Has anyone used SMD dome switches?

Been working on my PCB designs for the F/A-18C UFC, and has anyone played with the SMD dome switches? (Like these?)

If so, what are your thoughts on them?

I'm getting more into SMD, and curious why I was so afraid of them for so long. I'm digging the extra trace room on the opposite sides of boards.

I've been using smd resistors and caps where ever I can but I have never seen these type of switches before. They would have been an interesting choice for the CDU. Most of my panels are now complete but maybe I’ll try them in my next build.

Thanks for highlighting them.

Out of interest the link looks like a handkerchief, what is it, is that like a flexible top to a microswitch?

Out of interest the link looks like a handkerchief, what is it, is that like a flexible top to a microswitch?

Its basically a metal dome. It gets soldered onto 4 solder pads, with a center pad underneath it. When the switch gets pushed, it completes the circuit by shorting the center pads with the 4 others in it's footprint.

I'm going to order a bunch.

YOu will find them in real MFCDs and CDUs I have not had any fail but they are a price switch to use the dome is just half of the switch the other countach half would be built in to a custom PCB. IF they do fail or break easy enuf to fix with a replacement.

Its basically a metal dome. It gets soldered onto 4 solder pads, with a center pad underneath it. When the switch gets pushed, it completes the circuit by shorting the center pads with the 4 others in it's footprint.

 

I'm going to order a bunch.

I just read the datasheet (http://www.keyelco.com/product-pdf.cfm?p=14316) and there's a comment about the domes being placed on PCBs, not soldered, what would be the go with that?

Cheers

Peter

I just read the datasheet (http://www.keyelco.com/product-pdf.cfm?p=14316) and there's a comment about the domes being placed on PCBs, not soldered, what would be the go with that?

 

Cheers

Peter

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I've used them a couple of times, pretty handy things for when you want ultra low profile switches (I used them with a laminated sheet over it, like old style alarm panels), or when you are adding 3d printed covers over them (or anything else).

Like you noted, you don't solder them, they got some flex in them, so solder would be to brittle. You just stick them down with some tape/plastic.

Just make sure to get the pcb pads right for them (follow the datasheet), and get a good finish on your pcb, I've had some bad experiences with these in combination with HASL from cheap chinese suppliers (the 10pcb's for $8 kind), ENIG works great.

Regarding the caps, unless you want to buy 5000 at a time, buying them might be an issue. So you might want to get in touch with Snaptron in CO (http://www.snaptron.com/). They shipped me a sample kit with like 12 different kinds and ~20 of each type for free when I asked for one. (they got a ton of them, different kinds of push-forces, shapes, etc, including with holes in it, so you can even stick smd led under it.. :) )

I've used them a couple of times, pretty handy things for when you want ultra low profile switches (I used them with a laminated sheet over it, like old style alarm panels), or when you are adding 3d printed covers over them (or anything else).

 

Like you noted, you don't solder them, they got some flex in them, so solder would be to brittle. You just stick them down with some tape/plastic.

 

Just make sure to get the pcb pads right for them (follow the datasheet), and get a good finish on your pcb, I've had some bad experiences with these in combination with HASL from cheap chinese suppliers (the 10pcb's for $8 kind), ENIG works great.

 

Regarding the caps, unless you want to buy 5000 at a time, buying them might be an issue. So you might want to get in touch with Snaptron in CO (http://www.snaptron.com/). They shipped me a sample kit with like 12 different kinds and ~20 of each type for free when I asked for one. (they got a ton of them, different kinds of push-forces, shapes, etc, including with holes in it, so you can even stick smd led under it.. :) )

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