Research & Development in Capacitor Technology: 2010
06.03.2010 // Dennis M. Zogbi // Passives
The bits and pieces created today will impact the jigsaw of technology tomorrow.
The Technical-Economics of Capacitance:
Capacitance is equivalent to the physical size of the finished component. I say it this way because it's more lyrical and easier for the reader to remember, but caveat that by also saying that it is truly a matter of available surface area of dielectric materials. Understanding how to convert that science into value is the primary challenge of capacitor vendors today; and reflects the research and new product development of the entire supply chain working in harmony.
Understanding the roadmap in electronic capacitance begins with the fact that it is fundamental, and therefore a crossroad where the economics of development can be sufficiently measured.
Also, the fact that the technical reality of capacitance has changed from the time of its discovery to expand from “the physical size of the finished component” to the required caveat of “ available surface area” is a testament to the scientific realization that by manipulating the raw materials and packaging, that capacitance could be significantly enhanced in many valuable ways.
In the economics of capacitance, the reader should understand that the greatest return on investment in research dollars comes from the manipulation of available surface area of TRADITIONAL dielectric materials -most importantly- Ceramics (1); Plastics (2) Aluminum (3) and Tantalum (4).
Other technology developments that affect capacitance development can be considered NEW dielectric materials that have smaller total available markets, but higher levels of profitability and are either needs driven, or a competitive solution to existing, patented alternative technology.
Performance enhancements in how capacitance is delivered is sometimes a singular development- such as lowering equivalent series resistance and increasing the speed at which capacitance is created; or in conjunction with changes in variable performance- such as available voltage ranges or operating frequencies; or the unique marriage of the two- which is primarily customer driven and is determined by a harsh operating environment, such as operating temperature; vibration frequency, and proximity to toxic materials (corrosive materials). In other instances, such as in competing technologies (polymer cathode capacitors and high capacitance MLCC); technology developments are made as a result of R&D battles among competitors, and with less focus on the needs of the customer. This is the industry’s greatest weakness, and therefore, also its greatest opportunity for innovation to make a substantial move forward. We expect these changes to come from the smaller, more focused and well-funded start-ups in the capacitor industry because they can take more risks then established vendors.
Examples of Modern Research and Development
Therefore to summarize modern investment in research and development in electrical and electronic capacitance, it is possible to create three broad categories that include R&D in materials surface area in the existing core dielectrics; enhancing component performance and the development of new materials for various sub-elements of the finished capacitor.
Summary of R&D Focus in Electrical & Electronic Capacitance:
Cheaper, Better, Faster: Or That Which Has The Closest Proximity; is Usually the Most Successful
Customers throughout the supply chain want three things- Lower Cost, Enhanced Performance and Faster Time to Market; which are business concepts that are eternally in conflict with each other. Those efforts in research and development that come closest to a positive return on investment create the closest proximity to the ideal balance between the three. A basic understanding of this fundamental technical-economic equation would prevent many R&D efforts from getting off the ground, especially those sponsored by academic institutions or government agencies. In the end it is apparent from taking basic economic measurements over the past 20 years that the most successful research and development programs are those that enhance the surface area of the core dielectrics- barium titanate ceramic, aluminum foils, tantalum powders, polypropylene film and polyester film dielectric materials.
Investments in New Technology for The Capacitor Industry Must Meet The Following Economic Criteria
A) Cheaper B) Better C) Faster
“Cheaper, better and faster--these three business concepts do not work well together--seldom do you get all three, but when you do, you’re really onto something big.”
Increasing the Surface Area of Existing Dielectrics:
From a strict economical point of view, investment in research and development is much more suited to manipulation of the existing dielectrics. In the instances of using the traditional materials- ceramics, metals and plastics; the total available market that may be impacted by changes in existing dielectrics is well established, as is the supply chains associated with each respective material. Therefore the chance of success in increasing the surface area of an existing dielectric- such as barium titanate, aluminum foil, tantalum powder, polypropylene or polyester film, is more financially resilient and less likely to fail. There is also a certain comfort level among engineers at the capacitor manufacturer with working with materials they know and whose reactions they have come to understand over decades of trial and error. It is for this reason that the investments in the existing dielectrics have created the most value for the shareholder over time.
