As an interested observer, a few possibly DUMB Qs: Q1) So, OpenMoko has not committed to building the 10-20 protos?
Q2) What is design goal? a simple clean up & re-do of GTA02 (less Glamo...) in an open source hardware context? Q3) What is role of OpenMoko organization now? Sell remaining GTA02s? --- Ron K. Jeffries http://identi.ca/ronkjeffries/all On Tue, May 19, 2009 at 11:13, <joa...@verona.se> wrote: > Nils Faerber <nils.faer...@kernelconcepts.de> writes: > >> >> He ;) >> Many of the parts in the GTA02 cannot be reasonably placed by hand. >> There are almost a dozen (or more?) BGA chips which are extremely hard >> to handle (you do not see if the balls match the pads). Then there are >> almost microscopic parts like resistors and capacitors - which pitch? >> 0402 at least if not even 0201 or smaller. So populating the board is >> almost impossible by hand without highly qualified tools (and no, a >> tweezer and a stereo-microscope will not suffice). >> But the problem you will encounter beforehand is printing the solder >> paste. Stencil printing such high density with even and correct paste >> distribution is not exactly easy even if you have proper stencil >> printers. Adjusting them, having the right paste to print etc. is high >> art of SMT manufacturing. And finally you need a really proper nitrogen >> flooded full convection reflow oven for good quality soldering of such >> delicate parts (different heat absorption of parts, proper heat >> profiles, good energy distribution, etc.). > > Well this just goes to show that the last time I did serious electronics > we prototyped with wire wrap guns and stuff :) At least we made vlsi:s > with vhdl. > > >> >> So what you really need is a modern manufacturing line, with auto-placer >> for almost all parts. I do not know how many different parts there are >> on the GTA02, probably 100, or even more? This means very high initial >> effort for setting up the machine to pupulate a board. If you then run 1 >> or 10 or 100 does not make much difference for the machine cost anymore >> (you just need more parts). The setup effort is the thing that makes >> prototypes or small series such expensive. I just visited another >> electronics maker here in Germany and they have a placement machine >> which can set up to 85000 parts per hour. Compared to something like a >> day for setting up the machine, the time placing the parts is almost >> irrelevant. >> >> The smaller the parts have got in the past the more difficult it has >> become for hobbyists to catch up with technology. It will not take very >> long until home-grown PCBs will be almost impossible to do because all >> the interesting chips come as bare-die only (just the silicon, no case >> or pins). >> >> So what is needed is the real commitment by some professional hardware >> manufacturer to put the new design on one of his lines and care for the >> prototyping and small initial a-series. After the design has proven to >> work a small first production run should be easier to setup since you >> can then give proove that it will work and persuade potential customers >> to pay up-front for the device - or at least a part up-front. That would >> enable buying the parts and paying for setting up the production. I >> think the Open Pandora people did it quite similarly, i.e. they sold >> devices and had them made after sales. If your customers trust you >> enough this can work. >> >> So in the end hardware making is more a matter of money than motivation >> or man power, pitily... >> >> Cheers >> nils faerber > -- > Joakim Verona > > > _______________________________________________ > hardware mailing list > hardware@lists.openmoko.org > http://lists.openmoko.org/mailman/listinfo/hardware > _______________________________________________ hardware mailing list hardware@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/hardware