How close is too close?

Community PCB Design
1

I’m designing a driver board for an LED display and have very limited room. I’m trying to keep all of the IC’s on the top of the board as this will be more protected than the bottom. My current layout looks good (at least to me) on paper but I’m worried about how difficult it will be to solder all these components when it comes time for assembly.

I should say that I will be soldering by hand. I’ve never soldered smt components by hand but I work in an assembly house and have made friends with some of our most skilled reworkers :slight_smile:

The grid on the board is 100 thou.

Thanks

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2

If the wider pin spaced IC are SOICs then it should not be too difficult to solder them all by hand.

Of course if they are re-flow soldered then they could be much closer without problems.

3

That doesn’t look crowded to me. I’ve soldered much tighter boards than that by hand without issue.

4

Hello,

The board can be even smaller. Your routing is very clean. :slight_smile:

5

There’s plenty of space, that board could be made much smaller and still be easy to assemble with hand soldering.

6

Looking good, are you making the board yourself or getting it professionally made with plated holes?

If you don’t have plated holes then those connectors are going to be hard to solder given they are connected both sides.

I take it that there is plenty more routing to do yet.

7

Thanks for the confidence boost.

I thought about simply pasting and reflowing, especially since I work in SMT and have access to proper reflow ovens and paste. But then I have spend the extra money for a stencil on a board that will likely need revisions before I would try to do a small production run.

I do have more routing to do, there’s still a few, small components that aren’t even on there yet. And I will definitely be having my board professionally made. No sense in buying all the gear to etch my own boards. Besides, I’m pretty sure I’ll be wanting a solder mask when it comes time to do that QFP.

8

bveenema:
But then I have spend the extra money for a stencil on a board that will likely need revisions before I would try to do a small production run.

Just use a syringe to apply the solder paste. No need for a stencil on such a small prototype.
9

Are you working at a contract manufacturers or for a company that designs their own boards?

When I worked in & R&D dept if we wanted a personal board we would wait until we were getting a prototype

that we knew would soon have further revisions and put the personal ones in the corner of the screen so we could use that.

There is a [tutorial on here that mentions where you can buy cheap screens.](Solder Paste Stenciling - SparkFun Electronics)

10

mattylad:
There is a [tutorial on here that mentions where you can buy cheap screens.[/quote]That’s a nice tutorial, but I prefer Ryan O’Hara’s $25 stencils. Kapton is better than Mylar, since it cuts much smoother.

http://www.ohararp.com/Stencils.html](Solder Paste Stenciling - SparkFun Electronics)

11

You could also use PCB pool: http://www.pcb-pool.com/ . They have good prices and include a stainless stencil for free!