Connector technology still grapples with smaller platforms, higher speeds and placement issues.

There are thousands of application-specific electronic connector products, with pin counts numbering from one to thousands. Connector varieties mirror the huge diversity of electronics products and applications. Connectors are also used in electrical applications, such as automotive and appliance, and where electronic power connections are required.

A few types of electronic connectors include:

Terminals and splices.
Rectangular and circular connectors (including RF/coax).
IC sockets.
Connectors for electronic systems (production).
Connectors for IC test, burn-in and other test.
Printed circuit connectors.
I/O connectors.
Wire and cable connectors.
Fiber-optic connectors and associated hardware.
Many, many application-specific connector designs.

Table 1 breaks out electronic connectors by equipment type. Connectors can be made from a range of technologies, adopting a multitude of new materials and processes, as well as value-added properties such as embedded silicon (memory cards), signal conditioning components (filter connectors), and printed circuits (card edge, FEC – in short, anywhere circuit elements need to be connected).

General use of connectors will not change until PCBs become more integrated. As with other electronics components, connector technology is driven by higher frequency signals, increased packaging densities, assembly processes, industry standards and environmental regulations. Some of the key areas where challenges are expected to occur are described below:

Sub-miniaturization of electronics packaging platform (e.g., HDI, 3-D, printed electronics). Requirements below 200 mm pitch and 0.5 mm mated height may require prototype/experimental interconnect technologies, such as etched foil or MEMS-type micro machining, which would also require some form of micro-robotic insertion. For vertically integrated OEMs, this would have been possible, but is less likely with today’s pervasive outsourcing. Mainstream merchant PCB technology – an area where suppliers tend to have low R&D budgets – is moving in this direction with high-density interconnect (HDI) and microvia technology. Flexible etched circuitry comes closest to the boundary where subminiature connectors are approaching limits. This is primarily in small handheld portable applications such as cellphones, digital cameras, etc. Connector technology continually adapts to new circuit and packaging requirements, and future technologies are expected to enable smaller, subminiature connectors with very thin sections, tighter tolerances and higher temperatures.

Very high-speed interfaces. Serial circuitry and advanced signal conditioning have upped the ante to 10 Gb and beyond. Differential signaling and air dielectric backplane systems have increased copper connectors’ reach to 20 Gbps and beyond. Fiber optics, essentially a point-to-point technology, is a viable alternative (with architectural modifications), as are hybrid Cu-FO designs, which are already in limited use.

Materials cost inflation. Materials cost was a serious issue for connectors and other products in 2006-2007, when copper, nickel, tin gold and many plastic materials experienced major price escalation. Except for precious metals and some other materials, global pricing deflation has occurred with the current recession. Proprietary efforts have had some success in developing minimalist/substitute materials and processes. Connector costs have bottomed, with many units already being assembled in Asia.

Wireless interconnect. A multitude of wireless technologies are on the market. Some, such as Bluetooth and the recently released Certified Wireless USB, attempt to reduce cable clutter. This will shift some applications into the wireless realm, replacing some connectors. The net effect, however, will be more system-level product volume and, overall, more connector volume. Even in so-called wireless applications, connectors remain.

Potential supply disruptions. Supply-chain risks are associated with a global marketplace, including reduced or eliminated local manufacturing infrastructures as production migrates to Southeast Asia. Many mainstream products are now built in offshore manufacturing venues: notebook and desktop PCs, motherboards, most handheld devices and board-level products for many applications. This dependence on emerging world economies – where there are concerns about infrastructure stability, IP theft, counterfeit products, climate and other issues – could result in supply disruptions. A supply disruption with China, for example, would be catastrophic, and unrest elsewhere could constrict market and EMS manufacturing access.

Use of Connectors with Press-Fit Assembly

The Board Assembly chapter of the 2009 iNEMI Roadmap discusses some of the challenges of inserting connectors when using press-fit assembly. Some include:

Automation. Assembly automation continues to be a challenge for some connectors, although the industry has widespread tape-and-reel, tray and other pick-and-place packaging. In addition, odd-shaped component placement has come a long way. However, miniaturization increases the need for higher contact insertion precision. With press-fit assembly, for example, the industry (in some cases) uses slower, manual placement methods to load connectors on the board before the press operation. Manual insertion has become more difficult as pins get smaller, shorter and have higher density, and cycle time for manual placement has increased by an estimated 20%. But even here, some suppliers have designed new press-fit pins.

