裝配圖大學(xué)生方程式賽車設(shè)計（總體設(shè)計）（有cad圖+三維圖）

裝配圖大學(xué)生方程式賽車設(shè)計（總體設(shè)計）（有cad圖+三維圖）,裝配,大學(xué)生,方程式賽車,設(shè)計,總體,整體,cad,三維 Dynamic Characteristics on the Dual Power State of Flow in Hydro Mechanical Transmission Jibin Hu and Shihua Yuan Xiaolin Guo School of Mechanical and Vehicular Engineering Department of Automotive Engineering Beijing Institute of Technology Tsinghua University Beijing 100081 China Beijing 100084 China hujibin i jz is the mechanical path ratio i p is the transmission ratio from gear Z 22 to Z 3 i hz is the conflux ratio of mechanical path i hy is the conflux ratio of hydrostatic path i b is the transmission ratio from gear Z 5 to Z 7 MTF 1 is the variable displacement hydrostatic unit and can be describe as a variable gyrator The modulus of the gyrator is decided by parameter q p of the signal generator q m and q ml stand for conversion gain coefficient of the fixed displacement hydrostatic unit furthermore q m q ml 1 1 junction is a co flow node in which flow variables is equal 0 junction is a co effect node in which effect variables is equal 10 20 19 18 17 16 15 1413 12 11 29 28 27 26 25 24 2322 21 9 8 7 6 5 4 3 2 1 59 58 57 56 50 55 553 52 51 48 47 46 45 44 43 42 49 41 4039 38 37 36 35 34 33 32 31 30 1 I Io R g541o MTF MTF1 010 TF qm S f no Se Tb R Rp C Cp I Igl C Cm R Rm 1 R g541fm R g541b I Ib I Im 10 C Co 0 C Cb R Rgl 1 TF ihy 1 0 1TF qm1 R Rdl I Idl TF io R g541fp I Ip 1 Se pdl TF ip 1 TF ib 0 0 1 TF ihz R g541jz1 I Ijz1 C Cjz1 011TF ijz R g541jz3 C Cjz2 I Ijz3 I Ijz2 R g541jz2 qp Fig 2 Bond graph model of the HMT system g100 0 is coefficient of viscous friction on input shaft Ns m g100 fp is coefficient of viscous friction counteracting the rotation of the variable displacement hydrostatic unit g100 fm is coefficient of viscous friction counteracting the rotation of the fixed displacement hydrostatic unit g100 b is coefficient of viscous friction on output shaft R gl is leakage fluid resistance of oil in high pressure hydrostatic loop Ns m 5 R dl is leakage fluid resistance of oil in low pressure hydrostatic loop R p is leakage fluid resistance of oil in the variable displacement hydrostatic unit R m is leakage fluid resistance of oil in the fixed displacement hydrostatic unit g100 jz1 is coefficient of viscous friction in drive shafting of the mechanical path transmission g100 jz2 is coefficient of viscous friction in driven shafting of the mechanical path transmission g100 jz3 is coefficient of viscous friction in conflux shafting C o is coefficient of pliability of the input shaft m N C b is coefficient of pliability of the output shaft C p is the fluid capacitance of inner oil in the variable displacement hydrostatic unit m 5 N C m is the fluid capacitance of inner oil in the fixed displacement hydrostatic unit C jz1 is coefficient of pliability of the drive shafting of the mechanical path transmission C jz2 is coefficient of pliability of the driven shafting of the mechanical path transmission I o is the moment of inertia of the input shaft I p is the moment of inertia of the variable displacement hydrostatic unit I m is the moment of inertia of the fixed displacement hydrostatic unit I b is the moment of inertia of the output shaft I gl is the fluid inductance in high pressure oil loop Ns m 5 I dl is the fluid inductance in low pressure oil loop I jz1 is the moment of inertia of the drive shafting of the mechanical path transmission I jz2 is the moment of inertia of the driven shafting of the mechanical path transmission I jz3 is the moment of inertia of the conflux shafting C State equations of the HMT system Analyzing the dynamic characteristic of system using bond graph methods need to choose state variables of system reasonably and establish state equation of the system according to the known bond graph model of system In a general way the generalized momentum p of inertial unit and the generalized displacement of capacitive unit are introduced as state variables of system 5 10 If causalities of the bond graph are annotated according to principle of priority of the integral causality some energy storage elements in bond graph maybe have differential causality on occasion Under the circumstances the amount of state variables of the system is equal to the counterpart of energy storage elements which have the integral causality Energy variables of the energy storage elements which have the differential causality depend upon state variables of the system These variables are dependent variables Algebraic loop problem will occur while establishing state equation of 891 these kinds of bond graph The bond graph model of the HMT system established as above belongs to these kinds In Fig 2 energy variables in inertial elements