Half-Day Workshop

Course Description

The stencil printing process is the most critical process in surface mount electronics assembly. It tremendously influences the quality of the final PCB assembly. This course will provide a thorough understanding of the print process for lead based and lead free solder paste print applications. Topics include an in-depth look at stencils, aperture design, stencil selection, solder paste, squeegee, process parameters, process characteristics, inspection techniques, defect identification and corrective actions. Participants in this course are sure to acquire a sound understanding of the solder paste print process and its influence on yield. Half day equivalent of hands-on education provided in the state-of-the-art laboratory will allow participants to experiment with the process parameters. 

1. Importance of stencil printing process
2. Factors that affect the stencil printing process
3. An in-depth look at the various factors
   
   • Stencils
     • Construction
     • Materials
     • Manufacturing Techniques
     • Dimensional Accuracy
     • Surface and Wall Finish
     • Calculating area aspect ratios
     • Solder paste efficiency transfer and Area Aspect Ratio (AAR)
     • Aperture design for fine pitch and area array packages
   • Solder Paste
     • Solder Paste Thixotropic Rheology, Solder Powder, etc.
     • Flux Types
     • Flux Constituents - Activators, Rosin/Resin, Solvents
     • Solder Particles-Alloy composition, Shape, Size, Distribution and Percent Metal Content
     • Paste types
     • No-Clean and No-Lead Solder Paste Processing
     • Tackiness-Shelf Life and Print Life
     • Packaging of Solder Paste and Storage
     • Handling and Safety
   • Squeegee
     • Squeegee Materials
     • Types
     • Advanced print head technologies
   • Solder Paste Printer Types & Features
     • Manual
     • Semi-Automatic
     • Fully Automatic
   • Print Parameters
     • Squeegee Speed
     • Print Stroke
     • Squeegee Pressure
     • Squeegee Downstop
     • Snap-Off
     • Angle of Attack
     • Squeegee Hopover
     • Squeegee Durometer
   • Other Parameters
     • Temperature and Humidity
4. Process Characterization
5. Solder Paste Inspection Techniques 2D vs. 3D inspection
6. Defect Identification and Corrective Action
7. Stencil Printing for Adhesive Applications