Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [pcb-design]

About designing the boards which carry the components of an electronic circuit, including placement of parts and routing of traces. For questions about getting them built instead use PCB-fabrication. If your question is specific to a certain CAD tool, say which tool and version you are using.

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4161 questions
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Why route air gaps for voltage isolation on PCBs?

Learning about PCB design for power supplies, I frequently see boards with routed gaps to separate low and high voltage sections of the layout. Why go to the trouble of routing an air gap when etching the copper away should create the same level of…
JYelton
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Board Design for High Impact Environments

I'm looking to design a PCB that can reliably survive constant impact. The board will be rigidly mounted to an enclosure that will protect the board from actually hitting anything. The nature of the impact would be similar to a bowling ball, or a…
W5VO
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Removal of unused pads?

I was reviewing a design earlier, and I noticed something interesting. The designer had removed unused pads on the chip. I have never seen this done before. Is this something that is good practice? Is it even okay?
Reid
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What are 13 oz copper PCBs used for?

Reference https://www.pcbway.com/orderonline.aspx. This is from a Chinese PCB fab. You can see that they offer copper traces up to 13 oz. That seems thick, and according to my KiCad calculator, it's 0.45 mm thickness of copper carrying 23 A/mm…
Paul Uszak
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What should I put on my almost empty PCB layer?

I have a 3"x3" 4-layer PCB where my stack up is: Signal 1 Ground 5v Power Signal 2 My Signal 1 layer has a few traces that carry 500 MHz on them, some high resolution ADCs, and microcontroller/usb circuitry. I have SMA connectors that are carrying…
Kellenjb
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Is there a standard or "safe" distance between PCB components?

I am (still) designing my first PCB and, according to prices listed on websites, the smaller the board the cheaper it is. That is, batchpcb charges per square inch. goldphoenix will print "as many as they can" on an 100 square inch board. Smaller is…
rascher
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Naming (C1, C2, R1, R2...) components on PCB

I want to label all the components on my board C1, C2, R1, R2, IC1, IC2, etc. I am trying to think about the best naming convention for everything. On one hand, I want to group together all the components by the IC or function that they are…
Alexis K
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Techniques for placing components on PCB's

I know that placing components is quite an art rather than following some set of rules to get the job done, but I am looking for some references about the topic. I already saw this tutorial and it is pretty much useful, but one resource is never…
hkassir72
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How to indicate breakaway tabs in PCB design?

I'm designing two boards that'll always be used together. I'd like to place them both on a panel and break them apart after manufacturing. I found a document on PCB CAD Design Guidelines that explains breakaway tabs and lists guidelines for their…
Atav32
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how should I label components changing between PCB versions?

I have a current version of my PCB, and I'll make a new one where I will delete some resistors here and add some more there. What's the common rule for numbering? Should I re-use the numbers of deleted resistors for the new ones, should I re-number…
nraynaud
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When to change a PCB number and when to change the Revision?

I want to know if there are any guidelines about when it's supposed to change the PCB's number (1.0 or 2.0) or it's revision (Rev A, Rev B).
mFeinstein
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What is the purpose of the square vias with no solder mask on this board?

This board from an electronic combination lock contains a curious mix of two types of vias: Small round ones with green solder mask over the top. Larger square ones without green solder mask over the top. What is the purpose of the square…
Cybergibbons
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Current sense resistor using PCB tracks

I want to save up in buying a sense resistor and just use the PCB tracks. I need to sense up to 2.5A and I wanted to design the trace so it has a 0.1 ohm resistance. Is this a good approach? Also, can anybody share the calculations about how to…
RWeiser
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What does a race condition mean?

I'm a new electrical engineer so bear with me. I hear some of the other engineers I work with talk about a race condition that exists in one of our circuits. What does that mean?
Stihl Alighve
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Why are there slots around the transformers in this PCB?

I took apart an office printer a while back and this is a photo of one of the power delivery PCBs: (Please note I have removed some components from the PCB). What is the reason for the slots in the PCB around the transformers?
Darth Vader
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