Decapsulate a Chip Without Acid — By Blasting It With Plasma from a Miniature Tesla Coil

Pseudonymous Ukrainian maker "100dollarhacker" is working on a way to decapsulate integrated circuits for die-level inspection without the need to mess around with hazardous acids — by firing a Tesla coil at the chips instead.

"IC [Integrated Circits] are amazing," 100dollarhacker writes by way of introduction to the project, "but always closed in [epoxy] which seems impossible to remove. Here we propose a method to decap without acids [using a] small yet powerful Tesla coil."

A suitably powerful microscope, or even a halfway decent macro lens on a digital camera, is enough to reveal the inner workings of a silicon chip at the meso scale or better — but only if you can actually get to said chip. For most package types, the usual way to reveal the silicon chip beneath is with a bath in boiling acid — a somewhat hazardous approach with nasty waste. It's the waste 100dollarhacker is aiming to reduce — by replacing the acid with plasma generated by a compact Tesla coil.

"I have found an article about removing IC epoxy using microwave induced plasma," 100dollarhacker explains. "For me working with microwave was as dangerous as using nitric acid. So I have tried different approach, which is Tesla coil induced plasma. After about two hours (yeah, too much time in my opinion) I managed to remove [the] epoxy from [Microchip's] ATtiny85."

While 100dollarhacker has proven the core concept and is now working on speeding up and automating the process, there are a few obstacles to overcome. The biggest of these is that it's far from being intrinsically safe. "If you get the chip to close to the flame it burns [and it will] get too hot; if its too far away nothing happens," the maker explains, "[and the] fumes are terrible. [The radio-frequency] radiation is illegal [too]."

While getting die shots of most package types does involve decapsulation, there are sometimes easier alternatives: noted engineer Andrew "bunnie" Huang recently revealed IRIS, the Infrared In-Situ inspection system, which uses an off-the-shelf digital camera with its infrared filter removed and a high-intensity infrared emitter to peer through the silicon layer of chips packaged with their back side exposed to the viewer.

More details on the project are available on 100dollarhacker's Hackaday.io page.