EP2628359A1

EP2628359A1 - Led light comprising an integrated driver

Info

Publication number: EP2628359A1
Application number: EP11773230.5A
Authority: EP
Inventors: Alexander Dohn; Christian Schnagl; Alfred Thimm; Karl Degelmann; Ewald Sutor
Original assignee: Ceramtec GmbH
Current assignee: Ceramtec GmbH
Priority date: 2010-10-15
Filing date: 2011-10-14
Publication date: 2013-08-21
Also published as: CN103238372A; RU2013121971A; EP2734012A1; KR20140027057A; US20130241426A1; DE102011114882A1; JP2013545225A; TW201229427A; WO2012049284A1; BR112013009194A2

Abstract

Disclosed is an LED light comprising at least one LED (43) that is arranged on a ceramic support element (32) and is connected thereto in a thermally conducting manner, and an electronic driver (17) that is electrically connected to the LED (43) to supply power and control the power supplied to the LED (43). The driver (17) is connected in a thermally conducting manner to the support element (32) in order to improve the electric control function and performance of the LED (43) in the light.

Description

LED light with integrated driver

The invention relates to an LED lamp with at least one arranged on a ceramic support and heat-conductively connected to this LED and with an electrically connected to the LED electronic driver for power control and supply of the LED.

LEDs are light-emitting diodes, or light-emitting diodes, and the associated electronic driver circuits or assemblies that illuminate the respective LEDs are called LED drivers.

The brightness of an LED increases with the power consumption. At constant semiconductor temperature, the increase is approximately proportional. The efficiency decreases with increasing temperature, therefore the luminous efficacy at the power limit decreases depending on the type of cooling. The LED turns off when the temperature of the semiconductor exceeds a maximum of about 150 ° C.

The performance of luminaires with LEDs can be controlled, for example, via resistance elements or dimmers with phase control. These drivers are always at some distance from the actual LED, d. H. The disadvantage of this is that by removing the driver from the LED, the control of the LED is sluggish.

LEDs with high light output become so hot during operation that they have to be cooled in order not to fail.

WO 2007107601 AI proposes to cool the LEDs, to arrange them on ceramic support body, which are integrally connected to ceramic heat-dissipating cooling elements, so-called heat sinks. On the carrier body the conductor tracks are applied, so that the carrier body is formed as a circuit board. The special feature of this, however, is that sintered metallization regions are applied as conductor tracks on the surface of the carrier body. The LEDs are soldered onto the tracks. The heat dissipation is thus extremely high and can be variably adjusted by the choice of ceramic.

The invention has for its object to improve the electrical control and performance of the LED.

The LED lamp according to the invention is defined by the features of claim 1. Accordingly, at least one LED is arranged on a ceramic carrier body, wherein the driver for controlling the LED is thermally conductively connected to the carrier body. By the Wärmeleitverbindung the driver can react directly to temperature changes of the LED. The driver for regulating the supply current of the LED is preferably designed as a function of the temperature of the carrier body and thus as a function of the temperature of the LED. Driver is always understood below as an electrical driver circuit.

The ceramic carrier body may have on its surface sintered metallization regions, which are formed as conductor tracks. The LEDs are preferably soldered onto the conductor tracks. In this case, the driver can be soldered together with the LED on the carrier body with sintered metallization regions. The driver is preferably arranged in the immediate vicinity of or adjacent to the LED. In an alternative embodiment, the driver is housed in an electronic module which is located directly in the luminaire in close proximity to the LEDs.

The invention thus describes, in one embodiment, a ceramic luminaire with a driver in the immediate vicinity of the LED as a power module, mounted directly on the ceramic of the carrier body. Fluctuations in temperature are immediately perceived as a change in the light emission. The driver is preferably miniaturized in three parts and has a pre-stage (alternating current to low-voltage direct current), a temperature-controlled dimming stage (direct current) and an output stage for the supply of the LED. The carrier body preferably comprises a lamp holder such as E27, E26, GUIO or E14. The driver is preferably placed directly on the LED.

If the temperature of the LED or its immediate surroundings changes, the brightness of the LED immediately follows the temperature. Falling temperatures on the driver (due to wind, shadow, radiation reduction) usually lead to higher light emission. The speed of the control can be increased by using highly heat conductive ceramic as the base of the LED and its driver and slowed down by using low-conductivity ceramics, with the natural (unamplified) brightness variations behave inversely to the thermal conductivity of the ceramic. Thus, by interconnecting luminaires with individual control, brightness effects in a lamp array can be produced which, for example, make flow effects visible.

