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Chemical Decapsulation
Decapsulation Service Flyer (pdf - right click to download)  Overview of dual-in-line package (DIP) prior to decapsulation.  Mechanical polish through mould compound to bond wires. This minimizes exposure time to acid during decapsulation.  Polish to bond wires.  Die exposed by chemical decapsulation.  High magnification optical image of die after decapsulation. Decapsulation: Decapsulation is a chemical etching technique for opening IC plastic packages in order to expose their internal components for examination. Although physically destructive to the plastic casing, the process leaves the die, bond pads, and wire bonds largely intact. Depending upon the device and the customer’s requirements we can use one of two decapsulation methods (manual cavity etching and total package removal). Fuming nitric acid (HNO3), sulfuric acid (H2SO4) or a mixture of the two acids are typically used. With manual etching, a cavity is first milled into the surface of the package after which the acid is dropped into the cavity to dissolve the encapsulant over the die. Total package removal is performed by dissolving the entire package in a beaker of sulfuric acid leaving only the silicon die and some amount of undissolved metal. This technique is primarily used to inspect for cracks on the back of die. 
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