Mounting Vibration Motors to Flexible PCB

There are several design considerations when mounting vibration motors to flexible PCB, also known as FPCB, or just “flex”.

For mounting an SMD motor (with solder) to flex, you will require some kind of backing material around the motor to stabilise the joint (perhaps a circuit board base material such as 0.8mm FR4). Alternatively, you may be able to order your flex PCB with rigid sections.

If you choose to mount without solder, perhaps because you’ve chosen a spring-mounted motor such as the 310-105 then you need to ensure that there is sufficient pressure between the motor contacts and the PCB.

Also, if you choose an ERM motor with an exposed rotating mass such as the 304-008, then you’ll need to ensure your design prevents the mass from making contact with other components or the casing as the PCB flexes. This is because impeding the mass causes current spikes, reduces performance, and creates audible noise.

However you choose to mount the motor, there are a few additional design considerations:

1. If you mount to flex PCB you may damp the vibration
2. Depending on the mounting, there may be audible noise generated as the motor vibrates against the flex PCB

If you decide against using flex, we have application bulletins that will help you mount vibration motors to rigid PCB or bulkheads.

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