4 layer PCB, what extension for inner layers for gerber?

Go To Last Post
11 posts / 0 new
Author
Message
#1
  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Hi guys

I am making my first 4 layer PCB, what is the normal file extension name for the inner 2 layers when submitting gerber files. I know that the top layer is ".CMP" and the bottom is ".SOL".

Regards,

Alan To

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Just use the default .ly2, .ly3 e.t.c.

/Jesper
http://www.yampp.com
The quick black AVR jumped over the lazy PIC.
What boots up, must come down.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Doesn't really matter. The board houses have seen them all. They are going to take your files and as long as they are valid gerber data they'll figure it out. Just make sure to give them a layer stack diagram and if you have an impedance controlled signals, tell them what the impedance is and what stack-up you used to get it.

Go electric!
Happy electric car owner / builder

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

The Pulsonix software I use generates files with a .gbr extension by default. Typical Gerber file names defined in the Technology file for a 6 layer board are:

Top.gbr
Ground.gbr
Inner3.gbr
Inner4.gbr
Power.gbr
Bottom.gbr

Ground and Power are power-planes.

It's a good idea to include the layer name in copper on each layer to help the PCB supplier avoid mistakes, and define them in a separate document.

Leon

Leon Heller G1HSM

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I used to think that it was good to include the names of they layers until you get boards made in china.

I rememeber sending off gerber for a 4 layer board and i did just that. I had top copper, top inner, etc..makes perfect sense.

Unforunately there was something in the gerber that made them question this. I had some text on the bottom layer and it was not mirrored for bottom layer. So they did what they felt was right and made 3000 boards with the top and bottom layer swapped. Maybe that says more about china than the labels.

http://en.wikipedia.org/wiki/Ger...

This might be a better naming convention.

Trev

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Thanks for the info guys.

I submitted my 4 layer board for a quote, and got quite the sticker shock when I saw the price. It costs 3x more than a pcb of the same size with 2 layers.

I know for high volume the price gets much better, but dang I can not afford a 4 layer prototype.

I redid my board today using 2 layers,

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

That was a pretty hefty price jump. Who quoted you if I may ask?

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I agree. That's a pretty big jump. I'd re-quote elsewhere. Maybe a 2x jump but more than that sounds funny. Are you sure it wasn't something else? Minimum hole size? Trace/Space? If you cross over their capabilities then the price can really jump. Some board houses have separate lists of capabilities for cheap protos versus expensive full runs. If you have a feature that isn't on the "cheap" list you get the full price.

Go electric!
Happy electric car owner / builder

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

I use myropcb for the 4 layer quote. I have always used them for 2 layer boards, they do not have the best price for low quantity prototypes, but for mid-high quantity they have the best prices. I exaggerated a bit on the 3x price, it is closer to 2x than 3x.

My specs are 12mil hole size, 6mil spacing and 6 mil traces. It is the specs are exactly the same as the 2 layer boards I get from them.

I wanted to use batchpcb since I can get a single 4 layer board for only $32, but waiting time is 2-5 months.

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

You could try pcbcart.com a look. They do isntant online quotes. I have never used them but they offer 2 week services

TRev

  • 1
  • 2
  • 3
  • 4
  • 5
Total votes: 0

Or try speedypcb.com... I've used them many times and mostly been satisfied.
The biggest problem I had was once, when they made green soldermask, white silkscreen instead of black soldermask, yellow silkscreen.
They do mostly 7 or 14 days manufacturing, and they're dirt cheap.