Switchgear assembly with improved electrical contact

Abstract

The present invention relates to a circuit substrate arrangement comprising a base layer (2) made from aluminium, a circuit layer (3) made from copper, a dielectric layer (4) arranged between the base layer (2) and the circuit layer (3), an opening (5) passing through the base layer (2), the circuit layer (3) and the dielectric layer (4) and an electrical contact (6) between the base layer (2) and the circuit layer (3), wherein the electrical contact (6) comprises a rivet (7), wherein a frictionally connected joint (8) is formed between the rivet (7) and the base layer (2) and wherein an integrally bonded joint (9) is formed between the rivet (7) and the circuit layer (3).

Description

[0001] Description

[0002] title

[0003] Circuit carrier arrangement with improved electrical contact

[0004] State of the art

[0005] The present invention relates to a circuit carrier arrangement with significantly improved electrical contacting.

[0006] Circuit carrier arrangements are from the state of the art in

[0007] Various configurations are known. For example, so-called IMS (isolated metal substrates) are known in the form of single-layer or multi-layer printed circuit boards, which are laminated onto a metal substrate, particularly containing copper or aluminum. This metal substrate enables better thermal dissipation of power losses. However, copper-based IMS are significantly more expensive than aluminum-based IMS, assuming otherwise identical construction. In addition to the base layer, the IMS also comprises a copper-based circuit layer and a dielectric intermediate layer between the

[0008] Base layer and circuit layer. However, if the base layer is an aluminum-based layer, electrical contact problems arise between the base layers based on different metal substrates.

[0009] (aluminum) and the circuit layer (copper).

[0010] Disclosure of the invention

[0011] In contrast, the circuit carrier arrangement according to the invention with the features of claim 1 has the advantage that an improved

[0012] Contacting on different metal substrates

[0013] Circuit carrier arrangement is possible. Here, an aluminum

[0014] A comprehensive base layer and a copper-based circuit layer are used, separated from each other by a dielectric intermediate layer. Electrical contacting can be implemented very simply and cost-effectively, enabling particularly high reliability.

[0015] Robustness, which leads to significant advantages, especially when used in moving devices such as vehicles. According to the invention, an electrical contact is provided between the aluminum-encompassing

[0016] The base layer and the copper-containing circuit layer are connected by a rivet, with a force-fit connection between the rivet and the base layer and a metallurgical connection between the rivet and the circuit layer. Thus, the rivet is connected to the two different metal layers via two distinct connections. The circuit carrier assembly has an opening in which the rivet is located. This allows the more cost-effective aluminum-containing base layer to be used for the circuit carrier assembly, resulting in a wide range of applications, as the electrical contact between the different metal substrates can be significantly improved.

[0017] The dependent claims describe preferred embodiments of the invention.

[0018] The opening is preferably a through-opening. The opening is preferably created after the three layers of the

[0019] Circuit carrier arrangement inserted. Alternatively, the opening is a blind hole.

[0020] It is particularly preferred that the rivet length be shorter than the opening length. This results in at least one area within the opening of the circuit carrier assembly that is not occupied by the rivet. This allows for various design options. For example, the rivet can be only partially located in the base layer and / or only partially located in the circuit layer. This creates free spaces at the first and second ends of the rivet, which can be used for different purposes.

[0021] The rivet particularly preferably comprises a head, especially a flat head. The head particularly preferably rests on the circuit layer.

[0022] A material-bonded connection is preferably formed between the head and the circuit layer.

[0023] The material-bonded connection is preferably made using solder. Alternatively, the rivet is in the form of a headless pin, so that the rivet can be positioned completely within the opening in the circuit carrier assembly. Particularly preferred is a first end of the rivet flush with a

[0024] surface of the circuit layer finished, whereby the solder of the

[0025] The rivet then completely covers the first end of the rivet in a material-bonded connection. Alternatively, the first end of the rivet is countersunk in the opening in such a way that the rivet is only partially in contact with the wall of the opening.

