Technical Data Sheet 1544 Soldering Flux Activated Rosin Liquid Flux Product Description Kester 1544 Activated Rosin Liquid Flux is a homogeneous solution of high quality, purified Grade WW rosin blended into an alcohol solvent system. A very effective activating agent has been added to provide superior fluxing ability. 1544 is a liquid equivalent of Kester 44 Activated Rosin Core Solder. The desired flux activity and the amount of rosin residue are determined by the concentration (solids percentage) of the flux.1544 has been developed for fluxing applications where non-activated and mildly activated rosin fluxes are too inactive to remove metal oxides, where proper and complete res - idue removal of potentially corrosive water-soluble organic acid flux is not possible, and where soldering of electronic assemblies requires instant wetting and excellent capillary flow. 1544 can be used for solder coating or tinning bare leads. Performance Characteristics: Improves soldering performance Classified as ROM1 per J-STD-004 High thermal stability RoHS Compliance This product meets the requirements of the Restriction of Hazardous Substances (RoHS) Directive, 2015/863 for the stated banned substances. Physical Properties Flash Point: 18C (64F) Percent Solids (typical): 50% Specific Gravity: 0.917-0.928 Tested to J-STD-004, IPC-TM-650, Method Anton Paar DMA 25C 2.3.34 Reliability Properties Copper Mirror Corrosion: Moderate Silver Chromate: Fail Fluorides by Spot Test: Pass Tested to J-STD-004, IPC-TM-650, Method Tested to J-STD-004, IPC-TM-650, Method Tested to J-STD-004, IPC-TM-650, Method 2.3.32 2.3.33 2.3.35.1 Corrosion Test: Low Chloride and Bromides: 0.44% Tested to J-STD-004, IPC-TM-650, Method Tested to J-STD-004, IPC-TM-650, Method 2.6.15 2.3.35 Global Headquarters: 800 West Thorndale Avenue, Itasca, IL USA 60143 Phone: +1 800.2.KESTER Fax: +1 630.616.4044 Asia-Pacific Headquarters: 61 Ubi Avenue 1 06-01 UB Point, Singapore 408941 Phone: +65 6.449.1133 Fax: +65 6.242.9036 European Headquarters: Ganghofer Strasse 45, 82216 Gernlinden, Germany Phone: +49 (0) 8142 4785 0 Fax: +49 (0) 8142 4785 61 Asia Manufacturing: Hengqiao Road, Wujiang Economic Development Zone Suzhou, Jiangsu Province, China 215200 Phone: +86 512.82060807 Fax: +86 512.8206 0808 Website: www.kester.com Application Notes Flux Application 1544 can be applied by brush, dip or wave processes. Process Considerations The optimum preheat temperature for most circuit assemblies is 90-105C (194-221F) as measured on the top or component side of the printed circuit board. Dwell time in the wave is typically 2-4 seconds for leaded soldering process and 4-8 seconds for a lead-free process. The wave soldering speed should be adjusted to accomplish the proper solder contact range. The next step will be to adjust the temperature settings for the preheat section to achieve the proper preheat temperatures range as measured on the topside of the circuit board. Flux Control Specific gravity is normally the most reliable method to control the flux concentration of high solids rosin-based fluxes. To check concentration, a hydrometer should be used. Kester 104 Thinner is an appropriate solvent for diluting this activated rosin flux to the desired solids content and viscosity, and for restoring solvent loss through evaporation. The correct specific gravity range for 1544 is 0.917-0.928 (Anton Paar DMA 25C). Cleaning 1544 residues are non-conducive, non-corrosive and do not require removal in most applications. If residue removal is required, call Kester Technical Support. Storage, Handling and Shelf Life 1544 is flammable. Store away from sources of ignition. Shelf life is 2 years from the date of manufacture when handled properly and held at 10-25C (50-77F). Health and Safety This product, during handling or use, may be hazardous to your health or the environment. Read the Safety Data Sheet and warning label before using this product. Global Headquarters: 800 West Thorndale Avenue, Itasca, IL USA 60143 Phone: +1 800.2.KESTER Fax: +1 630.616.4044 Asia-Pacific Headquarters: 61 Ubi Avenue 1 06-01 UB Point, Singapore 408941 Phone: +65 6.449.1133 Fax: +65 6.242.9036 European Headquarters: Ganghofer Strasse 45, 82216 Gernlinden, Germany Phone: +49 (0) 8142 4785 0 Fax: +49 (0) 8142 4785 61 Asia Manufacturing: Hengqiao Road, Wujiang Economic Development Zone Suzhou, Jiangsu Province, China 215200 Phone: +86 512.82060807 Fax: +86 512.8206 0808 Website: www.kester.com