EP3404320B1 - Led lamp - Google Patents

Description

Technical area

The present invention relates to an LED light source and an LED lamp with such an LED light source.

State of the art

LED lamps for use in LED lamps, especially in LED retrofit lamps, are becoming increasingly popular as a replacement for classic lamps such as halogen or incandescent lamps due to their high energy efficiency. However, LED light sources have several disadvantages compared to traditional light sources.

LED lamps, for example, have significantly poorer radiation characteristics and a reduced lighting quality. Known LED lighting means, for example, have light flickering at a frequency of 100 Hz. In addition, the solid angle covered is usually much smaller than with classic light sources and / or the radiation is spatially highly inhomogeneous. Bad mounting or adjustment of the light-emitting diode chips within the LED lighting means can also lead to a reduction in the quality of the lighting.

Another disadvantage is the current size of the LED light sources or LED lamps. In the case of LED lamps, additional driver electronics are required, which are usually housed in the base of the LED lamps and / or in the connection areas of the LED lamps. As a result, conventional LED lamps are made relatively large. The heat sinks required for the driver electronics and / or the light-emitting diode chips are another reason for bulky and expensive LED lamps. However, poor cooling reduces the service life of the LED lamp and the quality of the lighting.

The pamphlet WO 2012/031533 A1 describes an LED lamp in which an omnidirectional radiation characteristic is guaranteed through the use of LED filaments. In addition, the driver electronics are arranged in the lamp base of the LED lamp. As a result, the LED lamp is made relatively large overall.

The pamphlet JP 2013-222782 A describes an LED light source in which light-emitting diode chips are attached to a printed circuit board by means of so-called bare chip assembly (English: chip-on-board assembly, COB). The radiation characteristic of the LED light source, however, corresponds to the one-sided Lambertian radiation of the light-emitting diode chips and is therefore very inhomogeneous. In addition, the already mentioned 100 Hz flickering occurs.

The pamphlet US 9,420,644 B1 Figure 12 shows a bypass driver module which dynamically adds a bypass current to an LED current so that the summed current maintains a predetermined minimum holding current requirement of a phased dimmer supply.

The pamphlet US 2016/0348852 A1 shows a lighting device comprising a substrate, a plurality of light sources and a housing made of a non-permeable material.

The pamphlet US 2013/0271972 A1 shows a gas-cooled LED lamp.

Presentation of the invention

Based on the known prior art, it is an object of the present invention to provide a compact and inexpensive to manufacture LED light source. Furthermore, an LED lamp with such an LED light source is to be provided.

The tasks are performed by an LED lamp with the features of the independent patent claim solved. Advantageous further developments result from the dependent claims, the description, the figures and the exemplary embodiments described in connection with the figures.

Accordingly, an LED lamp is proposed, comprising a housing and an LED lighting means arranged within the housing, having a glass bulb, a light module with at least one light-emitting diode chip which is applied to a printed circuit board by means of bare chip assembly, and driver electronics for the light module, the light module and the driver electronics are accommodated in the glass envelope, and wherein the glass envelope has an indentation which protrudes into the interior of the glass envelope and is in thermal contact with the circuit board.

The bare chip assembly of light-emitting diode chips also enables the cost-effective production of compact and small electrical modules. Here and in the following, the term “bare chip assembly” is to be understood as the direct assembly of semiconductor chips on a printed circuit board, in particular using bond wires. Bare chip assembly is preferably carried out with unhoused semiconductor chips and / or with so-called chip-scale components in which the housing makes up a maximum of 20% more than the area of the bare semiconductor chip.

By introducing the driver electronics into the glass bulb in combination with the bare chip assembly of the light-emitting diode chips, a compact LED light source can thus be provided in a cost-effective manner.

The light module preferably has a multiplicity of light emitting diode chips. The light-emitting diode chips can, for example, be connected to one another in series. Furthermore, the LED lighting means can have a multiplicity of lighting modules. In a preferred embodiment, the LED lighting means contains a single lighting module with a plurality of light-emitting diode chips.

According to a preferred embodiment of the LED lighting means, at least part of the driver electronics, in particular the entire driver electronics, is applied to the circuit board by means of bare chip assembly. The driver electronics have electronic components in particular. At least some of the electronic components, in particular all of the electronic components, of the driver electronics are preferably applied to the circuit board by means of bare chip assembly. As an alternative or in addition, it is possible for at least part of the driver electronics to be applied to an additional circuit board. Furthermore, at least some of the electronic components can be applied to the circuit board and / or the circuit board by means of surface mounting (English: surface mounted device, SMD) and / or be electrically conductively connected to the light-emitting diode chip by means of wire connections.

According to a preferred embodiment of the LED light source, the electronic driver includes a smoothing capacitor which is connected in parallel with the at least one light-emitting diode chip. In the case of a plurality of light-emitting diode chips, each light-emitting diode chip is preferably connected in parallel to the smoothing capacitor. An energy store is introduced into the system through the smoothing capacitor. As a result, flickering (also called light flickering), in particular 100 Hz flickering, of the light emitted by the at least one light-emitting diode chip can be significantly reduced or even completely prevented and the emission characteristics can thus be significantly improved.

The smoothing capacitor can be applied to the circuit board of the driver electronics and / or the circuit board of the lighting module, in particular by means of surface mounting. Alternatively, the smoothing capacitor can be applied to the printed circuit board of the light module or to another board by means of surface mounting or bare chip mounting. A laser soldering process is preferably used for surface mounting, which means that the use of a reflow oven can be avoided. It is also possible for the smoothing capacitor to be attached to the circuit board of the light module as a simple clamping capacitor. Alternatively, the smoothing capacitor can be applied by means of an electrically conductive adhesive and / or bonding wires.

If the smoothing capacitor and / or the other electronic components of the driver electronics are surface-mounted on the board (or the printed circuit board), the smoothing capacitor and / or the electronic components are preferred before the light-emitting diode chips are applied and the light-emitting diode chips are possibly potted with a potting material carried out. Alternatively or additionally, surface mounting in a common process step with the attachment of electrical connections for making electrical contact with the light module, whereby the production of the LED light source is simplified even further.

The smoothing capacitor can be a ceramic multilayer (chip) capacitor whose capacitance is, for example, in a range of 1 μm. Alternatively, an electrolytic capacitor can be used, which enables high capacities.

The driver electronics can comprise a rectifier circuit, which is set up to convert an AC mains voltage into a DC operating voltage of the LED lighting means. It is possible for the light-emitting diode chips, in particular exclusively the light-emitting diode chips, to be used as rectification components for the rectifier circuit. The driver electronics can furthermore comprise a transistor which is set up for current regulation and / or current limitation of the current flowing through the light-emitting diode chips.

According to at least one embodiment of the LED lighting means, the thickness of the circuit board is at most 400 μm. The thickness is preferably at most 300 μm, particularly preferably at most 200 μm. A small thickness is particularly advantageous for uniform emission characteristics. Here and in the following, the thickness of the circuit board is its extent along a vertical direction of the circuit board. The vertical direction runs perpendicular to the lateral directions of the circuit board along which it extends.

