CN219283099U

CN219283099U - LED bulb lamp

Info

Publication number: CN219283099U
Application number: CN202220968108.XU
Authority: CN
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: Jiaxing Super Lighting Electric Appliance Co Ltd
Current assignee: Jiaxing Super Lighting Electric Appliance Co Ltd
Priority date: 2020-08-24
Filing date: 2021-08-20
Publication date: 2023-06-30
Anticipated expiration: 2031-08-20
Also published as: CN216619385U; WO2022042431A3; EP4200907A2; CN219775501U; CN219283100U; WO2022042432A1; WO2022042431A2; JP3242967U; CN114087545A

Abstract

The utility model provides an LED bulb lamp, which is characterized by comprising the following components: a lamp housing; the lamp cap is connected with the lamp housing, and a power supply assembly is arranged in the lamp cap; the LED filament is arranged in the lamp shell; the power supply assembly comprises a substrate, wherein a heating element and a thermolabile element are arranged on the substrate, the substrate is provided with a first surface and a second surface, the second surface is far away from the filament, and the heating element and the thermolabile element are respectively arranged on the first surface and the second surface.

Description

LED bulb lamp

The utility model discloses a division application of a novel name of an LED bulb lamp, which is filed by China patent office with application number 202121960146.2 on 8 months and 20 days of 2021.

Technical Field

The application relates to the field of illumination, in particular to an LED bulb lamp.

Background

LEDs have the advantages of environmental protection, energy saving, high efficiency and long service life, and are therefore generally paid attention in recent years, and gradually replace the place of the conventional lighting fixtures. However, the light emitted by the conventional LED light source has directivity, unlike the conventional lamp, which can illuminate in a wide-angle range, so that the application of the LED to the conventional lamp has corresponding challenges depending on the type of the lamp.

In recent years, an LED filament capable of making an LED light source emit light similar to a conventional tungsten bulb lamp to achieve 360 ° full-angle illumination is receiving attention from the industry. The LED lamp filament is manufactured by serially connecting and fixing a plurality of LED chips on a narrow and slender glass substrate, wrapping the whole glass substrate with silica gel doped with fluorescent powder, and then electrically connecting.

The LED bulb lamp in the prior art comprises a lamp shell, an LED filament, a lamp cap and a power supply. The power supply is arranged in the lamp cap, and at least part of heat generated during working is dissipated to the outside of the LED bulb lamp through the lamp cap. Because of the small lamp cap, the small surface area available for heat dissipation by the lamp cap, how to make thermal management of the power supply is a major challenge for such lamps.

Disclosure of Invention

It is specifically noted that the present disclosure may actually include one or more inventive arrangements that are or are not presently claimed, and that in order to avoid confusion during the writing of the specification due to unnecessary distinction between the utility models, the various inventive arrangements that are possible herein may be collectively referred to herein as the "present application".

Many embodiments are described herein in summary in relation to the "present application". The word "present application" is used merely to describe some embodiments disclosed in this specification (whether or not already in the claims), and is not 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 different ways to form an LED bulb lamp or a portion thereof.

The embodiment of the utility model discloses an LED bulb lamp, which is characterized by comprising:

a lamp housing;

the lamp cap is connected with the lamp housing, and a power supply assembly is arranged in the lamp cap; and

the LED filament is arranged in the lamp shell;

the power supply assembly comprises a substrate, wherein a heating element and a thermolabile element are arranged on the substrate, the substrate is provided with a first surface and a second surface, the second surface is far away from the filament, and the heating element and the thermolabile element are respectively arranged on the first surface and the second surface.

According to the embodiment of the utility model, the first surface is covered with the heat-conducting glue, and heat generated by the heating element is transferred to the lamp cap through the heat-conducting glue.

The heat-conducting glue is covered on the heating element.

The heating element in the embodiment of the utility model is an IC or a resistor.

The thermolabile element according to the embodiment of the utility model is an electrolytic capacitor.

The inner surface of the lamp cap is provided with the heat conducting part, and heat generated by the heating element is transferred to the lamp cap through the heat conducting part.

According to the embodiment of the utility model, the heat conduction coefficient of the heat conduction part is larger than or equal to that of the lamp cap.

The heat conducting part is a metal piece contacted with the heating element.

The embodiment of the utility model also provides an LED bulb lamp, which is characterized by comprising:

a lamp housing;

the LED filament is arranged in the lamp shell;

the power supply assembly comprises a substrate, wherein a heating element and a thermolabile element are arranged on the substrate, and the heating element and the thermolabile element are respectively arranged on different surfaces of the substrate; the heating element is an IC or a resistor, and the thermolabile element is an electrolytic capacitor.

In the embodiment of the utility model, the substrate is parallel to the axial direction of the lamp cap, and the heating element is arranged on one surface of the substrate, which is close to the lamp cap.

Through the technical scheme, the application has the following or any combination of technical effects: the heating element and the thermolabile element are arranged on the two sides of the substrate separately, so that the influence of heat generated by the heating element during operation on the thermolabile element can be reduced, and the overall reliability and service life of the power supply assembly are improved; through the setting of heat conduction portion, can be with the quick conduction of the heat that heating element during operation produced to the lamp holder to dispel the heat through the lamp holder, can promote the radiating effect.

Drawings

FIG. 1A is a schematic structural view of another embodiment of an LED filament of the present application;

FIG. 1B is a schematic structural view of another embodiment of an LED filament of the present application;

FIG. 1C is a schematic structural view of another embodiment of an LED filament of the present application;

FIGS. 1D-1G are schematic structural views of various embodiments of the LED filament of the present application;

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

FIG. 2A is a schematic diagram of an embodiment of an LED filament according to the present utility model;

FIG. 2B is a bottom view of FIG. 2A;

FIG. 2C is a schematic partial cross-sectional view of the location A-A of FIG. 2A;

fig. 3A to 3E are schematic views showing a first embodiment of a method for manufacturing an LED filament according to the present utility model;

fig. 4A to 4D are schematic, side, other side and top views, respectively, of an LED bulb lamp according to one embodiment of the present application;

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

FIG. 6A is a schematic view of a lamp head according to an embodiment of the present application;

FIG. 6B is a schematic view of section A-A of FIG. 6A;

FIG. 7A is a schematic view of a lamp head according to an embodiment of the present application;

FIG. 7B is a schematic view of an embodiment of section B-B of FIG. 7A;

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

Fig. 8A to 8D are schematic, side, other side and top views, respectively, of an LED bulb lamp according to one embodiment of the present application.

Detailed Description

In order to make the above objects, features and advantages of the present application more comprehensible, embodiments accompanied with figures are described in detail below.

