Patent Application
20180182739
The present disclosure relates to a light-emitting diode arrangement and a method for producing a light-emitting diode arrangement.
In a conventional light-emitting diode arrangement, multiple LEDs are arranged on a substrate and electrically connected to electrical lines, which are formed on the substrate. The LEDs can be electrically connected in parallel and/or electrically connected in series. For example, the LEDs of one group of LEDs can be electrically connected in series, the LEDs of another group of LEDs can be electrically connected in series, and the two groups can be electrically connected in parallel. The LEDs can be designed as structurally equivalent or different. For example, one group of LEDs may include surface-emitting light-emitting diodes, which typically include an electrical contact on the upper side thereof and an electrical contact on the lower side thereof, and another group of LEDs may include volume-emitting light-emitting diodes, which typically include both electrical contacts on the upper side thereof. Furthermore, one group of LEDs may include blue-light-emitting light-emitting diodes and another group of LEDs may include red-light-emitting light-emitting diodes. The LEDs can be formed on a substrate, for example, which has a ceramic base body, on which the electrical lines for electrically contacting the LEDs are formed.
One object of the present disclosure is to provide a light-emitting diode arrangement, which is producible simply and/or cost-effectively, which is particularly efficient, which has a particularly long service life, and/or which is particularly compact.
One object of the present disclosure is to provide a method for producing a light-emitting diode arrangement, which can be carried out simply and/or cost-effectively and/or which contributes to the light-emitting diode arrangement being particularly efficient, having a particularly long service life, and/or being particularly compact.
One object is achieved according to one aspect of the present disclosure by a light-emitting diode arrangement, including a substrate; first LEDs, which are arranged on the substrate; second LEDs, which are arranged on the substrate laterally adjacent to the first LEDs; at least one cover body, which covers the first LEDs; at least one dam, which is arranged on the substrate and which encloses the first LEDs and the second LEDs in the lateral direction; and a first potting material, which covers the second LEDs and which is delimited in the lateral direction by the dam and the cover body, wherein the cover body and/or the first potting material include(s) a first converter material for converting electromagnetic radiation.
The cover body, which is arranged above, in particular on, the first LEDs, protects the first LEDs from external force effects, for example, from impacts and/or scratches, and can be used during the production of the light-emitting diode arrangement to prevent the first potting material from flowing over the first LEDs. The cover body and the dam therefore form lateral delimitations of a cavity, into which the first potting material is decanted during the production of the light-emitting diode arrangement and in which the first potting material is subsequently arranged. The cover body therefore has the double function that it protects the first LEDs, on the one hand, and is used as the lateral delimitations for the first potting material, on the other hand. One, two, three, or more cover bodies can be arranged, which each cover and protect a plurality of the first LEDs. The cover body or bodies may include, for example, a plastic and/or silicone or can be formed thereof. The light-emitting diode arrangement is color adjustable and/or CCT tunable.
The electromagnetic radiation is emitted by the first LEDs and/or the second LEDs. At least a part of the electromagnetic radiation is converted by means of the converter material. In particular, the converter material absorbs a part of the electromagnetic radiation, which has a specific wavelength or is in a specific wavelength range, and emits electromagnetic radiation, which has another wavelength or is in another wavelength range. The electromagnetic radiation can be, for example, light in the visible wavelength range. For example, the electromagnetic radiation can be red, green, or blue light. The converted electromagnetic radiation can be red or white light, for example.
A vertical height of the cover body and/or a vertical height of the dam can each be greater measured from a surface of the substrate than a thickness of the layer which is formed by the first potting material. The first LEDs can be arranged along a line, for example. In addition, two or more such lines of first LEDs can be arranged in parallel to one another or along intersecting lines. The first LEDs within one of these lines can be electrically connected in series, for example. The second LEDs can be arranged along a line, for example. In addition, two or more such lines of second LEDs can be arranged in parallel to one another or along intersecting lines. The second LEDs within one of these lines can be electrically connected in series, for example. The lines of LEDs can be electrically connected in parallel or electrically connected in series.
