An electric and/or electronic circuit including a printed cir ^¬ cuit board, a separate circuit board and a power connector The present invention relates to an electric and/or electronic circuit including a printed circuit board, at least one sepa ^¬ rate circuit board and at least one power connector for said printed circuit board. A power connector on a printed circuit board is usually me ^¬ chanically fastened and electrically connected by the through- hole-technology. Such a power connector comprises one or more pins penetrating through the printed circuit board. Said pins are connected by a solder point on the printed circuit board.

However, the through-hole-technology cannot be applied on an IMS (insulated metal substrate) printed circuit board. The IMS printed circuit board includes a metal baseplate, which is mostly made of aluminium and sometimes made of copper. Said metal baseplate is covered by a thin layer of a dielectric ma ^¬ terial, e.g. an epoxy-based layer, and a layer of copper. The layer of copper is subdivided into a plurality of areas, which are electrically insulated from each other. Electric and/or electronic components can be attached only on the side of the layer of copper. Thus, the SMD (surface mount device) technol ^¬ ogy is preferred for mounting electric and electronic compo ^¬ nents on the IMS printed circuit board.

In particular, the power connector, if attached by the SMD technology, is fragile, when a wiring counterpart of the power connector is plugged to or unplugged from said power connector In this case, a relative high force acts on the SMD connection between the power connector and the IMS printed circuit board. It is an object of the present invention to provide a circuit including a printed circuit board and at least one power con- nector, wherein the power connector is provided for the printed circuit board and attached with a sufficient stability at said printed circuit board. The object of the present invention is achieved by the circuit according to claim 1.

According to the present invention the electric and/or elec ^¬ tronic circuit includes a printed circuit board, at least one separate circuit board and at least one power connector for said printed circuit board, wherein:

the at least one power connector is connected or connect- able to a corresponding counterpart,

a number of electric and/or electronic components is sold at the separate circuit board,

the at least one separate circuit board is fastened at the printed circuit board by a number of solder joints,

the solder joints are connected to the separate circuit board by a through-hole-technology,

- the solder joints are connected to the printed circuit

board by SMD (surface mount device) technology, and

at least one power connector is fastened at the separate circuit board by the through-hole-technology. The main idea of the present invention is that the power con ^¬ nector is fastened on the separate circuit board by through- hole-technology, while said separate circuit board in turn is fastened on the printed circuit board by SMD technology. Since the separate circuit board is fastened with several solder joints, the forces are distributed to said solder joints, when the wiring counterpart of the power connector is plugged to or unplugged from said power connector.

Preferably, the printed circuit board is an IMS (insulated metal substrate) printed circuit board. Thus, substantial parts of the circuit may be arranged on the printed circuit board. In particular, at least one electric and/or electronic compo ^¬ nent is fastened at the separate circuit board by the through- hole-technology . Alternatively or additionally, at least one electric and/or electronic component is fastened at the separate circuit board by the SMD technology.

For example, the at least one the power connector is formed ac- cording to the standard "RAST5".

Further, the counterpart connected or connectable to the power connector is a wiring counterpart. Moreover, the separate circuit board is covered by a plastic box. The plastic box increases the security.

In particular, the IMS printed circuit board includes a metal baseplate .

Preferably, the metal baseplate is made of aluminium.

Alternatively, the metal baseplate may be made of copper. Further, the metal baseplate is covered by a layer of a dielec ^¬ tric material.

For example, the layer of the dielectric material is an epoxy- based layer.

In particular, the layer of the dielectric material is covered by a layer of copper.

Preferably, the layer of copper is subdivided into a plurality of areas, which are electrically insulated from each other. At last, the layer of copper is subdivided according to a wir ^¬ ing scheme of the circuit.

Novel and inventive features of the present invention are set forth in the appended claims.

The present invention will be described in further detail with reference to the drawings, in which

FIG 1 illustrates a perspective top view of a separate cir ^¬ cuit board for the circuit according to a preferred em ^¬ bodiment of the present invention,

FIG 2 illustrates a perspective bottom view of the separate circuit board for the circuit according to the pre ^¬ ferred embodiment of the present invention, and

FIG 3 illustrates a partial perspective view of the circuit according to the preferred embodiment of the present invention .

