PRINTED CIRCUIT BOARD, INVERTER, MOTOR VEHICLE AND METHOD FOR PRODUCING A PRINTED CIRCUIT BOARD

Abstract

The disclosure relates to a printed circuit board having at least two current-conducting layer plies, wherein the current-conducting layer plies extend in an axial direction of the printed circuit board and are arranged in succession in a thickness direction of the printed circuit board. A component fastened by THT is arranged on one side of the printed circuit board. At least one connecting element extends through the printed circuit board through a passage opening in the thickness direction. The current-conducting layer ply is adjacent to the component fastened by THT reaches as far as the connecting element and the current-conducting layer ply that is remote from the component fastened by THT is at a distance from the connecting element.

Claims

1. A printed circuit board comprising: at least two current-conducting layer plies, wherein the current-conducting layer plies extend in an axial direction of the printed circuit board and are arranged in succession in a thickness direction of the printed circuit board, wherein a component fastened to the printed circuit board by Through Hole Technology (THT) is arranged on one side of the printed circuit board, wherein at least one connecting element extends through the printed circuit board through a passage opening in the thickness direction, wherein one of the current-conducting layer plies that is adjacent to the component fastened by THT reaches as far as the connecting element and another of the current-conducting layer plies that is remote from the component fastened by THT is at a distance from the connecting element.

2. The printed circuit board according to claim 1, wherein the printed circuit board has more than two current-conducting layer plies and all current-conducting layer plies that are in communication with the connecting element follow one another.

3. The printed circuit board according to claim 1, wherein the printed circuit board has at least two current-conducting layer plies that are spaced away from the connecting element.

4. The printed circuit board according claim 1, wherein the current-conducting layer plies are arranged symmetrically in the thickness direction.

5. The printed circuit board according to claim 3, wherein the printed circuit board has an even number of current-conducting layer plies and half are in communication with the connecting element and the other half are spaced from the connecting element.

6. The printed circuit board according to claim 1, wherein electrically insulating layer plies are arranged between the current-conducting layer plies.

7. The printed circuit board according to claim 6, wherein an electrically insulating layer ply has a thickness that is greater than that of the other electrically insulating layer plies of the printed circuit board, is arranged between one of the current-conducting layer plies that is in communication with the connecting element and one of the current-conducting layer plies that is spaced from the connecting element (50) as a printed circuit board core.

8. The printed circuit board according to claim 1, in that the current-conducting layer ply that is in communication with the connecting element is connected in a materially bonded manner to the connecting element.

9. The printed circuit board according to claim 1, wherein at least one terminal that is connected to the component is connected in a materially bonded manner to the connecting element.

10. The printed circuit board according to claim 1, wherein the connecting element is designed as a copper sleeve.

11. An inverter comprising an intermediate circuit capacitor and a printed circuit board, wherein the printed circuit board is designed according to claim 1.

12. (canceled)

13. A method for producing a printed circuit board, comprising the steps of: providing a printed circuit board blank having current-conducting layer plies and a passage opening in which a sleeve-like connecting element is arranged, arranging a component on one side of the printed circuit board blank, wherein at least one terminal) o the component is routed through the connecting element, providing solder material, introducing the solder material into the connecting element, allowing the introduced solder material to cool to establish a materially bonded connection between the connecting element and the terminal.

14. The method according to claim 13, wherein the solder material used is soldering tin.

15. The method according to claim 13, wherein the solder material is introduced into the connecting element from a second side of the printed circuit board blank, wherein the second side is at an opposite end of the printed circuit board blank than the side where the component is arranged.

16. The printed circuit board of claim 1, wherein the printed circuit board comprises the current-conducting layer plies and a plurality of insulating layer plies assembled together to form a printed circuit board blank, wherein one of the insulating layer plies has a thickness within the range of 25 to 75% of the printed circuit board blank.

17. The printed circuit board of claim 1, wherein the printed circuit board comprises the current-conducting layer plies and a plurality of insulating layer plies assembled together to form a printed circuit board blank, wherein one of the insulating layer plies has a thickness up to 25% of the printed circuit board blank.

18. The printed circuit board of claim 3, wherein insulating material is located between ends of the two current conducting layer plies that are spaced away from the connecting element and the connecting element.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Further advantages, features and details of the disclosure can be gathered from the following description of exemplary embodiments and figures, in which:

[0048] FIG. 1 shows a motor vehicle,

[0049] FIG. 2 shows an inverter,

[0050] FIG. 3 shows a printed circuit board,

[0051] FIG. 4 shows a heat flow through the printed circuit board,

[0052] FIG. 5 shows a current flow through the printed circuit board, and

[0053] FIG. 6 shows a flowchart for a method for producing the printed circuit board.

DETAILED DESCRIPTION

[0054] FIG. 1 shows a motor vehicle 1 comprising a power electronics system 2, for example in the form of an inverter 3. This inverter 3 comprises a printed circuit board 4, as will be described in even more detail further below.

[0055] The motor vehicle 1 can have, for example, an electric axle 5. The motor vehicle 1 can be designed, in principle, as a purely internal combustion engine-driven motor vehicle, as a hybrid motor vehicle or as an electric vehicle , The last two variants are possible with the motor vehicle 1 according to FIG. 1.

[0056] FIG. 2 shows an inverter 3 together with a battery 6 and an electric motor 7. The inverter 3 comprises an intermediate circuit capacitor 8 and a B6 bridge 9. The intermediate circuit capacitor 8 is divided into several parts which are associated with a phase or half bridge. A plurality of circuit breakers 10 are arranged on a printed circuit board 4 on the B6 bridge 9.

