• Title/Summary/Keyword: WLP

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Relay-Based WUSB/DRD/WLP Cooperative Protocol Design in Ship Area (선박 내 Relay-based WUSB/DRD/WLP 연동 프로토콜 설계)

  • Lee, Seung Beom;Jeong, Min-A;Kwon, Jang-Woo;Lee, Seong Ro
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39C no.9
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    • pp.789-800
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    • 2014
  • In this paper, we propose a cooperative protocol of relay-based WUSB/DRD and WLP device in WSS of ship area WiMedia environment. For this purpose, we investigate a RNT table configuration and algorithm of RNS relay node used in relay-based cooperative communication. Then, we describe a device that makes up WLP network and propose a cooperative protocol for WUSB/DRD/WLP device communication. The proposed cooperative protocol can communicate with WUSB/DRD/WLP devices by using standard DRP reservation and WUSB DRP reservation.

A Bridge-Station Packet Marker for Performance Improvement of DiffServ QoS in WiMedia WLP-based Networks (WiMedia WLP 망에서의 DiffServ QoS 성능 향상을 위한 Bridge-Station 패킷 Marker)

  • Lee, Seung-Beom;Hur, Kyeong;Eom, Doo-Seop;Joo, Yang-Ick
    • Journal of Korea Multimedia Society
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    • v.13 no.5
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    • pp.740-753
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    • 2010
  • Performance of TCP can be severely degraded in WLP-based Mobile IP wireless networks where packet loss not related to network congestion occurs frequently during WLP-based inter-subnetwork handoff by user mobility. To resolve such a problem in the networks using WLP-based Mobile IP, the packet buffering method recovering seamlessly the packets dropped due to user mobility has been proposed. The packet buffering method at a bridge station recovers those packets dropped during handoff by forwarding buffered packets at the old bridge station to the WLP device. But, when the WLP device moves to a congested bridge station in a new WLP foreign subnetwork, those buffered packets forwarded by the old bridge station are dropped and TCP transmission performance of a WLP device in the congested bridge station degrades due to increased congestion by those forwarded burst packets. In this paper, a PBM(Packet Bridge Marker) is proposed for preventing buffered out-of-profile(OUT) packets from reducing the throughput of in-profile(IN) packets of an Assured Service WLP device. From this operation, the packet losses of buffered OUT packets are avoided and the throughput of IN and Total packets of an AS WLP device are increased.

Comparative Study on the Perceptions of Global and Korean HRD Professionals in Workplace Learning and Performance(WLP) Competencies (한국과 글로벌 HRD 전문가의 WLP 역량 인식 비교연구)

  • Kim, Young-Kil;Kil, Min-Wook
    • Journal of Digital Convergence
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    • v.10 no.6
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    • pp.99-109
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    • 2012
  • The purpose of this study was to scrutinize and compare the perceptions of Global and Korean HRD Professionals in Workplace Learning and Performance(WLP) competencies in Korea. To answer these questions, the following research methods were employed. A questionnaire, which was modified and translates from the 2004 ASTD model for WLP, was distributed to 319 HRD consultants working in Seoul and Kyounggi-Do. It was sent out directly and by email. Among returned questionnaires, 205 were valid to be examined. The important findings of the study were as follows. First, the role of business partner ranked highest in the level of importance of WLP roles in Korean and the role of special professional ranked highest in global. For the competencies of WLP, effective communication ranked highest both Korean and global. Based on the findings of this study, the conclusion was as follows. First, the perceptions of WLP roles were different between Korean and global HRD professionals. The reason why it's differences is because the size of market are different. Second, the perceptions of WLP competencies were similar between Korean and global HRD professionals. HRD professionals should need to professionalize the communication skills continuously.

