Minimum spacing between series components solder pads?

Community PCB Design
1

All,

I gave up on Altium, way to steep of a learning curve for me, picked up Eagle Cad and in less than an hour I found a great tutorial and learned how to make a proper footprint, versus a couple days of messing with Altium and never figured it out, ha ha.

Okay, I’m making an LED array of 52 LEDs. My question is, they are in series, and what is the minimum distance between the two component pads that will have a trace running in-between the two pads?

Right now they are spaced 10mil apart according to an article I read at aa-pcbassebly.com.

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2

It depends on the size of the track.

3

Leon,

Thank you for the response.

I will be running a layer for each die around the ring to handle the current with vias to the top layer.

The track width according to circuitcalculator.com’s calculator requires it to be a minimum of 0.874mil and that’s at 125% of the load, that is obviously very small.

What is the standard min width that’s generally accepted by board houses as manufacturable?

Also on another note I’ve googled if it is okay to put vias underneath a component, couldn’t find a answer to the question. Only that it was bad to put a via directly on the

solder pad.

The led’s I’m using are not high power leds and they do not have a thermal pad in the center and I’m wondering to save room as I’m restricted for space on this board. Can

I put a via underneath the component? I want to run a track from the solder pad to the center of the component and down a via to a power layer if I am allowed to do this.

According to an article I read it said to keep all components and traces 125mils away from the edge of the board so that the machine can grab the board. What about milling the inside? How far should I keep components and traces from a milled open area?

Thanks again for the help!

4

8 mil min. is most suitable for the low-cost PCB suppliers, like ITead.

It’s OK to put vias under parts. Vias in pads are a bad idea because they rob solder from the connection. They can be filled, but that is expensive.

You need to ask your board supplier about clearances.

5

Just make sure there are no metal bits on the component that can short out to the via…

/mike

6

Thanks for the solid advice guys.

Looks like there’s a bit less than a .20mm gap underneath the middle. I’ve attached a screenshot not very clear but it’s due to a poor quality pdf. Attached the datasheet.

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[free image uploader

Trying to source out a small SMD 1A 12-15vi to 12vo regulator I can mount on the board? All the ones I keep pulling up require 20vi to get 12vo.

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7

If they are 10th apart then your not going to get a track between them.

On a fine pitch board with a BGA & fine traces made professionally maybe (at higher cost) but not on a board being made by a relative newcomer using Eagle.

Run your trace elsewhere.