Indium 8.9E Pb-Free Solder Paste - SAC305, T4 (88.5 Percent), 600g Cartridge
Indium 8.9E
Indium8.9E is an air reflow, no-clean solder paste specifically formulated to accommodate the higher processing temperatures required by the SnAgCu, SnAg, and other alloy systems favored by the electronics industry to replace conventional Pb-bearing solders. Indium8.9E offers unprecedented stencil print transfer efficiency to work in the broadest range of processes. In addition, the high oxidation resistance of Indium8.9E virtually eliminates incomplete coalescence (graping) of small deposits.
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 and Type 4 powders are standard offerings with SAC305 and SAC387 alloys. The metal percent is the weight percent of the solder powder in the solder paste and is dependent upon the powder type and application. Standard product offerings are detailed in the following table.
Storage and Handling Procedures
Refrigerated storage will prolong the shelf life of solder paste. Solder paste packaged in cartridges should be stored tip down.
Storage Conditions
(unopened containers) | Shelf Life |
| <10°C | 6 months |
Solder paste should be allowed to reach ambient working temperature prior to use. Generally, the paste should be removed from refrigeration at least 2 hours before use. The actual time to reach thermal equilibrium will vary with container size. Paste temperature should be verified before use. Jars and cartridges should be labeled with the date and time of opening.
Compatible Products
- Rework Flux: TACFlux 020B, TACFlux 089HF
- Cored Wire: CW-802, CW-807
- Wave Flux: WF-7745, WF-9945
Printing
Stencil Design:
Electroformed and laser cut/electropolished stencils produce the best printing characteristics among stencil types. Stencil aperture design is a crucial step in optimizing the print process. The following are a few general recommendations:
- Discrete components - A 10–20% reduction of stencil aperture has significantly reduced or eliminated the occurrence of mid-chip solder beads. The “home plate” design is a common method for achieving this reduction.
- Fine-pitch components - A surface area reduction is recommended for apertures of 20mil pitch and finer. This reduction will help minimize solder balling and bridging that can lead to electrical shorts. The amount of reduction necessary is process-dependent (5–15% is common).
- For optimum transfer efficiency and release of the solder paste from the stencil apertures, industry-standard aperture and aspect ratios should be adhered to.
Cleaning
Indium8.9E is designed for no-clean applications; however, the flux can be removed, if necessary, by using a commercially available flux residue remover.
Stencil Cleaning is best performed using isopropyl alcohol (IPA) as a solvent. Most commercially available non-water-based stencil cleaners work well.