodiment of the present application. As shown in the figure, in the light-emitting diode filament 100, multiple deposition units 121 on the substrate 110 encapsulated by the first light conversion layer 141 are arranged in two rows. Adjacent deposition units 121 are electrically connected through a conductor layer 123. The first row group 120 located in the upper part of the figure and the second row group 220 located in the lower part of the figure are connected in parallel through an electrode connection layer 150D. The first row group 120 and the second row group 220 are electrically connected to independent filament electrodes 130 at the first end and the second end of the substrate 110, respectively, through the electrode connection layer 150D.

[0092] In yet another example of this embodiment, please refer to Figure 5 The figure shows a schematic diagram of the arrangement of the light-emitting diode filament in another embodiment of the present application. As shown, in the light-emitting diode filament 100, multiple deposition units 121 on the substrate 110 encapsulated by the first light conversion layer 141 are arranged in two rows. Adjacent deposition units 121 are electrically connected through a conductor layer 123. The first row group 120 located in the upper part of the figure and the second row group 220 located in the lower part of the figure are connected in series through the conductor layer 123. The first row group 120 and the second row group 220 are each connected to the electrode connection layer 150D. The electrode connection layer 150D is connected to the filament electrode 130 to achieve electrical conduction. That is, the first row group 120 and the second row group 220 share the same filament electrode 130 at the same end of the substrate 110 through their respective electrode connection layers 150D.

[0093] To facilitate the explanation of the utility model concept of this application, the following embodiments will be described using an example of multiple deposition units arranged in a row or a single column on the substrate.

[0094] In some embodiments, a filament having a single-row array of light-emitting diodes can achieve a lumen value per unit length of 2-10 Lm / mm, and further 4.5-8.5 Lm / mm, under standard operating voltage and current.

[0095] In some embodiments, a filament having a single-row array of light-emitting diodes can have 0.5-2.5 chips per unit length, i.e., 0.5-2.5 chips / mm, under standard operating voltage and current.

[0096] In some embodiments, a filament having a single-row array of light-emitting diodes has a chip count of 0.5-2.5 chips per unit area, i.e., 0.5-2.5 chips / mm, under standard operating voltage and current. 2 .

[0097] In some embodiments, a filament having a single-row array of light-emitting diodes has a lumen output of 2-10 lm / mm² per unit area under standard operating voltage and current. 2 Furthermore, it is 2.5-8Lm / mm. 2 .

[0098] It should be understood that, based on the above embodiments Figures from 2 to 5 Inspired by the revealed ideas, those skilled in the art can configure more rows on the same substrate to prepare the required filaments according to actual needs. For example, in an embodiment where the light-emitting diode array is a filament set in multiple columns, the above numbers are multiplied by the corresponding multiples.

[0099] In the following embodiments, the example of multiple deposition units arranged in a row or a single column on the substrate is still described, and this is hereby stated.

[0100] Please see Figure 6 The figure shows a side view of a light-emitting diode filament structure according to one embodiment of the present application. As shown, the light-emitting diode filament 100 includes: a chip strip structure 101, a light conversion unit 140 enclosing the chip strip structure 101, and electrodes 130 located at both ends of the chip strip structure 101 along its length and electrically connected thereto; at least a portion of the electrodes 130 are enclosed in the light conversion unit 140. In one embodiment, the light conversion unit 140 includes a first light conversion layer 141.

[0101] The chip strip structure 101 includes a substrate 110, a plurality of deposition units 121 formed on the substrate 110, and a bonding layer 122 located on the substrate 110 and disposed between the plurality of deposition units 121. The bonding layer 122 is disposed between adjacent deposition units 121, electrically isolating adjacent deposition units 121. The bonding layer 122 prevents short circuits caused by mutual contact between deposition units 121, and fills the blank areas between adjacent deposition units 121, improving heat dissipation performance and avoiding unnecessary light loss. It also includes a conductor layer 123 for electrically connecting each deposition unit 121. The deposition units 121 are arranged along the length direction of the substrate 110. The LED filament provided in this application differs from existing LED filament structures, which use individual independent LED filament chip units and then electrically connect these individual LED filament chips through wire bonding or flip-chip technology. This application, however, forms multiple deposition units 121 on a single substrate 110, further reducing the manufacturing process at the back end of the filament.

[0102] The substrate 110 includes a first end 110a, a second end 110b, and a deposition section 110c located between the first end 110a and the second end 110b. In one embodiment, the first end 110a or the second end 110b of the substrate 110 refers to the two end faces of the substrate 110 in the length direction, and the deposition section 110c is the body of the substrate 110. In this embodiment, the deposition section 110c is generally used to represent the area on the upper surface of the substrate 110 where semiconductor material is to be deposited.

[0103] In some embodiments, the substrate 110 is made of a high light transmittance material, for example, with a light transmittance of 50% or more, preferably between 60% and 95%. The light transmittance of the substrate 110 is, for example, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, or 95%.

[0104] In some embodiments, the material of the substrate 110 may include sapphire (Al2O3) substrate, silicon (Si) substrate, silicon carbide (SiC) substrate, GaN or composite substrate, glass substrate, metal substrate, fiberglass substrate, or PCB, but is not limited thereto. In this embodiment, the substrate 110 will be described as a sapphire substrate, which is transparent or substantially transparent, for example, a sapphire substrate with a light transmittance of about 85%, which allows photons generated from the light-emitting layer to pass through.

[0105] In some embodiments, the thickness of the substrate 110 is controlled between 0.25-0.45 mm, more specifically between 0.07-0.7 mm, and even more specifically between 0.01-1.0 mm. In one embodiment, the thickness of the sapphire substrate is controlled between 0.07-0.7 mm, i.e., between 70 μm and 700 μm.

[0106] In some embodiments, the length of the substrate 110 is 80-200mm, for example, approximately 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, or 200mm.

[0107] In some embodiments, the sapphire substrate used for depositing the plurality of deposition units 121 may be processed by thinning and / or texturing, roughening or patterning.

[0108] In another embodiment, the substrate 110 can also be a flexible substrate, also known as a flexible substrate. For example, in one example, the flexible substrate is an FPC substrate, which allows the filament to have a certain degree of bending. The flexible filament made using the FPC substrate can be bent to achieve more filament curves or shapes. For example, in another example, the flexible substrate is a flexible PCB board, which can be made of transparent or translucent material. The flexible PCB board is made by printing circuits on a polyimide or polyester film substrate.

[0109] In another embodiment of this application, the light-emitting diode filament 100 includes a substrate 110, a chip strip structure 101, and a filament electrode 130. The chip strip structure 101 is disposed on the substrate 110. In this embodiment of the application, the chip strip structure 101 is disposed on a single (or the same) substrate 110. The chip strip structure 101 includes a plurality of deposition units 121, a bonding layer 122, and a conductor layer 123. The plurality of deposition units 121 are disposed along the length direction of the substrate 110. In some embodiments, the deposition units 121 are implemented as conductive deposition units, such as metal deposition units, and the deposition units 121 have photoelectric conversion capabilities, that is, they can be implemented to have light-emitting functions. In some embodiments, the bonding layer 122 is implemented as an electrical bonding layer to achieve electrical isolation functions, and can also be called an electrical isolation layer or a dielectric layer. The bonding layer 122 is disposed between adjacent deposition units 121, electrically isolating adjacent deposition units 121. The connecting layer 122 avoids short circuits caused by contact between deposition units 121, and fills the blank area between adjacent deposition units 121. This improves heat dissipation performance and avoids unnecessary light loss. When light from adjacent deposition units 121 enters the blank area, some of it will be absorbed or some will not be reflected, thus causing light loss.

[0110] In this application, the plurality of deposition units 121 are directly deposited on a substrate, such as sapphire. The sapphire substrate 110 serves as the main substrate and there is no need to provide a main substrate of any other suitable material, such as silicon, ceramic, metal or any other suitable material.

[0111] In this application, the term "deposition" refers to a deposition process used in semiconductor fabrication processes, such as LED fabrication processes, including but not limited to the growth process of LED epitaxial wafers. Specifically, on a substrate heated to an appropriate temperature (e.g., sapphire, SiC, Si, etc.), a target gaseous material is controlled to be transported to the substrate surface to grow a specific single-crystal thin film, such as Metal-Organic Chemical Vapor Deposition (MOCVD), and other processes such as electron beam evaporation, sputtering deposition, physical vapor deposition, or some sputtering deposition processes, as well as masking and etching processes or photolithography processes.

[0112] In this application, the term "deposition unit" may also be referred to as a deposition layer, deposition layer unit, or deposition layer module in some embodiments or implementations, or as a conductive deposition layer, such as a metal deposition layer. The deposition unit 121 has photoelectric conversion capability, that is, it can be implemented to have light-emitting function. Therefore, in some embodiments, the multiple deposition units 121 combined with the substrate 110 can be collectively referred to as LED unit, LED chip, or LED chip unit. Furthermore, the LED chip unit may also be referred to as LED segment, which can be a single LED chip, two LED chips, or of course, it can contain multiple LED chips, that is, equal to or greater than three LED chips, etc.

[0113] The plurality of deposition units 121 are formed in the deposition section 110c of the substrate 110 and arranged along the length direction of the substrate 110. In the deposition section 110c of the substrate 110, each pair of adjacent deposition units 121 are electrically connected by a conductor layer 123 formed by the deposition process, so that the plurality of deposition units 121 form a continuous strip structure on the substrate 110. In this application, the deposition unit 121 has photoelectric conversion capability, that is, it can be implemented to have light-emitting function. In one embodiment, the deposition unit 121 is fabricated as a relatively independent LED light emitter or light-emitting unit.

[0114] In some embodiments, the number of multiple deposition units 121 formed in the deposition segment 110c of the substrate 110 is 50, and the voltage at both ends is 130V-135V.

[0115] In other embodiments, the number of multiple deposition units 121 formed in the deposition segment 110c of the substrate 110 is 100, and the voltage at both ends is 260V-265V.

[0116] In some embodiments, the specifications of each deposition unit 121 formed in the deposition segment 110c of the substrate 110 include 9 mil × 18 mil, 11 mil × 30 mil, or 13 mil × 30 mil, or combinations thereof.

[0117] Since the deposition units 121 forming the light-emitting diodes extend uninterruptedly from one end of the substrate 110 to the other, the entire filament emits light through a complete array of light-emitting diodes. Since most of the surface area of ​​the substrate 110 is covered by the deposition units 121, the deposition units 121 can maintain a large light-emitting area.

[0118] In some embodiments, the light-emitting area of ​​the deposition unit 121 can be understood as the top area of ​​the deposition unit 121 minus the portion of the deposition unit 121 covered by the conductor layer 123, its first electrode, and its second electrode, and the length and width of the conductor layer 123, the first electrode, and the second electrode can be adjusted as needed. For example, the proportion of the light-emitting area of ​​the deposition unit 121 to the top area of ​​the deposition unit 121 is greater than 94% and less than 100%, such as approximately 95%, 96%, 97%, 98%, or 99%. Since the deposition units 121 are connected by the conductor layer 123, rather than by wire bonding formed by wire bonding, it is not necessary to provide a pad structure for wire bonding on the deposition unit 121, so the deposition unit 121 can maintain a large light-emitting area.

[0119] In some embodiments, the ratio of the total area occupied by the plurality of deposition units 121 formed in the deposition segment 110c of the substrate 110 to the area of ​​the upper surface of the deposition segment 110c of the substrate 110 is 0.94-0.99, for example 94%, 95%, 96%, 97%, 98% or 99%.

[0120] In some embodiments, the conductor layer 123, the first electrode, and the second electrode can all be made of a light-transmitting material, meaning that the light emitted by the deposition unit 121 is unobstructed. In some embodiments, the light-emitting area of ​​the top surface of the deposition unit 121 accounts for more than 94% and less than 100% of the top area of ​​the deposition unit 121.

[0121] In some embodiments, deposition units can be configured on the light-emitting diode filament using the parameter relationships shown in Table 1 below, where the light-emitting diode filament is referred to as "filament" and the deposition unit as "chip"; as shown in Table 1 below:

[0122] Number of chips Length of filament (mm) Width of filament (mm) Length of chip (mil) Width of chip (mil) Voltage (V) Current (mA) Luminous flux (Im) 24 26 1.5 16 6 128-135 10 185 24 38 1.5 14 6 64-68 15 145 24 39 3.0 18 9 64-68 20 233 24 53 1.5 15 7 64-68 20 218 24 53 3.0 25 10 64-68 25 290 24 68 1.5 15 7 64-68 20 220 38 68 3.0 28 12 100-108 25 410 38 68 8.0 30 10 100-108 25 450 76×2 88 8.0 30 10 205-210 25 700 76×3 115 8.0 30 10 205-210 25 900

[0123] Please see Figure 7a The figure shows a schematic diagram of the structure of a deposition unit in one embodiment of the present application. As shown in the figure, each of the plurality of deposition units 121 includes: a first semiconductor layer S1, a first electrode E1, a second semiconductor layer S2, a second electrode E2, and a light-emitting layer LE formed between the first semiconductor layer S1 and the second semiconductor layer S2.

[0124] like Figure 7aAs shown, the first semiconductor layer S1 of the deposition unit 121 is formed on the substrate 110; the light-emitting layer LE is formed on the first semiconductor layer S1, and the second semiconductor layer S2 is formed on the light-emitting layer LE; the first electrode E1 is formed on the first semiconductor layer S1 and is spaced apart from the light-emitting layer LE; the second electrode E2 is formed on the second semiconductor layer S2; wherein, when electrical energy is applied between the second electrode E2 and the first electrode E1, the light-emitting layer LE formed between the first semiconductor layer S1 and the second semiconductor layer S2 generates photons.

[0125] A deposition unit 121, comprising a first semiconductor layer S1, a first electrode E1, a second semiconductor layer S2, a second electrode E2, and a light-emitting layer LE formed between the first semiconductor layer S1 and the second semiconductor layer S2, is considered a light-emitting diode (LED) unit. Its light-emitting principle involves applying a forward voltage to the two electrodes and a forward current to the PN junction of the semiconductor. When the forward current passes through the PN junction, charge carriers (electrons and holes) move. Holes in the P-type region move to the N-type region, and electrons in the N-type region (composed of N-type semiconductor material) move to the P-type region (composed of P-type semiconductor material). During this process, the injected charge carriers recombine, and the energy difference before and after recombination is released in the form of light.

[0126] In one embodiment, the first electrode E1 and the second electrode E2 of the deposition unit 121 are disposed on the side away from the substrate 110. Specifically, the first electrode E1 of one deposition unit 121 is connected to the second electrode E2 of another deposition unit 121 through the conductor layer 123 to achieve electrical connection. The light-emitting diode of the deposition unit 121 provided in this application does not have a chip package substrate or base, but is directly formed on the substrate 110 by the deposition process, thereby reducing the overall thickness of the light-emitting diode filament 100.

[0127] In this application, the first semiconductor layer S1 and the second semiconductor layer S2 have different conductivity types. For example, in one embodiment, the first semiconductor layer S1 is made of an N-type semiconductor material, and correspondingly, the second semiconductor layer S2 is made of a P-type semiconductor material. For example, the first semiconductor layer S1 is N-type doped gallium nitride (N-GaN), and correspondingly, the second semiconductor layer S2 is P-type doped gallium nitride (P-GaN), and the light-emitting layer LE is made of indium gallium nitride (InGaN).

[0128] like Figure 7aAs shown, the deposition unit 121 includes a light-emitting or active region sandwiched between an N-type semiconductor material and a P-type semiconductor material, namely the aforementioned light-emitting layer LE. In the fabrication process of the light-emitting diode filament 100, the N-type semiconductor material can first be grown on a sapphire substrate 110. The N-type semiconductor material can include multiple layers with different compositions and dopant concentrations, such as preparation layers like buffer layers or nucleation layers, and / or layers designed to facilitate the removal of the growth substrate, which can be N-type or unintentionally doped, and N-type device layers designed to obtain specific optical, material, or electrical properties desired for efficient light emission of the light-emitting region.

[0129] A light-emitting or active region is grown on an N-type semiconductor material to form a light-emitting layer (LE). Examples of suitable LEs include a single, thick or thin LE, or a multi-quantum-well LE comprising multiple thin or thick LEs separated by a barrier layer. A P-type semiconductor material can then be grown on the LE, similar to an N-type semiconductor material. The P-type semiconductor material can comprise multiple layers with different compositions, thicknesses, and dopant concentrations, including unintentionally doped layers.

[0130] After the growth of the first semiconductor layer S1 and the second semiconductor layer S2, a portion of the second semiconductor layer S2 and the light-emitting layer LE are removed using a masking and etching process or a photolithography process to expose a portion of the first semiconductor layer S1. Then, a first electrode E1 is formed on the exposed surface of the N-type semiconductor material, and a second electrode E2 is formed on the surface of the retained P-type semiconductor material. In one embodiment, the first electrode E1 can be referred to as the N-electrode, and the second electrode E2 can be referred to as the P-electrode. In this embodiment, the N-electrode and P-electrode between adjacent deposition units 121 are electrically isolated from each other by a gap, which can be filled with a dielectric such as silicon oxide or any other suitable material. The N-electrode and P-electrode between adjacent deposition units 121 are electrically connected by a conductor layer 123. The gap can be filled with a dielectric material or a different solid material, or it can be left unfilled and isolated by air.

[0131] In one embodiment, the first electrode E1, which is an N-electrode, or the second electrode E2, which is a P-electrode, may include one or more conductive layers, such as a reflective metal and a protective metal, which can prevent or reduce electromigration of the reflective metal. The reflective metal is typically silver, but any one or more suitable materials can be used.

[0132] During the fabrication of the N electrode, multiple N electrode vias can also be formed; the N electrode and P electrode are not limited to... Figure 7a The arrangement is shown in the diagram. The N and P electrodes can be redistributed to form bonding pads with dielectric / metal stacks.

[0133] In the above embodiments, the first electrode E1, which is an N electrode, or the second electrode E2, which is a P electrode, can be, for example, gold, copper, an alloy, or any other suitable material formed by plating or any other suitable technique.

[0134] In one embodiment, the first electrode E1, which is an N-type electrode, or the second electrode E2, which is a P-type electrode, is formed by electron beam vacuum evaporation deposition to form the first electrode E1 on the exposed surface of the N-type semiconductor material and the second electrode E2 on the retained surface of the P-type semiconductor material, respectively.

[0135] In one embodiment, the first electrode E1, which is an N-type electrode, or the second electrode E2, which is a P-type electrode, is prepared by a sputtering deposition process to form the first electrode E1 on the exposed surface of the N-type semiconductor material and the second electrode E2 on the surface of the retained P-type semiconductor material, respectively. In this embodiment, the sputtering deposition process is, for example, ion beam sputtering or cathode sputtering.

[0136] In some embodiments, the N-electrode or P-electrode may include a transparent electrode that is conductive and transparent to light. (See also...) Figure 7b The figure shows a schematic diagram of the deposition unit in another embodiment of this application. As shown, in this embodiment, the transparent electrode can be an indium tin oxide (ITO) thin film or layer of tin-doped indium oxide (i.e., Figure 7b (ITO as shown in the figure); In embodiments using an ITO thin film or layer as an electrode contact layer, the ITO thin film or layer is most typically deposited onto the surface using electron beam evaporation, physical vapor deposition, or some sputtering deposition techniques.

