Print

Printing negative and positive stencils

Written by Chuck. Posted in Preparation

The best program I could find for printing gerbers to stencils to use for resist and masks is ViewMate 11.0.71. You can down load it free from

http://www.pentalogix.com/

Almost all of the other programs I tried, GerbView, GCPrevue, CAM350, CircuitCam, CooperCam and Gerv either won’t permit moving the gerbers are for printing on one page or they print with the black areas as a hatch which won’t work for our application. (Note: Save is disabled on the free version of ViewMate. But once you print the negatives you need you don’t need to save the job.)

 

Select an empty layer from the Layers Dialog on the left, then import the Gerber files you need to the work space. Then you can select each layer and /Layers… and Edit/Edit Selection/Edit Move them to the appropriate location. Move each layer until they are all stacked like you want them.
Then print. For different stencils, using Eagle and ViewMate I use the CAM and Print settings below.
ViewMate Commands used
  • Import                  File/Import/Gerber
  • Select                    Select/Layers… (Enter Layer Number)
  • Move                    Edit/Edit Selection/Edit Move (Then select the layer and drag it.)
  • Unselect              Selection/Clear Selection
  • Zoom Out            Page Up
  • Zoom In               Page Down
Cadsoft Eagle CAM Processor Setup
Section Top Solder/Plate Mask Bottom Solder/Plate Mask Top Etch Bottom Etch Top Silk Screen Solder Stencil
File %N.stc %N.sts %N.cmp %N.sol %N.plc %N.sss
Device Gerber_RS274X Gerber_RS274X Gerber_RS274X Gerber_RS274X Gerber_RS274X Gerber_RS274X
Offset X 0inch 0inch 0inch 0inch 0inch 0inch
Offset Y 0inch 0inch 0inch 0inch 0inch 0inch
Mirror Checked Unchecked Checked Unchecked Checked Checked
Rotate Unchecked Unchecked Unchecked Unchecked Unchecked Unchecked
Upside Down Unchecked Unchecked Unchecked Unchecked Unchecked Unchecked
pos. Coord Checked Checked Checked Checked Checked Checked
QuickPlot Unchecked Unchecked Unchecked Unchecked Unchecked Unchecked
Optimize Checked Checked Checked Checked Checked Checked
Fill Pads Checked Checked Checked Checked Checked Checked
Layers
Top Not Selected Not Selected Selected Not Selected Not Selected Not Selected
Bottom Not Selected Not Selected Not Selected Selected Not Selected Not Selected
Pads Not Selected Not Selected Selected Selected Not Selected Not Selected
Vias Not Selected Not Selected Selected Selected Not Selected Not Selected
Dimension Selected Selected Selected Selected Selected Not Selected
tStop Selected Not Selected Not Selected Not Selected Not Selected Not Selected
bStop Not Selected Selected Not Selected Not Selected Not Selected Not Selected
tPlace Not Selected Not Selected Not Selected Not Selected Selected Not Selected
tNames Not Selected Not Selected Not Selected Not Selected Selected Not Selected
tCreame Not Selected Not Selected Not Selected Not Selected Not Selected Selected
ViewMate Printer Setup Kcam
Content Visible Layers Visible Layers Visible Layers Visible Layers Visible Layers NA
Colors Black on White Black on White White on Black White on Black White on Black NA
Scale By Factor 1 1 1 1 1 NA
Add Page Header Selected Selected Selected Selected Selected NA
Print Frame Also Unselected Unselected Unselected Unselected Unselected NA
User Raster Method Unselected Unselected Unselected Unselected Unselected NA

Notes

I've learned that when mechanically etching it is best to mask off everything you don't need plated.  Just doing the inside of the through holes is enough.  If you plate all the pads and borders, etc -- it increases the thinkness of the PCB inthose areas and causes the milling process to be harder to maintain consistency.