[Reference] Physical and Mechanical Properties of Solder Alloys

Physical and Mechanical Properties of Solder Alloys
Original source: http://alasir.com/reference/solder_alloys/

Solder Alloy Melting Point, °C
solidus / liquidus
Density,
g/cm³
Electrical
Resistivity,
µΩ⋅m
Thermal
Conductivity,
W/m⋅K
Tensile
Strength
at Break,
kgf/cm²
Tensile
Elongation
at Break,
%
Brinell
Hardness,
HB
alloys of tin (Sn) with silver (Ag) and / or copper (Cu)
Sn96.5Ag3.5
(alloy #121)
221 / 221 7.37 0.123 55 580 35 15
Sn95Ag05
(alloy #132)
221 / 240 7.40 0.137 - 565 30 14
Sn90Ag10
(alloy #156)
221 / 295 7.51 - - - - -
Sn99.3Cu0.7
(alloy #244)
227 / 227 7.31 0.126 66 300 21 9
Sn97Cu03
(alloy #160)
227 / 300 7.32 0.118 - - - -
Sn99.2Ag0.1Cu0.7
(SAC0107)
217 / 228 7.32 - - - - -
Sn99Ag0.3Cu0.7
(alloy #263 or SAC0307)
217 / 228 7.33 - - 300 22 14
Sn98.5Ag0.8Cu0.7
(SAC0807)
216 / 225 7.33 0.140 - 310 21 16
Sn98.5Ag1.0Cu0.5
(alloy #258 or SAC105)
215 / 227 7.32 0.133 60 400 13 13
Sn97.1Ag2.6Cu0.3
(SAC263)
217 / 224 7.36 0.132 - - - -
Sn96.5Ag3.0Cu0.5a
(alloy #256 or SAC305)
217 / 220 7.38 0.132 58 500 19 15
Sn95.5Ag4.0Cu0.5
(alloy #246 or SAC405)
217 / 220 7.44 0.132 62 530 17 15
Sn95.5Ag3.8Cu0.7b
(alloy #241 or SAC387)
217 / 220 7.44 0.132 60 600 16 15
alloys of tin (Sn) and lead (Pb) with or without silver (Ag)
Sn90Pb10
(alloy #118)
183 / 213 7.55 - - 490 40 -
Sn63Pb37
(alloy #106)
183 / 183 8.40 0.145 50 525 37 17
Sn62.5Pb36.1Ag1.4
(alloy #104)
179 / 179 8.41 0.145 50 490 - 16
Sn60Pb40
(alloy #109)
183 / 191 8.50 0.153 49 535 40 16
Sn55Pb45
(alloy #113)
183 / 200 8.68 - - - - -
Sn50Pb50 or Pb50Sn50
(alloy #116)
183 / 212 8.87 0.158 48 420 35 14
Pb55Sn45 or Sn45Pb55
(alloy #125)
183 / 227 9.07 0.166 - - - -
Pb60Sn40 or Sn40Pb60
(alloy #130)
183 / 238 9.28 0.171 44 380 25 12
Pb65Sn35 or Sn35Pb65
(alloy #135)
183 / 247 9.50 0.176 - - - 12
Pb70Sn30 or Sn30Pb70
(alloy #141)
183 / 257 9.72 0.185 41 350 18 12
Pb75Sn25 or Sn25Pb75
(alloy #145)
183 / 268 9.96 0.194 - 240 53 11
Pb80Sn20 or Sn20Pb80
(alloy #149)
183 / 280 10.21 0.198 37 340 20 11
Pb85Sn15 or Sn15Pb85
(alloy #153)
183 / 288 10.70 - - 330 - 11
Pb88Sn10Ag02
(alloy #228)
267 / 290 10.75 0.203 27 230 42 -
Pb90Sn10 or Sn10Pb90
(alloy #159)
275 / 302 10.75 0.194 25 310 30 10
Pb92.5Sn05Ag2.5
(alloy #151)
287 / 296 11.02 0.200 - 295 - -
Pb95Sn05 or Sn05Pb95
(alloy #171)
308 / 312 11.06 0.196 23 280 45 8
Pb97.5Ag1.5Sn01
(alloy #165)
309 / 309 11.28 0.287 23 310 23 9
alloys of bismuth (Bi) and / or cadmium (Ca) with tin (Sb) and / or lead (Pb)
Bi58Sn42
(alloy #281)
138 / 138 8.56 0.383 19 565 55 23
Sn60Bi40
(alloy #281-338)
138 / 170 8.12 0.345 30 525 35 24
Bi55.5Pb44.5
(alloy #255)
124 / 124 10.44 0.431 4 450 38 15
Sn43Pb43Bi14
(alloy #97)
144 / 163 9.02 - - 450 41 -
Sn51.2Pb30.6Cd18.2
(alloy #181)
145 / 145 8.45 - 35 440 - -
alloys of indium (In) with lead (Pb) and / or tin (Sn) and / or silver (Ag)
In70Pb30
(alloy #204)
165 / 175 8.19 0.196 38 245 - -
In60Pb40
(alloy #205)
173 / 181 8.52 0.246 29 290 - -
In50Pb50 or Pb50In50
(alloy #7)
184 / 210 8.86 0.287 22 330 55 10
Pb60In40
(alloy #206)
197 / 231 9.30 0.332 19 350 - -
Pb75In25
(alloy #10)
240 / 260 9.97 0.375 18 385 48 10
Pb81In19
(alloy #150)
260 / 275 10.27 0.383 17 390 - -
Pb95In05
(alloy #11)
300 / 313 11.06 0.338 21 305 52 6
In52Sn48
(alloy #1E)
118 / 118 7.30 0.147 34 120 83 5
In50Sn50 or Sn50In50
(alloy #1)
118 / 125 7.30 0.147 34 120 83 5
In97Ag03
(alloy #290)
143 / 143 7.38 0.075 73 55 - 2
In90Ag10
(alloy #3)
143 / 237 7.54 0.078 67 115 61 3
In80Pb15Ag05
(alloy #2)
149 / 154 7.85 0.133 43 180 58 5
Pb90In05Ag05
(alloy #12)
290 / 310 11.00 0.308 25 405 23 9
Pb92.5In05Ag2.5
(alloy #164)
300 / 310 11.02 0.313 25 320 - -
Sn77.2In20Ag2.8
(alloy #227)
175 / 187 7.25 0.176 54 480 47 17
Sn37.5Pb37.5In25
(alloy #5)
134 / 181 8.42 0.221 23 370 101 10
Sn54Pb26In20
(alloy #230)
136 / 152 8.05 - - - - -
Sn70Pb18In12
(alloy #9)
154 / 167 7.79 0.141 45 375 136 12
low temperature alloys
In51.0Bi32.5Sn16.5
(alloy #19 or Field's alloy)
60 / 60 7.88 0.522 - 340 - 11
Bi50Pb26.7Sn13.3Cd10
(alloy #158 or Wood's alloy)
70 / 70 9.58 0.431 18 420 120 15
Bi52Pb30Sn18
(alloy #39 or Newton's alloy)
96 / 96 9.60 0.750 13 365 100 16
Bi50Pb28Sn22
(alloy #41 or Rose's alloy)
100 / 100 9.44 - - - - -
other alloys
Sn95Sb05
(alloy #133)
235 / 240 7.25 0.145 28 415 38 13
Sn91Zn09
(alloy #201)
199 / 199 7.27 0.115 61 560 33 22
Au80Sn20
(alloy #182 or Orotin)
280 / 280 14.51 - 57 2800 2 -
Au88Ge12
(alloy #183 or Georo)
356 / 356 14.67 - - 2150 1 -
Pb97.5Ag2.5
(alloy #161)
303 / 303 11.33 0.200 - 310 42 -
Pb94.5Ag5.5
(alloy #229)
304 / 365 11.35 0.287 23 310 - -
Pb85Sb10Sn05
(alloy #233)
245 / 255 10.36 0.287 - 390 4 -