I o I jz2 and I m have differential causalities The resolution is to express the generalized momentum and the generalized displacement of energy storage elements which have the differential causality with involved state variables and to work out the first derivative of these equations toward time The expressions of the inertial elements I o I jz2 and I m are derived as follows 274 p I Iii p p opo g6g6 g32 1 11 1 2 15 p Ii I p jzjz jz g6g6 g32 2 43 1 49 p I qI p dl mm g6g6 g32 3 Therefore the amount of state variables of the HMT system is just 12 2 tq 9 tq 11 tp 18 tq 20 tp 27 tp 31 tq 34 tp 37 tq 43 tp 55 tq 58 tp The input state vector U g62g64 T bdlo Tpng32 According to the structural characteristics of the system shown by bond graph the differentials of state variables can be describe as functions of state variables related to input variables 12 state equations can be formulated as follows 272 p I ii nq p po o g16g32g6 4 2711 1 9 1 p I i p I q p p jz g14g16g32g6 5 18 21 112 11 21 2 9 11 11 11 q CiC p iIC i q CC p jzjzjzjz jzjzjz jz g16 g14 g16g32 g80g80 g6 6 20 3 11 1 18 11 p I p Ii q jzjzjz g16g32g6 7 5520 3 3 18 2 20 11 q Cii p I q C p bbhzjz jz jz g16g16g32 g80 g6 8 27 2 22 9 12 2 2 27 p IC li q CC i q CC ii p p opofp jz p o po g80g80 g14 g16g16g32g6 dl p p p p C qt q CC qt 2 31 2 g72g72 g14g16 9 34312731 11 p I q CR p I qt q glppp p g16g16g32 g72 g6 10 37343134 11 q C p I R q C p mgl gl p g16g16g32g6 11 43373437 111 p I q CR p I q dlmmgl g16g16g32g6 12 432 3 2 37 3 43 1 p IqC Rq q CC p dlm dlmfm m g14 g16g32 g80 g6 dl bbhym p C q CiiqC 3 55 3 11 g16g16 13 584320 3 55 111 p I p Iqii p Iii q bdlmbhyjzbhz g16g14g32g6 14 b b b b Tp I q C p g14g16g32 585558 1 g80 g6 15 Where 1 2 1 2 1 1 jzjz jz Ii I C g14g32 p opo I Iii C 22 2 1g14g32 23 1 mdl m qI I C g14g32 III SIMULATION RESULTS In these equations above with the structural and calculative parameters of the known HMT system dynamic simulation can be done in computer In the process of simulation initial values are given primarily After the system stabilized input signal is stimulated Meanwhile the results of dynamic response of the system are recorded The response curves of the output speed of system and the oil pressure in main pipe of the bump motor system under varied input signals are shown from Fig 3 to Fig 8 Fig 3 shows the pulsed response curves of the output speed and the oil pressure of the system as the load change instantaneously The rising time of the oil pressure response is 22ms The control time is 445ms The overshoot is equal to 86 Times s Fig 3 Pulsed response of the system as load changing Pressure Output speed Speed response rpm Pressure response MPa 892 Fig 4 shows the pulsed response curves of the output speed and the oil pressure of the system as the speed changes instantaneously The rising time of the speed response is 17ms The control time is 479ms The overshoot is equal to 65 Times s Fig 4 Pulsed response of the system as speed changing Fig 5 shows a group of slope response curves as the angle of swing plate of the variable displacement bump is a ramp excitation In this figure the ascending gradients of the angle of swing plate whose range is from 0 to its maximum correspondingly relative rate of changing displacement is from 0 to 1 i e 1 0g32g72 are assigned some values respectively such as 50 20 8 4 corresponding rising time for ramp excitation are 0 04 0 10 0 25 0 50s The rising times of response of the output speed are 43 108 255 505 ms Overshoot are respectively 47 12 4 2 Times s Fig 5 Slope response of the system as angle of swing plate changing Fig 6 shows the pulsed response curves of the output speed and the main oil pressure of the system as the angle of swing plate changes instantaneously The rising time of the speed response is 22ms The control time is 420ms The overshoot is equal to 73 The bond graph model of the two range HMT system established by the author is a linear system The results of simulation demonstrate that the speed of response of the system is quite fast and the stability is satisfactory but the overshoot of step response is too large On condition that the input signal is ramp type and the gradients is greater than 8 the time interval in which the angle of swing plate changed from 0 to the maximum is not less than 0 25s the transition process of the system whose overshoot will not exceed 5 will approach steady state Times s Fig 6 Pulsed response of the system as angle of swing plate changing The results of simulation indicated by Fig 3 Fig 6 is acquired on condition that the fluid capacitances C m and C p in the model denoted in Fig 2 are set to 0 0085 As other conditions are invariable response curves indicated by Fig 7 and Fig 8 can be obtained for