[0137] In some embodiments, since the ITO film or ITO layer cannot be used as a pad, in the specific fabrication process, ohmic electrodes (also known as electrode contacts or ohmic contacts) are first formed on the surfaces of the first and second semiconductor materials. Then, an ITO film or layer is deposited on the surface of the ohmic electrodes, and then a metal pad is deposited on the surface of the ITO film or layer to form a P-electrode or N-electrode. In this way, the current flowing through the deposition unit 121 is uniformly distributed to each ohmic contact electrode through the ITO film or layer. At the same time, since the refractive index of the ITO film or layer is between that of air and the deposition material, the light emission angle and luminous flux can be improved.

[0138] In some embodiments, a conductor layer 123 for connecting two deposition units 121 can be directly deposited on an ITO thin film or layer. In a specific fabrication process, ohmic electrodes (also known as electrode contacts or ohmic contacts) are first formed on the surfaces of the first and second semiconductor materials. Then, an ITO thin film or layer is deposited on the surface of the ohmic electrodes. The conductor layer 123 for connecting two adjacent deposition units 121 is then deposited on the surface of the ITO thin film or layer. This can further reduce the overall thickness of the filament, and the current of the deposition unit 121 is evenly distributed to each ohmic contact electrode through the ITO thin film or layer. At the same time, since the refractive index of the ITO thin film or layer is between that of air and the deposition material, the refractive indices of the deposition material, the ITO thin film, and the air change sequentially (e.g., increasing or decreasing), thereby improving the light emission angle and luminous flux.

[0139] Please see again Figure 6 ,exist Figure 6 In the illustrated embodiment, a connecting layer 122 is formed between adjacent deposition units 121 on the substrate 110 so that the plurality of deposition units 121 form a continuous strip structure on the substrate 110. The "continuous strip structure" means that there are no gaps or obvious steps or segments in the physical structure between the plurality of deposition units deposited on the substrate, so that the fabricated light-emitting diode filament 100 presents a chip strip structure as a whole, thereby strengthening the overall structure of the chip strip and ensuring that the electrical connection between the deposition units will not be broken due to "broken wires".

[0140] Please see Figure 8 The image shows a schematic diagram of a bonding layer formed between adjacent deposition units of a substrate in one embodiment of this application. Figure 6 and Figure 8 In the embodiment shown, not only is a connecting layer 122 formed between adjacent deposition units 121 on the substrate 110, but a connecting layer 122 is also provided on the outside of the deposition unit 121 near the first end 110a of the substrate 110 to form a protective layer, so as to isolate the electrode connection layer 150D from the contact between the first semiconductor layer S1, the light-emitting layer LE and the second semiconductor S2 of the deposition unit 121.

[0141] In one embodiment, the ratio of the height of the connecting layer 122 to the height of the deposition unit 121 is 0.80-1.20. In other words, in order to make the fabricated LED filament 100 present a chip strip structure as a whole, the height of the connecting layer 122 prepared by the deposition process is almost similar to or the same as the height of the deposition unit 121 during the fabrication of the LED filament 100, so that there is no gap or obvious height difference between the multiple deposition units 121 in terms of physical structure. Specifically, the ratio of the height of the connecting layer 122 to the height of the deposition unit 121 is 0.80, 0.90, 1.00, 1.10, or 1.20, etc.

[0142] To ensure that the fabricated LED filament 100 provides a higher lumen output or better heat dissipation efficiency per unit length, in one embodiment of this application, the spacing between adjacent deposition units 121 is controlled to maximize the number of deposition units 121. (See also...) Figure 9 The image shown is a side view of a light-emitting diode filament structure in another embodiment of this application, as illustrated below. Figure 9 In the illustrated embodiment, the ratio of the first length of the bonding layer 122 along the length direction of the substrate 110 to the second length of each deposition unit 121 along the length direction of the substrate 110 is 0.05-0.30, which can also be expressed as 0.05P2≤P1≤0.3P2. When the ratio of the first length P1 to the second length P2 is within the above range, the LED filament 100 can maintain better heat dissipation efficiency and light-emitting area.

[0143] Specifically, when the second length P2 of the deposition unit 121 along the length direction of the substrate 110 is 1 unit length, the first length P1 of the bonding layer 122 along the length direction of the substrate 110 is 0.05-0.30 unit lengths. The unit length of the first length P1 of the bonding layer 122 along the length direction of the substrate 110 can be, for example, 0.05, 0.06, 0.07, 0.08, 0.09, 0.10, 0.11, 0.12, 0.13, 0.14, 0.15, 0.16, 0.17, 0.18, 0.19, 0.20, 0.21, 0.22, 0.23, 0.24, 0.25, 0.26, 0.27, 0.28, 0.29, or 0.30, etc.

[0144] For example, corresponding to the parameters listed in Table 1 above, due to the different lengths of the light-emitting diode filaments and the different numbers of deposition units (LED chips), the value of the second length P2 of the deposition unit 121 along the length direction of the substrate 110 can be 14 mil, 15 mil, 16 mil, 18 mil, 25 mil, 28 mil, or 30 mil, etc., or it can be said to be in the range of 5 mil to 40 mil, or in the range of 0.1 mm to 1 mm; then the value of the connecting layer 122 can be set with reference to the relationship of 0.05P2≤P1≤0.3P2 to prepare the corresponding length.

[0145] In one embodiment, the first length P1 of the connecting layer 122 along the length direction of the substrate 110 is 0.03 mm to 0.30 mm, and the first length is, for example, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.10 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.20 mm, 0.21 mm, 0.22 mm, 0.23 mm, 0.24 mm, 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, or 0.30 mm. When the first length is within the above range, more deposition units 121 can be set within a unit length of the LED filament 100, thereby increasing the lumen value that can be provided within a unit length of the filament.

[0146] To ensure that the fabricated LED filament 100 exhibits a chip-strip structure, during the fabrication of the LED filament 100, the width of the bonding layer 122, prepared by a deposition process, is approximately the same as or identical to the width of the deposition unit 121. In one embodiment, the first width of the bonding layer 122 along the width direction of the substrate 110 is equal to the second width of each deposition unit 121 along the width direction of the substrate 110. Please refer to [link / reference]. Figure 10 Displayed as Figure 8The enlarged schematic diagram shown at point A illustrates that the first width P3 of the connecting layer 122 along the width direction of the substrate 110 is almost equal to the second width P4 of the deposition unit 121 along the width direction of the substrate 110, thus making the fabricated LED filament 100 present an overall chip strip structure. For example, corresponding to the parameters listed in Table 1 above, due to the different lengths of the fabricated LED filaments and the different numbers of deposition units (LED chips), the value of the second width P4 of the deposition unit 121 along the width direction of the substrate 110 can be 6 mil, 7 mil, 9 mil, 10 mil, or 12 mil, etc., or it can be said to be in the range of 1 mil to 20 mil, or it can also be in the range of 0.05 mm to 1 mm; then the first width P3 of the connecting layer 122 along the width direction of the substrate 110 can be fabricated according to the value of the second width P4 to obtain the connecting layer 122.

[0147] In one embodiment, adjacent deposition units 121 are electrically connected to each other on both sides of the connecting layer 122 by a formed conductive layer 123 covering the connecting layer 122. In this embodiment, the conductive layer 123 is located on the upper surface of the connecting layer 122, so that the conductive layer 123 between two adjacent deposition units 121 can be attached to the connecting layer 122.

[0148] In another embodiment, adjacent deposition units 121 are electrically connected to the deposition units 121 on both sides of the connecting layer 122 through a formed conductor layer 123. In this embodiment, both the upper and lower surfaces of the conductor layer 123 are in contact with the connecting layer 122. In the fabrication process, the connecting layer 122 can be formed between adjacent deposition units 121 first through a deposition process, and then the conductor layer 123 can be formed on the connecting layer 122 through a deposition process to electrically connect the adjacent deposition units 121 on both sides. After that, the connecting layer 122 can be covered on the conductor layer 123 through a deposition process to embed the conductor layer 123 therein, thereby strengthening the electrical connection between adjacent deposition units 121 and making the fabricated light-emitting diode filament 100 present a chip strip structure with more stable consistency.

[0149] In one embodiment, the conductor layer 123 electrically connecting two adjacent deposition units 121 has a more stable connection structure. When fabricating the connecting layer 122, it can be made to support or carry the conductor layer 123, allowing the conductor layer 123 between the two adjacent deposition units 121 to adhere to the connecting layer 122. For example... Figure 6 In the embodiment shown, the conductor layer 123 may be attached to the connecting layer 122 and electrically connected to the deposition units 121 on both sides.

[0150] In one embodiment, the bonding layer 122 is an electrically insulating material, such as an insulating material or a high-resistivity material. In some embodiments, the insulating material includes oxides, nitrides, oxynitrides, carbides, such as silicon oxide, silicon nitride, titanium oxide, or combinations thereof, but is not limited thereto.

[0151] In some embodiments, the connecting layer 122 can also be a protective layer, implemented as an electrical protective layer in these embodiments to achieve electrical isolation between adjacent deposition units 121. It can also be called an electrical isolation layer or a dielectric layer. The protective layer is disposed between adjacent deposition layers to electrically isolate adjacent deposition units 121 to prevent short circuits caused by contact between adjacent deposition units 121.

[0152] In one embodiment, the connecting layer 122 is a thermally conductive material. In this embodiment, the material of the connecting layer 122 includes, for example, glass, which has better heat dissipation performance than the deposition unit 121. It fills the blank area between adjacent deposition units 121. Since the connecting layer 122 is in contact with the conductor layer 123, it provides a faster heat dissipation path for the deposition unit 121. For example, the heat generated by the deposition unit 121 can be dissipated from above through the conductor layer 123, or it can be dissipated to the side through the connecting layer 122 and the conductor layer 123. In other words, the connecting layer 122 and the conductor layer 123 provide higher heat dissipation efficiency, thereby improving the overall heat dissipation performance of the LED filament 100.

[0153] When photons generated by adjacent deposition units 121 enter the area between them, some of them are absorbed or some are not reflected, resulting in light loss. Therefore, in one embodiment, the connecting layer 122 can be a light-transmitting or light-reflecting material. In this embodiment, the material of the connecting layer 122 includes materials with reflective or light-transmitting properties, such as glass, thereby avoiding unnecessary light loss and improving the light-emitting performance of the LED filament 100.

[0154] In this application, adjacent deposition units 121 on the substrate 110 of the LED filament 100 are electrically connected via a conductor layer 123. In one embodiment, one end of the conductor layer 123 formed by the deposition process is electrically connected to the first electrode E1 of one side of the deposition unit 121, and the other end is connected to the second electrode E2 of the other side of the deposition unit 121, thereby realizing the series connection between adjacent deposition units 121. For example... Figure 8As shown in the diagram; in this application, because the conductor layer 123 is formed by a deposition process, the thickness is thinner compared to the thicker lead layer formed by the traditional wire bonding process (the wires in wire bonding need to maintain an arc segment, resulting in a thicker overall thickness). This reduces the overall thickness of the LED filament 100. Furthermore, the conductor layer 123 formed by the deposition process avoids the problem of wire bonding detachment or breakage. Simultaneously, the plurality of deposition units 121 are electrically isolated only by a connecting layer 122, which is also formed by a deposition process. The plurality of deposition units 121 form an integrated structure with the connecting layer 122 as the electrical isolation layer, allowing for a greater number of deposition units 121 per unit length of the LED filament 100, thereby increasing the lumen output per unit length of the LED filament 100.

[0155] In one embodiment, the length of the LED filament 100 (i.e., the substrate length) is 83 mm. The deposition units 121 are connected by a conductor layer 123. The thickness of the bonding layer 122 between the deposition units 121 along the filament length is controlled between 0.02 mm and 0.3 mm. The number of deposition units 121 can be 100. In a comparative example, the length of the LED filament 100 is also 83 mm. The deposition units 121 are connected by wire bonding. The spacing between the deposition units 121 needs to be set between 0.3 mm and 1 mm, so the number of deposition units 121 is 50. Therefore, the number of deposition units 121 per unit length of the LED filament 100 in the above embodiment is twice that of the comparative example, thus providing nearly twice the lumen output. Similarly, with the same number of deposition units 121, the length of the LED filament 100 in this embodiment can be shortened to nearly half that of the comparative example, requiring only 0.5 times the length of the wire bonding method.

[0156] In one embodiment, the material of the conductor layer 123 includes, but is not limited to, conductive materials such as copper, gold, silver, and alloys.

[0157] In one embodiment of the fabrication of the conductor layer 123, the conductor layer 123 and the first electrode E1 and second electrode E2 of each deposition unit 121 are formed in a single deposition process. In this embodiment, for example, the first electrode E1 (N-type electrode) or the second electrode E2 (P-type electrode) can be formed by electron beam vacuum evaporation or sputtering to deposit the first electrode E1 on the exposed surface of the N-type semiconductor material and the second electrode E2 on the retained surface of the P-type semiconductor material. Simultaneously, the conductor layer 123 can be fabricated by electron beam vacuum evaporation or sputtering, allowing each section of the conductor layer 123 to directly integrate with the electrodes of the deposition units 121 on both sides. This not only strengthens the electrical connection between the deposition units 121 but also results in a more stable and consistent chip-strip structure for the fabricated LED filament 100. Please refer to [link to relevant documentation]. Figure 11a The figure shows a schematic diagram of the formation of a conductor layer and electrodes in one embodiment of the present application. As shown, the conductor layer 123 and the first electrode E1 and the second electrode E2 of each deposition unit 121 are formed by a single deposition process. The three are integrally formed and therefore do not have obvious dividing lines in structure.

[0158] In one embodiment of the fabrication of the conductor layer 123, the conductor layer 123 and the first electrode E1 and second electrode E2 of each deposition unit 121 are formed using the same material through a deposition process. The conductor layer 123, the first electrode E1, and the second electrode E2 can be formed simultaneously through the deposition process. For example... Figure 11a The illustrated embodiment. This deposition process may include, for example, chemical vapor deposition, atomic layer deposition, and physical vapor deposition, but is not limited thereto.

[0159] For example Figure 11a In the embodiment shown, the conductor layer 123 and the first electrode E1 and second electrode E2 of each deposition unit 121 are made of the same material and formed by deposition process. The first electrode E1 and second electrode E2 of each deposition unit 121 can be made using an ITO thin film or ITO layer, and the conductor layer 123 and the electrode extension 150D formed by the conductor layer can also be made at the same time. The ITO thin film or layer is most typically deposited on the surface by electron beam evaporation, physical vapor deposition, or some sputtering deposition techniques.

[0160] In another embodiment of the fabrication of the conductor layer 123, the conductor layer 123 and the first electrode E1 and second electrode E2 of each deposition unit 121 are formed using different materials through a deposition process, and the conductor layer 123, the first electrode E1 and the second electrode E2 are formed in separate steps by different deposition processes. The deposition process may include, for example, chemical vapor deposition, atomic layer deposition, and physical vapor deposition, but is not limited thereto.

[0161] Please see Figure 11b The figure shows a schematic diagram of the formation of a conductor layer and electrodes in another embodiment of this application. As shown, the second electrode E2 of the deposition unit 121 located at the first end 110a of the substrate 110 is electrically connected to the electrode extension end 150D of the second electrode E2, and the first electrode E1 of the deposition unit 121 located at the second end 110b of the substrate 110 is electrically connected to the electrode extension end 150D of the first electrode E1. They are made of the same material or using the same deposition process, such as copper, gold, silver, alloy, etc., so as to better achieve electrical connection with the filament electrode 130 of the first end 110a and the second end 110b of the substrate 110. The conductor layer 123 between adjacent deposition units 121 in the substrate 110 is made of a different material or another identical process. In this embodiment, the conductor layer 123 between adjacent deposition units 121 is made of, for example, an ITO thin film or an ITO layer.

[0162] As in the above embodiments, adjacent deposition units 121 on the substrate 110 are electrically connected by the conductor layer 123, which allows the spacing between the light-emitting diodes fabricated by the deposition units 121 to be shortened. This enables more deposition units 121 to be disposed per unit length of the light-emitting diode filament 100 to improve the lumen value per unit length of the light-emitting diode filament 100. Therefore, in one embodiment, the length of the conductor layer 123 formed by the deposition process between adjacent deposition units 121 along the length direction of the substrate 110 can be configured to be 0.03 mm to 0.30 mm. In some embodiments, the length may be, for example, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.20mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, or 0.30mm, etc.

[0163] In one embodiment, the third width of the conductor layer 123 along the width direction of the substrate 110 is smaller than the second width of the deposition unit 121 along the width direction of the substrate 110, thereby reducing the obstruction of light emitted by the deposition unit 121 by the conductor layer 123, for example... Figure 8The state shown. For example, in some specific examples, the third width of the conductor layer 123 along the width direction of the substrate 110 is 0.5mm-10.0mm, and the third width can be, for example, approximately 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm, 6.5mm, 7.0mm, 7.5mm, or 8.0mm, etc.

[0164] As Figure 8 , Figure 9 ,or Figure 11a In another embodiment of the illustrated embodiment for fabricating the conductor layer 123, when fabricating the conductor layer 123 formed between adjacent deposition units 121 by a deposition process, electrode extension ends 150D are respectively obtained by forming the conductor layer 123 in the deposition units 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110 through the same deposition process, so as to achieve electrical connection with the filament electrodes at both ends of the substrate 110. That is, in this embodiment, the conductor layer 123 formed between adjacent deposition units 121 and the electrode extension ends 150D of the deposition units 121 adjacent to both ends of the substrate 110 are obtained in a single fabrication process. In some embodiments, the electrode extension ends 150D and the conductor layer 123 obtained by the single fabrication process are made of the same material; the material of the electrode extension ends 150D includes conductive materials, such as copper, gold, silver, alloys, etc., but is not limited thereto.

[0165] In one embodiment, the conductive layer 123 formed between deposition units 121, the conductive layer 123 formed by deposition units 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110, the first electrode E1, and the second electrode E2 are made of the same material. The conductive layer 123, the first electrode E1, and the second electrode E2 can be formed simultaneously by a deposition process. This deposition process includes chemical vapor deposition, atomic layer deposition, and physical vapor deposition, but is not limited to these.

[0166] In some embodiments, the conductor layer 123 formed between adjacent deposition units 121 by the deposition process can also be referred to as the first conductor layer, and the conductor layer 123 formed by the deposition process in the deposition unit 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110 can also be referred to as the second conductor layer, which is the electrode extension end 150D.

[0167] The filament electrode 130 is disposed at the first end 110a and / or the second end 110b of the substrate 110, and is electrically connected to the deposition unit 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110. For example, in Figure 1a and Figure 1b, Figure 4 , Figure 5 , Figure 6 , Figure 8 , Figure 9 , Figure 11a and Figure 11b In the illustrated embodiment, the filament electrode 130 is disposed at the first end 110a and the second end 110b of the substrate 110; Figure 2 and Figure 3 In the illustrated embodiment, the filament electrode 130 is disposed at the same end of the substrate 110.

