A package for an integrated circuit chip is disclosed, along with structures and methods for making and mounting the package. Accordingly, it is made possible to carry the printing medium into the apparatus in a proper state even when the printing medium is a nonstandard-sized printing medium. The n coded signal slices are switched via matrix modules on n distinct matrix boards. However, the test MR sensor is fabricated with an area that is larger than areas of the MR sensors in the read elements. A method of using the above described assay plate is also provided.