frazzled routing dense boards

David Pollum wrote:

Using both EAGLE v4.16r2 and v5.2, I have routed relatively simple 2 and

4 layer boards, using mostly digital logic chips and CPLDs.  I used both

through-hole and SMD parts.  And except for bypass caps, all parts are

mounted on the top (layer 1).  I've gotten pretty good at doing these

low density digital boards.

 

However, I recently routed a small 4 layer analog/digital board (EAGLE

v5.2) that has dozens of components on each side.  This board was far

more dense than any boards that I had done before.  With both the top

and bottom layers active (1 & 16), plus a spaghetti bowel of airwires, I

had some problems positioning the parts and routing the board, and I

became quite frustrated with myself and sometimes with EAGLE.  Sometimes

it hard to know if an airwire is connected to a pad, or if it's merely

passing over a pad.  I'm hoping that someone has a better, less

frustrating approach or strategy to dense board design, and who would

willing to share some tricks of the trade.

Thanks!

 

-Dave Pollum

 

I might be over simplifying your situation but here goes; I usually turn

off airwires while I am placing my parts. I come up with a placement

strategy based on the schematic, which I notate. With printed and

notated schematic in hand (looking at it on paper is much nicer), I

place the parts with no regards to the airwires. I then turn on airwires

and start routing my critical signals...

I absolutely have to move the parts around in the routing process, but I

find that it gets me a good start at things.

Tony

Anthony Rolando wrote:

David Pollum wrote:

 

Using both EAGLE v4.16r2 and v5.2, I have routed relatively simple 2

and 4 layer boards, using mostly digital logic chips and CPLDs.  I

used both through-hole and SMD parts.  And except for bypass caps, all

parts are mounted on the top (layer 1).  I've gotten pretty good at

doing these low density digital boards.

 

However, I recently routed a small 4 layer analog/digital board (EAGLE

v5.2) that has dozens of components on each side.  This board was far

more dense than any boards that I had done before.  With both the top

and bottom layers active (1 & 16), plus a spaghetti bowel of airwires,

I had some problems positioning the parts and routing the board, and I

became quite frustrated with myself and sometimes with EAGLE. 

Sometimes it hard to know if an airwire is connected to a pad, or if

it's merely passing over a pad.  I'm hoping that someone has a better,

less frustrating approach or strategy to dense board design, and who

would willing to share some tricks of the trade.

Thanks!

 

-Dave Pollum

 

 

I might be over simplifying your situation but here goes; I usually turn

off airwires while I am placing my parts. I come up with a placement

strategy based on the schematic, which I notate. With printed and

notated schematic in hand (looking at it on paper is much nicer), I

place the parts with no regards to the airwires. I then turn on airwires

and start routing my critical signals...

I absolutely have to move the parts around in the routing process, but I

find that it gets me a good start at things.

 

Tony

Tony;

Good tips, thanks.

-Dave Pollum

Anthony Rolando wrote:

David Pollum wrote:

 

Using both EAGLE v4.16r2 and v5.2, I have routed relatively simple 2

and 4 layer boards, using mostly digital logic chips and CPLDs.  I

used both through-hole and SMD parts.  And except for bypass caps, all

parts are mounted on the top (layer 1).  I've gotten pretty good at

doing these low density digital boards.

 

However, I recently routed a small 4 layer analog/digital board (EAGLE

v5.2) that has dozens of components on each side.  This board was far

more dense than any boards that I had done before.  With both the top

and bottom layers active (1 & 16), plus a spaghetti bowel of airwires,

I had some problems positioning the parts and routing the board, and I

became quite frustrated with myself and sometimes with EAGLE. 

Sometimes it hard to know if an airwire is connected to a pad, or if

it's merely passing over a pad.  I'm hoping that someone has a better,

less frustrating approach or strategy to dense board design, and who

would willing to share some tricks of the trade.

Thanks!

 

-Dave Pollum

 

 

I might be over simplifying your situation but here goes; I usually turn

off airwires while I am placing my parts. I come up with a placement

strategy based on the schematic, which I notate. With printed and

notated schematic in hand (looking at it on paper is much nicer), I

place the parts with no regards to the airwires. I then turn on airwires

and start routing my critical signals...

I absolutely have to move the parts around in the routing process, but I

find that it gets me a good start at things.

 

Tony

Tony;

Good tips, thanks.

-Dave Pollum