by by Mitch DeCaire, Cogiscan, Inc. and Jason Spera, Aegis Industrial Software Corporation
1 September 2004
A scalable traceability system is critical to each customer request, no matter how simple or complex, both now and in the future.
Poka yoke-Japanese term which means mistake proofing, often referred to as "error-proofing". Error-proofing is a manufacturing technique of preventing errors by designing the manufacturing process, equipment, and tools so that an operation literally cannot be performed incorrectly.
The electronics manufacturing industry faces increasing demand for product traceability. Competitive pressures for improved product quality and reduced cost will dictate a higher level of control over materials usage and assembly process. Traceability requirements once limited to extreme reliability applications, such as aerospace and other life-critical products, are becoming a necessity in many sectors such as telecom, computing and automotive.
Demands for traceability Outsourcing: There is increased reliance on the outsourcing model to reduce costs and shift focus to core competencies. Maintaining and improving quality levels become critical because of the direct influence on customer satisfaction and future revenues. The ability to identify the root cause of a field failure, implement corrective actions and limit product recalls, are critical. Contractual traceability requirements assures a manufacturer that its suppliers will implement control systems, which are required for data generation and collection.
Product recalls: When there is a product recall, cost and customer impact can be minimized if there is data to identify the affected product serial numbers. Without data, assumptions are made when determining the units to recall, resulting in unnecessary removal of some good products from the field.
Liability: Manufacturing contracts with liability stipulations ensure that products are assembled according to proper customer specifications and industry standards, using accurate machine and process settings with a correct combination of materials and chemicals. A traceability database can significantly affect the outcome of liability claims within the supply chain.
Lead-free: Lead-free conversion schedules vary between manu-facturers, and between component suppliers. Some manufacturers are required to convert products to lead-free by specific dates. Others have to manage two processes (lead-based or lead-free), depending on the sales location of a particular product serial number. Lead-free legislation drives the need to know components, boards, and solder (bar, paste, wire) which are incorporated into each product serial number.
Moisture sensitive devices (MSDs): The logistical nightmare of MSD control and the related risks of moisture induced damage are exacerbated by increased sensitivity levels due to higher reflow temperatures (for lead-free); reductions in package body thickness and lead pitch; and increased use of plastic instead of higher cost hermetic body materials.
A real-time traceability system that accounts for MSD handling, relative to the industry standard (IPC/JEDEC J-STD-033A), reduces the risk of field failures due to moisture-induced damage.
Traceability at different levels The electronics manufacturing industry agrees that traceability has become more important. Definition of "traceability" depends on the depth and scope of customers' requirements. As a general framework, traceability systems can be classified into four levels (see "Traceability systems classified into four levels"). Traceability can be applied to other elements of the manufacturing process as long as data can be recorded and associated with the finished product. For example, tracing lot code data for raw materials such as solders and fluxes; associating operators involved at each stage of the assembly process; maintaining a log of process conditions such as stencil serial number and oven zone temperatures; and engineering activities including documentation revisions and process changes.
Choose a traceability system wisely When a customer asks for traceability from the shop floor, the possibilities are endless. The potential amount of data could quickly overwhelm a typical server PC.