As shown in fig. 1A-1H, 2A-2C, and 3A-3E, the LED filament has a light conversion layer 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 encapsulates the LED chip units 202/204 (or LED segments 402/404) and a portion of the electrodes (or conductive electrodes) 210, 212/410, 412, with a portion of the electrodes (or conductive electrodes) 210, 212/410, 412 exposed outside the light conversion layer 220/420, electrically connected to each other 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 the electrodes (or conductive electrodes) 210, 212/410, 412. The LED filament includes at least two LED chips 442, adjacent LED chips 442 are electrically connected to each other, and the LED chip units 202/204 (or LED segments 402/404) include 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 may be at least one layer respectively. The layered structure may be selected from: a phosphor paste having high formability (relative to the phosphor film), a phosphor film or transparent layer having low formability, or any combination of the three. The phosphor glue/phosphor film comprises the following components: the silicone modified polyimide and/or glue, phosphor glue/phosphor film may also include phosphor, inorganic oxide nanoparticles (or heat sink particles). The transparent layer may be composed of a light-transmitting resin (e.g., silicone, polyimide) or a combination thereof. The glue may 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 an embodiment, the carrier layer comprises a base layer, the height of the top layer being greater than the height of the base layer in the height direction of the LED filament. The base layer includes opposing upper and lower surfaces, the top layer includes opposing upper and lower surfaces, the upper surface of the base layer is in contact with a portion of the lower surface of the top layer; the LED chip comprises an upper surface and a lower surface which are opposite, the upper surface of the LED chip is close to the upper surface of the top layer relative to the lower surface of the LED chip, 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, the heat conduction coefficient of the top layer is larger than that of the base layer, and the distance from the heat conduction generated by the LED chip to the outer surface of the base layer is shorter, so that heat is not easy to gather, and the heat dissipation effect of the LED filament is good. In one embodiment, if no more than 8w of power is supplied to the LED filament, when lit, emits a luminous flux of at least 4lm on average per millimeter of LED filament length (either on average per millimeter of filament body length or on average per millimeter of top layer length). In one embodiment, the average LED filament length per millimeter (either the average filament body length per millimeter or the average top layer length per millimeter) includes at least 2 LED chips, and the temperature of the LED filament is no greater than the junction temperature of the LED filament when lit for 15000 hours in a 25 ℃ ambient environment.

FIG. 1A is a schematic diagram of an embodiment of an LED filament of the present application, an LEDThe 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, by a circuit film, a first conductive wire 440 in fig. 1B, and the like. The light conversion layer 420 comprises a top layer 420a and a carrier layer comprising a base layer 420b and a transparent layer 420c, the base layer 420b being located between the top layer 420a and the transparent layer 420c (at least in a certain cross section of the LED filament 400). In one embodiment, the base layer 420b includes an upper surface and a lower surface opposite to each other, the upper surface of the base layer 420b contacts a portion of the top layer 420a, the lower surface of the base layer 420b contacts the transparent layer 420c, and in some embodiments, a portion of the lower surface of the base layer 420b contacts the transparent layer 420c, the transparent layer 420c supports a portion of the base layer 420b, so as to enhance the strength of the base layer 420b, facilitate die bonding, and the portion of the base layer 420b not covered by the transparent layer 420c can enable a portion of the heat generated by the LED chip 442 to be directly dissipated through the base layer 420 b. 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 is smaller 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 is thin (for example, the width of the LED filament is less than or equal to 120 μm), the heat dissipation area of the LED chip is relatively reduced, and the transparent layer is located below the base layer, so that on one hand, deformation of the base layer due to heating can be reduced; on the other hand, the LED chip can be supported in an auxiliary way, and die bonding and wire bonding are facilitated. 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 extend along the length direction of the LED filament, the first transparent layer 420c1 extends from one end of the base layer 420b, 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 the extending direction of the second transparent layer 420c 2. In one embodiment, the light conversion layer 420 has a first end and a second end opposite the first end, which, in one embodiment, The LED chip 442 is located between the first end and the second end, and if the LED chip closest to the first end is denoted as LED chip n ₁ The LED chips from the first end to the second end are LED chips n in sequence ₂ ，n ₃ ，……n _m M is an integer and m.ltoreq.800, and in some embodiments, 50.ltoreq.m.ltoreq.300, the length of the first transparent layer 420c1 and/or the second transparent layer 420c2 in the length direction of the LED filament being at least greater than the distance from the first end to the LED chip n 2. The first transparent layer 420c1 and the second transparent layer 420c2 have a space therebetween, and a distance between the first transparent layer 420c1 and the second transparent layer 420c2 is greater than a length of the first transparent layer 420c1 and/or the second transparent layer 420c2 in a length direction of the LED filament. When the LED filament is bent, the part, which is close to the electrode and is easy to separate from the light conversion layer or is in contact with the electrode, is easy to crack, and the first transparent layer and the second transparent layer can perform structural reinforcement on the part, which is in contact with the electrode, of the light conversion layer, so that the crack is prevented from occurring at the contact part of the light conversion layer and the electrode.

Fig. 1B is a schematic structural view of another embodiment of an LED filament of the present application, as shown in fig. 1B, an LED filament 400 has: a light conversion layer 420;

LED segments

402, 404;

electrodes

410, 412; and a conductor segment 430 for electrically connecting between adjacent two

LED segments

402, 404. The LED segment 402/404 includes at least two LED chips 442, and the LED chips 442 are electrically connected to each other by a first conductive wire 440. In the present embodiment, the conductor segment 430 includes a conductor 430a connecting the

LED segments

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

adjacent LED segments

402, 404 is greater than the distance between two adjacent LED chips in the LED segments 402/404, and the length of the first wire 440 is smaller than the length of the conductor 430 a. In this way, it is ensured that the stress generated when bending between the two LED segments does not cause the conductor segments 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, which are respectively used 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. The upper surface of the base layer 420b is adjacent to the top layer 420a with respect to the lower surface of the base layer 420b, and the LED segments 402/404 and portions of the electrodes 410/412 are disposed on the upper surface of the base layer 420b, or at least one side of the LED segments 402/404 is in contact (either direct contact or indirect contact) with the upper surface of the base layer 420 b.

As shown in fig. 1C, in the present embodiment, the conductor segments 430 are also located between two

adjacent LED segments

402 and 404, and the LED chips 442 in the

LED segments

402 and 404 are electrically connected to each other by the first wires 440. However, the conductor 430a in the conductor segment 430 of fig. 1C is not in the form of a wire, but in the form of a sheet or film. In some embodiments, conductor 430a may be copper foil, gold foil, or other electrically conductive material. In this embodiment, the conductor 430a is attached to the surface of the base layer 420b and abuts the top layer 420a, i.e., between the base layer 420b and the top layer 420 a. The conductor segment 430 is electrically connected to the LED segments 402/404 through the second wire 450, that is, the two LED chips 442 located in the two

adjacent LED segments

402, 404 and having the shortest distance from the conductor segment 430 are electrically connected to the conductor 430a in the conductor segment 430 through the second wire 450. Wherein the length of the conductor segment 430 is greater than the distance between two adjacent LED chips 442 in the

LED segments

402, 404, and the length of the first wire 440 is less than the length of the conductor 430 a. With this design, since the conductor segment has a relatively long length, it is possible to ensure that the conductor segment has good flexibility. Assuming that the maximum thickness of the LED chip 442 in the radial direction of the LED filament is H, the thicknesses of the electrodes 410/412, the conductors 430a in the radial direction of the LED filament are 0.5H to 1.4H, preferably 0.5H to 0.7H. The LED chip has a height difference with the electrode and the LED chip with the conductor, so that the wire bonding process can be ensured to be implemented, meanwhile, the quality (namely, good strength) of the wire bonding process is ensured, and the stability of a product is improved.

