Tiny QFNs on 12mm tape and CL feeders - Page 1
Forum section: electronics / general

author: Mangozac
author_rank: Frequent Contributor
timestamp: September 21, 2021, 12:11:37 am
content: Hi all,We've noticed a few issues when placing really small packages like 3x3 QFNs and similar that are for some strange reason supplied on 12mm tape. Mounted to a Yamaha CL12 feeder. As indicated in the first photo, parts are regularly jumping out of the slot on the top of the feeder's tape cover!The issue seems to be that as the cover tape tensions up it's lifting the tape cover on the feeder. This allows too much slop in the tape as it travels through and obviously gives the part room to jump up once the cover tape has been peeled back. The feeder has a mechanism to limit this movement when locked into the pick and place, but this still allows for quite a lot of vertical movement of the plastic embossed carrier tape.Does anybody have any experience with this? Do we simply need to modify a specific 12mm feeder to prevent the tape cover from lifting? I'm thinking maybe just epoxy in a small piece to fill the gap when the feeder is locked in place.Thanks!

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: September 21, 2021, 02:10:57 am
content: I have been using 3x3mm QFN from TI on CL12 feeder, they work flawlessly. I think they are not very "light" to be popping out of tapes unlike LED.The gap you shown is about less than 2mm wide, so unless the cover is really lose and have too much of height left between the base and him, they might jump out.You seems to be having a lot of issues with feeders I believe? Maybe you can ask Kayo on how to adjust the feeder mechanically, they probably come across this sort of stuff all the time.I also notice if you buy feeder from different seller, they have slight variation and some perform better and more consistently than others.

author: Mangozac
author_rank: Frequent Contributor
timestamp: September 21, 2021, 02:46:49 am
content: I didn't believe it was possible for parts to pop out of the gap, but my machine operator witnessed it with his own eyes!No, we rarely have issues with feeders - this seems to be exclusively these small parts on the 12mm feeders. Sure, I will ask Kayo if they have any comments, but they don't make the feeders and the CL feeders are pretty commonly used here.

author: Matt-Brown
author_rank: Regular Contributor
timestamp: September 21, 2021, 05:02:06 pm
content: Couple of questions1) Is it ther same feeder, or different ones (try swapping out feeders)2) Is the feeder location always the same one? It could be the knock pin for advancing the feeder3) Most 3x3 ICs are in 12mm tape, so unsure why yu thought this was odd.

author: Mangozac
author_rank: Frequent Contributor
timestamp: September 21, 2021, 09:40:14 pm
content: 1. No, the problem has occurred on different feeders (swapping feeders is always the first thing to try).2. These are pneumatic feeders but no, the feeder location is different.3. I wasn't aware. Until now we've only used accelerometers in the 3x3 QFN and they came on 8mm tape.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: September 22, 2021, 05:31:47 am
content: I would suggest maybe trying to get a feeder from a different supplier maybe from a reputable distributor like Kingsun. These 12 mm are usually $70 a piece anyway, so it's worth a try. I have never bought from Kingsun before but I read good reviews on them here.

author: Smallsmt
author_rank: Frequent Contributor
timestamp: September 22, 2021, 06:39:36 am
content: It is simply an adjustment problem!If you look from top side you find a small hex screw locking the top slider adjustment screw.Release this screw and insert the tape.Turn the adjustment screw to lower the slider position. (it is an excenter screw)Finally fix the lock screw again.That's all!

author: Mangozac
author_rank: Frequent Contributor
timestamp: September 22, 2021, 11:43:10 pm
content: Quote from: Smallsmt on September 22, 2021, 06:39:36 amThese feeders we have don't have such an adjustment. There's only the cover slider spring tension. This is obviously a point of difference between lower end and higher end feeders!

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: September 23, 2021, 01:22:49 am
content: Quote from: Mangozac on September 22, 2021, 11:43:10 pmThis video is not adjusting what you want here but it basically show you how much adjustment you can do on other parts. Most of the adjustment require you to unscrew the HEX screw from the top. I can see 5 screws on my CL12 feeder.

author: mon2
author_rank: Frequent Contributor
timestamp: October 02, 2021, 03:16:45 pm
content: Our experience with embossed taped parts is to use the older FV12 feeders on our Yamaha SMT line. They work where the CL12 feeders did not.

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 03, 2021, 11:41:03 pm
content: Quote from: mon2 on October 02, 2021, 03:16:45 pmThat's good to know. I might end up adding a spacer to the 12mm feeders we have to help our issue.

author: 48X24X48X
author_rank: Frequent Contributor
timestamp: October 19, 2021, 03:45:26 am
content: @Mangozac A friend had the same issue but with a smaller 2x2 mm LGA package on CL12. After taking a further look, as the IC is 2 mm wide but the gap on the metal cover is also 2 mm, it's possible they pop out even in your 3x3 mm package. I think you can try putting a sellotape from the bottom of the metal cover with the adhesive part facing you. There's a metal shaft/rod that moves in and out along the 2 mm metal gap stretch but it's end doesn't reach the bottom side of the metal cover, so it could work in the sense that it won't disturb the sellotape. The tape will then prevent the IC from coming out of it's pocket. I also can't see if the metal cover can be further push down as it is already sitting flush at it's most minimum distance from the feeder body.

author: Mangozac
author_rank: Frequent Contributor
timestamp: October 21, 2021, 12:13:02 am
content: Thanks, that's good to have it confirmed!I haven't had time to investigate further but it may indeed be worth placing a piece of kapton tape in there as you describe.