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0.4mm PCB Thickness - production issues

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#43926

0.4mm PCB Thickness - production issues | 13 September, 2006

Hi, We have a customer that want us to produce a single sided 0.4 x 100 x 50 mm size RoHS pcba approx 1000 of them. The board only contains three 2.54mm pitch Non P.I.P, SMT-connectors. We have never produced such a thin pcb:s before. We are thinking of to make a panel, but our optimum panel size which is 265 mm in width (so they can fit in our existing cassettes) I think will not work, unless we use a palette. There is no problem for us to make a panel size who fit our needs, but what do You think about this?

Our line where we are going to produce these consist of; DEK-265, pass through the CP-6 and the placement will be at the UIC GSM1 and a BTU oven with a board support chain. Here comes the questions:

1.) Is it possible to make a panel with V-grove, small enough to run it. To me 0.4 mm bare board thicknes might be impossible, or should we just run the bare boards?

2.) If we go for a palette; how should we design this?

3.)I guess we need to have the board house to make 2 locator holes in the panel cut off area so we can locate the panel in the palette properly?

4.) If using a palette, I guess the panel can only be somewhat 0.3-0.35mm in depth of the palette, so the DEK stencil will not have any obstruction including any locator pins, nor get down during printing like a banana?

Please don't hesitate to get more info, if I have been unclear. Any ideas will be greatly appreciated. /Sincerely, Ps. Sorry for my poor english and grammar. Ds.

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Rob

#43929

0.4mm PCB Thickness - production issues | 14 September, 2006

Hi Mika,

We had roughly the same set up - AP27 -CP6x2, GSMx2, VIP98 & we ran the thin boards with durastone routed pallets.

If you route out a 0.4mm pocket on the pallet and either use kapton tape/high temp masking tape/ or 3M spraymount to hold the board down you should be fine. The printer & the pick and places can use the panel fids still as they will still be in the search area. If the pocket is accurate enough you will still get a good print.

We also used local fids for the CP & GSM so we could deal with X-outs better.

Please note they take a little time to cool down after reflow.

Hope that helps,

Rob.

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SWAG

#43952

0.4mm PCB Thickness - production issues | 14 September, 2006

I would try to panelize as big as you can for sure as you'll spend more time handling single boards than running anything. Additionally, this size is very close to smallest capabilities on GSM depending on your configuration. Fids on all boards in array is best as mentioned by Rob. I usually design pocket depth at .125mm less than board thickness with .25mm gap for each side of perimeter. You need this for expansion or you bow in reflow. If you are concerned that the carrier might be too much heat sink, machine pockets in the durostone beneath parts. However, this is very thin and you might consider machine pockets that do not go all the way trough the material so as to create a heat chamber beneath the part. Beware of proper printer support in both cases. Non-through pockets also greatly stabilize the profile = smoother ramps. Locating pins are trouble - kapton holds boards down well as Rob states and local fids are needed. Look at break-out tabs or post SMT routing to depanelize. Hope this helps...

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#44125

0.4mm PCB Thickness - production issues | 22 September, 2006

A bunch of thanks guys, we will take this in consideration. BTW, we will not go for the v-grove in the panel (2x8 boards + the extra cut of areas). The board house recommended us to go for braces/hinges, since this thin pcb-panel could easily break with v-groves. Of course there will a pallet/carrirer, just as you mentioned. Sincerly, Mika Ps. Sorry for my poor english & grammmar. Ds

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