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Ultrapure™ Post-Cleaning and Packaging

Contamination on the Surface of Kalrez Parts Is Dramatically Reduced By Ultrapure Post-Cleaning and Packaging

DuPont uses the the UltraPure (UP) post-cleaning process for finished Kalrez parts which gives cleanliness levels significantly superior to those obtained with processes used by other perfluoroelastomer manufacturers supplying parts to the semiconductor industry. Comparative tests were conducted by an independent third party.

Tests performed on various o-rings showed that Kalrez UltraPure parts cleaned with the DPE proprietary process exhibited significantly lower residual particle-contamination levels than semiconductor-grade o-rings from other suppliers---an average of 1.8 particles >1 µm/in2 in size of o-ring surface area (see Table 1).

In addition, test results also showed a significant reduction in residual hydrocarbon contamination (mold-release residues, etc.) (see Table 2) present on part surfaces, as evidenced by Electron Spectroscopy for Chemical Analysis (ESCA).

In these tests, o-rings of corresponding sizes cleaned with competitive processes exhibited much higher average particle counts over the same micron size range: for o-rings cleaned with deionized water, an average of 19.3 particles >1 µm/in2 in size of o-ring surface area; for o-rings cleaned with a solvent, an average of 25.1 particles >1 µm/in2 in size of o-ring surface area. All the o-rings tested were cleaned and packaged in a clean room.


Table 1
Average Number of Particles per Square Inch of O-Ring Surface Area
Product* Cleaning Process No. of Particles >1 µm
Kalrez UltraPure Proprietary 1.8
Competitive Perfluoroelastomer Deionized Water 19.3
Competitive Perfluoroelastomer Solvent 25.1
  * All clean room packaged

Table 2
ESCA Analysis—Atom % Excluding Hydrogen
Product* Fluorine Carbon Oxygen Other
Kalrez White UP 62.0 34.0 3.7 0.3
Kalrez White 36.0 57.0 5.0 2.0
Kalrez Black UP 63.0 33.0 3.6 0.4
Kalrez Black 44.0 50.0 4.9 1.1
Theoretical* 66.0 33.0 1.0 -
* Ideal atom % for the surface area of cleaned Kalrez parts.


The Kalrez UltraPure Advantage

According to John Legare, senior sales engineer, DPE uses the Ultrapure process to ensure the highest degree of part cleanliness. "DuPont [Performance Elastomers] post-cleans all Kalrez parts for semiconductor applications," Legare said. According to Legare, the proprietary post-cleaning process reduces the number of particles >1 µm in size present on part surface by a factor of 20. As an added benefit, residual hydrocarbon contamination present on the part surfaces is also reduced. Because DPE produces polymers, compounds and finished parts in-house, DPE has complete control over the entire supply chain. "DuPont [Performance Elastomers] is the only perfluoroelastomer parts supplier that offers customers this added advantage," Legare said.

Ultrapure post-cleaning and packaging is performed on Kalrez parts as a secondary operation in a Class 100 clean room. Parts are cleaned using a proprietary process, followed by multiple rinses in UPDI water, and then dried under a filtered airstream. For quality control, the parts are subjected to particle-count testing as a measure of surface cleanliness. Finally, the parts are sealed in certified-clean, antistatic packaging material and shipped double-bagged, permitting easy clean room use by OEMs and fablines. The inner bag is labeled to ensure full part traceability.

Kalrez UltraPure Parts Availability

Ultrapure post-cleaning and packaging is standard for all Kalrez semiconductor compounds. It is optional for Kalrez 4079, Kalrez 2037 and Kalrez 1050LF. For these compounds, ultrapure post-cleaning and packaging can be specified by adding a "UP" suffix to the compound designation (e.g., Kalrez 4079UP).

The information set forth herein is furnished free of charge and is based on technical data that DuPont and Problem Solving Products, Inc. believe to be reliable. It is intended for use by persons having technical skill, at their own discretion and risk. Handling precaution information is given with the understanding that those using it will satisfy themselves that their particular conditions of use present no health or safety hazards. Since conditions of product use and disposal are outside of our control, we make no warranties, express or implied, and assume no liability in connection with any use of this information. As with any material, evaluation of any compound under end-use conditions prior to specification is essential. Nothing herein is to be taken as a license to operate or a recommendation to infringe on any patents. While the information presented here is accurate at the time of publication, specifications can change. Check with us before making a decision about which product to use.

DuPont™ and Kalrez® are trademarks or registered trademarks of E.I. du Pont de Nemours and Company or its affiliates. All rights reserved.