In the following, embodiments of the invention will be explained in more detail with reference to FIGS. Show it :

1 shows a section through a first embodiment,

2 shows a section through a second embodiment,

3 shows a detail according to FIG. 2,

4 shows a further embodiment, FIGS. 5a, 5b another embodiment,

6 shows a further embodiment,

7 shows a further embodiment,

Fig. 8 - 13c electronic detail circuits of the embodiment according to

Fig. 7 and

Fig. 14 is a table with the components used in the electronic

Circuits of the embodiment of FIG. 14.

FIGS. 1 to 3 and 6 show a base GU10 luminaire according to the invention comprising a lower part 1 with a power supply 2, a lampshade 3 and a ceramic mounting substrate 4 which can be glued on. The lamp shown in Figure 6 has no lampshade. Otherwise, it is identical to the lamp of Figure 1 formed.

The mounting substrate 4 is in this example a support body or mounting plate for the LED and the driver 17 and consists in this example of gray hochwärmeleitfähigem AIN and the lampshade 3 of ruby-colored alumina with Chromoxiddotierung. The mounting substrate 4 is not visible. The lamp body or lampshade 3 is closed with a glass pane (not shown) at the upper end of the lampshade 3.

On the surface of the ceramic substrate 4, sintered metallization regions 15 for soldering the LED (s) are arranged. These sintered metallization regions 15 form conductor tracks and thus a circuit board. For reasons of clarity, the diodes on the metallization regions 15 are not shown. The drivers 17 are only schematic shown. In the embodiment shown, the drivers 17 are not arranged on the sintered metallization regions 14 or 15, but on the mounting substrate 4. With further miniaturization of the LED (2 * 2 mm are already possible today), the driver can also be mounted directly on the metallization regions 15 become. In the mounting substrate 4 bushings 16 (see Figure 3) or connector elements (2, 11) are arranged for the electrical connection wires. These connecting wires are electrically conductively connected to the drivers 17 and the drivers 17 to the metallization regions 15. On the mounting substrate 4 any number of metallization regions 15 may be arranged.

The mounting substrate 4 has a radial indentation 13 on the circumferential surface facing the metallization region 15 for better fixation.

In a preferred embodiment, the lamp is modularly formed from three ceramic parts, namely a lower part 1 with a power supply 2, a mounting substrate 4 or mounting plate and a lampshade 3. By the power supply 2, 11 are, for example, electrical connection wires (not shown in FIG the figure) in the lower part 1 and within the lower part 1 to the drivers 17 and from there to the LEDs. The mounting substrate 4 consists of a ceramic with preferably a high heat dissipation. On the mounting substrate 4, the LED are soldered to the conductor tracks. The lampshade 3 is also preferably made of a ceramic with cooling fins 5 on its outer surface. The cooling fins 5 extend in the longitudinal direction of the lampshade third

In this description, a mounting disk is shown for the mounting substrate 4. Mounting substrate is the more general term, since the mounting substrate is only a mounting plate. The mounting substrate can also not be disc-shaped. Otherwise both terms describe the same item. For better attachment of the lampshade 3 on the lower part 1 far this on its inner surface a paragraph 8, with which the lampshade 3 is seated on a corresponding paragraph or indentation 13 on the mounting substrate 4. The lower end of the lampshade 3 surrounds the mounting substrate 4 and the upper end 12 of the lower part 1. The mounting substrate 4 is arranged between the lampshade 3 and the lower part 1, that it is not visible from the outside. The upper, the mounting plate 4 facing away from the end of the lampshade 3 has an inner shoulder 6 for receiving a glass. Preferably, the lower part 1 is formed cylindrically with an inner cavity 7. This saves material.

The lamp thus consists of a lower part 1, a mounting plate 4 and a lampshade 3, which surrounds the LED. On the mounting substrate 4, the light source is attached.

The lower part 1 can also be equipped as a plug for the production of plug-in connections with appropriate sockets or with threads for screwing in brackets or, in occupied with terminal poles sockets, in lamp holders.

The lampshade 3 has on its circumference evenly distributed cooling fins 5, so that the outline of the lampshade 3 looks at its opening like a gear. The cooling fins 5 are, in particular in high-power LEDs, an advantage to dissipate the heat generated to the ambient air. Its cross section can take any other possible form such as semicircular or semi-elliptical. For LEDs with low heat losses, the screen can also be smooth. The screen may also have different shapes, such as oval or polygonal. The lower part 1 can also be formed in one piece with the mounting substrate 4, as shown in FIG. 2.

