Clean rooms came into vogue in the 1960s to fabricate precision technology required in the newly emerging aerospace industry. They are now commonly employed for manufacturing or research in industries like semi-conductors, space satellites, sterile medical devices, nano-fabrication, bio-technology, precision electronics like silicon chips and computer hard drives as well as optics. Clean rooms are needed because objects manufactured in these industries are sensitive to even microscopic contaminants. An invisible spec of dust inside a hard disk drive or a silicon chip can cause a "kill defect" that will render them useless, while contaminants inside a Petri dish can make gene therapy go wrong. Such high-precision manufacturing and research sensitive to contaminants is impossible without clean rooms.
Depending on the need, a clean room can be as small as an office cubicle or as large as a football field (called ballrooms). It can also be permanent, modular or portable with hard or soft walls. The sanitized, septic-clean environment is created by using layers of specialized air filters and cleaners like HEPA (High Efficiency Particulate Air Filter), air showers, air locks, directed air flow (laminar flow) and regular cleaning and upkeep operations. The biggest source of contaminants in a clean room is the people working there. They have to wear bunny suits or moon suites - masks, over-shoes and overalls of special fabric - so that they do not introduce any particles in the air by shedding skin flakes, sneezing or even wearing perfume.
Clean Room Classification
Clean rooms are classified according to the level of air cleanliness they are able to achieve.
The first such standard was set in 1963 in the US. The Federal Standard 209 has proved to be the most popular and universal benchmark to classify clean rooms worldwide. Officially called "Clean Room and Work Station Requirements, Controlled Requirements," it classifies a clean room by measuring particles of 0.5 microns or larger contained in a cubic feet of air. The standard was revised and updated in 1966 (209A), 1973 (209B), 1987 (209C), 1988 (209D) and 1992 (209E). The last version, 209E, has switched to metric units to measure airborne particles.
The Federal Standard 209 divides clean rooms into six classes - Class 1, Class 10, Class 100, Class 1,000, Class 10,000, and Class 100,000. A Class 100 clean room is designed to not exceed the count of 100 particles of 0.5 microns or more in a cubit foot of air, a Class 1,000 room will limit such particles to not more than 1,000, and so on. As comparison, an ordinary room in any office building would contain anywhere from 50,000 to 100,000 particles in a cubit feet of air.
In 1999, the UK published its own clean room standard, called British Standard 5295. Many other countries followed suit to establish their own standards. Soon, a need was felt for one universal standard that could be applied worldwide to achieve uniformity in clean-room classification. In June, 1999, the first ISO standard was published, called ISO 14644-I. It divides clean rooms into nine types, from ISO 1 to ISO 9. The Class 100 of Federal Standard 209 is equivalent to ISO 5 classification. The ISO standard now supersedes all earlier standards, though it is yet to get as popular as the Federal Standard 209.
Clean Room Recovery
The term "clean room recovery" is used in the computer industry to mean repair of hard-disk drives or other data storage media as well as recovery of recorded data that can no longer be accessed for some reason. Firms offering such services usually have clean rooms confirming to Class 10 or Class 100 of the Federal Standard 209, the same level as used by the hard drive manufacturers in their assembly plants. Clean room recovery covers the following areas:
Hard Disk Recovery - A computer hard disk may crash for a number or reasons like a hardware fault (defective motor, damaged head or controller card), software fault (virus attack, logical failure) or physical abuse like fire or water damage, over-voltage and impact trauma. Crashed disks leave users in the lurch as they are deprived of all data recorded on it. Such disks are brought to a clean room, disassembled, inspected and repaired so that they can be used again.
Data Recovery - If a crashed hard disk is beyond salvage or some data has been deleted by accident, specialised software is used to read the magnetic patterns on its individual platters. The analogue patterns are converted into digital form and copied onto another medium. The data is thus recovered and can be read on any computer. Data can also be recovered from damaged tape drives, RAID, email inboxes, corrupted databases and even cell phones.
Data Forensics - This is the age of electronic crime. It requires electronic evidence to get such criminals prosecuted. Data forensics is cyber-sleuthing and involves the collection of evidence from a wide variety of data storage media, for help in cases of online fraud, email abuse, cyber-stalking, pornography, industrial espionageFind Article, hacking and so on.
