WO2011069842A1 - Lighting module and lighting chain - Google Patents

Abstract

The invention relates to a lighting module having a substrate (2) having at least one light source (4), in particular a light diode, on the front face (3) thereof, wherein the substrate (2) is at least partially covered laterally (5) and on the front face (3) of a first casting compound (6) and wherein a respective light emission surface (7) of the at least one light source (4) and at least partially also a rear face (8) of the substrate (2) are free of the first casting compound (6). The lighting chain (31) according to the invention has a plurality of lighting modules (1), wherein adjacent lighting modules (1) are connected to each other by means of at least one electrical connection line (32), wherein the ends (33) of the electrical connection line (32) fastened to the adjacent lighting modules (1) are cast by the respective first casting compound (6).

Description

description

Light module and light chain

The invention relates to a light emitting module comprising a sub strate ^¬, which is on its front side, equipped with at least one light ^¬ source, in particular light emitting diode. The invention further relates to a light-chain together with a plurality of quantitative ^¬ off luminous modules.

So far, such lighting modules have been protected by a Lackie ^¬ ren their boards, by enclosing the boards in a closed housing or by a complete encapsulation of the board. However, these known measures either only a little protection against a particular mechanical but also chemical stress and / or a bad thermal contact, which greatly hinders heat dissipation from the LED module for cooling the light sources. It is the object of the present invention to provide a robust, protected lighting module that allows a good ther ^¬ mical connection to the environment.

This object is achieved according to the features of the independent claims. Preferred embodiments are insbesonde ^¬ re the dependent claims.

The object is achieved by a light module, comprising a substrate which is equipped on its front side with at least one light source, in particular light emitting diode, wherein the substrate is at least partially covered laterally and at the front by a first potting compound, and wherein a respective light exit surface of at least one light source ^¬ and at least partly a rear surface of the sub strats are free of the first potting compound. Due to the presence of the first potting compound, which acts as a protective sheath, the luminescent module can be protected from mechanical damage from the side and from the front. The first potting compound may in particular be selected for mechanical stress and does not need to be translucent. The protective jacket can also protect against moisture and / or chemical stress. The so equipped lighting module is correspondingly robust. The fact that the light exit surface is not covered by the first potting compound, light can escape unhindered. The fact that the back of the substrate is at least partially free of the typically heat-damping first potting compound, in other words is not completely covered by this, causes that there generated by the light sources and propagating through the substrate heat can be derived easily and effec ^¬ tively , which in turn enables effective thermal connection.

The at least one light source may in particular comprise at least one light-emitting diode. LEDs have a low profile and are mechanically relatively unempfind ^¬ Lich. The light-emitting module is particularly preferred for ^{luminescent ¬} the with a power of more than 0.5 watts, since the heat loss, if not dissipated, the lifetime and reliability of the light-emitting diodes sensitive shortened.

The substrate may be equipped with electronic components on the front side, in addition to the at least one light source, as well as with at least one circuit, e.g. a driver module, capacitors, resistors, etc. Depending on the design, these electronic components may be covered by the first potting compound or may be free of it.

Also, at least one electrical line, eg connection cable, can be fastened to the substrate, which can be covered in particular by the first potting compound for a secure connection. The first potting compound can best ^¬ hen, also known as hot-melt adhesives, hot adhesives or hot glue ^¬ known from hotmelt particular.

The first potting compound may be provided with colored fillers in order to be able to adjust the color of the light module. In particular, the achromatic potting colors white, gray and black are preferred. But there are also colorful colors possible.

It is an embodiment that the substrate is substantially completely covered on the side and on the front side by a first potting compound, and the back side of the substrate is substantially free of the first potting compound. Characterized the sides and to the front or toward the front ge ^¬ taught protection of the luminous module is combined with a good thermal connection system optimized for magnifying the back. It is a particular embodiment that the back of the substrate is flush with the first potting compound or protrudes rearwardly over the first potting compound. Thus, a simple and thermally effective surface mounting of the light module is made possible at the back of the substrate, for example on a heat sink.

