A universal substrate for assembling ball grid array (BGA) type integrated circuit packages has a non-conducting matrix, an array of conducting vias extending between top and bottom surfaces of the matrix, and one or more instances of each of two or more different types of fiducial pairs on the top surface of the matrix. Each instance of each different fiducial pair indicates a location of a different via sub-array of the substrate for a different BGA package of a particular package size. The same substrate can be used to assemble BGA packages of different size, thereby avoiding having to design a different substrate for each different BGA package size.