Thanks for your update! It takes the open phone concept a little further, if we have even x-rays of the boards ;-)
Kind regards, @ On Tuesday 03 July 2012 11:15:16 Dr. H. Nikolaus Schaller wrote: > Hi all, > I did a long telephone call this morning to discuss the production situation > of the GTA04A4 boards. > > Am 25.06.2012 um 20:56 schrieb Dr. H. Nikolaus Schaller: > > Hi, > > > > Am 25.06.2012 um 16:16 schrieb Gilles Filippini: > >> Hi Nikolaus, > >> > >> Dr. H. Nikolaus Schaller a écrit , Le 31/05/2012 17:36: > >>> So please expect that it will become End of June for delivery... > >> > >> Since we are near to End of June, time for asking how is it going? ;) > > > > Neither good nor bad... > > > > This means: > > * we have already shipped some of the GTA04 Group Tour boards > > * some friends have upgraded to a complete OpenPhoenux (we have a handful > > reworked GTA02) * but we still have a list of open orders for roughly 90 > > GTA04 Group Tour boards > > > > The production company had stopped again to do some more > > analyses and the last status I received today is that they had > > again made some X-Ray. Now they think they can again optimize > > the soldering process a little so that we don't get so much broken > > boards that need manual rework. > > So here is a copy of the latest X-Ray image of the DM3730CBP with short > circuits: > > http://download.goldelico.com/gta04/images/20120622-GTA04A4- schlecht-01.jpg > > If you want to compare to the GTA04A3 board X-Ray (with one short): > > http://download.goldelico.com/gta04/images/20110707-GTA04A3-schlecht- xr002. > jpg > > or the GTA04A2 board (where only 1 unit exists): > > http://download.goldelico.com/gta04/images/20101109-GTA04A2-overview.jpg > > > Every rework ruins some components (unfortunately 1 DM3730 > > + 1 Memory chip > 50 EUR) and costs intensive working time. > > And we simply can't afford that if it happens too often... > > > > So the highest priority is to get rid of the root cause for these > > soldering failures. > > After analyzing and discussing the X-Ray images we now think we > understand what happens (but you never know if you are right...). > > The reason appears that the DM3730CBP gets some warp during > the soldering process squeezing the balls in the middle of the BGA > grid so that they may touch a neighbor and make a short circuit. > And on the corners the balls lift off and this may result in interruptions. > > This theory correlates exactly with the error patterns we see: > > * some 50% of the boards come out of the soldering process with > shorts on VDD1, VDD2 and/or VIO which are mostly available > on the center balls > > * if the chip has no short on the power supply or is reworked some > 50% of the boards have interruptions which makes a single function > fail. Sometimes the SD interface has just 3 data lines, sometimes the > WLAN chip. Sometimes some sensor is not working. Sometimes > the USB is not working, or one display data link distorting the > colors etc. > > Now comes the crucial question: how can this be improved? > > The specialists of the production company have spent whole weekends > to do more experiments but did not yet find the right trick. It is not that > they do not want to solve the problem (they see it as a challenge) they > simply have not yet found the key. > > One factor is that our GTA04 board has exceptionally squeezed > components (since we must be small) so the soldering of a OpenPandora > or the BeagleBoard may be a little easier from heat distribution. > > I.e. we are pushing an experienced EMS to their limits... > An EMS who has produced more than 2000 different products in small > quantities (which is their strength) including some 0.4mm BGAs. > > A new experiment is scheduled for week 29 to use a different > reflow soldering machine and process which uses a little lower > temperature. > > Unfortunately, we can't contribute to this production improvement > to speed things up. > > Unless one of the readers on these list knows some real specialist > for such PoP soldering of BGAs who is willing and capable to > consult (even if it costs money). So if you know someone, please > let me know. > > > The good answer is that as soon as we decide to continue, > > So we had to decide to wait for the different reflow soldering process > first. > > > it takes less than 4 weeks to produce, test and ship all missing > > boards. They have planned that it works even if holiday season > > is coming. And our shipment plan is by sequence of order. So > > if you did order early, it is even a little closer. > > So it is a stony path towards a community driven independently > developed and produced open smartphone platform. But Rome > wasn't built in one day... > > And we have to solve this issue before we can start to think > about a future quad core LTE device with multitouch... Please > keep the faith. > > BR, > Nikolaus > > > _______________________________________________ > Openmoko community mailing list > community@lists.openmoko.org > http://lists.openmoko.org/mailman/listinfo/community _______________________________________________ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community