Building Quality In: Five Key Strategies for Eliminating Defect Opportunities

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1 Building Quality In: Five Key Strategies for Eliminating Defect Opportunities

2 Building Quality In: Five Key Strategies for Eliminating Defect Opportunities By Ken Gamber and Joe Zoghbi The key to ensuring quality in mission critical products is eliminating defect opportunities before they can occur. While inspection and test strategies do play a role in monitoring product quality, eliminating the root causes of the most common defects helps minimize the possibility that a defect will slip through. TeligentEMS, an EMS provider located in Havana, FL, has long been focused on eliminating defect opportunities wherever possible. The Company focuses on five key areas: DFX analysis and recommendations A robust New Product Introduction Process (NPI) Strong focus on materials integrity Internal systems which prevent common operator errors Real-time quality data collection and dissemination to evaluate developing trends. DFX Analysis and Recommendations At customer request, DFX including design for manufacturability, assembly and testability (DFM/DFA/DFT) is performed to eliminate issues likely to contribute to defects and ensure an optimized inspection and test process. In addition to evaluating the product for obvious variations from industry-standard design guidelines, the team looks at technology-specific issues. For example, with radio frequency (RF) products, the cumulative geometric dimension tolerance can create an unacceptable level of electrical noise, even when separately components are within acceptable tolerance limits. This typically occurs when components with fairly broad spacing tolerances exceed the total placement tolerance on the board. This can be mitigated through solder mask design to constrain movement and lock components in place. This example also underscores the value of having design engineers perform a geometric dimensioning and tolerance check after component selection. When the issue isn t discovered until manufacturing, often the only solution is to add special fixturing to lock the components more tightly in place during reflow. This increases production tooling non-recurring engineering expense plus adds variability that can increase defects. Ensuring a Robust NPI Process The NPI process is critical step in defect mitigation. TeligentEMS team also validates all parts against the approved vendor list (AVL) and verifies RoHS status. Following prototype and pre-production runs, customers are provided with detailed feedback on lessons learned, which are also incorporated into the production release work instructions. A team approach with the customer is utilized to correct or mitigate issues that have to carry into production.

3 Ensuring Materials Integrity Supply chain integrity is also an integral part in minimizing defect potential. The Company s proprietary Possible-X system integrates closely with the ERP system in receiving. The receiving inspection process has been designed to capture the bulk of the information required for both internal and customer requirements. Upon delivery each component is validated to the AVL. Any variance in labeling triggers additional inspection steps. Custom components are automatically routed to go through additional inspection including Critical-to-Quality (CTQ) measurements. Following inspection, a bar code label with purchase order receipt information is generated for each package and an ERP transaction is executed. The label data includes key information such as moisture sensitivity level (MSL), RoHS status, etc., ensuring proper storage and handling requirements are easily visible to stockroom personnel. Certificates of compliance are also validated at that point and automatically scanned into Possible-X, providing a complete record of required information for every part. TeligentEMS also has a robust process for counterfeit prevention that utilizes a design that conforms to AS5553. The Company also maintains membership in the Government-Industry Data Exchange Program (GIDEP), to ensure that process includes checks for identified trends in counterfeiting. Internal Systems Which Prevent Operator Errors TeligentEMS opted to build proprietary tools around an Epicor ERP system to fill the gaps its team had identified in their overall systems strategy. Possible-X is at the core of this system. As the central repository for documentation and production and test data collection, Possible-X supports configuration management. It tracks ECOs and deviations and links them to work orders so that as documentation is pulled to build a product, production associates are automatically served the correct documentation at the correct revision. Possible-X also contains a new production introduction (NPI) checklist and work instructions for each product. The checklist aligns with the Company s focus on Lean manufacturing since a standardized setup process helps minimize variability. This is particularly important with low volume and/or legacy builds as production on these products is typically infrequent and there may be little production floor memory of production setup. In the SMT area, feeders are loaded and validated offline to a SiPlace Pro Setup output compared to ManFact ERP BOM. A second check-and-balance is performed when the feeder carts are bar-code scanned as they are loaded into the machine. Inspection tools including Solder Paste Inspection (SPI), Automated Optical Inspection (AOI) and X-ray are used to validate processes and monitor product quality, particularly on printed circuit board assemblies (PCBAs) that have limited opportunities for visual inspection.

4 In addition to its automated SMT capability, TeligentEMS has assisted placement machines for plated through-hole (PTH) parts. This helps ensure that legacy PTH product is assembled correctly and efficiently. In final assembly areas, fixtures and jigs are used where needed to minimize variability in assembly processes. Workstation monitors display work instructions, supporting both fast changeover and configuration management via Possible-X. Production associates utilize Possible-X s Production Dashboard, known as p-dash. This tool is designed to help empower production associates by ensuring they have fast access to the information needed to do their jobs. Associates must log in using their id number. They utilize the system to clock in and out, plus it automatically accesses all relevant documentation related to their jobs and specific to a Work Order. This information is typically displayed at workstation monitors. p-dash also facilitates movement of cross-trained associates among different work areas as demand varies, since documentation access is linked to work order. This login access supports both intellectual property protection and ITAR compliance. p-dash also lets associates open support tickets which text a message to an engineer whenever a production issue arises that the associate needs help with. This helps ensure that issues that could impact product quality are corrected immediately. Real-Time Quality Data Collection and Shop Floor Control Possible-X includes a metrics menu that helps ensure both production and management are in the loop in terms of real-time quality and production status information. Defects per million opportunities (DPMO) is monitored in the SMT area in real time. Monitors showing a real-time, color coded graphical interface indicating both DPMO and production status relative to production targets are placed throughout the production floor and are also monitored by management. DPMO is measured in real time and the charts displayed on monitors show averages of the last hour, previous 24 hours and previous 7 days. The top identified defect categories are shown in a pareto diagram. A test data collection chart displays results from in-circuit test, functional, flying probe, RF, burn-in and hi-pot, making it easy to identify if any issues are developing in any test stage. Issues are addressed as they arise by the people closest to the issue. As with all Possible-X tools, it is possible to drill down to data related to specific work orders and serial numbers to determine root cause of any identified issues. The end result of this combination of real-time systems, centralized configuration management and robust process control is an exception-based process where production operators and management focus on variations as they occur, instead of inspecting out a far larger number of easily preventable defects. The production team stays more attuned to eliminating variation and is more efficient, since the information required to do the work correctly is always accessible. Ken Gamber is TeligentEMS Engineering Manager. He can be reached at kgamber@teligentems.com. Joe Zoghbi is TeligentEMS Quality Assurance Manager. He can be reached at jzoghbi@teligentems.com.

5 About TeligentEMS For more than 30 years, TeligentEMS has provided a full range of electronic manufacturing services to companies in the industrial, medical, military/aerospace, telecommunications and instrumentation industries. We specialize in technically complex printed circuit board assemblies, subassemblies and box build. Our superior RF expertise enables us to support a wide range of communication technologies. We are ITAR registered and ISO 9001 and ISO certified. Our global procurement and supply chain capabilities, combined with our real-time systems for project status, quality data collection and device history recordkeeping ensure we offer customers a cost effective and highly responsive solution.