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[仿真讨论] 好久没发帖,SIlist话题之PCB的损耗可否预测?

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发表于 2012-11-26 22:11 | 只看该作者 回帖奖励 |倒序浏览 |阅读模式

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故事是这样开始的:有人问树脂含量和损耗的关系。
* H! v( R3 P/ ~0 {% n2 C0 h
; }# W. \' ~2 g: v9 ADate: Tue, 30 Oct 2012 08:52:23 +0800 (CST)
3 J; e4 X1 A) x5 s
" L4 i0 J! i. {7 m' z8 _  C' g3 qHello experts,
' y: d) k2 L+ g! G" e4 ?  M6 p>
1 r9 P$ j, p9 r> I'm from PCB house.  Recently we have producted some insertion loss test
# z, ~4 w2 q9 O3 |* v> boards(16L, SET2DIL coupon, IS415/IT150DA/I-Speed Mid/low loss material with
% j: y2 Q1 k2 n. e& H  \4 W' f0 @> RTF copper foil). We found that the multiply core and high resin PP will 1 x+ o3 S. L: w$ V1 ~! y6 j
> result a lower loss result. It's a trouble to MI engineer.  I would like to
) `5 T1 R& I0 V1 f> know how to predict the loss base on stackup. Please help to suggest (papers, * b, `! f. d9 I9 o
> script, free software etc ). Thanks a lot!
) X, Z* z4 D/ T' G- O) V2 l- {/ m>! a3 g/ ?7 }7 q3 p# k2 l
>
( w' R+ i2 f( B>5 Y; e1 q% e3 P+ V" U: ~
> Best regards,$ G! g- c7 R/ y4 _8 B( y% |/ ?) ?
>% {% {) L: ?* O
> Terry Ho
  ^- R1 ~/ w# N5 o
: V7 z1 J3 G  G) u. Y; s然后 Scott McMorrow ,steve weir,Loyer Jeff 这些活跃分子开始依次发表意见.' M2 ~& N  A$ o( w0 |- H

4 M7 i7 c( n5 |8 c8 S! g2 OFrom: Scott McMorrow <scott@xxxxxxxxxxxxx>
- }; ^& L! G" \  NDate: Mon, 29 Oct 2012 21:02:36 -0400$ y# P. |3 y: d0 ^" t6 x
2 c& P9 A! z. M
Hmmm...  I'm in the middle of the middle of Hurricane Sandy.  Power is out.& u! v$ K$ E& D8 N1 s) U$ Y
Storm surge is causing the river across the street to rise to unprecedented9 K' O7 u( y! Q& i8 L) k6 W
levels.
1 W1 }3 H5 A  n6 S% n6 d... and this guy wants us to do his job and suggest free software.
% `/ x7 T! C2 m3 E9 `
$ L8 N3 h& G; d4 M+ k1 y9 P
$ d# i; i" \* X$ D: T$ a$ ZFrom: steve weir <weirsi@xxxxxxxxxx>
: B- t( L2 ?3 O4 y$ S1 \5 c3 N4 sDate: Mon, 29 Oct 2012 21:23:22 -0700
) h1 v6 m8 h8 ?0 ~9 z
5 o6 F( {4 a3 h0 u. SAs a PCB fabricator I think you need to develop in-house material
: s( w6 T9 t5 }( N. m; |properties expertise.  Your competitors who understand the materials
6 H. v( b4 z. O" _0 f5 @they use and their process limits are positioned to get higher yield
. n  Q0 @# e5 i/ ~' i0 X1 opercentages at lower cost because of their knowledge.( m# r/ y$ g8 P3 u# I, l- ]- ~

2 W( H1 a6 m0 p! N2 K8 X5 KI appreciate that you don't want to spend unnecessary money, but at , d5 p* z5 l6 l0 A) N
least spend the time to learn about what you are using.  I am troubled
! J/ T& d1 ~% R9 V& f, ~! ]that your engineer knows so little about the materials you use that he 4 S, K$ Q$ W* c. L! f
is surprised by common results.  Once your company understands materials
7 h8 m7 F  m" ]( `( p/ Nbetter you may well appreciate the value of commercial stack-up planning 5 U. P. a5 e0 G. R- N/ O1 m# [
software.
+ S7 w3 }- W( f6 o) p! p
; U3 w# p( f0 \0 \Steve.' j0 V+ J/ z7 ~3 z/ {; \# r( |

2 N% E" ]8 A3 x- s' bFrom: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>* j$ }# J' B9 N& s/ J
Date: Wed, 31 Oct 2012 21:33:48 +0000
; b! F6 ~8 C$ v* C, w( P9 U  @) ~) X- Y4 s