In the lateral directions, the printed circuit board has a width and a length running perpendicular to the width, which is preferably greater than the width. The circuit board is preferably held in the glass bulb in such a way that the length runs along an axis of symmetry of the glass bulb.

The lateral directions span a front side and a rear side of the circuit board. The light-emitting diode chips are mounted on the front and / or on the back.

According to a preferred embodiment of the LED light source, the circuit board is designed to be transparent. That is to say, at least 50%, preferably at least 70%, of the light emitted by the at least one light-emitting diode chip and incident on the circuit board is transmitted through the circuit board.

For example, quartz glass (SiO ₂ , thermal conductivity 1.0 W / mK), sapphire (Al ₂ O ₃ , thermal conductivity 25 W / mK), mullite ceramic (silicate ceramic type C610 / 620, thermal conductivity 10 W / mK) are suitable as materials for the circuit board. and / or aluminum nitride (AlN, thermal conductivity 200 W / mK). The thermal conductivities given in brackets relate to values measured at 20 ° C for compositions that are frequently used in industry. When using electrically non-conductive, in particular light-permeable materials for the circuit board, further metallizations below the light-emitting diode chips and / or further electronic components on the circuit board may be required in order to enable electrical contacting. To improve the aesthetics, a translucent and / or opaque material can be attached under electronic components that are not the light-emitting diode chips in order to reduce the visibility of these electronic components.

In particular in combination with a small thickness, a light-permeable printed circuit board enables the emission characteristics of the LED light source to be improved. Here, the solid angle covered by the light emitted by the LED lamp can be increased so that the typical Lambertian radiation characteristic of the light-emitting diode chip is homogenized, right up to omnidirectional radiation over the entire solid angle of 2n.

A further improvement in the radiation characteristics can be achieved by arranging light-emitting diode chips on both sides of the circuit board, that is to say on the front and the rear of the circuit board. Two printed circuit boards equipped with light-emitting diode chips on the front side can also be connected to one another on their unpopulated rear sides. An electrically conductive connection between the light-emitting diode chips on different sides of the circuit board can be provided, for example, by means of clips, in particular metal clips, and / or wires, in particular metal wires.

According to at least one embodiment of the LED illuminant, the interior of the glass bulb is filled with a heat-conducting gas. A heat conducting gas is understood to be a gas that conducts heat well. A heat conducting gas can in particular have a higher thermal conductivity than air. A heat conducting gas can have a thermal conductivity of at least 0.05 W / mK, preferably at least 0.10 W / mK and particularly preferably at least 0.13 W / mK at room temperature, i.e. at the dimensional reference temperature of 20 ° C (293.15 K) , exhibit. Helium gas (thermal conductivity 0.16 W / mK) and / or hydrogen gas (thermal conductivity 0.18 W / mK) are, for example, suitable as heat conducting gas. A mixture of helium with oxygen can also be used as a heat-conducting gas. The absolute pressure of the heat conducting gas in the interior can be up to 10 bar, preferably at most 5 bar. The absolute pressure is preferably at least 1 bar, preferably at least 2 bar. The specifications of the absolute pressure are to be understood at room temperature. The use of a high pressure of the heat-conducting gas enables improved heat dissipation within the LED light source.

The glass bulb is preferably designed to be vacuum-sealed. In other words, the glass bulb can be closed and / or fused in such a way that the absolute pressure inside the glass bulb is maintained without external devices, such as vacuum pumps. The glass flask can thus enclose a sealed or closed volume that forms the interior space. In particular, the glass bulb is designed to be gas-tight.

The glass bulb can be made of hard glass, soft glass and / or quartz glass. The glass bulb is preferably formed with quartz glass and / or hard glass or consists of at least one of these materials. Here and in the following, the term "exists" is to be interpreted in the context of manufacturing tolerances; that is, the glass bulb may have manufacturing-related impurities. For example, the glass bulb contains at least 99% silicon dioxide. By using quartz glass or hard glass, a glass bulb can be provided that can be filled with a gas pressure of up to 30 bar. In contrast, soft glass cannot be filled with high gas pressures (up to a maximum of 1 bar). Furthermore, quartz glass and / or hard glass have the advantage that these materials are extremely temperature-resistant and also have very good optical properties. In addition, the thermal conductivity of hard or quartz glasses is sufficiently high to enable good dissipation of waste heat generated during operation of the LED light source.

Duran glass, alumnosilicate glass and / or borosilicate glass can be used as hard glasses. Glasses that are also used in classic halogen lamp construction are particularly suitable as hard glasses. The glass bulb can be constructed in the manner of a glass bulb of a classic halogen lamp. In contrast to soft glasses. Where even a temperature shock of 100 K can cause the glass to crack or crack, quartz glass and hard glass can be exposed to high temperature shocks, for example up to 1000 K, without cracks or cracks occurring.

The glass bulb can also contain a getter material for binding (so-called gettering) of volatile organic compounds (VOC) and / or of volatile sulfur, phosphorus and / or chlorine-containing compounds. In particular, the volatile organic compounds can contain oxygen, nitrogen, hydrogen and / or carbon. The getter material can be introduced into the glass bulb in the solid and / or gaseous state. The volatile organic and / or sulfur, phosphorus and / or chlorine-containing compounds can also be referred to in general as “volatile compounds” below.

In sealed glass bulbs, the problem of outgassing of volatile organic compounds can increasingly occur in LED lamps with light-emitting diode chips and / or other components. This is partly due to the fact that the glass bulb of the LED light source is made relatively small due to the higher mechanical stress caused by the high pressure. Analogous to the technology of the classic halogen lamp, in which any evaporating tungsten compounds can be degassed by halogen compounds through the smaller bulb, volatile compounds can also be gettered off with small, closed glass bulbs for LED lamps with light-emitting diode chips.

The volatile compounds can come from flux residues or solder resists from soldering processes, for example. Furthermore, the volatile compounds can be outgassing of polymers of the light-emitting diode chips, adhesives and / or heat-conducting pastes. In addition, the volatile compounds can come from the circuit board.

Volatile organic compounds present in the glass bulb can be deposited on the material of the glass bulb and cause discoloration there. This is known under the term “fogging” of the glass bulb and can lead to a loss of luminous flux of up to 10%. Diffusion of the volatile organic compounds into an optionally present silicone shell of the light-emitting diode chips can be even more serious. Through this Hydrocarbon compounds in the silicone shell can be broken and the silicone shell can turn dark. This can lead to a loss of luminous flux of over 50%. This loss of luminous flux is usually associated with an additional shift in the color locus. These two phenomena are known under the terms "lumen degradation" and "change color chromaticity". Furthermore, compounds containing sulfur, phosphorus and / or chlorine can lead to reflection losses at a silver mirror that may be present below the emitting layers of the light-emitting diode chips.

