ANSI SP5.6-2009 pdf download For Electrostatic Discharge Sensitivity Testing – Human Metal Model (HMM) – Component Level
8.1.4 Each device pin to be tested shall be stressed at the intended stress voltage ten times positive and ten times negative, with a minimum of one second between stresses. Care must be taken to insure that the part being tested is discharged between each stress. To accomplish this, it is permissible to ground the stressed pins through a one megohm resistor between stresses to return the pin under test to a ground state.
8.1.5 After stress, the CUT can be removed from the test fixture for full functional testing. The component may be left on the test fixture if its functionality can be fully tested on the test fixture. Stressing can be repeated on the remaining units at the same stress level. If multiple stress levels are to be performed the stress may be done on separate units; three units for each stress level. For qualification, all stresses at a particular voltage level must be done on a single device. It is not permissible to divide positive and negative stresses or stressing of different pins between several units.
8.2 Waveform Integrity Measurement Procedure
8.2.1 Procedure for ESD Gun With Discharge Point Directly Connected to the Circuit Board Ground The circuit board shall be mounted on the ground plane and verified to have less than 0.2 ohms of resistance between the circuit board discharge point ground, point A in Figure 7, and the metal ground plane. For this measurement no component needs to be placed on the board, but a CUT is permissible. Connect the ground of the pulse source to one corner of the ground plane. With the current probe in place, connect the pulse source to the ground discharge point. Capture and save an 8 kV pulse. Verify that the pulse waveform is in compliance with the specifications for an 8 kV current waveform in Section 6.1.
8.2.2 Procedure for ESD Gun With Discharge Point Connected to Component Ground Pin The circuit board shall be mounted on the ground plane and verified to have less than 0.2 ohms of resistance between the circuit board ground plane and the ground plane. Connect the ground of the pulse source to one corner of the ground plane. A component shall be inserted into the socket and verified to have continuity with the socket if it is not installed directly to the board. With the current probe in place, connect the pulse source to the component ground discharge point, point B in Figure 7. Capture an 8 kV pulse. Compare the measured waveform with the waveform measured on the discharge point directly connected to the board ground. This comparison will yield insight into the amount of waveform distortion due to the socket and the ground to ground path within the CUT.