WO2008154952A1

WO2008154952A1 - Electronic component and method for the production of an electronic component

Info

Publication number: WO2008154952A1
Application number: PCT/EP2007/056021
Authority: WO
Inventors: Franz Bernitz; Peter Niedermeier
Original assignee: Osram Gesellschaft mit beschränkter Haftung
Priority date: 2007-06-18
Filing date: 2007-06-18
Publication date: 2008-12-24

Abstract

The present invention relates to an electronic component having an electrically conductive heat sink (18) and having a housing (16) for accommodating at least one LED, wherein the housing (16) comprises a recess (26) for the arrangement of the heat sink (18), said recess having a thickness (30), wherein the recess (18) has a depth (28) adapted to the thickness (30) of the heat sink (18) such that, after the arrangement thereof in the recess (26), the heat sink (18) is at least partially set back in the recess (26) of the housing (16). The invention further relates to a method for the production of an electronic component (12) having an electrically conductive heat sink (18) and having a housing (16) for accommodating at least one LED described by an operating loss output, comprising the following steps: a) ascertaining the operating loss output; b) determining a thickness (30) of the electrically conductive heat sink (18) adapted to the operating loss output; c) measuring a depth (28) of a recess (26) of the housing (16) such that the heat sink (18), upon the arrangement thereof in the recess (26), is at least partially set back in the recess (26) of the housing (16); and d) surrounding at least the heat sink (18) with the housing (16).

Description

description

Electronic component and method for manufacturing an electronic component

Technical area

The invention relates to an electronic component with egg ^¬ ner electrically conductive heat sink and with a housing for receiving at least one LED or the like electronic assembly. Furthermore, concerns the He ^¬ invention, a method for manufacturing such electronic component.

State of the art

The power loss of the electronic component, for example the LED, is largely released during the operation of the electronic component as heat loss. As high temperatures shorten the life of LEDs in particular, LEDs are provided with heat sinks to dissipate the heat loss. In order to enable efficient dissipation of the loss heat by means of the heat sink in the order of magnitude of 1 K / W, the heat sink coupled to the LED is designed to be electrically conductive.

Document US 2005/0161682 A2 describes an LED arrangement which is designed to operate at temperatures of up to 250 ° C. For this purpose, an LED is thermally coupled to a serving as a heat sink metallic base plate, which has thermally conductive coatings on ^¬ . One of the thermally conductive coatings is not electrically conductive, another is electrically conductive. The heat loss of the LED is by means of the base plate arranged board contact elements coupled into a circuit board.

In the operation of prior art heat-sink LEDs, failures of the LEDs which cause the LED to become short are observed.

Presentation of the invention

The object of the present invention is therefore to provide an electronic component of the type mentioned, in which an efficient dissipation of the heat loss and at the same time a more reliable operation of the LED is made possible.

This object is achieved by an electronic construction ^¬ part with the features of claim 1 and by a method with the features of claim 9.

Advantageous embodiments of the invention can be found in the dependent claims.

The present invention is based on the finding that, given a given areal extent of the heat sink, its thickness is of great importance for efficiently dissipating the heat loss. In particular, when the heat sink arranged on a housing for receiving the LED is inclined and / or laterally offset with respect to the board contact element, the heat sink may be in contact with electrically conductive structures, inter alia due to the thickness of the heat sink Board come. Therefore, the electrically conductive formation of the heat sink brings Restriktio ^¬ nen in the layout of the board with, since in assembling the electrically coupled to the LED heat sink on the board the probability of such a contact is to be kept low.

In the electronic component according to the invention with an electrically conductive heat sink and with a housing for accommodating at least one LED, it is therefore provided that the housing has a recess for arranging the heat sink, which has a thickness, wherein the recess has a depth which the thickness of the heat sink is adapted such that the heat sink is sunk after its placement in the recess at least partially in the recess of the housing.

