WO2010040645A2

WO2010040645A2 - Circuit carrier

Info

Publication number: WO2010040645A2
Application number: PCT/EP2009/062430
Authority: WO
Inventors: Markus Hofmann; Ralph Bertram; Robert Kraus
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2008-10-08
Filing date: 2009-09-25
Publication date: 2010-04-15
Also published as: WO2010040645A3

Abstract

The invention relates to a circuit carrier (11) comprising at least one predetermined bending point (4, 13). The retrofit lamp (28) comprises at least one bent circuit carrier. The method for producing a circuit carrier comprises the step of bending said circuit carrier (11) in at least one predetermined bending point (4, 13).

Description

description

circuit support

The invention relates to a circuit carrier, a retrofit lamp with at least one circuit carrier and a method for providing a circuit carrier.

In order to realize so-called retrofits (ie lamps that have a similar or the same technical performance and dimension as classic bulbs, such as incandescent lamps) with light emitting diodes (LEDs), so far several components must be mounted in a confined space and interconnected. Basically, there is a retrofit of a standard socket, a piston, a light source, a driver circuit and optionally a heat sink. So far, the LEDs on a rigid circuit board, such as a FR4 board or a metal core board mounted. This LED board is then mounted on a heat sink or other carrier. Especially at higher powers, a driver circuit used to drive the LEDs is mounted on a separate, rigid PCB. Both boards must then be electrically connected to each other with cables or other connection options. Furthermore, the driver board must be connected to the base of the retrofit via cable. This wiring has a negative effect on the electromagnetic compatibility (EMC); also an assembly effort is high.

It is the object of the present invention to provide a possibility for simplified construction of a circuit carrier, which is particularly suitable for use in a confined space. It is a further object of the present invention to provide a way of simplifying the internal structure of a retrofit. This object is achieved by means of a circuit carrier, a retrofit lamp having at least one such circuit carrier and a method for providing a circuit carrier. Preferred embodiments are in particular the dependent claims.

The circuit carrier has at least one predetermined bending point. Due to the predetermined bending point, the regions of the circuit carrier which are longitudinally adjacent to the predetermined bending point, referred to below as "carrier regions" for short, can be angled relative to one another. A carrier region may, in particular, be understood as meaning a region of the circuit carrier which has no predetermined bending point or a part thereof except at its edge.

By providing the predetermined bending point, a one-piece circuit carrier can be provided, which can bend compactly, in particular fold, leaves. By bending, even complex structures and radiation characteristics can be easily provided. In particular, LEDs can be arranged in a three-dimensional structure; In this way, for example, a radiation characteristic of an incandescent lamp can be simulated. The one-piece construction also eliminates the need for a complicated and expensive connection between an LED board and a driver board. The elimination of the connection cable leads to an improved EMC behavior of the system. Also, the reliability of the component is increased. Furthermore, components or components can be equipped in a process step on a circuit board.

A predetermined bending point is understood as meaning both an elastic predetermined bending point which, in the event of a decreasing or missing application of force, pushes back into its starting position, as well as a desired folding point, which remains permanently bent, possibly with a slight springback. The bending point may in particular have a radius of curvature of up to about 1 cm. A circuit carrier is preferred which has at least one carrier region adjacent to a predetermined bending point, on which at least one light-emitting diode is mounted. In other words, one or more light-emitting diodes can each be arranged on one or more carrier regions. In particular, if several carrier areas are equipped with one or more light-emitting diodes, an orientation of the emission direction of the LED (s) can be determined by the orientation of the carrier areas, which greatly simplifies the alignment of the LEDs.

Furthermore, a circuit carrier is preferred, which has at least one carrier region, on which at least one electronic component is mounted, for. B. one or more driver blocks, sensors, radio receiver u.v.m. In this case, one or more carrier areas can be mixed with LEDs and electronic components. However, it may be preferred for thermal reasons, if on at least one carrier area only (in particular a higher power consuming) electronic components and no LEDs are present. It may additionally or alternatively be preferred for thermal reasons, if on at least one carrier area only LEDs electronic components and no higher power consuming electronic components are present. Under a higher power consuming electronic components, for example, logic devices, eg. B. integrated circuits, power semiconductors, transformers, etc. understood.

Furthermore, a circuit carrier is preferred which has at least one carrier region which has at least one electrical contact element to the (with respect to the circuit carrier) external electrical connection. By means of the electrical contact element, the circuit carrier, for example, with an external power source, for. B. a voltage source, and / or an external control circuit ver to be bound. In other words, the electrical contact element may have contacts for transmitting electrical power and / or signals. The circuit carrier can be used for example for contacting the socket, which further reduces the assembly effort and an EMC susceptibility to interference.