[0026] The circuit layer is in contact, resulting in a solder-filled area of ​​the opening at the metallurgical connection between the rivet and the circuit layer. Preferably, the solder extends beyond the edge of the opening at the circuit layer to ensure reliable electrical contact between the rivet and the circuit layer.

[0027] The circuit carrier arrangement according to the invention is particularly preferably used in a DC / DC converter, especially in conjunction with electrical machines.

[0028] drawing

[0029] Exemplary embodiments of the invention are described in detail below with reference to the accompanying drawing. The drawing shows:

[0030] Figure 1 is a schematic, perspective representation of a

[0031] Circuit carrier arrangement according to a first

[0032] Exemplary embodiment of the invention,

[0033] Figure 2 is a schematic sectional view of the

[0034] Circuit carrier arrangement of Figure 1 ,

[0035] Figure 3 is a schematic sectional view of a

[0036] Circuit carrier arrangement according to a second

[0037] Exemplary embodiment of the invention, and Figure 4 a schematic sectional view of a

[0038] Circuit carrier arrangement according to a third

[0039] Exemplary embodiment of the invention.

[0040] Preferred embodiment of the invention

[0041] The following section, with reference to Figures 1 and 2, describes a

[0042] Circuit carrier arrangement 1 according to a first preferred

[0043] An embodiment of the invention is described in detail.

[0044] As can be seen from Figure 1, the circuit carrier arrangement 1 of this exemplary embodiment is a so-called IMS (insulated metal substrate) with an aluminium base layer 2, a dielectric layer 4 and a copper circuit layer 3.

[0045] The dielectric layer 4 is arranged as an intermediate layer between the base layer 2 and the circuit layer 3, electrically separating these two layers. Here, the dielectric layer 4 is applied directly to the base layer 2, and the circuit layer 3 is applied directly to the dielectric layer 4.

[0046] By using an aluminum-based base layer, it is possible in

[0047] In comparison with other materials for the base layer, a particularly cost-effective circuit carrier arrangement 1 is provided, with particularly high heat dissipation achieved through the aluminum-comprehensive

[0048] Base layer 2 can be reliably derived. This is particularly important in

[0049] Connection with high-performance electronic components, e.g., MOSFETs, IGBTs, transformers and / or coils, is highly advantageous. This prevents heat build-up in the high-performance electronic components.

[0050] The use of the aluminum-based base layer 2, for example, offers a significant price advantage compared to the use of copper-based base layers, with almost the same practical application.

[0051] Thermal conductivities of the base layers are achieved.

[0052] As shown in detail in Figure 2, the circuit carrier arrangement 1 further comprises at least one, preferably several openings 5, which are provided as through-openings through the circuit carrier arrangement 1, wherein a central axis of the opening 5 is perpendicular to a surface of the circuit carrier arrangement 1.

[0053] To establish an electrical connection between the circuit layer 3 and the base layer 2, an electrical contact 6 is provided, which includes a rivet 7. The rivet 7 in this embodiment is a

[0054] A cylindrical rivet made of solid material, which has a head 70. As shown in Figure 2, the head 70 rests on a surface 30 of the circuit layer 3 in the assembled state.

[0055] The electrical contact 6 is now connected to the base layer 2 and the circuit layer 3 by two different connection types. A force-fit connection 8 is provided between the rivet 7 and the base layer 2, and a material-fit connection 9 is provided between the circuit layer 3 and the rivet 7. In this embodiment, the material-fit connection is formed at the head 70 of the rivet. The material-fit connection is created by means of a solder 10, which is arranged along the outer circumference of the head 70.

[0056] As can be seen further in Figure 2, the rivet 7 has a first length L1 and the opening 5 in the circuit carrier arrangement 1 has a second length L2. The first length L1 is shorter than the second length L2. This results in an area 50 in the opening 5 at a first end 71 that is not filled by the rivet 7.

[0057] The electrical contact via the force-fit connection 8 between the base layer 2 and the rivet 7 enables a very good

[0058] Electromagnetic compatibility with reduced interference potential.

