The Shaughnessy Report: A Stack of Advanced Packaging Info
Connect the Dots: Designing for Reality: Strip-Etch-Strip
Dana on Data: Merging 2D Electrical, 3D Mechanical Worlds
Q&A: The Learning Curve for Ultra HDI
October 20, 2022 | Andy Shaughnessy, Design007 MagazineEstimated reading time: 2 minutes
For this issue on ultra HDI, we reached out to Tara Dunn at Averatek with some specific questions about how she defines UDHI, more about the company’s patented semi-additive process, and what really sets ultra HDI apart from everything else. Do designers want to learn a new technology? What about fabricators? We hope this interview answers some of those questions that you may be having about these capabilities and what it could mean for your designs.
Q: How do you define ultra HDI? What is the cutoff in mils or microns?
A: That is an excellent question. At this point I think it means different things to different people depending on where their current HDI capabilities are. IPC has created an ultra HDI working group and I believe the definition they are working with is that to be considered ultra-HDI, a design needs to include one or more of these parameters: Line width below 50 µm, spacing below 50 µm, dielectric thickness below 50 µm, and microvia diameter below 75 µm.
Q: Averatek has developed the A-SAP™ semi-additive process, which can produce traces down into the UHDI space. Can you clear up the differences between mSAP and A-SAP, and what this means to designers and design engineers?
A: In general, SAP, or a semi-additive process, is a process that starts with a very thin layer of copper and then builds the trace patterns from there. One common differentiating factor in these two approaches to SAP is the starting copper thickness. Typically, copper thickness that is 1.5 microns or above would be considered mSAP, or a modified semi-additive process. Because the copper is a little thicker than other SAP processes, it requires more etching, which can have impacts on trace width and space and also the sidewalls of the trace. This process can typically provide features as small as 30 microns in highly specialized facilities that are running extremely high-volume manufacturing. This technology is commonly seen in our smartphones.
Averatek’s A-SAP begins with a much thinner electroless copper, typically 0.2 µm and this copper thickness, or thinness if you will, enables the fabricator to produce much finer feature sizes. The technology is capable of traces and spaces as small as 1 micron if the fabricator has advanced imaging equipment. Typically, PCB fabricators have equipment that can image traces to 12.5 µm today. There are also signal integrity benefits to this process. Because the base copper is so thin, there is minimal impact on the trace sidewalls, and greater control to line width resulting in impedance control tolerance improvements.
One other difference between the mSAP and A-SAP technologies is in the ratio of trace height to trace width; mSAP processes allow a 1:1 ratio of height to width and A-SAP traces can be produced with aspect ratio of 2:1 or greater. For example, a 25 µm wide trace could be 40 µm tall. This has gotten a lot of attention from a signal integrity perspective.
To read this entire article, which appeared in the October 2022 issue of Design007 Magazine, click here.
Share on:
Suggested Items
Growth Unfolds: The First of STARTEAM’s Trio of Factories Set to Expand
12/05/2024 | STARTEAM GLOBALSTARTEAM is thrilled to share news of our upcoming 3-step expansion at JST, with each step adding 50,000m² per month which began on May 27, 2024. This carefully planned extension is designed to significantly increase our production capacity and expand our talented team. Currently, our production space covers 30,000m². Through this expansion, we are setting our sights on incrementally increasing our capacity from 70,000m²/month to a remarkable 130,000m²/month.
Connect the Dots: Designing for Reality: Strip-Etch-Strip
12/05/2024 | Matt Stevenson -- Column: Connect the DotsIn the previous episode of I-Connect007’s On the Line with… podcast, we focused on pattern plating. At this point, we are close to completing our boards and ready for the strip-etch-strip (SES) process. By this stage of the manufacturing process, we have laminated all the internal layers together, drilled the through-holes, applied the image to the external layers through photoresist, plated the copper in those channels to beef up the copper thickness for traces, pads, and through-holes, added a layer of electrolytic tin over the top of that copper to protect it during subsequent stages of production.
Fresh PCB Concepts: PCB Design Essentials for Electric Vehicle Charging
11/27/2024 | Team NCAB -- Column: Fresh PCB ConceptsElectric vehicles (EVs), powered by electricity rather than fossil fuels, are transforming transportation and reducing environmental impacts. But what good is an EV if it can't be easily charged? In this month's column, Ramon Roche dives into the role of printed circuit boards (PCBs) in electric vehicle charging (EVC)—and the design considerations.
Unlocking Advanced Circuitry Through Liquid Metal Ink
10/31/2024 | I-Connect007 Editorial TeamPCB UHDI technologist John Johnson of American Standard Circuits discusses the evolving landscape of electronics manufacturing and the critical role of innovation, specifically liquid metal ink technology, as an alternate process to traditional metallization in PCB fabrication to achieve ever finer features and tighter tolerances. The discussion highlights the benefits of reliability, efficiency, and yields as a tradeoff to any increased cost to run the process. As this technology becomes better understood and accepted, even sought out by customers and designers, John says there is a move toward mainstream incorporation.
Fresh PCB Concepts: The Critical Nature of Copper Thickness on PCBs
10/31/2024 | Team NCAB -- Column: Fresh PCB ConceptsPCBs are the backbone of modern electronics and the copper layers within these boards serve as the primary pathways for electrical signals. When designing and manufacturing PCBs, copper thickness is one of the most critical factors and significantly affects the board’s performance and durability. The IPC-6012F specification, the industry standard for the performance and qualification of rigid PCBs, sets clear guidelines on copper thickness to ensure reliability in different environments and applications.