IPC TM-650 2.5.33.3

Abstract

This test method measures DC and AC current leakage from the tip of the Unit Under Test (UUT) to ground. The AC frequency range measured is in the 20 Hz to 20 MHz range, which covers the currently known equipment base. If soldering systems with oscillator or microprocessor frequencies higher than 20 Mhz are to be qualified, then wider band width measuring equipment should be considered. Failure to do so is likely to qualify equipment that might otherwise be disqualified. There are three times when current leakage measurements should be done: Equipment qualification for purchase Incoming inspection of new or repaired equipment Process monitoring (periodic checks) Current leakage is measured and indicated by measuring the voltage developed across a resistor, which closes the circuit between the tip of the UUT and ground. DC and true rms AC measurements will be made separately. This test may be falsely influenced by radio frequency interference and electromagnetic interference from lighting and equipment found in the workplace and testing area. At a minimum, shielded test leads should be utilized. To avoid these influences it may be necessary to perform the leakage and transient tests in a screen room. In lieu of a screen room, a separate test procedure (see Method 2.5.33.4) has been provided to make a low cost shielded enclosure, which should provide adequate shielding for the performance of these test procedures. <br>Warning: These are laboratory test procedures that may, of necessity, expose terminals that carry line voltages. All standard laboratory safety procedures regarding the setup and performance of tests with line voltage equipment must be observed at all times. <br>Caution: These tests are performed with soldering systems at their normal operating temperature. Test personnel must take adequate precautionary steps to protect themselves and others from potential burns.