How Qualitel Washes Away Worries of PCBA Contamination

Precision cleanliness is critical for Qualitel to manufacture high-reliability, complex printed circuit board assemblies that won’t fail under harsh conditions. However, proper cleanliness levels are difficult to achieve for components with solderable areas under them.

3 Flux residues trapped under the body of the component may lead to electrical shorts and/or intermittent operation of equipment. Also, smaller spacing between conductors yields a larger electronic field, which in conjunction with insufficient cleaning can lead to electrical leakage and/or dendritic growth. Tighter lead pitches results in low standoff gaps.

Penetrating these gaps to wet and dissolve flux residues requires strong chemical and mechanical forces provided by a recently-purchased Nu/Clean 824 XLR-FB PCB Washing System. The purchase from Technical Devices is part of Qualitel’s ongoing commitment to better serve the exacting requirements of our aerospace, medical device and defense customers by investing in the best available production line equipment.

More sophisticated than any PCBA washing system on the market

The Nu/Clean washing system is the most sophisticated PCBA washing system on the market, and provides the cleanliness required to apply conformal coating such as parylene.

“More than 90% of Qualitel’s customers need the aqueous cleaning process for cleanliness and conformal coating offered by the Technical Devices’ Nu/Clean 824 washing system,” said Qualitel president Tuanhai Hoang. “Qualitel engineers determined that the Nu/Clean 824 offers the most advanced cleaning technology available as well as a robust, touch-screen user interface that provides ease of operation and total command of all system operations.”

“The advanced cleaning capability of the Nu/Clean 824 provides an essential cleanliness element in Qualitel’s production process to ensure long-term reliability,” Hoang said.

Cleanliness essential to apply conformal coating include parylene

Extreme reliability cleanliness is essential for high-speed, high-frequency signal integrity, and for the application of parylene and all available conformal coatings. Parylene, often the coating of choice for Qualitel’s customers, is generally regarded by the industry as the most durable and effective coating for the protection of electronic components and instrumentation.

The Nu/Clean 824 allows the surface of the printed circuit board assembly to be completely submersed in an agitated solution. This flooding allows the chemical solution to reach everywhere possible on the circuit board.

There are no concerns about shadowing from components because the entire board is submersed. Low standoff components are engulfed in the solution so that the cleaning liquid will invade every possible opening for optimal penetration. The wetting effects of the cleaning solution at process temperature soften the residues. When the board is hit with impingement spray, the softened residues are flushed away.

Advanced features of the Nu/Clean 824

The Nu/Clean 824 offers an array of advanced features that make it the ideal cleaning system to meet Qualitel’s exacting standards:

• Fan sprays with less impact are used rather than coherent spray jets which can undercut labels, remove part marking and potentially affect other material compatibility effects.
• Programmable, touchscreen displays for ease of use as well as alarms to alert technicians to any problems in the wash cycle
• Award-winning flood box technology for the most effective cleaning possible
• Dual tank washing bays in each machine, allowing for chemical or water cleaning both independently or in combination
• An Isolation rinse stage and powerful air knives that prevent chemical drag out from one wash stage to another
• Dual high performance 15 HP turbine air blowers with triple-bladed air knives for drying
• Custom water processing and recycling systems that meet local and state water treatment and disposal regulations

Qualitel purchased the machinery from Technical Devices Company, located in Torrance, CA. The new system has gone through Qualitel’s rigorous, three-step implementation process – Installation Qualification, Operation Qualification and Process Qualification. The Nu/Clean system went into production in mid-December and replaced one of two older inline systems. These acquisitions are part of Qualitel’s strategy to have redundant production equipment like the Nu/Clean system where most companies have no redundancy.

Technical Devices has been in business since 1952 and has a well-established track record of offering cutting-edge technologies to its customers as well as an excellent reputation for customer service and support. Detailed specifications of the Nu/Clean 824 can be found on the Technical Devices website.