Solder Paste for Hollow Squeegees
With a standard squeegee the solder paste is spread on the top side of the stencil. During the printing process the squeegee is rolling the paste by pushing.
By printing with a hollow squeegee the paste stays in a closed system all the time. Due to a good insulation between sqeegee and stencil the paste is not pressed out of the closed system so that no paste is being spread on the stencil.
During the printing process pressure is put onto the paste all the time by the piston / the Schubvorrichtung / den Schieber. Therefore openings of the stencil are well filled. The behaviour of the rolling paste for hollow squeegees is different from standard squeegees. It depends very much on which hollow sqeegee is used. Presently the following systems are on the market:
