Layout/Component Placement Tutorials?

[BuGG]

I know this is a rather tough subject to "explain", varies from project to project, and is more of an acquired skill, but does anyone here know of any good tutorials or videos on the subject of PCB layout and component placement?

I'm not referring to technically operating the software itself, but possibly some tips/tricks to finding good placement of the components?

I've picked up some useful info/pointers from various members but was wondering if there were any "tutorials" similar in quality to Jacobs videos on learning Eagle?

I'm considering grabbing a copy of RG Keens book "PCB Layout for Musical Effects"...

[alanp]

I'm still a noob at this, but all I can suggest is a combination of practice, and constantly refining your layout (ie have a crack at it, then strip traces and move problem parts around, then trace it out again, repeat...)

[RobA]

This Sparkfun video is a tutorial on parts layout. It isn't pedal or even audio specific, but many of the considerations are the same. I thought it was pretty informative.

https://www.youtube.com/watch?v=NJKZZArjdg8

[BuGG]

I have a feeling that practice and trial/error is going to be my best lesson... It's just one of those things.

My layouts just always end up so bad, I figured there must be some super top secret trick no one is letting me in on.     

That SparkFun video looks interesting, I'll have to watch it after work today.

[culturejam]

I have a feeling that practice and trial/error is going to be my best lesson... It's just one of those things.

I believe RG Keen did a book on this exact topic. I have not read it, but I can only assume it is a useful guidebook.

But your feeling is definitely correct (at least in my experience). Some people just have a mental knack for making tight layouts...and then there are guys like me who start off awful and slowly get incrementally better over time with practice. My suggestion to you is to take a look at a few layouts you think are well done and start to analyze what about them you think is good.

It's an effort to remind myself not to get too hung up on the aesthetic of the layout. Sometimes what is "pretty" is not the best design in terms of noise control, etc. But luckily, for most analog effects circuits, you can pretty much throw things anywhere and it will work just fine.

Here's my general approach for most things:

• If there is board-mounted hardware (pots, switches, etc), put those on the board first.
• Next the actives (trannies, ICs, etc) go on. I sort of just have a feel for this after doing so many layouts. Think about the device inputs and outputs and where the outputs need to go next.
• Follow the schematic to help you figure out where to spot the passives. Lay them all out before routing.
• When you start routing, connect the longest, most complicated route first. Then work backward from longest to shortest.
• Don't be afraid of using vias (for 2-sided work) or jumpers (for 1-sided boards). But keep in mind that there is probably another way to make the connection (in many, but certainly not all, cases).
• After all the routes are done, take a good look at when can be optimized. Then start ripping up and moving things.
• I always use a ground plan/pour on the bottom layer. And the top layer is also either a ground plane or maybe VREF if there are a lot of connections. You can also have multiple planes connected to different nets. I did this on the original Shoot the Moon layout.

That's my process in general. Every project is different, and maybe my way isn't the best for everyone (or anyone!). But that's how I do it.

[culturejam]

Forgot one relatively recent part of my methodology:

• If designing for fabrication at iTead or Seeedstudio, the first thing I do is set the board size just a hair under the dimensions of one of their options (5x5cm, 5x10cm, etc).

Sometimes having a strict limit on size makes me more creative. 

[jkokura]

I also do things in this order:
- Set board size
- Put Pots, switches, DC, and the header (L/I/G/O) to the right spots on the board
- Do a bottom layer ground pour
- Start with the input, work to the output adding parts in order
- Try to keep parts aligned so that you have resistors laying next to each other, try and keep everything neat and tidy
- After parts are on the board, routing starts with the simplest and shortest wires (opposite of CJ), so if two pads are side by side, they get connected quickly and easily
- Sometimes I do a top vRef pour as well. This is usually +9V, but sometimes it's +5V or vbias or something like that. Depends on what needs to be connected most often.
- I don't know why, but I work hard to not have vias. However, I'm learning that part placement and easy of build/assembly is more important than board size and via content. Jumpers are unnecessary in two sided building.

Jacob

[culturejam]

- After parts are on the board, routing starts with the simplest and shortest wires

I guess I should say that for simple layouts, I just start at the input and work my way around. For more complex layouts, I usually start with the longest. I find that if I start with the longest, I usually can avoid vias better. But it's probably just  how my brain works. 

[jkokura]

It's not a bad way of doing things, just different than what I do. Your way is probably faster too.

Jacob

[BuGG]

Thanks for all the input!   

So far all of my layout attempts have been single layer boards,  since I'm easing my way into having some boards fabbed I'm going to give double layer layouts a shot. 

I'm just going to have to get in there and practice, that's the bottom line I think.   As soon as I have some spare cash I'm going to order RG Keens book, it certainly couldn't hurt.