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

LED segments

402, 404;

electrodes

LED segments

402, 404. The LED segment 402/404 includes at least one LED chip 442, and the conductor segment 430 is electrically connected to the LED segment 402/404 through a second wire 450, that is, two LED chips 442 located in two

adjacent LED segments

402, 404 and having the shortest distance from the conductor segment 430 are electrically connected to the conductor 430a in the conductor segment 430 through the second wire 450. The LED chips 442 are electrically connected to each other by a first conductive wire 440, and the conductor segment 430 includes a conductor 430a connecting the

LED segments

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

adjacent LED segments

402, 404 is larger than the distance between two adjacent LED chips in the LED segments 402/404, and the length of the first wire 440 is smaller than the length of the conductor 430 a. Therefore, when the two LED sections are bent, the stress area of the conductor section is larger, and the generated stress does not cause the breakage of the conductor section. 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 comprises a top layer 420a and a bearing layer, the bearing layer comprises 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, the heat conductivity coefficient of the transparent layer 420c is larger than that of the base layer 420b, the thickness of the base layer 420b in the radial direction of the LED filament is smaller than or equal to that of the conductor 430a in the radial direction of the LED filament, when the LED filament is thinner (for example, the width of the LED filament is smaller than or equal to 120 mu m), the heat dissipation area of the LED chip is relatively reduced, and by adopting the transparent layer, deformation of the base layer caused by heating can be reduced on one hand, on the other hand, the LED chip can be supported in an auxiliary manner, and die bonding and wire bonding are facilitated. In this embodiment, the top layer 420a, the base layer 420b and the transparent layer 420c wrap the conductor 430a, on the one hand, reduce the influence of the external environment on the conductor, on the other hand, increase the bearing capacity when the conductor is electrically connected, and improve the stability of the electrical connection when the conductor is bent.

Referring to fig. 1E to 1G, in some embodiments, the conductor 430a includes a covering portion 430b and an exposing portion 430c, the length of the exposing portion 430c in the axial direction of the LED filament is smaller than the distance between adjacent LED chips in any LED segment 402/404, and when the LED filament is bent, the exposing portion 430c is slightly deformed due to stress, so that the bending area is small, the deformation degree is small, and the bending form of the LED filament is maintained. As shown in fig. 1E, the exposed portion 430c includes a first exposed portion 430c1 and a second exposed portion 430c2, a portion of the top layer 420a exposed to the conductor 430a is the first exposed portion 430c1, a portion of the transparent layer 420c exposed to the conductor 430a is the second exposed portion 430c2, and a length of the first exposed portion 430c1 in the axial direction (length direction) of the LED filament is greater than or equal to a length of the second exposed portion 430c2 in the axial direction of the LED filament, so as to ensure electrical connection stability and uniform stress when the conductor is bent. As shown in fig. 1F, the exposed portion includes only 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 LED filament is bent, the stress generated during bending is concentrated on the conductor segment, so as to reduce the breaking risk of the wires connecting the adjacent LED chips. As shown in fig. 1G, the exposed portion includes only the second exposed portion 430c2, and thus the conductor stress concentration can be relieved. 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 one of the LED segments 402/404, and since a portion of the conductors are located between adjacent transparent layers, the stability of the support of the conductors by the transparent layers can be ensured.

Referring to fig. 1h, the led filament 400 includes: a light conversion layer 420;

LED segments

402, 404;

electrodes

LED segments

402, 404. The

LED segments

402 and 404 include at least one LED chip 442, and the conductor segment 430 is electrically connected to the

LED segments

402 and 404 through the second wire 450, that is, the two LED chips 442 located in the two

adjacent LED segments

402 and 404 and having the shortest distance from the conductor segment 430 are electrically connected to the conductor 430a in the conductor segment 430 through the second wire 450. The conductor segment 430 includes a conductor 430a that connects the

LED segments

402, 404, the conductor 430a being, for example, a conductive sheet or strip of metal, such as a sheet of copper or iron. Wherein the shortest distance between two LED chips 442 respectively located in two

adjacent LED segments

402, 404 is greater than the distance between two adjacent LED chips in the LED segments 402/404, the LED chips are electrically connected by a first wire 440, and the length of the first wire 440 is smaller than the length of the conductor 430 a. When the two LED sections are bent, the stress area of the conductor section is larger, and the generated stress does not cause the breakage of the conductor section. 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), a carrier layer including a base layer 420b and a transparent layer 420c, and the LED chips 442 in the LED segments 402/404 are arranged along a radial direction of the LED filaments (or a width direction of the LED filaments), and each LED chip 442 in the LED segments 402/404 is connected to the conductor 430a and/or the 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 420 c. 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) contacts with the base layer and the transparent layer 420c, the thickness of the base layer 420b is smaller than the thickness of the top layer, and the heat emitted by the LED chip is simultaneously transferred to the top layer and the transparent layer through the base layer, so that the heat dissipation efficiency of the LED filament is improved, and secondly, the base layer is fully wrapped by the top layer and the transparent layer, so that the base layer is not influenced by external environment, and the LED filament can be protected by multiple sides of the top layer when being bent, the breakage probability of the second conducting wire 450 is reduced, and the product yield is improved.

With continued reference to fig. 2A to 2C, fig. 2A is a schematic perspective partial cross-sectional view of an embodiment of an LED filament according to the present utility model; FIG. 2B is a schematic bottom view of FIG. 2A; FIG. 2C is a schematic partial cross-sectional view of the location A-A of FIG. 2A. The LED filament 300 includes a plurality of

LED chip units

202, 204, at least two

conductive electrodes

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

LED chip units

202 and 204 are electrically connected to each other, and 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 and 204 and the

conductive electrodes

210 and 212, and at least a portion of the two

conductive electrodes

210 and 212 are exposed, wherein the light conversion layer 220 includes silica gel, fluorescent powder and heat dissipation particles. In some embodiments, the LED chip units 202/204 include at least one LED chip, and the concentration of the fluorescent powder corresponding to each surface of the LED chip is the same, so that the light conversion rate of each surface is the same, and the light uniformity of the LED filaments 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 206a and a second electrical connection 206b. The distance between the first connection portions 206a of two adjacent

