Cheap PCB fab place (for non-urgent stuff)
in [Design]
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From: RST Engineering on 17 Apr 2010 02:39 > >I design stuff that goes into things that fly :-) > >But that's not the only reason why I avoid them. Me too, y'aall but I learned how to snip YEARS ago. PLEASE SNIP. PLEASE SNIP. Jim
From: Nico Coesel on 17 Apr 2010 06:27 Joerg <invalid(a)invalid.invalid> wrote: >Joel Koltner wrote: >> "Joerg" <invalid(a)invalid.invalid> wrote in message >> news:82r67sFha4U1(a)mid.individual.net... >>> Thanks, sounds like a good deal. Unfortunately they seem to do RoHS >>> boards which I avoid whenever possible. >> >> This is a good strategy. >> >> But do you think it'll even be possible in another, say, 5 years? Today >> pretty much all the parts are meant for RoHS processes, so I'm thinking >> that since running RoHS and non-RoHS means having to keep two reflow >> ovens around, over time most all CMs will just go all-RoHS? ... > > >Possibly. But that would be sad. > >> ... (Especially >> for commercial products -- for the military/NASA/etc. where price is no >> object, I expect niche "leaded" assemblers will stick around... just as >> there's already a niche market in de-balling lead-free BGAs and >> re-balling them with leaded solder, often at a cost close to or >> exceeding the original price of the part!) >> > >BGA is another story. I avoid them when at all possible because they are >causing so much grief. Having a stiff ceramic-like chip with solder pads >on a structure such as FR-4 that is by nature somewhat flexible has >IMHO always been a rather sick concept. AFAIK BGAs are based on an FR4-ish laminate so it can bend along with the PCB. In my experience some assembly houses do not master their soldering process and some PCBs are difficult to solder because the heat absorbtion is not evenly distributed (hot spots/cold spots). If a BGA package is causing problems its usually not the package itself but the PCB or the assembly house. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico(a)nctdevpuntnl (punt=.) --------------------------------------------------------------
From: Nico Coesel on 17 Apr 2010 06:30 Joerg <invalid(a)invalid.invalid> wrote: >Gents, > >Was mentioned in this month's IEEE Spectrum: > >http://batchpcb.com/index.php/Faq > >It's not something for urgent projects, you can't have more than four >layers and no really small drill sizes but it sure is cheap. Seems like >this is run by Sparkfun. There is also makepcb.com. Never tried them though. -- Failure does not prove something is impossible, failure simply indicates you are not using the right tools... nico(a)nctdevpuntnl (punt=.) --------------------------------------------------------------
From: Joerg on 17 Apr 2010 10:12 Nico Coesel wrote: > Joerg <invalid(a)invalid.invalid> wrote: > >> Joel Koltner wrote: [...] ... (Especially >>> for commercial products -- for the military/NASA/etc. where price is no >>> object, I expect niche "leaded" assemblers will stick around... just as >>> there's already a niche market in de-balling lead-free BGAs and >>> re-balling them with leaded solder, often at a cost close to or >>> exceeding the original price of the part!) >>> >> BGA is another story. I avoid them when at all possible because they are >> causing so much grief. Having a stiff ceramic-like chip with solder pads >> on a structure such as FR-4 that is by nature somewhat flexible has >> IMHO always been a rather sick concept. > > AFAIK BGAs are based on an FR4-ish laminate so it can bend along with > the PCB. In my experience some assembly houses do not master their > soldering process and some PCBs are difficult to solder because the > heat absorbtion is not evenly distributed (hot spots/cold spots). If a > BGA package is causing problems its usually not the package itself but > the PCB or the assembly house. > The failures I've heard about were in mass products which are definitely professionally soldered. The BGAs I've seen were some sort of ceramic. After all, a die cannot bend. Even if it was FR-4, think about it, what will happen if two circuit boards soldered together via bumps are bent? Same goes for larger DFN packages but often one doesn't have a choice. I will always prefer MSOP or anything with pins because there is some movement compliance in the pins. -- Regards, Joerg http://www.analogconsultants.com/ "gmail" domain blocked because of excessive spam. Use another domain or send PM.
From: krw on 17 Apr 2010 11:45
On Sat, 17 Apr 2010 07:12:00 -0700, Joerg <invalid(a)invalid.invalid> wrote: >Nico Coesel wrote: >> Joerg <invalid(a)invalid.invalid> wrote: >> >>> Joel Koltner wrote: > >[...] > ... (Especially >>>> for commercial products -- for the military/NASA/etc. where price is no >>>> object, I expect niche "leaded" assemblers will stick around... just as >>>> there's already a niche market in de-balling lead-free BGAs and >>>> re-balling them with leaded solder, often at a cost close to or >>>> exceeding the original price of the part!) >>>> >>> BGA is another story. I avoid them when at all possible because they are >>> causing so much grief. Having a stiff ceramic-like chip with solder pads >>> on a structure such as FR-4 that is by nature somewhat flexible has >>> IMHO always been a rather sick concept. >> >> AFAIK BGAs are based on an FR4-ish laminate so it can bend along with >> the PCB. In my experience some assembly houses do not master their >> soldering process and some PCBs are difficult to solder because the >> heat absorbtion is not evenly distributed (hot spots/cold spots). If a >> BGA package is causing problems its usually not the package itself but >> the PCB or the assembly house. >> > >The failures I've heard about were in mass products which are definitely >professionally soldered. The BGAs I've seen were some sort of ceramic. >After all, a die cannot bend. Even if it was FR-4, think about it, what >will happen if two circuit boards soldered together via bumps are bent? > >Same goes for larger DFN packages but often one doesn't have a choice. I >will always prefer MSOP or anything with pins because there is some >movement compliance in the pins. We don't like Q/DFNs because they're harder reflow reliably, particularly with RoHS solder. BGAs above .8mm, OTOH, are simple so we use them whenever possible. There is rarely a choice between packages this diverse though. |