CN113793845B - Alternating current LED filament and filament lamp - Google Patents

Abstract

The present invention discloses an AC LED filament and a filament lamp. The AC LED filament comprises a substrate, a terminal, an LED chip, a first resistor, a diode and a packaging glue. The substrate can transmit visible light. The upper and lower surfaces of the substrate are respectively provided with a first circuit layer and a second circuit layer. The second circuit layer is at least metal-connected to the first circuit layer, and there are multiple connection modes. Therefore, the heat emitted by the voltage-dividing resistor is dispersed to both sides of the upper and lower surfaces of the substrate instead of simply being gathered on the upper surface of the substrate, thereby avoiding heat accumulation, effectively reducing the temperature of the resistor body, avoiding local high temperature inside the filament causing degradation of the packaging glue, and realizing a highly reliable AC LED filament. Also disclosed is a filament lamp, which comprises the AC LED filament of the present invention. By combining the AC LED filament of the present invention, the life of the filament lamp and the diversity of design can be improved.

Description

AC LED Filament and Filament Lamp

Technical Field

The invention relates to the field of LEDs, in particular to an AC LED filament and a filament lamp.

Background technique

With the development of LED technology, LED packaging technology has shown a diversified development trend, forming a technical pattern in which multiple packaging technologies such as SMD packaging, COB packaging, and LED filament packaging are equally important. LED filament packaging uses a slender transparent or translucent substrate with power terminals at both ends. The LED chips are fixed on the surface of the substrate with transparent solid crystal glue and arranged in a row. The entire surface of the substrate is covered with packaging glue. With the help of the transparent characteristics of the substrate, the light emitted by the LED chip is emitted from both sides of the substrate at the same time, thereby achieving a full-body luminous effect. LED filaments not only have high luminous efficiency, but also can achieve 360-degree all-around lighting, and can easily achieve the filament lighting effect of imitating incandescent lamps, and the market prospects are bright.

However, since LED filament lamps need to imitate the appearance of incandescent lamps, their driving power can only be hidden in the lamp holder, and the available space is extremely small, which puts higher requirements on the optoelectronic integration of LED filaments. How to simplify the driving power of LED filament lamps has become a problem that needs to be solved.

Chinese patents CN202022082013.1 and CN202022082352.X both propose AC LED filament structures. Their common technical point is that four diodes are directly encapsulated on the substrate of the LED filament to replace the rectifier bridge stack required for the driving power supply, so that the filament can be directly lit with AC power. Two conductive circuits are provided on the ceramic circuit substrate. The left and right ends of each conductive circuit are connected to the power terminal through a diode. The diodes at both ends of the same conductive circuit are set in reverse. The diodes connected to different conductive circuits on the same power terminal are set in reverse to each other. There are more than two LED chips between the two conductive circuits. The four diodes encapsulated on the LED filament ceramic substrate and the two conductive circuits constitute a bridge rectifier, so that the AC power input on the power terminal is converted into DC power between the two conductive circuits, thereby realizing DC drive of the LED chip.

Chinese patent CN202022217458.6 further sets a current limiting resistor at the AC LED filament power supply terminal to play a current limiting role, prevent the grid voltage fluctuation from burning the semiconductor chip, and effectively improve the reliability of the LED filament. Its disadvantage is that the current limiting resistor is connected in series in the circuit and becomes the main heating element. The current limiting resistor generates serious heat and is easy to burn. The reliability of the current limiting resistor becomes the main problem. How to reduce the temperature of the current limiting resistor and ensure its reliability has become a new technical bottleneck.

Summary of the invention

In view of the current problems of how to reduce the temperature of the current limiting resistor of the AC LED filament and improve the reliability of the AC LED filament, the embodiments of the present application propose an AC LED filament and a filament lamp to solve the above problems.

An embodiment of the present application proposes an AC LED filament, comprising a substrate, an LED chip, a first resistor, a diode and a terminal. A first circuit layer is provided on the upper surface of the substrate, a second circuit layer is provided on the lower surface of the substrate, the LED chip is arranged on the upper surface of the substrate, the first resistor and the diode are arranged on the surface of the first circuit layer near the end of the substrate, the diode forms a rectifier circuit with the first resistor and the LED chip, the terminals are arranged at two ends of the substrate, the terminals include a fixed area bonded to the first circuit layer and a bending pawl bent from the fixed area along the side wall of the substrate to the lower surface of the substrate, and the second circuit layer is thermally and/or electrically connected to the first circuit layer.

