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Suzhou Facility Uses Lean Manufacturing Principles

The team at SigmaTron International’s Suzhou, PRC facility is focused on optimizing productivity through use of Lean manufacturing principles.  Some key areas include:

  • A paperless factory approach to NPI and production documentation
  • Standardization of equipment capabilities and processes
  • Design For Manufacturability/Testability (DFM/DFT) analysis
  • Use of continuous flow layout, where possible
  • Use of automation, wherever possible
  • Worker cross-training
  • Optimized supply chain management.


In terms of Lean philosophy this approach is designed to:

  • Eliminate unnecessary labor and cut the time needed to launch new projects
  • Minimize variation in processes
  • Minimize transport within the facility
  • Minimize production constraints through a flexible workforce with the concomitant benefit of minimizing turnover
  • Minimize inventory
  • Eliminate the possible manufacturing defects to minimize the future rework cost
  • Continuously improve the manufacturing process to overcome manufacturability issues
  • Continuously improve the testing process to enhance the fault spectrum
  • Confront the facts and plan ahead to smooth out the operations to minimize the waste.

“Our team is focused on working smarter and on continually finding ways to improve,” said Hom-Ming Chang, SigmaTron’s V.P. China operations.

One example of the team’s approach to Lean would be in the systems area. SigmaTron uses a combination of proprietary and internally-developed systems for enterprise and shop floor management. All facilities utilize a common ERP system plus Agile Product Lifecycle Management (PLM) tools. The China team wanted to further enhance traceability and shop floor control and developed a Manufacturing Execution System (MES) system known as Tango to do that. The Tango system will be launched in other facilities in 2014. The Company takes a distributed approach to continuous improvement in its systems by letting teams at individual manufacturing facilities identify specific gaps in shared systems and develop appropriate software tools. These solutions are then tested at the facility that identified the need and later transferred across all facilities. This combination of standardized core systems deployed through the corporate IT group and focused innovation which taps the regional IT expertise at each facility drives improvements faster than would be possible solely with a centralized IT function.

In China, the combination of these systems has created significant progress toward in becoming a paperless factory in terms of documentation creation and control, and work order scheduling and tracking.

Product documentation is transferred electronically from customers, eliminating potential errors associated with more manual processes. Electronic work instructions are displayed on monitors at each workstation. These work instructions include video showing the steps necessary to perform the designated operation, ensuring that operators have clear examples of the optimum way to perform specific tasks. Product is bar coded and tracked through each operation. Real-time production status monitors display data in each work area, and customers can access production status remotely. The end result is a production environment where all workers have access to real-time production metrics and bottlenecks or quality issues become immediately apparent.

Another strong area of focus has been worker cross training. While most companies utilizing Lean philosophy cross-train workers to add flexibility in supporting varying demand for different production operations, in China there is an additional benefit to this practice.

“Younger workers in China are typically well-educated and interested in contributing their ideas. Companies that provide a clear career path, offer training in higher level skills, listen to their employees and give them opportunities to contribute ideas have lower turnover than companies that don’t have these types of job enrichment/job enlargement programs,” added Chang.

SigmaTron allows employees to train for every job in the process they were hired for and teams with the government in providing advanced training opportunities enabling operators to become technicians or engineers. There are internal skills competitions for prizes. The Chinese government has annual skills competitions among representatives from factories in that region for cash awards and promotions. Representatives from SigmaTron’s team participate in these, as well.

“We’ve got a great team in Suzhou. An environment focused on continuous improvement, where individual contributions can make difference, aligns well with our team members’ desires to do an excellent job and progress in their career fields. It is truly a win-win situation,” said Chang.

SigmaTron’s Conflict Minerals Policy

SigmaTron International is committed to the highest standards of ethical behavior, respect for every member of our team, and compliance with environmental and business regulations in the regions in which we do business. An evolving area of social responsibility, particularly for publicly-traded companies relates to “Conflict Minerals”.

“Conflict Minerals” refers to minerals or other derivatives (including gold, wolframite, casserite, columbite-tantalite and their derivative metals, which include tin, tantalum and tungsten) mined in the eastern provinces of the Democratic Republic of the Congo (DRC) and in the adjoining countries where revenues may be directly or indirectly financing armed groups engaged in civil war resulting in serious social and environmental abuses. In July 2010, the United States passed HR4173, the Dodd-Frank Financial Reform Bill Section 1502(b) requiring all US stock listed companies and their suppliers to disclose the chain of custody usage of Conflict Minerals.
SigmaTron shares concerns about the use of resources to fund armed conflict in the Democratic Republic of the Congo, and is intent on making sure its activities are not contributing to the issue.

