Getting started with Surface mount

[soggybag]

I'm looking for advice to get started with surface mount parts.

I'm using Eagle. I see a few surface mount parts in the library. Typically the parts are 603, 805, or 1206. What should I use? What is available? I need to spec parts I can actually find.

For electrolytic caps, should I go surface mount or through hole? Or does it matter for size? For example 100µ caps should I go through hole or can caps this large be found surface mount?

What about other parts like op-amps? Can these be found surface mount for typical part numbers used in pedals?

What about transistors? What can you get surface mount?

Looks like my library has ICs in SOP. Is this a goo choice to replace DIP parts?

[Ripthorn]

I like 0805 passive components. Unless I really need the space I stick with through hole electrolytic caps. SOP/SOIC is great for IC'S. You can get most anything surface mount these days, and usually cheaper than through hole. For passive and really common components, LCSC is super cheap, $15 min order, and reasonable shipping.

[mark2]

The main advantage of surface mount electrolytics, in my experience, is if you're having them assembled for you in bulk. i.e. time savings.

But they aren't much smaller, and if you go with JLCPCB they're extended parts, so usually not really worthwhile for one offs and prototypes.

[soggybag]

Thanks for the replies.

@ripthorn what is LCSC?

[Ripthorn]

LCSC is a parts supplier out of China. They are the component an of JLCPCB. It's where I buy my SMD passive components.

[sk99builder]

LCSC is a parts supplier out of China. They are the component an of JLCPCB. It's where I buy my SMD passive components.

Is the quality of jlcpcb ok? being a Chinese production?

[Ripthorn]

Never had an issue or of the over 100 boards made. You can't get ENIG,I don't think, and the silk screen can get a little tough to read when very small, but it works great for guitar effects.

[mark2]

Is the quality of jlcpcb ok? being a Chinese production?

You can in fact get ENIG now. It more than doubles the cost though.
I've ordered tons of boards from JLCPCB and just do their cheap HASL and I wouldn't say it's great; e.g. the surface of the plating is wavy and sometimes floating free in the holes, but it doesn't really add much if any hassle to assembly, and once you have it assembled it's going to last just as long as a nicer PCB.

Or more simply: quality is good enough, and IMO doesn't make any practical difference.

[amptramp]

I would imagine the biggest thing to sort out is the solder and soldering iron.  In series production, we used paste solder that had flux in it and for most production, we used vapour phase soldering (basically a hot freon vapour bath) or infrared soldering.  For simple projects, it is possible to use a soldering iron with a fine point tip and a magnifier but there is a great probability of solder bridges between, say, leads on a flatpack.

I think the manufacturing process will be more of an issue than the availability of components.  The problem with components is they are sold in reels of thousands, so you have to buy from someone who is willing to ship you the quantity you want off a reel.

[vigilante397]

The problem with components is they are sold in reels of thousands, so you have to buy from someone who is willing to ship you the quantity you want off a reel.

Even that isn't a big deal, all the suppliers now sell "cut tape" where you order as many of something as you want and they cut tape off the reels for that quantity. Agreed that the manufacturing process is the biggest learning curve.

When I started in SMD I soldered by hand using an Amscope microscope and got decent results, but it was tedious and looking at the boards you could tell they were hand soldered. Eventually I got a cheap (~$150) infrared reflow oven and started applying paste with a syringe for everything. I got better results, but squeezing paste by hand for every single pad on a complex PCB is awful and hurts your hand after a while. So then I started ordering stencils with my boards so I could squeegee on the paste with a putty knife, and that's when I started getting faster and more professional-looking results. Elecrow and JLCPCB both have easy-to-order stencil services for less than $10 per stencil. I used to "panelize" my stencils, putting up to 6 designs per stencil to save a few bucks instead of doing one board per stencil.

All this became irrelevant when I decided pick-and-place assembly was the way to go for larger-scale production, and now I get pre-assembled boards direct from JLC.