The origins – and future – of standards, the foundation of electronics manufacturing.

Today, every step in electronics manufacturing – from the components to the board to the physical and electrical connections themselves – is governed by standards. Standards regulate the acceptability of workmanship, the choice and quality of materials, and the end-product performance. With the global proliferation of successful, reliable electronics in virtually every aspect of our individual lives, from personal products such as mobile phones, to critical medical electronics and defense avionics, standards are the unseen yet powerful guidelines behind the explosive success of electronics technology. Standards did not come about by themselves. Time was, there were no standards; some 50 years ago, conceiving and developing them became the mission of the IPC and many hard-working visionaries over the decades since. Electronics would not be where it is today were standards not developed and implemented. How standards came about, however, is a story that, although true, reads something like fiction, with remarkable twists and turns – including luck, chance, timing and a dash of humor.

When IPC began, in 1957, in conjunction with the birth of the printed wiring board industry, representatives from six of the major independent PWB manufacturers met in Chicago to officially form a trade association. At this meeting, they outlined a number of key objectives. One of them was to develop standards and specifications to provide believable yardsticks for manufacturers and users to move forward in using the products of the new industry.

Three years later, IPC published its first standard: IPC-D-300, “Dimensions and Tolerances for Single- and Double-Sided PWBs.” In 1963, IPC formed a Technical Planning and Standards Coordinating committee to oversee standards activity and make recommendations to its board. At that time, PWB acceptability requirements were to some extent based on opinion. In 1964, to provide a common set of standards for customers and suppliers, IPC published the first version of IPC-A-600, “Acceptability of Printed Boards.” To appreciate the significance of this document, it is worth noting that, since 1964, this document has been revised and updated seven times. IPC-A-600 and IPC-6012, “Qualification and Performance Specification for Rigid Printed Boards,” have set the standard for PCB workmanship quality, providing comprehensive acceptance criteria accompanied by illustrations and photographs showing all types of printed board surface and internal conditions. Because of its importance to PWB fabricator and assembler, IPC-A-600 has become one of the most widely used documents published by IPC.

“A standard is a document that is usually established for people to use in the development of their product(s), or so that there can be meaningful communication between the product developers and their suppliers as to the requirement details,” explains IPC’s Dieter Bergman.  Bergman ought to know; during nearly five decades serving IPC in various leadership capacities, he has had a hand in the development of virtually every standard promulgated by the organization, including the outright authorship of many. Bergman says a standard “identifies what is required to be compliant with the characteristics of the standard, whatever the scope is. Probably most important is its scope.”

Standards on printed circuitry evolved as IPC evolved, Bergman explains. “If you go back to the early 1950s, most standards were developed by the military in order to establish uniformity, the lack of which was a problem back in those years of evolving technology. Initially the Secretary of Defense was trying to prevent the different services from creating their own individual standards. It was a little difficult in those early years, because the Navy and the Army, for example, each had their own view, and there were a couple of topics that really went awry, such as the business of soldering.”

At one time, Bergman says, there were 48 different standards on soldering from different agencies. “But in those early days, what the Secretary of Defense did was to indicate that in order to keep the individual agencies from squabbling with one another, they created a concept called the Tri-services, which consisted of the Army, Navy, Air Force, and then any other outside folks that wanted to participate.”

Bergman adds that when a standard was written, all three services, plus anyone else involved, selected one individual as “custodian,” and it was incumbent on that person to handle comments to the standard. In those early years, the Defense Department was the largest customer of all. The telecommunications and computer industries existed, of course, but didn’t need standards as much as the military, due to the latter’s mission of using and reusing the various branches’ hardware. “In those early days, mil specs were the way to work, and those of us who built product for the services wanted to be sure we understood what it was this customer really wanted,” Bergman recalls. “Initially, they wrote their standards in an unusual way. They would hire somebody from industry, and that person would create a draft of what he thought this potential customer wanted. Let’s say it was the Army; they would hire an individual from Hughes Aircraft, for example, and they would write the standard based on what they were asked to do, and then would open it up for comment from the industry, and basically the industry would come to what they called, at that time, a Coordination Meeting, which usually had representatives from the Tri-services and the industry, and by that I mean that part of the industry that built product for the military. So, getting involved in standards took place in those early years at a mil spec level, and the coordination was an opportunity to see what you could do to influence the custodian of the standard, or the military Tri-services representatives.” They were going to create a standard that was useful, that could be followed, and that suppliers could be measured against in meeting the requirements.