[0057] The intermediate circuit capacitor 8 is connected to the negative pole of the battery 6 via a line 12 and to the positive pole of the battery 6 via a line 14. Each of the capacitor elements 16 is then again correspondingly connected by way of two lines 18 and 20 to a half-bridge 22 which comprises two circuit breakers 10 in each case. For reasons of clarity, only some of the lines, capacitor elements and half-bridges are provided with reference signs here.

[0058] Three or else six lines 24, which are each associated with a phase, lead out of the B6 bridge 9.

[0059] FIG. 3 shows a detail of an exemplary arrangement of a printed circuit board 4. This printed circuit board includes a printed circuit board blank 26 and a component 28 fastened by THT. Here, the thickness direction of the printed circuit board 4 is in the direction of the arrow 30 and the axial direction is in the direction of the arrow 32.

[0060] In the exemplary arrangement shown, the printed circuit board 4 has four current-conducting layer plies 34, 36, 38 and 40. Electrically insulating layer plies 42, 44 and 46 are arranged between the current-conducting layer plies. Here, the current-conducting layer plies 34 and 36 reach a connecting element 50 that is arranged in a passage cutout 48. In one exemplary arrangement, the connecting element 50, like the current-conducting layer plies 34, 36, 38 and 40, preferably consists of copper. It can be applied, for example, by an electroplating process. It connects the current-conducting layer plies 34 and 36 both to the component 28 on one side 52 of the printed circuit board and to the other side 54 of the printed circuit board 4.

[0061] In contrast, the current-conducting layer plies 38 and 40 are spaced from the connecting element 50 by a distance. That is to say they are not electrically connected to one another. There is a terminal 56 in the middle of the connecting element 50 which may be designed as a copper sleeve. This terminal is connected to the component 28. In one exemplary arrangement, the terminal 56 is connected in a materially bonded manner to the connecting element 50 by soldering tin 58. In this exemplary arrangement, the terminal 56, which is fastened to the component 28, is first introduced into the interior of the connecting element 50 from the side 52. Afterwards, the soldering tin 58 is introduced, for example, by way of a selective soldering process from the side 54. In order to connect the terminal 56 to the connecting element as far as possible in the vicinity of the component 28, the soldering tin 58 has to cross the entire connecting element 56 where possible.

[0062] This is made easier by way of the current-conducting layer plies 38 and 40, on the side on which the soldering tin is introduced, in contrast being at a distance from the connecting element 50 and therefore not spreading heat.

[0063] In one exemplary arrangement, the printed circuit board 4 is of symmetrical construction with respect to the middle 60: the current-conducting layer ply 36 at the top and the current-conducting layer ply 38 at the bottom are constructed at the same distance from the middle 60, as are the current-conducting layer ply 34 at the top and the current-conducting layer ply 40 at the bottom.

[0064] The current-conducting layer plies 34 and 36 are connected in a materially bonded manner to the connecting element 50, also called plated-through hole. This region can also be called the copper connecting region KAB since the current-conducting layer plies are connected to the connecting element in this region.

[0065] The printed circuit board core LK with the electrically insulating layer ply 44 is located in the middle of the printed circuit board 4. In one exemplary arrangement, the layer ply 44 can constitute up to 25% of the thickness of the printed circuit board blank 36, in additional arrangements, more than 25% to 50%. In yet an additional exemplary arrangement, the layer ply 44 is more than 50% to 75% of the thickness of the printed circuit board blank 26. Therefore, the thickness of the component 28 is not included.

[0066] The copper cutout reaion KFB contains those current-conducting layer plies 38 and 40 that are not connected to the connecting element 50. Instead, an electrically insulating material is located therebetween.

[0067] Therefore, starting from the component 28, first only current-conducting layer plies 34, 36 that are connected to the connecting element 50 and then current-conducting layer plies 38, 40 that are at a distance from the connecting element 50 are present. This applies irrespective of the number of current-conducting layer plies. There have to be at least two, but there can be as many as desired in principle.

[0068] The advantage of this design can be seen in FIG. 4. FIG. 4 shows the printed circuit board 4 according to FIG. 3 with heat flow drawn in and being indicated by the arrows 62 and 64. If, for example, soldering tin 58 is introduced into the passage opening 48 and therefore into the interior of the connecting element 50 from the side 54, the soldering tin 58 and the heat propagate in the direction of the component 28 along the arrow 62.

[0069] Noticeable removal of heat to the side, illustrated by the arrows 64, takes place only starting from the level of the current-conducting layer ply 36 since this is electrically connected to the connecting element 50. As a result, the solder material, here the soldering tin 58, passes through in an improved manner.

[0070] FIG. 5 shows, for the printed circuit board 4 according to FIG. 3, the current flow through the current-conducting layer plies 34 and 36 that are connected to the component 28 by means of the arrows 66 and 68. This shows that the current-conducting layer plies 34 and 36 are electrically connected to the component 28 via the connecting element 50, the soldering tin 58 and the terminal 56.

[0071] FIG. 6 shows a flowchart for producing a printed circuit board 4. In step S1 a printed circuit board blank 26 is provided. In one exemplary arrangement, the printed circuit board blank 26 has current-conducting layer plies 34, 36, 38, 40, electrically insulating layer plies 42, 44 and 46 and a passage opening 48 in which a sleeve-like connecting element 50 is arranged. The connecting element 50 connects the current-conducting layer plies 34 and 36 to one another and to the side 54.

[0072] In step S2, a component 28 is arranged on the side 52 of the printed circuit board blank 26 by way of a terminal 56, wherein the terminal 56 of the component 28 is routed through the connecting element 50.

[0073] In step S3, solder material, such as, for example, soldering tin 58, is provided.

[0074] In step S4, the soldering tin 58 is introduced into the connecting element 50. A materially bonded connection between the connecting element 50 and the terminal 56 is produced when the soldering tin 58 cools down. This produces a printed circuit board as described further above.