PCB is the acronym to Printed Circuit Board. A PCB is a carrier for the circuit's components and their electrical connections.

learn more… | top users | synonyms (2)

0
votes
0answers
54 views

Is there any way to inspect small holes (in micron scale) inside a PCB non-destructively?

I have PCBs with two layers of copper at top and bottom. PCBs with low quality have holes between top layer copper and epoxy. The holes are in near circle shape with 20 - 70 micrometres of diameter ...
0
votes
0answers
52 views

Professional PCB design

First I want know different solder mask(Paint or sheet) and photoresist(Paint or sheet)? Photoresist(Paint or sheet) use for etching and solder mask use for show pads on PCB. is it so? If I use ...
0
votes
1answer
20 views

KiCad net names

I'm trying to assign footprint's pad to a net in a schematic but for some reason nets in Eeschema aren't generated from components' pin names (EN, VIN etc.), but are always auto-generated ...
-3
votes
0answers
68 views

Where is the audio data stored in the circuit? [on hold]

I have this MP3 player sort of a thing where you can play songs by pressing a button. I want to know where the audio data is stored in this circuit and how it can be changed by a PC. The circular ...
2
votes
2answers
34 views

How to connect board outlines - EAGLE

I've designed a particular shape PCB with 2 round corners using arc tools. Since I needed precise dimensions I've set them when I was drawing PCB outline. The problem is that PCB outline now isn't ...
0
votes
2answers
100 views

How to measure resistance of resistor in PCB? [on hold]

I have a resistor 1MOhm soldered in a PCB that looks like that And the schematic is looking like that: When I measure the resistance by touching the a multimeter on the two ends of the resistor the ...
1
vote
0answers
29 views

Altium - Component outline

The default outline selection of a component is rectangular: Is there a way to set it to follow the real outline?: I'd like to do it to be able to place components in the middle without adding a ...
0
votes
0answers
30 views

Test a ssd1322 based display

What's up folks? I have a problem with one OLED display based on the ssd1322 controller. The DD-25664GE-1A is a 5.5 inches display for which I made a custom PCB connecting the controller to a ...
2
votes
2answers
75 views

Best way to fix burnt PCB trace?

So I accidentally burnt a PCB trace and I'm trying to fix it with a wire + some solder. The PCB trace clearly connects two metal pins. My question is, would it be better to completely bypass the ...
1
vote
2answers
77 views

Does the polygon pours has to be either ground or supply voltage? [duplicate]

I was wondering if it is possible to have polygon pours but not connected to anything . Will that effect the circuit in some manner ? Because for the pcb I'm designing , if I used the polygon pours ...
0
votes
3answers
75 views

10A/115V Jumper

What component would you use for a 10A/115V jumper header (I need the user to be able to choose among a few power settings)? I have relatively small space on the PCB and I am also trying to be ...
2
votes
1answer
59 views

Via's without annular ring on internal layers

My PCB layout package (Altium) has an option to define the full stack of a via so one may have different sized annular rings on different layers. I was wondering if it is considered "manufacturable" ...
0
votes
2answers
221 views

4 Digit 7 segment display LED missing one light (on all four digits) [closed]

Hi I ordered online a voltage meter and got this tiny cute little fast refreshing pretty darn precise reliable meter. HOWEVER I am missing on all four digits the left lower vertical light piece. What ...
0
votes
1answer
80 views

Too noisy ground

Here is noise on the ground of my pcb taken from two point: Yellow line is "Point 2". Blue line is "Point 1". Here is that points on pcb: There is Altium filled ground polygon. It seems that it ...
6
votes
3answers
266 views

How to connect these pads

I have trouble connecting a THT HDMI Connector to a pcb: The HDMI Connector I'm talking about is this. The holes are too close to go in between them: (The blue line is 0.15mm thick) Is this ...
2
votes
1answer
59 views

Fiducial marks on board vs panel

Do I need fiducial marks on both my board and my panel for automated assembly? And how many fiducial marks do I need per board for a round 80 mm diameter board?
5
votes
3answers
100 views

For a 4 layers PCB (with ground plane), covering with ground polygon on Layer 1&4 necessary?

