Application Note How-To Document Problem Description How to ensure accurate front to back registration utilizing target holes. Requirements CircuitCAM template file: targetholes_32.cam for CircuitCAM Version 3.0 and 3.2 targetholes_40.cam for CircuitCAM Version 4.0 Problem Solution 1. First import your complete drawing 2. Go to the lower left corner and hold the left mouse button down and drag it diagonally to the right. This will highlight the entire drawing. 3. Hit Ctrl+B. This is the combine function, which connects endpoints making such things as your board outline one entity vice 4. 4. Hit the Esc key. 5. Go back to the lower left corner and left click the mouse button once. This will select the board outline. You should see the little boxes around your board outline, and the word board outline in the first dialogue box. 6. With the board outline highlighted, go to Edit/Set Zero Point (short cut Shift+N), or press the Set Zero point icon in CircuitCAM. 1 Application Note 7. Now continue with the process of insulating your drawing and setting up your contour routing. 8. When finished insulating your drawing, go to File/Open. 9. Select the targetholes_32.cam (for CircuitCAM 3.0 and 3.2) or targetholes_40.cam (for CircuitCAM 4.0) file associated with the CircuitCAM version in use. 10. Go to the lower left corner of the drawing and hold down the left mouse button and drag it across your drawing to highlight the entire drawing. Right click your mouse button and select copy. 2 Application Note 11. Select File/Close. If asked if you want to save changes select No. 12. Your main drawing should be back on your computer screen at this point. Right click the mouse button and select paste. You should now see your target holes just outside your board outline. (The above drawing has been magnified) 12. Now go to File/Export/LPKF/LPKFCircuitBoardPlotter. 13. Open your Board Master and import your drawing. 3 Application Note 14. Complete the Marking Drills, Drilling Plated, Drilling Unplated, and Milling Bottom phases and flip your board. 15. Before you proceed with milling the top layer, we will utilize the target holes to check and make adjustments to the placement of the drawing if need be. 16. Select the MillingTop phase. 17. Zoom in on your drawing until you can plainly see your target holes. 4 Application Note 18. Select the button to the left of the magnifying glass. Hold down your left mouse button and create a window around one individual target hole. 19. The target hole should then turn White. 20. Select the + (plus) button and the hole will turn Red. 21. Select the Start button and Board Master will prompt you for a tool. 5 Application Note 22. Insert the tool if it isn’t already in and hit OK. 23. At this point, your ProtoMat® milling machine will mill that individual target hole. 24. Select GoTo/Pause. 25. This will allow you to look at the pad to determine if it is centered on the drill hole. 26. A graticle microscope will help determine the offset so you can make a precise adjustment in the drawing placement. 27. Using the scope, look at the target hole. The sample below is what may be seen through the scope (Remember that what is seen through the scope is 180 Degrees out of phase). +X C -Y A -X +Y D B 28. Measure the distances on each side of the hole to the inside of the cut. 29. The idea is to move the milling data (or drawing placement so that the hole is centered inside of the path. The formula for the Y offset is A-B/2=Y Offset. The formula for the X offset is C-D/2=X Offset. I.E: If +Y was 14 mils and -Y is 8 mils, plug in the numbers, (14-8)/2=3 mils Offset. 6 Application Note 30. Right click, with the cursor over the board in Board Master, this will open the placement window. 31. Based on the example used to demonstrate the formula above, we would add 3 mils (0.003 inches) to the Y origin. As you can see, Y is a negative number, so we would add .003 to –1.580, which equals –1.577 32. After making the adjustments in the placement, repeat steps 18-31 on the remaining Target Holes until satisfied with the results. References Board Master Supplement Instruction TargetHoles.cam file for CircuitCAM version 3.2 or TargetHoles.cam file for CircuitCAM version 4.0 LPKF Technical Support Author Jeffrey R Bengtson 7