Passive alignment of polymer waveguides

A method for passively aligning two parts of a chip packaging, the method comprising:

• providing a first part comprising:
• a support;
• a core polymer layer extending over an inner region and an outer region of the support, the core polymer layer transversally structured so as to exhibit distinct residual portions, each having a same first height, which corresponds to a thickness of the core polymer layer, the residual portions comprising:
• first waveguide cores disposed within said inner region,
• one or more first alignment structures disposed within said outer region;
• and
• wherein the support comprises one or more additional polymer cladding portions extending over a polymer cladding layer, the outer region defined on the one or more additional polymer cladding portions, so as for the inner region to be recessed with respect to the outer region;
• providing a second part comprising:
• second waveguide cores, each having a same second height;
• and
• one or more second alignment structures complementarily shaped with respect to the one or more first alignment structures;
• wherein the first part is structured such that said inner region is recessed with respect to the outer region, to enable:
• the second waveguide cores to contact the first waveguide cores;
• the one or more second alignment structures to respectively receive, at least partly, the one or more first alignment structures;
• and
• bringing together the first part and the second part such that the second waveguide cores respectively contact the first waveguide cores and the one or more second alignment structures respectively receive, at least partly, the one or more first alignment structures.