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Researchers Submit Patent Application, "High-Voltage Led Multichip Module and Method for Adjusting an Led Multichip Module", for Approval

June 4, 2014



By a News Reporter-Staff News Editor at Electronics Newsweekly -- From Washington, D.C., VerticalNews journalists report that a patent application by the inventors Baumann, Frank (Regensburg, DE); Biebel, Ulrich (Rennertshofen, DE); Biebersdorf, Andreas (Regensburg, DE); Maiwald, Hubert (Neutraubling, DE); Schoell, Hansjoerg (Bad Abbach, DE); Kaltenbacher, Axel (Mintraching, DE), filed on June 26, 2012, was made available online on May 22, 2014.

The patent's assignee is OSRAM GmbH.

News editors obtained the following quote from the background information supplied by the inventors: "Light-emitting means in which light-emitting diodes (LEDs) are used can contain individual LED chips or else a plurality of LED chips connected to one another to form a module. US 2010/0006868 A1 describes an LED component which has series and parallel circuits of LEDs for operation on different predetermined AC voltages.

"In order to match the mains voltage to the operating voltage of an LED multichip module, driver circuits are generally used which can have a particularly simple, compact, efficient and inexpensive design when the required operating voltage is relatively high. A high operating voltage of typically 280 V, for example, is made possible by a series circuit of LEDs. In this case, there is the problem of the actual operating voltage fluctuating as a result of the manufacturing tolerances of the LED. Therefore, the aim is to find possible ways of keeping the operating voltages of the LED multichip modules in a predetermined narrow tolerance range."

As a supplement to the background information on this patent application, VerticalNews correspondents also obtained the inventors' summary information for this patent application: "Various embodiments specify how a property of an LED multichip module, in particular the operating voltage thereof, can be adjusted to a preset value in a reliable and inexpensive manner.

"The LED multichip module has a plurality of LED chips, which have electrical terminals and are connected in series via electrical connections. At least one short-circuiting connection is provided, which connects two of the terminals or connections electrically conductively to one another and bypasses at least one of the LED chips or a resistor, with the result that the operating voltage is in the range of between 150 V and 350 V.

"In one embodiment of the LED multichip module, the operating voltage is in the range of between 270 V and 300 V.

"In a further embodiment of the LED multichip module, the operating voltage is in the range of between 250 V and 290 V.

"In a further embodiment of the LED multichip module, the short-circuiting connection is effected by a bonding wire.

"In a further embodiment of the LED multichip module, the short-circuiting connection is effected by a conductor track of a structured metal plane.

"In a further embodiment of the LED multichip module, an electrical resistor is connected into one of the connections and/or into the at least one short-circuiting connection, and the resistor is dimensioned such that it increases the operating voltage by a value in the range of between 0.1 V and 3 V, in particular in the range of between 1 V and 3 V.

"In a method for adjusting an LED multichip module, LED chips which have electrical terminals are connected in series via electrical connections, and at least one short-circuiting connection is produced between the terminals or connections.

"In another method for adjusting an LED multichip module, LED chips which have electrical terminals are connected in series via electrical connections. Various short-circuiting connections are produced between the terminals or connections. At least one of the short-circuiting connections is interrupted retrospectively.

"In embodiments of the method, the operating voltage is adjusted within the range of between 150 V and 350 V, and in further embodiments said operating voltage is adjusted within the range of between 270 V and 300 V or within the range of between 250 V and 290 V.

"In further embodiments of the method, at least one optical property of the LED multichip module is adjusted. The optical property can be, for example, the brightness of the radiation emitted during operation of the LED multichip module, the color of said radiation, the color rendering index (CRI) thereof or the emission characteristic thereof. In order to enable the adjustment, the LED multichip module can in particular be constructed of LED chips with different optical properties.

"In further embodiments of the method, an electrical resistor is provided which is bypassed by the at least one short-circuiting connection or by a further short-circuiting connection. The resistor is connected between two of the terminals or connections by virtue of the short-circuiting connection bypassing the resistor being interrupted. The operating voltage is increased by the resistor by a value in the range of between 0.1 V and 3 V, in particular in the range of between 1 V and 3 V.

"In further embodiments of the method, one of the LED chips is provided with further electrical connections, with the result that the terminals of further LED chips which are connected to one of the terminals of this LED chip are also connected to the respective other terminal of this LED chip. Two of the further electrical connections are interrupted, with the result that each terminal is now only connected to in each case one other terminal. With this configuration of the method, it is possible in particular to match parallel-connected series circuits of LEDs to one another: a last LED in the arrangement is connected to one of the series circuits depending on the selection of the interrupted further electrical connections, with the result that the relevant series circuit is thus extended.

BRIEF DESCRIPTION OF THE DRAWINGS

"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:

"FIG. 1 shows a schematic of an arrangement of LED chips which are connected via bonding wires and are provided with short-circuiting connections;

"FIG. 2 shows the arrangement shown in FIG. 1 after the interruption of a short-circuiting connection;

"FIG. 3 shows a schematic of an arrangement of LED chips which are connected via conductor tracks and are provided with short-circuiting connections;

"FIG. 4 shows the arrangement shown in FIG. 3 after the interruption of a short-circuiting connection;

"FIG. 5 shows a schematic of an arrangement of LED chips which are connected via conductor tracks and are provided with bypassed resistors;

"FIG. 6 shows the arrangement shown in FIG. 5 after the interruption of bypasses;

"FIG. 7 shows a schematic of an arrangement of LED chips which are connected via conductor tracks and are provided with further electrical connections for implementing different circuit arrangements;

"FIG. 8 shows the arrangement shown in FIG. 7 for an example of a circuit arrangement;

"FIG. 9 shows the arrangement shown in FIG. 7 for a further example of a circuit arrangement;

"FIG. 10 shows a schematic of an LED multichip module in a plan view;

"FIG. 11 shows an LED driver circuit including a current controller; and

"FIG. 12 shows an LED driver circuit as shown in FIG. 11 with an input capacitor."

For additional information on this patent application, see: Baumann, Frank; Biebel, Ulrich; Biebersdorf, Andreas; Maiwald, Hubert; Schoell, Hansjoerg; Kaltenbacher, Axel. High-Voltage Led Multichip Module and Method for Adjusting an Led Multichip Module. Filed June 26, 2012 and posted May 22, 2014. Patent URL: http://appft.uspto.gov/netacgi/nph-Parser?Sect1=PTO2&Sect2=HITOFF&u=%2Fnetahtml%2FPTO%2Fsearch-adv.html&r=5141&p=103&f=G&l=50&d=PG01&S1=20140515.PD.&OS=PD/20140515&RS=PD/20140515

Keywords for this news article include: OSRAM GmbH, Electronics, High Voltage.

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Source: Electronics Newsweekly


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