PRODUCT

WS-488 Series (Water-Soluble Solder Cream)
Polyethylene Glycol and Halide Free

The 488 Series is a fourth generation product designed for SMT assemblies where post reflow cleaning is performed with water alone. This non-resin formula was developed to replace earlier water-soluble creams, containing no insoluble components. This formulation is based on the popular WS-486, with slight modifications to increase the production window. Excellent printability and stencil life is obtained for the most demanding applications, including hard-to-solder metalizations and harsh operating environments.

SPECIAL PROCESSING PROPERTIES

• Stencil Life: 8-10 hours.
• Tack time: 8-10 hours before or after placing components.
• Excellent print definition, no cold slump or warm slump.
• No corrosion concerns when batch cleaning, may be left on longer than competitive formulations.
• Very bright solder fillets, after cleaning, no visible residues under magnification.

RECOMMENDED CLEANING

40-50 PSI at 50-60° C. Rough rinse cycle of soft water. Final rinse of DI water. No saponifier or other chemicals needed.

CREAM PROPERTIES

While SIR and IONIC contamination results will vary with board design, component density and cleaning machine efficiency, the following results are typical of the 400 Series creams.

Ionics:

• 1.0-3.1 µ g NaCl eq./Sq. in.

SIR:

• Control Board: 4.5x10E10
  Cleaned: 6.38x10E9
  IPC-SF-818 B25 Class 1, 2 168 hrs.

Copper Mirror:

• Pass (20 hrs.) IPC-SF-818

Halide %:

• Pass IPC-SF-818

Water Extract Resistivity:

• Over 1x10E5 ohm/cm
  MIL-F-14256F

Tackiness vs. Time Exposure:

(Chatillion force gauge IPC-SF-819

Time (hrs) 0 2 4 8

Force (grams) 44 49 56 42

Viscosity

• Viscosity is dependent upon alloy, metal loading and particle size distribution. For 63/37, T3, 90% the viscosity (+/- 10%) is 190kcps (Malcom), 800kcps (Brookfield).

Handling and Storage:

The 488 series will have a minimum shelf life of three months when stored below 75° F. This can be extended to six months or more if temperature is maintained below 40° F. Always allow creams to naturally reach room temperature before opening (minimum of 12 hours). Stir for 2-3 minutes before using. Do not put used cream back in jar with unused cream.

The 486 Series is available in 63/37 and 62/36/2Ag, in both fine pitch (type 3) and ultra fine pitch (type 4).