Patent Application
20150300574
Various embodiments relate to a lighting module printed circuit board including at least one electrical contact, which lighting module printed circuit board is therefore provided and configured for use with a lighting module. Various embodiments further relate to a lighting module including at least one such lighting module printed circuit board.
Light-emitting diode (LED) modules have been produced in different constructions heretofore. This makes it considerably more difficult in practice to implement concepts involving identical parts for such LED modules. The geometrical form factors of the LED modules are predefined by circuit boards populated on one side. LED modules including a plurality of printed circuit boards are generally connected by cable connections.
Various embodiments provide lighting modules having improved suitability for concepts involving identical parts.
Various embodiments provide a printed circuit board (of a lighting module, designated hereinafter as “lighting module printed circuit board”) including at least one electrical contact, wherein the at least one electrical contact includes at least one spring contact.
As a result, a simple electrical contact-connection that manages without further soldering methods, etc. is provided. Consequently, in particular, a reduction of thermal processes required for assembly is made possible. Moreover, a particular compact design is made possible in this way. In addition, the spring contacts simplify a use of concepts involving identical parts.
The spring contact may be an elastic, electrically conductive spring element, e.g. a leaf spring, which enables a simple configuration.
The spring contact may be, in particular, a spring contact pin. A spring contact pin may have, in particular, two parts elastically displaceable relative to one another, in particular a sleeve with a pin mounted elastically displaceably therein.
In addition to the at least one spring contact, the lighting module printed circuit board may also have other electrical contacts, e.g. bonding pads and/or feedthroughs or drilled holes.
In one configuration, the at least one spring contact has been applied to the printed circuit board in a reflow soldering method. This affords the advantage that the spring contacts do not have to be applied in a separate method, if at least one further component (or element or unit) applied to the lighting module printed circuit board is likewise applied by means of a reflow soldering method. Such components are often used, e.g. surface-mounted components (SMD components).
In another configuration, provision is made of at least two spring contacts for connecting an operating voltage to the lighting module printed circuit board. The operating voltage may include, for example, a low voltage or a power supply system voltage. The operating voltage may be, in particular, between 10 and 250 volts.
The lighting module printed circuit board can furthermore carry electronic components, such as, for example, capacitors, diodes, integrated circuits or semiconductor lighting elements, in particular light-emitting diodes.
Various embodiments also provide a lighting module including at least one printed circuit board, wherein at least one printed circuit board is a lighting module printed circuit board as described above. This lighting module enables the same advantages as the lighting module printed circuit board and can be embodied analogously.
A lighting module can be understood to mean, in particular, a light-emitting unit or module which is not provided for independent lighting, but rather is typically provided for incorporation into a superordinate lighting unit, e.g. into a luminaire or a lighting system. In this regard, the lighting means typically does not have a dedicated power supply system connecting plug or the like. On the other hand, the lighting module is typically also not provided as a simple consumable article like a lamp or a lighting means.
In one configuration, the lighting module includes a housing having an open rear side, the lighting module printed circuit board is accommodated in the housing, the open rear side is closed with a closure element having at least one plated-through hole, and at least one spring contact of the lighting module printed circuit board makes contact with at least one plated-through hole of the closure element.
The contact-connection of the termination plate by means of the spring contacts makes it possible to provide a simple, reliable and diverse electrical contact-connection which supports contacts involving identical parts. This configuration enables the advantage, inter alia, that the lighting module can be closed in a sealing fashion in the housing and, in particular, can also fulfill various protection classes, e.g. protection classes of type I, II or III. As a result, the lighting module printed circuit board is also protected against contact from touching, etc.
In one development, the housing is electrically conductive, e.g. consists of metal. As a result, in particular, a protective conductor may be connected to the housing. In addition, a good thermal conductivity and hence heat dissipation are thus also provided.
In one development, the closure element has the same number of plated-through holes as the number of spring elements present on the lighting module printed circuit board. In this regard, a lighting module with a comparatively low material outlay is provided.
In another development, the closure element has a higher number of plated-through holes than the number of spring elements present on the lighting module printed circuit board. In this regard, a use of a standardized closure element with in each case different lighting module printed circuit boards is simplified.
In one development, moreover, the closure element has a smaller number of plated-through holes than the number of spring elements present on the lighting module printed circuit board. This enables a use of a plated-through hole for energizing a plurality of spring contacts and thus a simplified construction, in particular wiring of the lighting module printed circuit board.
In a further configuration, at least one plated-through hole of the closure element is configured in a rotationally symmetrical fashion. This enables contact to be made with the lighting module rotationally independently in a lighting device that accommodates the lighting module, e.g. a luminaire, a lighting system, etc. Moreover, the closure element may thus be screwed into the housing in a simple manner. For this purpose, the axis of symmetry of the rotationally symmetrical plated-through hole expediently coincides with the rotational axis of the closure element.
In yet another configuration, at least one plated-through hole is configured in a ring-shaped fashion.
Ring-shaped and/or rotationally symmetrical plated-through hole should in this sense also be understood to mean plated-through holes having respectively ring-shaped and/or rotationally symmetrical contact areas on one or both sides of the closure element, wherein the form of the connection between the contact areas can be fashioned arbitrarily. In other words, by way of example, a rotationally symmetrical contact track can be connected to a further rotationally symmetrical contact track on the opposite side by means of a pin-type intermediate element.
In particular, a plated-through hole may be present in the form of a connection point arranged concentrically with respect to the at least one ring-shaped plated-through hole. This simplifies a contact-connection that is more reliable in terms of avoiding incorrect contact, for example.
Moreover, in one development, the housing has a hollow-cylindrical basic shape, which simplifies a rotationally independent incorporation. By way of example, this also makes it possible to provide an outer thread on the outer lateral surface of the housing for the incorporation of the lighting module. In one development thereof, the lighting module printed circuit board and/or the closure element have/has a circular-disk-shaped basic shape.
Furthermore, in one configuration, a contact area of the at least one spring contact and/or a contact area of the at least one plated-through hole have/has a surface layer having a high abrasion resistance. The surface layer can be in particular thick gold or an Ni/Au mixture, in particular alloy. A mechanically particularly robust and failsafe contact-connection is provided as a result.
In addition, in one configuration, the closure element is a printed circuit board, in particular of the FR or CEM type. This type of printed circuit board enables a particularly simple and inexpensive possibility of integration of plating processes.
In one development thereof, one base material of the printed circuit board includes CEM-1 to CEM-5, in particular CEM-3. Alternatively or additionally, one base material of the printed circuit board may include FR-2 to FR-5, in particular FR-4.
Moreover, in one configuration, the lighting module includes at least one light source substrate with at least one light source fitted thereon, said at least one light source substrate being electrically connected to the lighting module printed circuit board, and the lighting module printed circuit board includes at least one electrical and/or electronic component or unit for operating the at least one light source, e.g. an integrated circuit, resistor, capacitor, etc. This enables a particularly high occupation density of light sources on the light source substrate and a protected accommodation of the driver required for operating the light sources. The lighting module printed circuit board can in particular in this case also be designated as a “driver circuit board” or the like, but generally also as a functional substrate or the like.
In one development thereof, the light sources are arranged on the light source substrate and the driver (or its electrical and electronic components) is (are) arranged exclusively on the lighting module printed circuit board.
Furthermore, in one development, the at least one light source includes at least one semiconductor light source. Preferably, the at least one semiconductor light source includes at least one light-emitting diode. In the event of a plurality of light-emitting diodes being present, they can emit light in the same color or in different colors. A color can be monochromatic (e.g. red, green, blue, etc.) or multichromatic (e.g. white). Moreover, the light emitted by the at least one light-emitting diode can be an infrared light (IR LED) or an ultraviolet light (UV LED). A plurality of light-emitting diodes can generate a mixed light; e.g. a white mixed light. The at least one light-emitting diode can contain at least one wavelength-converting phosphor, (conversion LED). Alternatively or additionally, the phosphor can be arranged in a manner remote from the light-emitting diode (“remote phosphor”). The at least one light-emitting diode can be present in the form of at least one individually housed light-emitting diode or in the form of at least one LED chip. A plurality of LED chips can be mounted on a common substrate (“submount”). The at least one light-emitting diode can be equipped with at least one dedicated and/or common optical unit for beam guiding, e.g. at least one Fresnel-Lens, collimator, and so on. Instead of or in addition to inorganic light-emitting diodes, e.g. on the basis of InGaN or AlInGaP, organic LEDs (OLEDs, e.g. polymer OLEDs) can generally also be used. Alternatively, the at least one semiconductor light source may include e.g. at least one diode laser.
In one development thereof, moreover, the substrate is a ceramic substrate, in particular composed of an electrically insulating ceramic such as AlN. Ceramics have the advantage of a typically very good thermal conductivity of, for example, more than 50 W/(m·K), thus AlN of approximately 180 W/(m·K).
In an alternative development thereof, the substrate is a printed circuit board or circuit board, e.g. a metal-core circuit board.
Furthermore, in one development thereof, the light source substrate is electrically connected to the lighting module printed circuit board by means of at least one electrically conductive contact pin, e.g. composed of copper. The at least one contact pin can be inserted for example into a respective, in particular narrow, feedthrough through the lighting module printed circuit board, in particular can be led through it. The contact pin may preferably be electromechanically connected to the lighting module printed circuit board, e.g. by soldering or a respective solder location.
In one configuration, the light source substrate is arranged outside the housing. This enables a high luminous efficiency without any influencing by the housing. Moreover, this enables an effective dissipation of heat from the light sources by heat convection. A cover can be provided for example for one or a plurality of lighting modules jointly by the luminaire, etc. When a contact pin is used for electrically connecting the light source substrate to the lighting module printed circuit board, the housing has a corresponding feedthrough. For the purpose of simple contact-connection it is preferred for an end face of the contact pin that is led through the housing toward the outside to serve as an electrical contact area. The contact area can serve for example as a contact area for a bonding wire connected to the light source substrate at the other end.
The bonding wire can consist e.g. of gold, silver, copper and/or aluminum. In order to produce or improve its bondability, the contact area may be coated with a material layer suitable for this purpose, e.g. Ni/Au for bonding wires composed of aluminum or Ni/Pd/Au for bonding wires composed of gold.
In particular for the case where the light source substrate is arranged outside the housing, the contact pin can be surrounded by an electrically insulating enclosure, in order to prevent an electrical connection to the housing.
In one development, moreover, the housing has at least one fixing device for (optionally) fixing at least one optical unit disposed downstream of the at least one light source. The at least one optical unit may include, for example, at least one light-transmissive (transparent or diffuse) cover, reflector, lens, collimator, etc. In one development thereof, the fixing device has a groove arranged on an outer side of the housing and extending circumferentially at least in sectors (in particular completely). The groove may be arranged, in particular, in a manner laterally surrounding the at least one light source substrate, in order to enable the at least one light source to be covered in a structurally simple manner.
In an alternative configuration thereof, the light source substrate is arranged within the housing. This enables the light source substrate and thus the light sources also to be accommodated in a leaktight manner.
For the emission of light generated by the at least one light source, the housing can then have, for example, a light-transmissive cover, arranged in particular on the front side.
In one configuration, moreover, the closure element is embodied in a plate-shaped fashion and has at its lateral edge cutouts into which projections arranged on an inner wall of the housing engage. A latching fixing of the closure element on the housing is made possible as a result. The latching fixing may be realizable in particular without a tool and by simple pressing of the closure element into the housing. The projections may have a triangular shape or a sawtooth shape, for example, in cross section. The recess and the projection are embodied in particular in a manner extending circumferentially, the recess e.g. in the form of a ring groove.