In one refinement, the cover body is formed as a beamforming element for influencing a beam path of electromagnetic radiation emitted by the first LEDs, in particular as an optical lens. In other words, the cover body is used not only as a protection for the first LEDs and as a delimitation for the first potting material, but rather also for beamforming of one or more beam paths of the electromagnetic radiation which is emitted by the first LEDs. In addition, by means of the cover body as a beamforming element, an efficiency of the light-emitting diode arrangement, in particular of the first LEDs, can be increased, since a component of the electromagnetic radiation generated by the first LEDs, which leaves the light-emitting diode arrangement as usable light, can be increased in relation to a light-emitting diode arrangement without corresponding beamforming element. In particular, the beamforming element can be used for the purpose of reducing an internal total reflection of the electromagnetic radiation generated by the first LEDs, so that a particularly large component of the electromagnetic radiation can leave the light-emitting diode arrangement. This is particularly advantageous if the first LEDs emit red light, since the critical angle for the total reflection is particularly small in the case of red light.
The cover body therefore has the four functions of the protection of the first LEDs, the delimitation of the first potting material, the beamforming of the electromagnetic radiation emitted by the first LEDs, and the increase of the efficiency of the light-emitting diode arrangement. In addition to the advantages inherent to these functions, this has the additional advantage that a particularly small amount of space is required on the substrate, since individual bodies do not have to be arranged for the individual functions, but rather all of these functions are assumed by the cover body or bodies.
In one refinement, the cover body is made transparent and the first potting material includes the first converter material. The electromagnetic radiation, which is generated by the first LEDs, therefore exits from the cover body without wavelength conversion. The electromagnetic radiation generated by the second LEDs, in contrast thereto, is at least partially converted with respect to its wavelength spectrum. For example, a part of the electromagnetic radiation generated by the second LEDs can be converted and can mix with the nonconverted part of the electromagnetic radiation generated by the second LEDs. A mixed light is thus generated having a wavelength spectrum, which is composed of the wavelength spectrum of the electromagnetic radiation generated by the second LEDs and the wavelength spectrum of the converted electromagnetic radiation. The electromagnetic radiation generated by the second LEDs and/or the converted electromagnetic radiation can mix with the electromagnetic radiation emitted by the first LEDs. Electromagnetic radiation can thus in turn be generated having a wavelength spectrum composed of the individual wavelength spectra. For example, the electromagnetic radiation can be generated and the wavelength spectra can be mixed such that the light-emitting diode arrangement emits white light.
Alternatively to only the first potting material including converter material, only the cover body may include converter material and the first potting material can be transparent. Alternatively thereto, the cover body and the first potting material may include converter material. In the latter case, the cover body and the first potting material may include the same or different converter materials.
In one refinement, the first LEDs emit electromagnetic radiation in the wavelength range of red visible light, in particular red light, and the second LEDs emit electromagnetic radiation in the wavelength range of blue visible light, in particular blue light. This can contribute to generating white light by means of the light-emitting diode arrangement, wherein the blue light can be completely or partially converted for this purpose, for example, into mint-colored or yellow light.
In one refinement, the first LEDs are surface-emitting light-emitting diodes and the second LEDs are volume-emitting light-emitting diodes. For example, the first LEDs can be surface-emitting light-emitting diodes which generate red light and the second LEDs can be volume-emitting light-emitting diodes which generate blue light. This can contribute to the first LEDs, in particular the light-emitting diodes which emit red light, being easily producible.
In one refinement, the substrate includes a ceramic body, which has a highly reflective surface, on which the first LEDs and the second LEDs are arranged, and electrical lines, which are formed on the ceramic body and which are electrically coupled to the first LEDs and the second LEDs. This enables the highly reflective surface of the ceramic body to be able to be used as a receptacle surface for the first LEDs and the second LEDs.
