DE202005019094U1 - Electrical circuit for electrical lines and for cooling of components of electrical circuit has metal core printed circuit board with metal core layers are separated with isolation layers forming high current path - Google Patents

Abstract

The electrical circuit has metal core printed circuit board (10) and the metal layers are separated by the isolation layers and have conduction strips (17). The two metal cores are separated by isolation forming high current path. The arrangement has several power transistor (14), which are coupled with one of metal core through connection elements (33,34) for cooling of components.

Description

The The invention relates to an electrical circuit with a metal core board.

The electrical or electronic components and cable connections electrical circuits are conventionally on printed circuit boards (boards) arranged that this electrically insulating material (eg FR4) continuously exhibit. Multilayer printed circuit boards are also available with a variety provided by intermediate layers, on or in which electrical conductors are formed (interconnection layers).

In addition, so-called metal core circuit boards are known in the prior art, which have at least one metal core layer, which is covered on top and bottom sides with an insulation material layer. Such metal core circuit boards have good mechanical stability. In addition, the metal core layer (s) may be used to conduct electrical currents and to cool components of the electrical circuit (see DE 203 09 692 U1 . DE 101 02 353 A1 . DE 42 18 419 C2 and JP 0 501 3972 A ).

Of the Invention is based on the object, an electrical circuit with a metal core board to create an effective Thermal connection of power dissipation generating components and the leadership allows high electrical currents.

• – einer Metallkernleiterplatte, die eine Metallkernlage und ober- und/oder unterhalb dieser eine Isolationsmateriallage sowie auf zumindest einer von diesen Leiterbahnen aufweist, wobei die Metallkernlage mindestens zwei und elektrisch voneinander isolierte Metallkerne aufweist,
• – einem Hochstrompfad, der von den mindestens zwei Metallkernen gebildet ist, und
• – mehreren elektrischen Leistungsbauelementen, die jeweils einen Leitungspfad mit Anschlusselementen aufweisen,
• – wobei die Leistungsbauelemente zwecks Kühlung mit einem der Metallkerne thermisch gekoppelt und die Leitungspfad-Anschlusselemente zwecks elektrischer Verbindung zweier Metallkerne mit diesen elektrisch gekoppelt sind.

To solve this problem, an electrical circuit is provided with the invention, which is provided with

• A metal core circuit board having a metal core layer and an insulating material layer above and / or below it and at least one of these conductor tracks, the metal core layer having at least two metal cores which are electrically insulated from one another,
• A high current path formed by the at least two metal cores, and
• A plurality of electrical power components each having a conduction path with connection elements,
• - Wherein the power components for the purpose of cooling with one of the metal cores thermally coupled and the line path connection elements for the purpose of electrical connection of two metal cores are electrically coupled thereto.

The electrical according to the invention Circuit is with (in particular) semiconducting power devices each one (in particular) with respect to their electrical conductivity have controllable conduction path with connection elements. In these Power devices are in particular transistors. The metal core board of the circuit according to the invention also has a multi-part metal core layer, the at least two in particular adjacent and electrically isolated metal cores having. According to the invention Conduction path of at least one of the power devices with the two Metal core layers electrically connected, leaving a high current path the electrical circuit from the one metal core over the Wiring path of the relevant power device to the aforementioned Metal core extending adjacent to other metal core. In addition is provided according to the invention, that the power component for the purpose of cooling thermally with one of Metal cores is coupled.

The Use of a split metal core layer of a metal core board for power supply has the advantage of being over the metal core relatively high currents (greater than 150 A and in particular up to 800 A) can be performed. This allows it, the inventive electrical Circuit for high-level controllers Switching capacity such. B. in the automotive field for electric heaters and Blower regulator use. With the conventional concepts the power electronics needed separate busbars with high assembly and production costs. Furthermore, this also increases the space requirement associated. The separate busbars must fit well with the circuit board be tethered, which means that in operation and during assembly relatively high mechanical and electrical voltages on the printed circuit board and thus applied to the components. moreover is the conventional concept the power electronics also also not taken into account, the circuit board for cooling purposes use.

With the invention, it is now possible to electrically connect high-power components both electrically insulated with metal cores isolated from each other and to couple thermally with at least one of the metal cores. While conductor tracks and electrical components not designed for high current application are arranged on the insulation material layer, ie on the upper side of the metal core circuit board, the power components can be electrically connected to the next layer under the previously known mounting plane, that is to say to the metal core layer. This can be done for example by contacting and / or blind holes. By simplifying the Pluspotential- and ground potential leadership on the electrically isolated metal cores of the metal core board, there are further advantages in equipping, since a pure SMD assembly in one plane is possible. By eliminating separate busbars is thus the problem of electrical connection of these busbars to the circuit board and here in special the relevant critical solder joints omitted.

