DfRSoft...           Detail Information      Failure is not an Option

RELIABILITY SOFTWARE (Click Images)

Reliability Plotting:  Probability Plotting with or without Suspensions, Group or non-Group data, Weibull Maximum Likelihood Estimate, Weibull, Lognormal, Exponential, Normal regression results, Three-Parameter Weibull Analysis and Mixed Multi-modal analysis (as many modes as in your data can be separated using DfRSoft's iterative method). Also available small sample size Weibull-Bayesian ("WeiBayes") MLE analysis as well as Bayesian method for Weibull Regression Beta over-ride entry and Lognormal small sample size sigma-over ride analysis. Confidence bounds both single-sided and two-sided options displayed graphically and analytically. DfRSoft Best Predictor - which distribution is best predictor of entered data.  Excel friendly graphics interface –easily change titles, scales, grid lines, copy and past to word documents…)

General Distribution Shapes: Once a distribution key parameters are know such as Weibull characteristic life and beta, then quick plots for the distributions can be obtained over any time period for: Exponential, Weibull, Lognormal, Normal. Simply enter the distribution key parameters. Plots include, PDF, CDF, Reliability, and the Hazard Rate. Alternately use the Reliability Statistics and Confidence area for predictions (see description below).

System Reliability Analysis: Items in Series or Parallel, block diagram entry. Special parallel units: N of K, Stand-By Units, Parallel items with different FR and Repair Rates assessment. Work in either MTBF or failure rate units. System analysis includes friendly block diagram entry format - simple transfer to power point of word document via copy paste.  

SEE DfRSoft SYSTEM RELIABILITY ANALYSIS INSTRUCTIONAL VIDEO

Reliability & Quality Statistics and Confidence: Continuous Distributions: Weibull, Lognormal, Normal,  Exponential Distributions - with confidence assessment. This area allows user to make prediction when distribution parameters are known. For example given the Weibull characteristic life and beta, what percent failure is expected at a certain time period. What are the confidences around this value.

Discrete and Sampling Distributions: Chi Square, Standard Limits, Poisson and Binomial - with confidence assessment.

 MTBF Manufactures Predictions and/or MIL HDBK 217, 217+M, Telcordia…): A variety of methods for detailed stress and parts count: DfRSoft offers a corporate manufacturers’ MTBF detailed stress prediction model with part failure rates library from companies like Analog devices, National Semiconductor, TI etc. DfRSoft also provides MIL HDBK 217+M detailed stress. A traditional MIL HDBK 217 Notice 2 with the +M option of using a supplemental DfRSoft manufacturers' database as well as parts count for Telcordia (SRS 332 Issue 1). Where appropriate on these prediction methods, the user may add junction temperatures, and part stress levels in addition to global parameter for base assembly temperatures.

SEE DfRSoft MTBF INSTRUCTIONAL VIDEO

Acceleration Models: Arrhenius Temperature, Temperature-Humidity (Peck), Temperature-Cycle (Coffin-Manson), Vibration Acceleration Model. Vibration Fatigue X, Y, Z Axis model, Modified Temperature-Cycle (Norris Lanzburg) acceleration model, Arrhenius Least Squares Fit analysis for Activation Energy determination, Arrhenius lifetime model, Electromigration acceleration factor model, moisture diffusion time through common plastic encapsulates at 85%RH , Dielectric Breakdown accelerated E-Model, temperature acceleration popular doubles every 10^oC compared to Arrhenius model , Chi Square additional sample size and/or test times needed for qualification (Per Jedec JESD47-A ). 

Accelerated Test Planning: Chi-square life test planning for specific tests, multiple tests, including High-Temperature-Operating-Life, Temperature-Humidity-Bias, Temperature Cycle, and Vibration. Exclusive from DfRSoft is an optional sample size optimization search for multiple tests to demonstrate one failure rate and optimization success details provided.. All with handy test planning print out summary. Multiple Chi-Square test plan failure rate plotted over temperature test time. Confidence provided for zero or non zero failures with failure rates and device hours analysis.

SEE DfRSoft ACCELERATED TEST PLANNING INSTRUCTIONAL VIDEO

Parametric Reliability Analysis (2013 Version Only)

Exclusive from DfRSoft - Parametric Reliability Analysis. Assess device degradation failure rates over time without having to test to failure and with more accuracy saving hours of test time, at lower stress and with smaller sample sizes. Here is how:

SEE DfRSoft PARAMETRIC RELIABILITY INSTRUCTIONAL VIDEO

Reliability Growth: 

Exclusive from DfRSoft - Chi-Square Multi-Test Reliability Growth as well as the traditional Crow/AMSAA-Duane Reliability Growth (MIL STD 189) with and without test acceleration factors. Assessing your reliability growth from one test to the next can be difficult especially if you have few failures. DfRSoft now provides a simple breakthrough Chi-Square accelerated reliability growth tool for any one or more tests  (RAMS Publication in 2013). Results are in simple terms of MTBF, AFR or PPM growth over test time. For example - take your results from different tests such as thermal shock, humidity, life test, or even drop tests, and now analyze your reliability growth amongst these test in a simple straight forward way and assess your product’s MTBF including Chi-square confidence and fix effectiveness.