LED chip units

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

LED chip units

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

LED chip units

202, 204 is greater than a distance between the adjacent two

LED chip units

202, 204 in a length direction of the LED filament, and at least a portion of the first and second

electrical connection portions

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

In an 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 206b of the LED chip unit 202 can be electrically connected to the first electrical connection portion 206a of the LED chip unit 204 through the second conductive portion 260, the second conductive portion 260 has an end point a and an end point b, the connection line of the end point a and the end point b is a straight line ab, and the straight line ab intersects the length direction p of the LED filament. 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 and 204 and the

conductive electrodes

210 and 212, and at least a portion of the two

conductive electrodes

210 and 212 are exposed, the carrier layer includes a base layer, the base layer includes an upper surface and a lower surface opposite to the upper surface, the upper surface of the base layer is close to the top layer with respect to the lower surface of the base layer, at least one of the first conductive portion 240 and the second conductive portion 260 is in contact (directly contact or indirectly contact) with the upper surface of the base layer, and when the LED filament is bent, a radius of curvature of the base layer after being bent by force is relatively small, and the first conductive portion and the second conductive portion are not easily broken. In one embodiment, the first electrical connection 206a and the second electrical connection 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 the mini LED refers to an LED with the package size ranging from 0.1 mm to 0.2mm, and is also called a sub-millimeter light emitting diode. When the LED chip units are electrically connected, for example, the second electrical connection portion 206b of the LED chip unit 202 may be a positive connection point, the first electrical connection portion 206a of the LED chip unit 204 may be a negative connection point, and the second electrical connection portion 206b of the LED chip unit 202 may be electrically connected to the first electrical connection portion 206a of the LED chip unit 204 through the second conductive portion 260. For example, the second electrical connection portion 206b of the LED chip unit 202 may be a negative electrode connection point, the first electrical connection portion 206a of the LED chip unit 204 may be a positive electrode connection point, and the second electrical connection portion 206b of the LED chip unit 202 may be electrically connected to the first electrical connection portion 206a of the LED chip unit 204 through the second conductive portion 260. The first and second

conductive parts

240 and 260 may be in the form of wires, films, such as copper wires, gold wires, circuit films, or copper foils, etc.

Please refer to fig. 3A to 3E, which are schematic diagrams illustrating an embodiment of a method for manufacturing an LED filament according to the present utility model. The manufacturing method of the LED filament comprises the following steps:

s20: the

LED chip units

202, 204 and the

conductive electrodes

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

S22A: the top layer 220a is coated on the portion of the

LED chip units

202, 204 and the

conductive electrodes

210, 212 not contacting the carrier 280, and then the curing (or solidification) process is performed on the

LED chip units

202, 204 and the

conductive electrodes

210, 212 coated with the top layer 220a, 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 a portion of at least two

conductive electrodes

210, 212 is exposed (as shown in fig. 3B). Such as, but not limited to, heating, or Ultraviolet (UV) radiation;

S22B: there are several ways to turn over the

LED chip units

202, 204 and the

conductive electrodes

210, 212 coated with the top layer 220a, one way is that the

LED chip units

202, 204 and the

conductive electrodes

210, 212 are only disposed on the carrier 280, there is no adhesion therebetween, and the turned-over semi-finished product can be directly turned over and then placed on the carrier 280.

Secondly, if a glue-like substance for adhesion, such as a photoresist used in a semiconductor process or a die attach adhesive for easy removal, is provided between the carrier 280 and the

LED chip units

202, 204, and the

conductive electrodes

210, 212, the glue-like substance has the effect of temporarily fixing the

LED chip units

202, 204, and the

conductive electrodes

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

LED chip units

202, 204 and the

conductive electrodes

210, 212 coated with the top layer 220a are turned over, the photoresist coated on the carrier 280 may be cleaned with acetone, or the die bond adhesive coated on the carrier may be removed with a corresponding solvent, so that the

LED chip units

202, 204 and the

conductive electrodes

210, 212 coated with the top layer 220a may be separated from the carrier 280. In addition, the photoresist or the die bond adhesive can be further cleaned to remove the residual photoresist or the die bond adhesive.

S24: electrically connecting adjacent

LED chip units

202, 204 and LED chip units 202/204 to conductive electrodes 210, 212 (shown in fig. 3C);

s26: after step S24, the base layer 220b is coated on the portions of the

LED chip units

202 and 204 and the

conductive electrodes

210 and 212 not coated by the top layer 220a, and the coating is cured (as shown in fig. 3D).

After step S26, step S28 may further include cutting the

LED chip units

202 and 204 and the

conductive electrodes

210 and 212, which encapsulate the light conversion layer 220, at the cutting positions as drawn by the dashed lines in fig. 3E, so that the cut strip-shaped element is the LED filament 300. The cutting method in step S28 is not limited to fig. 3E, and the

LED chip units

202 and 204 of each two adjacent columns may be cut into a single LED filament.

In the method for manufacturing the LED filament according to this embodiment, the top layer 220a and the base layer 220b may be made of the same material, and if the top layer 220a and the base layer 220b also contain oxidized nanoparticles, the top layer 220a and the base layer 220b have the same ratio of the fluorescent powder, the silica gel, and the oxidized nanoparticles, in other words, the top layer 220a and the base layer 220b are made of the same material, which is only distinguished into the top layer 220a and the base layer 220b for convenience of description. Of course, in other embodiments, the ratio of phosphor, silica gel, oxidized nanoparticles in the top layer 220a to the base layer 220b may be different.

In one embodiment, the substrate comprises a silicone modified polyimide, a thermal curing agent, a heat dissipating particle and a fluorescent powder, wherein the thermal curing agent is an epoxy, isocyanate or bisoxazoline compound, and the heat dissipating particle comprises silicon dioxide (SiO ₂ ) Alumina (Al) ₂ O ₃ ) Zirconia (ZrO) ₂ ) Etc. In one embodiment, the thermal curing agent is used in an amount of 3 to 12% by weight of the silicone modified polyimide based on the weight of the silicone modified polyimide. A silicone-modified polyimide comprising a repeating unit represented by the following general formula (i):

ar in the general formula (I) ¹ Is a 4-valent 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, may have a bridged alicyclic hydrocarbon structure, may be a bicyclic alicyclic hydrocarbon structure, or may be a tricyclic alicyclic hydrocarbon structure. The organic group may be a benzene ring structure or an alicyclic hydrocarbon structure containing an active hydrogen functional group, and the active hydrogen functional group may be any one or more of a hydroxyl group, an amino group, a carboxyl group, an amide group and a thiol group.

Ar ² The organic group may have, for example, an alicyclic hydrocarbon structure of a monocyclic system, or a 2-valent organic group having an active hydrogen functional group, and the active hydrogen functional group may be any one or more of a hydroxyl group, an amino group, a carboxyl group, an amide group, and 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 5000 to 100000, preferably 10000 to 60000, more preferably 20000 to 40000. The number average molecular weight is a polystyrene equivalent based on a calibration curve prepared by a Gel Permeation Chromatography (GPC) apparatus using standard polystyrene. When the number average molecular weight is 5000 or less, it is difficult to obtain good mechanical properties after curing, and particularly, elongation tends to be lowered. On the other hand, when it exceeds 100000, the viscosity becomes too high, making it difficult for the resin to be formed.

Ar ¹ The acid anhydride may include aromatic acid anhydrides and aliphatic acid anhydrides, and the aromatic acid anhydrides include aromatic acid anhydrides containing only benzene rings, fluorinated aromatic acid anhydrides, aromatic acid anhydrides containing amide groups, aromatic acid anhydrides containing ester groups, aromatic acid anhydrides containing ether groups, aromatic acid anhydrides containing sulfur groups, aromatic acid anhydrides containing sulfone groups, aromatic acid anhydrides containing carbonyl groups, and the like.