" w* q0 _" o* vI'm surprised at the tone of the responses to this posting (but perhaps I
" B7 o% u! E. W- W* hshouldn't be, unfortunately); I don't see anything untoward in it.  I would 9 L; g, T+ k0 W* K$ c
like to provide some context (with some assumptions on my part) for the message
1 I/ W8 f7 ^" Dlest other innocent postings meet with similar fates.  I'll also (eventually)
- Q8 |) ^0 G! u; E$ U1 k4 wprovide my answer to the question, as I understand it.
, W6 S9 ^: G. ]* a3 Y8 M
- U& u) L6 I, @# @1 n9 c- i/ P) o/ x
There is a significant portion (majority?) of the industry which is extremely - u* k# I- S$ s
cost constrained.  For instance, to them rotating a design 10 degrees is & ?6 L& Z3 S6 B
impractical, much less 22 or 45 degrees.  Thus, they find other cost-effective ! @* y. D+ j9 m# }# }' x# p
yet effective means of solving problems (such as zig-zag routing), even though 5 W$ d8 Y4 f" @0 e. |6 w
those don't appear efficient to others to whom cost is not an issue.
1 c7 O* {4 K, |9 d# e" ]2 Y; x* v7 `5 a% Z9 l4 ^$ q
5 [/ t8 T- h; f6 C# w9 X+ L
5 M' u. r3 c; @4 `+ w# h! C# L
There are new pressures being applied to this segment - designers are now not
0 d) }# m7 ?! u# R4 j" ^  U  Eonly requiring impedance control, but are also insisting on insertion loss , x% ^9 d/ M. U2 a0 s% D1 \  Q
control.  This is a HUGE paradigm shift, very similar to what we encountered ) k+ U0 U/ k$ I/ m, m
when traceable impedance control was first introduced.  That was a very 6 i0 _7 N- M% h+ Q7 Z
challenging evolution, and this will be also.
8 D$ x1 r7 k- x7 j% \
. E7 i3 D2 Z' b0 u; b& t
+ m9 w. u+ w- Q( o2 p! i2 l
% d4 K$ T8 M5 `% hAs an example, PCB vendors are now being advised to smooth their copper, after " X+ C* D0 k4 u( d; \. K
years of purposely roughening it for best mechanical integrity.  It should come
  B8 ~0 v& |$ L! d+ j4 ~* Aas no surprise that this is not a trivial change, considering the effort that
& [, e( ]8 M6 d2 U; }has gone into ensuring mechanically robust designs.
) s2 p; E( k6 _& b) |  g) m& G. y
6 Y. [0 N$ z' F

/ w- S6 L# w% C) QLikewise, many other basic assumptions that we've been able to apply for years . v/ Y8 h+ A3 y6 n0 C- W: t* `2 g
are now being drawn into question, and PCB vendors are looking for help to
2 x+ S+ u, s, X" P/ s  yintelligently and cost-effectively explore options - "How much effect does
% B2 r$ e) r* trougher copper have on insertion loss?".   I believe Terry is highlighting the
( N$ B' ~5 t' ^2 V2 G! q, E* C  qfact that, while there are many tools available for impedance prediction, : ^7 N" S1 }# B4 q
insertion loss modeling is much less accessible.   I don't think it is
4 {; \/ V3 Q. g2 a1 minappropriate to ask if there are cost-effective, reliable tools available to
8 U' \4 I& Q3 b6 [predict insertion loss based on a proposed stackup.
5 T# |7 q2 {9 s/ }
6 S( k  L- C$ V0 u- d0 ^* O" z2 \$ ?$ z3 {) x- K
; j4 M; Q6 h  a1 R; k* q
Unfortunately, I believe the answer to the question is that there are no
- Q/ Q  a& i8 y; n2 x' I& Ireliable, cheap (~free) modelers available to predict insertion loss.  And, the ; M' k) \3 j/ ?7 i1 o
ones that are available require a great deal more knowledge about the stackup
3 f* o9 C) {- h9 u$ othan impedance modeling does, and that information is not easily obtained.  
, Y- Q1 N  v: V- O  q5 P# T0 @/ f6 [There are some of us working with a vendor to test their modeler against a   C2 e) F; w: x' G/ X- V4 R
variety of stackups and we'll present results at DesignCon.  My personal goal
3 K0 k; \" @- \7 ?/ l4 L! zis not so much to test a specific modeler but to judge how effective a modeler , \6 m  T" I8 x! s2 m+ s; e9 K4 W
can be given information that can reasonably be gleaned prior to building with $ m, ^  x. w- N9 ]) u
various materials, copper types, etc.
5 U& c* P, B9 G" k
, ]! {* g% y2 ~4 q8 U; G+ R' {; l3 d" l, z* s3 _0 z# C) H  E
2 p; i; x5 Y* r8 }, R
In the absence of a modeling tool, or in addition to one, I believe empirical
9 |  `% q& T/ J3 c2 e& z# Adata is the best predictor of insertion loss.  To do this, however, you have to
- K- h7 F- [0 N5 Z4 E0 y- r" jbuild a stackup representing the final design, and it's not clear at this point * |; B; \$ k0 G- C, Z& N. ~
how broadly you can extrapolate those results to other stackups.  But, I know
* W; E+ [' I, Y- t% t1 U+ }+ Dmany material vendors and PCB shops are engaged in similar efforts.
% P; x! t, }( `6 e5 A- o/ x- S" D& y/ S