In one refinement, the substrate includes a metal core board, on which the first LEDs are arranged, and a metal template, which is arranged on the metal core board, the surface of which facing away from the metal core board is highly reflective, and on which the second LEDs are arranged and which includes recesses, in which the first LEDs are arranged and through which the cover bodies protrude. This enables the first LEDs to be arranged on the metal core board, whereby a particularly good heat dissipation away from the first LEDs is possible, and the second LEDs to be arranged on the highly reflective surface of the metal template, whereby light decoupling from the second LEDs is particularly good. This is advantageous in particular if the first LEDs are red-light-emitting light-emitting diodes, since they are typically particularly temperature sensitive such that the efficiency thereof decreases strongly with increasing temperature, and since the efficiency of the first LEDs and therefore of the light-emitting diode arrangement can be particularly high due to the good thermal coupling via the metal core board. In addition, this is advantageous in particular if the second LEDs are volume-emitting light-emitting diodes, since the light decoupling thereof in conjunction with the highly reflective surface of the metal template is particularly good. Moreover, the first LEDs, if they are surface-emitting light-emitting diodes, can be arranged directly on the metal core board and electrically connected thereto, for example, by soldering.
A thickness of the metal template is less, for example, significantly less, than a vertical height of the cover bodies. The fact that the surface of the metal template and/or the ceramic body is highly reflective can mean, for example, that a reflectivity of the highly reflective surface is in a range, for example, of 90% to 98%, for example, 92% to 96%, for example, 94% to 95%.
In one refinement, the light-emitting diode arrangement includes third LEDs, which are arranged on the substrate laterally adjacent to the first LEDs and the second LEDs. The third LEDs can be used to generate light having a wavelength spectrum which does not correspond to the wavelength spectrum of the electromagnetic radiation generated by the first LEDs or the wavelength spectrum of the electromagnetic radiation generated by means of the second LEDs. Alternatively or additionally, the electromagnetic radiation of the third LEDs can be converted by means of a second converter material such that the wavelength spectrum of the converted electromagnetic radiation does not correspond to the wavelength spectrum of the electromagnetic radiation generated by the first LEDs or the wavelength spectrum of the electromagnetic radiation generated by the second LEDs or the wavelength spectrum of the electromagnetic radiation generated by the first converter material.
In one refinement, the third LEDs are designed as structurally equivalent to the first LEDs or the second LEDs.
In one refinement, a second potting material, which includes a second converter material for converting electromagnetic radiation, covers the third LEDs. For example, the second LEDs and the third LEDs can be designed as structurally equivalent and the first LEDs can be covered by the first potting material having the first converter material and the second LEDs can be covered by the second potting material having the second converter material. This enables light having different wavelength spectra to be generated by the second LEDs and the third LEDs, although they are structurally equivalent.
In one refinement, the light-emitting diode arrangement includes at least one intermediate dam, which is arranged on the substrate laterally between the first LEDs, the second LEDs, and/or the third LEDs and which delimits the first potting material and/or the second potting material in the lateral direction. The intermediate dam can be understood by way of illustration as a dummy cover body, which does not cover any LEDs and therefore is not used as a beamforming element, nor has a protective function, but otherwise acts like the cover body. In particular, the intermediate dam is used as a delimitation for the first potting material and/or the second potting material. Moreover, the intermediate dam can optionally correspond to the cover body with respect to its shape. A vertical height of the intermediate dam measured from the substrate can be greater than a height of the first potting material and/or the second potting material.
One object is achieved according to one aspect of the present disclosure by a method for producing a light-emitting diode arrangement. In the method, the substrate is provided; the first LEDs are arranged on the substrate; the second LEDs are arranged on the substrate laterally adjacent to the first LEDs; at least the one cover body is formed and arranged over the first LEDs so that it covers the first LEDs; at least the one dam is arranged on the substrate so that it encloses the first LEDs and the second LEDs in the lateral direction; the first potting material is poured in the liquid state between the cover body and the dam over the second LEDs so that it is delimited in the lateral direction by the dam and the cover body, wherein the cover body and/or the first potting material includes the first converter material for converting electromagnetic radiation; and the first potting material is dried and/or cured.
The cover body and the dam form the lateral delimitation for the first potting material and a cavity into which the first potting material can be decanted. The cover body and the dam cause the first potting material to remain in the liquid state at the intended location for the first potting material, in particular over the second LEDs, and not to flow unobstructed over the substrate.
