Using Cleanrooms for Electronics Manufacturing

by Dr. Sreeram Srinivasan, CEO, Syrma Technology


A tiny particle of dust on certain products can be very damaging, which is why OEMs cannot risk particulate contamination when it comes to manufacturing certain electronics like camera modules, night vision devices, and precision audio products. In fact, contaminated products cost electronics manufacturers millions of dollars each year, as well as leads to the loss of their ISO certifications. To ensure product sterility and stability, manufacturers have strict electrostatic and micro-pollutant requirements. They often use cleanrooms, which are facilities specifically designed to maintain extremely low levels of particulates, such aerosol particles, airborne microbes, dust, and vaporized particles.

Chip-on-board and direct-chip-attach assembly (COB/DCA) are typically performed in a Class 10,000 cleanroom (10,000 particles per cubic foot) or better, since the manufacturing floor isn’t particle-free. With small wires, airborne particles from the surface mount assembly can cause contamination on top of the die or the bonding wire, and a particle on a fine pitch bond pad can interfere with bonding. Particles can cause items to not stick to a chip, leading to water being accumulated at the particle site, and eventually corroding the device.

How Cleanrooms Keep Products Clean

To remove internally generated contaminants, the air inside is constantly recirculated via high-efficiency particulate air (HEPA) and/or ultra-low particulate air (ULPA) filters and the air entering a cleanroom from outside is filtered. Some cleanrooms are kept at a positive pressure to prevent unfiltered air from entering the room when there’s a leak. Staff enter the cleanroom via airlocks, and wear protective clothing, like face masks. Equipment and furniture are designed to produce minimal particles and to be easy to clean. Materials made from natural fibers, such as paper, are often excluded from cleanrooms.

A discrete, light-scattering airborne particle counter is used to determine the concentration of airborne particles, equal to and larger than the specified sizes, at designated sampling locations. Each facility’s cleanliness level is often defined by the number of particles per cubic meter. The number of particles of size 0.5 µm or larger per cubic foot of air are represented by large numbers, like a Class 1,000. They’re not free of uncontrolled microbes or sterile; only airborne particles are controlled. To limit microbial contamination, the U.S. and EU designed guidelines, which are very stringent.

Syrma’s Cleanroom for Manufacturing

Built in 2006, our main facility is based in Chennai’s Special Economic Zone (SEZ). This site is ANSI/ESD S20.20-2014, ISO9001, ISO 13485, ISO 14001, and IATF 16949 certified, as well as IPC-A-610 class II and III quality standards. It provides semi-cleanroom conditions for optical sensors and other precision electronics. Our equipment at this facility includes: Fuji SMT lines that provide a total placement capacity of 200,000 parts per hour with 40-micron accuracy and capable of 3-sigma. This site provides product design, manufacturing, box build assembly, and aftermarket services for our global customers.

Our new 24,000 square foot facility in Bawal was built in April 2018. It’s located within the Delhi-Mumbai Industrial Corridor inside a Domestic Tariff Area (DTA), which provides cost-savings for our customers. This facility contains a Class 10,000 cleanroom for our Fuji SMT lines. Our SMT lines in each of facilities, have a total placement capacity of 200,000 parts per hour with 25-micron accuracy and capable of 3-sigma. This facility manufactures products designed and sold within India for aerospace, automotive, defense, industrial, and medical verticals. It’s 100% RoHS compliant and fully certified for international quality standards.