C m and C p are set to 0 0850 Fig 7 shows the slope response curves of the rotation speed and the pressure as the angle of swing plate changes on the principle of ramp excitation The rising times of response of the output speed are 87 121 204 519 ms Overshoot are respectively 52 38 11 5 Times s Fig 7 Slope response of the system when C m and C p are set to 0 0850 Pressure Output speed Speed response rpm Pressure response MPa Pressure Output speed Speed response rpm Pressure response MPa Pressure Output speed Speed response rpm Pressure response MPa Pressure Output speed Speed response rpm Pressure response MPa 893 Fig 8 shows the pulsed response curves of the rotation speed and the pressure The rising time of response of the output speed is 68ms Overshoot is 57 Compared with the results of simulation indicated in Fig 5 and Fig 6 the speed of response of the system is slowing down and the time interval needed to reach the steady state is delayed At the same time the number of oscillations of the response and fluctuating quantity of the pressure is decreasing The overshoot of the pulsed response increased a little but the overshoot of the slope response increased a bit as well Times s Fig 8 Pulsed response of the system when C m and C p are set to 0 0850 IV CONCLUSIONS A bond graph model of the dual power state of flow of the two ranges HMT system is established based on the bond graph theory The model can be applied to simulate and study the dynamic characteristics of a hydro mechanical transmission HMT system On conditions that the displacement of the hydrostatic bump is constant the system focused in this article can be simplified to a linear stationary system On conditions that the displacement of the hydrostatic bump changes along with time the system is a linear time varying system the transition of the system approaches to stable state while the ramp input signal draws 8s The value of the fluid capacitance in the hydrostatic system affects the dynamic response performance of the system A further study on the influence of the fluid capacitance and the fluid resistance will be done REFERENCES 1 X Liu Analysis of Vehicular Transmission System Beijing National Defense Industry Press 1998 pp 255 310 2 D Margolis T Shim A Bond Graph Model Incorporating Sensors Actuators and Vehicle Dynamics for Developing Controllers for Vehicle Safety Journal of the Franklin Institute Vol 338 pp 21 34 2001 3 M Cichy M Konczakowski Bond Graph Model of the IC Engine as an Element of Energetic Systems Mechanism and Machine Theory Vol 36 pp 683 687 2001 4 N Chenglie N Chen Y Na Dynamic Simulation Research of Power Matching on Axial Plunger Pump Journal of Gansu University of Technology Vol 26 24 pp 54 59 2000 5 Z Wang Bond Graph Theory and Its Application in System Dynamic Harbin Harbin Engineering University Press 2000 6 J Liu The Application of Bond Graph Theory for Dynamic Simulations on Driving Mechanism of Automobile Brake System Journal of Xi an Highway University Vol 19 pp 97 100 April 1999 7 J Zheng W Peng The Application of Bond Graph Theory for Dynamic Simulation on Hydraulic Control System Journal of Wuhan Automotive Polytechnic University Vol 20 pp 43 45 April 1998 8 R F Ngwompo P J Gawthrop Bond Graph based Simulation of Non linear Inverse Systems Using Physical Performance Specifications Journal of the Franklin Institute Vol 336 pp 1225 1247 1999 9 W Borutzky B Barnard J U Thoma Describing Bond Graph Models of Hydraulic Components in Modelica Mathematics and Computer in Simulation Vol 53 pp 381 387 2000 10 R Cacho J Felez C Vera Deriving Simulation Models from Bond Graphs with Algebraic Loops Journal of Franklin Institute Vol 337 pp 579 600 2000 Pressure Output speed Speed response rpm Pressure response MPa 894 IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART B VOL 18 NO I FEBRUARY 1995 Electrical Characterization of the Interconnected Mesh Power System IMPS MCM Topology L W Schaper Member IEEE S Ang Member IEEE Yee L Low and Danny R Oldham Abstract A simcant decrease in MCM substrate production cost can be achieved by reducing the number of substrate layers from the conventional four or five power ground X signal Y signal pad to two or three Besides reducing direct processing steps yield will also increase as defect producing operations are eliminated This paper describes the Interconnected Mesh Power System IMPS a new interconnection topology which leverages the production technologies of fine line lithography and batch via generation to allow planar power and ground distribution and dense signal interconnection on only two metal layers Several possible implementations of the topology in MCM D and MCM L are described The design of a test vehicle which