In one refinement, the cover body is formed as a beamforming element for influencing the beam path of the electromagnetic radiation emitted by the first LEDs, in particular as an optical lens.
In one refinement, the first LEDs are arranged on the metal core board. The cover body is arranged over the first LEDs. The metal template, the surface of which facing away from the metal core board is highly reflective and which includes the recesses, is formed and arranged on the metal core board so that the first LEDs are arranged in the recesses and the cover body protrudes through the recesses. The second LEDs are arranged on the highly reflective surface of the metal template. The metal core board and the metal template form the substrate.
In one refinement, the third LEDs are arranged on the substrate laterally adjacent to the first LEDs and the second LEDs. The second potting material, which includes a second converter material for converting electromagnetic radiation, is poured in the liquid state over the third LEDs such that it covers the third LEDs. The second potting material is dried and/or cured.
In one refinement, the intermediate dam is formed on the substrate laterally between the first LEDs, the second LEDs, and/or the third LEDs so that it delimits the first potting material and/or the second potting material in the lateral direction.
In the drawings, like reference characters generally refer to the same parts throughout the different views. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the disclosed embodiments. In the following description, various embodiments described with reference to the following drawings, in which:
In the following comprehensive description, reference is made to the appended drawings, which form part of this description and in which specific exemplary embodiments are shown for illustration, in which the present disclosure can be performed. Since components of embodiments can be positioned in a number of various orientations, the directional terminology is used for illustration and is in no way restrictive. It is apparent that other embodiments can be used and structural or logical modifications can be performed without deviating from the scope of protection of the present disclosure. It is apparent that the features of the various embodiments described herein can be combined with one another, if not specifically indicated otherwise. The following comprehensive description is therefore not to be understood in a restrictive sense, and the scope of protection of the present disclosure is defined by the appended claims. In the figures, identical or similar elements are provided with identical reference signs, if this is expedient.
A light-emitting diode arrangement may include two, three, or more light-emitting diodes (LEDs). A light-emitting diode arrangement can optionally also include one, two, or more electronic components. An electronic component may include, for example, an active and/or a passive component. An active electronic component may include, for example, a computer, control, and/or regulating unit and/or a transistor. A passive electronic component may include, for example, a capacitor, a resistor, a diode, or a coil.
An LED is a component which emits electromagnetic radiation. The electromagnetic radiation can be, for example, light in the visible range, UV light, and/or infrared light.
The first LEDs 20 are arranged on the metal core board 14, in particular directly on the metal core board 14. The first LEDs 20 are arranged along three straight lines, wherein the straight lines are parallel to one another. Alternatively thereto, the first LEDs 20 can be arranged along more or less straight lines and/or the first LEDs 20 can be arranged along non-straight lines, for example, curved, circular, or angled lines.
The first LEDs 20 are surface-emitting light-emitting diodes. The first LEDs 20 are red-light-emitting light-emitting diodes. Moreover, the first LEDs 20 include thin-film chips. Alternatively thereto, the first LEDs 20 can be volume-emitting light-emitting diodes and/or light-emitting diodes which emit light other than red light, for example, blue light, and/or may include sapphire chips.
The second LEDs 22 are arranged on the metal template 16, in particular directly on the metal template 16. The second LEDs 22 are arranged along straight lines, wherein the straight lines are parallel to one another. Alternatively thereto, the second LEDs 22 can be arranged along more or less straight lines and/or the second LEDs 22 can be arranged along non-straight lines, for example, curved, circular, or angled lines.
The second LEDs 22 are volume-emitting light-emitting diodes. The second LEDs 22 are blue-light-emitting light-emitting diodes. Moreover, the second LEDs 22 include sapphire chips. Alternatively thereto, the second LEDs 22 can be surface-emitting light-emitting diodes and/or light-emitting diodes which emit a light other than blue light, for example, red light, and/or may include thin-film chips.
The metal core board 14 includes a metal core, for example, made of aluminum or copper, a dielectric layer applied to the metal core, and an electrically conductive layer, for example, made of copper, applied to the dielectric layer. Because of the metal core, the metal core board 14 has particularly good thermal conductivity. The electrically conductive layer is used for electrically contacting the first LEDs 20, wherein a plurality of electrical lines (not shown) can be formed by the electrically conductive layer.
