I've placed the component of a simple power supply circuit on PCB layout screen using auto-placer and auto-router. I would like to know many things about dimensions:

  1. Is there a standard space between each couple of components?

If No, What should be the space between two components that are next to each other?

  1. Do .BMP images keep the dimensions as it is?

I mean If I exported my design using the following method:

Output > Export graphics > Export bitmap.

Then, I printed the exported .BMP image.

Will it have the same dimensions as if I printed it directly from Proteus using ( output > print layout)?

  1. I feel like the lines that connect the components are very thin, Is that OK?

Can I make them thicker?

  1. What is the easiest way to measure the dimensions? and How can I now the final dimensions (Width and length) of my BCP?
  • \$\begingroup\$ Typo! In. The. Title. \$\endgroup\$ – Marcus Müller Nov 23 '16 at 15:10
  • \$\begingroup\$ Ask one question at once please. \$\endgroup\$ – Marcus Müller Nov 23 '16 at 15:14
  • \$\begingroup\$ Botswanan Communist Party? \$\endgroup\$ – Andy aka Nov 23 '16 at 15:48
  • \$\begingroup\$ "PCB" backwards? \$\endgroup\$ – Leon Heller Nov 23 '16 at 16:23

My first unrequested advise is to read this excellent PCB Design & Layout Tutorial

My second unrequested advise is to keep away from auto-placing and auto-routing until you are more experienced. Those are wonderful tools, but they take a lot of decisions in your name, and those decisions have consequences you're probably unaware of. Designing a PCB is a process, and you should read about it.

Now I'll try to answer your questions as best as I can:

  • Is there a standard space between each couple of components? When you design a PCB you usually follow a grid, so components are regularly spaced in multiples of the grid step. As the tutorial says "100 thou is a standard placement grid for very basic through hole work, with 50 thou being a standard for general tracking work, like running tracks between throughhole pads. For even finer work you may use a 25"
  • BMP images have no scale information. Scale information specifies what is the dimension of one pixel. In consequence BMP don't keep dimensions. When you export your design for a manufacturer you should use Gerber format, also available in Proteus. Alternatively, use Output->Print to print your design.
  • Each manufacturer has a minimum layer thickness limit imposed by the technology he is using. Today manufacturers can do wonders, but you shouldn't be challenging them. If you plan to do your own PCB, then don't go under 25th. You can make lines thicker by right-clicking and change their style.
  • BMP don't have dimensions. Don't use them. Use the Output->Print action in Proteus. Print your design at 100% scale on paper, and then measure it with a ruler.

Firstly, auto placers ALWAYS SUCK, and for simple boards auto routers mostly suck... The time it takes to configure the autorouter and to add the net classes and annotations required to get a sane job out of it vastly exceeds the value unless you are doing something REALLY complex.

The single most important part of laying out a board, is component placement, get that right and the routing will mostly be obvious.

There are IPC standards for courtyard sizing, but it depends as well on such things as heat dissipation (Do not for example place an electrolytic right next to a linear regulator heatsink).

For small SMT stuff somewhere in the 1mm to 0.25mm between the courtyards works, and I usually place on a 1mm grid, sometimes 2mm, sometimes 0.25 or 0.2mm depending. Do use a grid when placing components, snap is your friend.

BMP is not going to reliably preserve scaling, use Gerbers that is what they are for, also laser printers are notoriously prone to be slightly off on scale.

Trace width depends on required current and allowable voltage drop/Temperature rise, for power supply stuff, wider is usually better (Exception, switching nodes), so don't be shy about bumping track sizes and pouring copper polygons as required.

I don't know Proteus, so I cannot answer about the measurement, list time I used Aries was a while ago now, there will be a way to do it.

Protip: You need some way to mount that board, remember to make sure you have mounting holes.

  • \$\begingroup\$ wow. that is an opinionated, half-informed, imprecise answer if I ever saw one. It would be a good answer if you removed the opinions and actually focused on the facts: · There's standards to follow · you need mounting holes. · Bitmaps, being bitmaps, don't scale well. The rest is just ranting and hand-waving. \$\endgroup\$ – Marcus Müller Nov 23 '16 at 15:11
  • \$\begingroup\$ Not sure mounting holes qualifies as a "pro"tip. In many scenarios its the first thing you are gonna place, next to connectors and other mechanically constrained components.. \$\endgroup\$ – Wesley Lee Nov 23 '16 at 15:18
  • \$\begingroup\$ True, but remarkably common to see them forgotten until way too late by the inexperienced. \$\endgroup\$ – Dan Mills Nov 23 '16 at 15:19
  • \$\begingroup\$ I was trying to answer the questions as well as pass on some of the things I wish I had been told before doing my first layout (Ok autoplacers did not exist back then, but placement being IMPORTANT would have saved me a lot of pain). Mounting, connectors, EMC/RFI parts, heavy things then everything else paying due attention to what nets to what, and any likely SI issues. You will not really find two engineers who would lay out a board identically, and there is no perfect board, so a lot of this stuff is somewhat handwavy by nature, there is a reason they call it artwork. \$\endgroup\$ – Dan Mills Nov 23 '16 at 15:26
  • \$\begingroup\$ Personally, I like those opinions! \$\endgroup\$ – Andy aka Nov 23 '16 at 15:46

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