VUTRAX SOFTWARE ADVICE NOTICE 206 Issue 3- (4 July 2002)

USING VUTRAX FOR STRIPBOARD (VEROBOARD)

 

Stripboard (also known by its commercial name Veroboard in the UK) is pre-prepared wiring board consisting of strips of copper, normally at 0.1" pitch, with holes drilled along each strip at the same pitch.

Components are conventionally mounted (or Surface Mount components mounted on conventionally soldered carriers), and the connections accomplished by a combination of carefully arranged alignments, wire links between strips, and cuts in the strips made either with a knife or a special tool. Using such boards, small circuits can be prototyped or even produced in small quantities.

Vutrax can be used to automate and formalise design of such layouts, using either the complete schematic to layout approach, a simple pin-list, or even a straight to layout approach.
 

1. Prepare schematic, pin list or whatever, or produce the basic layout directly (see taping Table).
    
2. Generate libraries at 0.1" pitch if required.
    
3. Make the Rats nest normally.
    
4. Now make a .brd file the right size and shape, and include on it a recessive image of the stripboard on layer 10. Copy and Paste this command file into file veroboard.dex .
   
   In this set of commands 80 = 8" wide, 50 = 5" deep:-

   DEF W 60 L 10 SZ 2
   GOTO 0 0
   F H
   *80;; RIGHT 100;; C H
   GOTO 0 0
   NOTE
   *50;; DOWN 100;; COPY
   Z F

   Remove any spaces that your browser happens to have added at the start of the lines (particularly those starting '*')
   Execute the created file through the menu, or by using typed command X  veroboard.dex
   If the grid is ridiculously large for your project try again with changed 80 and 50, or use Keep All Inside from Edit > Boxed Items to pick the area you want
    

5. For cosmetic appearance, and to keep the artwork within limited capacity system allowances, you should now set up 2 pad shapes as Annular rings. Select Define Pad from (Options > Pads & Tables), select pad 2 and change the pad from 'Assumed' to 'Annular Ring' with Inside = 16 and Outside = 32. Click OK and acknowledge the dimensional warning you get.
   Now move to pad 11 and do the same but with Inside = 44 and Outside = 88.
   You can change these dimensions later if you prefer others.
    
6. Merge the .brd into the rats nest in the usual way. So you can see the rats nest, click on the layers/colour bar at the bottom of the window, and change the colour of layer 0 (Magenta is a good choice). While you are at it, on 16/24 bit colour displays, select Mix display mode.
    
7. Shuffle/turn the parts about until you see a sensible layout. Remember to Optimise interconnects, and/or repaint, if the layout gets in a mess. Try to align a worthwhile number of signals horizontally to save wire links. Particularly worthwhile is to attempt to maximise alignment of 0V (ground) and other Power supply connections to discrete components.
   Remember that conventional stripboard wire connections requires an uncommitted hole adjacent to the device pin, into which to insert the wire. For easiest manufacturing spread your design as much horizontally (along the line of the strips) as you can.
    
8. Route your efforts normally (using VIAs, layer 1 for Horizontal, layer 2 for Vertical (these will become wire links so minimise them.).
   If you decide to use auto-routing use Basic Autorouting from (Tools > Routing) (AUTOTRAK) rather than Ripup Autorouting (VUROUTE), because its right angled style better fits the restrictions of Stripboard. Set the grid to match the board pitch. You will probably have to place a few tracks yourself when AUTOTRAK has finished - it does not rip up and re-try. For suitable starting rules file Copy and Paste this command file into file veroboard.rul . Don't worry about leading spaces here.
   
   

   ONENODE N/C  ;
   TRACKS 1 2
   WIRES 0 5
   MINGAP 12
   ENDRULES
   PITCH 100
   LEVEL 0
   MAPGRID 8
   VIASIZE 8
   VERLAY 2 NODESFROM 5
   HORLAY 1 NODESFROM 0
   PASSES  0 10
   SIGOPT EDIT
   ENDAUTO

   If your routing is not very successful, update the placement in the light of congested areas and unnecessary long connections, and try again.
    

9. Manually modify the routing so that there are no tracks existing vertically from component pads - you will only be able to make such connections by fudging joints of the copper side of the stripboard. To find these try showing just layer 2. Try to arrange that each track that has a vertical run in it goes to a VIA on the same strip, and then runs vertically to another VIA on another strip.
    
10. You can check the routing by using Save As to (say) temp.art, and in this temporary copy Delete all stripboard strips, and then use Design Check and Artwork Compare from (Tools > Routing)
     
11. Mark cut points (places where a single strip has to be cut to be used by more than one signal) with Size 11 Node on Layer 5 (magenta). You previously defined Pad shape 11 as a large Annular ring.
     
12. According to how you work, print or display flipped or normal images in colour or with layer 2 & 5 black and all else gray to show you where to cut and link. The best selection of colour for the strips depends on usage. We use dark blue on the screen, and light blue for printing, with tracks in Red, linked in Green
     
13. All the top-down and backward modifications work, except that you have to update the cut points yourself.

Vutrax is a big system - you will need to work through the thorough on-screen tutorials so you know what is going on BEFORE you start varying the scheme as above. If you want to use the direct layout on to the grid, you should work through the Taping Table section of the tutorial when you are prompted to after the basics sections - you don't need to learn about schematics or library building.

If you find a more convenient or functional variations please let us know.

Distribution:

• Internet Site.
• Sent on Request.