With regard to production reliability, automated stencil cleaning is preferred to manual processes. This ensures that the cleaning results are always reproducible which is not guaranteed when cleaning stencils manually. Furthermore, manual cleaning processes can often cause mechanical damages, e.g. of sensitive fine pitch apertures.
Per the recognized IPC standard (IPC 7526), the use of an automated cleaning system is recommended in order to meet all production requirements.
In principle, a variety of process types are available for cleaning stencils. These include spray and ultrasonic dip tank processes that, depending on the type, can be used with solvent and aqueous based cleaners. These cleaning machines can be further differentiated by the number of chambers that are available for the various process steps such as cleaning, rinsing and drying. This enables the cleaning process to take place in one or more chambers. Furthermore, stainless steel cleaning equipment has been proven to work particularly well. Steel stencils, fine pitch and nano coated stencils as well as screens are commonly cleaned in these machines.
When cleaning pump print stencils, one should pay particular attention to the correlation between the aperture thickness and size compared to standard SMT stencils. Pump print stencils require longer cleaning cycles than typical SMT stencils.
ZESTRON offers water based MPC® cleaners as well as solvent based cleaners. Our stencil cleaners as well as the cleaning equipment provided by internationally leading manufacturers can be tested under production floor conditions in our Technical Center.