Currently, there are a limited number of equipment vendors or high-cost robots to automate odd-shaped connector placement onto boards. One reason for the lack of equipment is the lack of standardization of connector trays. Connector manufacturers tend to use trays that match their packaging, and no collaborative industry effort has been undertaken to standardize the trays. Such standardization could go a long way toward being able to automatically place parts for the press operation. Better communication from OEMs and EMS providers to connector vendors would also help.
As cost pressures increase, throughput will become more of a focus, and there will be more demand for automatic placement machines, provided they can do some (if not all) of the following steps: pre-optical/laser inspection of pintails, placement, and inspection before the press fit operation.

The size of the connector pintail, alignment, true position and average offset of the wafers play a role in the ability to place a connector. AOI use for pintail alignment and true positioning would provide some assurance that connector pins are placed into the holes without stubbing against the PTH wall.

The need for a standard system for automatic pick-and-placement of connectors has been understood for more than 10 years. Different platforms to address this need were released to the market, but due to market conditions, sales were weak and the systems were withdrawn because of demand.
Current systems on the market range from semiautomatic presses through fully automatic press systems. However, the automation only pertains to the actual press cycle, while loading the connectors onto the PCB is still manual.

A re-evaluation of the need for a pick-and-place solution is expected with the recovery of the telecommunications and networking industry. The move to smaller pins and denser pin fields is also expected to further drive the need for a pick-and-place option. As the market evolves, one potential solution is to modify an existing automatic press system to act as a pick-and-place or a pick-place-and-press solution. Another potential solution is to take an existing odd-form pick-and-place-system and modify it for use with connectors.

Inspection. Inspection is a critical area of the press operation. Regardless of the type of deformation (accordion, smashed, etc.), the primary concern is a connection that may pass an open/short test, but fail in the field due to the connection opening up. This can occur if the pin shorts to the top of the barrel and passes the electrical test.

If the pins are long enough to protrude through the board, AOI or visual inspection can catch a pin that does not protrude fairly easily. However, if the board is so thick that pins cannot protrude, inspection becomes tougher. Different methods to detect pin presence have been attempted, but no solution works in all situations and is scalable. The feedback system of the press is used at many sites to determine if the press was successful, but even this method is not 100% accurate.

The most difficult and elusive inspection in the press-fit connector process is when two connectors are pressed from both sides of a board, with pins from each connector entering the same hole. There currently is no high-volume algorithm, machine or technique to accurately determine whether both pins are properly inserted into the barrels. As shown in Figure 1, the bottom pin can be bent and still maintain contact with the barrel during assembly and testing. Without a means of accurately identifying that one of the pins is bent, this  defect can reach the field and then open up.

Repair. EMS companies are challenged by many different connector types and the rework methods required to remove pins, wafers and connectors. Many assembly sites use pliers to pull the pins, although most connector suppliers sell repair tooling. The need for connector manufacturers to design unique features to permit easy removal, while preventing damage to the PCB, is encouraged, and common tooling to rework connectors is suggested. Connector bodies need to be designed for removing the connector, as well as placing it. Strategically located tooling holes for removal tools need to be designed into the housing. Also, the mechanical strength of the body should be sufficient to permit removal of all pins at once, without mechanical failure of the body.

Key Areas in Development and Commercialization

Connector developments follow OEM requirements, which are now shared with – or referred to – EMS providers. Key areas of interest will include micro and nano materials and process developments, high-speed electrical performance and miniaturization. Mobile/system-in-package (SiP) interconnect requirements may drive future micro-scale robotic connector design plus other dimensional requirements outside the realm of conventional stamp and form/mold connector processes:

BGA attachment with mechanical integrity for advanced SMT applications is now a reality.
10 Gbps now, 20-40 Gbps in the future, with higher-density connectors (> 100 signal contacts per inch), both differential and single-ended signal applications, or low-pin-count serialized interfaces (i.e., backplane systems).
High-speed copper and FO cables (Infiniband, Fiber Channel, 10 Gb Ethernet, etc.).
LGA socket I/Os have reached 1366 with PC processors; I/Os may drop to 1 or 0.5 mm pitch.
New high-performance memory sockets – DDR3, DDRx.
Sockets with multi-GHz level signals are dependent on PCB layout; future DIMM may be a two-piece or new design.
Serial or parallel optical interconnects; board-level waveguide packaging with optical ICs.
Value-added connector assemblies to reduce system cost and complexity, yet sustain the connector function.

