[Gta04-owner] GTA04 Production Status

Dr. H. Nikolaus Schaller hns at goldelico.com
Thu Nov 1 11:36:03 CET 2012

Am 30.10.2012 um 21:37 schrieb Boudewijn:

> On Tuesday 30 October 2012 17:14:06 Dr. H. Nikolaus Schaller wrote:
>> Hi all,
>> since last Friday things have developed very positively.
>> Results are excitingly good. Much better than with the big
>> reflow machine.
> Great!
>> Therefore I asked them to do some tests to simply solder
>> a second time some boards that had some minor issues
>> (e.g. no sound, no GPS, no WLAN etc.) and therefore did
>> pile up instead of being shipped. In some cases this simple
>> resoldering was sufficient to make the hardware bugs go away.
> That's very good to read.
>> So they continue with this hand-operated machine to produce
>> the still missing boards. And tomorrow they will start to
>> resolder/rework the others.
>> This means:
>> * some more boards are now ready for immediate shipment
>> * I have already notified the next buyers on the waiting list
>>   to confirm their shipment address
>> * there will be as many boards to ship by end of this week
>>   as in the past 2 months, i.e. more than we can test, flash and
>>   pack immediately
>> * I expect that we can now work through the backlog quite
>>  quickly
>> * So if you ordered the installation service, please prepare
>>  to send your GTA02 to us.
> Those are "amazing" points ;-)
>> What makes the vapour phase soldering machine so much
>> better?
>> (...)
>> And, it uses a lower temperature! This finally reduces the
>> warpage of the DM3730 chip we had already been fighting
>> with for a while.
>> When choosing a production facility for future GTA boards
>> we will keep this in mind and check if they have such
>> a soldering machine :)
> Thanks for the introduction to this way of soldering. It sounds simple enough 
> ;-) 
> At first sight/search I got the idea that vapour/condensing soldering is 
> relatively new, compared to convection soldering. Is that the reason such a 
> machine was not at our production company to try that out earlier? Any idea? 

Yes. They know about this technology but never had a project (roughly 2000 in
the past 15 years they are in this business) which did require such a soldering

> Good they did (was it more or less by coincidence, or was it aimed at solving 
> our production problems?)

After doing the X-Ray sessions in summer we finally learned what was going
wrong (warpage of chips if air is too hot and missing connections if air is too
cold - but for different and non-overlapping temperature ranges for all components).

By asking around we got more and more hints that other projects using this
DM3730 chip (e.g. OpenPandora) did run into exactly the same problems and
could solve them reliably only with this soldering technology.

So I insisted and proposed every now and then to try this method and finally
they tried and were also excited.


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