WO2022042432A1

WO2022042432A1 - Light emitting diode filament, and light bulb using light emitting diode filament

Info

Publication number: WO2022042432A1
Application number: PCT/CN2021/113685
Authority: WO
Inventors: 熊爱明; 周林; 王名斌; 陈振坤; 余志善; 江涛; 黎岳兴; 鳗池勇人; 斎藤幸广; 张志超
Original assignee: 嘉兴山蒲照明电器有限公司
Priority date: 2020-08-24
Filing date: 2021-08-20
Publication date: 2022-03-03
Also published as: CN216619385U; WO2022042431A3; EP4200907A2; CN219775501U; CN219283100U; WO2022042431A2; CN219283099U; JP3242967U; CN114087545A

Abstract

The present application relates to the field of lighting. Disclosed is an LED filament, comprising an LED segment, an electrode, and a light conversion layer. The LED segment comprises at least one LED chip; the adjacent LED chips, and the LED chip and the electrode are electrically connected in the LED filament; the light conversion layer comprises a top layer and a bearing layer; the bearing light comprises a transparent layer and a base layer; the top layer, the base layer and the LED chip make contact with each other; the transparent layer and the base layer make contact with each other; in a length direction of the LED filament, the length of the transparent layer is shorter than the length of the base layer.

Description

A light-emitting diode filament and a bulb lamp using the light-emitting diode filament

technical field

The present application relates to the field of lighting, and in particular, to an LED filament and a bulb lamp using the LED filament.

Background technique

Light-emitting diodes (LEDs) have the advantages of environmental protection, energy saving, high efficiency and long life, so they have been paid attention to in recent years and gradually replaced the status of traditional lighting fixtures. However, the light emission of traditional LED light sources is directional, unlike traditional lamps that can provide illumination in a wide and wide-angle range. Therefore, the application of LEDs to traditional lamps has corresponding challenges depending on the type of lamps.

In recent years, an LED filament that enables LED light sources to emit light similar to traditional tungsten filament bulbs and achieve 360° full-angle illumination has been increasingly valued by the industry. This kind of LED filament is made by connecting multiple LED chips in series on a narrow and slender glass substrate, then wrapping the entire glass substrate with silicone doped with phosphor powder, and then making electrical connections. In addition, there is also a flexible LED filament, which is similar in structure to the above-mentioned filament, but the glass substrate part is replaced with a flexible substrate (hereinafter referred to as FPC), so that the filament can have a certain degree of bending. However, the soft filament made of FPC has some disadvantages, such as the thermal expansion coefficient of FPC is different from that of the silica gel covering the filament, and the long-term use leads to the displacement or even degumming of the LED chip; or the FPC is not conducive to the flexible change of process conditions.

The applicant has disclosed a soft filament (for example: some embodiments of Chinese Patent Publication No. CN106468405A), in which a soft filament structure without a carrier substrate is provided, so as to have a flexible fluorescent package with wavelength conversion function , to replace the traditional structure that the chip must be mounted on the substrate first, and then the phosphor powder/package is applied. However, some of the filament structures pose challenges to the stability of metal bonding between chips when they are bent. When the chips in the filament are carefully arranged, if the adjacent LED chips are connected by metal bonding, it is easy to When the filament is bent, the stress is too concentrated on a specific part of the filament, and the metal wire connecting the LED chips is damaged or even broken. Therefore, some embodiments still have room for improvement in quality.

In the prior art, most LED lamps use a combination of blue LED chips and yellow phosphors to emit white light, but the emission spectrum of LED lamps is weak in the red light region, and the color rendering index is low, which makes it difficult to achieve low color temperature. To improve the color rendering index, generally add a certain amount of green phosphors and red phosphors, but the relative conversion rate of red phosphors is low, which usually leads to a decrease in the overall luminous flux of the LED lamp, that is, a decrease in luminous efficiency.

This application further optimizes the above application to further correspond to various process and product requirements.

In addition, the LED filament is generally set in the LED bulb, and in order to present the beauty of the appearance, and to make the lighting effect of the LED filament more uniform and broad, the LED filament will be bent to show various curves. However, LED chips are arranged in the LED filament, and the LED chips are relatively hard objects, which makes it difficult for the LED filament to be bent into a desired shape. In addition, the LED filament is also prone to cracks due to stress concentration during bending.

At present, LED filament lamps generally use a driving power supply to convert alternating current into direct current and then drive light. However, there is ripple in the process of rectifying alternating current into direct current by the driving power supply, which will cause the LED filament to flicker when emitting light. In order to reduce or even eliminate the stroboscopic flicker generated during the lighting process of the LED filament, an electrolytic capacitor for ripple removal is usually added to the driving power supply. The heat generated by the heating element in the driving power supply will have a great impact on the service life of the electrolytic capacitor. .

SUMMARY OF THE INVENTION

It is particularly noted that this disclosure may actually include one or more inventive aspects currently claimed or not yet claimed, and in order to avoid confusion due to unnecessary distinctions between these inventions in the course of writing the specification, multiple The inventive aspects may be collectively referred to herein as the "application."

A number of embodiments with respect to the "application" are briefly described herein. However, the word "application" is only used to describe certain embodiments disclosed in this specification (whether or not claimed), rather than a complete description of all possible embodiments. Certain embodiments of the various features or aspects described below as "the present application" may be combined in various ways to form an LED light bulb or part thereof.

The present application discloses an LED filament. The LED filament includes an LED segment, an electrode and a light conversion layer. The LED segment includes at least one LED chip. In the LED filament, adjacent LED chips and between the LED chips and the electrodes are provided. They are electrically connected to each other. The light conversion layer includes a top layer and a carrier layer. The carrier layer includes a transparent layer and a base layer. The top layer and the base layer are in contact with the LED chip, and the transparent layer is in contact with the base layer. In the length direction of the LED filament, the length of the transparent layer is smaller than that of the base layer. length.

Preferably, the base layer includes opposing upper and lower surfaces, the upper surface of the base layer is in contact with a portion of the top layer, and the lower surface of the base layer is in contact with the transparent layer.

Preferably, the transparent layer includes a first transparent layer and a second transparent layer, and there is a space between the first transparent layer and the second transparent layer.

Preferably, the LED chip closest to the first end of the light conversion layer is denoted as LED chip n1, and the chips from the first end to the second end are sequentially LED chips n2, n3, ... nm, m is an integer and m≤800, The length of the first transparent layer and/or the second transparent layer in the length direction of the LED filament is at least greater than the distance from the first end of the light conversion layer to the LED chip n2.

The application also discloses an LED bulb lamp, the LED bulb lamp comprises a lamp housing and a lamp cap connected to the lamp housing, and the lamp housing is provided with at least one cantilever, a stem and any one of the above claims 1 to 5. The LED filament, the stem includes a vertical rod, each cantilever includes a first end and a second end opposite, the first end of the cantilever is connected to the vertical rod, the second end of the cantilever is connected to the LED filament, and the LED bulb is located at a spatial coordinate In the system (X, Y, Z), where the Z axis is parallel to the stem, each cantilever has an intersection with the LED filament, and on the XY plane, at least two intersections are located on the circumference with the stem as the center.

Preferably, the lamp housing is divided into an upper part and a lower part by a plane A, the lamp housing has the maximum width at the plane A, and when there is an intersection between the stem and the plane A, the lamp housing has the opposite top of the lamp housing and the bottom of the lamp housing. The bottom is close to the lamp cap, and the length of the LED filament located between the top of the lamp housing and the plane A is less than the length of the LED filament located between the plane A and the bottom of the lamp housing.

Preferably, the conductor segment includes a conductor connecting two adjacent LED segments, and the thickness of the base layer in the radial direction of the LED filament is less than or equal to the thickness of the conductor in the radial direction of the LED filament.

Preferably, the lamp housing is divided into an upper part and a lower part by a plane A, the lamp housing has the maximum width at the plane A, and when there is an intersection between the stem and the plane A, the lamp housing has the opposite top of the lamp housing and the bottom of the lamp housing. The bottom is close to the lamp head. In the height direction of the LED bulb, the distance from the highest point of the LED filament to the plane A is smaller than the distance from the lowest point of the LED filament to the plane A.

Preferably, the spectral intensity of the light emitted by the LED filament has three peaks P1', P2', P3' between wavelengths 400nm to 800nm, the peak P1' is between 430nm and 480nm, and the peak P2' is between 430nm and 480nm. The wavelength is between 480nm and 530nm, and the peak P3' is between the wavelength 630nm and 680nm.

Preferably, the average color rendering index of the LED bulb lamp is greater than 95, and the light efficiency of the LED filament is greater than or equal to 100lm/w.

The application has the following or any combination of technical effects through the above-mentioned technical solutions: (1) by filling the lamp housing with nitrogen and oxygen, the service life of the base can be effectively improved due to the effect of oxygen and the groups in the base; ( 2) By designing the relationship between the diameter of the lamp cap, the maximum diameter of the lamp housing and the maximum width of the LED filament in the Y-axis direction on the YZ plane or the maximum width in the X-axis direction on the XZ plane, the ball can be effectively improved. The heat dissipation effect of the bulb; (3) the thickness of the base layer is less than the thickness of the top layer, because the thermal conductivity of the top layer is greater than that of the base layer, and the heat generated by the LED chip is conducted to the outer surface of the base layer. The distance is relatively short, so the heat is not easy to accumulate, and the LED filament (4) The carrier layer includes a transparent layer and a base layer. The transparent layer supports part of the base layer, thereby enhancing the strength of the base layer, which is conducive to bonding and bonding. The part of the base layer that is not covered by the transparent layer can make some LEDs The heat generated by the chip is directly dissipated after passing through the base layer; (5) The transparent layer includes a first transparent layer and a second transparent layer. When the LED filament is bent, the part near the electrode is easily separated from the light conversion layer or the part where the light conversion layer is in contact with the electrode Cracks are prone to occur, and the first transparent layer and the second transparent layer can reinforce the structure of the part in contact with the light conversion layer and the electrode to prevent cracks in the contact part between the light conversion layer and the electrode; (6) The conductor includes a covering part and an exposed part. When the LED filament is bent, the exposed part will be slightly deformed by force, the bending area is small, and the degree of deformation is small, which is conducive to maintaining the bending shape of the LED filament.

