The first step in microelectronic die level fault isolation is the destructive step of microelectronic package decapsulation. For clarification, the term destructive refers to a procedural step where the device is modified in such a way that material is removed from the package, while maintaining full electrical functionality and performance of the device, but it’s not reasonably possible to return the device to its original physical form.
Examples where we would perform package decapsulation may be any of the following:
Microelectronic packages are complex engineered systems designed to ensure devices and products function in the electronic application, physical environment, and are compatible with the form, fit, and function of the end use application. The package body may be constructed from various plastics, metal cavity, and ceramics. Electrical interconnects between the die and package may be made with gold bondwires, aluminum bondwires, copper bondwires, silver bondwires, PbSn flip-chip bumps, Pb free flip-chip bumps, and copper pillars. All these factors are taken into consideration when defining the package decapsulation process.
There are two primary approaches to package decapsulation liquid chemical, plasma chemical, and mechanical.
Liquid chemical decapsulation is performed by heating the package to a specific temperature. An acid or mixture of acids is then applied to the package to dissolve the plastic packaging over a period of time. The acid/mixture is then rinsed from the package with a solvent to stop the etching process and remove the acid from the package. This process it typically repeated in multiple steps until the desired area of the device is exposed. This is the most common and fastest process used for package decapsulation of plastic based packages.
Plasma chemical decapsulation utilizes a reactive ion etch (RIE) system to remove microelectronic package mold compound. The area of mold compound which needs to be removed is masked to defined the etch area. Process gases, flow rates, process pressures, RF power, and process time are selected based on the mold compound material and package technology. The masked device is then processed in the RIE to remove the mold compound. This process typically is more time consuming than the liquid chemical decapsulation process.
Ceramic and metal cavity type packages require mechanical a decapsulation process. The processes to decapsulate packages in these technologies involve cutting, grinding, or prying the package under controlled conditions. The technique utilized is determined on a case by case basis.
Examples where we would perform package decapsulation may be any of the following:
- Expose the die for optical examination to inspect the die for damage, defects, or counterfeit examination.
- Expose the die for photon emission microscopy (PEM / EMMI)
- Expose the die for Laser injected fault isolation techniques
- Expose the die for hot spot analysis
- Expose the die for thermal mapping / thermal characterization
- Expose the die for focused ion beam circuit edit (FIB-CE)
- Expose the bondwires for modification
- Relieve package related die stress
Microelectronic packages are complex engineered systems designed to ensure devices and products function in the electronic application, physical environment, and are compatible with the form, fit, and function of the end use application. The package body may be constructed from various plastics, metal cavity, and ceramics. Electrical interconnects between the die and package may be made with gold bondwires, aluminum bondwires, copper bondwires, silver bondwires, PbSn flip-chip bumps, Pb free flip-chip bumps, and copper pillars. All these factors are taken into consideration when defining the package decapsulation process.
There are two primary approaches to package decapsulation liquid chemical, plasma chemical, and mechanical.
Liquid chemical decapsulation is performed by heating the package to a specific temperature. An acid or mixture of acids is then applied to the package to dissolve the plastic packaging over a period of time. The acid/mixture is then rinsed from the package with a solvent to stop the etching process and remove the acid from the package. This process it typically repeated in multiple steps until the desired area of the device is exposed. This is the most common and fastest process used for package decapsulation of plastic based packages.
Plasma chemical decapsulation utilizes a reactive ion etch (RIE) system to remove microelectronic package mold compound. The area of mold compound which needs to be removed is masked to defined the etch area. Process gases, flow rates, process pressures, RF power, and process time are selected based on the mold compound material and package technology. The masked device is then processed in the RIE to remove the mold compound. This process typically is more time consuming than the liquid chemical decapsulation process.
Ceramic and metal cavity type packages require mechanical a decapsulation process. The processes to decapsulate packages in these technologies involve cutting, grinding, or prying the package under controlled conditions. The technique utilized is determined on a case by case basis.