"silver" solder versus normal solder - Page 1
Forum section: electronics / general

author: Simon
author_rank: Unknown
timestamp: April 05, 2010, 10:20:55 am
content: How better a conductor is "silver" solder than normal solder. by silver solder I'm refering to solder that has 2-5 % of silver in it, ie: can be used with ease on PCB's

author: DJPhil
author_rank: Frequent Contributor
timestamp: April 05, 2010, 03:07:17 pm
content: It's primarily intended for soldering components that have a bit of silver in their leads. The datasheets of most components will tell you how or if the leads are tinned.From Kester's website:QuoteIt has no other real appeal I'm aware of, though I'm sure there are some audiophile types who'd disagree. It's available in 60/40ish and lead free.

author: Simon
author_rank: Unknown
timestamp: April 05, 2010, 03:12:45 pm
content: I see,yea audiophiles tell me about them, anything gets them going, I still haven't forgotten the CD's promissing better reproduction of sound than any other !Well I odered some, when it arrives I'll measure and let you all know

author: jimmc
author_rank: Frequent Contributor
timestamp: April 05, 2010, 07:25:19 pm
content: I've used dielectric resonators at UHF which are effectively silver plated ceramic tubes, if you don' use silver loaded solder the plating dissolves in the solder and ruins the device.Jim

author: claylj
author_rank: Newbie
timestamp: April 05, 2010, 11:21:23 pm
content: Silver solder is not used instead of lead based solder because it is a better conductor. For soldering electronic components, silver solder is used as a "lead free" solder because it is less toxic then lead solders.Silver solder actually presents several problems including but not limited to increased heat to melt the solder thereby stressing electronic components as well as creating solder joints that are more brittle.I use lead based solder and just don't worry about the toxic effects. I am sure that it this doesn't kill me then something else most certainly will.Silver solders are also used where hardness and strength of the joint is desirable such as in the making of jewelry.

author: Simon
author_rank: Unknown
timestamp: April 06, 2010, 06:09:30 am
content: Quote from: claylj on April 05, 2010, 11:21:23 pmI think it has something to do with when you get fed up with your project and throw it in the bin, which maens the lead is going into the ground where your water supply potentially comes from. The project i need this for should be used on a car for as many years as possible so that's not my concern in this case

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 06, 2010, 06:46:37 pm
content: In my villageUsing properly the solder iron , its most important than the solder.15 years back , the boss of one shop that does electronics repairs , invited me to work in it .He gave me two wires and said " solder them together " .I did , then he tried to separate them with naked hands ... he did not make it , ans said " You are hired ".Just my 0,2 EUR

author: Simon
author_rank: Unknown
timestamp: April 06, 2010, 09:35:07 pm
content: I understand your point but I'm not trying to test the joint strength although that too is important, I'm delaing with high currents and not a lot of room to work in

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 06, 2010, 10:45:23 pm
content: I understand your point too , but the soldering its all about chemistry and timing.No matter the materials , even if gold was used , the average skills will destroy the final result.Anyway , I do not have any contest in mind , I just add my view on the table..regards.Now days robots do the job mostly , with the ultimate precision in all aspects ,that why we have hard times to desolder those tiny SMD s ...

author: Simon
author_rank: Unknown
timestamp: April 07, 2010, 06:53:43 am
content: Well basically what I've been asking is if silver solder has a lower resistance as I wish to load my PCB tracks carrying 20 amps with solder as the recomended current for the tracks without is 6 amps. I've been told that ordinary solder has a resistance 10 times higher than copper and with this increased resistance come reduced ability to dissipate heat so I just trying to not shoot my project before I've even begun

