LED module, LED light fixture and method for production thereof

Abstract

A light emitting diode (LED) module is disclosed having an elongated flat support with a first long end, a second long end opposite the first long end, and electrically conductive regions. The disclosed LED module includes at least one LED mounted on the flat support as well as an electronic driver with at least one electronic driver component mounted on the flat support for driving the at least one LED. The electrically conductive regions have a first pair of contact points on one of the two long ends for connection of the LED module to a current source and a second pair of contact points on one of the two long ends for connection of a smoothing capacitor on the LED module.

Claims

1. A light emitting diode (LED) module comprising: an elongated flat support with a first long end, with a second long end opposite the first long end and with electrically conductive regions; at least one LED mounted on the flat support; and an electronic driver with at least one electronic driver component mounted on the flat support for driving the at least one LED, wherein the electrically conductive regions comprise a first pair of contact points on one of the two long ends for connection of the LED module to a current source and a second pair of contact points on one of the two long ends for connection of a smoothing capacitor to the LED module.

2. The LED module of claim 1, wherein the at least one LED is constructed as a bare LED chip.

3. The LED module of claim 1, wherein the at least one LED is provided with an encapsulation.

4. The LED module of claim 3, wherein the encapsulation has at least one fluorescent substance for conversion of the LED light with an LED light wavelength into a light with a wavelength different from the LED light wavelength.

5. The LED module of claim 1, wherein the flat support is at least somewhat light-permeable.

6. The LED module of claim 1, wherein the electronic driver comprises diodes interconnected to provide a bridge rectifier and a current regulator series-connected to the at least one LED.

7. The LED module of claim 6, wherein the bridge rectifier is electrically connected on an input side to the first pair of contact points and on an output side to the second pair of contact points.

8. The LED module of claim 1, wherein the first pair of contact points and the second pair of contact points are formed on opposing long ends of the flat support.

9. A light emitting diode (LED) light fixture having the LED module recited in claim 1.

10. The LED light fixture of claim 9, wherein the LED light fixture is designed as an LED replacement light fixture.

11. The LED module of claim 1, wherein the at least one electronic driver component mounted on the flat support comprises: a bridge rectifier; and a current regulator.

12. The LED module of claim 1, wherein the at least one electronic driver component mounted on the flat support comprises: at least one transistor; and at least one diode.

13. The LED module of claim 1, wherein the electronic driver is at least partially constructed as a bare chip.

14. The LED module of claim 1, wherein the at least one electronic driver component is mounted on the flat support in a chip-on-board (COB) configuration.

15. The LED module of claim 1, wherein: the flat support comprises at least one circuit board; and the at least one electronic driver component is populated on the at least one circuit board.

16. A method for producing a light emitting diode (LED) module, the method comprising: providing an elongate flat support with a first long end, with a second long end opposite the first long end and with electrically conductive regions, wherein the electrically conductive regions comprise a first pair of contact points on one of the two long ends for connection of the LED module to a current source and a second pair of contact points on one of the two long ends for connection of a smoothing capacitor to the LED module; mounting at least one LED on the flat support; and mounting on the flat support at least one electronic driver component for driving the at least one LED.

17. The method of claim 16, wherein the mounting of the at least one LED and the mounting of the at least one electronic driver component take place substantially simultaneously.

18. The method of claim 16, further comprising: wire bonding at least one of the at least one LED and the at least one electronic driver component; and potting of the at least one LED with an encapsulation.

19. The method of claim 18, wherein the method further comprises: providing solder contacts for connection of the first pair of contact points with contact pins for connection to a current source; and providing solder contacts for connection of a smoothing capacitor to the second pair of contact points.

20. The method of claim 19, wherein the providing of the solder contacts takes place after the potting of the at least one LED.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The present disclosure will now be explained in greater detail with reference to the appended drawings. The same references are used for the same or equivalent parts.

(2) FIG. 1 shows a schematic view from above of an LED module according to an exemplary embodiment.

(3) FIG. 2 shows a schematic view from above of an LED module according to another exemplary embodiment.

(4) FIG. 3 shows an electrical circuit diagram of an LED module according to FIG. 2.

(5) FIG. 4 shows a schematic view from above of an LED module according to another exemplary embodiment.

(6) FIG. 5 shows a schematic view from above of an LED module according to another exemplary embodiment.

