Screaming Circuits: PCB Finishes

PROTOTYPE AND SMALL VOLUME
PCB ASSEMBLY MADE EASY

Let's Talk About HAL - For Big Parts Only

The board surface names: HAL and HASL (hot air leveling and hot air surface leveling) refer to the same thing. They are interchangeable terms. With that out of the way, I'll get to my point, which is that HASL is... Read more

Milling Madness

Sometimes, we find things that kind of defy explanation. Fortunately, this didn't come from Sunstone, our normal board house. Regardless of who it came from, I'm sure it was a one-off mistake, but, wow. How could anyone miss this? It... Read more

Fiducials and Odd PC Boards

One of the handy aspects of getting boards assembled at Screaming Circuits is that we don't require fiducial marks for standard process boards. I would say that we build far more boards without fiducials than with. That's cool, but there... Read more

Happy St Patrick's Day!

In honor of St Patrick's day and all things green, I give you the PCB... And some trivia. You may have noticed that the soldermask used on most PC boards is green, as is the paint used on most steel... Read more

Proper PC board storage - The top three hazards

It's late. Do you know where your PC boards are? Let me rephrase that: Can unused PC boards be stored for future use? Yes, they can - if stored properly. Keep them wrapped up, or sealed in a bag. Anti-static... Read more

Panel Rails - What Are They?

I referred to "panel rails" in my blog about V-score panels, but I didn't explain the "whats" and whys" of panel rails. You might find yourself asking "what are panel rails and why would I want to use them?" Well,... Read more

Open The Pod Bay Doors, HASL

Does anyone use HASL (Hot Air Surface Leveling) anymore? It's also known as HAL. Prior to the RoHS days, HASL was probably the most common surface finish. You can get it lead free, but most boards seem to use immersion... Read more

How not to trick your BGA friends

Continuing with yesterday's theme, I have a couple examples that should have been fine, but due to issues at the board house, improper storage or contamination, ended up very much not fine. Behind door number one, we have an OSP... Read more

How not to treat your BGA friends

Over the years, most of what we see are good PC boards. But some standout in the other direction as examples of what not to do. Some didn't make it through the board house alive. Some were unknowingly rendered useless... Read more

Via Current Capacity

Over on the Circuits Assembly blog, Michael asked a question about my Via in Pad Myth #5. He asked: "I have a question about vias. I have seen charts on the current carrying capacity of traces, but what about vias?"... Read more