The positioning and size of Vias - Page 1
Forum section: electronics / beginners

author: Blix
author_rank: Newbie
timestamp: August 08, 2019, 01:12:15 pm
content: Hi, I am going to create a PCB to connect lithium-ion batteries and the parallel groups can reach current spikes up to 60 Amps, now I am wondering how I should place the vias the best way possible (2oz PCB and 18um Via plating)? As even as possible or right behind the connection point with the battery, or where the batteries are connected in series... I really don`t know and would appreciate the help a lot.Thank you in advance, JonasEdit: I have used Saturn PCB, still don't know which diameter is the best and where to place the vias (small 0,3mm vias seem the best but if I want, could I fill them with solder or are they too small?)... I have an area of 30mm width x 70mm length and 30mm width x 140mm length.I can post pictures if required.

author: schratterulrich
author_rank: Regular Contributor
timestamp: August 08, 2019, 01:45:39 pm
content: Hi,you could make some crude simulations with this tool:https://leiterplatte.jimdo.com/thermal-pcb-sim/

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: August 09, 2019, 05:23:56 am
content: With 60 amps 0.3mm via's will be just blown off the pcb.For power pcb's I tend to use much bigger via's.But the main trick is to avoid them if at all possible.I designed a power supply pcb and managed to get rid of most of the via's and used components to pass from layer to another.If you use component holes they are filled with a component leg and solder and this increases current capability massively.

author: Blix
author_rank: Newbie
timestamp: August 13, 2019, 04:48:07 pm
content: Sadly this program was kind of weird, stacking Vias on top of each other(without noticing(this changed the results somehow)) and placing them all 1 by 1 is very exhausting, also I got different results for the same setup... because it crashed and I forgot to save.Which diameter do I need? I thought it depends more on the plating thickness and with enough amount you can compensate it?!It should end up like this 2oz and 2 layers like I already said:http://prntscr.com/os76s4

author: schratterulrich
author_rank: Regular Contributor
timestamp: August 13, 2019, 06:08:12 pm
content: I am right in assuming that you only change the layer so that you can use the bottom copper side in parallel with the top side to get a greater current carrying capacity?If you don't need to change the layer you could use pressfit connectors on which you can screw a copper busbar to bypass the pcb.We have used this method for a 300 A step down converter.

author: Blix
author_rank: Newbie
timestamp: August 15, 2019, 10:44:10 am
content: Sadly I don`t have that much space... Can I somehow simulate the nickel strips in your program to get better results so, use a third layer, which is directly connected to one without the fr-4 in between?Can they really burn if I have them parallel?

author: JustMeHere
author_rank: Frequent Contributor
timestamp: August 15, 2019, 11:17:23 pm
content: Are solder covered traces an option? Dave did a video on them. They are going to be much thicker than a trace on an additional layer.

author: schratterulrich
author_rank: Regular Contributor
timestamp: August 18, 2019, 11:01:37 am
content: Quote from: Blix on August 15, 2019, 10:44:10 amWhat do you mean with nickel strips? But no you can't use my simulation tool for this purpose at the moment...PCB shop Häusermann (now KSG) integrates copper profiles in FR-4. This is an interesting technology...https://www.fed.de/fileadmin/user_upload/RGH_08.11._Belastbarkeit_von_Leiterbahnen_auf_und_in_Leiterplatten.pdf