Understanding basic PCBs? Resources? - Page 1
Forum section: electronics / beginners

author: FireHazard
author_rank: Contributor
timestamp: May 16, 2022, 10:17:16 pm
content: Hi all,I'm finding that sadly my understanding of basic double sided PCBs is sorely lacking.Can anybody suggest any resources (maybe a video series, or articles) that will take me through the basics with a through hole technology slant. I'd particularly like to under how the through hole connects to the trace.Thanks in advance.

author: sahko123
author_rank: Frequent Contributor
timestamp: May 16, 2022, 10:31:25 pm
content: Is there any particular topic the confuses you? Double sided pcbs for most applications are nothing more than just wires connecting back and forth and generally dont need much more thought than that

author: FireHazard
author_rank: Contributor
timestamp: May 16, 2022, 11:14:22 pm
content: Just to understand a bit more about what I'm seeing, for example when I scrape off a bit of the green surface (on a scrap board), I see copper..does this copper only exist where the traces run...some boards seem to have a big copper layer that runs throughout?I have some damaged thru holes on a board I need to replace/repair, and would like to understand the physical connection of the thing in the hole and how it connects to the trace ...the hole goes all the way through the board...but the trace it connects to is only on one side...why does the thing in the hole go to both sides of the board in that case?Also situations where components are connected in parallel and next to each other, I see there isn't really a 'trace' as such run between them, it looks as if one large 'rectangular' area exists with two thru holes. What is the terminology for that?

author: TimFox
author_rank: Super Contributor
timestamp: May 16, 2022, 11:19:54 pm
content: The green surface is probably an insulating coating or solder mask.The board can contain narrow "traces" or complete "ground planes", made from copper.A rectangle with two holes is a form of "pad".

author: ledtester
author_rank: Super Contributor
timestamp: May 16, 2022, 11:36:36 pm
content: Quote from: FireHazard on May 16, 2022, 11:14:22 pmThat's most likely a ground plane. Here's a good synopsis of why ground plans are used on PCBs:https://en.wikipedia.org/wiki/Ground_plane#Printed_circuit_boardsQuoteCan you upload pictures of these parts of the board?Update: This video goes over "vias" in PCBs - what they are and the different kinds:What is a PCB Via? | Sierra Circuitshttps://youtu.be/X39BHqvSTvk

author: Doctorandus_P
author_rank: Super Contributor
timestamp: May 17, 2022, 12:24:50 pm
content: Search a bit around on youtube. There are quite some video's about PCB production which let you see all the steps of how a PCB is made.

author: Siwastaja
author_rank: Super Contributor
timestamp: May 17, 2022, 12:41:45 pm
content: Quote from: FireHazard on May 16, 2022, 11:14:22 pmMany names, depending on the PCB design software used.Plane - this name is usually used when the area is fully or nearly contiguous, i.e., there are no other tracks that need to be avoided. Just like a copper sheet, with just enough etching to remove copper around those vias that donotconnect to this plane.Polygon pour or polygon fill - basically the same, but this term is used in situations when there something else (tracks) on the same layer. Polygon pour looks for the empty areas and "flood fills" everything, keeping configured minimum safe distance to existing tracks. The idea is to automatically produce as wide "tracks" as possible. Manually drawing wide tracks leaves a lot of unused space, you see.Fill, poly region, region, etc. - an arbitrary shape manually drawn by the designer. Basically just a wide "track".The advantage of wide fills is, you get minimized resistance and inductance, and also better thermal conductivity.Very usually in 2-layer extra low voltage design, one just draws all the tracesexceptthe ground tracks, and after done, fills every gap with ground polygon pour. If you have more layers at your disposal, then you usually can dedicate some of them as ground or power planes with very little or no other traces running on them at all.

author: FireHazard
author_rank: Contributor
timestamp: May 18, 2022, 11:20:17 pm
content: Very useful responses thank you.Over the last couple of days I've watched many videos on the production process and it makes a lot more sense. Looking at some of the boards I have here is starting to 'click' a bit more. Yes, I know the basic concept of what a PCB was for, but that's a long way from understanding the aspects of how they are done in practice.

author: Infraviolet
author_rank: Super Contributor
timestamp: May 20, 2022, 09:37:30 am
content: I'd suggest having a go at designing one, try KiCAD or Autodesk Eagle. Doing it yourself should give you a feel for common design tricks and contraints.

author: FireHazard
author_rank: Contributor
timestamp: May 21, 2022, 01:51:13 am
content: Quote from: Infraviolet on May 20, 2022, 09:37:30 amThanks I've been going through some EasyEDA tutorials and it is very illuminating. Getting a feel for what is going on on a PCB seems key and is a really interesting process. Really does help understanding what's going on.

author: tepalia02
author_rank: Regular Contributor
timestamp: May 22, 2022, 10:14:14 am
content: I think you can go through these blogs:https://pcbtracks.com/blog/These are quite well-written. These explain the basics of PCB designing easily. Hopefully, you'll get a thorough idea regarding designing and manufacturing of different types of PCB.

author: FireHazard
author_rank: Contributor
timestamp: June 02, 2022, 05:55:31 am
content: These were excellent. Thank you.