Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [copper]

The Element Cu known for its electrical and thermal conductivity, both of which are exploited in EE. THis material is typically what is used in PCB's for the traces and also modern CMOS processes have Cu layers in them due to it's superior conductivity. You also see copper in heat sinks to carry heat away from components.

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Why are copper cables round?

Why are cables only made of round shapes? What is the advantage of it? Why aren't there triangular or quadrilateral or pentagon shapes of cables?
Keno
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How do I determine the area of copper needed on a PCB to provide adequate heatsinking for a power SMD MOSFET?

I am planning to use the IRFR5305PBF Power MOSFET (http://www.irf.com/product-info/datasheets/data/irfr5305pbf.pdf) to switch on a load. I have determined that I need an external heatsink with Rthsa < 29 C/W. How would I go about determining the…
dla59
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In PCBs, why is copper etched away instead of added?

I know that in virtually every case, PCBs start as a substrate with a layer of copper laminated on top, which is then etched away, leaving the traces. But why are the traces not added on an empty substrate instead? I am well aware that the etching…
David Cian
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Why does water short out PCBs? (i.e. Why doesn't electricity follow the path of least resistance?)

If copper is more conductive than water (at any reasonable PH), submerging copper electronic circuits in should have no effect, as the electricity should continue to follow the path of least resistance (the highly conductive copper PCB paths, for…
Asker
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Why is the PCB part number traditionally on a copper layer?

I'm an experienced board designer, having designed 100+ boards over the past decade, and I have yet to hear a good answer for why the PCB part number is traditionally on an external copper layer, and the PCBA part number is on a silkscreen layer. To…
Fix It Until It's Broken
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How do I calculate the temperature rise in a copper conductor?

If I pass a current through a copper conductor, how can I calculate how hot the conductor will get? For example, if I have a 7.2kW load powered by 240VAC, the current will be 30A. If I transmit this power to the load via a \$2.5mm^2\$ copper…
BG100
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Why are copper tracks orange-gold?

I have in front of me a raw PCB. The surface mostly has three colors: dark green, orange-gold and white. As I understand, the green is resist, the orange-gold is copper, and the white just the silk screen. I find it surprising the color of the PCB's…
Randomblue
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Why is there copper on the side of this package?

I'm searching around digi-key when I noticed one of the MEMS oscillators has these copper pieces on the edge of the package: I'm not talking about the pads, I'm just talking about those little copper pieces on the side of the package. I've seen…
Funkyguy
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Is it better to have a poor top layer copper pour or no copper at all?

For a few small 2 layers boards I'm doing, I'm using the top layer for parts and signals and a ground pour on the bottom layer with no or very short traces, based on comments and answers to my previous question Since the top layer becomes too…
mux
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multi-layer board copper pour

I have a 6-layer board where the internal 4 planes are +15,GND,VCC,-15. I was wondering if there was any advantage to doing a copper pour on the top and bottom layers? I would probably leave them floating as I don't want to use micro-vias to say…
Ross W
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Electricity not conducted by copper wire

Im am quite stunned as to what might be wrong. electronics beginner I bought today some copper wire, 20SWG /0.9MM from maplin (UK), for a project I am working on. There is no power going through the wire. I got positive and negative of 9V battery…
Giannis
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Does oxidized copper conduct electricity?

When the surface of copper turns that greenish oxidized color, does the resistance to current flow increase or isn't affected? For instance if the point of contact is secure and clean but bare visible copper wire has oxidized will it still conduct…
ohmmy
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Reason not to use aluminium wires, other than higher resistance

So aluminium is 3.3 times lighter than copper (8.96 vs 2.70 g/cm3). And its resistance is only 55% bigger. So in weight/resistance ratio it is actually better than copper. Also it is cheaper. Why aluminium is not a primary choice in cables? Does it…
Ri Di
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Using a PCB trace as a heater / Hilbert Curves

I'm considering making a PCB to use as a heater for a 3d printer bed. This has been common practice for ~10 years (https://www.thingiverse.com/thing:3919). I was playing around with KiCad and python, and made a PCB trace that could (in theory) be…
Raph
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PCB Design Considerations - Copper Pouring

So after a very long effort, I think I've finally come towards the end of my PCB board design. It's a two layer board with no ground or VCC plains (Re-routing is not an option) as I can't go though the grief process again. My question is should I…
Peter H
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