Backplane Sources Shifting
By Bob Hult, Bishop & Associates Inc.

As the market for high-speed backplane connectors matures, connector manufacturers are shifting their backplane sourcing strategies.

When backplane speeds approached and passed the one Gb/s threshold, system design engineers recognized the need for a greater level of design and fabrication support from their connector vendors. The concept of signal integrity was new to the industry, and relatively few designers had much practical experience in modeling multi-gigabit low-voltage differential circuits. Printed circuit board design and layout rules that had worked for years were questioned and concerns about the use of exotic PCB materials, as well as advanced assembly processes, caused OEMs to scrutinize the capabilities of their backplane vendors.

In the process of designing and tooling next-generation high-speed connectors, leading manufacturers had developed extensive modeling and simulation experience, as well as understanding of the influence of each element in the high-speed channel. This created an excellent opportunity to share their application expertise with prospective connector users, and establish deep, long-term, engineer-to-engineer relationships at the earliest stage of new product development, a very fertile period for interface selection.

Many OEMs make their connector selection at least partially on the availability of support resources from their vendors, a relationship that tends to continue to the next generation of equipment. Of the four current industry leaders in high-speed backplane connectors, all offer extensive design services in support of their individual products. Design engineers are able to access a variety of resources, including access to 3-D connector models, a matrix of simulation results, noise analysis, footprint recommendations, routing guides, counterboring recommendations, as well as product evaluation test boards.

One-on-one consultation is also available to discuss the characteristics of a specific application on an individual project. Amphenol TCS provides a library of design tools, which are available by subscription on the web. The need to maintain this level of technical support will remain as system speeds continue to ratchet up.

The philosophy of taking the project to the next step by providing the capability of building prototype and production backplanes is changing. When multi-gigabit systems were new, it was thought by some connector suppliers that offering a complete turnkey package of concept, design, simulation, verification, and production would offer the greatest value to the customer. A single point of responsibility for design success could reduce risk and assure the designer that the system will perform to specification at the first iteration, thus reducing the critical time-to-market mandate. The connector supplier could offer quick turnaround of prototype boards for design verification with the hopes that production orders would follow.

Some connector suppliers additionally offered complete sheet metal card cage design and assembly, including fan trays and power supply modules, as a one-stop system solution.

This strategy was initially successful, but has since declined as Asian-based PCB fabrication skills and capacity have dramatically increased. OEM designers continue to utilize domestic board shops for prototypes and pre-production, or they can build their own boards internally using an increasing array of bench-top equipment. It appears that as OEM designers have gained experience and confidence in designing gigabit circuits, the linkage between connector supplier design support and backplane production is breaking down.

Customers are changing their sourcing strategies to align with the massive transition of electronic manufacturing to Asia that has been occurring at an accelerating rate for the past 10 years. Engineers continue to utilize the design resources of their chosen connector supplier, but once the board is finalized, the priority becomes best price, opening the opportunity to both domestic and off-shore board shops. Once considered inferior, Asian PCB fabrication skills are now rated at least equal or superior to those found within the U.S., resulting in the migration of production contracts. In this scenario, the OEM assumes responsibility for insuring that the material selections, dimensions, tolerances, layout, and process control resulting from the collaboration with the connector vendor is meticulously followed.

Today, the four high-speed backplane connector leaders have chosen a variety of approaches to providing complete backplane assemblies. Amphenol TCS has an extensive PCB fabrication capability based in New Hampshire. Their primary focus of military and aerospace applications allows them to address the most stringent requirements in both materials and assembly techniques, which are available to commercial customers. Molex has no internal PCB fabrication capability, but will partner with a selected vendor to build custom boards, then internally apply their connectors to offer a completely tested assembly to the end customer. They are focusing their production capability on custom assemblies based on an industry standard, such as Micro TCA assemblies. Tyco Electronics had an entire division dedicated to the fabrication and stuffing of PCBs, which included sheet metal enclosures and fan trays, but sold these assets to TTM in the fall of 2006. Both Tyco Electronics and FCI Electronics will partner with outside PCB fabrication shops, but have chosen not to maintain an internal capability.