author: DJPhil
author_rank: Frequent Contributor
timestamp: April 07, 2010, 09:23:43 am
content: Quote from: Simon on April 07, 2010, 06:53:43 amI think I understand what you mean, it sounds like you're making a pcb yourself and adding solder to certain tracks to thicken them for a higher current load. I don't think the small silver content in silver solder will make a difference over any other type for this application. You're still going to be dealing with almost the sameintermetallic resistancegiven that the vast majority of the solder (>90%) is either tin or tin and lead. This resistance is very small, and is not likely to be a problem even at the currents you describe. I believe the inherently higher resistance of the solder and intermetallics actually generates more heat as opposed to reducing the trace's naked dissipationIt sounds as though you're following instructions from somewhere. I'm assuming they recommend adding solder to the traces to improve it's current carrying capacity primarily because you're multiplying the cross section of the conductor. This may work, but it seems unlikely to help to the degree you reqire (6A to 20A). You might consider using blank board with a thicker copper layer. If you haven't found it yet in your travels, here'sa good pcb trace width calculator for currentthat's good to 35A according to the comments. By playing with it a bit you can see how much you benefit by increasing the copper coating on the board from 1oz to 3oz (above which it can be difficult to find). A word of warning: if you're etching the board yourself you will have to use caution with thick copper boards because they will undercut their traces much more easily than thinner boards. This makes it much easier to lift thin traces by accident, for example, and reduces the effective cross section.If you have the time and materials to experiment, you may try soldering a wire along the trace as well to improve it's cross section. Keep in mind that anything you put over a wire or a trace will thermally insulate it somewhat and reduce it's ability to dissipate it's waste heat into the air. A more extreme example of this is in the calculator above, visible in the difference between the width requirement for an internal trace (buried between board layers) and an open air external trace.This all assumes that you can't simply directly wire your high current connections. In short, the solder composition is not likely to noticeably matter in comparison to the method you choose.I hope that helps some.P.S. Is this for an HHO power generator project? I had a hunch and had to ask

author: Simon
author_rank: Unknown
timestamp: April 07, 2010, 11:38:43 am
content: THis is for a dynamo regulator, I have decided to use direct wiring but as I need a SMD Resistor for current sensing a small amount of PCB is neccesary, i am now considering 2 oz copper for this seperate board, anything heavier seems to be unavailable, the idea of loading the trace with solder was my own, according to the supplier of the pcb software 0.15" tracks can carry 6 amps but i'm sure other sources will have a different opinion

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 07, 2010, 05:28:37 pm
content: Quote from: Simon on April 07, 2010, 11:38:43 amUsing wiring its the best way .About the Resistor .. I have an idea , I do not now if it will work for you .You can use double sided PCB , as one layer ... Just one small square piece, as base for the resistor.With small holes from side to side and metallic bridges soldered both ways , could possibly work.

author: Simon
author_rank: Unknown
timestamp: April 07, 2010, 05:41:50 pm
content: are you saying use the copper track as a resistor ?, I have to use a proper resistor that has a 1% tollerance so that it is accurate over temperature range, as we are discussing this is about carrying high current and things will get warm so it is wise to use a proper resistor

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 07, 2010, 05:52:28 pm
content: No ..... I am saying to create one pad for it .... using double sided PCB .And connect or solder wires , at the input and output of this small PCB .

author: Simon
author_rank: Unknown
timestamp: April 07, 2010, 06:00:28 pm
content: oh, well I'm managing it fine with a single sided board and as the resistor now goes on it's own little board i will up the copper weight to 2 oz (heaviest I can buy in the UK)

author: Simon
author_rank: Unknown
timestamp: April 07, 2010, 08:06:19 pm
content: well I got a 5 m length of solder today and took some resistance measurements of the silver and normal: same resistance so point made and taken

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: April 08, 2010, 11:11:30 pm
content: Nop ... it does not work that way .All measurements about resistance , are taken at 100 meters .In my villageonly the people who repairs jewelry , uses the silver solder.If you finish your project , post a photo , it would be interesting to see your doings .Regards

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 09, 2010, 12:32:32 am
content: I've always used the 2% silver stuff - I find it's just plain nicer to use - lower melting point, flows & wets better . Didn't hurt that I scored 10 rolls cheap on ebay a while ago...2% silver also makes lead-free rather less painful.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: May 09, 2010, 10:29:57 am
content: Quote from: mikeselectricstuff on May 09, 2010, 12:32:32 amWell comrade ( electrician & ebayer ), keep your eyes and your lungs , away from the fumes of it,and you will be fine ..The point are that is impossible to do so.

author: mikeselectricstuff
author_rank: Super Contributor
timestamp: May 09, 2010, 02:41:08 pm
content: I've been using leaded solder daily for about 35 years with no obvious effects. I find leadfree flux much worse than leaded & when I need to do a lot lf LF is the only time I feel the need to use a fan to blow he smoke away. LF also eats the plating off tips way faster.

author: Kiriakos-GR
author_rank: Super Contributor
timestamp: May 09, 2010, 04:45:22 pm
content: Well I do not do lots of soldering this days, but its recommended to the ones that does,to add an extra ventilation system in the room.The little fan its an good idea .