-
- News
- Books
Featured Books
- pcb007 Magazine
Latest Issues
Current IssueWet Process Control
In this issue, we examine wet processes and how to obtain a better degree of control that allows usable data to guide our decisions and produce consistently higher-quality products.
Don’t Just Survive, Thrive
If we are to be relevant and prosper during these next critical decades in electronics, we must do more than survive. As an industry, we can and must thrive. In this issue, our contributors explore these concepts meant to help you take your business to the next level.
Material Matters
Materials management is nuanced, multifaceted, and requires a holistic systems approach for business success. When building high mix, low volume, and high technology, managing materials and overall cost containment are even greater challenges.
- Articles
- Columns
Search Console
- Links
- Events
||| MENU - pcb007 Magazine
Substrates for Advanced PCB Technologies: What Will the Future Hold?
November 6, 2018 | Pete Starkey, I-Connect007Estimated reading time: 9 minutes
![](https://iconnect007.com/application/files/4216/3125/6526/pete-starkey-300.jpg)
The UK chapter of the global IMAPS community of electronics and microelectronic packaging engineers shared a wealth of knowledge and wisdom about PCB substrate technology trends, developments, and future requirements in a webinar on the first of November. The webinar was introduced on behalf of IMAPS-UK by National Physical Laboratory’s electronics interconnection expert Martin Wickham and featured presentations by Piers Tremlett and Jim Francey.
“Who knows which future substrate will be successful?” Aware of a need to exercise caution when attempting predictions, Piers Tremlett, engineering specialist at Microsemi, quoted an example from ancient Greece: “The Oracle at Delphi knew how to error-proof her future predictions. Everyone else gets it wrong; it’s just a question of by how much.” Nevertheless, his presentation painted a very clear picture of the future for printed circuit substrates, even exploring the possibilities for “substrateless” circuits.
Driven by a need to satisfy the desires of users, substrate technology aimed to improve performance and eliminate waste whilst minimising cost. Tremlett discussed the fluidity of future circuit structures, the potential growth of flexible substrates, the rise in substrates for handling power and heat, and trends from two-dimensional to three-dimensional circuit assemblies. He focused on four relevant topics: miniaturisation for mobile products, heat and power, printed electronics, and substrateless circuits.
Mobile products, especially smartphones, and the cost savings of using less material were the primary drivers for miniaturisation. As an example, Tremlett showed a cross-section of an iPhone 7 with a coreless 10-layer 500-micron substrate and sub-20-micron tracks densely populated with components and a lot of interconnect in a very small space. The interconnect was realised by semi-additive processing, pattern plating on a very thin base copper, and flash etching. As laser direct imaging capability improved and track widths trended towards 10 microns, it was preferred to embed them into the substrate surface to improve reliability, as demonstrated by the Daisho Denshi ultra-narrow pitch flush pad interposer. In his iPhone 7 example, the memory chip was mounted on a very thin three-layer PCB, underneath which was the processor chip with no substrate as such—all the tracks were laid on the packaging material itself and had produced significant performance improvements. He commented that fan-out wafer-level packaging was moving from silicon wafer technology to PCB technology with more than one component inside the mould compound, which could be seen as a paradigm shift away from FR-4 and surface mount.
Conventional assembly technology was giving way to embedded die technology and ultra-thin chip technology, leading to smaller and thinner devices. But whereas the trend had always been to push components off the PCB and on to the silicon, this was now becoming a more expensive option, and the components were being pushed back up into the packaging fab to continue the drive towards integration. Packaging was moving towards complete subsystems, placing more emphasis on substrate capability in terms of layer count and track width and presenting considerable competition to conventional PCB concepts.
Tremlett turned his attention to thermal management, increasing heat being generated by faster processors, RF chips, power chips and LEDs. It was becoming less practicable to use ceramic substrates except for special applications because of considerations of cost, small panel geometries, and high-temperature processing. So, could organic substrates be used as alternatives? He discussed thermal via designs, several forms of integrated metal substrates, metal inserts, and even water-cooled PCBs, and compared their efficiencies as a means of heat dissipation. He reviewed innovations in chip embedding for power packaging that had proven benefits for low- and high-power analogue and digital and RF products and described proprietary embedding package solutions such as SESUB and aEASI. The EmPower project was an international consortium developing embedded power semiconductors for the drive electronics in electric vehicle applications in a module that enabled heat removal on both sides over the shortest possible heat conduction paths.
Page 1 of 3
Suggested Items
Atotech to Participate at KPCA Show 2024
09/03/2024 | AtotechMKS’ Atotech will participate in this year’s KPCA Show 2024 in Incheon, held at Songdo Convensia from September 4-6, 2024.
Victory Announces Breakthrough in PCB Technology with New Product Launch
08/29/2024 | openPRShenzhen Victory Electronics Technology Co., Ltd., a leader in the printed circuit board (PCB) manufacturing industry, is proud to announce the successful development of a groundbreaking new product.
Connect the Dots: Designing for Reality—Electroless Copper
08/28/2024 | Matt Stevenson -- Column: Connect the DotsRoll up your sleeves because it's time to get messy. In a recent episode of I-Connect007’s On the Line with… podcast, we discussed electroless copper deposition. This process deposits a copper layer into the through-holes and vias of what will eventually be a PCB. Electroless copper deposition feels like a black box to many people. It sort of looks like a black box, too. The boards go in one side, come out the other, and emerge differently. So, let's crack open that black box and look inside.
Maximizing ROI Through Better Wet Process Control
08/20/2024 | I-Connect007 Editorial Team“When things get out of control, the variation in your wet process begins,” says Mike Carano,. “Just because they look like good boards and may even pass electrical test, it does not necessarily mean you have good boards. Once the chemistry is headed toward the right or left side of the process control parameter cliff, the plating is compromised. If the copper is thinner than it should be, when the customer puts it into service, the board may fail after 500 cycles vs. the requisite 1,000 or 2,000 cycles. The root cause issue is that you plated 7/10ths of a mil of copper instead of one-mil of copper because you were not controlling your process. The fact that you passed your own electric test becomes inconsequential.”
The Chemical Connection: Controlling an Alkaline Etch Bath With Low Copper Loading
08/07/2024 | Don Ball -- Column: The Chemical ConnectionThis month, I wanted to continue my discussion on how much process control is actually needed for high-density circuit production. However, in the last month, I have been called on to help with a specific process control problem: how to control an alkaline etch bath when you’re not etching much copper. This problem has been cropping up more frequently as smaller shops (and a few larger ones) concentrate on low-volume, high-value plated through-hole panels such as prototypes, resistor cores, etc.