It is still an embodiment that the substrate has at least one laterally protruding projection, which is surrounded by the first potting compound. Thus, a positive connection of the first potting compound with the sub ^¬ strat can be achieved.

It is yet another embodiment that the substrate has at least one laterally introduced recess and / or at least one passage from the front to the rear ^¬ side, which are at least partially filled before the first potting compound. Even so, a form-fitting Connection of the first potting compound to the substrate can be achieved.

It is also an embodiment that the substrate is designed as a circuit board, in particular as a metal core board or a ceramic board. These two types of boards have the advantage that they can derive the heat generated by the at least one light source particularly effectively to its rear ^¬ side. This allows a particularly good cooling of the at least one light source.

It is for an increase in robustness, a development that the metal core board has a non-rusting metal on ^¬ , especially aluminum.

It is yet an embodiment that a wall thickness of the ers ^¬ th potting compound is at least 1 mm. This wall thickness si ^¬ chert high impact and abrasion resistance. It is further an embodiment that the respective light exit surface of the at least one light source is surmounted by the first potting compound surrounding it. Thus, the at least one light source is also largely protected from mechanical ^loading , in particular abrasion.

It is also an embodiment that the respective light exit surface which is covering at least a light source of egg ^¬ ner light-transmissive second potting compound. Thus, the at least one light source is also largely protected directly from mechanical stress, in particular abrasion. The translucent second potting compound may be transparent or translucent (opaque). The lichtdurchläs ^¬ sige second potting compound, for example, from a low-pressure injection molding material, eg silicone or hotmelt exist.

Generally, the first molding compound and the second Ver ^¬ casting compound also be identical, and so the light module to be able to at least a part of the back of the substrate to be surrounded by a uniform, translucent potting compound or shed it. The non-cast surface of the rear side of the substrate can then be connected to a heat sink, for example, or be. The heat sink may be at least partially surrounded with.

It is still an embodiment that the first potting compound is bevelled to the respective light exit surface. This allows a wide light beam angle can be maintained.

It is also a further development that the back of the sub ^¬ strats and / or the lighting module is at least partially coated with egg nem protective lacquer, for example to protect against corrosion, or a slight mechanical stress.

It is also a further development, that the lighting module, in particular ^¬ sondere the substrate, at least one bore for receiving a screw has to the light module threadedly buildin ^¬ term to.

It is also advantageous for a simple attachment development that the back of the light module at least partially has at least one adhesive element, for example, a double-sided adhesive tape.

There is one for effective heat dissipation from the Leuchtmo ^¬ dul, particularly even without a connection to an additional loan heatsink advantageous embodiment that the backside of the substrate comprising a cooling body structure, including at least one cooling fin, the cooling pin and / or blade. Since ^¬ by a cooling body is integrated in other words, in the substrate. The heat sink may be cast at least partially, in particular at the edge, together with the substrate. The cooling structure (s) of the heat sink (ribs, fins, pins) te, etc.) can protrude ^¬ in particular about the potting ago.

There is an alternative or additional embodiment, for effective heat dissipation, that at the rear of the sub ^¬ strats or the lighting module, a heat sink is attached.

The object is also achieved by a luminous chain aufwei ^¬ send a plurality of lighting modules according to one of the preceding claims, wherein adjacent lighting modules are connected to each other by means of at least one electrical connection line, wherein sealed at the adjacent light emitting ends of the electrical connection line by means of the respective first potting compound are.

An intermediate section between the potted ends may in particular be free of the first potting compound or may not be potted. The encapsulation of the ends of the at least one electrical connecting line protects against damage to the contact between the at least one electrical connecting line and the substrate and also fixes the two elements against each other.

For achieving a flexible light chain for laying on curved surfaces and / or in lateral curves, it is a further development, the at least one electrical ^¬ specific connection line is flexible.

