Consider Packaging in Your PCB Design
July 13, 2023
After creating the RP20-Footie capacitive foot (hand, or other body part) interface, I realized there was a small problem. It is very hard to get into the standard 4 x 8in bubble mailer that I use to send most of my small boards. Sure, I could use a larger box or mailer, but efficiency and inventory management is the name of the game at jcdevices.com. As of now, I do all the packaging myself, and inventory resides in a closet.
So, the decision was made to reduce the size of this board from 100 x 100mm to 99 x 99mm. This will make little difference to those that purchase an RP20-Footie. However, it seems like a rather silly reason to modify a design parameter–almost like neglecting to chamfer a corner because you can’t figure out how to draw it in CAD. Or maybe it’s perfectly reasonable.
Packaging Isn’t Rocket Science… Or is it?
Image Credit: By Photo credit: NASA/Ben Cooper - http://mediaarchive.ksc.nasa.gov/detail.cfm?mediaid=49261, Public Domain, https://commons.wikimedia.org/w/index.php?curid=13272196 (cropped/rotated)
According to a story found here and elsewhere, the design of the Space Shuttle’s solid rocket boosters (SRBs) can be traced back to the width of a horse’s behind. It posits that roman chariot wheel spacing was based on the width of two side-by-side horses, which led to uniform ruts in the roads, which was the reason that the standard spacing of railroad tracks is 4 feet, 8 ½ inches apart. Since the Space Shuttle’s SRBs had to be transported by rail, this spacing restricted their diameter, even though they otherwise might have been a bit fatter.
While this makes for a nice story, the correlation between Roman chariots and the Space Shuttle’s solid rocket boosters may be at least a bit apocryphal, according to a rather involved fact-check on Snopes.com. At the same time, manufacturer Thiokol did have to take transportation into effect as they moved the 12.17 ft diameter, 149.16 ft length boosters from Utah to Florida on the rail system.
Notably, in 2007, a train carrying segments of these boosters did derail after a trestle collapsed. Nero may have burned Rome, but one might say it’s a bridge too far to blame him or his countrymen for this particular space-age error. All that being said, if you need to adjust your PCB size or other project to account for shipping, I say it’s a perfectly legitimate reason.
Other Notable Packaging Examples
Efficient packaging is essential in our global economy. Consider that home goods giant IKEA is synonymous with “flat pack” furniture, specifically designed for efficient shipping and a low price point. While less ubiquitous, triangular crayons are an especially clever innovation, allowing for packaging without the wasted space inherent in cylindrical designs… or maybe it’s to keep them from rolling off the table.
One might even call 3D-printing an advanced packaging methodology. Here, a “thing” is sent in the form of a file from one person to another with no physical medium at all, save the general-purpose filament at the “receiver’s” location.
Do Consider Space and Packaging
Packaging and logistics may not be the most exciting part of a project. However, in our world where we buy and sell online, and pay for transportation, shippability can be the difference between a project’s success or failure. If better transportation properties mean shaving a millimeter or two off the edge of your PCB in a non-critical manner, don’t hesitate to take a chop or two!