Using in situ capacitance measurements to monitor the stability of interface materials in complex PCB assemblies and other structures

• Main Authors: CHAINER TIMOTHY J, GAYNES MICHAEL A, YARMCHUK EDWARD J
• Format: Patent
• Language: English
• Published: 19.11.2013
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

An electric potential is applied to first and second electrodes on opposite sides of a gap between an electronic component and a heat spreader. At least one of a thermal interface material in the gap, the electronic component and the heat spreader is subjected to a changing physical condition. The electrical capacitance between the electrodes is monitored during the changing physical condition. Such a method can be practiced using an array of components sharing a common heat spreader. An assembly for testing thermal interfaces includes a printed circuit board, a plurality of electronic components mounted to and operatively associated with the printed circuit board, a heat spreader positioned for absorbing heat generated by the electronic components, a first electrode associated with the heat spreader, a plurality of second electrodes associated, respectively, with the electronic component, and a device for monitoring electrical capacitances between the first and second electrodes. The technique may be employed for monitoring physical changes in electronic devices and other structures having interfaces between components.