Ar ² The diamine is a component derived from diamine, and the diamine may be classified into aromatic diamine and aliphatic diamine, and the aromatic diamine includes aromatic diamine having only a benzene ring structure, fluorinated aromatic diamine, aromatic diamine having an ester group, aromatic diamine having an ether group, aromatic diamine having an amide group, aromatic diamine having a carbonyl group, aromatic diamine having a hydroxyl group, aromatic diamine having a carboxyl group, aromatic diamine having a sulfone group, aromatic diamine having a sulfur group, and the like.

The addition of different thermosetting agents has different effects on the light transmittance of the organosilicon modified polyimide.

Even if the same thermosetting agent is added, the light transmittance is affected differently when the amount added is different. Table 1-1 shows that the light transmittance is improved when the added amount of the thermosetting agent BPA of the fully aliphatic silicone-modified polyimide is increased from 4% to 8%. However, when the amount of the additive was increased to 12%, the light transmittance was hardly changed. The light transmittance was shown to be improved as the amount of the thermosetting agent added was increased, but when the amount was increased to a certain extent, the effect of adding a further amount of the thermosetting agent on the light transmittance was rather limited.

TABLE 1-1

A phosphor composition as part of the top layer 420b, comprising a first phosphor, a second phosphor, a third phosphor, and a fourth phosphor, wherein the first phosphor has a peak wavelength of 490-500 nm and a full width at half maximum (FWHM) of 29-32 nm under blue excitation; the wavelength peak value of the second fluorescent powder is 520-540 nm under the excitation of blue light, and the half-wave width (FWHM) is 110-115 nm; the wavelength peak value of the third fluorescent powder is 660-672 nm under the excitation of blue light, and the half-wave width (FWHM) is 15-18 nm; the wavelength peak value of the fourth fluorescent powder is 600-612 nm under the excitation of blue light, the full width at half maximum (FWHM) is 72-75 nm or the wavelength peak value is 620-628 nm, the full width at half maximum (FWHM) is 16-18 nm or the wavelength peak value is 640-650 nm, and the full width at half maximum (FWHM) is 85-90 nm. The center particle diameter (D50) of any one of the first, second, third and fourth phosphors is 15 to 20 μm, the D50 of the second and third phosphors is preferably 15 to 16 μm, and the D50 of the first and fourth phosphors is preferably 16 to 20 μm. When the blue light excites the phosphor, the thickness of the top layer with different concentrations of the same phosphor affects the half-peak bandwidth of the phosphor, and in this embodiment, the thickness of the top layer 420b is 80-100 μm. The weight percentage of each fluorescent powder in the fluorescent powder composition is as follows: the light performance of the blue LED chip with the wavelength peak value of 451nm and the FWHM of 16.3nm and the current of 30mA is measured as shown in the table 1:

TABLE 1

As is clear from the numbers No. 1 to No. 4 in Table 1, the contents of the third phosphor and the fourth phosphor in the blended phosphor composition have an effect on the luminous efficacy (Eff), the average color rendering index (Ra) and the saturated red (R9). As is clear from the numbers No. 1 and 2, when the content of the fourth phosphor having a peak wavelength of 670nm is increased, eff is increased, and Ra and R9 are decreased; when the phosphor having a peak wavelength of 630nm was used instead of the phosphor having 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 having a peak wavelength of 670nm was increased, eff was decreased, and Ra and R9 were increased. Therefore, according to actual needs, when the fourth fluorescent powder with different wavelength peaks is selected, the dosage of the third fluorescent powder and the fourth fluorescent powder is blended so as to obtain better luminous performance.

Ratio of phosphor to glue

The same fluorescent powder is selected, the proportion of the fluorescent powder composition and the glue is prepared, as shown in the table 2, as can be seen from the table 2, the proportions of the fluorescent powder composition and the glue are different, and the proportions of Eff, ra, R9 and CCT are different, and the more the fluorescent powder composition occupies the glue, the lower the proportions of Eff, ra and CCT are, and the trend of R9 rising after being lowered is that; in addition, when the fluorescent powder composition is matched with glue (such as silica gel) to be used as the top layer of the LED filament, in the process of manufacturing the top layer, because the specific gravity of the fluorescent powder composition is larger than that of the silica gel, obvious sedimentation of the fluorescent powder can occur, so that the color temperature of the white LED is shifted, when the fluorescent powder occupies a larger amount, the sedimentation of the fluorescent powder is more, and the color temperature is more severely shifted, so that the weight ratio of the fluorescent powder composition to the glue in the top layer is 0.2-0.3:1, and preferably 0.25-0.3:1. In one embodiment, a certain amount of hollow glass beads can be added into the fluorescent powder composition, when the fluorescent powder subsides, the glass beads float upwards, the back scattering/emitting degree of light in the floating process is reduced, and the effect of the fluorescent powder subsides on the light scattering is counteracted, so that the phenomenon of color temperature drift can be relieved, and in addition, the influence of the added glass beads on the initial brightness of the white light LED is smaller due to the fact that the absorption of the glass beads on visible light is smaller. The mass ratio of the glass beads to the fluorescent powder composition is 1:5-15, and the weight ratio of the glass beads to the fluorescent powder composition is 1:10-15.

TABLE 2

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

In some embodiments, the phosphor composition that is part of the top layer 420b includes a first phosphor, a second phosphor, a third phosphor, the first phosphor having a peak wavelength of 500 to 550nm and a full width at half maximum (FWHM) of 100 to 130nm under blue excitation; the wavelength peak value of the second fluorescent powder is 580-620 nm under the excitation of blue light, and the half-wave width (FWHM) is 70-90 nm; the wavelength peak value of the third fluorescent powder is 620-670 nm under the excitation of blue light, and the full width at half maximum (FWHM) is 70-95 nm. The center particle diameter (D50) of any one of the first phosphor, the second phosphor and the third phosphor is 15 to 20 μm, the D50 of the first phosphor is preferably 15 to 16 μm, and the D50 of the second phosphor and the third phosphor is preferably 16 to 20 μm. When the blue light excites the phosphor, the thickness of the top layer with different concentrations of the same phosphor affects the half-peak bandwidth of the phosphor, and in this embodiment, the thickness of the top layer 420b is 80-100 μm. The dosage of the first fluorescent powder in the fluorescent powder composition is less than or equal to ten times of the sum of the dosages of the second fluorescent powder and the third fluorescent powder, namely, the dosage of the first fluorescent powder is less than or equal to 10 (the dosage of the second fluorescent powder and the dosage of the third fluorescent powder), the weight ratio of the fluorescent powder composition to the glue in the top layer is 0.4-0.8:1, the closer the dosage of the fluorescent powder composition to the dosage of the silica gel, the light conversion efficiency of the LED chip is improved, in addition, the contact area of the fluorescent powder and the LED chip is increased, and the heat dissipation efficiency of heat generated by the LED chip is improved.