Next the in several respects advantageous electrical connection of the Power components to the electrically isolated metal cores of Metal core layer of a metal core board is but the metal core board in the circuit according to the invention also for the heat distribution and removal of the power components effectively used. About the Metal core layer results in a homogeneous heat distribution, which exceeds it allows the temperature detection to optimize and higher power losses to allow in the power components.

in the Case of implementation of the electrical circuit of a vehicle auxiliary heater with electrical (for example PTC) heating elements according to the inventive concept The metal cores function electrically like busbars. The single ones electric power components, which are in the case of a Automotive auxiliary heater to power transistors is, are with the one their connection element assigned to the controllable line path electrically connected to one of the metal cores. That lie the electrical power components parallel to each other. Advantageous it is when the metal cores start from their high current infeed or high current discharge ports consider decreasing in their latitudes; because with increasing distance from the Hochstromeinspeisungs- or Hochstromabführungsstelle the metal cores reduces the current still to be carried by the metal core high current.

The the high-current guide serving metal cores can over or be arranged side by side. The first case requires one electrical contacting of the lower metal core by the upper Metal core, wherein the contact with respect to the upper metal core isolated have to be. In terms of the contacting of the metal cores is advantageous if this be arranged side by side.

In this regard of It is an advantage if the high-current infeed and high-current discharge connections of two adjacent metal cores at opposite ends of the metal core layer are arranged and in plan view of the metal core board considered, occupied by the two metal cores surface substantially rectangular with a substantially along the diagonal running Separation area is formed. Preferably, the are High current injection and high current discharge connections in opposite Corner areas of the substantially rectangular metal core board.

As mentioned above, is at least according to the invention one of the power components thermally to one of the metal cores coupled. about This metal core is the removal of the distribution in shape of heat present power loss. To further optimize this process it is useful if the metal core board has another metal core layer, the opposite the multi-part metal core layer electrically insulated and thermally good is coupled. This further metal core layer extends over two adjacent metal cores of the electrical and thermal with the power devices coupled metal core layer. One of the metal cores of this metal core layer leads the Heat of the power components from. This heat will then be transferred to the further metal core layer, which in turn for a further discharge and Distribution of the loss energy into another metal core of the adjacent metal core layer provides.

The Invention will be described below with reference to the drawing an embodiment explained in more detail. in the single show:

1 a plan view of a circuit board with assembled power components and indicated interconnects, as used for example for the electrical circuit of a motor vehicle auxiliary heater, and

2 a section along the line II-II of 1 ,

1 shows in plan view a metal core board 10 on top of it 12 several power transistors 14 are arranged. The other electrical or electronic components as well as conduction paths of the metal core circuit board 10 worn electrical circuit are for reasons of simplicity in the Fign. not shown.

The metal core board 10 shows how to use the 1 and 2 it can be seen, a top-side insulation layer 16 on, among other things, interconnects 17 are formed. Below this insulation layer 16 there is a first metal core layer eighteen , the two electrically isolated metal cores 20 . 22 having. Below this first metal core layer eighteen there is a second metal core layer 24 , which has a continuous metal core 26 which extends over the whole of the two metal cores 20 and 22 the first metal core layer eighteen occupied surface area extends. Between the two metal core layers eighteen and 24 and underside of the second metal core layer 24 there are insulation layers 28 . 30 , The production of the metal core board 10 For example, by laminating the individual layers, as is customary in the production of metal core circuit boards per se. For the material of the metal cores 20 . 22 respectively. 26 it is preferably copper.

As based on 1 can be seen, runs the electrical separation area 32 between the two metal cores 20 and 22 essentially along the diagonal, causing the two metal cores 20 and 22 have a shape that varies in width.

The peculiarity of the metal core board 10 is that the high power components having high power losses 14 electrically and thermally with the metal cores 20 and 22 the first metal core layer eighteen are coupled.

