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I'm designing a 4 layer PCB, using positive and negative power planes along with a ground plane and a top signal layer. While making the schematic I've notice strange little Xs in some of the through holes of my through hole parts. Here is an example. enter image description here

I'm wondering if the little cross in the middle of the through hole means that a connection is being made from pin 4 of this chip to the VS- layer. In other words, is the via connecting the VS- layer (layer 15) to pin 4 unnecessary?

Also, I know that the via shows up as a design rule violation. I need to change the minimum blind via ration for this board, and I'm not looking for advice about this.

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Yes, the via is unnecessary. Any through-hole connection can connect directly to any layer in the board.

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The cross indicates a "thermal relief" connection to the plane. The horizontal and vertical tracks make the connection to the plane, and the darker non-copper areas around the pad provide a thermal break, so you can more easily solder the component lead to the hole.

Without the thermal relief, you would have to heat a large area of the plane to make a good solder joint.

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