Connectors are unique among electronic components because the applications, designs, materials and processes are almost limitless. Many designs have unique customer requirements, while others are multiple sourced industry standard products.

Thus, the industry really has two parts: a huge multi-billion-unit industry or OEM-specific standard segment, and a large semi-to-full customization segment with many market niches and unique customer designs. The roadmap will combine all these diverse characteristics as it seeks to fulfill future industry requirements. 

John MacWilliams is a senior consultant and analyst with Bishop & Associates (bishopinc.com.com) and chaired the Electronic Connector chapter of the 2009 iNEMI Roadmap; uscompetitors@yahoo.com.

Though different in size and scope, these six companies have long track records of success.

In highly competitive industries like EMS, what business practices ensure ongoing success? Based on experience gleaned from tracking the EMS market for more than 15 years through industry surveys and field research, we set out to measure successful companies and determine if any themes stand out to differentiate those firms from average ones.

Certain business practices work time and again. We define a successful company as one that grows sequentially, maintains a healthy profit margin (15% topline growth with EBITDA margins of 10% or more), and maintains unusual customer loyalty.

Below are several successful companies that have achieved high levels of growth, profitability and customer satisfaction. The companies profiled have demonstrated superior performance on an ongoing basis, and reside in the small- to mid-tier market sectors. They include Creation Technologies, EPIC Technologies, EN ElectronicNetwork, Morey Corp., NexLogic and Zollner. These EMS companies stand out as leaders in our Best Practices Survey and have articulated important concepts critical to their success over the years.

Creation Technologies. Based in Vancouver, BC, Creation Technologies (creationtech.com) has one of the best performance records of any contract manufacturer; the company has been continuously profitable since 1991. Its 2008 revenues reached $385 million through 10 operations in North America and one in Changzhou, China. While other companies have struggled with multiple downturns, Creation has continued to expand its top- and bottom-line revenues each year through organic growth and acquisition. Creation has successfully acquired and merged seven EMS providers since 2003, giving it a broad manufacturing footprint to support and grow its customer base. When asked how the company has been so successful, president and CEO Arthur Tymos points to four elements:

“The first key to success is our customer-focused people and solutions, and the long-term, loyal relationships this results in. The second is our people and culture. Our culture is amazing and is a true differentiator. Approximately 540 of our 2,300 employees are owners in the company. Third is our focus on ‘Lean Thinking In Action’ through every facet of the company. And fourth, our financial stability. We believe we are an industry leader in each of these areas.”

Creation’s customers would agree. The company surveys its 190 customers on a regular basis, and is rated extremely high in each of the four key areas. Tymos says customers notice its unique culture; its lean processes (it has 14 black belts and 15 green belts in quality); its 18 years of continuous profitability, and the regional locations of its business units that permit “a lot of close personal touch with our customers,” says Tymos.

The downside Tymos sees is the company’s lack of visibility. “We are not as well-recognized in the market as we would like to be. We need to get better at creating awareness. Our growth has been fast, but we are a private company, and we don’t share a lot of information, so our great success story hasn’t gotten around yet. We do have a strong brand for those who know about us.” Creation‘s service offerings best align with business products versus high-volume consumer products. Most assemblies are medium-volume, complex products, PCBA to systems to fulfillment, and after-market services.

Creation believes its service offerings to be top-notch and highly competitive. “Competitors that have caused us the most grief are those that come down-market and confuse the customer with their offering. It often takes a while for a customer to discover that it is a bad fit. We always encourage OEMs to look at true strategic alignment, rather than just price alone. Under-priced suppliers will, eventually, go out of business.”

EPIC Technologies. Headquartered in Norwalk, OH, EPIC Technologies’ (epictech.biz) growth almost rivals Creation’s, with revenues of nearly $300 million in 2008, with three operations in the U.S. and two in Mexico. EPIC has been recognized for its Lean manufacturing operations and exceptional customer satisfaction. The company acquired certain assets of Siemens Energy and Automation and Philips Consumer Electronics in 2006, and is owned by the private equity firm CIVC Partners L.P.