(7) FIG. 6 shows an electrical circuit diagram of an LED module according to FIG. 5.

(8) FIG. 7 shows a schematic view from above of an LED module according to another exemplary embodiment.

(9) FIG. 8 shows a schematic view from above of an LED module according to another exemplary embodiment.

(10) FIG. 9 shows a schematic view from above of an LED light fixture according to an exemplary embodiment.

(11) FIG. 10 shows a schematic view from above of an LED light fixture according to another exemplary embodiment.

DETAILED DESCRIPTION

(12) FIG. 1 shows a schematic view from above of an LED module according to an exemplary embodiment. The LED module 1 has a flat substantially rectangular support 2 or substrate constructed lengthwise with a first long end 3 (at the bottom in FIG. 1), a second long end 4 opposite the first long end 3, a first lateral end 5 (on the left in FIG. 1) and a second lateral end 6 opposite the first lateral end. The support 2 also has a first main surface 7 which can be seen in the view from above in FIG. 1, a second main surface 8 opposite the first main surface 7, and a lateral surface 9. In this exemplary embodiment the support 2 is a ceramic support or a ceramic printed circuit board, wherein the first main surface 7 is constructed as a mounting surface for mounting electronic components. Furthermore, the LED module 1 has a series of LEDs 10, a transistor 11 and four diodes 12. These components are mounted on the first main surface 7 of the support 2. The first main surface 3 has metal plated structures 13, 14, 15, 16. The metal plated structures 13, 14, 15, 16 comprise a first contact point 17, a second contact point 18, a third contact point 19 and a fourth contact point 20. The contact points 17, 18, 19, 20 are regions of the metal plated structures 13, 14, 15, 16 which are free of components and are constructed for contacting with or mounting of external components. In the exemplary embodiment shown in FIG. 1 the first and the second contact points 17, 18 are constructed on the first long end 3 or on the lower edge of the support 2. The third and the fourth contact points 19, 20 are constructed on the second long end 4 or on the upper edge of the support 2.

(13) Furthermore, the LED module 1 has a number of bonding wires 21 for connection of the electrical components arranged on the support 2 to the metal plated structures 13, 14, 15, 16 or to other electronic components. The diodes 12 are connected by the bonding wires 21 or by the metal plated structures 13, 14, 15, 16 to a bridge rectifier for power supply to the LEDs 10, wherein the first metal plated structure 13 or first contact point 17 and the second metal plated structure 14 or the second contact point 18 form alternating current inputs of the bridge rectifier. The two outputs of the bridge rectifier are formed by the metal plated structures 15 and 16, so that the third and fourth contact points 19, 20 formed by the metal plated structures 15 and 16 constitute outputs of the bridge rectifier on the second long end 4 or on the upper edge of the support 2. The LEDs 10 are series-connected to the transistor 11 between the two outputs of the bridge rectifier.

(14) The LED module 1 also has an encapsulation (not shown) which covers the LEDs 10. In some exemplary embodiments the encapsulation is a silicone encapsulation which is applied flat to one or both mounting surfaces.

(15) The LED module 1 can be electrically connected by the first contact point 17 and the second contact point 18 to an alternating current source, for example, by contact pins or wires. In this case the LEDs 10 are supplied with electrical current by the driver formed by the diodes 12 and the transistor 11 and are illuminated. For smoothing the output voltage of the LED driver or of the current flowing through the LEDs 10, a smoothing capacitor can be connected between the third contact point 19 and the fourth contact point 20.

(16) FIG. 2 shows a schematic view from above of an LED module according to another exemplary embodiment. The LED module of FIG. 2 corresponds substantially to the LED module of FIG. 1 and also has a first contact 22 at the first contact point 17, a second contact 23 at the second contact point 18, a third contact 24 at the third contact point 19 and a fourth contact 25 at the fourth contact point 20. The contacts 22, 23, 24 and 25 are constructed as solder contacts. The first contact 22 and the second contact 23 are connected to a first contact pin 26 and to a second contact pin 27 for connection of the LED module 1 to an alternating current source. A smoothing capacitor 28 is connected or soldered to the third contact 24 and to the fourth contact 25. In this exemplary embodiment the smoothing capacitor 28 is an electrolytic capacitor with a positive contact, with a negative contact and with a capacitance of 1 F. In some embodiments the smoothing capacitor 28 is constructed as a ceramic capacitor. In some embodiments the smoothing capacitor has a capacitance between 1 F and 10 F. The smoothing capacitor 28 is soldered with legs to the contacts 24 and 25. Alternatively or in addition the smoothing capacitor 28 can be connected by wires or contact pins to the contacts 24, 25. In some embodiments the smoothing capacitor 28 is concealed under a tubular cover. Alternatively, or additionally, the smoothing capacitor 28 can be encapsulated with a silicone, for example, coloured silicone, in order to shield it from direct view.

