3-4
TM109902 (5/03)
USE OR DISCLOSURE OF DATA CONTAINED ON THIS PAGE IS SUBJECT TO THE
RESTRICTION ON THE TITLE PAGE OF THIS DOCUMENT
.
C
O M M A N D
S
Y S T E M S
D
I V I S I O N
B. Electrostatic Discharge Sensitive (ESDS) Devices
Devices sensitive to electrostatic discharge are used in this equipment. These devices, including
Metal Oxide Semiconductors, some metal film resistors, and other devices, are susceptible to
damage by electrostatic charges or high-voltage fields. Because of the very high resistances in
ESDS devices, they can be damaged by electrical sources that cannot deliver enough current to
damage conventional semiconductors. Therefore, special precautions must be taken during
handling and repair procedures to prevent damaging the device. The most common low-energy
source causing damage to ESDS devices is the human body, which generates and retains static
electricity, in conjunction with non-conductive garments and floor covering. An individual can
easily develop several thousand volts of electrostatic charge while simply walking across the
floor or moving around in a chair. Electrostatic charges of 20 kV have been measured on
personnel, and 35 kV has been measured on their garments.
The capacitive elements in all MOS devices can be destroyed by a voltage field, even when
assembled into the circuit. Similar capacitive elements in linear integrated circuits, hybrids, and
in bipolar integrated circuits are also susceptible to field voltages.
Not all electrostatic damage will result in immediate catastrophic failure. Damaged devices may
remain operating within the minimum limits but could experience early field failure or erratic
performance.
The following precautions are recommended for ESDS circuits, and are especially important in
low humidity or dry conditions when electrostatic problems are more prevalent.
ESDS devices include, but are not limited to,
C-MOS, J-MOS, PMOS, NMOS, SOCMOS,
HMOS, MOS/FET, microwave mixer diodes,
some bipolar devices, and some metal film
resistors.
(1) Storage
Store and transport all ESDS devices in conductive material. Do not insert ESDS devices
into conventional plastic “snow” or plastic trays used for storing and transporting standard
semiconductor devices. Special bags or containers must have a maximum resistivity of 10
4
ohms/cm, or the leads of the device must be shorted together through a conductive material
(special foam) having a maximum resistivity of 10
4
ohms/cm.
Modules, circuit boards, or assemblies containing ESDS devices must be stored in static
shielding bags with a maximum resistivity of 10
4
ohms/cm in the outer layer of the bag,
and 10
12
ohms/cm resistivity in the inner layer.
A caution label shall be attached to the outside of all containers containing ESDS devices.
The ESDS labels are identified in the advisory information located in the front of this
manual. Do not remove device from container until actually used or tested.
CAUTION
The document reference is online, please check the correspondence between the online documentation and the printed version.