What Works: 20 Years of Data Does Not Lie:
One only need to look back 20 years at those projects in research and development that were successful to realize that the greatest return on investment came from changes in dielectric materials that enhanced surface area in the primary dielectrics. For example, surface area in ceramic capacitors was increased through the development of advanced processing methods for barium titanate- the true application of nanotechnology and a major success in the sales and marketing of an advanced technology breakthrough. A radical improvement in the effective capacitance per gram of ceramic capacitor. Other material developments that enhanced surface area came in tantalum, whose material vendors increased capacitance value per gram of tantalum anode through the application of advanced electro-chemistry. This development worked well in the creation of the unique porous structure of the tantalum pellet; so that surface area was enhanced by making sure that the amount of material inside the pellet was maximized. This increasing surface area by using most of what was available. This was an achievement in chemistry and also an important application that created value for shareholders.
In plastics, the focus has been to create thinner and stronger sheets of film, thus increasing capacitance by increasing the amount that could be rolled up inside a can. Also, both aluminum and film capacitors took a cue from ceramic capacitors and stacked up layers of dielectric as opposed to rolling them inside a can.
In 2010, there is a continued push along the same road toward enhancing surface area in the existing dielectrics. Vendors of advanced barium titanate for example, still invest research and development dollars in creating even smaller and more uniform materials through new and exciting chemical precipitation processes such as sol-gel derived barium titanate; and in tantalum the materials vendors still experiment with ways to create even higher capacitance value per gram in tantalum powders.
What are the Limitations of the Modern Science of Capacitance?
However, lead scientists in both ceramics and tantalum worry that the threshhold of technology has been reached in both dielectrics and that research and development dollars would be better spent in enhancing the performance characteristics of what is currently available, as opposed to trying to push the technology further in its current form. One direction is to move successful changes in technology in consumer electronics into the smaller, specialty component markets for infrastructure, space, mining, agriculture and medical electronics devices. Another method of investment success is to apply what has been learned in one dielectric and apply it to another dielectric. Visibility on alternative technologies through ownership of subsidiaries is a competitive advantage of large manufacturers in this respect. Therefore manufacturers like AVX, Kemet and Vishay can pool their research and development capabilities from multiple technology platcorms, and apply that theory to the future direction of research and development, which seems to be moving in the direction of hybrid capacitor solutions- devices that offer the best of multiple dielectric materials in one capacitor package- a smart capacitor® for e smart world of future electronics.
Today we see greater materials opportunities in enhancing aluminum foils and plastic films as these dielectrics still have a long way to go in reaching the thresholds of their ability, but lack the massive R&D dollars of ceramic and tantalum manufacturers. In aluminum capacitors for example, we can see early developments in increasing capacitance value per cubic centimeter of anode and cathode foils by building up metal layers as opposed to etching the metal down (A unique concept out of Israel that has great promise.) In traditional dielectric films, such as polypropylene and polyester, we see less overall activity in attempts to enhance the performance of materials but more attention focused on creating a material that can withstand the high temperatures of advanced processing without melting or deforming.
Enhancements in Increasing Surface Area Through Research and Development: 1990-2010
Over the next five years we believe that more emphasis will be placed on combining traditional dielectric materials in one single package. This trend may serve to increase the overall capacitance of a finished product through the application of multiple dielectrics, but also serve to enhance the performance of the finished capacitors by bring added benefits that are inherent in each dielectric.
Improving Component Performance:
Having established that enhancements to the surface area of traditional, established dielectrics offers the greatest potential return on investment for manufacturers due to the large total available market, the second area of research and development spending that has had the most significant impact on supply chain profitability, is enhancements to the performance of the finished capacitor. These enhancement in performance enable materials vendors and component manufacturers alike to charge a premium for the finished “enhanced” component. Some enhancements to standard parts for example, would include an extension of operating voltage, lowering of ESR, extending operational life of the component, higher frequency operation and higher temperature operation and greater resistance to chemical corrosion.
More Salt for the Soup:
Enhancements have been the result of materials additives to standard dielectrics, changes in the production process, or advanced levels of packaging. In each instance, based upon Paumanok estimations, the return on investment for enhancing component performance is generally a profitable exercise. In tantalum and aluminum capacitors for example, the introduction of conductive polymer cathode materials improved ESR substantially and now accounts for 25% of the market value for tantalum and 10% of the market value for aluminum capacitors. Additional tweaks in manufacturing- such as adding more than one anode per package, have also lowered ESR in electrolytic type capacitors. In plastic dielectrics, we note that segmentation of the capacitor film has enhanced voltage performance.
