Circuit-level traceability: recent software developments help to monitor placement machines.

Problem

We will consider two companies--the first makes air bag sensors and the second produces pacemakers. Both have very stringent traceability requirements. The number of mission-critical parts for both automotive devices and medical implants is increasing so tighter production control over incoming components and outgoing goods in the automotive and medical markets is demanded. Companies must know not only where, when and how the components were consumed, but also on which product. Such demands for traceability will not only improve product quality but also help when production and field problems occur.

Problem Solved

In the last few years, many different attempts have been made to support traceability in and around assembly equipment. The attempts have run the spectrum from relatively simple component validation systems over multiple board levels to circuit-level traceability. Most of the previous attempts to implement traceability relied heavily on manual intervention, which creates many opportunities for error.

Recent developments for integrated software solutions allow advanced circuit-level traceability. Such solutions allow the placement of several different components on multiple circuits on a panel or individual circuits in a carrier. Circuit-level traceability provides enough detail to determine which component from which vendor and which feeder was assembled on what circuit at what time. With this ability, multiple reels of the same component can be run concurrently. Software can now merge the component part number and the individual circuit with a time stamp. All reference pick-and-place data is added to a database with reports that help extract the pertinent information.

The following example will give you an idea of the potential savings. Four reels with the same component are on a machine or line and are used for a board with four individual circuits. Each reel has 5,000 components. If one reel is bad, you have two options. You can recall all 5,000 boards--20,000 circuits--or you can recall 5,000 individual circuits.

The database structure used by most suppliers allows precise monitoring of component consumption. Specific reports can be generated for better inventory control and automatic part reordering. Quality and volume warning thresholds can be programmed, and the integrated system allows real-time remote notification of feeder quality performance or feeders running low. Post-placement automated optical inspection (AOI) tools can be linked in a closed feedback loop, Security is paramount throughout the system at the machine and network level.

Summary

Automotive electronic devices, medical implant devices and complex router boards all use different options to monitor the factory, including the inventory. Rigorous traceability systems are imperative not only for mission-critical automotive and medical devices but also for other applications, such as expensive boards. The integrated use of new software systems and improved networking capability gives companies more options for their traceability requirements, inventory and closed loop quality control.

Richard Boulanger (pictured; [e-mail]) is vice president of the Advanced Semiconductor Assembly Division, and Heinz Dommel ([e-mail]) is systems manager--both with Universal Instruments Corp., Binghamton, NY.