A semiconductor device includes a semiconductor substrate, cavities, and an element isolating region. For example, the substrate package includes a first set of reference markers and a second set of reference markers. A second patterned adhesive is disposed over a portion of a surface area of the tag. In the present invention, the cylindrical lens array is used in combination with the optical waveguide. A further component referred to as a let engine communicates with the devlets, infolets, and applets, and maintains user and device profile information to provide a flexible framework for the mobile device server that can readily support new devices and protocols. The bottom frame unit includes a generally V-shaped bottom frame member adapted for mounting rotatably a pair of rear wheels thereon, and a wheel mounting frame member connected to the bottom frame member and adapted for mounting rotatably a front wheel thereon.