EEVblog #317 - PCB Tinning Myth Busting

What people said

Recommends Daniel · 2014-07 · Electrical Engineering Stack Exchange · on “PCB Track Width for High Current”

What matters is your total copper cross section and the trace length. Both of these numbers contribute to the total resistance of the trace (if that's important) and the resistance per unit length which contributes to temperature rise (if that's important). If it's a DC current, there are no issues that I can see. For higher frequencies, you might be generating magnetic noise if your return trace is farther away. (Magnetic noise is proportional to current x current path loop area) Here is a website that can help you calculate the total amount of copper based on the target temperature rise: [LINK] Edit: Another way to go on the cheap side is investigated by Dave Jones and Mike: EEVblog #317 -

Recommends bigjosh · 2015-10 · Electrical Engineering Stack Exchange · on “Adding solder to PCB traces to increase current flow”

It does work, but it is hard to model reliably and you should use empirical testing to see how well it works for your boards, process, environment, solder. There can be a lot of variance from little things that are hard to predict and measure. For example, are you soldering by hand or running though a wave machine? The resulting solder profile cross sectional area can be off by 50% or more depending on which process you use- and neither of them resemble a half circle :) . EEVBlog feauted a video where he tests exactly this question... EEVblog #317 - PCB Tinning Myth Busting [this video] And a similar video... Does putting solder on high current PCB tracks help? [LINK]

Recommends Pentium100 · 2015-11 · Electrical Engineering Stack Exchange · on “What kind of tracks is this?”

Yes, the solder is there to increase the thickness and lower the resistance/increase the current capacity of the track. Dave from EEVBlog has an episode [this video] on this topic. He found that you get 15% - 50% decrease in the resistance of the trace depending on the thickness of the solder coating.

Recommends Wesley Lee · 2017-01 · Electrical Engineering Stack Exchange · on “Why break a PCB trace plane into multiple parallel traces?”

Something like this [LINK] ? Watch this [this video] video for more info. If they are all connected anyway, you can add wires do increase current carrying capacity.

Recommends Whiskeyjack · 2019-05 · Electrical Engineering Stack Exchange · on “Why are these traces shaped in such way?”

What are those parallel soldered-traces on the PCB traces? When you are designing a PCB with high current traces, you want to keep the trace resistance as low as possible. You can do this by multiple methods: (a) Use a thicker copper layer eg 70 microns instead of 35 microns. (b) Use bus bars to carry the current instead the PCB traces. These bars are copper metal that can be soldered on a PCB. [LINK] (c) Use a wider trace - not possible in all cases due to space constraints. (d) put additional solder on the traces which will reduce the resistance to certain extent. The benefit is 25 - 50 % reduction in resistance as per this video. [this video] Again, it will depend upon the copper thickness and

Recommends Gabriel Godoi · 2023-03 · Electrical Engineering Stack Exchange · on “How do high current paths work in PCB design?”

My reference is Mean Well. This technique is used in most of their power supply. I would like to share this video too [this video]

Cites Armandas · 2015-04 · Electrical Engineering Stack Exchange · on “Designing a high-power PCB”

I've worked on PCB-based bus bars before (over 1kW total power) and we were able to get by with just a PCB, no external bus bars. Here are some of the things to consider: Copper thickness: use 2oz / 70um (or greater) copper for your PCB. Add solder islands to further increase current carrying capability. [ 1 [LINK] ] [ 2 [this video] ] Calculate the temperature rise and add forced cooling if necessary. Here's a quick example calculation using the Saturn PCB Toolkit:

Cites P. Koch · 2017-08 · Electrical Engineering Stack Exchange · on “How to carry high current on PCB”

With tinning you can decrease the resistance of the the path by 20% to 70% 1 [this video] depending on how thick it's soldered on. If you need just a tad more it seems reasonable. Soldering a copper wire will bring big gains as a standard PCB is 35µm. In comparison with a 1mm and a 2mm copper wire: A = h * w = 35µm * 1mm = 35 000 µm² A = h * w = 35µm * 7mm = 245 000 µm² ~1/7 resistance per length A = r² * pi = (1mm/2)² * pi = 785 398 µm² ~1/23 resistance per length A = r² * pi = (2mm/2)² * pi = 3 142 000 µm² ~1/90 resistance per length [1] EEVBLOG Tinning PCB [this video]

Cites Harry Svensson · 2018-05 · Electrical Engineering Stack Exchange · on “How to increase veroboard's current capacity?”

This [this video] might be applicable to your problem, it's a video by Dave Jones who compares different amount of tinning. - You can easily make a tinned path on the PCB, though you will waste an insane amount of tin that way. - Why can't you do what Chris Stratton/Laptop2d suggests? So far I haven't seen any proper reasoning showing why their solutions are not okay.

Cites Spehro 'speff' Pefhany · 2021-04 · Electrical Engineering Stack Exchange · on “How to add solder traces on PCB surface”

They removed the solder mask and the board was wave soldered. Dave Jones [this video] found it reduces the resistance of 1oz copper by 50%, so the equivalent of 2oz copper in resistance (and higher in thermal capacity, which might come into play for surge currents). His methods were good. He depended on looking up the copper thickness. Mike of mikeselectricstuff [LINK] found a 30% reduction. His methods were a bit less good than Dave's but good enough (verified when Dave removed the solder and it was verified that the thin remaining layer did not significantly affect the resistance). I did not see him attempt to find the thickness of the copper- he assumed it was 1oz. If it was actually 2oz then