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SMT Component Yield Factors

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SMT Component Yield Factors | 9 July, 2007

Does anyone have any industry standard yield factors to load at the component level to account for set up scrap and machine waste during production? I'm assuming there are different percentages used for each package size (0402, 0603, SOIC8, etc) but I haven't been able to locate any.


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SMT Component Yield Factors | 10 July, 2007

Multiple Factors that account for Scrap:

During Set-Up: A percentage will not work. When setting up feeders you will normally use a certain length of populated pockets. The amount of parts this affects depends on 1.type of feeder 2.type of part 3.operator attention 4.populated pockets You can account for this by setting up an average qty of scrap by part type... assuming you use the same feeder types and operator skill lvls.

During Run: The scrap amount off of the machines will depend more on package and feeder type than anything else. A percentage will probably work at this stage although many things can scew the numbers.

You will need to determine your own numbers based on all the factors. We use (2%scrap + 6" Leader and Footer on 0402-0603)(1%scrap +6" L&F on 0805-1206)(all other passives are at 0.5% while IC's are 0%-0.5% depending on package - tape, track, tray, bulk) We use 5% on 0201 packages but are currently seeing around 3%, and we have not used 01005 outside of testing.

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