microscopySCARsupplier corrective action requestSEMscanning electron microscopeSEUsingle‐event upsetSIGsignalSILsafety integrity levelSIMSsecondary ion mass spectroscopySiO2silicon dioxideSiPsystem in packageSIRsurface insulation resistanceSITsystem integration testSMDsurface‐mounted deviceSMTsurface‐mount technologySnPbtin leadSoCsystem on a chipSOHstate of healthSPCstatistical process controlSPPsteam pressure potSQUIDsuperconducting quantum interfering device microscopyTaambient temperatureTAtechnical authorityTALtime above liquidusTAPtest access pointsTBDto be determinedTccase temperatureTCtemperature cycle; thermal cyclingTddecomposition temperatureTDDBtime‐dependent dielectric breakdownTDRtime domain reflectometryTgglass transition temperatureTHBtemp, humidity, and biasTIDtotal ionizing doseTIMthermal interface materialTjjunction temperatureTMAthermo‐mechanical analysisTMFthermo‐mechanical failureTOFtime of flightTRAPtechnical risk assurance processTsheat sink temperatureTSLtemperature sensitivity levelTSOPthin small‐outline packageTTFtime to failureTVtelevisionμgmicrogramUHFultra‐high frequencyULUnderwriter LaboratoriesUPSuninterruptible power supplyUUTunit under testUVultravioletVvoltVACvolts alternating currentVCCIC voltage pinVDRvoltage‐dependent resistorsVdsvoltage drain to sourceVIPvia in padWwattWEEEwaste electrical and electronic equipmentWOAweak organic acidX7Rtemperature‐stable dielectric
1 Introduction to Design for Excellence
1.1 Design for Excellence (DfX) in Electronics Manufacturing
Design for Excellence (DfX) is based on the premise that getting product design right–the first time–is far less expensive than finding failure later in product development or at the customer. The book will specifically highlight how using the DfX concepts of Design for Reliability, Design for Manufacturability, Design for the Use Environment, and Design for Life‐Cycle Management will not only reduce research and development costs but will also decrease time to market and allow companies to issue warranty coverage confidently. Ultimately, Design for Excellence will increase customer satisfaction, market share, and long‐term profits. The Design for Excellence material is critical for engineers and managers who wish to learn best practices regarding product design. Practices need to be adjusted for different manufacturing processes, suppliers, use environments, and reliability expectations, and this DfX book will demonstrate how to do just that.
Design for Excellence is a methodology that involves various groups with knowledge of different parts of the product life‐cycle advising the design engineering functions during the design phase. It is also the process of assessing issues beyond the base functionality where base functionality is defined as meeting the business and customer expectations of function, cost, and size. Key elements of a DfX program include designing for reliability, manufacturability, testability, life cycle management, and the environment. DfX efforts require the integration of product design and process planning into a cohesive, interactive activity known as concurrent engineering.
The traditional product development process (PDP) has been a series of design‐build‐test‐fix (DBTF) growth events. This is essentially a formalized trial‐and‐error process that starts with product test and then evolves into continuous improvement activities in response to warranty claims. DfX moves companies from DBTF into the realm of assessing and preventing issues beyond the base functionality before the first physical prototype has been made. DfX has further evolved as an improvement of the silo approach where electrical design, mechanical design, and reliability work (among others) were all performed separately. DfX allows for maximum leverage during the design stage. Approximately 70% of a product's total cost is committed by design exit. Companies that successfully implement DfX hit development costs 82% more frequently, average 66% fewer redesigns, and save significant money in redesign avoidance. Practicing DfX allows companies to focus on preventing problems instead of solving them or redesigning them.
Each chapter in this book describes and illustrates a specific core element of a comprehensive DfX program. The chapters provide best practices and real‐world case studies to enable effective implementation.
1.2 Chapter 2: Establishing a Reliability Program
The chapter will educate you on the core elements of a reliability program, common analysis pitfalls, performing and reviewing reliability data analysis.
At the end of this chapter, readers will be better prepared to:
Understand the basic elements of a successful reliability program
Understand the principles associated with reliability analysis and management of the factors that affect product reliability
Understand the probability density function (PDF) and the cumulative distribution function (CDF) used in reliability
Understand the reliability prediction models available
1.3 Chapter 3: Design for Reliability (DfR)
The process of Design for Reliability (DfR) has achieved a high profile in the electronics industry and is part of an overall DfX program. Numerous organizations now offer DfR training and tools (sections, books, etc.) in response to market demand. However, many of these are too broad and not electronics‐focused. They place too much emphasis on techniques like failure modes and effects analysis (FMEA) and fault tree analysis (FTA) and not enough emphasis on answers. FMEA and FTA rarely identify DfR issues because of the limited focus on the failure mechanism. And they incorporate highly accelerated life testing (HALT) and failure analysis when HALT is testing, not DfR. In addition, failure analysis occurs too late. This frustration with test‐in reliability, even HALT, has been part of the recent focus on DfR.
As the design for philosophy has expanded and spread through the electronics marketplace and has become identified with best practices, a diluted understanding of DfR has occurred. True DfR requires technical knowledge of electronics packaging, discrete components, printed boards, solder assemblies, and connectors and how these aspects of electronics can fail under environmental stresses.
This chapter is designed for engineers and manufacturing personnel who need to fully comprehend the characteristics of DfR and how it applies to their unique applications.
1.4 Chapter 4: Design for the Use Environment: Reliability Testing and Test Plan Development
Scientific principles are based on the understanding that products fail when environmental stress exceeds the material strength.
At the end of this chapter, you will:
Understand the basic elements of a successful reliability testing program
Understand how reliability testing can be used for the process, part and assembly qualification
Understand failure patterns based on the ensemble of environmental stressors chosen
Have a basic understanding of the concepts of accelerated aging rates and acceleration factors
Understand the difference between a stress screen and an accelerated life test
Understand the basics of stress‐screening equipment
Have a basic understanding of frequency analysis and power spectral density for vibration and mechanical shock testing
Have a basic understanding of setting stress levels based on the step‐stress algorithm to establish the product operational and destruct limits
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