FIG. 6 shows an embodiment of the luminaire according to FIG. 1 without lampshade 3. This umbrellaless variant is advantageous because heat and / or solar radiation directly (not shielded) influence the driver temperature and the LEDs can be readjusted in a very short time due to this temperature change. The same reference numerals in Figures 1, 2 and 6 also show the same article.

FIG. 4 shows an array of 9 diode carriers 20, which consist of the ceramic heat sinks described in WO 2007/107601 A2 (see the introduction to the description) with sintered metallization regions as conductor tracks. On each diode support 20, 6 diodes or LEDs 23 are applied (shown only schematically) and electrically connected to each other via the metallization regions (not shown). For cooling, the diode carrier 20 on Finns 27.

In FIG. 4, square diode carriers 20 are shown. It can also be used any other form. The individual diode carrier 20 are installed or suspended in a metal frame 21, which also serves as a power supply for the LEDs 23 at the same time. The array of diode supports 20 is used for surface illumination, but can also be used for point illumination. For this purpose, the diode carrier 20 are fixed in different angles in the metal frame 21, that results in a focused light.

By folding up the corners 22 creates, for example, a parabolic arrangement with a light focal point. The array can also be just for surface lighting or curved for a point lighting. According to the invention, the driver of the driving of the LEDs is also arranged on at least one, preferably on each diode carrier 20 at the same time. This is not shown in the figures. The sintered metallization regions are in this case formed as conductor tracks on which the LEDs are arranged.

5a, 5b show a ceramic diode support 40 in plan view, Figure 5a and in section, Figure 5b, which consists of a ceramic support body 32 which is integrally provided with heat dissipating ceramic cooling elements 37, here fins, provided. On the surface 33 of the carrier body 32, sintered metallization regions 41 are applied, so that the diode carrier 40 is a circuit board. On the diode support 40 LEDs 43 are attached, which are soldered onto the metallization 41. For the current-conducting and / or mechanical connection of two or more diode carriers 40 to form an array, the diode carriers 40 have plugs and / or sockets as connecting elements with which the diode carriers 40 are connected directly or indirectly to each other.

On the diode supports 40, in addition to the LEDs at the same time their drivers are arranged and connected in accordance with the LEDs.

In a further embodiment, the plugs are pins 36, in particular according to the standard GU 5.3 and the sockets are adapted to the pins. Figure 5 shows an embodiment with only plugs, which consist of pins 36 here. These pins 36, two for each plug, are located at the periphery of the diode carrier 40 with the plugs 36 on opposite sides of the diode carrier 40. For connecting two diode carriers 40, a separate connecting element 38 is used here. This connecting element 38 is in the variant shown here a rectangular or square shaped plate with through holes 44. In these holes 44, the pins 36 on the diode support 40, establishing an electrical contact, plugged. each Connecting element 38 has four holes 44. Two holes 44 on the connecting element 38 are electrically connected to each other.

For fixing the diode carriers 40 in a frame, they have at least at one edge a strip 34 without metallization areas 41 and without LEDs 43 and drivers. This strip 34 thus forms a ceramic spring for attachment to a frame or a rail. At least two rails then form the frame.

The strip 34 has at least one recess for attachment to preferably a screw.

Figure 7 shows in section and in an exploded view an alternative preferred embodiment of a lamp according to the invention. This lamp is similar to that of Figure 1 and is intended for the version E27. The lamp consists of six parts or units, namely a metallic threaded bushing 52, a ceramic lower part 1, an electronic module 51 as a driver for driving the LEDs 43, a ceramic mounting substrate 4, a ceramic lampshade 3 with cooling fins 5 and a glass pane 50.

The lower part 1 is formed as a hollow cylinder body open on both sides and is the central support body of the lamp. At its end facing away from the lampshade 3, the lower part 1 has an outer thread 54 radially retracted to the outer wall of the lower part 1. On this outer thread 54, the threaded bushing 52 is turned up with its inner thread. This threaded bush 52 is designed in accordance with standard E27 and consists of metal.

In the lower part 1, the electronic module 51 is inserted, which contains the driver. The electrical connection of the electronic module 51 is only indicated for a better overview. The electronic module 51 is electrically connected to the LEDs 43 on the mounting substrate 4. For this purpose, the mounting substrate 4 two holes through which the electrical connection is made from the electronic module 51 to the LEDs.