Referring to fig. 4A and fig. 4B to fig. 4D, fig. 4A is a schematic diagram of an LED bulb 40h according to an embodiment of the present application, and fig. 4B to fig. 4D are a side view, another side view and a top view of the LED bulb 40h of fig. 4A, respectively. In this embodiment, as shown in fig. 4A to 4D, the LED bulb lamp 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), a stem 19 and a single LED filament 100. The stem 19 comprises opposite stem bottom and stem top, the stem bottom being connected to the lamp cap 16, the stem top extending into the interior of the lamp envelope 12, e.g. the stem top may be located at a position about the center inside the lamp envelope 12. The conductive holder is connected to the stem 19. The LED filament 100 includes a filament body and two filament electrodes (or electrodes or conductive electrodes) 110, 112, wherein the two

filament electrodes

110, 112 are located at opposite ends of the filament body, and the filament body is the other part of the LED filament 100 excluding the

filament electrodes

110, 112. The two

filament electrodes

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

In the conventional bulb lamp manufacturing process, in order to avoid oxidation fracture failure caused by burning tungsten wires in air, a horn stem glass structure is designed to be sleeved at an opening of a glass lamp housing for sintering and sealing, then the port of the horn stem is connected with a vacuum pump to pump air in the lamp housing into nitrogen, so that the tungsten wires in the lamp housing are prevented from being burnt and oxidized, and finally the port of the horn stem is sintered and sealed. Therefore, the vacuum pump can pump and replace the air in the lamp housing into full nitrogen or the combination of nitrogen and helium in a proper proportion through the stem, so that the heat conductivity of the air in the lamp housing is improved, and meanwhile, the water mist hidden in the air is removed. In one embodiment, the LED bulb lamp can be replaced by nitrogen and oxygen or a moderate proportion combination of nitrogen and air, the content of oxygen or air is 1-10%, preferably 1-5% of the volume of the lamp housing, when saturated hydrocarbon is contained in the base layer, the saturated hydrocarbon can generate free radicals under the actions of light, heat, stress and the like in the use process of the LED bulb lamp, the generated free radicals or activated molecules are combined with oxygen to form peroxide free radicals, and oxygen is filled into the lamp housing, so that the heat resistance and the light resistance of the base layer containing the saturated hydrocarbon can be improved.

In the process of manufacturing the LED bulb, in order to increase the refractive index of the lamp housing 12 to the light emitted from the LED filament, some foreign matters, such as rosin, may be attached to the inner wall of the lamp housing 12. The average thickness of the foreign matter deposit per square centimeter of the inner wall area of the lamp housing 12 is 0.01 to 2mm, and the thickness of the foreign matter is preferably 0.01 to 0.5mm. In one embodiment, the content of the foreign matter per square centimeter of the inner wall area of the lamp housing 12 is 1% to 30%, preferably 1% to 10% of the content of the foreign matter on the entire inner wall of the lamp housing 12. The 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 gas filled in the lamp housing 12, the impurity content in the gas filled is 0.1% -20%, preferably 0.1% -5% of the volume of the lamp housing 12, and the impurity content may be adjusted by, for example, vacuum drying the lamp housing.

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, YZ plane and XZ plane are length L1, length L2 and length L3, respectively. 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 the length L1, the length L2 and the length L3 is (0.5 to 0.9): 1 (0.6 to 1), the ratio of the length L1, the length L2 and the length L3 is close to 1:1:1, the luminous effect of the LED bulb lamp is better, and the full ambient light is realized. The LED filament 100 has at least one first bending point and at least two second bending points when bending, the first bending points and the second bending points are arranged at intervals, the height of any first bending point on the Z axis is greater than that of any second bending point, in one embodiment, the spacing between two adjacent first bending points on the Y axis or the 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 the X axis has a maximum value D1 and a minimum value D2, D2 ranges from 0.5D1 to 0.9D1, and the luminous flux distribution on each plane is more uniform. Let the diameter of the lamp cap 16 be R1 (see fig. 4B), the maximum diameter of the lamp envelope 12 or the maximum horizontal distance of the lamp envelope 12 in the YZ plane be R2 (see fig. 4B), the maximum width of the LED filament 100 in the Y axis direction on the YZ plane (see fig. 4B) or the maximum width in the X axis direction on the XZ plane be R3 (see fig. 4C), R3 is between R1 and R2, that is, R1 < R3 < R2, when 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 wider, which is beneficial to improving the heat dissipation effect of the LED filament. In the manufacturing process of the LED bulb lamp, the LED filament 100 may be first placed in the inner space of the lamp housing 12 in a folding manner, and then the LED filament 100 is stretched in the lamp housing 12 manually or mechanically, so that the maximum length of the LED filament 100 in the XZ plane satisfies the above relation.

As shown in fig. 4A to 4D, in the present embodiment, there are one conductor segment 130 of the LED filament 100, two

LED segments

102 and 104, and each two

adjacent LED segments

102 and 104 are connected through the conductor segment 130, and the LED filament 100 exhibits an arc bending in the bending mode of the highest point, that is, the

LED segments

102 and 104 respectively exhibit an arc bending at the highest point of the LED filament 100, and the conductor segments also exhibit an arc bending at the low point of the LED filament. The LED filament 100 may be defined as one segment following each bent conductor segment 130, with the

respective LED segments

102, 104 forming a corresponding segment.

Also, since the LED filament 100 employs a flexible base layer, the flexible base layer preferably employs a silicone modified polyimide resin composition including a silicone modified polyimide, a thermosetting agent, heat dissipating particles, and a phosphor. In the present embodiment, the two LED segments 102 are 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 segments 102. That is, the two LED segments 102 are each bent at the high point of the LED filament to form an inverted U-shape and have a value of a bending radius r1, and the conductor segment 130 is bent at the low point of the LED filament 100 and has a value of a bending radius r2, wherein r1 is greater than r 2. By the arrangement of the conductor segments 130, the LED filament 100 is bent with a small radius of gyration in a limited space. In an embodiment, the bending points of the

LED segments

102 and 104 are at the same height in the Z direction, and the LED bulb emits light more uniformly because the LED filaments have a certain symmetry. In one embodiment, the heights of the bending points of the LED segment 102 and the LED segment 104 in the Z direction are different, for example, the height of the bending point of the LED segment 102 is greater than the height of the bending point of the LED segment 104, and in the case that the lengths of the LED filaments are the same, when the LED filaments are placed in the lamp housing in this way, part of the LED filaments are biased toward the lamp housing, so that the heat dissipation effect of the LED filaments is better. In addition, in the Z direction, the upright 19a of the present embodiment has a lower height than the upright 19a of the previous embodiment, the height of the upright 19a being the height corresponding to the conductor segment 130, or the upright 19a being approximately in contact with a portion of the conductor segment 130. For example, the lowest portion of the conductor segment 130 may be connected to the top of the upright 19a to make the overall shape of the LED filament 100 less deformable. In various embodiments, the conductor segments 130 may be connected to each other through perforations at the top of the uprights 19a, or the conductor segments 130 may be glued to the top of the uprights 19a to be connected to each other, but are not limited thereto. In one embodiment, the conductor segment 130 and the pole 19a may be connected using a guide wire, such as by drawing a guide wire on top of the pole 19a to connect the conductor segment 130.

