nRF52840 package

[backstreet.devisor]

Good Day.

I plan to use nrf52840 in my development, but at the moment this microcontroller is not on sale. But there is an nrf52840-Dongle on sale.

Can you please tell me if it is possible to remove the microcontroller from this board and put it in my board?

Need new balls for aQFN-73 package?

Thanks.

[Martin Sivertsen]

Hi,

It's possible, but it is very laborious.

How many are you planning to use?

You'd have to carefully desolder it, thoroughly and carefully remove the solder that's on the pads of the device (without removing any of the pads on the device at the same time), before re-balling it, which requires specific equipment.

Have you looked at any of our alternative devices to see if they meet your specifications?
https://www.nordicsemi.com/Products/Bluetooth-Low-Energy

I don't have specifics on what devices are available, but could put you in contact with a regional sales manager who'll have more information.

Best regards,

Martin S.

[backstreet.devisor]

Thanks Martin for your answer.
Yes, I understand that this will not be an easy task. But at the moment I need to develop a prototype and there is no time to wait for the microcontroller to be available. If I understood you correctly, then for this case it is not necessary to install new solder balls?

[Martin Sivertsen]

Hi,

When you say "develop a prototype", do you mean writing firmware or creating a custom PCB, because we have development kits for creating firmware and developing an application before transferring it over to custom hardware.

backstreet.devisor said:

If I understood you correctly, then for this case it is not necessary to install new solder balls?

Yes, actually when soldering it to a new board you don't need to re-ball it, it just needs to be absolutely clean and have no solder remaining on it, but you will need to use a stencil and apply solder paste to get an even distribution of solder on all pads.

Re-balling is necessary if you want to solder it to a board that already has components on it and no way of laying down solder paste through a stencil, I misremembered in my first post.

Here is an application note that has a chapter (chapter 6) regarding rework of aQFN (advanced Quad Flat No-Lead) packages such as the nRF52840: Application Notes for aQFN-17.pdf

Best regards, Martin S.

[backstreet.devisor]

Thanks Martin for your time. You fully answered my question.

[Martin Sivertsen]

I'm glad to hear it.

You're welcome.

Best regards,

Martin S.