As well as this new tool, DfRSoft provides the traditional growth methods for analysis with Crow/Amsaa & Duane models for reliability growth assessment. Here as well we provide very up-to-date reliability growth published methods. SEE DfRSoft RELIABILITY GROWTH VIDEO

Design FMEA:  Handy look up table of the most common failure modes for PCBAs and components, their failure mechanisms and suggested design controls. Include your own database to the look up table as well. Very friendly cut and paste common DFMEA Excel format spreadsheet. Sorting capability with handy table pull downs. 

Corrective Action Review (CAR):  DfRSoft provides a handy report form for CAR assessment that includes a Fishbone diagram assessment

Environmental Profiling - Enter the stress and time for each environmental type such as Temperature, Temperature Cycle, Vibration and/or Temperature-Humidity. For example, your system over its life may be exposed to 25C for 10% of the time, 55C for 60% of the time and 70C for 30% of the time. DfRSoft will calculate the equivalent time at any temperature and the reliability given these inputs. This Module also includes a step-stress correction for temperature stress.

QUALITY SOFTWARE

SPC Charting with Variable Sample Capability: Plot SPC charts of lots displaying X bar & R Charts with S Charts as well. Unlike most commercially-available SPC software, this spreadsheet accepts variable sample sizes, and sets appropriate control limits.

Lot Sampling Plans (single and double sampling): DfRSoft provides two types of automated lot sampling plans : Hypergeometric method (N, n, c) where N is the lot size, n is the sample from the lot, and c is the number of sample(s) that are allowed before the entire lot is rejected and the Binomial method (n, c) "N not used". Two key values, AQL (Acceptable Quality Level), and LTPD (Lot Tolerance Percent Defective) values. OC Binomial and Hypergeometric lot curves plotting Probability of Acceptance vs. Lot Percent Defective. Select N, n, c and AIQ obtain AQL and LTPD, and AOQ with confidences. This makes MIL-STD 105E or ANSI/ASQ Z1.4 Standards on Lot Sampling look easy and is much more flexible. Sometimes we are not sure about a lot and we would like to do more inspection or we may wish to take a risk and sample less but decide that if we do this and exceed a certain criteria, we might do a second sampling to decide whether or not to accept or reject a lot. In addition to the single sampling, an example is provided on using this tool for Double sampling which can actually reduce the number of single samples taken.

Normal & Lognormal Probability Plotting: Determine if your data is normally, lognormally distributed or another distribution. Assessing normality or lognormality is now easy and in one step. Extensive probability plots not only providing active probability graph and histogram of entered data with cumulative and probability density plots, but also providing a visual and statistical measure of normality.  Full statistics including Mean, Median, Mode, Std. Dev., Std. Error, Skewness, Kurtosis, , probabilities and confidences. Probability plots of fixed distribution with mean and std. dev. also available.

Cpk - Six Sigma Analysis: Full, Upper, or Lower Cpk for specification limits, Six Sigma Assessment. DfRSoft also automatically links Cpk to resulting yield to help the user understand and interpret Cpk values. , one- and two-sided with Cpk confidences. A Six Sigma analysis tool is also provided with Cpk. Industrial guidelines are given for both six sigma and Cpk analysis. DfRSoft also provides target guidelines for Cpk and Six Sigma values.
Other Tools: Derating Guidelines, Availability, Sparing, Preventative maintenance, Field Returns Analysis, Corrective Action Reporting (CAR) with Fishbone Diagraming and ESD (see Reliability Section for Details)

SEE DfRSoft SPC & NORMALITY VIDEO          SEE DfRSoft LOT SAMPLE PLAN VIDEO

Physics of Failure & DfRQ Library

DfRQ ENGINEERING TOOLS

Derating Guidelines: Basic suggested parts derating guidelines - Incorporating a mix of industry standards including NASA, MIL STD 1547A, RAC, JPL with programmed derating over temperature.

Thermal Analysis Tools: Thermal resistance, Heating, Time constant of material, basic semiconductor Case-Junction temperature models, CTE mismatch and solder joint  shear stress and fatigue risks, Thermal Junction Temperature of a hermetic power device, Transient Thermal Response time, Pulse Mode Junction Temperature Rise, experimental method of finding Tau Transient Temperature Rise Time. IGBT Junction Temperature model with switching. Numerous look up tables for many materials & allows providing thermal properties.

