Methane, amen. Here goes this one........
>-----Original Message-----
>From: Paul Klasek [SMTP:[log in to unmask]]
>Sent: Wednesday, March 15, 2000 6:04 PM
>To: [log in to unmask]
>Subject: Re: [TN] ??: [TN] Gold Removal
>
>Oh, gee, ehm, Ryan, mate, close, not sure if enough :
>1
>Steve's maths ?(sorry Steve, you ARE one of the LEGENDS):
>"nearly" 75u" = 1.875um (or close enough);
>is NOT in line with ITRI's recommended 1.5um ceiling :
>me the coward never had guts to digest even 1um on soldered pads .
>I'll give you; with latest pad size trends (smaller); you may creep touch
>higher,
>but i do know if i'd got totally stoned and placed more than 1umAu on specs,
>my fellow in QA would be after my skin .
>Besides, Tim 's been just quizzing me where the hell do i squeeze 0.5um from
>flush;
>whining bitterly all he gets from his fabs is 0.25um tops on flash .
>Record i MEASURED on flash was some 0.8um,
>so i presume it's my turn in Tim's shoes :
>Where would you get saturation's which throws 75u" on Ni ?
>Presume only academic maths ?
>
>And the bible talks, i think (?) about 4% , not 3,
>but i won't be making scenes about that one
>(less is better, almost, hahaha)
>
>And NiAu (0.5umAu average = 20u") costs us less than HASL .
>
>Getting gold ears from all this off hip traffic ;
>getting dark here too: Inge : deleted some dozen methaned messages today !
>
>All in good humor Ryan , ok ?, just let's retain the functionality.
>
>
>Paul
>
>-----Original Message-----
>From: Ryan Grant [mailto:[log in to unmask]]
>Sent: Thursday, 16 March 2000 10:47
>To: [log in to unmask]
>Subject: Re: [TN] ??: [TN] Gold Removal
>
>
>I agree with this. Do the math. If a five mil stencil is used, and the
>component leads are NOT gold plated, the board gold thickness can reach
>nearly 75 micro inches before the percentage of gold in the joint reaches
>the magical number of 3%. Below 3%, gold is not shown to induce
>embrittlement. If you are soldering to BGA balls, there is even more Tin to
>dilute the gold, so the gold thickness can be even thicker. The reason for
>the 5 to 8 micro inches of gold thickness is, that is the MINIMUM needed to
>prevent oxidation of the nickel. Thicker gold is more expensive in terms of
>processing and material cost, and it is unnecessary, so why do it?
>
>Of course, if I buy a new stereo, and it has a scratch on it, I'll take it
>back. Functionality be damned. Rick can do the same with his boards.
>
>Ryan G.
>
>> -----Original Message-----
>> From: Timothy Reeves [SMTP:[log in to unmask]]
>> Sent: Wednesday, March 15, 2000 3:08 PM
>> To: [log in to unmask]
>> Subject: Re: [TN] ??: [TN] Gold Removal
>>
>> Does anyone agree with this? I hope not.
>>
>> > ----------
>> > From: Jonathan A Noquil
>> > Sent: Tuesday, March 14, 2000 15:57
>> > Subject: Re: ??: [TN] Gold Removal
>> >
>> > Higher gold thickness does not affect
>> > reliability (solderability),
>>
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