DE102009047569A1 - Light i.e. LED, manufacturing method, involves providing integral part in contact with another integral part during arrangement of heat conductive elements, so that heat is discharged from driver circuit during actuation of light - Google Patents

Abstract

The method involves actuating a light i.e. LED, in a driver circuit (12) that is formed as an integral part, where one of the integral part is provided with heat conductive elements (26, 28). Housing (10) is designed as another integral part. The former integral part is provided in contact with the latter integral part during arrangement of the elements, so that heat is discharged from the driver circuit through the elements during an actuation of the light. One of the elements is deformed, so that a contact surface of the elements is extended with the latter integral part. An independent claim is also included for a light comprising housing.

Description

Technical area

The invention relates to a method for producing a lamp which comprises as a first component a circuit arrangement for operating a luminous means and as a second component a housing, wherein in the method the circuit arrangement is arranged in the housing. The invention also relates to a lamp having a housing as a first component and having a circuit arrangement arranged in the housing as a second component. The term lamp is hereinafter referred to an electrically operable light source, as they can be used in sockets of lights to hold the lamp in the lamp and to provide them with voltage and power.

State of the art

To generate light, light-emitting diodes (LED - Light Emitting Diode) can be provided as lighting means in a lamp. These have a particularly high efficiency. Similarly efficient are also gas discharge lamps, in which light can be generated by a gas discharge in a container filled with a gas. To operate a light emitting diode and to generate a gas discharge, an additional electrical driver circuit is required in the corresponding lamp. By means of this driver circuit, the voltage provided to the socket is converted to operate the respective lighting means. The driver circuit is located in a housing of the lamp. On the one hand, this protects the driver circuit from mechanical damage and, on the other hand, prevents an electrical short circuit from occurring between an electrical component of the driver circuit and another component of the lamp.

The driver circuit often consists of a plate of an electrically insulating material to which electrical and electronic components are attached. Between contacts of the components while electrical lines are provided on the plate, via which individual contacts are electrically connected to each other. The components and the lines together form a circuit arrangement. The leads and the plate may be provided together in the form of a single- or multi-layer printed circuit board (PCB). In the case of a multilayer printed circuit board, lines are provided not only on a surface of the board but also inside the board. The circuitry may also include one or more additional layers or sheets of a conductive material which may be mounted on or, in the case of a multilayer circuit board, also in the drive circuit board. Such a layer may be provided for distributing heat in the driver circuit. In the following, such a layer is also considered to belong to the circuit arrangement, even if it does not electrically connect two components with one another. By contrast, a plate made of an electrically insulating material on which the circuit arrangement can be arranged does not itself belong to this circuit arrangement.

The driver circuit thus comprises the plate of an electrically insulating material and the circuitry carried thereby. In a housing, such a driver circuit may be fixed by holding the plate made of the electrically insulating material in a holding device of the housing.

During operation of a lamp, the circuit arrangement of the driver circuit heats up. The components and the lines then release this heat to the air in the vicinity of the driver circuit. Since the driver circuit is located in a housing, the warm air can not, for. B. by convection, away from the circuitry and thereby cool them. It therefore accumulates the heat in a space between the driver circuit and a wall of the housing. The temperature inside the housing, in particular the temperature of the components and the lines, can thereby rise to an undesirably high level. The components then age faster, resulting in a shortened overall operating life of the lamp.

In order to be able to cool the circuit better, it can be thermally connected to the housing wall. As a result, the insulating air layer is bridged, which is located between the circuit arrangement and the housing. A thermal connection of the circuit arrangement to the housing can be achieved in that after arranging the driver circuit in the housing, this is filled with synthetic resin. However, this requires an additional step in the manufacture of such a lamp. Accordingly, then the price for the production of the lamp becomes more expensive. In addition, a resin cast with a lamp is relatively heavy.

Presentation of the invention

It is an object of the present invention to provide a way to inexpensively avoid unwanted heating of a circuit arrangement of a lamp can.

The object is solved by en method for producing a lamp according to claim 1. The object is also achieved by a lamp according to claim 5. Advantageous developments of the method and the lamp according to the invention are given by the dependent claims.

