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  • Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface

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#91565

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface | 18 November, 2024

Hello everyone,

We're currently experiencing an issue with placing Kingbright ATS2013UV385 type LEDs on our PCBs using Siplace X equipment. The component has a sticky silicone coating on its surface, which causes it to adhere to the nozzle, preventing successful placement on the board.

We have tried using various types of nozzles, including standard and ceramic ones of different sizes, but the result remains the same – the part sticks to the nozzle and fails to detach during placement.

Has anyone encountered a similar issue or have suggestions for potential solutions? Any advice or insights would be greatly appreciated.

Thank you in advance for your help!

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#91568

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface | 18 November, 2024

Can you repackage them using tape & reel? Add the masking dots on top of the LED would do the trick.

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#91571

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface | 19 November, 2024

Since you are using Siplace X series equipment, have you checked the Siplace ProDesk software for the component shape settings for that part? There is a section in 'handling' that has 'placement air kiss' settings. That gives a little burst of air to help release sticky parts from a nozzle.

Besides that, we have also had issues with sticky components. Some parts we needed to put in a humidity oven to increase the amount of moisture on the component surface. Unless your part is moisture sensitive. Maybe it needs to be dried more?

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#91574

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface | 19 November, 2024

One option is to put the coil in the refrigerator (tried it works), but everything is at your own peril and risk.

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#91576

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface | 19 November, 2024

I have the pleasure of dealing with LED placements daily with many LED suppliers.

What is the temp & humidity of your facility, i have found this to be the biggest impact when placing "tacky" LED's cree are wonderful as the temps increase. to the point where i now have fitted various temp & humidity sensors around the place & am able to put critical points in of if temps hit x amount then we know it is pointless even trying to place some LED's but its been useful to obtain capex to improve the facility to allow continues running

Also as advised, air kiss settings are critical along with the placement height. Some LED's will also require specific or custom nozzles for repeatability.

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#91590

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface | 20 November, 2024

Thanks to everyone for their participation and advice. This is what i got from ASM support:

LED's are used more and more without an external body (with and without lens dome). The LED nozzle contact area is than an overall soft silicone surface.

Influencing parameters and their variation onto stickiness:  the soft silicone mixture of the LED types respectively of the manufacturing lot variation  the Curing of the LED types respectively of the manufacturing lot variation  a material mix up with residues in the soft silicone packaging  barrier layers of thin materials or material mixtures All that doesn't allow one excellent solution for all only a best state of anti- stickiness is to achievable.

To achieve the lowermost stickiness / adhesion for the placement moment we:  optimize a polyurethane (PU) –base mixture (Shore hardness 90 A) with special additives.  reduced nozzle–LED–contact area (no contact to lens surface inside the nozzle / plane LED's possibly placed with PU-Melf nozzle / other special surface geometries)  use only rough surfaces in contact area.  have additional vent hole(s) to reduce vacuum holding force on LED contact surface.  For air kiss placement use 150mbar or increase this to max. 255 mbar.

To achieve the lowermost stickiness / adhesion for the placement moment we suggest you:  to gain for the shortest possible residence time of the LED on the nozzle. (by: placement force standard 2N / No waiting time between pickup & placing(also not for 2nd gantry of one Placement area) / No acceleration reduction /no special profile / no special mode in vision / no step mode / No safety mode / If necessary use only half of the available segment from head (example: 6 from 12segments) / (also not with other different nozzle types)  Temperature in production surrounding of that LED's as low as possible. Mean: best for X-Feeders single position on the feeder table (no neighbor feeder heats up pickup area and the air flow avoid temperature hold up inside the machine.)  Clean the PU-nozzle tips from residues. Residues increasing the stickiness after a placement period. Use Soap water (dish liquid) to remove soft silicone from PU nozzle tip.  The Solder paste depots should be as large and thick as recommended from LED manufacturer.  Possibly the operator has to remove LEDs from nozzle after an extended residence time (long lasting machine stop after pickup increase the sticking force on the Nozzle surface).  It might be helpful to place not latest manufacturing batches – with time the silicone loose stickiness.  It also helpful if you have the chance to place with the more `sensitive´ CP 20 plus (4/6Xxx) Cp20plus plus(4/6Xxx) placement heads.

Miscellaneous:  Set X-feed modules to slow mode improves pickup situation for LEDs with 'oversized lens' (e.g. lens 2.0mm on 1.6x1.6mm footprint)  Cree Tape pocket in the past - XTE – HV 3,7mm square with rounded edges (barreled pocket with R=2.2mm) (see XLamp XTE Datasheet page 15) for a better access to LED's with round nozzles.

 Feedback especially 12mmS-Feeder: for a reliable pickup rate respectively due to the very high lenses in the tape pocket, deactivate the shutter of the 12mm S-Feeder (through cover foil in pickup window & not at removal edge) or order a special Pickup window for 12mm S-Feeder without shutter "176188" (e.g. useable for Rebel DS/ES and Cree XP/XT.)

May be this will be useful for siplace users and not only.

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#91596

Issues with Placement of Kingbright ATS2013UV385 LED on Siplace X – Sticky Silicone Surface | 20 November, 2024

There are one more try on silicone surface LEDs. Use rotated nozzle on LED. Catch them on shorter side and not on longer side. Turn off pick-up vaccum if the nozzle have bigger surface as LEDs have - false vaccuum response. Keep turn on placement vaccuum measuring. If the machine gives you fail, than turn on placement vaccuum also and do a try again. This settings works on 5630 LEDs which also can be really sticky at certain suppliers.

If this not works, do the placement on basic placement settings (as ASM recommended) and use less sleeves on head to have bigger airkiss volume during placement.

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