Vice president of supply chain management Todd Baggett states EPIC’s extremely high customer satisfaction ratings are the result of its exceptional flexibility and responsiveness. “We typically turn customer orders within a three-to-five day lead time, and have several customers where we demonstrate 99%-plus on-time delivery with 24 to 48 hour contractual order fulfillment lead times. We have implemented a unique manufacturing strategy to facilitate this level of agility.” Additionally, Baggett believes EPIC’s program management is second to none in the EMS industry, noting, “Our PMs have P/L responsibility from a cost management standpoint. They are responsible for on-time delivery, quality and scheduling, as well as the health and growth of the customer relationship, performance metrics and customer satisfaction, and are empowered to adapt their teams as necessary to meet and exceed customer expectations.”

EPIC thinks supply-chain management is its biggest challenge to success in EMS, since the cost of purchased components accounts for nearly 80% of the cost of doing business. Given the company’s short order turnaround expectations, materials management requires an even higher level of focus at EPIC. The company uses a kanban component purchasing methodology, with protected buffer quantities to support flexibility. This breaks sharply from the traditional MRP approach to materials management in EMS. As Baggett says, “In many ways, you don’t need buyers or planners in the traditional sense, as we have automated tools to respond to kanban replenishment signals. Our buyers are, therefore, able to focus more on strategic supply-chain initiatives, such as customer-specific bonding or buffering strategies.”

EPIC believes its extreme flexibility is a true differentiator, and recent customer service awards support that contention. The company uses a customer focus team (CFT) approach that becomes an extension of the customer organization. EPIC’s motto is “any product, anywhere and anytime,” with real-time order flexibility, made possible as a result of its non-dedicated line operations. Baggett states, “Most EMS companies are driven by an MRR model, whereby a customer forecast is loaded, and component parts pipelined and transformed to finished goods as quickly as possible for shipment to the customer, regardless of current customer needs. EPIC works with a “delayed transformation” model, whereby parts are pipelined, preferably on vendor consignment models, but EPIC delays product transformation until it sees consumption on the part of the customer from the established finished goods bins. This ensures EPIC builds only what customers need, and does not waste manufacturing resources on products customers do not need. Therefore, resources are available to support immediate customer requirements on very short lead times.

EN ElectronicNetwork. Another mid-tier EMS company, EN ElectronicNetwork AG (electronicnetwork.de) is based in Germany with sites around Europe. It has experienced strong growth during the past five years, with the exception of 2008, when its revenues were flat ($274 million). The company’s focus on the industrial market segment drives revenue and profits, which accounts in part for its good profit and strong revenue growth. EN’s leading customers include ABB, Bosch, Moeller and Siemens. Other market segments are medical electronics, renewable energy and railway transportation.

EN was established as a result of a spinoff from Philips, and is privately held, which makes it flexible concerning investments and focus on customers’ needs. Customer satisfaction is taken seriously and checked quarterly by surveys. “We want to keep our customers happy because that’s the only way to participate in each other’s success,” explains Ernst Gockel, chief sales officer. “Just recently, a long-term worldwide customer returned to EN from one of the big players in Asia. The customer was disappointed by the poor quality, lack of interest and long-term decisions. Turn these three reasons around, and you will know why they want to be with EN. We’re proud of that.” Due to the focus on quality, EN invests heavily in certifications. A recent one was IRIS (International Railway Industry Standard), a requirement to manufacture for the railway industry.

EN differentiates itself by excelling in so-called “Germany preciseness” in its operations throughout the whole product lifecycle. Leading products include drive technologies, such as measurement and control, frequency converters, motors, power supplies, production technology, robotics, automation technology (ticket, beverage, deposit, cash, cigarette and gaming machines), and military systems. EN offers support in the design process by offering ODM services in its areas of expertise, manages the supply chain, produces prototypes, as well as launches low-to-high volume products, and offers repair services and distribution as required.

Gockel points to the company’s rapid response time as a competitive strength. EN offers ODM services, but if there are many projects at once, it partners with an outside R&D company with deep experience in the medical, defense and aerospace markets. Yet, EN faces challenges in providing services in metals and plastics, which some of its competitors can offer. Increasing market awareness of the company is another problem, Gockel notes, stating, “It’s a gap we need to close and will.”

The Morey Corp. The Morey Corp. (moreycorp.com) is one of the EMS industry’s better-kept secrets. This family-owned operation started in the 1930s and evolved through three generations, yet stands out as being one of the most successful privately held companies in the industry. Morey Corp. achieved revenues of $120 million in 2008, up approximately 50% from the previous year.

