PCB doubt

Thread Starter

JosXD

Joined Mar 16, 2022
16
Hello Mates, hope you can help me with this problem:

I want to send to print a pcb desing with 2 layers but without any copper in the bottom layer, yes i know i could just choose 1 layer but " Black Mate " solder mask is only available for 2 layers.

So my doubt is, i don't have any track or pads in the bottom layer just the silkscreen, if i export the Gerber file without the " Bottom layer " and without " Bottom paste " what will happen when printing?

1.- will the CNC milling ignore that there is not traces in bottom layer, and copper will stay there intact to later be covered by the solder mask?.
2.- or will the CNC milling remove all the copper, so if you scratch the bottom solder mask won't be conductive?
 

MrSalts

Joined Apr 2, 2020
2,599
Hello Mates, hope you can help me with this problem:

I want to send to print a pcb desing with 2 layers but without any copper in the bottom layer, yes i know i could just choose 1 layer but " Black Mate " solder mask is only available for 2 layers.

So my doubt is, i don't have any track or pads in the bottom layer just the silkscreen, if i export the Gerber file without the " Bottom layer " and without " Bottom paste " what will happen when printing?

1.- will the CNC milling ignore that there is not traces in bottom layer, and copper will stay there intact to later be covered by the solder mask?.
2.- or will the CNC milling remove all the copper, so if you scratch the bottom solder mask won't be conductive?
Gerber files are a set of text files. Your program will just not output the text file that defines the layers you don't want. The problem is, the PCB maker may leave all the copper on the bottom if you don't submit a bottom. They may coat the whole bottom with solder mask of you don't submit a layer. You might want to specify the layers with the exact description you want.
 

Jon Chandler

Joined Jun 12, 2008
431
Include all the Gerber layers along with a note that says "no traces on bottom layer." This will help ensure you get what you want without the fab house making assumptions or holding up your board with a string of emails asking for clarifications.


You generally need:


Top copper

Top silkscreen

Top soldermask


Bottom soldermask

Bottom silkscreen

Bottom copper


Excellon drill file.


You don't need solderpaste layers unless the fab house is doing assembly.

It's a good idea to include a "readme.txt" file, listing the board dimensions, number of layers, the layer names and any special requests. Include your name, shipping address, and email address.
 

Thread Starter

JosXD

Joined Mar 16, 2022
16
Gerber files are a set of text files. Your program will just not output the text file that defines the layers you don't want. The problem is, the PCB maker may leave all the copper on the bottom if you don't submit a bottom. They may coat the whole bottom with solder mask of you don't submit a layer. You might want to specify the layers with the exact description you want.
Thank You Mate!
 

Thread Starter

JosXD

Joined Mar 16, 2022
16
Include all the Gerber layers along with a note that says "no traces on bottom layer." This will help ensure you get what you want without the fab house making assumptions or holding up your board with a string of emails asking for clarifications.


You generally need:


Top copper

Top silkscreen

Top soldermask


Bottom soldermask

Bottom silkscreen

Bottom copper


Excellon drill file.


You don't need solderpaste layers unless the fab house is doing assembly.

It's a good idea to include a "readme.txt" file, listing the board dimensions, number of layers, the layer names and any special requests. Include your name, shipping address, and email address.
Hey Mate! just saw your comment a minute after place an order.

I've already uploaded a inquiry to the pcb manufacturer, i've been talking with their support.

They told me that isn't necessary to choose " Bottom layer " and " Bottom paste " when exporting the gerber file.

I don't know if they understood my point at all of " Zero Copper ", so i wrote them a note where i explain why my geber file doesn't contain those 2 layers, i also wrote them to remove all the copper from the Bottom layer and contact me if they have doubts.
 
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