; B5 c5 F; w, h% w8 y
' K7 N$ |; y4 d3 @  WI think this is very similar to what we went through with impedance control -
+ {" ?5 u0 }2 i9 y/ y: vthe shops which most quickly were able to predict and control that / u6 q  d, v! n2 {7 \
characteristic had an advantage.  I think successful PCB vendors will need
9 t- a. p4 J  Q% ereliable modeling software and empirical data on insertion loss for their % B+ x9 [- q2 [8 m9 `9 t
particular choices of materials, etc. - they will be able to find the most cost 6 I( |+ ]; r. y4 D! P
effective solution.! T5 v. ~2 V- C& J7 _' R0 P
5 t, ~% I- P, g6 Q  t# U

9 M; O2 B: Y5 d/ F7 d. Q" _
8 `1 \% |1 j9 l: S( Q( NBottom line: I doubt a reliable modeling tool is going to be cheap, but is
3 l/ G, b, ~; _+ _3 z4 x) bgoing to be necessary, and you'll want to compare any tool you do purchase $ s% G' H- Y2 r3 _3 B6 R# {
against empirical data before you trust it.
6 H$ U8 U2 E: N# B" d: U4 s2 ~5 g3 k( @4 O
  o2 e# u0 r$ `" l2 f3 O( v

9 T4 w9 z: b9 P3 u" nI hope this helps,
% G% w! o$ E( l+ V
  B" c/ n' P/ @. m7 O3 |Jeff Loyer/ x. p5 L7 Z' B* z* S

4 u0 M+ l; r3 Y3 y9 Z& }
* D  n3 ^) F) N% |! _) D& u+ N- wFrom: steve weir <weirsi@xxxxxxxxxx>4 t: {% T& F6 f* W( D6 r; r$ d% ?0 H
Date: Wed, 31 Oct 2012 20:14:41 -07008 p8 u- \7 S4 x4 Y
$ }( F  I7 O4 C3 l. ?
; I5 k, ?5 ?" c8 ?4 y) ?7 d
Jeff, given that the only two responses were Scott and mine, I am
0 s* ^7 ]' n+ W3 e5 F1 m" k, Isurprised that you are disappointed with both.0 A4 z5 `, c0 v  r- a$ m% ]
2 Z8 z% Z  M# ?$ a0 C. W4 x
In a fabrication market filled with intense competition it is up to 7 W/ h* h4 j1 C, f
individual players to keep up with the technology requirements of the ) M/ X2 {! {% Y) I. g0 a* j
market or get left behind.  The task is not simple. Depending on how far 9 r: u. l' ]  N0 k* ~$ E: b9 {
up the frequency range one needs to go, dialing in cost effective
4 ?0 X" e6 n! y. `" e* @4 i% r( d/ iprocess requires substantial skills, time, effort and serious money.  It
7 i( c4 _6 J; ~0 Q- Erepresents competitive advantage to OEMs and their partner pcb fab - D9 b% J, Y  D
houses alike.  Neither who have invested are likely to hand over that
% @' K" M2 B3 `kind of advantage especially when it is so costly to obtain.- h6 _9 E1 F8 s0 Z7 d& w0 j. `