The ceramic mounting substrate 4 is glued to the lower part 1. The mounting substrate 4 is the support body or the mounting plate for the LEDs 43 and is preferably made of gray hochwärmeleitfähigem AIN and the lampshade 3 of ruby-colored aluminum oxide with Chromoxiddotierung. The mounting substrate 4 is not visible from the outside. The lampshade 3 is closed with a glass plate 50 at the upper end of the lampshade 3.

On the surface of the ceramic substrate 4, sintered metallization regions for soldering the LEDs 43 are arranged. These sintered metallization areas form conductor tracks and thus a circuit board. The drivers are arranged in the electronic module 51 on three vertically stacked printed circuit boards 51a, 51b, 51c. If space is sufficient, the drivers are preferably placed on the sintered metallization areas or on the bare mounting substrate 4. The drivers are electrically connected to the LED. Alternatively, the LEDs and the carrier body, i. H. the ceramic substrate 4, be electrically connected to each other via an electrically conductive intermediate layer.

On the mounting substrate 4 any number of metallization can be arranged. In the embodiment of FIG. 7, however, the drivers are arranged in the electronic module 51, which is located in the cavity 7 of the lower part 1. Preferably, the electronic module 51 is fixed in the lower part 1 with a thermally conductive electrically insulating potting compound.

The mounting substrate 4 may not be disc-shaped. The mounting substrate 4 has a radial intake 13 for better fixation. The mounting substrate 4 consists of a ceramic, preferably a high Heat dissipation. On the mounting substrate 4, the LED are soldered to the conductor tracks.

The lampshade 3 is preferably made of a ceramic with cooling fins 5 on its outer surface. The cooling fins 5 extend in the longitudinal direction of the lampshade third

For better attachment of the lampshade 3 on the lower part 1, this has on its inner surface a paragraph 8, with which the lampshade 3 is seated on a corresponding paragraph or indentation 13 on the mounting substrate 4. The lower end of the lampshade 3 surrounds the mounting substrate 4 and the upper end 12 of the lower part 1. Preferably, the lower part 1 is cylindrically formed with an inner cavity 7. This material is saved and there is space for the electronic module 51 created.

The lampshade 3 has on its circumference evenly distributed in the longitudinal direction of the lamp extending cooling fins 5, so that the outline of the lampshade 3 looks at its opening like a gear. The cooling fins 5 are, in particular in high-power LEDs, an advantage to dissipate the heat generated to the ambient air. Its cross-section can also take any other possible form such as semicircular or semi-elliptic for example. For LEDs with low heat loss, the screen can also be smooth. The screen may also have different shapes, such as oval or polygonal. Through the use of ceramic housing and board components, the electrical insulation is given and the driver can be connected directly without galvanic isolation. Due to the thermal heat conduction properties of the ceramic in conjunction with a thermally conductive potting compound and spatially compact sandwich construction (see Figure 7), there is a very good overall heat distribution in the base interior or in the interior of the lower part 1. The driver's own power dissipation and heat generation Through the LEDs come with little time delay to the electronics, which then regulate the supply current of the LEDs so far linearly that a freely predetermined maximum temperature of the entire system is not exceeded. Thus, the driver circuit itself, but also the LEDs are protected against overheating. The better the cooling, the brighter the LEDs shine and vice versa. Thermal overload is largely excluded. In addition, the entire circuit can be manually dimmed with commercial phase dimmers in a wide range.

Figure 8 shows the complete electronic circuit of the driver, wherein in Figure 14, the components used are listed.

FIG. 9 shows the electronic circuit of the electronic module 51c (see FIG. 7). Figures 12a and 13a show a schematic view of the electronic module 51c from above and below. The electronic module 51c is responsible for connection to the 230-volt network and has a bridge rectifier with diodes D2. To limit the input current, the bridge rectifier is preceded by the two resistors R17 and R21 in order to avoid a short circuit in the case of discharged capacitors. The resistors R17 and R21 also serve as overvoltage protection for mains voltages up to 500 volts. The bridge rectifier bridge is equipped with smoothing capacitors C1, C2 and C7, which are designed as ceramic capacitors and have a lifetime of up to 500,000 operating hours. The capacitors and the coil LI are used to filter in order to short-circuit high interference frequencies. The capacitor C9 is an aluminum solid-state capacitor for dimming the generated DC voltage

FIG. 10 shows the electronic circuit of the electronic module 51b (see FIG. 7). FIGS. 12b and 13b show a schematic view of the electronic module 51b from above and below. The electronic module 51b is a dimming circuit for phase control dimming. The dimming circuit uses voltage dividers, diodes and MOS field-effect transistors. The dimming circuit simulates an ohmic load in the range of approx. 10 watts so that the power required for their operation is applied to the dimmers.

