UCON Solder Assist Fluid 25

UCON™ Solder Assist Fluid 25 is a low viscosity, water soluble polyalkylene glycol fluid with excellent thermal stability. It is designed for use in solder reflow fluids, fluxes, fusing fluids, and other process fluids where high temperature stability and water washability are
critical. Solder Assist Fluid 25 does not contain any additives which could be deposited on the circuit board during aqueous cleaning procedures.
UCON Solder Assist Fluid 26 is based on the same polyalkylene glycol polymer as Solder Assist Fluid 25. It differs from Solder Assist Fluid 25 in that it has been formulated with a proprietary additive package to further improve the product’s stability at high temperatures and to raise its flash point.
Product Features
Good Thermal Stability
High Flash Point
Excellent Water Washability
Low Foam Tendency
Biodegradable, Low Toxicity
Low Odor
High Product Clarity
SAF-25 and SAF-26 have been found particularly useful in various heat transfer andblanketing applications. They are used to fuse Sn-Pb electroplate into solder-coating duringfabrication and to “reflow” solder-coat and solder preform in assembly operations. Solder Assist Fluids 25 and 26 are also used as hot liquid leveling fluids to smooth solder coatingsand clear plated through-holes, and as blanketing fluids to protect liquid solder from oxidizing.
Typical Physical Properties
Property                                        SAF-25                SAF-26
Viscosity (cSt at 40°C)                    90                            90
(cSt at 100°C)                12                            12
Specific Gravity (20/20°C)              1.151                      1.152
Density (lbs/gal, 68°F)                    9.57                         9.59
(g/cm3, 20°C)                       1.15                         1.15
Pour Point (°F)                                 -29                           <-30
(°C)                                     -33.9                        <-34
Flash Point, closed cup (°F)          360                           535
(°C)                  182                           279
open cup (°F)                 535                           590
(°C)                    279                           310
Surface Tension (dynes/cm)            37.8                          38.1
Water Solubility (25°C)                  complete                   complete*
Cloud Point (°F)                              >210                          >210*
(°C)                                  >99                            >99*
(temperature above which a 1% aqueous
solution of the product separates)
†Typical properties, not to be construed as specifications
*Product contains small amounts of water-insoluble additives which are present to improve thermal stability
Dow encourages its customers and potential users to review their applications from the
standpoint of human health and environmental aspects. To help ensure that Dow products
are not used in ways for which they are not intended or tested, Dow personnel will assist
customers in dealing with environmental and product safety considerations. Dow literature,
including Material Safety Data Sheets, should be consulted prior to the use.