文化的融合與喪葬禮儀的變遷

 
雖然儒家确立了中國喪葬禮儀的大傳統，但習俗是在民間約定俗成的，具有其自身的特殊性。考察中國傳統民俗的成立，約略可以看出兩條途徑，其一爲由上而下，由禮而俗；另一條則爲由下而上，由俗而禮。喪葬禮儀也是如此，既有所謂儒家制定的禮，又有種種民間雜俗，前者具有濃厚的倫理化傾向，而後者則充滿了宗教氣氛。 喪葬禮儀中的民間雜俗大多是由于宗教的影響，因爲幾乎人類的所有宗教都以關心死亡及生命的歸宿爲主旨。影響中國傳統文化最大者莫過于佛教、道教、儒教以及民間宗教。儒家具有濃厚的世俗色彩，因此有些學者否認它是一種宗教。它對傳統喪葬習俗的影響便是上文所論述的種種禮制。下面我們試探讨佛、道教與儒教的融合以及由此而來的喪葬禮儀變遷。佛教原成長于印度，兩漢之際，中國通向西域各國的絲綢之路已經開通，這是中西文化交通的第一次高峰。佛教勢力也從印度本土擴展到大夏(阿富汗)、安息(伊朗)，最後傳入中國。漢末戰亂，民不聊生，佛教迅速在民間興盛起來，經過魏晉南北朝及隋唐曆代，佛教終于成爲中國三大教之一，對中國文化的各方面均帶來了不可忽略的影響。佛教對中國喪葬文化的影響首先表現在它帶來了一種新的死亡觀念。在傳統中國文化中，一直存在靈魂不死的信仰，但經儒家倫理化解釋，越來越關心的是死者的靈魂，靈魂附于虞主，供奉于祖廟。但對于死者生活的世界及靈魂的歸宿、變化則幾乎沒有什麽說明。佛教則帶來了“善有善報，惡有惡報”及“六道輪回，轉世托生”等觀念，從而爲人類的死亡世界做出了明确的解釋。佛教的“善有善報，惡有惡報”和中國上古信仰中的報應有類似之處，這也是兩種文化融洽溝通的結合點，但佛教教義更加系統化、更加明确，這也是它爲民間乃至上層廣泛接受的原因。按照佛教的理論，衆生有身口意三種活動，其中身是身體發生的動作，口是嘴說的言語，意是人的思維活動，三種活動又稱爲業。衆生有善、惡二業之分，順理利人爲善，違理損人爲惡。善業有十種：不殺生、不偷盜、不邪淫、不妄語、不兩舌(搬弄是非)、不惡口(說不恭敬的話)、不绮語(花言巧語)、不貪欲、不嗔圭心(上下結構，念仇)、不邪見。前三種是身業道，後三種是意業道，中間四種則是口業道。與此相對的則是十不業道。佛教認爲業是産生結果的原因，即業因，由業因而來的果報便是業果。衆生按照今世的業力可在來世獲得不同的果報，行善者得善報，行惡者得惡報。果上又可造新業，再感未來果報，如此往複流轉，在過去、現在、未來三世，天上、人間、阿修羅、地獄、餓鬼、牲畜六道，胎生、卵生、化生、涅生四生裏輪回貫通轉生不止。這就是所謂“善有善報，惡有惡報”，“六道輪回，轉世托生”。佛教的傳入對喪葬禮儀之變遷所産生的影響也是不容忽略的。首先，佛教爲華夏民族帶來了一種新的喪葬習俗——火葬。 火葬在中國古已有之，如《墨子·節葬下》雲：“秦之西有儀渠國者，其親戚死，聚柴薪而焚之，熏上，謂之  退，然後成爲孝 子。”《荀子·大略》亦雲：“氏羌之虜也，不憂其系壘也，而憂其不焚也。”但中國曆史上的火葬在佛教傳人以前，一直隻限于邊少數民族，爲中原華夏族所不斥。佛教因爲信奉六道輪回、轉世托生的死亡觀念，對死者肉體并不關切，實行的是所謂“荼毗”——火葬。佛教在中國的傳播，使火葬亦随之傳布開來，唐代敦煌地區由于地處中西文化交通的最前沿，便已開始流行火葬。至宋，火葬已廣泛流行于中國各地，尤以河東、江南、福建等地爲盛，以至宋、明統治者不得不嚴加禁止，并設立漏澤園、義冢，以解決貧困者無力購置墓地的問題。這些措施又反證了中國火葬之盛，據有些學者研究，“凡是佛教昌盛的地方大多也是火葬流行的地區”。佛教還給中國傳統喪葬禮儀程序帶來了所謂“七七追薦”。七七追薦又稱七七齋、水陸道場、水陸大會、水陸會、水陸齋儀等，是一種超度死者亡靈的大法會，主要來源于佛教信仰。在佛教的輪回轉世觀念中，人死後在七七四十九日内，分七階段随業力受生，七七追薦便是爲了替死者消罪免禍、誦經修佛，以投入善良之家，因而延請和尚設齋念經，禮佛拜仟，追薦亡靈。七七追薦在南北朝開始流行于世，《北史》卷八o《胡國珍傳》記載了北魏靈太後之父胡國珍死後延請和尚做七七齋的情景。