PCB cleaning fluids are going green

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With increasing environmental concerns, PCB cleaning fluids are going green and are also biodegradable and free of halogenated compounds

By Richa Chakravarty

Sunday, August 17, 2014: While cleaning populated PCBs, the aim is to remove the flux residues that accumulate on them. State-of-the-art PCB cleaning processes can effectively remove all types of flux residues, ranging from rosin mildly activated (RMA) to newly developed synthetic materials. Although ‘no clean’ production has proved itself in many low-end production processes, the cleaning of high-end assemblies is even more critical. To ensure the reliability of the bonding and coating processes, it is of utmost importance to clean the assemblies well before bonding/coating.

What’s new in the market

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With increasing environmental concerns, PCB cleaning fluids are going green by transitioning to neutral pH products that are composed of ingredients derived from renewable resources. A shift to halide-free and lead-free soldering materials has resulted in advanced paste and flux formulations which combine synthetic resins and natural rosins for greater thermal stability.

Today, most customers demand water-based (aqueous) chemicals as they are environment-friendly. These have no flash point and do not foam. They can, therefore, be applied in all spray-in-air equipment, such as inline or batch systems. These chemicals are also biodegradable and free of halogenated compounds

Aqueous cleaning: Kyzen’s new Aquanox A4241 is a concentrated aqueous cleaning solution designed for electronics assembly, aerospace and automotive industries. It is designed to be effective on the toughest residues while protecting even the most sensitive parts from etching or darkening. “Kyzen’s high precision cleaning solutions thoroughly clean the PCBs from all types of contaminants without polluting the environment. They are also very gentle on the various markings on the PCBs and on components,” informs Prasad Gujral, managing partner, Drive Technologies.

Semi-aqueous cleaning: Zestron has introduced a PCB cleaning agent called Atron AC 205 for the Indian market. Atron AC 205 belongs to the category of fast, technology-based cleaning agents and is specifically recommended for the removal of flux residues from assemblies in spray-in-air applications. It has a high bath loading capacity, which results in a significantly longer bath lifetime, reduced cleaning agent consumption and less frequent bath changes. All of this makes it highly cost effective. Additionally, the cleaner has a user friendly formulation. It has no flashpoint, a mild odour and is free of any hazardous substances.

Conformal coatings: HumiSeal has come up with an improved UV curing material and water-based (solvent free) coatings. Its product, UV40, is UL recognised and represents an exciting innovation in UV curable chemistry, which provides performance superiority over both traditional UV curable products and solvent-based materials. UV40 offers higher insulation resistance and moisture insulation resistance, besides resistance to a wider range of solvents and more flexibility.

Hexane-free flux removal: Electrolube has developed a new hexane-free flux remover, called HFFR, for use during PCB manufacture. This HFFR is a fast-drying cleaning solvent that eliminates the use of the hazardous material n-Hexane. It has been carefully formulated to provide efficient removal of a wide range of flux residues from PCBs and leave a perfectly clean, dry surface. HFFR incorporates the latest advancements in solvent-based cleaning technologies, while addressing concerns regarding operator safety when using chemical products. It is available in a convenient 400ml aerosol form with an integral brush or in 5-litre bulk containers.

A PCB solvent cleaner: ACC Silicones’ ACC50 PCB solvent cleaner is a fast evaporating solvent that does not contain chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCF), chlorinated or brominated solvents. It is specifically designed to clean flux and residues, uncured surface mounted adhesives, and solvent soluble coatings from PCBs and associated equipment such as stencils. It can also be used as a very effective label remover.

Choosing the right product

Correct cleaning of electronic components and equipment is necessary as this not only saves time and money but also increases the productivity and reliability of the product. Hence, when looking for a PCB cleaning agent, it is important to zero in on the right one. With so many brands available in the market, users should opt for a reputed brand that can assure consumers both quality and service. Besides, users should select solutions relevant to their own specific requirements. For instance, while there are various agents available to clean a PCB, users should pick a cleaning agent that will ensure a long shelf life of the end product. Along with this, users should also check whether the solutions meet industry standards and are environment-friendly.

HumiSeal’s UV40 conformal coating

  • humsealDensity: 1.06 g/cm³

  • Minimum solids content: 95 per cent

  • Recommended coating thickness: 25 – 125 microns

  • Shelf life at room temperature, DOM: 12 months

  • Thermal shock, 50 cycles per MIL-I-46058C: -65°C to 125°C

Kyzen’s Aquanox A4241 PCB cleaning solution

  • kyzen2-for-1 (241), two processes – one chemistry, for PCBs and stencils

  • Bright mirror solder joints

  • Works on all the latest flux formulations; and is even lead-free

  • Mild odour, long bath life

  • No sump-side additives needed

Zestron’s Atron AC 205 PCB cleaning agent

  • zestronHigh bath loading capability

  • The cleaning medium does not require any specific explosion-proof environment

  • Surfactant-free formulation, hence easily rinsed

  • Increased wire bonding/moulding quality for power modules, lead frame-based discrete components and power LEDs

  • Ensures a void-free underfill and improves the image resolution by removing all tacky fluxes from Flip Chips/CMOS

Electrolube’s hexane-free flux remover

  • electrolubeEliminates the use of the hazardous material n-Hexane

  • Efficient in removal of a wide range of flux residues from PCBs

  • Leaves the PCB with perfectly clean and dry surface with no residue

  • Available in a convenient 400ml aerosol form with an integral brush or in 5 litre bulk containers

ACC Silicones’ ACC50 PCB solvent cleaner 

  • accsiliconRemoves fluxes and residues, especially ‘in no clean’ and lead free process

  • Removes uncured surface mount adhesive residues from stencils and application equipment

  • Removes solvent soluble coatings (ACC acrylic and silicone coatings)

  • Excellent low odour label remover for (unvarnished) paper labels

  • Fitted with an antistatic brush to aid removal of polymerised residues

Electronics Bazaar, South Asia’s No.1 Electronics B2B magazine

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