page19
Composition
Melting point (°C)
Toxic
Eutectic
Comments
Solidus
Liquidus
Sn
93
Ag
7
221
302
[44]
No
No
Produces strong and ductile joints on Copper and Stainless Steel. The resulting joints have high tolerance to vibration and stress, with tensile strengths to 31,000 psi on Stainless.
[44]
Audio industry standard for vehicle and home theater speaker installations. Its 7% Silver content requires a higher temperature range, but yields superior strength and vibration
resistance.
[45]
Sn
95
Ag
4
Cu
1
No
Sn
232
No
Pure
Sn99. Good strength, non-dulling. Use in food processing equipment, wire tinning, and alloying.
[12]
Susceptible to tin pest.
Sn
99.3
Cu
0.7
228
[1]
No
Yes
Sn99Cu1. Also designated as Sn
99
Cu
1
. Cheap alternative for wave soldering, recommended by the US NEMI consortium. Coarse microstructure with ductile fractures. Sparsely
distributed Cu
6
Sn
5
.
[1][46]
Forms large dendritic ß-tin crystals in a network of eutectic microstructure with finely dispersed Cu
6
Sn
5
. High melting point unfavorable for SMT use. Low
strength, high ductility. Susceptible to tin pest.
[42]
Addition of small amount of nickel increases its fluidity; the highest increase occurs at 0.06% Ni. Such alloys are known as nickel
modified or nickel stabilized.
[47]
Sn
99.3
Cu
0.7
Ni
0.05
Ge
0.009
227
[48]
Yes
Sn100C, a lead-free silver-free nickel-stabilized alloy. Similar to Sn99Cu1. The nickel content lowers copper erosion and promotes shiny solder fillet. The presence of germanium
promotes flow and reduces dross formation. Performance similar to SAC alloys at lower cost. Dross formation rate comparable to lead-tin alloys.
Sn
99.3
Cu
0.7
Ni
?
Bi
?
227
[49]
Yes
K100LD, a lead-free silver-free nickel-stabilized alloy, with low dissolving (LD) of copper. Proprietary of Kester. Similar to Sn99Cu1. The nickel content lowers copper erosion and
promotes shiny solder fillet. Bismuth acts in synergy with nickel to further reduce copper dissolution and reduces surface tension. Performance similar to SAC alloys at lower cost.
K100LDa has 0.2% copper, used to refill wave soldering pots to counteract copper buildup. Lower than optimal nickel content to avoid patents?
[50]
Sn
99
Cu
0.7
Ag
0.3
217
228
[51]
No
No
SCA, SAC, or SnAgCu. Tin-silver-copper alloy. Relatively low-cost lead-free alloy for simple applications. Can be used for wave, selective and dip soldering. At high temperatures
tends to dissolve copper; copper buildup in the bath has detrimental effect (e.g. increased bridging). Copper content must be maintained between 0.4–0.85%, e.g. by refilling the bath
with Sn
96.2
Ag
3.8
alloy (designated e.g. SN96Ce). Nitrogen atmosphere can be used to reduce losses by dross formation. Dull, surface shows formation of dendritic tin crystals.
Sn
97
Cu
3
227
232
250
[52]
332
[9]
No
For high-temperature uses. Allows removing insulation from an enameled wire and applying solder coating in a single operation. For radiator repairs, stained glass windows, and
potable water plumbing.
Sn
97
Cu
2.75
Ag
0.25
228
314
[9]
No
High hardness, creep-resistant. For radiators, stained glass windows, and potable water plumbing. Excellent high-strength solder for radiator repairs. Wide range of patina and colors.
Zn
100
419
No
Pure
For soldering aluminium. Good wettability of aluminium, relatively good corrosion resistance.
[53]
Bi
100
271
No
Pure
Used as a non-superconducting solder in low-temperature physics. Does not wet metals well, forms a mechanically weak joint.
[28]
Sn
91
Zn
9
199
[54]
No
Yes
KappAloy9 Designed specifically for Aluminum-to-Aluminum and Aluminum-to-Copper soldering. It has good corrosion resistance and tensile strength. Lies between soft solder and
silver brazing alloys, thereby avoiding damage to critical electronics and substrate deformation and segregation. Best solder for Aluminum wire to Copper busses or Copper wire to
Aluminum busses or contacts.
[54]
UNS#: L91090
Sn
85
Zn
15
199
260
[54]
No
No
KappAloy15 Designed specifically for Aluminum-to-Aluminum and Aluminum-to-Copper soldering. It has good corrosion resistance and tensile strength. Lies between soft solder and
silver brazing alloys, thereby avoiding damage to critical electronics and substrate deformation and segregation. Has a wide plastic range this makes it ideal for hand soldering
Aluminum plates and parts, allowing manipulation of the parts as the solder cools.
[54]
Zn
95
Al
5
382
No
Yes
For soldering aluminium. Good wetting.
[53]
Sn
91.8
Bi
4.8
Ag
3.4
211
213
[55]
No
No
Do not use on lead-containing metallizations.
[56]
Sn
70
Zn
30
199
316
[54]
No
No
KappAloy30 For soldering of aluminium. Good wetting. Used extensively in spray wire form for capacitors and other electronic parts. Higher temperature and higher tensile strength
compared to 85Sn/15Zn and 91Sn/9Zn.
[54]
Sn
80
Zn
20
199
288
[54]
No
No
KappAloy20 For soldering of aluminium. Good wetting. Used extensively in spray wire form for capacitors and other electronic parts. Higher temperature and higher tensile strength
compared to 85Sn/15Zn and 91Sn/9Zn.
[54]
Sn
60
Zn
40
199
343
[54]
No
No
KappAloy40 For soldering of aluminium. Good wetting. Used extensively in spray wire form for capacitors and other electronic parts. Higher temperature and higher tensile strength
compared to 85Sn/15Zn and 91Sn/9Zn.
[54]
Pb
63
Sn
35
Sb
2
185
243
[6]
Pb
No
Sb2
Pb
63
Sn
34
Zn
3
170
256
Pb
No
Poor wetting of aluminium. Poor corrosion rating.
[34]
Pb
92
Cd
8
310?
Cd, Pb
?
For soldering aluminium.
[57][58]
Sn
48
Bi
32
Pb
20
140
160
[18]
Pb
No
For low-temperature soldering of heat-sensitive parts, and for soldering in the vicinity of already soldered joints without their remelting.
Sn
89
Zn
8
Bi
3
191
198
No
Prone to corrosion and oxidation due to its zinc content. On copper surfaces forms a brittle Cu-Zn intermetallic layer, reducing the fatigue resistance of the joint; nickel plating of
copper inhibits this.
[59]
Sn
83.6
Zn
7.6
In
8.8
181
187
[60]
No
No
High dross due to zinc.
[61]
Sn
86.5
Zn
5.5
In
4.5
Bi
3.5
174
186
[62]
No
No
Lead-free. Corrosion concerns and high drossing due to zinc content.
Sn
86.9
In
10
Ag
3.1
204
205
[63]
No
Potential use in flip-chip assembly, no issues with tin-indium eutectic phase.
Sn
95
Ag
3.5
Zn
1
Cu
0.5
221
[59]
No
No