In100
(pure indium)
157 / 157 7.31 0.0837 86 20 - 1
Sn100
(pure tin)
232 / 232 7.29 0.124 73 135 - 4
Bi100
(pure bismuth)
271 / 271 9.78 1.29 8 - - 7
Pb100
(pure lead)
327 / 327 11.34 0.218 35 125 55 4
Ag100
(pure silver)
960 / 960 10.49 0.0163 429 1480 50 25
Au100
(pure gold)
1064 / 1064 19.30 0.0221 318 1405 42 25
Cu100
(pure copper)
1085 / 1085 8.94 0.0172 401 2460 40 35
a) U.S. patent #5527628 issued on the 18-June-1996 to SMIC (Senju Metal Industry Co.), will expire internationally on the 24-Feb-2015;
b) U.S. patent #4929423 issued on the 29-May-1990 to Cookson Group, expired internationally on the 31-Mar-2009;

NOTES:
1. Electrical resistivity and thermal conductivity are evaluated usually at 20°C and 85°C respectively.
2. Electrical resistivity is inverse to electrical conductivity.
3. Electrical conductivity is often expressed in % IACS which stands for International Annealed Copper Standard.
100% IACS is electrical conductivity of annealed copper which equals to 58.0 × 106 S⋅m-1.
4. Tensile strength in kgf/cm² may be converted to psi (pounds per square inch) by multiplying with 14.22.

very useful, thank you!

