הכינוס הלאומי ה- 13 של האיגוד הישראלי לאיכות בנובמבר 2015, תל אביב NPI בתעשיית האלקטרוניקה דב פרי יו"ר האיגוד הישראלי לאיכות

Transcription

1 משוב בשלב ה- הכינוס הלאומי ה- 13 של האיגוד הישראלי לאיכות בנובמבר 2015, תל אביב "קו היצור" ל"פיתוח התכן" NPI בתעשיית האלקטרוניקה דב פרי יו"ר האיגוד הישראלי לאיכות

2 PCBA- Printed Circuit Board Screen Printer Assembly Dispenser Pick & Place Machines AOI X-RAY ICT 2 Reflow TH Assy. Wave Soldering

3 Estimated Yield Scope To know the expected yield at the very early stage (NPI), before production In case the actual yield is lower than the estimated, to initiate corrective actions in the design as pointed out by the detailed calculations 3

4 DPMO - Defects Per Million Opportunities Sigma level DPMO Percent defective Percentage yield 1 691,462 69% 31% 2 308,538 31% 69% 3 66, % 93.30% 4 6, % 99.38% % % % % % %

5 Component Categories Placement Termination Assembly 5 Index

6 Component Categorization Component Opportunities (o c ) each device or piece of hardware that may be assembled onto PCB. Component Defect (d c ) damage to a component exceeding the limits of the component specification, or those described in IPC/EIA J-STD-001 or IPC-A-610, and/or damage that results in non-usability of that component. (Ex: Circuitry damaged, Improper stress relief, Lead bend problem, Lead coplanarity out of spec, Solderability problem) 6

7 Placement Categorization Placement Opportunity (o p ) proper placement of components based on the bill of material. Placement Defect (d p ) any component presence and/or positioning error that has occurred during an assembly operation that violates the dimensional criteria for that component in IPC/EIA J-STD-001or IPC-A-610. (Ex: Component/Parts/Hardware loose/ missing/ wrong, Part height wrong, Part misaligned, Part extra, Wire connected wrong, Wire routing wrong) 7

8 Termination Categorization Termination Opportunity (o t ) any hole, land or other surface (such as component to component attachment) to which a component is electrically terminated. Termination Defect (d t ) any electrically joined termination that violates the requirements specified in IPC/EIA J-STD-001 (Ex: Cold solder joint, Fractured solder joint, Insufficient solder, Solder bridge, Solder wetting unacceptable, Unsoldered connection) 8

9 Assembly Categorization Assembly Opportunity (o a ) is an overall opportunity for a defect that is not captured within termination, component and placement opportunity categorization. Assembly Defect (d a ) that applies once to a PWA. (Ex: Assembly not clean, Conformal coating not present where required, Conformal coating peeling, Conformal coating present where not wanted, Solder balls/splash) 9

10 DPMO Calculation Component DPMO d c DPMO c = ---- x10 6 o c d c = Number of component defects o c = Number of component opportunity Placement DPMO d p DPMO p = ---- x10 6 o p d p = Number of placement defects o p = Number of placement opportunity Termination DPMO d t DPMO t = ---- x10 6 o t d t = Number of termination defects o t = Number of termination opportunity 10 Assembly DPMO d a DPMO a = ---- x10 6 o a d a = Number of assembly defects o a = Number of assembly opportunity

11 DPMO Index Calculation For a single assembly d c +d p +d t +d a DPMO Index = x 10 6 o c +o p +o t +o a For a lot of assemblies d c + d p + d t + d a DPMO Index = x 10 6 o c + o p + o t + o a 11

12 Sub-categorization Component Side / Print side SMT / TH / Manual Component Shapes Reflow / Wave / Hand soldering 12

13 Yield Yield = e - DPU = 1 DPU + ((DPU)^2)/2! + Yield = Number of output nondefective units divided by number of input units. DPU (Defects Per Unit) = average number of defects per board 13

14 Fraction Linear vs. Exponential Yield FY Linear versus Exponential FY lin FY expo DPU 14

15 Yield Estimation NPI Calculation of Opportunities: o c o p o t o a Calculation of category DPU by: DPU CAT = DPMO CAT x o CAT / 10 6 Summation of DPU Calculation of Estimated Yield by: Estimated Yield = e - DPU 15

16 Yield Estimation Conceptual Diagram PCBA o c Historical DPMO c Expected DPU c = Expected DPU t = =(DPMO c )(o c )/10 6 =(DPMO t )(o t )/10 6 PCBA o t Historical DPMO t PCBA o p Historical DPMO p Expected DPU p = Expected DPU a = =(DPMO p )(o p )/10 6 =(DPMO a )(o a )/10 6 PCBA o a Historical DPMO a 16 DPU c + DPU p + DPU t + DPU a E.Y.=e -DPU total

17 E.Y. Calculation Example PCB double side placement 141 Components 140 Placements 1780 Terminations 17

18 E. Y. Calculation Example Category Process ox Placement Termination Historical DPMOx DPU Estimated Yield Chip Place Top FP Place Top Chip Place Bottom Manual Place Reflow Soldering Wave Soldering Placement Combined Termination Combined Component Total Assembly Total Overall

19 Conclusions E.Y. at a very early stage, before production Real quality targets E.Y. at total, category and subcategory level Detailed calculation per subcategory DPMO increase accuracy of E.Y. Corrective actions in case the actual yield is lower than the estimated 19

20 Summary Needs and benefits of E.Y. Terms definition: DPMO x, o x, d x, DPU Yield: linear and exponential Method of E.Y. calculation Example of E.Y. calculation 20

21 21 Questions and Answers

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