The getter material is preferably at least partially introduced into the glass bulb as a gas. For example, the gaseous getter material is hydrogen- and / or oxygen-rich compounds which preferably bind volatile carbon-containing compounds and react, for example, to form CH ₄ or CO / CO ₂ . The setting can prevent a reaction with a silicone cover and / or a deposit on the glass bulb. In particular, the getter material can contain oxygen gas and / or a silane, for example a monosilane (SiH ₄ ). Due to the high pressure inside the gas piston, it may be possible to introduce the silane at a maximum concentration below an ignition limit or explosion limit. For example, the flask can be filled with 8% by volume of silane. In particular, the amount of gaseous getter material can be increased in direct proportion to the absolute pressure of a heat-conducting gas that may be introduced into the glass bulb.

Alternatively or additionally, the getter material can be introduced into the glass bulb at least partially as a solid. A pure metal such as zirconium Zr, tantalum Ta, titanium Ti, palladium Pd, vanadium V, aluminum Al, copper Cu, silver Ag, magnesium Mg, nickel Ni, iron Fe, calcium Ca, strontium Sr and is suitable as a solid getter material Barium Ba, or alloys made of pure metals, such as ZrAl, ZrTi, ZrFe, ZrNi, ZrPd and / or BaAl ₄ . The use of a ZrAl alloy is preferred here. Oxides and hydrides of pure metals are also suitable as getter material. In particular, metal hydroxides, such as magnesium hydroxide or aluminum hydroxide, are suitable as solid getter materials within the glass bulb. Metal hydroxides are suitable for example for a gettering off volatile carbon compounds in the closed volume of the glass bulb.

Solid getter materials are preferably applied in such a way that they have a large reactive surface, for example as a coating and / or as a sintered material. Alternatively or additionally, the getter material can be introduced into the glass bulb as solid metal, for example in the form of a wire.

It is possible here for solid getter materials to be optimized with regard to their getter behavior by additionally introduced gaseous getters. For example, the getter materials can be activated after a pumping-out process and baking in the oven (tempering). In this way, for example, reactive oxides of metallic getter materials can form.

According to at least one embodiment of the LED lighting means, the circuit board is thermally connected to the glass bulb. Alternatively or in addition, the smoothing capacitor is thermally connected to the glass bulb. The smoothing capacitor is preferably applied to the circuit board and thermally connected to the glass bulb together with the circuit board. "Thermally connected" means here and below that the printed circuit board or the smoothing capacitor is connected to the glass bulb in a thermally conductive manner. In particular, the circuit board and / or the smoothing capacitor can be in direct contact with the glass bulb in places. This enables efficient cooling of the at least one light-emitting diode chip or the light-emitting diode chip applied to the circuit board Smoothing capacitor and consequently a constant lighting quality in connection with an increased operating time.

According to the invention, the glass bulb has an indentation (English: dimple), preferably a plurality of indentations. The indentation protrudes into the interior of the glass bulb. In other words, the indentation is concave with respect to the interior. The indentation is in thermal contact with the printed circuit board and / or the smoothing capacitor. The indentation preferably adjoins the circuit board and / or the smoothing capacitor. The indentation can be formed, for example, during the production of the LED lighting means by pressing in and / or squeezing together the still soft material of the glass bulb.

The conduction of heat between the glass bulb and the circuit board with the light-emitting diode chips and / or the smoothing capacitor can be further improved by means of the indentation. It is advantageous here if the indentation is in thermal contact with temperature-sensitive (opto) electronic components. The indentation can also hide the direct view of electronic components in the interior of the glass bulb and thus improve the aesthetic appearance of the LED light source. This is particularly advantageous when the indentation directly adjoins the smoothing capacitor, since it can appear unaesthetic, for example due to its size.

According to at least one embodiment of the LED illuminant, the glass bulb has two indentations lying opposite one another and the circuit board is clamped between the two indentations. The indentations thus fix the circuit board within the glass bulb. A distance between the indentations then preferably corresponds to the thickness of the printed circuit board. However, further components can also be arranged between the circuit board and the indentations, so that the distance between the Indentations can also be larger than the thickness of the circuit board.

The indentations can in particular be designed mirror-symmetrically with respect to one another with respect to an axis of symmetry of the glass bulb. In this case, the indentations center the circuit board in the glass bulb. The circuit board then runs along the axis of symmetry. The axis of symmetry of the glass bulb can here and subsequently run along the main direction of extent of the glass bulb. For example, the glass bulb has a cylindrical or elongated, in particular rounded, cuboid shape, the axis of symmetry then being the height of the cylinder or the length of the cuboid.

As a result of indentations on both sides that are in thermal contact with the circuit board, the heat dissipation can be improved and homogenized on the one hand and the mechanical holding of the circuit board, in particular a heavy circuit board, within the glass bulb can be reinforced on the other hand. In particular, if the circuit board is centered by the glass bulb, the aesthetic appearance can thus be further improved. Furthermore, the mechanical stability of the lamp can be improved in the so-called postal drop test according to DIN ISO 2206 or DIN ISO 2248 (respective version at the time of registration). The postal drop test simulates the maximum mechanical loads during the transport of the lamp. Without the indentations, the respective bending moments on the wire sections of the holder and / or the crushed glass during transport can be very high.

The indentations are preferably located on an upper side of the glass bulb, which is opposite a holder of the light module. The holder of the light module is located on the underside of the glass bulb, in particular together with electrical connections of the light module. The holder can in particular correspond to the electrical connections. The electrical connections can be, for example Trade wire pins. The wire pins can be soldered and / or clamped to the circuit board. On a side facing away from the circuit board, the wire pins can be fused to the glass bulb, which ensures that the circuit board is mechanically held. If the indentation is on the upper side, the clamping of the printed circuit board can reduce the mechanical load, in particular the mechanical tension, on the holder and also prevent the light module from bending or breaking off by shaking the LED light source. In the case of a single indentation, this can also be located on the upper side of the glass bulb facing away from the holder.

For electrical contacting of the light module from the outside, the electrical connections can be connected to contact pins arranged at least partially outside of the glass bulb via an electrically conductive connection area. The connection area can be fused or welded to the glass bulb. The fusing can in particular be carried out in such a way that the glass bulb continues to be vacuum-sealed. For example, a molybdenum foil and / or a molybdenum wire is attached between the glass bulb and the connection area, in particular in a fusion area of the connection, in order to facilitate the fusion. The molybdenum foil or the molybdenum wire is formed with molybdenum or consists of molybdenum. The molybdenum foil or the molybdenum wire can also contain a getter material, for example in the form of a coating.

