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Manual handling aftrer Pick n place

Manual handling aftrer Pick n place

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Dear All, We are planing to put a new SMT assembly plant.... - Jan 16, 2011 by leo

Leo, Everyones goal is to minimize the manual handling of... - Jan 17, 2011 by robgd3

Theres something to be said for having a machine operator or... - Jan 18, 2011 by iddgmbj

Hi Rob, You pointed out the right factors, for me its Cap... - Jan 22, 2011 by leo

Hi eadthem, Issues like ? To be honest, i am yet to st... - Jan 22, 2011 by leo

Your typical high mix line would consist of, Stencil printe... - Jan 22, 2011 by iddgmbj

leo

#63534

Manual handling aftrer Pick n place | 16 January, 2011

Dear All,

We are planing to put a new SMT assembly plant. I wish to know, if the following is ok

SMT Pick and Place procedure -> Manual Picking of PCB -> Manual Placing into oven

The procedure after Pick and place should be Completely Automatic ?

Rgrds, leo

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robgd3

#63539

Manual handling aftrer Pick n place | 17 January, 2011

Leo,

Everyones goal is to minimize the manual handling of assemblies in process. To that end, conveyorizing your entire line, from board onload, through reflow, and potentially inspection is the ideal.

However, that isn't always possible. There are numerous factors that would factor into the decision making, some of which are volume/mix of assemblies, physical plant layout space availability, capital investment availability.

My plant has two stand alone pick/place machines, and a single stand alone reflow oven; we operate in the low volume high mix space. My circumstances did not allow conveyorizing/automating my SMT assembly lines in all three of the categories I presented above.

We currently move boards from pick and place to reflow, with very few issues.

Cheers, ..rob

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iddgmbj

#63559

Manual handling aftrer Pick n place | 18 January, 2011

Theres something to be said for having a machine operator or inspection person carry the board from the output to the oven.

Id say about 1/2 of our issues are fixed/noticed in this simple step of transferring the board from the PNP to the oven.

If your not doing fancy stuff tall/wide parts or parts with a small pick point for its weight (SMT inductors and AL electrolytic caps), then its not as important.

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leo

#63599

Manual handling aftrer Pick n place | 22 January, 2011

Hi Rob,

You pointed out the right factors, for me its Capital investment :-(

thanks a lot, i am high on confidence now.

Cheers, leo

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leo

#63600

Manual handling aftrer Pick n place | 22 January, 2011

Hi eadthem,

Issues like ?

To be honest, i am yet to start with SMT Assembly production. I am understanding the procedure, searching right equipment and hence probably i couldnt understand your practical point, would appreciate, if you could please elaborate, so that it would help me fix any such arising issues.

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iddgmbj

#63605

Manual handling aftrer Pick n place | 22 January, 2011

Your typical high mix line would consist of, Stencil printer, 1-2 foot conveyor belt, fast PNP machine (say a universal 30 spindle turret lightning head), 1-2 foot conveyor belt, large/heavy part PNP (say a universal flex jet 7 spindle or 4 Spindle), output conveyor belt 1-2 foot.

then you would have a walking space and the entrance to the oven.

now if your doing all small parts 1cm x 1cm x 4mm and smaller there is less risk of parts miss picking, And you can have the output conveyor go right in to the ovens chain conveyor(provided you don't have large boards that would do better flowing on the flat screen than hanging by there edges.

the advantage of requiring someone to manually move the board from conveyor to oven belt or chain(Edge hold), is that person will almost always spend a moment to check for missing solder paste, misplaced parts, train wrecks(1 part gets on anthers pad and it just goes down the line). Sometimes you may have parts that need hand placed as well, because there to big/wide/heavy, or the PNP machine just wants to have a bad day.

The common problems are... Someone loaded the wrong part in to the wrong feeder. The stencil printer ran dry. A aperture was clogged in the stencil printer. A placement location was wrong and the part is 1 of backwards, on its side, no where near the pads it needs to be on. The PNP machine thought it found a fidual and proceeded to pick the whole board shifted down and left 1 inch. The PNP machine had to be palmed down(cycle stop + estop) to fix, reject bin, board on top of another board, clogged nozzle, missing nozzle, any number of jams: and the machine instead of resuming from the correct location decided to repick every part on the board.

My experience is with universal instruments PNP machines, they work well in general with a few bits of character here and there, i doubt theres much better/faster.

If you want more advice you might also consider joining the #robotics and ##electronics channel on irc.freenode.com .

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