+ \# K- \1 S' U& BI don't mind that Terry is looking for a solution on the cheap or free.  % |' R5 T5 h) k, c5 T
If one could obtain such a sweet deal, one would be foolish not to take
% ~7 h$ i* Y9 v& |7 B5 eit.   I am troubled that in this day in age, his organization hopes to - ^/ g& g, I: r8 J* N
address a sophisticated issue before his technical staff has a grip on
9 T) _; f# m7 ^2 F% y+ p+ m$ J9 Xthe basics.   I fail to understand what you find inappropriate about
1 U* Z, G! ]/ b7 Pthat concern.  I would rather yell at someone headed for a cliff to stop 4 \" i  L6 L+ ~$ l& ^
than smile and wave.
* E3 N' Y- X# Z% h
9 s5 O( ^8 N) s$ k! g8 y1 JBest Regards,) h3 k! W% H2 u* @3 ^6 s5 m

; A3 [4 ]5 r) f( P% A4 z/ f. y$ W  ]+ Y
Steve.% _# N& T6 X' J# Q

! R, |7 F& \# C7 P. U& |From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>
: x4 [3 l1 ?3 T7 XDate: Fri, 2 Nov 2012 15:37:46 +0000( M/ `$ C! d3 z: t/ h( m2 \3 A' z% l

# c* p8 F. ?# z 9 H, k5 Y) T' {5 i
I realized we hadn't answered the basic question - "why does a high resin 3 x% p. W- [6 `+ W8 g
prepreg give lower loss?"  The prediction of loss vs. resin content isn't
% V6 X, D* W7 Strivial; as Steve said, a tool which allows you to model loss for the various : y1 c6 ]: ]1 Q; z- I4 B7 k, y
scenarios should be on your Christmas wish list.  Here are the factors that I   f! w0 Z% H+ j4 `  `  j. d8 S
know of (thanks to Richard Kunze for clarifying things for me, and I welcome
9 R/ ]5 B) {: S) n. i# Nothers' data/opinions):5 m8 ?0 I$ [: D) \4 r
* Resin has a lower Er than glass
. w. j8 x& J5 Z; k( ]8 g4 \" l2 M( R0 S& b
     * loss is approximately proportional to Df * sqrt(Er), so lowering Er
1 z* m; M1 Q% M) [lowers loss
4 F# E6 b0 h. q2 H7 }- v( g3 [. o* t7 N6 Y7 a4 q7 f% W, n
     * lower Er allows wider traces for the same impedance - this may decrease
5 _/ f  @9 u4 v* X, floss also
# F6 p/ Q3 p7 L5 Z' Y4 h! y" {' u' X- Q9 c5 L
* But, resin is more lossy than glass, so Df may increase
* V# ?& R7 A1 i' {7 `
( i4 D/ ~" \/ j% j* n$ |# q  ^4 f     * for standard FR4 constructions, this is especially true.  The data sheet 2 E  i0 `2 Y  A% {. p9 R4 H9 u
for IS370HR, for instance, shows Df varying from 0.0177 to 0.0247 (1GHz),
% r1 \. ~% b0 V# P" D2 I4 Gdepending on the resin content- W# M0 D  l; L5 M3 }' _1 M4 X3 g0 P

8 L$ V  M; f( j* ]# Y! W8 h     * for low loss materials, this doesn't hold.  The data sheet for Meg6
( S- p' b; Y* `shows Df constant (0.002 @ 1GHz) for all its flavors of prepreg+ L8 g8 j. p  ?& r# M

' ^; f7 N  b1 O5 U* a3 _2 T" g* Where the factors dominate will depend on your relative conductor vs. " `4 |8 `- k* x+ P
dielectric loss effects: for FR4, dielectric loss dominates at >~1GHz; for
  G, t; N+ b8 O$ X! R5 Klow-loss materials, conductor loss dominates up to much higher frequencies (as $ A# S5 u/ q0 M- O
much as 10GHz).
5 ^. V$ W# x" g/ g% }- o
: }  P4 X8 ^" n8 M, {2 ^2 I
5 p& L! T  w8 R
+ u$ D0 A3 g9 d& v0 Z/ _) GIn your particular (low loss) case, the lower Er of the resin-rich case is
! o0 J  C: G* l) T3 Mtrumping the Df change (or lack of) so you get lower loss.
: i  y- B% Q& D) \6 N& U
; P: S$ o/ Y6 g% x: w, c7 q
: V) G' Z6 x- U- Y$ y! j0 q2 U) n% d1 L
Only a tool which takes into account the properties of the specific material " v- S4 K* d1 h  J. \
under consideration can be expected to give an accurate prediction of insertion 5 z5 d5 S. q5 [  V
loss for various resin contents.5 n; R2 _& C- q2 ?' o3 L3 ?

