an assembly process provides a chip scale package which characteristically includes a perforated substrate in which vias can be embedded , a solder mask on which the integrated circuit die can be attached , and efficient use of the surface area for electrically routing signals from the integrated circuit die to the external terminals attached to the perforated substrate . the resulting package is highly compact and therefore has a foot print minimally larger than the surface area of the integrated circuit chip . consequently , the costs of substrate and capsulation materials are minimized . the assembly process allows very high volume production because a large number of integrated circuits can be made on a single unit of the substrate , and singulation is performed in the assembly process at a stage much later than the corresponding stage in a conventional process .