In recent years, Morey Corp. has positioned itself as an ODM in the area of high-level controls, displays and telematics. Some of its leading customers include Caterpillar, International Truck and Engine and Case; therefore, it has gained considerable expertise in the industrial segment involving heavy equipment and process control applications. President and CEO Scott Morey states, “Caterpillar is the number one OEM supplier of ruggedized equipment in the world, and we are one of its primary ruggedized electronic subcontractors.”

The company recently opened a 27,500 sq. ft. R&D center to support its 100,000 sq. ft. manufacturing facility. This ODM capability gives the company advantages in providing the latest generation of technologies, improved technical problem solving, improved speed-to-market, and greater flexibility in configuration and quality. Morey has also applied these skills to the aerospace/military and energy markets by focusing on low-to-medium volume/high-mix products.

Scott Morey is supported by brothers Dana and Jay, and sets the standard and vision for the company. He has joked that some of the long-time employees jab that he “couldn’t hold a candle to his grandfather,” yet the loyalty within the company is palpable. The moral and ethical values that he advocates engender an integrity to which customers instinctively respond. “We all work best with companies and people with whom we share values. Who are you friends with? It’s the same with our customers.”

Morey’s success is derived not from any one thing; rather, it is a combination of business values and practices that make it unique among its employees and customers. These include the philosophies of Lean manufacturing, Deming, Goldratt and the Bible. The company pursues a conservative growth strategy, often eschewing acquisitions and opportunistic customer engagements. As a result, Morey focuses on the markets and products it can excel in, and then excels in applying its value proposition.

NexLogic. NexLogic (nexlogic.com) is a Silicon Valley-based operation that has demonstrated exceptional financial performance by achieving some of the strongest profit margins in the industry, according to our statistics. While the company is small ($16 million in sales in 2008), it is well-positioned in the industrial, medical and military market segments, which seem the only ones where good profitability can be achieved.

Asked how it came to be so successful, president and CEO Zulki Khan replies, “We have developed an ideal customer profile to help us understand the kind of customer we want to serve. Once we decide on a customer, we go the extra mile to do what we need to get the product finished. We are extremely flexible in terms of delivery and in rapid turnaround time. We like to spoil them and are constantly achieving miracles. After a while, if you do that enough times, they will come to rely on you, and price becomes second to service. Eventually, they become champions for you inside the company.”

NexLogic doesn’t lose many contracts once it sets its sites on a particular customer. Yet, it is quite particular about the kinds of projects it will take on, focusing on those it believes it can excel with. Khan says, “We offer a one-stop shop like the big guys, providing layout, testing, assembly, but try to reduce the suppliers to one contact. We try to keep our finger on the pulse of the technology needs, processes and package requirements, and will invest in equipment, as well as certifications, if necessary. Additionally, we try to solve problems in advance, before it’s too late. We upgrade our capacity and capability by buying things that will help us to better serve the customer.”

NexLogic has kept some customers up to 10 years, and nearly 80% of its business is from repeat customers. Nearly 25% of the company’s staff are engineers. NexLogic invests considerably in certifications (RoHs, medical and military, etc.) and other specialties to keep on the leading edge of its field. The company realizes it needs to maintain high levels of technical, quality and performance capabilities to be successful.

Zollner. Zollner (zollner.de) is the second-largest EMS company in Europe (behind Elcoteq), and the largest in Germany, with 12 locations in Europe, one in China and one in North Africa. The company exceeded $1 billion in revenue in 2008, more than doubling its revenue since 1993. The company does this by developing a strong customer base around medium- to high-volume, low-mix assemblies, as well as complex and low-volume production involving advanced technology. Zollner has a diverse product base of electronics assemblies across all major industry segments.

Similar to other companies profiled here, Zollner is privately held, allowing it to plan for the long-term, whereas most public companies operate quarter to quarter. This advantage permits Zollner to invest in a range of portfolio products. Zollner is a full-service, vertical provider, including offerings in sheet metal, plastics and full turnkey services.

Markus Aschenbrenner, VP of business development, believes these features permit the company to act as a medium-sized business that can offer plenty of personal attention. He reiterates, “Our program management is very good at hearing what the customer really needs. The customer is only one step away from being able to call executive management if a problem doesn’t get satisfactorily solved. Every three years, we do an extensive customer satisfaction survey, where the PM and a member of executive management go to the customer’s site to address our performance and their needs.”

