A new (to me anyway), very nice, momentary switch...

Thread Starter

Ya’akov

Joined Jan 27, 2019
5,657
Just received an order from AliXpress of some unusual membrane switches which I am very impressed with.

They come in a variety of styles, with 1, 2, 3, and 4 button configurations. The switch itself is a membrane type dome switch. They are surface mount using a self-adhesive backing and are only 1mm thick, so very unobtrusive when mounted and taking up no space at all inside the case.

I got the grey ones, but there are four colors (and a numeric keypad) available. I have subsequently ordered more colors.
1650964748472.png

The leads are flex PCB terminated in .1" (2.54mm) female headers which is very convenient. Mounting is simple and clever. A ¼" (6mm) hole allows the connector through the panel, the gap the left side of the cable (in photo) is enough to completely cover the hole. The appearance is very neat.
1650964885714.png 1650964920899.png
A quick test shows they are relatively low bounce and the construction suggests that if they are not waterproof, they would still be quite water resistant.

1650965131402.png
Of course I don't know about longevity yet, but they seem robust and are very inexpensive. I ordered more in case they were no longer available when I needed them.
 
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MrSalts

Joined Apr 2, 2020
1,762
membrane type dome switch
Is it a dome switch
- a stamped piece of sheet metal that is soldered to a rigid PCB - the spring action of the stamping creates a return spring for a momentary switching effect as the center of the switch plate to make contact.

or...
is it a membrane switch?
- a flex film circuit mounted copper (or conductive printed ink) side down over an FR4 PCB or a second flex circuit and sealed with some amount of air inside to create a return air spring to create a momentary switch
 

meowsoft

Joined Feb 27, 2021
549
Just received an order from AliXpress of some unusual membrane switches which I am very impressed with.

They come in a variety of styles, with 1, 2, 3, and 4 button configurations. The switch itself is a membrane type dome switch. They are surface mount using a self-adhesive backing and are only 1mm thick, so very unobtrusive when mounted and taking up no space at all inside the case.

I got the grey ones, but there are four colors (and a numeric keypad) available. I have subsequently ordered more colors.

The leads are flex PCB terminated in .1" (2.54mm) female headers which is very convenient. Mounting is simple and clever. A ¼" (6mm) hole allows the connector through the panel, the gap the left side of the cable (in photo) is enough to completely cover the hole. The appearance is very neat.
A quick test shows they are relatively low bounce and the construction suggests that if they are not waterproof, they would still be quite water resistant.

Of course I don't know about longevity yet, but they seem robust and are very inexpensive. I ordered more in case they were no longer available when I needed them.
What oscillocope model do you use ?
 

MrChips

Joined Oct 2, 2009
26,077
I received a large number of dome switches as samples from a manufacturer.
I have used them in my home projects by laying out the contact pattern on the PCB. I simply taped the dome switches on to the PCB with "Scotch" tape. They work very well.

1650975201683.png
 

MrSalts

Joined Apr 2, 2020
1,762
@MrChips I was going to say, they can be soldered, but, now that I think of it, they are available with peel-and-place adhesive and I saw one company offering them on a tape spool for automated assembly.
 

Thread Starter

Ya’akov

Joined Jan 27, 2019
5,657
I received a large number of dome switches as samples from a manufacturer.
I have used them in my home projects by laying out the contact pattern on the PCB. I simply taped the dome switches on to the PCB with "Scotch" tape. They work very well.

View attachment 265865
These are described by the seller as "membrane" but they certainly use a dome. The base part, though, is flexible so I think the flex PCB leads are part of a flex PCB with the contacts on it. I really like the way they can be mounted with effectively zero space needed behind.

When the additional ones arrive I might take one apart to see what the internals are like.
 
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maxcburk

Joined Oct 23, 2018
1
These are described by the seller as "membrane" but they certainly use a dome. The base part, though, is flexible so I think the flex PCB leads are part of a flex PCB with the contacts on it. I really like the way they can be mounted with effectively zero space needed behind.

When the additional ones arrive I might take one apart to see what the internals are like.
Ya'akov,
I know this a couple months old but figured i'd chip in since I am an engineer at a <link removed>.
Even though a membrane switch assembly uses a dome it is still a membrane switch, this is due to the flexibility of the metal dome acting as a flexible membrane. The ASTM defines a membrane switch as "switches that have at least one contact that is made of or attached to a flexible substrate". So as long as something is flexing in the assembly, it is likely considered a membrane switch, but to more accurate, it has to be in a sandwhich of layers as opposed to a residing inside an enclosure (like an smd or thru switch). Read More info on membrane switches <link removed> which shows the various common layer stack ups of membrane switches, along with exploded animations to get a better idea.

<MOD: removed links>
 
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Thread Starter

Ya’akov

Joined Jan 27, 2019
5,657
Ya'akov,
I know this a couple months old but figured i'd chip in since I am an engineer at a <link removed>.
Even though a membrane switch assembly uses a dome it is still a membrane switch, this is due to the flexibility of the metal dome acting as a flexible membrane. The ASTM defines a membrane switch as "switches that have at least one contact that is made of or attached to a flexible substrate". So as long as something is flexing in the assembly, it is likely considered a membrane switch, but to more accurate, it has to be in a sandwhich of layers as opposed to a residing inside an enclosure (like an smd or thru switch). Read More info on membrane switches <link removed> which shows the various common layer stack ups of membrane switches, along with exploded animations to get a better idea.

<MOD: removed links>
Thanks. I was unsure of the taxonomy and didn't look it up.
 
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