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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


normal waste

#24081

normal waste | 10 April, 2003

Hi all.We have between 2 and 3 percent waste of components.The software gives info about the whole waste and I am interested what's the limit for component waste?Where I can read about it?Are there any tables with given limits? Any posts,please!

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#24087

normal waste | 10 April, 2003

Where is the 2 - 3 perc? On the SMC placement machine only or througout all your processes?

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#24089

normal waste | 10 April, 2003

Pete,it's only in placement process.

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#24091

normal waste | 10 April, 2003

I do assume the only machine capable of reporting rejected components is the placement machine. 2-3% is certainly way too much. Expect rejects ( out of visible tolerance ) in the permille range but not percent. If components are rejected with vacuum problems, you will have to narrow the problem down to the nozzle shape and size, and/or component shape and size. If the components are rejected directly after pick up, your component feeder pick position may be off. I doubt, the machine could ever been delivered to the customer with 2-3% rejected components. If the machine developed this attitude over the time, the machine requires some serious servicing.

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#24095

normal waste | 10 April, 2003

It will vary by placement machine mfg. and type. I had 4x Fuji CP3 (turret chip-shooter) and 2x Fuji IP2 (split axis general app-fine-pitch)and tracked component shrinkage at 0.05%-0.5% on average. Above 0.5% triggered maint. & process eng. response.

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