optimiSE Gmbh Mnchen Bruchsal Germany

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optimiSE GmbhMünchen BruchsalGermany

• Werner-von-Siemens-Straße 47a
• D-76646 Bruchsal
• Telefon [phone]
• Fax [phone]
• Email webmaster_at_optimiSE.de
• Internet www.optimiSE.de

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What reduTec accomplishes
reduTec or how to cut down on your test cost
budget

• reduTec analyses test data of complex electronic
  products with respect to underlying redundancies
• reduTec regroups tests into necessary ones and
  those without information gain
• Benefits
• Controlled dismissal of redundant tests of intact
  devices for high yield product lines
• Earliest possible detection of damages to shorten
  test cycles of defect devices for low yield
  products

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reduTec optimises your test management
Exampel Chip-Testing

• Input
• real-valued (acceptance intervals) or binary
  (pass / fail) intact / defect data from frontend
  / backend tests
• optional extra process data, e.g. chip location
• Methods
• deterministic, product-independent mathematical
  procedure without arbitrary statistical
  assumptions
• neuro-fuzzy-system for test data mining and
  process monitoring
• Output
• identification of redundancies for high yield
  products
• optimised test sequences w.r.t. first failure out
  for low yield product lines
• yield learning and process control

raw wafer
wafer fabrication
frontend
processed wafer
wafer probe
assembled chip
sawing assembly
backend
tested device
final test
time
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What means redundant test in the context of
reduTec ?

• A test Tk is redundant with respect to a given
  series of tests Tj j?k,j1,...,N, if the
  information gain obeys for some
  user-defined ? gt 0. Here
• where and represent the information
  vectors corresponding to the test subsets
  Tjj1,...,N and Tjj?k,j1,...,N respectively.
  In most cases, the suitable metric is the
  Euclidean distance.
• Applies to intact devices, where
• tests resulting in large deviations from the
  ideal value and/or large variations around the
  actual mean value of the test series carry
  information about the control of the production
  process they are essential
• tests which are well-passed by all devices are
  superfluous and potentially redundant
• and defect objects, where
• binary tests are ordered with respect to first
  stop on failure and probes without information
  gain can be neglected

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Test ranking by reduTec intact objects

• reduTec assigns quantitative, weighted redundancy
  factors to each test

weighted information gain
obsolete tests (for instance)
excerpt from (400) - test sequence
digital engine control unit
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Test ranking by reduTec stop on first failure
tests
potentially redundant tests (white)
defect devices
test analysis protocol
essential tests (black)
information gain
optimal test sequence w.r.t. first failure out
original pass / fail test sequence
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Sequencing with reduTec - basics for the binary
case
test
object
19 single tests to detect deficiencies
14 single detection tests 1 globally redundant
test
reduTec
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Estimation of test cost savings
0,31
0,31
Materials
Personell
0,26
0,20
Overhead
Capex (Handler)
Capex (Tester)
Tester T5365 T5581H
T5365 reduTec Parallelity 64
128 Price Tag 0,9 Mio. 1,9 Mio.
50-100 T Investment 1,0 Mio.
50-100 T Devices under test (DUT) for 10
Mio. DUT 0,3-0,8 Mio. DUT amortization
10 savings under 80 correlation with test time
reduction
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Further developments within reduTec

• Test Data Mining
• Automated test- and object qualification based on
  user-specific expert system
• Online neuro-fuzzy-system association rules
• Online analytic processing (OLAP)
• Test and know-how data bases for improved process
  control and test management
• ? from data to knowledge