According to the invention, the two metal cores 20 and 22 used for high-current conduction, these high currents also through the parallel-connected power devices 14 flow. As indicated in the drawing, the housing 33 the power transistors 14 with the metal core 20 electrically connected during one (or more parallel) connection legs 34 with the metal core 22 are electrically connected. The housing 33 and the connecting pins 34 So form the lead out of the power transistors connection elements of the respective conduction paths of the power transistors

The current distribution within the metal cores 20 and 22 is in 1 indicated. The power supply and current discharge connections of the two metal cores 20 and 22 are at 36 respectively. 38 indicated. Near the connections 36 and 38 must the current carrying capacity of the metal cores 20 and 22 be the biggest. This is inventively ensured by the fact that the metal cores 20 and 22 have maximum width in these areas.

With the electrical contacting of the housing 33 the power transistors 14 with the metal core 20 is also accompanied by a thermal coupling of these two components. In the exemplary embodiment, the electrical contacting of the power transistors 14 with the metal core 20 for reasons of simplification, the undersides of the housing 33 the metal core 20 Contact the whole area. Alternatively and practically feasible, it is possible that the upper-side insulation layer 16 also between the housings 33 and the metal core 20 extends and that through the insulation layer 16 Through holes or blind holes run, both for the electrical and the thermal connection of the housing of the power transistors 14 to the metal core 20 to care.

Due to the thermal connection of the power transistors 14 to the metal core 20 This ensures the distribution and dissipation of thermal loads, as reflected by the power dissipation in the power transistors 14 be generated. But these thermal loads are not just about the metal core 20 distributed and dissipated but also on the metal core 26 the further metal core layer 24 , Because this metal core 26 down to the area of the metal core 22 the first metal core layer eighteen extends, it finally comes to a heat transfer from the metal core 26 to the metal core 22 the above the metal core 26 arranged first metal core layer eighteen , This is in 2 indicated in the drawing. In that regard, so with the two-ply metal core structure of the metal core board 10 an effective cooling option for the power transistors 14 given, in addition, the metal cores 20 and 22 serve the high-current conduction. Overall, this results in a compact high-current and high-cooling structure having structure, which is electrically, thermally and, above all, mechanically robust. Precisely these requirements play an important role in the automotive sector, which is why the inven tion proper electrical circuit is particularly suitable for use in control units for high-current, automotive components such as electric booster heaters and fan controller.

10

Metal core printed circuit board

12

top

14

power transistors

16

topside insulation layer

17

conductor tracks

18

first Metal core layer

20

isolated metal cores

22

isolated metal cores

24

second Metal core layer

26

through metal core

28

insulation layers

30

insulation layers

32

separation area

33

Housing / terminal

34

connecting pins

36

connections

38

connections

Claims (5)

Electrical circuit with - a metal core board ( 10 ), which has a metal core layer ( eighteen ) and above and / or below this an insulation material layer ( 16 . 26 ), as well as on at least one of these tracks ( 17 ), wherein the metal core layer ( eighteen ) at least two electrically isolated metal cores ( 20 . 22 ), a high-current path which is separated from the at least two metal cores ( 20 . 22 ), and - a plurality of electric power devices ( 14 ), each having a conduction path with connection elements ( 33 . 34 ), wherein the power components ( 14 ) for cooling with one of the metal cores ( 20 . 22 ) are thermally coupled and the line path connection elements ( 33 . 34 ) for the purpose of electrical connection of two metal cores ( 20 . 22 ) are electrically coupled with these. Electrical circuit according to claim 1, characterized in that the conduction paths of the two metal cores ( 29 . 22 ) connecting power components ( 14 ) are connected in parallel with each other. Electrical circuit according to claim 1 or 2, characterized in that the metal cores ( 20 . 22 ) High current injection or high current discharge terminations ( 36 . 38 ) and that the widths of the metal cores ( 20 . 22 ) from their high current injection or high current discharge ports ( 36 . 38 ) reduce. Electrical circuit according to Claim 3, characterized in that the high-current injection and high-current discharge connections ( 36 . 38 ) of two adjacent metal cores ( 20 . 22 ) at opposite ends of the metal core layer ( eighteen ) and that in plan view of the metal core board ( 10 ), of the two metal cores ( 20 . 22 ) occupied area substantially rectangular with a substantially along the diagonal separating region ( 32 ) is trained. Electrical circuit according to one of claims 1 to 4, characterized in that the metal core circuit board ( 10 ) another metal core layer ( 24 ), both metal core layers ( eighteen . 20 ) are electrically isolated from each other and the further metal core layer ( 24 ) based on the two metal cores ( 20 . 22 ) is arranged overlapping with these.