Elite Electronic Engineering

Transcription

1 Durability Growth through Elite Electronic Engineering

2 Topics Covered Review Your Requirements Overview of Accelerated Stress Testing HALT HALT Equipment, Test Methods, Expectations HASS Other Accelerated Tests Summary Q&A

3 Test Requirements & Goals Is Testing Desired by Manufacturer to Reduce Cost of Development, Manufacturing, and Warranty Obligations? Mandated by Manufacturer s Client? What are your expectations and goals for this testing?

4 New Product Development Testing Screens New Product Analysis Phase HALT, HAST, ESD, Power Cycle, EMI RTCA DO-160 MIL-810, SAE J1455 Temp, Vibration, Shock, Waterproofness, Altitude, Humidity HASS Development Phase Qualification Testing Qual Retest Qualitative Testing Quantitative Testing Manufacturing Screen

5 Quantitative Testing Success Run Testing Test to Failure- Weibull Reliability Block Diagrams =

6 Which Tests To Run Input from all departments Determine failure modes (FMEA) Consider complete life cycle of product Suggest stresses that will precipitate failures Maximum Stress vs Time Dependent Develop test plan Execute test

7 Time Dependent Failure Mechanisms Failure Mode Failure Mechanism Accelerating Factors Loss of signal Silicon Diffusion Temperature Power Failure Dielectric Breakdown Electric Field Loss of signal Electromigration Temperature & Power Cycling Intermittent Output Corrosion & Oxidation of Fractures Humidity, Voltage, Temperature Loss of signal Dendrite Growth Humidity, Temperature Water Intrusion Seal Leaks Pressure Cracked Solder Joint Fatigue Thermal cycling & vibration

8 HALT Testing (Qualitative) Highly Accelerated Life Testing (HALT) Temperature and Thermal Shock (60C/min) Vibration 6 axis simultaneous (6 DOF) Very high stress levels to achieve time compression & quickly find the weakest links. Additional stresses likely to precipitate flaws can be used as a part of the HALT/HASS program. power cycling, voltage /electrical stress

9 HALT Testing Design Optimization Provide data to designers for risk assessment Weak links- opportunity to improve the product before the design is locked in. Build in lifetimes of use in its field environment, very large margins. Proactive technique focusing on the mode and mechanism of failure, not on the specifications or the level of stress. No pass/fail criteria HALT specification. Some HALT specifications describe a common method Product Comparisons Side-by-side evaluation of various products and product revisions under similar extreme stress HASS Endpoints Large margins enables the use of high levels of stress in the HASS screen. Leave several if not many lifetimes of use remaining in the product. Enables the use of HASS to quickly detect any slippage that might occur in the manufacturing process.

10 HALT Testing

11 HALT Testing Halt Chamber Workspace 42 x42 x40 Heating & Cooling -100C to +200C >60C/min depending on product loading and temperature range

12 HALT Testing Heating Elements Nichrome Coils FLA 135A Min Service 175A 460VAC 3ph Airflow 4,000CFM

13 HALT Testing LN2 Cooling 4.5GPM 30 PSIG

14 HALT Testing RS Vibration Table Multi-axis repetitive shock 3 linear, 3 rotational Axes 2Hz-10,000Hz Up to 60GRMS (depending on loading) Table Size 30 x 30 Payload up to 400lbs (reduced vibration amplitude) Compressed Air 90PSIG, 48CFM

15 HALT Testing RS Impactors

16 HALT Testing

17 G^2/Hz HALT Testing 1.E+01 1.E+00 HALT PSD 1.E-01 1.E-02 1.E-03 1.E-04 1.E-05 Frequency (Hz) 1.E E E E E E E+05

18 HALT Testing Components on PWB Ckt board resonant frequencies Chip capacitors and die bond wires

19 Acceleration (G²/Hz) RS vs. ED 1x 10-1 Acceleration Profile 1x 10-2 Control Demand 1x Frequency (Hz) Feb 11, :23:11Level 1) 100% Output: 0 V RMS Ice Corporation (33141) Demand: G Level T ime: 0:05:00 De-Icing Control Unit (9510 Rev T) Control: 6.06 G Total Time: 0:05:22 End of Test Y Axis sn: C SAC

20 RS vs. ED ED (Electrodynamic Vibration) Controllable Vibration Spectra 5Hz-2000Hz Single Axis 2 Displacement RS Random Only 6 Axis 30Hz-10,000Hz 10x -15x higher peak accel vs. ED

21 Steps Involved with HALT STEP 1: Pre-HALT Planning Discuss product with multi-functional team Develop test plan Bench test to confirm operation before starting HALT

