On this week's episode we talk about something that at first glance might seem mundane, but is actually one of the most important steps and literally the foundation of pcb assembly: past printing. In fact, approximately 65% of all assembly defects come from this process. Chris breaks down all of the components that are a part of the often misunderstood process and provides some design tips on how to make it go smoother.
Show notes:
-Chris will be speaking at the upcoming virtual Altium Live conference. This year's event is free! https://www.altium.com/summit/
-We discuss what paste printing is and why it's so important.
Solder paste
-What is paste, what is it used for, and what are the different types of paste that can be used?
-Clean vs no clean paste
-Metal whiskering: https://en.wikipedia.org/wiki/Whisker_(metallurgy)
Jet printing vs stencil printing
-What is the difference between jet printing and stencil printing and what are the advantages and disadvantages of each?
-https://www.worthingtonassembly.com/blog/2015/4/9/visit-to-mycronic-to-learn-about-the-my600-jet-printer
Process
-What does the stencil printing process look like?
Stencils
-How are stencils made and what are they made of?
-http://www.stentech.com/Products/stencils
-https://www.youtube.com/watch?v=1gEcJvpinco
-https://nanoslic.com/nanoslic-coating-system/
Design tips:
-Use appropriately sized parts.
-Always avoid gang masking
-Tips to avoid via-in-pad issues
-Don't assume we'll use your data. Just leave it 1:1
-Be specific if you want paste on test points or battery contacts
-https://www.photostencil.com/technical-papers.php