Achieving harmonization

Recognition for the work done by IEC TC 40 experts around the world

Capacitors, resistors and inductors are passive components. Together with active components (semiconductors), circuit boards, connectors and some other components such as filters, switches and fuses, they represent the basic building blocks of myriads of electronic products across the world.

Panasonic miniature aluminium electrolytic capacitors
Miniature aluminium electrolytic capacitors used in industrial automation, automotive, power management, audio and white goods (Photo: Panasonic)

A huge market

The use of ever smaller, high-performance electronic devices and equipment in all fields of industry as well as in residential and commercial applications, the advent of the internet of things (IoT) and a smarter global environment have boosted the demand for passive components. More than 4 000 billion discrete resistors, capacitors and inductors are used annually. The market is fully global and its value exceeds EUR 25 billion (2015). 

In the 21st century, five major technological trends have been influencing the development of all components and will continue to do so: miniaturization, automatic assembly, electronics assembly technology – surface mounting is now increasingly giving way to component embedding – digitization of electronics and a requirement for zero defects. 

Facing challenges

These trends have meant huge technological challenges when developing passive components. At the same time, passive component prices have fallen, leading to important mergers and acquisitions in the sector and reducing drastically the number of players involved. Production has moved to low-cost countries and the primary users of passive components – the consumer goods industry – have for a large part left Europe, Japan and North America for the Asia-Pacific region. In 2000, Europe, Japan and North America produced about 55% of all capacitors; in 2015, their share of production was 20%. 

Keeping abreast of technological advances

Technological advances have also had a major influence on standardization in this field. New standards have emerged for new component families and there have been updates of existing specifications, test methods and requirements in order to address the trends outlined above. 

IEC Technical Committee (TC) 40: Capacitors and resistors for electronic equipment, created in the mid-50s to tackle standardization in the emerging electronics sector, has had to face these challenges head on and adapt to the ever increasing pace of technological developments in the past 20 years or so. 

Harmonization: the first steps

Some 20 years ago, TC 40 experts noticed that the IEC International Standards it developed were being adopted by Japan as national standards. That gave the experts the idea of following closely how their Standards were harmonized and adopted at regional and national levels. 

They focused on three geographical areas: Europe, Japan and the US. Representatives from each area were asked to give a progress report on adoptions at each subsequent plenary meeting of the TC. 

In Europe

Originally the link between IEC International Standards and European ones was a de facto harmonization of the technical contents of standards due to the fact that the same experts were working on both developments. The Dresden Agreement between the IEC and the European Committee for Electrotechnical Standardization (CENELEC), originally approved in 1991 and amended in 1996, aimed to avoid duplication of efforts and reduce development time when preparing standards made monitoring of true harmonization straightforward. A revision of the partnership in 2016 led to the signing of the Frankfurt Agreement

New standards projects are planned jointly by IEC and CENELEC and, whenever possible, are carried out at the international level. Both organizations vote in parallel during the standards development process. If the outcome of the parallel voting is positive, the IEC publishes the International Standard and CENELEC ratifies the European standard. 

As far as TC 40 is concerned, the vast majority of European standards are harmonized with the corresponding IEC International Standards. 

In Japan

In 1995, the Ministry of International Trade and Industry (MITI), reorganized in 2001 into the Ministry of Economy, Trade and Industry (METI), made the decision that all IEC International Standards – including those developed by TC 40 – should be translated into Japanese and adopted as Japanese Industrial Standards (JIS). The decision aligned with the World Trade Organization (WTO) Technical Barriers to Trade (TBT) Agreement that came into force in January 1995. Today, Japan is very close to equating to the European level of harmonization. Generally speaking, all active Standards developed by TC 40 have been adopted as national ones. While the numbering system Japan uses is different from the IEC numbering system, the content is identical. Japan also participates in IEC work when a new edition is underway, and, once it is published, the Japanese standard is revised accordingly. 

Japan has put in place a complex mechanism, involving several governmental agencies, for tackling the huge task of selecting, translating and approving the publications to be harmonized. They include, among others, the Japan Electronics and Information Technology Industries Association (JEITA), the Japanese Industrial Standards Committee (JISC) and the Japanese Standards Association (JSA). All come together under the METI umbrella. 

Since 1995, Japan’s involvement in TC 40 has grown tremendously and the number of Japanese experts participating in the committee’s work has increased. At national level, the TC 40 mirror committee is extremely active in the harmonization process and several committees have been established, addressing specific technologies – passive components, packaging and so forth. At the beginning their task was to follow the development of a new IEC Standard until publication and then to translate it into Japanese for final approval by METI before adoption. Over time, the committees started to make proposals for new IEC Standards, for amendments and revisions of existing IEC Standards or for the adoption at IEC level of existing JEITA and JIS standards. Today Japan has more convenorships of Working Groups (WGs), Project Teams (PTs) and Maintenance Teams (MTs) in TC 40 than any other country. 