In an optional embodiment, the first circuit layer includes a first circuit layer end circuit area, a first circuit layer component circuit area and a first circuit layer parallel circuit area, the first circuit layer end circuit area is located at the end of the substrate, the first circuit layer component circuit area is adjacent to the first circuit layer end circuit area and a first insulating gap is arranged in the middle, the first resistor is welded between the first circuit layer end circuit area and the first circuit layer component circuit area at at least one end of the substrate and covers the first insulating gap, the fixed area of the terminal is attached to the first circuit layer end circuit area, and the second circuit layer is connected to at least one area of the first circuit layer end circuit area and the first circuit layer component circuit area.

In an optional embodiment, the second circuit layer includes a second circuit layer end circuit area and a second circuit layer component circuit area. The second circuit layer end circuit area and the second circuit layer component circuit area are symmetrical with the first circuit layer end circuit area and the first circuit layer component circuit area respectively with the substrate as the symmetry plane. The bending pawl is tightly fitted and connected to the second circuit layer end circuit area, and the bending pawl becomes a heat conduction channel connecting the first circuit layer and the second circuit layer.

In an optional embodiment, a second resistor is welded between the second circuit layer end circuit area and the second circuit layer component circuit area of at least one end of the substrate, the bent ratchet becomes a first conductive channel connecting the first circuit layer and the second circuit layer, and a second conductive channel is arranged between the first circuit layer component circuit area and the second circuit layer component circuit area to realize the parallel connection of the first resistor and the second resistor.

In an optional embodiment, the first circuit layer is provided with a jumper ring that fits with the component circuit area. The jumper ring is bent from the side wall of the substrate to the lower surface of the substrate and is tightly connected to the component circuit area of the second circuit layer. The jumper ring is a conductive metal with high thermal conductivity, and the jumper ring becomes a second conductive channel connecting the first circuit layer and the second circuit layer.

In an optional embodiment, the substrate is provided with a first via hole passing through the first circuit layer component circuit area and the second circuit layer component circuit area, and a connecting metal is provided in the first via hole, and the connecting metal becomes a second conductive channel connecting the first circuit layer and the second circuit layer.

In an optional embodiment, the first circuit layer also includes a series circuit layer arranged between the end circuit area of the first circuit layer and the component circuit area of the first circuit layer, and there is a second insulation gap between the series circuit layer and the end circuit area of the first circuit layer and the component circuit area of the first circuit layer, respectively. The first resistor is welded between the end circuit area of the first circuit layer and the series circuit layer and covers the second insulation gap.

In an optional embodiment, the second circuit layer includes a gate-shaped circuit area and a central circuit area located within the gate-shaped area of the gate-shaped circuit area. A third insulating gap exists between the central circuit area and the gate-shaped circuit area. The bent pawls tightly fit the lower surface of the substrate. A third resistor is also provided on the second circuit layer. The third resistor is welded between the gate-shaped circuit area and the central circuit area and covers the third insulating gap.

In an optional embodiment, a second via and a third via are provided on the substrate, and connecting metal is provided in the second via and the third via. The second via connects the series circuit layer of the first circuit layer and the central circuit area of the second circuit layer, and the third via connects the component circuit area of the first circuit layer and the gate-shaped circuit area of the second circuit layer, so that the first resistor is connected in series with the third resistor.

In an optional embodiment, it also includes packaging glue, which at least covers the substrate, the LED chip and the diode.

In an optional embodiment, the second circuit layer is provided with a second circuit layer end circuit area and a second circuit layer component circuit area located outside the bending pawl, the substrate is provided with a fourth via hole connecting the first circuit layer component circuit area and the second circuit layer component circuit area, a high thermal conductivity metal is provided in the fourth via hole, and heat sink fins are provided on the end circuit area and the component circuit area of the second circuit layer, and the height of the heat sink fins is higher than the thickness of the packaging glue.

In an optional embodiment, the diode is arranged on the first circuit layer component circuit area.

In an optional embodiment, a first circuit layer end circuit area and a first circuit layer component circuit area are provided on the first circuit layer at one end of the substrate, the first circuit layer component circuit area is adjacent to the first circuit layer end circuit area and a fourth insulating gap is provided in between, the first resistor is welded above the first circuit layer end circuit area and the first circuit layer component circuit area at one end and covers the fourth insulating gap, only the first circuit layer end circuit area is provided on the first circuit layer at the other end of the substrate, and the diode is provided on the first circuit layer end circuit area at the other end.

In an optional embodiment, the parallel circuit area includes a first parallel circuit area and a second parallel circuit area respectively close to the edges of the substrate, the LED chip is arranged between the first parallel circuit area and the second parallel circuit area of the first circuit layer, and a plurality of LED chips are connected in series, one of the LED chips is connected to the first parallel circuit area through a lead, another LED chip is connected to the second parallel circuit area through a lead, and the diode is connected to the parallel circuit area through a lead.

