Turning a 600 mil chip to 300 mil

We’ve seen a few builds featuring NXP’s LPC1114 microcontroller before. This chip – theĀ only breadboard friendly ARM microcontroller available – comes in a ‘still a little too large for prototyping’ 600 mil, 28 pin package. We won’t hazard a guess why NXP chose this rather large package, but the good news is it’s possible to shave this chip down to the more common 300 mil, 28-pin package used by AVRs and PICs.

In the video tutorial of this procedure, the chip is first taped down to a desktop CNC mill. 150 mil on each side of the die are removed, exposing the very cool-looking pattern of leads coming out of the chip. This isn’t enough area to solder, so the chip had to be further milled to expose some of the internal wiring.

After soldering everything to a set of pins, the new 300 mil package is covered in epoxy putty, milled down again into a nice cube shape and painted. Yes, the modified chip does work, and no, we can’t figure out why NXP chose a 600 mil package for this microcontroller over the far more common 300 mil chip.

Video after the break. Tip ‘o the hat to [Ian] for sending this one in.

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