The method according to the invention for producing a lamp relates to a lamp comprising, as a first component, a circuit arrangement for operating a luminous means and, as a second component, a housing. In the method, the circuit arrangement is arranged in the housing. In a first step of the method, at least one of said components of the lamp is provided with at least one heat-conducting element. When arranging the circuit arrangement in the housing, the at least one heat-conducting element of the at least one component is then brought into contact with the respective other component, so that heat is dissipated from the circuit arrangement via the heat-conducting element during operation of the lamp. Under heat conduction here is the transport of heat energy within a solid and the exchange of heat between two solids to understand. A heat conducting element can be provided in accordance with an implementation of the invention by a separate solid or by a suitable shape of the housing or the circuit arrangement. If it is a separate solid, it can then be brought together with one of the components before or during the placing in a suitable position. By providing a heat-conducting element together with one of the components, ie the circuit arrangement or the housing, a heat-conducting connection results automatically during the arrangement of the circuit arrangement in the housing, namely when the heat-conducting element of one component contacts the respective other component.

The housing no longer has to be potted with a synthetic resin in order to ensure improved heat conduction between the circuit arrangement and a wall of the housing. This eliminates a complete step in the manufacture of the lamp. This advantageously reduces the cost of manufacturing such a lamp compared to a lamp with a molded housing. Another advantage is that the heat-conducting elements can be made of a material that conducts heat particularly well. Then the heat-conducting elements can also be very light.

An advantageous development of the method according to the invention results if, when arranging the circuit arrangement in the housing, at least one heat-conducting element is deformed and as a result a contact surface of the heat-conducting element with the other component is increased. Preferably, the heat-conducting element is subjected to deformation with a force and / or heated. By deforming the heat-conducting element in the manner mentioned, the heat-conducting element adapts to a shape of the other constituent. The resulting enlarged contact surface advantageously improves the heat conduction. There may be other benefits. If the heat-conducting element is deformed by application of a force, it can also be ensured by means of the heat-conducting element that the circuit arrangement sits without play in the housing. If the heat-conducting element is heated to deform, there is the advantage that it is particularly easy to adapt a shape of the heat-conducting element to an outer shape of components of the circuit arrangement.

In another advantageous development of the method according to the invention, in the step of arranging the circuit arrangement is pushed along a thrust direction in the housing and thereby rotated about an axis which is determined by the thrust direction. This can be z. B. be advantageous in the following case. It is conceivable that a housing has in its interior one or more heat-conducting elements in the form of soft plastic lamellae. Then it can be provided that these plastic slats are pushed aside during insertion of the circuit arrangement in the housing by components of the circuit arrangement and thereby deformed in the manner already described. But then there is the risk during insertion that a component of the circuit is torn off. This is particularly likely if one of the heat-conducting elements has an edge and the component is pressed against it when the circuit arrangement is inserted. By rotating the circuit arrangement during insertion, it is advantageously ensured that a component slides laterally past such an edge and thus is not torn off.

The lamp according to the invention comprises a housing as a first component and a circuit arrangement arranged in a space of the housing as a second component. At least one of the components in this case comprises at least one heat-conducting element, which contacts the respective other component and via which heat can be derived from the circuit arrangement. In the case of the lamp according to the invention, therefore, a heat-conducting element can extend from the circuit arrangement to the housing and touch it. It can also be provided that the housing has such a heat-conducting element which conversely the circuit arrangement is touched. Of course, a combination of these two principles is possible. Likewise, each of the two components of the lamp can also have a plurality of heat-conducting elements. In the context of the invention, a heat-conducting element which is provided together with the housing does not mean the abovementioned holding device, by means of which the plate on which the circuit arrangement can be arranged can be held in the housing. Namely, this holding means touches only the plate, not the circuit arrangement.

The heat-conducting elements make it possible for heat to be dissipated directly from the circuit arrangement, that is, from the components of the driver circuit or their electrical lines.

Preferably, at least one of the heat-conducting elements is formed integrally with the housing. As a result, the lamp according to the invention can be produced particularly inexpensively.

In a further embodiment of the lamp according to the invention at least one heat-conducting element is formed by an extension which protrudes from a wall of the housing into the room and touches the circuit arrangement, ie in particular an electrical or electronic component and / or a conductor element thereof.

Such an extension may for example have the shape of a lamella or a web. Such a lamella can then be attached to the wall. Another example of such extensions are tips or fibers that protrude from the wall into the room.