Description of drawings

1A is a schematic structural diagram of another embodiment of the LED filament of the present application;

1B is a schematic structural diagram of another embodiment of the LED filament of the present application;

1C is a schematic structural diagram of another embodiment of the LED filament of the present application;

1D to 1G are schematic structural diagrams of various embodiments of the LED filament of the present application;

1H is a top view of an embodiment of the LED filament of the present application with the top layer removed;

2A is a schematic structural diagram of an embodiment of an LED filament of the present invention;

Figure 2B is a bottom view of Figure 2A;

Fig. 2C is the partial cross-sectional schematic diagram of A-A position in Fig. 2A;

3A to 3E are schematic diagrams of the first embodiment of the manufacturing method of the LED filament of the present invention;

4A to 4D are respectively a schematic diagram, a side view, another side view and a top view of an LED bulb lamp according to an embodiment of the present application;

5 is a schematic diagram of an LED bulb lamp according to an embodiment of the present application;

6A is a schematic diagram of a lamp holder according to an embodiment of the present application;

Fig. 6B is the schematic diagram of A-A section in Fig. 6A;

7A is a schematic diagram of a lamp holder according to an embodiment of the present application;

7B is a schematic diagram of an embodiment of the B-B section in FIG. 7A;

FIG. 7C is a schematic diagram of an embodiment of section B-B in FIG. 7A;

8A to 8D are respectively a schematic diagram, a side view, another side view and a top view of an LED bulb lamp according to an embodiment of the present application;

FIG. 9 is a schematic diagram of the light emission spectrum of the LED bulb lamp according to an embodiment of the present application;

FIG. 10 is a schematic diagram of the light emission spectrum of the LED bulb lamp according to an embodiment of the present application;

FIG. 11 is a schematic diagram showing the light emission spectrum of the LED bulb lamp according to an embodiment of the present application.

detailed description

In order to make the above objects, features and advantages of the present application more obvious and easy to understand, specific embodiments of the present application will be described in detail below with reference to the accompanying drawings.

As shown in FIGS. 1A to 1H , 2A to 2C and 3A to 3E, the LED filament has light conversion layers 220/420, LED chip units 202/204 (or LED segments 402/404) and electrodes (or conductive electrodes) 210, 212/410, 412. The light conversion layer 220/420 wraps the LED chip unit 202/204 (or LED segment 402/404) and part of the electrodes (or conductive electrodes) 210, 212/410, 412, and part of the electrodes (or conductive electrodes) 210, 212/410, 412 exposes the light conversion layer 220/420, between adjacent LED chip units 202, 204 (or LED segments 402, 404) and between the LED chip units 202/204 (or LED segments 402/404) and electrodes (or conductive electrodes) 210, 212/410, 412 are electrically connected to each other. The LED filament includes at least two LED chips 442 , and adjacent LED chips 442 are electrically connected to each other. The LED chip unit 202 / 204 (or LED segment 402 / 404 ) includes at least one LED chip 442 . The light conversion layer 420 includes a top layer 420a and a carrier layer, and the top layer 420a and the carrier layer can each be a layered structure of at least one layer. The layered structure can be selected from: phosphor glue with high plasticity (relative to phosphor film), phosphor film or transparent layer with low plasticity, or any combination of the three. The phosphor glue/phosphor film includes the following components: silicone modified polyimide and/or glue, and the phosphor glue/phosphor film may also include phosphor, inorganic oxide nanoparticles (or heat-dissipating particles). The transparent layer can be composed of light-transmitting resin (eg, silica gel, polyimide) or a combination thereof. The glue can be, but is not limited to, silica gel. In one embodiment, the top layer 420a is made of the same material as the carrier layer. In one embodiment, the carrier layer includes a base layer, and in the height direction of the LED filament, the height of the top layer is greater than that of the base layer. The base layer includes opposing upper and lower surfaces, the top layer includes opposing upper and lower surfaces, and the upper surface of the base layer is in contact with a portion of the lower surface of the top layer; the LED chip includes opposing upper and lower surfaces, and the upper surface of the LED chip is opposite Since the lower surface of the LED chip is close to the upper surface of the top layer, the distance from the lower surface of the LED chip to the lower surface of the base layer is smaller than the distance from the lower surface of the LED chip to the upper surface of the top layer, because the thermal conductivity of the top layer is greater than that of the base layer, and the LED chip The distance that the generated heat is conducted to the outer surface of the base layer is relatively short, so that the heat is not easy to accumulate, and the heat dissipation effect of the LED filament is good. In one embodiment, if the power supplied to the LED filament does not exceed 8w, when the LED filament is lit, the average length of the LED filament per millimeter (or the average length of the filament body per millimeter or the average length of the top layer per millimeter) emits at least 4lm of luminous flux. In one embodiment, the average length of the LED filament per millimeter (or the average length of the filament body per millimeter or the average length of the top layer per millimeter) includes at least 2 LED chips, and the temperature of the LED filament is not greater than that of the LED filament lighting in an ambient environment of 25° C. Junction temperature at 15000 hours.

FIG. 1A is a schematic structural diagram of an embodiment of the LED filament of the present application. The LED filament 400 has: a light conversion layer 420 ; LED segments 402 / 404 and electrodes 410 / 412 . The LED segments 402/404 have at least one LED chip 442, and the adjacent LED chips in the LED filament, the LED chips and the electrodes 410/412 are electrically connected to each other, for example, through a circuit film, such as the first wire in FIG. 1B described later 440 and other methods to achieve the above electrical connection. The light conversion layer 420 includes a top layer 420a and a carrier layer, the carrier layer includes a base layer 420b and a transparent layer 420c, and the base layer 420b is located between the top layer 420a and the transparent layer 420c (at least on a certain section of the LED filament 400). In one embodiment, the base layer 420b includes opposing upper and lower surfaces, the upper surface of the base layer 420b is in contact with a portion of the top layer 420a, and the lower surface of the base layer 420b is in contact with the transparent layer 420c. In some embodiments, a portion of the base layer 420b The lower surface is in contact with the transparent layer 420c, and the transparent layer 420c supports a part of the base layer 420b, thereby enhancing the strength of the base layer 420b and facilitating die bonding and wire bonding. The generated heat is directly dissipated after passing through the base layer 420b. In this embodiment, the total length of the base layer 420b is the same as the total length of the top layer 420a. In one embodiment, the total length of the transparent layer 420c is 5-100% of the total length of the base layer 420b. In one embodiment, the length of the transparent layer 420c Less than the length of the base layer 420b, the total length of the transparent layer 420c is 10-80% of the total length of the base layer 420b. In one embodiment, the total length of the transparent layer 420c is 10-50% of the total length of the base layer 420b. When the LED filament When it is thinner (for example, the width of the LED filament is ≤120μm), the heat dissipation area of the LED chip is relatively reduced. Since the transparent layer is located under the base layer, on the one hand, the deformation of the base layer caused by heat can be reduced; on the other hand, it can help support the LED chip. , which is conducive to solid crystal bonding. In one embodiment, the transparent layer 420c includes a first transparent layer 420c1 and a second transparent layer 420c2, the first transparent layer 420c1 and the second transparent layer 420c2 both extend along the length direction of the LED filament, and the first transparent layer 420c1 extends from the base layer 420b. One end extends, the second transparent layer 420c2 extends from the other end of the base layer 420b, and the extending direction of the first transparent layer 420c1 is opposite to that of the second transparent layer 420c2. In one embodiment, the light conversion layer 420 has a first end and a second end opposite to the first end. In one embodiment, the LED chip 442 is located between the first end and the second end. The LED chips are denoted as LED chips n ₁ , then the LED chips from the first end to the second end are LED chips n ₂ , n ₃ , . . . n _m , m is an integer and m≤800, in some embodiments, 50 ≤m≤300, the length of the first transparent layer 420c1 and/or the second transparent layer 420c2 in the length direction of the LED filament is at least greater than the distance from the first end to the LED chip n2. There is a gap between the first transparent layer 420c1 and the second transparent layer 420c2, and in the length direction of the LED filament, the distance between the first transparent layer 420c1 and the second transparent layer 420c2 is greater than the first transparent layer 420c1 and/or the second transparent layer 420c1. The length of the transparent layer 420c2. When the LED filament is bent, it is easy to detach from the light conversion layer near the electrode or the part where the light conversion layer is in contact with the electrode is prone to cracks. It has a strong effect to prevent cracks in the contact portion between the light conversion layer and the electrode.

