1 square inch

So here’s the BGA fallout…

I am now using Alitum as part of a new part time job so I decided to do a pet project I have been wanting to do for awhile now which is a STM32F4 based board using a BGA.

Now the main issue with the STM BGA’s is they use a smaller ball pitch at 0.65mm than the usual cuplrits like the Hydra uC which are 0.8mm pitch balls. Me being me I didn’t let that freak me out too much.

The STM I have chosen is a STM32F427IIH6 which has 140 IO’s, 2mb and 256kb of ram in a 10mm package with 201 balls.

17 pins are rout out the headers, SPI, Uart, I2C, PWM and Analog

So out with Alitum, mad random clicking and I have a board routed out. Main highlights are 0.2mm drilled and tented VIA’s and 6mil traces under the BGA using 4 layers
PCB’s where made using PCB - Pool in Ireland.

Plugged in and wee all good - running Mountaineer 4.3 firmware (Huge thanks to Cuno and team)

Video shows digital out for the onboard LED’s, SPI for the 7 segment display and UART for the 3 Dongbu Servos.

Any questions just ask away - and yes I did use a £5 Maplin soldering Iron for the headers :smiley:



Good job!

nice, so will we get to play with those tiny boards :slight_smile:

Microduino et al EAT LEAD!!!

Whats the power specs? And purpose?

@ Jay Jay - i have 14 spare boards and a Mouser BOM if you want to try your hand :wink:
Unless i win lotto i don’t think the day job would be overly amused with me playing manufacturer…

@ njbuch - many mega watts, and it’s only purpose was to see if i could pull it off :smiley:

Well done :clap:

Thanks Gus,

Was a fun exercise.

Hey, I’ve got the same laptop! Those Dells are really handy 8)

Very nice work!
Sorry if I missed that, but how did you solder the BGA? Hot air?

@ Simon from Vilnius - when i first got it i spent 15 mins spinning the screen around - yes i am easily amused ::slight_smile:

@ dominik38 - Board was cooked in an oven


Awesome job! Where were you able to get the single quantity BGA version of the chip, I’ve checked Mouser and none of the BGA version are available to order in single quantities. I would be interested in getting one of your boards as well. I am working on a similar project also including on board Wifi.

@ munderhill - I got mine from Arrow $12.98ea in singles


Ping me an email re the board - justin at ingenuitymicro dot com

@ Justin - awesome job,

What kind of servos are you using ?

@ Rajesh - ta

They are HerkuleX DRS-0101 Smart Robot Servos - whizzy little things…