Tag Archives: plated through-hole components

Cost Reduction in Design — More Advice

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If you’re looking for the absolute, cheapest possible assembly service, you’ll need to look outside of North America. If you really need a decent price with good quality and good service, you can keep your gaze West of the Atlantic and East of the Pacific.

Like everything else in the modern world, design decisions can have a pretty big impact on your cost. So, lets take a look at some design decisions that can make your manufacturing more affordable.

  • Accept longer lead times

Lead times are one of the biggest factors in electronics manufacturing. Screaming Circuits can turn a kitted assembly job overnight, but it costs a lot of money to do that. Screaming Circuits also has a 20 day turn-around that is much, much more affordable. Accepting longer lead times on PCB fab will drop your cost as well.

  • Avoid leadless packages like QFNs and BGAs

We build tons of QFN and BGA boards – even down to 0.3mm pitch micro-BGAs. That’s great if you need those packages. However, since all of the leads are underneath, we have to x-ray every part. That adds a bit of cost to the process. If you can, stick with TSSOPs and other parts with visible leads.

  • Use reels, or 12″ or longer continuous strips

We will gladly assemble parts on strips of almost any size. But, to save costs, use full or partial reels or continuous strips of at least 12″ long. It costs us less time to work with reels and continuous strips, and we pass those saving on.

  • Stick with surface mount

These days, through-hole components tend to be hand-soldered. That costs more than machine assembly, so use surface mount wherever possible. Surface mount components tend to be less expensive than through-hole too. If you do need a few through-hole parts, this is an opportunity to put in a little sweat equity by soldering the through-hole yourself and save a bit of money.

  • Panelize small boards

We can work with really tiny boards individually, but sticking with a larger size makes the job easier, and, again, we’ll pass those saving on. If your PCB is smaller than 16 square inches, panelize it. We put in less labor and you get a price break.

By following these guidelines, you get a decent price and really good quality and service.

Duane Benson
That would be telling

http://blog.screamingcircuits.com/

Through-Hole Parts

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Screaming Circuits uses machines to place surface mount parts; even if it’s just one board. Through-hole is a different story, though. Way back in the cobwebby section of the building, we do have a through-hole part sequencing and insertion machine. Our volume manufacturing division still uses it on occasion, but it’s just not efficient for small quantities, which is why through-hole parts get hand-inserted at Screaming Circuits. We have three options for soldering the parts into your prototype. We can hand-solder all the parts, we can send the board through our selective solder machine or we can send it through the wave solder machine. We’ll pick whichever route makes the most sense based on quantity and configuration.

It’s good that we can solder through-hole parts, but how, you might wonder, do we know where to put the through-hole parts? The SMT has the centroid file to tell our machines where to put them. Through-hole locations being more of a manual process, we rely on visual data. If your silkscreen markings are readable, we can use that as a reference. If the parts will only fit one way into one footprint on the board, then it’s not much of a challenge. Regardless, make sure that the polarity is clear for any polarized components.

Sometimes, though, there isn’t enough room on the PCB for clear silkscreen and parts will fit in a number of different places. That’s where the assembly drawing comes in. This illustrates an example of a suitable assembly drawing. It’s got your web order number in the image and all of the parts are clearly pictured and their locations clearly identified. If any of the parts are polarized, make sure you include that information as well. Send the assembly drawing as a .JPG or PDF file format in your ZIP file with the BOM, Gerbers and Centroid.

Duane Benson

It just goes to the back side of the board. It’s not a wormhole going to another galaxy. Or is it?

http://blog.screamingcircuits.com/