-
- News
- Books
Featured Books
- design007 Magazine
Latest Issues
Current IssueOpportunities and Challenges
In this issue, our expert contributors discuss the many opportunities and challenges in the PCB design community, and what can be done to grow the numbers of PCB designers—and design instructors.
Embedded Design Techniques
Our expert contributors provide the knowledge this month that designers need to be aware of to make intelligent, educated decisions about embedded design. Many design and manufacturing hurdles can trip up designers who are new to this technology.
Manufacturing Know-how
For this issue, we asked our expert contributors to share their thoughts on the absolute “must-know” aspects of fab, assembly and test that all designers should understand. In the end, we’re all in this together.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - design007 Magazine
TTM’s Approach to Stackup Design: Train the Customer
January 12, 2021 | I-Connect007 Editorial TeamEstimated reading time: 2 minutes
In this interview with the I-Connect007 Editorial Team, TTM’s Julie Ellis and Richard Dang drill down into stackup design, detailing some of the common stackup challenges that their customers face when designing for both prototype and volume levels, and offering advice to designers or engineers who are struggling with stackup issues. They also discuss why having too many different prepregs in a stackup can be asking for trouble, and how proper stackup design can optimize both the fabrication and assembly processes.
Andy Shaughnessy: Julie, why don’t you start by explaining why proper stackup design is so critical.
Julie Ellis: A stackup not only has to meet all of the customer requirements and industry standards, such as IPC-6012, but it also should be designed for best cost for fabrication using the least number of processes and available material that we can buy in time to meet the delivery, and be planned for special requirements, such as laser microvias or thick copper for high current. For products destined for volume manufacturing, stackups and minimum design guidelines should be verified with the final fabrication site capabilities in mind. We also take into account long-term reliability issues when we create our stackups for very high voltage devices (>500V) that are being driven by the electric vehicle and energy markets.
So, there’s a lot that goes into a stackup, and it’s not only 2D in the vertical cross-section view (Z-axis), where we’re trying to figure out the copper layers and the dielectric thicknesses. We need to achieve designs that accommodate registration process limitations in lamination, drilling, plating, and etching, which drive the minimum design guidelines. Depending on the design and the components that the customer is using, we determine the minimum trace, space, pad and via geometries on the horizontal X–Y plane. But it can be kind of difficult for customers to accept minimum design rules that are slightly larger than they planned when they don’t understand all the trade-offs and tolerances that we have to consider in our fabrication processes.
Shaughnessy: It’s where the rubber meets the road.
Ellis: It’s totally where the rubber meets the road. It’s better to plan carefully before you start putting the rubber to the road.
Shaughnessy: That’s one of the things that we hear: Some designers are doing stackups as they go.
Ellis: Yes, and if they don’t have all the fabricator’s input, which they would not necessarily know from their experience and point of view, they can accidentally start a design with extreme features and end up with a finished product that can be manufactured in small prototype quantities, but not in production volumes.
Shaughnessy: I’ve heard some designers say that if they can get the stackup right, that’s 80% of the design, basically.
Ellis: It could be, especially if their fabricator also provides all the minimum design guidelines, before they start routing their circuits.
Shaughnessy: Give us a quick overview of how you work with a customer who has a potential problem with the stackup.
Ellis: With my regular customers, if they have a new product and it’s got special requirements, they call me before they even start routing their boards. For rigid designs, we begin by discussing project requirements to determine the subgroup, which establishes which fab sites should be considered, by the complexity of the stackup.
To read this entire interview, which appeared in the January 2021 issue of Design007 Magazine, click here.
Suggested Items
Trouble in Your Tank: Supporting IC Substrates and Advanced Packaging, Part 5
03/19/2024 | Michael Carano -- Column: Trouble in Your TankDirect metallization systems based on conductive graphite or carbon dispersion are quickly gaining acceptance worldwide. Indeed, the environmental and productivity gains one can achieve with these processes are outstanding. In today’s highly competitive and litigious environment, direct metallization reduces costs associated with compliance, waste treatment, and legal issues related to chemical exposure. What makes these processes leaders in the direct metallization space?
AT&S Shines with Purest Copper on World Recycling Day
03/18/2024 | AT&SThe Styrian microelectronics specialist AT&S is taking World Recycling Day as an opportunity to review the progress that has been made in recent months at its sites around the world in terms of the efficient use of resources:
Matrix to Exhibit at IPC APEX EXPO 2024 in Anaheim, CA
03/05/2024 | MatrixMatrix will be exhibiting at IPC APEX EXPO 2024, to be held on April 9-12, 2024, at the Anaheim Convention Center, Anaheim, CA.
The Chemical Connection: Getting to Know Your Vendor
02/16/2024 | Don Ball -- Column: The Chemical ConnectionAfter working for a capital equipment supplier for almost 50 years, I’ve found that the most important part of getting to know your vendor is good communication among all parties. While contact between fabricators of a constantly changing product line and the designers of those products may occur daily or weekly, conversations between you and your equipment supplier may be years apart. That lengthy gap often means that previous contacts may have been promoted, retired, or moved on to other opportunities. You may have also migrated to a new supplier with whom you have little or no history. In either case, you will be interacting with someone you are unfamiliar with (as they are with you). Therefore, it is essential for both sides to communicate clearly so expectations will align.
EIPC Winter Conference 2024, Day 2: A Closer Look at Global Trends
02/14/2024 | Pete Starkey, I-Connect007The opening session of the second day’s conference proceedings focused on global PCB trends and was introduced and moderated by Dr. Michele Stampanoni, vice president of strategic sales and business development at Cicor Group in Switzerland. He opened the session with Dr. Hayao Nakahara’s knowledgeable and enlightening video presentation on the IC substrates industry.