How to add a metal tab or other parts for passing power around the board?

Other Hardware Hardware Development
1

In a project I'm doing, I need to pass 5V USB power from left to right of my 4in (100mm) wide board. The geometry of the board can't be changed. The right side has a usb host that connects to a device. The left side has a USB port to receive power and acts as a device. If I just use PCB trace, as wide as I can make it, it still isn't good enough because the usb device on the right is a bit power hungry and the left side usb port could be connected to some rather weak usb ports that only outputs borderline 5V. So when current draw is "high", voltage drop across the PCB trace is "high" and causing some power issues to the right side usb device.

I've seen metal tabs on key fobs so I thought what if I add a metal tab or something acting as a wire so I can pass the voltage across with minimal resistance but still the part must be wave soldered or reflowed to the board to reduce cost of manual soldering?

Any advice? Thanks.

2

Not able to visualize the interconnection.

You can cut a strip of copper clad SS material and use it as a bus bar.

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But, a silicone insulated wire (multi strand) will do the job as well.

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3

Remember!!!! The 5 volt trace and the ground trace both carry the identical current. If you increase the capability of one, you need to do the same on the other.
The usual way to increase a traces current handling is to solder a tinned, non-insulated wire to the entire trace.
Paul

4

Good point! Thanks. I'll inspect my ground plane to see if I need more vias or not. OK just checked. I have an unbroken bottom ground plane where both left and right USB connectors are soldered to, from the bottom side thruhole pins.

5

Thanks LarryD. Do you have any experience with manufacturing? I suspect wires add cost because they require hand soldering. I'm looking for things that can be soldered to the board by machines such as wave soldering or reflowing.

6

Use a thicker trace ?

Can you flood fill one side of the PCB with 5V copper and the other with GND copper ?

7

Either method of soldering REQUIRES the addition to be fastened securely, mechanically, to the original copper trace.
Paul

8

I am using a 2-layer board so I can't do that. Maybe I should move to 4-layer board so I can reserve areas of one middle layer for this purpose. That will be major PCB revision I have to justify to my client though.

9

Yeah, I realized that now. Let me think about it. Between adding manual soldered wires and going to 4-layer board, either way is increasing cost. :thinking:

10

What if you ensure the copper power trace is unmasked so it can solder wave?

11

Can you have the PCB supplier increase the copper weight so it's thicker? Most of them can do this.

12

Wave solder only solders the under side of a circuit board. The power trace will be on top with all the signal traces.
Paul

13

I can do 2oz copper, which helps somewhat. Indeed my power trace is on the top so maybe not good for adding solder with wave solder.

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