For a single or double layered PCB board, usually I will cover all the empty spaces in the layout with Ground. This is the 1st time I am designing a 4 layer PCB layout. Layer 1: top signal (high ...
0
votes
1answer
79 views

Show Pad Nets Seemingly Not Working in Altium

For some reason, the PCB is not showing net names on the pads I have all connections (rats nests) visible I have checked the "Show Pad Nets" and "Show Via Nets" under the View Configurations > View ...
0
votes
2answers
75 views

How an electrical component behave after being exposed to excessive current/voltage? [closed]

I wan't to know more about how to recognize a damaged component due to excessive impulse or constant current exposure. Particularly resistors, ceramic/electrolyte capacitors, protective diodes, ...
0
votes
1answer
66 views

Hydrogen Peroxide for PCB Etching

I found 500 mL of hydrogen peroxide. It says 12% and food grade. Normally, before, what I found was 3% only, and there wasn't any note like food grade at all. Is this suitable while etching PCB? Is ...
5
votes
2answers
824 views

Why are PCB-mount AC DC converters so expensive? [closed]

In a thrown-together prototype, I used a few wall warts to get the various voltages I needed. Now, I'm trying to build a cleaner version with a single plug and put it all on a PCB to eliminate my rats ...
0
votes
1answer
68 views

Cleaning a computer [closed]

I have a (self-built) desktop computer, that was kept and used for a few days in a house that was infested with mold. I've been sensitized to mold, and the computer is contaminated enough to cause ...
3
votes
2answers
220 views

Problem in redesigning one EAGLE schematic

In the past I designed a PCB on EAGLE, and now I want to make some changes on it, but it's impossible. You can see it in the picture below: In the old schematic part I can move and delete nets, but ...
0
votes
1answer
61 views

Advice on precision CNC milling machines for PCB prototyping

I am an EE professor at an University and I was asked to provide a solution (machine) for PCB prototyping. Specs are milling down to about 8 mil (0.2032 mm) trace thickness, 8 mil trace clearance, 8 ...
0
votes
0answers
50 views

What happens if I swap the power supplies on am OP-AMP?

I designed a simple audio amplifier - for learning purpose. After getting PCBs made, I realized some critical errors and stupidities in my design. One of the mistakes I made is that +12V and -12V ...
1
vote
1answer
78 views

I2C PCB Layout Considerations

I wanted to ask, what general layout guidelines and/or routing concerns exist for I2C in a PCB design? Edit - Consider a 31mil thick, 4Layer PCB with stack up: L1 = signal - 0.5oz + 1oz plating L2 ...
0
votes
1answer
59 views

Identifying an LCD screen

I have opened the PCB of an old device in order to use its LCD screen, the problem is that the pcb indicates no model ID or whatsoever. I was wondering if someone could give me a hint here of whether ...
-3
votes
1answer
48 views

How can we identify particular signal is a high speed signals? [closed]

How can we identify or determine a signal is a high speed signal? Is there any way to find out or calculation mechanism available to find HSS? (it may calculated from Frequency ranges or special ...
1
vote
1answer
79 views

Sodium metasilicate pentahydrate and Photoresist Universal Developer Crystals same chemical?

I'm thinking about using the photo method for etching PCBs so I need a developer for the positive photo resist. There is this sodium metasilicate based universal developer that people online seem to ...
3
votes
1answer
83 views

PCB Layout and Trace Widths for Buck Converter

I am doing a PCB layout for a simple 12V DC to 5VDC buck converter. The rated output is 3A continuous 5A peak. Here are links to the schematic and first go at the pcb layout. I realize the traces are ...
0
votes
1answer
36 views

Pads for wire connection in KiCad

It's my first time making a PCB. I've got pretty far with all the YouTube tutorials however I'm now stuck on what to do next. My PCB is going to be made up of WS2812B chips (4 pin LEDs comprising VDD, ...
1
vote
1answer
47 views

How do I make a through-hole via? [duplicate]

Using a simple PCB with copper on both sides but naturally in between, is it feasible for a hobbyist to make through-hole vias like this: It seems there is copper in the via itself, isn't there? ...
0
votes
1answer
41 views

Installing a USB-A Port on D-Link DIR-300NRU B7 with Ralink RT5350F Chipset [closed]

I am writing to enquire about the installation of a USB-A port into the existing but soldered pins on DIR-300NRU B7. The board is given below: The USB pins are located on the bottom right. The ...
0
votes
1answer
67 views

From what organization or document are connector symbols like this referenced?