When IPC was founded, its focus was not on establishing standards; there were other areas of immediate need, such as countering Zenith’s campaign against printed wiring technology. The first document IPC wrote and published was not a standard, but was actually a book about how to design and specify printed wiring boards. “Its purpose was really marketing this new technology,” Bergman said. Three years went by, and some of the designers who were trying to follow the book’s concepts grew confused over matters such as conductor width, spacing, hole size and so forth. That led to IPC’s first foray into standards, the aforementioned IPC-D-300, whereas “D” stood for dimensioning. It was published in May 1960.

IPC standards are the result of industry consensus and collaboration (Figure 1). They cover most disciplines in board manufacture and assembly. Standards permit manufacturers, customers and suppliers to speak the same language. For example, post-process cleaning of assemblies is still a major issue in manufacturing and an area of much confusion. IPC cleaning standards offer a wide variation of processes and solutions that cover many areas of production cleaning. There are many different types of cleaning and associated chemistries, each one critical to its particular application. IPC-M-108, “Assembly Cleaning Guides and Handbooks,” is the complete guide to cleaning and is an amalgamation of six standards, including all areas of cleaning, from post-solder solvent (IPC-SC-60) and post-solder aqueous (IPC-AC-65A) to the cleaning of PWBs and assemblies (IPC-CH-65) and surface insulation (IPC-9201).

Figure 1. How standards evolve from concept to publication.

Industry/military coordination. As work on standards progressed into the 1960s, there was also coordination activity between the industry and military to try to make the information available for designing and building more robust boards. There came to be “pairing” of related and supporting documents, and, as Bergman says, this became an important concept. “You had MIL-STD-275, and it was the design of single- and double-sided printed circuit boards, and the companion document that showed the performance of the board was MIL-P-5510. All the military suppliers knew those numbers well. Although those were MIL specs, IPC decided they also needed to have a companion document, or to move ahead a little to see if they could get the idea of multilayer product moved into the arena.”

Multilayer boards. The concept of developing multilayer circuits evolved during the early 1960s. An IPC task group created a technical handbook titled Multilayer Printed Circuit Boards that wasn’t necessarily a standard so much as a statement of the advantages of using multilayer circuitry. It referenced some of the characteristics of what one could and couldn’t do, and it defined a standard that could deal with the design and manufacture of a multilayer printed board. “This became an important document,” Bergman says. “It defined what multilayer was. Then they created a couple of standards that related to the characteristics of the multilayer product. The first one was IPC-ML- 900, ‘Rigid Multilayer Printed Wiring Boards with Hole Spacings 0.100" or Greater,’ because it became important to define. Some multilayer boards were easy to make, but as the spacing got closer, it became more difficult. They took a page out of the MIL specs and created another document, which turned out to be IPC-ML-925, ‘Rigid Multilayer Printed Wiring Boards with Hole Spacings Less Than 0.100"’ for those who needed tighter product.”

Consequently, Bergman says, these all tied in to the performance specification, which dealt with multilayer PWB performance. This was generated around 1965-66. It resulted in the establishment of different classes, the first time such a structure appeared in an industry standard. “It was important because if you’re trying to get the consensus of a group, you need to understand that not everyone needs the same reliability or precision; thus IPC created this class structure, which is a little different now, but at that time it included Class A, which was the most stringent, Class B, which was stringent, and Class C, which was normal. Today that is slightly inverted from a complexity point of view; “C” is now the most difficult.” The classes were turned around in the event they needed to reflect classes of product more difficult than what was already in place.

