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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。0 l+ ~0 _* H6 y# X

! K) r; r& e0 DDate: Tue, 30 Oct 2012 08:52:23 +0800 (CST) : g1 H8 y6 w3 V  W9 V, ^4 m

3 T# j6 i) F1 Q* H" J6 \# xHello experts,/ |. c# L0 N- u4 D
>6 a% U; J; ?: }6 c; Z! }
> I'm from PCB house.  Recently we have producted some insertion loss test , A% e9 R1 X+ k6 {7 I2 L+ Q/ o
> boards(16L, SET2DIL coupon, IS415/IT150DA/I-Speed Mid/low loss material with ( g/ c9 o( I( ?* V, b+ G3 I
> RTF copper foil). We found that the multiply core and high resin PP will * _5 F! n5 F$ w
> result a lower loss result. It's a trouble to MI engineer.  I would like to
2 [0 n4 m: \2 E. s+ s> know how to predict the loss base on stackup. Please help to suggest (papers,
' M0 L# t) ?: [1 w( q4 N> script, free software etc ). Thanks a lot!
6 A8 O" }  q1 Z3 I% A) V>, a( d% {5 A8 @
>
& T9 `2 \* }$ ?% _>
. d1 N5 d# ^# n( V5 o> Best regards,# V3 k/ w# ~7 D+ `- t3 @) O
>: l! h* a! k: }0 v: G
> Terry Ho
, Y# z7 }+ R0 |- O0 ]0 S
% R1 c' g6 l% @3 f* Z" m) s然后 Scott McMorrow ,steve weir,Loyer Jeff 这些活跃分子开始依次发表意见.) }# @0 i1 M0 e% ?8 P/ S! W4 k! S
( m6 q9 n. P" M9 J" o+ S, z
From: Scott McMorrow <scott@xxxxxxxxxxxxx>
) `& ]# D+ o/ JDate: Mon, 29 Oct 2012 21:02:36 -04007 _; B( [4 M$ N# h9 \; @0 {
4 p: A1 e1 e9 |& d' L( K
Hmmm...  I'm in the middle of the middle of Hurricane Sandy.  Power is out.
/ t1 c8 i- ^, i- pStorm surge is causing the river across the street to rise to unprecedented& t+ R' R" h+ y& d: y: k$ E1 Q: P
levels.
  [! X5 g8 T8 c. e4 F, R9 W* t... and this guy wants us to do his job and suggest free software.6 g# `4 M% P0 \: V

2 F4 G( t- v7 e1 f/ {2 A, i! R
4 V+ M5 ~1 c" [, Y( u2 i( c- gFrom: steve weir <weirsi@xxxxxxxxxx>8 z$ F- {0 e. W$ n! G2 @
Date: Mon, 29 Oct 2012 21:23:22 -07006 B. d( B0 B! i+ ^; L. K/ o4 O) v* q
7 X) T% M! n" B( H4 X7 S+ K/ \& G! }
As a PCB fabricator I think you need to develop in-house material
/ ?7 M2 M; b4 G( F' b: `5 ]properties expertise.  Your competitors who understand the materials 7 H/ D3 z. l' i7 y& ]% X
they use and their process limits are positioned to get higher yield ; L1 t1 r( T' ?3 D( v+ A$ Z/ J; ]
percentages at lower cost because of their knowledge.( T# b0 G% o+ f4 \8 s0 C

* b) s$ y1 J! J% H" XI appreciate that you don't want to spend unnecessary money, but at : L1 Z7 z2 @6 e
least spend the time to learn about what you are using.  I am troubled
, g9 B5 x4 ]5 d& c' Uthat your engineer knows so little about the materials you use that he 4 t% v0 \( |4 j# Z' Y- W
is surprised by common results.  Once your company understands materials
( ~0 E+ N6 a4 P1 N# m. G5 `- N/ rbetter you may well appreciate the value of commercial stack-up planning / @' K8 i: j6 X- K7 B3 o8 e9 m5 K
software.
$ _, J/ h- I  M
3 I" {/ \" N- n' Q& D  @Steve.
+ ]; V- