The present invention relates to a joining method for transmission
welding, in which at least a first layer (1), a second layer (2), and a third layer (3) are arranged one above the other to form a composite component (15), and a press device (8) is applied to the first layer, and subsequently a
mechanical pressure force (6) is exerted by the press device (8) on the first layer (1) and thereby also on the second layer (2) and the third layer (3).
Radiation (5) emitted from a
radiation source (4) is directed from the side on which the press device (8) exerts the pressure force (6) onto the at least three
layers (1, 2, 3), wherein the press device (8) is transparent to the
radiation (5) and at least the two
layers (1, 2) facing the press device (8) are formed from a material transparent to the
radiation (5).On at least two of the
layers (1, 2, 3) at least one area (9) with an increased
absorption capacity for the radiation (5) is formed on their surface and / or the radiation (5) is directed only selectively onto at least one
single area of one of the layers (1, 2, 3), such that the radiation (5) forms a
welding lens (7, 10) in the area onto which it is directed for the local metallurgical joining of two of the layers (1, 2, 3) in such a way that the
welding lens (7, 10) is transparent to the radiation (5) and subsequently the radiation (5) is directed through the welding lens (7, 10) onto an area (9) with an increased
absorption capacity for the radiation (5) of an underlying layer (2, 3) and / or the radiation (5) is directed selectively onto at least one
single area of one of the underlying layers (2, 3) and a second welding lens (11) is formed there.