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.

Further reading:

5458 questions
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Decoupling caps, PCB layout

I guess I've been somewhat ignorant when it comes to the finer details of pcb layout. Lately I've read a couple of books that try their best to lead me on the straight and narrow. Here is a couple of examples of a recent board of mine, and I have…
morten
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Should chassis ground be attached to digital ground?

I'm working on a PCB that has shielded RJ45 (ethernet), RS232, and USB connectors, and is powered by a 12V AC/DC brick power adapter (I do the 5V and 3.3V step down on board). The entire design is enclosed in a metal chassis. The shields of the I/O…
cdwilson
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Why does Samsung include useless capacitors?

I do component-level repair of tablet mainboards, and I have seen this puzzling situation on two different models of Samsung tablet mainboards so far (SM-T210, SM-T818A). There are ceramic chip capacitors on the PCB that are clearly connected to the…
Crash Gordon
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Best One-Off DIY PCB Creation Technique

I have finally built up a lab to design electronics in. I have quite a few designs I would like to test. I have tried the printer toner/iron technique a few times but have found that I cannot create small pitch sizes as they tear off while removing…
ThaKidd KG5ORD
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Looking for circuit board material that can be dissolved

We are working on a product where the entire device needs to be dissolved in liquid after the device has operated and the device is no longer usable or desired. This is a down-hole application. The device body is either aluminum or magnesium. There…
Dwayne Reid
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How to connect USB Connector shield?

How should I route USB Connector shield on PCB? Should it be connected to GND plane right where USB is placed, or should the shield be isolated from GND, or should it be connected to ground through ESD protection chip, high resistance resistor or…
Andrzej H
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How do I identify SMD components? (or how do I identify any component)

How do I identify the markings on an SMT component and match it up with a part number so I can be a good designer and actually look at a datasheet (and read the whole thing)? Or identify a part to replace an unknown part on a PCB?
Voltage Spike
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What is Copper Thieving and why use it?

On many boards I've seen, there are little copper dots used for the purpose of "Copper Thieving". They're small round copper dots connected to nothing and arranged in an array. Supposedly they're for balancing the copper on the boards to improve…
Gustavo Litovsky
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What do the PCB markings mean?

On a printed circuit board, I see lots of tiny letters and numbers. Is there some kind of standard that dictates what letter indicates what type of component?
kinokijuf
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Competing PCB Crystal layout recommendations

This is related to this question: How's my crystal oscillator layout? I'm trying to layout a 12MHz crystal for a micro controller. I've been reading through several recommendations specifically for crystals as well as for high frequency design. For…
helloworld922
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What is the usage of Zero Ohm & MiliOhm Resistor?

I am new to PCB design and I noticed that some schematics use 0Ω or 100mΩ resistors. What is their purpose and why do we need to use them in our PCB design? Normally if we wish to probe how much current the load is taking, we put a jumper pin across…
Dennis
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Standard PCB trace widths?

Is there a standard for the sizes of PCB traces? That is are some 25 mil and others 10 mil or is can you choose your own? I plan to run 400mA through some thicker traces, but less than 30mA for all other traces. About what size would I need?
Thomas O
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How to go from a development board to a production board?

Ok, I am a software guy and new to electronics. My product needs a small computer and currently I have developed everything on development boards like raspberry pi and such. As the development board does not have all the hardware that I need, I have…
iCode
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The best stack-up possible with a four-layer PCB?

I'm designing a 4 layer PCB and I know that the standard stack-up is Signals GND VCC Signals (GND and VCC can be switched depending on the layer with more signals) The problem is, I don't really want to connect all ground pins through vias, there…
mux
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Why are vias placed this way on a PCB?

I used to check complex commercial PCBs specially those of graphics cards to see how professional PCB designers do their layout and learn from their techniques. When I checked the card shown below I noticed two things regarding the placement of…
Abdella
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