Patent ID: 7425243

Claim:
A method of joining two workpieces, at least one of which is micro-structured or nano-structured, without extraneous materials to produce a workpiece which is joined over a joining area which is formed by two fully adjoining planar surfaces of the two workpieces, with the first workpiece being of plastic and the second workpiece being of a material different from plastic, which comprises: activating at least the surface of the first workpiece by radiation in a first step, which radiation has sufficiently high energy for it to break the molecule chains on the plastic surface, so that free bonds are formed, bringing the irradiated surfaces of the first workpiece and a surface of the second workpiece into contact in a second step, and in a third step, pressing the two workpieces against one another with a force and for a period of time and in a temperature range of from 15° C. to 30° C., to join them at the surfaces in contact with one another because the free bonds on the surface of the first workpiece and increased surface energy cause bonding to the surface of the second workpiece, wherein pressure is applied to the two workpieces in the third step between two parallel pressing platens in a joining press at a pressure from 300 to 600 bar and for a period of from 10 s to 600 s, and wherein the second workpiece comprises silicon or glass.