SigmaTron is working to comply with HR4173, the Dodd-Frank Financial Reform Bill Section 1502(b) requiring all US stock listed companies and their suppliers to disclose the chain of custody usage of Conflict Minerals on company web sites and in filings with the Securities Exchange Commission (SEC). Further, SigmaTron is adopting reporting processes and obtaining chain of custody declarations from all SigmaTronsourced and managed suppliers to ensure transparency in its supply chain.

Beginning with May 2014 reporting, customers will be able to view the Company’s latest SEC required information releases related to Conflict Minerals in the Investor Relations section of the website. The website’s Social Responsibility tab includes a link to the Company’s detailed Conflict Mineral Policy. Suppliers can learn more about the new reporting requirements by visiting the Supplier link on the website.
Persons with any questions regarding SigmaTron and Conflict Minerals, product compliance, or corporate social responsibility issues, can email: conflictminerals@sigmatronintl.com.

Tijuana Facility Develops System to Enhance ESD Protection

A team at SigmaTron International has developed an innovative system to “lock-out” production operators that fail to test their straps twice per day. The facility’s ESD program requires the twice a day test and records were manually kept on paper logs. Now this is monitored automatically. While this feature has only been in place a month, it is part of a larger system, known as SAIS (SigmaTron Automated Information System) that was developed by the facility’s Production and IT team two years ago. SAIS also has features that monitor preventative maintenance schedules, profiling and product validation processes.

Production Manager Roman Rodelo wanted a better set of checks and balance and was the architect of the program. He teamed with Julio Leon, a programmer in Tijuana’s IT department. Leon then wrote the program.

Now when production operators bar code into the production area, they also log the status of the ESD test. This data is linked to the production operators’ work-stations.  If the test data hasn’t been entered the operator is locked out of the machine until a successful test is performed and logged.

This is Phase One of the system development. After a period of testing at the
Tijuana facility, it will be rolled out to other facilities. As with the Suzhou facility, this is one more example of ways innovative teams at each facility are helping to drive continuous improvement and repeatable processes.

X-Ray Laminography Test Capability Enhanced

SigmaTron International has purchased an additional Agilent 5DX x-ray laminography unit. When the Union City facility originally adopted the platform in 1995, it was the first company in the San Francisco Bay area to acquire a unit. Originally, the equipment was purchased to support a customer with leading edge technology and very complex printed circuit board assemblies (PCBAs). Today, the equipment supports a number of customers with complex PCBAs.

The newly acquired model is a 5DL XL, which can handle PCBAs up to 24 inches x 30 inches.

“The Union City facility processes large PCBAs on a regular basis. We have set up our lines to accommodate up to 24-inch PCBAs in all areas except x-ray. This unit addresses that issue,” said Yousef Heidari, Sigmatron International’s V.P. Engineering.

One of the existing units will be moved to the Tijuana facility to support complex PCBA production in that facility.

“This will give both facilities fully automatic inspection equipment. 100% of solder joints can be inspected, as needed. We also use them for to dial in process parameters when we do assembly profiling, as part of the first article acceptance process and in initial production. Once production is validated, we test on a sampling basis,” Heidari said.

The testing is most relevant to customers with mission critical applications such as those found in medical and military products. It is also used on PCBAs containing high pin count BGAs. The equipment is very fast and has a focal plane that makes it easier to automatically inspect double-sided boards, particularly in the areas of through-hole solder fill, QFNs, QFPs and any other components with hidden solder joints. It measures the profile of solder joints in a way that is similar to the visual inspection done on solder joint geometry in a workmanship standard. This ensures identification of marginal joints that might otherwise pass incircuit (ICT) or functional tests.

“Expanding this capacity is part of our overall test strategy. While this is legacy equipment for Agilient, they still support both this and our 3070 ICTs, so it aligns with our existing service contracts,” Heidari added.

As part of the events of the National Manufacturing Day on Oct. 4th, the Tijuana EDC hosted the Near-Shore Contract Manufacturing Industrial Tour right after the MFG Day Breakfast & Conference organized by  the San Diego Regional EDC.

Sigmatron International, Inc. was one of the two companies selected and provided both a factory tour and presentations on the benefits on its capabilities and advantages.