In an optional embodiment, the second circuit layer further includes a second circuit layer parallel circuit area, and the second circuit layer parallel circuit area is symmetrical with the first circuit layer parallel circuit area with the substrate as a symmetry plane.

In an optional embodiment, the bending pawl is a conductive metal with high thermal conductivity.

In an optional embodiment, the substrate is a transparent substrate, and its material includes one of aluminum oxide ceramics, glass and sapphire.

On the second aspect, an embodiment of the present application further proposes a filament lamp, comprising a bulb, a lamp holder and the above-mentioned AC LED filament, wherein the terminal of the AC LED filament also includes a straight shank area, one end of the AC LED filament is fixed to the lamp holder through the straight shank area, and the other end of the AC LED filament is arranged in the bulb.

The embodiments of the present application disclose an AC LED filament and a filament lamp. By arranging a first circuit layer and a second circuit layer on a substrate, and a connected portion between the first circuit layer and the second circuit layer, the heat emitted by the voltage divider resistor is changed from being simply accumulated on the upper surface of the substrate to being dispersed to the first circuit layer and the second circuit layer on the upper and lower surfaces of the substrate, thereby avoiding heat accumulation, effectively reducing the temperature of the resistor body, avoiding local high temperature inside the filament causing degradation of the packaging glue, and realizing a highly reliable AC LED filament. The embodiments of the present application also propose a filament lamp, which includes the above-mentioned AC LED filament, which can increase the life of the filament lamp and the diversity of design.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a further understanding of the embodiments and are incorporated into and constitute a part of this specification. The accompanying drawings illustrate the embodiments and are used together with the description to explain the principles of the present invention. It will be easy to recognize other embodiments and many expected advantages of the embodiments because they become better understood by reference to the following detailed description. The elements of the accompanying drawings are not necessarily to scale with each other. The same reference numerals refer to corresponding similar parts.

FIG1 is a side view of an AC LED filament according to Embodiment 1 of the present application;

FIG2 is a light path diagram of an AC LED filament according to the first embodiment of the present application;

FIG3 is a side view of a substrate of an AC LED filament according to the first embodiment of the present application;

FIG4 is a top view of a substrate of an AC LED filament according to the first embodiment of the present application;

FIG5 is a bottom view of the substrate of the AC LED filament of the first embodiment of the present application;

FIG6 is a side view of a substrate of an AC LED filament according to the second embodiment of the present application;

FIG7 is a top view of a substrate of an AC LED filament according to the second embodiment of the present application;

FIG8 is a bottom view of the substrate of the AC LED filament of the second embodiment of the present application;

FIG9 is a side view of a substrate of an AC LED filament according to the third embodiment of the present application;

FIG10 is a top view of a substrate of an AC LED filament according to the third embodiment of the present application;

FIG11 is a bottom view of the substrate of the AC LED filament of the third embodiment of the present application;

FIG12 is a side view of a substrate of an AC LED filament according to a fourth embodiment of the present application;

FIG13 is a top view of a substrate of an AC LED filament according to a fourth embodiment of the present application;

FIG14 is a bottom view of a substrate of an AC LED filament according to a fourth embodiment of the present application;

FIG15 is a cross-sectional schematic diagram of a filament lamp composed of an AC LED filament according to Embodiment 5 of the present application;

FIG16 is a side view of a substrate of an AC LED filament according to a fifth embodiment of the present application;

FIG17 is a top view of a substrate of an AC LED filament according to a fifth embodiment of the present application;

FIG18 is a bottom view of the substrate of the AC LED filament of the fifth embodiment of the present application;

FIG19 is a side view of a substrate of an AC LED filament according to a sixth embodiment of the present application;

FIG20 is a top view of a substrate of an AC LED filament according to a sixth embodiment of the present application;

FIG. 21 is a bottom view of the substrate of the AC LED filament of the sixth embodiment of the present application.

Detailed ways

The present application will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It should also be noted that, for ease of description, only the parts related to the relevant invention are shown in the accompanying drawings.