In another configuration, the lighting module printed circuit board is potted in the housing. This affords the advantage that it can be fixed particularly firmly in the housing. Furthermore, an effective electrical insulation of the current-carrying regions situated on the lighting module printed circuit board with respect to the housing can thus be ensured (if the potting material is electrically insulating, e.g. consists of silicone). Given the presence of contact pins for electrical connection between the lighting module printed circuit board and the light source substrate, they can likewise concomitantly be potted, which also reinforces their electrical insulation and mechanical fixing.
In one development, the housing is completely filled with the potting compound. In particular, in an alternative configuration, the housing is only partly filled with the potting compound and, in particular, leaves free a movable part of the at least one spring contact, that is to say forms a clearance therefor. This affords the advantage that an attachment, an adaptation and/or an exchange of the covering element is possible without any problems even with the potting having been introduced. In one development, the potting compound provides a clearance with regard to the closure element, that is to say that the latter is not potted.
For large-area distribution of the associated potting compound, the lighting module printed circuit board may have at least one channel, preferably a plurality of channels, e.g. potting/ventilation holes. For the case where the potting is intended to be carried out with the closure element already having been attached, it is preferred for the closure element to have at least one channel, preferably a plurality of channels, e.g. potting/ventilation holes.
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:
The following detailed description refers to the accompanying drawing that show, by way of illustration, specific details and embodiments in which the disclosure may be practiced.
The lighting module 11 includes a metallic housing 12 having a hollow-cylinder-like basic shape, having a basically closed front side 13 and an open rear side 14. A circular-disk-shaped lighting module printed circuit board 15 including CEM-3 or FR-4 as the base material thereof is accommodated in the housing 12. For simple and correct positioning of the lighting module printed circuit board 15, the latter bears by an outer edge of its front side on an internal projection 16 or taper of the housing 12.
The lighting module printed circuit board 15 is electrically connected to a light source substrate 18 by means of two vertical, electrically conductive contact pins 17. The light source substrate 18 is arranged outside the housing 12; to be precise, it bears by its rear side in a planar manner on the front side 13 of the housing 12, here by means of a thermally conductive adhesive 40. A free front side 19 of the light source substrate 18 is equipped with a plurality of light sources in the form of light-emitting diodes 20, which e.g. emit white light, as also shown in
The contact pins 17 lead, on the one hand, through respective narrow feedthroughs 21 through the lighting module printed circuit board 15 and are electrically and mechanically interconnected with the latter on the rear side at a soldering location 41. On the other hand, the contact pins 17 project through corresponding feedthroughs 22 of the housing 12 and of the light source substrate 18. In order to prevent an electrical connection between the housing 12 and the respective contact pin 17, a portion of the contact pins 17 that is on the front side relative to the lighting module printed circuit board 15 is laterally surrounded by an electrically insulating enclosure 23, e.g. composed of plastic. An end face 24 of the contact pin 17 that is led toward the outside through the housing 12 serves as an electrical contact area for a respective bonding wire 25. The respective bonding wire 25 is in turn connected to the light source substrate 18, e.g. by means of a so-called bonding pad 42 thereof. The bonding pad or the bonding pads 42 is/are connected to the light-emitting diodes 20 by means of wirings (not shown). Instead of a bonding pad 42, e.g. a soldering contact area or “solder pad” can also be used. The end face 24 of the contact pin 17 may include a particularly readily bondable or solderable layer (not illustrated).
The lighting module printed circuit board 15 has a plurality of electrical and/or electronic components 26 which form a driver for operating the light-emitting diodes 20. The lighting module printed circuit board 15 therefore serves as a driver circuit board. An operating signal generated by means of the components 26 is applied to the light-emitting diodes 20 via the contact pins 17. The components 26 are at least in part SMD components, which facilitates their simple application, in particular by means of a reflow soldering method.
A fixing device for fixing at least one optical unit (not illustrated) disposed downstream of the light-emitting diodes 20 jointly is furthermore situated at the front side 13 of the housing 12. The fixing device is embodied in the form of a radially laterally aligned groove 27 which extends circumferentially around the light source substrate 18 or the light-emitting diodes 20 and which can have e.g. perforations for fixing by means of a plugging/turning connection or bayonet connection.
