General Description
Stencils are used to print solder paste onto electronic assemblies. This course covers in detail what stencils are, the different types, why some apertures are larger or smaller than the patterns, the formulas for calculating apertures, what the impact of fiducials and misalignment cause, all the terms relating to a stencil, and how to handle and store them. The average learner should take 1hour to 1½ hours to complete the course.
Target Audience
The course is suitable for a general audience but will have special applicability to manufacturing engineers, product engineers, and production/assembly personnel.
Course Prerequisites
There is no prerequisite for this course.
Author and Subject Matter Expert
The author and subject matter expert is Mr. James C. Blankenhorn, the co-founder and current president of TechEdgeOnline.com. His experience includes 33 years in electronics, 10 years in semiconductor design and management for TI, Motorola and Honeywell. He has 20 years in managing start-ups including Test International, AWI and SMT Plus. He held the position of VP for Jabil Circuit during a period of rapid growth from $100M to $400M. Mr Blankenhorn holds a Bachelor of Science in Electrical Engineering degree from Arizona State University and is a founding member of the SMTA organization. He has authored over 20 books on SMT and related technologies. He is a featured speaker at many conferences and seminars.
System Requirements
- High speed Internet Connection (DSL, cable, ISDN 128)
- Browser: Explorer 4.01 Service Pack 2 (or greater), or Netscape 4.7 (or greater).
- Explorer 5 is recommended
- Flash 4 or greater plug-in
- 16 bit colour, 800 x 600 resolution (minimum requirement)
- Audio card (optional)
- 200 megahertz minimum, 300 megahertz recommended
- 32 RAM minimum, 64 RAM recommended
- 50 mb of available disk cache space
Detailed Course Outline
Module 1
Topics covered:
- Introduction to stencils
- State the definition of a stencil.
- Describe what a land is.
- State what components can be printed using a stencil.
- State who has land pattern libraries.
- State what the workmanship standard is.
- State what the alignment required for solder paste is.
- State what the volume of solder paste is that’s needed.
- Describe what a stencil aperture is.
- State what the thickness of a stencil means.
- Define what the stencil aperture ratio is.
- State the volume formula for an aperture.
- State the volume formula of solder paste needed.
- State the formula for calculating an aperture opening.
- State when aperture sizes are reduced.
- Describe what stencil misalignment is.
- State when aperture sizes are increased.
- State the different types of stencils.
- Describe what a laser cut stencil is.
- Describe what additive stencils are.
- Describe chemical etch stencils.
- Describe the print area on a stencil.
- Describe what a stencil frame is.
- State the flatness of a frame.
- Describe what the mesh is for a stencil.
- Describe micro stencils.
- Describe what a universal frame is.
- Describe what fiducials are.
- State what is required to order a stencil.
- State when stencils should be replaced.
- State how to properly store stencils.
- State how to properly clean stencils.
- State the most common problems with stencils.
- Summary