Ventilation System Design for Electronic Component Manufacturing

Hazardous Materials in Electronic Component Manufacturing

Electronics manufacturing can use a complex cocktail of materials and chemicals, many of which pose potential hazards to worker health and the environment. 

Metals

• Lead: Still used in some solder alloys and components, lead can cause neurological damage and developmental problems, especially in children. Exposure primarily occurs through inhalation of fumes or dust.  
• Tin: While generally considered less toxic, tin can cause respiratory irritation with prolonged exposure to fumes or dust.
• Copper: Exposure to copper fumes or dust can lead to irritation of the eyes, nose, and throat. High levels of copper exposure can cause liver and kidney damage.  

Solvents

• Isopropyl Alcohol: Commonly used for cleaning, isopropyl alcohol can cause eye and respiratory irritation. Prolonged exposure can lead to headaches, dizziness, and nausea.  
• Acetone: A powerful solvent used for degreasing and cleaning, acetone can irritate the eyes, skin, and respiratory tract. High concentrations can cause central nervous system depression.  
• Trichloroethylene (TCE): Though its use is declining due to environmental concerns, TCE is still found in some cleaning applications. It’s a known carcinogen and can cause liver and kidney damage.  

Acids and Bases

• Hydrochloric Acid: Used in etching and cleaning processes, hydrochloric acid is highly corrosive and can cause severe burns to the skin and eyes. Inhalation of fumes can damage the respiratory tract.  
• Sulfuric Acid: Another strong acid used in various processes, sulfuric acid poses similar hazards to hydrochloric acid, including severe burns and respiratory damage.
• Sodium Hydroxide: A strong base used in cleaning and etching, sodium hydroxide can cause severe burns to the skin and eyes.  

Resins and Polymers

• Epoxy Resins: Used in adhesives and encapsulants, epoxy resins can cause skin sensitization and allergic reactions. Some epoxy components are also known carcinogens.  
• Polyvinyl Chloride (PVC): Used in cable insulation and other applications, PVC can release toxic fumes when heated or burned, including dioxins and hydrochloric acid.  

Gases

• Nitrogen: Used for inerting and soldering, nitrogen can displace oxygen in confined spaces, leading to asphyxiation.  
• Ozone: Generated during some plasma cleaning processes, ozone is a powerful respiratory irritant and can damage lung tissue.

Navigating the Regulations for Electronic Manufacturing

Regulations are intended to ensure environmental responsibility for manufacturers. Many chemicals used in electronics manufacturing are considered Hazardous Air Pollutants (HAPs). The EPA sets limits on their emission into the atmosphere, which impacts your exhaust system design and filtration requirements. National Emission Standards for Hazardous Air Pollutants (NESHAPs) specifically target certain industrial categories and may apply to your operations depending on the materials you use and the processes you employ.

There are also key standards for protecting workers from exposure to hazardous substances. OSHA defines permissible exposure limits (PELs) for various chemicals commonly used in electronics manufacturing, such as solvents, solder fumes, and epoxy resins. Beyond government regulations, industry organizations like the IPC (Association Connecting Electronics Industries) provide guidelines for ventilation and air quality in electronics manufacturing. These standards often offer best practices and recommendations for specific processes.

Important Components for Ventilation System Design

Air Filtration

Air filters are the lungs of a ventilation system. They remove harmful contaminants from the air to prevent them from circulating in the workspace. Different types of filters target specific pollutants. Choosing the right filter type depends on the specific contaminants generated in your processes. 

HEPA Filters: High-Efficiency Particulate Air (HEPA) filters are essential for capturing tiny dust particles, which can be detrimental to sensitive electronic components. They are highly efficient in removing particles as small as 0.3 microns.

Activated Carbon Filters: These filters excel at absorbing gases and vapors, making them ideal for removing volatile organic compounds (VOCs) released during soldering, cleaning, and other processes.

Electrostatic Precipitators: These filters use an electrical charge to attract and capture dust and fumes, offering high efficiency and requiring less frequent replacement compared to traditional filters.

Air Exchange Rates

Air exchange rate, measured in air changes per hour (ACH), determines how frequently the air within your facility is replaced with fresh, filtered air. A higher ACH means more rapid removal of contaminants and better overall air quality. Factors influencing ACH requirements include:

• Size of the space: Larger spaces generally require higher ACH to effectively dilute and remove contaminants.
• Number of occupants: More people in a space means more carbon dioxide and other pollutants, necessitating increased ventilation.
• Types of processes: Manufacturing processes that generate significant fumes or dust require higher ACH compared to cleaner processes.

Exhaust Systems

Exhaust and dust collector systems capture contaminants at the source, preventing them from spreading throughout the facility. Proper hood placement, capture velocity, and ductwork design are critical for efficient exhaust airflow and contaminant removal.

Fume Hoods: Enclosed hoods with controlled airflow, ideal for processes involving hazardous fumes or volatile chemicals.

Canopy Hoods: Mounted above workstations to capture rising contaminants, suitable for processes generating heat and lighter fumes.

Slot Hoods: Linear hoods placed near the source of emission, effective for capturing contaminants released in a concentrated area.

Makeup Air Supply

Exhausting air creates negative pressure, requiring a balanced inflow of fresh air to maintain comfortable working conditions. Makeup air units introduce filtered and conditioned air into the facility, compensating for the exhausted air.

Proper distribution of makeup air is crucial to avoid drafts, pressure imbalances, and temperature fluctuations. Factors like the location of exhaust points, building layout, and climate conditions will affect the design of your system.

Best Practices for Optimal Ventilation

Implementing industry best practices can significantly enhance the effectiveness and efficiency of your ventilation system design. A one-size-fits-all approach rarely works in electronics manufacturing. Add additional support for specific possesses, such as:

• Soldering: Implement local exhaust ventilation, such as fume extractors at each soldering station, to capture fumes directly at the source.  
• Solvent Cleaning: Use enclosed cleaning systems with dedicated exhaust ventilation to minimize solvent vapor release into the workspace.
• Conformal Coating: Employ spray booths with high-efficiency exhaust systems to contain and remove overspray and volatile organic compounds (VOCs) released during the coating process.

Real-time monitoring of air quality is worth adding to your ventilation system design. Sensors can detect concentration of particulate matter, the presence of VOCs, and fluctuations in temperature or humidity. Integrate these sensors with automated control systems to adjust ventilation rates based on real-time data. This ensures optimal air quality while helping to minimize energy consumption, which can be valuable as ventilation systems can be significant energy consumers.

Other methods for helping to offset the high energy consumption are Variable Frequency Drives (VFDs) to control fan speeds, allowing the system to adjust airflow based on demand. During the ventilation system design phase, you can also minimize ductwork length and ensure smooth airflow to reduce pressure drops and improve fan efficiency. Heat recovery systems can also reclaim heat from exhaust air to preheat incoming makeup air, which reduces your heating costs.  

Experienced Design for Ventilation Systems in Manufacturing

Effective ventilation isn’t just about meeting minimum standards; it’s about optimizing your operations for long-term success. A well-designed system protects your most valuable assets while ensuring product integrity and minimizing environmental impact.

At Eldridge, our team of experts can provide tailored ventilation system designs for your manufacturing facility. Contact us for more information.