Preferably, a web is arranged as a heat conducting element on a wall of a housing. By such a web, which extends along a wall of the housing, heat can be distributed particularly well along the wall. A housing with such an inner web is also particularly inexpensive to produce - for example by means of an injection molding process. The housing preferably has the shape of a hollow cylinder, d. H. a tube. The web then preferably extends parallel to an axis of the hollow cylinder. He can also z. B. be arranged spirally around this axis.

In the wall of the housing, an access opening for introducing the circuit arrangement may be provided in the room. If this housing then also has a web as already described, the result is an advantageous development of the lamp according to the invention if an access opening facing the end of the web is wedge-shaped and thus the space seen from the access opening through the web funnel-shaped is narrowed. The web then has no edge against which a component of the circuit arrangement could encounter during insertion of the same into the housing. As a result, it is advantageously prevented that the circuit arrangement is damaged during insertion into the housing.

As already described in the introduction, the housing may have a holding device, by which an edge of a plate is held, on which the circuit arrangement is arranged. For this case, an advantageous development of the lamp according to the invention results if at least one heat-conducting element is arranged on the edge. Such a heat-conducting element may in particular be a strip of solder. With a solder here is meant a solder, z. As a solder, via which also contacts of the components of the circuit arrangement can be soldered to the electrical lines.

The heat-conducting element emits heat to the holding device in this development of the lamp according to the invention. By providing a heat-conducting element in a region of a driver circuit in which a holding device of the housing acts on the driver circuit, a good conduction of the heat away from the circuit arrangement can be ensured in a particularly simple manner. A crucial difference to a lamp of the prior art is then that in the lamp according to the invention by the holding device not only the plate for the circuit arrangement, but a heat-conducting element of the circuit arrangement is touched. In a lamp according to the prior art, however, only one edge of the plate, on which the circuit arrangement is arranged, held by the holding device. But this is made of an electrically insulating material that conducts heat poorly.

In the event that the heat conducting element is a strip of solder, there are two further advantages. On the one hand, the strip of solder can be provided in the same working step, in which solder is also applied for soldering components on lines of the driver circuit. This results in the advantage that the lamp can be made particularly inexpensive, because no additional step is necessary. On the other hand, solder can be formed without requiring a particularly large force. In particular, it is thus possible in an advantageous manner for the solder to adapt to a shape of the holding device when arranging the circuit arrangement in the housing, thereby ensuring particularly good heat conduction.

Brief description of the drawings

The invention will be explained in more detail below with reference to preferred embodiments of the lamp according to the invention. This shows:

1 a schematic representation of a housing and a driver circuit, which are located in a lamp according to an embodiment of the lamp according to the invention;

2 a section of the presentation 1 ;

3 a perspective view of a portion of a housing for a lamp according to an embodiment of the lamp according to the invention;

4 a lamp body with a base in cross-section, wherein the lamp body is part of a lamp according to an embodiment of the lamp according to the invention; and

5 a section of the representation of 4 ,

Preferred embodiment of the invention

In 1 are a housing 10 and a driver circuit located therein 12 shown in cross section. You are in a 1 not shown lamp body of a lamp which is screwed into a socket of a ceiling light. The lamp has a in 1 Edison socket not shown in accordance with the Standard E24 on. By means of the driver circuit 12 LEDs are operated the lamp.

The housing 10 has a wall 14 on, through which an interior 16 is enclosed. The wall has the shape of a cylinder which is perpendicular to the image plane of 1 extends. The housing 10 consists of a plastic. The plastic has a coefficient of thermal conductivity which is greater than that of air.

The driver circuit 12 in the interior 16 consists of a circuit board 18 on which a transformer 20 and other components, such. B. an SMD component 22 (SMD - surface mounted device) are soldered. The board 18 consists of a support plate made of an electrically insulating material and copper interconnects (in 1 not shown in detail). In an area on the surface of the carrier plate in which there are no traces, the board has an additional copper layer 24 on. The board 18 is a multilayer board. Through the transformer 20 , the SMD component 22 , the remaining components as well as the conductor tracks and the copper layer 24 the board 18 a circuit arrangement is formed.

