Rubber domes automatic assembly - Page 1
Forum section: electronics / general

author: 3Deye
author_rank: Contributor
timestamp: December 04, 2024, 01:44:19 am
content: Hi,I'm looking for a pick-and-place system that works well with silicone rubber domes typically used in keyboards. See attached images. The input to the system is randomly placed rubber domes (basically unloaded from a bag) that need to be aligned, picked, and then placed precisely in their locations on the keyboard membrane (PET sheet). A nice bonus if the solution can dispense glue on specific locations and then put the rubber domes on top of it. This will be used for the production phase of a keyboard project I'm working on.

author: thm_w
author_rank: Super Contributor
timestamp: December 04, 2024, 09:43:30 pm
content: If its rubber dome then this must be a cheap product with high volumes no?Wouldn't it make more sense to do it by hand, then for production phase use a sheet as you show in your first image.

author: Kean
author_rank: Unknown
timestamp: December 05, 2024, 07:56:37 am
content: I imagine the solution might be to use a rotary vibration feeder, probably customized to the part shape, then a generic placer. Some placers have dispensing options for glue/paste.If this is for mass production, then you might want trays to carry the product through the placer, and some kind of automated optical inspection.

author: 3Deye
author_rank: Contributor
timestamp: December 05, 2024, 11:15:21 am
content: Thanks thm_w and Kean.I've looked into bowl feeders and am concerned about sticking to the surface and getting deformed due to how thin and elastic they are. That being said, after contacting some suppliers, some said it's not possible and others requested samples for the rubber domes, so hopefully they can figure out a solution.For picking and placing the rubber domes, I'm not sure which off the shelf solution would work here. I was hoping to find a gantry-style option similar to the pnp machines for SMT components but no luck so far. Also saw some robotic arms options but I think they're an overkill.

author: Kean
author_rank: Unknown
timestamp: December 05, 2024, 12:06:23 pm
content: The pick and placement part I would think is reasonably simple with a gantry system, but getting them oriented upright first is the trick.I am sure the vacuum picking would require some customisation due to the softness of the silicone parts.But this must be a solved problem if they are commonly sold as separate domes like that rather than molded into a complete sheet which is how I've seen them, but I see Apple used them like this and I amd sure others have too as they are the most common keyboard style.Have you tried asking your supplier of the domes?A quick search pointed me at this supplier, and they have some production videos of the domes where they mold them in a sheet then manually pick them off...https://www.rubber-keypad.com/Silicone-Keypad-Manufacturing-Process.htmlBut I didn't see anything for full keyboard assembly.

author: Benta
author_rank: Super Contributor
timestamp: December 05, 2024, 10:28:43 pm
content: If this is for mass production, why not have to domes produced as a full sheet that can be mounted in one go?That's the kind of dome keyboards I've seen so far. Using individual domes makes little sense to me.

author: thm_w
author_rank: Super Contributor
timestamp: December 05, 2024, 10:44:53 pm
content: Quote from: Benta on December 05, 2024, 10:28:43 pmThats what I said. Maybe the product is unique and an odd shape it could make sense, if not I don't understand it.

author: Benta
author_rank: Super Contributor
timestamp: December 06, 2024, 12:30:13 am
content: We're on the same page. I don't understand either.

author: 3Deye
author_rank: Contributor
timestamp: December 09, 2024, 07:19:45 am
content: I can't use the domes produced in one sheet because the keyboard switches are custom-made and use many mounting holes that must be cut in this dome membrane. Due to the many cutouts, doing so will cause manufacturing issues in these membranes as it creates a sort of Swiss cheese structure.