It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

Embodiment 1

Please refer to FIG1 . In the embodiment of the present application, an AC LED filament is provided, including a substrate 1, terminals 2 at both ends of the substrate 1, an LED chip 3, a first resistor 4, a diode 5 and a packaging glue 6. The upper surface of the substrate 1 is provided with a first circuit layer, and the lower surface of the substrate 1 is provided with a second circuit layer 7. The first circuit layer includes a first circuit layer end circuit area 8, a first circuit layer component circuit area 9 and a first circuit layer parallel circuit area 10. The first circuit layer component circuit area 9 is adjacent to the first circuit layer end circuit area 8 and a first insulating gap 12 is provided in the middle. The first resistor 4 is provided above the first circuit layer end circuit area 8 and the first circuit layer component circuit area 9 at at least one end of the substrate 1 and covers the first insulating gap 12. The second circuit layer 7 is completely symmetrical with the first circuit layer, and the second circuit layer 7 also has a second circuit layer end circuit area, a second circuit layer component circuit area and a second circuit layer parallel circuit area. The LED chip 3 and the diode 5 are both connected to the first circuit layer through a lead 11 to achieve electrical conduction. The lead 11 is an alloy wire or a gold wire.

Referring to FIG. 2 , the LED chips 3 are fixed on the surface of the substrate 1 by transparent bonding adhesive and arranged in a row, the first resistor 4 is welded on the first circuit layer of the substrate 1, the LED chip 3 is packaged on the upper surface of the substrate 1, and the diode 5 is arranged on the first circuit layer. The packaging adhesive 6 covers all surfaces of the substrate 1, the LED chip 3, the first resistor 4, and the diode 5. The substrate 1 includes alumina alumina ceramics, glass, sapphire, etc. For example, an alumina ceramic substrate can be selected. With the help of the transparent characteristics of the substrate 1, the light emitted by the LED chip 3 is emitted from both the upper and lower sides of the substrate 1 at the same time, thereby achieving the effect of full-body luminescence.

In a specific embodiment, referring to FIGS. 3-5 , the first circuit layer end circuit area 8 is located at the two ends of the substrate 1 , and is provided with a left first circuit layer end circuit area 81 and a right first circuit layer end circuit area 82 , which are symmetrically arranged at the left and right ends of the substrate 1 with the center line of the substrate as the symmetry line. The first circuit layer component circuit area 9 is provided with a left first circuit layer component circuit area 91 and a right first circuit layer component circuit area 92 , which are symmetrically arranged with the center line of the substrate 1 as the symmetry line. The first circuit layer parallel circuit area 10 is arranged between the left first circuit layer component circuit area 91 and the right first circuit layer component circuit area 92 , and the first circuit layer parallel circuit area 10 includes an upper first circuit layer parallel circuit area 101 and a lower first circuit layer parallel circuit area 102 , which are respectively arranged on both sides of the substrate 1 near the edge.

The LED chip 3 is arranged between the upper first circuit layer parallel circuit area 101 and the lower first circuit layer parallel circuit area 102. A plurality of LED chips 3 are connected in series, one of which is connected to the upper first circuit layer parallel circuit area 101, and one of which is connected to the lower first circuit layer parallel circuit area 102. The diode 5 is a vertical electrode structure, and the diode 5 is provided with two electrodes, one positive and one negative, which are respectively arranged on the upper and lower surfaces of the diode 5, one electrode of the diode 5 is welded on the first circuit layer, and the other electrode is connected to the first circuit layer parallel circuit area 10 through a lead.

Specifically, the diode 5 is divided into a first diode 51, a second diode 52, a third diode 53, and a fourth diode 54. The positive electrode of the first diode 51 is welded on the first circuit layer component circuit area 91 on the left side, the negative electrode faces upward, and the negative electrode is connected to the first circuit layer parallel circuit area 101 on the upper side through a lead. The negative electrode of the second diode 52 is welded on the first circuit layer component circuit area 91 on the left side, the positive electrode faces upward, and the positive electrode is connected to the first circuit layer parallel circuit area 102 on the lower side through a lead. The positive electrode of the third diode 53 is welded on the first circuit layer component circuit area 92 on the right side, the negative electrode faces upward, and the negative electrode is connected to the first circuit layer parallel circuit area 101 on the upper side through a lead. The negative electrode of the fourth diode 54 is welded on the first circuit layer component circuit area 92 on the right side, the positive electrode faces upward, and the positive electrode is connected to the first circuit layer parallel circuit area 102 on the lower side through a lead.

The first resistor 4 is provided with a left first resistor 41 and a right first resistor 42, both of which have equal resistance values. The left first resistor 41 is welded between the left first circuit layer end circuit area 81 and the left first circuit layer component circuit area 91, and the right first resistor 42 is welded between the right first circuit layer end circuit area 82 and the right first circuit layer component circuit area 92.

