Re: Fwd: Re: gEDA-user: Plastic Ball Grid Array (PBGA) packages?

[Kenneth Long <kelong_2000@xxxxxxxxx>]

no problem.  Good general information. :-)

thanks again

--- Stephen Meier <smeier@xxxxxxxxxxxxxxxxxxx> wrote:

> Ken,
> 
> Placing a BGA device is not a hand solder job. It is
> done in an oven 
> along with all the other devices or on a specific,
> fairly expensive, 
> piece of equipment.
> 
> I will do my best to describe it such a tool.
> 
> The BGA device is held by a vacum gripper from the
> top. The gripper also 
> has heating elements. At this time flux might be
> applied to the solder 
> balls that make up the bottom of the BGA.
> 
> The PCB is held above another set of heating
> elements but below the bga 
> device and its gripper.
> 
> An optical probe is placed between the bottom of the
> BGA and the top of 
> the pcb. This optical device is looking both up and
> down and is used to 
> align the BGA directly above its target landpattern
> on the PCB.
> 
> When alignment is achieved, the optical probe is
> removed.
> 
> A heating cycle is then started both from bellow the
> PCB and from above 
> the BGA at a specified point in the heating cycle
> the BGA is lowered 
> very gently onto the the PCB and released from the
> vacum gripper. The 
> heating cycle eventualy is ramped down and the
> entire board is allowed 
> to cool.
> 
> A shop that I work with typically charges $100.00 to
> place one BGA. The 
> price drops rapiddly if placing a lot of them on
> multiple boards.
> 
> Steve M.
> 
> P.S. I hope you don't mind. But this is a general
> enough question that I 
> am going to post my answer back to the GEDA mailing
> list.
> 
> 
> 
> >How do you get the chip (BGA) to soldier? 
> >  
> >
> 
> 


=====
Kenneth James Long II
a man in love with his wife...


		
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