There were conflicts, however. The military, Bergman says, was not going to readily accept what IPC was doing, and decided that it would ready its own multilayer board documentation. The DoD felt, for example, that it needed to write a multilayer document to complement the single/double-sided spec like MIL-STD-275, and thus started work on MIL-STD-1495, the military version of a double-sided board spec. Likewise, the multilayer equivalent to MIL-P-55110 was MIL-P-55640.

At the time, Philco employed Bergman. He attended many coordination meetings between the industry and military. “We wanted to make sure that we understood how the standards impacted our military customers and our desire to satisfy them. They decided that, because I ran the design group, I would become the official representative from Philco. [A leading IPC committee chairman named] George Messner knew that I was interested in multilayer, and said, ‘Why don’t you be chairman of the multilayer design committee?’  We began a practice of holding an industry caucus, a day or two before the meeting. We would go through the document they were proposing, make all sorts of comments, which I would write down, and we would elect a spokesman, so that if there were 16 of us attending the meeting, we didn’t want all 16 chirping up. The spokesman would be the first to speak; following that, the meeting would be open for everyone to discuss the pros and cons of the issue. The military would indicate what it wanted, and why.

“There were quite a few of these that IPC got involved in, and in the end, the government’s needs became important for us to understand, and that’s how we wound up with Class 3 being for the government, because the IPC felt it might get some of its standards accepted by the DoD. Then, it turned out that several of the Army/Navy/Air Force representatives who attended those early meetings got involved in IPC activities, and we had a lot of give and take between what the military needed and what industry felt it wanted to commit to, so we wound up with Class 1 being mainly commercial product, Class 2 telecommunications, somewhere in the middle, and Class 3 high-rel and military. So the IPC standards mirrored, a little bit, what the military wanted, as a result of this coordination activity.”

Eventually the DoD handed more and more responsibilities to IPC, which took MIL-STD-275 and created a more complex industry version and numbered it IPC-D-275. But it didn’t stop there. “IPC-D-275 got so full and so large with people wanting more stuff in there about flex, and PCMCIA cards, and embedded passives and other things, that it got broken up into the 2200 series, where today the evolution of that first set of MIL specs can be traced back to the present version of IPC-2221, which is a generic design standard for rigid, flex, single/double-sided, multilayer, all of that. There is also a performance document that went along with that, where initially we started off with 276; 275 became the design, and 276 applied to single and double-sided boards, and then that evolved into a single multilayer specification for IPC, so the performance standards are all in the 6010 series, with 6011 the generic and 6012 rigid, and 6013 for flex.”

Living Documents

Standards are not carved in stone; they are living documents, subject to perpetual reexamination and revision as times, legislation and technology changes. “All standards are in the works right now, constantly under review and revision,” Bergman adds. In his opinion, the most popular standard worked on currently is IPC-7095, “Implementation of BGA Technology.” “We’re just finishing the B revision, which is intended to characterize the conditions for lead-free,” he says.

Standards grew in size and scope, and people in the industry wanted more, Bergman says, due in part to the work of the Surface Mount Council, a group of industry experts who represented component manufacturers, assemblers and board fabricators. IPC and EIA jointly formed the SMC, whose mission was to promote the orderly implementation of surface mount technology through standardization, among other means. This group of 35 individuals represented companies, trade associations and others, all trying to influence the standards under-developed by the DoD. “The goal was orderly implementation, so that the standards could complement each other and not conflict, so that you would not have to choose whom you supported, or whom you felt you could follow.”