/ |2 b8 N) k. z; `* w* O1 y
( Q1 \! F0 _% X* D& M: J
. @) v% S! h. `8 j9 dThere are also environmental effects (I haven't heard or seen these stressed at
! \0 S- x7 p" M8 \9 M8 ]  x, gthis point, though that may change soon):* G% J2 e* T, u5 }# b7 B5 y

8 N4 R/ ^6 z9 M) S* Higher resin content will absorb more moisture, and thus your loss will be
* l2 [& \4 `. g1 h% w. Kmore susceptible to humidity effects; |/ d9 N. U; f9 z3 D0 d6 S& h

. O( K! o- V+ v7 T2 x* There's a difference in how the various materials' Df changes w/ temperature 8 P' Z. q9 ]. T2 u. g* P- U) U2 x+ ?/ G
- more at DesignCon
* h& d; c6 J1 c, c' f1 r& d( N8 W) s7 y, N' E

( o7 z) @6 v, c# }2 P5 a
5 s+ i( _; v0 E/ y! X/ O/ qI hope this helps,3 L' {# x0 }! t' z' B* F6 v

- D# \; R% Z/ i( ~Jeff Loyer- C; e0 ]3 H  W# H! [1 u8 C7 D3 z

$ _1 J7 h, ~* HFrom: Scott McMorrow <scott@xxxxxxxxxxxxx>( V9 G  }! B8 n- s
Date: Thu, 8 Nov 2012 09:12:46 -0500  J& w: f# O% X% ]$ ^# T- P$ D

& u& E" d! f2 _: j) o/ N2 p 2 c6 ^4 Z0 k; @
Jeff, P  \) t0 l& y9 q
A few quick comments.  Although the tanD of Meg 6 is stated to be flat, it
9 f8 {" e- T, {' ^" \2 E) m6 b! [) K2 Jis not if you measure it.  The manufacturer reported characterization in, r' @- L% ~  C7 I
the data sheet is not correct.  Causality is violated when tanD is flat.1 a7 o0 b8 ^, ^

: I, r& ?1 b1 ^; t" ?8 YLoss is generally due to molecular dipole losses in the material.  It can1 I6 M5 I  Y: k# w( R
be low for high Er, as is the case with ceramic.. K4 c& u, [9 u4 z' P
+ Q0 g- Y/ \5 G
Hygroscopic loss is due to molecular polarity. Polar molecules "glom" on to# u* a3 [+ H+ `9 x+ Z- z3 x% J
water molecules, which are also polar. Same property makes the material
% R( [" G$ N& @! o) iextremely "sticky."5 {$ P* L( G8 P! w5 z) T

$ P2 s8 R: R( hThe paper that Jason Miller of Oracle and I wrote for DesignCon last year
0 z6 n* h% V) X. V( B% B% I! Ncovers some of the impact of temperature and humidity on measured losses.
: t. E3 M2 m# D( y3 q I don't have access to my storage server right now, otherwise I'd give a& v6 _' S3 P0 [- y, H$ ?
paper citation.
1 ^& G: o: f8 t4 J) o
, I3 D4 u& C0 p+ j, N. xregards,
' I+ K) e" g5 K3 B/ f* T( Y" }4 q& e# ]- q. K4 f2 F0 ?0 @2 ?4 q
Scott" f* `' w/ W+ }1 l+ X. v8 {/ k6 A
: c; J/ I* Q6 F
From: Kirby Goulet <kgoulet@xxxxxxxx>' @2 D4 H- b- W: |  @
Date: Fri, 9 Nov 2012 11:08:49 -0800 (PST)
4 k% S* M8 I: w- E4 X( |% s4 ]7 q& Q/ G# N0 z

6 T% K1 i. b$ {, H  LIt's not production quality software but you could try the mdtlc calculator to 4 a" J; Q4 U; ~! I8 G  Z7 |
experiment.  I tried Jeff's example and it seems to point to an explanation. - G9 v9 s  A2 k2 H& P% X4 x. C
The source code is available so you might extend it to do what you want if you
; @3 D4 F" @7 V7 bhave more time than money.8 m& F: D+ N7 Y; `
It looks like a race between loss due to increasing loss due to resin and - B+ x% E; n' m
decreasing loss due to wider traces.  There is a bigger increase in the resin . k  B8 k- {1 Y9 k" K& I, F3 U
content for the IS370 case over the IS415 case.  Not only that, but the IS370   C4 u) [7 t' T6 V
resin is lossier: 0.0169 versus 0.02984 so the winner is increasing loss.  
6 }' O! p. d7 ~" n5 f! W
  v+ Y$ f& T' d2 |1 LFrom the field solver, ' g! ?" q. J) a4 @7 n- F' _) W