In the case of a quartz glass bulb, a molybdenum foil is preferably used, and in the case of a hard glass glass bulb, a molybdenum wire is used. This is due to the different thermal expansion coefficients of quartz glass and hard glass. The thermal expansion coefficient of molybdenum is 5.1 · 10 ^-6 K ^-1 , of quartz glass 0.6 · 10 ^-6 K ^-1 and of hard glass 4.7 · 10 ^-6 K ^-1 . Tempered glass thus has a similar thermal Expansion coefficients such as molybdenum (the difference is less than 10%), which is why, in contrast to quartz glass, direct fusing is possible. Alternatively, in the case of hard glass, a wire with an iron-nickel-cobalt alloy (so-called KOVAR) and / or a tungsten wire can be used.

Furthermore, transition glasses can be attached between the glass bulb and the connecting area. It is also possible for the connection and / or any retaining wires that may be present for a circuit board to consist of a getter material or to be coated with a getter material. The solid getter materials mentioned above are suitable for this, for example.

According to at least one embodiment of the LED lamp, the glass bulb has a notch protruding into the interior of the glass bulb, which runs along an axis of symmetry of the glass bulb and is designed to center the lighting module within the glass bulb. For example, the notch is used to clamp the circuit board on an edge of the circuit board opposite the holder of the circuit board.

In accordance with at least one embodiment of the LED lighting means, the circuit board has a width which essentially corresponds to a largest inner diameter of the glass bulb. "Essentially" is to be understood here in such a way that the width can deviate by up to +/- 20%, preferably +/- 10%, from the largest inner diameter. Both the largest inner diameter and the width of the circuit boards run perpendicular to the axis of symmetry of the glass bulb. The glass bulb preferably has a cylindrical shape with an elliptical or circular cross section; the largest inside diameter in this case is the major axis of the ellipse or the diameter of the circle. Alternatively, the glass bulb can have the shape of a, in particular rounded, cuboid with a rounded rectangular cross section; the largest inside diameter in this case is the longer side of the rectangular cross-section. Due to the similar dimensions of the largest inner diameter of the glass bulb and the width of the printed circuit board, the printed circuit board can be clamped and held by means of the walls of the glass bulb. Further materials can be located between the printed circuit board and the glass bulb, so that a thermal connection of the printed circuit board to the glass bulb and / or compensation of manufacturing-related deviations in the geometries is made possible.

According to at least one embodiment of the LED light source, the glass bulb has a bulge that is convex with respect to the interior of the glass bulb. The circuit board and / or the smoothing capacitor is / are at least partially received in the bulge. The bulge can be the glass nose known from classic halogen lamps, which can be used to fill the glass bulb with a heat-conducting gas. Due to the bulge, the design of the LED light source can be approximated to that of a classic halogen lamp, which increases the aesthetics and customer acceptance. Furthermore, the bulge can be used to center and / or at least partially fix the light module within the glass bulb.

In accordance with at least one embodiment of the LED lighting means, the circuit board and / or the smoothing capacitor is / are at least partially embedded in a mechanically flexible potting body. The potting body can in particular be a silicone potting. Mechanical flexibility is given, for example, when the potting body can be compressed non-destructively by at least 30% of its expansion and / or when the potting body is elastic. The potting body can in particular be attached to the points on the printed circuit board and / or the smoothing capacitor which are located at the indentation and / or the notch. In general, the potting body enables this Compensation of manufacturing-related tolerances in the dimensions of the circuit board, the smoothing capacitor and / or the glass bulb. For example, when clamping between two indentations, the potting body is compressed more strongly, that is to say elastically deformed, in the case of a thick circuit board than in the case of a thinner circuit board. Similarly, a reduction in the largest inside diameter of the glass bulb can be compensated for by potting the edges of the circuit board with the potting material, since this is then compressed when the circuit board is clamped in the glass bulb.

The potting body can alternatively or additionally be applied to the at least one light-emitting diode chip. This makes it possible to adapt the emission characteristics of the light-emitting diode chip. For example, the potting body contains scatter particles and / or wavelength-converting particles for this purpose. Furthermore, the potting body can be designed in the form of a lens. In particular if the potting body contains wavelength-converting particles, the smoothing capacitor can also be attached under the potting body so that the direct view of the smoothing capacitor is blocked. In this way, the aesthetic appearance of the LED light source can be further improved.

According to at least one embodiment of the LED illuminant, the glass bulb is made of frosted glass and / or has a matt finish. The glass bulb preferably consists of frosted glass and / or a frosted glass. For example, the glass bulb has been treated with a sandblast for this purpose. By using frosted glass, the solid angle area covered by the LED illuminant can be increased further and the radiation characteristic can be improved.

To improve the aesthetics of the LED lighting means, it is also possible that the lighting module comprises different sections, the sections of the lighting module Emit light of a different color temperature. As an alternative or in addition, it is possible for the LED lighting means to include several lighting modules which emit light of a color temperature that differs from one another.

For example, the LED lighting means includes a first section that emits, in particular white, light of a first color temperature, and a second section that emits, in particular white, light of a second color temperature that is higher than the first color temperature. The color temperature or the color locus of the light emitted by the LED lighting means is then specified by the respective color temperatures or color loci of the light emitted by the individual sections and / or light modules.

For example, the first section and the second section can each include at least one blue light-emitting light-emitting diode chip, the blue light being converted into white light by means of a wavelength conversion element that includes wavelength-converting particles, in particular a phosphor. The wavelength conversion element of the first section can comprise different wavelength-converting particles such as the wavelength conversion element of the second section and / or different compositions of the wavelength-converting particles, so that light of a different color temperature is emitted in the first section than in the second section. The use of different wavelength conversion elements can analogously also be used for the case of several light modules. Furthermore, more than two sections, each with different wavelength conversion elements, can also be used.

The second section can be closer to the top of the glass envelope than the first section. It is also possible that the sections can be controlled electrically separately and / or are dimmable. In particular, the light-emitting diode chips of one section can become dark during dimming (ie they emit less light than in the other section), as a result of which the color locus of the light that is emitted as a whole by the LED lighting means changes. This arrangement enables a dimming effect similar to that of an incandescent lamp to be achieved, for example when dimming the LED light source, in particular by means of phase section dimming.

The circuit board can have a contact point that can be contacted by means of an electrical connection, wherein the contact point can preferably be formed by a high-temperature material, particularly preferably by uncoated material or by, for example, nickel, platinum, ruthenium, silver, tin, zinc, copper coated molybdenum, niobium, tantalum and / or stainless steel.

The electrical connection can be formed by a metal clamp, the metal clamp having an opening in which the circuit board can be clamped, a contact area of the metal clamp being brought into direct contact with the contact point of the circuit board.

In this way, quick and easy contacting and connection of the circuit board with the electrical connection can be achieved. The clamping also creates a mechanical connection that makes subsequent soldering or other material-to-material connection superfluous.

The metal clamp can be formed by two wire tracks which are welded to one another at a connection point.

A metal clamp designed in this way can be manufactured inexpensively and with a precise fit and offers quick and easy contacting.

An LED lamp is also specified. The LED lamp includes an enclosure and one within the enclosure arranged LED light source. The LED illuminant of the LED lamp is a previously described LED illuminant. This means that all the features described for the LED lamp are also described for the LED lamp and vice versa. The LED lamp can be, for example, an LED retrofit lamp or an LED light.