characterizes both the signal transmission and power distribution properties of the IMPS topology is discussed The test vehicle has been built in an aluminumlpolyimide on silicon process developed at DEC Results of signal transrmss ion measurements impedance delay and crosstalk for various sigoavpOwer ground configurations are presented Power distribution characteristia de drops and ac noise are presented and compared with measurements on a test vehicle implemented with solid power and ground planes From the measured characteristics of the test vehicle the applicability clock frequency power etc for the IMPS topology has been determined Most MCM applications can benefit from the substrate cost reduction enabled by IMPS Indew rem Mdtichip modules cost reduction power distri bution decoupling interdigitated mesh planes I INTRODUCTION ESIDES producing MCM substrates in large panel for B mat to achieve economies of scale the surest way to achieve substrate cost reduction is to reduce the number of manufacturing process steps Though material cost reduction and process tweaking can have some impact more substantial cost reduction can be obtained by eliminating substrate layers Although some simple MCM s have been made with one or two metal layers almost all MCM D implementations have used four or five power plane ground plane X signal Y signal and perhaps a pad layer This topology is a natural extension of printed wiring board construction Unfortunately for most MCM D s every metal layer costs approximately the same no matter if it is a solid plane or a wiring layer with Manuscript received February 1994 revised July 13 1994 This work is supported by the Advanced Research Projects Agency under Grant MDA972 93 1 0036 This paper was presented at the 44th Electronic Components and Technology Conference Washington DC May 4 1994 The authors are with the High Density Electronics Center HiDEC University of Arkansas Fayetteville AR 72701 USA IEEE Log Number 9407917 x Y via Y Y Ground Grynd Pov la 99 b Fig 1 Derivation of the IMPS topology 300 cdcm2 of wiring capability this is due to deposition and lithography techniques employed Moreover the capabilities of batch via production methods have not heretofore been used to advantage in MCM D and some MCM L compared with the sequentially drilled vias of wiring boards 11 THE IMPS TOPOLOGY The Interconnected Mesh Power System IMPS is a new systematic topology which allows low inductance planar power and ground distribution as well as dense controlled impedance low crosstalk signal transmission in only two physical wiring layers It utilizes the production methods of fine line lithography and batch via fabrication characteristic of MCM D and some MCM L to create a structure not economically possible using standard printed wiring board methods The derivation of the power distribution structure is shown sequentially in Fig 1 Consider a familiar meshed plane used in many MCM s for power or ground Think of this construction not as a plane with holes however but as a set of X and Y conductors In Fig l a the X conductors and Y conductors have been placed on two separate metal layers and at each crossover a via has been provided to retain the planar characteristics Vias typically have low resistance and inductance compared with lines This interconnected mesh 1070 9894 95 04 000 1995 IEEE 100 IEEE TRANSACTIONS ON COMPONENTS PA Signal Signal Fig 2 Sparse IMPS implementation ZKAGING AND MANUFACTURING TECHNOLOGY PART B VOL 18 NO 1 FEBA p Grid Ground Grid plane is reasonably electrically equivalent to but topologically different from the conventional mesh plane The mesh of Fig l a includes enough space between con ductors to insert interdigitated conductors of opposite polarity power or ground with their own set of interconnecting vias on the same two physical metal layers Fig l b The resulting interconnecied mesh structure forms a complete power distribution system with the necessary characteristics of low resistance and inductance In this dense mesh of power and ground conductors there is no room for signals Yet if every other power and ground conductor and the corresponding vias were omitted the resulting sparse power distribution mesh structure would still be planar but containing less metal would be more resistive and inductive Signal wiring at an average spacing twice that of minimum conductor pitch could be provided as in Fig 2 However this arrangement results in adjacent signal tracks with potentially high crosstalk and poor impedance control Many variations of a fine i e minimum design rule interconnected mesh are possible with signal conductors sub stituting for up to almost half of the power and ground conductors but always keeping at