PCB speaker breaking due to shock

I have a simple project which uses a PCB mount speaker like this one: https://www.cui.com/product/components/speakers/miniature-(10-mm~40-mm)/cls0201mp

The PCB is mounted inside a plastic enclosure, but if it experiences some shock (like being dropped on a hard floor) sometimes the connections between the speaker pins and the magnet wire breaks, since the speaker is basically a suspended cantilever. I'm thinking of filling the gap between the speaker center and PCB with something like RTV silicone, but I need something that won't expand or contract while curing/vulcanizing, or with age. Anyone know of a suitable product?

The rigid pin mounts are not helping you. Could be better if you make a springy mount. Possibly made from 3 or 4 small tabs of folded paper, glued on.

Clip away the rigid pins. Solder on wire leads that can flex a little.

That would likely work, but this is for a potential production design, so handcraft solutions aren't feasible. Squirting a blob of goo isn't too much trouble though. I could also use some press fit sockets instead of soldering the pins to give some wiggle, but I wonder how reliable that connection would be...

I also see similar speakers with bare solder terminals, some with wires already soldered on, but I cannot find any reference on how these are supposed to be mounted. No screw holes or studs on the speakers at all. Do they just glue the rim of the cone to the enclosure or something?

Looking closely at your speaker, it resembles transducers I've seen in headphones. Similar transparent flexible mylar membrane. Good quality sound, not tinny. I'm pretty sure its volume is soft, although ideal if your ear is very close.

Headphones consist of a plastic shell with a round cavity to hold this shape of transducer. It's held in by molded plastic snaps or clips (which are easily snapped off if you're not careful).

Is your device intended for distant listening? If so then I think you need a larger speaker. One which 'throws' the sound further.

The transducer is mismatched with those large sturdy clips (as you have discovered). I have a hunch it was made for headphones which are large (and probably expensive looking).

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Your question was about mounting it. There is double-sided foam tape, although it may be too thin.

There is expanding foam which adheres to whatever it touches, fills up the entire space, and even perhaps would lift the speaker a little to ensure a permanent bond despite slight shrinking.

The heavy part causing the problem is the magnet. Presuming that the magnet is correctly fixed to the speaker base, attaching the speaker base with silicone rubber to the PCB should increase the shock hardiness.

BradtheRad said:

Is your device intended for distant listening? If so then I think you need a larger speaker. One which 'throws' the sound further.

Click to expand...

Actually it's meant to generate a simple loud indicator tone. Originally I had used a magnetic buzzer, but needed more bandwidth, which buzzers don't have. The volume I get from this speaker is fine.

Your question was about mounting it. There is double-sided foam tape, although it may be too thin.

There is expanding foam which adheres to whatever it touches, fills up the entire space, and even perhaps would lift the speaker a little to ensure a permanent bond despite slight shrinking.

Click to expand...

Using foam and adhesive occurred to me as well, but I'm wary of using anything that will put residual pressure on it, since the shock might come in any direction.

FvM said:

The heavy part causing the problem is the magnet. Presuming that the magnet is correctly fixed to the speaker base, attaching the speaker base with silicone rubber to the PCB should increase the shock hardiness.

Click to expand...

Yeah I will likely give RTV silicone a try since it's so available, but from what I've seen it's probably not as rigid as I'd like. Ideally I want something like superglue, except with better adherence, and very low viscosity so it can fill that gap without making a mess. But it's important that it not expand or shrink once cured... maybe JBweld makes something like that?

Can anyone recommend me a brand name?

You need 3 points to make something stable. Add a third dummy away from the other 2 to give yourself a sturdy mounting base.

Hi,

Are products like "No More Nails" (I have a Spanish version called "Montack" which is good) suitable for this purpose? Forms a nice thick paste, and is not watery, very adhesive and robust. If you need "springy" may not be the thing you're looking for. Not sure if for commercial product wouldn't have some issue like heat resistance/flame resistance, or other.

I forgot the word pin in my post above.

You need 3 points to make something stable. Add a third dummy pin away from the other 2 pins to give yourself a sturdy mounting base.

This has to cost less than having a manual gluing operation or buying a automatic gluing dispenser.

d123 said:

Hi,

Are products like "No More Nails" (I have a Spanish version called "Montack" which is good) suitable for this purpose? Forms a nice thick paste, and is not watery, very adhesive and robust. If you need "springy" may not be the thing you're looking for. Not sure if for commercial product wouldn't have some issue like heat resistance/flame resistance, or other.

Click to expand...

Sounds worth a shot, thank you.

FlapJack said:

I forgot the word pin in my post above.

You need 3 points to make something stable. Add a third dummy pin away from the other 2 pins to give yourself a sturdy mounting base.

This has to cost less than having a manual gluing operation or buying a automatic gluing dispenser.

Click to expand...

Extra pins on the opposite side would be great, but how do you suppose such a thing would be done? I don't think the CUI will redesign a product just because I ask them to.

Idea number 2. Out with the old, in with the new.

The existing speaker has the terminals on the side. Several speakers are available with the terminals centered.

https://www.digikey.com/product-sea...1&stock=1&quantity=0&ptm=0&fid=0&pageSize=500