deencapsulation

Deencapsulation is the process of removing the outer protective encapsulation or packaging from an electronic device, such as an integrated circuit or microelectromechanical system, to expose the underlying die, bond wires, and interconnects. The term is commonly used in failure analysis, materials investigation, and reverse engineering, where access to the internal structures is required for inspection or testing.

In semiconductor failure analysis, deencapsulation enables direct visual examination and analytical techniques such as microscopy, energy-dispersive X-ray spectroscopy (EDS), or cross-sectioning. Packages typically targeted include common device forms such as DIP, SOIC, QFP, BGA, and CSP. Access to the die allows researchers to assess bonding integrity, delamination, corrosion, or presence of contaminants that may contribute to device failure.

Techniques for deencapsulation vary with the encapsulant material and package type. Chemical methods use acids (for example, nitric acid, sulfuric acid, or specialized solvent mixtures) to dissolve polymers. Thermal methods soften or melt encapsulants, permitting mechanical removal. Mechanical approaches, including micro grinding or laser-assisted ablation, physically remove the outer layer. Each method carries risks of damage to the die, alteration of features, or introduction of contaminants, and process conditions must be carefully controlled.

Safety and environmental concerns are significant: handling caustic chemicals, fumes, and high temperatures requires appropriate facilities, protective equipment, and waste disposal protocols. Deencapsulation is inherently destructive to the tested package, and results may not generalize to intact devices.

See also: encapsulation, failure analysis, reverse engineering, SEM, X-ray inspection.