[0168] In one embodiment, the filament electrode 130 can be disposed on the first end 110a and / or the second end 110b of the substrate 110 via the encapsulation structure of the light-emitting diode filament 100. This encapsulation structure is, for example, a light conversion layer for encapsulating the entire filament strip. In this embodiment, the encapsulation structure is, for example, a first light conversion layer; in some cases, this encapsulation structure is also referred to as an encapsulating layer.

[0169] In another embodiment, the filament electrode 130 may be configured as a conductive ring or conductive sleeve; see [link to relevant documentation]. Figure 12 The figure shows a side view of the light-emitting diode filament structure in another embodiment of this application. As shown, conductive rings are provided on the first end 110a and the second end 110b of the substrate 110 as filament electrodes 130. Taking the first end 110a of the substrate 110 as an example, the conductive ring of the filament electrode 130 is sleeved on the first end 110a of the substrate 110, and the first end 110a of the substrate 110 and the electrode extension end 150D formed on the first end 110a of the substrate 110 are electrically connected. This ensures that the electrode extension end 150D and the filament electrode 130 have a larger contact area. Figure 13 As shown, Figure 13 Displayed as Figure 12 The schematic diagram of the cross section of BB is shown in the figure. The conductive ring of the filament electrode 130 is wrapped around the first end 110a of the substrate 110 and the electrode extension end 150D thereon. This ensures that the electrode extension end 150D and the filament electrode 130 have a larger contact area, which is beneficial for the filament electrode 130 to achieve electrical connection with peripheral components such as conductive brackets or drive circuits.

[0170] For example, the structure of the conductive ring or conductive sleeve is prepared by a metal sheet so that it can be wound or fitted around both ends of the substrate 110 to act as a filament electrode 130 when electrically connected to the deposition unit 121 of the first end 110a or / and the second end 110b of the substrate 110. In specific implementations, the metal sheet is, for example, a copper sheet or an aluminum sheet or other metal sheets with conductive properties.

[0171] In another embodiment where the filament electrode 130 employs a conductive ring or conductive sleeve, the encapsulation structure for packaging the light-emitting diode 100 may not completely encapsulate the substrate 110 within it. Please refer to [link to previous document]. Figure 14 The figure shows a schematic diagram of a packaging form of a light-emitting diode filament in one embodiment of the present application. As shown in the figure, the packaging structure (i.e., 140 in the figure, i.e., the first light conversion layer 141 described later) completely encapsulates the multiple deposition units 121 and conductor layer 123 formed on the substrate 110. The first end 110a and the second end 110b of the substrate 110, as well as a portion of the electrode extension end 150D on the first end 110a and the second end 110b of the substrate 110, are not wrapped by the packaging structure. The conductive rings provided on the first end 110a and the second end 110b of the substrate 110 as part of the filament electrode 130 are also not wrapped by the packaging structure.

[0172] In one embodiment, the filament electrode 130 is electrically connected to a conductive support to receive power from a drive circuit. The connection between the filament electrode 130 and the conductive support can be a mechanical clamping connection or a welding connection. The mechanical connection involves first passing the conductive support through a specific perforation formed in the filament electrode 130, then folding back the free end of the conductive support to clamp the electrode and form an electrical connection. The welding connection can be achieved by using silver-based alloy solder, silver solder, tin solder, or other methods to connect the conductive support to the filament electrode 130.

[0173] In one embodiment, the deposition units adjacent to the first end and / or the second end of the substrate are electrically connected to the filament electrode of the substrate via wire bonding formed by a wire bonding process. (See also...) Figure 15a The figure shows a schematic diagram of a deposition unit electrically connected to a filament electrode via a lead wire in one embodiment of this application. As shown, in this embodiment, the filament electrode 130 is electrically connected to the electrodes of the deposition unit 121 at both ends of the substrate 110 via a lead wire 150W formed by a wire bonding process. At the first end 110a of the substrate 110, one end of the lead wire 150W is electrically connected to the second electrode E2 of the deposition unit 121, and the other end is connected to the filament electrode 130 at the first end 110a of the substrate 110. At the second end 110b of the substrate 110, one end of the lead wire 150W is electrically connected to the first electrode E1 of the deposition unit 121, and the other end is connected to the filament electrode 130 at the second end 110b of the substrate 110. In some embodiments, the lead wire 150W may also be referred to as a wire.

[0174] Please see Figure 15bThe figure shows a schematic diagram of a deposition unit electrically connected to a filament electrode via a lead wire in another embodiment of this application. As shown, in this embodiment, the second electrode E2 of the deposition unit 121 located at the first end 110a of the substrate 110 and the first electrode E1 of the deposition unit 121 located at the second end 110b of the substrate 110 are made of the same material or using the same deposition process, such as copper, gold, silver, alloy, etc., so that they can be better electrically connected to the filament electrodes 130 at the first end 110a and the second end 110b of the substrate 110 via the lead wire 150W. The conductor layer 123 between adjacent deposition units 121 in the substrate 110 is made of a different material or using a different same process. In this embodiment, the conductor layer 123 between adjacent deposition units 121 is made of, for example, an ITO thin film or an ITO layer.

[0175] In another embodiment, the filament electrode 130 may be configured as a metal sheet disposed at a first end 110a and / or a second end 110b of the substrate 110. In specific implementations, the metal sheet may be, for example, a copper sheet or an aluminum sheet, or other metal sheets with conductive properties. Figure 6 , Figure 8 , Figure 9 , Figure 11a and Figure 11b The structure is characterized in the illustrated embodiment. Electrode extensions 150D are formed in the conductive layer 123 of the deposition unit 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110, respectively, to electrically connect to the filament electrode 130. In this embodiment, when the conductive layer 123 formed between adjacent deposition units 121 is prepared by the deposition process, electrode extensions 150D are also obtained in the conductive layer 123 formed in the deposition unit 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110, respectively, so as to achieve electrical connection with the filament electrodes 130 at both ends of the substrate 110. That is, in this embodiment, the conductive layer 123 formed between adjacent deposition units 121 and the electrode extensions 150D of the deposition unit 121 adjacent to both ends of the substrate 110 are obtained in a single fabrication process.

[0176] To ensure sufficient electrical contact between the filament electrode 130 and the deposition unit 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110 without causing an open circuit, or to facilitate the arrangement of the filament electrode 130 on both sides of the substrate 110, the deposition area of ​​the electrode extension 150D can be controlled by the deposition process during the fabrication of the electrode extension 150D. For example, in some embodiments, the deposition area of ​​the electrode extension 150D on the substrate 110 accounts for more than 70% of the deposition area of ​​the deposition unit 121 adjacent to the first end 110a and / or the second end 110b of the substrate 110. For example, the deposition area of ​​the electrode extension 150D on the substrate 110 accounts for approximately 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the deposition area of ​​the deposition unit 121 adjacent to the end side of the substrate 110.

[0177] In one embodiment, the electrode extension 150D is electrically connected to the filament electrode 130 by welding or hot-melt process.

[0178] In another embodiment, the electrode extension 150D is formed on the upper surface of the first end 110a and / or the second end 110b of the substrate 110 so that its upper surface is electrically connected to the filament electrode 130. For example, after the conductor layer 123 is prepared, the prepared filament electrode 130 is placed on the upper side of the electrode extension 150D formed by the conductor layers 123 at both ends of the substrate 110, and the filament electrode 130 is fixed on the upper side of the electrode extension 150D by welding or hot-melt process or directly by sealing process so that the two are electrically connected. The electrode connection layer 150D and the filament electrode 130 at least partially overlap in the filament thickness direction, that is, the filament electrode 130 at least covers the electrode connection layer 150D at the end of the substrate 110, that is, the electrode connection layer 150D is located between the substrate 110 and the filament electrode 130. Figure 11b The state shown.

[0179] In some embodiments, the electrode connection layer 150D at least partially overlaps with the filament electrode 130 in the filament thickness direction, that is, the electrode connection layer 150D at least covers a portion of the filament electrode 130, and the filament electrode 130 is located between the electrode connection layer 150D and the substrate 110. Figure 16 As shown.

[0180] The electrode bonding layer 150D and the filament electrode 130 do not overlap in the filament thickness direction, for example... Figure 1a As shown in the top view.

[0181] In another embodiment, all or part of the electrode extension is disposed between the substrate and the filament electrode 130 to electrically connect the filament electrode. See also... Figure 16The diagram shows a connection between the filament electrode and the electrode extension end in one embodiment of this application. Figure 16 In the illustrated embodiment, to ensure the stability of the connection between the filament electrode 130 and the electrode extension end 150D, a portion of the filament electrode 130 can be configured between the electrode extension end 150D and the substrate 110. That is, the filament electrode 130 is configured through a stacked structure consisting of the electrode extension end 150D, the filament electrode 130, and the substrate 110. For example, in the process, after the deposition unit 121 is prepared by the deposition process, the two filament electrodes 130 are respectively placed at both ends of the substrate 110, specifically on the upper surface of the substrate 110. Then, the conductor layer 123 is prepared by the deposition process, so that the electrode extension ends 150D formed at both ends of the substrate 110 are directly deposited on the upper side of the filament electrode 130 to electrically connect the filament electrode 130. Then, the encapsulation process is used to complete the encapsulation of the entire filament.

[0182] The light-emitting diode filament 100 further includes a first light conversion layer 141, which covers the substrate 110, a plurality of deposition units 121 and a conductor layer 123 formed on the substrate 110, and a portion of the filament electrode 130. A portion of the filament electrode 130 not covered by the first light conversion layer 141 is exposed for electrical connection to a conductive bracket, lamp holder, lamp base, or external power supply device to receive power from the driving circuit. In this application, the first light conversion layer 141 may also be referred to as a "light conversion layer" or "light conversion coating." In certain embodiments, the light conversion coating may also be referred to as a silicone layer. The first light conversion layer 141 includes materials capable of absorbing light emitted by the light-emitting layer LE, such as materials that absorb blue light and emit yellow or green light from the light-emitting layer LE. For example, phosphors disposed in the first light conversion layer 141 can absorb certain radiation (such as light), so that when the filament electrode 130 is connected to a power source (voltage source or current source), it can emit the desired light.

[0183] In one embodiment, the first light conversion layer 141 includes particles / materials distributed therein. In this embodiment, the first light conversion layer 141 includes a plurality of solid particles, which include phosphor particles, nano-particles for heat dissipation, color-developing particles, or combinations thereof. In specific implementations, the particles / particles / materials distributed in the first light conversion layer 141 can be selectively added. These particles / particles / materials are, for example, modifiers (thermosetting agents), light-reflecting / light-diffusing particles, light-guiding particles, coupling agents (one or more of these can be added in the top and bottom layers), defoamers, leveling agents, or adhesives. The heat dissipation particles (also referred to as inorganic oxide nanoparticles) include, but are not limited to, alumina, silica, magnesium oxide, magnesium carbonate, aluminum nitride, boron nitride, or diamond. The light-guiding particles are, for example, particles of varying sizes made of polymethyl methacrylate (PMMA) or resin, but are not limited thereto. In other embodiments, the particles included in the conductor layer 123 may also have excellent plastic deformation properties, such as particles made of plastic, which can improve the bendability of the conductor layer 123, for example, in embodiments where the substrate 110 is a flexible substrate, it can enhance the support of the filament when bending.

[0184] In some embodiments, the first light conversion layer 141 further comprises silicone, silicone-modified resin (or silicone-modified polyimide), heat-dissipating particles, or combinations thereof, but is not limited thereto. In some embodiments, the nanoparticles are made of alumina, silicon dioxide, titanium dioxide, but are not limited thereto. Notably, the nanoparticles can improve the heat dissipation efficiency of the LED filament 100, and at the same time, the nanoparticles have a light scattering effect, reducing the graininess of the light emitted from the filament. In some embodiments, the solid particles are in contact with each other, forming a faster heat dissipation path.

[0185] In one embodiment, the phosphor is, for example, a phosphor adhesive / phosphor film, comprising the following components: adhesive, phosphor, and inorganic oxide nanoparticles. The adhesive may be, but is not limited to, silicone. In one embodiment, the adhesive may contain 10% wt or less of the aforementioned organosilicon-modified polyimide to increase the overall hardness, insulation, thermal stability, and mechanical strength of the filament. The solid content of the organosilicon-modified polyimide may be 5-40% wt, and the rotational viscosity may be 5-20 Pa·s. The inorganic oxide nanoparticles may be, but are not limited to, alumina or aluminum nitride particles, with a particle size of 100-600 nanometers or 0.1 to 100 micrometers. Their function is to promote heat dissipation of the filament, and the incorporated inorganic heat-dissipating particles may have various particle sizes.

[0186] In one embodiment, the organosilicon-modified polyimide can be replaced by the organosilicon-modified polyimide resin composition described above. The inorganic oxide nanoparticles can be, but are not limited to, alumina or aluminum nitride particles, and the particle size can be 100-600 nanometers or 0.1-100 micrometers. Their function is to promote heat dissipation of the filament, and the incorporated inorganic heat dissipation particles can have various particle sizes.

[0187] In one embodiment, the first light conversion layer 141 can be formed by a composition comprising silicone-modified polyimide. In addition to satisfying the above-mentioned characteristics, the composition can also adjust the characteristics of the filament substrate or light conversion layer by adjusting the type and content of the main materials, modifiers, and additives in specific or partial compositions to meet specific environmental requirements.

[0188] In another embodiment, the first light conversion layer 141 may be formed by a silicone-modified polyimide resin composition comprising the aforementioned silicone-modified polyimide and a thermosetting agent, wherein the thermosetting agent is an epoxy resin, isocyanate, or bisoxazoline compound. In one embodiment, the amount of thermosetting agent is 5-12% of the weight of the silicone-modified polyimide, for example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, or 12%, etc., based on the weight of the silicone-modified polyimide; furthermore, the silicone-modified polyimide resin composition may further include heat dissipation particles and phosphors.

[0189] Different heat dissipation particles have different light transmittance. If heat dissipation particles with low light transmittance or low light reflectance are used, the light transmittance of the silicone-modified polyimide resin composition will decrease. The heat dissipation particles in the aforementioned silicone-modified polyimide resin composition are preferably transparent powders, or particles with high light transmittance, or particles with high light reflectance, because the filament in this application is mainly used for light emission; therefore, the filament substrate needs to have good light transmittance. Furthermore, when mixing two or more types of heat dissipation particles, a combination of particles with high light transmittance and particles with low light transmittance can be used, with the proportion of high-transmittance particles being greater than that of low-transmittance particles. For example, in one embodiment, the weight ratio of high-transmittance particles to low-transmittance particles is 3-5:1.

[0190] Factors affecting the thermal conductivity of silicone-modified polyimide resin compositions include at least the type and content of phosphor, the type and content of heat-dissipating particles, and the addition and type of coupling agent. Among these, the particle size and particle size distribution of the heat-dissipating particles also affect the thermal conductivity. In some embodiments, to achieve superior mechanical properties, thermal conductivity, and low warpage in the substrate, the phosphor contained in the silicone-modified polyimide resin composition is granular. The phosphor can be spherical, plate-like, or needle-like, preferably spherical; the maximum average length of the phosphor (average particle size in spherical form) is 0.1 μm or more, preferably 1 μm or more, more preferably 1-100 μm, and more preferably 1-50 μm; the amount of phosphor used is not less than 0.0% of the weight of the silicone-modified polyimide. The ratio is 5 times, preferably not less than 0.1 times and not more than 8 times, preferably not more than 7 times. For example, if the weight of the organosilicon-modified polyimide is 100 parts by weight, the content of phosphor is not less than 5 parts by weight, preferably not less than 10 parts by weight and not more than 800 parts by weight, preferably not more than 700 parts by weight. When the content of phosphor in the organosilicon-modified polyimide resin composition exceeds 800 parts by weight, the mechanical properties of the organosilicon-modified polyimide resin composition may not reach the strength required as a filament base layer, resulting in an increase in the product defect rate.

[0191] In one embodiment, when two phosphors are added simultaneously, such as red phosphor and green phosphor, the addition ratio of red phosphor to green phosphor is 1:5~8, preferably 1:6-7.

[0192] In another embodiment, when two phosphors are added simultaneously, such as red and yellow phosphors, the ratio of red to yellow phosphors is 1:5 to 8, preferably 1:6 to 7. In other embodiments, three or more phosphors may be added simultaneously.

[0193] In one embodiment, a high content of heat-dissipating particles (such as SiO2 or Al2O3) with high light transmittance or high reflectance can be added. In addition to maintaining the light transmittance of the silicone-modified polyimide resin composition, it can also improve the heat dissipation of the silicone-modified polyimide resin composition.

[0194] In one embodiment, the particle size of the heat dissipation particles suitable for addition to the silicone-modified polyimide resin composition can be broadly classified into small particle size (less than 1 μm), medium particle size (1-30 μm), and large particle size (greater than 30 μm).

[0195] In other specific embodiments of this application, to further improve the properties of the silicone-modified polyimide resin composition during the synthesis process, additives such as defoamers, leveling agents, or adhesives can be selectively added during the synthesis process, as long as they do not affect the product's optical rotation resistance, mechanical strength, heat resistance, and color change. Defoamers are used to eliminate bubbles generated during printing, coating, and curing; for example, acrylic or silicone surfactants can be used as defoamers. Leveling agents are used to eliminate unevenness on the coating surface generated during printing and coating. Specifically, it is preferable to contain 0.01-2 wt% surfactant components, which can suppress bubbles and make the coating smooth by using leveling agents such as acrylic or silicone agents; nonionic surfactants without ionic impurities are preferred. Examples of adhesives include imidazole compounds, thiazole compounds, triazole compounds, organoaluminum compounds, organotitanium compounds, and silane coupling agents. Preferably, the amount of these additives is no more than 10% of the weight of the silicone-modified polyimide. When the amount of additives exceeds 10 wt%, the physical properties of the resulting coating tend to decrease, and there is also the problem of deterioration in light resistance caused by volatile components.

[0196] In some embodiments of this application, defoamer may not be provided. Instead, bubbles generated during printing, coating and curing may be used as optical cavities. This is because bubbles are widely distributed in the filament structure during the forming process. The irregular shape of the bubbles can achieve effects such as focusing or diffusing light. For example, using bubbles as optical cavities can achieve directional light emission. Using bubbles as optical cavities can also achieve light diffusion, improve light emission uniformity and reduce graininess.

[0197] In some embodiments, in the conversion layer covering the substrate 110, the particles in the region corresponding to the deposition unit 121 and the region corresponding to the electrode extension end 150D, or the region corresponding to the conductor layer 123 between the deposition units 121, may have different structures, materials, effects, or distribution densities. This is because the deposition unit 121 and the conductor layer 123 perform different functions. Therefore, the first light conversion layer 141 of the deposition unit 121 and the conductor layer 123 may be provided with different types of particles to achieve different effects. For example, the particles distributed in the deposition unit 121 of the light-emitting diode filament 100 and the particles distributed in the conductor layer 123 have different sizes, materials, and / or densities.

