Unsealing method of plastic package copper bonding lead semiconductor device

Abstract

The invention belongs to the technical field of unsealing of electronic components, and discloses an unsealing method of a plastic package copper bonding wire semiconductor device, which comprises the following steps: positioning the position of a chip of the device under X-ray, identifying the type of a bonding wire, and determining an unsealing scheme and an etching area; thinning a plastic package material of the device through laser; preparing a mixed solution of concentrated sulfuric acid, concentrated nitric acid and benzotriazole, and standing; wrapping the device by tinfoil, and stripping until an area to be unsealed is exposed; the preheated heating furnace is used for heating the prepared solution; dropwise taking the heated mixed solution through a dropper, and dropwise adding the mixed solution to a to-be-unsealed area of the device; when the bonding wires of the chip and the device are not completely exposed, continuously dripping the heated mixed solution to an unsealed area of the device until the bonding wires of the chip and the device are completely exposed; and carrying out ultrasonic cleaning on the unsealed device. The method is simple to operate, low in equipment requirement and high in test efficiency.

Description

technical field [0001] The invention belongs to the technical field of unsealing of electronic components, in particular to a method for unsealing a plastic-sealed copper bonding lead semiconductor device. Background technique [0002] At present, copper has good electrical conductivity, higher electrical conductivity than gold and aluminum, and its heat dissipation is significantly higher than that of gold and aluminum; in addition, copper has stable performance and is not easy to react with other metal compounds in the welding process; its higher The higher elongation and tensile breaking force are more conducive to bonding and improve the reliability of the device. With the development of the integrated circuit packaging industry, copper bonding wires are used more and more widely in plastic-encapsulated integrated circuits because of their unique advantages. In the process of destructive physical analysis and failure analysis, chemical reagents are used to remove the pl...

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Problems solved by technology

[0004] (1) Add CuSO to concentrated acid 4 ·5H 2 O crystals, using Cu 2+ The saturation effect can be unsealed, but the overall operation time of this method is relatively long, and it is not suitable for large-scale production

[0005] (2) The chemical electrolytic immersion method and the chemical low-temperature spray etching method are used for unsealing, but the chemical electrolytic immersion method requires a special device and the operation is more complicated; the chemical low-temperature spray etching method will fully contact the acid with the bonding wire, which is beneficial Copper bonding wires react with acid and take longer to unpack, less efficient for production

[0006] (3) Low temperature wet etching in pure nitrogen environment, the disadvantage of this method is that the cost is too high and the equipment requirements are very high

[0009] (1) The prior art adds CuSO to concentrated acid 4 ·5H 2 O crystals are unpacked, and the overall operation time is relatively long, which is not suitable for large-scale production

[0010] (2) The chemical electrolytic soaking method in the prior art is unsealed, and special devices are required, and the operation is more complicated; the chemical low-temperature jet etching method is unsealed in the prior art, and the unsealed time is longer, and the efficiency is lower for production

[0011] (3) Low-temperature wet etching under pure nitrogen environment in the prior art is too expensive and requires high equipment requirements

[0012] (4) The unsealing temperature is 300±10°C. If the temperature is too high, the activity of the acid is too strong, and the rate cannot be accurately grasped. It is very easy to cause corrosion of the internal copper bonding wires, and the unsealing effect is not good.

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