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36PB/62Sn/2Ag Vs 63Sn/37Pb

Pete

#17197

36PB/62Sn/2Ag Vs 63Sn/37Pb | 14 August, 2001

Hi,

would like to get good info on the above solder paste metal content regarding their advantage and disadvantage against each other and their effect on fine pitch solderability.

regards,

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#17200

36PB/62Sn/2Ag Vs 63Sn/37Pb | 14 August, 2001

2% silver will be a little shinier. [Some inspectors hate that.] After that differences get murkier.

Some people believe that 2% silver does something er other to scavange gold and silver to produce a less brittle connection. We have never seen evidence of that.

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mugen

#17201

36PB/62Sn/2Ag Vs 63Sn/37Pb | 14 August, 2001

Basic understanding,

1) the 2% silver (Ag) gives better shine *joint surface*.

2) Ag improves stength & fatigue resistance of solder joints

3) reduces leech-out of silver from silver-base substrates (eg of such silver-base surface contact: metallized faces of CAP & RES)

4) Extract from a book:

Sn63/Pb37 Tensile Strength : 4.0 tons/sq.inch @20 deg-C Elongation : 50%

Sn63/Pb35/Ag2 Tensile Strength : 4.2 tons/sq.inch @20 deg-C Elongation : 40%

This means better mechanical performance....

Caution : monitor that ur paste has no more than 2% Ag, too much of a good thing can kill.....

Inquire with your paste supplier(s), and compare their technical discussion details....

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#17202

36PB/62Sn/2Ag Vs 63Sn/37Pb | 14 August, 2001

Say isn't creep a more key issue, rather than strength?

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mugen

#17203

36PB/62Sn/2Ag Vs 63Sn/37Pb | 14 August, 2001

true.... tata why the elongation% is there.....

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#17204

36PB/62Sn/2Ag Vs 63Sn/37Pb | 14 August, 2001

But isn't elongation more of a quantification of ductility than of creep?

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mugen

#17233

36PB/62Sn/2Ag Vs 63Sn/37Pb | 16 August, 2001

Say din't someone previously claim, "Dave F" stands for :

Damm.Averted.Verified.Eggbrain.Freakin *smart* ?!?

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#17248

36PB/62Sn/2Ag Vs 63Sn/37Pb | 16 August, 2001

Just feel relieved that we didn't go to the matt on the use of "leaching" rather than "dissolution".

And you thought this was easy, eh?

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