least one power or ground conductor between adjacent signal conductors An ongoing tradeoff between available signal line density and power distribution integrity results and care must be taken not to disconnect portions of a power or ground plane The following wire sequences indicate several possibilities with the nP figure denoting average signal line pitch as a multiple of minimum wire pitch GSGPGPSPGPGSG 5P GSGPSPGSGPSP 3P GSGSGPSPSPGS 2 5P GSGSGSGSGSGS 2P NO The last sequence could potentially disconnect or at least non planarize the power plane A better solution is to adopt a coarse i e non minimum design rule mesh for power distribution For example in an MCM D technology with 20 pm minimum line and space a design rule of 100 pm line and 60 pm space could be adopted for the power wiring Power or ground conductors on 320 pm pitch are shown in Fig 3 Signal wiring in areas not requiring very high density would be inserted 20 pm wide Fig 3 Cl LUARY 1995 Fig 4 density a Signal lines between power and ground b Signal lines at high conductor into the 60 pm space between power and ground conductors 160 pm signal wire pitch Fig 4 a In areas where greater signal wire density might be required signal wires could be dropped into power or ground conductors Fig 4 b with a resulting signal line pitch of 80 pm Note that the split power or ground conductor uses four signal sized vias to replace the large power vias at the appropriate crossovers to maintain mesh continuity The implications of these geometries on signal propagation characteristics will be discussed later The 80 pm signal line pitch compares well SCHAPER et al ELECTRICAL CHARACTERIZATION OF THE INTERCONNECTED MESH POWER SYSTEMS IMPS MCM TOPOLOGY 101 BGA fl Pads Fig 5 IMPS on film carrier with the 75 pm pitch 25 pm line and 50 pm space used on many conventional MCM signal layers to reduce crosstalk The IMPS topology offers far greater crosstalk reduction by interposing an ac ground conductor between every pair of signal conductors III IMPS TOPOLOGY IMPLEMENTATIONS The IMPS topology is easily implemented in a conventional MCM D process where fine line lithography and batch fine via fabrication are intrinsic to normal manufacturing An MCM L implementation is quite practical if via fabrication is by other than normal mechanical drilling and via size is small enough not to impact line pitch A two layer process however opens up the possibility of fabricating conductors on either side of a piece of poly mer film which could be processed in reel to reel format Fig 5 a The resulting substrate could be populated and tested then encapsulation applied to form a rigid structure Fig 5 b Inexpensive screen printing materials and meth ods could be used to form a ball grid array BGA on the bottom of the module providing a convenient system interface Fig 5 c Modules of this kind could be extremely inexpensive yet still yield high performance Iv IMPS ANALYSIS AND EXPERIMENT Because the IMPS topology is radically different from the conventional microstrip or stripline MCM transmission line environment with solid power and ground planes a detailed study to determine the characteristics of the power and signal environments was undertaken A Power Distribution Normal MCM power distribution is by solid metal power and ground planes sometimes with an intervening thin di electric which creates a parallel plate decoupling capacitor to supply all or part of transient current demands In most cases however surface mounted ceramic capacitors are needed as charge reservoirs to keep transient di dt noise on these planes below acceptable margins Conventional chip capacitors have relatively high parasitic inductance and low resonant frequency however Special low inductance capacitors made by AVX originally designed for the IBM Thermal Conduction Module provide far better decoupling The parallel plate P G planes themselves form a low inductance distribution structure Wirebonds from these planes to the chips even though many are paralleled contribute far more inductance and can critically affect on chip noise The IMPS topology replaces solid planes with a mesh of conductors In a dual mesh plane of 100 pm wide conductors on 320 pm pitch net metal coverage is reduced to 62 that of a solid plane Even with substantial power and ground conductor cuts to accommodate signal wires metal coverage of 40 can be realized Increased resistive and inductive parasitics are thus expected However since the contribution of these parasitics to dc and ac drops in the solid plane case is I02 IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART 8 VOL 18 NO 1 FEBRUARY 1995 111 Fig 6 Test vehicle power transient measurement setup often insignificant this performance