[0198] For example, in one embodiment, the first light conversion layer 141 corresponding to the deposition unit 121 in the LED filament 100 may include phosphor, while the first light conversion layer 141 corresponding to the conductor layer 123 includes light-guiding particles. The phosphor can absorb the light emitted by the deposition unit 121 and convert the wavelength of the light to lower or raise the color temperature. At the same time, the phosphor also has the effect of light diffusion. Therefore, setting phosphor in the first light conversion layer 141 of the deposition unit 121 helps to change the color temperature of the light and also makes the light more uniformly dispersed. The conductor layer 123 does not have deposition units 121, and the conductor layer 123 is the main bending part of the filament (for example, when the filament needs to be bent and shaped). Therefore, light-guiding particles are set in the first light conversion layer 141 of the conductor layer 123. The light-guiding particles have the effects of light diffusion and light conduction, which helps to conduct the light in the adjacent deposition unit 121 to the section where the conductor layer 123 is located, and further diffuse it uniformly in the conductor section of the conductor layer 123.

[0199] For example, in another embodiment, the first light conversion layer 141 corresponding to the deposition unit 121 in the LED filament 100 may include light-diffusing particles, such as phosphor, while the first light conversion layer 141 corresponding to the conductor layer 123 does not contain particles. In this embodiment, the deposition unit 121 and the first light conversion layer 141 of the conductor layer 123 are made of silicone, for example, and there are no particles in the first light conversion layer 141 of the conductor layer 123, which can improve the bendability of the conductor layer 123, for example, when the filament needs to be bent into shape.

[0200] In one embodiment, the first light conversion layer 141 includes a first layer covering the substrate 110, a plurality of deposition units 121 and a conductor layer 123 formed on the substrate 110, a portion of the filament electrode 130, and a second layer covering the lower surface of the substrate 110. In this embodiment, the first layer of the first light conversion layer 141 is a top layer, and the second layer of the first light conversion layer 141 is a base layer. The top layer is, for example, silicone, which includes phosphor; the base layer is, for example, a composition based on silicone-modified polyimide, which includes phosphor and heat dissipation particles. It should be understood that the materials of the top layer and the base layer are not limited. For example, in some embodiments, the first layer and the second layer of the first light conversion layer 141 may be made of the same material or different materials, and may both be silicone or a composition based on silicone-modified polyimide.

[0201] In the fabrication process, the second layer of the first light conversion layer 141 can be prepared first as a base film, and then the deposition unit 121 and the conductor layer 123 can be placed or deposited, and the filament electrode 130 and the deposition unit 121 can be electrically connected. Then, the first layer of the first light conversion layer 141 can be formed on the light-emitting diode filament 100 to cover the substrate 110, the multiple deposition units 121 and conductor layer 123 formed on the substrate 110, and a part of the filament electrode 130.

[0202] In embodiments where the first and second layers of the first light conversion layer 141 are made of different materials, the top and bottom layers can have different particles or different particle densities depending on different requirements. For example, when the main light-emitting surface of the deposition unit 121 faces the top layer, more light-scattering particles can be added to the bottom layer to improve the light dispersion of the bottom layer, maximizing the brightness that the bottom layer can produce, or even approaching the brightness that the top layer can produce. In addition, the bottom layer can also have a higher density of phosphor to improve the hardness of the bottom layer.

[0203] In one embodiment, the top layer of the first light conversion layer 141 has a large number of light-reflecting / diffusing particles (e.g., phosphors), which can reflect or diffuse light toward the substrate, and the light can easily penetrate the thinner substrate, thus making the brightness of the top layer and the substrate uniform. In another embodiment, when the top layer and the substrate have the same thickness, the phosphor concentration of the top layer can be configured to be greater than that of the substrate, making the color temperature of the LED filament more uniform.

[0204] In embodiments where the substrate 110 is a flexible substrate, the first light conversion layer 141 includes a first layer and a second layer. For example, in one embodiment, the first layer is located on the side of the deposition unit 121 away from the substrate 110, and the second layer is located on the side of the deposition unit 121 closer to the substrate 110. In this embodiment, for example, a set of parallel planes intersects the first light conversion layer 141 in the space between adjacent deposition unit 121 segments. The deposition unit 121 is disposed in the deposition unit 121 segment. A portion of the conductor layer 123 for electrically connecting two adjacent deposition unit 121 segments is disposed in the first layer, and another portion is disposed in the second layer. The conversion wavelength / particle size / thickness / transmittance / hardness / particle ratio of the first layer and the second layer may also be different and can be adjusted as needed.

[0205] In one embodiment, the first layer is harder than the second layer, meaning the first layer is harder than or equal to the second layer, and the first layer contains more phosphor than the second layer. Because the first layer is harder, it is configured to better protect the linear array of deposition units 121 when the filament is bent to maintain a desired orientation within the luminaire, ensuring the luminaire does not malfunction. The second layer is made more flexible so that the entire filament bends within the luminaire to produce omnidirectional light, specifically, a single filament producing omnidirectional light.

[0206] Of course, in other embodiments, the hardness of the second layer can also be set to be greater than or equal to the hardness of the first layer.

[0207] In another embodiment, the first layer has better thermal conductivity than the second layer, for example, by adding more heat-dissipating particles to the first layer than to the second layer. The higher thermal conductivity of the first layer allows it to conduct heat from the deposition unit 121 segments to the outside of the filament, thus better protecting the linear array of deposition unit 121 segments from degradation or combustion. Because the conductor layer 123 is spaced apart from the deposition units 121, its role in conducting heat from the deposition units 121 is less significant than that of the deposition units 121. Therefore, when the second layer has less heat-dissipating particle content than the first layer, the cost of manufacturing the filament can be reduced. The size ratio of the first layer, where the deposition units 121 are placed, to the overall first light conversion layer is determined by reference factors such as light conversion capability, flexibility, and thermal conductivity. Similarly, the larger the proportion of the first layer in the entire first light conversion layer, the greater the light conversion capability and thermal conductivity of the filament, but the less flexible it will be.

[0208] In one embodiment, the light-emitting diode filament of this application further includes a second light conversion layer, which covers the chip strip structure and is located between the chip strip structure and the conductor layer, for enabling the light-emitting diode filament to have good color reproduction or high color rendering. Please refer to... Figure 17 The figure shows a side view of a chip strip structure with a second light conversion layer formed on it in one embodiment of this application. As shown, the light-emitting diode filament 100 includes: a chip strip structure 101, a light conversion unit 140 enclosing the chip strip structure 101, and electrodes 130 located at both ends of the chip strip structure 101 along its length and electrically connected thereto; at least a portion of the electrodes 130 are enclosed in the light conversion unit 140. In this embodiment, the light conversion unit 140 includes a first light conversion layer 141 and a second light conversion layer 142.

[0209] In this embodiment, the first light conversion layer 141 is an encapsulation structure for encapsulating the entire filament strip. In some cases, this encapsulation structure is also called a sealing layer, as described above. Figures from 6 to 16 The relevant descriptions of the first optical conversion layer 141 in the corresponding embodiments will not be repeated here.

[0210] exist Figure 17In the illustrated embodiment, the second light conversion layer 142 covers the chip strip structure 101 and is located between the chip strip structure 101 and the first light conversion layer 141. Alternatively, it can be said that the light conversion layer 142 is located between the conductor layer 123 and the first light conversion layer 141. Specifically, the second light conversion layer 142 completely covers the substrate 110, deposition unit 121, bonding layer 122, conductor layer 123, electrode bonding layer 150D, and at least a portion of the filament electrode 130. In other words, the second light conversion layer 142 covers (encapsulates) the substrate 110, the deposition unit 121, the bonding layer 122, the conductor layer 123, the electrode bonding layer 150D, and at least a portion of the filament electrode 130. The light-emitting diode (LED) filament electrode 130 comprises unit 121, connecting layer 122, conductor layer 123, electrode connection layer 150D, and at least a portion thereof (i.e., electrode extension 150D in the aforementioned embodiment). A first light conversion layer 141 surrounds the outside of a second light conversion layer 142 and at least covers a portion of the second light conversion layer 142. In this embodiment, the second light conversion layer includes a fluoride-based red phosphor, which can be effectively excited by the blue light emitted by the LED chip in the LED filament, exhibiting beneficial effects such as narrow-band red light emission, high quantum efficiency, and good thermal stability. In some embodiments, the fluoride-based red phosphor is, for example, KSF-based red K2SiF6:Mn. 4+ K2TiF6:Mn 4+ NaYF4:Mn 4+ NaGdF4:Mn 4+ K3SiF7:Mn 4+ wait.

[0211] The composition of the phosphor should basically conform to stoichiometry, and each element can be replaced by other elements in their respective groups of the periodic table. For example, strontium (Sr) can be replaced by alkaline earth elements such as barium (Ba), calcium (Ca), and magnesium (Mg); and yttrium (Y) can be replaced by elements such as terbium (Tb), lutetium (Lu), scandium (Sc), and gadolinium (Gd); in addition, depending on the required energy level, the activator europium (Eu) can be replaced by cerium (Ce), terbium (Tb), praseodymium (Pr), erbium (Er), and ytterbium (Yb), and the activator can be used alone or additionally as a co-activator to change the properties.

[0212] Inspired by the ideas described above in this application, to enhance reliability under high temperature and high humidity conditions, fluoride-based red phosphors or fluoride-based red phosphors can be coated with manganese (Mn)-free fluorides or may also include organic substances coated on the surface of a manganese (Mn)-free fluoride coating. Unlike other phosphors, fluoride-based red phosphors can achieve a narrow full width at half maximum (FWHM) of 40 nm or less.

[0213] In one embodiment provided in this application, the second light conversion layer 142 includes K2SiF6∶Mn 4+Red phosphor, K2SiF6∶Mn 4+ (In short: KSF) As a red phosphor with a narrow half-width, KSF phosphor has a very narrow half-width of about 10 nm, thus enabling it to achieve good color reproducibility.

[0214] In particular, based on this, the white light produced by combining yellow, green and KSF phosphors into a blue LED and / or by combining green and red LEDs into a blue LED can have two or more peak wavelengths.

[0215] For example, a high color rendering index (CRI) is typically required for lighting devices that produce white light (such as the LED illumination device provided in one embodiment of this application). CRI is a property of a lighting source that indicates how similar the color of an object illuminated by the lighting device is to the color of an object illuminated by a reference light source. CRI is evaluated using the color rendering index (CRI), and the general CRI (Ra) is mostly used. Ra is the average value of each CRI (special CRIs; R1 to R8) quantified using eight test color samples. When using red phosphors with a narrow half-width, such as the KSF phosphor described above, unwanted tails can be removed to emit light in the desired red region, thus achieving a high R8 even with a relatively low Ra. That is, a suitable Ra and R8 can be achieved without excessive or significant reduction in luminance.

[0216] exist Figure 17 In the illustrated embodiment, the above-described preparation method involves forming a conductive layer on multiple deposition units using a deposition process to electrically connect adjacent deposition units, thereby creating a continuous strip-like structure on the substrate. Specifically, after forming deposition units 121, a bonding layer 122, a conductive layer 123, and an electrode connection layer 150D on the substrate 110, the second light conversion layer 142 completely covers the substrate 110, deposition units 121, bonding layer 122, conductive layer 123, and electrode connection layer 150D, forming a structure as shown. Figure 17 The structure is shown in the diagram. In this embodiment, in the step of completely covering the substrate 110, deposition unit 121, bonding layer 122, conductor layer 123 and electrode connection layer 150D with the second light conversion layer 142, a position is specifically reserved on the electrode connection layer 150D for subsequent electrical connection of the filament electrode 130 without covering the second light conversion layer 142, so that the filament electrode 130 and the electrode connection layers 150D at both ends can make sufficient electrical contact.

[0217] In another embodiment, the second light conversion layer may also be formed in the chip strip structure after filament electrodes are connected to both ends of the substrate. Please refer to [link to relevant documentation]. Figure 18 The figure shows a side view of a chip strip structure with a second light conversion layer formed on it in another embodiment of this application. As shown, in the fabrication method provided in this embodiment, after forming a deposition unit 121, a bonding layer 122, a conductor layer 123, and an electrode connection layer 150D on a substrate 110, the deposition unit 121 adjacent to the first end 110a and the second end 110b of the substrate 110 is electrically connected to the filament electrodes 130 disposed at both ends of the substrate 110. After that, the second light conversion layer 142 completely covers the substrate 110, the deposition unit 121, the bonding layer 122, the conductor layer 123, the electrode connection layer 150D, and the portion of the filament electrode 130 located in the chip strip structure 101, forming a structure as shown in the figure. Figure 18 As shown in the diagram, the second light conversion layer 142 also almost covers the filament electrode 130 that is encapsulated in the substrate 110 by the first light conversion layer 141.

[0218] In another embodiment, the LED filament further includes a second light conversion layer for enabling the LED filament to have good color reproduction or high color rendering. In this embodiment, the second light conversion layer covers the plurality of deposition units, the bonding layer, and the conductor layer, and is located between the first light conversion layer and the chip strip structure. Please refer to [link to relevant documentation]. Figure 19 The figure shows a side view of a chip strip structure in another embodiment of this application, where a second light conversion layer is formed on it. As shown, the second light conversion layer 142 covers the deposition unit 121, the bonding layer 122, the conductor layer 123, and the electrode connection layer 150D (i.e., the electrode extension 150D in the aforementioned embodiment). In this embodiment, the second light conversion layer 142 includes a fluoride-based red phosphor, which can be effectively excited by the blue light emitted by the LED chip in the light-emitting diode filament, and has beneficial effects such as narrow-band red light emission, high quantum efficiency, and good thermal stability. In some embodiments, the fluoride-based red phosphor is, for example, KSF-based red K2SiF6:Mn. 4+ K2TiF6:Mn 4+ NaYF4:Mn 4+ NaGdF4:Mn 4+ K3SiF7:Mn 4+ Wait, in Figure 19 In the embodiment shown, the second light conversion layer 142 includes K2SiF6∶Mn 4+ (KSF) Red fluorescent powder.

[0219] To further improve the filament of the light-emitting diode and make it have better color reproduction or higher color rendering, red phosphor can be added to the substrate 110 to form a fluorescent glass-ceramic substrate. For example, in Figure 19 In the illustrated embodiment, the substrate 110 is a fluorescent glass-ceramic substrate inlaid with a fluoride-based red phosphor to improve the white light color rendering index (CRI) and enable the LED chip of the lighting device to improve luminous flux and color temperature under blue light power density excitation. In some embodiments, the fluoride-based red phosphor is, for example, KSF-based red K2SiF6:Mn. 4+ K2TiF6:Mn 4+ NaYF4:Mn 4+ NaGdF4:Mn 4+ K3SiF7:Mn 4+ Red phosphor, etc. In a specific example, the substrate 110 is, for example, embedded with K2SiF6:Mn. 4+ (KSF) fluorescent glass-ceramic substrate with red phosphor.

[0220] exist Figure 19 In the illustrated embodiment, K2SiF6:Mn is deposited on the deposition unit 121, the bonding layer 122, the conductor layer 123, and the electrode connection layer 150D. 4+ The second light conversion layer 142 of the (KSF) red phosphor and the fluorescent glass-ceramic substrate 110 formed by adding red phosphor enable the filament of the light-emitting diode to have good color reproduction or high color rendering.

[0221] In another embodiment, the LED filament further includes a coating layer that completely covers the first light conversion layer and has a different color from the first light conversion layer when the LED filament is not in operation, thereby changing the surface color of the LED filament. For example, the coating layer can be prepared by mixing different materials to make the LED filament present different colors, or to make the LED filament present different colors when it is lit and when it is not lit, thereby improving the aesthetics and light emission effect of the lamps using the LED filament.

[0222] Please see Figure 20The figure shows a side view of a light-emitting diode filament with a cover layer in one embodiment of this application. As shown, the chip strip structure 101 of the light-emitting diode filament 100 is wrapped with a conversion unit 140 and electrodes 130 located at both ends of the chip strip structure 101 along its length and electrically connected thereto. At least a portion of the electrodes 130 are wrapped in the light conversion unit 140. The light conversion unit 140 includes a first light conversion layer 141, and in another embodiment, it may also include a second light conversion layer 142. The first light conversion layer 141 is a packaging structure for encapsulating the entire filament strip. In some cases, this packaging structure is also called a sealing layer, as described above for... Figures from 6 to 16 The relevant descriptions of the first optical conversion layer 141 in the corresponding embodiments will not be repeated here.

[0223] exist Figure 20 In the embodiment shown, the coating layer 160 completely covers the first light conversion layer 141, and the coating layer 160 is a different color from the first light conversion layer 141. The coating layer 160 can also be referred to as a layered body. The coating layer 160 covers the first light conversion layer 141 and at least covers a portion of the filament electrode 130. A color-developing material or a photoconversion material is disposed in the coating layer 160.

[0224] In some embodiments of this application, the coating layer 160 may be made of silicone or a silicone-based material. When silicone is used directly, the coating layer 160 can be made white by the color of the silicone itself, so that the LED filament 100 appears white. Adding a colorant to the silicone can make the coating layer 160 exhibit different colors as described above. In addition, a photoreactive substance can be added to the coating layer 160, so that after the deposition unit 121 emits light, it undergoes a first light conversion through the first light conversion layer 141, and then a second light conversion through the photoreactive substance in the coating layer 160. This achieves a first color when the LED filament 100 is not lit, and a second color different from the first color when lit, with the first and second colors having primary color differences.

[0225] In some embodiments, the first light conversion layer 141 further comprises a first layer and a second layer. The first layer of the first light conversion layer 141 is a top layer, and the second layer of the first light conversion layer 141 is a base layer (or a carrier layer). The top layer and the base layer can each be a layered structure with at least one layer. The upper surface of the top layer and the lower surface of the base layer are different colors. Since the light-emitting diode filament 100 presents two different colors when it is not lit, it can be applied to multi-color application scenarios.

[0226] In some embodiments, the coating layer 160 may also be made of other materials besides silicone or silicone-based materials, such as resin, plastic, polyimide (PI), polyvinyl alcohol (PVA), polyester (PET), polyethylene naphthalate (PEN), polydimethylsiloxane (PDMS), etc.

[0227] In some embodiments, the coating layer 160 may be based on silica gel mixed with other solid powders (particles). The solid powder particles may be non-conductive white powders, such as titanium dioxide powder, but are not limited to this, such as a mixture of inorganic oxide nanoparticles. The solid powder particles account for a certain proportion of the total weight of the coating layer 160 to meet the overall filament performance requirements.

