I have this IC here wherein pin 6 will take around 3A of current and a quick use of some online calculator says that the trace width for 3A on a 1oz. cu is 140mil (70mil for 2oz). On pin six it is impossible for me to place a 140 mil trace as it would hit the pads beside it. Even if we use a 2oz cu it would still have to taper in, as shown in the picture below.

enter image description here

Is what I did okay? Would the traces handle the current? I have noticed it to be also the case for BGA PMICs rated for high amps wherein I could not place a enough copper near where pads and will have to taper out.

  • 2
    \$\begingroup\$ Length matters, not just width. Look at typical designs and you will see such neckdowns, you might consider using a pour instead of a trace. Many power and RF IC's have relevant design guidance in the data sheet or another document; often there's a reference design with actual PCB artwork; in complex cases you may be able to import this as a graphic layer and draw over it. \$\endgroup\$ Commented Aug 30, 2020 at 17:26
  • \$\begingroup\$ @ChrisStratton The datasheet of the IC seems to weirdly use a thinner trace than the pads, can you check it out if im missing something \$\endgroup\$
    – Jake quin
    Commented Aug 30, 2020 at 17:38
  • \$\begingroup\$ Height (thickness) matters too; usually fine pitch components require 0.5oz copper due to etch, but plating up to 1oz or 2oz after etch can help double or quadruple the conductivity of the traces. Then there is this extreme: electronics.stackexchange.com/questions/518521/… \$\endgroup\$
    – MarkU
    Commented Aug 30, 2020 at 22:13
  • \$\begingroup\$ @MarkU I would love to see an actual application for this Thats some very very very thick traces \$\endgroup\$
    – Jake quin
    Commented Aug 31, 2020 at 14:36
  • \$\begingroup\$ @MarkU wont the trace at the pad be a weak point? since its smaller ? \$\endgroup\$
    – Jake quin
    Commented Aug 31, 2020 at 15:48

1 Answer 1


One technique used for high current traces is to not cover them with solder mask and as post processing add some solder on top of the trace. Like so:

enter image description here


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