Surface Mount Prototyping

Hey Everyone,

Here’s what’s going on with the Analog Voltmeter Alarm Clock. The plain AWK-105 Clocks are rolling through production, so we can focus on the task at hand, Alarm Clocks! Our big milestone has been a prototype circuit board made. Read on for pictures and more details.

Equipment Upgrade

For the longest time, I’ve been using my grandpa’s soldering iron along with a roll of tin/lead rosin core solder, both of which look like they were purchased in the late 60′s / early 70’s. They worked (lead solder works great!), but the iron took forever to heat up, and soldering fine pitch surface mount components could be tough. We upgraded to a more modern hot air solder reflow station, which let’s us melt solder paste and even do lead free work for our prototypes. (Our production manufacturer has always built lead free, RoHS compliant boards for us.)

older soldering iron

Prototype Circuit Board

All this brings us to the reason for the equipment… our prototype Alarm Clock circuit board! There are hundreds of interconnections on the circuit board and if any one was designed or built incorrectly, the board won’t work, so we always build one on our own(sometimes more!) before unfortunately ordering what would amount to a couple hundred expensive drink coasters.

This circuit board differs from the base Clock in a few ways… namely it has more components on it, like the buzzer and the LED indicators, and it has a couple other cool features we’d like to point out.

smt board design option

A big theme with this board is designing for flexibility. For example, depending on our supply chain, the buzzer might be soldered directly to the circuit board as a surface mount component, it may have short lengths of wire called “flying leads” that get soldered to the board, or the wires might have a connectorized plug on the end. We’ve designed in the various “footprints” on the board so that we can adapt to what’s available.

Now that the board is done, we’ll also have a software test bed to develop the alarm clock “firmware” on.

So what’s next?

Well, as we just mentioned, getting the software up and running is our next main task. In parallel, we’ll also be procuring some of the off the shelf components, and getting the build procedures ready for our assembly team.
Best regards!
aka THE Awkward Engineer

1 comment

  • It’s too bad that your production facility meets RoHS, because you are guaranteed to eventually get tin whiskers (which will cause short circuits) when you use lead-free solder. The only thing that prevents tin whiskers from forming is to use solder containing at least 4 or 5% lead, but RoHS requires 0% lead. There are no requirements to use lead-free solder on electronics devices manufactured or sold in the USA, but you have to use lead-free solder to sell to EU countries because they require everything they make or import to meet RoHS requirements.

    Steven Karty

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