[0228] In some embodiments, a certain amount of titanium dioxide powder (particles) is mixed in the coating layer 160, and the titanium dioxide powder (particles) are relatively uniformly distributed in the coating layer 160. The coating layer 160 is prepared from silicone and titanium dioxide powder (particles). When the silicone exhibits liquid properties under certain conditions, a certain amount of titanium dioxide is added to the silicone. Through common mixing treatment methods such as stirring, high-speed vibration, and planetary mixer processing, the titanium dioxide powder (particles) are relatively uniformly distributed in the silicone. Under the condition that the mixture of silicone and titanium dioxide is in a liquid state, the coating layer 160 is set on the surface of the first light conversion layer 141 by methods such as spin coating, spraying, doctor blade coating, and immersion (immersing the entire material into the liquid and then taking it out, with the liquid covering the surface of the material). Then, the coating layer 160 is solidified on the surface of the first light conversion layer 141 by exposure, baking, natural curing, etc. The thickness of the coating layer 160 is less than or equal to the thickness of the first light conversion layer 141, to avoid the coating layer 160 being too thick and affecting the light output and flexibility of the LED filament 100. The mass of titanium dioxide accounts for 0.2% to 10% of the total mass of the coating layer 160, and more specifically 0.7% to 5%. Titanium dioxide powder (particles) is white in color and has the lowest relative density among commonly used white pigments. For the same mass of white pigment, titanium dioxide has the largest surface area and the highest pigment volume, making it more effective than other materials in bringing mixed materials closer to the color of titanium dioxide. For example, if a mixed material needs to be close to white, less titanium dioxide is needed compared to other materials. Titanium dioxide has a high reflectivity (e.g., over 80%) and refractive index (e.g., 2.5 to 2.8), which is uniformly distributed in the coating layer 160. The light excited by the deposition unit 121 is converted by the first light conversion layer 141 and reaches the coating layer 160. After being refracted and reflected multiple times by the titanium dioxide powder (particles) distributed therein, it is finally emitted from the coating layer 160. The specific directionality of the emitted light is greatly reduced, and the emitted light is more uniform and softer.

[0229] In some embodiments, a certain amount of titanium dioxide is disposed in the coating layer 160. The light processed by the first light conversion layer 141 is further disordered in the coating layer 160, significantly reducing the specific directionality of the final emitted light and creating an effect similar to diffuse reflection. The light emitted from the coating layer 160 is ultimately uniform and soft. However, the amount of titanium dioxide added should not be excessive, as this will lead to significant light loss. For example, if the total mass of titanium dioxide exceeds 10% of the coating layer 160, further increasing the amount of titanium dioxide will not improve the soft light effect but will cause even greater light loss, resulting in insufficient light output. The amount of titanium dioxide added should also not be too small, as this will fail to achieve the function of uniform light distribution and will not yield ideal color effects. For example, if the total mass of titanium dioxide is less than 0.2% of the coating layer 160... While softening the light, titanium dioxide can make the LED filament 100 (or coating layer 160) appear white or close to white with a small amount of addition. More precisely, it makes the LED filament 100 (or coating layer 160) in the RGB standard range (R (235~255), G (235~255), B (235~255)) when it is not lit. The absolute value of the difference between any two of R, G, and B is less than or equal to 10% of the smaller or larger value. Furthermore, the absolute value of the difference between any two of R, G, and B is less than or equal to 5% of the smaller or larger value.

[0230] Of course, the materials added to the coating layer 160 can also be other color-developing materials or photoconversion materials, such as one or more combinations of alumina, silicon dioxide, magnesium oxide, titanium dioxide, graphene, phosphor, sulfate, silicate, nitride, nitrogen oxide, oxysulfate, or garnet. For example, it can be a combination of alumina and silicon dioxide with titanium dioxide, wherein the mass percentage of titanium dioxide is 5% to 15% of all solid particles, preferably 8%. It can also be a combination of alumina and silicon dioxide with magnesium oxide or sulfate (such as barium sulfate), and is not limited to this; it can be a combination of one or more materials. In some embodiments, the color setting of the filament when it is not lit can be achieved by using a variety of different phosphors, for example, by mixing different phosphors to achieve a series of colors such as white, gray, and black when the filament is not lit.

[0231] In some embodiments, light conversion particles, such as phosphors, may also be provided in the coating layer 160. The mass ratio of the light conversion particles is 2% to 10% of the total solid particles in the coating layer 160, preferably 4%, so that the coating layer 160 has a light conversion effect. This allows the light that has not been converted by the first light conversion layer 141 in the light excited by the deposition unit 121 to continue to be converted by the coating layer 160 and then emitted, thereby improving the overall light conversion efficiency of the light-emitting diode filament 100. That is, a high light conversion effect is achieved through two independent light conversions.

[0232] In some embodiments, the coating layer 160 is uniformly thick and is disposed on the two surfaces of the first light conversion layer 141 that are substantially parallel to the light-emitting surface of the light-emitting diode filament 100.

[0233] In some embodiments, the coating layer 160 is uniformly thick and is disposed on the two surfaces of the first light conversion layer 141 that are substantially parallel to the light-emitting surface of the LED filament 100 and on the long side perpendicular to the light-emitting surface of the LED filament 100 (i.e., the surface through which the filament electrode 130 passes).

[0234] In some embodiments, the coating layer 160 completely covers the first light conversion layer 141 and at least covers a portion of the filament electrode 130, wherein the coating layer 160 has a certain strength and toughness, which can enhance the overall strength of the light-emitting diode filament 100.

[0235] In some embodiments, the cladding layer 160 may be only a portion of the surface of the first light conversion layer 141 and the corresponding surface of the filament electrode 130.

[0236] In some embodiments, the filler material in the coating layer 160 may be selected from alumina or silicon dioxide, and prepared by combining titanium dioxide and graphene. The titanium dioxide accounts for 0.5% to 5% of the total solid particles in the coating layer 160, preferably 1.25%. The titanium dioxide accounts for 0.1% to 3% of the total weight of the coating layer 160, more preferably 0.4% to 2.5%. The graphene accounts for 0.1% to 1% of the total weight of the coating layer 160, preferably 0.5%. In some embodiments, the graphene may be fluorinated graphene, which has excellent non-conductive properties, excellent thermal conductivity and thermal stability, and good dispersion stability, maintaining a relatively stable position in some materials. In terms of particle size selection, the particle size of alumina (or silicon dioxide) is larger than that of titanium dioxide, and the particle size of titanium dioxide is larger than that of graphene. That is, there are three particle sizes in the coating layer 160. When the three particles are mixed and evenly distributed in the coating layer 160, it is difficult for them to form gaps or thermally conductive break areas, resulting in better heat dissipation.

[0237] In one embodiment, the particle size of the filling material particles in the coating layer may be the same. In another embodiment, the particle size of the filling material particles in the coating layer may be different. In yet another embodiment, the particle size of the filling material particles in the coating layer may be the same in one segment and different in another segment.

[0238] Please see Figure 21a and Figure 21b 21a shows a schematic diagram of heat dissipation paths with different particle sizes of the filling material particles in one embodiment of this application; 21b shows a schematic diagram of heat dissipation paths with the same particle size of the filling material particles in another embodiment of this application; as shown Figure 21a As shown, in the filling material 1601, particle 1602 represents the largest particle size (e.g., alumina or silicon dioxide), particle 1603 represents the medium-sized particle size (e.g., titanium dioxide), and particle 1604 represents the smallest particle size (e.g., graphene). When different particle sizes are used, smaller particles fill the gaps between larger particles. The heat dissipation path can extend and interweave between smaller particles (particle 1604), medium particles (particle 1603), and larger particles (particle 1602) to form a complete heat dissipation path. Particle 1603 has a better heat dissipation effect, while silicone has a relatively poor heat dissipation effect. The path length through the heat dissipation particles is much longer than the path length through silicone (or another material replacing silicone as the substrate), meaning that the proportion of high-heat-dissipation paths in the overall heat dissipation path is high, resulting in better heat dissipation. On the other hand, during heat transfer, areas with large temperature differences and good thermal conductivity dissipate heat quickly, and heat is preferentially dissipated (lost) from these areas. In filler material 1601 with different particle sizes, the particles have good thermal conductivity, and the heat on the particles can be dissipated relatively quickly. Then, there will be a certain temperature difference between particles that are at different distances from the heat source. Heat is preferentially transferred between particles with temperature difference. However, silicone has poor heat dissipation capacity and heat is easy to accumulate. Therefore, the temperature difference is small. Thus, the heat dissipation path will preferentially choose the path composed of particles and reduce the path composed of silicone.

[0239] contrast Figure 2 and ​ The heat dissipation path is preferably a path formed by particles connected in series. Under the condition of the same path length, as shown in path PA... ​ The 1601 filler material, containing particles of varying sizes, exhibits good heat dissipation due to the high proportion of particle path length in its heat dissipation path, while... ​ The single particle shown has no smaller particles filling the gaps between it, so its heat dissipation path can only be silicone. Under the same heat dissipation path length, silicone occupies a higher proportion of the heat dissipation path, resulting in inferior heat dissipation performance compared to other materials. ​ .like ​By mixing different particles (at least two particle sizes, such as aluminum oxide or magnesium oxide with a particle size between 2.5 mm and 25 mm, titanium dioxide with a particle size between 0.3 mm and 1 mm, and graphene with a particle size between 5 nm and 300 nm) with silicone, the proportion of particles with direct contact on the outermost side of the heat dissipation surface is increased, while the gaps between large-particle-size particles are filled with smaller-particle-size particles, thus optimizing the micro heat dissipation path and improving the overall heat dissipation effect. Graphene (or fluorinated graphene) is often chosen as an additive material due to its good thermal conductivity, insulation, and thermal stability. In some embodiments, the filler material 1601 can be made to appear gray or close to gray (i.e., the filament appears gray or close to gray). More precisely, the color value of the LED filament 100 (or filler material 1601) under the RGB standard is within the range of R value (100~234), G value (100~234), and B value (100~234) when it is not lit. The absolute value of the difference between any two of the R value, G value, and B value is less than or equal to 10% of the smaller or larger value. Furthermore, the absolute value of the difference between any two of the R value, G value, and B value is less than or equal to 5% of the smaller or larger value.

[0240] In some embodiments of this application, heat dissipation is conducted from the chip strip structure to the light conversion layer and finally to the outside environment; that is, heat dissipation is completed at least through a portion of the chip strip structure, such as... ​ As shown, new heat dissipation paths PA1, PA2, and PA3 are formed by different components of the chip strip structure and the heat dissipation path PA. PA1 is a schematic diagram of heat passing through the first semiconductor layer S1, the light-emitting layer LE, the second semiconductor layer S2, the conductor layer 123, the second electrode E2, and then to the heat dissipation path PA. PA2 is a schematic diagram of heat passing through the first semiconductor layer S1, then the first electrode E1, and then to PA. PA3 is a schematic diagram of heat passing through the connecting layer 122, then to the first electrode E1, then to the conductor layer 123, and finally to PA. PA1, PA2, and PA3 all pass through at least a portion of the chip strip structure 101 with good thermal conductivity and are all provided with the conductor layer 123. Compared with the traditional filament structure, where most of the heat dissipation path is located in the light conversion layer, the heat dissipation path of this design is mostly located in the chip strip structure, and this path mostly passes through the metal structure with good thermal conductivity, which greatly improves the heat dissipation performance. Of course, it can also be said that it greatly shortens the length of the heat dissipation path in the light conversion layer and reduces the proportion of the heat dissipation path in the low thermal conductivity area to the overall heat dissipation path.

[0241] In one embodiment, the first light conversion layer 141 has a top layer 1411 and a base layer 1412, and a cladding layer 160 may be disposed on the top layer 1411. In some embodiments, please refer to... ​This is a schematic diagram showing the cladding structure of a light-emitting diode filament according to some embodiments of this application. For example... ​ As shown, the cladding layer 160 can completely cover the top layer 1411 and at least both ends of the filament electrode 130 facing at least a portion of the surface of the top layer 1411.

[0242] In some embodiments, the cladding layer 160 may cover only the top layer 1411 without contacting at least a portion of the surface of the filament electrode 130 facing the top layer 120.

[0243] Please see again ​ The first light conversion layer 141 has a top layer 1411 and a base layer 1412, wherein the cladding layer 160 can completely cover the top layer 1411 and at least cover at least a portion of the surface of the filament electrodes 130 at both ends onto the top layer 1411, and the base layer 1412 is uncovered. The thickness of the cladding layer 160 along the radial direction of the LED filament 100 is less than or equal to the thickness of the top layer 1411 along the radial direction of the LED filament 100, further less than or equal to one-half the thickness of the top layer 1411 along the radial direction of the filament, and even further less than or equal to one-third.

[0244] In some embodiments, the thickness of the top layer 1411 of the first light conversion layer 141 can be set to 0.2 mm to 0.7 mm, and more specifically, 0.35 mm to 0.5 mm. The thickness of the base layer 1412 of the first light conversion layer 141 can be set to 0.05 mm to 0.15 mm, and more specifically, 0.08 mm to 0.15 mm, to ensure that the LED filament 100 has sufficient flexibility.

[0245] In some embodiments, due to differences in the materials added to the base layer 1412 and the top layer 1411 of the first light conversion layer 141, there are differences in deflection and strength per unit volume between the base layer 1412 and the top layer 1411. When the thicknesses of the base layer 1412 and the top layer 1411 are similar, the cumulative difference can lead to an excessively large difference in the overall deflection or strength of the base layer 1412 and the top layer 1411, making them prone to delamination or breakage when bent. For example, when the ratio of the thickness of the base layer 1412 to the thickness of the top layer 1411 is greater than one-half, the overall flexibility and reliability of the LED filament 100 are insufficient, and the LED filament 100 may exhibit the aforementioned lack of flexibility and susceptibility to delamination or breakage when bent. Therefore, in this embodiment, the ratio of the thickness of the base layer 1412 to the thickness of the top layer 1411 is less than or equal to one-half, and more specifically, less than or equal to three-eighths. Therefore, in this embodiment, when the ratio of the thickness of the base layer 1412 to the thickness of the top layer 1411 is controlled within the aforementioned ratio range, better flexibility can be achieved. That is, by controlling the thickness, the physical properties such as deflection and strength of the base layer 1412 and the top layer 1411 caused by the difference in the added materials can be adjusted, so that the base layer 1412 and the top layer 1411 have similar physical properties, which can prevent delamination or breakage when the LED filament 100 is bent.

[0246] In some embodiments, the ratio of the thickness of the cladding layer 160 to the base layer 1412 is less than or equal to one-half, and even less than or equal to three-quarters. For example, if the thickness ratio is greater than one-half, the cladding layer 160 (in which solid particles are added) may affect the overall light output of the filament.

[0247] In some embodiments, the thickness of the coating layer 160 can be set to 0.05mm to 0.4mm, and more specifically, 0.1mm to 0.2mm. In some embodiments, if the thickness of the base layer 1412 is too large, for example, if the base layer 1412 is greater than one-quarter of the sum of the thicknesses of the coating layer 160, the top layer 1411, and the base layer 1412, it will affect the heat dissipation of the base layer 1412, meaning that the heat dissipation path of the LED filament 100 is long and prone to heat accumulation. Therefore, in this embodiment, the thickness of the base layer 1412 is less than or equal to one-quarter of the thickness of the LED filament 100. Specifically, the thickness of the base layer 1412 is less than or equal to one-quarter of the sum of the thicknesses of the coating layer 160, the top layer 1411, and the base layer 1412. This maintains the heat dissipation of the base layer 1412, shortens the heat dissipation path of the LED filament 100, and avoids heat accumulation.

[0248] In some embodiments, such as ​As shown, the first light conversion layer 141 includes a top layer 1411 and a base layer 1412. The cladding layer 160 can completely cover the top layer 1411 and at least cover at least a portion of the surface of the filament electrode 130 facing the top layer 1411. The base layer 1412 is uncovered. The same or similar additives as those in the cladding layer 160 are added to the base layer 1412 so that the base layer 1412 and the cladding layer 160 ultimately appear within the same RGB value range. For example, if titanium dioxide is added to the existing materials, both the cladding layer 160 and the base layer 1412 will appear white or close to white, with color values ​​in the R range (235-255). The color values ​​are within the range of G value (235-255) and B value (235-255), or graphene is added to make the coating layer 160 and the base layer 1412 appear gray or close to gray, with color values ​​within the range of R value (100-234), G value (100-254), and B value (235-254). For example, white powder particles are added to both the coating layer 160 and the base layer 1412. For example, titanium dioxide is added to the coating layer 160 and the base layer 1412. The amount of titanium dioxide added is 1% to 20% of the total weight of solid particles (powder) in the base layer 1412, and further to 3% to 15%.

[0249] In some embodiments, the first light conversion layer 141 includes a top layer 1411 and a base layer 1412, wherein the cladding layer 160 can completely cover the top layer 1411 and at least cover at least a portion of the surface of the filament electrode 130 facing the top layer 1411, and the base layer 1412 is uncovered, wherein different additive materials are added to the base layer 1412 than to the cladding layer 160, so that the colors ultimately displayed by the base layer 1412 and the cladding layer 160 are within different RGB value ranges. In some embodiments, the RGB color standard can be converted to other color standards.

[0250] In some embodiments, the added materials in the base layer 1412 and the cladding layer 160 are the same, so that the base layer 1412 and the cladding layer 160 have the same color, for example, the base layer 1412 is white, and the cladding layer 160 is disposed on the top layer 1411, the cladding layer 160 completely covering part of the first light conversion layer 141, or in other words, completely covering the top layer 1411, so that the formed filament appears white when not lit. Of course, the cladding layer 160 may at least cover part of the first light conversion layer 141.

[0251] In some embodiments, the added materials in the base layer 1412 and the cladding layer 160 are the same, so that the base layer 1412 and the cladding layer 160 have the same color, for example, the base layer 1412 is white, and the cladding layer 160 is then disposed on the base layer 1412. The cladding layer 160 completely covers a portion of the first light conversion layer 141, or in other words, completely covers the base layer 1412, so that the formed filament appears white when not lit. Of course, the cladding layer 160 may at least cover a portion of the first light conversion layer 141.

[0252] In some other embodiments of this application, silver-gray or silver-white thermally conductive particles are added to the base layer 1412. These thermally conductive particles include, but are not limited to, aluminum powder or aluminum oxide, silver powder, or aluminum-silver mixture powder. These silver-gray or silver-white thermally conductive particles can be disposed on the base layer 1412 or the coating layer 160, such that at least one side of the flexible filament is silver-gray or silver-white.

[0253] When silver-gray or silver-white thermally conductive particles are provided in the base layer 1412, the thermally conductive particles account for 0.15% to 10% of the total proportion of solid particles in the base layer 1412, and further 0.3% to 5%. The total weight of the thermally conductive particles (including but not limited to alumina or silicon dioxide) and phosphor particles in the base layer 1412 is 95% to 99% of the total weight of solid particles in the base layer 1412. By controlling the proportion of solid particles in the base layer 1412, the thermal conductivity of the substrate 110 is improved, and the heat generated when the deposition unit 121 emits light is conducted away.

[0254] The silver-gray or silver-white thermally conductive particles are distinguished from the thermally conductive particles themselves. Specifically, the silver-gray or silver-white thermally conductive particles can be referred to as color-developing particles. These color-developing particles account for 0.15% to 10% of the total solid particles in the base layer 1412, and further, 0.3% to 5%. Of course, the silver or silver-gray thermally conductive particles, thermally conductive particles, and fluorescent powder particles can also be added to the base layer 1412 in different proportions.

