Wern-Shiarng Jou

Effective electromagnetic shielding of plastic packaging in low-cost optical transceiver modules

A low-cost plastic package of the standard 1 /spl times/ 9 type with effective electromagnetic (EM) shielding ability is developed. Optical transceiver modules with transmission rates of 155 Mb/s and 1.25 Gb/s are tested to evaluate the EM shielding against emitted radiation from the plastic packaging. The results show that the packaged optical transceiver modules exhibit shielding effectiveness (SE) of over 20 dB. The EM shielding properties of plastic materials consisting of nylon66 and liquid crystal polymer (LCP) with carbon fiber reinforced are investigated. The effects of weight percentage of fibers, carbon fiber length, and material thickness on the SE of the plastic composites are studied both from the plane-wave and near-field sources approaches. The packaged plastic optical transceiver modules with their good SE are suitable for use in low-cost and low electromagnetic interference (EMI) Gigabit Ethernet lightwave transmission systems.

High-Performance Electromagnetic Susceptibility of Plastic Transceiver Modules Using Carbon Nanotubes

A high-performance electromagnetic susceptibility (EMS) of plastic transceiver module using carbon nanotube (CNT) composites is proposed. The shielding effectiveness (SE) of the CNT composites increases as the weight percentage of the CNTs increases. The SE of CNT composites with 50% weight percentage CNTs exhibits 38-45 dB. The EMS performance is experimentally evaluated by the eye diagram and bit-error-rate test for a 2.5-Gbps lightwave transmission system. The results show that the eye diagram and power penalty caused by the radiated interference of the plastic transceiver modules are dependent on the EMS. The plastic transceiver modules with the more weight percentage of the CNTs exhibit a higher SE, and hence show effective EMS performance, a better mask margin, and a lower power penalty. The likely cause for effective EMS performance with higher weight percentage CNTs of the plastic transceiver modules is due to the high-aspect ratios of CNTs, more structural to form overlapping conductive networking to provide high SE. Therefore, the CNT composites with their high SE are suitable for packaging high-performance EMS optical transceiver modules used in fiber to the home (FTTH) lightwave transmission systems

High electromagnetic shielding of plastic package for 2.5-Gb/s optical transceiver modules

A lightweight, low-cost plastic package for a 2.5-Gb/s optical transceiver module, that also has good electromagnetic shielding properties, has been fabricated using woven continuous carbon fiber (CCF) epoxy composite. The shielding effectiveness (SE) of the CCF epoxy composite has been modeled theoretically and measured from 500 MHz to 3 GHz using the ASTM D4935 and a near-field test method. Two types of weaving patterns were studied: a balanced twill structure (BTS) and a parallel structure. The BTS was able to achieve an SE of about 80 dB under plane wave conditions and about 50 dB under near-field conditions because of the numerous conductive between crossing fibers. The SE of the proposed package is at least 20 dB greater than the previous package which used a liquid crystal polymer composite. In addition to better shielding performance, the proposed package costs less because it uses less carbon fiber. The proposed package for an optical transceiver is suitable for use in a low-cost lightwave transmission system

High Electromagnetic Shielding of a 2.5-Gbps Plastic Transceiver Module Using Dispersive Multiwall Carbon Nanotubes

A novel polyimide film, consisting of finely dispersed multiwall carbon nanotubes (MWCNTs) in an ionic liquid (IL), is demonstrated to be high shielding effectiveness (SE) for use in packaging a 2.5-Gbps plastic transceiver module. The IL-dispersed MWCNT composite exhibits a high SE of 40 ~ 46 dB. By comparison, the composite fabricated by nondispersive process requires a higher loading of MWCNTs at 50 wt- % than the IL-dispersed process at only 30 wt-%. The electromagnetic susceptibility (EMS) performance is experimentally evaluated by the eye diagram and bit-error-rate for a 2.5-Gbps lightwave transmission system. The package housing fabricated by the dispersive MWCNT composites shows an enhanced EMS performance, an improved mask margin, and a lower-power penalty. These results indicate that the IL-dispersed MWCNT composites are suitable for packaging low-cost and high-performance optical transceiver modules used in the fiber to the home lightwave transmission systems.

Electromagnetic Shielding Performance for a 2.5 Gb/s Plastic Transceiver Module Using Dispersive Multiwall Carbon Nanotubes

Electromagnetic (EM) shielding performance for a plastic composite by employing polyimide-based dispersive multiwall carbon nanotubes (MWCNTs) is presented. A well-dispersed MWCNT composite offers a higher electrical conductivity with a lower weight percentage of MWCNTs. The dispersive MWCNT composites with their high shielding effectiveness (SE) are suitable for packaging low-cost optical transceiver modules used in fiber to the home (FTTH) lightwave transmission systems.

A low-cost plastic package for 2.5Gbps optical transceiver module with high electromagnetic shielding

A high electromagnetic shielding, light weight, and low cost plastic package for a 2.5 Gbps optical transceiver module is developed by using a woven continuous carbon fiber (CCF) epoxy composite. The shielding effectiveness (SE) of the packaged optical transceiver modules is measured and theoretically modeled. By weaving the CCF in a balanced twill structure (BTS) with excellent conductive networks, the SE of the proposed package is significantly higher (about 20 dB) than a previous package using a liquid crystal polymer (LCP) composite. Besides better SE performance, the package is lower cost due to reduced usage of the carbon fiber. The proposed package for the optical transceiver module is suitable for use in low cost and low electromagnetic interference (EMI) lightwave transmission systems.

Effect of carbon-fiber orientation on the EM shielding for the plastic laser module packages

Electromagnetic shielding of nylon66 and liquid crystal polymers (LCP) applied to laser modules package was studied. Carbon fiber was used in being filled in nylon66 and LCP to improve shielding effectiveness (SE). The optic laser module is packaged in the composite materials with different carbon fiber orientations and their electromagnetic Interference (EMI) performance is measured in the 3m EMC chamber. The results show the orientation of the carbon fiber filled in LCP plays a key role to improve the shielding effectiveness of the composite materials.

Shielding effectiveness of multi-wall carbon nanotube composite

A novel polymer-based multi-wall carbon nanotubes (MWCNT) with high shielding effectiveness (SE) is proposed. The MWCNT composites are tested to evaluate the electromagnetic (EM) shielding against emitted radiation from the plastic packaging. The results show that the SE of MWCNT composites exhibit 38-45 dB in far field and 28-40 dB in near field at a frequency range of 1 to 3 GHz. The MWCNT composites with their good SE are potentially suitable for use in low-cost optical transceiver modules with low electromagnetic interference (EMI)

Electromagnetic shielding of plastic material in laser diode modules

Electromagnetic shielding of plastic materials in laser modules was studied experimentally and theoretically. The conductive carbon fiber fillers into plastics to produce electrically conductive composites were proposed for the evaluation of electromagnetic interference (EMI) shielding effectiveness (SE). The different volume fractions of conductive carbon fiber fillers ranging from 5, 10, 20, and 30% were used. The SE of conductive plastics was measured to be 45 dB at the low frequency of 30 MHz and 60 dB at the high frequency of 1 GHz. The measured results are in good agreement with the calculated results. The laser modules have a transmission speed up to 622 Mb/s and more than 1 mW fiber output power. With these excellent SE and good optical characteristics, plastic MiniDIL laser modules are suitable for use in low-cost OC-12 lightwave transmission systems.