(17) FIG. 3 shows an electrical circuit diagram of an LED module according to FIG. 2. In FIG. 3 the number of LEDs 10 is represented by way of example by four LEDs 10. The LEDs 10 as well as the transistor 11 are series-connected or connected to form a strand which is connected between a cathode-side or positive output and an anode-side or negative output of the diode bridge or the bridge rectifier. The smoothing capacitor 28 is an electrolytic capacitor of which the positive contact is connected to the cathode-side output of the bridge rectifier and of which the negative contact is connected to the anode-side output of the bridge rectifier. Thus, in the configuration shown, the smoothing capacitor 28 is electrically connected directly to the outputs of the bridge rectifier. This electrical connection between the smoothing capacitor 28 and the outputs of the bridge rectifier takes place through the contacts 24 and 25 or metal plated structures 15 and 16 of the LED module 1, cf. FIG. 2 at the top.

(18) During operation the smoothing capacitor 28 ensures that the output voltage of the bridge rectifier or the current flowing through the LEDs 10 is smoothed in order to suppress or to reduce the oscillation of the current flowing through the LEDs 10 which is attributable to the current or voltage oscillation of the alternating current source. The smoothing effect depends upon the capacitance of the smoothing capacitor and is more pronounced with greater capacitance of the smoothing capacitor 28.

(19) FIG. 4 shows a schematic view from above of an LED module according to another exemplary embodiment. The LED module 1 in this exemplary embodiment corresponds substantially to the LED module illustrated in FIG. 1. The LED module 1 of FIG. 4 differs from the LED module illustrated in FIG. 1 inter alia by the configuration of the metal plated structures formed on the first main surface 7. The LED module 1 of FIG. 4 has in particular a further metal plated structure 29 or a metal plated island, from which the metal plated structure 15 forming the third contact point 19 is separated by a gap 30 which is spanned by a bonding wire 21 connecting the transistor 11 to the metal plated structure 15. In the configuration shown in FIG. 4 the metal plated island or the metal plated structure 29 serves as negative output of the bridge rectifier on which the transistor 11 and two diodes 12 are arranged on the anode side. Like the LED module of FIG. 1, the LED module of FIG. 4 can be connected by contact points 17, 18, 19, 20 to an alternating current source or to a smoothing capacitor as in FIG. 2.

(20) FIG. 5 shows a schematic view from above of an LED module according to another exemplary embodiment. As in FIG. 2, the LED module of FIG. 1 has a first contact 22 at the first contact point 17, a second contact 23 at the second contact point 18, a third contact 24 at the third contact point 19 and a fourth contact 25 at the fourth contact point 20. The first contact 22 and the second contact 23 are connected to a first contact pin 26 and to a second contact pin 27 for connection of the LED module 1 to an alternating current source. A smoothing capacitor 28 is connected to the third contact 24 and to the fourth contact 25.

(21) FIG. 6 shows an electrical circuit diagram of an LED module according to FIG. 5. The circuit diagram shown in FIG. 6 corresponds substantially to the topology of the circuit diagram shown in FIG. 3 with the difference that the smoothing capacitor 28 is not parallel-connected but series-connected with respect to the transistor 11. In the configuration shown, the smoothing capacitor 28 ensures that the voltage applied to the LEDs 10 or the current flowing through the LEDs 10 remains constant.