In addition, a circuit carrier which has at least one carrier region which has at least one electrical contact element for external electrical connection is preferred.

A circuit carrier is also preferred which has at least one carrier region on which no component is mounted. Such a support region can be used in particular for electrical insulation and / or for mechanical support.

To simplify the wiring, a circuit carrier is preferred which has at least one electrical line which already crosses a predetermined bending point in the unbent state. This line can rest in the region of the predetermined bending point on the substrate of the circuit substrate or be lifted from this like a bridge. Since the circuit substrate can be fitted in the planned state, but also a bridging of the predetermined bending point by separately produced lines or line sections without too much effort is possible, for. B. by soldering.

The circuit carrier or its substrate can be made in principle basically of an elastic material, for. B. be a flexible circuit board. Possible printed circuit board materials include, for example, polyester, PEN (polyethylene naphthalate) or PI (polyimide).

However, it is preferred if at least one carrier area adjoining a predetermined bending point is at least partially counterposed. is stiffened over the material of the predetermined bending point. For example, parts of the flexible printed circuit board ('Flexboard') can be provided on one or more support areas with a rigid material (for example aluminum or FR4). As a result, these support areas are stiffened and easier to assemble, in particular equipped, be.

In particular, a circuit carrier is preferred which has at least one heat sink attached thereto. The circuit carrier can for example be glued directly to the heat sink, whereby a very good heat dissipation is ensured.

Furthermore, a circuit carrier is preferred in which, in the bent state, the heat sink is thermally connected via at least one electrically insulating carrier region on which preferably no component is mounted to at least one carrier region which carries at least one component. In particular, one or more carrier areas of the circuit carriers can then be used by skillful bending, in particular folding, as an electrical insulator between a carrier area equipped, in particular with a driver circuit, and a metallic heat sink. In this case, a circuit carrier is particularly preferred which uses at least one carrier region for electrical insulation, on which no component is mounted.

In addition, a circuit carrier is preferred in which a contact surface of the heat sink for contacting the circuit carrier has a plurality of facets whose transitions are shaped and positioned such that they correspond to those predetermined bending points of the circuit carrier which are arranged on the contact surface of the heat sink. Thereby, a molding of the circuit substrate to the heat sink can be achieved particularly easily. In the assembled state The predetermined bending points are thus on the facet transitions (edges) of the heat sink.

The retrofit lamp has at least one circuit carrier as described above. The light sources, in particular LEDs, can be easily arranged in a three-dimensional structure by means of the flexible circuit carrier. As a result, preferably a radiation characteristic of an incandescent lamp can be reproduced.

A retrofit lamp is preferred in which the circuit carrier is equipped with LEDs, although this is not mandatory.

In particular, a retrofit lamp is preferred in which an electrical contact element of the circuit carrier, as already described, for example, has at least one electrical plug contact and is provided for receiving in a contact counter element of a base of the retrofit lamp. As a result, the circuit substrate no longer needs to be wired consuming and EMC disadvantageous to the base of the retrofit lamp.

In the method for providing a circuit carrier, in particular for installation in a retrofit lamp, this is bent at least one predetermined bending point.

In the following figures, the invention will be described schematically with reference to exemplary embodiments. It can be provided with the same reference numerals for better clarity identical or equivalent elements.

1 shows in two partial images a circuit carrier according to a first embodiment in plan view of the unfolded circuit carrier (FIG. 1A) and as a side view of the folded circuit carrier (FIG. 1B); 2 shows a partial circuit diagram of a circuit carrier according to a second embodiment in plan view of the unfolded circuit carrier (FIG. 2A) and as a side view of the folded circuit carrier (FIG. 2B);

3 shows, in two partial images, a circuit carrier according to a third embodiment in a plan view of the unfolded circuit carrier (FIG. 3A) and as a side view of the folded circuit carrier (FIG. 3B);

4 shows a sectional representation of a circuit carrier according to a fourth embodiment, which is connected to a heat sink;

5 shows a circuit carrier according to a fifth embodiment, which is applied to a further heat sink;

6 shows a retrofit incandescent lamp with a circuit carrier according to a sixth embodiment.

