Indium 3.1 Pb-Free Water-Soluble Solder Paste - SAC305, T3 (88.5 Percent), 600g Cartridge
Pb-Free Solder Paste
Over the last decade, the electronics industry has shifted to no-clean fluxes for surface mount assembly. Despite this industry trend, Indium Corporation has not only maintained a variety of water-soluble solder pastes and fluxes, but has revolutionized the category with the release of several new and versatile solder pastes. These solder pastes allow current water-wash manufacturing processes to not only survive, but to thrive.
Storage and Handling Procedures
Refrigerated storage will prolong the shelf life of solder paste. The shelf life of Indium3.1 is no less than 4 months when stored at less than 10°C.
Solder paste should be allowed to reach ambient working temperature prior to use (about 4–6 hours). Actual time to reach thermal equilibrium will vary with container size. Paste temperature should be verified before use. Use paste within 8 hours of exposure to atmosphere. Jars and cartridges should be labeled with date and time of opening.
When storing solder paste contained in syringes and cartridges, the solder paste should be stored with the tip down.
Alloys
Indium Corporation manufactures low-oxide spherical powder composed of a variety of Pb-free alloys that cover a broad range of melting temperatures. Type 3 powder is the standard offering with SnAgCu, SnAg, and other Pb-free alloy systems. The metal percent is the weight percent of the solder powder in the solder paste and is dependent upon the powder type and application.
Printing
The sharp print definition of Indium3.1 is ideal for fine-pitch applications. The unprecedented stencil life of this water-soluble product virtually eliminates waste of solder paste.
Wetting
Indium3.1 exhibits excellent wetting under both air and nitrogen reflow atmosphere. The solder joints yielded are shiny and smooth, including those of ultrafine-pitch components. Indium3.1 has low-voiding performance, including joints of BGAs and CSPs.
Residue Removal
Indium3.1 flux residues are water-soluble and best removed by an inline or batch type cleaning process using spray pressure and heated DI water. A spray pressure of 60psi and a DI water temperature of 55°C can be used as a starting point. The optimal spray pressure and temperature are a function of board size, complexity, and the efficiency of the cleaning equipment and should be optimized accordingly. For gaps less than about 50μm (2mil), the addition of an appropriate surfactant in the water washing tank will lower the surface tension of the water to allow for faster penetration of the cleaning medium and improve cleaning effectiveness. We recommend cleaning the flux residue 12 hours (or sooner) after reflow for optimal test performance.
Stencil Cleaning
This is best performed using an automated stencil cleaning system for both stencil and misprint cleaning to remove extraneous solder particles. Most commercially available stencil cleaners and isopropyl alcohol are acceptable.