Zollner is a technology-driven company. “In Europe we are the first ones to adopt new technology,” asserts Aschenbrenner. “For example, we were first to purchase the new series of Agilent x-ray equipment.” Moreover, its flexibility is key to customers. “They rely on us today for everything and want manufacturing to be the same as it used to be in-house. As a result, we have standard systems, equipment, processes and software across all our sites, as we did not acquire other companies and thus have no need to integrate different setups into our organization. We’re not like the big guys that buy customer manufacturing operations and inherit inefficient operations.”

Like many growing EMS firms, Zollner believes it needs to do better in supply chain management. The company has a fully established procurement capability in China to improve pricing on components, although there is room for improvement.  Zollner perceives business will pick up again in 2010. Executive management pays close attention to these trends and the specific needs of its more than 500 customers.

Certain best practices consistently work for EMS companies that are unique to their culture and customer base. EMS companies that are not cognizant of their own best practices need to assess and make sure they align with customers’ organizations and needs. When this happens, two critical things result: First, customer loyalty becomes embedded and switching to other suppliers counterproductive. Second, superior financial performance can result, since the customer and the contractor have parallel goals and an economically compatible relationship. 

Randall Sherman is president and CEO of New Venture Research Corp. (newventureresearch.com); rsherman@newventureresearch.com. Dave Leone is principal consultant of David Leone & Associates. Frank Klomp is principal consultant of Alerta Marketing Intelligence (alerta-intelligence.com).

Why commercial off-the-shelf components are incompatible with high-rel processes.

Military manufacturers are employing “off-the-shelf” components or parts in systems designed for military use. Manufacture of these systems and assemblies involves processes not typically used for commercial products such as multiple sequential solder assembly operations, multiple cleaning operations, conformal coating, etc. Commercial parts use is essential, as often equivalent military components are not available, or use thereof would increase cost and cycle time and compromise system performance. However, experience has shown that commercial components are often incompatible with processes used to build military hardware. This frequently results from the requirement that PCBs must be cleaned, typically multiple times, during processing.

Board wash complications. Military electronics assemblies typically are subjected to one or more board cleaning procedures during production. These are commonly carried out using automated inline cleaning systems. This is much less common in commercial enterprises. In fact, there has been a trend in commercial products toward no-clean and low-residue fluxes. However, board cleaning is essential if a PCB is to be conformally coated, and remains common to military production even when coating is not required. COTS parts are built for commercial customers, and typically not designed with exposure to board cleaners in mind.

Raytheon has experienced several failure scenarios resulting from exposure of components to our standard cleaning procedures. While a variety of board cleaner compositions are available, they all have three common features: water, a “saponifier,” and surfactants. Saponification refers to the conversion of water-insoluble fatty acids to soluble salts by exposure to a base (typically sodium hydroxide) to make soap. In electronics, the term is used to describe the conversion of insoluble flux acids to soluble salts by the action of bases. This permits their removal using inline cleaners. The basic nature of these materials can cause several issues, including corrosive failures.

Surfactants lower the surface tension of water, permitting better component wetting. This permits cleaners to enter small openings – gaps under parts; small, unexpected crevices in non-hermetically sealed devices; between individual capacitors of a stacked capacitor, and many others. This becomes problematic because, in most cases, DI water, free of surfactant, is used to remove the cleaners. Because of its high surface tension, the water cannot wash away the cleaner from the areas mentioned. Result: You can get the cleaner in, but you can’t get it out.

While most failures can be resolved by changing cleaning procedures, the result is that the one-size-fits-all approach to manufacturing – all products built using common shop practices – cannot be used in these cases. This often results in downtime, from the initial failure-and-resolution phase to the unexpected increase in man-hours required for production, as special procedures must be implemented for specific cases.

The following are examples in which Raytheon experienced failures as a direct result of component exposure to board wash chemicals. As is common in these cases, the initial supplier response typically was, “We sell these components to several customers, and you are the only one with reported failures.” This inevitably is related to the fact that “other customers” do not expose the parts to the aqueous cleaning common to military production.
Shorting capacitors. Included in the recent trend toward “green” manufacturing is the chemical industry’s effort toward “green” chemistry. One “green” solution to board cleaner chemistry is the use of environmentally benign bicarbonate salts, such as potassium bicarbonate, as saponifiers. This creates unique failure modes, as these are highly ionizable salts and, as such, are strong electrolytes – materials that conduct electricity in the presence of moisture. When these materials are washed into small crevices of boards and not removed by water rinsing, shorting failures at electrically sensitive areas, as well as corrosive failures, are common.