[0255] In one embodiment of this application, the coating layer 160 is provided with silver or silver-gray thermally conductive particles, which account for 0.05% to 10% of the total weight of the coating layer 160, and more specifically 0.15% to 5%. The thickness of the top layer 1411, disposed on the surface of the base layer 1412 facing the deposition unit 121, is 0.2mm to 0.6mm, and more specifically 0.35mm to 0.5mm; the thickness of the base layer 1412 is 0.05mm to 0.3mm, and more specifically 0.1mm to 0.2mm; the thickness of the base layer 1412 is 0.04mm to 0.3mm, and more specifically 0.08mm to 0.15mm; and the thickness of the base layer 1412 is less than or equal to one-third, and more specifically one-quarter, of the sum of the thicknesses of the base layer 1412, the top layer 1411, and the coating layer 160. This satisfies both the appearance requirements and the requirements for light emission and heat dissipation.

[0256] In some other embodiments, gold-colored thermally conductive particles are added to the base layer 1412, including but not limited to bronze powder, brass powder, gold powder, or combinations thereof. These gold-colored thermally conductive particles may be disposed on the base layer 1412 or the coating layer 160, such that at least one side of the flexible filament is gold.

[0257] When gold-colored thermally conductive particles are incorporated into the base layer 1412, these particles constitute 0.5% to 15% of the total solid particles in the base layer 1412, and more specifically, 1% to 10%. The combined weight of the thermally conductive particles (including but not limited to alumina or silica) and phosphor particles in the base layer 1412 is 90% to 99% of the total weight of the solid particles. The gold-colored thermally conductive particles are distinguished from the silver-gray or silver-white thermally conductive particles; they can be referred to as color-developing particles. These color-developing particles constitute 0.5% to 15% of the total solid particles in the base layer 1412, and more specifically, 1% to 10%. Of course, the gold-colored thermally conductive particles, thermally conductive particles, and phosphor particles can be added to the base layer 1412 in different proportions.

[0258] In one embodiment, the coating layer 160 contains gold-colored thermally conductive particles, which account for 0.05% to 10% of the total weight of the coating layer 160, and more specifically 0.1% to 5%. The thickness of the top layer 1411, disposed on the surface of the base layer 1412 facing the deposition unit 121, is 0.1 mm to 1 mm, and more specifically 0.35 mm to 0.5 mm; the thickness of the base layer 1412 is 0.05 mm to 0.3 mm, and more specifically 0.1 mm to 0.2 mm; the thickness of the base layer 1412 is 0.04 mm to 0.3 mm, and more specifically 0.08 mm to 0.15 mm; and the thickness of the base layer 1412 is less than one-third, and more specifically one-quarter, of the sum of the thicknesses of the base layer 1412, the top layer 1411, and the coating layer 160, thereby satisfying both its appearance requirements and its light emission and heat dissipation requirements.

[0259] As described above, the light conversion unit includes a first light conversion layer and a second light conversion layer. In one embodiment, the second light conversion layer covers the chip strip structure and is located between the chip strip structure and the first light conversion layer, used to give the LED filament good color reproduction or high color rendering. Furthermore, the LED filament includes a coating layer that completely covers the first light conversion layer and has a different color from the first light conversion layer when the LED filament is not in operation, thereby changing the surface color of the LED filament. For example, the coating layer can be prepared by mixing different materials to make the LED filament exhibit different colors, or to make the LED filament exhibit different colors when lit and unlit, improving the aesthetics and light emission effect of the lamps using the LED filament.

[0260] Please see ​ The figure shows a side view of a chip strip structure with a second light conversion layer and a coating layer formed on it in one embodiment of this application. As shown, the light-emitting diode filament 100 includes: a chip strip structure 101, a light conversion unit 140 that surrounds the chip strip structure 101, and electrodes 130 located at both ends of the chip strip structure 101 along its length and electrically connected thereto; at least a portion of the electrodes 130 are surrounded by the light conversion unit 140, and a coating layer 160. The coating layer 160 completely covers the first light conversion layer 141 of the light conversion unit 140, and its color differs from that of the first light conversion layer 141 when the light-emitting diode filament 100 is not in operation. This is used to change the surface color of the light-emitting diode filament 100, for example, by mixing different materials to prepare the coating layer, so that the light-emitting diode filament 100 presents different colors, or so that the light-emitting diode filament 100 presents different colors when lit and when not lit, thereby improving the aesthetics and light emission effect of the lamps using the light-emitting diode filament 100.

[0261] In this embodiment, the first light conversion layer 141 is an encapsulation structure for encapsulating the entire filament strip. In some cases, this encapsulation structure is also called a sealing layer, as described above. ​ The relevant descriptions of the first optical conversion layer 141 in the corresponding embodiments will not be repeated here.

[0262] In this embodiment, the second light conversion layer 142 covers the chip strip structure 101 and is located between the chip strip structure 101 and the first light conversion layer 141. Specifically, the second light conversion layer 142 completely covers the substrate 110, the deposition unit 121, the bonding layer 122, the conductor layer 123, and the electrode connection layer 150D (i.e., the electrode extension 150D in the aforementioned embodiment). In this embodiment, the second light conversion layer includes a fluoride-based red phosphor, which can be effectively excited by the blue light emitted by the LED chip in the light-emitting diode filament, and has beneficial effects such as narrow-band red light emission, high quantum efficiency, and good thermal stability. In some embodiments, the fluoride-based red phosphor is, for example, KSF-based red K2SiF6:Mn. 4+ K2TiF6:Mn 4 + NaYF4:Mn 4+ NaGdF4:Mn 4+ K3SiF7:Mn 4+ wait.

[0263] exist ​ In the embodiment shown, the coating layer 160 completely covers the first light conversion layer 141, and the coating layer 160 is a different color from the first light conversion layer 141. The coating layer 160 can also be referred to as a layered body. The coating layer 160 covers the first light conversion layer 141 and at least covers a portion of the filament electrode 130. A color-developing material or a photoconversion material is disposed in the coating layer 160.

[0264] In some embodiments of this application, the coating layer 160 may be made of silicone or a silicone-based material. When silicone is used directly, the coating layer 160 can be made white by the color of the silicone itself, so that the LED filament 100 appears white. Adding a colorant to the silicone can make the coating layer 160 exhibit different colors as described above. In addition, a photoreactive substance can also be added to the coating layer 160, so that after the deposition unit 121 emits light, it undergoes a first light conversion through the first light conversion layer 141, and then a second light conversion through the photoreactive substance in the coating layer 160. This achieves a first color when the LED filament 100 is not lit, and a second color different from the first color when lit, with the first and second colors having a primary color difference. As described above... ​The relevant descriptions of the covering layer 160 in the corresponding embodiments will not be repeated here.

[0265] To further improve the filament of this light-emitting diode and enhance its color reproduction or color rendering, a fluorescent glass-ceramic substrate can be formed by adding red phosphor to the substrate 110. (See also...) ​ The image shown is a side view schematic diagram of a chip strip structure having a second light conversion layer and a cladding layer formed on it in another embodiment of this application. ​ In the illustrated embodiment, the substrate 110 is a fluorescent glass-ceramic substrate inlaid with a fluoride-based red phosphor to improve the white light color rendering index (CRI) and enable the LED chip of the lighting device to improve luminous flux and color temperature under blue light power density excitation. In some embodiments, the fluoride-based red phosphor is, for example, KSF-based red K2SiF6:Mn. 4+ K2TiF6:Mn 4 + NaYF4:Mn 4+ NaGdF4:Mn 4+ K3SiF7:Mn 4+ Red phosphor, etc. In a specific example, the substrate 110 is, for example, embedded with K2SiF6:Mn. 4+ A fluorescent glass-ceramic substrate containing (KSF) red phosphor. In this embodiment, K2SiF6:Mn is deposited on the deposition unit 121, the bonding layer 122, the conductor layer 123, and the electrode connection layer 150D. 4+ The second light conversion layer 142 of the (KSF) red phosphor and the fluorescent glass-ceramic substrate 110 formed by adding red phosphor enable the filament of the light-emitting diode to have good color reproduction or high color rendering.

[0266] exist ​ In the illustrated embodiment, the deposition unit 121, the bonding layer 122, the conductor layer 123, and the electrode connection layer 150D (i.e., the electrode extension 150D in the aforementioned embodiment) are further covered with a second light conversion layer 142. In this embodiment, the second light conversion layer 142 includes a fluoride-based red phosphor, which can be effectively excited by the blue light emitted by the LED chip in the light-emitting diode filament, and has beneficial effects such as narrow-band red light emission, high quantum efficiency, and good thermal stability. In some embodiments, the fluoride-based red phosphor is, for example, KSF-based red K2SiF6:Mn. 4+ K2TiF6:Mn 4+ NaYF4:Mn 4+ NaGdF4:Mn 4+ K3SiF7:Mn 4+ Wait, in​ In the embodiment shown, the second light conversion layer 142 includes K2SiF6∶Mn 4+ (KSF) Red fluorescent powder.

[0267] Based on the aforementioned LED filament having a fluorescent glass-ceramic substrate embedded with fluoride-based red phosphor and a second light conversion layer including fluoride-based red phosphor, the first light conversion layer of this light conversion unit is further provided with a cladding layer, such as... ​ As shown, the coating layer 160 completely covers the first light conversion layer 141 of the light conversion unit 140, and the color of the coating layer 160 is different from that of the first light conversion layer 141 when the light-emitting diode filament 100 is not working, so as to change the surface color of the light-emitting diode filament 100. For example, the coating layer 160 is prepared by mixing different materials, so that the light-emitting diode filament 100 presents different colors, or makes the light-emitting diode filament 100 present different colors when it is lit and when it is not lit, thereby improving the aesthetics and light output effect of the lamps using the light-emitting diode filament 100.

[0268] exist ​ In the embodiment shown, the coating layer 160 completely covers the first light conversion layer 141, and the coating layer 160 is a different color from the first light conversion layer 141. The coating layer 160 can also be referred to as a layered body. The coating layer 160 covers the first light conversion layer 141 and at least covers a portion of the filament electrode 130. A color-developing material or a photoconversion material is disposed in the coating layer 160.

[0269] In some embodiments of this application, the coating layer 160 may be made of silicone or a silicone-based material. When silicone is used directly, the coating layer 160 can be made white by the color of the silicone itself, so that the LED filament 100 appears white. Adding a colorant to the silicone can make the coating layer 160 exhibit different colors as described above. In addition, a photoreactive substance can also be added to the coating layer 160, so that after the deposition unit 121 emits light, it undergoes a first light conversion through the first light conversion layer 141, and then a second light conversion through the photoreactive substance in the coating layer 160. This achieves a first color when the LED filament 100 is not lit, and a second color different from the first color when lit, with the first and second colors having a primary color difference. As described above... ​ The relevant descriptions of the covering layer 160 in the corresponding embodiments will not be repeated here.

[0270] To further improve the luminous flux of LED filaments, in one embodiment, the conductor layer used to achieve series connection between adjacent deposition units can be implemented using a transparent conductive film or a transparent conductive layer. See also... ​The figure shows a side view of a filament using an ITO thin film or layer as a conductive layer in one embodiment of this application. As shown, the light-emitting diode filament 100 includes: a chip strip structure 101, a light conversion unit 140 enclosing the chip strip structure 101, and electrodes 130 located at both ends of the chip strip structure 101 along its length and electrically connected thereto; at least a portion of the electrodes 130 are enclosed in the light conversion unit 140. The chip strip structure 101 includes a substrate 110, a plurality of deposition units 121 formed on the substrate 110, a connecting layer 122 located on the substrate 110 and disposed between the plurality of deposition units 121, and a conductor layer 123 for electrically connecting each deposition unit 121. ​ In the illustrated embodiments, indium tin oxide (ITO) or tin-doped indium oxide films or layers are used as transparent conductive layers or transparent conductive films. ​ In the implemented embodiments, the conductor layer 123 is, for example, a transparent conductive layer of an ITO thin film or layer, or a transparent conductive thin film deposited onto the surface of the electrodes (N electrode and P electrode) of the semiconductor layer by means of electron beam evaporation, physical vapor deposition, or some sputtering deposition techniques.

[0271] In this embodiment, in order to ensure that the transparent conductive layer or transparent conductive film, which is an ITO thin film or layer, is fully electrically connected to the electrode of the deposition unit, a light-transmitting omega contact layer can be prepared as the N electrode and P electrode of the deposition unit. The thickness of the light-transmitting omega contact layer is, for example, a metal layer with a thickness of 10-30 nanometers.

[0272] In one embodiment, the first electrode E1, which is an N electrode, or the second electrode E2, which is a P electrode, can be, for example, gold, copper, an alloy, or any other suitable material formed by plating or any other suitable technique.

[0273] In one embodiment, the first electrode E1, which is an N-type electrode, or the second electrode E2, which is a P-type electrode, is formed by electron beam vacuum evaporation deposition to form the first electrode E1 on the exposed surface of the N-type semiconductor material and the second electrode E2 on the retained surface of the P-type semiconductor material, respectively.

[0274] In one embodiment, the first electrode E1, which is an N-type electrode, or the second electrode E2, which is a P-type electrode, is prepared by a sputtering deposition process to form the first electrode E1 on the exposed surface of the N-type semiconductor material and the second electrode E2 on the surface of the retained P-type semiconductor material, respectively. In this embodiment, the sputtering deposition process is, for example, ion beam sputtering or cathode sputtering.

[0275] In another embodiment, the electrode extension formed by the conductor layer can also be implemented using a transparent conductive film or a transparent conductive layer. See also...​ The figure shows a side view of a filament in another embodiment of this application, where an ITO thin film or layer is used as a conductive layer. As shown, electrode extensions 150D formed by the conductive layer are located at both ends of the substrate 110 (i.e., ends 110a and 110b) for electrical connection to the filament electrode 130. In this embodiment, the electrode extensions 150D can be fabricated simultaneously with the conductive layer 123, which is also an ITO thin film or layer. For example, an indium tin oxide or tin-doped indium oxide thin film or layer can be used as a transparent conductive layer or transparent conductive film. For example, a transparent conductive layer or transparent conductive film, such as an ITO thin film or layer, can be deposited onto the surface of the semiconductor layer electrodes (N-electrode and P-electrode) using electron beam evaporation, physical vapor deposition, or some sputtering deposition techniques.

[0276] In one embodiment, the filament electrode 130, which is formed at both ends (110a and 110b) along the length of the substrate 110 and is electrically connected to the electrode extension ends 150D of the ITO thin film or layer, can be referred to the above. ​ and 13 The provided implementation is that the conductive rings of the filament electrodes 130 on both sides are wrapped around the first end 110a or the second end 110b of the substrate 110 and the electrode extension end 150D thereon. This ensures that the electrode extension end 150D and the filament electrode 130 have a larger contact area, which is beneficial for the filament electrode 130 to achieve electrical connection with peripheral components such as conductive brackets or drive circuits.

[0277] In another embodiment, the filament electrode 130, which is formed at both ends (110a and 110b) along the length of the substrate 110 and is electrically connected to the electrode extension end 150D of the ITO thin film or layer, can be referred to the above. ​ In the provided implementation, the first light conversion layer 141 completely encapsulates the multiple deposition units 121 and the conductor layer 123 formed on the substrate 110. The first end 110a and the second end 110b of the substrate 110, as well as a portion of the electrode extension end 150D on the first end 110a and the second end 110b of the substrate 110 and on which there is an ITO thin film or layer, are not encapsulated by the encapsulation structure. The conductive rings provided on the first end 110a and the second end 110b of the substrate 110 as part of the filament electrode 130 are also not encapsulated by the encapsulation structure.

[0278] In another embodiment, the conductor layer used to realize the series connection between adjacent deposition units can be implemented by a transparent conductive film or a transparent conductive layer, but the deposition units adjacent to the first end and / or the second end of the substrate are electrically connected to the filament electrode of the substrate by wire bonding process, as shown in 15b above.

[0279] In another embodiment where the electrode extension end formed by the conductor layer can also be implemented using a transparent conductive film or transparent conductive layer, in order to ensure the stability of the connection between the filament electrode 130 and the electrode extension end 150D, which is an ITO film or layer, a portion of the filament electrode 130 can be disposed between the electrode extension end 150D and the substrate 110. That is, the filament electrode 130 is configured through a stacked structure consisting of the electrode extension end 150D, the filament electrode 130, and the substrate 110. Refer to the above. ​ and 13 The provided implementation method.

[0280] In some embodiments, by improving ​ and ​ In the embodiments shown, where the electrode extension end formed by the conductor layer can also be implemented by a transparent conductive film or a transparent conductive layer, the above-mentioned second light conversion layer can still be used to cover the chip strip structure and be located between the chip strip structure and the conductor layer, so as to enable the light-emitting diode filament to have good color reproduction or high color rendering.

[0281] In some embodiments, by improving ​ and ​ In the embodiments shown, where the electrode extension end formed by the conductor layer can also be implemented by a transparent conductive film or a transparent conductive layer, the first light conversion layer can still be completely covered by the above-mentioned coating layer. In the case of the LED filament not working, the coating layer is different in color from the first light conversion layer, which is used to change the surface color of the LED filament. For example, the coating layer can be prepared by mixing different materials to make the LED filament present different colors, or to make the LED filament present different colors when it is lit and when it is not lit, thereby improving the aesthetics and light emission effect of the lamps using the LED filament.

[0282] The second aspect of this application provides a lighting device including a lamp housing and a light-emitting diode (LED) filament disposed within the lamp housing. In this application, adjacent deposition units on the substrate of the LED filament are electrically connected by a conductor layer, thus shortening the spacing between the LEDs fabricated by the deposition units. This allows for a greater number of deposition units to be disposed per unit length of the LED filament, thereby increasing the lumen output per unit length. In some embodiments, the LED filament can be configured in LED lighting devices of different shapes, specifications, or power ratings, such as bulbs, tube lights, panel lights, flat panel lights, pendant lights, recessed lights, recessed lights, and ceiling lights. In the embodiments described below, the application of the LED filament to a tube light is used as an example, and it should be understood that this is not a limitation. In some embodiments, the implementation of the LED filament can be referred to the above description. ​ The various embodiments described herein will not be repeated here.

[0283] In some embodiments, the substrate of the light-emitting diode filament includes a sapphire (Al2O3) substrate, a silicon (Si) substrate, a silicon carbide (SiC) substrate, a gallium nitride (GaN) substrate or a composite substrate thereof, a glass substrate, a metal substrate, or a rigid substrate such as a glass fiber substrate. (See also...) ​ The figure shows a schematic diagram of the structure of the lighting device of this application in one embodiment. As shown, the lighting device 200 includes a lamp housing 210 and a light-emitting diode filament 100 disposed in the lamp housing 210.