Can you send me a 250g sample of the AU88GE12 :money_mouth_face:

LOL, actually I’m wondering what’s its real world uses.

So to maximize thermal conductivity for overdriving emitters one should use pure Indium or Tin?
I suspect using pure Silver, Copper or Gold will fry the emitter

The question will be: is it worth the money spend/lumen gain?
Depends on intended applications. Pure Indium fluxless wire price is very expensive USD 95/3 ft.

I do not know on either count, but pure Tin may be a decent compromise

Pure Indium is very good as a thermo safety switch off :smiley: . You overdrive the LED and beyond 157C it fell off the MCPCB :laughing:
Good only for low temp application. Any metals usually annealed far below their melting point. For example, SAC305 (Sn96,5Ag3Cu0,5) starts to anneal at 125C. TIM made from pure Indium also exhibit extremely soft physical characteristic, too soft for solder application hence the additives.

Pure Tin while has much higher melting point at 232C is not much harder than Indium. You can slice it with razor easily.

I often use the BiSn solder for super low temp soldering. Don’t really know the composition. It melts slightly below the PVC melting temp, used as convenient waterproof wire joiner.

Sorry to “necro” this thread, but I am hoping to find some information.

This week I bought a seringe of solder paste: Sn96,5Ag3Cu0,5 . This is the paste I bought:

This my first time using solder paste, and I am no expert on this (or anything else!).

I will use this paste mainly to reflow some emitters that I will get soon.
I started practising on some older MCPCBs and with some old leds (just to test the “melting point”), and I noticed that it didn’t “melt” as good as my solder wire.

It started melting but then it became a sort of past with lots of tiny blobs that didn’t melt and that were a bit sticky :zipper_mouth_face:

As I don’t have any tool or appropriate platform to make the reflow, I used my electrical stove, put the MCPCBs with the solder and waited for it to melt with time. It never reached that point and what happened was just what I described above…

So, my questions are,
How do we use this solder paste to get it to melt well to reflow the emitters?
How long does it normally take to melt?
What precautions must be taken?
What temperature should the stove reach to make it melt?

Last but not least, should I buy/use other type of solder to reflow, given the conditions I have (stove / lighter / soldering iron)?

I am sorry these are some questions I would like to see answered if possible.

Also, if anyone can point me to a video reflowing with this specific paste, that would be nice, as I searched but couldn’t find one.

BTW, here are the photos of the sh**y work I did :zipper_mouth_face:

Thanks in advance!! :+1:

Either you need more heat or the flux is shit burning up before it bonds the solder balls together

Never seen such bad stuff, even with the cheap Chinese paste
You may try some more flux that does not burn, but I guess that paste does not work

To keep the LEDs in safe max temp go for leaded solder paste it behaves a lot better

Thanks for your reply Lexel!
Hum, I just tried different approaches (heating the stove before putting the plate, progressively heating the stove, using some piece of copper below the pcb to maintain the heat so that it didn’t have a break…) and all failed. I guess that adding flux wouldn’t be any good too in this case :zipper_mouth_face:
The blobs never cease to exist in any situation…
It seems that this is indeed a bad solder paste :zipper_mouth_face: Or, the fact that I don’t have the appropriate tools is what leads to those images :zipper_mouth_face:

Solder paste is hard to find in national stores, and those that have them are sold out :zipper_mouth_face: Ali and Ebay are full of fake stuff.
What could be a “good” product to use for reflowing leaded or non leaded?

MascaratumB,

While looking for Mechanic “XG-50” solder paste jars, it happens that I found this Karmor Tools store advertisement where Sn42Bi58, Sn63Pb37 and Sn96.5Ag3Cu0.5 solder pastes are sold. Nothing really wrong there, except that…

… a whopping 260 °C is claimed as Sn96.5Ag3Cu0.5's melting point. You need to raise the MCPCB temp above the melting point figure, and keep it above while you reflow. As a rule I manage to get any job done without exceeding +35 °C above solder melting point, which is less than 220 °C for Sn63Pb37 (183 °C melting point).

SN96.5Ag3Cu0.5 is probably a paste with too high melting point for reflowing leds. Standard Sn63Pb37 is cheap, good and beautiful:

I myself am very happy with “Mechanic” Sn63Pb37 solder paste.

Hope this is of help.

