High-speed capacitor leakage measurement systems and methods
View Patent ↗Systems and methods according to aspects of the present invention are described. The systems and methods enable charging, soaking, and measuring of capacitors to be conducted quickly. Charging and soaking typically occurs in parallel and certain embodiments facilitate the measuring of capacitor leakage by sequentially disconnecting each capacitor and measuring the time for voltage on the capacitor to reach a predetermined threshold. Further, all capacitors can be disconnected from a charging source simultaneously and voltages can be measured for each capacitor simultaneously. Monitoring can be periodic in nature. Substantial time savings in the calculation device of leakage values and parameters can be attained.
1. A method for measuring capacitor leakage comprising:
applying a current to a plurality of capacitors simultaneously, the current being applied for sufficient time to charge and soak each of the plurality of capacitors;
discharging simultaneously the plurality of capacitors;
measuring successively a voltage for each of the plurality of capacitors as the plurality of capacitors discharges;
determining whether the measured voltage of a particular capacitor of the plurality of capacitors has reached a predetermined threshold value;
recording the time duration, as measured from the start of the simultaneous discharge of the plurality of capacitors, it took for the measured voltage of the particular capacitor of the plurality of capacitors to reach the predetermined threshold value; and
repeating the measuring, determining, and recording steps until all of the plurality capacitors has reached the predetermined threshold value.
2. The method of testing capacitor leakage of claim 1 wherein the measuring and recording the measured voltage and time duration for each of the plurality of capacitors is complete as of the recordation of the last measured voltage and time duration.
3. The method of claim 2 and further comprising calculating capacitor leakage for each of the plurality of capacitors.
4. The method of testing capacitor leakage of claim 1 wherein the plurality of capacitors are coupled to a charging circuit and a measuring circuit.
5. The method of testing capacitor leakage of claim 4 wherein the charging circuit and measuring circuit are part of a probe card testing system.
6. A system for measuring capacitor leakage comprising:
a plurality of charging switches each charging switch controlling connection of one of a plurality of capacitors to a charging source;
a plurality of sensing switches, each sensing switch controlling connection of one of the plurality of capacitors to a voltage sensing device;
a controller operative to control the plurality of charging switches and the plurality of sensing switches wherein the controller is configured to cause all of the plurality of capacitors to be charged and soaked simultaneously, discharge the plurality of capacitors simultaneously, connect selected ones of the plurality of capacitors to the voltage sensing device to measure successively a voltage for each of the plurality of capacitors as the plurality of capacitors discharges, determine when the measured voltage of a particular capacitor of the plurality of capacitors has reached a predetermined threshold value, record the time duration, as measured from the start of the simultaneous discharge of the plurality of capacitors, it took for the measured voltage of the particular capacitor of the plurality of capacitors to reach the predetermined threshold value, and repeat the measurement, determination and recordation until all of the plurality of capacitors has reached the predetermined threshold value.
7. The system of testing capacitor leakage of claim 6 wherein the measurement and recordation of the measured voltage and time duration for each of the plurality of capacitors is complete as of the recordation of the last measured voltage and time duration.
8. The system of claim 7 wherein the controller is further configured to calculate capacitor leakage for each of the plurality of capacitors.
9. The system of claim 7 wherein the system is a probe card testing system.