PV Standards Update: Annual Europe Strategy Meeting; First PV Water Standard

PV Standards Update: Annual Europe Strategy Meeting; First PV Water Standard

One of SEMI PV Group’s first initiatives dealt with International Standards development, and PV standards development is now underway in Europe, North America, Japan, and Taiwan, and is an area of major growth in the SEMI International Standards Program. While a few industry stakeholders question the need for manufacturing standards in PV, fearing standards stifle innovation and reduce IP value, the majority points to the lessons learned in 40 years of semiconductor manufacturing and the impact that industry standards have had on reducing manufacturing cost and increasing supply chain efficiency.

Standardization speaks clearly to the needs of the young manufacturing supply chain to collaborate, exchange, and share. Standards development is a proven method to overcome shared challenges and help expand manufacturing business worldwide. This article reviews PV Standards progress in the last month, including European Standards activities and the new PV3-0310: Guide for High Purity Water Used in Photovoltaic Cell Processing.

Europe’s Annual Strategic Standards Review

Once a year, European leaders of the SEMI Standards Program convene for a Standards strategy review meeting. Based on a sound quality management model, the meeting addresses key industry needs that can be tackled through effective standards.

Presentations and discussions at this year’s event, hosted by the Fraunhofer Institute of Solar Energy in Freiburg, Germany, confirmed the importance of PV standardization for most current committees, including materials, automated manufacturing processes, and equipment safety aspects.

In addition, specific standardization needs in crystalline silicon PV were suggested: feedstock production, ingot production, wafer production, cell production, module production, and module test and certification (click here for details of Fraunhofer presentation)

There are high expectations for standardization in the PV industry, based on evidence from other sectors: “At Bosch we experience the benefits of manufacturing in highly standardized industries, such as the automotive, and expect the same from the photovoltaic industry,” says Lars-Oliver Stock, VP of Crystalline Production at Bosch Solar Energy.

Annual Strategy Meeting of the European Regional Standards Committee

While some semiconductor standards may serve as the basis for PV standards, they may be overly complex for PV and need to be modified. This is where the expertise and leadership of the PV industry is critical, to ensure that PV standards directly address the real needs of PV manufacturing: “Schott and other PV manufacturers are ready to work with equipment and materials suppliers to set standards to enhance the efficiency of PV manufacturing,” says Ingo Schwirtlich, VP Technology at Schott Solar AG.

SEMI PV Group, with almost forty years experience in standards development, is the right organization to support the PV industry. A recent example of SEMI driving PV Standards is the new SEMI Standard PV3-0310, which addresses high purity water used in photovoltaic cell manufacturing.

“SEMI has a long history of successful standardization; this is why SEMI is the preferred platform to develop the standards needed to drive down PV cell manufacturing cost.”

Gerhard Rauter

COO, Q-Cells

SEMI PV3: Guide for High Purity Water Used in PV Cell Processing

Water is used extensively in the production of photovoltaic (PV) cells and associated manufacturing for all wet processing steps such as rinsing chemical residues from equipment and rinsing of substrate wafers and panels. Overly stringent specifications lead to unnecessarily high investment in equipment and negatively impact profitability, while insufficient specifications adversely impact manufacturing yield. Thus, a standard for water quality is needed to create a common understanding of requirements between High Purity Water (HPW) suppliers and users.

Addressing Water Quality Requirements

Up until recently, there have been no industry standards on water quality for Photovoltaic manufacturing. SEMI PV3-0310, Guide for High Purity Water Used in Photovoltaic Cell Processing, published in March 2010, is the first industry PV water standard. While SEMI F63 and ASTM D5127 have long been used by the semiconductor and electronic industries, the needs of photovoltaic end users differ from those in semiconductor when it comes to high purity water used during production. This is driven by different (lower) sensitivity to water quality parameters and higher sensitivity to facility system cost.

Standards Developed by the PV Industry for the PV Industry

In the course of developing PV3, the SEMI Standards PV Water Working Group, comprised of PV manufacturers, suppliers, engineers and facilities managers, evaluated different qualities of water. This evaluation provided cost consideration, based on the idea that higher quality requirements require additional investment in the treatment process. At the same time, industry feedback was sought via surveying. Input was gathered, discussed and ultimately incorporated into the document. This combination of valuable industry input and the working group’s collaborative assessment resulted in an industry-accepted guideline for high purity water used in photovoltaic cell processing.

SEMI PV3 addresses both High Purity and Standard Purity, which reflect current state-of-the-art PV manufacturing (see below):

Resistivity on-line @ 25°C (Mohm–cm)

High Purity = >17.5

Standard Purity = >10

High Purity is applicable for higher sensitivity PV processes and Standard Purity is targeted for lower sensitivity PV processes. Depending on performance requirements, PV3 may be used to establish performance criteria for purchase of new HPW equipment. Facility engineers may also use this standard to set process control parameters for operating their HPW systems, and process engineers may use PV3 to establish reasonable expectations on supplied HPW in their facilities.

How will this standard provide cost savings or overall economic benefits?

This standard will help optimize HPW quality specifications and as a result will minimize investment in HPW systems. Standardizing water quality helps not only to speed up the decision-making process, but to also standardize the HPW system configuration. Standard configurations will further reduce the cost of HPW systems, as they will not have to be custom made. Additionally, using sufficient specifications will protect manufacturing from adverse yield and quality impacts.

PV Standards Meetings

The European PV Standards Committee recently met in Berlin during the PV Fab Managers Forum(March 7-9), and SEMI recently hosted Standards meetings from March 29-31 at SEMI Headquarters in San Jose, California. In addition to the PV Standards Committee, several other groups, including the PV Materials Task Force (TF), the PV Analytical Test Methods TF, the PV Electrical & Optical Properties TF, the PV Gas & Liquid Chemicals TF, the Minority Carrier Lifetime Working Group (WG), the Transparent Conductive Oxide WG, and the c-Si Cell Specification WG met to review current proposals as well as to chart out future work. Additionally, the Taiwan PV Standards Committee met in late March, while Japan will conduct PV Standards meetings on April 8 at the SEMI Office in Tokyo. See the full calendar of events.

For more information, please contact your local SEMI Standards staff.

The SEMI PV Group needs your participation. If you are in the PV supply chain, please contact SEMI PV Group International Standards Director James Amano at jamano@semi.org. Over 71 percent of companies participating in Standards Committees believe that it helps them anticipate future market requirements! Participation is free, but registration is required.

SEMI PV Group Standards Links

April 7, 2010