22 HALT Process STEP 2: Preparing for the HALT Setup Design appropriate vibration fixture Tune chamber proportional & integral parameters Configure air flow for maximum product temperature change rate Apply thermocouples and accelerometers to device under test Setup functional test equipment

23 HALT Process STEP 3: Thermal Step Stressing Cold Begin at ambient Step down in 5 C or 10 C increments Use caution as fundamental limit is approached Approximate dwell time of 10 minutes at each temperature Allow sufficient time to run functional tests Find and fix failures Verify operation of thermal safeties Disable safeties to determine actual operating & destruct limits Continue until fundamental limit of technology is reached Practice continuous failure monitoring

24 HALT Process STEP 4: Thermal Step Stressing Hot Begin at ambient Step up in 5 C or 10 C increments Use caution as fundamental limit is approached Approximate dwell time of 10 minutes at each temperature Allow sufficient time to run functional tests Find and fix failures Verify operation of thermal safeties Disable safeties to determine actual operating & destruct limits Continue until fundamental limit of technology is reached Practice continuous failure monitoring

25 Limits Encountered in HALT Data from Gregg Hobbs of Hobbs Engineering Lower Destruct Limit Lower Operating Limit Operating Margin Destruct Margin Product Specs Operating Margin Upper Operating Limit Destruct Margin Upper Destruct Limit Stress

26 HALT Process STEP 5: Rapid Thermal Cycling Transition temperature at maximum product temperature change rates Select temperatures 5 C inside upper and lower operational limits Reduce change rate by 10 C/min if product cannot withstand maximum rate Continue thermal cycling until operating limit ( C/min) is found Continue cycling for a minimum of 10 minutes Apply functional testing and continuous failure monitoring Depending on the product or application, this step is sometimes omitted

27 HALT Process STEP 6: Vibration Step Stress Understand how product responds to vibration input Vibration is stepped-up in increments, normally 3-5 Grms on the product Dwell time of 10 minutes at each level is typically sufficient Start dwell once product reaches vibration set point Continue until operational or destruct limit is found Apply additional product stresses during process

28 HALT Process STEP 7: Combined Environments Develop thermal profile Use established thermal operating limits, dwell times and change rates Incorporate functional tests and continuous failure monitoring Begin with constant vibration level of approximately 3-5 Grms Step up in 3-5 Grms increments upon completion of each thermal cycle Use tickle vibration when higher Grms levels are reached Add 3-5 Grms tickle to determine if failures were precipitated at high G level but only detectable at lower G level

29 Suggested HALT Process Per GMW 8287

30 Other Stresses The Product Determines the Stress Power Cycling Output Loading Voltage/Electrical Stresses Humidity (HAST) Pressure Altitude Corrosion

31 HALT Process STEP 8: Lessons Learned Determine root cause of all failures that occurred Meet with design engineers to discuss HALT results Management cost justification & risk assessment Determine and implement corrective action Perform Verification HALT Insure problems are fixed and new problems were not introduced Periodically evaluate product as it is subjected to engineering changes

32 HALT Testing Other considerations Quantity of Samples Product Improvement Preparation for HASS/HASA Comparison Testing Fixturing Stimulation vs. Simulation Product and Fixture Weight Test Uniformity Lower Operating Limit Operating Margin

33 25 & 55 Grms Input Scale 5 Grms Input Scale HALT Testing Cross Table Uniformity Grms Input 55 Grms Input 5 Grms Input Table Location 0.0

34 HALT Testing Response Level Test Location Control Level Grms- X Grms-Y Grms-Z Mean MAX (55) MAX (55) MAX (55) MAX (55) MAX (55) MAX (55)

35 HALT Testing

36 HALT Testing

37 HALT Testing

38 HALT Testing

39 HALT Testing Failure Analysis Services

40 HALT Testing Failure Analysis Services SEM photographs showing and overall view (top, ~40x) and a typical closer view (bottom, ~800x) showing some surface debris but no damage to the integrated circuit from sample D4.

41 HALT Testing

42 Other Uses of HALT Component Selection Did vendor perform HALT AND HASS? Use to verify products operating limits. Use to select most robust product. Vendor Selection If subcontracting, vendor needs to meet your standards (Halt and Hass equipment, should be the same.)

43 HASS- Highly Accelerated Stress Screening HASS is used as a production quality screen quickly identify any weaknesses that might enter the product due to changes or malfunctions in the manufacturing process. Each weakness detected, represents an opportunity to take corrective action prior to shipping large quantities of flawed product. The screen is tuned so that it detects weak product while still leaving several, if not many lifetimes of field use in the shipped product.