The housing can be a glass envelope and / or an at least partially transparent housing. In particular, the housing is formed with a material which has a high thermal conductivity, which in particular corresponds at least to the thermal conductivity of quartz glass. The housing of the LED lamp is preferably a glass envelope. A heat-conducting gas can be located in a space between the glass envelope and the glass bulb. The pressure of the heat-conducting gas within the glass envelope is preferably lower than the pressure of the heat-conducting gas within the glass bulb. For example, the pressure in the glass envelope is at least 0.5 bar, preferably at least 1 bar, lower than in the glass bulb. The pressure in the glass envelope is preferably 1 bar. Alternatively or additionally, a thermally conductive material, such as a silicone potting and / or glass diffuser, can be introduced into the space between the glass bulb and the housing.

The glass envelope is preferably formed with or consists of a soft glass, in particular soda-lime glass. Soft glass is characterized by its low manufacturing costs and easy processability.

The housing can alternatively or additionally comprise a reflector which is designed to be reflective for the light emitted by the LED illuminant. The LED lamp can then be designed in particular as a retrofit for a classic halogen reflector lamp.

The LED lighting means described here is particularly compact and can be manufactured inexpensively. The radiation characteristics are significantly improved compared to known LED light sources.

Brief description of the figures

• Die Figuren 1A, 1B, 1C, 2A, 2B, 2C, 3A und 3B zeigen Ausführungsbeispiele eines hier beschriebenen LED-Leuchtmittels sowie von Leuchtmodulen für ein hier beschriebenes LED-Leuchtmittel.
• Die Figuren 4A, 4B und 4C zeigen Ausführungsbeispiele einer hier beschriebenen LED-Lampe.
• Die Figuren 5A, 5B, 5C, 5D und 5E zeigen Ausführungsbeispiele eines hier beschriebenen LED-Leuchtmittels.
• Die Figuren 6A, 6B und 6C zeigen Ausführungsbeispiele von Metallklemmen für ein hier beschriebenes LED-Leuchtmittel.
• Die Figuren 7A, 7B, 7C, 7D, 7E, 8A, 8B, 9A, 9B, 10A, 10B zeigen Ausführungsbeispiele eines hier beschriebenen LED-Leuchtmittels.
• Die Figuren 11A, 11B, 12A und 12B zeigen gemessene Beleuchtungsstärken und Abstrahlcharakteristiken für Ausführungsbeispiele eines hier beschriebenen LED-Leuchtmittels.

Preferred further embodiments of the invention are explained in more detail by the following description of the figures.

• The Figures 1A, 1B, 1C , 2A, 2B, 2C , 3A and 3B show exemplary embodiments of an LED lighting means described here and of lighting modules for an LED lighting means described here.
• The Figures 4A, 4B and 4C show exemplary embodiments of an LED lamp described here.
• The Figures 5A, 5B, 5C, 5D and 5E show exemplary embodiments of an LED light source described here.
• The Figures 6A, 6B and 6C show exemplary embodiments of metal clamps for an LED lamp described here.
• The Figures 7A, 7B, 7C, 7D, 7E , 8A, 8B , 9A, 9B , 10A, 10B show exemplary embodiments of an LED light source described here.
• The Figures 11A, 11B , 12A and 12B show measured illuminance levels and radiation characteristics for exemplary embodiments of an LED light source described here.

Detailed description of preferred exemplary embodiments

In the following, the lighting means described here and the LED lamp described here are explained in more detail on the basis of exemplary embodiments and the associated figures. Identical, identical, similar or identically acting elements are provided with the same reference symbols. A repeated description of these elements is partly dispensed with in order to avoid redundancies.

The figures and the proportions of the elements shown in the figures are not to be regarded as being to scale. Rather, individual elements can be shown in exaggerated size for better illustration and / or for better understanding.

Based on the schematic representations of the Figures 1A, 1B and 1C a first embodiment of an LED lighting means 1 described here is explained in more detail. The LED lamp 1 shown can be used as an LED lamp, for example, in a so-called pin-base lamp, in particular a G9 pin-base lamp that can be operated at 230 V. The Figure 1A shows a circuit diagram of a lighting module 100 for the LED lighting means 1, the Figure 1B shows a schematic sketch of the lighting module 100 for the LED lighting means 1 and the Figure 1C shows a schematic sketch of the LED illuminant 1.

The light-emitting module 100 comprises a multiplicity of light-emitting diode chips 11. Specifically, four light-emitting diode chips 11 are shown in the example. Unlike in the Figure 1A shown, the light module 100 can also have more or fewer light-emitting diode chips 11. The light-emitting diode chips 11 are connected in series with a transistor 31. The transistor 31 can be used, for example, to set a current through the series-connected light-emitting diode chips 11. A smoothing capacitor 30 is connected in parallel with the light-emitting diode chips 11. The smoothing capacitor 30 is used to filter modulations, in particular at 100 Hz, in the operating voltage of the light-emitting diode chips 11. The operating voltage is provided by a voltage source 33. A rectifier circuit 32, which in the present case is formed with four diodes 321, is located between the voltage source 33 and the light-emitting diode chips 11. The rectifier circuit 32 and the transistor 31 can be part of driver electronics, which can be attached within the glass bulb 20 of the LED illuminant 1.

In the Figure 1B are the electronic components of the Figure 1A shown schematically together on a circuit board 12. Alternatively, it is possible for at least some of the components of the light module 100 to be applied to a separate circuit board. At least light-emitting diode chips 11 of light module 100 are preferably applied to printed circuit board 12 by means of bare chip assembly. The electrical contacting of the light module 100 takes place by means of contact points 44 which are located on the circuit board 12.

In the case of a G9 pin-base lamp, the circuit board 12 preferably has a width of at least 5 mm and at most 11 mm. The length is preferably at least 10 mm and at most 30 mm. The contact points 44 are spaced 6 mm apart.

The Figure 1C shows an LED lamp 1, which is a in connection with the Figures 1A and 1B may include the light module 100 described. The light module 100 of the LED light source 1 is shown purely by way of example as a filament of a classic halogen lamp. The LED lighting means 1 comprises two lighting modules 100 in the present case. In a preferred embodiment of the LED lighting means 1, contrary to the illustration in FIG Figure 1C -but only one light module 100 may be provided. The light modules 100 are located in a glass bulb 20. The glass bulb 20 further comprises electrical connections 43, which are electrically conductively connected to the contact points 44 of the light module 100. The position of the electrical connections 43 defines an underside of the glass envelope 20.

The glass bulb 20 has a bulge 21 on an upper side opposite the lower side. The bulge 21 is arranged on an axis of symmetry of the glass bulb 20. A part 101 of the lighting module 100 protrudes into the bulge 21 into it and can thereby be centered by means of the bulge 21.

