Data I/O PSV5000, Руководство пользователя

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Maximizing Programming Yields ≡ Quality Control of Devices
PSV5000 Owner’s Manual - 77 -
Maximizing Programming Yields
Occasional declines in system yields may occur during day to day
operation of the PSV5000 System. While overall yield levels can vary
depending on device manufacture, any steep change in yields is
sufficient reason for investigation of an immediate cause of variation.
These changes in yield can be attributed to a number of causes,
including device quality control, socket issues, system maintenance,
and process errors.
Quality Control of Devices
Variations in the manufacture of devices may affect yields in an
automated system, such as:
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Variation in dimensions from different manufacturing lots or
facilities can cause devices to fit improperly in the sockets or require
reteaching the Package File to be placed successfully.
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Presence of residual plastic on the edges of the devices (flashing) can
cause devices to rest improperly in the sockets.
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Die changes (shrinks, process improvement for improved wafer
yield, etc.) require new algorithms. Data I/O tracks these changes
with vendors and recommends all customers subscribe to the
algorithm update program.
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Die processes vary. Programming yields can sometimes vary on a
normal die. Device families recently introduced to the market tend
to have more fluctuations in yields until the semi-vendor's
manufacturing process stabilizes.
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Multiple fabrication sites often produce the same devices.
Performance characteristics, including programming yield, can vary
from location to location.
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Lead oxide accumulating on device leads is an issue for some
devices. This can vary with age and the storage conditions.
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Programming yields decrease with the number of programming
cycles. Devices that are processed more than once are more likely to
experience problems.
Socket Issues
The programming sockets are perhaps the most important and
vulnerable element of the PSV5000 System. They are subject to residue