Arnold, White & Durkee
Printed circuit board tester using magnetic induction
An apparatus and method are disclosed for testing connections between printed circuit boards and components mounted thereon. A conductive loop is formed by forward biasing a parasitic diode that is inherently present between an integrated circuit (IC) lead and the ground plane of the IC. A magnetic field is created by an antenna mounted above the component to be tested. When the antenna is energized by an RF source, a voltage is induced in the conductive loop if the loop is continuous, i.e., if all of the connections are properly made. The voltage in the loop is measured and compared to a selected threshold to produce a pass/fail indication. This tester may be implemented as an improvement to a standard type of "bed-of-nails" printed circuit board tester. The antenna may be implemented as an array of spiral loop antennas, with adjacent antennas producing magnetic fields that are 90 degrees out of phase with each other.
Teradyne, Inc.
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inventional inventional inventional
Jiann-Neng Timothy W. Joseph F. Stephen A. Michael A.
Chen Sheen Wrinn Cohen Baglino