decrease is manageable in almost all cases Attachment of both normal and low inductance decoupling capacitors in the conventional manner provides the necessary decoupling capacitance over a wide frequency range To examine the effectiveness of IMPS power distribution two test vehicles were designed and built one with solid planes the other with IMPS On each four n channel power FET s are arranged to connect on module resistive loads between power and ground thus inducing large di dt into the power distribution structure As shown in Fig 6 several sites are provided for normal ceramic as well as low inductance chip capacitors For clarity other features of the test vehicle for signal transmission measurements have not been shown Various combinations of capacitors and loads as well as current rise times were tried Resulting measurements are described later B Signal Transmission The IMPS signal transmission environment is shown in Fig 7 Each signal conductor lies between ac ground con ductors on the same metal plane and over orthogonal power ground and signal conductors on the other metal plane Because the ac ground conductors in the second plane are orthogonal to the signal line of interest return currents flow only in the coplanar conductors the orthogonal conductors moderately reduce the line impedance through capacitive loading This was initially demonstrated by building large scale physical models 160 times the size of MCM dimensions and doing TDR measurements and has been confirmed by measurements on the IMPS test vehicle described below C Test Vehicle The test vehicle shown in Fig 8 was designed and fabricated in a HiDEC developed four mask process using aluminum conductors and photodefinable polyimide dielectric on 5 sil icon substrates The fabrication process began with 2 pm of Fig 7 IMPS signal transmission environment Si02 deposited by PECVD on bare Si wafers or an 8 pm layer of DuPont 2721 polyimide Next 2 pm of AVl Si was sputtered and defined by photolithography and wet etching Next a layer of polyimide was spun on exposed and devel oped Mask features of 50 pm for large power vias and 15 pm for signal and small power vias were used The metal deposition and patterning was repeated to form the second metal layer and a final polyimide step formed a protective overcoat Several thicknesses of interlayer and base layer dielectric were compared The 33 x 26 mm substrate was populated with decoupling capacitors and terminating resistors and was used unpack aged for transmission line and power distribution impedance measurements or it received power FET chips decoupling capacitors and load resistors and was mounted in a 256 lead CQFP package for measurements of dc drop and ac power distribution noise The solid plane version used for power distribution measurements was likewise configured Both substrates were fabricated using the same four masks with the IMPS substrate occupying six of the eight possible 5 wafer sites and the solid plane substrate the remaining two sites D Signal Transmission Structures and Measurement Results Several different signal transmission test structures have been included in the IMPS test vehicle All have microwave probe pads on 150 pm pitch at either end and provision to terminate the line using a 50 R 0603 size 1 6 x 0 8 mm chip resistor bonded to the substrate with conductive epoxy For all transmission line measurements decoupling capacitors sufficient to hold the power distribution impedance below 0 5 R from 1 MHz to 1 GHz were installed See the following section on power distribution impedance Second level metal lines either 24 6 mm or 26 6 mm long were configured as signal between power and ground conductors PSG signal inside a split power conductor PSP and signal inside a split ground conductor GSG There is also a crosstalk measurement set of lines on 80 pm pitch the driven line lying between power and ground and the victim line within the adjacent split ground conductor First level lines lying on the Si02 or polyimide dielectric 18 2 mm long configured as PSP GSG and PSG were also measured to see if line impedance differed from second metal One aspect of the IMPS topology raised particular concern This was the effect on impedance and particularly on prop agation velocity of changing from for example an X going SCHAPER et al ELECTRICAL CHARACTERIZATION OF THE INTERCONNECTED MESH POWER SYSTEMS IMPS MCM TOPOLOGY 0 10 1 Fig 8 IMPS test vehicle PSP line to a Y going GSG line There is a discontinuity at the point of return current path change which has some effect depending on how well P and G are decoupled at frequencies of interest This has not appeared to be a problem in many MCM s where signal layers are routinely referenced