RE: [amsat-bb] Prototyping BGA's

[<alan_bloom@xxxxxxxxxxx>]

Since you can't access BGA pads with a soldering iron, you have to use solder paste, which is liquid rosin solder flux mixed with powdered solder.  Apply a small dab of paste to each pad, place the BGA IC with the proper registration and heat.

The heating is the hard part - you have to get the temperature hot enough to melt the solder but not so hot it damages components.  63%/37% tin/lead solder melts at 183 degC (361 degF).  You need to get both the PC board and the BGA component above that temperature to assure good joints.

Al N1AL


> -----Original Message-----
> From: owner-AMSAT-BB@amsat.org [mailto:owner-AMSAT-BB@amsat.org]On
> Behalf Of Dave G.
> Sent: Monday, January 10, 2005 9:58 AM
> To: amsat-bb@amsat.org; Howard Long
> Subject: Re: [amsat-bb] Prototyping BGA's
> 
> 
> Howard,
> 
> You might want to check out the archives on building the 
> Micro908 (AA908) on the AMQRP web site. (WWW.AMQRP.ORG )
> 
> There is a link to the AA908 page. On that page there is a link 
> to a discussion on soldering SMT's.
> 
> There were many (tried) methods used on this project to solder 
> SMT's in place. Summarized as follows;
> 
> 1. Just plain using a fine tipped temperature controlled 
> soldering station.
> 
> 2. Use a hand held soldering iron to flood the pins with solder, 
> and then use solder wick to remove the excess from between 
> the pins. Comment: Actually works!!
> 
> 3. Use a solder paste and place the components on the PCB, 
> then put the whole thing in the oven. Comment: I have not tried 
> this one... but several folks have said this works fine.
> 
> 4. Place the component on the pads then, using a Pencil torch 
> or a narrow nozzle heat gun, melt the solder. 
> 
> There are probably quite a few more 'home brew' ways of 
> doing this.
> 
> I also found a lot of information on the individual SMT/BGA 
> vendors' sites..
> 
> Don't know if this will help...
> 
> Dave KK7SS
> 
> On 10 Jan 2005 at 10:11, Howard Long wrote:
> 
> > If anyone has had any experience of small scale prototyping BGA's onto
> > PCBs without resorting to third party commercial operations, I'd be
> > glad of any tips.
> > 
> > I'm fine hand soldering the 0.4 and 0.5mm QFP's, but I'm not sure how
> > to go about dealing with BGA packages.
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