Material Comparison
All surface finishes have strengths and weaknesses. This matrix is designed to allow
you to make the best decision for your circuit board needs.
View Sunstone's offerings to here.
Please review the information below for a side-by-side comparison.
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Lead free compatible, RoHS compliant
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required
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yes
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yes
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yes
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yes
|
yes
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no
|
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Solder joint integrity (how good and reliable is the solder joint)
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self explanatory
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very good *
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good
|
good
|
good
|
good
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best
|
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Shelf life (with proper storage**)
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self explanatory
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12 months**
|
12 months
|
12 months**
|
12 months**
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12 months
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12 months +
|
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Assembly heat cycles (# of passes through reflow)
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> is better
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multiple
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multiple
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multiple
|
multiple
|
multiple
|
multiple
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Fab thermal shock (thermal shock during PCB fabrication)
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very low is best
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very low
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low *
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very low
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very low
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high
|
high
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Wettable (how easily does the solder flow onto the surface)
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self explanatory
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very good *
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good
|
good
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good
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acceptable *
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best
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Solder paste printability (co-planarity of the finish for fine pitch devices)
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self explanatory
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excellent
|
excellent
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excellent
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excellent
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poor
|
poor
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Solder pot compatible (low possibility of solder pot contamination)
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desired
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yes
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monitor Au concentration
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yes
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yes
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yes
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no (if using no lead solder pot)
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Low contact resistance (resistance of the finish)
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yes is good
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yes
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yes
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yes
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no
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no
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no
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Aluminum wire bonding (can this finish be used with Al wire bonding)
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yes is good
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yes
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yes
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no
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no
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no
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no
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Process cost to PCB fabricator
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self explanatory
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med
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high
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low
|
med
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high
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low
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Sources: (1) Cookson Electronics, (*) Sunstone testing data (**)
Package & Handling Sheet
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For more information on the immersion silver process used by Sunstone please go
to: http://www.microvoids.org/alphastar.aspx
