A new series of 0.40mm (.016”) pitch Micro Coax connectors from Molex offers space savings and improved signal integrity for mobile device applications. The Micro Coax system was initially designed to run signaling through the hinge area of new swivel-type cell phones that have rotating LCDs. Previously FPC cable was used, but proved unable to withstand the bending and twisting needed to maneuver through tightly-packed hinge-style applications. The Micro Coax system is now finding use in other portable applications that require flexible circuit routing, shielding, higher speeds and space savings.
A core feature of the new Micro Coax system is the Insulation Displacement Technology (IDT) method used to terminate the ultra-thin 42 AWG coaxial cable. Molex was the first company in the world to utilise IDT termination technology with coaxial cable on a pitch as small as 0.40mm (.016”). Other 0.40mm pitch coaxial connector systems use traditional hand-soldering termination, which is less precise and reliable than automated IDT termination. In addition, some other systems utilize unshielded discrete wire, but this does not address the need for noise protection and high speed in a growing number of handheld applications.
Another distinguishing feature of the Molex Micro Coax system is its patented “double-clamp” wire grounding method. Unlike traditional hand soldering methods that lay a solid ground bar across all wires, the Molex double-clamp method places a grounding/retention feature between each tiny coaxial wire. A second retention clamp bites into the cable insulation for firm mechanical wire retention. This double-clamp method offers several key benefits over solder-bar types, including: avoidance of hardened wires and wire pull out; up to 30% diameter space savings; consistent grounding between circuits and the shell; better prevention of signal skew; and up to 60% less transmission (dB) loss at frequencies of between 1-3MHz.
The high-speed signal carrying capabilities of Micro Coax make it a suitable replacement for both FPC and board-to-board connectors in certain applications. For instance, a 40-pin Micro Coax connector could replace a 100-pin board-to-board version, saving up to about 30% of space while using 60% less signals and tracing lines.
Along with the IDT connector, the Micro Coax system also includes shielded top-entry and right angle SMT PCB receptacles. These compact connectors include grounding springs and a very short grounding path. Combined with the systems’ double-clamp grounding method, these additional shielding features provide consistent impedance control and high-frequency characteristics. This results in superior signal integrity compared to competitive designs. Other features of the PCB receptacles include gold-plated leaf-style contacts for reliable repeat cycling, long wipe length for good electrical contact, and friction locks for secure mating retention. The right-angle version offers a low-profile height of 1.50mm (.059”), while the top-entry version has a mated depth of just 3.94mm (.155”).
The system is rated at 0.2 amps and 30 volts. Connectors come in embossed tape packaging, while cable harnesses are offered in several standard variations and lengths. Cable assemblies are produced in-house and provide up to 65% higher cable harness output compared to hand-soldering termination assembly. Insertion and extraction tools are available to assist in assembly.