FIG. 1B is a schematic structural diagram of another embodiment of the LED filament of the present application. As shown in FIG. 1B , the LED filament 400 has: a light conversion layer 420;

LED segments

402, 404;

electrodes

410, 412; The conductor segment 430 between the two

LED segments

402 and 404 is adjacent. The LED segments 402 / 404 include at least two LED chips 442 , and the LED chips 442 are electrically connected to each other through first wires 440 . In this embodiment, the conductor segment 430 includes a conductor 430a connecting the

LED segments

402 and 404, wherein the shortest distance between the two LED chips 442 located in the adjacent two

LED segments

402 and 404 is greater than the phase within the

LED segments

402 and 404. The distance between two adjacent LED chips, the length of the first wire 440 is smaller than the length of the conductor 430a. In this way, it can be ensured that when the two LED segments are bent, the generated stress will not cause the conductor segment to break. The light conversion layer 420 is coated on at least two sides of the LED chip 442/

electrodes

410, 412. The light conversion layer 420 exposes a portion of the

electrodes

410 , 412 . The light conversion layer 420 has a top layer 420a and a carrier layer, respectively serving as an upper layer and a lower layer of the LED filament. In this embodiment, the carrier layer includes a base layer 420b, and the base layer 420b includes an upper surface and a lower surface opposite to the upper surface. Relative to the lower surface of the base layer 420b, the upper surface of the base layer 420b is close to the top layer 420a, and the LED segments 402/404 and part of the electrodes 410/412 are placed on the upper surface of the base layer 420b, or at least one side of the LED segments 402/404 is adjacent to the base layer 420b. The upper surfaces are in contact (direct or indirect contact).

As shown in FIG. 1C , in this embodiment, the conductor segment 430 is also located between two

adjacent LED segments

402 and 404 , and the plurality of LED chips 442 in the

LED segments

402 and 404 are connected to each other through the first wire 440 . Electrical connection. However, the conductors 430a in the conductor segments 430 of FIG. 1C are not in the form of wires, but in the form of sheets or films. In some embodiments, the conductor 430a may be copper foil, gold foil, or other electrically conductive materials. In this embodiment, the conductor 430a is attached to the surface of the base layer 420b and adjacent to the top layer 420a, that is, between the base layer 420b and the top layer 420a. In addition, the conductor segment 430 and the LED segments 402/404 are electrically connected through the second wire 450, that is, the two LED chips 442 which are located in the adjacent two

LED segments

402 and 404 respectively and have the shortest distance from the conductor segment 430 are connected by the second wire. 450 is electrically connected to the conductor 430a in the conductor segment 430 . The length of the conductor segment 430 is greater than the distance between two adjacent LED chips 442 in the

LED segments

402 and 404, and the length of the first wire 440 is less than the length of the conductor 430a. With this design, since the conductor segment has a relatively long length, good bendability of the conductor segment can be ensured. Assuming that the maximum thickness of the LED chip 442 in the radial direction of the LED filament is H, the thickness of the electrodes 410/412 and the conductor 430a in the radial direction of the LED filament is 0.5H-1.4H, preferably 0.5H-0.7H. There is a height difference between the LED chip and the electrode, and between the LED chip and the conductor, so that the wire bonding process can be implemented, and the wire bonding process quality (ie, good strength) can be ensured, and the stability of the product can be improved.

As shown in FIG. 1D , the LED filament 400 has: a light conversion layer 420 ;

LED segments

402 , 404 ;

electrodes

410 , 412 ; The LED segments 402/404 include at least one LED chip 442, and the conductor segments 430 and the LED segments 402/404 are electrically connected through a second wire 450, that is, they are located in the adjacent two

LED segments

402 and 404 respectively and have the shortest distance from the conductor segment 430. The two LED chips 442 are electrically connected to the conductors 430 a in the conductor segments 430 through the second wires 450 . The LED chips 442 are electrically connected to each other through the first wires 440. The conductor segments 430 include conductors 430a connecting the

LED segments

402 and 404. The conductors 430a are, for example, conductive metal sheets or metal strips, such as copper sheets or iron sheets. The shortest distance between the two LED chips 442 located in the two

adjacent LED segments

402 and 404 respectively is greater than the distance between the two adjacent LED chips in the LED segments 402/404, and the length of the first wire 440 is less than the length of the conductor 430a . In this way, it can be ensured that when the two LED segments are bent, the stress-bearing area of the conductor segment is larger, and the generated stress will not cause the conductor segment to break. The light conversion layer 420 covers at least two sides of the LED chip 442/

electrodes

410, 412. The light converting layer 420 exposes a portion of the electrodes 410,412. The light conversion layer 420 includes a top layer 420a and a carrier layer, the carrier layer includes a base layer 420b and a transparent layer 420c, the base layer 420b is located between the top layer 420a and the transparent layer 420c, the base layer 420b and the top layer 420a cover at least two sides of the LED chip 442, and the transparent layer 420c The thermal conductivity of the base layer 420b is greater than that of the base layer 420b, and the thickness of the base layer 420b in the radial direction of the LED filament is less than or equal to the thickness of the conductor 430a in the radial direction of the LED filament. ), the heat dissipation area of the LED chip is relatively reduced. By using the transparent layer, on the one hand, the deformation of the base layer caused by heat can be reduced, and on the other hand, it can help support the LED chip, which is conducive to bonding and bonding. The transparent layer 420c can be, for example, a hard substrate such as an alumina ceramic plate or a sapphire substrate, or a soft substrate with high thermal conductivity (eg, thermal conductivity ≥ 2.0 (W/(m·K)), a translucent alumina ceramic plate or a transparent sapphire substrate. The substrate is conducive to the transmission of the light emitted by the LED chip towards the transparent layer, thereby realizing the full circumference of the LED filament. In this embodiment, the top layer 420a, the base layer 420b and the transparent layer 420c wrap the conductor 430a, which reduces the influence of the external environment on the conductor on the one hand, On the other hand, the bearing capacity of the conductor is increased when the conductor is electrically connected, and the stability of the electrical connection when the conductor is bent is improved. In some embodiments, the thickness of the base layer 420b in the height direction of the LED filament is less than or equal to that of the conductor 430a at the height of the LED filament In other embodiments, the thickness of the transparent layer 420c in the height direction of the LED filament is greater than that of the base layer 420b at the height of the LED filament. The thickness in the direction of the LED chip is short, and the conductive path of the heat generated by the LED chip to the transparent layer is short, which improves the heat dissipation effect of the LED filament. In some implementations, the absolute value of the height difference between the LED chip 442 and the conductor 430a in the height direction of the LED filament is greater than The height of the LED chip 442 in the height direction of the LED filament, when the LED filament is bent, the second wire is deformed after being stretched by force, and the second wire is not easily broken. In some embodiments, the base layer 420b is at least one of the LED chip 442. In this embodiment, the LED chip 442 and the conductor 430a are located on different sides of the base layer 420b.

1E to 1G, in some embodiments, the conductor 430a includes a covering portion 430b and an exposed portion 430c, and the length of the exposed portion 430c in the axial direction of the LED filament is smaller than that between adjacent LED chips in any LED segment 402/404 When the LED filament is bent, the exposed portion 430c will be slightly deformed by force, the bending area is small, and the degree of deformation is small, which is conducive to maintaining the bending shape of the LED filament. As shown in FIG. 1E , the exposed part 430c includes a first exposed part 430c1 and a second exposed part 430c2 , the part of the top layer 420a exposing the conductor 430a is the first exposed part 430c1 , and the part of the transparent layer 420c exposing the conductor 430a is the second exposed part 430c2 , the length of the first exposed portion 430c1 in the axial direction (length direction) of the LED filament is greater than or equal to the length of the second exposed portion 430c2 in the axial direction of the LED filament, so as to ensure the stability of the electrical connection and the stress when the conductor is bent evenly. As shown in FIG. 1F , the exposed portion only includes the first exposed portion 430c1 , and the length of the first exposed portion 430c1 in the axial direction of the LED filament is less than or equal to the distance between adjacent LED chips in any LED segment 402/404. When the filament is bent, the stress generated during the bending is concentrated on the conductor segment, which reduces the risk of breakage of the wires connecting adjacent LED chips. As shown in FIG. 1G , the exposed portion only includes the second exposed portion 430c2, which can relieve the stress concentration of the conductor. The length of the second exposed portion 430c2 in the axial direction of the LED filament is less than or equal to the distance between adjacent LED chips in any LED segment 402/404. Since a part of the conductor is located between the adjacent transparent layers, the transparent layers can ensure that the The stability of the conductor's support.

1H, the LED filament 400 has: a light conversion layer 420;

LED segments

402, 404;

electrodes

410, 412; The

LED segments

402 and 404 include at least one LED chip 442 . The conductor segments 430 and the

LED segments

402 and 404 are electrically connected through the second wires 450 , that is, they are located in the adjacent two

LED segments

402 and 404 respectively and have the shortest distance from the conductor segment 430 . The two LED chips 442 are electrically connected to the conductors 430 a in the conductor segments 430 through the second wires 450 . The conductor segment 430 includes a conductor 430a connecting the

LED segments

402, 404, and the conductor 430a is, for example, a conductive metal sheet or metal strip, such as a copper sheet or an iron sheet. The shortest distance between the two LED chips 442 respectively located in the adjacent two

LED segments

402 and 404 is greater than the distance between the two adjacent LED chips in the LED segments 402/404, and the LED chips are electrically connected through the first wires 440. For connection, the length of the first wire 440 is less than the length of the conductor 430a. When the two LED segments are bent, the stress area of the conductor segment is large, and the generated stress will not cause the conductor segment to break. The light conversion layer 420 covers at least two sides of the LED chip 442/

electrodes

410, 412. The light conversion layer 420 exposes a portion of the

electrodes

410 , 412 . The light conversion layer 420 includes a top layer (not shown) and a carrier layer. The carrier layer includes a base layer 420b and a transparent layer 420c. The LED chips 442 in the LED segments 402/404 are along the radial direction of the LED filament (or the width direction of the LED filament). Arranged, each LED chip 442 within LED segment 402/404 is connected to conductor 430a and/or electrode 410/412, respectively. In this embodiment, the widths of the base layer 420b and the transparent layer 420c in the radial direction of the LED filament are equal, the contact area between the base layer 420b and the transparent layer 420c is large, and delamination is not easy to occur between the base layer 420b and the transparent layer 420c. In other embodiments, the width of the base layer 420b in the radial direction of the LED filament is smaller than the width of the transparent layer 420c in the radial direction of the LED filament, the top layer (not shown) is in contact with the base layer and the transparent layer 420c, and the thickness of the base layer 420b Less than the thickness of the top layer, the heat emitted by the LED chip is simultaneously transferred to the top layer and the transparent layer through the base layer, thereby improving the heat dissipation efficiency of the LED filament. Secondly, the top layer and the transparent layer fully wrap the base layer, which can protect the base layer from the external environment. In addition, when the LED filament is bent, the top layer is protected by multiple sides, which reduces the probability of the second wire 450 breaking, and improves the product yield.