In this example, a stacked capacitor on a COTS product with very tight clearances between the individual capacitors was failing as a result of exposure to a bicarbonate salt cleaner. Failures were immediately noted upon testing of new assemblies. Electrical testing revealed shorting between stacked capacitors to be the cause; a distance of about 0.030˝ separated individual capacitors. In some cases, fiberglass spacers were placed between capacitors, in others not. Step-by-step analysis of the production flow revealed failures occurred only after the assembly’s exposure to board cleaning. Disassembly of a unit that did not have spacers revealed the residue in Figure 1. Masking the component prior to washing proved sufficient to avoid contamination. This did result in more “touch” time for product assembly, however.

BGA device: the problem with “weep” holes. The previous example focused on the presence of strong electrolytes in board cleaners leading to shorting conditions. More commonly, board cleaners do not contain such salts. For example, ethanolamine (an organic base) is perhaps the most common saponifier found in these products. While use of such cleaners can alleviate failures directly attributable to salt residues deposited by board cleaning, any aqueous solution, and even pure water, also can cause catastrophic failures if trapped in devices.

This example concerns a particular BGA device design that led to cleaner entrapment. Severe corrosion was evident in many of these devices as a result. Additionally, as the chemicals in the cleaner are hygroscopic (attract moisture from the environment), they represented a long-term reliability concern.

Figures 2 and 3 show the device construction. A central chip, topped with thermally conducting grease, is surrounded by capacitors and covered with an epoxy bound lid (take particular note of the “weep hole” – the top of the lid in Figure 3 – built into the design). Discussions with the manufacturer revealed the lid was placed over the device for mechanical support, while the weep holes (others not shown) were incorporated to vent gasses assumed created from soldering heat. It should also be noted the device in Figures 2 and 3 suffered from cleaner entrapment, which accounts for the overall appearance and presence of deposits. In this case, the cleaner is composed of 75% water and 25% cleaner concentrate.

As indicated in the images, cleaner entrapment led to deposit formation, which ultimately led to device failure. When the lids were removed from devices, in most cases, droplets of cleaner were obvious if the PCBs were less than about a week old. This created, in effect, a condition in which many of the exposed components were akin to being submerged in the cleaner.

In some cases, boards were not immediately powered up and as a result, components were permitted to dry significantly prior to use. In other cases, boards were powered up soon after production; the applied voltage in this environment led to some interesting phenomena. For example, selective electromigration of the metals in the solder (SnPb) was evident between many capacitors. As well as causing corrosion, this led to leakage pathways.
Figure 4 depicts two distinct phenomena related to board cleaner exposure: corrosion of copper under the solder mask leading to blistering, and electromigration of metals between the capacitor leads. In Figure 4, the dark side of the capacitor is lead rich, lead corrosion products forming the black color, while the brighter side is tin rich. (Scanning electron microscopy/energy dispersive spectroscopy analyses were employed.) Copper is also observed over much of the capacitor. This phenomenon was more pronounced in boards that were electrically tested soon after exposure to board wash.

While electrically testing components submerged in cleaning solution creates obvious failure scenarios, long-term reliability is also a concern in this case. Analysis of the failure mechanisms revealed the following sequence of events occurs with these devices:

1. Water wash is entrapped after entry through the weep holes upon exposure to board cleaning. This is not removed by DI rinse for reasons mentioned.
2. Native no-clean flux mixes with the wash solution, forming gelatinous residues concentrated around the capacitors. (The capacitors were soldered using a rosin-based no-clean flux by the supplier.)
3. The more volatile components of the cleaner evaporate over time (the base saponifier, an organic alcohol, and some of the water).
4. Nonvolatile components of the cleaner remain indefinitely.

The initial phases, when the more-corrosive components of the cleaner are present, can lead to extreme corrosion (Figure 5), even without powering on the devices. Corrective actions, including instituting post-clean bakes, removing the lids, etc., have proven to mitigate these issues; however, long-term consequences of this exposure are still worrisome.

Figure 5 is illustrative of a COTS issue faced by military customers that use board-cleaning operations. Discussions with the supplier revealed that, to their knowledge, we were the first customer to experience such failures. This resulted from the fact that none of the other customers, which are overwhelmingly commercial, exposed these components to board washing. Interestingly, a military build was available from this supplier that would have avoided this issue; however, it was not yet available in the BGA models employed for the projects in question.

These examples illustrate typical problems associated with insufficient removal of board cleaner components from assemblies post-processing. While such issues are certainly not new, they are increasingly becoming a point of concern in military applications. This results from the trend of increasing use of COTS parts designed for no-clean commercial assembly procedures. 

