Abstract: An arrangement and method for pressing down a semiconductor package arrangement with a controlled down-force balances a pressure bar on a fulcrum. The pressure bar is biased by a spring in a first direction downwardly towards a semiconductor package to be held. An adjustment device limits the amount of rotation of the pressure bar around the fulcrum. An adjustment device controls moves the limit of rotation of the pressure bar around the fulcrum so that the pressure applied by the spring and pressure bar against the semiconductor package may be precisely controlled. This controlling of the pressure applied against the semiconductor package allows for a consistency of testing during the electrical characterization testing of the semiconductor package and eliminates the manual holding down of the package during testing.

Abstract: A test fixture with an isolation plate grounds all of the solder balls of a ball grid array (BGA) of a chip scale package, except for a selected subset of the solder balls, to perform electrical characterization of the package. The isolation plate includes at least one hole extending through the isolation plate that exposes the selected subset of the electrical contacts. The hole has a sidewall angled at a non-perpendicular angle from the horizontal plane of the isolation plate. The angle sidewall of the hole provides increased clearance for a fixed compliant probe to land on the solder balls to be tested in an electrical characterization process.