[Coco] Surface Mount Soldering

Tue Jul 6 16:25:03 EDT 2010

Mark

I agree the newer fine pitch BGAs with 0.8 mm pitch are really out of the range of hobbyists. 
In fact there is not hardly any PCB fab house that will does that pitch and pin count even with 
protoboards. 

For 584 pin FBGA package you are going to need at least 8 layers to get all the pins wired. 
You are talking 12 mil pads and 3 to 5 mil runners along with 5 mil vias. The smallest via tha 
tI have found that a shop will do for hobbyist is aobut 8 mil vias. That is only on 4 layer 
boards. ALso no blind vias. I hate blind vias. They are the creation of the devi. 

The 80 pin 100 mil pitch (2.54 mm) I could route that on a two layer board. Man that was fun. 
It took me almost a day to get just that part routed out from under the BGA. I dare not used 
an autorouter for that either. 

james

On 6 Jul 2010 at 16:33, Mark Marlette wrote:

> 
> Trust me, 5 mil bumps are not easy to deal with.
> 
> As I recall, the DE1's FPGA has 584 pins on it, BGA form, about 1" sq.
> 
> As it is easy to put down a BGA, it is harder to do it correctly and be able to verify your workmanship which, IMHO requires xray.
> 
> Not to many hobbyist are going to drop $100k for Xray... :)
> 
> I avoid BGA packaging as much as I can. 
> 
> Mark
> Cloud-9
> 
> ----- Original Message -----
> From: Little John (GIMEchip.com) <sales at gimechip.com>
> To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> Sent: Tue, 06 Jul 2010 16:06:59 -0000 (UTC)
> Subject: Re: [Coco] Surface Mount Soldering
> 
> Uh Oh - I've started a debate :-)
> J/K - I've often wondered how a hobbyist could work with BGA and then I 
> decided this morning to look at youtube. Man there are all kinds of videos 
> on there - some of the techniques by hobbyists such as myself don't look 
> like they could possibly work, and yet they do. I am amazed at the ingenuity 
> of some of these folks.
> -John
> ----- Original Message ----- 
> From: "Mark Marlette" <mmarlette at frontiernet.net>
> To: "CoCoList for Color Computer Enthusiasts" <coco at maltedmedia.com>
> Sent: Tuesday, July 06, 2010 10:51 AM
> Subject: Re: [Coco] Surface Mount Soldering
> 
> 
> > james,
> >
> > How does one manually locate/align(x/y/z/theta,down force) of a BGA on to 
> > the pads using a hotplate?
> >
> > I use our Air-Vac DRS25 unit and I am spoiled with it.
> >
> > Mark
> > Cloud-9
> >
> >
> > ----- Original Message -----
> > From: jdaggett at gate.net
> > To: CoCoList for Color Computer Enthusiasts <coco at maltedmedia.com>
> > Sent: Tue, 06 Jul 2010 13:57:08 -0000 (UTC)
> > Subject: Re: [Coco] Surface Mount Soldering
> >
> > The key to using a soldering iron for SMT work is having enough flux on 
> > the board and not to
> > much solder.
> >
> > There are other alternatives to the soldering iron approach.
> >
> > One is a hot plate. A 4in square hotplate by Thermalake is very good 
> > alternative.
> >
> > Second is the few toaster oven reflow boards out there. The stand alone 
> > controllers range in
> > the $60 to $100 and then add what ever your local Walmart or Taget has in 
> > a 1500 watt
> > toaster oven.
> >
> > The lone issue with the toaster oven is that it should have burners on the 
> > top and bottom and
> > a circulating fan inside to reduce hot zones. ALso the toaster oven method 
> > needs to work at
> > max temperature to melt the newer lead free solders. Also the different 
> > preheat times will
> > need adjusting.
> >
> > I still like the hotplate for small boards. especially with BGA packages.
> >
> > james
> >
> > On 6 Jul 2010 at 0:30, Aaron Wolfe wrote:
> >
> >> On Mon, Jul 5, 2010 at 9:39 PM, Little John (GIMEchip.com)
> >> <sales at gimechip.com> wrote:
> >> > This guy has some amazing videos on SMT soldering - I never get bored 
> >> > just watching these. Some have sound, some are silent, but they are 
> >> > beatiful nonetheless :-)
> >> > http://www.youtube.com/watch?v=wQXhny3R7lk
> >> > This is the vertical drag technique that my dad uses too.
> >> > -John
> >> > P.S. check out all of this guys videos if you have time. They are 
> >> > amazing.
> >> > -Lil' J
> >> >
> >>
> >> That is interesting to watch.  I recently got a ham license and have
> >> been soldering together some very simple circuits to reduce
> >> interference when connecting a radio to an PC to decode digital
> >> modes.. anyway, boy am I bad at soldering!  That guy is like the
> >> maestro of solder.
> >>
> >> There are a lot of good "how to" videos on youtube for all kinds of
> >> things, if you're in to do-it-yourself, its a great resource.
> >>
> >>
> >> > --
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> >> >
> >>
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> >
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