Review

As sure as night follows day, interconnects follow semiconductor advances in speed, density, size and other parameters. Further, interconnects play on the leading edge of standards such as PCMCIA, Bluetooth and USB. So it is not surprising this year to see a bevy of exciting new products.

High-speed connectors nowadays need to perform at rates of 10 Gbps or higher—tricky business for connector companies. But several of these devices made it to market this year. For example, MOLEX (molex.com) introduced the Plateau HS Mezz mezzanine connector line. It employs a plated plastic housing that enables the connector to support differential data rates in excess of 10 Gb/s. The housing also includes full shielding of each pair of differential contacts.

High-density interconnects attempt to squeeze more and more into less and less. An example of the progress made on this front this year is the thin-film, single- and multi-layer high-density interconnects (HDIs) from Vishay Electro-Film (vishay.com). The HDIs integrate conductor patterns and other passive components to form low-noise products with enhanced signal routing and response conditioning characteristics. Because multi-layer HDIs are built up rather than out, they can achieve dimensions as small as 0.02"x 0.02". They can also be made as large as 4" x 4", with thickness ranging from 0.005" to 0.050". Another example of an HDI is a line of nano-miniature interconnects from Airborn (airborn.com). These were developed for use where reliability must be maintained in critical environments and where extremely small size and light weight are required. The N-series high-density, dual-row connectors have ruggedized, polarized metal shells for board-to-cable, cable-to-cable, and board-to-board applications. The interconnects feature 0.635 mm pitch contacts side-by-side and 0.318 mm offset row-to-row, helping qualify the connectors for use in high-density packaging applications.

As standards change and evolve, such as PCMCIA, USB, and so forth, companies must produce a new generation of connectors that comply with the new specs. Such was the case this year. An example is the ExpressCard connector from Tyco Electronics (tycoelectronics.com). It addresses the ExpressCard product specification, which is the next-generation PCMCIA PC card. The connector is a beam-on- blade design that promises low-cost and reliable performance. The connector is compliant to the current specification Revision 1.0 of the Express Card Standard.

Another example is a vertical module connector from Molex that is designed to mate with memory modules complying with the 244-pin miniDIMM format.

Sockets and adapters have to keep pace with new technologies, too. For example, Emulation Technology (emulation. com) has developed production sockets and prototyping adapters for use with Ericsson's Bluetooth ROK 104 001 multi-chip module (MCM), a second-generation MCM that has a footprint 70% smaller than the original, ROK101 device. Used in products such as PDAs and cell phones, the SMT pc board sockets are designed to make insertion and removal of the Bluetooth modules easier. The adap-ters, in turn, are designed to be plugged into standard prototyping boards.

As far as cable assemblies go, the number of flex cycles is an important parameter. For instance, the W.L. Gore & Associates (gore.com) high-flex planar cables feature, among other things, a maximum life of over 100 million flex cycles. The planar cables are designed with specialty materials, including toughened polytetrafluoroethylene. The product combines non-outgassing materials with non-contaminating interconnects and can be used in Class 1 Clean Rooms and in mini-environments under vacuum.

—Joe Desposito

Outlook

Interconnect Challenges Abound
Interconnect manufacturers who play on the leading edge of electronics technology certainly have their work cut out for them. If you have read the October Interconnects Design Tutorials supplement of EE Product News, you have an idea of the complexity involved in designing for 10 Gpbs backplane systems. We expect to see breakthrough products for this application as well as innovative new designs for tackling the "space" problem in modern portable electronics.

Finally, will 2004 be the year when some connectors and wires go away altogether? Bluetooth technology is supposed to facilitate this transformation. It has been slow in coming, but we expect it to start making an impact in 2004.

—JD