The electrical connections 43 are connected in an electrically conductive manner to contact pins 41 via a connection area 42. In the connection area 42 there is a molybdenum foil, with the use of which a different coefficient of thermal expansion of the material of the electrical connections 43 or of the contact pins 41 and the material of the glass bulb 20 can be compensated. In particular, in the example shown, the glass bulb 20 can be formed with quartz glass. In the case of hard glass, it is alternatively possible that the connection area 42 only comprises a wire, for example a molybdenum wire, a tungsten wire or an iron-nickel-cobalt wire, since in hard glass in connection with the mentioned electrically conductive materials none Adjustment of the thermal expansion coefficient is required.

Based on the schematic representations of the Figures 2A, 2B and 2C Another embodiment of an LED lamp 1 described here is explained in more detail. The LED lamp 1 shown can also be used as an LED lamp in a pin-base lamp, in particular a G4 pin-base lamp that can be operated at 12 V. The Figure 2A shows a circuit diagram of a light module 100 for the LED light source 1, the Figure 2B shows a schematic sketch of the lighting module 100 for the LED lighting means 1 and the Figure 1C shows a schematic sketch of the LED illuminant 1.

In contrast to the light module 100 of Figure 1A comprises the light module 100 of Figure 2A only three light-emitting diode chips 11. The rest of the configuration does not differ from the light-emitting module 100 of FIG Figure 1A . By reducing the number of light-emitting diode chips 11, it is possible to operate the light-emitting module 100 even at low voltages, in particular at 12 V.

The Figure 2B FIG. 11 shows a schematic representation of the electronic components of FIG Figure 2A . The structure of the other components corresponds to that of Figure 1B . In the case of a G4 pin-base lamp, the circuit board 12 preferably has a width of at least 5 mm and at most 10 mm and a length of at least 5 mm and at most 20 mm. The contact points 44 are spaced 5 mm apart.

The Figure 2C shows an LED lamp 1, which in connection with the Figures 2A and 2B may include light module 100 described. The light module 100 of the LED light source 1 is shown purely by way of example as a filament. The light module 100, however, comprises the light-emitting diode chips 11 of FIG. 4 which are applied to a printed circuit board 12 by means of naked assembly Figures 2A and 2B . The LED light source 1 differs from the LED light source 1 Figure 1C in particular through a partially spherical structure of the glass bulb 20 through a more pronounced bulge 21. As a result, the LED illuminant 1 is even more similar to a classic halogen or incandescent lamp.

The LED light source 1 of the Figure 1C can of course also with the light module 100 of the Figures 2A and 2B be populated and vice versa.

Based on the schematic representations of the Figures 3A and 3B Another embodiment of an LED lamp 1 described here is explained in more detail. The LED lamp 1 shown can be designed as a halogen tube lamp, for example. The LED lighting means 1 has an elongated, rod-like shape. The light module 100 can be used in conjunction with the Figure 1A as well as the connection with the Figure 2A described light module 100 can be used. Due to the elongated shape, the circuit board 12 should also be elongated. The printed circuit board 12 preferably has a width of 5 mm and a length of at least 50 mm and at most 100 mm.

In contrast to the LED light sources 1 of the Figures 1A to 2C , in which the contact pins 41 were arranged on the same side of the glass bulb 20, the contact pins 41 are now arranged on opposite sides of the glass bulb 20. The contact points 44 are preferably also attached to opposite sides of the circuit board 12 (see FIG Figure 3B ).

Based on the schematic representations of the Figures 4A, 4B and 4C embodiments of an LED lamp described here are explained in more detail. The LED lamps are each designed as LED retrofit lamps. Each of the LED lamps comprises an LED illuminant 1 and a housing 60. There are also bases 62 for inserting the LED lamp into a lamp socket and for making electrical contact with the LED lamp.

With the LED lamp of the Figure 4A the housing 60 is a glass envelope which preferably corresponds to the glass envelope of a classic light bulb. In the Figure 4A the housing 60 is pear-shaped. Alternatively, the housing 60 can also be designed in the shape of a cylinder. A heat-conducting gas is preferably introduced between the housing 60 and the glass bulb 20 of the LED lighting means 1. The LED illuminant 1 is connected to the base 62 by means of two mounting wires 61. The mounting wires 61 serve, on the one hand, to hold the LED illuminant 1 and, on the other hand, establish an electrically conductive connection between the base 62 and the contact pins 41 of the LED illuminant 1.

The LED lamp of the Figure 4B comprises a housing 60 which is designed as a reflector of a (halogen) reflector lamp. The LED lamp 1 (in the Figure 4B not visible) is located in a cavity of the housing 60. The housing 60 of the LED lamp Figure 4C is formed with a glass envelope which partially has a reflective coating to form a reflector. The housings 60 of the LED lamps Figures 4B and 4C can also contain a heat-conducting gas in an intermediate space between the housing 60 and the LED lighting means 1.

Based on the schematic representations of the Figures 5A to 5E embodiments of a lighting module 100 for an LED lighting means 1 described here are explained in more detail. In the Figures 5A to 5E a circuit board 12 with contact points 44 and electrical connections 43 connected to them in an electrically conductive manner is shown in sketch form. The light-emitting diode chips 11 and the electronic components, in particular the smoothing capacitor 30, of the light module 100 (in FIGS Figures 5A to 5E not shown). The light modules 100 of the Figures 5A to 5E differ in the electrical contacting of the contact points 44.

In the embodiment of Figure 5A the electrical connections 43 are designed as wires that are soldered to the contact points 44. A high-temperature solder (melting temperature above 400 ° C.) in conjunction with a wire and contact points that each have a high melting temperature is preferably used for soldering. In particular, the melting temperature of the solder, the wire and the material of the contact points 44 is at least 1800 ° C. For example, coated or uncoated molybdenum, niobium, tantalum and / or stainless steel are suitable as such high-temperature materials. By choosing such a material, it can be ensured that the mechanical connection between the electrical connections 43 and the contact points 44 does not come loose when the glass bulb 20 fuses around the electrical connections 43 due to the heat development associated therewith.

In the embodiment of Figure 5B the electrical connections 43 designed as wire are connected to the contact points 44 by means of rivets 441. For the riveting 441, holes are made in the contact points 44 and the electrical connections 43 are riveted to the contact points 44 by means of a riveting tool. The contact points 44 and the electrical connections 43 are preferably formed from one of the high-temperature materials described above.

The light module 100 of the Figure 5C In contrast to the previous lighting modules 100, it has no electrical connections 43. Instead, a connection area 42 designed as a molybdenum foil is connected directly to the contact points 44. In particular, the molybdenum foil is soldered directly onto the contact points 44, so that material can be saved. To mechanically stabilize the thin film and / or to improve the soldering or welding properties, it can be coated, for example with ruthenium. The use of a molybdenum foil instead of a wire is particularly advantageous in the case of quartz glasses.