As shown in fig. 4B, in the present embodiment, the height of the conductor segment 130 is higher than that of the two

electrodes

110 and 112 in the Z direction, and the two

LED segments

102 and 104 extend from the two

electrodes

110 and 112 to the highest point respectively, and then bend down to the conductor segment 130 connecting the two

LED segments

102 and 104. As shown in fig. 4C, in the present embodiment, the profile of the LED filament 100 in the XZ plane is similar to V-shape, that is, the two LED segments 102 extend obliquely upward and outward respectively, and after bending at the highest point, extend obliquely downward and inward respectively to the conductor segments 130. As shown in fig. 4D, in the present embodiment, the profile of the LED filament 100 in the XY plane has an S shape. As shown in fig. 4B and 4D, in the present embodiment, the conductor segment 130 is located between the

electrodes

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

electrodes

110, 112 are located substantially on a circumference centered on the conductor segment 130 (or the stem 19 or the upright 19 a) on the XY plane, for example, the bending point of the LED segment 102, the bending point of the LED segment 104 are located on the same circumference centered on the stem 19 or the upright 19a on the XY plane; in some embodiments, the inflection point of the LED segment 102, the inflection point of the LED segment 104, and the

electrodes

110, 112 are located on the same circumference centered on the stem 19 or leg 19a in the XY plane.

Referring 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 the present embodiment has the same basic structure as the LED bulb 40H of fig. 4, and 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), a stem 19 and a single LED filament 100, wherein the LED bulb 40i of the present embodiment has no upright 19a, the stem 19 includes an air tube, the air in the lamp housing 12 is filled through the air tube, as shown in fig. 5, in the Z-axis direction, the shortest distance from the LED filament 100 (or the inflection point of the LED segment 102/104) to the lamp housing 12 is H1, the shortest distance from the conductor segment 130 of the LED filament 100 to the stem 19 is H2, H1 is less than or equal to H2, and the inflection point of the LED segment is closer to the lamp housing, so that the path of the LED filament is short, thereby improving the effect of the bulb, in other embodiments, the H1 is greater than H2, and thus the LED filament is better in the heat dissipation area.

Referring to fig. 6, fig. 6 is a schematic structural diagram of a lamp cap according to an embodiment of the present application. In this embodiment, the power supply assembly 20 is disposed in the lamp cap 16, the power supply assembly 20 includes a substrate 201, a heating element (an element generating more heat during operation, such as an IC, a resistor, etc.) and a thermolabile element (such as an electrolytic capacitor, etc.) are disposed on the substrate 201, the lamp cap 16 has an inner surface and an outer surface opposite to the inner surface, the outer surface of the lamp cap 16 is far away from the power supply assembly 20, the heating element is closer to the inner surface of the lamp cap 16 than the thermolabile element, an insulating sheet 202 is disposed on the heating element, the insulating sheet 202 is in contact with the inner surface of the lamp cap 16, and for example, the insulating sheet 202 can be in contact with the inner surface of the lamp cap 16 by welding or fastening. In one embodiment, the heating element is integrally packaged as a component, the component has a heat sink thereon, the heat sink contacts the inner surface of the lamp cap 16, for example, after the IC and the rectifier bridge are packaged as a component, the heat sink contacts the inner surface of the lamp cap 16 by welding or fastening, etc., 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, and the heat dissipation effect of the bulb lamp can be improved on the basis of reducing the heat transfer medium by adopting a direct contact manner compared with an indirect contact between the substrate and the lamp cap through glue.

In another embodiment, the heat-generating element is covered with a heat-conducting glue, for example, the substrate 201 has a first face 2011 and a second face 2012, the second face 2012 is far away from the LED filament, the heat-generating element and the thermolabile element are respectively located on the first face 2011 and the second face 2012, the first face 2011 is covered with the heat-conducting glue, and heat generated by the heat-generating element can be transferred to the lamp cap through the heat-conducting glue, so as to improve the heat dissipation effect of the bulb lamp.

In another embodiment, as shown in fig. 7, a heat conducting portion 203 is disposed on an inner surface of the lamp cap 16, the heat conducting portion 203 may be a net bag for accommodating a heating element or a metal piece contacting with the heating element, the heat conducting coefficient of the heat conducting portion 203 is greater than or equal to that of the lamp cap 16, and heat generated by the heating element can be quickly transferred to the lamp cap 16 through the heat conducting portion 203, so as to improve the heat dissipation effect of the bulb lamp.

In another embodiment, each face of the power assembly 20 is covered with a heat-conductive paste, and a portion of the heat-conductive paste contacts the inner surface of the lamp cap 16, for example, by using a flexible substrate, and integrally mounting the flexible substrate in the lamp cap 16, and filling the heat-conductive paste into the lamp cap 16. The power supply assembly is integrally covered with the heat-conducting glue, and the heat dissipation area is increased, so that the heat dissipation effect can be greatly improved.

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, 5 and 8), and since the heating elements can be all placed on the surface of the substrate close to the lamp cap, the heat generated by the heating elements can be quickly transferred to the lamp cap, thereby improving the heat dissipation efficiency of the power supply assembly; in addition, the thermolabile element and the heat-resistant element are respectively arranged on different surfaces of the substrate, so that the influence of heat generated by the heating element during operation on the thermolabile element is reduced, and the overall reliability and service life of the power supply module are improved. In an embodiment, the substrate 201 is provided with a heating element (such as an IC, a resistor, etc. which generates more heat during operation) and a thermolabile element (such as an electrolytic capacitor, etc.), the heating element is closer to the inner surface of the lamp cap 16 than other electronic elements (such as thermolabile elements or other non-heat-sensitive elements, such as capacitors), so that the heating element has a shorter heat transfer distance from the lamp cap 16 than other electronic elements, and is more beneficial to heat generated during operation of the heating element being transferred to the lamp cap 16 for heat dissipation, thereby improving the heat dissipation efficiency of the power supply assembly 20.

As shown in fig. 5 to 7, projections of the gas tube and the substrate 201 on the XY plane overlap, respectively. In some embodiments, the projections of the gas tube and the substrate 201 on the XZ and/or YZ planes respectively have a space (or do not overlap), or in the height direction (Z axis direction) of the lamp cap, a certain distance is provided between the gas tube and the substrate, and the gas tube and the substrate are not contacted with each other, so that the accommodating space of the power supply assembly is increased and the utilization rate of the substrate is improved. In addition, when the substrate 201 contacts the inner surface of the lamp cap 16, a cavity is formed between the first surface 2011 of the substrate 201 and the stem 19, and heat generated by the heating element located on the first surface of the substrate can be transferred through the cavity, so that the thermal influence on the thermolabile element located on the second surface is reduced, and the service life of the power supply assembly is prolonged.