To the case 10 also include slats, of which for clarity in 1 only two with reference numerals 26 and 28 are provided. The slats 26 . 28 are integral with the wall 14 educated. The housing 10 has been manufactured in an injection molding process. Each lamella is in the form of a ridge which is parallel to the axis of the cylinder passing through the wall 14 of the housing 10 is formed. The slats 26 . 28 So run perpendicular to the image plane of 1 ,

The slat 26 touches the copper layer 24 , The slat 28 touches the SMD component 22 , More slats touch the transformer 20 or other components of the driver circuit and their interconnects. The fins have been elastically deformed during assembly of the lamp, as the driver circuit 12 in the case 10 was pushed. As the driver circuit 10 not yet in the case 10 The lamellae were starting from the wall 14 radially into the interior 16 extends. In

1 It is shown how these have adapted to the shape of the driver circuit by the elastic deformation of the slats. Due to the elastic deformation, each blade also exerts a force on the driver circuit 12 out.

The board 18 is in the case 10 through brackets 30 held, each one edge of the board 18 mounting.

In 2 is in an enlarged section one of the. brackets 30 shown again. The section corresponds to the one in 1 through a circle II delimited area. Every holder 30 consists of two walls 32 , Through the two walls 32 is a rail formed in which an edge 34 the board 18 is inserted. In the area of the edge 34 is on a copper layer, not shown, of the board 18 one solder strip each 36 on a top and a bottom of the board 18 been applied. The solder strips 36 extend perpendicular to the image plane of 2 along the edge 34 , The solder strips 36 are when plugging the driver circuit 12 in the brackets 30 deformed so that they conform to a shape of the walls 32 have adjusted. The walls 32 therefore do not have to be made very accurately. Already during the insertion process, the solder adapts to the holders due to the slight grinding movement 30 at. The housing 30 is thus very favorable in its production. By the solder strips 36 against the walls 32 Pressed, there is also the advantage that by the resulting contact pressure a good connection of a surface of the solder strips 36 to the walls 32 is guaranteed. The lot of the solder strips 36 thus creates a thermally well-conductive, metallic and relatively soft transition between the edge 34 the board 18 and the housing 10 ,

A surface of the edge 34 is outside the area where the solder strips are 36 located, with a varnish layer 38 sealed, by which underlying tracks and copper layers are protected from corrosion.

Between the walls 32 the holder 30 there is another lamella 40 of the housing 10 , The slat 40 touches the board 18 in an area where a majority is inside the board 18 located copper layer (not shown) a part of the surface of the board 18 forms. This copper layer is also part of the circuit arrangement.

The driver circuit 12 is in the by the 1 and 2 illustrated example supplied with power from the socket of the lamp, so that the light emitting diodes of the lamp light up. The transformer warms up 20 , the SMD component 22 and also the other components of the driver circuit. Part of the heat is transmitted through the printed circuit board 18 , the copper layer 24 and also inside the board 18 extending copper layer distributed. At contact points of the slats, such. B. the slats 26 and 28 , with the driver circuit 12 Heat passes from this into the slats. The transferred heat is inside the slats in the wall 14 directed. From there it will be in an environment 42 of the housing 10 issued. By the board 18 also in the area of the edge 34 Copper layers are formed and on these the solder strips 36 can be arranged, part of the heat from the components of the driver circuit 12 Diffuse to the edge and there over the solder strips 36 in the walls 32 the brackets 30 be derived.

The thermal conductivity of the material from which the housing 10 and in particular, the fins are larger than that of the air extending between the fins in the interior space 16 located. By means of the fins thus more heat from the circuit arrangement 12 to the environment 42 passed as it is possible without the slats. Therefore, the driver circuit heats up 12 less during operation. This prolongs a life of the components of the driver circuit 12 ,

In 3 is a housing 10 ' shown, which has a similar structure as the housing 10 having. 3 makes a longitudinal section through the tubular housing 10 ' dar. The housing 10 ' has an opening 50 through which a driver circuit similar to the driver circuit 12 in the case 10 ' can be inserted. In the case 10 ' extend along a longitudinal axis of the housing 10 ' Slats, all shaped according to the same principle. Therefore, in the following, only representative is a slat 26 ' described in more detail. The slat 26 ' points to one of the opening 50 facing the end of an area 52 in which it is tapered wedge-shaped. From the opening 50 out in one direction 54 along the longitudinal extent of the housing 10 ' Seen thus takes a height of the lamella 26 ' in the radial direction with respect to an inner wall 56 steadily too. Through the slat 26 ' is thus from the opening 50 Seen at no point one perpendicular to the direction 54 running edge formed. This prevents the insertion of a driver circuit into the housing 10 ' Components thereof through the lamella 26 ' or one of the other slats to be demolished.

