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

Printed Circuit Board Assembly & PCB Design Forum

SMT electronics assembly manufacturing forum.


Reflow Oven

Jeff Tamagi

#3822

Reflow Oven | 13 June, 2000

Someone was telling me that there was a requirement to bake / dry bare boards prior to reflowing?

Where can I obtain information on this?

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#3823

Re: Reflow Oven | 13 June, 2000

Jeff: Last place I can recall seeing something like that is NASA-STD-8739.3

Requirements like this are not currently in vogue. A modern solder process should conform to J-STD-001, which makes no mention of prebaking boards.

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Jeff Tamagi

#3824

Re: Reflow Oven | 15 June, 2000

In section 7.3.2 of ANSI J-STD 001 " Drying / Degreasing states the assembly may be treated to remove moisture and other volitiles"

I have contacted one board manufacturer who states that it is recommended to bake a board to remove volitles.

Are all board manufacturers like this? Do I have remove something that they can not fix themselves. Or am I dealing with a poor supplier?

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#3825

Re: Reflow Oven | 15 June, 2000

Jeff: You're correct �7.1.3 of ANSI J-STD-001C states " Drying / Degreasing states the assembly may be treated to remove moisture and other volitiles."

We don't bake "FR4" for love nor money. The archive are littered with threads along this line.

Years ago, we baked every thing, primarily to remove moisture that would cause blow holes in wave soldered boards. Better buy scheduling, board design, and plant environmental control have eliminated this negative value step. Now, the only thing we bake is multiwire boards.

As far as your volatiles are concerned, your board supplier should be able to tell you what the volitiles are, their hazards to your employees, required engineering and environmental controls, bake schedule, recommended equipment, inventory swell, etc. From that you should be able to price your baking effort. From that price, your buyer should a concrete incentive to negotiate with another supplier.

Yano what I think? Your supplier block builds your entire order, ships portions of it to you on schedule, and suckers you into baking the moisture that naturally collects in the later shipments. Now that's a volatile I can understand!!!

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reflow oven profiler

Reflow Oven