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Technologies > Immunity > ESD Scan

Amber Precision Instruments is a research-oriented EMC solution provider

Immunity/ESD Scan > Principles

As an ESD simulator (a gun) discharges to a test point of a DUT, currents flow to chassis and internal PCB. The currents radiate E&M fields, and the field couples to components or traces in the PCB, inducing voltages or currents to the circuit. The induced voltages and currents can cause functional or unrecoverable failures to the circuit.

ESD scanning is;
(1) emulating the fields that induce voltages or currents by magnetic field probes or electric field probes, respectively,
(2) finding the sensitivity level at local areas of the circuit,
(3) and recording the responses of the DUT to the induced voltages or currents.
Currents can be injected directly to the circuit by direct injection probes and DUT response can be monitored, too.
• See the video of 'SmartScan ESD Scanner Introduction' >




Immunity/ESD Scan > Applications

● ESD failure debugging
● Quality inspection of functionally identical components or modules
● Qualification of components and modules for system level ESD

ESD Failure Debugging

ESD scan is an excellent tool to localize and debug IEC 61000-4-2 failures. Evaluation of countermeasure that applied to modules is another area of application.




Quality inspection of functionally identical components or modules

The ESD scan is very effective inspecting which supplier's part has the least likelihood of causing ESD failures among multiple suppliers for functionally identical components.





Qualification of components and modules for system level ESD

It is more desirable that screening out potentially problematic IC's and modules before they are assembled into complete systems. The ESD scan can provide good information to determine minimum ESD immunity level with accumulated database by products.




"ANSI/ESD SP 14.5-2015, For electrostatic Discharge Sensitivity Testing - Near-Field Immunity Scanning - Component/Module/PCB Level", that was published on Sept. 2015, provides good guidelines.


Immunity/ESD Scan > Required Equipment

● SmartScan-ESD
● TLP (Transmission Line Pulser) as a disturbance source
● Probes
● Failure monitoring feature


TLP (Transmission Line Pulser)

The disturbance source of the ESD scan is a TLP with < 350 pSec rise time. For more information on backgrounds of selecting TLP as the source, please, check the paper in Library section.





Probes

ESD probes are in-house designed to have maximum E&M radiation. Several different sizes of magnetic field, electric field and direct injection probes are available. Drawings below show concepts of four different types of probes.






Failure Detection Module

Automatic failure detection capability increases ESD scanning efficiency significantly because it enables users to leave the scanner runs by itself. It has capabilities of monitoring four analog, four digital, output from a photo sensor and 1 kHz acoustic signals. It equipped with one 120 ~ 240V AC relay, and a NO/NC DC relay for DUT power cycle. It is software controlled and more details. Learn more about FD module >>>

It is expected to provide a certain level of customization for automatic failure detection because failure definition is very different by products. Contact API for customization details.


Immunity/ESD Scan > Test Flow

1. Turn on the DUT
2. Move a probe to the test position
3. Inject disturbance (field direct injection)
4. Monitor response of the DUT
5. If failed,
-- Power cycle the DUT
-- Lower the disturbance level (lower TLP voltage)
-- Go to step #3
6. If not failed,
-- Move to net step
7. Move to next test point