Continue to Site

Welcome to EDAboard.com

Welcome to our site! EDAboard.com is an international Electronics Discussion Forum focused on EDA software, circuits, schematics, books, theory, papers, asic, pld, 8051, DSP, Network, RF, Analog Design, PCB, Service Manuals... and a whole lot more! To participate you need to register. Registration is free. Click here to register now.

Register Log in

What is a good PCB layout procedure?

Status
Not open for further replies.
D

dunn

Full Member level 3
Joined
Apr 12, 2001
Messages
154
Helped
22
Reputation
44
Reaction score
7
Trophy points
1,298
Activity points
1,277
pcb layout procedure

What is a good PCB layout procedure?

The situation.
Schematic completed.
Transferred to PCB (birds nest).

Now what?
1) Put the component with the most connections in the middle of the PCB (good for EMC)?

What if it is a connector that has a lot of connections (and can not be placed in the middle)?

Or Place the components in a logical order (easy for fault finding)

2) Does any body use “auto placement”?

What grid is it best to start off with?

Thanks in advance to all the replies.
 

how to do a good layout fo emc

well, first I suggest you search google for layout. there are good resources. I never use auto-placement and auto-routing. I think auto-routing only is useful for simple circuits and if one dosn't concern about EMI, noise,....
a good practice for placing parts is to place them in different areas(clusters) according to their speeds.
 

Re: PCB Layout

Just out of interest you say "I think auto-routing only is useful for simple circuits and if one dosn't concern about EMI, noise,.... "

Does this mean that computer PCB's are hand routed?
 

Re: PCB Layout

dunn said:
1) Put the component with the most connections in the middle of the PCB (good for EMC)?
Click to expand...
I cannot see any reason why it should be "good fo EMC" :?
It is good for layout, because most connections will be relatively short. But it is bad for EMC, because parts in the centre of PCB are hit by noise currents flowing in any direction.
For example, if you put uC in the centre, quite likely it will be susceptible to external noise. But if you put uC in a "calm" corner of PCB, away from noise path, it will not be affected by noise.
 

Re: PCB Layout

dunn said:
Does this mean that computer PCB's are hand routed?
Click to expand...
honestly, I don't have enough expertise to answer this question accurately, but I presume that it is highly unlikely that routings of computer PCB's can be done blindly by an auto-router.
 

Re: PCB Layout

I would separate the layout of the board in "zones". For example, a mobile phone has the Tx zone, Rx zone both are part of the RF zone. Then there is the power supply zone and the digital zone.
You would like to place the antenna connector near the edge of the board probably, the same for the digital+battery connector. Also you have to think if you want components on both sides of the PCB or not. Solder method, etc. You can find some books about SMT design + EMC-SI that can help you. Best regards,

otomi
 

Re: PCB Layout

In reply to "akouz" post.

The statement says "..component with the most connections in the middle of the PCB (good for EMC)? " by most I ment, say an amplifier or an 555 IC.

You ask about uC.
Yes you are correct"...quite likely it will be susceptible to external noise."
but a good designer would use an EMC can to reduce the effect of external noise and keep signals apart.

In any case thanks for the post. It brought up some interesting points.
 

Status
Not open for further replies.

Similar threads

Part and Inventory Search

Welcome to EDABoard.com

Sponsor

Back
Top