Wafer-level test method for optoelectronic chips

A method for testing of optoelectronic chips which are arranged on a wafer and have electrical interfaces in a form of contact pads and optical interfaces which are arranged to be fixed relative thereto in a form of optical deflection elements with a specific coupling angle, comprising:

• a positioning table receiving the wafer the positioning table being adjustable relative to a contacting module in an X direction, Y direction and Z direction of a Cartesian coordinate system and being rotatable around the Z axis, wherein the contacting module has electrical interfaces in a form of needles which are associated with the contact pads, and optical interfaces which are associated with the optical deflection elements, and
• in a first adjustment step, feeding the wafer is to the contacting module in such a way that the needles are disposed vertically above centers of the contact pads of a first one of the chips in a first adjustment position,
• wherein the contacting module has an adjustment distance in the Z direction from a first one of the chips that is greater than a free length of the needles,
• in further adjustment steps, carrying out a relative alignment of the optical deflection elements with respect to the optical interfaces provided on the contacting module,
• then feeding the positioning table to the contacting module in the Z direction using a feed displacement in an optical working distance in which the needles contact the contact pads with a predefined pressing force, and
• subsequently routing electrical signals and optical signals via the interfaces which are associated with one another, wherein:
• the relative alignment of the optical deflection elements with respect to the optical interfaces provided on the contacting module is carried out by:
• in a scanning field smaller than a size of the contact pads, initially deflecting the positioning table into a second adjustment position in the X direction and the Y direction relative to the first adjustment position, while routing an optical signal via at least one of the optical interfaces of the contacting module and one of the optical deflection elements, wherein the second adjustment position is occupied when the optical signal is coupled in with a maximum intensity, and
• subsequently deflecting the first one of the chips is subsequently deflected in the X-Y direction by an adjustment displacement into a third adjustment position, wherein the adjustment displacement was calculated from the feed displacement and the coupling angle (α) of a relevant optical deflection element before the positioning table is fed to the contacting module in the Z direction by the feed displacement in the optical working distance.