The housing 10 ' unlike the case 10 No brackets on that with the brackets 30 comparable. The driver circuit can therefore when inserted into the housing 10 ' also be turned. This means that you can drive the driver along the direction 54 through the opening 50 in the case 10 ' while rotating it can rotate around an axis, with the direction 54 coincides. As a result, the slats are then bent to the side. This in turn additionally reduces the risk that components of the driver circuit will be damaged. The lamellae can also spiral around the longitudinal axis of the housing 10 ' on the inner wall 56 run. Then there is the same advantage as is achieved when rotating the driver circuit during insertion.

4 shows a lamp body 60 a lamp in cross section. In the lamp body 60 there is a driver circuit 62 , With the driver circuit 62 LEDs of the lamp can be operated. To supply the driver circuit 62 with electricity this is over (in 4 not shown) lines with an Edison socket 64 connected to the lamp. The driver circuit 62 corresponds in principle to the driver circuit 12 , In particular, it comprises a circuit board 66 , to which electrical and electronic components as well as a transformer 68 are soldered.

The lamp body 60 consists of a lower housing part 70 and an upper housing part 72 , The upper housing part 72 is via a snap connection 74 in the lower housing part 70 held. Through the lower housing part 70 and the upper housing part 72 is an interior 78 delimited, in which the driver circuit 62 located. The lower and the upper housing part 70 . 72 thus form, inter alia, a housing for the driver circuit 62 ,

A wall 80 of the lower housing part 70 and a wall 82 of the upper housing part 72 each have small peaks 84 on, in their entirety similar to an artificial turf from the walls 80 and 82 protrude. The tips 84 protrude into the interior 78 into it and touch parts of the driver circuit 62 ,

When operating the lamp, the driver circuit heats up 62 , About the tips 84 This is heat from the driver circuit 62 in the wall 80 and the wall 82 directed. This will prevent the interior 78 and the driver circuit 62 heat to an undesirably high temperature. Part of the heat is also about a socket 86 for the driver circuit 62 in the walls 80 . 82 directed. The version 86 is related to below 5 explained in more detail. Of course, it has nothing to do with a version in which the Edison base 64 the lamp can be screwed.

In 5 is a section of 4 shown. The clipping is in 4 marked by a circle V. In 5 is shown as through the socket 86 a border 88 the board 66 is held. Along the edge 88 extend on the board 66 solder fillets 90 , About the Lotränder 90 gets heat from copper layers on the board 66 in the walls 80 . 82 , The edge 88 is during insertion of the upper housing part 72 in the lower housing part 70 between the walls 82 and 80 been trapped. When mounting the upper housing part 72 it was a pressure on the solder edges 90 exercised, so that these have deformed and conformed to a shape of the walls 80 . 82 in the area of the version 86 have adjusted. As a result, a particularly large contact surface of the solder edges 90 with the walls 80 . 82 emerged.

Instead of the snap connection 74 can the upper housing part 72 with the lower housing part 72 also be bolted.

In the lamp body 60 may also be provided to heat this after the driver circuit 62 in the lower housing part 70 is arranged and the upper housing part 72 is mounted. In this way, the Lot of the solder edges 90 even better on the shape of the walls 80 . 82 to adjust. This is of course synonymous with other cases, such. B. the housing 10 , possible.

The tips 84 are so long that they snap into place when the upper part of the housing 72 in the lower housing part 70 at their ends, with which they drive the driver 62 touch, be bent over. As a result, they are elastically deformed and thus generate a force on the driver circuit 62 , This is particularly firm in the interior 78 fixed. In addition, this is a transfer of heat from the driver circuit 62 in the tips 84 improved.

In the examples shown, by applying heat from driver circuits to the driver circuit housing via louvers, lands and tips, the interiors of the housings need not be filled with a potting compound to prevent heat accumulation in the housings. The lamps are therefore lighter. In addition, there can be no chemical reaction between hot components and the potting compound. Even mechanical tension due to heating can be better compensated in the examples shown. Due to the good cooling, it is also possible to build the driver circuits and the housing very compact, so that with relatively small driver circuits large benefits can be provided for operating bulbs. Except for the optional heating of the housing after assembly to soften the solder of Lotränder no additional steps in the manufacture of the lamp are necessary. In particular, costs for material and tools for potting the housing accounts.

