2007: The Year of the Backplane
By Bob Hult, Bishop & Associates Inc.

Evolving backplane and midplane connectors incorporate some of the most advanced technology currently being applied within the connector industry today. For the past few years, flagship products, including Z-Pack HM Zd from Tyco Electronics, GbX from Amphenol TCS, and AirMax VS from FCI Electronics, fought for position in the high-speed/high-density backplane arena. An escalation in the race for supremacy in this market segment has been evident throughout 2007, as four leading contenders have announced a continuous stream of new products that push the limits of both bandwidth and signal density. The opening salvos occurred at DesignCon 2007, where two new connectors were announced.

Molex has participated in the high-speed backplane connector market as the second source to several Amphenol TCS connectors, including HDM, VHDM, VHDM-HSD, and GbX. They have aggressively marketed and supported these products with a series of backplane evaluation boards, allowing customers to measure high-speed connector and channel performance under a variety of conditions.

In February, Molex introduced the I-Trac™ family of connectors, which feature a shieldless broadside-coupled design that is rated to 12.5 Gb/s. This connector features skew equalization and excellent impedance control, along with reduced crosstalk. I-Trac is an example of the trend to offer a complete system-wide solution with a variety of packaging options, including a right-angle male for coplanar applications and a vertical receptacle for mezzanine boards. Reverse gender components are also part of the family.

Increased market interest in orthogonal midplane applications can be addressed by using the same backplane components to achieve this configuration.

Amphenol TCS and Molex recently announced a cross-licensing agreement that will result in Amphenol TCS offering an identical second source I-Trac product pending the resolution of current litigation with FCI Electronics.

Also at DesignCon 2007, Amphenol TCS broke new ground by being the first to introduce a backplane connector rated to 20+Gb/s.

 

The XCede™ connector platform provides a clear long-term migration path for customers who are designing equipment that is expected to evolve over many years with successive levels of performance. XCede connectors incorporate unique 3D shielding structures to damp resonances within the connector, as well as modifications to the plastic housing to de-skew differential pairs. It offers exceptional signal density of up to 82 differential pairs per linear inch of board edge. The XCede PCB launch has been optimized through the optional use of shorter compliant pins and dual-diameter vias, which can reduce return losses.

Amphenol TCS recently announced a cross-licensing agreement naming FCI Electronics to be the qualified second source for the XCede connector. A prior agreement gave Amphenol the ability to second source the AirMax VS connector developed by FCI Electronics.

During the summer months, Tyco Electronics modified its Z-Pack Max connector to include internal shields and reintroduced it as the TinMan connector family.  This connector is intermateable and functionally identical to its Z-Pack Max predecessor, and is being promoted for all new applications.

This cost-effective backplane connector system is offered in three, four, and five differential pair configurations, and has a reported bandwidth of 10+ Gb/s. Right-angle pin headers are also available to support co-planar applications.

An orthogonal midplane version of TinMan is also available and rated to 25 Gb/s.
 

In early October, Molex and Tyco Electronics issued a joint announcement of second source agreements that allow Molex to manufacture and sell the Tyco TinMan connector, and Tyco to be the second source for a new Molex interface named Impact™. The Impact connector combines the features of high-speed and increased signal density.

The physical size of backplane connectors is becoming a major concern to system packaging engineers who must cram greater system functionality into reduced space. A lower profile connector, that consumes less PCB real estate, is very attractive from electrical performance as well as thermal management perspectives. Impact addresses customer demand for high-speed, greater density, and high pin-count backplane connectors. This interconnect family utilizes internal shields to achieve 25 Gb/s performance in three, four, five, and six-pair configurations, and offers two optional compliant pin sizes as well as a series of compatible power modules.

The emphasis on packaging density was highlighted again in mid-November with the introduction of the ZipLine™ backplane connector family from FCI Electronics.

Designed to support backplane speeds of up to 12.5 Gb/s, ZipLine connectors can provide up to 101 differential pairs per linear inch at 1.5mm column pitch. This shieldless interface is currently available in a six-pair/column version with a three-pair version to be tooled next.

Responding to demand for connector systems that offer complete system solutions, the ZipLine family includes power modules, as well as the ability to add power wafers to signal connector assemblies.

 A six-pair orthogonal midplane configuration of ZipLine is also available.
 

FCI Electronics and Amphenol TCS have agreed to cross-license the FCI ZipLine, and the Amphenol TCS XCede and Crossbow connectors, assuring identical second sources for all three products.

The most recent entry to this competitive market is the Z-Pack Slim UHD™ connector from Tyco Electronics. This modular connector is specifically designed for high-density 15mm (0.6 inch) card slot pitches. Each eight-contact column can be configured to balance signal speed up to 12.5 Gb/s, with density of up to 55 pins/cm². This open pin-field connector is easily adaptable to single-ended, as well as differential signaling applications. The PCB footprint on both the backplane and daughtercard are identical.

 

Bishop & Associates Comments: 

• The market for high-speed/high-density backplane connectors is now dominated by four leading manufacturers: Amphenol TCS, FCI Electronics, Molex, and Tyco Electronics.

• The latest product introductions designed to compete in this product segment are focused on addressing three major market demands: 1.) High-speed; 2.) High-density; and 3.) Viable second sources.

• Backplane connectors designed to perform at speeds of up to 20+ Gb/s are now being introduced to demonstrate a long-term migration path. Designers are assured that connectors currently being designed into circuits operating at four to six Gb/s will be capable of supporting much higher speeds planned for future generation products. It may be several years before commercial silicon chips that operate at 20+ Gb/s will be available on the market. Offering 20+ Gb/s connectors now positions a supplier for consideration on long-term projects.

• Backplane connectors designed for multi-gigabit channels require much more than second sources that are mechanically intermateable. Recently announced cross-licensing agreements allow sharing of detailed intellectual property to assure that connectors from designated second sources will perform identically in high-speed channels. This sharing of design and manufacturing detail is unprecedented in such a highly competitive market, but reflects an absolute requirement of users. All major high-speed connectors currently on the market have announced second sources.

• System packaging density, rather than higher speed, is emerging as a more immediate need for system design engineers and is being addressed by the flurry of new backplane interfaces that feature reduced centerlines. Many of these new connectors feature electrical performance similar to existing flagship interfaces, but consume less volume.

• Although considered a niche design, orthogonal midplane architecture continues to generate interest among packaging engineers. Connector manufacturers often include an orthogonal interface option as an integral part of new backplane connector family offerings.

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.