Printed Circuit Board Assembly & PCB Design SMT Electronics Assembly Manufacturing Forum

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Outgoing QC Measurements for Board Operations

bwet

#26123

Outgoing QC Measurements for Board Operations | 21 October, 2003

In terms of an outgoing QC measurement does anyone have some guidance? If ppm defect rates are established is it per board or per solder joint? We are a contract manufacturter trying to establish such a measurements without having to cover old ground.

This message was posted Add this forum to your site! Click to learn more. the Electronics Forum @

reply »


RDR

#26124

Outgoing QC Measurements for Board Operations | 21 October, 2003

Whoever established the PPM rates should tell you what it is covering (solder joints/assemblies) PPM is nothing more than a ratio. Determining quality levels is really up to you/company and how you want to measure your quality. This can be anything from the yield of passing/failing assemblies at Final Q.C. to a DPMO which can be every solder joint every polarity each component that is placed etc... For example a single 1206 resistor can have up to 7 opportunities maybe more, if you desire.

2 for paste being present 2 for solder joint acceptability 1 for orientation 1 for value 1 for presence

Most places however would deem it 2 opportunties (solder joints)

I personally prefer a simple yield at final quality with DPMO data being used throughout the process. I find this helpful since you could theoretically have a DPMO of <50 and still have a 0% yield dependant upon the assembly and its opportunities. In this case is your process bad?

Probably not much help but Quality measurements need to be determined by each organization as to what, how, and when you keep data. This provides you the most bang for the buck Un-used meaningless data is just as bad if not worse than no data at all.

Russ

reply »

PCB X-Ray Inspection

Used PCBA Equipment