! D0 z, G% h, q4 G* d; t% ]* IIS370: the effective dielectric loss went up 14.7%.  The perimeter of the $ U. ^3 U! e* k# `2 Z$ C2 `8 w# q
conductor went up 3.6%.  
1 r, \* w/ N! u. ]1 A% qIS415: the effective dielectric loss went up 6.7%. The perimeter of the
7 @% I7 ~; y- |! J/ I4 M9 g7 Uconductor went up 5.7%.
  I( ]* L8 J5 O" C9 g# a( ?2 u  E0 d; Y
In the second case, overall dielectric loss is a smaller fraction than the
% a, E% L6 w: t1 j3 Ffirst case.  The missing bit of information you need to add is the conductor
# H6 K2 B7 H8 _) o3 X1 }loss.' J) v8 ?# ?# |( R& R. S

; c! J' Q0 q3 o+ O  EINPUT PARAMETERS:3 L9 ?! k9 ]/ j1 j

5 ]/ X8 L' W7 @0 \9 S7 O7 K      Layer             Thick   Specifications 8 q9 l$ y1 }/ L- H8 n
      Copper Plane Top   1.30    Opening w=0.0  offset=0.0
2 j: m* L. h7 D: _  }      Laminate Layer 1   3.90    Resin Content  57.0% 3.4-4.9
: Q% p8 R7 r% y6 |        Signal Layer 1   1.20  4.3-7.2-4.3  Etchback=0.000 b/ r/ m! m0 {1 \. ]. D& f9 t5 k) m/ E
      Laminate Layer 2   3.90    Resin Content  57.0% 3.4-4.9
1 {4 v' g4 @8 A+ L; Q9 o9 L   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.00 U' G& b5 f9 z( \5 L& X

! l& d- S+ e8 y; x' G      Layer             Thick   Er    Loss Tangent9 ]4 `% w! o! E& `1 Q) ~# f. Q
      Copper Plane Top   1.30  3.20   
& U6 a. Y/ n3 d; R( @6 v7 N3 v* i      Laminate Layer 1   3.90  4.02    0.02100
' B+ R: [: u$ E/ F  U: z7 k        Signal Layer 1   1.20  3.38    0.02984* {) B: m& E# y. L6 _# }2 S9 f, @
      Laminate Layer 2   3.90  4.02    0.02100; v) T/ W0 a1 }6 L* z& x6 C
   Copper Plane Bottom   1.30  3.20; M' t; T$ K. E3 L1 x. c5 F5 c

) t. e( z$ v4 I7 R- m DC resistance by dimensions:- c' Z, i8 X1 [' T- m
Rdc_trace_1= 131.53      Rdc_trace_2 = 131.53  milliohms/in 20C
! A0 V0 X$ R! m+ ^  }
  K# s" ^% p  o3 x  L! A, W DC resistance by pixel count:( `6 f% o9 M% u+ h, D& U0 E
Rdc_trace_1= 131.531     Rdc_trace_2 = 131.531 milliohm/in
, t. C- D" k+ q! k. E C_odd      =   4.221 pF/in    C_even =   3.968 pF/in* @4 D* |; p0 ]( S0 m2 C
Er_odd     =   3.923         Er_even =   3.947
3 f9 ~& |& b" r/ L1 G5 @5 s. | Loss_tan_o = 0.02212     Loss_tan_e  = 0.02184  
$ u& S2 M5 _( G& t Delay_odd  = 167.801      Delay_even = 168.314  ps/in.
5 n3 N1 p% m% y7 r, e$ ~$ f Z_diff     =  79.501  ohms   Z_comm  =  21.209  ohms
& S2 E* W& i4 a* z % k+ {5 e# w" Z6 Z/ t. }, {
Simulation pix map 122 pixels high by 800 pixels wide.
5 t- y- D0 Q; S* f) N' q293824 bytes allocated for bmp.
! {, h9 A: W4 D7 O& p6 d! V ' L7 \9 r2 l4 U% _! i7 c
INPUT PARAMETERS:
) i/ t  C: h6 w9 U* n
* G( y( X# D  f+ y( I' V4 p% `      Layer             Thick   Specifications
# v+ o8 U5 ^8 ]" b2 c      Copper Plane Top   1.30    Opening w=0.0  offset=0.0- I3 @  F8 u6 I$ I3 ]
      Laminate Layer 1   4.20    Resin Content  75.0% 3.4-4.9
* ]- v$ M# D3 ]* E" \" z        Signal Layer 1   1.20  4.5-7.0-4.5  Etchback=0.00
1 g* `! a4 C0 y; B      Laminate Layer 2   4.20    Resin Content  75.0% 3.4-4.9 4 D$ \+ u! S, c  w, ]  }" m4 _
   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0$ ^6 U/ X5 x; d+ L
, A. y: v0 q  B
      Layer             Thick   Er    Loss Tangent
* M0 E. L/ V( d. u; }8 M% B! S      Copper Plane Top   1.30  3.20   2 Y0 R6 ]- O& n2 B9 j
      Laminate Layer 1   4.20  3.75    0.02470 3 K* {) E) @3 d4 j+ I+ P$ z5 Y
        Signal Layer 1   1.20  3.38    0.02984
3 g9 Q; N, R+ m" i      Laminate Layer 2   4.20  3.75    0.024701 E* t( Q' S: \) p
   Copper Plane Bottom   1.30  3.20- ]9 z* F( E1 A: x: V: h1 _
+ ]$ K& @' z/ ?* o5 [( R0 C
DC resistance by dimensions:
7 A" A) z- T8 F. A0 \9 s# G* a* M Rdc_trace_1= 125.69      Rdc_trace_2 = 125.69  milliohms/in 20C! k: L& Y; h0 P  {

