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January 2006
High Performance Interconnect Systems For Mobile Communications
By Paul Carter, Whitney Blake
Advances in technology touch every manner in which we conduct our daily lives and nothing has become more important than clear, concise communications. Just as technology has driven advances in wireless communications and the expansion of communications networks, the need for high performance tethered product has expanded as well.
Modern battlefields are replete with electronics systems, radar signals and equipment generating an enormous amount of EMI (electro magnetic interference) which pose unique challenges for communications systems. Such hostile environments demand engineered products that provide a high degree of shielding effectiveness while maintaining high flexibility and long service life under rugged environmental conditions.
To execute their mission, today’s military personnel must have the best technology at hand. Increasingly important in today’s technology rich battlefield, are sophisticated mobile communication handsets and headsets.
The need for constant contact is not limited only to military applications. Life or death situations can hinge on the intelligibility of communication with police, fire and rescue personnel as well. Entertainment industry professionals also benefit from the use of handsets and headsets for security at concerts, sporting events and other public assemblies. Specialty cables utilized in extreme environments such as avionics and fire rescue require additional consideration for flame retardants and survivability under catastrophic conditions.
Defining the interconnect challenge
Many of today’s headsets and handsets rely on advanced interconnectivity solutions – connections designed to ensure that cable products deliver the most reliable and consistent data and power transfer. In robust environments where optimum performance is required, technology is the driver for product design. Today’s high performance applications have specific requirements related to data rates, shielding and flexibility requiring a broad scope of core competence to meet these requirements.
As communications equipment has become lighter and more portable a distinct need has developed for highly flexible cable, coiled cords and custom over molds. Specific design requirements must be achieved to yield a highly flexible yet durable product. Selections of conductor material, strand count, primary jacket compound, shielding and overall jacket each play a critical role in product performance. These materials must all work as a complete system, requiring that product design consider lay length and direction, jacket wall thickness, metal to plastic ratios and a number of other considerations in order to optimize performance.
It is not just the material selection, but the parameters used in manufacturing that impact results. The communications cable or coiled cord must be married to a connector system, through the development of an appropriate over mold utilizing specific materials to enhance performance. To achieve these results requires a vertically integrated interconnect supplier having cable design / manufacture, cable assembly and over molding expertise.
Interconnect Technology drivers
Today’s technology driven companies need cable systems (integration of cable, over mold and assembly expertise), rather than mere cable assemblies, to achieve the desired results.
Custom high performance communications applications require the expertise of a fully integrated engineering driven company, possessing the ability to produce both cable and cable assemblies, along with the technical expertise to design and produce custom over molds. Of primary concern is the need to maintain a very high degree of shielding effectiveness while providing a supple cable usually in the form of a coiled cord that will allow the user free range of motion.
High performance over mold design is the lynch pin between the cable and connector system. Design considerations include application mobility, operating temperature, mechanical requirements and compound compatibility with jacket materials, all playing a key roll in the success of the overall system. Shielded assemblies require special consideration to ensure that the shield remains contiguous throughout the mold.
Over molding can also provide environmental protection to the mated pair through the designed introduction of an interfacial moisture sealing ring. The seal rings inhibit the migration of moisture into the connector system, moisture that can affect the signal integrity and enhance corrosion. Over mold systems can also provide protection to the cable and equipment through development of systems that de-mate at designed pull strength. If excessive force is put on the cable, it will simply unplug rather than incurring the damages that usually result from a positive mating system.
Staying Flexible / Performance vs. Cost
Performance vs. cost consideration is a conundrum faced by all development engineers when considering product applications. Materials selection, driven by application requirements, plays a large part in driving cost.
A number of extrusion compounds can be used for insulation and jacket materials, each of which offers particular cost vs. performance trade offs. These materials are divided into two categories, thermoplastic and thermoset. Thermoplastics, such as PVC (polyvinyl chloride), polyurethane, and TPR (thermoplastic rubber) are resins that can be readily softened and reformed by heating and be rehardened by cooling. Thermoset materials, such as Neoprene and SBR (styrene butadiene) contain resin which cures by chemical reaction.
