Reliability Assessment, Growth Objectives Review of Statistics, Normal Dist, Exponential Dist, Weibull Dist 6 Sigma Quality and Basic Statistical Data Analysis Introduction to Reliability Prediction Methods and Databases Environmental, Electrical, Mechanical and other Stresses Introduction to Reliability Growth Strategies Define a COMMON Reliability Prediction Database for your team

Reliability Assessment, Growth Deliverable – Individual (Excel Tool and PPT Slides) Decide which Reliability Database your team will use Compile as much of your BLOCK BOM (Bill of Materials) as possible Find the appropriate p stress factors and l values Compile your overall BLOCK l and MTBF using the Excel Tool Summarize in PPT slides Conclusions or takeaways about … What is the total FITs, MTBF? What are the dominant parts for unreliability? What if anything could be done to improve the reliability?

Reliability Assessment, Growth Deliverable – Team (Excel Tool and PPT Slides) Compile the overall Product l and MTBF by Totaling Block l Calculate R(warranty), % failures within the original Warranty Period Then, find a modified warranty period by finding “t” for R(t) = 0.99 (99%) Decide in your team which Warranty Period is Acceptable or if your design needs to be modified to provide better reliability Update your requirements table, slides, etc if needed to reflect new warranty - Summarize the above calculations to show the following in PPT slides Conclusions or takeaways about … Use the Template Slide or Show a Table of Block Numbers, Names, Block l, Total l and MTBF Identify the dominant parts for unreliability? ( highest individual l) What design improvements can you or or will you make to increase reliability?

Reliability Assessment, Growth Deliverable – Team (PPT Slide) Compile a 10 year life stress model using Voltage, Thermal and Vibration stresses for your product that quantifies the following (see template) Total # of power cycles Max Voltage Input Max range of thermal cycles Max Number of thermal cycles Max Vibration in Grms and Total Duration Max Shock Grms and Total Repetitions Document the Stress Model in ppt slide For each of the above stresses, determine the acceleration strategy Compile and Document the Reliability Growth Plan by using the Template as shown Add any additional details regarding the plan such as number of samples tested

595 Standard Failure Rates in FIT (Data is not accurate in all cases) Component Type Method A - l Method B - l Method C - l Method D - l Method E - l BJT/FET 5.0 3.8 3.2 7.6 4.0 Switch 44.0 30.0 1.0 20.0 Metal Film Res 0.7 2.5 0.05 0.2 Carbon Res 18.2 2.7 1.1 2.6 Varistor, tc Res 6.0 10.0 Electrolytic Cap 210 22.0 120 16.0 Polyester Cap 8.5 2.0 3.0 0.5 7.0 Tantalum Cap 15.0 8.0 Ceramic Cap 0.25 1.2 Si PN, Shottkey, PIN Diode 2.4 1.6 3.6 Zener Diode 13.6 17.4 18.8 70.0 LED 9.0 280 65.0 BJT Dig IC <100 Gates 138 2.3 6.7 BJT Dig IC < 1000 Gates 150 1.5 MOS Dig IC < 1000 Gates 27.3 301 13.3 MOS Dig IC => 1000 Gates 55.0 550 2.2 31.0 EM Coil Relay 385 302 220 715 SSR, Optocoupler 105 47.0 190 12.0 BJT Linear IC < 1000 Transistors 14.0 27.0 4.3 50.0 MOS Linear IC < 1000 Transistors 19.0 54.0 Transformer < 1VA 33.0 90.0 60.0 Transformer > 1VA

595 Standard Failure Rates in FIT (Data is not accurate in all cases) Component Type Method A - l Method B - l Method C - l Method D - l Method E - l Plastic Shell Connector, Plug, Jack 100.0 55.0 150.0 120.0 105.0 Metal Shell Connector, Plug, Jack 33.0 18.0 57.0 40.0 35.0 Pb, NCd, Li, Lio, NmH Battery 7.0 1.0 50.0 8.0 22.0 Quartz Crystal Thru Hole 115.0 113.8 113.2 117.6 114.0 Quartz Crystal SMT 15.0 34.0 30.0 51.0 20.0 Quartz Oscillator Module CMOS 10.0 12.5 10.5 Diode Bridge 4.8 1.6 3.6 2.4 LED Display 19.0 280 165.0 21.0 LCD Display 119.0 215.0 380 1165.0 206.0 BJT Linear IC > 1000 Transistors 217.0 41.3 91.0 MOS Linear IC > 1000 Transistors 29.0 74.0 113.3

595 Standard Stress Factors Factor Definitions (may not represent standard models) pT = Temperature Stress Factor = e[Ta/(Tr-Ta)] – 0.4 Where Ta = Actual Max Operating Temp, Tr = Rated Max Op Temp, Tr>Ta pV = Cap/Res/Transistor Electrical Stress Factor = e[(Va)/Vr-Va]-2.0 Where Va = Actual Max Operating Voltage, Vr = Abs Max Rated Voltage, Vr>Va pE = Environmental (Overall) Factor >>> Indoor Stationary = 1.0 Indoor Mobile = 2.5 Outdoor Stationary = 3.0 Outdoor Mobile = 5.0 Automotive = 7.0 pQ = Quality Factor (Parts and Assembly) Mil Spec/Range Parts = 0.75 100 Hr Powered Burn In = 0.75 Commercial Parts Mfg Direct = 1.0 Commerical Parts Distributor = 1.25 Hand Assembly Part = 3.0

Example: Method A, 0-50C Ambient, Indoor Mobile, Distributor Components +5VDC +12VDC C1 0.1uf 50V Polyester C4 0.1uf 50V Ceramic +5VDC LED Vf=1.5V R1 2KW 1/4W Brand A Metal Film Vin BPLR OP AMP C2 0.1uf 50V Polyester 5V 1W Zener 74HCT14 R2 150W 1/4W Brand B Metal Film C3 10uf 15V Electrolytic -12VDC Part Max Tr Max Vr pT pV pE pQ C1 105C  50V  2.082  0.186  2.5  1.25 C2 C3 85C  15V  3.773  0.223 C4 125C 50V   1.548  0.151 R1 120C 20V  1.643  0.232 R2 150C 6V  1.249  0.549 Zener Diode 100C N/A  2.318 1.0 Op Amp 36V  1.0 74HCT14 7V  1.649 1.25  LED   1.25 lFITS 10.29 10.29 552.2 1.46 0.83 1.50 23.18 67.73 217.77 106.16 991.37 Fits  115.1 Yrs MTBF

Block Reliability Estimation Tool

Project Reliability Rollup Initial 90 Day Warranty Period Selected would result in 3% total failures Consider setting warranty to 1 month or 30 days based on the 1% Total Failure Guideline or …. Decrease l Total

Accelerated Stress Model Accelerated 1 Cycle Time Reliability Test Plan Stress 24 Hour Model 10 Year Model Accelerated Stress Model Accelerated 1 Cycle Time Acceleration Factor Max Input Voltage N/A Number of Power Cycles Thermal Range Number of Thermal Cycle Max Shock Grms Number of Shock Cycles