StencilWash PLUS
Stencil Cleaning Chemistry

Description 
StencilWash Plus is a unique blend of select detergents and solvents formulated to offer safe, non-flammable cleaning in aqueous stencil cleaning equipment. Used in dilution, StencilWash Plus effectively cleans uncured surface mount device (SMD) adhesives and solder pastes from stencils and misprinted assemblies, and it does not require heating. It is an ideal cleaning agent for electronics manufacturers who want (1) to clean both SMD adhesives and solder paste in one cleaning process and cannot heat the cleaning solution, (2) to reduce or eliminate VOC emissions, (3) to reduce odor in the workplace, (4) to reduce or eliminate flammable or combustible solvents, and (5) to improve operator safety. 

Application 
StencilWash Plus is designed to remove all types of uncured SMD adhesives and rosin, water-soluble, and no-clean solder pastes from stencils and misprinted SMD assemblies. It also removes new epoxy solder pastes such as Alpha AP 4000. The product can be used to remove water-soluble flux residues as well as rosin and some no-clean flux residues after wave solder or reflow. 

Process 
StencilWash Plus is fully compatible with ultrasonic immersion stencil/misprint cleaning equipment. Optimal wash bath operating temperature is machine ambient (75°-90°F, 24°-32°C), but the product can also be heated to 120°F (49°C) for stencils and to 140°F (60°C) for misprints. Follow washing with a DI water rinse. After rinsing stencils or assemblies, surfaces should be allowed to air dry or be blown dry with forced air. 

Compatibility 
Stencils – StencilWash Plus is compatible with stencil materials of construction, including adhesives and emulsions. Always keep operating temperatures below 125°F (52°C) when cleaning stencils. Studies show that stencil materials of construction are much more susceptible to attack at temperatures above 125° F (52°C), regardless of cleaning product. Misprinted SMD adhesives – StencilWash Plus is compatible with epoxies, flex laminates, and other cross-linked polymers. It does not affect cured solder mask, RTV silicone, polystyrene or polycarbonate. Equipment – StencilWash Plus is compatible with metals, plastics and elastomers that are compatible with water-based organic and inorganic saponifiers and detergents. It does not affect polymeric tank and/or plumbing materials of construction such as PP, PE, PVC or CPVC.

Bath Life 
The concentration of StencilWash Plus in the wash bath can be monitored using refractive index. Please contact Aqueous Technologies for a refractive index versus concentration curve.  After normal use, the StencilWash Plus bath will become contaminated or "loaded" with solids from solder paste and/or SMD adhesive residues. As loading increases, cleaning performance decreases. Either an oily film or visible solids will be left behind on the stencil after drying indicating the bath has lost its effectiveness. Depending on the amount of paste or adhesive being cleaned from stencils and misprints, the typical bath life for StencilWash Plus ranges from 2 weeks to more than 8 weeks. 

Product and/or Rinse Water Disposal 
For internal disposal, used StencilWash Plus can be evaporated in commercially available evaporator equipment. For external disposal,

Aqueous Technologies recommends contacting your current or local environmental service company for wastewater disposal options. Please note that while StencilWash Plus is considered non-hazardous, materials cleaned such as solder pastes, which contain heavy metals, may make StencilWash Plus wash baths hazardous. 

Packaging
StencilWash Plus is commercially available worldwide in 5-gallon and 55-gallon containers.  

Shipping
This product is classified as non-hazardous. No special packaging is required to ship by air domestically or internationally. 

Handling
Aqueous Technologies recommends that operators always use protective safety glasses and gloves when handling process chemicals such as StencilWash Plus. Gloves made of nitrile or Buna N are recommended. 

Storage
StencilWash Plus is considered to be non-flammable and noncombustible

by the (US) National Fire Protection Agency and therefore its storage is not regulated. The product should be stored in the original container, preferably in a ventilated, fire-resistant building. 

Shelf Life
The shelf life for this product is indefinite when it is stored in its original, sealed container at room temperature. However, the product should be inspected after the designated date on the product label (twenty-four months from the date of manufacture) prior to customer use.