The light module and / or the light chain may e.g. produced with the following steps:

- Equipping the circuit board of a respective light module with the at least one light emitting diode and optionally at least one electronic component;

- Fix, eg soldering, the at least one electrical line, eg cable connection; for a light chain in particular for connecting individual lighting modules to the light chain;

 - Inserting the assembled and, in a light chain, connected board in a mold, e.g. by suction on the bottom by means of a vacuum;

 Closing the mold and casting it with a first potting compound, e.g. by means of an injection molding process; and

 - Opening the mold and remove the light module or

 Luminous chain.

In the following figures, the invention will be described schematically with reference to exemplary embodiments. Identical or identically acting Ele ^¬ elements may be provided with the same reference numerals for clarity.

Fig.l shows a sectional view in side view of a potted LED module according to a first Ausfüh ^¬ tion example;

 2 shows a section of a potted LED module according to a second embodiment;

3 shows a sectional side view of a potted LED module according to a third Ausfüh ^¬ tion example; and

4 shows a sectional side view of a

Light chain with a plurality of LED modules according to the ers ^¬ th embodiment.

Fig.l shows a sectional view in side view of an LED module 1 according to a first embodiment. The LED module has a substrate in the form of a metal core board 2, on the front side of which 3 light sources in the form of light-emitting diodes 4 are mounted. The side or side wall 5 and the Vordersei ^¬ te 3 of the metal core board 2 are covered with a first Verguss ^¬ mass 6 or shed, wherein both upper-side light exit surfaces 7 of the LEDs 4 and a rear side 8 of the metal core board 2 is not shed or from the first potting compound 6 are covered. The page 5 shows a NEN projection in the form of a circumferential chamfer 9 or a circumferential recess in the form of a corresponding recess 10. As a result, the first potting compound is held in a form-fitting manner with the metal core board 2 and can not detach therefrom.

The LED module 1 shown is protected by the first potting compound 6 laterally and from the front especially against mechanical, but also chemical stress. The back 8 of the metal core board 2 is not protected, the rear ^¬ side 8 is typically used for attachment of the LED module 1 and is thus exposed to only low mechanical loads. For a sufficiently wide light cone, the surface of the first potting compound 6 at the front side of the LED module 1 falls obliquely down to the light exit surfaces 7 in the shape of a truncated cone or truncated pyramid. The maximum height of the first potting compound 6 is thus higher on the front side 3 of the metal core board 2 than the height of the light emitting diodes 4, whereby the light emitting diodes 4 are protected, in particular, against a laterally directed or extensively applied mechanical stress. On the large back 8, one of the light emitting diodes 4 generated and spread by the metal core board 2 Ver ^¬ heat loss can be effectively dissipated. The metal core board 2 allows a particularly good heat spreading. The LED module 1 can be attached to a heat sink for a particularly effective dissipation of heat loss with its back 8, for example on a heat sink or a metallic support.

For clarity, electrical lines, such as connecting cables, and electronic components are not shown, but may be present and in particular by the first potting compound 6 with shed. 2 shows a sectional side view of a section of a potted LED module 11 according to a second embodiment. In contrast to the LED module 1 and additionally or alternatively to the chamfer 9 or the recess 10, the metal core board 12 has a vertical passage 13 from the front side 3 to the rear side 8, which is widened in the region of the rear side and the is filled with the first potting compound 6. Also as can be achieved fes ^¬ te, form-fitting connection of the first sealing compound 6 to the metal core board 2 or amplified.

3 shows a sectional side view of a potted LED module 21 according to a third Ausführungsbei ^¬ game. In contrast to the LED module 1, the metal-core circuit board 22 is now back via the first potting compound 6 forth ^¬ from. In the projecting region 23, the metal core ^plate 22 is configured as an integrated heat sink structure with a plurality of cooling pins 24. This improves a Wärmeablei ^¬ tion. The rear side 8 of the metal core board 2, which is formed in particular by the ends of the cooling pins 24, can furthermore be used for fastening the LED module 21.

In addition, the light exit surfaces 7 of the light-emitting diodes 4 are now covered by a light-transmitting (transparent or translucent) second potting compound 35, which results in direct protection of the light exit surfaces 7.

