Component Traceability Issues
December 31, 1969 |Estimated reading time: 4 minutes
By Inovaxe Corp.
In addition to the nightmare of managing component-lot traceability from receipt to final assembly, manufacturers also must routinely manage RoHS-compliancy, time- and moisture-sensitive devices (MSDs), and the integration of vendor- or customer-consigned materials into the product. These items have very different concerns and requirements; each must be managed throughout the manufacturing process. A manufacturer must determine how to identify the needs of each process, effectively train employees, systematically capture and record required data, and analyze and deliver data to concerned parties.
This places companies under stress to manage these points without slowing the manufacturing process or adding significant non-value-added costs to the product. Currently, most companies throw labor at the issue or avoid it altogether. Most are in line with a hybrid version in which some amount of manual data collection occurs for one or more of these areas.
In reality, data traceability provides the foundation for most quality standards. Data will be used primarily when there is a quality issue considered severe enough to either alert customers to the problem or identify the extent of a product-recall situation. Ultimately, data provide the foundation for understanding the limits of risk management (Figure 1). The following can be found when looking at a fundamental point of each traceability issue:
Component-lot numbers - A final assembly may contain hundreds or thousands of components, so it is important that each lot number is captured during each stage of the manufacturing process, and associated with its corresponding subassembly. Each subassembly must be attached to a final-assembly serial number. EMS providers often cannot compete on valuable government, medical, and automotive business due to an inability to track lot numbers effectively.
RoHS compliance - Identify the RoHS status of each component used in an assembly, regardless of whether the final assembly must be RoHS-compliant or not. Using RoHS-compliant parts is not simply a yes/no scenario because some RoHS-compliant parts are backward-compatible and acceptable for use in the process. But process adjustments may be required. What makes this somewhat difficult is that most manufacturers’ component transitions to RoHS-compliance are based on date-code changes, and not on a change in part number.
MSDs - Adhering to J-STD-033A is a different animal, but boils down to tracking. All MSDs have requirements to control exposure time to moisture (Table 1). Moisture sensitivity and associated tracking of these devices is becoming a larger problem.
Vendor/customer-supplied materials - How do you segregate and integrate components into products that are consigned from the customer? With vendor-consigned materials, what triggers are used to segregate physical and perpetual inventories?
Lowest Common Denominator
What are the commonalities with these issues, and where does data needed to develop a total system solution reside? Identify the lowest common denominator for each issue, and a single-system solution can be developed to handle all requirements.
Figure 1. Traceability needs and input.
The lowest common denominator is the status of an individual reel, tube, or tray of components. For example, each reel has an identifier on it indicating its part number, quantity, lot number, RoHS-compliance status, and moisture-sensitivity level. If this lowest common denominator forms the basis of a data-collection system, one system can be created to handle all tracking requirements, and provide a foundation for future requirements.
Given that the all of data needed to track is available in a single unit of measure, you must decide at which stage of the process data will be captured, its definition, and the system of capture (barcode, type, label, etc) that will be used. This answers the question of how to identify data-capture needs for each process element. Having a process description, combined with a vehicle for data capture, addresses the question of how to train employees. Documented process and data recording will meet the requirements of all registered quality management systems.
Data collected in one system allows for the creation of standard reports. However, it provides a system that can be queried when something goes wrong, enabling the company to access business risks associated with a historical quality issue. This may include a quality issue that needs to be recalled or, at a minimum, a quality alert that must be sent to the customer of the potential problem, illustrating what to look for and giving direction on possible solutions.
With data collected in one source, users can identify a product by a serial number for that assembly, identify each component lot used, ensure that RoHS requirements were met, check the status on how long any MSDs were subjected to humidity, and check on consigned parts used in the assembly. Additionally, with this single contained-system approach, there will be minimum impact on expenses required to manage the system, such as non-value-added labor or transactions.
Conclusion
The business of traceability in electronics manufacturing becomes more complex in a time of increased pressure to run lean, cost-competitive businesses. In the future, increased regulatory compliance and quality system standards will continue to place additional requirements on data collection, recording, and analysis. If the emphasis in system development is placed on the lowest common denominator - a single reel, tube, or tray - then initiating additional data-collection requirements will be easy.
Bob Douglas, president, Inovaxe Corp., may be contacted at bob.douglas@inovaxe.com.