Zinc Oxide Varistors

Manufacturing Process and Quality Assurance

Raw material incoming Weight: every batch Grinding Grinding time: every batch Mixing Density and viscosity: 1 time per batch Spray drying Temperature, pressure, particle size: every batch Mixing Weight, mixing time, moist: every batch Electrical test Every batch by sampling - Voltage/current characteristicsdegradation, physical characteristics Pressing Weight, thickness, visual inspection: every batchby sampling Binder burn out Thermal cycle: every batch Stacking Visual inspection 100% Sintering Thermal cycle: every batch Electrical test Every batch by sampling: physical characteristics, capacitance,V1mA, leakage current, clamping voltage, degradation Silvering Visual inspection: every batch 100% Silver firing Thermal cycle: every batch Soldering Temperature, visual inspection: every batch 100%. Every batch by sampling: spacing between leads Cleaning Thermal cycle: every batch Coating Thermal cycle, visual inspection: every batch by sampling Marking Visual inspection: every batch 100% Polymerization Thermal cycle: every batch Cutting leads Visual inspection lead length: every batch by sampling Final control Electrical: every batch 100%: V1mA; leakage current: sampling. Visual: every batch 100%, aspect, marking Quality control Every batch by sampling. AQL: V1mA, leakage current clamping voltage, visual inspection, dimensions, solderability Packaging Bulk: every batch pieces quantity. On tape: batch bysampling, visual inspection of taping Packaging Quality Control Every batch, taping dimensions, missing parts, taping defects, label check Shipping consignment Outgoing shipping - Verification Every batch, every shipment, packaging, documentation

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