Hello everyone,
First when defining any criteria for process control, one should identify quantiatively that criteria. Then one establishes an effective method for measuring such a criteria. Once you have a test method, your gateway to a solving your production issues through data analysis is open.
The balancing act is going to be implementing test methods in a cost effective manner.
1. With all of your screen printing concerns, try offline or online paste inspection, the resulting data should better assist you in determining where your issues really lie.
2. For Placement of components you can implement on line placement inspections both before and after reflow.
a. the pre-reflow inspect will help to id issues in Pick and Place. b. The post reflow inspect will help to id issues in your reflow profile.
These inspections can be performed manually by operators qualitatively, but quantitatively, that's another question. Not to mention with repeatability. We all know the concerns of operator errors/training, etc.
If one steps back to examine the big picture, ie by inspecting the sum result of each process, you can then work your way back to the root causes for each issue.
There are companies that can provide these inspection tools. Personally, I'm a CyberOptics representative but I won't press the group here with any bias (Best Best Best Best Best.....woops sorry!).
One question to examine is if you force these quantitative criteria onto your supplier, what kind of costs will you eventually see come back to you as a result of establishing these new parameters?
Good luck with your suppliers,
Sean D.
reply »