Within the thermoplastic group, the polyurethanes are most expensive. However, they offer better chemical and flame resistance than PVC’s and tend to provide better retractile properties for coiled cords. Although the thermoset products are more expensive to purchase and process, they offer outstanding chemical resistance. Additionally, when used in coiled cords, thermoset products exhibit more linear force to extend and they offer better retractile properties at elevated operating temperatures.
Other primary challenges for interconnect solution providers are shielding effectiveness and noise cancellation, which also come with performance and cost trade-offs. Shielding for retractile cords is performed using several different methods and materials, including the shielding individual wires, twisted pairs or groups of wires, and or the utilization of an overall shield. Common shielding materials include spiral served copper or copper alloy wires, laminated aluminum and copper tapes, braided copper or copper alloy wires, and semi-conductive thermoplastics.
Conclusion
Users of headsets and handsets count on clear reliable communications to maintain situational awareness and accomplish their missions. Manufacturers of these devices require the technical expertise of a fully integrated, engineering-driven manufacturer of high performance interconnect systems. Without this expertise, mobile communications products cannot be guaranteed as durable, lightweight, weather-resistant and reliable in the most severe operating environments.
About the Author
Paul Carter is a Vice President at Whitney Blake Company, an industry leader in the design & manufacture of custom cable, cable assemblies & custom over molds for high performance, high flex applications. Whitney Blake services include contract assembly and plastic mold injection utilizing its Mexican manufacturing capabilities. The company’s cable assemblies are used by OEM’s as a component in the manufacture of a variety of commercial and military communications, transportation, electronic data processing, medical electronics, durable goods and other equipment. In business since 1899 and incorporated in Vermont in 1985, Whitney Blake Company has ISO 9001:2000 certification and UL approval. For more information, contact Whitney Blake Company, PO Box 579, 20 Industrial Drive, Bellow Falls, VT 05101, USA; tel: 800-323-0479; email sales@wblake.com. Information is also available on the company’s website at www.whitneyblake.com.
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January 2006
Choosing the Right Interconnect Solution for Your Application
By Paul Carter, Whitney Blake
Today’s world population, although greater than ever, is also more connected than ever.
We are linked by satellite, Internet, fiber optic cables, and high tech communication cords. We transmit data and power in fractions of seconds, often not giving a moment’s thought about the sophisticated technologies that allow these transmissions to take place.
Many of the devices that keep us connected rely on advanced interconnectivity solutions – connections designed to ensure that cable products deliver the most reliable and consistent data and power transfer. The industries that rely on advanced interconnect solutions are almost endless in their variety and number.
With so many potential applications, and different types of interconnect solutions available, how do you know where to turn? What are the parameters that you should consider when you are selecting an interconnectivity product provider?
In the current marketplace, technology can be the differentiator in supplier selection. If your requirements fall into the commodity category, then price and off the shelf availability are typically the prime factors in supplier selection. If your needs are simple, there are thousands of potential suppliers who can meet those needs. If your application has specific requirements related to data rates, custom cable design, high flex assembly designs and over molding, the field of potential suppliers narrows significantly.
Entering the world of custom interconnect solutions requires a detailed analysis to find the right supplier capable of cost effectively filling your requirements. There are many companies that produce both commodity and custom cable, but do not possess the capability to provide cable assemblies. Other companies purchase the cable from these suppliers, providing the assembly services which sometimes includes over molding. These companies fill the niche of low technology interconnect solutions where applications are typically not performance driven.
Custom high performance applications require the expertise of a fully integrated engineering driven company, possessing the ability to produce both cable and cable assemblies, along with the technical expertise to design and produce custom over molds. Suppliers in this market place may differentiate into high speed interfaces such as high speed coax, SCSI (small computer system interface), or Infiniband technologies typically used for enterprise computer applications. Of primary concern, for these applications is the need to maintain as low a dielectric constant as possible, while providing improved signal performance at high frequencies with performance measured according to differential impedance and skew.
As electronics packaging has become lighter and more portable a distinct need has developed for highly flexible cable, coiled cords and custom over molds. Specific design requirements must be achieved to yield a highly flexible yet durable product. Selection of conductor material, strand count, primary jacket compound, shielding and overall jacket each play a critical role in product performance. These materials must all work as a complete system, requiring that product design consider lay length and direction, jacket wall thickness and a number of other considerations in order to optimize performance.
It is not just the material selection, but the parameters used in manufacturing that impacts results. The cable must be married to a connector system, with subsequent strength added, through the development of an appropriate over mold utilizing specific materials to enhance performance. To achieve these results requires a vertically integrated interconnect supplier having cable, cable assembly and over molding expertise.
Today’s technology driven companies need cable systems (integration of cable, over mold and assembly expertise), rather than mere cable assemblies, to achieve the desired results. Selection of a supplier with the core competence to meet your needs is a key ingredient for success. OEM’s sometimes move business to the lowest bidder, only to find out later that they received what they paid for (typically very little), and they are forced to deal with customer complaints driven by field failures.
High performance over mold design is the lynch pin between the cable and connector system. Design considerations include application mobility, operating temperature, mechanical requirements and compound compatibility with jacket materials, all playing a key roll in the success of the overall system. Shielded assemblies require special consideration to ensure that the shield remains contiguous throughout the mold.
Over molding can also provide environmental protection to the mated pair through the designed introduction of an interfacial moisture sealing ring. The seal rings inhibit the migration of moisture into the connector system, moisture that can affect the signal integrity and enhance corrosion. Over mold systems can also provide protection to the cable and equipment through development of systems that de-mate at designed pull strength. If excessive force is put on the cable, it will simply unplug rather than incurring the damages that usually result from a positive mating system.
Sophisticated product requirements demand specific company expertise to achieve cost-effective design solutions. Very low volume, high performance applications are typically manufactured in the United States; however, medium and high volume markets require companies with ready access to lower labor rates, typically found in Asia or Mexico. Companies with these capabilities are able to support your product through the entire product life cycle from design through full production, providing cost effective product from a consistent technology base.
As the world increasingly focuses on improving the environment, many government initiatives have been launched that are having sweeping impacts on industry. Today’s environmental directives, such as RoHS ( restriction of hazardous substances) and WEEE,( waste electrical and electronic equipment) are driving the industry to seek acceptable alternatives to restricted substances, while maintaining product performance for electronic applications. The ability to meet performance requirements and still achieve these environmental objects poses a great challenge for interconnect systems—particularly for highly mobile applications. The use of environmentally friendly solders and appropriate alternate alloy constructions is critical to compliance. An interconnect suppliers’ ability to perform a complete range of mechanical testing, including flex and extension testing, is imperative to qualify alternate designs.
Ease of supply chain management should be considered as part of the selection process as well. Interconnect suppliers that can support Kanban and EDI order replenishment systems ensure proper management of product inventory. Order replenishment support ensures timely product delivery while significantly reducing inventory and the cost of order processing.
Electro-mechanical contract manufacturing is another key offering to look for when choosing an interconnect solutions provider. The ability to support contract manufacturing provides additional benefits in the area of cost and supply chain management. Low cost manufacturing centers significantly lower over all manufacturing costs, ensuring a market competitive end product.
Regardless of your industry, there are certain specific product design parameters, and possibly a number of stringent environmental regulations to comply with. Nearly every industry—from medical to military to telecommunications—relies on advanced interconnect solutions everyday. There are four key capabilities that should be strongly considered as constants in your selection process: custom design and manufacturing, custom assembly, contract manufacturing and custom over mold. In today’s increasingly competitive marketplace selection of an appropriate interconnect supplier capable of meeting all your interconnect needs is more important than ever.
Paul Carter is Vice President of Sales &Marketing for Whitney Blake Company, a leading interconnect solutions provider. The company’s core areas of expertise include: custom cable design and manufacturing; custom cable assemblies; cord assemblies for "hi-flex" applications and custom over mold design and development. For more information please call 1-800-323-0479 or visit www.whitneyblake.com.
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