Method for manufacturing at least one heat exchanger plates by superposing plates with alignment patterns

The main object of the invention is a method for manufacturing at least one heat exchanger (50) plates (10) to at least two fluid circuits, characterized in that it comprises the following steps: a) forming a plurality of plates (10) each having a reference pattern; b) forming one or more alignment patterns (11) on each plate (10) by circular pattern of the reference pattern around an axis of revolution (X); c) forming a plurality of grooves (12) on each plate (10). The method further comprises the following successive steps: d) joining the plates (10) by superposition with respect to each other, each reference pattern of one plate being superimposed on an alignment pattern (11) of a plate adjacent; e) performing an assembling process on the assembly obtained at the end of step d) above by diffusion bonding, brazing and / or by diffusion brazing.