Good Practice for PCB CAD

[Brian Fairchild]

Hi

I'm looking for input from other people as to how they present their
Gerber files for manufacture.

Specifically, what information do you put onto the layers to identify
them.

Do you put text inside the board or outside it? Text or numbers?

I've seen some people use a 1,2,3,4,5... box

Basically I'm trying to develop a standard for myself and
subcontractor to use. Mostly 2 layer or 4 layer PTH stuff.

Any pointer gratefully received.

Brian

reply e-mail address doe not work. see sig.


--
Brian Fairchild
B dot Fairchild at Dial dot Pipex dot Com

"But apart from that Mrs Lincoln, how did you enjoy the play?"

 

[Spam Hater]

I put the "boxed numbers" inside the board. Right near the edge. So
I can check them visually when I get the boards back. Yes, I have
gotten boards with missing layers.

I also name the gerbers 'layer01.gbr', 'layer02.gbr', etc. Not
compent, plane, solder, etc.

It also helps to have plain reading text on top and bottom layers.
Part numbers and country of origin are good things to use.

When in doubt, be painfully obvious.

HTH,
SH7

On Mon, 28 Jul 2003 20:07:06 +0100, Brian Fairchild
<spam.spam@spam.com> wrote:

Hi

I'm looking for input from other people as to how they present their
Gerber files for manufacture.

Specifically, what information do you put onto the layers to identify
them.

Do you put text inside the board or outside it? Text or numbers?

I've seen some people use a 1,2,3,4,5... box

Basically I'm trying to develop a standard for myself and
subcontractor to use. Mostly 2 layer or 4 layer PTH stuff.

Any pointer gratefully received.

Brian

reply e-mail address doe not work. see sig.

 

[Hal Murray]

I'm looking for input from other people as to how they present their
Gerber files for manufacture.

Specifically, what information do you put onto the layers to identify
them.

Do you put text inside the board or outside it? Text or numbers?

I suggest asking your board vendor what they prefer.

You can put big text with the layer info (and version/time stamp)
outside the board outline. The board vendor will have to throw it
away, but it makes it easy for them to check that they are doing
the right thing.

If you have room, you can put "Layer <n>" on each layer, perhaps
staggering the numbers so you can read them all if you hold it
up to the light. (That gets tricky for plane/negative layers.)

--
The suespammers.org mail server is located in California. So are all my
other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.

 

[Brian Fairchild]

In a flurry of electrons Hal Murray spake thus:

I'm looking for input from other people as to how they present their
Gerber files for manufacture.

Specifically, what information do you put onto the layers to identify
them.

Do you put text inside the board or outside it? Text or numbers?

I suggest asking your board vendor what they prefer.

The problem is that my boards typically get made by three different
companies: the people I use for fast prototypes, the people who make
the pre-production/first run batches for the people I 'work' for and
the final production house.

Not ideal I know. Luckily we're not doing anything difficult.

You can put big text with the layer info (and version/time stamp)
outside the board outline. The board vendor will have to throw it
away, but it makes it easy for them to check that they are doing
the right thing.

Good idea.

If you have room, you can put "Layer <n>" on each layer, perhaps
staggering the numbers so you can read them all if you hold it
up to the light. (That gets tricky for plane/negative layers.)

--
Brian Fairchild
B dot Fairchild at Dial dot Pipex dot Com

"But apart from that Mrs Lincoln, how did you enjoy the play?"

 

[Hal Murray]

I suggest asking your board vendor what they prefer.

The problem is that my boards typically get made by three different
companies: the people I use for fast prototypes, the people who make
the pre-production/first run batches for the people I 'work' for and
the final production house.

Ask all 3 vendors - you have to do what they want/need eventually.
If you are lucky, you can find a least-common-denominator they will
all be happy with. If not, consider some script hacking to
automate the conversion so you won't forget a step or fat finger
something. That might be something as simple as renaming files.

In the old days (5-10 years ago), there was a person involved
with every board. They would call you if there was any confusion.
Now, some/most of the inexpensive order-via-web board shops are
bypassing that step. You have to do exactly what they say, but
they will have the fine print on their web pages.

--
The suespammers.org mail server is located in California. So are all my
other mailboxes. Please do not send unsolicited bulk e-mail or unsolicited
commercial e-mail to my suespammers.org address or any of my other addresses.
These are my opinions, not necessarily my employer's. I hate spam.

 

[Paul Burke]

Hal Murray wrote:

I suggest asking your board vendor what they prefer.


In the old days (5-10 years ago), there was a person involved
with every board. They would call you if there was any confusion.
Now, some/most of the inexpensive order-via-web board shops are
bypassing that step. You have to do exactly what they say, but
they will have the fine print on their web pages.

I find PCB-Pool particualry good in this respect- the Gerber files seem
to be thoroughly checked, and call to sort out any ambiguities. Even
when I MEANT to leave no hole in a pad (for a polarising pin). They have
been in fact better than some regular manufacturers I have used in the past.

Usual disclaimer.

Paul Burke

 

[William Lenz]

Brian Fairchild:

Howdy.

Hi

I'm looking for input from other people as to how they present their
Gerber files for manufacture.
Specifically, what information do you put onto the layers to identify
them.

Our standard was:
The Gerber Data is clean to avoid anyone needing to edit them.
The files names were the "board number" then "_Sx.grb" the x being 1-however
many sheets you have.
A hard copy packet was then created and sent to the board house (faxed,
mail, or PDF)

Detail on the hard copy stuff
We paced common text on a common layer. Then layer spicific text on other
layers, you then print out the layers you want. This works well if you have
a software package that has enough layers to do this, and can save printing
styles.

Do you put text inside the board or outside it? Text or numbers?
I've seen some people use a 1,2,3,4,5... box

Not that we didn't trust our board houses, but....we didn't trust them ).
We tried to supply to the board house a clean gerber file no touch up
necessary on there part (other than to array them when needed).

Basically I'm trying to develop a standard for myself and
subcontractor to use. Mostly 2 layer or 4 layer PTH stuff.

Our standard was:
Sheet 1: Board and mfg info (Hard copy only)
Sheet 2: Top (Hard copy with text, and clean gerber
file)
Sheet 3: Bottom (Hard copy with text, and clean gerber
file)
Sheet 4: Solder mask top (Hard copy with text, and clean gerber file)
Sheet 5: Solder mask bot (Hard copy with text, and clean gerber file)
Sheet 6: Solder paste top (Hard copy with text, and clean gerber file)
Sheet 7: Solder paste bot (Hard copy with text, and clean gerber file)
Sheet 8: Array info if applied (Hard copy only)

Multi layer boards sheets were inserted between sheets 2 and 3 and all
sheets incremented by 1.

Any pointer gratefully received.

Brian

This works best if you can save all the work involved as a series of
defaults then just recall them.

At least an idea.

Bill

 

[Brian Fairchild]

In a flurry of electrons I spake thus:

I'm looking for input from other people as to how they present their
Gerber files for manufacture.

Specifically, what information do you put onto the layers to identify
them.

Do you put text inside the board or outside it? Text or numbers?

I've seen some people use a 1,2,3,4,5... box

Basically I'm trying to develop a standard for myself and
subcontractor to use. Mostly 2 layer or 4 layer PTH stuff.

Any pointer gratefully received.

Just a quick thanks to all who made suggestions.
--
Brian Fairchild
B dot Fairchild at Dial dot Pipex dot Com

"But apart from that Mrs Lincoln, how did you enjoy the play?"