I'm making a PCB in Eagle. First I found my components, and now I have to put them in Eagle so I can draw the actual board.

Now the problem is, I have found this power resistor (I need 0.5 Ohm dissipating at least 4.5W. This one dissipates more, but is apparantly the cheapest I could choose from).

As you can see, there is no CAD design associated with this component. In the datasheet there is a recommended pad layout, but this would mean that the resistor is layed down on the pcb, whilst al other transistors that might need a heat sink are placed vertical on the PCB.

So my question is - how must I orient this component (horizontal/vertical/doesn't matter), and how an I find a CAD design to add this to Eagle?


1 Answer 1


TO-263 is a SMT package and lays flat on the board, with the metal back soldered to a copper pour with optional vias large enough to dissipate the heat generated by the device.

You are unlikely to find this exact component in Eagle. Take the TO-263 layout from another component and use it to create this component in your library. Add the copper pour on your PCB layout, not the component.

  • \$\begingroup\$ Is the copper pour only for the two pins of the resistor, or also for heat sink, as displayed in the datasheet recommended pad layout section? I've never made my own components yet since it seems like very much work. \$\endgroup\$
    – jdepypere
    Jan 22, 2014 at 16:57
  • 2
    \$\begingroup\$ Most of the heat will be dissipated via the heat sink. The traces on the leads should be large enough to handle the current being passed through the device. \$\endgroup\$ Jan 22, 2014 at 17:18

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