Duane BensonSometimes you don't want to buy a reel, full or partial, but still want your PCB parts all in one continuous strip. Everyone wants to use up their odds and ends, but once those are gone, it's easier for you if each part is one strip.
If you want to save a little money and can use a longer turn-time, you might want to choose a short-run production service with continuous strips. Short-run requires reels or a continuous strip of at least 12 inches in length.
Here are two questions you'll probably ask:
How can I make sure my parts add up to at least 12 inches (305 mm)?
There are two ways to do this. First, if you have some of the parts, measure the length and calculate the number of components per inch. Use that to determine the number of parts you need to get 12 inches. Make sure to calculate the length based on the quantity you need plus 10 percent (+50 percent) with 0201 passives.
If you don't have any of the parts already on hand, you can download the datasheet for the component. In the pack, you'll usually be able to. If the length comes out to less than 12 inches, use the parts per inch to figure out the total you need. If it comes out to 12 inches or more, you're set. Passives commonly come in 2 mm pitch tape or 4 mm pitch tape.
How can I make sure that my supplier sends my parts in continuous strips?
It's not uncommon for suppliers to send 50 parts in 5 different strips of tape. I've even received parts in strips of one. Each part was still in the tape, cut from the reel. They were just cut into strips of one. Neither distributor has a setting for a continuous strip, however they do have a place to enter special instructions. Simply state in the special instructions that you need uncut, continuous tape for all parts that come in strips of tape.
Duane Benson is the Chief Technology Champion at Screaming Circuits.