ELECTRONIC UNIT COMPRISING AN ESD PROTECTIVE ARRANGEMENT

Abstract

The disclosure relates to an electronic unit with a circuit board having at least one component arranged on a main surface of the circuit board and a casing element, which incorporates the at least one component, as well as with an ESD protection arrangement for the circuit board. According to the disclosure, open areas on the circuit board, which are not covered by the casing element, are covered with a gold layer directly mounted on a copper surface of the circuit board.

Claims

1. An electronic unit with a circuit board comprising: at least one component arranged on a main surface of the circuit board and, a casing element, which encloses the at least one component, wherein the electronic unit comprises an ESD protection arrangement for the circuit board where open areas on the circuit board, which are not covered by the casing element, are covered with a gold layer directly mounted on a copper surface of the circuit board.

2. An electronic unit with a circuit board comprising: at least one component arranged on a main surface of the circuit board and, a casing element, which encloses the at least one component, wherein the electronic unit comprises an ESD protection arrangement for the circuit board where open areas on the circuit board, which are not covered by the casing element, are covered with a conductive covering arranged on the casing element.

3. The electronic unit according to claim 1, wherein the casing element covers at least an edge region of the gold layer.

4. The electronic unit according to claim 2, wherein the conductive cover is a form-bending part, which is attached on the casing element and mounted on the circuit board at an edge region of the circuit board.

5. The electronic unit according to claim 1, wherein the electronic unit is designed for an integrated transmission control system for motor vehicles.

6. The electronic unit according to claim 2, wherein the electronic unit is designed for an integrated transmission control system for motor vehicles.

7. The electronic unit according to claim 1, wherein a dimension of the gold layer is larger than a dimension of the open area that is covered with the gold layer.

8. The electronic unit according to claim 1, wherein the gold layer extends into the casing element adjacent to the open areas.

9. The electronic unit according to claim 1, wherein the gold layer directly contacts a non-copper portion of the circuit board.

10. The electronic unit according to claim 1, wherein the at least one component is sealed by the casing element against fluids.

11. The electronic unit according to claim 2, wherein the at least one component is sealed by the casing element against fluids.

12. The electronic unit according to claim 1, wherein the at least one component comprises a first component arranged on an upper surface of the circuit board and a second component arranged on a lower surface of the circuit board.

13. The electronic unit according to claim 2, wherein the at least one component comprises a first component arranged on an upper surface of the circuit board and a second component arranged on a lower surface of the circuit board.

14. The electronic unit according to claim 1, further comprising a perforation in the circuit board such that the casing element on an upper side of the circuit board is directly connected to the casing element on a lower side of the circuit board.

15. The electronic unit according to claim 2, further comprising a perforation in the circuit board such that the casing element on an upper side of the circuit board is directly connected to the casing element on a lower side of the circuit board.

16. The electronic unit according to claim 2, wherein the conductive covering is supported on the casing element.

17. The electronic unit according to claim 1, wherein the at least one component is either a sensor or a heat dissipation element.

18. The electronic unit according to claim 2, wherein the at least one component is either a sensor or a heat dissipation element.

19. The electronic unit according to claim 1, wherein the ESD protection arrangement is configured to allow the at least one component to be operational after an electrostatic discharge of up to 15 kV.

20. The electronic unit according to claim 2, wherein the ESD protection arrangement is configured to allow the at least one component to be operational after an electrostatic discharge of up to 15 kV.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The disclosure shall be explained in greater detail below based on the figures. In the figures, it is shown:

[0022] FIG. 1 is a sectional view of a diagram of a first version of an electronic unit,

[0023] FIG. 2 is a sectional view of a diagram of a second version of an electronic unit.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0024] Identical components, or components having at least the same function, are provided with identical reference symbols in the figures.

[0025] FIG. 1 shows a diagram of the first version of an electronic unit. On the main surface 3,4 of a circuit board 2 a component 5, 6 and a casing element 7, which surrounds the component 5, 6, are arranged. Advantageously, an electronic component 5 is respectively arranged on both main surfaces 3, 4 of the circuit board 2, i.e., on the upper side 3 and the lower side 4 of the circuit board 2. Assembling the circuit board 2 on both sides has advantages regarding the packing density of the electronic unit.

[0026] The electronic unit 1 comprises a casing element 7, which surrounds the electronic components 5. Advantageously, the casing element 7 consists of a material (for example, thermosetting material), which fulfills predetermined protection arrangements, for example, resistance to water and/or oil, but also predetermined radiation characteristics. The casing element 7 is located on the upper side 3 and the lower side 4 of the circuit board 2. In this connection, the material 10 of the casing element 7 fills the perforations 9 in the circuit board 2, as well as the area between the electronic components 5 and the circuit board 2. Advantageously, the casing element 7 completely surrounds the circuit board 2. However, it is also possible that the casing element 7 covers only sections of the upper side 3 and lower side 4 of the circuit board 2. Because of the fact that the material 10 of the casing element 7 fills the perforations 9 in the circuit board 2, the casing element is formed in one piece. This results in a direct connection between the casing element section 7 on the lower side 4 and the casing element section 7 on the upper side 3, which increases the stability of the entire casing element 7 and thus also the circuit board 2.

