PSV5000_OwnersManual - 第81页
Maximiz ing Programming Yields ≡ Qu ality Control of Devices PSV5000 O wner ’s M anual - 77 - Ma x imizing Programming Yields Occasion al declines i n system yield s may occur d uring day to d ay operation of the PSV50…
Administrative Functions ■ Administrator Functions
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2: dX
3: dY
4: dZ
E
XAMPLE:
100.0|85.0|-152.4|-1022.4
dX,dY are recorded in μm, dR is in microdegree (μdeg)
Figure 42: Sample SPC Log File line entry defined.
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:
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.
Presence of residual plastic on the edges of the devices (flashing) can
cause devices to rest improperly in the sockets.
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.
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.
Multiple fabrication sites often produce the same devices.
Performance characteristics, including programming yield, can vary
from location to location.
Lead oxide accumulating on device leads is an issue for some
devices. This can vary with age and the storage conditions.
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
Administrative Functions ■ Maximizing Programming Yields
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Socket life is generally
rated by the
manufacturer as the
number of insertions per
socket after which yields
may drop significantly.
buildup, damage from mis-inserted devices (perhaps due to poor
calibration of the placement system), and general wear and tear.
Socket conditions that cause varying yields include the following:
Debris of any type can prevent sockets from closing completely.
Debris may not be visible. Simple actuation may clear debris, or it
may be necessary to clean sockets with low pressure, clean dry air.
Blow out sockets every day. Refer to Inspecting the Socket Adapters
on page 98. Actuate the socket to blow out debris from beneath the
contacts. More frequent cleaning is recommended in a dirty
environment.
Bent or distorted contact pins can cause intermittent socket
failures.
System Maintenance that Affects Yield
PSV5000 machine maintenance is critical to maintaining high yields.
Periodic cleaning, adjustment and replacement of worn elements ensure
the best possible performance. These periodic procedures are outlined in
Maintenance Schedule on page 4-2 and should be followed closely.
Part of regular maintenance is ensuring that the system hardware is in
good working order, and that settings are accurate.
To check programmer hardware see FlashCORE Programmer Diagnostics
on page 119.
For accurate placement, ensure that workspace locations (also known as
a Package File) are taught correctly.
If throughput is down, perform Get Movetimes again: see Optimize
Movetimes on page 70.
Process Errors
Finally, some process errors can result in reduced yield. While an
automated approach eliminates most human error during production,
errors in setup or maintenance can result in reduced yield:
Using old algorithms may affect programming yields. PSV5000
System algorithms are updated weekly at
http://www.dataio.com/algorithms/ and are available depending
on your maintenance plan. Algorithms are updated via TaskLink or
Job Creator. See the apropos online Help for more information.
Selecting the wrong device part number for the job in TaskLink/Job
Creator, and therefore the wrong algorithm.