Vibration and Shock Analysis : Exclusive from DfRSoft is full Vibration and Shock Analysis. One of the more advanced analysis tools you will find. General conversion for Sine vibration between acceleration, velocity, displacement, frequency. PSD Random Vibration Spectral Analysis (plots PSD vs Freq and finds Grms content, Average and Max Velocity and Max Displacement likely and possible. Also available – Sine-on-Random plotting with Grms content, Average and Max Displacement, Velocity likely and possible. Random-vibration- fatigue-test analysis for X, Y, Z axis with strategies to demonstrate fatigue life from field data and minimal test times for each axis needed. Constant Acceleration (RPM versus radius, Gs), As well requirements for  UD load for shaker, Octave Sine analysis (time to run resonance search test), Sine Vibration Q analysis. Mechanical ED Shaker Shock for multiple wave forms input Gs and Pulse duration obtain stroke and max velocity. Drop Shock height estimations for - Half-Sine, Triangle, Sawtooth for given Gs and Pulse Duration. Also available is packaging foam thickness analysis for different Drop Heights and G capabilities of your product. As well a strategy for Resonance Sine test conversion to a Random test and Random to Sine.
CLICK TO SEE VIDEO ON DOING SHOCK AND VIBRATION ANALYSIS IN DfRSoft

Electrical Analysis: Power conversions (dBm<>Watts), Voltage to Power conversions, dB, Insertion loss, Power, & Voltage assessment, VSWR and Return Loss calculator, Forward and Reflected power conversions, American Wire Gauge calculator, Fusing current of Wire and Circuit Traces analysis, Wire Bond current Density to Avoid Electromigration/Fusing analysis,  RC & Inductor Time Constant Assessment, Capacitance and Inductor Impedance calculators, Voltage Breakdown in Air at any Pressure (Pachen's Law). Voltage Breakdown in a solid dielectric vs distance for different material (with material table look up), Local Relative Humidity, Temp at die surface, temperature rise in PCB circuit traces per IPC-222, Life Expectancy of an Al Electrolytic capacitors, Thermocouple Information, Resistivity and Temperature Coef. of metal lookup table. Coming soon Smith Chart Calculator.

Corrosion Prevention: Corrosion analysis tools are not easy to find, DfRSoft provides a lot of help in this area. Corrosion Conductivity-Resistivity calculator, Corrosion Rate of Metals analysis, Oxidation Corrosion Rate, Corrosion rate of metals when anode and cathode currents are known, Hydrogen Poisoning assessment, Forms of Corrosion Table (such as Galvanic corrosion, Uniform corrosion, Etc.). Galvanic Series in Sea Water, Corrosion Prevention of Galvanic Corrosion Help, Tables provided for material properties including full detailed periodic table of the elements.

Engineering Conversions: A highly practical engineering set of conversion tools needed everyday for reliability, mechanical, and electrical engineering. Failure Rate Conversion (Exponential Distribution), Temperature Conversion, Length Conversion, Energy & Work & Torque, Power dBm  <-> Watts, Voltage to Power in dBm with Load , dB &  Insertion Loss, Foward & Reflected Power - VSWR & Return Loss, 3-Phase Voltage - Current - Power conversion, Mass Conversions, Volume Conversions, Pressure & Gage Pressure Conversions, Density & Mass with look up tables, Altitude versus Pressure and Temperature, Time-Hours-Minutes-Seconds-Weeks-Date-Time test schedule planning, Energy and Wavelength Conversion, E & M Spectrum, Universal Constants, Circular Conversion, Relative Humidity - Dew Point -Temperature - Absolute Humidity-Vapor Pressure-Specific Humidity-Saturated Vapor Pressure Conversion, Local Versus Ambient Relative Humidity, Temp At Die Surface Calculator, American Wire Gauge (AWG), Casimir Effect compared to Electrical Attraction in MEMS

E&M Skin depth penetration and attenuation given material conductivity, MU, and thickness over specified frequency range. Skin dept helps to calculate wire size & conductive path sizes for RF to avoid getting transmission losses. We can also assess skin depth for shielding against ESD events such as with ESD bags. Examples are provided.

ESD Design & Guidelines: Basic ESD definitions, specifications, auditing guidelines, basic models (HBM, CDM, MDM), sensitivity classifications, ESD protection circuits for design - methods and concepts, humidity usage, Triboelectric series, shielding effect etc. Key circuit protection devices and how they are commonly used is illustrated. We also include proper ESD fixture design for electrical testing so that you will not zap your product during electrical test due to a not well understood CDM scenario. Don't get zapped - get protected.

Misc. Tools: 

Design for Reliability & Quality Cost Analysis: (2013 Version Only) With this handy calculator, one can quickly assess DfRQ tasks including laboratory work like test loading labor hour, test set up man-hours, chamber run time charges, engineering analysis time, etc. to estimate the total cost for any task quickly with summary output sheet.

Handy Spread Sheet of Engineering Information: Detailed Periodic Table of the Elements, Series Expansions, Reliability Acceleration Models...