I'm designing a compact PCB.

It consists of non-addressable 5050 RGB LEDs.

I'm concerned about how close they are. I'm going to use the SMD assembly service provided by JLCPLB.

Should I change the design?

Please feel free to recommend any other solutions, I'm all ears.

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You haven't given a part number for your LEDs, but the datasheet should tell you this information.

As an example, look at this excerpt of a datasheet:

enter image description here

You can see that for each dimension there is a 'MAX' column. You simply need to ensure your component placement respects this with regards to the LED package outer dimensions. Sometimes you may see a global tolerance on dimensions rather than a nice table like this.

I like to make my component silk outlines to the package maximum tolerances rather than the nominal. That way I can place them right up next to each other in the PCB capture software without having to worry.

Edit: Please also see @dim's excellent comment about some assemblers having a process requirement for component separation. So, check your component maximum package size tolerances and check that your particular assembler does not have a process limitation.

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    \$\begingroup\$ Pretty sure the minimum distance between components for manufacturability is also dependant on the characteristics of the pick-and-place machine, not just the components themselves. \$\endgroup\$ – dim May 6 at 8:32
  • \$\begingroup\$ Good point. Thinking about it, I've never had an issue with machine placement accuracy being the limiting factor. Have I just been lucky, or is this something that should always be considered/queried with the assembler? \$\endgroup\$ – Cursorkeys May 6 at 8:37
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    \$\begingroup\$ I think this should be asked to the assembler. Most of them have explicit specifications for this: for example, look at blog.seeedstudio.com/2017/05/15/component-layout-considerations, paragraph 4.2.2, it says: "The required distance between SMD components is: - Same component: ≥ 0.3mm - Different components: ≥ 0.13 × h + 0.3mm (where h is the maximum height difference of the surrounding neighbors)". Other manufacturers may have different requirements, but this shouldn't be ignored. \$\endgroup\$ – dim May 6 at 8:42
  • \$\begingroup\$ I've just spoken to one of my assembly houses and they claim (average) placement accuracy of 30um! Obviously there is a bit of variation between suppliers... They only cautioned that placing very tall and very shallow components side by side may be limited by tool reach. I would definitely make your comment an answer, I had no idea that this could be an issue. \$\endgroup\$ – Cursorkeys May 6 at 8:50
  • \$\begingroup\$ I'm too lazy to make an answer out of it now, but I think it indeed would be worth mentioning to make a full answer. I have a deal: if you think it makes sense, integrate this in your own answer somehow, and I'll upvote it. \$\endgroup\$ – dim May 6 at 11:48

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