The terminal 2 is provided with two left and right terminals, which are respectively connected to the circuit area 81 at the end of the first circuit layer on the left and the circuit area 82 at the end of the first circuit layer on the right. The terminal 2 includes a straight handle area, a fixed area 21 and a bending pawl 22. The lower surface of the fixed area 21 is connected to the circuit area 8 at the end of the first circuit layer of the first circuit layer and is electrically conductive. The bending pawl 22 is bent from the fixed area 21 along the side wall of the substrate 1 to the lower surface of the substrate 1. The lower surface of the substrate 4 is provided with a second circuit layer 7. Therefore, the bending pawl 22 is connected to the second circuit layer 7 and is electrically conductive, so that the second circuit layer 7 is electrically conductive to the circuit area 8 at the end of the first circuit layer of the first circuit layer. Whether there is electrical conduction is tested to determine whether the bending pawl 22 is in contact with the first circuit layer and the second circuit layer 7. Only close contact can ensure heat conduction. The second circuit layer 7 can effectively increase the heat dissipation area. The bending pawl is a conductive metal with high thermal conductivity. The thermal conductivity of the metal is not less than 30W/m·K. Its material includes copper, aluminum, silver, etc. The diode 5 is arranged on the first circuit layer to form a bridge rectifier circuit with the first resistor 4 and the LED chip 3. The diode 5 and the first circuit layer are connected in parallel with the circuit area 10 to form a bridge rectifier circuit, so that the input AC power can be converted into DC power to supply the LED chip 3, so that the LED chip 3 works under the drive of DC power. At the same time, two first resistors 4 are symmetrically arranged and arranged between the terminal 2 and the bridge rectifier circuit, providing the same resistance voltage division protection for the positive and negative half cycles of the AC power, ensuring the stability of the current and avoiding the burning of the LED chip 3 caused by the fluctuation of the AC power.

The terminal 2 is made of metal with good thermal conductivity, such as aluminum. Since the first resistor 4 generates a lot of heat, it is necessary to provide good heat dissipation for it to avoid local high temperature inside the filament causing degradation of the packaging glue. Since the substrate 1 is made of alumina ceramic, the thermal resistance of vertical heat conduction is relatively large. With the help of the first circuit layer end circuit area 8 of the first circuit layer, the heat emitted by the first resistor 4 is conducted to the terminal 2, and then conducted from the terminal 2 to the second circuit layer 7, forming a heat conduction path from the front side of the substrate 1 to the back side of the substrate 1, thereby expanding the effective thermal capacity and improving the heat dissipation of the first resistor 4.

When the LED chip 3 is a blue light chip and the filament is a blue light filament, the encapsulation glue 6 is a transparent optical glue; when the LED chip 3 is a blue light chip and the filament is a green light filament, the encapsulation glue 6 is a transparent optical glue mixed with green phosphor; when the LED chip 3 is a blue light chip and the filament is a red light filament, the encapsulation glue 6 is a transparent optical glue mixed with red phosphor; when the LED chip 3 is a green light chip and the filament is a green light filament, the encapsulation glue 6 is a transparent optical glue; when the LED chip 3 is a red light chip and the filament is a red light filament, the encapsulation glue 6 is a transparent optical glue; when the LED chip 3 is a blue light chip and the filament is a white light filament, the encapsulation glue 6 is a transparent optical glue mixed with red phosphor and green phosphor; when the LED chip 3 is a white light chip and the filament is a white light filament, the encapsulation glue 6 is a transparent optical glue.

The embodiment of the present application also provides a filament lamp, which includes a lamp holder, a bulb shell and the AC LED filament mentioned above, wherein one end of the AC LED filament is fixed to the lamp holder and the other end is placed in the center of the bulb shell. One end of the AC LED filament is fixed to the lamp holder through a straight handle area.

Embodiment 2

Referring to Figures 6-8, the difference between the second embodiment and the first embodiment is that the second circuit layer 7 is arranged on the lower surface of the substrate 1 and is completely symmetrical with the first circuit layer. The first circuit layer is provided with a left first circuit layer end circuit area 81 and a right first circuit layer end circuit area 82, and the component circuit area of the first circuit layer is provided with a left first circuit layer component circuit area 91 and a right first circuit layer component circuit area 92. The second circuit layer 7 is provided with a left first circuit layer end circuit area 83 and a right first circuit layer end circuit area 84, and the component circuit area of the second circuit layer is provided with a left first circuit layer component circuit area 93 and a right first circuit layer component circuit area 94. No circuit layer is provided below the second circuit layer 7 corresponding to the upper first circuit layer parallel circuit area 101 and the lower first circuit layer parallel circuit area 102 of the first circuit layer, and the substrate 1 is exposed.

