Patent ID: 6465757
Filing Date: 2002-10-15
Classification: B23K,B29C,B29K,B29L

Abstract:
A laser joining method of joining different workpieces made of plastic, or joining plastic to other materials, which comprises: making a top workpiece of a material that is transparent to the laser beam facing a laser source with a laser beam; making a second workpiece of a material that is absorbent for the laser beam, so that adjacent contact surfaces of the two workpieces begin to melt and are bonded together in subsequent cooling under pressure; including the step of arranging a mask of a material that is impermeable for the laser beam adjacent the workpieces between the laser source and the workpieces to be joined for bonding the workpieces in a joining area of the contact surfaces; wherein the structure of said mask is larger than the wavelength of the laser beam used, and the laser source is directed at the contact surfaces to provide an essentially vertical laser beam curtain at essentially a right angle through the mask in such a way that a laser line joining area is formed on said contact surfaces, heating and joining the workpieces by moving the laser beam and the workpieces relative to each other to move the laser line and to provide an extended joining area, wherein the laser beam is arranged at a right angle above the joining area of the contact surfaces, and wherein a linear laser beam is created by at least one semiconductor laser.