) h# N; X7 F) @7 o: }6 C DC resistance by pixel count:% ~" q6 |1 k) y% d. _% G7 i9 v
Rdc_trace_1= 125.685     Rdc_trace_2 = 125.685 milliohm/in
( [6 i: ]+ ]" d- C( C; z C_odd      =   3.929 pF/in    C_even =   3.624 pF/in$ }- _. P! w1 J0 G  }
Er_odd     =   3.694         Er_even =   3.710% c9 q, _7 p, `7 y& e  w( i$ d0 o
Loss_tan_o = 0.02537     Loss_tan_e  = 0.02518  
% N8 V) g) M1 U% e5 {9 Z: J4 u Delay_odd  = 162.844      Delay_even = 163.195  ps/in.
, Q: V7 z* d' I Z_diff     =  82.900  ohms   Z_comm  =  22.519  ohms
' I' z& R2 h& ] # Z" h! g$ f# @, b4 X
Log file save name:
- d) Z/ h& W, l/ N" }' p; `mdtlc_12100946383.txt7 d; X  H! C  ?
) ]* X  S' s8 S' _4 w" s$ R1 r% M
Simulation pix map 118 pixels high by 780 pixels wide.
) k8 `& Q; b" P& w% c+ b8 |- M8 h277144 bytes allocated for bmp.2 j5 G. l3 g! _8 f; T5 Q
& u1 G3 j3 ~. k' F% S
INPUT PARAMETERS:
, M! W) o: L  A, C
; d) \/ G& S/ G$ o; B      Layer             Thick   Specifications   b$ b8 r7 t) E8 f
      Copper Plane Top   1.30    Opening w=0.0  offset=0.0
# C3 z$ h: q  Q' o      Laminate Layer 1   4.00    Resin Content  45.0% 2.6-5.1 , J7 o4 z5 N/ F( K% q$ H! b
        Signal Layer 1   1.20  4.1-7.4-4.1  Etchback=0.000 ], B. H- F# D% O- f( z
      Laminate Layer 2   4.00    Resin Content  45.0% 2.6-5.1
8 y  s* u& g8 g   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0! x! C8 }5 ?# e1 N( i( w. C
8 _1 s2 Y! l' f9 c* n$ Y/ T5 x* P
      Layer             Thick   Er    Loss Tangent
& {) J4 ~( N1 g7 [) P      Copper Plane Top   1.30  3.20   5 G" K$ r! [, Y
      Laminate Layer 1   4.00  3.98    0.01140 ; q. B! H& D& L' W. R1 R( x' q5 k
        Signal Layer 1   1.20  2.64    0.01690
: ~+ ^. m8 M' Y      Laminate Layer 2   4.00  3.98    0.01140
4 p% T( D8 v4 i+ D   Copper Plane Bottom   1.30  3.20" c# i& }3 J7 P  K

; h" U, ~  B7 j DC resistance by dimensions:
& ^3 y7 @5 Y3 }1 B Rdc_trace_1= 137.95      Rdc_trace_2 = 137.95  milliohms/in 20C3 i5 j' D; H6 h2 h