Specifically, a first jumper buckle 121 and a second jumper buckle 122 are also provided. The lower surface of the first jumper buckle 121 is electrically connected to the first circuit layer component circuit area 91 on the left side of the first circuit layer, the first jumper buckle 121 is bent from the side wall of the substrate 1 to the lower surface of the substrate 1, and the first jumper buckle 121 is connected to the first circuit layer component circuit area 93 on the left side of the second circuit layer 7 and is electrically connected. The lower surface of the second jumper buckle 122 is connected to the first circuit layer component circuit area 92 on the right side of the first circuit layer and is electrically connected, the second jumper buckle 122 is bent from the side wall of the substrate 1 to the lower surface of the substrate 1, and the second jumper buckle 122 is connected to the first circuit layer component circuit area 94 on the right side of the second circuit layer and is electrically connected.

A left second resistor 43 and a right second resistor 44 are also provided, and the resistance values of the two are equal. The left second resistor 43 is welded between the left first circuit layer end circuit area 83 and the left first circuit layer component circuit area 93 of the second circuit layer 7, and the right second resistor 44 is welded between the right first circuit layer end circuit area 84 and the right first circuit layer component circuit area 94 of the second circuit layer 7. The rest is the same as the first embodiment. Through the conduction of the jumper buckle, the left first resistor 41 is connected in parallel with the left second resistor 43, and the right second resistor 42 is connected in parallel with the right second resistor 44, thereby reducing the heat generated on a single resistor, and at the same time dispersing the heat generated to the upper and lower sides of the substrate 1 to avoid local heat concentration.

Embodiment 3

Referring to Figures 9-11, the difference between Example 3 and Example 2 is that: the substrate 1 is provided with a first via hole that passes through the first circuit layer component circuit area 9 of the first circuit layer and the component circuit area of the second circuit layer 7, and a connecting metal is provided in the first via hole. Specifically, the first via hole includes a first metallized via hole 131 and a second metallized via hole 132. The first metallized via hole 131 electrically connects the first circuit layer component circuit area 91 on the left side of the first circuit layer with the first circuit layer component circuit area 93 on the left side of the second circuit layer. The second metallized via hole 132 electrically connects the first circuit layer component circuit area 92 on the right side of the first circuit layer with the first circuit layer component circuit area 94 on the right side of the second circuit layer. The rest is the same as Example 2.

By utilizing the ceramic substrate and taking advantage of the characteristics of the metallized vias to conduct the upper and lower surface circuit layers, the first circuit layer and the second circuit layer 7 can be connected and conducted, thereby reducing the heat generated on a single resistor and dispersing the heat to the upper and lower sides of the substrate 1 to avoid local heat concentration.

Embodiment 4

Referring to FIGS. 12-13 , the difference between the fourth embodiment and the third embodiment is that a series circuit layer 85 is further arranged between the left first circuit layer end circuit area 81 and the left first circuit layer component circuit area 91 of the first circuit layer, a second insulating gap is arranged between the left first circuit layer end circuit area 81 and the series circuit layer 85, and a second insulating gap is arranged between the left first circuit layer component circuit area 91 and the series circuit layer 85. The left first resistor 41 is welded between the left first circuit layer end circuit area 81 and the series circuit layer 85 of the first circuit layer and covers the second insulating gap. The right side of the first circuit layer is also arranged symmetrically, which is not shown in the figure.

The second circuit layer 7 is provided with a gate-shaped circuit area 96 and a center circuit area 95 on both the left and right sides, and the second circuit layer is not provided in the area where the bending pawl 22 is located. The center circuit area 95 is located in the gate-shaped area of the gate-shaped circuit area 96, and there is a third insulating gap between the center circuit area 95 and the gate-shaped circuit area 96. The substrate 1 is provided with a second via and a third via, the second via connecting the series circuit layer 85 of the first circuit layer and the center circuit area 95 of the second circuit layer, the third via connecting the component circuit area 91 of the first circuit layer and the gate-shaped circuit area 96 of the second circuit layer, and the second via and the third via are provided with connecting metals to form a third metallized via 133 and a fourth metallized via 134, respectively.

The first circuit layer series circuit layer 85 and the second circuit layer central circuit area 95 are connected through the fourth metallized via 134, and the second circuit layer gate-shaped circuit area 96 and the first circuit layer component circuit area 91 on the left side of the first circuit layer are connected through the third metallized via 133. The third resistor 45 is welded between the second circuit layer gate-shaped circuit area 96 and the central circuit area 95, so that the left first resistor 41 and the third resistor 45 are connected in series. The rest is the same as the third embodiment, the first circuit layer and the second circuit layer 7 are connected through the metallized via, and the series connection of the resistors is realized, so as to reduce the heat generated on a single resistor, and at the same time, the heat is dispersed to the upper and lower sides of the substrate to avoid local heat concentration.

