Electronic – WLCSP MCU’s – what hardware is needed for programming these tiny chips


I just received my DigiKey order of some Atmel ATTiny4 MCU's from DigiKey. I wanted to tinker with one of the smallest MCU's I could find, and this was one of them.

It is, in fact, so small because it is wafer level chip scale packaging (WLCSP), described here. This image from that document indicates scale.

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This question may be very naive, but how do I "hobby" with a chip this size?

I cannot directly plug it in to a breadboard. (Unless there is some socket I can buy that I am unaware of?) Programming the chip is the next step, but I do not know what hardware I need to interface with my PC. There are plenty of tutorials out there on the web that show to program a DIP (with an Arduino, for example). I cannot, however, find any information on how to program these tiny chips.

Is this even possible for someone (me) tinkering out his apartment? Or are these chip sizes primarily sold to manufactures of electronic devices with automated systems for integrating these chips?

Note: I am not sure how to tag this question. Feel free to edit.

Best Answer

I'm sorry, but you've got no chance.

It's basically an ultra-small BGA - you need to reflow it properly onto a PCB, and at that scale it's going to be very very hard to both get and keep the alignment properly (and even generate the PCB in the first place). Better to stick to DIP.

As for programming them - you route the programming pins out to a header on your PCB and connect a normal AVR ICSP of some form into it.