Once a wet bench process step is completed, the remaining chemicals and waste water have to be drained and transferred to an area for neutralization and disposal. Depending on the physical layout of the semiconductor manufacturing facility, gravity draining may either not be possible at all or may be insufficient in terms of flow and speed. Chemical lift station pumps take over the transfer of chemical solvent in a controlled and optimized way. The removal of chemical solvents and waste liquids is accomplished rapidly and completely, leaving the wet bench station ready for a new process step.

Lift Station Pumps for New Installations

While it may be possible to design new installations without lift station pumps and relying only on gravity drains, changes in the facility, expansions or upgrades may require the retrofitting of pumps. In that case, lift station pumps have to be included in separate stations that are often located behind the wet bench stations. These separate stations take up valuable floor space that could otherwise be dedicated to productive process elements. As a result, incorporating lift station pumps in new wet benches is more desirable.

Modutek can add lift station pumps to their wet bench stations and use them to pump acids, solvents and related chemicals and solutions in their semiconductor manufacturing equipment. The lift stations automatically monitor the lift station tanks. When fluids are detected in the tank via the installed level sensors, the corresponding pump is activated to transfer the liquid from the processing station to the facility’s neutralization area. Incorporating the lift pumps in the processing stations is an efficient and compact solution for new installations.

Adding Lift Stations to Existing Processing Lines

When wet bench processing lines are used with a new process or are upgraded, the gravity drains that were previously adequate may no longer deliver the required flow. Lift stations have to be added to deliver the anticipated performance. Often extensive customization of the lift stations is required to accommodate them in the existing facility.

Modutek can help find solutions to adding chemical lift stations to wet processing lines. The company has a complete line of chemical lift stations for installation outside existing wet processing stations. Modutek engineers evaluate process requirements and plant layout to propose equipment that works best for a particular application.

Modutek’s chemical lift stations have all-plastic fluid paths for resistance to corrosion and feature an automatic constant ON with level sensing governing operation. Standard pumps are vertical centrifugal polypro with other pump options and a double containment option available. The polypro holding tank can be built to the size required and the designs are customized to meet flow requirements. Level sensing is via four float-type level sensors signaling low/low, low, high and high/high. Remote control is available.

Modutek Delivers Customization and Support

Modutek can analyze the requirements of a wet bench installation and propose ideal solutions because the company designs and builds their wet bench equipment in house at their facility in San Jose. With almost 40 years experience in wet bench technology, Modutek has the expertise to find optimum solutions and implement them using their own equipment. Chemical lift stations for existing installations and lift station pumps incorporated into new wet bench stations often require extensive customization. Such customization can include different geometry, size, materials, and control logic to meet unique customer requirements. Modutek can rely on in house experience to adapt its equipment for a specific application. Once delivered and installed, Modutek can provide unparalleled customer support because the company doesn’t use third party suppliers. The Modutek specialists carrying out wet bench and lift station service are backed up by the Modutek personnel who designed and built the equipment.

Reviewed and Approved by Douglas Wagner
President & CEO, Modutek Corporation

Timely preventive maintenance of wet bench equipment allows semiconductor manufacturers to avoid costly unexpected downtime due to equipment failure and quality issues. Wet bench equipment is complex and is typically used in a demanding manufacturing environment. Calibration, cleaning and replacement of parts that wear out has to be performed regularly to maintain facility performance and output quality. Once scheduled, preventive maintenance has to be carried out quickly and professionally, completing the required tasks on time and using personnel with the required expertise. If the necessary preventive maintenance is not completed or is not done correctly, poor quality products, equipment damage and compromised worker safety can result.

Scheduling Preventive Maintenance

Wet bench stations operate with corrosive chemicals while at the same time relying on the highest standards of cleanliness and control of contamination. Chemical dosages and control of variables such as temperature are critical for a successful production line. Some components have to be changed, cleaned or serviced regularly while others have to be inspected to see if any action is required.

The semiconductor manufacturing equipment supplier will often specify what preventive maintenance measures are required and which ones are recommended. Some tasks can be carried out by the semiconductor manufacturer’s personnel, but others will often require specialists from the supplier. Developing an overall schedule that limits downtime for the production line to a minimum while ensuring that all preventive maintenance tasks are scheduled and carried out can be challenging.

Carrying Out Preventive Maintenance

Depending on the details of the semiconductor manufacturing operation, some preventive maintenance tasks can be performed while the line is in operation. For some lines, production steps are sequential so that a particular piece of equipment may be at rest for a given period. Preventive maintenance can then be carried out on that equipment.

Other parts of the production line may be in more or less continuous use for periods exceeding the recommended preventive maintenance interval. In such cases the required downtime has to be factored into the production schedule with reduced throughput. When all these factors are taken into account, it becomes clear that preventive maintenance for wet bench equipment may have to be flexible and reactive to manufacturing requirements rather than based on a fixed schedule.

Coordinating with a Competent Supplier

Developing an ongoing wet bench preventive maintenance program is easiest when partnering with a supplier who is familiar with the installation and who can handle all preventive maintenance tasks, even if the stations are highly customized. Such a supplier can help the semiconductor manufacturer develop and adapt a suitable schedule and help complete the work. The supplier can offer to carry out those tasks that specialists can perform quickly and competently while giving instructions for on-site semiconductor manufacturing personnel to complete simple tasks and inspections. Such an approach is ideal from the facility owner’s point of view.

Modutek can offer this type of field service and customer support because it has in house expertise based on almost 40 years of experience in the wet processing technology field. Scheduling and carrying out preventive maintenance on wet bench stations while keeping disruptions to production at a minimum requires such experienced personnel.

In addition to highly qualified specialists, Modutek designs and builds all its own wet bench stations at its manufacturing facility in San Jose. As a result, it can offer first-hand service, repair, and upgrade support without having to call on third parties. Working with a competent partner such as Modutek helps customers carry out the necessary preventive maintenance that keeps their equipment functioning at an optimum level while reducing downtime and avoiding compromised product quality.

Reviewed and Approved by Douglas Wagner
President & CEO, Modutek Corporation

SEMICONDUCTOR WET PROCESS EQUIPMENT AND WET BENCH MANUFACTURER

Monthly Archives: January 2019

Why Chemical Lift Station Pumps Are Needed for Wet Bench Stations

Why Preventative Maintenance of Wet Bench Equipment is Important