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LED Stick To Cover Tape

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#61842

LED Stick To Cover Tape | 17 May, 2010

Big problem. Certain LED from certain manufacturer sticks to the tape and reel cover tape. Peel back the cover tape and every LED lifts out of the embossed pocket and sticks to the cover tape. I believe this is from static and not any sort of adhesive residue. Can't pick the parts with nozzle because of this problem. Of course no one has ever heard of this happening.

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#61843

LED Stick To Cover Tape | 17 May, 2010

If it's not adhesive, try an ESD-type ionizer.

The objective of an ionizer is to eliminate surface charge on insulators and on isolated/ungrounded conductors. Practically speaking, the action of an ionizer is to drive the voltage on the surface of an object to be a small but non-zero value. Factors that affect this value are the fields emitted from the ionizer and the electric field of the earth. ANSI ESD STM3.1 defines a parameter called the Balance Voltage intended to be a measure of this value. [A Study of the Short Term Balance Properties of Ionizers of Various Technologies; C Newberg, River’s Edge Testing Service & L Levit, Ion Systems; ESD Journal, ]

No ones heard of it before. Right!!! We wonder why we've talked about this here on SMTnet previously. Look here for one of those threads: http://www.smtnet.com/Forums/Index.cfm?CFApp=1&Message_ID=28898

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#61850

LED Stick To Cover Tape | 18 May, 2010

The ionizer was something we thought about right away. I need to investigate further. Somehow I need to get the ionizer mounted on the chipshooter. An oldschool chipshooter. A turret machine. My other concern is can I blow the ionizer at the parts without blowing the parts out of the embossed pocket. Maybe I can ionize upstream of the pickup point or ionize the entire reel.

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#61852

LED Stick To Cover Tape | 18 May, 2010

We have seen the same thing on small parts (8mm tape) and what we did is sprayed some ESD mat cleaner on a lint free towel and wiped the cover and carrier tape down. Since the cleaner is static dissipative the issue went away and we were able to get through the troublesome reel.

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#61880

LED Stick To Cover Tape | 20 May, 2010

Hello,

We have also used an antistatic ESD mat cleaner as you described and it works well. Fortunately, this issue does not happen often.

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#61962

LED Stick To Cover Tape | 28 May, 2010

What is the humidity level in your facility? We maintain ~40% year round and never have any issues regarding ESD from cover tape peeling.

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#62043

LED Stick To Cover Tape | 11 June, 2010

Are these silicon based LED's? If so we are experiencing the same issue at our facility.

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#62193

LED Stick To Cover Tape | 6 July, 2010

hey, I'm having the same problem as you are. the component is sticking on the cover tape prior to pick and place. hoe do you address the problem??

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#62195

LED Stick To Cover Tape | 7 July, 2010

We have this problem only with one manufacturer of LEDs. Avago LEDs give us the problems where SunLED and KingBright do not. We put a magnet under the embossed cover tape. The magnet is mounted to the feeder. Holds the part in the tape pocket. LEDs are usually slightly magnetic. Check with pick and place manufacturer. Some have magnets available for their feeders. Otherwise you will have to buy a magnet and mount it yourself. I did this with one of our machines and the other machine feeders had the magnet option available from manufacturer.

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#62199

LED Stick To Cover Tape | 8 July, 2010

thank you very much...i'll try this up...

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#62200

LED Stick To Cover Tape | 8 July, 2010

I soldered a wire in the tape press lever of th feeder, so as to create a small gap where the cover tape passes and the component doesn't: in this way the component is pushed down in the pocket as soon as it tries to follow the cover tape.

regards, Olas

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#62204

LED Stick To Cover Tape | 8 July, 2010

Could this wire be helping by a second means, becuase it is grounded to the feeder it may be discharging the static at the point it is being produced? If so it could be bent to contact the film and not scratch the LED lenses.

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#62208

LED Stick To Cover Tape | 9 July, 2010

I don't know if it has also an antistatic effect: I intended it for its mechanical function.

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