Residual material detection in backdrilled stubs
AssigneeInternational Business Machines Corporation
InventorsGerald K. Bartley, Darryl J. Becker, Matthew S. Doyle, Philip R. Germann, Mark O. Maxson
Life of this patent
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Abstract
A stub of a via formed in a printed circuit board is backdrilled to a predetermined depth. A capacitance probe is positioned within the via. Then the capacitance probe is used to obtain a test capacitance measurement. The test capacitance measurement is compared to a predetermined baseline capacitance measurement. Residual conductive plating material in the backdrilled stub causes the test capacitance measurement to exceed the predetermined baseline capacitance measurement. An indication is made that the predetermined baseline capacitance measurement has been exceeded.
Claims16
A method for measuring and assessing the adequacy of a backdrilling operation, the method comprising:
- obtaining a test capacitance measurement of a backdrilled stub of a via formed in a printed circuit board;
- comparing the test capacitance measurement to a baseline capacitance measurement, residual conductive plating material in the backdrilled stub causing the test capacitance measurement to exceed the baseline capacitance measurement;
- and
- indicating that the test capacitance measurement exceeds the baseline capacitance measurement.
A system for measuring and assessing the adequacy of a backdrilling operation, the system comprising:
- a capacitance probe deployment device;
- and
- a computer operatively coupled to the capacitance probe deployment device, the computer configured to:
- instruct the capacitance probe deployment device to use a capacitance probe to obtain a test capacitance measurement of a backdrilled stub of a via formed in a printed circuit board;
- compare the test capacitance measurement to a baseline capacitance measurement, the residual conductive plating material in the backdrilled stub causing the test capacitance measurement to exceed the baseline capacitance measurement;
- and
- indicate that the test capacitance measurement exceeds the baseline capacitance measurement.
A computer program product for measuring and assessing the adequacy of a backdrilling operation, the computer program product comprising a computer readable storage medium having instructions embodied therewith, the instructions executable by a computer to cause the computer to:
- instruct a capacitance probe deployment device to use a capacitance probe to obtain a test capacitance measurement of a backdrilled stub of a via formed in a printed circuit board;
- compare the test capacitance measurement to a baseline capacitance measurement, the residual conductive plating material in the backdrilled stub causing the test capacitance measurement to exceed the baseline capacitance measurement;
- and
- indicate that the test capacitance measurement exceeds the baseline capacitance measurement.
Dependencies are inferred from the claim text.