Microcomputer Unit - Index of

QUALITY ASSURANCEstances such as temperature, humidity and dust,and the control of submaterials, like gas, and purewater used in a manufacturing process, are intensivelyexecuted.Dust control is essential to realize higher integrationand higher reliability of devices. At Hitachi,maintenance and improvement of cleanliness atmanufacturing sites is accomplished throughattention to buildings, facilities, air conditioningsystems, delivered materials, clothes, work environment,and periodic inspection of floating dustconcentration.3.3.3 Final Product Inspection and ReliabilityAssurance(1) Final Product InspectionLot inspection is done by the quality assuranceProcess Control Point Purpose of ControlPurchase of Materialwafer~ Wafer Characteristics, Appearance Scratch, Removal of CrystalDefect Wafer, Surface Oxidation Oxidation Assurance of ResistanceInspection on Surface Appearance, Thickness of Pinhole, ScratchOxidationOxide FilmPhoto ResistPhotoResistInspection on Photo Resist Dimension, Appearance Dimension Level PQC Level Check Check of Photo ResistDiffusion Diffusion Diffusion Depth, Sheet Diffusion StatusResistanceInspection on Diffusion Gate Width Control of Basic Parameters PQC Level Check Characteristics of Oxide Film (VTH, etc.) Cleanness of surface,Breakt.!own VoltagePrior Check of VIHBreakdown Voltage CheckEvaporation Evapora- Thickness of Vapor Film, Assurance of Standardtion Scratch, Contamination ThicknessInspection on Evaporation PQC Level CheckWafer Inspection Wafer Thickness, VTH Characteris- Prevention of Crack,ticsQuality Assurance of ScribeInspection on Chip Chip Electrical CharacteristicsElectrical CharacteristicsChip ScribeAppearance of ChipInspection on ChipAppearance PQC Lot JudgementFrameAssembling Assembling Appearance after Chip Quality Check of ChipBondingBondingAppearance after WireQuality Check of WireBondingBonding PQC Level Check Pull Strength, Compression Prevention of Open andWidth, Shear StrengthShortInspection afterAppearance after AssemblingAssembling PQC Lot JudgementSealing Sealing Appearance after Sealing Guarantee of AppearanceOutline, Dimensionand DimenSion PQC Level Check Marking Marking StrengthFinal Electrical Inspection Failure Analysis AnalySis of Failures, Failure Feedback of Analysis Infor-Mode, MechanismmationAppearance InspectionSampling Inspection onProductsReceivingShipmentFigure 3 Example of Inner Process Quality ControleHITACHI 29