Please continue to refer to FIGS. 2A to 2C. FIG. 2A is a three-dimensional partial cross-sectional schematic diagram of an embodiment of the LED filament of the present invention; FIG. 2B is a bottom view schematic diagram of FIG. 2A; The LED filament 300 includes a plurality of

LED chip units

202 and 204 , at least two

conductive electrodes

210 and 212 , and a light conversion layer 220 . The

LED chip units

202 and 204 are electrically connected to each other. The

conductive electrodes

210 and 212 are disposed corresponding to the

LED chip units

202 and 204 , and are electrically connected to the

LED chip units

202 and 204 through the first conductive portion 240 . The light conversion layer 220 wraps the

LED chip units

202, 204 and the

conductive electrodes

210, 212, and exposes at least a part of the two

conductive electrodes

210, 212, wherein the light conversion layer 220 includes silica gel, phosphors and heat dissipation particles. In some embodiments, the LED chip unit 202 / 204 includes at least one LED chip, and each surface of the LED chip has the same phosphor concentration, so that the light conversion rate of each surface is the same, and the light uniformity of the LED filament is good.

The LED chip unit 202/204 includes at least one LED chip, and the LED chip unit 202/204 has a first electrical connection part 206a and a second electrical connection part 206b. In the length direction of the LED filament, the distance between the first connecting portions 206 a of the two adjacent

LED chip units

202 and 204 is greater than the distance between the two adjacent

LED chip units

202 and 204 . In some embodiments, in the length direction of the LED filament, the distance between the first connecting portion 206 a and the second connecting portion 206 b of two adjacent

LED chip units

202 , 204 is greater than that between the two adjacent

LED chip units

202 , 204 At least a part of the first electrical connection portion 206 a and the second electrical connection portion 206 b are in contact with the light conversion layer 220 . The first electrical connection part 206a and the second electrical connection part 206b are located on the same side of the LED chip units 202/204.

In one embodiment, the second electrical connection portion 206b of the LED chip unit 202 is electrically connected to the first electrical connection portion 206a of the LED chip unit 204 . For example, the second electrical connection portion of the LED chip unit 202 can be electrically connected through the second conductive portion 260 . The portion 206b is electrically connected to the first electrical connection portion 206a of the LED chip unit 204. The second conductive portion 260 has a terminal a and a terminal b. The connection between the terminal a and the terminal b is a straight line ab, and the straight line ab is connected to the length direction of the LED filament. p intersects. In some embodiments, the light conversion layer 220 includes a top layer and a carrier layer (not shown), the top layer wraps the

LED chip units

202, 204 and the

conductive electrodes

210, 212, and exposes at least a part of the two

conductive electrodes

210, 212, The carrier layer includes a base layer, the base layer includes an upper surface and a lower surface opposite to the upper surface, relative to the lower surface of the base layer, the upper surface of the base layer is close to the top layer, and at least one of the first conductive portion 240 and the second conductive portion 260 is connected to the base layer. When the LED filament is bent, the curvature radius of the base layer after being bent by force is relatively small, and the first conductive part and the second conductive part are not easily broken. In one embodiment, the first electrical connection portion 206a and the second electrical connection portion 206b are in contact (direct contact or indirect contact) with the upper surface of the base layer. The LED chip unit can be a flip chip or a mini LED chip, and a mini LED refers to an LED with a package size in the range of 0.1-0.2mm, also known as a sub-millimeter light-emitting diode. When the LED chip units are electrically connected, for example, the second electrical connection part 206b of the LED chip unit 202 can be the positive connection point, the first electrical connection part 206a of the LED chip unit 204 can be the negative connection point, and the second electrical connection part 206a of the LED chip unit 202 can be the negative connection point. The electrical connection portion 206b is electrically connected to the first electrical connection portion 206a of the LED chip unit 204 through the second conductive portion 260 . For another example, the second electrical connection portion 206b of the LED chip unit 202 may be the negative connection point, the first electrical connection portion 206a of the LED chip unit 204 may be the positive connection point, and the second electrical connection portion 206b of the LED chip unit 202 may be connected through the first electrical connection point 206b. The two conductive parts 260 are electrically connected to the first electrical connection part 206 a of the LED chip unit 204 . The first conductive part 240 and the second conductive part 260 may be in the form of wires or films, such as copper wires, gold wires, circuit films or copper foils.

Please refer to FIGS. 3A to 3E , which are schematic diagrams of an embodiment of a manufacturing method of an LED filament of the present invention. The manufacturing method of LED filament includes:

S20: laying the

LED chip units

202, 204 and the

conductive electrodes

210, 212 on a carrier 280 (as shown in FIG. 3A);

S22A: Coating the top layer 220a on the parts of the

LED chip units

202, 204 and the

conductive electrodes

210, 212 that are not in contact with the carrier 280, and then curing the

LED chip units

202, 204 and the

conductive electrodes

210, 212 on which the top layer 220a has been coated ( or solidification) process, so that the top layer 220a is cured and covers the

LED chip units

202, 204 and the

conductive electrodes

210, 212 above the carrier, and exposes a part of at least two conductive electrodes 210, 212 (as shown in FIG. 3B). Such curing procedures such as, but not limited to, heating, or ultraviolet (UV) irradiation;

S22B: There are several ways to invert the

LED chip units

202, 204 and the

conductive electrodes

210, 212 on which the top layer 220a has been coated. One is that the

LED chip units

202, 204 and the

conductive electrodes

210, 212 are only disposed on the carrier 280, and therebetween There is no adhesive relationship, it can be turned over directly, and the turned semi-finished product can be placed on the carrier 280 again.

The second is, if there is a glue-like substance for adhesion between the carrier 280 and the

LED chip units

202, 204, the

conductive electrodes

210, 212, such as a photoresist used in the semiconductor process or a die-bonding glue that is easy to remove, The jelly-like substance has the effect of temporarily fixing the

LED chip units

202 and 204 and the

conductive electrodes

210 and 212 on the carrier 280 after being properly baked. Therefore, before or after turning over the

LED chip units

202, 204 and

conductive electrodes

210, 212 coated with the top layer 220a, the photoresist coated on the carrier 280 can be cleaned with acetone, or cleaned with a corresponding solvent The die-bonding glue on the carrier can separate the

LED chip units

202 , 204 , the

conductive electrodes

210 , 212 , which have been coated with the top layer 220 a , from the carrier 280 . In addition, further cleaning can be performed to remove residual photoresist or die-bonding adhesive.

S24: electrically connecting the adjacent

LED chip units

202 and 204 and the LED chip units 202/204 with the conductive electrodes 210 and 212 (as shown in FIG. 3C );

S26: After step S24, the base layer 220b is coated on the parts of the

LED chip units

202, 204 and the

conductive electrodes

210, 212 that are not coated with the top layer 220a, and cured after the coating is completed (as shown in FIG. 3D).

After step S26, step S28 may be further included to cut the

LED chip units

202, 204 and the

conductive electrodes

210, 212 wrapped with the light conversion layer 220, that is, the cutting positions drawn by the dotted line in FIG. 3E, so that , the strip-shaped element after cutting is the LED filament 300 . The cutting method of step S28 is not limited to FIG. 3E , and every two adjacent column

LED chip units

202 and 204 can also be cut into a single LED filament.

The top layer 220a and the base layer 220b in the manufacturing method of the LED filament of this embodiment may contain phosphors and silica gel in the same proportion. If the top layer 220a and the base layer 220b also contain oxide nanoparticles, the phosphor powder and silica gel in the top layer 220a and the base layer 220b The ratio of the oxide nanoparticles is the same, in other words, the top layer 220a and the base layer 220b are made of the same material, and they are only distinguished into the top layer 220a and the base layer 220b for the convenience of description. Of course, in other embodiments, the proportions of phosphors, silica gel, and oxide nanoparticles in the top layer 220a and the base layer 220b may be different.

