IPC-7912 DPMO的计算与印制板装配的制造指标

? 0.9091 )( 1 ? 0 )( 1 ? 0 )]x10 6 = 909,100 Examples of OMI and DPMO calculations are provided in Appendix A. July 2000 IPC-7912 3 Following is a Conceptual Diagram for calculations pertaining to IPC-7912. IPC-7912-4-1 Figure 4-1 Calculations pleted Electronic Assemblies: Conceptual ponents Placements Terminations d = Number ponent defects o = Number ponent opportunities DPMO = __ x10 d ponent Opportunity Yield p = 1- __ d o d = Number of placement defects o = Number of placement opportunities DPMO = __ x10 d o Placement Opportunity Yield p = 1- __ d o d = Number of termination defects o = Number of termination opportunities DPMO = __ x10 d o Termination Opportunity Yield p = 1- __ d o DPMO Index = _______ x10 d +d +d o +o +o OMI = [1-(p )(p )(p )]x10 IPC-7912 July 2000 4