Flip chip technology. “The SMC got into a discussion about flip-chip technology, and decided that it needed to promote it, so we made a shopping list of what we thought would be in the standard, and what standards would be needed to promote this concept of taking bare die and mounting them on a printed circuit board in a flip chip application. Basically, you had a blank sheet of paper; you had a list of topics that were important to this technology, and at the end of the first day, I said, ‘Hey guys, each one of you pick one or two of these, and go back to your hotel tonight and write me a scope statement for what you think should be in that standard, and when we come back tomorrow, we’ll read your scope statement and we’ll make sure it’s going to be OK, and then everybody’s happy with it, and then we’ll create a table of contents for this standard on flip chip technology, and we’ll go from there.’” The Council members did as requested, Bergman recalls, and when they reconvened the next day, “we had this preliminary table of contents, and a scope statement for about 21 standards that needed to be developed in order for the technology to take hold, because that was the vision; yet, we realized flip chip technology, without standards, would never evolve.”

The Troubled Birth of DOD-2000

The need for a single soldering standard, derived from proliferating soldering standards at the time, became a priority for IPC and the military. How a single standard came about is, as Bergman relates, the stuff of legend. “We had a meeting at General Electric. There were 18 people – nine from the military, nine from industry – and we looked at the 48 standards on soldering, and asked, What are we going to do? Everyone’s doing something different, and they’re conflicting! I said, “Well, let’s get a table of contents,” so we started with the blackboard, and we wrote out a ToC for a single soldering standard – just one – and then basically we took the best paragraphs of the 48 Mil specs that could populate those standards. I took them to IPC headquarters and gave my secretary a pile of 48 standards, and said, “Pam, type me up a draft where I have a notation under a heading; put in the paragraph that comes from the appropriate spec, whether it is Navy, Signal Corps, whatever was called out. So she typed it up, and we labeled it MIL-S-XXXX and gave it to the MIL-STD-454 committee, which responded by saying that we did too much! So we took the work that was completed, removed some of the military jargon, and created IPC-S-815. As that was published, our members began to come to meetings; Ericsson sent experts in soldering, and revision A came out, then revision B, and at the same time, the government was going really crazy with its 48 standards. The Secretary of Defense said we needed kind of a standard coordination activity, and so an individual at the Defense Secretary level created a concept called the Soldering Program, and it was called DOD Standard 2000.” DOD-2000, as many may still recall, was a nightmare. “I got the best experts the industry had to offer, and for six years the bickering between Army, Navy and Air Force drove these people so crazy that many dropped out. I think I burned out more experts. They just said, ‘Don’t ask me to go anymore, Dieter; this is a waste of my time.’ And so at the end of the day, the Secretary was beside himself. The CEOs of all the hardware developers from government agencies who built for the government were calling him, and it got so bad that DOD 2000 became a bad name at the Pentagon. They were going to change the name to DOD 3000 just to get rid of the bad connotation.”

No one wanted to try to pull the standard out of the morass, but Bergman attempted one last shot, with the help of a friend, Jack Wyatt of EIA, a former U.S. Navy captain. “We met in his office, and got all of the people together who had spent those six to eight years, and all that pain, and I said, ‘We’re going to try it one more time.’” After nearly 10 months, Bergman recalls, “We had our first draft, and then Jack says,  ‘Are we going to call this an IPC standard or an EIA standard?’ We didn’t want people to take sides, so I said, ‘Let’s go to ANSI [the American Nationals Standards Institute].’ We were two trade associations that had worked together, and we knew it was definitely a standard needed by the military, but we want to make it an industry standard; we want to end the bickering between the different branches of the military. That’s how J-STD-001 was born.”

The crossover between military and commercial didn’t end with J-STD-001. In 1983, IPC released IPC-A-610, “Acceptability of Electronic Assemblies.” It is now the most published and most referenced standard in IPC’s history, the bridge between the J-STD-001 requirements and how operators implement those requirements.

Web-Based Comparisons

The key to IPC’s 50 years of standards development, begins Bergman, is “the ANSI rules of openness, consensus, cooperation and sharing. The greatest success is when a group of industry experts are willing to give of their time and effort, as well as gaining support of their management, to create a standard that benefits the industry. If encouraged properly, and the efforts are held up for recognition, everyone benefits. The delegates are recognized; the companies find it useful, and the combination of users, manufacturers and suppliers have their needs addressed. The task is worth effort. This must not change as we move into the future.