FIG 1 illustrates a perspective top view of a separate circuit board 10 for the circuit according to a preferred embodiment of the present invention.

The separate circuit board 10 comprises a number of power con ^¬ nectors 12. In this example, the separate circuit board 10 com ^¬ prises four power connectors 12. The power connectors 12 are attached on the separate circuit board 10. The power connector 12 includes one or more pins, and the separate circuit board 10 allows the through-hole-technology, so that the power connec ^¬ tors 12 are fastened by the through-hole-technology. Further, the separate circuit board 10 comprises electric and/or elec ^¬ tronic elements. In this example, the separate circuit board 10 comprises a number of capacitors 14, wherein the separate cir ^¬ cuit board 10 forms a capacitor block provided for the circuit. Moreover, the separate circuit board 10 comprises five solder joints 16 for fastening said separate circuit board 10 on an IMS (insulated metal substrate) printed circuit board 20. In this example, the five solder joints 16 are L-shaped pins. One end of each L-shaped pin is fastened at the separate circuit board 10 by the through-hole-technology. The other end of each L-shaped pin is fastened at the IMS printed circuit board 10 by the SMD (surface mount device) technology. Both ends of each L- shaped pin are soldered. The five solder joints 16 allow a suf- ficiently strong connection between the separate circuit board 10 and the IMS printed circuit board 20.

In this example, the power connectors 12 are formed according to the standard "RAST5". The power connectors 12 are provided for the connection to corresponding wiring counterparts.

FIG 2 illustrates a perspective bottom view of the separate circuit board 10 for the circuit according to the preferred em ^¬ bodiment of the present invention. FIG 2 clarifies that the power connectors 12, the capacitors 14 and the solder joints 16 are fastened at the separate circuit board 10 by the through- hole-technology. The bottom side of the separate circuit board 10 comprises solder points 22 for the through-hole-technology connections .

FIG 3 illustrates a partial perspective view of the circuit ac ^¬ cording to the preferred embodiment of the present invention. The circuit includes the IMS printed circuit board 20 and the separate circuit board 10, wherein said separate circuit board 10 is covered by a plastic box 18.

The IMS printed circuit board 20 includes a metal baseplate, which is made of aluminium. Alternatively, the baseplate may be made of copper. Said metal baseplate is covered by a thin layer of a dielectric material. For example, said dielectric material is an epoxy-based layer. In turn, the layer of the dielectric material is covered by a layer of copper. The layer of copper is subdivided into a plurality of areas according to the wiring scheme of the circuit. Said areas are electrically insulated from each other. Electric and/or electronic components 24 are arranged on a top side of the IMS printed circuit board 20. The layer of copper is also arranged on the top side of the IMS printed circuit board 20. The electric and/or electronic compo ^¬ nents 24 are attached on the side of the layer of copper by the SMD (surface mount device) technology. The separate circuit board 10 is fastened on the IMS printed circuit board 20 by the SMD technology. One end of the five solder joints 16, which are formed as L-shaped pins, is fas ^¬ tened on the IMS printed circuit board 20 by the SMD technology in each case. In contrast, the other end of the five solder joints 16 is fastened at the separate circuit board 10 by the through-hole-technology in each case. In FIG 3, the separate circuit board 10 is covered by the plastic box 18 and not visi ^¬ ble. However, the power connectors 12 are arranged outside the plastic box 18.

When the wiring counterpart of the power connector 12 is plugged to or unplugged from said power connector 12, then the occurrent force between the power connector 12 and the IMS printed circuit board 20 is distributed to the five solder joints 16. Thus, the power connector 12 is attached with a suf ^¬ ficient stability at the IMS printed circuit board 20.

Although an illustrative embodiment of the present invention has been described herein with reference to the accompanying drawings, it is to be understood that the present invention is not limited to that precise embodiment, and that various other changes and modifications may be affected therein by one skilled in the art without departing from the scope or spirit of the invention. All such changes and modifications are in- tended to be included within the scope of the invention as de ^¬ fined by the appended claims. List of reference numerals

10 separate circuit board

12 power connector

14 capacitor

16 solder joint

18 plastic box

20 insulated metal substrate (IMS) printed circuit board

22 solder pad

24 electric and/or electronic components