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Andy Cheung. New Product Development Engineer Micrel Inc. November 26, 2003. Product Design Cycle. Product. Datasheet Specification Example. Absolute Maximum Ratings. Operating Ratings. Testing IC’s. Correlation Characterization Wafer Sort Final Test. Correlation.
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Andy Cheung New Product Development Engineer Micrel Inc. November 26, 2003
Product Design Cycle Product
Testing IC’s • Correlation • Characterization • Wafer Sort • Final Test
Correlation • Test Matrix by design • All tests listed • Typically follows datasheet • Tests implemented on automatic tester • Responsibility of test engineer • TMT, Eagle Test Systems
Correlation • Bench • Confirm all TMT data • Learn Device • Find problems • Accurate measurements • Equipment • Method
Typical Equipment Setup • Oscilloscope with Probes • Pair of DC Power Supplies • 0-25V • 0-4A • Pair of Digital Multi Meters • Test Board • Solder Station • Parametric Analyzer • Source Meter • Current Probe • Freeze Spray and Heat gun
Dropout Voltage & Ground Current Measurement • DC Errors • Ground wire length • 100mOhm*500mA = 50 μV • Introduces losses in current measurements • Need voltage accuracy to 1 or 2 μV • 4 wire sense • Kelvin contacts
Dropout Voltage & Ground Current Measurement + - V I Sense Node (Kelvin Contact) Normal Wire LDO Vin Ammeter Ground
Characterization • Characterization is Done to: • Find the Device’s Capabilities and Limitations • Performance over Temperature • Find Randomness • Results: • Single Insertion Test Limits • Specification Change • Determine Problems
Characterization • Parts typically follow a normal (gaussian) distribution. • Test parts at all possible operating conditions per specification parameters. • Typically done on handlers to simulate production environment. • Most stringent testing.
Datasheet Review • Device Realized? • Changes? • Deletions? • Yield Improvements? • Problems?
SIT Limits • Use characterization data to ensure device operation over temperature. • Guardbands • Temperature • Tester
Wafer Sort • Tightest Limits • Wafer Trim • Bandgap • Frequency • Wafer Probe Station for Bench Testing • Gate Stress Pads • Ensure Test is Correct
Final Test • Guarantee parts operated as written on datasheet. • Uses SIT limits generated from characterization.
HAPPY THANKSGIVING!!! • Major Test Checkpoints • Correlation • Characterization • Wafer Sort • Final Test • Questions?