MP34DT05TR do work with flaying wires but does not work when solder on STEVAL-MIC001V1 PCB.

[RJosh.3]

We are exploring MP34DT05TR microphone for our new product. If we connect flying wires on soldering pads then it works fine. But when we have hand soldered it on STEVAL-MIC001V1 PCB (Gerber of this PCB available on ST website), it is not working.

We also done soldering the second time with APP machine by following proper heat flow as per datasheet recommendation, but this time also mic not working. This time Clock and data signal are proper but we can hear only noise, it is not capturing anything.

[Peter BENSCH]

Welcome, @RJosh.3​, to the community!

First of all, the MP34DT05TR is already discontinued and unfortunately there is no support for it anymore. However, there is still the MP34DT05-A, which is almost identical except for very few timing details, and which you can use instead.

The AN4428 describes many reasons why a MEMS microphone can be damaged. Please read this application note carefully and check your production process.

Regards

/Peter

[RJosh.3]

Hi, we are using the new part only i. e. MP34DT05-A. We know the old and new mic part are compatible. Also as I mentioned we have followed the recommended soldering profile. But facing issue. Could there be problem with gerber file STEVAL-MIC001V1 gerber files ?

[Peter BENSCH]

The layout in the GERBER data is correct, all pins of the MP34DT05-A are routed to the designated pins.

If you also check this, you will find that the GERBER looks at the component side, while the pin connections in the MP34DT05-A data sheet look at the bottom side of the microphone, i.e. mirrored.

In addition, the illustration on page 1 of the data sheet is somewhat irritating, because the bevel on pin 1 is on the narrow side of the housing opposite the hole. However, it is shown correctly in the technical drawing fig. 11 of the data sheet:

Regards

/Peter