Through the electrically conductive heat sink with the prescribed thickness ^¬ be an efficient deriving the comparison is pleasurable heat possible. At the same time through the at ^¬ least partially sunk in the recess of the housing arranging the heat sink, the probability of Kon ^¬ clock of the heat sink is reduced with electrically conductive struc ^¬ ren a circuit board. This allows a more reliable operation of the LED electrically coupled to the heat sink.

In a particularly advantageous embodiment of the invention, the depth of the recess is greater than or equal to the thickness of the heat sink. The probability of a con- clock of the thus completely sunk in the recess of the Gehäu ^¬ ses disposed heat sink with electrically leit ^¬ enabled structures of the board is thereby further reduced.

As a further advantage, it has been found that a PI tin ink contact element is provided, by means of which the Heat sink can be coupled to the board, wherein the depth of the recess is dimensioned such that after coupling the heat sink to the board by means of Platinenkontaktelements the board contact element is at least partially recessed in the recess of the housing. It is thereby possible, the platinum contact element, game as positional accuracy introduce at ^¬ in the form of a thermally conductive adhesive or a thermally conductive paste. A contact of the heat sink with electrically conductive structures of the board is in this case also reduced if the heat ^¬ sink with respect to the board contact element inclined and / or laterally offset coupled to the board.

It is also advantageous if the board ^{contact ¬} element is electrically non-conductive. The board contact ^element thus constitutes an insulation path for the electrically conductive heat sink.

In a further advantageous embodiment of the invention, the electrically non-conductive board ^{contact ¬} element is at least up to an outer edge of the heat sink ke formed surface. As a result, the heat sink is fully ^¬ constantly galvanically isolated coupled to the board.

In a preferred embodiment in which housing at least one channel is provided, which from ^¬ is at least sectionally formed radially away from the recess leading off. Through the channel, an excess amount of thermal adhesive or thermal paste during Montie ^¬ Ren of the electronic component on the board from the recess emerge. If a quantity of heat-conducting adhesive or the thermal paste is metered during the assembly of the printed circuit board, which amounts to a capacity of the recess. increases, so after exiting the excess amount, a maximum contact surface of the board contact element is given to the heat sink and thus enables a particularly ef ^¬ efficient discharge of the heat loss.

Furthermore, it is advantageous if the electronic component is designed to be surface-mountable, since particularly flat designs of the electronic component can thus be achieved in particular in conjunction with the arrangement of the heat sink sunk in the recess of the housing.

In a further advantageous embodiment, the board has an electrically conductive zone at least in the region of the board contact element. Is the elekt ^¬ driven conductive zone of the board in the region of Plati- nenkontaktelements for example, copper, can here particularly efficient ^¬ coupled with the deduced from the heat sink heat loss of the LED in the printed circuit board ^¬ the.

The preferred embodiments described in connection with the electronic component according to the invention and their advantages apply, if applicable, correspondingly to the method according to the invention for producing an electronic component.

Short description of the drawing (s)

In the following, the invention will be explained in more detail by means of exemplary embodiments. Showing: Figure 1 is a schematic side view of a mounted on a circuit board electronic component according to the prior art.

2 is a schematic sectional view of an electronic component mounted on a circuit board according to the invention;

FIG. 3 shows a schematic view of an underside of the electronic component according to FIG. 2; FIG. and

FIG. 4 shows a schematic sectional view of the electronic component according to FIG. 2 along a line IV-IV; FIG.

wherein the same or functionally identical elements are provided with identi ^¬ reference numerals.

Preferred embodiment of the invention

Fig. 1 is a schematic side view of an assembled on a board electronic component 10 shows 12 ge ^¬ Mäss the prior art. The electronic component 12 is electrically connected to the circuit board 10 by means of two connection elements 14. In a housing 16, an LED not shown in the present case is arranged which is 18 gekop ^¬ pelt with egg ner disposed on the housing 16 a heat sink. The heat sink 18 is designed to derive the heat loss ^¬ loss of the LED electrically conductive.

