Patent ID: 7538546
Filing Date: 2009-05-26
Classification: H01F

Abstract:
1. An apparatus comprising: a set of magnets for producing an in-plane magnetic field with respect to an article having a top surface and a bottom surface, the set of magnets comprising a first magnetic pole and a second magnetic pole above and generally facing a plane of symmetry and a third magnetic pole and a fourth magnetic pole below and generally facing the plane of symmetry, the first magnetic pole is closer to the third magnetic pole than the fourth magnetic pole and the second magnetic pole is closer to the fourth magnetic pole than the third magnetic pole, the first magnetic pole and the second magnetic pole having opposite magnetic polarities and the third magnetic pole and the fourth magnetic pole having opposite polarities, the first magnetic pole and the third magnetic pole having the same magnetic polarities and the second magnetic pole and fourth magnetic pole have the same magnetic polarities; wherein the article is one or more magnetoresistive elements, the apparatus further comprising a chuck for holding the one or more magnetoresistive elements, an electrical connector for contacting the one or more magnetoresistive elements under test and a positioning system, the positioning system providing relative movement between the chuck with respect to the set of magnets and the electrical connector to position the one or more magnetoresistive elements under test under the electrical connector.