“The world has changed, and so has the industry’s skills and needs. The senior members know the roadmap to developing a requirement that is descriptive and clear enough to become a contractual commitment; the newbees have great software access skill sets and are impatient to redefine or reinvent the wheel. This energy level needs to be nurtured and directed toward a useful methodology for global manufacturing acquisition. So, two things will change: One is the development system; the other is the information delivery system.

“During the past 50 years, OEMs contributed their knowledge to the industry and it was based on work they did in captive facilities. When IBM came to a meeting and talked about multilayer boards, the committee listened since the data were gained from experience. IPC used much of these data as the basis for standards development. It was also appropriate to get more than one opinion, since many OEMs had similar data.

“If the information was too different, IPC members created a round robin test program. This is another technique we can't lose. This is akin to the IPC Solder Products Value Council, which structured a program to develop reliability data for alloys that did not contain lead.

“The use of OEM captive facility information is gone due to outsourcing; however, the information is still available from suppliers that now perform manufacturing. The overriding element is the Internet and the ability to find almost any piece of knowledge, on many different levels of details. The other thing is that much of this availability is without charge, provided one has the tools. So now the development of a good standard will take on a new methodology. One still starts with a blank sheet (except it is no longer paper, it is a screen), and the domain experts get together to define the effort. They create a scope of the standard or project and develop a UML model (Figure 2).

Figure 2. The UML model for standards development.

“UML is a family of graphic notations. The graphics help in designing software systems, especially object-oriented systems. UML is an open standard managed by Object Management Group and intended to support interoperability. There are different ways to use UML. The graphic notation can result either in a sketch, blueprint or programming language. The most common usage of UML is developing a sketch. This is where you rough out some issues and discuss them with committee members. These are usually domain experts. You communicate ideas and alternatives. Don't talk about computer code; the group should only review important issues that need to be run by the committee. Sketching is pretty dynamic; it is a way to emphasize communication, not specification, and can take as little as 10 minutes or one day. The standard can be developed after agreement is reached on the model. An example is the UML for laminate (Figure 3).

Figure 3. The specific UML for laminate (click to view image).

“The delivery system for standards will also change. Actually, change has already started. Here again the Internet and electronic data capture and transfer comes into play. The new standard developers want information and they want it quickly. Developers can’t take five years to deliver a useful standard. As it turns out, some marketing managers can’t wait until all the signoffs are obtained before taking orders for a product. When the IPC developed a change in the laminate standard, before the final ballot was ever cast, laminate manufacturers had already taken orders for IPC-4101B. This will become more intense. The conversion of standard information into useful code is also already upon the industry. Take, for example, the land pattern calculator based on IPC-7351. Thousands of free downloads of the LP Viewer have spurred the need for automation into different engineering and CAD/CAM tools.

“The information must also provide precision and accurate accumulation of data and technical requirements. New tools address this. IPC has a graphic called the specification tree. That illustration shows the relationship of various standards based on the focus of the particular topic; i.e., board material, design, assembly testing, etc. What the future holds is a Web-based search engine with precise ability to focus on a particular subject and show a quick look to the subscriber of all the standard requirements as published, and provide access to requirements for design, performance, test, accept/reject criteria, and so on.

“Named IPC Expert (Figure 4), the software will be able to automatically find any complementary or conflicting information in any of the released standards. The search engine uses international industry terminology of IPC-T-50/IEC-60194; however, the user can call up any topic that might have a relationship. To minimize error, links to all referenced sections, tables and figures are generated dynamically in any standard, and the Print Screen function permits the user to prepare for a meeting or provide and input to a customer or supplier in real time.

Figure 4. A screenshot of IPC’s new search engine
for comparing published specifications.

“These concepts are the beginning. Having electronic snapshots in a database of text, illustration and tables permits conversion to other languages. The tools, therefore, become the entry to global standards development – and global use.”

Michael Martel is a freelance writer; mmc@mmc-marketing.com.

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