' ~" B$ b( L: T) i" n; a; P9 s DC resistance by pixel count:
7 V4 D5 d4 `. R6 F! r2 i0 N. C, V& W Rdc_trace_1= 137.947     Rdc_trace_2 = 137.947 milliohm/in
" u7 `, v$ }8 G% t# z C_odd      =   3.910 pF/in    C_even =   3.695 pF/in- S: W1 A7 j# f$ ]- m5 p5 o
Er_odd     =   3.769         Er_even =   3.8174 x* U+ U9 Y" S4 r  }$ _- |4 H
Loss_tan_o = 0.01202     Loss_tan_e  = 0.01189  * T$ O* \: Z3 A3 `" o
Delay_odd  = 164.490      Delay_even = 165.524  ps/in.
: J( L: _+ P  B Z_diff     =  84.134  ohms   Z_comm  =  22.396  ohms, g0 i2 c+ m0 P- ^; y1 |

) |1 b& X; @" ], dSimulation pix map 118 pixels high by 795 pixels wide.% a. b8 O1 B: l2 h5 J; r% Q
282454 bytes allocated for bmp.0 B8 ~9 ?& X4 y& K6 m) s6 P, r
+ ?; D2 Q1 n9 J7 R+ k9 ?3 x' N* x
INPUT PARAMETERS:# P; `8 p1 h9 m/ h3 x
4 ]& N8 Z& W& f/ C# W
      Layer             Thick   Specifications
2 i5 w/ ?6 G& y- c9 W* S      Copper Plane Top   1.30    Opening w=0.0  offset=0.0
  |3 G& S7 |# r3 A% L  [0 z      Laminate Layer 1   4.00    Resin Content  54.0% 2.6-5.1 2 b) I+ X- R+ X
        Signal Layer 1   1.20  4.4-7.1-4.4  Etchback=0.002 E& ?  y3 p/ M2 a8 f
      Laminate Layer 2   4.00    Resin Content  54.0% 2.6-5.1 5 y. W. ^  T! m" a5 c$ l
   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0& Y* g: K" z* {$ v

# \0 A5 M# H2 b3 n$ r& I! p6 \      Layer             Thick   Er    Loss Tangent
# N' G2 p" c1 [! H' @      Copper Plane Top   1.30  3.20   
5 \9 D3 v7 h. Y9 D( D      Laminate Layer 1   4.00  3.76    0.01230 " ~9 F! M# Y3 B( o
        Signal Layer 1   1.20  2.64    0.01690
4 G8 b  [6 n- {7 R1 y; c      Laminate Layer 2   4.00  3.76    0.01230) h: l/ ]2 S  L/ ]& {
   Copper Plane Bottom   1.30  3.20! r/ Z3 B4 \) y# W- p1 o
- C- u. {3 x( v4 Y% ^, e! W" ^
DC resistance by dimensions:+ p. C4 r; D4 G; z6 U2 a( L
Rdc_trace_1= 128.54      Rdc_trace_2 = 128.54  milliohms/in 20C
7 W  B. f1 ]+ W) R* j9 Z4 R% s: G
* [, o' Z7 ]3 I DC resistance by pixel count:
! S1 O& c) Y" N# m: j% D Rdc_trace_1= 128.542     Rdc_trace_2 = 128.542 milliohm/in
- _7 Q6 a6 b+ @0 _; B+ a# P C_odd      =   3.865 pF/in    C_even =   3.623 pF/in
  n& K! }0 A/ u: f% J Er_odd     =   3.588         Er_even =   3.631
" ]2 n' _9 o2 R; ^0 Q Loss_tan_o = 0.01283     Loss_tan_e  = 0.01270  
( F6 M5 m1 K/ l$ _; F% X' C Delay_odd  = 160.480      Delay_even = 161.455  ps/in.
& r! w+ z; w3 D' G Z_diff     =  83.041  ohms   Z_comm  =  22.280  ohms
8 x- X" ?' X# O" M1 J; A9 `4 r* f
看完之后,我有一事不明,我总是分不清奇偶,不知道这两者到底如何区分,亲,你能告诉我吗?
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收藏收藏1 支持!支持! 反对!反对!

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发表于 2012-12-1 14:21 | 只看该作者
我以前也分不清奇偶,后来强行记住了even是偶,搞的后来一看到odd,就要先想even是“偶”,odd只好是“奇”了,很是麻烦!
6 ^  X/ k/ \  n! F8 p' T+ f; z你这一提醒,我以后可以换个记法了:odd是3个字母,“奇”数个字母;even是4个字母,“偶”数个字母。哈哈

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参与人数 1贡献 +4 收起 理由
beyondoptic + 4 方法很给力

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发表于 2012-12-23 21:19 | 只看该作者
晕, 版主居然转贴到这里来了!: c( G5 K7 f" S0 q
汗!!!{:soso_e110:}
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