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Start Micro Dispensing Today
The DL Micro Valve is specifically designed for dispensing micro volumes of material in precise, repeatable patterns. Learn more about the DL Micro Valve.
DL Technology
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iX7059 Series by Viscom: Inline X-ray Inspection Power
High-performance Inline X-ray Inspection Systems for complex electronics, semiconductors, and power modules up to 200 kg. Seamless integration, AI-powered accuracy, and maximum reliability for every application.
Viscom SE
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| Ask the Experts |
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August 15, 2011 - Updated
August 15, 2011 - Originally Posted
Stepped Stencil Limit
I've used stencils with 1 and 2 mil steps successfully, but recently I've seen a problem with a 3 mil step (8 mil foil stepped down over most of the printed area to a 5 mil thickness).
The problem I'm seeing is that the stencil tends to warp around apertures, particularly in areas like fine pitch QFPs, where there are long apertures close together, and the remaining material is a thin strip. This warp makes the stencil act thicker and allow more paste to be deposited, leading to bridges in the fine pitch QFPs.
Is there a rule of thumb regarding the amount of step that can be etched into a stencil?
B. B.
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| Expert Panel Responses |
IPC 7525 recommends 35 to 50 mils keep-out for each 1 mil of step.
Bill Coleman
Vice President Technology
Photo Stencil
For over 18 years, Dr. Coleman has been the vice president of technology for Photo Stencil, working closely with customers to understand their printing requirements. His efforts have resulted in several new stencil products.
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Vapor Phase Profiling
Thermal profiling the vapor phase soldering process – especially those with vacuum – is challenging. ECD's M-VP™ sealed barrier can take it. Learn more.
ECD
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