[0059] The rivet 7 is preferably made of brass or copper and has a coated surface, preferably a gold or tin coating.

[0060] The material-bonded connection 9 using the solder 10 is particularly preferably carried out by means of a reflow soldering process. Thus, in the circuit carrier arrangement 1, electrical contact is achieved via two different connection types, namely a force-fit connection 8 for connection with the base layer 2 and a material-bonded connection 9 for connection with the circuit layer 3, which achieves a particularly robust electrical contact between layers made of different materials, namely the base layer, which is essentially made of aluminum, and the circuit layer 3, which is essentially made of copper.

[0061] Figure 3 shows a circuit carrier arrangement 1 according to a second

[0062] An embodiment of the invention, wherein identical or functionally equivalent parts are designated with the same reference numerals. As can be seen in Figure 3, the rivet 7 of the electrical contact 6 is exclusively a cylindrical rivet without a head. Here, the rivet 7 is completely countersunk in the opening 5. The first region 50 at the first end 71 of the rivet 7 remains free in the opening, as does a second region 51 at the free or second end 72 of the rivet 7. In the final state, a solder region 10a of the solder 10 of the metallurgical connection 9 is present in region 51 and fills this region 51, as shown schematically in Figure 3.

[0063] Figure 4 shows a circuit carrier arrangement 1 according to a third

[0064] This embodiment essentially corresponds to the second embodiment. The rivet 7 is also headless and has a cylindrical shape. However, in this embodiment, the second end 72 of the rivet 7 is flush with a surface 30 of the circuit layer 3. The solder 10 of the metallurgical connection 9 covers the second end of the rivet 7 and establishes the electrical contact with the circuit layer 3.

[0065] Thus, according to the invention, as shown in the preferred embodiments, a very cost-effective printed circuit board with an aluminum-based base layer 2 and a copper-based circuit layer 3 can be manufactured. The electrical contact between the base layer 2 and the circuit layer 3 is made via a rivet 7, which is connected once by frictional connection and once by material bonding.

Claims

Claims 1. Circuit carrier arrangement, comprising: an aluminium-comprising base layer (2), a copper-encompassing circuit layer (3), a dielectric layer (4) arranged between the base layer (2) and the circuit layer (3), an opening (5) passing through the base layer (2), the circuit layer (3) and the dielectric layer (4), and an electrical contact (6) between the base layer (2) and the circuit layer (3), wherein the electrical contact (6) comprises a rivet (7), wherein a force-fit connection (8) is formed between the rivet (7) and the base layer (2), and wherein a material-bonded connection (9) is formed between the rivet (7) and the circuit layer (3).

2. Circuit carrier arrangement according to claim 1, wherein the opening (5) is a through opening.

3. Circuit carrier arrangement according to one of the preceding claims, wherein a first length (L1 ) of the rivet (7) is smaller than a second length (L2) of the opening (5).

4. Circuit carrier arrangement according to one of the preceding claims, wherein the rivet (7) comprises a head (70).

5. Circuit carrier arrangement claim 4, wherein the head (70) rests on a surface (30) of the circuit layer (3) and the material-bonded connection (9) between the head (70) and the circuit layer (3) is formed.

6. Circuit carrier arrangement according to one of claims 1 to 3, wherein the rivet (7) has a cylindrical shape without a head.

7. Circuit carrier arrangement according to claim 6, wherein the rivet (7) has a free end (72) which is flush with the surface (30) of the Circuit layer (3) is closed, with the material-bonded connection (9) covering the free end (72) of the rivet (7).

8. Circuit carrier arrangement according to claim 6, wherein a free end (72) of the rivet (7) is arranged in the opening (5) of the circuit carrier arrangement such that a region (51) is provided in the opening (5) which is filled with solder (10a) of the metallurgical connection (9).

9. Circuit carrier arrangement according to claim 8, wherein the solder (10) of the material-bonded connection (9) extends beyond the opening (5) and establishes an electrical contact on the surface (30) of the circuit layer (3).