The heat sink 18 is coupled to the circuit board 10 by means of an electrically non-conductive board contact element 20. The circuit board 10 has an electrically leitfähi ^¬ ge zone 22nd During operation of the LED, the LED is cooled, by their loss of heat is coupled in particular in the zone 22 of the board 10.

If the housing 16 with the arranged according to the prior art heat sink 18 with respect to the Platinenkontakt- elements 20 inclined coupled to the board 10, so there may be an unwanted electrical connection of the heat sink 18 with the board 10. Likewise, with respect to the platinum contact element can lead 20 laterally staggered ^¬ te mounting the housing 16 to the heat sink 18 contacts electrically conductive, placed ^¬ presently not Darge structures of the circuit board 10, which ge ^¬ genüber of the housing 16 facing surface 24 of the Board 10 are formed raised.

Fig. 2 shows a schematic sectional view of an assembled on the circuit board 10 by surface mount technology, the electronic component according to the invention 12. The electrically conductive heat sink 18 is arranged in an off ^¬ recess 26 of the housing 16. A depth 28 of the recess 26 in this case is greater than a thickness 30 of the heat sink 18, so that it is completely recessed in the Ausneh ^¬ tion 26 of the housing 16.

The heat sink 18 is designed to conduct the heat loss of the arranged in the housing 16 LED electrically conductive and connected, for example, with an anode of the LED. The power loss of the LED, which is released during its operation as heat loss is so particularly effi ^¬ cient coupled into the existing example of copper, elec ^{¬ ¬} electrically conductive zone 22 of the board 10. The associated cooling of the LED is particularly important when using a high-power LED in order to not be shortened by high temperatures.

As can be seen in FIG. 2, the board contact element 20, which in the present case is designed as an electrically non-conductive heat-conducting adhesive, is partially sunk in the recess 26 of the housing 16. The embodiment of the recess 26 shown in Fig. 2 thus allows a particularly accurate insertion of the thermal adhesive. Even with respect to the board contact element 20 inclined or laterally offset mounting of the electronic component 12 is a galvani ^¬ cal insulation of the heat sink 18 of the cooling, presently made of copper zone 22 of the board 10 ge ^¬ give.

The board contact element 20 may alternatively be formed as a heat ^¬ conductive paste. A use of heat ^¬ conductive adhesive or thermal compound is particularly preferable if the LED pre-mounted plastic lenses, so that the electrically coupled to the LED heat sink 18 can not be soldered by means of a reflow soldering to the board 10. The heat-conducting adhesive is, as shown in Fig. 2, up to an outer edge 32 of the heat sink 18 formed flat. An isolati ^¬ onsstrecke between the heat sink 18 and the surface 24 of the board 10 is always guaranteed. This allowed ^¬ light one optimized for thermal management of the LED out ^¬ blank layout or design of the board 10th

In Fig. 3 a schematic view is berfläche in a mon ^¬ oriented state of the electronic component 12 of the O- 24 of the board 10 opposite bottom of the electronic component shown in FIG. 2. In the substantially circular recess 26, the substantially round heat sink 18 is arranged sunk. Au ^¬ ßerdem are arranged in the housing 16 includes two channels 34 which are radially from the recess 26 away leader ausgebil ^¬ det. Is introduced in the mounting of the electronic component 12 on the board 10 thermally conductive adhesive in the recess 26, an excess amount of heat ^¬ conductive adhesive can escape through the channels 34 out of the recess 26th A metered when fitting the circuit board 10 in the surplus amount of thermally conductive adhesive, thus ensuring ei ^¬ ne maximum contact area of the platinum contact element 20 to the heat sink 18 and for a particularly efficient dissipating the heat loss.

4 shows a schematic sectional illustration through the housing 16 and the channel 34 of the electronic component 12 arranged on the underside of the housing 16 along a line IV-IV indicated in FIG. 2.