[0027] The height of the electronic unit 1 can be defined by the thickness of the casing element 7. This also determines the external surface of the electronic unit 1.

[0028] The casing element 7 has open areas 13. These open areas 13 expose the upper side 3 or the lower side 4 of the circuit board 2, so that these areas 13 are not covered by the casing element 13. For example, in FIG. 1 such open areas 13 are provided on the upper side 3 of the circuit board 2. However, the open areas 13 can also be located on the lower side 4 or on the upper side 3 and the lower side 4.

[0029] In the open areas 13, a gold layer 12 is provided, which completely covers the copper layer 11 in the open areas 13 on the circuit board 2. The gold layer 12 in the open areas 13 is directly applied to the copper layer 11. The gold layer 12 extends into the casing element 7. As a result, the casing element 13 covers at least the marginal or edge region of the gold layer 12. This ensures that the copper layer 11 in the open areas 13 is shielded from the surrounding area of the electronic unit 1 and the possibly present transmission oil (not shown).

[0030] Advantageously, the aerial extension of the gold layer 12 in the open areas corresponds to the aerial extension of the copper layer 11 such that the gold layer 12 completely covers the copper layer 11 on the upper side 3 of the circuit board 2 in the open areas, without the gold layer 12 covering the upper side 3 of the circuit board 2. However, it is also possible that the aerial extension of the gold layer 12 is larger than the aerial extension of the copper layer 11, so that the gold layer 12 in the open area 13 is arranged, on the one hand, directly on the copper layer 11 and, on the other hand, directly on the upper side 3 of the circuit board 2. In both cases, the marginal or edge region of the gold layer 12 protrudes into the casing element 13.

[0031] In the circuit board 2, perforations 9 are made, which lead from the upper side 3 to the lower side 4 of the circuit board 2. Advantageously, these perforations 9 are made in the area around the individual electronic components 5. However, they can also be made in the marginal or edge region of the circuit board 2. Advantageously, the perforations 9 are evenly distributed in the circuit board 2, especially corresponding to a honeycomb structure. However, it is also possible that a larger or smaller number of perforations 9 are made around specific electronic components 5. Advantageously, the perforations 9 can be made in accordance with a predefined pattern. In particular, the perforations 9 are made in the form of drill holes. However, it is also possible that the perforations 9 are made in the form of straight or curved grooves.

[0032] Further connection areas (not shown) for plugs (not shown) or sensors (not shown) are provided on the circuit board 2.

[0033] On the lower side 4 of the circuit board 2, a heat dissipation element 6, for example, a cooling element, is arranged. This cooling element 6 is also at least partially surrounded by the casing element 7. A section of the cooling element 6 has no enclosure of the casing element 7. As a result, the heat can be freely discharged. However, it is also possible that the cooling element 6 is completely surrounded by the casing element 7. The area B between the circuit board 2 and the cooling element 6 is also filled with the material 10 of the casing element 7.

[0034] The casing element 7 comprises undercuts 14, which are formed with the material 10 of the casing element 7 and which are therefore surrounded by the casing element 7. This further ensures the stability of the electronic unit 1. It also results in the fact that the cooling element 6 is held in a fixed position. At the same time, the upper surface of the cooling element 6 can be directly connected with an electronic component 5 or it can be connected via a thermal material 19.

[0035] FIG. 2 shows a diagram of a second version of an electronic unit. To avoid repetition, reference is made to the explanations made in FIG. 1. Identical reference numerals used in FIG. 2 and FIG. 1 have the same meaning.

[0036] The first version shown in FIG. 1 and the second version shown in FIG. 2 differ in that in FIG. 2 the copper layers 11 in the open areas 13 of the circuit board 2 are not covered with a gold layer 12, but instead with a conductive shielding element 15. The shielding element 15 is supported on the casing element 7 and completely covers the open areas 13 in that the shielding element 15 completely covers the open area 13 formed by the casing element 7 and protects it from the surrounding area.

[0037] The shielding element 15 is directly or indirectly mounted on the upper side 3 of the circuit board 2. The attachment can be performed by means of screw, solder, clamp or weld connections. An indirect attachment indicates that the shielding element 15 is mounted on one or multiple components, which are directly mounted on the circuit board 2.

REFERENCE NUMERALS

[0038] 1 Electronic unit [0039] 2 Circuit board [0040] 3 Upper side [0041] 4 Lower side [0042] 5 Electronic component [0043] 6 Heat dissipation element [0044] 7 Casing element [0045] 8 Further casing element [0046] 9 Perforation [0047] 10 Injection molded material [0048] 11 Copper layer [0049] 12 Gold layer [0050] 13 Open areas on circuit board [0051] 14 Undercut [0052] 15 Conductive shielding element [0053] 19 Thermal material [0054] B Area between circuit board and heat dissipation element