Method and apparatus for dispensing small amounts of liquid material

• Main Authors: JAMES C SMITH, JAMES W MESSERLY, LAURENCE B. SAIDMAN
• Format: Patent
• Language: English
• Published: 23.11.1999
• Edition: 6
• Subjects: APPARATUS FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TO SURFACES, IN GENERAL; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; MACHINE TOOLS; MEASURING; MEASURING VOLUME, VOLUME FLOW, MASS FLOW OR LIQUIDLEVEL; METAL-WORKING NOT OTHERWISE PROVIDED FOR; METERING BY VOLUME; PERFORMING OPERATIONS; PHYSICS; PROCESSES FOR APPLYING LIQUIDS OR OTHER FLUENT MATERIALS TOSURFACES, IN GENERAL; SOLDERING OR UNSOLDERING; SPRAYING OR ATOMISING IN GENERAL; TESTING; TRANSPORTING; WELDING; WORKING BY LASER BEAM

Apparatus and methods for dispensing droplets of liquid or viscous material. The apparatus generally comprises a valve operated dispenser and a control for moving the valve member with respect to a valve seat in rapid succession. This rapidly accelerates liquid or viscous material in a stream from the dispenser outlet and immediately breaks the stream into a minute droplet. Various embodiments of the valve seat include both rigid valve seats and resilient valve seats. Resilient valve seats are especially useful for dispensing solder pastes as they can prevent material flaking, compacting and clogging conditions. Low friction polymer or plastic material for dispenser components such as the valve member and outlet structure can also prevent such problems.