Buffer Management for Improving Performance in WiMedia WLP-Based Mobile IP Networks of Ship Area (선박 내 WiMedia WLP 기반 Mobile IP 네트워크에서 성능향상을 위한 버퍼관리)

  • Lee, Seung Beom;Lee, Seong Ro
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.40 no.6
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    • pp.1208-1216
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    • 2015
  • In this paper, we use WiMedia WLP-based networks to meet the demand for IT services of a ship. If a mobile node moves to a congested base station of a new subnetwork, we will propose a scheme for improving performance of radio link of existing communicating mobile nodes. An old base station denotes packets stored during a handover. And, a proposed buffer management determines to discard the buffered packets in accordance with congestion degree at the congested new base station. Simulation results show that the proposed buffer management scheme improves link utilization in congested wireless links.

WLP and New System Packaging Technologies

  • WAKABAYASHI Takeshi
    • Proceedings of the International Microelectronics And Packaging Society Conference
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    • 2003.11a
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    • pp.53-58
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    • 2003
  • The Wafer Level Packaging is one of the most important technologies in the semiconductor industry today. Its primary advantages are its small form factor and low cost potential for manufacturing including test procedure. The CASIO's WLP samples, application example and the structure are shown in Fig.1, 2&3. There are dielectric layer , under bump metal, re-distribution layer, copper post , encapsulation material and terminal solder .The key technologies are 'Electroplating thick copper process' and 'Unique wafer encapsulation process'. These are very effective in getting electrical and mechanical advantages of package. (Fig. 4). CASIO and CMK are developing a new System Packaging technology called the Embedded Wafer Level Package (EWLP) together. The active components (semiconductor chip) in the WLP structure are embedded into the Printed Wiring Board during their manufacturing process. This new technical approach has many advantages that can respond to requirements for future mobile products. The unique feature of this EWLP technology is that it doesn't contain any solder interconnection inside. In addition to improved electrical performance, EWLP can enable the improvement of module reliability. (Fig.5) The CASIO's WLP Technology will become the effective solution of 'KGD problem in System Packaging'. (Fig. 6) The EWLP sample shown in Fig.7 including three chips in the WLP form has almost same structure wi_th SoC's. Also, this module technology are suitable for RF and Analog system applications. (Fig. 8)

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Warpage Analysis during Fan-Out Wafer Level Packaging Process using Finite Element Analysis (유한요소 해석을 이용한 팬아웃 웨이퍼 레벨 패키지 과정에서의 휨 현상 분석)

  • Kim, Geumtaek;Kwon, Daeil
    • Journal of the Microelectronics and Packaging Society
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    • v.25 no.1
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    • pp.41-45
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    • 2018
  • As the size of semiconductor chip shrinks, the electronic industry has been paying close attention to fan-out wafer level packaging (FO-WLP) as an emerging solution to accommodate high input and output density. FO-WLP also has several advantages, such as thin thickness and good thermal resistance, compared to conventional packaging technologies. However, one major challenge in current FO-WLP manufacturing process is to control wafer warpage, caused by the difference of coefficient of thermal expansion and Young's modulus among the materials. Wafer warpage induces misalignment of chips and interconnects, which eventually reduces product quality and reliability in high volume manufacturing. In order to control wafer warpage, it is necessary to understand the effect of material properties and design parameters, such as chip size, chip to mold ratio, and carrier thickness, during packaging processes. This paper focuses on the effects of thickness of chip and molding compound on 12" wafer warpage after PMC of EMC using finite element analysis. As a result, the largest warpage was observed at specific thickness ratio of chip and EMC.

A Fully Integrated Dual-Band WLP CMOS Power Amplifier for 802.11n WLAN Applications

