Method for unsealing plastically-packaged apparatus containing un-passivated metal layer structure

Abstract

The invention diswcloses a method for unsealing a plastically-packaged apparatus containing an un-passivated metal layer structure, comprising the following steps of: firstly, etching the plastically-packaged apparatus for 5-10 seconds in an environment at 80-90 DEG C by fuming nitric acid, starting to perform a cleaning process in 30 seconds, cleaning the etched apparatus by acetone and deionized water, and then drying in air; secondly, etching the plastically-packaged apparatus for 10-20 seconds in an environment at 70-80 DEG C by an etching acid I formed by mixing fuming nitric acid with 98% concentrated sulphuric acid in a volume ratio of 2: 1, and immediately cleaning the apparatus by acetone, isopropyl ketone and deionized water after etching; and lastly, drying in air. The plastically-packaged semiconductor integrated circuit with a chip surface made of nickel-copper, nickel-tungsten and the like and produced by a structure which is not protected by a passivation layer is unsealed by a method of precisely controlling unsealing technique parameters and performing an etching process twice, the interior structure of the apparatus can be completely reserved after the apparatus is unsealed, and the apparatus is ensured to be able to keep electrical performance after being unsealed, so that the demand on the integrity of the apparatus by the follow-up inspections of destructive physical analysis, failure analysis and the like is completely satisfied.

Description

[technical field] [0001] The invention relates to the technical field of unsealing of electronic components, in particular to an unsealing method of a plastic-encapsulated device with an unpassivated metal layer structure. [Background technique] [0002] At present, the chip surface of some devices adopts a process structure such as nickel copper that is not protected by a passivation layer. This special structure of plastic-encapsulated integrated circuits is commonly found in the power management (abbreviation: TPS) series designed and produced by Texas Instruments Corporation (referred to as TI). Among plastic-encapsulated semiconductor devices and some magnetic isolation devices, these devices are currently widely used in various fields. In order to test the performance indicators of plastic-encapsulated devices, plastic-encapsulated devices are generally unsealed. At present, plastic-encapsulated devices (such as plastic-encapsulated semiconductor integrated circuits) a...

AI Technical Summary

Problems solved by technology

In order to test the performance indicators of plastic-encapsulated devices, plastic-encapsulated devices are generally unsealed. At present, plastic-encapsulated devices (such as plastic-encapsulated semiconductor integrated circuits) are generally unsealed by nitric acid wet method. The method often damages the structure inside the device that is not protected by the passivation layer and makes the product device lose its function, resulting in subsequent inspections such as destructive physical analysis (abbreviation: DPA) and failure analysis (abbreviation: FA).

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