Dear Bob:

A couple of QFN rework resources are here:

QFN rework methods outline here:
http://www.soldertools.net/product_images/PDFs/Reworking%20QFNs%20Newly%20Developed%20Cost%20Effective%20Approach.pdf

One of the methods that is straightforward for many parts is done here:
https://www.youtube.com/watch?v=CTttuhiqqjk

The tools can be all the way from a soldering iron, to an uncontrolled
 heat source like a hot air pencil/gun (Metcal pencil is nice for tiny
parts), to a full-fledged rework system like the Weller, SRT, APR etc....

For very tiny parts like you are describing you may want to consider a
small IR system like the ones PACE sells that feature a temperature probe
feedback.

Regards

Bob / BEST



On Sun, Jan 14, 2018 at 2:04 PM, Robert Kondner <[log in to unmask]>
wrote:

> Bob
>
>  Let's break down rework into two phases, removal and replacement. Removal
> is easy with a simple hot plate and hot air gun. Only a little experience
> is required.
>
> Replacement takes more skill. The hard parts are QFNs. Getting a good even
> amount of paste or solder on the pads (or on the leads) is difficult. After
> that reflow on the hot plate with hot air gun is simple. The best little
> hot air gun I have seen is the Weller 6966, a gotta have in my book.
>
> We bought a Manncorp RW1210 for about $15K about a year ago. Folks don’t
> use it much as it is more complicated than the hot plate and air gun but
> the RW1210 is a nice machine. It is great especially with doing the same
> part on a bunch of boards. It also helps with getting parts down where you
> want them.
>
> The other rework tool I live by is the a Hakko 807 type tool. I find the
> pencil type tool easier to handle than a gun type.
>
> Much of rework tool selection is based on experience. At 62 I have had a
> fair amount of experience but I have not played with all the new tools.
>
> Bob K.
>
> -----Original Message-----
> From: TechNet [mailto:[log in to unmask]] On Behalf Of Bob Cochran
> Sent: Saturday, January 13, 2018 10:04 PM
> To: [log in to unmask]
> Subject: [TN] low cost rework station to remove small BTCs...
>
> Hi,
>
> I'm looking for recommendations on a suitable manual workstation to remove
> small BTCs (e.g., < 7 mm**2 QFNs).
>
> I'm thinking the Weller WR3M would do the trick, but I would like to spend
> less.   I also want to make sure it's a unit others have had success with
> in pulling BTCs.
>
> https://www.youtube.com/watch?v=P_joODf2R8Y
>
> Thank you,
>
> Bob
>



-- 
Bob Wettermann
BEST Inc
[log in to unmask]
Cell: 847-767-5745