FIG. 1A shows a plan view of an unfolded circuit carrier 1 which is equipped with light-emitting diodes 2 and driver components 3. Between the light-emitting diodes 2 and the driver modules 3 runs consistently a Sollfaltstelle 4, which divides the circuit substrate 1 in two adjacent to the Sollfaltstelle 4 carrier areas 5, 6. The equipped with the light emitting diodes 2 light source support portion 5 is circular except for the straight edge at the Sollfaltstelle 4, wherein the light-emitting diodes 2 are evenly distributed over the light source carrier region 5. The driver support portion 6, however, is rectangular in shape and has at its Sollfaltstelle 4 opposite end of a contact element 7, which here with two electrical plug-in contacts 8 is shown equipped. For ease of illustration has been dispensed with a representation of a wiring.

The light-emitting diodes 2 can be present, for example, as individual LEDs or as a group of a plurality of LED chips, which are mounted on a common substrate (LED modules). The light-emitting diodes 2 can shine in a different color or in the same color, including white. The LEDs 2 can be equipped with a downstream optics. Alternatively, the light source carrier region can also be equipped with one or more OLEDs. The number of LEDs 2 is limited only by the available space and may include one or more light-emitting diodes 2. The LEDs 2 can be tunable color.

In an alternative embodiment, the driver support portion 6 may have one or more further Sollfaltstellen.

FIG. 1B shows in a side view the circuit carrier 1 from FIG. 1A in a folded state, as is suitable, for example, for use in a retrofit incandescent lamp, as will be described in more detail with reference to FIG. The light source carrier region 5 is angled at the Sollfaltstelle 4 against the driver support portion 6 that the LEDs 2 in a predetermined Hauptabstrahlrichtung (up here) can radiate and simultaneously contacting the circuit substrate 1 in the back of the light source carrier region 5 can be done by inserting the contact element 7. In the embodiment shown, the driver components 3 are also positioned in a space-saving manner at the rear of the light source carrier region 5.

In the presence of further Sollfaltstellen (not shown) on the driver support portion 6, an alignment of the contact element 7 can be simplified. In contrast to the prior art, the circuit substrate 1 needs to be populated only once in the unfolded state according to IA and can then be folded by folding along the Sollfaltstelle 4 in a suitable form for use in a retrofit incandescent form, with a further post-processing of the circuit substrate. 1 (Additional wiring, attachment of the carrier areas 5, 6) due to its one-piece deleted. The possibility of externally connecting the circuit carrier 1 by means of a simple non-wired contacting (here: plug connection) reduces the EMC susceptibility.

The circuit carrier 1 is constructed so that it has a flexible printed circuit board 9, which is stiffened in the carrier regions 5, 6 by stiffening layers 10 made of FR4 material (optionally, indicated by dashed lines), whereby a Bestück- availability is improved. Of course, the stiffening layer (s) may also be arranged rearwardly with respect to the side to be loaded.

2A shows a plan view of a circuit carrier 11 according to a further embodiment. In contrast to the circuit carrier 1 according to the first embodiment of FIG. 1, a further insulator carrier region 12 made of dielectric material is now present between the driver carrier region 6 and the light source carrier region 5, which by means of the Sollfaltstelle 4 against the light source carrier region 5 and fold by means of another Sollfaltstelle 13 against the driver support portion 6. For this purpose, the driver carrier region 6 and the insulator carrier region 12 are approximately the same length. As a result, in the folded state, which is shown in side view in FIG. 2B, the driver carrier region 6 can be protected against contact from this side due to the dielectric material property of the insulator driver region 10, as indicated by the arrow, for example. B. against contact with a heat sink (not shown). This can, for example the circuit substrate 9 are fitted with higher reliability in a recording. The heat sink can then be fastened in particular flat on the insulator support region 12, z. B. by sticking by means of a thermally conductive adhesive, whereby a heat dissipation in particular from the driver support portion 6 to the heat sink in a simple manner possible.

FIG. 3A shows a circuit carrier 14 according to a third embodiment, in which two insulator carrier regions 12 of equal length are present laterally on the driver carrier region 6, which can be folded against the driver carrier region 6 by means of respective desired folds 15, these desired folds 15 being along the longer side of the driver-carrier area. To protect the populated side of the driver carrier region 6 from contact, in particular with metallic conductive surfaces, for. As a heat sink, the two insulator support portions 12 along their Sollfaltstellen 14 by 180 ° forward as shown by the driver components 3 fold.

Alternatively, the insulator carrier regions 13 can also be folded over the surface (rear side) of the driver carrier region 6 that is not provided with the driver components 3, which then preferably angles or folds in the opposite direction relative to the light source carrier region 5, as shown in FIG. 2B becomes.

FIG. 4 shows yet another folded circuit carrier 16 in which only a plurality of light source carrier regions 17 are shown for the sake of simplicity. Each light source carrier region 17 has at least one light-emitting diode 2 and is' separated 'by a corresponding Sollfaltstelle 18 of vertical wall support areas 19', which carry no light-emitting diode 2. In the case of the folding shown, a two-sided, one-piece staircase pyramid results, with all light-emitting diodes 2 facing in the same direction (here: after above). At least the portion of the circuit carrier 16 shown is mounted flat on a suitably shaped heat sink 20, wherein the surface contour of the contact surface 21 of the heat sink 20 corresponds to the contour of the back of the shown portion of the circuit substrate 16. In particular, the Sollfaltstellen 18 are on edges 22 of the heat sink 20, which separate the individual facets of the heat sink 20 from each other.

5 shows a circuit carrier 23 according to a further embodiment with a plurality of adjoining light source carrier regions 24, which are delimited from each other by Sollfaltstellen 25. The light-emitting diodes 2 now do not radiate in the same direction, but essentially in an upper half-space. For aligning the light-emitting diodes 2, the individual light source carrier regions 24 are angled relative to one another. The substrate 26 carrying the light source carrier regions 24 is here also fastened flat on a suitably contoured heat sink 27.

6 shows an LED retrofit lamp 28, which by means of a standard socket 29, z. As an Edison socket (as shown) or a bayonet cap, etc., can be used in known, standardized versions. The LED retrofit lamp 28 also has a transparent and / or translucent (opaque) piston 30, which conducts the light generated by the light sources 2 of the lamp 28, possibly scattered, to the outside. In the embodiment shown, between the base 29 and the piston 30 there is an in practice opaque, in particular metallic, receptacle 31 for the circuit carrier, which is shown here as transparent only for a better description. In the shown receptacle 31, the circuit carrier 1 of FIG. 1 is used by way of example, wherein the receptacle 31 is almost completely closed on the upper side by the light source carrier region 5 and the driver carrier region 6 extends down to the base 29 and there by means of its electrical contact element 7 is electrically connected to the socket, namely by plugging into a matching contact counter-element 32nd

Such a LED retrofit lamp 28 is particularly easy to produce due to the foldable circuit substrate 1 and also very reliable, in particular EMC-safe.

Of course, the present invention is not limited to the embodiments shown.

Thus, only Sollfaltstellen have been shown in the figures for ease of description. However, the circuit carrier may also have only elastic spring-backable predetermined bending points in the strict sense, or a combination of resiliently spring-loaded predetermined bending points and non-elastically springing-back predetermined bending points (desired folding points).

Thus, instead of the circuit carrier of FIG. 1, another flexible, in particular foldable, circuit carrier can be used in the retrofit lamp, for example according to FIGS. 2 to 5. In particular, the embodiment according to FIGS. 2 and 3 has the advantage that the driver -Barrier area against the metallic receptacle, which serves as a heat sink, is electrically isolated and yet the heat sink or the recording in thermally good contact with the driver blocks 3 is.

In general, optionally some or all support regions can be provided at least partially with stiffening elements, in particular with layers or plates.

In general, one or more carrier regions can have at least one light-emitting diode as the light source. The light source can be present, for example, as a single light-emitting diode or LED module with a plurality of light-emitting diode regions, in particular LED chips. The individual light-emitting diodes or LED chips can each monochrome or multichromic, z. B. white, radiate. In the presence of multiple light emitting diodes or LED chips, these z. B. same color (monochrome or multichrome) and / or different colors shine. For example, an LED module may have a plurality of LEDs or LED chips ('LED cluster'), which together may result in a white mixed light, e.g. B. in 'cold white' or 'warm white'. To generate a white mixed light, the LED cluster preferably comprises light-emitting diodes (individual LEDs or LED chips) which shine in the primary colors red (R), green (G) and blue (B). In this case, single or multiple colors can also be generated by several LEDs simultaneously; Combinations RGB, RRGB, RGGB, RGBB, RGGBB etc. are possible. However, the color combination is not limited to R, G and B (and A). For example, one or more amber LEDs 'amber' (A) may also be present to produce a warm white hue. But other suitable combinations are possible, such as RGBW, with another white LED, RGBYW with another yellow LED, etc. For LEDs with different colors, these can also be controlled so that the LED module radiates in a tunable RGB color range , To produce a white light from a mixture of blue light with yellow light, phosphor LED blue chips can also be used, e.g. B. in surface mounting technology, z. In ThinGaN technology. Then, an LED module can also have a plurality of white LED chips, which can be a simple scalability of the luminous flux can be achieved. The LED chips and / or the modules can be equipped with suitable optics for beam guidance, z. B. Fresnel lenses, collimators, and so on. It can be arranged on a contact several identical or different types of LED modules, for. B. several similar LED modules on the same substrate. Instead of or in addition to inorganic light emitting diodes, z. B. based on InGaN or AlInGaP, organic LEDs (OLEDs) are generally used.