(22) FIG. 7 shows a schematic view from above of an LED module according to another exemplary embodiment. The LED module 1 of FIG. 7 has substantially the same elements as exemplary embodiments described above, wherein the LED module 1 is already fitted with the smoothing capacitor 28 and with the contact pins 26, 27. In contrast to the first two exemplary embodiments, however, the metal plated structures 13, 14, 15, 16 are constructed in such a way that all the contact points 17, 18, 19, 20 with the contacts 22, 23, 24, 25 are arranged on the first long end 3 (at the bottom in the picture) of the LED module, wherein the connection of the electrical components corresponds to the topology shown in FIG. 3. As can be seen from FIG. 7, with corresponding dimensions of the smoothing capacitor 28 or of the LED module the smoothing capacitor 28 can be accommodated in a space-saving manner between the contact pins 26 and 17.

(23) FIG. 8 shows a schematic view from above of an LED module according to another exemplary embodiment. In this exemplary embodiment the LED module 1 has a similar construction to that of the exemplary embodiment of FIG. 7 in such a way that the contact points 17, 18, 19, 20 with the contacts 22, 23, 24, 25 are arranged on the first long end 3 (at the bottom in the picture) of the LED module 1. However, the connection of electronic components corresponds to the second topology or the topology shown in FIG. 6. The contacts 22 and 23 for connection of an alternating current source are located between the contacts for connection of the smoothing capacitor. In some circumstances, in particular in the event of specific dimensions of the smoothing capacitor and as a function of the space available in the light fixture for the use of the LED module, this configuration can be particularly advantageous in order to accommodate the LED module together with smoothing capacitor in a light fixture.

(24) Due to the arrangement of the contact points 17, 18, 19, 20 or the contacts 22, 23, 24, 25 in all the exemplary embodiments shown here, external contact pins for connection to an alternating current source and the smoothing capacitor 28 can be arranged longitudinally with respect to the support 2 in such a way that the three-dimensional configuration or the shape factor and thus also the capability of installation of the LED module 1, in particular in a light fixture, is not or is not significantly hampered by the smoothing capacitor.

(25) For the production of the LED module, in a first step a longitudinally constructed flat support with electrically conductive regions or conductive tracks can be provided, wherein the electrically conductive regions are constructed according to one of the exemplary embodiments of the LED module described above. The support can be an at least partially light-permeable ceramic support or a correspondingly structured leadframe.

(26) In a subsequent step LEDs and electronic driver components, in particular as bare or unhoused components, are mounted on the support. The mounting of the LEDs and the electronic driver components can take place substantially simultaneously in a die bonding step.

(27) In a further step, bonding wires for connection of the electrical components arranged on the support 2 to the conductive regions or to other electronic components can be mounted (bonding wires), after which the LEDs can be provided with an encapsulation. The encapsulation can be constructed as a diffuse or milky light-scattering encapsulation, for example, a silicone encapsulation.

(28) After this, if applicable, solder contacts can be provided for connection of the first pair of contact points with contact pins for connection to a current source and solder contacts can be provided for connection of a smoothing capacitor to the second pair of contact points.

(29) The attachment of the solder contacts to the contact points 17, 18, 19 and 20 or the soldering of the smoothing capacitor 28 and the contact pins 26 and 27 can take place in a soldering step immediately after the potting of the LEDs 10 with the encapsulation.

(30) FIG. 9 shows a schematic view from above of an LED light fixture according to an exemplary embodiment. The LED light fixture 50 comprises an LED module 1 which is constructed according to the embodiment of FIG. 2. The LED light fixture 50 also comprises a glass body 51 with a wall 52, wherein the LED module 1 is located inside the glass body 51. The LED module 1 comprises a smoothing capacitor 28 which is provided with a cover 53. In this exemplary embodiment the cover is constructed as a substantially white silicone tube. In FIG. 9 the encapsulation 54 or the LED encapsulation is also illustrated schematically. The LED light fixture 50 also has contact pins 55 which are connected by contact plates 56 of the glass body 51 to the contact pins 26 and 27 of the LED module 1 through the wall 52. The glass body 51 has a flattened area 57 on which the contact plates 56 are sealed on the wall 52 of the glass body 51. In the region of the contact pins 55, in particular between the contact pins 55, a reinforcement 58 or reinforcement structure is provided for mechanical reinforcement of the connection region of the LED light fixture 50. The reinforcement 58 can comprise insulating reinforcing plates or protrusions arranged transversely with respect to the contact pins in the region of the flattened area 57.

