optimiSE Gmbh München – Bruchsal Germany

1. optimiSE GmbhMünchen – BruchsalGermany Werner-von-Siemens-Straße 47a D-76646 Bruchsal Telefon +49-7251- 930 667/668 Fax +49-7251- 930 666 Email: webmaster@optimiSE.de Internet: www.optimiSE.de

2. 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

3. 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

4. What means redundanttest in the context of reduTec ? • A test Tkis redundant with respect to a given series of tests {Tj} jk,j=1,...,N, if the information gain obeys for some user-defined  > 0. Here • where and represent the information vectors corresponding to the test subsets {Tj}j=1,...,N and {Tj}jk,j=1,...,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 testseries 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

5. 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

6. 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

7. 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

8. - 33% - 16% 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

9. 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