In 2010 we have also seen advancements in the voltage handling capability of tantalum, as well as the displacement of wet electrolytes with dry ones to enhance shelf life and harsh environment performance. We have also seen some key developments in high temperature handling capabilities of existing dielectrics through materials modifications and additives (such as glass) and new focus on packaging (heat shields) and novel lead attachments. 2010 also saw the year where corrosive exposure became a key area of profitability for those vendors who offered products that could withstand the unusual corrosive nature of sulfer in automotive environments.
Additional areas of note underway in 2010 is enhancing the operational life of high capacitance MLCC, whose thin dielectric layers make them more vunerable to failure; and limit their long term performance. New materials developments in Japan and Germany point toward the potential for advanced super ceramic dielectrics to be developed that will address the key issue of limited operational life for high capacitance MLCC.
Noted Improvements in Capacitor Performance by Key Dielectric: 1990-2010
Exciting New Materials for Capacitance:
Enhancements in component performance are usually driven by the component manufacturer; however, in certain instances, new developments are customer and/or process driven and this opens the door to the potential for new dielectric materials to be developed to augment the existing traditional dielectric technologies. Examples of dielectrics that have been successfully introduced into the market over the past twenty years include activated carbon materials for supercapacitors, niobium metal and niobium-oxide materials for niobium capacitors; polyphenylene sulfide (PPS) and polyethylene napthalate (PEN) plastics for DC film capacitor applications; and diamond-like carbon (DLC) materials used for Diamond capacitors. Each of these new materials have carved out small niches in the existing marketplace and are driven by high temperature requirements (either processing temperature or operating temperatures- such as PEN and PPS; and DLC capacitors; extremely high capacitance requirements (such as carbon supercapacitors), or alternative solutions to problematic supply chain dielectrics (i.e. niobium targeting tantalum).
In 2010 we note certain companies are experimenting with new materials for capacitance, such as metallized free-standing thin films derived from fluorinated polybenzoxazoles (6F-PBO) and fluorenyl polysters that incorporate diamond like hydrocarbon units (FDAPE) in their lattice structures. These dielectric films are being developed by joint activities of industry and government and are being develop on a needs basis for mission critical applications where extremely high temperatures (200 degrees C and above) and the self-healing aspect of film are required for space applications of the future.
New Dielectrics Successfully Introduced into the Marketplace: 1990-2010
What Holds the Most Promise: 2010-2015:
In my opinion it is those research and development projects that focus on the core dielectrics that will have the greatest return on investment over the next five years. Certainly any breakthrough in ceramic dielectric material that will increase the expected operational shelf life of high capacitance MLCC will be well-received by the industry and has a substantial total available market that should insure a high degree of return on investment. This is where I expect continued breakthroughs.
There are also customer driven opportunities for polypropylene capacitors, especially for applications in renewable energy systems and for “smart grid” development within the power transmission and distribution segment, especially for power factor correction. The market for polypropylene capacitors is substantial (about $1.5 billion USD worldwide) and there has been little change in the dielectric materials employed over the past 20 years (with exception of segmented films and thinner gage films). We expect further developments in double layer carbon supercapacitors as well, but are more convinced than ever that increased voltage per cell will be the technological breakthrough that will drive the technology forward.
What is more exciting and holds the greatest potential is in the area of hybrid solutions- in effect, those capacitor components that combined more than one type of dielectric in a single package. Currently we are closely watching developments in tantalum and aluminum combination thin film sheets; as well as plastic dielectric sheets doped with barium titanate as area of future developments of new capacitor technologies.
We are also on the verge of changes in integral passive materials and integral passive substrates that address the increasing concerns of miniaturization. The concept of how small a discrete capacitor can be has raised concerns for the past two decades, but now the reality of too small of a discrete component is becoming all too real – the limitations of discrete technology translates into an apparent opportunity to create capacitance inside the printed circuit board- a three dimensional solution to a two sided board. As portable electronic devices continue to become more complex, and are limited by the size of the human hand to hold them; greater emphasis will be placed in targeting high volume components to start to move inside the layers of the board. This opens up a whole new market opportunity to expand into the world of LTCC modules and FR4 modules and widen the total available market worldwide.
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