4 shows a sectional side view of a section of a luminous chain in the form of an LED chain 31 with, by way of example, two LED modules 1 according to the first exemplary embodiment. Now, the electrical Verbindungslei ^¬ lines 32 between the adjacent LED modules 1 are located. The ends 33 of the connection line 32 contact the respective metal core board 2 and are cast in the first potting compound 6, whereby they are mechanically securely fastened to the LED module 1. A middle section 34 between the LED modules 1 is free of the first potting compound and thereby flexible, whereby the LED modules 1 of the LED chain 31 are flexibly positionable.

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

So the first potting compound can stand ^¬ using the controller board. The back of the board can then for example on an upstanding base of a heat sink or support are ^¬ be strengthened, or a heat sink can be attached plunging into the recess of the first molding compound on the board.

Also, instead of a metal core board, in particular another good heat-conducting substrate can be used, for example a ceramic substrate. In general, the type of board is not limited and may, for example, also include other board types, eg of the type FR4.

Reference sign list

1 LED module

 2 metal core board

 3 front side of the metal core board

4 LED

 5 sidewall

 6 first potting compound

 7 light exit surface

 8 Rear side of the metal core board

9 circumferential chamfer

 10 return

 11 LED module

 12 metal core board

 13 implementation

 21 LED module

 22 metal core board

 23 projecting area

 24 cooling pin

 31 LED chain

 32 connecting lines

 33 End of the connecting line

 34 middle section

 35 second potting compound

Claims

claims 1. light module (1; 11; 21),  - comprising a substrate (2; 12; 22) which is equipped at its front side (3) with at least one light source (4), in particular light-emitting diode,  - wherein the substrate (2; 12; 22) is at least partially covered laterally (5) and at the front side (3) by a first potting compound (6), - wherein a respective light exit surface (7) of the at least one light source (4) and at least partially ^¬ as well as a back side (8) of the substrate (2; 12; 22) are free from the first potting compound (6). 2. Luminous module (1; 11; 21) according to claim 1, characterized in that the substrate (2; 12; 22) is substantially completely covered on the side (5) and on the front side (3) by the first potting compound (6) and the back print ^¬ te (8) of the substrate (2; 12; 22) is substantially free of the first potting compound (6). 3. lighting module (1; 11; 21) according to claim 2, characterized in that the rear side (8) of the substrate (2; 12; 22) is flush with the first potting compound (6) or at the rear over the first potting compound (6). out ^¬ stands. 4. lighting module (1; 11; 21) according to any one of the preceding claims, characterized in that the substrate (2; 12; 22) at least one laterally projecting Projection (9) which is surrounded by the first potting compound (6). 5. lighting module (1; 11; 21) according to any one of the preceding claims, characterized in that the substrate (2; 12; 22) at least one laterally introduced recess (10) and / or at least one passage (13) of the Front side (3) to the back (8), which are at least partially filled ^¬ before the first potting compound (6). A light emitting module (1; 11; 21) according to one of the preceding claims, wherein the substrate (2; 12; 22) is designed as a ^¬ Me tallkernplatine or a ceramic board. Light module (1; 11; 21) according to one of the preceding claims, in which a wall thickness of the first Vergussmas ^¬ se (6) is at least 1 mm. A light emitting module (1; 11; 21) according to one of the preceding claims, wherein the respective light exit surface (7) of the at least one light source (4) from which it is surmounted by ^¬ forming first potting compound (6). A light emitting module (1; 11; 21) according to claim 8, wherein the first molding compound (6) sloped to the respective light exit ^¬ surface (7) towards. Lighting module (1; 11; 21) according to one of the preceding claims, in which the respective light exit surface (7) of the at least one light source (4) is covered by a translucent second potting compound (35). Luminous chain (31), comprising a plurality of lighting modules (1; 11; 21) according to one of the preceding claims, adjacent lighting modules (1; 11; 21) being connected to one another by means of at least one electrical connection line (32), wherein at the adjacent lighting modules (1 ; 11; 21) fixed ends (33) of the respective electrical connection line (32) are encapsulated by means of the respective first potting compound (6).