In one embodiment, the above-mentioned base layer includes silicone-modified polyimide, thermal curing agent, heat-dissipating particles and phosphors, the thermal curing agent is epoxy resin, isocyanate or bisoxazoline compound, and the heat-dissipating particles include two Silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), zirconium oxide (ZrO ₂ ), and the like. In one embodiment, based on the weight of the silicone-modified polyimide, the amount of the thermal curing agent is 3-12% of the weight of the silicone-modified polyimide. Organosilicon-modified polyimide includes repeating units represented by the following general formula (I):

In the general formula (I), Ar ¹ is a tetravalent organic group. The organic group has a benzene ring or an alicyclic hydrocarbon structure, and the alicyclic hydrocarbon structure may be a monocyclic alicyclic hydrocarbon structure or an alicyclic hydrocarbon structure containing a bridged ring. The cyclic alicyclic hydrocarbon structure may be a bicyclic alicyclic hydrocarbon structure or a tricyclic alicyclic hydrocarbon structure. The organic group can also be a benzene ring structure or an alicyclic hydrocarbon structure containing an active hydrogen functional group, and the active hydrogen functional group is any one or more of a hydroxyl group, an amino group, a carboxyl group, an amide group or a thiol group.

Ar ² is a bivalent organic group, and the organic group may have, for example, a monocyclic alicyclic hydrocarbon structure, or a bivalent organic group containing an active hydrogen functional group, and the active hydrogen functional group is a hydroxyl group, an amino group, a carboxyl group, Any one or more of an amide group or a thiol group.

R is independently selected from methyl or phenyl.

n is 1 to 5, preferably n is 1 or 2 or 3 or 5.

The number average molecular weight of the general formula (I) is 5,000 to 100,000, preferably 10,000 to 60,000, and more preferably 20,000 to 40,000. The number average molecular weight is a polystyrene-equivalent value based on a calibration curve prepared by a gel permeation chromatography (GPC) apparatus using standard polystyrene. When the number-average molecular weight is 5,000 or less, it is difficult to obtain good mechanical properties after curing, and in particular, the elongation tends to decrease. On the other hand, when it exceeds 100,000, the viscosity becomes too high, making resin formation difficult.

Ar ¹ is a component derived from a dianhydride, the dianhydride may include an aromatic acid anhydride and an aliphatic acid anhydride, and the aromatic acid anhydride includes an aromatic acid anhydride containing only a benzene ring, a fluorinated aromatic acid anhydride, an amide group-containing aromatic acid anhydride, Ester group-containing aromatic acid anhydrides, ether group-containing aromatic acid anhydrides, sulfur group-containing aromatic acid anhydrides, sulfone group-containing aromatic acid anhydrides, carbonyl group-containing aromatic acid anhydrides, and the like.

Ar ² is a component derived from diamines, which can be divided into aromatic diamines and aliphatic diamines. Aromatic diamines include aromatic diamines containing only benzene ring structures, fluorinated aromatic diamines, and Aromatic diamine containing ester group, aromatic diamine containing ether group, aromatic diamine containing amide group, aromatic diamine containing carbonyl group, aromatic diamine containing hydroxyl group, aromatic diamine containing carboxyl group, Aromatic diamine containing sulfone group, aromatic diamine containing sulfur group, etc.

Adding different thermal curing agents will have different effects on the light transmittance of silicone-modified polyimide.

Even if the same thermal curing agent is added, when the amount of addition is different, the light transmittance will be affected differently. Table 1-1 shows that when the addition amount of the thermal curing agent BPA of the fully aliphatic silicone-modified polyimide is increased from 4% to 8%, the light transmittance is improved. But when the addition amount is increased to 12%, the performance of light transmittance is almost unchanged. It is shown that the light transmittance will improve with the increase of the amount of thermal curing agent added, but when it increases to a certain extent, the effect of adding more thermal curing agent on the light transmittance is quite limited.

Table 1-1

The phosphor composition as a part of the top layer 420b includes a first phosphor powder, a second phosphor powder, a third phosphor powder and a fourth phosphor powder. The width (FWHM) is 29-32nm; the wavelength peak of the second phosphor is 520-540nm and the half-peak width (FWHM) is 110-115nm under the blue light excitation; the wavelength peak of the third phosphor is 660 under the blue light excitation ～672nm, the half-peak width (FWHM) is 15-18nm; the wavelength peak of the fourth phosphor is 600-612nm under blue light excitation, the half-peak width (FWHM) is 72-75nm or the wavelength peak is 620-628nm, The half-peak width (FWHM) is 16-18 nm or the wavelength peak is 640-650 nm, and the half-peak width (FWHM) is 85-90 nm. The central particle size (D50) of any one of the first phosphor powder, the second phosphor powder, the third phosphor powder, and the fourth phosphor powder is in the range of 15-20 μm, and the range of D50 of the second phosphor powder and the third phosphor powder is Preferably, it is 15-16 μm, and the range of D50 of the first phosphor powder and the fourth phosphor powder is preferably 16-20 μm. When the phosphor is excited by blue light, the thickness of the top layer with different concentrations of the same phosphor will affect the half-peak wavelength of the phosphor. In this embodiment, the thickness of the top layer 420b is 80-100 μm. The weight percentage of each phosphor in the phosphor composition is: the first phosphor is 5.45-5.55%, the second phosphor is 70-88%, the third phosphor is 0.6-7%, and the fourth phosphor is the remainder, The phosphor powder is prepared in a certain ratio of phosphor powder to glue, and phosphor powder with different peak wavelengths is selected. Under the conditions of a blue LED chip with a wavelength peak of 451 nm, a FWHM of 16.3 nm, and a current of 30 mA, the measured optical properties As shown in Table 1:

Table 1

It can be seen from the numbers No. 1 to 4 in Table 1 that the content of the third phosphor powder and the fourth phosphor powder in the formulated phosphor composition will affect the luminous efficacy (Eff), the average color rendering index (Ra) and the saturated red color (Eff). R9) has an impact. It can be seen from the numbers No1 and 2 that when the content of the fourth phosphor with a peak wavelength of 670nm increases, Eff will increase, while Ra and R9 will decrease; when the phosphor with a peak wavelength of 630nm is used to replace the phosphor with a peak wavelength of 652nm , it can be seen from the numbers No. 3 and 4 in Table 1 that when the content of the fourth phosphor with a peak wavelength of 670 nm increases, Eff will decrease, while Ra and R9 will increase. Therefore, according to actual needs, when the fourth phosphor with different wavelength peaks is selected, the amount of the third phosphor and the fourth phosphor can be adjusted in order to obtain better luminous performance.

The ratio of phosphor to glue

The same phosphor is selected, and the ratio of the phosphor composition to the glue is prepared, as shown in Table 2. It can be seen from Table 2 that the ratio of the phosphor composition to the glue is different, and Eff, Ra, R9 and CCT are all different. , the more the phosphor composition accounts for the glue, the Eff, Ra and CCT decrease, while R9 shows a trend of decreasing and then rising; in addition, when the phosphor composition is used with glue (such as silica gel) as the top layer of the LED filament, the During the production process, since the specific gravity of the phosphor composition is greater than that of the silica gel, the fluorescent powder will settle significantly, resulting in the color temperature drift of the white LED. Therefore, the weight ratio of the phosphor composition to the glue in the top layer is 0.2-0.3:1, preferably 0.25-0.3:1. In one embodiment, a certain amount of hollow glass microbeads can be added to the phosphor composition. When the phosphor powder settles, the glass microbeads float up. The effect of light scattering is cancelled, so the phenomenon of color temperature drift can be alleviated. In addition, since the absorption of visible light by microbeads is small, the addition of glass microbeads has little effect on the initial brightness of white LEDs. The mass ratio of the glass microbeads to the phosphor composition is 1:5-15, preferably the weight ratio of the glass microbeads to the phosphor composition is 1:10-15.

Table 2

In one embodiment, an LED filament is provided. The LED filament is made of the above-mentioned phosphor composition and a blue light chip. The blue light chip has a peak wavelength of 450-500 nm and a half-peak width of 15-18 nm.

In some embodiments, the phosphor composition as a part of the top layer 420b includes a first phosphor powder, a second phosphor powder, and a third phosphor powder, and the wavelength peak of the first phosphor powder is 500-550 nm under the excitation of blue light, and the half-peak value is 500-550 nm. The wavelength width (FWHM) is 100-130 nm; the wavelength peak of the second phosphor is 580-620 nm under the blue light excitation, and the half-peak width (FWHM) is 70-90 nm; the wavelength peak of the third phosphor under the blue light excitation is 620～670nm, half-peak width (FWHM) is 70～95nm. The central particle size (D50) of any one of the first phosphor powder, the second phosphor powder and the third phosphor powder is in the range of 15-20 μm, the D50 range of the first phosphor powder is preferably 15-16 μm, and the second phosphor The range of D50 of the third phosphor is preferably 16-20 μm. When the phosphor is excited by blue light, the thickness of the top layer with different concentrations of the same phosphor will affect the half-peak wavelength of the phosphor. In this embodiment, the thickness of the top layer 420b is 80-100 μm. The dosage of the first phosphor in the phosphor composition is less than or equal to ten times the sum of the dosage of the second phosphor and the third phosphor, that is, the dosage of the first phosphor ≤ 10*(the dosage of the second phosphor + the dosage of the third phosphor ), the weight ratio of the phosphor composition to the glue in the top layer is 0.4-0.8:1. The closer the amount of phosphor composition and silica gel is, the higher the conversion efficiency of light emitted by the LED chip. In addition, the contact area between the phosphor and the LED chip increases. Larger, the heat dissipation efficiency of the heat generated by the LED chip is improved.

