How low can you go? Les offers tips to achieve a zero-defect line.

Q: Our plant has three lines producing printed wiring assemblies with many small surface-mount components. We place approximately 500,000 components per month. Our current goal is to have zero defects. As supervisor of the surface-mount technology department, I have been given the task of reducing

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A: The quality, cleanliness and solderability of your incoming printed wiring boards (PWBs) and components play a major role in achieving success. Your vendors and your in-house operations must use adequately defined purchased component specifications and must enforce your specified engineering and quality requirements. Compliance in both cases is critical to your success.

Get Backup

You may have been given the leadership role for achieving your stated goal, but you cannot do it alone. All of the employees in every department of your operation must be involved. This includes design, purchasing, vendor quality control, production and test operations, maintenance operations, test engineering and the in-house quality control operation. Management support for your company's effort is critical to success.

The First Time's a Charm

Total process management requires a mindset focused on prevention of defects and an operating mantra of do it right the first time, rather than an operational philosophy based on detection and repair of defects. To do it right the first time, you must have knowledgeable, concerned and trained personnel, manufacturable designs, solderable terminations and PWBs, controlled process parameters and reproducible equipment functions. Losing control of any part of the process will lead to process complexity because of the extra steps required to deal with errors.

Take Control of the Stockroom

Good stockroom procedures are essential. Control of your stockroom environment includes rigidly enforcing humidity control, cleanliness and electrostatic discharge (ESD) protection. Overall stockroom orderliness is also beneficial. Mixed and outdated parts can lead to assembly errors and defective product.

Excessive humidity in the stockroom and contamination on components and PWBs may accelerate surface finish degradation and negatively affect solderability. Establish shelf life rules and adhere to them. Good packaging of components and adequate environmental controls in the stockroom are also necessary for a high-yield process.