How On-Site Acid Neutralization Systems Provide Safe Chemical Disposal

When the right acid neutralization system is chosen, it can automatically add the required neutralizing chemicals to acid waste left over after a semiconductor manufacturing process step. Ideally such a system should use the least amount of chemicals while ensuring adequate neutralization of waste to comply with environmental standards. The system has to have enough capacity to handle the waste chemical flow and it must operate reliably, protecting against spills and documenting chemical use and discharge. With overall environmental standards tightening and local regulations becoming more stringent, semiconductor manufacturers need acid neutralization systems that provide safe and reliable disposal of chemical waste.

How to Choose Continuous Flow or Batch Acid Neutralization Systems

Acid neutralization systems can operate on a continuous basis or can neutralize individual batches of waste chemicals. For mass production of semiconductor parts, fabrication lines operate over extended periods, using fixed amounts of chemicals and producing uniform quantities of waste.

For these large-scale operations, a continuous flow acid neutralization system is the best choice. Because the nature of the waste chemicals is known and remains consistent over time, the neutralization process can add fixed amounts of low-pH chemicals to continuously neutralize the waste flow. Neutralization can be fine-tuned because the overall process doesn’t change.

Batch neutralization systems are better suited for the production of small quantities of semiconductor products. Typical applications are prototype production, production of small quantities for testing or the manufacture of special components. For these operations, the waste chemicals have to be neutralized in small volumes and each process is different. The batch acid neutralization system has to measure the pH of the waste chemicals, and determine what low-pH additions are appropriate. The neutralization is different for each batch as is each outflow.

Automation Can Play a Key Role in Effective Acid Neutralization Systems

Automated acid neutralization systems can help reduce chemical use, ensure regulatory compliance and reduce spills. The system automatically adds the required chemicals to the waste solution, tracks chemical use, measures outflow pH and records the results. Workplace safety is increased and human error is reduced. The records of chemical use and outflow pH can demonstrate that environmental standards are met.

Automating continuous flow systems is comparatively easy because the process parameters are known and they don’t change. The complete automation of batch neutralization systems can be challenging because key variables as well as the chemicals involved can vary from batch to batch.

For a continuous flow chemical acid neutralization system, the acid to be neutralized and the low-pH chemical to be used are known. The automation only has to add the required amount of neutralizing chemical on a continuous basis and record the resultant pH. For slight variations, a control loop can adjust the amount of neutralizing chemical to achieve the required output pH.

A fully automated batch neutralization system first has to measure the batch pH and add an amount of low-pH neutralizer. Depending on the chemicals involved, the automated system may have to add different neutralizing chemicals in several stages to achieve the required output. The automated system is complicated to program and difficult to set up. For batch neutralization systems, operator involvement to select the type of neutralization required can simplify the operation of the automated system and make it more effective.

Modutek Can Help Select the Right Acid Neutralization System

Modutek has a full line of chemical handling equipment, including acid neutralization systems. The company works closely with customers to determine their needs and can customize systems to meet special requirements. Once delivered, Modutek makes sure that the acid neutralization systems operate as specified and customers are completely satisfied. Contact Modutek for a free consultation to discuss the chemical disposal requirements needed at your facility.

Using Acid Fume Scrubbers to Maintain a Clean Work Environment

When semiconductor manufacturing process steps include etching or cleaning with acids, the process station exhaust can be harmful. Acid droplets in the discharge air can create health risks for workers and can corrode equipment. Worker safety standards and more stringent environmental regulations may set limits on the permissible acid droplet concentration.

To address these issues, semiconductor manufacturers need acid fume scrubbers to remove and neutralize acid droplets in the process discharge air. Once the acidic mist is passed through the scrubbers, the output air is clean enough to be discharged into the workspace or outside. Employees can work in a clean and safe work space and the outside environment is not contaminated with acid.

Acid Fume Scrubbers Can Remove up to 99 Percent of Acid Mist

Acid fume scrubbers work by passing the acid mist over a wet bed made up of special, large surface packing material. The scrubber has to be able to handle the flow volume from the process exhaust. Modutek’s scrubbers can remove up to 99% of acid mist and are available in sizes ranging from 500 to 25,000 CFM. This capacity range will satisfy the flow requirements from the smallest to the largest process volumes.

Modutek’s acid fume scrubbers use a high surface area packing material made by industry leader Lantec. The packing material is kept wet with a solution containing acid neutralizing chemicals. As the acid mist passes over the surface of the wet packing material, the acid droplets dissolve in the neutralizing solution. The acid droplets are almost completely removed from the process discharge air, resulting in a clean and non-corrosive air output. The acid in the neutralizing solution is rendered harmless and the solution can be discharged safely.

When Modutek’s high-efficiency acid fume scrubbers are used with the right flow capacity, the corrosive air output from wet process manufacturing stations can made safe for release into the work environment. This is especially important for semiconductor manufacturing operations that rely on a clean, particle-free process space.

Advantages of Modutek’s Fume Scrubbers

Modutek has built its fume scrubbers for a low total cost of ownership combined with design flexibility and ease of operation. The high efficiency resulting from careful design and the use of the Lantec packing material means that a higher percentage of acid fumes are removed and the resulting output air is cleaner and safer. The neutralizing solution from the packing material is recycled, reducing the use of water. A bottom drain makes maintenance easier and the scrubbers have a double containment system for extra safety.

The operator interface gives operators all the information they need for effective operation of the scrubbers. Pressure gauges and flow meters allow operators to get a complete picture of scrubber operation while water level indicators with discharge metering give operators control of neutralizing solution discharge. In addition to wet process station applications, acid fume scrubbers can be used with other chemical handling equipment Modutek offers to provide a safe working environment.

Benefits from Using Modutek Acid Fume Scrubbers

Modutek’s acid fume scrubbers allow facility managers to maintain a clean and safe work environment and neutralize acidic droplets that are discharged from wet process semiconductor manufacturing stations. Even when the use of fume scrubbers is not mandated by worker safety standards or environmental regulations, it often makes sense to install the scrubbers for the many benefits they provide. Benefits can include the following:

  • The high acid mist removal rate improves workplace air quality and results in higher employee job satisfaction.
  • Ease of use means operators don’t need extensive training and can reliably achieve operational targets.
  • Low cost of operation and maintenance allows for a quick return on investment.
  • The flexible design and wide range of capacities ensure that there is a system suitable for most applications.

Based on the needs of your facility Modutek can recommend specific acid fume scrubbers from its complete product line to ensure the installed unit meets application requirements.