[0284] In another embodiment, the substrate of the LED filament can also be a flexible substrate, also known as a flexible substrate. For example, in one example, the flexible substrate is an FPC substrate, allowing the filament to have a certain degree of bending. The flexible filament made using an FPC substrate can be bent to achieve more filament curves or shapes. For example, in another example, the flexible substrate is a flexible PCB board, which can be made of transparent or translucent material. The flexible PCB board is fabricated by printing circuitry on a polyimide or polyester film substrate. The LED filament can be used as a bulb lamp. Please refer to [link to relevant documentation]. ​ and ​The figure shows a schematic diagram of the lighting device of this application in another embodiment. As shown, the lighting device 300 includes a bulb-shaped lamp housing 310 and at least one light-emitting diode filament 100 disposed in the lamp housing 310. It also includes a lamp holder 330 and a core post 320. In some embodiments, at least one conductive support 340 is also provided. The light-emitting diode filament 100 is connected to the core post 320, or the light-emitting diode filament 100 is connected and conductive to the conductive support 340, and the conductive support 340 is connected and conductive to the core post 320 (wherein the filament electrode is the conductive connection part between the light-emitting diode filament and the core post or the conductive support). That is, the light-emitting diode filament 100 is connected to the core post 320 and electrically conductive, and the core post 320 is connected and conductive to the lamp holder 330. The core post 320 is located inside the lamp housing 310. The lamp housing 310 and the lamp holder 330 are connected and fixed to form a sealed space for accommodating the light-emitting diode filament 100, the core post 320, the conductive support 340, etc.

[0285] A third aspect of this application also provides a method for fabricating a light-emitting diode filament. The light-emitting diode filament obtained by this method has adjacent deposition units on its substrate electrically connected by a conductor layer. The spacing between light-emitting diodes fabricated from the deposition units is shortened, allowing more deposition units to be set within a unit length of the light-emitting diode filament, thereby increasing the lumen value per unit length of the light-emitting diode filament.

[0286] In some embodiments, the light-emitting diode filament can be configured in LED lighting devices of different shapes, specifications, or power, such as bulbs, tube lights, panel lights, flat panel lights, pendant lights, recessed lights, recessed lights, and ceiling lights. In the embodiments described below, the application of the light-emitting diode filament to a tube light is used as an example, and it should be understood that this is not a limitation.

[0287] Please see ​ The flowchart shown is a preparation method of this application in one embodiment. As shown, the preparation method of the light-emitting diode filament includes the following steps:

[0288] First, step S400 is performed, providing a substrate. The substrate includes a first end, a second end remote from the first end, and a deposition section located between the first and second ends. In one embodiment, the substrate includes a sapphire (Al2O3) substrate, a silicon (Si) substrate, a silicon carbide (SiC) substrate, a gallium nitride (GaN) substrate or a composite substrate thereof, a glass substrate, a metal substrate, a fiberglass substrate, or a PCB, but is not limited thereto. In this embodiment, a sapphire substrate will be used as an example for explanation. The sapphire substrate is transparent or substantially transparent, allowing photons generated from the light-emitting layer to pass through.

[0289] In some embodiments, the thickness of the substrate is controlled between 0.25-0.45 mm, and more specifically between 0.07-0.7 mm. For example, the thickness of the sapphire substrate is controlled between 0.07-0.7 mm, i.e., between 70 μm and 700 μm.

[0290] In some embodiments, the length of the substrate 110 is 80-200mm, for example, approximately 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, or 200mm.

[0291] In the embodiment where the substrate is sapphire, the sapphire substrate used to deposit multiple deposition units can be processed by thinning and / or texturing, roughening, or patterning.

[0292] In another embodiment, the substrate can also be a flexible substrate, also known as a flexible substrate. For example, in one example, the flexible substrate is an FPC substrate, which allows the filament to have a certain degree of bending. The flexible filament made using the FPC substrate can be bent to achieve more filament curves or shapes. For example, in another example, the flexible substrate is a flexible PCB board, which can be made of transparent or translucent material. The flexible PCB board is made by printing circuits on a polyimide or polyester film substrate.

[0293] In one embodiment, the first end and / or the second end of the substrate provided in step S400 may be respectively pre-set with filament electrodes so that the conductive layer (the electrode extension end formed by the conductive layer) can be deposited in a subsequent step to achieve electrical connection with the filament electrode.

[0294] In another embodiment, the first end and / or the second end of the substrate provided in step S400 does not have a pre-set filament electrode, so a filament electrode can be provided separately in step S430 to complete the electrical connection between the filament electrode and the deposition unit.

[0295] In another embodiment, the substrate provided in step S400 is a fluorescent glass-ceramic substrate embedded with a fluoride-based red phosphor to improve the white light color rendering index (CRI) and enable the LED chip of the lighting device to improve luminous flux and color temperature under blue light power density excitation. In some embodiments, the fluoride-based red phosphor is, for example, KSF-based red K2SiF6:Mn. 4+ K2TiF6:Mn 4+ NaYF4:Mn 4+ NaGdF4:Mn 4+ K3SiF7:Mn 4+Red phosphor, etc. In a specific example, the substrate is, for example, embedded with K2SiF6:Mn. 4+ (KSF) fluorescent glass-ceramic substrate with red phosphor. For example, the one described above. ​ In the illustrated embodiment, K2SiF6:Mn is deposited on the deposition unit 121, the bonding layer 122, the conductor layer 123, and the electrode connection layer 150D. 4+ The second light conversion layer 142 of the (KSF) red phosphor and the fluorescent glass-ceramic substrate 110 formed by adding red phosphor enable the filament of the light-emitting diode to have good color reproduction or high color rendering.

[0296] In step S410, a plurality of deposition units are formed on the upper surface of the deposition section of the substrate by a deposition process, which are arranged along the length of the substrate, so that the plurality of deposition units are arranged along the length of the substrate to form a continuous strip structure. In this application, each deposition unit has photoelectric conversion capability, that is, it can be implemented to have light-emitting function. In one embodiment, the deposition unit is prepared as a relatively independent LED light emitter or light-emitting unit.

[0297] In one embodiment, the plurality of deposition units are directly deposited on a substrate, such as sapphire, and the sapphire substrate serves as the main substrate without the need to provide a separate main substrate, such as silicon, ceramic, metal or any other suitable material.

[0298] In some embodiments, the number of multiple deposition units formed in the deposition section of the substrate is 50, and the voltage across the two ends is 130V-135V.

[0299] In other embodiments, the number of deposition units formed in the deposition section of the substrate is 100, and the voltage across the two ends is 260V-265V.

[0300] In some embodiments, the specifications of each deposition unit formed in the deposition section of the substrate include 9 mil × 18 mil, 11 mil × 30 mil, or 13 mil × 30 mil, or combinations thereof.

[0301] Because the deposition cells forming the light-emitting diodes extend uninterruptedly from one end of the substrate to the other, the entire filament emits light through a complete array of light-emitting diodes. Since the vast majority of the substrate surface is covered by the deposition cells, these cells can maintain a large light-emitting area.

[0302] In some embodiments, the luminescent area of ​​the deposition unit can be understood as the top area of ​​the deposition unit minus the portion of the deposition unit covered by the conductor layer, its first electrode, and its second electrode, and the length and width of the conductor layer, the first electrode, and the second electrode can be adjusted as needed. For example, the proportion of the luminescent area of ​​the deposition unit to the top area of ​​the deposition unit is greater than 94% and less than 100%, such as approximately 95%, 96%, 97%, 98%, or 99%. Since the deposition units are connected by conductor layers rather than by wire bonding processes, there is no need to set up pad structures for wire bonding on the deposition units, so the deposition units can maintain a large luminescent area.

[0303] In some embodiments, the ratio of the total area occupied by the plurality of deposition units formed in the deposition section of the substrate to the area of ​​the upper surface of the deposition section of the substrate is 0.94-0.99, for example 94%, 95%, 96%, 97%, 98% or 99%.

[0304] In some embodiments, deposition units can be configured on the light-emitting diode filament using the parameter relationships shown in Table 1 above.

[0305] By executing step S410, each of the plurality of deposition units includes: a first semiconductor layer, a first electrode, a second semiconductor layer, a second electrode, and a light-emitting layer formed between the first semiconductor layer and the second semiconductor layer, as described above. ​ or ​ The structure shown.

[0306] In this application, the first semiconductor layer and the second semiconductor layer have different conductivity types. For example, in one embodiment, the first semiconductor layer is made of an N-type semiconductor material, and correspondingly, the second semiconductor layer is made of a P-type semiconductor material. For example, the first semiconductor layer is N-type doped gallium nitride (n-GaN), and correspondingly, the second semiconductor layer is P-type doped gallium nitride (p-GaN), and the light-emitting layer is made of indium gallium nitride (InGaN).

[0307] The deposition unit includes a light-emitting or active region sandwiched between an N-type semiconductor material and a P-type semiconductor material, namely the aforementioned light-emitting layer. In step S410, the N-type semiconductor material can first be grown on a sapphire substrate. The N-type semiconductor material can include multiple layers with different compositions and dopant concentrations, such as preparation layers like buffer layers or nucleation layers, and / or layers designed to facilitate the removal of the growth substrate, which can be N-type or unintentionally doped, and N-type device layers designed to obtain specific optical, material, or electrical properties for efficient light emission from the light-emitting region.

[0308] In step S410, a light-emitting or active region is grown on the N-type semiconductor material to form a light-emitting layer. Examples of suitable light-emitting layers include a single thick or thin light-emitting layer, or a multi-quantum-well light-emitting region comprising multiple thin or thick light-emitting layers separated by a barrier layer. A P-type semiconductor material can then be grown on the light-emitting layer. Like the N-type semiconductor material, the P-type semiconductor material can comprise multiple layers with different compositions, thicknesses, and dopant concentrations, including unintentionally doped layers.

[0309] In step S410, after the growth of the first and second semiconductor layers, a portion of the second semiconductor layer and the light-emitting layer is removed using a masking and etching process or a photolithography process to expose a portion of the first semiconductor layer. Then, a first electrode is formed on the exposed surface of the N-type semiconductor material, and a second electrode is formed on the surface of the remaining P-type semiconductor material. In one embodiment, the first electrode may be referred to as an N-electrode, and the second electrode may be referred to as a P-electrode. In this embodiment, the N-electrode and the P-electrode are electrically isolated from each other by a gap, which may be filled with a dielectric such as silicon oxide or any other suitable material. The gap may be filled with a dielectric material or a different solid material, or it may be left unfilled, with air isolating the space.

[0310] In one embodiment of step S410, the first electrode, which is an N-electrode, or the second electrode, which is a P-electrode, may include one or more conductive layers, such as a reflective metal and a protective metal, which can prevent or reduce electromigration of the reflective metal. The reflective metal is typically silver, but any one or more suitable materials can be used.

[0311] In one embodiment of step S410, multiple N-electrode vias may be formed during the fabrication of the N-electrode; the N-electrode and P-electrode are not limited to... ​ The arrangement is shown in the diagram. The N and P electrodes can be redistributed to form bonding pads with dielectric / metal stacks.

[0312] In one embodiment of step S410, the first electrode, which is an N electrode, or the second electrode, which is a P electrode, can be, for example, gold, copper, an alloy, or any other suitable material formed by plating or any other suitable technique.

[0313] In one embodiment of step S410, the first electrode, which is an N-type electrode, or the second electrode, which is a P-type electrode, is prepared by electron beam vacuum evaporation deposition to form the first electrode on the exposed surface of the N-type semiconductor material and the second electrode on the surface of the retained P-type semiconductor material, respectively.

[0314] In one embodiment of step S410, the first electrode, which is an N-type electrode, or the second electrode, which is a P-type electrode, is prepared by a sputtering deposition process to form the first electrode on the exposed portion of the N-type semiconductor material and the second electrode on the retained P-type semiconductor material surface, respectively. In this embodiment, the sputtering deposition process is, for example, ion beam sputtering or cathode sputtering.

[0315] In one embodiment of step S410, the N-electrode or P-electrode may include a transparent electrode that is conductive and transparent to light, such as... ​ In the illustrated embodiment, the transparent electrode can be made of indium tin oxide (ITO) or a thin film or layer of tin-doped indium oxide (i.e., ​ (ITO as shown in the figure); In embodiments using an ITO thin film or layer as an electrode contact layer, the ITO thin film or layer is most typically deposited onto the surface using electron beam evaporation, physical vapor deposition, or some sputtering deposition techniques.

[0316] In some embodiments, since the ITO film or ITO layer cannot be used as a pad, the specific fabrication process first involves forming ohmic electrodes (also known as electrode contacts or ohmic contacts) on the surfaces of the first and second semiconductor materials. Then, an ITO film or layer is deposited on the surface of the ohmic electrodes, followed by the deposition of a metal pad on the surface of the ITO film or layer to form a P-electrode or N-electrode. In this way, the current flowing through the deposition unit is uniformly distributed to each ohmic contact electrode via the ITO film or layer. Simultaneously, because the refractive index of the ITO film or layer is between that of air and the deposited material, the light emission angle and luminous flux can be improved.

[0317] In some embodiments, a conductor layer for connecting two deposition units can be directly deposited on an ITO thin film or layer. In a specific fabrication process, ohmic electrodes (also known as electrode contacts or ohmic contacts) are first formed on the surfaces of the first and second semiconductor materials. Then, an ITO thin film or layer is deposited on the surface of the ohmic electrodes. A conductor layer is then vapor-deposited on the surface of the ITO thin film or layer to connect the two adjacent deposition units. This further reduces the overall thickness of the filament, and the current from the deposition unit is evenly distributed to each ohmic contact electrode through the ITO thin film or layer. Simultaneously, because the refractive index of the ITO thin film or layer is between that of air and the deposition material, the light emission angle and luminous flux can be improved.

[0318] In one embodiment of step S410, the method further includes forming a connecting layer between adjacent deposition units on the substrate using a deposition process. This allows the multiple deposition units to form a continuous strip structure on the substrate, resulting in a chip strip structure for the fabricated LED filament. This strengthens the overall structure of the chip strip and ensures that the electrical connections between the deposition units are not broken due to "broken wires." For example... ​ The figure shows a side view of a light-emitting diode filament according to another embodiment of this application. As shown, since the chip strip structure 101 extends uninterruptedly from one end of the substrate 110 to the other, the entire filament emits light through a complete chip strip structure 101. The vast majority of the surface area of ​​the substrate 110 is covered by the chip strip structure 101, so the light-emitting diode 100 can maintain a large light-emitting area. The top area of ​​the chip strip structure 101 accounts for more than 94% and less than 100% of the top area of ​​the substrate 110, for example, 95%, 96%, 97%, 98%, or 99%.

[0319] In some embodiments, the length of the substrate 110 is 80 mm to 200 mm, for example 80 mm, 100 mm, 120 mm, 140 mm, 160 mm, 180 mm or 200 mm.

[0320] In one embodiment of step S410, while a bonding layer is formed between adjacent deposition units on the substrate, a bonding layer is also provided on the outside of the deposition unit adjacent to the first end of the substrate to form a protective layer, so as to isolate the contact between the conductor layer and the first semiconductor layer, light-emitting layer and second semiconductor layer of the deposition unit.

[0321] In one embodiment of step S410, the ratio of the height of the bonding layer to the height of the deposition unit is 0.80-1.20. In other words, in order to make the light-emitting diode filament present a chip strip structure, the height of the bonding layer prepared by the deposition process is almost similar to or the same as the height of the deposition unit during the preparation of the light-emitting diode filament, so that there is no gap or obvious height difference between multiple deposition units in terms of physical structure. Specifically, the ratio of the height of the bonding layer to the height of the deposition unit is 0.80, 0.90, 1.00, 1.10, or 1.20, etc.

[0322] In one embodiment of step S410, in order to ensure that the prepared light-emitting diode filament can provide more lumens or better heat dissipation efficiency per unit length, in this embodiment, as many deposition units as possible are set by controlling the spacing between adjacent deposition units. The ratio of the first length of the bonding layer along the length direction of the substrate to the second length of each deposition unit along the length direction of the substrate is 0.05-0.30. When the ratio of the first length to the second length is within the above range, the light-emitting diode filament can maintain better heat dissipation efficiency and light-emitting area.

[0323] In one embodiment of step S410, to ensure that the fabricated LED filament exhibits a chip-strip structure, the width of the bonding layer fabricated using the deposition process is approximately the same as or similar to the width of the deposition unit during the fabrication of the LED filament. In one embodiment, the first width of the bonding layer along the width direction of the substrate is equal to the second width of each deposition unit along the width direction of the substrate. In this embodiment, the first width of the bonding layer along the width direction of the substrate is almost equal to the second width of the deposition unit along the width direction of the substrate, thereby ensuring that the fabricated LED filament exhibits a chip-strip structure. For example, the parameters listed in Table 1 above will not be repeated here.

[0324] In one embodiment of step S410, adjacent deposition units are electrically connected to each other on both sides of the junction layer by a formed conductive layer covering the junction layer. In this embodiment, the conductive layer is located on the upper surface of the junction layer so that the conductive layer between two adjacent deposition units can be attached to the junction layer.

[0325] In another embodiment of step S410, adjacent deposition units are electrically connected to the deposition units on both sides of the connecting layer through a formed conductor layer. In this embodiment, both the upper and lower surfaces of the conductor layer are in contact with the connecting layer. In the fabrication process, the connecting layer can be formed between adjacent deposition units first through a deposition process, and then a conductor layer can be formed on the connecting layer through a deposition process to electrically connect the adjacent deposition units on both sides. After that, the connecting layer can be covered on the conductor layer through a deposition process to embed the conductor layer therein, thereby strengthening the electrical connection between adjacent deposition units and making the fabricated LED filament present a more stable and consistent chip strip structure.

[0326] In step S420, a conductive layer is formed on the plurality of deposition units through a deposition process to electrically connect adjacent deposition units, so that the plurality of deposition units form a continuous strip structure on the substrate.

[0327] In one embodiment of step S420, a conductor layer is further formed between adjacent deposition units and on deposition units adjacent to the first and second ends of the substrate using a vapor deposition or sputtering process. In this application, the conductor layer formed by the deposition process is thinner than the thicker wire bonding process (the wires in wire bonding need to maintain an arc segment, resulting in a thicker overall thickness) due to the traditional wire bonding process. This reduces the overall thickness of the LED filament. In addition, the conductor layer formed by the deposition process in this application avoids the problems of wire bonding detachment or breakage.

[0328] For example, if the length of the LED filament (mainly the substrate length) is 83 mm, the deposition units prepared in step S420 are connected by a conductor layer. The thickness of the bonding layer between the deposition units along the filament length is controlled between 0.02 mm and 0.3 mm, and the number of deposition units can be 100. In a comparative example, if the length of the LED filament 100 is also 83 mm, the deposition units are connected by wire bonding, and the spacing between the deposition units needs to be set between 0.3 mm and 1 mm, then the number of deposition units is 50. Therefore, the number of deposition units per unit length of the LED filament in the above embodiment is twice that of the comparative example, thus providing nearly twice the lumen output. Similarly, with the same number of deposition units, the length of the LED filament in the embodiment can be shortened to nearly half that of the comparative example, requiring only 0.5 times the length of the wire bonding method.

[0329] In one embodiment of step S420, the material of the conductor layer includes, but is not limited to, conductive materials such as copper, gold, silver, and alloys.

[0330] In step S420, when the conductor layer is prepared, it is formed together with the first and second electrodes of each deposition unit using a single deposition process. In this embodiment, for example, the first electrode (N-type) or the second electrode (P-type) can be prepared by electron beam vacuum evaporation or sputtering to form the first electrode on the exposed surface of the N-type semiconductor material and the second electrode on the remaining surface of the P-type semiconductor material. Simultaneously, the conductor layer can also be prepared by electron beam vacuum evaporation or sputtering, allowing each conductor layer to be directly integrated with the electrodes of the deposition units on both sides. This not only strengthens the electrical connection between the deposition units but also makes the overall LED filament exhibit a more stable and consistent chip-strip structure. For example, since the conductor layer and the first and second electrodes of each deposition unit are formed in a single deposition process, the three are integrally molded, thus there is no clear boundary line in the structure.

