NOISEKEN

Overview

Electrostatic discharge (ESD) generated inside a vehicle or during vehicle entry and exit can cause malfunctions in automotive electrical and electronic systems. As modern vehicles incorporate an increasing number of electronic components and control systems, ESD immunity has become an increasingly important design consideration. ISO 10605 specifies test methods for evaluating the immunity of electrical and electronic equipment to electrostatic discharge. The standard simulates ESD events from a charged human body by using an equivalent electrical circuit to reproduce the discharge current waveform.

In addition to immunity tests performed while the equipment is operating under normal vehicle conditions, the standard also specifies test procedures for evaluating the immunity of individual modules to simulated human-body ESD events during vehicle assembly and service operations.

Test Levels

The following tests levels are reference. The categories are classified according to functional importance of the electronics devices/components.

Component test – Example severity levels for direct contact discharge and direct air discharge (Function performance status)

Component test – Example severity levels for indirect contact discharge (Function performance status)

Component test — Packaging and handling — Example severity levels —

Vehicle test — Example severity levels for contact discharge and air discharge (Test points accessible only from inside vehicle)

Vehicle test — Example severity levels for contact discharge and air discharge (Test points accessible only from outside vehicle)

Specification of generator and verification of output waveform

CONTACT DISCHARGE MODE CURRENT SPECIFICATIONS

Following discharges characteristics should be verified.

Typical capacitance / resistance values	Peak current / charge voltage	Current at T1 / Charge voltage	Current at T2 / Charge voltage
①150pF/330Ω	3.75A/kV ±10%	2A/kV ±30% (t1=30ns)	1A/kV ±30% (t2=60ns)
②330pF/330Ω		2A/kV ±30% (t1=65ns)	1A/kV ±30% (t2=130ns)
③150pF/2kΩ	3.75A/kV +30% -0%	0.275A/kV±30% (t1=180ns)	0.15A/kV±50% (t2=360ns)
④330pF/2kΩ		0.275A/kV±30% (t1=400ns)	0.15A/kV±50% (t2=800ns)

Discharge resistance 330 Ω (at 5kV)

Discharge resistance 330 Ω (at 5kV)

VERIFICATION OF OUTPUT CURRENT WAVEFORM

The waveform shall be verified with an oscilloscope whose bandwidth is 1GHz or more in a Faraday cage or with a 1.2m x 1.2m metallic board mounting an ESD current target in the center of the cage or the board. The discharge electrode (Discharge tip of the gun) shall be touched onto the target and the discharge mode shall be set at the contact discharge mode.

The discharge return cable shall be turned up the center of the length and connected to vertically 0.5m under the target on surface of the Faraday cage or board.

Calibration of target

Adaptor for calibrating ESD current target (Model:06-00068A)

a : Calibration points with networks analyzer

Figure of attaching ESD current target and the calibration adaptor(Left : Target Right : Adaptor)

Test setup and test procedure

Common Points:

• Ground plane: at least 1.6 x 0.8m in size, at least 0.2m larger than the DUT or peripherals during setup, and with a connection resistance of 2.5mΩ or less.
• Insulating block: height 50±5mm. Extend 20mm beyond the test configuration on all sides.
• The DUT shall be connected to all peripheral devices required for functional testing of the DUT with the wire harness length of 1.7m (+0.3m- 0).
• All components should be at least 0.2 m apart from each other.
• Bundle the wire harness 0.1m away from the edge of the ground plane and secure it to the insulating block.
• The supply battery shall be on the test table, with the negative terminal of the battery directly connected to the GP.
• The test stand should be at least 0.1m away from other dielectric structures.
• For direct discharge, connect the electrostatic simulator's discharge return cable to the ground plane.
• Use discharge network of 150pF or 330pF depending on the EUT device location, and use 330Ω or 2kΩ.
• The test should be conducted for two or more test levels.
• Isolating block should be used for electronic equipment that are not directly chassis-mounted.



Component immunity test method (powered-up test) - Direct contact and air discharge -

• Test at least 3 times with positive and negative polarity, separated by at least 1 second.
• Apply to every location available for human touch.
• Isolating block should be used for electronic equipment that are not directly chassis-mounted.



【 Contact Discharge 】

• The discharge electrode is brought into contact with the discharge point of the DUT before activating the discharge switch.
• For painted surfaces, if the coating is not an insulating coating, the pointed tip of the generator should penetrate the coating so as to make contact with the conducting substrate.
• The ESD discharge tip is held perpendicular to the surface of the DUT.



【 Air Discharge 】

• After operating the discharge switch, move the discharge electrode tip to the DUT as quickly as possible (0.1m/s to 0.5m/s) until it contacts the discharge point and apply voltage.
• If the conductive material is declared to be an insulating coating, perform air discharge.



Component immunity test method (powered-up test) - Indirect Discharge -

• Apply discharge to the ground plane with contact discharge.
• Test 10 times or more at intervals of 1s or more.
• Apply to the ground plane at points on each side of the DUT.
• Position the DUT so that the nearest surface is 0.1 m away from the edge of the ground plane that receives the discharge.
• Apply at a position 0.1m from the DUT and harness.
• Select 330pF as the CR constant depending on the mounting position of the device, and use 330Ω.



Component immunity test method (powered-up test) - Direct Discharge using FCP -

• At least 3 discharges shall be applied both to the positive and negative polarities with the interval not less than 1s.
• Select 150pF or 330pF as the CR constant depending on the mounting location of the device, and use 330Ω.



Component immunity test method (powered-up test) - Indirect Discharge using FCP -

• Apply at least 10 contact discharges for each polarity to each discharge island with the time interval 1 s or longer.
• The CR constant is selected to be 330pF depending on the mounting position of the device, and 330 is used.



Component immunity test method (unpowered) - Packaging and Handling - ESD Sensitivity Test

• Use 150pF capacitance and test with resistances that simulate direct contact with the human body (2kΩ) and touch with a metal object (330Ω).
• Conduct tests of two or more levels.
• At least 3 discharges shall be applied both to the positive and negative polarities with the interval not less than 1s.
• Contact discharge shall be applied to all locations human finger may touch.
• After applying the voltage, remove the static electricity from the DUT with a static elimination resistor of 1MΩ±20%, then energize it and confirm that it operates normally.



Vehicle test – Internal and external points –

• Areas that can be easily touched by people inside the vehicle are tested with 330pF/330Ω or 2kΩ.
• Areas that can be easily touched by people from outside the vehicle are tested with 150pF/330Ω or 2kΩ.
• The ground wire connects to the chassis, such as the seat rail. During external testing connect to a nearby chassis or metal plate under the tire.
• Both the contact discharge and air discharge tests shall be done both for the internal and external tests.



Notes : This test set-up is quoted from ISO 10605 ed.3.0 (2023) Standard.
Please go through the Standard if more details are required.