The United States 

EIA standards

The situation in the US is somewhat different. The country has a large number of bodies developing standards but in the capacitor/resistor field, TC 40 works with two organizations. 

One is the Electronic Components Industry Association (ECIA) which continues the work previously undertaken by the Electronic Industries Alliance (EIA), a standards and trade organization for US electronic manufacturers which ceased its operations in 2011. At the time, EIA had designated the Electronic Components Association (ECA) to continue to develop standards for interconnect, passive and electromechanical (IP&E) electronic components under the American National Standards Institute (ANSI)-designation of EIA standards. However, the same year, ECA merged with the National Electronic Distributors Association (NEDA) to form the Electronic Components Industry Association (ECIA). 

Some years ago, ECIA started to harmonize the EIA capacitor standards with those of the IEC. The 2008 edition of IEC 60384-1, Fixed capacitors for use in electronic equipment - Part 1: Generic specification, was the first publication to be considered. Today, the harmonization process for the 2016 edition of the Standard is underway and most of the TC 40 International Standards have been adopted as EIA standards. 


The other partnership, with Underwriters Laboratories (UL), focuses on safety aspects. The first IEC International Standard harmonized was published in 2013: IEC 60384-14, Fixed capacitors for use in electronic equipment - Part 14: Sectional specification - Fixed capacitors for electromagnetic interference suppression and connection to the supply mains

The safety issue is of the utmost importance. Risks associated with defective capacitors include fires or electric shocks. 

TC 40 has been working with UL to find common grounds for the harmonization of Standards that cover filter units for the suppression of electromagnetic interference. UL filter standards are much more complex than IEC Standards due to the greater number of filters involved. The objective has been to reach a compromise that accommodates all important safety aspects on both sides. The first commonly agreed Standard in this area, covering appliance filters, is IEC 60939-3:2015, Passive filter units for electromagnetic interference suppression - Part 3: Passive filter units for which safety tests are appropriate

As a rule, UL doesn’t formally adopt IEC Standards but common work between TC 40 and UL ensures that, ultimately, they possess the same specifications and requirements. 

Huge amounts of money are involved in the certification of electromagnetic interference (EMI) filters. Companies can save significantly if they have only one standard to comply with, rather than several. 

Harmonization status in Europe, Japan and the US

At the end of November 2017, TC 40 reported that the majority of its International Standards had been harmonized in Europe, Japan and the United States. They include most of the publications in the IEC 60384 series on fixed capacitors for use in electronic equipment, four Standards in the IEC 60115 series on fixed resistors for use in electronic equipment, four in the IEC 60938 series on fixed inductors for electromagnetic interference suppression and three in the IEC 62391 series on fixed electrical double-layer capacitors for use in electronic equipment. 

Resistors resist change…

Nevertheless some IEC Standards developed by TC 40 have not been harmonized in Europe or elsewhere. They are predominantly old publications covering resistors that have not been modified or updated but are still in use, mainly in the defense sector. 

Why have these publications not been updated? It has become increasingly difficult to find industry experts. Important changes have taken place in the capacitor and resistor industry sector. While in the 1980s Europe had the lead in manufacturing these components, interest in the technology started to wane in the following decade; many European companies disappeared or merged with others, which were often larger, until very few were left. Experts who previously had been working for different companies ended up working for the same group. As a result, companies sent fewer experts to TC 40. Over the years, the diminishing number of experts has slowed down and delayed work considerably in that field. This accounts for the old standards never having been revised. 

…up to a point

Today, a high proportion of all capacitors and resistors come from China and the workforce there has become extremely knowledgeable about the technology. In 2013, Chinese experts participating in the TC 40 plenary meeting in New Delhi, India, came up with a proposal to develop new testing methods for certain variable resistors, one of the areas in which the TC had had problems finding experts in the past. This will enable maintenance of older Standards to be undertaken. Having China as the lead may incite experts from other regions to join in this effort.

About IEC TC 40

IEC TC 40 develops International Standards for: 

  • Capacitors, resistors, thermistors and varistors intended for use in electronic equipment
  • Capacitors, resistors and inductors and complete electromagnetic interference (EMI) suppression filter units for EMI suppression
  • Passive integrated circuits (ICs) or networks containing resistors, capacitors, inductors or combinations of these devices
  • Packaging of electronic components for automatic handling (activity undertaken on behalf of all relevant component technical committees)
  • Electric double layer capacitors for use in electric and electronic equipment