either to power or ground planes with no effect To determine if a problem exists in IMPS a five segment path was created with 2 4 mm PSP 6 3 mm GSG 11 5 mm PSP 6 3 mm GSG and 2 4 mm PSP sections in series Substrates with an interlevel and overcoat polyimide thick ness of 4 0 pm and initial Si02 dielectric thickness of 2 pm were built and measured Measurements were performed using a Tektronix IPA 310 Interconnect Parameter Analyzer The results are shown below Z the M1 figures were higher due to the proximity of the substrate No problems were caused 103 by signals being referenced to power or ground the delay of the five segment line was no different from the other M2 lines The mask set was revised and the experiment was repeated with 8 pm thick polyimide for the initial dielectric layer and 5 4 pm of polyimide between M1 and M2 The following results were obtained ZoR t ps cm M1 PSP 42 72 M1 GSG 42 72 M1 PSG 42 70 M2 PSP 52 66 M2GSG 52 66 M2PSG 52 66 M2 5 Seg 52 68 Even with an 8 pm layer of polyimide the semiconducting silicon still has an effect As we are currently using test wafers as substrates the wafer resistivity is not known Further fabrication will use measured resistivity wafers to determine the resistivity necessary to eliminate the difference between M1 and M2 transmission lines Detailed simulations of lines above semiconducting substrates are also in progress Of course a different implementation of the topology on an insulating substrate of low dielectric constant would not have this problem The crosstalk measurement was made on M2 lines with 28 5 mm coupled length Both ends of the victim line were terminated Measurements were made on the IPA 310 by injecting the 20 pS rise time TDR pulse into the driven line and measuring the victim line Peak crosstalk was less than 3 6 on this set of long coupled lines This result indicates 104 IEEE TRANSACTIONS ON COMPONENTS PACKAGING AND MANUFACTURING TECHNOLOGY PART B VOL 18 NO 1 FEBRUARY 1995 m c 12 1 0 0 100 200 300 400 500 Frequency MHz Millions Fig IO impedance meter Power distribution impedance versus frequency using the HP 4291A that crosstalk should not be a problem at reasonable clock frequencies and line lengths E Power Distribution Impedance Measurements Power distribution impedance was measured using both an HP 8510 Network Analyzer and an HP 4291A Impedance Meter A range of 45 MHz to 1 GHz could be measured with the 8510 Fig 9 shows the measured impedance for several substrates with various combinations of decoupling capacitance The effect of even the low inductance AVX capacitors only appears below 300 MHz above this frequency the intrinsic capacitance of the planes in either solid 3 2 nF or IMPS 1 6 nF versions dominates the measured impedance The rising impedance from 600 to 900 MHz is due to inductive effects With the 4291A measurements were made from 1 to 500 MHz as shown in Fig 10 The resonance of the 0 1 pF chip capacitors is clearly seen around 20 MHz These measurements were made without AVX capacitors in place in order to confirm the SPICE models which predict the rise in impedance with the normal caps in place between 200 and 300 MHz The results indicate that there is little difference between the IMPS power distribution structure and one using solid planes Any planar effects will be masked by attachment or wirebonding impedances and by the number and type of capacitors used The procedure used to attach chip capacitors is extremely important as the aluminum lines of the substrate form native aluminum oxide rapidly and even this roughly 80 A of oxide can produce measurable resistances in power paths This may account for the inability to achieve extremely low impedances F Power Distribution DC and AC Measurements The test vehicle shown in Fig 6 was built in both IMPS and solid plane designs Each was assembled with two 0 1 pF chip capacitors and four 135 nF AVX capacitors for decoupling Six paralleled 50 R resistors were used as loads 8 3 R resistance for each of the four power FET s The substrates were assembled into 256 lead CQFP packages with 110 ground and 80 power connections to ensure solid power distribution to the substrate These packages were soldered to custom well decoupled test boards The resulting assemblies were measured for dc voltage drops with large currents flowing through the load resistors and for ac noise on the substrate planes with large dI dt induced by driving the FET gates with a pulse generator Because of assembly problems only three of the four FET load sections could be activated and some load resistors were inoperative so the effective resistance of these test vehicles was 3 9 R However this was sufficiently low that ample current could be drawn even with the 10 V m