How to Clean Flux from a PCB

Author: Elizabeth Norwood

This article provides detailed instructions on efficiently cleaning flux residue from printed circuit boards (PCBs) for optimal functionality and reliability, including safety precautions, materials required, and cleaning methods. It introduces a specific product, VeriClean™ No Clean Flux Remover, for effective flux residue removal in electronics assembly and repair.

Cleaning Flux with Isopropyl Alcohol

Isopropyl Alcohol (IPA) has long been favored for electronics cleaning, yet it may not be the optimal choice. IPA's efficacy as a PCB cleaner is limited, with a Kauri-butanol (Kb) value of around 50, rendering it insufficient for tackling modern lead-free and no-clean flux residue. Its ineffectiveness extends to removing oils, greases, and fingerprints. Moreover, IPA's susceptibility to moisture absorption, compounded by its tendency to attract contaminants from the air or its container, compromises its cleaning potency. Even high-grade IPA quickly loses purity upon transfer, complicating its reliability.

Alternatively, MicroCare offers engineered flux removers in hermetically sealed containers, ensuring consistent purity and minimizing worker exposure to fumes. Weak IPA dilutions necessitate labor-intensive cleaning processes, whereas the MicroCare specialized fluids efficiently target stubborn contaminants, reducing the need for multiple applications and extended soak times.

Furthermore, IPA poses significant safety hazards due to its flammability, necessitating stringent storage and handling protocols. To mitigate risks, MicroCare offers nonflammable alternatives designed for worker and facility safety. IPA's environmental impact, characterized by its status as a Volatile Organic Compound (VOC), necessitates adherence to stringent regulations, whereas MicroCare's environmentally sustainable options comply with evolving standards. In light of these considerations, many PCB fabricators are transitioning to MicroCare's high-performance, safer, and eco-friendly flux removers, guided by expert recommendations to streamline the switch to superior cleaning practices.

Cleaning Flux with Acetone

Like IPA, cleaning PCBs with acetone is not advisable due to several reasons. Firstly, acetone is a highly volatile and flammable solvent, posing significant safety risks, especially in industrial settings where proper ventilation and handling procedures are crucial.

Additionally, acetone is aggressive and can damage sensitive electronic components and circuitry, leading to malfunctions or complete failure of the PCB. Its strong solvency properties also make it prone to stripping away protective coatings on PCB surfaces, further compromising their integrity and reliability.

Furthermore, acetone's environmental impact is concerning as it is classified as a hazardous air pollutant and can contribute to ground-level ozone formation. Overall, utilizing acetone for PCB cleaning presents substantial safety hazards, risks damaging electronic components, and poses environmental concerns, making it an unsuitable choice for this application.

A Better Alternative: No Clean Flux Remover - VeriClean

The best-selling flux remover at MicroCare, VeriClean™ No Clean Flux Remover, stands out for its exceptional features and benefits.

  • Designed for efficiency and convenience, it offers a no-residue, no-rinsing formula, ensuring a thorough yet hassle-free cleaning process.
  • Its mild, non-corrosive composition makes it safe for use on plastics, safeguarding delicate components and surfaces.
  • With a Kb value of approximately 18, it effectively removes flux residues while drying quickly for expedited cleaning operations.
  • Utilizing methyl siloxanes as its chemical family, it balances effectiveness with economy, offering a flammable yet more cost-efficient solution.
  • Its low odor enhances the work environment, promoting a comfortable and productive workspace.
  • Compliant with various regulatory standards such as RoHS, WEEE, REACH, and EPA SNAP, it meets industry requirements while prioritizing environmental responsibility.
  • VeriClean™ is ESD-safe
  • People-friendly, it uses ingredients commonly found in cosmetics, ensuring safety without compromising performance.
  • Its aerosol cans are designed for compatibility with TriggerGrip™ Cleaning Tool and StatZAP™ ESD Eliminator Tool, enhancing versatility and usability across applications.

Application:

VeriClean is typically used in conjunction with benchtop, manual cleaning methods to effectively remove no-clean flux residues from electronic components. It can be used in various industries, including electronics manufacturing and repair.

The 4 Steps of PCB Cleaning

When cleaning PCBs, the 4 step process of wet, scrub, rinse and dry is recommended. The four-step method of wet, scrub, rinse, and dry is a systematic approach widely employed in cleaning printed circuit boards (PCBs) to ensure thorough and effective removal of contaminants.

First, the PCBs are wetted with a suitable cleaning solution, typically a solvent or cleaning fluid, to loosen and dissolve stubborn residues. Following wetting, the surfaces are gently scrubbed using brushes or lint-free swabs to dislodge any remaining debris or contaminants. Next, the PCBs undergo a rinsing process, where they are flushed with clean solvent to remove both the cleaning solution and loosened contaminants. Finally, the PCBs are dried thoroughly to eliminate any moisture, typically through air drying or the use of a lint-free wipe. This four-step method ensures that PCBs are cleaned effectively while minimizing the risk of residue buildup or damage to sensitive components, resulting in optimal performance and reliability.

How the TriggerGrip™ Enhances Cleaning

The TriggerGrip cleaning tool offers significant enhancements to each step of the wet, scrub, rinse, and dry process in PCB cleaning. During the wetting phase, its ergonomic design allows for precise and controlled application of cleaning solutions, ensuring thorough coverage while minimizing waste. When it comes to scrubbing, the TriggerGrip's comfortable grip and interchangeable brush heads enable efficient and consistent scrubbing action, effectively removing stubborn contaminants without risking damage to delicate components. In the rinsing stage, the TriggerGrip's compatibility with various rinsing agents and adjustable flow control facilitates targeted rinsing, ensuring complete removal of cleaning residues while conserving resources. Finally, in the drying phase, simply place the TriggerGrip in the handy bench mouningt bracket and use a lint-free wipe to ansorb any remaining flux remover. Overall, the TriggerGrip cleaning tool enhances each step of the PCB cleaning process, optimizing efficiency, effectiveness, and reliability.

Safety Precuations

When using VeriClean or any cleaning solution, it's essential to follow safety guidelines provided by the manufacturer. This may include wearing appropriate personal protective equipment (PPE), working in a well-ventilated area, and proper disposal of used cleaning solution.

For specific usage instructions, safety information, and compatibility details, it's recommended to refer to the product's safety datasheet, technical data sheet or contact MicroCare directly. Always follow the manufacturer's recommendations to ensure the best results and safety when using VeriClean or similar cleaning products.

Conclusion:

Cleaning flux residues from PCBs and other surfaces is essential for maintaining the quality and reliability of soldered connections. Whether using isopropyl alcohol or alternative solvents like acetone, following proper cleaning procedures is crucial. Specific products like "No Clean Flux Remover VeriClean" can provide effective cleaning solutions for various applications, ensuring residue-free surfaces and reliable soldering results.