Embodiment 5

Referring to Figures 15-18, the difference between the fifth embodiment and the fourth embodiment is that the first circuit layer does not have a first circuit layer component circuit area 92 on the right side, only a first resistor 41 on the left side is set on the first circuit layer, and the third diode 53 and the fourth diode 54 are welded on the first circuit layer end circuit area 82 on the right side of the first circuit layer, and the rest is the same as the fourth embodiment. In the application of the whole filament lamp, the position where the resistor at the other end of the filament is located (the dotted line position in the figure) does not emit light and will block the emission of light, thereby forming a shadow, affecting the overall appearance. Since the first resistor 42 on the right side of the substrate 1 does not exist, the problem of the top shadow of the filament in the whole filament lamp is avoided.

Embodiment 6

Referring to Figures 19-21, the difference between Example 6 and Example 3 is that the position where the second resistor was originally welded on the second circuit layer 7 is changed to welding heat sink fins 46 and 47, and the height of the heat sink fins 46 and 47 is higher than the thickness of the packaging glue 6, so that the outer surface of the heat sink fins 46 and 47 is exposed outside the packaging glue 6, and can perform heat radiation or heat convection heat dissipation, realize heat exchange with the environment where the AC LED filament is located, and improve the heat dissipation capacity. The second circuit layer 7 is provided with a second circuit layer end circuit area and a second circuit layer component circuit area located outside the bending pawl 22, and the second circuit layer 7 is not provided in the area where the bending pawl 22 is located. The substrate 1 is provided with a fourth via hole connecting the first circuit layer component circuit area 9 and the second circuit layer component circuit area, and a high thermal conductivity metal is provided in the fourth via hole, and the thermal conductivity of the metal is not less than 30W/m·K. Longitudinal heat conduction is realized, and the rest is the same as Example 3.

The above describes the specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any technician familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed in the present application, which should be included in the protection scope of the present application. Therefore, the protection scope of the present application should be based on the protection scope of the claims.

In the description of the present application, it should be understood that the terms "upper", "lower", "inside", "outside", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, which are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. The word "comprising" does not exclude the presence of elements or steps not listed in the claims. The word "one" or "an" preceding an element does not exclude the presence of multiple such elements. The simple fact that certain measures are recorded in mutually different dependent claims does not indicate that a combination of these measures cannot be used for improvement. Any reference symbols in the claims should not be interpreted as limiting the scope.

Claims (18)

