Dalsa Dalsa DS-4x-06M18, User'S Manual And Reference

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6M18 Camera User’s Manual 35
DALSA 03-32-10017-03
5
Cleaning and Cleaning and Cleaning and Cleaning and
Maintenance
Maintenance Maintenance
Maintenance
5.1 Cleaning
Electrostatic Discharge and the CCD Sensor
Charge-coupled device (CCD) image sensors are metal oxide semiconductor (MOS) devices and
are susceptible to damage from electrostatic discharge (ESD). Although many sensor pins have
ESD protection circuitry, the ESD protection circuitry in CCDs is typically not as effective as
those found in standard CMOS circuits.
Electrostatic charge introduced to the sensor window surface can induce charge buildup on the
underside of the window that cannot be readily dissipated by the dry nitrogen gas in the sensor
package cavity. When charge buildup occurs, surface gated photodiodes (SGPDs) may exhibit
higher image lag. Some SGPD sensors may also exhibit a highly non-uniform response when
affected by charge build-up, with some pixels displaying a much higher response when the sensor
is exposed to uniform illumination. The charge normally dissipates within 24 hours and the sensor
returns to normal operation.
Preventing ESD Damage
To prevent ESD damage, DALSA advises you to take the following handling precautions.
1. Ground yourself prior to handling CCDs.
2. Ensure that your ground and your workbench are also properly grounded. Install conductive
mats if your ground or workbench is non-conductive.
3. Use bare hands or non-chargeable cotton gloves to handle CCDs. NOTE: Rubber fingercots
can introduce electrostatic charge if the rubber comes in contact with the sensor window.
4. Handle the CCD from the edge of the ceramic package and avoid touching the sensor pins.
5. Do not touch the window, especially in the region over the imaging area.
6. Ground all tools and mechanical components that come in contact with the CCD.
7. DALSA recommends that CCDs be handled under ionized air to prevent static charge buildup.