Please refer to FIGS. 4A and 4B to 4D. FIG. 4A is a schematic diagram of an LED bulb 40h according to an embodiment of the present application. Side view, other side view and top view. In this embodiment, as shown in FIGS. 4A to 4D , the LED bulb includes a lamp housing 12 , a lamp cap 16 connected to the lamp housing 12 , at least two conductive brackets disposed in the lamp housing 12 , a cantilever (not shown), The stem 19 and a single LED filament 100. The stem 19 includes opposite stem bottoms and stem tops, the stem bottoms are connected to the lamp cap 16 , and the stem tops extend to the inside of the lamp envelope 12 , for example, the stem tops can be located at about the center inside the lamp envelope 12 . . The conductive support is connected to the stem 19 . The LED filament 100 includes a filament body and two filament electrodes (or electrodes or conductive electrodes) 110 and 112. The two

filament electrodes

110 and 112 are located at opposite ends of the filament body. The filament body is the LED filament 100, which does not include the filament electrodes. 110, other parts of 112. The two

filament electrodes

110 and 112 are respectively connected to the two conductive supports. One end of the cantilever is connected to the stem 19 and the other end is connected to the filament body.

In the production process of the traditional bulb lamp, in order to prevent the tungsten filament from burning in the air and causing oxidative fracture and failure, a glass structure of the horn stem is designed to be sintered and sealed at the opening of the glass lamp shell, and then passed through. The port of the horn stem is connected to a vacuum pump to replace the air inside the lamp housing with nitrogen, so as to prevent the tungsten wire inside the lamp housing from burning and oxidizing, and finally the port of the horn stem is sintered and sealed. Therefore, the vacuum pump can pump the air inside the lamp housing to all nitrogen or a combination of nitrogen and helium through the stem, so as to improve the thermal conductivity of the gas in the lamp housing, and also remove the water mist hidden in the air. . In one embodiment, it can also be replaced by a combination of nitrogen and oxygen or nitrogen and air in an appropriate ratio. The oxygen or air content is 1-10%, preferably 1-5%, of the volume of the lamp envelope. When the base layer contains saturated hydrocarbons, the During the use of LED bulbs, saturated hydrocarbons will be subjected to light, heat, stress, etc. to generate free radicals. The generated free radicals or activated molecules combine with oxygen to form peroxide free radicals. Filling the lamp shell with oxygen can increase the content of saturated hydrocarbons. Heat and light resistance of hydrocarbon base.

In the manufacturing process of the LED bulb, in order to increase the refractive index of the lamp housing 12 to the light emitted by the LED filament, some foreign objects, such as rosin, may be attached to the inner wall of the lamp housing 12 . The average thickness of the foreign matter deposited per square centimeter of the inner wall area of the lamp housing 12 is 0.01-2 mm, and preferably, the thickness of the foreign matter is 0.01-0.5 mm. In one embodiment, the foreign matter content per square centimeter of the inner wall area of the lamp housing 12 accounts for 1%-30% of the total foreign matter content on the inner wall of the lamp housing 12, preferably 1%-10%. The above-mentioned foreign matter content can be adjusted, for example, by vacuum drying the lamp envelope. In another embodiment, a part of impurities may be left in the inflation gas of the lamp housing 12, and the impurity content in the inflation gas is 0.1%-20%, preferably 0.1-5%, of the volume of the lamp housing 12. The method of vacuum drying the shell is used to adjust the impurity content. Because the inflatable gas contains a small amount of impurities, the light emitted by the LED filament is emitted or refracted by the impurities, and the luminous angle increases, which is beneficial to improve the luminous effect of the LED filament.

The LED bulb is located in a space coordinate system (X, Y, Z), wherein the Z axis is parallel to the stem 19, and the projection lengths of the LED filament on the XY plane, the YZ plane and the XZ plane are the length L1, the length L2 and the Length L3. In one embodiment, the ratio of length L1 , length L2 and length L3 is 0.8:1:0.9. In one embodiment, the ratio of length L1, length L2 and length L3 is (0.5to 0.9):1:(0.6to1), the ratio of length L1, length L2 and length L3 is close to 1:1:1, and the LED ball The light-emitting effect of the bulb is better, achieving full ambient light. When the LED filament 100 is bent, it has at least one first bending point and at least two second bending points. The first bending point and the second bending point are spaced apart, and any first bending point is on the Z axis. The height is greater than any second bending point. In one embodiment, the distance between two adjacent first bending points on the Y-axis or X-axis is equal, and the appearance of the LED filament is neat and beautiful. In one embodiment, the distance between two adjacent first bending points on the Y-axis or X-axis has a maximum value D1 and a minimum value D2, and the range of D2 is 0.5D1 to 0.9D1, and the luminous flux distribution on each plane is relatively consistent. Let the diameter of the lamp cap 16 be R1 (see FIG. 4B ), the maximum diameter of the lamp housing 12 or the maximum horizontal spacing of the lamp housing 12 in the YZ plane is R2 (see FIG. 4B ), and the Y-axis direction of the LED filament 100 on the YZ plane The maximum width on the LED (see Figure 4B) or the maximum width in the X-axis direction on the XZ plane is R3 (see Figure 4C), R3 is between R1 and R2, that is, R1 < R3 < R2, the LED filament is bent , the distance between the adjacent first bending points and/or the adjacent second bending points in the Z-axis direction is relatively wide, which is beneficial to improve the heat dissipation effect of the LED filament. In the manufacturing process of the LED bulb, the LED filament 100 can be folded into the inner space of the lamp housing 12 first, and then the LED filament 100 can be stretched in the lamp housing 12 manually or mechanically. The maximum length of the LED filament 100 on the XZ plane satisfies the above relationship.

As shown in FIGS. 4A to 4D , in this embodiment, the number of conductor segments 130 of the LED filament 100 is one, and the number of the

LED segments

102 and 104 is two, and there is a transparent space between every two

adjacent LED segments

102 and 104 . Connected through the conductor segment 130, the bending state of the LED filament 100 at the highest point presents an arc bending, that is, the

LED segments

102 and 104 respectively present an arc bending at the highest point of the LED filament 100, and the conductor segment is at the low point of the LED filament. Also showing arc bending. The LED filament 100 can be defined as a segment followed by each bent conductor segment 130, and then each

LED segment

102, 104 forms a corresponding segment.

In addition, since the LED filament 100 adopts a flexible base layer, the flexible base layer preferably adopts a silicone-modified polyimide resin composition, and the silicone-modified polyimide resin composition includes a silicone-modified polyimide, a thermal curing agent , cooling particles and phosphors. In this embodiment, the two LED segments 102 are respectively bent to form an inverted U shape, and the conductor segment 130 is located between the two LED segments 102 , and the bending degree of the conductor segment 130 is the same as or greater than that of the LED segment 102 . degree of bending. That is to say, the two LED segments 102 are respectively bent at the high point of the LED filament to form an inverted U shape and have a bending radius r1, and the conductor segment 130 is bent at the low point of the LED filament 100 and has a bending radius r2. where r1 is greater than the r2 value. Through the configuration of the conductor segments 130 , the LED filament 100 can be bent with a small turning radius in a limited space. In one embodiment, the bending points of the LED segment 102 and the LED segment 104 are at the same height in the Z direction. Since the LED filament has a certain symmetry, the LED bulb lamp emits relatively uniform light. In one embodiment, the inflection points of LED segment 102 and LED segment 104 have different heights in the Z direction, eg, the height of the inflection point of LED segment 102 is greater than the height of the inflection point of LED segment 104 under the same LED filament length , When the LED filament is placed in the lamp housing in this way, part of the LED filament will be biased towards the lamp housing, so the heat dissipation effect of the LED filament is better. In addition, in the Z direction, the vertical rod 19a of the present embodiment has a lower height than the vertical rod 19a of the previous embodiment. The conductor segments 130 are in contact. For example, the lowest part of the conductor segment 130 can be connected to the top of the vertical rod 19a, so that the overall shape of the LED filament 100 is not easily deformed. In different embodiments, the conductor segments 130 may be connected to each other through through holes at the top of the upright rod 19a, or the conductor segments 130 may be glued to the top of the upright rod 19a to be connected to each other, but not limited thereto. In one embodiment, the conductor segment 130 and the vertical rod 19a can be connected by a guide wire, for example, a guide wire is drawn out from the top of the vertical rod 19a to connect the conductor segment 130.

As shown in FIG. 4B , in this embodiment, in the Z direction, the height of the conductor segment 130 is higher than that of the two

electrodes

110 and 112 , and the two

LED segments

102 and 104 respectively extend upward from the two

electrodes

110 and 112 to the highest point. Afterwards, it is bent and extended down to the conductor segment 130 connecting the two

LED segments

102 and 104 . As shown in FIG. 4C , in this embodiment, the outline of the LED filament 100 on the XZ plane is similar to a V-shape, that is, the two LED segments 102 extend obliquely upwards and outwards respectively, and after being bent at the highest point, then It extends obliquely downward and inward to the conductor segment 130 . As shown in FIG. 4D , in this embodiment, the outline of the LED filament 100 in the XY plane has an S shape. As shown in FIG. 4B and FIG. 4D , in this embodiment, the conductor segment 130 is located between the

electrodes

110 and 112 . As shown in FIG. 4D , in the present embodiment, on the XY plane, the bending point of the LED segment 102 , the bending point of the LED segment 104 and the

electrodes

110 and 112 are approximately located at the conductor segment 130 (or the stem 19 or the vertical axis). Rod 19a) is on a circle with the center of the circle, for example, in the XY plane, the bending point of the LED segment 102, the bending point of the LED segment 104 is located on the same circle with the stem 19 or the vertical rod 19a as the center; in some implementations For example, on the XY plane, the bending point of the LED segment 102, the bending point of the LED segment 104, and the

electrodes

110 and 112 are located on the same circumference with the stem 19 or the vertical rod 19a as the center.

