Electronic Chemicals: Flux, Cleaner, Thinner & SMT Adhesive

SICAL: STAR.I’s electronic chemicals brand

SICAL is one of STAR.I’s brands, focused on the R&D and production of electronic chemical materials, with an R&D and after-sales engineering team. The range covers flux, solder paste, cleaners, SMT adhesive (red glue), antioxidants, dross reducers and lead-free soldering materials, supported by technical service and process guidance.

SICAL products serve SMT, wave soldering, hand soldering and electronic cleaning, and special-purpose fluxes can be developed for specific customer processes.

What does flux do?

Flux is a mixed liquid of resins, activators, additives and solvents, widely used in SMT electronic assembly. It should provide the following:

• Enough oxide removal from the base metal and molten solder surface.
• An activation temperature range that matches the solder alloy melting range.
• Good wetting on the metals being joined.
• Low post-solder residue and no corrosiveness.
• High post-solder insulation resistance.

Activity levels: R, RMA, RA and RSA

Flux is classified by activity as R (low), RMA (medium), RA (high) and RSA (special). Higher activity generally means stronger oxide removal, but also more corrosive residue and greater cleaning requirements.

SICAL offers the following flux directions:

• Lead-free high-activity and traditional rosin fluxes.
• Lead-free no-clean and matte no-clean fluxes.
• Low-solids transparent no-clean and low-VOC fluxes.
• Rosin-free no-clean and water-soluble fluxes.
• Hot-air leveling (HAL) fluxes.

Lead-free halogen-free flux CS805-A

CS805-A is a halogen-free flux for wave soldering, applied by spray. It is designed for lead-free processes, meets RoHS requirements, supports multiple alloys and maintains high yield in both lead-free and Sn-Pb processes.

Typical values from the brochure/technical data. Refer to the current TDS and batch report for actual specifications.

Low-residue flux CS505-2

CS505-2 is designed for wave and hand soldering. Its modified resin and active flux system improve solderability while reducing residue and leaving a clean board. Without cleaning, it provides high surface insulation and reduces electromigration risk.

Low residue does not automatically mean no cleaning is needed. For high-reliability products, evaluate residue, insulation resistance and cleaning requirements.

Cleaners and thinners

SICAL cleaners remove rosin/resin residue, oils and greases after soldering and repair. Low-ozone-depleting formulations can replace traditional CFC-113 solvents.

• 904R-A lead-free cleaner (heavy duty): for misprinted boards, flux residue and equipment; no ozone depletion; improves surface impedance; high-impedance solution; fast evaporation; suitable for ultrasonic cleaning; RoHS compliant.
• Thinners CS902, CS903, CS907 and CS908: reduce flux solids or replace evaporated solvent to maintain stable flux performance.
• CS903 is a dedicated thinner for lead-free processes; CS907 and CS908 are matched to specific flux systems.
• Machine cleaner: removes surface stains, cleans effectively, evaporates quickly and leaves no trace.

SMT adhesive (red glue) CS100

CS100 is a one-component, storage-stable epoxy adhesive that cures rapidly when heated. It is thixotropic and low-moisture-absorbing, suitable for high-speed pin-transfer and stencil printing. Cured joints have moderate strength, thermal shock resistance and high insulation resistance.

Typical values. Confirm cure conditions and bond strength against dispense volume, components and PCB surface.

Antioxidant powder, dross reducer and lead-free solder paste

• Antioxidant powder: added to automatic wave solder pots to increase oxidation resistance and greatly reduce dross.
• Dross reducer: inorganic white powder, stable, low fume, high melting point, moisture-resistant, non-corrosive to the pot, RoHS compliant; improves dross reduction, saves solder and lowers cost.
• Lead-free solder paste CS805-100: light yellow paste, transparent and free of impurities, for lead-free BGA, strain gauge, sensor, fuse, connector and wire soldering/repair. Good wettability on passivated metals (nickel/gold plating) and ordinary tin/copper pads.

Chemical safety and precautions

• Keep away from ignition sources and prohibited oxidizers.
• Store sealed, away from direct sunlight and high temperature.
• Use ventilation equipment and keep the work area ventilated.
• Wear protective equipment (glasses, mask, gloves).
• Avoid prolonged skin contact. If eyes are splashed, rinse with plenty of water and seek medical attention.
• Do not swallow. Keep out of reach of children.

Customers should run application trials before volume use and select the best-matched, optimized process to ensure product quality.

FAQ