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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Storage

Views: 4871

#48481

Storage | 19 March, 2007

Hello - adding to my other current questions on here at the moment - i have a storage problem.

I want to fix it by not having to store the boards at the end of the SMT line at all, but i have a feeling it might take a while to get to that point, so i need some interim suggestions from all you low/medium volumn, high varity smt-ers out there.

Current storage is black boxes with 'ridges' inside so you slide in the board - problem with this is, when you slide in the board, there's a high probability that you are going to knock off some of the R's & C's on the edge of the board.

Before anyone suggests it - redesign of the boards is not an option!!

Any and all suggestions welcome! Chrissie

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#48483

Storage | 19 March, 2007

Hi Chrissie,

Can you add breakaways to your baord? If you have all 4 sides with components then you'll probably need custome carriers.

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#48492

Storage | 19 March, 2007

We picture that the 'ridges' are partitions that run parallel in the box and are spaced wide enough to: * Hold the boards vertical by sliding them into the ridges * Prevent the boards from bumping together

Can you rearrange these partitions to form volumes that separate one board from the other and be ample enough that the board can be placed in the box without using the ridges? These 'volumes' would require: * Moving the ridge partitions further apart * Adding dividers that fit into the ridges [in place of the boards] to keep the boards upright and from touching

We recognize that this is a less tham ideal use of the box volume. Here's the trade-off: rework versus box efficiency.

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#48499

Storage | 20 March, 2007

Guys,

Unfortunately breakaways aren't an option - they are large boards and we already have problems hand placing components and probing them.

The ridges - yes we can remove a few - and that solves one problem (boards bashing together and damaging themselves), unfortunately the main problem is that when they are put into the box and 'run' down one of the ridges, that seems to make it very easy to knock off r's & c's that are placed near the edges - these don't get noticed (the boards go in and out of these boxes about 20 times at the moment which is another problem) and it may well be after flying probe - and if they make it to test without an r or c it takes about 6 hours to find it.

There's an underlying problem of very poorly controlled processes here - which is something else i'm working on, i'm hoping alot of these problems will get a lot smaller. I'm being lazy and after a few quick fixes to start somewhere.

Chrissie

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dyoungquist

#48513

Storage | 20 March, 2007

Could you use a conductive PCB holder rack instead of a box? check out http://www.stanleysupplyservices.com/product-group.aspx?id=874 for what I have in mind.

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#48515

Storage | 20 March, 2007

Ancient company secret, C.F.M. Don't start until you can finish, don't stop until you are done!

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#48518

Storage | 20 March, 2007

Chrissie,

Are you given any type of budget? If so, Bliss Carts are a good option. http://www.blissindustries.com is a good solution if you're still working in a batch shop.

C.F.M.... easier said than done my friend. Some companies never "get it", and have business processes and models where C.F.M. is not possible.

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#48539

edited because this forum dislikes certain symbol combinations | 21 March, 2007

"Unfortunately breakaways aren't an option - they are large boards and we already have problems hand placing components and probing them."

Not sure what this means in this context....if you frame the perimeter with a 1/2" border on a V-score, how does it present a problem? Other than cost, that is.

Edited to add that apparently the syntax requirements of this forum don't allow some ascii renderings, but we had some carts that used pleated (alternating 90� folds) sheet metal panels to hold boards by the edge so that edge components weren't effected unless they were high profile.

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#48542

Storage | 21 March, 2007

Chrissie also says, "Before anyone suggests it - redesign of the boards is not an option!!", so I'm assuming that re-design means panelization too. She's probably sitting on thousands of these unpanelized PCB's in stock.

Now, for the future, as Steve suggests, a .25" to .50" v-score breakaway will alleviate alot of your edge component damage issues, and if the ICT fixture is "designed" to have no-breakaways, they can be pizza-cut before ICT.

Chrissie doesn't tell us if she has a budget or not, but if she does, another option would be pallets. (but this depends on how much volume is run).

Any option involving money should be cost-justified. That's where the "Engineering" portion of the job comes in.

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#48737

Storage | 29 March, 2007

Very nice trolleys - perfect for what i want / need i think. Budget wise - if i can justify it, i think i can have it. Thing is at the moment there are so many problems i can't actually tell how much of the rework is being generated by the storage problem and how much of it is something else.

Thanks for the link!

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Cmiller

#48853

Storage | 3 April, 2007

If the Bliss carts would help you can cut some money out by buying aluminum bakers carts at your local restaurant supply house for less than $100/each and then buy ESD trays from another local source (Bliss is rather pricy). You will have to hang a chain off the bottom of the cart to conduct to the floor and although aluminum trays are cheaper than ESD trays dont be tempted to use them as aluminum against aluminum friction will give you a bunch of tiny aluminum flakes on your boards (trust me).

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