Modutek Provides Solvent Delivery Pump Station for Large Pharmaceutical Company

Modutek Provides Solvent Delivery Pump Station for Large Pharmaceutical CompanyWith over 35 years of experience in the semiconductor manufacturing industry, Modutek has the expertise to handle large projects and challenging applications. The most recent example is a solvent delivery pump supply for a large pharmaceutical company. Nine solvent pump cabinets are required to transfer solvents to centrally located distribution stations. The custom-built cabinets are subject to tight specifications and rigorous compliance with applicable standards.

Project Details

Modutek will supply nine solvent pumping cabinets, each containing two pneumatically operated pumps. The pumps will have pulse dampers and will be fitted with air-actuated ball valves on the inlets and discharge outlets of each pump. Pilot valves will control the supply of clean, dry air (CDA). A series of valves and monitoring systems controls and supervises the transfer of solvents to distribution points close to the process.

Each cabinet will have an ultrasonic leak detector housed in a one-inch pipe “T” at the lowest point in the cabinet. A drain On/Off selector switch will be mounted near the drain port on the outside of the cabinet, and a 4-20 ma pressure transmitter will be mounted on the outside of each cabinet so the local display can be read easily.

Pump Cabinet Operation

The pumps will be controlled by a Programmable Logic Controller (PLC) and will deliver up to four gallons per minute. Solvents handled include acetone, methanol, ethyl acetate, heptane, isopropyl acetate and methyl tert-butyl ether. The system is rated up to 200 degrees Fahrenheit, and the passivation of the stainless steel parts is per ASTM standards. The pressure drop can be controlled through the PLC and the installation must be FDA compliant.

When a request for a pump is received, the drain valve On function is disabled and the pilot valve supplying CDA to the pump opens. The pump inlet and discharge ball valves open allowing solvent to flow past the pressure transmitter to the process. If a leak is detected in the pipe “T,” the pilot valve and the corresponding ball valves close, stopping transfer of the solvent.

When the drain function is switched On, the pilot valves and pump inlet and discharge ball valves are disabled. The pneumatically operated drain valve opens and the solvent drains into a collection container outside the cabinets. Once draining is completed, the operator can close the drain valve and resume normal operation of the pumps.

During normal operation of one of the pumps, the 24 V DC 4-20 ma pressure transmitter displays pressure in the line from the pump to the process. The pressure range is 1 to 150 psi. The pressure reading is displayed on a local LCD display and is available for remote indication and for HMI or SCADA systems.

Partnering With Modutek

Modutek can help customers that have complex or wide-ranging chemical delivery system requirements. The company offers standard solutions from its complete chemical delivery system equipment line or it can design and manufacture custom solutions to meet the needs of specific applications. All of Modutek’s┬áchemical delivery system equipment is engineered and manufactured in-house at the company’s San Jose facility. As a result, the company can rely on in-house expertise to build and service the required equipment.

Modutek’s chemical handling systems are built using the latest technology and the highest quality materials to achieve un-paralleled output quality at reduced overall cost. When chemical handling/delivery systems are precisely designed to match application requirements, waste is reduced, and the use of water and chemicals are minimized. There are fewer operator errors, and systems become safer and more productive. Choosing Modutek as a supplier can help improve production facility performance and increase profitability.

Why Quartz Baths Are Used in the Wafer Cleaning Process

Why Quartz Baths Are Used in the Wafer Cleaning ProcessThe cleaning of silicon wafers during semiconductor manufacturing uses strong, corrosive chemicals to remove deposits from the surface of the silicon. Critical factors for effective cleaning are an absence of contamination in the chemical bath, the impervious nature of the container and a tight control of the bath temperature. Baths made from high purity quartz don’t react with chemicals used in semiconductor manufacturing and are inert as a source of contamination. Quartz conducts heat well so fast temperature rise and accurate control are possible. A high-quality quartz bath is an ideal container for the semiconductor wafer cleaning process.

How Quartz Baths Are Used

The semiconductor manufacturing process involves multiple steps, each of which may require cleaning of the silicon wafer before or after the production process segment. Highly corrosive chemicals such as sulfuric acid, hydrogen chloride or hydrogen peroxide are used to remove materials such as organic residue from the surface of the wafers in preparation for manufacturing steps such as etching or diffusion. Effective cleaning is a critical factor in the success of semiconductor manufacturing because impurities or contaminating particles left on a wafer can lead to defective products or products of inferior quality.

During the cleaning process, the silicon wafers are immersed in chemicals within the quartz bath. Depending on the cleaning process, the baths may be heated, kept at a given temperature for a defined time period and chemicals may be re-circulated. For example, in RCA clean, wafers are first immersed in a mixture of ammonium hydroxide and hydrogen peroxide. These chemicals remove organic contaminants and particles from the surface of the silicon wafers. After rinsing and drying, the wafers are immersed in a mixture of hydrochloric acid and hydrogen peroxide. In this step metallic contaminants and particles are removed. The wafers are then cleaned for subsequent processing steps.

If particles remain on the wafers or if impurities are introduced during the cleaning process, manufacturing steps such as diffusion will be affected. With microscopic semiconductor structures, even tiny particles can obstruct an electrical connection or affect electrical characteristics. The semiconductor product may then fail prematurely or not work properly. When the quartz container is eliminated as a source of contamination, the focus is on the wafer cleaning process itself and its effectiveness in removing contaminants and particles.

How Quartz Baths Facilitate Reliable Cleaning

Quartz baths can meet all the criteria for effective cleaning of silicon wafers but they have to be designed well and constructed with top quality materials. Modutek series QFa re-circulating baths are made with semiconductor grade flame polished quartz to reduce the possibility of contamination. They feature quick, even heating and are available in a variety of standard as well as custom sizes. Operation is reliable and safe with excellent wafer cleaning performance and high quality output.

Operating characteristics include a temperature range of 30 to 180 degrees centigrade and the tanks can heat the bath at a rate of 2 degrees centigrade per minute. Temperature control is accurate within plus/minus 1 degree centigrade and heating is even through the bath. Standard tank sizes range from 7.75 inches to 21.5 inches a side with a depth of up to 14.5 inches. Custom sizes are available.

Modutek uses its experience of over 30 years designing quartz baths to deliver the highest quality baths with excellent cleaning performance. Modutek baths feature safe operation, reliable output and a low cost of ownership. The company can advise customers how best to meet their semiconductor wafer cleaning needs and can make specific proposals for solutions based on the company’s complete range of wet bench processing equipment.