But there are also other types of light sources used, such as other semiconductor light sources, eg. B. diode lasers, as for example, incandescent, halogen, fluorescent and other light sources.

Also, the support area are stiffened in a different way, for. B. by stiffening layers of a different material. Also, the stiffening z. B. be present on one or both sides, wherein the stiffening layers need not be identically shaped nor need to be made of identical material. For example, a stiffening layer on one side may consist of FR4 material and an aluminum stiffening layer on the other side.

Reference sign list

1 circuit carrier

2 LED

3 driver block

4 Sollfaltstelle

5 light source carrier area

6 driver carrier area

7 contact element

8 plug contact

9 flexible circuit board

10 stiffening position

11 circuit carrier

12 insulator carrier area

13 Sollfaltstelle

14 circuit carrier

15 Sollfaltstelle

16 circuit carrier

17 light source carrier area

18 Sollfaltstelle

19 wall support area

20 heat sinks

21 contact area

22 edge of the heat sink

23 circuit carrier

24 light source carrier area

25 Sollfaltstelle

26 substrate

27 heat sink

28 LED retrofit lamp

29 sockets

30 pistons

31 recording

32 Contact counter element

Claims

claims

1. circuit carrier (1; 11; 14; 16; 23), comprising at least one predetermined bending point (4; 13, 15; 18; 25).

2. Circuit carrier (1; 11; 14; 16; 23) according to claim 1, comprising at least one carrier region (5; 17; 24) bordering on a predetermined bending point, on which at least one light-emitting diode (2) is mounted.

3. Circuit carrier (1; 11; 14) according to claim 1 or 2, comprising at least one bordering on a predetermined bending support portion (6) on which at least one electronic component (3), in particular driver component, is attached.

4. Circuit carrier (1; 11; 14) according to one of the preceding claims, comprising at least one carrier region (6) which adjoins a predetermined bending point (4; 13) and has at least one electrical contact element (7) for external electrical connection.

5. Circuit carrier (11; 14) according to one of the preceding claims, comprising at least one of a predetermined bending point (4; 13) adjacent carrier region (12) on which no component is mounted.

6. The circuit carrier according to one of the preceding claims, comprising at least one electrical line which already crosses a predetermined bending point in the unbent state.

7. circuit carrier (1) according to one of the preceding claims, wherein at least one of a predetermined bending point (4) adjacent carrier region (5; 6) is at least partially stiffened.

8. circuit carrier (16; 23) according to one of the preceding claims, comprising a heat sink attached thereto

(20, 27).

9. circuit carrier (16; 23) according to claims 5 and 8, wherein in the bent, in particular folded, state of the heat sink (20; 27) via at least one electrically insulating support region (12) on which no component is mounted, with at least a support region (5; 6) is thermally connected, which carries at least one component.

10. The circuit carrier (16; 23) according to claim 8, wherein a contact surface (21) of the heat sink (20) for contacting the circuit carrier (16) has a plurality of facets whose transitions are shaped and positioned to correspond to those Corresponding predetermined bending points (18) of the circuit carrier (16; 23), which are arranged on the contact surface (21) of the heat sink (20).

11. retrofit lamp (28), comprising at least one bent, in particular folded, circuit carrier (1; 11; 14; 16; 23) according to one of the preceding claims.

12. retrofit lamp (28) according to claim 11 with a circuit carrier according to claim 2.

13. Retrofit lamp (28) according to claim 11 or 12 with a circuit carrier (1) according to claim 5, wherein the electrical contact element (7) of the circuit carrier (1) has at least one electrical plug contact (8) and for receiving in a contact counter-element (32) of a base (29) of the retrofit lamp (28) is provided.

14. Method for providing a circuit carrier

(1; 11; 14; 16; 23) in which the circuit carrier (1; 11; 14; 16, 23) at at least one predetermined bending point (4; 13, 15; 18; 25) is bent, in particular folded, becomes.