ASSEMBLY HAVING TWO COPPER SHEETS SCREWED TO EACH OTHER AND METHOD FOR PRODUCING SAID ASSEMBLY

Abstract

A method and an assembly use two copper sheets, which are connected to each other by a screw connection. The screw connection is performed by a screw that is screwed directly into the copper sheets without screw holes having been provided. Therefore the production tolerances for preset screw holes can be dispensed with.

Claims

1-6. (canceled)

7. An assembly, comprising: a screw; and two copper sheets being connected to each other by a screw connection, wherein said screw is screwed directly into said copper sheets without a provision of screw holes being pre-formed in said copper sheets.

8. The assembly according to claim 7, wherein at least one of said copper sheets is made of Cu-ETP.

9. The assembly according to claim 7, wherein said screw has a thread geometry adapted to a copper material of said copper sheets.

10. A method for establishing a connection between two sheets, which comprises the steps of: providing two copper sheets; and screwing a screw directly into the copper sheets without a provision of pre-formed screw holes being provided in the copper sheets.

11. The method according to claim 10, which further comprises performing the screwing step in a protective atmosphere.

12. The method according to claim 10, which further comprises performing the screwing step on a load-bearing support.

Description

[0013] The invention will be explained further below with reference to an exemplary embodiment and with the aid of a figure, in which:

[0014] FIG. 1 shows a screw for connecting two copper sheets.

[0015] The screw in FIG. 1 has a screw head 1, preferably with a recessed drive. In that context, the diameter of the screw head must be matched to the recessed drive that is to be used, e.g. 2.5 mm for Torx plus. Both the screw material and the recessed drive must be designed for briefly very high rotational speeds of 4000 revolutions per minute and above.

[0016] The screw has, at its opposite end from the screw head 1, proceeding from the screw tip 6 to a calibration section 4, a flow hole forming zone 5 which in the example shown is designed as a square that narrows from the calibration section to the screw tip. After the calibration section 4, there follows a short thread-forming zone 3, adjoining which is the load-bearing thread 2.

[0017] According to the invention, a screw of this type is pressed with great force, against a load-bearing support, and with high rotational speed against the copper sheets that are to be connected, causing the screw-in point to heat up and to begin to flow, and the screw can cut its own thread. The form-fitting connection achieved thereby results in a low current transition resistance, which is highly advantageous in the case of high-current connections. Furthermore, tolerances of the individual lead frames with respect to each other are not as critical as is the case for a through-hole, since the screw forms the hole itself.