44 HASS Testing HASS- 100% Production Screening HASA- 1-10% Production Auditing Safety of of HASS Repeat screen a minimum of 20 times Assuming remove less than 5% life Failures after less than 10 times, too harsh Re-HALT- Confirm margins

45 Other Accelerated Stress Testing Acceleration Factors Temperature Arrhenius Model Humidity Arrhenius-Peck Model Vibration Miner Criteria Voltage Inverse Power Law Product Life Cycling CALT Testing Test to Failure & Apply Weibull Analysis

46 Product Life Cycling Calibrated Accelerated Life Testing (CALT) Suggest primary fatigue mechanism Simulate loads at three stress levels 90% of foolish load (first test) 80% of first test load Third stress level Depends on first two and ultimate life Test all units to failure Plot S-N curve, Determine AF s Generate Weibull Plot

47 Product Life Cycling Accelerated Life Testing Accelerated Testing: Statistical Models, Test Plans, and Data Analysis By Wayne Nelson CALT GMW 8758 Example Automatic Lubricating System

48 CALT Test Example Simulate loads at three stress levels Monitor test counting cycles to failure

49 Cycles to Failure CALT Test Example Collect Failure Data Plot and determine Inverse Power Relationship Stress Cycles To Failure Pump S-N Curve AF = (S accel /S normal ) b y = x Applied Stress (PSI) 100 Determine AF's Condition High Stress Mid Stress Confirm Stress Normal Stress Stress Value (PSI) Accel Factor N/A

50 CALT Test Example Sort and apply median ranks Generate Weibull Plot Stress Level Test Stress Accel Factor Cycles at Normal Stress Rank High (IG) High (IG) High (IG) High (PP) Medium (PP) Medium (IG) Medium (PP) Medium (IG) Confirm (PP) Confirm (PP) Confirm (PP) Confirm (PP) Sorted Least to Most (Resort these numbers for each change to spreadsheet) Median Rank

51 Unreliability, F(t) CALT Test Example Weibull Plot ReliaSoft Weibull Probability - Weibull Probability-Weibull Obtain distribution parameters Reliability metrics Data 1 Weibull-2P RRX SRM MED FM F=12/S=0 Data Points Probability Line B1, B10 Reliability vs life Reliability Block Diagrams Steve Laya Elite Electronic Engineering 6/12/ :58:49 PM E+7 Time, (t)

52 HAST Testing Accelerated Humidity Testing HAST (Highly Accelerated Stress Testing) JESD22-A110 B Compress 1000 Hour 85/85 Humidity to 96 Hours High Temperatures may stimulate uncorrelated failures Arrhenius-Peck Accelerated Model for Temperature Humidity

53 HAST Testing Photographs showing environmental damage to the solder joints of A8.

54 Instrumentation & Data Acquisition Yokagawa DL708 Scope Ten Systems In-House 4, 8, and 16 Channel LeCroy Digital Storage Scopes 1.5GHz Bandwidth, 8GS/s, 16M data points Seven Systems In-House 400MHz, 500Mhz scopes Agilent 34970A Data Acquisition System 120 Single Ended or 60 Differential Input AC/DC, Volts, Amps, Frequency, Ohms

55 Advanced Material Center Materials Testing and Failure Analysis Physical Testing Thermal Testing Chemical Testing Light & Appearance Exposure Testing Product Comparisons Location: Ottawa, Illinois

56 Advanced Material Center Physical Testing Tensile Tear Dart Flextural Friction Surface Tension Specific Gravity Density COF

57 Advanced Material Center Thermal Analysis Differential Scanning Calorimeter (DSC) Melt range Purity Thermal Mechanical Analyzer (TMA) Expansion/Contraction Thermal Gravimetric Analyzer (TGA) Thermal degradation Ash

58 Materials Engineering Incorporated Complete Metallurgical Laboratory Failure Analysis Analysis of Processing Problems Contamination Identification Engineering Support/Consulting Laboratory Testing Specialized Testing Litigation Support and Expert Testimony Location: Virgil, Illinois

59 Materials Engineering Incorporated Complete Metallurgical Laboratory Scanning Electron Microscope (SEM) with EDS OES Chemical Composition Metallography and Microscopy Microhardness and Hardness Electrical Conductivity Density/Specific Gravity Surface Roughness (Ra) Pressure and Torque Testing Specialized Product and Component Testing ISO Accredited by A2LA

60 Other Tests to Failure

61 Other Tests to Failure

62 Durability Growth to HALT HASS Any Questions? Thank You!