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IPC has created a new standard and specification for traceability practices across all levels of electronics manufacturing, and specifically for electronics assembly. The IPC-1782 standard defines four levels for material and process traceability. With this new standard, companies that are practicing basic levels of traceability can evolve to higher levels (Table 1). Implementing this standard means that companies will be able to clearly define the expectations of what is required for compliance and conformance to customer needs.
Traceability is often a key component of quality standards across the electronics industry. But it has been approached from various points of view, and it can be defined as any combination of material traceability, product tracking, and process recording. And even within material traceability, views can differ on what should be recorded, how detailed it is, and how accurate it needs to be. Materials traceability could mean tracking specific materials to a work order, to a specifically identified PCB within a work order, or even to a specific component placement on that PCB. It may include all types of materials or perhaps only high-value, safety-critical parts or serialized parts. It may include or exclude parts replaced at repair stations or where an alternative or substitute part has been used, and it can include many more examples where a choice in the depth and breadth of recording is needed.
Table 1: IPC-1782 summary of traceability levels.
Accuracy is another area of contention. Process operational efficiency may conflict with the accuracy with which the traceability data is collected, as for example trays are re-filled without positive poka-yoke confirmation of verification. These are just some typical variations in the level and degree of material traceability. For product tracking and process data recording, an immense number of other similar decisions have to be made.
Individual companies typically have created their own set of high-level rules for traceability data that should be collected as part of their conformance requirements. The problem with all of these different specifications, often made without an in-depth understanding of the processes involved, was that exactly what data should be recorded, from where, and how it was supposed to relate to the product and process was left undefined. This has resulted in the collection of traceability data that is unreliable, incomplete, and/or irrelevant.
Negotiations around traceability requirements between the product owner and manufacturing have become increasingly difficult because neither speaks the same language, and they have common no point of view. Spectacular and public cases of product recalls have been the result, even while electronic systems are becoming more of a critical part of our everyday lives, and counterfeiters are having a significant effect on product quality and brand trust.
Compliance to internal or external standards helps assure manufacturers that work is only placed into manufacturing centers which demonstrate the appropriate compliance certificates or approvals. Today, compliance requirements extend to all quality sensitive markets for electronic goods such as military, medical, automotive, aerospace, telecommunications, and industrial controls. Even lower-priced consumer goods, such as handsets, toys, and games, require safety and environmental compliance. Manufacturers who are not able to demonstrate this compliance simply do not win business in these markets. These trends are driving manufacturers to implement higher levels of traceability for a wider range of industry segments.
The IPC-1782 Critical Components Traceability Task Group was created to address these issues. This committee has completed the first all-encompassing traceability standard for electronics, which is designed to be applicable to every product, in every company. Traceability is seen by many as a burden to the manufacturing process, and no one wants to have to comply or conform to yet another process or standard in the office or factory. The IPC-1782 committee members who all contributed so much to the creation of the traceability standard agreed that traceability ought to be implemented based on the merit that it brings to the manufacturing operation, rather than through some compliance mandate.
The nature of electronics assembly is hierarchical. A finished product, represented by an assembly cell, is typically made up of raw materials plus subassemblies. Each of the subassemblies is, in turn, a finished product of another assembly process also made up of raw materials and potentially other subassemblies. Thus, the IPC-1782 task group thought that the structure of traceability data should align with this physical reality. Figure 1 is a simple illustration of this structure.
Figure 1: The hierarchical data structure approach adopted by the IPC-1782 standard.
The assembly cell, here identified as “724435,” contains data about the work order and process sequence, BOM, the process traceability data, which is a record of events and transactions that have taken place during the assembly process, and the materials traceability data which contains information about specific raw materials, as well as other “roots” of information about each subassembly.