(31) The contact plates can be constructed as molybdenum films, and when this film is used it is possible to compensate for a different thermal coefficient of expansion of the material of the electrical contact pins 26, 27 or the contact pins 55 and the material of the glass body 51 or glass bulb. In particular, the glass body 51 can be formed with quartz glass. Alternatively, in the case of tempered glass it is possible that the connection of the LED module towards the exterior comprises a wire, for example a molybdenum wire, a tungsten wire or an iron-nickel-cobalt wire, since with tempered glass in conjunction with the said electrically conductive materials no adaptation of the coefficients of thermal expansion is necessary.

(32) FIG. 10 shows a schematic view from above of an LED light fixture according to another exemplary embodiment. The LED light fixture 50 of FIG. 10 largely corresponds to the LED light fixture of FIG. 9 and likewise comprises an LED module 1 which is located inside a glass body 51. The LED module 1 of FIG. 10 is constructed according to the embodiment of FIG. 7, so that all contact points of the LED module 1 are located on one long end of the support. The LED module 1 comprises a smoothing capacitor 28 which is likewise provided with a cover 53. In contrast to the LED light fixture of FIG. 9, the smoothing capacitor 28 is accommodated in a compact manner in the light fixture on the base side between the two contact pins 26 and 27.

(33) In the exemplary embodiments illustrated in FIGS. 9 and 10 the LED light fixture 50 of a halogen lamp is simulated. In particular the LED light fixture 50 according to FIGS. 9 and 10 is substantially constructed as a conventional halogen lamp with a G9 plug-in base.

(34) The LED light fixture can be produced in a simple manner, in that an LED module already fitted with contact pins and with the smoothing capacitor is used in a glass body used, for example, in conventional light fixtures.

(35) In some embodiments of the LED light fixture 50, the glass body or glass bulb is vacuum sealed, wherein the interior space of the glass bulb is filled with a gas filling which has a gas or gas mixture with high thermal conduction, for example at least 0.05 W/mK, at least 0.10 W/mK, or at least 0.13 W/mK. In particular, the gas filling can have helium gas and/or hydrogen gas. The gas filling of the glass bulb can also have a mixture of helium with oxygen.

(36) The absolute pressure of the heat-conducting gas in the interior space 25 can be up to 10 bars, or up to 5 bars. The absolute pressure is preferably at least 1 bar, or at least 2 bars. The details of the absolute pressure should be understood to relate to room temperature. The use of a high pressure of the heat-conducting gas enables an improved heat removal inside the LED light fixture 20.

(37) During operation, the LED light fixture 20 is connected to an electrical current source, so that the electronic components 23 or LED driver are supplied with current by the contact pins 24, the contact wires 25 and by the electrical leads (not shown). The LEDs which are electrically connected to the LED driver are likewise supplied with the electrical current and illuminated by the LED driver. The dispersion of the light emitted from the LEDs 6 in the light-scattering encapsulation 9 lets the light-scattering encapsulation 9 appear as a light source, for example, with a diffuse scattering effect. Due to the positioning of the smoothing capacitor along the longitudinal support of the LED module the LED module can be accommodated in a glass body, the dimensions of which do not or not significantly exceed the dimensions of the standard G9 halogen lamp. Thus, an LED replacement light fixture with reduced flickering can be implemented in a simple manner without, in this case, exceeding the standard dimensions of the light fixture to be replaced (i.e., the halogen lamp).

(38) Although at least one exemplary embodiment has been set out in the preceding description, various amendments and modifications can be carried out. The aforementioned embodiments are merely examples and not provided in order to limit the validity range, the applicability or the configuration of the present disclosure in any way. In fact the preceding description provides the person skilled in the art with a plan for implementation of at least one exemplary embodiment, wherein numerous changes in the function and the arrangement of elements described in an exemplary embodiment can be made without departing from the scope of protection of the attached claims and their legal equivalents.

LIST OF REFERENCE NUMERALS

(39) 1 LED module 2 support 3 first long end 4 second long end 5 first lateral end 6 second lateral end 7 first main surface 8 second main surface 9 side surface 10 LED 11 transistor 12 diode 13, 14, 15, 16 metal plated structure 17, 18, 19, 20 contact point 21 bonding wire 22, 23, 24, 25 contacts 26, 27 contact pins 28 smoothing capacitor 29 metal plated structure 30 gap 50 LED light fixture 51 glass body 52 wall 53 cover 54 encapsulation 55 contact pin 56 contact plate 57 flattened area 58 reinforcement