The one in the Figure 5D In the exemplary embodiment shown, the electrical connections 43 have first connection areas 431 and second connection areas 432. The electrical connections 43 can be designed as a wire which is soldered to the contact points 44. The second connection regions 432 are designed to be bent in a double manner. This makes it possible to use the Figure 5D The front side of the printed circuit board 12 shown in FIG Figure 5D not shown) contact points which are attached to the rear side of the printed circuit board 12 facing away from the front side to be connected in an electrically conductive manner. This is particularly advantageous if both sides of the circuit board 12 are equipped with light-emitting diode chips 11, since the light-emitting diode chips 11 on the front and the light-emitting diode chips 11 on the rear can be contacted with one wire each as the electrical connection 43.

The Figure 5E shows an embodiment of a light module 100, in which a contact point 44 is attached to the front side of the circuit board 12 and the second contact point 44 is attached to the rear side of the circuit board 12 facing away from the front side (in Figure 5E not visible). This arrangement is advantageous, for example, for equipping the printed circuit board 12 with light-emitting diode chips 11 on both sides. The electrical connections 43 can be soldered to the contact points 44, for example.

The embodiments of Figures 5A to 5E can be combined with each other. For example, the one in the Figure 5C connection area 42 shown in connection with one of the electrical connections 43 of Figures 5A, 5B, 5D or 5E are used and / or the two connection areas 431, 432 of the Figure 5D by means of riveting 441 of Figure 5B are connected to the contact points 44.

The Figures 6A, 6B and 6C each show metal terminals 444 for transferring an electrical contact from the front side of the circuit board 12 to the rear side of the circuit board 12.

Such metal clips 444 can be used in conjunction with the FIGS Figures 5A to 5E Light modules 100 shown are used, in particular when contact points 44 are attached both to the front and to the rear of the circuit board 12. They can also serve for contacting only one contact point lying on one of the two sides of the circuit board 12.

The metal clips 444 are each made of an electrically conductive material such as stainless steel.

The metal terminals 444 each have contact areas 446 and an opening 445 which is designed for inserting the printed circuit board 12. A diameter of the opening 445 corresponds essentially to the thickness of the circuit board 12. The circuit board 12 is clamped into the opening 445 and the contact areas 446 are brought into direct contact with the contact points 44, whereby an electrical contact between contact points 44 on the front side and contact points 44 the back of the circuit board 12 is made.

The metal clamp 444 of the Figure 6A is designed like a spring and has a curved area that provides a clamp facilitated. The metal clamp 445 of the Figure 6B is planar on its outer sides facing away from the opening 445, whereby the metal clamp 445 can be made extremely narrow.

With the metal clamp 444 of the Figure 6C two wire tracks, which can in particular be designed as protective conductors, were arranged at an angle to one another and welded to one another at a connection point 447. A metal clamp 444 can hereby be provided in a simple manner.

Based on the representations of the Figures 7A to 7E further exemplary embodiments of an LED light source 1 described here are explained in more detail.

The Figures 7A and 7B each show photographs of an LED light source 1, the top side of the LED light source 1 being shown on the left side and the bottom side with the electrical connections 43 and the contact pins 41 separately on the right side. The Figure 7A shows the LED lamp 1 in a side view and FIG Figure 7B shows the LED lamp 1 in a plan view.

The LED lighting means 1 contains two indentations 22 in the glass bulb 20. The light modules 20 arranged in the glass bulb 20 are held and centered by means of the indentations 22. The electrical contact is made by means of a connection area 42 (see also Figure 1C ).

The Figures 7C and 7D show enlargements of indentations 22 in the glass bulb 20. The indentations 22 are formed as cavities in the glass bulb. A free space into which the circuit board 12 can be clamped is formed between the indentations 22.

The Figure 7E shows a schematic sketch of an LED lighting means 1. Only the glass bulb 20 and the contact pins 41 and the connection area 42 of the LED lighting means 1 are shown. The glass bulb 23 has a Notch 23 which is used to center a printed circuit board 12 in the glass bulb 20. For example, the circuit board 12 can be clamped firmly in the interior of the glass bulb 20 by means of the notch 23.

Using the schematic sketches of the Figures 8A and 8B Embodiments of an LED lamp 1 described here are explained in more detail. The Figures 8A and 8B each show enlargements of the area around an indentation 22 in the glass bulb 20 (see also Figures 7A to 7D ).

Between the in the Figures 8A and 8B The indentations 22 shown are each a space in which the circuit board 12 is located. Furthermore, the smoothing capacitor 30 applied to the printed circuit board 12 is located between the indentations 22, whereby the smoothing capacitor 30 is virtually hidden. In the Figure 8A the smoothing capacitor 30 is only attached to one side of the circuit board 12, for example the front side, while the circuit board 12 of the Figure 8B has a smoothing capacitor 30 on both sides, that is to say on the front side and on the rear side of the circuit board 12.

The circuit board 12 is embedded together with the smoothing capacitor 30 in a mechanically flexible potting body 122. The potting body 122 can be formed from silicone. Furthermore, the potting body 122 can have wavelength-converting particles, as a result of which the view of the smoothing capacitor 30 is additionally obscured.

By means of the potting body 122, manufacturing-related deviations in the thickness d of the circuit board 12 and / or in the expansion of the space between the indentations 22 can be compensated. In this way, the potting body 122 is compressed to a greater or lesser extent in accordance with the deviation, as a result of which clamping is made possible even when there are deviations from an optimal dimension.

Based on the schematic representations of the Figures 9A and 9B further exemplary embodiments of an LED light source 1 described here are explained in more detail. Possible shapes for the glass bulb 20 are specifically shown. In the Figure 9A the glass bulb 20 has the shape of a classic halogen glass bulb, namely cylinder-like with a bulge 21 along an axis of symmetry of the glass bulb 20. Part of the circuit board 12 of the LED lamp 1 can be arranged in the bulge 21 and thermally in the area of the bulge 21 be connected to the glass bulb 20, whereby the heat dissipation can be improved without adversely affecting the appearance of the LED lamp 1.

Like in the Figure 9B As shown, the glass bulb 20 can alternatively have a cuboid shape and follow a rectangular shape of the printed circuit board 12. In general, the fact that the shape of the glass bulb 20 is selected to be similar to the shape of the printed circuit board 12 can improve the heat dissipation away from the printed circuit board 12.

Based on the schematic representations of the Figures 10A and 10B further exemplary embodiments of an LED light source 1 described here are explained in more detail. In the exemplary embodiments shown, the width b of the printed circuit board 12 corresponds approximately to the largest inner diameter r of the glass bulb 20. As a result, the printed circuit board 12 can be held by the walls of the glass bulb 20. It is possible for the circuit board 12 to be embedded in a mechanically flexible potting body 122, as a result of which manufacturing tolerances in the width b of the circuit board 12 and / or the largest inner diameter r of the glass bulb 20 can be compensated.