1. An AC LED filament, characterized in that it includes a substrate, an LED chip, a first resistor, a diode and a terminal, wherein a first circuit layer is provided on the upper surface of the substrate, a second circuit layer is provided on the lower surface of the substrate, the LED chip is arranged on the upper surface of the substrate, the first resistor and the diode are arranged on the surface of the first circuit layer near the end of the substrate, the diode forms a rectifier circuit with the first resistor and the LED chip, the terminals are arranged at two ends of the substrate, the terminals include a fixing area bonded to the first circuit layer and a bending pawl bent from the fixing area along the side wall of the substrate to the lower surface of the substrate, and the second circuit layer is thermally and/or electrically connected to the first circuit layer. 2. The AC LED filament according to claim 1 is characterized in that the first circuit layer includes a first circuit layer end circuit area, a first circuit layer component circuit area and a first circuit layer parallel circuit area, the first circuit layer end circuit area is located at the end of the substrate, the first circuit layer component circuit area is adjacent to the first circuit layer end circuit area and a first insulating gap is arranged in the middle, the first resistor is welded between the first circuit layer end circuit area and the first circuit layer component circuit area at at least one end of the substrate and covers the first insulating gap, the fixing area of the terminal is attached to the first circuit layer end circuit area, and the second circuit layer is connected to at least one area of the first circuit layer end circuit area and the first circuit layer component circuit area. 3. The AC LED filament according to claim 2 is characterized in that the second circuit layer includes a second circuit layer end circuit area and a second circuit layer component circuit area, the second circuit layer end circuit area and the second circuit layer component circuit area are symmetrical with the first circuit layer end circuit area and the first circuit layer component circuit area respectively with the substrate as the symmetry plane, the bending pawl is tightly fitted and connected with the second circuit layer end circuit area, and the bending pawl becomes a heat conduction channel connecting the first circuit layer and the second circuit layer. 4. The AC LED filament according to claim 3 is characterized in that a second resistor is welded between the second circuit layer end circuit area and the second circuit layer component circuit area at at least one end of the substrate, the bending pawl becomes a first conductive channel connecting the first circuit layer and the second circuit layer, and a second conductive channel is provided between the first circuit layer component circuit area and the second circuit layer component circuit area to realize the first resistor and the second resistor being connected in parallel. 5. The AC LED filament according to claim 4 is characterized in that the first circuit layer is provided with a jumper buckle that fits with the component circuit area, the jumper buckle is bent from the side wall of the substrate to the lower surface of the substrate and is tightly connected with the component circuit area of the second circuit layer, the jumper buckle is a conductive metal with high thermal conductivity, and the jumper buckle becomes a second conductive channel connecting the first circuit layer and the second circuit layer. 6. The AC LED filament according to claim 4 is characterized in that the substrate is provided with a first via hole passing through the first circuit layer component circuit area and the second circuit layer component circuit area, and a connecting metal is provided in the first via hole, and the connecting metal becomes a second conductive channel connecting the first circuit layer and the second circuit layer. 7. The AC LED filament according to claim 2 is characterized in that the first circuit layer also includes a series circuit layer arranged between the end circuit area of the first circuit layer and the component circuit area of the first circuit layer, and there is a second insulation gap between the series circuit layer and the end circuit area of the first circuit layer and the component circuit area of the first circuit layer respectively, and the first resistor is welded between the end circuit area of the first circuit layer and the series circuit layer and covers the second insulation gap. 8. The AC LED filament according to claim 7 is characterized in that the second circuit layer includes a gate-shaped circuit area and a central circuit area located in the gate-shaped area of the gate-shaped circuit area, a third insulating gap exists between the central circuit area and the gate-shaped circuit area, the bending pawl tightly fits the lower surface of the substrate, and a third resistor is also arranged on the second circuit layer, and the third resistor is welded between the gate-shaped circuit area and the central circuit area and covers the third insulating gap. 9. The AC LED filament according to claim 8 is characterized in that a second via hole and a third via hole are provided on the substrate, and connecting metal is provided in the second via hole and the third via hole, the second via hole connects the series circuit layer of the first circuit layer and the central circuit area of the second circuit layer, and the third via hole connects the component circuit area of the first circuit layer and the gate-shaped circuit area of the second circuit layer, so that the first resistor and the third resistor are connected in series. 10 . The AC LED filament according to claim 2 , further comprising a packaging adhesive, wherein the packaging adhesive at least covers the substrate, the LED chip and the diode. 11. The AC LED filament according to claim 10 is characterized in that the second circuit layer is provided with a second circuit layer end circuit area and a second circuit layer component circuit area located outside the bending pawl, the substrate is provided with a fourth via hole connecting the first circuit layer component circuit area and the second circuit layer component circuit area, a high thermal conductivity metal is provided in the fourth via hole, and heat dissipation fins are provided on the end circuit area and the component circuit area of the second circuit layer, and the height of the heat dissipation fins is higher than the thickness of the packaging glue. 12 . The AC LED filament according to claim 1 , wherein the diode is arranged on the first circuit layer component circuit area. 13. The AC LED filament according to claim 1 is characterized in that a first circuit layer end circuit area and a first circuit layer component circuit area are provided on the first circuit layer at one end of the substrate, the first circuit layer component circuit area is adjacent to the first circuit layer end circuit area and a fourth insulating gap is provided in the middle, the first resistor is welded above the first circuit layer end circuit area and the first circuit layer component circuit area at one end and covers the fourth insulating gap, the first circuit layer at the other end of the substrate is only provided with the first circuit layer end circuit area, and the diode is arranged on the first circuit layer end circuit area at the other end. 14. The AC LED filament according to any one of claims 1-11, characterized in that the parallel circuit area includes a first parallel circuit area and a second parallel circuit area respectively close to the edge of the substrate, the LED chip is arranged between the first parallel circuit area and the second parallel circuit area of the first circuit layer, a plurality of the LED chips are connected in series, one LED chip is connected to the first parallel circuit area through a lead, another LED chip is connected to the second parallel circuit area through a lead, and the diode is connected to the parallel circuit area through a lead. 15. The AC LED filament according to any one of claims 1-11, characterized in that the second circuit layer further comprises a second circuit layer parallel circuit area, and the second circuit layer parallel circuit area is symmetrical with the first circuit layer parallel circuit area with the substrate as a symmetry plane. 16 . The AC LED filament according to claim 1 , wherein the bending claw is a conductive metal with high thermal conductivity. 17 . The AC LED filament according to claim 1 , wherein the substrate is a transparent substrate, and the material thereof comprises one of alumina ceramics, glass and sapphire. 18. A filament lamp, characterized in that it comprises a bulb, a lamp holder and the AC LED filament according to any one of claims 1 to 17, wherein the terminal of the AC LED filament further comprises a straight shank area, one end of the AC LED filament is fixed to the lamp holder through the straight shank area, and the other end of the AC LED filament is arranged in the bulb.