[time-nuts] HP 5370B low frequency modulation

[SAIDJACK at aol.com]

In a message dated 7/26/2007 01:28:55 Pacific Daylight Time,  
magnus at rubidium.dyndns.org writes:

>sy  cooling flange. On another board we glued a nut to the top of the  BGA
>and hanged 50-70 kg of it and while the board was clearly bent the  BGA was
>still firmly hooked to it. Now that's the difference between a  few um of 
gold
>too much or not.

>There are other cases where  the gold-plating is not an issue.

>This has been covered in public  sources, so a dig around would give  some
>indication.

>Cheers,
>Magnus



Hi Magnus,
 
I've had a board with what the manufacturer called "black pad" syndrom: the  
BGA literally popped off by just bending the PCB sufficiently. The solder 
joint  was useless.
 
Is this caused by the problem you described?
 
Also, what do you think is a better process: gold-flash, or  gold-immersion?
 
bye,
Said



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