Please refer to FIG. 5. FIG. 5 is a schematic diagram of an LED bulb 40i according to an embodiment of the present application. The LED bulb 40i of this embodiment has the same basic structure as the LED bulb 40h of FIG. 4, including: The lamp housing 12 , the lamp cap 16 connected to the lamp housing 12 , at least two conductive brackets, a cantilever (not shown), a stem 19 and a single LED filament 100 disposed in the lamp housing 12 . The difference lies in the LEDs of this embodiment. The bulb 40i does not have a vertical rod 19a, and the stem 19 includes a gas-filled tube through which the gas in the lamp housing 12 is filled. As shown in FIG. 5, in the Z-axis direction, the LED filament 100 (or the LED segment 102/ The shortest distance from the bending point of the Therefore, the heat dissipation path of the LED filament is short, thereby improving the heat dissipation effect of the bulb lamp. In other embodiments, H1 is greater than H2, so the LED filament is generally located in the middle area of the lamp housing, and the luminous effect is better.

Referring to FIG. 6 , FIG. 6 is a schematic structural diagram of a lamp holder according to an embodiment of the present application. In this embodiment, the lamp holder 16 is provided with a power supply assembly 20, the power supply assembly 20 includes a substrate 201, and the substrate 201 is provided with heating elements (elements that generate more heat during operation, such as ICs, resistors, etc.) and heat-resistant elements (such as electrolytic capacitors, etc.), the lamp holder 16 has an inner surface and an outer surface opposite to the inner surface, the outer surface of the lamp holder 16 is far away from the power supply assembly 20, and the heating element is closer to the inner surface of the lamp holder 16 than the heat-resistant element. There is an insulating sheet 202, and the insulating sheet 202 is in contact with the inner surface of the lamp cap 16. For example, the insulating sheet 202 can be in contact with the inner surface of the lamp cap 16 by welding or fasteners. In one embodiment, the heating element is integrally packaged into a component, the component is provided with a heat sink, and the heat sink is in contact with the inner surface of the lamp cap 16. For example, after the IC and the rectifier bridge are packaged into a component, welding or fasteners are used. The heat sink is brought into contact with the inner surface of the lamp cap 16, and the heat sink can be welded to the inner surface of the lamp cap 16 as a negative wire.

In another embodiment, the substrate 201 is in direct contact with the inner surface of the lamp cap 16. Compared with the indirect contact between the substrate and the lamp cap through glue, the direct contact method can improve the heat dissipation effect of the bulb lamp on the basis of reducing the heat transfer medium. .

In another embodiment, the heating element is covered with thermally conductive adhesive. For example, the substrate 201 has a first side 2011 and a second side 2012, the second side 2012 is far away from the LED filament, and the heating element and the heat-labile element are respectively located on the first side 2011 And on the second surface 2012, the first surface 2011 is covered with thermally conductive adhesive, and the heat generated by the heating element can be transferred to the lamp cap through the thermally conductive adhesive, thereby improving the heat dissipation effect of the bulb lamp.

In another embodiment, as shown in FIG. 7 , the inner surface of the lamp holder 16 is provided with a heat-conducting portion 203 . The coefficient is greater than or equal to the thermal conductivity of the lamp cap 16 , and the heat generated by the heating element can be quickly transferred to the lamp cap 16 through the heat conducting portion 203 , thereby improving the heat dissipation effect of the bulb lamp.

In another embodiment, each surface of the power supply assembly 20 is covered with thermally conductive adhesive, and a part of the thermally conductive adhesive contacts the inner surface of the lamp holder 16. For example, a flexible substrate can be used, so that the flexible substrate can be integrated into the lamp holder 16, and the lamp holder 16 is filled with thermal conductivity. Glue is achieved. The power supply components are covered with thermally conductive adhesive as a whole, and the heat dissipation area is increased, which can greatly improve the heat dissipation effect.

In another embodiment, as shown in FIG. 7C , the substrate 201 is parallel to the axial direction of the lamp cap 16 (or the axial direction of the stem 19 in FIG. 4 , FIG. 5 , and FIG. 8 ). On the side of the substrate close to the lamp head, the heat generated by the heating element can be quickly transferred to the lamp head, thereby improving the heat dissipation efficiency of the power supply assembly; in addition, the heat-labile element and the heat-resistant element can be arranged on different surfaces of the substrate respectively to reduce the heating element. The heat generated during operation affects the heat-labile components, improving the overall reliability and life of the power module. In one embodiment, the substrate 201 is provided with heating elements (elements that generate more heat during operation, such as ICs, resistors, etc.) and heat-labile elements (such as electrolytic capacitors, etc.), and the heating elements are compared with other electronic components ( For example, heat-labile components or other non-heat-sensitive components, such as capacitors, are closer to the inner surface of the lamp cap 16. Therefore, compared with other electronic components, the heating element has a shorter heat transfer distance from the lamp cap 16, which is more conducive to heat generation. The heat generated during the operation of the element is conducted to the lamp cap 16 for heat dissipation, so that the heat dissipation efficiency of the power supply assembly 20 can be improved.

As shown in FIGS. 5 to 7 , the respective projections of the gas tube and the base plate 201 on the XY plane overlap. In some embodiments, the projections of the gas tube and the base plate 201 on the XZ and/or YZ planes are spaced apart (or not overlapped), or in the height direction of the lamp head (Z axis direction), there is a space between the gas tube and the base plate. With a certain distance, the inflatable tube and the base plate do not contact each other, which increases the accommodation space of the power supply assembly and improves the utilization rate of the base plate. In addition, when the substrate 201 is in contact with the inner surface of the lamp cap 16, a cavity is formed between the first surface 2011 of the substrate 201 and the core post 19, and the heat generated by the heating element located on the first surface of the substrate can be transferred through the cavity, reducing the need for Thermally insensitive components located on the second side, thereby increasing the life of the power components.

Please refer to FIGS. 8A to 8D . FIGS. 8A to 8D are schematic diagrams of an LED bulb 40j according to an embodiment of the present application. The LED bulb 40j of this embodiment is basically the same as the LED bulb 40h of FIG. 4 . The structure is the same, including a lamp housing 12, a lamp cap 16 connected to the lamp housing 12, at least two conductive brackets arranged in the lamp housing 12, at least one cantilever 15, a stem 19 and an LED filament 100. The cantilever 15 is shown in FIG. 8B and FIG. 8C. Not shown. The stem 19 includes a vertical rod 19a, each cantilever 15 includes opposite first and second ends, the first end of each cantilever 15 is connected to the vertical rod 19a, and the second end of each cantilever 15 is connected to the LED Filament 100. The difference between the LED bulb shown in FIG. 8C and the bulb shown in FIG. 4 is that in the Z-axis direction, the height of the vertical rod 19a is greater than the distance between the bottom of the vertical rod and the conductor segment 130, and the vertical rod 19a Consists of opposing pole bottoms and pole tops, with the pole bottom near the inflation tube. As shown in FIG. 8D , on the XY plane, the central angle corresponding to the arcs where at least two bending points of the LED filament are located is in the range of 170° to 220°, so that there is a suitable distance between the bending points of the LED segments. Ensure the heat dissipation effect of the LED filament. At least one cantilever 15 is located at the bend point of the LED filament 100, eg, at the bend point of the LED segments 102/104. Each cantilever 15 has an intersection with the LED filament 100 . On the XY plane, at least two intersection points are located on the circumference with the stem 19 (or the vertical rod 19a) as the center, so that the LED filament has a certain symmetry, the luminous flux in all directions is approximately the same, and the LED bulb emits evenly. In one embodiment, at least one intersection point and the bending point of the conductor segment 130 are connected to form a straight line La, the intersection on the straight line La and the electrodes 110/112 of the LED filament form a straight line Lb, and the angle α between the straight line La and the straight line Lb is The range is 0°<α<90°, preferably 0°<α<60°, so that the LED segment has a suitable spacing after bending, and has better light extraction effect and heat dissipation effect. The bending point of the LED segment has a radius of curvature. For example, the bending point of the LED segment 102 has a radius of curvature r3, and the bending point of the LED segment 104 has a radius of curvature r4. r3 can be set larger than r4 or smaller than r4 to meet the lighting requirements and/or heat dissipation requirements in some specific directions. The bending point of the conductor segment 130 has a radius of curvature r5, and r5 is smaller than the maximum value of r3 and r4, that is, r5<max(r3, r4), the LED filament is not easy to break, and it is close to the part of the LED segment that is closer to the stem. There is a certain distance between them to prevent the heat generated by the two LED segments from affecting each other.

In one embodiment, the LED segment 102/104 includes a first segment and a second segment, and the first segment is formed from the electrode 110/112 extending upward (the direction of the top of the lamp housing) to the bending point, and the first segment is formed from the bending point downward (the direction of the lamp head). ) extending to the conductor segment 130 connecting the two

LED segments

102 and 104 to form a second segment, the first segment and the second segment and the lamp housing 12 have opposite first and second distances respectively, and the first distance is smaller than the second distance, In the first distance direction, the base layer 420 b of the LED filament is close to the lamp housing 12 , and the top layer 420 a of the LED filament is away from the lamp housing 12 . For example, in FIG. 8B , the first segment of the LED segment 104 and the lamp housing 12 have relative first distances D1 and second distances D2, the first distance D1 is smaller than the second distance D2, and in the direction of the first distance D1, the distance of the LED filament The base layer 420b is close to the lamp housing 12 , and the top layer 420a of the LED filament is far away from the lamp housing 12 . When the LED filament is bent, the wire in the LED filament is subject to a small bending stress and is not easily broken, which improves the production quality of the LED bulb.

