Electronic device and method for producing an electronic device

Abstract

The invention relates to an electronic device comprising a printed circuit board (14) and comprising an electronic component (16) arranged on a first surface (15) of the printed circuit board (14). The printed circuit board (14) has a cutout (23) extending from a second surface (24) of the printed circuit board (14), said second surface being situated opposite the first surface (15), in the direction of the electronic component (16). The electronic device comprises a coolant container (25), which has an opening closed by the second surface (24) of the printed circuit board (14). The invention additionally relates to a method for producing such an electronic device.

Claims

1. An electronic device comprising: a printed circuit board; an electronic component arranged on a first surface of the printed circuit board; the printed circuit board has a cutout extending from a second surface of the printed circuit board, the second surface being situated opposite the first surface, in the direction of the electronic component; and a coolant container which has an opening closed by the second surface of the printed circuit board.

2. The electronic device as claimed in claim 1, wherein the material thickness of the printed circuit board in the region of the cutout is less than 50%, preferably less than 30%, more preferably less than 20%, with respect to the thickness of the printed circuit board.

3. The electronic device as claimed in claim 1, wherein the cutout has side faces aligned perpendicularly to the plane of the printed circuit board.

4. The electronic device as claimed in claim 1, wherein the cutout overlaps the electronic component in a direction perpendicular to the plane of the printed circuit board.

5. The electronic device as claimed in claim 1, wherein the opening of the coolant container is larger than the cutout of the printed circuit board.

6. The electronic device as claimed in claim 1, wherein the cutout is arranged completely within the opening of the coolant container.

7. The electronic device as claimed in claim 1, wherein, relative to a direction perpendicular to the plane of the printed circuit board, the extent of the coolant container is larger than the extent of the cutout.

8. The electronic device as claimed in claim 1, wherein an electrically insulating layer is arranged between the cutout and the electronic component.

9. The electronic device as claimed in claim 1, wherein a surface region of the printed circuit board that is arranged within the opening of the coolant container is electrically insulated from the electronic component.

10. The electronic device as claimed in claim 1, wherein a surface region of the printed circuit board that is in contact with the coolant is covered with a diffusion-impermeable protective layer.

11. The electronic device as claimed in claim 10, wherein the protective layer is a coating composed of Cu, Ni or Au or a layer sequence composed of said metals.

12. The electronic device as claimed in claim 1, wherein the printed circuit board comprises a plurality of electrically conductive layers, which are electrically connected to one another, and wherein all the electrically conductive layers are electrically insulated from the coolant.

13. A method for producing an electronic device, wherein a cutout is produced in a printed circuit board, said cutout extending from a second surface of the printed circuit board in the direction of a first surface situated opposite the second surface, without perforating the printed circuit board, wherein a coolant container having an opening is connected to the second surface of the printed circuit board in such a way that the opening is closed by the printed circuit board, and wherein a cooling liquid is filled into the coolant container.

14. The method as claimed in claim 13, wherein, when producing the cutout, an electrically conductive layer of the printed circuit board is cut, and wherein an electrically insulating layer is applied within the cutout, such that the surface of the cutout is electrically insulated from the electrically conductive layers.

15. The method as claimed in claim 13, wherein a diffusion-impermeable protective layer is applied on the second surface of the printed circuit board and covers at least the surface region of the printed circuit board which comes into contact with the coolant.

Description

BRIEF DESCRIPTION OF THE INVENTION

[0027] The invention is described by way of example below on the basis of an advantageous embodiment with reference to the accompanying drawing, in which:

[0028] FIG. 1: shows a schematic sectional illustration of an electronic device according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0029] An electronic device shown in FIG. 1 comprises a printed circuit board 14 with a semiconductor component 16 arranged on its top side 15 (first surface). The semiconductor component 16 is a power semiconductor in the form of a MOSFET, during the operation of which a considerable amount of heat is emitted. The semiconductor component 16 is electrically contacted with an electrically conductive layer 17 that partly covers the top side of the printed circuit board 14.

[0030] The electrically conductive layer 17 is applied on a layer 18 of the printed circuit board 14 which is electrically insulating, but may have a good thermal conductivity. The printed circuit board 14 is constructed in a multilayer fashion, which means that further electrically conductive layers 19, 20 alternating with insulating layers 21, 22 succeed one another below the electrically insulating layer 18. Between the electrically conductive layers 17, 19, 20 there are plated-through holes 22 that establish an electrical contact between different layers in the Z-direction.

[0031] A cutout or recess 23 is formed in the printed circuit board 14, which cutout is rectangular in cross section and extends from the underside 24 (second surface) of the printed circuit board 14 in the direction of the semiconductor component 16. The cutout 23 is dimensioned such that its extent in the X-Y-direction substantially corresponds to the semiconductor component 16. The cutout 23 is arranged such that it overlaps the semiconductor component 16 in the Z-direction.

[0032] A coolant container 25 is connected to the underside 24 of the printed circuit board 14, said coolant container being open at its upper end. The coolant container 25 is connected to the underside 24 of the printed circuit board 14 via an end face 26, such that a closed-off space is formed which is enclosed between the coolant container 25 and the printed circuit board 14. The cutout 23 of the printed circuit board 14 is part of this closed-off space. A sealing material 27 is applied between the end face 26 of the coolant container 25 and the printed circuit board 14, such that no coolant can emerge even at the connection point.

[0033] The coolant container 25 is provided with an inlet opening and an outlet opening (not illustrated), via which the coolant container 25 is connected to a cooling system. In the cooling system, the coolant is guided in a closed circuit extending between the coolant container 25 and a heat exchanger. In the heat exchanger, heat is emitted to the surroundings.

[0034] The underside of the printed circuit board 14 is covered with a protective layer 28 in the form of a Cu—Ni/Cu—Ni—Au coating, such that there is no contact between the coolant and the electrically insulating layers of the printed circuit board. The protective layer 28 is electrically insulated from the electrically conductive layers 17, 19, 20.

[0035] In the configuration according to the invention, the semiconductor component 16 is separated from the coolant merely by the electrically conductive layer 17, the thin insulating layer 18 and the protective layer 28. A low thermal contact resistance thus results, such that the heat can readily be transferred from the semiconductor component to the cooling liquid. With the cooling liquid, the heat is transported away in the cooling system, such that the semiconductor component 16 is effectively cooled.