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First time with reflow oven....

Chad

#23340

First time with reflow oven.... | 11 February, 2003

My small R&D company (15 people) is considering the purchase of a bench top reflow oven & associated gear. The reasoning is that it would be nice to have reflow capability for 5 to 50 piece prototype runs in-house. As the only person with any real knowledge of board layout, fab, and assembly here, I am terrified of this notion. I've done lots of layout, hand assembly, and interacting with board assemblers, but this sounds like a bridge too far; any opinions?

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matherat

#23341

First time with reflow oven.... | 11 February, 2003

The assembly process involves activity before you get to reflow. Reflowing is the easy part. Putting paste down and placing parts in wet paste is the terrifying part.

Benchtop reflow ovens can be a real handy tool for small production but with the glut of used equipment toady you can pick up a small footprint floor model that would work as well with better capacity.

While investigating reflow ovens, look into methods of applying paste or "alternatives" to applying it in house.

Small batch prototypes? Try serching for solid solder deposit technology. It may be a solution

mkehoe@sipad.net

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MA/NY DDave

#23342

First time with reflow oven.... | 11 February, 2003

Hi

I think I agree with this poster.

You will be surprised once you get the reflow oven working well how much you will say

"And why did I do it the other way"

I know, I know "I'm an artist" "I'm an inventor"

Nothing wrong with being either yet some simple good manufacturing techniques go a long way toward success to free up the true artist or inventor.

YiEng DDave

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Stephen

#23344

First time with reflow oven.... | 11 February, 2003

How are you doing things now? I'm trying to picture a place going from no reflow oven to a reflow oven without also getting a screen printer at the same time. Are you now handsoldering parts on? With these batchs you plan on doing are you going to place the parts then reflow them? Populating 50 boards and reflowing them is different from hand soldering one board. Populating 50 identical boards is not the same as populating 50 different boards. At least if you do it same you will be very inefficient. I know a CM that did mainly through hole, when they got a relfow oven they got a little 3 zone one. As far I know they consider it a waste of money and a lesson learned. Last I heard they have a bigger oven that cost a bit more but was worth the money. And dont' forget some form of data logger with thermocouples. Even if you buy an oven that takes thermocouples and does profiling, the oven software will probably be inadequate. What are you doing now, and what do you plan on doing?

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Chad

#23347

First time with reflow oven.... | 11 February, 2003

Currently we hand-assemble all prototypes, usually quantities less than ten. I mentioned the 5 to 50 number because a client will occasionally request more than ten, which has been handled previously by using an outside contract manufacturer (we are strictly R & D). We would be applying paste with a stencil and hand-placing the components. Personally, I feel that hand-placing more than about ten boards would be a disaster, since each one would be unique to debug. Ditto for hand-placing things like BGAs or CSPs.

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Matherat

#23348

First time with reflow oven.... | 11 February, 2003

Traditional methods of hand assembly are as you described. For a company that is concentrating on the 1-5 or 5-50 quantities you've described, you need to look for ways to accomplish your task with speed, repeatablilty, quality and at a fair price. Thinking inside the box may not accommodate this.

It is possible to hand place/assemble BGA, CSP, .4mm pitch, and any other smd package perfectly if you know where to look. Again, for this type of operation you need to look at "solid solder deposit", (ssd). I am trying my best to keep from turning this into a sales pitch but ssd is probably not something you've tried yet and it was invented and perfected for this very reason. Don't be fooled by those that say hand placing and assembling surface mount boards is archaic or non productive. They probably have not looked into ssd either. Its been around for 16 years, in the US for 5. It is being used by companies, OEM's, that have a complete assembly line in house except for the printer as they do not want raw paste/lead in their facility. Reflow is not an issue for them and would not be for you. Almost any oven would do.

mk

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#23350

First time with reflow oven.... | 11 February, 2003

As others have stated, there are a few other things in the aveage assembly shop that are much more scary that a reflow oven. For instance, we have a wonderful wave soldering machine and w've been doing that kind of stuff for tens of years, but every time we run a new board, it's an event.

As with most things, there are some excellent "bench-top" ovens and there are some that are a waste of money. You can almost tell which is which by looking at the machine.

Consider: * Doing a "process audit" at your contract service house as a starting point in developing an understanding of reflow soldering. [In fact you should go to several of the contact shops in your area to compare notes. Their business is probaly so poor, they'll buy you lunch, while you're wringing them out.] * Talking to sales reps for the better ovens that you're thinking about. [They should be able and willing to lessen your concerns throughout the purchase and board toasting processes.] * Talking to sales reps for reflow process monitors [ie, KIC, ECD, etc]. [They should be able to make you thing that with their equipment that you could reflow boards in your jamies.]

Finally, as other posting on this thread have implied, you can find a very good used oven for the price a new POS cheap oven.

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