The metal template 16 may include a carrier, for example, which is coated using a highly reflective layer. Optionally, the highly reflective layer can be coated using a transparent protective layer.
For example, the metal template 16 includes an aluminum carrier, which is coated using a highly reflective silver layer, which is coated for protection using a transparent dielectric material. Furthermore, the metal template 16 may include multiple conductor tracks (not shown), which can be formed on the transparent dielectric material, for example, and which can be used for electrically contacting the second LEDs 22.
The cover bodies 24 are arranged directly on the first LEDs 20 and directly on the substrate 12, in particular directly on the metal core board 14. The cover bodies 24 have a greater height, at least measured from a surface of the substrate 12 adjoining the first potting material 28, than the first potting material 28. The cover bodies 24 have the shape of an optical lens for beamforming a beam path of the electromagnetic radiation generated by the first LEDs 20 on the side thereof facing away from the first LEDs 20. The cover bodies 24 are therefore designed as beamforming elements. Alternatively thereto, the cover bodies 24 cannot have the shape of an optical lens for beamforming a beam path of the electromagnetic radiation generated by the first LEDs 20 on the side thereof facing away from the first LEDs 20, but rather can be formed as planar or flat, for example. The cover bodies 24 are made transparent or at least translucent. That is to say, the cover bodies are at least essentially transparent or include scattering elements for scattering the electromagnetic radiation generated by the first LEDs 20. The cover bodies 24 may include silicone, for example, HRI (high-refractive index) silicone, or glass, or can be formed thereof.
The dam 26 includes a plastic or is formed thereof. For example, the dam 26 includes silicone or is formed thereof. Moreover, the dam 26 may include a highly reflective material, for example, titanium dioxide. The highly reflective material can be embedded, for example, in the dam 26. The dam 26 has a height, at least measured from a surface of the substrate 12 adjoining the first potting material 28, which is greater than a height of the first potting material 28.
Optionally, the light-emitting diode arrangement 10 may include a driver circuit for operating the LEDs 20, 22. Alternatively thereto, the light-emitting diode arrangement 10 can be electrically connected to the driver circuit for operating the LEDs 20, 22.
The first potting material 28 includes a first converter material. For example, the first converter material is embedded in a carrier material of the first potting material 28. The first converter material may include converter particles 34. Alternatively, the first potting material 28 can be formed by the first converter material. The first converter material is suitable for converting electromagnetic radiation with respect to its wavelength. In particular, the first converter material converts the electromagnetic radiation generated by the second LEDs 22. For example, the second LEDs 22 emit blue light, the first converter material absorbs at least a part of the blue light and emits yellow or mint-colored light, whereby white light can be generated. Alternatively thereto, the blue light can be converted by means of first converter material into yellow light and can be converted by second converter material into bluish-white light, whereby adjustable or tunable white light can be generated.
Alternatively thereto, the cover bodies 24 may include the first converter material or a second converter material and/or the second potting material may include no converter material. The second converter material possibly differs from the first converter material. For example, the excited second converter material can emit light of a different wavelength than the first converter material and/or the second converter material can be excited by light of different wavelengths than the first converter material. Furthermore, the first converter material can be arranged laterally adjacent to one of the cover bodies 24 on a first side of the corresponding cover body 24 and the second potting material can be arranged on a second side of the corresponding cover body 24, which faces away from the first side. Thus, for example, in the exemplary embodiment shown in
While the disclosed embodiments have been particularly shown and described with reference to specific embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein without departing from the spirit and scope of the disclosed embodiments as defined by the appended claims. The scope of the disclosed embodiments is thus indicated by the appended claims and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10 2015 007 750.3 | Jun 2015 | DE | national |
The present application is a national stage entry according to 35 U.S.C. § 371 of PCT application No.: PCT/EP2016/062626 filed on Jun. 3, 2016, which claims priority from German application No. 10 2015 007 750.3 filed on Jun. 17, 2015, and is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/062626 | 6/3/2016 | WO | 00 |
