Bubbles Are Bad News - Reading Fire Damage on Storage Chips

Fire damaged devices are some of the most common submissions we receive. Most of them arrive looking catastrophic - melted housings, delaminated circuit boards, components scattered across the evidence bag. The board condition alone is enough to make most people assume the data is gone.

But the board condition doesn't determine recoverability. The chip condition does.

What actually holds the data

Before assessing whether fire-damaged storage is recoverable, it helps to understand what a chip actually is at the component level.

The data itself is stored on the die - a tiny silicon element at the core of the chip which stores the 1s and 0s. The die is connected to external pins through wire bonds, which are microscopic conductive wires that create the electrical pathways needed to communicate with the chip and read its contents. All of this - the die, the wire bonds, and the connection points - is encapsulated inside a black plastic package that protects the internal components and provides the physical structure for mounting the chip to a circuit board.

Those external pins are how forensic tools communicate with the chip. Without intact wire bonds connecting the die to those pins, communication isn't possible and data recovery isn't viable.

What fire does to a chip

The circuit board around the chip fails first. Solder mask melts, layers delaminate, capacitors detach, and the board becomes a structural and electrical mess. None of that is necessarily fatal to the chip itself - the chip can survive conditions that destroy everything mounted around it.

What matters is whether the heat reached the chip packaging directly and what happened when it did.

Black plastic chip packaging contains trace moisture. Under high heat, that moisture doesn't just evaporate - it expands rapidly before it can escape. When gases expand rapidly inside a confined space the result is a pressure event. In a chip package, that pressure event damages or severs the wire bonds connecting the die to the external pins.

The external indicator of this event is bubbling on the surface of the chip package. The plastic surface develops raised, irregular bubbles where the internal pressure deformed it from the inside. It's a visible sign that the chip was exposed to temperatures high enough to cause internal moisture expansion - and that the wire bonds connecting the die to the external pins may have been compromised in the process.

What bubbling means for recovery

Bubbling on the chip package is not a definitive finding - it's a warning. It indicates that the chip was exposed to significant heat and that internal damage is possible. Wire bonds are microscopic. Visual inspection of the exterior can identify the risk but can't confirm whether the bonds are intact or severed.

When bubbling is present, an X-ray examination of the chip is the appropriate next step. X-ray imaging can show the internal structure of the package without opening it - revealing whether the wire bonds are intact, partially damaged, or completely severed. That finding determines whether data recovery is viable before any invasive procedure is attempted.

No bubbling on the package is a positive sign - it suggests the chip's internal components may have been protected by the packaging even if the board around it was destroyed. Bubbling present means the recovery assessment needs to go deeper before any conclusions are drawn.

The practical takeaway

When a fire-damaged device arrives for examination, board condition tells you about the severity of the fire. Chip condition tells you whether the data survived it. The two are related but they're not the same assessment.

Look at the chips. If the packaging is smooth and intact, the path to recovery is likely open. If you see bubbling, treat it as a flag - not a conclusion - and pursue X-ray confirmation before determining whether recovery is viable.

The data bearing component is the last thing to fail in a fire. When it does fail, it usually tells you.