  • Baek, Seungjun;Ahn, Hyunjin;Ryu, Hyunsik;Nam, Ilku;An, Deokgi;Choi, Doo-Hyouk;Byun, Mun-Sub;Jeong, Minsu;Kim, Bo-Eun;Lee, Ockgoo
    • Journal of electromagnetic engineering and science
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    • v.17 no.1
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    • pp.20-28
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    • 2017
  • A fully integrated dual-band CMOS power amplifier (PA) is developed for 802.11n WLAN applications using wafer-level package (WLP) technology. This paper presents a detailed design for the optimal impedance of dual-band PA (2 GHz/5 GHz PA) output transformers with low loss, which is provided by using 2:2 and 2:1 output transformers for the 2 GHz PA and the 5 GHz PA, respectively. In addition, several design issues in the dual-band PA design using WLP technology are addressed, and a design method is proposed. All considerations for the design of dual-band WLP PA are fully reflected in the design procedure. The 2 GHz WLP CMOS PA produces a saturated power of 26.3 dBm with a peak power-added efficiency (PAE) of 32.9%. The 5 GHz WLP CMOS PA produces a saturated power of 24.7 dBm with a PAE of 22.2%. The PA is tested using an 802.11n signal, which satisfies the stringent error vector magnitude (EVM) and mask requirements. It achieved an EVM of -28 dB at an output power of 19.5 dBm with a PAE of 13.1% at 2.45 GHz and an EVM of -28 dB at an output power of 18.1 dBm with a PAE of 8.9% at 5.8 GHz.

Design and Fabrication of a Low-cost Wafer-level Packaging for RF Devices

  • Lim, Jae-Hwan;Ryu, Jee-Youl;Choi, Hyun-Jin;Choi, Woo-Chang
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.2
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    • pp.91-95
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    • 2014
  • This paper presents the structure and process technology of simple and low-cost wafer-level packaging (WLP) for thin film radio frequency (RF) devices. Low-cost practical micromachining processes were proposed as an alternative to high-cost processes, such as silicon deep reactive ion etching (DRIE) or electro-plating, in order to reduce the fabrication cost. Gold (Au)/Tin (Sn) alloy was utilized as the solder material for bonding and hermetic sealing. The small size fabricated WLP of $1.04{\times}1.04{\times}0.4mm^3$ had an average shear strength of 10.425 $kg/mm^2$, and the leakage rate of all chips was lower than $1.2{\times}10^{-5}$ atm.cc/sec. These results met Military Standards 883F (MIL-STD-883F). As the newly proposed WLP structure is simple, and its process technology is inexpensive, the fabricated WLP is a good candidate for thin film type RF devices.

Cure Characteristics of Naphthalene Type Epoxy Resins for SEMC (Sheet Epoxy Molding Compound) for WLP (Wafer Level Package) Application (WLP(Wafer Level Package)적용을 위한 SEMC(Sheet Epoxy Molding Compounds)용 Naphthalene Type Epoxy 수지의 경화특성연구)

  • Kim, Whan Gun
    • Journal of the Semiconductor & Display Technology
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    • v.19 no.1
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    • pp.29-35
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    • 2020
  • The cure characteristics of three kinds of naphthalene type epoxy resins(NET-OH, NET-MA, NET-Epoxy) with a 2-methyl imidazole(2MI) catalyst were investigated for preparing sheet epoxy molding compound(SEMC) for wafer level package(WLP) applications, comparing with diglycidyl ether of bisphenol-A(DGEBA) and 1,6-naphthalenediol diglycidyl ether(NE-16) epoxy resin. The cure kinetics of these systems were analyzed by differential scanning calorimetry with an isothermal approach, and the kinetic parameters of all systems were reported in generalized kinetic equations with diffusion effects. The NET-OH epoxy resin represented an n-th order cure mechanism as like NE-16 and DGEBA epoxy resins, however, the NET-MA and NET-Epoxy resins showed an autocatalytic cure mechanism. The NET-OH and NET-Epoxy resins showed higher cure conversion rates than DGEBA and NE-16 epoxy resins, however, the lowest cure conversion rates can be seen in the NET-MA epoxy resin. Although the NETEpoxy and NET-MA epoxy resins represented higher cure reaction conversions comparing with DGEBA and NE-16 resins, the NET-OH showed the lowest cure reaction conversions. It can be figured out by kinetic parameter analysis that the lowest cure conversion rates of the NET-MA epoxy resin are caused by lower collision frequency factor, and the lowest cure reaction conversions of the NET-OH are due to the earlier network structures formation according to lowest critical cure conversion.