Connecting for speed and density

It’s no secret that both the operating frequency and density of electronic components in systems is constantly increasing. These increases place a demand on interconnect companies to come up with smaller products that none-the-less can carry high-speed signals without letting them interfere with other waveforms. At the recent DesignCon meeting in Santa Clara, CA, a solid example of the interconnect industry’s response to these demands was seen in the 28-Gb/s-plus Z-Ray micro array interposers from Samtec (www.samtec.com).

Samtec's Z-Ray interposers

An ultra-low-profile (1.00-mm) solution for board-to-board, cable-to-board, and complex-IC-to-board applications, the highly customizable Z-ray interconnects consist of high-density arrays (up to 1,200 contacts / in.2) of micro-formed 0.80- and 1.00-mm-pitch BeCu contacts on an FR4 substrate. The interposers are available in a variety of standard and custom configurations, including dual compression, and solder ball, and offer a choice of fastener options, including application specific designs, screw downs, quick install (easy on/off), and thermal spreaders.

Another company providing high-speed solutions is Micro-Coax (www.micro-coax.com). At the show the company was exhibiting coax cables as thin as ordinary wire. The company, which cut its teeth on military contracts, can now offer its products for commercial applications that require the same sort of robust, high-frequency, high-density interconnects. Of particular interest is its Aracon shielded cabling line, which can be provided in ribbon form. The cabling is up to 40% lighter than shielded coax and 80% lighter that braided EMI shielding.

Molex (www.molex.com) also demonstrated a high-speed interconnect at DesignCon, one it had worked on with Avago. Referred to as a Nano Pitch I/O Pluggable technology, the connector was demonstrated in a QSFP form factor to create a one-meter link between Avago boards. The link was able to support serial data rates of 32 Gbit/s (128 Gbit/s quad).

Molex's Nano Pitch I/O connector

Combined with the company's IT3 and IT5 series high-speed mezzanine connectors, Hirose Electric’s (www.hirose-connectors.com) IT-P Series board-to-board power pin connectors consist of three pieces: a mating receptacle, an interposer, and a mounting receptacle. The wide range of variable height interposers offered permit board-to-board stack heights ranging from 13.5 to 44 mm. Combining high-speed differential and single-ended signaling with power, the series offers a current rating of 60A, and features multiple contact points between the receptacle crown contacts and interposer pins. The receptacles are equipped with a latching mechanism to hold the interposers securely in place, and are keyed to prevent incorrect assembly.

TE Connectivity's STRADA Whisper system

TE Connectivity’s (www.te.com) DesignCon exhibit included its STRADA Whisper backplane connection system. Designed for high-performing, high-bandwidth systems, the interconnect can transfers data 25 Gb/s, and offers scalability up to 40 Gb/s. The connection system’s performance is achieved using signal contacts arranged horizontally in high-speed differential pairs for zero skew; each differential pair is surrounded by six ground connection points. The connector allows for 1.5-mm mating separation (between both the ground and signal) through a patented C-shaped, 360-grounding design, which includes an extra “orphan” shield at the bottom of the horizontal stack of contacts for complete shielding.