Of course, the channel 34 may also have a different cross-sectional shape than shown in Fig. 4. Likewise, in alternative embodiments, more or less than two channels 34 or similar hollow shapes may be provided in the housing 16, which are at least sectionally ^fashioned leading away from the recess. These can also be executed blind in the housing 16 ending. It can be arranged in the housing 16 and more than one LED or the like electronic components such as transistors or rectifier diodes.

The LED has an operating mode at a power consumption associated with a given operating state. loss of energy, which is mainly released as heat loss. Therefore, the LED can be described by an operating ^loss power, in particular by the maximum power loss corresponding to the maximum power consumption.

In a method for producing the electronic component 12 shown in FIG. 2 in a preferred embodiment with the electrically conductive heat sink 18 and with the housing 16 for receiving the at least one LED that can be written by the operating power loss, first the operating power loss at maximum power consumption is determined. The thickness 30 of the heat sink 18 is tuned to the maximum operating power dissipation of the LED. The depth 28 of the recess 26 of the housing 16 is greater than the thickness 30 of the heat sink 18 dimensioned so that the heat sink 18 is completely sunk in the recess 26 of the housing 16 when arranged in the recess 26. The heat sink 18 is then foamed, for example in egg ^¬ nem molding method by insert molding or posterior surrounded together with the electrically coupled to the LED heat sink 18 to the housing sixteenth In this case, the LED can already have a pre-assembled plastic lens.

It is also conceivable to tune the thickness 30 of the heat sink 18, for example, to a corresponding with a normal operation of the LED operating power loss.

Claims

claims

An electronic component having an electrically conductive heat sink (18) and a housing (16) for receiving at least one LED, characterized in that the housing (16) has a recess (26) for arranging the heat sink (18), which has a Thickness (30), wherein the recess (18) has a depth (28) which is adapted to the thickness (30) of the heat sink (18) such that the heat ^¬ sink (18) after their arrangement in the recess ( 26) is at least partially recessed in the recess (26) of the housin ^¬ ses (16).

2. Electronic component according to claim 1, characterized ge ^¬ indicates that the depth (28) of the recess (26) is greater than or equal to the thickness (30) of the heat sink (18).

3. Electronic component according to claim 2, characterized ge ^¬ indicates that a board contact element (20) is provided, by means of which the heat sink (18) to a board (10) can be coupled, wherein the depth (28) of the recess (26) in such a way is dimensioned such that after coupling the heat sink (18) to the board (10) by means of the board contact element (20), the board contact element (20) at least partially recessed in the recess (26) of the housing (16).

4. Electronic component according to claim 3, characterized ge ^¬ indicates that the board contact element (20) is electrically non-conductive.

5. Electronic component according to claim 4, character- ized in that the board contact element (20) at least up to an outer edge (32) of the heat ^{sink ¬} (18) is flat.

6. Electronic component according to one of claims 1 to

5, characterized in that in the housing (16) at least one channel (34) is provided, which at least partially radially from the recess

(26) is formed leading away.

7. Electronic component according to one of claims 1 to

6, characterized in that the electronic component (12) is formed surface mountable.

8. System with an electronic component (12) according to any one of claims 2 to 7, and a board (10), characterized in that the board (10) at ^¬ least in the region of the platinum contact element (20) (an electrically conductive zone 22 ) having.

9. A method for producing an electronic component (12) with an electrically conductive heat sink (18) and with a housing (16) for receiving at least one ^{¬ be described} by an operating power loss LED with the following steps: a. Determining the operating power loss; b. Determining a thickness (30) of the electrically conductive heat sink (18) tuned to the operating power dissipation; c. Sizing a depth (28) of a recess (26) of the housing (16) such that the heat sink

(18) is sunk at least partially in the recess (26) of the housing (16) when arranged in the recess (26); and d. Surround at least the heat sink (18) with the housing (16).