Sun, 03/29/2020 - 05:39; Sun, 03/29/2020 - 08:10

I have used some good paste in the beginning I had from an old work
Since 2 years I use the cheap leaded Chinese paste, it has its flaws not liking any pressure like in a syringe with small hole or repeatedly used over a stencil in small quantity, it gets harder fast

Its so cheap I don’t hesitate to likely have to trash half of it, just put used in an old 50g container
Always pushing small fresh amounts out of the syringe with no tip or needle

Anyways unless you use a stencil I would always apply solder wire and some Amtech flux, the Chinese Amtech copy is as good as the original
Then moving the emitter around to make sure it wets everywhere
Then give dome a light tap to push out uneven/too much solder

I made a video here, those LEDs were scrap that someone soldered with lead free solder too hot, problem is they did not soak themselves to the pads as the lead free was not at its melting point before mixing with leaded one
usually when flux added new LEDs pretty much jump to a center position as they wet then very good

generally I top off at about 200°C with solder wire, above 195°C it flows very good

thank you for posting the video, that is a great camera arrangement to show both views.

i’ve never used paste or lead-free solder so have a question about the process.

Usually when soldering i first apply flux to the surfaces, then heat and touch the solder wire to “tin” the items, or to make the joint to connect a part to a pad.

It appears that flux was added as the final step in the paste/floating process. Is this due to mixing leaded and lead-free solder, or is this typically the way it is done?

Thanks very much for your reply and help and for your video Lexel, it was really helpful! :+1:
I normally don’t use solder flux because the wire I have melts well, but for the reflows I guess I will have to get some.

About the paste, I’ve been reading and receiving some other suggestions about the quality of the paste, and as I am not soldering so frequently, I will probably try to get some better paste that can last for a while, so that I don’t waste many.

One thing I noticed was that your plate was slowly heating and the solder went melting evenly.
Seeing that, I and not sure if the process/method I did was the ideal one. I will have to try again to see how it works if I heat it slowly (with lower temperatures).

I am also takiung note of the solder composition to see what I can get locally. Some stores are pretty expensive in terms of shipping and many of them either don’t have the produts I am looking for, or ther are, eventually, fake!

Again, thank you very much for the help!

Thanks for noticing that too Barkuti!
I start to see that the composition will, indeed, have some troubles to me, so I may opt for other type of solder!

Thanks you too :+1:

……

A noob like me surelly has a lot to learn from you folks!!!

LoL I wrote SN96.5Ag3Cu0.5 is probably a “too hot” thermal paste… :P

Edited it, paste with too high melting point for reflowing leds sounds better. O:)

MascaratumB, I recommend you to get some standard “Mechanic” Sn63Pb37 solder paste besides any other stuff. True, tried and tested classic recipe, works pretty good imho. It is cheap, so you can practice plenty with the paste thing. Best if stored in some fridge, and take proper care of it.

Solder paste has a shelf life of like 6-12 months at 7°C, if you use not it often go ahead and buy cheap Chinese mechanic paste, if it gets worse buy new one for like 2 pounds

Rosin core flux tends to oxidase when it’s a longer time hot
The Amtech (fake) flux not, but adding it as final step likely gives the best result

As I wrote the LEds were used and full of lead free solder on the pads, so they behaved not like new LEDs which would likely soak themselves easily on the pads even without additional flux added
Basically adding flux always makes the result better, so you cant overdo it

Balling occurs most certainly with too fast heating. Soaking in 100°C for a minute or two will greatly reduce balling. Other cause is the expired, dried, or deactivated flux. You can reuse dried paste by adding thin flux to it. SAC305 requires a bit longer soaking than 63/37.
The other important thing is post reflow heating. Rather than 260°C I prefer to post reflow at 240°C for 2 minutes to make sure all solder granules diffused to each other completely. This is very important with gold plated pads to make sure all gold diffused as much as possible. In many cases, not enough post reflow soak time will cause solder joint failure in the long run. Gold - Tin and gold - Indium boundaries will create brittle interface which easily cracks. NEVER use Indium on gold plated solder pad. Indium will migrate and diffuse to gold and cause joint failure.
Although tricky to master, manual soldering with SAC305 will create superior thermal performance compared to 63/37. Pure Indium solder is better than SAC305 but has some limitations such as maximum running temp, pads compatibility, and ease of reflowing.

[Clemence]

Thanks for the flux tip Lexel.
I find it curious that fake Amtech NC-559 costs twice as much as generic brand NC-559. I wouldn’t expect them to perform any different thought the price difference suggests that maybe they are not the same. Have you tried the generic ones?