Question about tape and reel and component brokers

I encountered this quite recently. In my case, the assembler was willing to put the components on a reel (or maybe they just let them dangle, I'm not sure), but I needed to put the dummy leader on.

In the US, I found only two suppliers for dummy leader, both of them apparently small companies. The one I bought from was SmartSplice

I see that they have recently revamped their web page and it is now painfully slow and contains inconsistent and incorrect information - ah, progress - so you'd probably be best off emailing them. They were a bit hard to deal with but they did eventually ship what I asked for at the quoted price.

The other supplier I found (but didn't buy from) was Sierra Electronics

Their price was in the same ballpark, but the web page didn't list price and it took a while for them to get me a quote; so I ended up ordering from the other supplier. Other than that, I have no reason to prefer one over the other.

Another possibility (which I have also done) is to just order enough excess components that the assembler can throw some away to get the needed amount of leader. This is okay (might be cheaper than dummy leader) for inexpensive components such as R's, C's, diodes, and maybe even jellybean transistors; not so good for things like ICs or FETs, where throwing away

100 components would be a big expense.

Don't throw them out, keep them for prototypes and repairs.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Have you heard about Minireel? They sell smaller reeels of SMD parts.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida

Thanks for all the replies so far.

I can only guess from pictures of pick-and-place machines on how they do their job. It seems like there are 3 reels. The input reel with components feeds in and the cover tape is peeled open. On the output side, the cover tape is collected on one reel and the empty tape is collected on another reel.

Does the machine always peel the right amount of cover tape? Or does it peel more than necessary, wasting a few components whenever I do not use up the entire tape?

If you can "only guess", then you're working with the wrong assembly vendor. Even if you are only placing very small orders, your vendor should be able to take the time to tell you exactly what they need, and what they can do for you. Give them a call. There's no sense guessing.

It needs a certain amount of tape to feed into the machine, before it starts pulling components. That's the "leader". It actually pulls on the cover tape, rather than the carrier tape; when you get back partly-used reels, you'll see that they trim the excess carrier tape but they leave a lot of cover tape, to serve as leader for the next time you use the reel. I think the only reason they reel up the used carrier tape is because otherwise it would spill all over the floor.

Assuming you have enough leader, the machine doesn't, in general, use any more components than necessary. However, there's always human error, machine glitches, and so forth; so in general a vendor will request 5 to 10% more parts than are actually needed, and they'll give you back (on the reel) the unused ones. For instance, if you're making 100 boards, and each board uses one of a certain part, you'd want to supply them a reel of at least 110 parts.

"reglarnavy" mentioned that you can request reeled parts with leader from your vendor. In my own experience, if you're ordering less than one reel worth of parts, they will not include any leader nor will they include a reel. What you *can* always request is contiguous parts; that is, if you order 110 parts, you want to be sure that they're all on one piece of tape, rather than getting a piece with 100 parts and another piece with 10 parts. If you don't specify, you're liable to get the latter. So, you can request to get it all on one piece of tape; but it still won't have leader.

I have used the MiniReel products for small runs and they worked great. They are also inexpensive. The unused parts (from the run) are now part of my lab / skunkworks

Cheers

PeteS

I caught my former employer dumping out all the resistors from the rework department. Most were pulls from select in test, so I have thousands of good pulls from new boards to sort. I need to order a set of the Pomona SMD test tweezers to sort them with. I had a set on my bench and they were a real timesaver looking for wrong values, or cracked resistors. They came in handy for larger SMD ceramic caps, as well.

--
Service to my country? Been there, Done that, and I've got my DD214 to
prove it.
Member of DAV #85.

Michael A. Terrell
Central Florida