Target Condition: Are Autorouters Friend or Foe?
Fresh PCB Concepts: Assembly Challenges with Micro Components and Standard Solder Mask Practices
Elementary Mr. Watson: Retro Routers vs. Modern Boards—The Silent Struggle on Your Screen
One Partial HDI Technique: mSAP
November 5, 2024 | Andy Shaughnessy, Design007 MagazineEstimated reading time: 2 minutes
Partial HDI has shown itself to be very useful, allowing designers to escape route tight-pitch BGAs without moving to full HDI and the required sequential lamination. It’s almost the best of both worlds.
Chris Hunrath, vice president of technology at Insulectro, believes that mSAP just might be the trick for designers considering partial HDI. As Chris explains, the materials and equipment required for the mSAP process are easily available, and the process is well established. This could be a great option for designers working with BGAs that have a pitch of 0.5 mm or less.
Andy Shaughnessy: Chris, why would somebody choose to move to partial HDI? When does that process make sense, and when is mSAP the answer?
Chris Hunrath: It’s all about BGA pitch, microvia location, and circuit routing. I've not heard anyone call it partial HDI, but I like that expression because that explains it just right: the rest of that layer or the board might be more, let's say, conventional. But you neck down the traces to be able to do your fan-out. One of the things I've learned in the past couple of years from designers is that it's okay to make the trace narrower—you won’t degrade the signal integrity as long as that neck-down area is a short length. You can get your routing and still have some registration budget where you won't risk having defects like shorts and whatnot.
First, there’s a lot of what we call “head trash” about exactly what mSAP is. It's also really important to remember that pattern plating, which is done in North American PCB shops every day, is a semi-additive process. We're just taking it to the next level with mSAP. A lot of things are converging right now. You have the finer-pitched BGA packages that are being developed for multiple markets. That's another thing. It's one thing to have lots of room, but if the component is made for multiple markets, you're stuck with that pitch. You just can't go to a bigger pitch.
Another point is that exposure units keep getting better and more capable. If your board shop has a direct imaging machine, you likely already have that 25-micron capability. Some of the materials have come together as well, and we supply those materials.
To read this entire conversation, which appeared in the October 2024 issue of Design007 Magazine, click here.
Share on:
Suggested Items
The Death of the Microsection
06/26/2025 | Bob Neves, Reliability Assessment Solutions, Inc.I got my start out of college grinding and polishing PCB microsections. My thumbs are a bit arthritic today because of the experience (microsection grinders know what I mean). Back then, via structures were rather large, and getting to the center in six steps of grinding and polishing was easy compared to what my team has been doing recently at the lab.
Day 2: More Cutting-edge Insights at the EIPC Summer Conference
06/18/2025 | Pete Starkey, I-Connect007The European Institute for the PCB Community (EIPC) summer conference took place this year in Edinburgh, Scotland, June 3-4. This is the third of three articles on the conference. The other two cover Day 1’s sessions and the opening keynote speech. Below is a recap of the second day’s sessions.
American Standard Circuits to Exhibit at IMS 2025
06/12/2025 | American Standard CircuitsAnaya Vardya, President and CEO of American Standard Circuits & ASC Sunstone Circuits, announced that his companies will exhibit at the IEEE International Microwave Symposium (IMS 2025), taking place June 15-20, 2025, at San Francisco’s Moscone Center.
UHDI Fundamentals: UHDI Drives Unique IoT Innovation—Smart Homes
06/03/2025 | Anaya Vardya, American Standard CircuitsThe combination of UHDI's high-bandwidth capabilities and IoT's real-time data processing can lead to more efficient, immersive, and smarter IoT systems. This convergence of two revolutionary technologies is enabling quantum advancements in some very “unconventional” applications.
Choosing the Right Strategic Path
04/29/2025 | Marcy LaRont, PCB007 MagazineTom Yang, CEO of CEE PCB, discusses the current economic challenges, noting reduced purchasing power post-pandemic. He highlights the growing demand for HDI in consumer electronics due to AI growth. Tom also expresses concerns about tariffs under the new U.S. administration, prompting CEE to diversify production locations, including new plants in Southeast Asia. He emphasizes the need for PCB manufacturers to adapt strategically amidst rising costs and fierce competition, particularly for mid-sized shops facing unique challenges in the industry.