METHOD FOR DIFFUSION JOINING AND DEVICE THEREFOR WITH PRESSURE VARIATION

Abstract

A method for diffusion joining by way of a first and a second stamp, wherein plate-like joining parts are arranged between the two stamps. A pressure is applied to the joining parts by way of the first and/or the second stamp for the purpose of diffusion joining. In addition, a variation of the pressure is also introduced. The pressure and the pressure variation are applied via the first stamp, whereas the second stamp can be rigid. Further disclosed is a device for carrying out the method.

Claims

1.-10. (canceled)

11. A method for diffusion joining by using a first and a second stamp, wherein at least two plate-like joining parts are arranged between the first and the second stamp with a joining plane between the at least two joining parts, wherein, for diffusion joining, by means of the first and/or the second stamp, a pressure is applied perpendicular to the joining plane to the at least two joining parts, and wherein a pressure variation is additionally applied to the pressure, wherein the pressure and the pressure variation are applied to the at least two joining parts via the first stamp, wherein the pressure variation is introduced in the pressing direction, wherein the second stamp is used as a rigid anvil-like stamp, characterized in that the minimum pressure which is applied by means of the pressure variation is chosen to be between 25% and 75% of the maximum pressure, in that the frequency of the pressure variation is chosen in the range from 10 Hz to 20 Hz, and in that the pressure and also the pressure variation are applied by an apparatus.

12. The method as claimed in claim 11, wherein the amplitude of the pressure variation 5 μm to 50 μm.

13. The method as claimed in claim 11, wherein the first stamp is chosen as an upper stamp and in that the second stamp is chosen as a lower stamp.

14. The method as claimed in one of claim 11, wherein the pressure variation is a cyclic pressure variation.

15. The method as claimed in one of claim 11, wherein the method is used for diffusion welding, diffusion soldering and/or TLP diffusion welding.

16. A device for diffusion joining, comprising a first and a second stamp, wherein at least two plate-like joining parts can be arranged between the first and the second stamp with a joining plane between the least two joining parts, comprising a pressure generating apparatus for applying a pressure perpendicular to the joining plane to the at least two joining parts by means of the first and/or the second stamp, wherein the pressure generating apparatus is designed to introduce the variation of the pressure in the pressing direction, wherein the second stamp is rigid and designed in the manner of an anvil, wherein the first stamp is designed and coupled to the pressure generating apparatus for applying the pressure and the pressure variation to the at least two joining parts, wherein the pressure generating apparatus is designed to apply the pressure and also to vary the pressure, in that the pressure generating apparatus is designed that the minimum pressure which is applied by means of the pressure variation lies between 25% and 75% of the maximum pressure, and the pressure generating apparatus can generate a pressure variation with a frequency of 10 Hz to 20 Hz.

17. The device as claimed in claim 16, wherein a joining chamber is provided, in which the first and the second stamp are arranged, and in that a heating element is provided in the joining chamber.

18. The device as claimed in claim 16, wherein the pressure generating apparatus is designed for the mechanical, hydraulic and/or Piezo electric generation of the pressure variation.

Description

[0034] The invention will be explained in more detail below by using a schematic exemplary embodiment with reference to the appended FIGURE, in which:

[0035] FIG. 1 shows a schematic section through a device according to the invention for diffusion joining.

[0036] FIG. 1 shows a highly simplified schematic illustration of a device according to the invention for diffusion joining.

[0037] This has, as essential components, a first stamp 11 and a second stamp 12. The second stamp 12 is arranged on a supporting structure 13. The first 11 and the second stamp 12 and the supporting structure 13 are enclosed by a reaction chamber 14. In addition, a heating element 16 is provided in the reaction chamber 14.

[0038] The device 1 according to the invention is, according to the invention, constructed in such a way that the second stamp 12 is arranged fixedly on the supporting structure 13. Only the first stamp 11 is movably provided. Via the latter, both a pressure and also a pressure variation can be applied.

[0039] In the chamber 14 itself, a vacuum can prevail, depending on the exact implementation of the diffusion joining method according to the invention. However, it is also possible to provide an inert gas atmosphere or else the normal atmosphere with a different or the same pressure as the ambient pressure.

[0040] In FIG. 1, two joining parts 21, 22 are provided between the first stamp 11 and the second stamp 12. These touch at their joining plane 23.

[0041] In the following, the method according to the invention will be explained in more detail by using the structure from FIG. 1.

[0042] After two joining parts 21, 22 have been arranged on the second stamp 12, which is the lower stamp in this embodiment, the first stamp 11 is moved onto the joining parts 21, 22. As soon as there is contact, pressure is further applied to the two joining parts 21, 22 via the first stamp 11.

[0043] In addition to a constant pressure, according to the teaching of the invention, a pressure variation is applied via the first stamp 11 to the two joining parts 21, 22 and in particular to the joining plane 23. By means of this pressure variation, it is possible to break up an oxide layer which exists on both joining parts 21, 22, in particular on the joining plane 23, so that a good and high-quality joining connection can be carried out. The production of the joining connection is improved in that, by means of the heating element 16, the temperature in the chamber 14 is elevated. Here, temperatures up to more than 1000° C. may be necessary.

[0044] It is advantageous in the design according to the invention that since the pressure and the pressure variation are introduced only via the first stamp 11, no two components which are moved actively and apply a pressure act against each other. In this way, the wear is reduced overall. In addition, designing the second stamp 12 is more simply possible, since the latter is not moved and can thus be arranged fixedly in the chamber 14 with the supporting structure 13.

[0045] According to the invention, the pressure variation is preferably introduced only with a frequency between 0.5 Hz and 200 Hz, advantageously in the range from 10 Hz to 20 Hz or around 100 Hz. Embodiments of this type make it possible to produce the application of the pressure difference even by simple, rapid mechanical movement of the first stamp 11 up and down. In principle, however, other possibilities for this are also conceivable, for example a mechanical imbalance can be provided or else the pressure can be varied smoothly hydraulically.

[0046] By using the method according to the invention and the device according to the invention, is thus possible to provide a simple structure and nevertheless to specify a method that can be applied efficiently, which produces a high-quality connection of two joining parts.