The examples show how, with the lamp according to the invention, heat can be conducted away from a driver circuit of the lamp in order to cool it. By mechanically deforming the lamellas, the solder edges and the tips during assembly, a secure fit of the driver circuits in their housings is also ensured. Therefore, it is not necessary that dimensions for the housing are kept particularly accurate, d. H. It can be allowed relatively large tolerances. This makes it possible to manufacture the housing low.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited non-patent literature

• Standard E24 [0029]

Claims (10)

Method for producing a lamp, comprising as a first component a circuit arrangement ( 12 . 62 ) for operating a light source and as a second component a housing ( 10 . 10 ' . 60 ), wherein in the method the circuit arrangement ( 12 . 62 ) in the housing ( 10 . 10 ' . 60 ), characterized by the steps: a) providing at least one of the constituents with at least one heat-conducting element ( 26 . 28 . 36 . 40 ; 26 '; 84 . 90 ); b) when arranging the at least one heat-conducting element ( 26 . 28 . 36 . 40 ; 26 '; 84 . 90 ) of the at least one component with the respective other component, so that during operation of the lamp heat from the circuit arrangement ( 12 . 62 ) via the heat-conducting element ( 26 . 28 . 36 . 40 ; 26 '; 84 . 90 ) is derived. The method of claim 1, wherein in step b) at least one heat conducting element ( 26 . 28 . 36 . 40 ; 26 '; 84 . 90 ) is deformed and thereby a contact surface of the heat conducting element ( 26 . 28 . 36 . 40 ; 26 '; 84 . 90 ) is enlarged with the other component. Method according to claim 2, wherein the heat-conducting element ( 26 . 28 . 36 . 40 ; 26 '; 84 . 90 ) is subjected to deformation with a force and / or heated. Method according to one of the preceding claims, wherein in step b) the circuit arrangement along a thrust direction ( 54 ) in the housing ( 10 ' ) and thereby about an axis, which by the thrust direction ( 54 ) is determined, is rotated. Lamp comprising - a housing ( 10 . 10 ' . 60 ) as a first component and - one in a room ( 16 . 78 ) of the housing ( 10 . 10 ' . 60 ) arranged circuit arrangement ( 12 . 62 ) as a second component, characterized in that at least one of the components at least one heat conducting element ( 26 . 28 . 36 . 40 ; 26 '; 84 . 90 ), which contacts the respective other component and via which thereby heat from the circuit arrangement ( 12 . 62 ) is derivable. A lamp according to claim 5, wherein at least one of the heat-conducting elements ( 26 . 26 ' . 28 . 40 . 84 ) in one piece with the housing ( 10 . 10 ' . 60 ) is trained. Lamp according to claim 5 or 6, wherein at least one heat conducting element ( 26 . 26 ' . 28 . 40 . 84 ) is formed by an extension which of a wall ( 14 . 56 . 80 . 82 ) of the housing ( 10 . 10 ' . 60 ) in the room ( 16 . 78 ) and which the circuit arrangement ( 12 . 62 ), in particular an electrical or electronic component ( 20 . 22 . 68 ) and / or a conductor element ( 24 ) of the same, touched. Lamp according to one of claims 5 to 7, wherein as a heat conducting element ( 26 . 26 ' . 28 . 40 ) on a wall ( 14 . 56 ) of the housing ( 10 . 10 ' ) a web is arranged. A lamp according to claim 8, wherein in the wall ( 56 ) an access opening ( 50 ) is designed for insertion of the circuit arrangement into the room and one of the access opening ( 50 ) facing end ( 52 ) of the bridge ( 26 ' ) is wedge-shaped and thereby the space from the access opening ( 50 ) seen through the bridge ( 26 ' ) is narrowed funnel-shaped. A lamp according to any one of claims 5 to 9, wherein the housing ( 10 . 60 ) a holding device ( 30 . 86 ) through which an edge ( 34 . 88 ) a plate ( 18 . 66 ) is held, on which the circuit arrangement is arranged, and on the edge ( 34 . 88 ) at least one heat conducting element ( 36 . 90 ), in particular a strip of solder, is arranged.

Images