No Need to Waste Parts

We love parts on reels. Who doesn’t? But reels aren’t always practical — and it’s not just about cost. Cost is, of course, important, but there may be other factors to consider.

Say, for example, you need 20 2.2K Ohm, 5% 0805 resistors. You could buy a small strip of 25 from Digi-Key for $0.32. That gives the 20 you need, plus a few spares just in case.

Alternately, you could buy a digi-reel ( a custom quantity reel). On the reel, you’ll probably want more parts to keep the strip long enough for the feeder. Let’s go with 250 parts for $1.39. Digi-Key charges $7 extra to create a custom reel, so that’s a total of $8.39. Still peanuts.

For a third choice, you could just buy a full reel of 5,000 for $10.64. Still peanuts. If you’re gong to need the same part for a lot of designs, this might make sense. But, there’s more than just cost to consider. You need to store and ship it. Shipping two dozen reels gets pretty expense. Storing and inventorying several dozen reels can become a hassle too. 6a00d8341c008a53ef01b8d1356272970c-320wi

The beauty of Digi-Key, Mouser and other places that sell cut strips is that they essentially become your parts warehouse. You pay the 32 cents and never have to worry about whether the part is in your inventory, how many are in your inventory, digging it out of wherever you stuffed the reel when you last needed it.

If you do buy and store the whole reel, you don’t need to ship the entire reel to us. Just cut a strip with the number you need, plus about 5% for that “just in case.”

Of course, if you need a few thousand of the parts go ahead and send us the reel. It would make sense then.

Duane Benson
Reel, reel your part
Solder it, solder it, solder it, solder it
Cost is but a factor

Pin BGA Interconnects

My “Speaking of Art in the Process” post used a photo of a point of load power module as an example. The specifics aren’t really relevant to this post though, but a commenter by the name of “Me” asked about the type of pins connecting the module to the main PCB.

“Do you know where to get those pins to attach two boards like that? I mean, do they sell just the pin for example on Digi-Key and give it a name, or is it just wire. Can’t see if they are pins with a lip to lift board to a set height.”

The part (above) came with the pins already on, so I don’t have a specific part number for the interconnect pins. I have some underside photos (below) that give a better view. They are basically solder-type terminal pins with a solder washer and BGA ball on one side (to attach to the main PCB) and either a press-fit or solder type side to affix to the module PCB.

I wasn’t able to find this exact part from Digi-Key or Mouser. Vector sells the solder washers and lots of interconnect pins of this sort, so they may be able to steer you to them with a phone call. This board uses the BGA style, but we’ve seen other POL modules of a similar type with thru-hole solder pins too. Digi-Key has lots like that. Here’s one example of some through-hole terminal pins from Mil-Max. You could use the solder-washers (like a T124 from Vector) to put some space between the module and the PCB.

Duane Benson