W. John Wolfgong, Ph.D., is a chemist at Raytheon Network Centric Systems (raytheon.com); wolfgong@raytheon.com.

Designers,” the former chief technology officer of a Tier I EMS company once told me, “are lazy.” Then he laughed, adding he knew this from experience, as he once was a designer.

What I’ve come to understand is that while “lazy” makes for a good punch-line, what he probably meant was designers are a risk-averse crew. They find something that works – a particular component, a land pattern, a finish – and stick with it.

That holds true for choosing their board suppliers, too. When I was editor of Printed Circuit Design (now Printed Circuit Design & Fab), we polled subscribers on the number of board shops they used and how likely they were to stick with them. (These generally were for quickturn jobs; when programs ramp to volume, purchasing takes over.) The former figure was typically two to four, depending on the complexity and number of part numbers. The latter figure was something slightly longer than forever, provided the fabricator kept pricing in line with competitors and maintained good on-time delivery.

Even in a recession, it’s hard to shake individuals from their established ways. Whether the number of new program starts has slowed – and it’s been hard to get a handle on this, as all anecdotal evidence and public company reporting points down, but Digi-Key vice president of Semiconductor Products Dave Doherty in late September told me that the distributor has seen no drop in the number of new designs – design engineers seem more committed than ever to stick with the tried and true. A recent IPC data point suggested 75% of the total final PCB cost is driven by decisions made at the design level. With unemployment spiking, why put company profitability – and your own job – on the line by trying something unproven?

Except that sometimes something comes along that couples best practices with known good supply. A bevy of leading suppliers have since April been formally developing a new model for an end-to-end PCB design, assembly and test solution. This group, which includes a small number of software companies, component manufacturers and distributors, PCB manufacturers and assemblers, believes the design process has a staggering impact on end-product development and time-to-market, and by helping design engineers take into account all the pertinent information for a specific type of product, they can shave weeks off the average build cycle.

Calling their model the ECOSystem, this group of suppliers insists the bane of time-to-market – re-spins – causes, on average, a delay of 1.5 to 2 months per spin.  

Moreover, it’s not just the number of spins but the reason behind them that begs for salvation. a “Many designers think in 2-D, but the board is 3-D, so we see many re-spins due to dimensional interference,” says Vince Accardi, general manager of National Instruments, another partner. Adds ECOSystem member Jim Scholler, vice president of technology at EMS company MEC, “I want the design engineer to know whether the PCB meets his proof of concept. What I don’t want is bad data – not incorporating manufacturing knowledge into the design. Spins that are done quickly and show the possibilities of an NXP [yet another ECOSystem member] chip are good.” That acknowledgment doesn’t even begin the discussion on cost savings due to yield improvements.

This month, the partners roll out the latest integration, adding instant online quoting and ordering of prototype bare boards and assemblies in one spot (sunstone.com). This move takes the concept to a much more useful level. The roadmap also calls for NI suite order integration, parts definition testing, and the addition of reference designs, among other capabilities.

It’s almost a return to the days when the vertically integrated OEMs like IBM and Digital Equipment did everything in-house. In the next wave, most processes were outsourced. As product build took place farther from design, walls grew up – some geographical, some virtual. The ECOSystem tries to pull all the various parts and processes back into a single, common platform. Knowledge about everything from design for manufacturing and test to component selection and pricing is embedded into that platform. The difference is now the coordination among the suppliers comes with best practices for design, fabrication, assembly and test, honed by years of competition on the open market.

I’ve mentioned several of the partners: MEC (and its assembly quickturn prototype subsidiary, Screaming Circuits), NI, NXP and Digi-Key. Others include Altium, CadSoft, Stilwell Baker and Stratford Digital. But orchestrating the band is PCB fabricator Sunstone Circuits. By far the smallest company of the cabal, it is Sunstone that had the vision to create this new model. The goal is simple. As Sunstone CEO and president Terry Heilman humbly puts it: “We hope we are breaking down the walls.”

The ECOSystem partners rolled out the concept last April. I’ve held off on commenting on it until now because I felt the actual functionality didn’t yet match the potential of the concept. While I know from experience efficiency is a hard-won pursuit, it strikes me that the timing now aligns with the capability of what this small band of suppliers is offering. If you haven’t checked it out, I’d suggest taking a few minutes to do so.