唐以後，此風更盛，而且和尚開始參與儒家所制定的其他喪葬程序，故司馬光說：“世俗信浮屠狂誘；于始死及七七日、百日、期年、再期、除喪，飯僧，設道場，或作水陸大會，寫經造像，修建塔廟，雲爲此者，減彌天罪惡，必生天堂，受種種快樂；不爲者，必人地獄，剉燒舂磨，受無邊波吒之苦”。道教是中國本土宗教，早期道家隻講煉丹成仙，在民間并無多大影響。但在發展過程中，它逐漸吸收了儒、佛教的許多觀念，終于和儒、佛成鼎足之勢。從道教對中國傳統喪葬禮儀的影響中，亦可看到道教與儒、佛二教的關系，可以說，道教本身便是一種文化溝通和融合的産物。道教給喪葬文化帶來的首先是十殿冥王的地府信仰。在道教形成之前，中國文化中已有較爲模糊的陰間概念，漢代的鎮墓文中，便發現了很多陰間的官吏和職稱，如墓皇墓主、蒿裏君、泰山令等等。同時，佛教也有彼岸世界的種種信仰和觀念，但道教将這些系統化、具體化，建構了一個具有嚴密組織體系的地下世界。傳說中道教的冥界在酆都(今重慶豐都)，其君主稱爲酆都大帝，下轄十位冥王： 第一殿爲秦廣王，是鬼魂的報到處，稱黃泉黑将，管生死壽天；第二殿爲楚江王，掌功過，是初動刑處，有16個小地獄； 第三殿爲宋帝王，主管刑法，有黑蠅大地獄和16個小地獄； 第四殿爲五官王，專管詐僞、欺人之類案子； 第五殿爲閻羅王，這是從佛教中借過來的，梵名爲奈落伽(naraka)、泥犁(niraga)，據說是“地獄之王”； 第六殿是卞城王，專管奸淫、盜竊；第七殿是泰山王，這是從中國傳統信仰中移置過來的，在道教信仰中，專管僧、道犯罪； 第八殿是平等王，專管大案要案，有阿鼻地獄，這也是從佛教中借>的； 第九殿是都市王，專管不孝不悌、邪惡作僞； 第十殿是轉輪王，這也是從佛教中來的，他所管轄的也是佛教信仰中的“六道輪回”。道教給中國傳統喪葬文化帶來的還有相墓術等等。筮宅蔔日是《儀禮》中便已記載的喪葬禮儀，但到了道教手中，已發生了根本的變化，俨然成了一門大學問。由于相墓術與儀禮關系不大，而且本身非常複雜，此處從略。但相墓術的興盛卻給喪葬禮儀帶來了新的變化，即停葬之風的出現。儒家所制定的喪禮中，本有停葬之風，如《禮記·禮器》雲：“天子崩七月而葬……諸侯五月而葬……士三月而葬。”但自相墓術流行以後，因選擇吉地頗費時間，竟有停葬達二十九年之久的。道教的影響還深深體現在喪葬禮儀程序中，雖然官禮及司馬光、朱煮等人所修的家禮極力排斥佛、道二教對喪禮的影響，力主恢複儒家禮制，但在民間習俗中，往往各教并行不悖，聖人、術士、和尚。因道教的影響而産生的喪葬禮儀有山人批書、出殃、接煞等等。所謂山人批書是指在人死初始時請陰陽先生選擇入殓吉時。這些在古禮中本是由蔔人通過占蔔的方法來決定，但道教興起後，全部由術士替代了。出殃是指将死者亡靈從家中導引出去，據說死者亡靈在此日化着紅、黃、青、白、黑五色之一成氣狀從家中出來，凡遇者必有大災。因此需請陰陽生推算出殃日期、方位、顔色等，以趨吉避兇。接煞則因南北地域差異而不一，在南方是接死者本命之神返家，在北方則是驅除不祥之氣，因此清人盧文弨《顔氏家訓》校訂本雲：“北人逃煞，南人接煞。”但不論是逃煞還是接煞，其方法均是請道士作法，目的也同在于避兇趨吉。以上論述了佛教和道教對中國傳統喪葬文化的影響，其實，在中國民間，并沒有像學者那樣将儒、佛、道截然分開，尤其是唐宋時期，三教呈現出互相溝通、互相融合的趨勢。宗教的融合也深刻地體現在喪葬禮儀中，那便是以儒家傳統喪禮爲主體，融合了佛、道二教的喪葬禮儀的出現。明代小說《金瓶梅》中所描繪的李瓶兒葬禮是一個典型的個案。其基本程序是儒家的，如裝斂、報喪、飯含、成服、大斂、出殡等等；但其中又雜以衆多佛、道習俗，如請陰陽生批書、置七星闆、釘長命釘等是道教習俗；而念倒頭經、做七七齋則是佛教習俗。更爲有趣的是做七七齋時，首七由和尚念經，二七由道士做法事，三七是和尚念經，四七爲喇嘛念經，五七又是道士做法事，六七不念經，七七又由女尼誦經，真是魚龍混雜，但正是這種看似矛盾的習俗形成了自明清以後中國傳統喪葬禮儀的主流>。

