A method of assembling a semi-hermetic semiconductor package includes bonding a semiconductor die having bond pads to a top side of a base region of a package substrate having vertical side walls that are hollow which define an inner open volume (gap) having an adhesive or thermoplastic material therein. There are a plurality of metal terminals providing top terminal contacts on the top side of the base region and bottom terminal contacts on a bottom side or below the base region. The bond pads are coupled to the top terminal contacts. A lid is placed which provides a top for the semiconductor package, where the lid extends to vertically oriented end protrusions so that the protrusions are positioned within the adhesive or thermoplastic material to secure the protrusions within the adhesive or thermoplastic material to provide a seal for the semiconductor package.