Referring to FIGS. 4A to 4D and FIGS. 8A to 8D, the lamp housing 12 is divided into an upper part and a lower part by a plane A, and the lamp housing 12 has a maximum width at the plane A, such as the one formed by R2 (maximum horizontal spacing) in FIG. 4B. The plane figure is located on the plane A, when the stem 19 and the plane A have an intersection, the lamp housing 12 has the opposite top and bottom of the lamp housing, the bottom of the lamp housing is close to the lamp cap 16, and the LED filament located between the top of the lamp housing and the plane A The length of the LED filament (or the distance from the highest point of the LED filament to the plane A in the height direction of the LED bulb) is less than the length of the LED filament located between the plane A and the bottom of the lamp housing (or in the height direction of the LED bulb). The distance from the lowest point of the LED filament to the plane A), because when the stem 19 and the plane A have an intersection, the inner diameter of the lamp housing 12 above the top of the stem 19 is small, and the volume of gas contained is small. If most of the LED filaments are located in the core The top of the column will affect the overall heat dissipation effect of the LED filament, thereby reducing the quality of the product; if there is a certain distance between the core column 19 and the plane A and the distance from the top of the core column to the plane A is smaller than the height of the vertical rod 19a, the core column 19 includes a relative The bottom of the stem and the top of the stem, the bottom of the stem is connected to the lamp cap 16, the top of the stem extends toward the top of the lamp housing, and the length of the LED filament (or the length of the LED filament between the top of the stem and the top of the bulb The distance between the highest point and the top of the stem) is less than the length of the LED filament located between the top of the stem and the bottom of the lamp housing (or the distance between the top of the stem and the lowest point of the LED filament), and most LED filaments can pass through the core. The column is indirectly supported to ensure the stability of the LED filament shape during the transportation of the LED bulb. In some embodiments, when there is a distance between the stem 19 and the plane A and the distance from the top of the stem to the plane A is greater than the height of the upright rod 19a, the stem 19 includes opposite stem bottom and stem top, the stem The bottom of the column is connected to the lamp cap 16, and the top of the stem extends toward the top of the lamp housing. The length of the LED filament located between the top of the stem and the top of the bulb is greater than the length of the LED filament located between the top of the stem and the bottom of the bulb. The gas volume contained between the top of the column and the bottom of the lamp housing is large, and most of the LED filaments are located between the top of the stem and the bottom of the lamp housing, which facilitates heat dissipation of the LED filaments.

Please refer to FIG. 9 . FIG. 9 is a schematic diagram of a light emission spectrum of an LED bulb according to an embodiment of the present application. In this embodiment, the LED bulb can be any LED bulb disclosed in the previous embodiments, and any single LED disclosed in the previous embodiments is disposed in the LED bulb. filament. The light emitted by the LED bulb is measured by a spectrometer, and a schematic diagram of the spectrum shown in FIG. 9 can be obtained. From this spectrum diagram, it can be seen that the spectrum of the LED bulb is mainly distributed between the wavelengths of 400nm and 800nm, and there are three peaks P1, P2, and P3 at three places in this range. The peak P1 is about 430 nm to 480 nm in wavelength, the peak P2 is about 580 nm to 620 nm in wavelength, and the peak P3 is about 680 nm to 750 nm in wavelength. In intensity, the intensity of the peak P1 is smaller than that of the peak P2, and the intensity of the peak P2 is smaller than that of the peak P3. As shown in FIG. 9 , such a spectral distribution is close to that of a conventional incandescent filament lamp, and is also close to that of natural light. In an embodiment, a schematic diagram of the light emitting spectrum of a single LED filament is shown in FIG. 10. From the spectrum schematic diagram, it can be seen that the spectrum of the LED bulb is mainly distributed between the wavelengths of 400nm to 800nm, and the wavelengths in this range are There are three peaks P1, P2, P3 at three places. The peak P1 is about 430 nm to 480 nm in wavelength, the peak P2 is about 480 nm to 530 nm in wavelength, and the peak P3 is about 630 nm to 680 nm in wavelength. In intensity, the intensity of the peak P1 is smaller than that of the peak P2, and the intensity of the peak P2 is smaller than that of the peak P3. As shown in Fig. 10, such a spectral distribution is close to that of a conventional incandescent filament lamp, and also close to that of natural light.

Please refer to FIG. 11 . FIG. 11 is a light emitting spectrum diagram of an LED bulb according to an embodiment of the present application. It can be seen from the figure that the spectral distribution of the LED bulb has a wavelength similar to that shown in FIG. 10 between 400 nm and 800 nm. The three peaks P1', P2', P3' are shown, the peak P1' is about 430nm to 480nm, the peak P2' is about 480nm to 530nm, and the peak P3' is about 630nm to 680nm. . In intensity, the intensity of the peak P1' is smaller than that of the peak P2', and the intensity of the peak P2 is smaller than that of the peak P3'. The difference is that the intensity of P1' is greater than that of P1, and the half-wave width of P3' is greater than that of P3. The LED bulb has an average color rendering index Ra (R1-R8) greater than 95, a saturated red color (R9) greater than or equal to 90, and the luminous efficacy (Eff) of the LED filament is greater than or equal to 100lm/w.

The term "one LED filament" and "one LED filament" referred to in this application refers to the common connection of the aforementioned conductor segments and LED segments, or only composed of LED segments (or LED chip units), with the same and continuous The light conversion layer (including the same and continuously formed top layer or bottom layer), and only two conductive electrodes electrically connected to the light bulb conductive bracket are provided at both ends, conforming to the above structure description is the single LED filament structure referred to in this application .

The present application has been disclosed above with preferred embodiments, but it should be understood by those skilled in the art that the embodiments are only used to describe some of the embodiments of the present application, and should not be construed as limiting. It should be noted that all the equivalent changes and replacements or reasonable combinations between the embodiments (and especially the LED filament embodiment in FIG. 4, which is combined into the light bulb embodiment in FIG. 4) should be set to cover. within the scope supported by the specification of this application. Therefore, the protection scope of the present application shall be subject to the scope defined by the appended claims.

Claims

An LED filament, characterized in that, the LED filament includes an LED segment, an electrode and a light conversion layer, the LED segment includes at least one LED chip, and the adjacent LED chips in the LED filament, between the LED chips and the electrodes They are electrically connected to each other. The light conversion layer includes a top layer and a carrier layer. The carrier layer includes a transparent layer and a base layer. The top layer and the base layer are in contact with the LED chip, and the transparent layer is in contact with the base layer. In the length direction of the LED filament, the length of the transparent layer is smaller than that of the base layer. length.
The LED filament of claim 1, wherein the base layer comprises opposite upper and lower surfaces, the upper surface of the base layer is in contact with a portion of the top layer, and the lower surface of the base layer is in contact with the transparent layer.
The LED filament according to claim 1, wherein the light conversion layer comprises a first end and a second end opposite to the first end, and the LED chip is located between the first end and the second end.
The LED filament according to claim 3, wherein the transparent layer comprises a first transparent layer and a second transparent layer, and there is a space between the first transparent layer and the second transparent layer.
The LED filament according to claim 4, wherein the LED chip closest to the first end of the light conversion layer is denoted as LED chip n1, and the chips from the first end to the second end are LED chips n2, n3, . . . ...n m , m is an integer and m≤800, the length of the first transparent layer and/or the second transparent layer in the length direction of the LED filament is at least greater than the distance from the first end of the light conversion layer to the LED chip n2.
A bulb lamp, characterized in that the LED bulb lamp comprises a lamp housing and a lamp cap connected to the lamp housing, and the lamp housing is provided with at least one cantilever, a stem and the LED according to any one of the above claims 1 to 5. Filament, the stem includes a vertical rod, each cantilever includes a first end and a second end opposite, the first end of the cantilever is connected to the vertical rod, the second end of the cantilever is connected to the LED filament, and the LED bulb is located in a space coordinate system ( X, Y, Z), wherein the Z axis is parallel to the stem, each cantilever has an intersection with the LED filament, and on the XY plane, at least two intersections are located on the circumference with the stem as the center.
The LED bulb lamp according to claim 6, wherein the lamp housing is divided into an upper part and a lower part by a plane A, the lamp housing has a maximum width at the plane A, and when the stem and the plane A have an intersection point, the lamp housing There are opposite lamp housing top and lamp housing bottom, the lamp housing bottom is close to the lamp cap, and the length of the LED filament located between the lamp housing top and the plane A is less than the length of the LED filament located between the plane A and the lamp housing bottom.
The LED bulb lamp according to claim 6, wherein the lamp housing is divided into an upper part and a lower part by a plane A, the lamp housing has a maximum width at the plane A, and when the stem and the plane A have an intersection point, the lamp housing The top of the lamp housing and the bottom of the lamp housing are opposite, and the bottom of the lamp housing is close to the lamp head. In the height direction of the LED bulb, the distance from the highest point of the LED filament to the plane A is smaller than the distance from the lowest point of the LED filament to the plane A.
The LED bulb lamp according to claim 6, wherein the spectral intensity of the light emitted by the LED filament has three peaks P1', P2' and P3' between the wavelengths of 400nm and 800nm, and the peak P1' is at The wavelength is between 430nm and 480nm, the peak P2' is between 480nm and 530nm, and the peak P3' is between 630nm and 680nm.
The LED bulb according to claim 6, wherein the average color rendering index of the LED bulb is greater than 95, and the light efficiency of the LED filament is greater than or equal to 100lm/w.