FAG bearing areas of application and the reasons for failure

　　　　Since 2001, FAG became a part of Schaeffler Group, and in the group the aerospace, automotive and industrial sector has played an active and important role. Phase combined with the INA products, FAG rolling bearing industry in the licensed products with the industry's most Special Bearing complete framework. Covering consumer machinery, energy transmission and rail technology, heavy industry and consumer operations of all areas of application.

　　FAG bearing failure caused the cause of

　　FAG bearing surface grinding based on the task transformation layer formation mechanism of grinding is an important factor transformation layer grinding heat and grinding force. The above analysis we come to look for the cause of FAG bearing failure.

　　1.FAG bearing grinding heat

　　FAG bearings in grinding, the grinding wheel and workpiece contact area, a small amount of energy consumption, the occurrence of a small amount of grinding heat, forming part of Shashi grinding zone temperature. Practical application of linear stationary heat transfer formula, plan or application of red paint method and thermocouple Shashi measured Needle Roller Bearing the temperature under test conditions, can be invented in the 0.1 ~ 0.001ms Shashi within the grinding zone temperature can be as high as 1000 1500 ℃. This Shashi low enough to make the task of the outer surface appearance of the depth of occurrence of certain low-temperature oxidation, amorphous organization, low-temperature tempering, secondary hardening, cracking and even burns and other changes.

　　(1) oxide surface

　　Lost all appearance of steel under low temperature and the role of oxygen in the air or into very thin (20 ~ 30nm) thin layer of iron oxide. It is noteworthy that the oxide thickness and surface grinding of the consequences of transformation is the total thickness test was the corresponding relationship. This explains the oxide thickness is coherent with the grinding process indirectly, is an important marker grinding quality.

　　(2) amorphous layer of tissue

　　Shashi grinding zone temperature reaches the melting of the workpiece surface condition, the molten metal molecular flow has been evenly coated on the task looks, and is the base metal to be cooled extremely rapidly, forming a thin layer of amorphous state of tissue layers. It has high hardness and toughness, Pressed Bearing but it is about as long as the 10nm, it is easy to be in fine grinding removed.

　　(3) layer of low-temperature tempering

　　Shashi grinding zone temperature can make sure the depth of appearance (10 ~ 100nm) is heated to above the workpiece within the heating tempering temperature. Did not reach the austenitizing temperature in the situation, as was the progress of the heating temperature, the surface layer will occur with the heating temperature should be the absolute return fire or to Thrust Bearing change the organization of low-temperature tempering, the hardness also will be landing. The higher heating temperature, hardness, also landed the more fierce.

Crushers And Grinding Mill products employed For metal Ore Mining

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RF Module Design: Requirements and Issues

At the hub of a top-down design flow for an RF-system-design-to-product implementation is the RF module design for RF integrated circuits (RFICs), boards and a final RF system prototype. Both RF module design and prototype development are receiving lots of industry and electronic design automation (EDA) attention today due to three factors: rapid growth in module business coupled with growth in system and module complexity; multiple RFIC manufacturing passes costing approximately $1 million per pass; and a production bottleneck at the system/module prototype test.

Multiple RFIC manufacturing passes often result from the lack of design tool interaction between design domains (IC to module), and an inability to accurately model RF load effects of the RFIC in the target RF module. Increasing RF module and system complexity have spawned the need for more accurate models of various module implementations so system engineers can make proper system performance and cost trade-off decisions. A lack of EDA tool integration and/or standard data-interfaces for the various design disciplines — such as the RF system, printed circuit boards (PCBs), IC packages and IC designs, and prototype testing — have contributed to the difficulty of achieving more accurate models.

This article will highlight these issues and discuss PCB Assembly appropriate solutions for related RF module design examples. It will explore:

RF module performance in an RF system model;

Two types of RF module technologies;

An RF module design example of accuracy problems — 802.11 XCVR multichip module;

Design tool flows and interfaces;

Design concurrency and regression; and

What's feasible today and what's possible for tomorrow.

RF module performance in an RF system model

Usually more than one level of abstract representation exists for the RF module and functional blocks within the RF system, facilitating varying degrees of simulation/evaluation accuracy. Three levels of design abstraction representation are defined below.

‧ Algorithmic architecture levels (Level I), derived from SystemC, C/C++, Microsoft's Excel spread sheets, Cadence's signal processing worksystem (SPW) or Ptolemy libraries. An entire suite of stimulus standards, channel models, air interfaces and measurement blocks contribute to the development of the full RF system test bench for bit error rate (BER) and error vector magnitude (EVM) simulations.

2. Level II of model representation consists of a more accurate and comprehensive behavioral model (VHDL, VHDL-AMS, Verilog, Verilog-A/AMS or C/C++) of RFIC functionality with board parasitic effects or electromagnetic (EM) models and discrete device/component models (S-Parameters). The Level II model is useful for refining performance analysis accuracy to a second order of parameter analysis and simulation accuracy within the RF system. A Level II model also, in most cases, is a representative model for intellectual property (IP) reuse of various functions (such as low noise amplifier, mixer, voltage controlled oscillator, in-phase and quadrature demodulation).

3. Level III of RF module modeling is at the device/component level or circuit schematic. Only a true mixed-signal simulation EDA tool such as the Cadence Design Systems Inc.'s AMS Designer or Mentor Graphics Corp.'s ADVanced MS can provide reasonable and efficient simulation/analysis of design representations of blocks at this level. Most often, due to design complexity, only mixed-level simulation (one block at behavioral level, with other blocks at circuit level) can be facilitated within a reasonable amount of time, such as a few days, versus several days to weeks.

Another area of modeling, known as data characterization models or model extraction technology is quickly becoming a crucial part of the total solution. It offers the best accuracy and simulation throughput time for final system, module and block regression testing. Several companies, including Cadence, Agilent Technologies Inc. and Xpedion Design Systems Inc. are developing “data characterization modeling” methods and technologies. All of these modeling methods address the need for design regression validation. In many cases, the value of these models for RF systems and RF module design is greatly enhanced when they are an “extraction” of real data/performance or final circuit simulations of RF module/RFIC functions in the test lab. “Model extraction” technology is also a key enabler for fully facilitating design IP reuse.

Therefore, the entire issue of RF systems/RF module simulation/evaluation accuracy can be addressed with two critical pieces of technology:

Behavioral models of a common language (C/C++, VHDL, VHDL-AMS, Verilog, Verilog-A/AMS), and

Data characterization models of standard formats (S-Parameters, table-based behavioral models, extraction models).

If both technologies were readily available today — and supported by the major EDA tool suppliers and common to the system, module, IC, and package design domains — actual usage would occur at a reasonable adoption rate if and only if:

Credible libraries of behavioral models for RF and analog functions existed requiring minimal customization; and

Data characterization and extraction modeling technologies had been validated for performance/accuracy and simulation throughput for a classical RF system top-down design flow.

Two RF module technologies

It's important to consider the types of physical media used for RF module assembly, due to the variations of RF passives library requirements, resident EM field solving technologies, and access to IC package parasitic modeling that may or may not exist for PCB and IC design tools.

Most Common RF module Configurations

RF Module physical assembly technologies include:

Various dielectric substrates depending on application (such as FR4, PTFE), high temperature cofired ceramic (HTCC) or low temperature co-fired ceramic (LTCC);

Multilayer wiring with plated through hole (PTH) and via layer connect technologies; and

Surface mount devices/components (SMTs), chip-on-board (COB), IC package on board, thin/thick film components.

An RF system and/or RFIC designer must be able to fully model and analyze the RF module within each respective design domain. Further, these designers must have access to S-Parameters for surface-mount components from discrete device component vendors, S-Parameters for EM effects of PCB parasitic effects, and mathematical expressions of discrete device behavior (such as RF nonlinearity for a varactor diode) using Matlab or C/C++ equations.

These models must be available or already linked into the system and IC design domains. This capability has enabled a complete, accurate RF module target-design that surrounds the RFIC.

What's missing from this type of RF module modeling is the ability to import and use other EM Field Solver tools and models, noise and cross-coupling analysis technologies from the PCB design domain, and other special discrete device and component models (equations and S-Parameters) not currently supported by the PCB design tool's library.

It's important to note that an IC package design and analysis tool is not part of the data-interchange capability of the RFDE tool, because this tool is part of the PCB design tool environment.

Advanced RF Module Configurations

The most distinguishing characteristic of advanced RF module configurations can be summed up in the terminology of imbedded passive devices (IPDs). This means that advanced RF module passive devices (such as resistors, capacitors, inductors, and micro-strip lines) are embedded within the silicon-on-substrate or sandwiched between layers of the combination of LTCC and metal (LTCC-M) compositions.

Why is this different than common RF modules, or why is it even an issue? IPDs are created and design-sized at the RF module and/or RFIC design stage. Therefore, RF component characterization and modeling must be done as a custom library development effort.

If advanced RF module an LTCC-M type, the IPDs are modeled and characterized within the PCB design domain in cooperation with the LTCC-M process foundry. The IPD library and its design components are available to the design engineer as part of the IC design tool kit. The same is true for the silicon-on-substrate advanced RF module. To establish a fully characterized IPD library that's ready to use for advanced RF module design, significant modeling and device characterization work must be planned.

Advanced RF module design lacks a complete RF module and RFIC modeling environment. For example, EM Field Solvers for silicon-on-substrate parasitic analysis and custom bond-wire modeling for COB of an LTCC-M are not necessarily available within the IC design tool environment.

Accuracy problems example

The following 802.11 XCVR multichip module design example shows the RFIC design accuracy risks when accurate models do not exist within the IC design domain of the RF module elements (such as passives, and substrate parasitics) interfacing to and from the RFIC.

The RF module consists of two RFICs, a diplexer/duplexer, an antenna, a module substrate, and surface-mount technology (SMT) components. Refer to figure 1.

Transmitter performance indices of the PA RFIC are evaluated because of the critical RFIC-to-RF module interface and load matching media. This example depicts differences in power-gain and noise accuracies for the transmitter simulation performance with distributed versus extracted (S-Parameter) load models for: SMTs, strip-lines, and board parasitics. Based on the simulation results shown in Table 1, power amplifier (PA) RFIC (and potentially the Tx/Rx RFIC) would require design modification if only distributed models were used for PCB components: ML1 to ML4, Cc, S1 to S3, and LP at the RFIC design domain.

Design tool flows and interfaces

RF top-down design flow and methodology forms the basic design process for accurate and efficient RF module design. The basic steps and data-interchange requirements are depicted in figure 2.

Flow step number 1: Top-level design at the RF system level is the beginning point of design and the end-point for regression validationand testing of the RF module within the RF system.