So in this picture I am asking about the representation of the Plug and Jack. Where does the idea that the plug is rounded on the back side come from? I am trying to put together a best practices ...
0
votes
0answers
24 views

How to change layer order in EAGLE

I want to ask how I can change layer order in EAGLE. For ex. I have 4 layer where layer 2 is vcc and layer 3 is gnd, I want to change layer 2 to 3 and layer 3 to 2, but EAGLE don't allow me change ...
0
votes
1answer
82 views

PCB Board drawing high current when little bit of liquid gets into it. How to debug the board?

I am new to circuit design and debugging them. I have recently helped in building a PCB with certain kind of circuits on it which includes opamp, boost converter, microcontroller and accelerometer. ...
0
votes
1answer
70 views

quality checks on PCBs

I am trying to implement a quality check for our PCBs. We have a pick and place machine and a vapour solder machine. But, unfortunately, even after optical inspection and such, we end up with a lot of ...
0
votes
0answers
34 views

Need advice regarding FPC design

Good day to all. I'm working on a project that uses an off-the-shelf radio module that I have to interface with. This module uses Molex FPC connectors 502250-4120 which are 41 pin, 0.3mm lead pitch ...
0
votes
0answers
26 views

Eagle swap layers

I would like to swap two layers in the my 4 layer PCB. For example currently the ground plane is the Bottom layer, is there a way to take all the signals in layer 2 and move them to the Bottom layer ...
0
votes
1answer
53 views

Altium: Error in importing changes to PCB

When I first imported everything from schematic to a new PCB project, it all went smoothly. But note that I have duplicate schematic sheets that have the exact same circuit, net, I/Os, etc. I tried ...
1
vote
2answers
88 views

newbie confused with PCB designing a TO3 transistor

hi guys im a first year electronics student with no background on PCB designing or anything and im confused on how to connect this collectors of a to3 transistor into the capacitor cause the ...
0
votes
2answers
51 views

Layout of doubled SW pin on buck converter IC

I'm working on a PCB for the MP2617. That IC integrates a buck converter and has two physical SW pins sandwiching the VIN pin, as shown in my tentative layout below. No other pins on the IC are ...
3
votes
0answers
98 views

How to remove copper from inner planes on cut PCB

I'm in the middle of designing a specialized communications device that uses an off-the-shelf radio module. This radio module is larger than desired and the PCB area that is not needed is easily cut ...
1
vote
3answers
89 views

PCB layout of buck converter: capacitor placement

I'm designing a PCB for an IC that includes a DC/DC buck converter (MP2617). This is my first PCB, so I've been using the following resources for the layout: 1 and 2 (PDF files, the first one is a ...
3
votes
1answer
46 views

Altium: Assigning testpoints

So I'm working on the PCB layout to assign testpoints to pads. I've created vias to connect to the pads as testpoints, double clicked on the via, checked the 'Assembly Top/Bottom' I then went to ...
3
votes
2answers
421 views

Place a component on specific height above the PCB

what I have as a big issue is the following layout with two connectors. The problem is that the connector K201 (in right bottom) is very close to the frame. This frame will the attached to a device so ...
3
votes
2answers
108 views

What's the point of this thick trace in my PCB?

I'm looking at a trace that goes from Pad 2 of a component to pin 22 of the QFN. What's the point of the thick trace at the beginning if it ends up being as small the pin where it is run?
0
votes
1answer
60 views

Unknown LCD display circuit design

I opened up the case of an old toy to take a look at what is inside. The device had what seemed to me a bizarre LCD display with a controller(or microcontroller?) I have never seen before(middle ...
1
vote
0answers
93 views

PCB Ground and Power Plane Design Guidelines

I am converting a design from through hole components to SMT components. The schematic is identica, except the maximum allowable current through an onboard a relay will be halved from 20A to 10A. ...
0
votes
1answer
41 views

Keep getting “Only input pin on net” error

I am doing ERC check and keep getting this error : only input pins on net ADC7 that net is a pin from an mcu that has a name ADC7 but is not connected to ...