FIG. 11 shows the electronic circuit of the electronic module 51a (see FIG. 7). FIGS. 12c and 13c show a schematic view of the electronics module 51a from above and below. The electronic module 51a has an HV9961LG integrated circuit for controlling the output side LED current. At the input 7 of the integrated circuit, a temperature-dependent resistor (NTC) R19 is arranged, which generates a temperature-dependent control signal for the integrated circuit for temperature-dependent activation of the LED. The temperature-dependent dimming is done using the pulse width modulation. The integrated circuit HV9961LG is designed for the military temperature range for temperatures from - 55 ° C to + 125 ° C with a power class of 10 watts to achieve a long service life. Depending on the temperature, the integrated circuit generates a supply voltage for the LED which is reduced compared to the mains voltage, the remaining voltage being dissipated as heat. On the output side, the integrated circuit is provided with a MOS field-effect transistor Q1 and with a choke coil L2 with an inductance of 3 millihenries. With the control circuit according to FIG. 11, up to 8 LEDs can be operated. e of the invention are thus, inter alia: Optimal protective insulation by using ceramic materials. Optimum heat dissipation through the use of ceramic materials. Attractive design by using ceramic materials as housing. Overheating protection by built-in, by casting thermally coupled electronic module 51 or NTC.

Claims

claims

1. LED lamp with at least one on a ceramic support body (4, 32) arranged and heat-conductively connected to this LED (43) and with an electrically connected to the LED electronic driver (17) for power control and supply of the LED, dadu rc hge ke nnzeichnet that the driver (17) is thermally conductively connected to the carrier body (4, 32).

2. LED light according to claim 1, characterized in that the driver (17) for regulating the supply current of the LED (43) in dependence on the temperature of the carrier body (4, 32) is formed.

3. LED light according to claim 1 or 2, characterized in that the driver (17) together with the carrier body (4, 32) is cast in a thermally conductive potting compound.

4. LED light according to one of the preceding claims, characterized in that the carrier body (4, 32) on its surface sintered metallization regions, with which the LED (43) and the carrier body are electrically connected either directly or via an electrically conductive intermediate layer ,

5. LED light according to one of the preceding claims, characterized in that the LED (43), the Trägerköper (4, 32) and the driver (17) are enclosed by a common housing.

6. LED light according to claim 5, characterized in that the driver (17) on the LED (43) opposite side of the carrier body (4, 32) is arranged.

7. LED light according to claim 6, characterized in that the driver (17) has at least two stacked printed circuit boards (51a, 51b, 51c).

8. LED light according to claim 7, characterized in that the carrier has three stacked printed circuit boards (51 a, 51 b, 51 c), wherein the first printed circuit board (51 c) a precursor, the second printed circuit board (51 b) a temperature controlled dimming stage and the third printed circuit board (51a) form an output stage for the supply of the LED (43).

9. LED light according to claim 8, characterized in that the first printed circuit board (51c) as a precursor has a bridge rectifier circuit with smoothing capacitors and a filter circuit in the bridge branch.

10. LED luminaire according to claim 9, characterized in that at least one of the smoothing capacitors has an aluminum electrolytic capacitor with a capacitance in the range between about 1-10 microfarads.

11. LED light according to one of claims 8 - 10, characterized in that the second printed circuit board (51b) has at least one ohmic voltage divider to a resistive load in the range of about 5 - 20 watts, and preferably about 10 watts for the To simulate LED dimmers.

12. LED light according to one of claims 8 - 11, characterized in that the third printed circuit board (51 a) has a temperature-dependent resistor (R 19), the LED (43) with respect to the Mains voltage supplied dependent on temperature dependent supply voltage.

13. LED light according to claim 12, characterized in that the third printed circuit board (51a) for controlling the LED current has an integrated circuit which is designed for a temperature range between - 55 ° C and + 125 ° C and with its input the temperature-dependent resistor (R19) is connected.

14. LED light according to claim 13, characterized in that between the output of the integrated circuit and the LED (43) a MOS field effect transistor (Ql) and / or a choke coil (L2) is arranged.

15. LED light according to one of the preceding claims, characterized in that the carrier for power control of the LED (43) has a circuit for phase control.