Referring to fig. 8A to 8D, fig. 8A to 8D are schematic views of an LED bulb 40j according to an embodiment of the present application, the LED bulb 40j of the present embodiment has the same basic structure as the LED bulb 40h of fig. 4, and 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, at least one cantilever 15, a stem 19 and an LED filament 100, and the cantilever 15 is not shown in fig. 8B and 8C. The stem 19 includes a leg 19a, each cantilever 15 including opposite first and second ends, the first end of each cantilever 15 being connected to the leg 19a and the second end of each cantilever 15 being connected to the LED filament 100. The LED bulb lamp shown in fig. 8C is different from the bulb lamp shown in fig. 4 in that: in the Z-axis direction, the height of the pole 19a is greater than the distance between the pole bottom and the conductor segment 130, and the pole 19a includes opposite pole bottoms and pole tops, the pole bottoms being adjacent to the inflation tube. As shown in fig. 8D, on the XY plane, the central angle range corresponding to the arc where at least two bending points of the LED filament are located is 170 ° to 220 °, so that the bending points of the LED segment have a suitable distance therebetween, and the heat dissipation effect of the LED filament is ensured. At least one cantilever 15 is located at the inflection point of the LED filament 100, for example at the inflection 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 positioned on the circumference taking the core column 19 (or the upright 19 a) as the center of a circle, so that the LED filaments have certain symmetry, the luminous flux in all directions is approximately the same, and the LED bulb lamp emits light uniformly. In an embodiment, at least one intersection point is connected with the bending point of the conductor segment 130 to form a straight line La, the intersection point located on the straight line La forms a straight line Lb with the electrode 110/112 of the LED filament, and the included angle α between the straight line La and the straight line Lb is in a range of 0 ° < α < 90 °, preferably 0 ° < α < 60 °, so that the LED segment has a proper interval after bending, and has better light emitting 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, the bending point of the LED segment 104 has a radius of curvature r4, r3 is equal to r4, light is uniformly emitted on each plane, and r3 is larger than r4 or r3 is smaller than r4, so as to meet the lighting requirement and/or the heat dissipation requirement in certain specific directions. The bending point of the conductor section 130 has a curvature radius r5, r5 is smaller than the maximum value of r3 and r4, namely r5 is smaller than max (r 3 and r 4), the LED filament is not easy to break, and a certain distance is reserved between the LED sections which are close to the core column, so that the heat generated by the two LED sections is prevented from affecting each other.

In one embodiment, the LED segments 102/104 comprise a first segment formed by the electrode 110/112 extending upward (in the direction of the top of the lamp envelope) to the inflection point and a second segment formed by the inflection point extending downward (in the direction of the lamp head) to the conductor segment 130 connecting the two

LED segments

102, 104, the first segment and the second segment having opposite first and second distances to the lamp envelope 12, respectively, the first distance being less than the second distance, in the direction of the first distance the base layer 420b of the LED filament is adjacent to the lamp envelope 12 and the top layer 420a of the LED filament is remote from the lamp envelope 12. For example, in fig. 8B, the first segment of the LED segment 104 has a first distance D1 and a second distance D2 opposite to each other, the first distance D1 is smaller than the second distance D2, in the direction of the first distance D1, the base layer 420B of the LED filament is close to the lamp envelope 12, and the top layer 420a of the LED filament is far from the lamp envelope 12. When the LED lamp filament is bent, the lead in the LED lamp filament is subjected to small bending stress and is not easy to break, and the production quality of the LED bulb lamp is improved.

Referring to fig. 4A to 4D and fig. 8A to 8D, a plane a is used to divide the lamp housing 12 into an upper portion and a lower portion, the lamp housing 12 has a maximum width at the plane a, for example, a plane pattern formed by R2 (maximum horizontal distance) in fig. 4B is located on the plane a, when the stem 19 and the plane a have an intersection point, the lamp housing 12 has a top and a bottom opposite to each other, the bottom of the lamp housing is close to the lamp cap 16, the length of the LED filament located between the top of the lamp housing and the plane a (or the distance from the highest point of the LED filament to the plane a in the height direction of the LED bulb) is smaller than the length of the LED filament located between the plane a and the bottom of the lamp housing (or the distance from the lowest point of the LED filament to the plane a in the height direction of the LED bulb), when the stem 19 and the plane a have an intersection point, the inner diameter of the lamp housing 12 above the top of the stem 19 is smaller, and the contained gas volume is small, so that the overall effect of the LED filament is affected if most of the LED filament is located at the top of the stem, and the product quality is reduced; if the stem 19 has a certain distance from the plane a, and the distance from the stem top to the plane a is smaller than the height of the upright 19a, the stem 19 includes a stem bottom and a stem top opposite to each other, the stem bottom is connected to the lamp cap 16, the stem top extends toward the lamp housing top, the length of the LED filament (or the distance between the highest point of the LED filament and the stem top) between the stem top and the lamp housing top is smaller than the length of the LED filament (or the distance between the stem top and the lowest point of the LED filament) between the stem top and the lamp housing bottom, and most of the LED filaments can be indirectly supported through the stem, thereby ensuring the stability of the LED bulb lamp in the shape of the LED filament during transportation. In some embodiments, when the distance from the stem 19 to the plane a is greater than the height of the upright 19a, the stem 19 includes a stem bottom and a stem top opposite to each other, the stem bottom is connected to the lamp cap 16, the stem top extends toward the top of the lamp housing, the length of the LED filament between the stem top and the top of the lamp housing is greater than the length of the LED filament between the stem top and the bottom of the lamp housing, and the majority of the LED filament is located between the stem top and the bottom of the lamp housing due to the large volume of gas contained between the stem top and the bottom of the lamp housing, thereby facilitating heat dissipation of the LED filament.

The application refers to an LED filament and an LED filament, which are formed by jointly connecting the conductor sections and the LED sections or are formed by only the LED sections (or LED chip units), and the LED filament has the same and continuous light conversion layer (comprising the same and continuously formed top layer or bottom layer), and two conductive electrodes electrically connected with a bulb conductive support are arranged at two ends of the LED filament, so that the LED filament is a single LED filament structure according with the above structure description.

While the present application has been disclosed in terms of preferred embodiments, it will be understood by those skilled in the art that the examples are illustrative of only some of the embodiments of the present application and are not to be construed as limiting. It should be noted that any reasonable combination of variations and permutations or embodiments equivalent to this embodiment (and in particular the LED filament embodiment, into the bulb embodiment of fig. 4) is intended to be encompassed within the scope of the present description. The scope of the application is therefore intended to be defined only by the following claims.

Claims

1. An LED bulb lamp, comprising:

a lamp housing;

The LED filament is arranged in the lamp shell;

2. The LED bulb lamp of claim 1, wherein: the first surface is covered with heat conducting glue, and heat generated by the heating element is transferred to the lamp cap through the heat conducting glue.

3. The LED bulb lamp of claim 2, wherein: the heating element is covered with the heat conducting glue.

4. The LED bulb lamp of claim 1 or 2, wherein: the heating element is an IC or a resistor.

5. The LED bulb lamp of claim 1 or 2, wherein: the thermolabile element is an electrolytic capacitor.

6. The LED bulb lamp of claim 1, wherein: the inner surface of the lamp cap is provided with a heat conducting part, and heat generated by the heating element is transferred to the lamp cap through the heat conducting part.

7. The LED bulb lamp of claim 6, wherein: the heat conduction coefficient of the heat conduction part is larger than or equal to that of the lamp cap.

8. The LED bulb lamp of claim 6, wherein: the heat conducting part is a metal piece contacted with the heating element.

9. An LED bulb lamp, comprising:

a lamp housing;

the LED filament is arranged in the lamp shell;

10. The LED bulb lamp of claim 9, wherein: the base plate is parallel to the axial direction of the lamp holder, and the heating element is placed on one surface of the base plate, which is close to the lamp holder.