Table 2 describes the characteristics of design representation, the system design tool (basic) features, and data-interchange characteristics related to linking (bi-directional) of the RF module through the various design domains of RF module, RF module test, and RFIC.

The RF system model for the RF module (signal and stimulus, channel models and RF building blocks) becomes the “Golden Test Bench” (by linking to module and RFIC design domains) for the rest of the design flow.

Because most system design tools utilize synchronous data flow simulation architecture, the full set of S-Parameters for any discrete devices or components on the PCB cannot to be utilized at the RF system test model. However, in the technology development of data characterization models (in particular, low-pass equivalent models), modeling of S-Parameter effects during data characterization is being evaluated to better represent PCB environment impedance effects at the RF system level.

Flow step number 2: Re-validate system performance criteria (such as EVM) at the RF module/RFIC design domain. At this stage the RF module has been evaluated to Level I design modeling accuracy (architectural or algorithmic). The RF module model and input stimulus (via the Golden Test Bench represented in C/C++) are linked to the RF module/RFIC design domain. The RF module Golden Test Bench is re-evaluated with the module and IC design domain simulators (refer to table 2). A combination of time and/or frequency domain simulators are used (such as harmonic balance, envelope analysis or periodic steady state) to provide signal power and noise analysis capability.

This simulation process is one of “evaluate-by-observation” the performance of the RF module using the same (Level I) models, but using a different simulation technology than that used for the RF system simulation. All design data models and model parameters used in this Level I simulation are common to the RF system simulation. Only the simulator is different.

Flow step number 3: Replace RF module with behavioral models and component and board models (Level II design). This is the first stage of design refinement and structure definition beyond Level I representation. It is the first point of design accuracy improvement enabling design exploration and trade-off analysis. In addition, because the Golden Test Bench is being used to validate RF module performance, this is the first time within the flow that the RF module design is regression tested. Level II design simulation performance is compared directly (over-laid) to Level I performance.

Flow step number 4: Replace RF module with circuit schematics and keep accurate component/board models in place.

Flow step number 5: Replace RF module with data characterization models. Accurate simulation results from flow step number 4 are modeled in various forms (low-pass equivalent, extraction models depending on evaluation criteria), resulting in a very accurate RF module model (typically within five percent compared to Level III simulations) that is at least 100-times faster for simulation than Level III circuit simulations.

Finally, the RF Module of flow step number 5 is re-linked to the RF system and RF module design domains to close the final loop of bottom-up design regression validation.

Design concurrency and regression

The concept of “concurrent design” for IC silicon, IC package, PCB and prototype test development within the RF system design environment is a “must-do” requirement for meeting time-to-market demands and first-pass acceptable prototypes for today's RF systems.

The need for development of a concurrent design process is being driven by the demand for top-down design methodology for RF system, RF module and RFIC design, respectively. Further, the requirement exists to perform a final Golden Test Bench validation based on final design implementations, using a bottom-up regression design methodology at each design level: — RFIC-to-RF module, and later RF module-to-RF system.

Once system partitioning has been defined for boards and ICs, concurrent design, with iterative design refinement, should begin in conjunction with the top-down design flow shown in figure 2. Although design domains and tool database structures have been separate and independent entities in the past, market demands today require convergence and linkage.

The first steps for bringing together these design domains are the use of RF behavioral models functions using a common language, and provisions of various forms of data characterization model technologies (such as S-Parameters representing Field Solver analysis or extraction models), using measured or transistor-level simulated data from each design domain (such as IC, package, passive components, and board).

RF system and module design domains could be linked together effectively if the industry (design, test and EDA) would support and establish standards concerning the interaction of EDA design tools. Two important items to be standardized are a behavioral language (C/C++, VHDL, VHDL-AMS, Verilog, Verilog-A/AMS), and data characterization modeling formats (S-Parameter parameter or extracted into a C/C++ model).

Open Access (common database) is an important industry initiative that can further facilitate concurrent design for system, PCB and IC design domains.

What's feasible today and possible for tomorrow?

Design technologies available today include:

Behavioral models;

Extraction modeling techniques;

Data characterization models — sometimes referred to as table-based modeling; and

S-Parameters for discrete components and EM Field Solver parasitic effects.

All are available today within various EDA design tool environments, but not necessarily bi-directionally linked between design domains (such as PCB design to IC design).

Two other technologies that could be critical for the future for each design domain (System, IC, and PCB) are design-constrained (physical and electrical) floor planning, and combined analysis capability for noise and cross-coupling analysis and Field Solver integration.

The existence of design-constrained floor planning for ICs and separate/independent noise analysis technologies (substrate noise analysis, parasitic coupling analysis) is common knowledge. Some of these technologies also apply to PCB 21/2 D and full 3-D Field Solver technologies. What's lacking is the integration of these technologies for use at the “early design evaluation/ analysis” stage of design, including system, module and IC.

Industry demands of EDA suppliers should drive the need for this early design evaluation/analysis capability. To perform this first-order analysis, it is usually sufficient to utilize 21/2 D Field Solver and physical media input data; cross-section thickness, dielectric constants and conductivities for noise and parasitic coupling analyses.

Without the early design evaluation/analysis technologies, at best approximately 30 percent of field, noise and parasitic effects on the overall RF system and RF module design can be estimated.

