[Coco] assembly questions?

[jdaggett at gate.net]

David

If you are real careful and have proper alignment marks on the 
PCB,  then a hot plate and a lot of liquid flux will do. I recommend 
this process for 100 pin BGAs or less.  when you get over 10x10 
ball array on the bottom the pictch gets to fine even for a hot plate. 

I did the hot plate with method with BGA packages that had 20 mill 
balls and 30 mil spacing. Some packages now have 12 mill balls 
and 20 mill spacing.

Flip chips are even tighter. I think something like 4 mill balls and 8 
mill spacing.  

james


On 26 Jul 2004 at 15:05, David Gacke wrote:

From:           	"David Gacke" <dgacke at ektarion.com>
To:             	"'CoCoList for Color Computer Enthusiasts'" 
<coco at maltedmedia.com>
Subject:        	RE: [Coco] assembly questions?
Date sent:      	Mon, 26 Jul 2004 15:05:03 -0500
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> BGAs really need to be set on a board by machine.
> 
> Normally both sides of the board are heated for a predetermined time
> and/or temperature when the chip is set.
> 
> You can see what a small BGA rework station looks like at
> coopertools.com
> 
> The Weller one is real nice for small scale stuff, and it's a bargain
> at 12 grand!  ;)
> 
> 
> Dave
> 
> -----Original Message-----
> From: coco-bounces at maltedmedia.com
> [mailto:coco-bounces at maltedmedia.com] On Behalf Of Kevin Diggs Sent:
> Monday, July 26, 2004 2:28 PM To: CoCoList for Color Computer
> Enthusiasts Subject: Re: [Coco] assembly questions?
> 
> Hi,
> 
>  Regarding previous discussions on this thread, Is there
> no way to use these new packages (BGA) with some kind of
> adapter on older circuit boards that hobbyists can make?
> 
>      kevin
> 
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