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Adhesive printing with double side board

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MM

#51177

Adhesive printing with double side board | 24 July, 2007

Does anyone out there run the adhesive side first and then the solder side and wash? I was just wondering if this is a good practice or not. I am afraid that we will lose some of the parts, that are just glued on, in the washer? Basically I am trying to save on changeover time. Please let me know any information you can give me. Thanks

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#51180

Adhesive printing with double side board | 24 July, 2007

Michelle,

Traditionally, the adhesive side is always run first since most designers put passives (resistors, caps) on the adhesive (solder side) of the board.

I worked in an environment where we did the adhesive side first, sometimes the boards "sat around" for a while with glued-on parts, and then we ran the reflow side.

The only difference is - we wave soldered the boards and THEN washed, so we never had the concern with parts falling off.

We were using a water-soluble solder paste at the time, and didn't experience any residues after wash - even if the boards sat around for several days. But then again, we had a high-pressure, in-line washer with 5MOhm resisistivity water.

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#51181

Adhesive printing with double side board | 24 July, 2007

Is there a reason why you want to wash the board before wave?!?!?

What is your process flow?

I run bottom side of my boards first, then top just to make it easier to setup (easier to put those support pins around those smaller components).

But, I am reflowing both bottom and top side of the PCB.

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MM

#51183

Adhesive printing with double side board | 24 July, 2007

> Is there a reason why you want to wash the board > before wave?!?!? > > What is your process > flow? > > I run bottom side of my boards first, > then top just to make it easier to setup (easier > to put those support pins around those smaller > components). > > But, I am reflowing both bottom > and top side of the PCB.

We can not aoi unless they are washed. Also we may run thru the reflow on Friday and not run thru the wave till Monday.

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#51190

Adhesive printing with double side board | 24 July, 2007

Unless you've got an extremely agressive cleaner, the epoxy should hold the parts during the delay time. That's their job basically. We ran reflow first pass, glue parts, then wave solder second pass. There were potential delays between adhesive bonding and wave, but then again we didn't wash the boards either.

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