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Process validation and standards compliance

cess in such a manufacturing environment and providing validation that the operation is properly managing MSD components is critical to maintaining industry specific certifications and passing customer based process audits. Any MES system imple- mented in such an environment must have the ability to manage the processes associ- ated with MSD components including: • identification of MSD components and their classification based on IPC/JEDEC standards

• management of the time a compo- nent can be exposed to moisture in the environment before they need to be dried

• alerting operators and interlock- ing of placement machines when a component has been exposed to the environment for too long and there is an attempt to assemble it into a product

• management of components when placed in dry stock or dry ovens to properly account for exposure time to the environment

Some manufacturers have even more spe- cialized needs when it comes to ensuring that their operation is following the proper process for assembling their products. One example is related to the automotive indus- try where a dashboard assembler needs to ensure that all the LEDs are the same brightness. Given the fact that LEDs come in different light classes (that is, they will shine at a different level of brightness), the manufacturers will compensate for this by adjusting the value of other components (such as resistors) placed on the printed circuit board to ensure that all LEDs shine at a consistent brightness level. Tis com- plex scenario can result in many different variants of component sets, related to LED light classes, being required for a single printed circuit assembly. Validating that the proper components are set up on assem- bly equipment, and managing this when material is replenished to the manufactur- ing line during a production run, is almost impossible to do unless an automated set up verification system that understands all the variants is in place. Making sure that other required

resources are at particular operations during assembly and product

testing are

the correct ones is also important in ensur- ing that an MPD is being properly executed. Tis includes the ability to verify that the proper paste or glue stencil is being used at a screen printer and that procedures are being followed concerning proper stencil cleaning. Te most advanced MES systems

Figure 4. A comprehensive report system provides data in multiple ways to allow thorough analysis and implementation of efficiency-improving changes.

manage a closed loop process between the stencil cleaning and screen printer opera- tions and will interlock the printer if the process is not being followed. Other fixtures are equally important, such as partial wave solder fixtures, ICT fixtures, and others. Properly maintaining fixtures and other

resources needed in the manufacturing pro- cess is also critical to ensure full validation of adherence to the manufacturing process. As an example, ensuring that all the feed- ers used in a operation are properly main- tained can not only improve the overall throughput of the manufacturing lines, but can have a significant impact on the overall quality of the SMT placement process and can help to reduce material waste. A com- prehensive MES system for the electron- ics manufacturing industry provides a full feeder maintenance management


which includes logging of feeder usage and related errors, the ability to block feeder usage and recall them for maintenance, and comprehensive tools for managing preven- tative maintenance on feeders.

Quality management Te quality levels of the products being produced at a manufacturing site are a cornerstone of measuring the overall com- pliance to an optimized manufacturing process. Tis includes making sure that all inspections and tests are carried out cor- rectly on a unit during production, that all measurements are being logged, and when any measurements are outside of specified tolerances these symptoms are analyzed to determine the underlying defects so that the unit can be properly repaired. Along with the logging of information concern- ing the testing and repair of units, an MES system that provides full quality manage- ment must also work with the MPD control aspects of the solution to ensure that no

18 – Global SMT & Packaging – February 2011

product can ever move through the manu- facturing process unless all tests have been passed. If a test has been failed, the system must guide the operators to bring the unit to the correct repair location. Te bottom line being that no product must ever be packaged and shipped unless all required tests and inspection steps identified in the MPD have been passed. Te most advanced MES systems in the

electronics industry also provides compre- hensive solutions for automatically con- necting to and collecting measurement and symptom information from automated test platforms including easily extensible solu- tions that allow the system to communicate with customized functional test equipment. Advanced systems also provide compre- hensive guidance to the analysis and repair technicians which will aid them in quickly finding the root cause of symptoms to iden- tify the exact defect in the unit and what repair actions need to be taken. All of these capabilities help to ensure that an operation will easily be able to meet the most strin- gent of quality management standards, and pass the most picky customer quality pro- cess audits.

Reporting and Analysis A site must be able to easily produce all the required reports to prove that they are manufacturing products according to the MPD. Tat is, that they can validate they have been running the proper manufactur- ing processes. Te basis for this reporting is the collection of a comprehensive build record. An MES system must provide the capabilities to provide an extensive set of reports about the manufacturing process, or about any particular unit that had been manufactured. Tis includes, but is not lim- ited to, reports related to: • the proper completion of the MPD

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