Conclusion

EDA tools offer the capability to fully model, design and simulate an RF module, with some limitations and dedicated development of behavioral models. This existing capability can greatly reduce the very expensive risk of RFIC photo mask and silicon respins. However, system, board and IC design domains are not sufficiently interfaced to support a seamless, fully integrated top-down design environment. In addition, TTM requirements are forcing the need for RF system, module and IC designers to have readily available libraries for behavioral models, RF passives, and extraction models. When early design analysis technologies of design constrained floor planning and cross-coupling and substrate analysis are integrated within these design domains, RF module design accuracy will be much more comprehensive and precise.

Handling Electronic Assemblies

OUTLINE

This procedure covers the proper methods for handling circuit boards.

ACCEPTABILITY REFERENCES

IPC-A-610 3.0 Handling Electronic Assemblies

PROCEDURE REFERENCE

1.0 Foreword

IPC 7721 2.1 Handling Electronic Assemblies

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Electrostatic Discharge (ESD)

Certain components used in electronic assemblies are sensitive to static electricity and can be damaged by its discharge. Static charges are created when non-conductive materials are separated, such as when plastic bags are picked up or opened, when friction occurs between articles of synthetic clothing, when plastic tapes are dispensed and many other causes.

Destructive static charges are induced on nearby conductors, such as human skin, and delivered in the form of sparks passing between conductors, such as when the surface of printed board assembly is touched by a person having a static charge potential. If touched at the right solder joint or conductive pattern, the PCB Assembly can be damaged as the discharge passes through the conductive pattern to a static sensitive component. It is important to note that usually the static damage level for components cannot be felt by humans. (Less than 3,000 volts.)

Figure 1: Handle components by edges to prevent contaminating leads with skin oil.

Electrical Overstress (EOS)

Electrical overstress damage can be caused by generation of unwanted energy; such as spikes, occurring within soldering irons, solder extractors, testing instruments and other electrically operated equipment. This equipment must be designed as to prevent unwanted electrical discharges.

ESD/EOS Safe Work Areas

The purpose of an ESD/EOS safe work area is to prevent damage to sensitive components from spikes and static discharges. These areas must be designed and maintained to prevent ESD/EOS damage.

Handling and Storage Methods

1. circuit board assemblies must always be handled at properly designated work areas.

2. Designated work areas must be checked periodically to ensure their continued safety from ESD. Areas of main concern include:

Proper grounding methods.

Static dissipation of work surfaces.

Static dissipation of floor surfaces.

Operation of ion blowers and ion air guns.

3.

Figure 2: Always handle circuit boards by the edges.

Designated work areas must be kept free of static generating materials such as Styrofoam, vinyl, plastic, fabrics or any other static generating materials.

4. Work areas must be kept clean and neat. To prevent contamination of circuit board assemblies, there must be no eating or smoking in the work area.

5. When not being worked on, sensitive components and circuit boards must be enclosed in shielded bags or boxes. There are three types of ESD protective enclosure materials including:

Static Shielding - Prevents static electricity from passing through the package.

Antistatic - Provides antistatic cushioning for electronic assemblies.

Static Disipative - An "over-package" that has enough conductivity to dissipate any static buildup.

6. Whenever handling a circuit board assembly the operator must be properly grounded by one of the following:

Wearing a wrist strap connected to earth ground.

Wearing 2 heel grounders and have both feet on a static dissipative floor surface.

7. Circuit board assemblies should be handled by the edges. Avoid touching the circuits or components. (See Figure 2).

8. Components should be handled by the edges when possible. Avoid touching the component leads. (See Figure 1).

9. Hand creams and lotions containing silicone must not be used since they can cause solderability and epoxy electronic assembly adhesion problems. Lotions specifically formulated to prevent contamination of circuit boards are available.

10. Stacking of circuit boards and assemblies should be avoided to prevent physical damage. Special racks and trays are provided for handling.