[0331] In one embodiment of the fabrication of the conductor layer, the conductor layer and the first and second electrodes of each deposition unit are formed using the same material through a deposition process. This allows the conductor layer, the first electrode, and the second electrode to be formed simultaneously during the deposition process, as described above. ​ The illustrated embodiment. This deposition process may include, for example, chemical vapor deposition, atomic layer deposition, and physical vapor deposition, but is not limited thereto.

[0332] In step S420, when the conductor layer is prepared, the method further includes forming electrode extension ends by a deposition process on the conductor layer formed on the deposition unit adjacent to the first end and / or the second end of the substrate, so as to electrically connect the filament electrode.

[0333] In one embodiment of the fabrication of the conductor layer, the conductor layer is formed by a deposition process using the same material as the first and second electrodes of each deposition unit. The first and second electrodes of each deposition unit can be fabricated using an ITO thin film or ITO layer, and the conductor layer and electrode extensions formed by the conductor layer can also be fabricated at the same time. The ITO thin film or layer is most typically deposited on the surface using electron beam evaporation, physical vapor deposition, or some sputtering deposition techniques.

[0334] In another embodiment of the fabrication of the conductor layer, the conductor layer and the first and second electrodes of each deposition unit are formed using different materials through a deposition process, with the conductor layer, the first electrode, and the second electrode formed in separate steps by different deposition processes. These deposition processes may include, for example, chemical vapor deposition, atomic layer deposition, and physical vapor deposition, but are not limited to these.

[0335] In another embodiment of the fabrication of the conductor layer, the second electrode of the deposition unit located at the first end of the substrate, electrically connected to the electrode extension end of the second electrode, and the first electrode of the deposition unit located at the second end of the substrate, electrically connected to the electrode extension end of the first electrode, are made of the same material or using the same deposition process, such as copper, gold, silver, alloys, etc., to better achieve electrical connection with the filament electrodes at the first and second ends of the substrate; while the conductor layer between adjacent deposition units in the substrate is made of a different material or using a different identical process. In this embodiment, the conductor layer between adjacent deposition units is made, for example, using an ITO thin film or an ITO layer, as described above. ​ or ​ In the described embodiment, to further improve the luminous flux of the light-emitting diode filament, the conductor layer used to realize the series connection between adjacent deposition units can be implemented by a transparent conductive film or a transparent conductive layer.

[0336] As described in the above embodiments, adjacent deposition units on the substrate are electrically connected by the conductor layer, which allows the spacing between the light-emitting diodes fabricated by the deposition units 121 to be shortened. This enables more deposition units to be set within a unit length of the light-emitting diode filament, thereby increasing the lumen value per unit length of the light-emitting diode filament. For this purpose, in one embodiment, the length of the conductor layer formed by the deposition process between adjacent deposition units along the length direction of the substrate can be configured to be 0.03 mm to 0.30 mm. In some embodiments, the length may be, for example, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.20mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, or 0.30mm, etc.

[0337] In one embodiment, the third width of the conductor layer along the width direction of the substrate is smaller than the second width of the deposition unit along the width direction of the substrate, thereby reducing the obstruction of light emitted by the deposition unit by the conductor layer, as described above. ​ The state shown. For example, in some specific examples, the third width of the conductor layer along the width direction of the substrate is 1.5mm-8.0mm, and the third width can be, for example, approximately 1.5mm, 2.0mm, 2.5mm, 3.0mm, 3.5mm, 4.0mm, 4.5mm, 5.0mm, 5.5mm, 6.0mm, 6.5mm, 7.0mm, 7.5mm, or 8.0mm, etc.

[0338] In another embodiment of the fabrication of the conductor layer, when fabricating the conductor layer formed between adjacent deposition units through a deposition process, conductor layers are also formed on the deposition units adjacent to the first end and / or the second end of the substrate through the same deposition process to obtain electrode extension ends, so as to achieve electrical connection with the filament electrodes at both ends of the substrate. That is, in this embodiment, the conductor layer formed between adjacent deposition units and the electrode extension ends of the deposition units adjacent to both ends of the substrate are obtained in a single fabrication process. In some embodiments, the electrode extension ends and the conductor layer obtained by the single fabrication process are made of the same material; the material of the electrode extension ends includes conductive materials, such as copper, gold, silver, alloys, etc., but is not limited thereto.

[0339] In one embodiment of the fabrication of the conductor layer, the conductor layer formed between the deposition units, the conductor layer formed by the deposition units adjacent to the first end and / or the second end of the substrate, the first electrode, and the second electrode are made of the same material. The conductor layer, the first electrode, and the second electrode can be formed simultaneously by a deposition process. This deposition process includes, but is not limited to, chemical vapor deposition, atomic layer deposition, and physical vapor deposition processes.

[0340] In some embodiments of the preparation of the conductor layer, the conductor layer formed between adjacent deposition units by the deposition process can also be referred to as the first conductor layer, and the conductor layer formed by the deposition process at the deposition unit adjacent to the first end and / or the second end of the substrate can also be referred to as the second conductor layer, which is the electrode extension end.

[0341] In step S430, the deposition units adjacent to the first and second ends of the substrate are electrically connected to the filament electrodes disposed at both ends of the substrate. In one embodiment, the filament electrode is used to electrically connect to a conductive support to receive power from the drive circuit. The connection between the filament electrode and the conductive support can be a mechanical clamping connection or a welding connection. The mechanical connection can be achieved by first passing the conductive support through a specific perforation formed on the filament electrode, and then folding back the free end of the conductive support so that the conductive support clamps the electrode and forms an electrical connection. The welding connection can be achieved by using silver-based alloy solder, silver solder, or tin solder to connect the conductive support to the filament electrode.

[0342] In one embodiment, filament electrodes can be pre-set at the first end and / or the second end of the substrate provided in step S400, so that the conductive layer deposited in step S430 (the electrode extension end formed by the conductive layer) can be directly electrically connected to the filament electrode; or the leads formed by the wire bonding process can be electrically connected to the electrodes of the deposition units at both ends of the substrate.

[0343] In another embodiment, the first end and / or the second end of the substrate provided in step S400 does not have a pre-set filament electrode, so a filament electrode can be provided separately in step S430 to complete the electrical connection between the filament electrode and the deposition unit.

[0344] In one embodiment, the filament electrode can be disposed at a first end and / or a second end of the substrate via a light-emitting diode filament encapsulation structure, such as a light conversion layer for encapsulating the entire filament strip. In this embodiment, the encapsulation structure is, for example, a light conversion layer; in some cases, the encapsulation structure is also referred to as an encapsulating layer.

[0345] In one embodiment, the filament electrode may be configured as a conductive ring or conductive sleeve, for example... ​ and ​In another embodiment of the presented structure, the filament electrode can be configured as a metal sheet disposed at the first end and / or the second end of the substrate. In a specific implementation, the metal sheet is, for example, a copper sheet or an aluminum sheet, or other metal sheet with conductive properties. ​ , ​ , ​ , ​ and ​ The structures characterized in the illustrated embodiments.

[0346] In one embodiment of step S430, the deposition unit adjacent to the first end and / or the second end of the substrate is electrically connected to the filament electrode of the substrate via wire bonding formed by a wire bonding process, such as the one described above. ​ The embodiments shown will not be described in detail here.

[0347] In another embodiment of step S430, the second electrode of the deposition unit located at the first end of the substrate and the first electrode of the deposition unit located at the second end of the substrate are made of the same material or using the same deposition process, such as copper, gold, silver, alloys, etc., so that they can be better electrically connected to the filament electrodes at the first and second ends of the substrate through leads; while the conductor layer between adjacent deposition units in the substrate is made of a different material or another identical process. In this embodiment, the conductor layer between adjacent deposition units is made of, for example, an ITO thin film or an ITO layer, as described above. ​ The example shown.

[0348] In another embodiment of step S430, electrode extension ends formed by the conductive layer formed by the deposition process electrically connect the deposition units adjacent to the first and second ends of the substrate to the filament electrodes disposed at both ends of the substrate. In this embodiment, in step S420 above, when the conductive layer formed between adjacent deposition units is prepared by the deposition process, electrode extension ends are obtained by forming conductive layers in the deposition units adjacent to the first and / or second ends of the substrate, so as to achieve electrical connection with the filament electrodes at both ends of the substrate. That is, in this embodiment, the conductive layer formed between adjacent deposition units and the electrode extension ends of the deposition units adjacent to both ends of the substrate are obtained in a single fabrication process.

[0349] To ensure sufficient electrical contact between the filament electrode and the deposition units adjacent to the first and / or second ends of the substrate without causing an open circuit, or to facilitate the placement of filament electrodes on both sides of the substrate, the deposition area of ​​the electrode extension can be controlled by the deposition process during the fabrication of the electrode extension. For example, in some embodiments, the deposition area of ​​the electrode extension on the substrate accounts for more than 70% of the deposition area of ​​the deposition units adjacent to the first and / or second ends of the substrate on the substrate. For instance, the deposition area of ​​the electrode extension on the substrate accounts for approximately 70%, 75%, 80%, 85%, 90%, 95%, or 100% of the deposition area of ​​the deposition units adjacent to the substrate end.

[0350] In one embodiment, the electrode extension is electrically connected to the filament electrode via welding or hot-melt process.

[0351] In another embodiment, the electrode extension is formed on the upper surface of the first end and / or the second end of the substrate to electrically connect the upper surface of the filament electrode. For example, after the conductor layer is prepared, the prepared filament electrode is placed on the upper side of the electrode extension formed through the conductor layers at both ends of the substrate, and the filament electrode is fixed on the upper side of the electrode extension by welding or hot-melt process or directly by sealing process to achieve electrical connection between the two. ​ The state shown.

[0352] In another embodiment, all or part of the electrode extension is disposed between the substrate and the filament electrode 130 to electrically connect the filament electrode. To ensure the stability of the connection between the filament electrode and the electrode extension, a portion of the filament electrode can be disposed between the electrode extension and the substrate. That is, the filament electrode is configured through a stacked structure consisting of the electrode extension, the filament electrode, and the substrate. For example, in the manufacturing process, after the deposition unit is prepared by a deposition process, two filament electrodes are placed at both ends of the substrate, specifically on the upper surface of the substrate. Then, a conductor layer is prepared by a deposition process, so that the electrode extensions formed at both ends of the substrate are directly deposited on the upper side of the filament electrode to electrically connect the filament electrode. Then, a sealing process is used to complete the encapsulation of the entire filament. For example... ​ The state shown in any embodiment.

[0353] In one embodiment, the fabrication method of this application further includes the step of coating the substrate with a light conversion material, and forming a plurality of deposition units and a conductor layer on the substrate, as well as a portion of the filament electrode, to form an encapsulation structure, which may also be referred to as step S440: Please refer to ​The figure shows a flowchart of the preparation method of this application in another embodiment. As shown, in step S440, a light conversion material is coated onto the substrate, a plurality of deposition units and conductor layers formed on the substrate, and a portion of the filament electrode and cured to form an encapsulation structure.

[0354] The packaging structure is, for example, a light conversion layer that covers the substrate, a plurality of deposition units and conductor layers formed on the substrate, and a portion of the filament electrode. A portion of the filament electrode not covered by the light conversion layer is exposed for electrical connection to a conductive bracket or lamp holder or an external power supply device, so as to receive power from the drive circuit.

[0355] In one embodiment, the step of forming the encapsulation structure further includes: using a light conversion material to form a first layer covering the substrate, a plurality of deposition units and conductor layers formed on the substrate, a portion of the filament electrode, and a second layer covering the lower surface of the substrate. In this embodiment, the first layer of the first light conversion layer is the top layer, and the second layer of the light conversion layer is the base layer.

[0356] The light conversion layer includes particles / materials distributed therein, as described above. ​ The description of the light conversion layer includes, for example, step S440, where a second light conversion layer is prepared to cover the chip strip structure and is located between the chip strip structure and the conductor layer, to give the LED filament good color reproduction or high color rendering. Another example is step S440, where a coating layer is prepared to completely cover the first light conversion layer, and the coating layer is a different color from the first light conversion layer when the LED filament is not in operation, to change the surface color of the LED filament. For example, the coating layer can be prepared by mixing different materials, allowing the LED filament to exhibit different colors, or allowing the LED filament to exhibit different colors when lit and unlit, thereby improving the aesthetics and light emission effect of the lamps using the LED filament. As described above... ​ The embodiments described herein will not be repeated here.

[0357] In some embodiments, in the conversion layer encapsulating the substrate, the particles in the region corresponding to the deposition unit and the corresponding electrode extension end, or the region corresponding to the conductor layer between the deposition units, can have different structures, materials, effects, or distribution densities. This is because the deposition units and the conductor layer perform different functions, and therefore the light conversion layers of the deposition units and the conductor layer can be respectively provided with different types of particles to achieve different effects. For example, the particles distributed in the deposition unit of the light-emitting diode filament and the particles distributed in the conductor layer have different sizes, materials, and / or densities. As mentioned above... ​The relevant descriptions of the optical conversion layer in the text will not be repeated here.

[0358] In some embodiments, the light conversion layer includes a first light conversion layer and a second light conversion layer; as described above regarding ​ The relevant descriptions of the first and second optical conversion layers will not be repeated here.

[0359] In general, the method for forming the light-emitting diode filament 100 can be described as follows: In one step, a plurality of deposition units 121 are disposed on the substrate 110 along the length direction of the substrate 110. In the next step, a bonding layer 122 is formed between adjacent deposition units 121 to electrically isolate adjacent deposition units 121. In the next step, a conductor layer 123 is formed on adjacent deposition units 121 to electrically connect adjacent deposition units 121. Specifically, the first electrode E1 of one deposition unit 121 is connected to the second electrode E2 of another deposition unit 121 via the conductor layer 123 to achieve electrical conduction.

[0360] The lighting device, LED filament, and fabrication method provided in this application form a conductive layer electrically connecting multiple deposition units during the deposition process, thereby creating a continuous strip structure on the substrate. Compared to the traditional wire bonding process, which results in thicker wires and a higher risk of wire breakage or detachment, the LED filament of this application has a more stable electrical connection. Furthermore, an interconnecting layer is formed between adjacent deposition units on the substrate, allowing multiple deposition units to form a continuous strip structure. This results in an overall chip-strip structure for the LED filament, strengthening the overall chip-strip structure and preventing electrical breaks between deposition units due to wire breakage. Moreover, compared to traditional filaments, the conductive layer formed by the deposition process allows for a shorter spacing between deposition units, enabling more deposition units to be placed per unit length, thus increasing the lumen output per unit length.

[0361] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.

Claims

1. A lighting device, characterized in that, include: The lamp housing and the lamp holder are connected to form a sealed space; At least one light-emitting diode filament is disposed in the enclosed space; A core post is connected to the lamp holder and electrically connected to the filament of the light-emitting diode; the filament of the light-emitting diode includes: a chip strip structure; a light conversion unit enclosing the chip strip structure; and electrodes located at both ends of the chip strip structure along its length and electrically connected thereto; wherein at least a portion of the electrodes are enclosed in the light conversion unit; the chip strip structure includes a substrate, the substrate including a first end and a second end away from the first end, and a deposition section located between the first and second ends; the deposition section includes a plurality of deposition units, a connecting layer being disposed between the deposition units; and a conductor layer for electrically connecting each deposition unit.

2. The lighting device according to claim 1, characterized in that: The plurality of deposition units are arranged along the length of the substrate, wherein adjacent deposition units are electrically connected through the conductor layer formed by the deposition process, so that the plurality of deposition units form a continuous strip structure on the substrate.

3. The lighting device according to claim 2, characterized in that: The electrode is a filament electrode disposed at the first end and / or the second end of the substrate, for electrically connecting to a deposition unit adjacent to the first end and / or the second end of the substrate.

4. The lighting device according to claim 3, characterized in that: The substrate can be made of transparent or opaque material.

5. The lighting device according to claim 4, characterized in that: The substrate is a sapphire substrate, silicon substrate, silicon carbide substrate, glass substrate, metal substrate, fiberglass substrate, PCB, or flexible substrate.

6. The lighting device according to claim 5, characterized in that: The thickness of the substrate is 70μm-700μm.

7. The lighting device according to claim 6, characterized in that: The connecting layer formed between adjacent deposition units on the substrate enables the plurality of deposition units to form a continuous strip structure on the substrate.

8. The lighting device according to claim 7, characterized in that: The ratio of the height of the connecting layer to the height of the deposition unit is 0.80-1.

20.

9. The lighting device according to claim 8, characterized in that: The ratio of the first length of the connecting layer along the length direction of the substrate to the second length of each deposition unit along the length direction of the substrate is 0.05-0.

30.

10. The lighting device according to claim 9, characterized in that: The first width of the bonding layer along the width direction of the substrate is equal to the second width of each deposition unit along the width direction of the substrate.

11. The lighting device according to claim 10, characterized in that: The first length of the connecting layer along the length direction of the substrate is 0.03 mm to 0.30 mm.

12. The lighting device according to claim 11, characterized in that: Adjacent deposition units are electrically connected to each other on both sides of the bonding layer by a conductive layer that covers the bonding layer.

13. The lighting device according to claim 12, characterized in that: The deposition unit includes: a first semiconductor layer formed on the substrate; a light-emitting layer formed on the first semiconductor layer; a second semiconductor layer formed on the light-emitting layer; a first electrode formed on the first semiconductor layer and spaced apart from the light-emitting layer; and a second electrode formed on the second semiconductor layer.

14. The lighting device according to claim 13, characterized in that: The deposition units adjacent to the first end and / or the second end of the substrate are electrically connected to the filament electrode of the substrate by wire bonding process.

15. The lighting device according to claim 13, characterized in that: The deposition units adjacent to the first end and / or the second end of the substrate form electrode extensions through the conductor layer formed by the deposition process to electrically connect to the filament electrode.

16. The lighting device according to claim 14 or 15, characterized in that: The deposition area of ​​the electrode extension end on the substrate accounts for more than 70% of the deposition area of ​​the deposition unit adjacent to the first end and / or the second end of the substrate on the substrate.

17. The lighting device according to claim 1, characterized in that: The optical conversion unit includes a first optical conversion layer and a second optical conversion layer. The second optical conversion layer covers the chip strip structure and is located between the first optical conversion layer and the conductor layer. The first optical conversion layer wraps around the outside of the second optical conversion layer and covers at least a portion of the second optical conversion layer.

18. The lighting device according to claim 17, characterized in that: The second light conversion layer includes K2SiF6∶Mn4+ (KSF) red phosphor.

19. The lighting device according to claim 18, characterized in that: It also includes a coating layer that completely covers the first light conversion layer and has a different color from the first light conversion layer when the light-emitting diode filament is not in operation.

20. The lighting device according to claim 19, characterized in that: The conductor layer and the first and second electrodes of each deposition unit are formed by a single deposition process, and the first and second electrodes are made of the same material.

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