How On-Site Acid Neutralization Provide Safe Chemical Disposal

 

Choosing the right acid neutralization system is crucial. With overall standards getting tighter, it is important to have a system that can automatically add the required neutralizing chemicals to acid waste left over once the semiconductor process step is done.

Such a system should use the least amount of chemicals while ensuring adequate neutralization of waste to comply with the environmental standards. It has to have enough capacity to handle the waste chemical flow. It must also operate reliably, protecting against spills and documenting chemical use and discharge.

Automated acid neutralization systems can operate in either two ways:

·         Continuous flow – this is ideal for large-scale operations. 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 – this is 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. In this system, the waste chemicals have to be neutralized in small batches. Each process is different. This type of 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.

Complete automation of a continuous flow comparatively easy because the process parameters are known and don’t change. The automation only has to add the required amount of neutralizing chemical on a continuous basis and record the resulting pH.

However, doing a complete automation of batch neutralization systems, however, can be challenging. The key variables, the process, and the chemicals involved can vary depending on the batch. First, it 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. Compared to a fully automated continuous flow system, a fully automated batch neutralization system is complicated to program and difficult to set up. Operator involvement to select the type of neutralization required can simplify the process of the automated system, making it more effective.

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

Modutek offers a full line of chemical handling equipment, along with acid neutralization systems. Read their complete article, “How On-Site Acid Neutralization Systems Provide Safe Chemical Disposal”. If you have questions, or would like to set up a free consultation, send an email to Sales@modutek.com or call 866-803-1533.

Choosing an Acid Neutralization System to Safely Handle Chemical Disposal

Wet process semiconductor manufacturing lines use aggressive chemicals to clean and etch silicon wafers. Once the cleaning or etching step has been completed, disposing of the remaining chemicals safely is necessary.

Before being discarded, the remaining chemicals have to be neutralized first. For instance, low pH acids (like hydrochloric acid) have to be neutralized with high pH chemicals, so that it can reach the neutral value of seven. An acid neutralization system can be used continuously or in batches, and either process can be fully automated.

An acid neutralization system can be used with little supervision and will record chemical use and discharge to demonstrate compliance with environmental regulations.

The choice of acid neutralization reflects on the type of semiconductor manufacturing that takes place. For example, a continuous flow of waste chemicals is usually the result of large-scale continuous manufacturing. Therefore, a continuous acid neutralization system is ideal for this situation, as it can be designed to neutralize the outflow automatically and reliably.

The neutralization of waste chemicals in batch manufacturing is usually more complicated because each batch is different. Batch manufacturing usually takes place in developing prototypes, unique components, or small quantities of special parts. Therefore, batch neutralization is used, where the pH of the waste chemicals is measured and added with specific neutralizers (instead of adjusting chemical dosages of an established process like as in the continuous flow systems).

Once the choice of continuous flow or batch system is made, the acid neutralization system must fulfill a few basic requirements. The system capacity must be sufficient for the proposed application, with capacities ranging from a few gallons to a hundred gallons per minute. If automated, the exact automatic functions have to be programmed and set up. Finally, the monitoring and record-keeping functions have to be determined.

Another thing to be considered is the operational characteristics. If the system is automated, it may operate without supervision, but alarms will be required for situations such as low chemical supply or a pH level going beyond allowable limits. Recording of neutralization process parameters can be done digitally, with a log or on a chart recorder. Spill detection has to be incorporated into the alarm system as well, and the whole operation has to comply with environmental regulations.

For more details, read the complete article, “Choosing an Acid Neutralization System to Safely Handle Chemical Disposal”. The article discusses Modutek’s acid neutralization systems and how they can be customized to meet specific needs.  Contact Modutek at 866-803-1533 or email Modutek@Modutek.com if you have questions or would like to set up a free consultation.