Elaborate an international brand name in China bearing away

Distribution of imported bearings in nearly nine years, when the thought of bearing meditation, think of imported bearings, I think of China's bearing, are surging in the unconscious mind a thought ---- when China can have its own international brand of bearings? Par these international brands SKF \ FAG \ INA \ NTN \ NSK \ TIMKEN bearings, when we land in their own international brands to sell their bearings, and sell it around the world, earned an international currency. . . I would like to share with you this review SKF international brands of success, explore the world of China's bearing brand. We know, SKF bearings and now has gone through a hundred years of history, SKF Group since its inception in 1907, it quickly developed into a global company. Back in 1920, the company's business to Europe, America, Australia, Asia and Africa. Today, SKF is represented in more than 130 countries, institutions, with more than 100 production units and more than 15,000 dealers support the sales of the company. SKF also has a wide range of e-commerce market and efficient global distribution network. 1, SKF in innovation, production and other aspects of the main growth process from the day the establishment of SKF has been no stop over the course of development of their innovation, they developed continue to develop their own products, but also with various types of production plants to start all kinds of cooperation and development, along with which must continue to build the factory development. From the beginning of self-aligning bearings, the spherical roller, and later the ball bearings, roller bearings, tapered roller bearings and other types of bearings continue to emerge and serve production. Them to the evolving needs of customers to develop their innovative products to improve and expand their facilities, research and a series of relevant supporting agencies. In 1907, a young Swedish engineer Sven Wingquist bright in the sketch book to show the world's first self-aligning ball bearings. In 1909, SKF's subsidiary in New York - SKF ball bearing company. In 1911, SKF established a factory in the United Needle Roller Bearing Kingdom Luton, SKF in Sweden this is the first established outside the factory. SKF's first research laboratory built in Gothenburg, Sweden. 1918, Arvid Palmgren invented the spherical roller bearings, which is a railway equipment designed for the rugged self-aligning bearings. 1919-1924, the product range expanded to include spherical, cylindrical, tapered roller bearings. In 1926, SKF subsidiary Volvo (AB Volvo) to begin production test car. In 1934, single and double row angular contact ball bearings to begin production. In 1940, the spherical roller thrust bearings come out heavy load it is designed for the axial self-aligning bearings. In 1947, the International Organization for Standardization published the SKF life theory used to calculate the bearing, and it set an international standard. In 1963, Prussia in the United States established a research center of entries. SKF Engineering Research Center in 1972 in the Netherlands Nieuwegein completed. In 1995, SKF will be a new turning bearing - CARB? Ring roller bearings market. In 1988, SKF Engineering completed. In 1999, a new generation of spherical roller bearings - "Explorer Series" began production, with Internet-based electronic market Endorsia.com operation. In 2000, SKF Services introduced the "Comprehensive maintenance solutions" (IMS) concept, SKF and Brembo Group decided to develop high-performance car market of electronic - mechanical brake system. In 2001, CARB? Ring bearing the metal industry was established as the industry standard for continuous casting machine. In 2002, SKF Reliability Systems to start using @ ptitude?, Which is the reliability of maintenance for the end-user decision support system, "SKF Explorer bearing" series expanded, includes cylindrical roller bearings and angular contact ball bearings. The process of fully certified SKF innovation, development and expansion of the production history 2, SKF cooperation, acquisition process in 1916, Sweden was the most suitable in the production of high quality bearing steel melting steel, after careful evaluation, SKF acquired Hofors Bruk. In addition, the acquisition of SKF Katrineholm, it was the transmission equipment used in the production of ball bearings and one of casting. In 1929, SKF acquired another well-known Swedish engineering company Lidkoping Machine Tool Plant (LMT), has acquired seven other German ball bearing factory, and the establishment of Vereinigte Kugellagerfabrik subsidiaries. 1950, SKF has 18 factories, 31,000 employees, of whom 66% work outside Sweden. In France and Spain began to build factories. Product range was extended, when the rotation included nearly all types of bearings and components, such as bearing housing and the casing. 1957 SKF acquisition Hellefors Jernverk. In the same year, a progressive predecessors ball bearings and rotating bearings factory built in Gothenburg, which is the construction company's history, one of the largest. In 1965, SKF Bearing Company acquired the Italian rotating two-thirds of the shares RIV and set up the RIV-SKF company. In 1995, SKF China Ministry of Railways, a joint venture between a subsidiary of SKF Railway Bearings Co., Ltd. Beijing South Side. In 1997, SKF established in China with two new joint ventures: one is the leading bearing manufacturer in China Wafangdian Group, a joint venture between spherical roller bearing manufacturer and sales company, Chicago Rawhide, and another is a joint venture formed ANZAG seal manufacturing company. In 1988, SKF Bearing Company acquired the Austrian Steyr W? Lzlager Ges.mbH and British companies AMPEP plc. In 1989, SKF acquired the bearing condition monitoring equipment manufacturers Palomar Technology International Inc's majority stake, and rename it to SKF Condition Monitoring. 1990, SKF acquired the pieces of the U.S. oil seal manufacturer Chicago Rawhide (CR). In 2000, SKF, FAG and NN Ball & Roller Inc. Combined group and co-owned independent NN Euroball Aps company that makes and sells chrome steel ball. In 2001, SKF acquired high-precision machine tool precision electric roller screw spindle and Pressed Bearing a leading manufacturer of: Italy Gamfior SpA company. SKF and Timken joint venture in Brazil, the casting and machining production of bearing rings. SKF and SNR in the exchange and use of wheel hub bearing assembly seal patent agreement. And Shanghai Bearing Group Co., Ltd. concluded an agreement, a joint venture established in Shanghai, deep groove ball bearing factory. SKF and Sandvik, Rockwell Automation, INA and Timken signed an agreement to jointly owned endorsia.com electronic market ownership and use. In 2002, following the acquisition of the Dutch Delta Consult engineering companies and research firm, the United States after Erin, SKF Reliability Systems to expand. SKF Reliability Systems to start using @ ptitude?, Which is the reliability of maintenance for the end-user decision support system. SKF for more acquisitions, including the Swiss-based motor actuators leading manufacturer of Magnetic Group, jet aircraft engines and gearbox main shaft bearing manufacturer Aerospace Bearings UK, with four bearing factories Bulgarian company SBB, ground ball screw manufacturers and the U.S. The Twentieth Century Machine Co.. The new SKF Bearing Co., Ltd. Shanghai joint venture plant began production of small ball bearings. In 2006, the acquisition of the North American