This evolution has widened the opportunity for additional PCB vendors to enter the market. Global contract manufacturers, such as Sanmina-SCI and Jabil Circuit, as well as ELMA and Schroff, offer extensive design and manufacturing resources. These are well-established suppliers with extensive reputations for quality. Most maintain PCB fabrication and assembly in multiple locations, including Asia.

Sensing an opportunity in the market for standards-based backplanes, HARTING is expanding its high-speed backplane design and assembly capability.

The Harting Integrated Solutions (HIS) organization has enhanced its signal integrity resources and can offer a complete menu of engineering design support capabilities, including design, layout, modeling, simulation, validation, as well as assembly, inspection, packaging, and delivery of the completed system. Backplanes, as large as 33” X 16”, with up to 28 layers, have been built. Components can be attached to the backplane using press-fit, pin-in-hole reflow, or surface mount technology.

Utilizing partnered PCB fabrication and sheet metal resources, HARTING is focusing on the rapidly expanding market for “custom” backplanes based on a standard such as Advanced TCA, Micro TCA, AMC, VME, and others. HIS has created three assembly and test facilities located in Elgin, Illinois; Northampton, England; and Zhuhai, China. All are HARTING-owned facilities, each with identical equipment and processes. HARTING has made a major investment in state-of-the-art high-speed test equipment and experienced personnel to insure signal integrity, and can now offer characterization of backplanes, S-parameter simulation, and performance verification.

In addition to these resources, HARTING Central Technology Services can perform environmental and mechanical testing, as well as conducted and radiated electromagnetic compatibility measurements.

Backplanes produced in any of these plants are indistinguishable from those built in another plant, providing greater customer flexibility in delivering the final backplane exactly where it is needed. The intent is to offer the most efficient and cost effective mix of partners and internal resources to address the needs of each customer in terms of local sourcing, convenience, reliability, and speed of delivery. Although they prefer to utilize HARTING connectors, they will build backplane assemblies using connectors from any specified manufacturer.

HARTING is targeting small to medium-sized OEMs with an integrated interconnect solution that features PCB design and production of backplanes based on industry standards, exceptional signal integrity resources, and a global production footprint. Mining this niche may prove to be a successful strategy in a crowded and highly competitive market.

Competition for backplane assemblies that are variations of an industry standard has become fierce, as OEMs increasingly adopt the economic and time-to-market advantages that standards-based systems offer. Successful backplane assembly suppliers must offer global access to advanced design, simulation, and production resources to provide the flexibility and low cost demanded by designers of next-generation equipment.

 

Bishop & Associates Comments

• OEM designers have developed internal expertise in the design and simulation of high-speed circuits.

• Connector suppliers are expected to provide accurate 3-D simulation models, as well as help in interpreting the results of circuit simulations.

• The connection between design support and backplane production orders has been reduced as price pressure forces OEMs to shop the market for the lowest price.

• Many of the leading high-speed connector suppliers have limited their emphasis on pursuing backplane assembly business.

• A collection of global contract manufacturers, backplane assembly specialists, as well as a host of small PCB shops, are competing for the growing market for “custom” hybrid backplanes based on an industry standard.

• Harting has recently beefed up their commitment to the production of high-speed backplanes by expanding their signal integrity, design, and manufacturing resources on three continents. Their long-term focus on industry standard connectors gives them market recognition among a crowd of suppliers attempting to serve this growing segment.

Robert Hult
Director of Product Technology, Bishop & Associates, Inc.
Robert Hult has been in the connector industry for over 36 years. Hult began his career as a sales engineer for Amphenol. He joined AMP in 1972 and served in several management positions through 1996. In 1997, Hult joined Foxconn as group marketing manager for Intel, Chandler, Arizona, U.S.A. Prior to joining Bishop & Associates, Hult was the regional application engineering manager for Tyco Electronics.

Hult graduated in 1968 from Bradley University with a Bachelor of Science degree in electronics technology and a minor in business.