The glass bulb 20 of the Figure 10A has a cylindrical cross section and the glass bulb 20 of Figure 10B has a circular cross-section, the cross-section in each case being formed perpendicular to an axis of symmetry and the glass bulb 20 in each case having a cylindrical shape. To maximize the radiating surface, the width corresponds to Printed circuit board b with an elliptical cross section preferably of the large semiaxis of the ellipse, so that when the printed circuit board 12 is clamped by means of the walls of the glass bulb 20, the maximum width of the glass bulb 20 can be used.

Using the measured illuminance levels 71, 72 (in lux) and radiation characteristics 711, 722 (also called: light intensity distribution curves) of the Figures 11A and 11B and 12A and 12C are exemplary embodiments of an LED lighting means 1 described here explained in more detail. The measurements are each with an LED lamp 1, which is the Figures 1A to 1C has been carried out. The Figures 11A and 12A show measurements in the case of an LED illuminant 1 with a regular glass bulb 20, while the glass bulb 20 of the LED illuminant 1 is used for the measurements Figures 11B and 12B was matted with a sandblast.

The Figures 11A and 11B each show a first illuminance 71, which was measured in the plane spanned by the lateral directions of the circuit board 12 (i.e. in a plan view of the light-emitting diode chips 11), and a second illuminance 72, which was measured in a vertical direction and that along the length of the Circuit board 12 extending lateral direction of the circuit board 12 spanned plane (that is, in a side view) was measured. The measurement takes place as a function of the respective angle α to the vertical on the plane. The Figures 12A and 12B show a first emission characteristic 711 which was measured in the measuring plane of the first illuminance 71 and a second emission characteristic 722 which was measured in the measuring plane of the second illuminance 72.

The matting reduces the overall illuminance 71, 72 (a total of 211 lumens for the Figures 11A and 12A and 191 lumens for that Figures 11B and 12B , each measured at a power of 1.9 watts). However, the radiation characteristics are clearly homogenized and improved. The left maximum of the first illuminance 71 is in FIG Figure 11A at about 250 lux and the right maximum of the first illuminance 71 at about 53 lux, that is only about 20% of the value of the left maximum. The second illuminance 72 is in FIG Figure 11A on average significantly lower than the first illuminance 71 (maximum about 51 lux). In the Figure 11B the left maximum of the first illuminance 71 is approximately 215 lux and the right maximum is approximately 73 lux, that is approximately 30% of the value of the left maximum. The second illuminance 72 is compared to Figure 11A significantly increased (maximum at around 83 lux).

This homogenization of the light intensity distribution is also in the Figures 12A and 12B clearly. In particular, more light is emitted in the 0 ° plane and the Lambertian radiation characteristic of the light-emitting diode chips 11 is widened. In the Figure 12A It can be clearly seen that the light-emitting diode chips 11 are only attached to the front side of the circuit board 12 (higher radiation in the left-hand area), while the radiation in the Figure 12B less unilateral.

The description based on the exemplary embodiments is not restricted to the invention. The invention is defined by the claims.

List of reference symbols

1

LED bulbs

11

LED chip

12

Circuit board

122

Potting body

100

Light module

20th

Glass bulb

21st

bulge

22nd

indentation

23

score

30th

Smoothing capacitor

31

transistor

32

Rectifier circuit

321

diode

33

Voltage source

41

Contact pin

42

Connection area

43

electrical connection

431

first connection area

432

second connection area

44

Contact point

441

Riveting

444

Metal clamp

445

opening

446

Contact area

447

Connection point

23

score

60

Enclosure

61

Mounting wires

62

base

71

first illuminance

72

second illuminance

711

first radiation characteristic

722

second radiation characteristic

d

PCB thickness

r

largest inner diameter of the glass bulb

Claims (14)

1. LED lamp comprising an enclosure (60) and an LED lighting means (1) arranged within the enclosure (60), having a glass bulb (20), a lighting module (100) with at least one light-emitting diode chip (11), which is mounted to a printed circuit board (12) as a chip on board assembly, and driver electronics of the lighting module (100), the lighting module (100) and the driver electronics being accommodated in the glass bulb (20)
   characterized in that
   the glass bulb (20) has an indentation (22) which projects into the interior of the glass bulb (20) and is in thermal contact with the printed circuit board (12).
2. LED lamp according to the preceding claim, wherein at least a part of the driver electronics, in particular the entire driver electronics, is mounted to the printed circuit board (12) as a chip on board assembly.
3. LED lamp according to one of the preceding claims, wherein the drive electronics comprise a smoothing capacitor (30) which is connected in parallel with the at least one light emitting diode chip (11).
4. LED lamp according to one of the preceding claims, wherein a thickness (d) of the printed circuit board (12) is at most 400 µm.
5. LED lamp according to one of the preceding claims, wherein the printed circuit board (12) is designed to be transparent and/or wherein an interior of the glass bulb (20) is filled with a heat conducting gas and/or wherein the glass bulb (20) is formed with frosted glass and/or is designed to be frosted.
6. LED lamp according to one of the preceding claims, wherein the printed circuit board (12) and/or the smoothing capacitor (30) is/are thermally connected to the glass bulb (20) and/or wherein the printed circuit board (12) and/or the smoothing capacitor (30) is/are at least partially embedded in a mechanically flexible encapsulation body (122).
7. LED lamp according to the preceding claim, wherein the indentation (22) is in thermal contact with the printed circuit board (12) and the smoothing capacitor (30).
8. LED lamp according to one of the preceding claims, wherein the glass bulb (20) has two opposing indentations (22) and the printed circuit board (12) is clamped between the two indentations (22).
9. LED lamp according to one of the preceding claims, wherein the glass bulb (20) has a notch (23) projecting into the interior of the glass bulb (20), which extends along an axis of symmetry of the glass bulb (20) and is adapted to center the lighting module (100) within the glass bulb (20).
10. LED lamp according to one of the preceding claims, wherein the printed circuit board (12) has a width (b) which substantially corresponds to a largest inner diameter (r) of the glass bulb (20).
11. LED lamp according to one of the preceding claims, wherein the glass bulb (20) has a bulge (21) formed convexly with respect to the interior of the glass bulb (20) and wherein the printed circuit board (12) and/or the smoothing capacitor (30) are at least partially accommodated in the bulge (21).
12. LED lamp according to one of the preceding claims, wherein a contact point (44) is provided on the printed circuit board (12), which is contacted by means of an electrical connection (43), wherein the contact point (44) is preferably formed by a high-temperature material, particularly preferably by uncoated molybdenum, niobium, tantalum and/or stainless steel or by molybdenum, niobium, tantalum and/or stainless steel coated with nickel, platinum, ruthenium, silver, tin, zinc, copper.
13. LED lamp according to claim 12, wherein the electrical connection (43) is formed by a metal terminal (444), wherein the metal terminal (444) has an opening (445) in which the printed circuit board (12) is clamped, wherein a contact area (446) of the metal terminal (444) is brought into direct contact with the contact point (44) of the printed circuit board (12).
14. The LED lamp according to claim 13, wherein the metal terminal (444) is formed by two wire paths welded together at a junction point (447).

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