The aggregation, arrangement and bonding together of a set of components to form a postsynaptic density, a region that lies adjacent to the cytoplasmic face of the postsynaptic membrane at excitatory synapse. [ http://www.ncbi.nlm.nih.gov/pubmed/21525273 GOC:sjp GOC:BHF ]

Synonyms: PSD assembly post synaptic density assembly post-synaptic density assembly