Low cost Current Regulator with High Current and Sufficient Precision for Solder Electromigration Testing

In many industrial and research applications, devices need to operate under constant current (CC) conditions, where voltage precision is not necessary. In some applications, such as reliability testing of solder joints needed in electronics, we aim to maximize the number of devices-under-test (DUTs). In contrast to testing these DUTs in series using one CC supply, the DUTs need to be tested with individual current sources so that the failure of one DUT does not disturb the testing of the others. This necessitates the scaling of CC power supplies. To address this issue, we present a low cost solution for an adjustable constant current regulator (CCR) device with high current capacity and precision sufficient for solder joint testing. The final build cost of the current regulator  was CAD 56.14. Specifications include 10 A maximum current, an accuracy of ±53 mA, and a precision of ± 50 uA. The maximum power output of the device was found to be 15.9 W.