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I have made a tactile switch package and as the picture shows pin 1 and 2 are internally connected, same for pin 3 and 4.

Package and symbol

The package have 4 pads and the symbol only 2. I have connected pads 1+2 with symbol pin 1 and pads 2+4 with symbol pin 2.

enter image description here

Now, here comes the problem: The router insists on connecting pin 1 and 2 to each other, same for pin 3 and 4. (as shown here)

enter image description here

Since these already are connected inside the package it isn't necessary to connect them on the board. In fact the router should be able to use this fact to optimize the result (as in this mock up where the yellow trace can run straight under the package).

enter image description here

How can I get the router to understand that these pins already are connected internally? In fact it can benefit from it and use them as a bridge to span over whatever traces running under the package.

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  • \$\begingroup\$ How did you connect the pads internally in the package? Or perhaps you mean the internal connection is in the device itself? \$\endgroup\$ – KnightsValour Jul 30 '15 at 20:31
  • \$\begingroup\$ Internally connected pads must have names such as name@1, name@2, name@3, name@4, ... But the problem remains, Eagle still wants you to connect them once egain with the traces on PCB. \$\endgroup\$ – Chupo_cro Oct 29 '17 at 1:18
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enter image description here

In eagle 7 your problem is solved. klick on the symbol in the connect-dialog (red cyrcle), so you can change if the pins of the same signal have to be connected in the layout.

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The important part of the answer is yes, but for what it seems you're actually interested in the answer is no.

Eagle is treating them as connected internally for the design rule checks (DRC). But that doesn't mean the autorouter can be smart about it.

In Eagle 6 you can define connections the way you have in your part; you only need to create one pin to connect to multiple pads, as Cadsoft puts it:

You can now connect one pin in the schematic symbol to any number of pads of the package. With this function EAGLE can handle components internal connected pins. Compared to previous versions schematic symbols look nicer and you save time in defining them.

The autorouter is not that clever though. Its default behavior actually makes sense too, if at all possible, pads should be connected externally as well. It takes a human to see the 'cleaner' way. With a bit of thought on the plethora of additional combinations the autorouter would have if it opened the option of not externally connecting internally connected pads it makes sense why Cadsoft left it out.

The modification you made to what the autorouter did is not a violation because Eagle recognizes those pads as internally connected. You could, in fact, connect only half the pads (not any half) without error.

You'll often need to clean up after the autorouter, at least in this case you don't need to waive any DRCs.

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Look at the Omron switch from Sparkfun's library. Package: TACTILE-PTH, value: SWITCH-MOMENTARY-2PTH. It is under SparkFun > SWITCH-MOMENTARY-2

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