Altium Board Slots

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  1. Altium Board Slots Game

I’ve been working recently on a new top secret project that used multiple slots in the board. Normally I just define them as slotted pads in Altium and the board house deals with it.

Define an oval slot-type cut? -Justin I had to create oval holes in a project at work though I was using. Altium and not Eagle. What I did was overlap three holes so it looked. Like an oval shape. The board house we used was Prototron Circuits. They seemed to know what I wanted though they did call and ask just to. For FR4 or HTFR4 PCBs greater than or equal to 0.06 in. (1.5 mm) thick, allow no more than five boards, side by side, up to 1.5-in. Board width, four boards up to 2.5-in. Board width, three boards. The definition of plated slot. For a board, it may contain plated slot or unplated slot. Plated slot means this slot is plated with copper which can be used for electrical connection. Pictures to show. Size of plated slot. The min side of plated slot is 0.5mm for PCBWay. For unplated slot, the min size is 0.8mm width. (slots are 2mm - default milling bit size, with tabs with 5-hole perfs). I realize the board house will most likely want just the path for the router and not its actual shape, but I want to create gerbers with the routed slots so there's no confusion about inside vs. As well as I like having the 3D view look like what I expect to get. Make sure the width of the lines is at least 1 mil or larger. The board is milled/cut to the middle of the line, so thickness of the line does not impact the result. Making the thickness of the lines a non zero number will reduce problems down the road with external gerber viewers. Drawing Cut Outs and Slots.

Usually I just add a pad that’s defined as a slot with a very small pad in the middle

Altium Board Slots

This time I was using OSH Park, and as it turned out things were not that easy. Their process does not support milled slots in the drill file. Instead slot outlines need to be on the board outline layer, and at least 100 mills wide. After a bit of fiddling, here is how I got there (This assumes you have the part footprint open for editing in PCB Library editor) :

  1. Draw a closed outline of the slot on the keepout layer, making sure it’s 100mil or wider. This also helps making sure polygon pours stay away.
  2. Go to Tools> Convert>Create Region from Selected Primitives
  3. Click on the newly created region and check “Board Cutout” box

    Making region a board cutout

  4. Add “CUTOUT” text inside the cutout on the keepout layer
  5. Update your parts from the library or place your new parts
  6. Do placement/routing/design rule checks
  7. When generating Gerbers, go under Gerber Setup>Layers and make sure to check Plot box near Keep-Out-Layer GKO. This will be your board outline/slots drawing for Oshpark
  8. Check Gerbers and confirm that GKO layer now contains outlines for the slots:

    Section of Keepout layer showing board outline, slots and the text for the fab

  9. Submit files as usually

Altium Board Slots Game

Big Disclaimer(s)- I am yet to receive my boards back, so while it appears everything satisfies the specs, I may be completely wrong and the boards will be ruined. I’ll post an update once they come in. The directions are for Altium 13, so if you use 14, some menus may look different. My keepout layer contains board outline as I generate that from board shape by default.