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The Southwest Test Workshop was held at the Princess
Resort Hotel in San Diego from May 31 to June 3, 1998. This was
the fifth year the workshop focused on microelectronic wafer
level testing, and 415 wafer test professionals attended. It
was a record attendance for the SWTW and surprising in light
of the severe travel restrictions in place at numerous semiconductor
manufacturers.
The workshop began Sunday afternoon with special
activities for early arrivals. There was an excursion to the
nearby Torrey Pines Hang Glider port where we enjoyed taking
photos of gliders and parasails overlooking the Pacific on a
beautiful afternoon. We were all surprised to discover that the
glider port was just a little north of San Diego's famous, bathing
suit optional, Black's Beach. Out came the telephoto lenses!
Meanwhile, 175 attended the SWTW first Probe Technology Tutorial.
Three presentations were given on Gauge R&R, probe card manufacturing
and metrology, and a description of the SEMI task force Probe
Standards recently sent out to ballot.
The official workshop began at 5:00pm with registration,
a get acquainted reception, and a Mexican buffet dinner. This
year, the customary Sunday evening panel session took on a unique
challenge. One mission of the SWTW has always been to inform
the equipment and service suppliers about the needs and expectations
of the semiconductor manufacturers, but we had never specifically
addressed this task. Therefore, the six panel members, all semiconductor
manufacturers, describe in detail what they wanted and expected
today, and in the future, and their priorities in terms of price,
performance and other factors. Their opening statements were
followed by an active audience discussion.
The technical sessions began Monday morning with
a contact resistance session including a presentation on the
theoretical aspects and two presentations on the extensive empirical
data taken for a Sematech study. The next session focused on
two brand new probe card technologies and unique advances made
in probe needles. After lunch, we had a session on probe needle
cleaning including insitu methods on probers, unusual tricks
and lessons learned, and an excellent survey of five different
cleaning methods (which ended up winning the best presentation
award).
Following the afternoon break, we had three non-overlapping
parallel breakout sessions. The first session was in the specialized
area of RF probing where three presentations discussed RF characteristics
of materials used in probe test fixturing, new RF software simulation
and modeling tools, and characterization of some membrane probe
cards. The second parallel session was a panel and audience discussion
of activities to reduce the cost of wafer testing. Discussion
topics included baselining where the costs were, improved equipment
utilization, sample probing, reduced test times, and many others.
One important point discussed was that sometimes wafer test cost
is actually increased to achieve reductions in the back-end test
cost; the goal is to reduce the overall product cost. The third
session was also a panel and attendee discussion. It concentrated
on the somewhat unique technologies of memory probing including
massively parallel probing, offline redundancy repair, BIST,
and full wafer burn-in.
After a hard day of probe technology, the attendees
enjoyed a cocktail party at the hotel's Barefoot Bar, and then
a great dinner in the Sunset Ballroom overlooking Mission Bay.
After dinner, everyone was invited to continue informal technical
discussions, have a little more dessert, and enjoy some after-dinner
"cordials" in another conference area.
Tuesday morning began with a session on overall
probing accuracy. Four presentations discussed the effects of
docking, prober accuracies, and temperature on the ability to
hit within a few microns of the center of the probe pad, every
pad, all the time. The next session focused on area array probing,
where the probe pads are distributed over the entire area of
the die instead of being restricted to the perimeter. The first
presentation was an overview from Sematech describing interesting
technology drivers, the present and future trends, and some informative
cost benchmarks. The next presentation was an excellent summary
of the over 20 years experience of IBM, and this was followed
by another presentation of the cost issues of vertical probe
cards.
Tuesday afternoon was dedicated to social interaction.
Since everyone knows that more than 50% of the value of a workshop
is the informal technical discussions, the SWTW does not simply
encourage them; it makes them happen. Three activities were available.
Thirty-seven people played miniature golf at the hotel course
and a few more opted for a higher level of play at a nearby Torrey
Pines course. Two hundred and fifty attendees and spouses spent
the afternoon at Sea World. About 125 boarded a misplaced Mississippi
Stern Wheeler from the hotel dock for a two-hour sightseeing
cruise around Mission Bay. Official SWTW hats and suntan lotion
were passed out to all.
Tuesday evening we had another cocktail party and
then our awards banquet. Awards were given for the best data
presented, best overall presentation, lowest miniature golf score,
and poorest disguised sales pitch (The Royal Order of the Golden
Wheelbarrow full of Crap). It is somewhat unusual to have an
awards banquet before the workshop is completely over, so the
SWTW also gives an award to all the Wednesday presenters. The
coveted Worst Sunburn Award could not be given because the SWTW
had accidentally received only SPF4 suntan lotion, and there
were too many qualified recipients.
Our first session Wednesday morning was on fine
pitch probe cards. With higher I/Os and device shrinks, tighter
pitch perimeter cards are becoming more important. This session
had three presentations on cards with pitches of 67, 45, and
40 micrometers. The final session was on the various issues of
wafer testing in order to supply Known Good Die. The first presentation
was an overview of KGD including the activities of a Die Products
Consortium of major manufacturers. This was followed by a presentation
on full wafer burn-in, and then a presentation of the EIA/JEDEC
JC-13 KGD standard. The final presentation described the successful
approach for testing a complex 1500 I/O device requiring over
70 watts, appropriately entitled, "Scotty, I need more power!"
By most measures the 1998 SWTW was the best. We
tried some new things such as the Probe Tutorial, and we increased the
activities for informal discussions. We had 3 excellent panel and audience
discussions and 29 technical presentations. A copy of the presentations
will be posted on the Computer Society web, a CD ROM is being made for the
attendees in addition to the printed conference proceedings handed out
during the workshop, and we plan to give copies of the CD ROM to attendees
of the special probe session at the 1998 ITC. The next SWTW will begin
Sunday afternoon, June 6, 1999 at the Paradise Point Resort in San Diego
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