An outer thread 28 for the incorporation of the lighting module 11 is situated on the external or outer lateral surface of the housing 12.
The open rear side 14 of the housing 12 is closed with a circular-disk-shaped closure element in the form of a further printed circuit board, the closure printed circuit board 29, as shown in plan view in
The plated-through holes 30, 31 have contact areas 30o and 30u and, respectively, 31o and 31u, widened at the top side (directed into the housing 12) and at the underside (outer side), which facilitates their contact-connection, soldering, etc.
The plated-through holes 30, 31 or the contact areas 30o, 31o thereof on the top side are connected to the lighting module printed circuit board 15 via two spring contact pins 32, 33. Consequently, the driver formed by means of the components 26 can be supplied or fed, e.g. with a power supply system voltage, via the plated-through holes 30, 31 and furthermore the spring contact pins 32, 33. The spring contact pins 32, 33 have been fitted to the underside of the lighting module printed circuit board 15 by reflow soldering and produce a pressure contact at the plated-through holes 30 and 31, respectively. An abrasion-resistant surface layer in the form e.g. of an Ni/Au alloy is situated on the contact areas 30o, 30u, 31o, 31u of the plated-through holes 30, 31.
For fixing to the housing 12, the closure printed circuit board 29 has at its side edge sawtooth-shaped recesses 36 into which conformal projections 37 arranged on an inner wall of the housing 12 engage in a latching manner.
In particular also for electrical insulation from the housing 12, the lighting module printed circuit board 15 is potted in the housing 12, e.g. with silicone as potting compound 38. The contact pin 17 and their enclosures 23 are concomitantly potted.
However, the spring contact pins 32, 33 or their displaceably mounted pins 34 are not potted, with the result that they remain mobile. This is achieved by means of a corresponding clearance 35.
For large-area distribution of the associated potting compound 38, both the lighting module printed circuit board 15 and the closure printed circuit board 29 have a plurality of continuous channels in the form of potting/ventilation holes 39, wherein the potting/ventilation holes 39 of the closure printed circuit board 29 are tightly closed.
The contact pin 52 has, at its (lower) end fixed to the lighting module printed circuit board 15, a cold-deformable end region 53, which is inserted into the narrow feedthrough 21 and may protrude slightly downward. For electrical contact-connection and mechanically stable mounting, a metallic or metalized sleeve 54 is inserted into the feedthrough.
The end region 53 is firstly inserted into the sleeve 54 and then widened by cold caulking in such a way that it is fixed in a force-locking manner or in a frictionally locking manner in a press-fit in the sleeve 54. The sleeve 54 serves as electrical contact of the lighting module printed circuit board 15, such that soldering or some other connection method with thermal loading can be dispensed with.
The insulating enclosure 23 is present only on a portion of the contact pin 52 above the end region 53.
It goes without saying that the present disclosure is not restricted to the embodiment shown.
In this regard, the cold-caulkable contact pins may additionally or alternatively be cold-caulkable or cold-caulked to the light source substrate 18.
Moreover, by way of example, an end section at the top side of the contact pin, which runs in the light source substrate, may have no insulating enclosure.
In addition, a plurality of lighting module printed circuit boards may be accommodated in the housing, which are spaced apart from one another, in particular, and are aligned parallel to one another, in particular. The lighting module printed circuit boards can be electrically interconnected preferably by means of contact pins.
Generally, the occupation of the printed circuit board(s)/substrate(s) is not restricted to light sources or driver components.
Generally, the printed circuit board(s)/substrate(s) can be designated as functional substrates, e.g. the light source substrate as one possible embodiment of a first functional substrate and the lighting module printed circuit board as one possible embodiment of a second functional substrate.
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 2012 202 353.4 | Feb 2012 | DE | national |
The present application is a national stage entry according to 35 U.S.C. §371 of PCT application No.: PCT/EP2013/053002 filed on Feb. 14, 2013, which claims priority from German application No.: 10 2012 202 353.4 filed on Feb. 16, 2012, and is incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2013/053002 | 2/14/2013 | WO | 00 |
