Cleaning Small X-ray Tube Components

June 16th, 2015

An Electrowave Explosion-Proof Ultrasonic Cleaner

An Electrowave Explosion-Proof Ultrasonic Cleaner

Cleanliness is absolutely critical when assembling x-ray tube components.  Stainless steel and Kovar™, the latter an iron-nickel-cobalt alloy with a coefficient of thermal expansion similar to that of borosilicate glass, are widely used in the manufacture of x-ray tubes.  Kovar, in this case, is bonded to glass parts in the tube and is joined by welding to stainless steel components used in the tubes.

Decontamination in an Explosion-Proof Ultrasonic Cleaner

An ultrasonic cleaning cycle is part of the process used to yield absolutely contamination-free very small X-ray tube components at a leading X-ray technology company.  Because the first three steps involve volatile solvents an Electrowave explosion-proof ultrasonic cleaner is employed.  These cleaners conform to National Electrical Code and National Fire Protection Association guidelines and carry the “Explosion Proof Apparatus” label.  All interior electronics are thoroughly sealed in high density foam to isolate any spark source from contact with solvent and solvent vapors.

The Ultrasonic Cleaning Cycle

A 1.3 gallon EW-5 EXP explosion proof ultrasonic cleaner is used in the 3-step ultrasonic cleaning cycle.  The unit operates at 54 kHz, is equipped with a 30-minute timer and operates with a “sweep” function to provide uniform distribution of cavitation action throughout the cleaning solvent.

Up to six X-ray tube components are placed in the cleaner’s wire mesh basket.  The first step uses IPA to remove oils that are deposited on the stainless/Kovar assembly.  Following this cycle the tank is drained and filled with acetone for the second cycle.  After the acetone is drained the tank is refilled with IPA for the third ultrasonic cleaning cycle to achieve the extreme cleanliness required.

Each cleaning cycle lasts approximately 30 minutes during which the ultrasonic cleaner is covered to minimize solvent evaporation.

A plasma cleaner is used for the final step then the components are assembled under an ultra-high vacuum in a class 1000 clean room.

Safety Guidelines for Explosion Proof Ultrasonic Cleaners

The explosion proof apparatus label carried by Electrowave EXP cleaners means that there is no danger from fire or explosions from the equipment itself.   But operating it creates what is called a hazardous area.  This means that fumes or spilled solvents could be ignited by extraneous sources such as electrical equipment and associated wiring.  For more information on these critical points please view our post on safety guidelines for explosion-proof ultrasonic cleaners.

Feel free to contact our scientists for answers to your questions on explosion-proof ultrasonic cleaners or for information on ultrasonic cleaning systems designed for water-based cleaning solutions.