seals company Macrotech Polyseal Inc. The amount of 51% of the shares. Air France also acquired the application of bearings and machine tool manufacturers SNFA SAS. In 2007, the acquisition includes the production of linear guides in Taiwan's ABBA, the French leader in magnetic bearings S2M. In 2008, the acquisition of U.S. QPM and the U.S. company PEER Bearing Company of Thailand, the company decided to produce medium and large size bearings in Dalian, China to double plant capacity, the establishment of railway bearing in Russia Tyer new plant. In fact, take a look at SKF's cooperation, acquisition, development in the process, you can see is a constant throughout the absorption, integration and expansion process. One combination of the process, one optimal combination of process 3, SKF in marketing , service history and other aspects of the growth and development throughout the course of SKF, his marketing systems and services play a decisive role in the system! Expanding the site's marketing system to ensure its products in a wider scope for the production of smooth, normal operation and development of the company provide a guarantee. Strong logistics and distribution system ensures timely and accurate product to the customer, while SKF global product deployment of the most reasonable, but also efficient and reasonable use of the funds has played a guarantee. In 1908, SKF in Germany and France set up a branch in Finland, Switzerland, Belgium, Denmark, Austria and Australia to appoint agents agents agents. In 1912, SKF has been set up 32 overseas representative offices, most of them in Europe, but also including Tokyo, Melbourne and Mexico City. In 1914, SKF Technical Customer Service Department was established. In Norway, Belgium, the Netherlands and Russia set up a subsidiary in South Africa established a new distribution points. In 1916, SKF established a sales company in Shanghai. In 1918, SKF has been opened in 100 countries, 12 plants and sales offices, employees, 1.2 million people. In 1988, SKF established an office in Shanghai. In 1994, SKF Tongeren in Belgium set up a new central warehouse - SKF European distribution centers. In 2001, SKF Logistics Services Asia in Singapore, the new distribution center. In 2003, the establishment of two vehicles in Bangalore, India Development Center, is to apply innovation and technology, optimize the existing product range. The new publication "SKF Bearing Catalog comprehensive" revision. Today, SKF is represented in more than 130 countries, institutions, with more than 100 production units and more than 15,000 dealers support the sales of the company. 4, a little personal understanding and awareness of SKF Special Bearing Throughout the development process, each milestone is a monument! A monument is hard to match! As we all know, SKF is a banner bearing industry, leader, pacesetter, boss, top industry brands, is worth all the bearings industry, collective and individual learning and respect. The reason why say this for the following reasons: most of the high standards of product demand, creating a high-quality products; for efficient marketing and service management system, creating a top industry brands; SKF has created a variety of bearing types of intellectual property products; on industry standards to provide a great contribution and support; bearing products created a model of rapid expansion abroad; to create a huge precedent for the size of the industry; create a model for the financing of listed companies; sales performance among the industry forefront ; wide range of products; product quality and superb; brand distinguished; development, production, marketing, and services into the system, and efficient. . . All of these constitute the SKF brilliant today, creating a resounding international industry leading brand! Worthy of our study and admiration of the brand! 5 to explore the world of Chinese bearings SKF brand saw the course of the road, combined with his many years of exposure to imported brands bearing the practice and thinking, and build China brand in the world make their own bearing some suggestions and observations: First, to build their own high quality bearing products. This is the basic fundamental, not high-quality products, there can be the top brand, create top international brands, we must begin to create top-level products. Have their own high-quality products, we must have their own high-end R & D design team, but also an improvement of production equipment and production of the older generation, the production of fine arts managers. Second, to establish a rational, efficient and comprehensive marketing model and system. Even the best products will not sell the real value of their products, let alone use of the product value, not to mention other people know your product. How to choose your marketing model is very important, he is put your product into an important means of commodities. With a good marketing model, but also an improvement predecessors efficient marketing methods or means to complete. These models, tools and methods form a comprehensive and efficient system. Third, to establish an efficient system of logistics and distribution services. In addition to efficient service systems to customers timely and accurate product hand, but also can readily provide high quality comprehensive and efficient professional services. The above three points is the basic requirement to build a brand. China Bearing in international trade now to build a brand, in addition to the above requirements with the individual aspects that should have the following conditions: To break the existing bad system of state-owned industry to re-establish a strategic vision of industry structure and team; may consider the use of existing resources, under the conditions of national industry to optimize the combination, which is a shortcut, but requires larger and more support. There are two roads before us: one that is: starting from scratch, also used a hundred years time, whether recreating a bearing international brand in China? One is: the use of existing resources and conditions, how long can rebuild a bearing international brand in China? SKF's development process is definitely worth bearing in China to learn from the development, along with many international famous brands within the industry also has much to learn from a place I know to build a Chinese bearing the international branding is definitely not This simple one-on into that, he may need the relentless pursuit of generations may be completed and the efforts of a hundred years to build the SKF, then a hundred years can build a Chinese Thrust Bearing international brand? I am sad, I dream, I call, I look forward to.

Beware of caterers bearing gifts

The Democrat-Gazette's Debra Hale-Shelton does it again (pay wall) — unearthed a most salient fact missing from a University of Needle Roller Bearing Central Arkansas Board of Trustees discussion. That $700,000 gift from food service operator Aramark to renovate the president's house at no cost to students and taxpayers? Er, it's conditioned on Aramark keeping and extending its food service contract at UCA long enough to "amortize" the gift — meaning get the money back, with profit — through charges to Pressed Bearing school and student and visitor.

There's some indication that this baksheesh is typical in the industry. That only goes to suggest that there's a pretty hefty margin built Special Bearing into such arrangements, which in turn suggests Thrust Bearing competitive bidding might be in the public institution's interest.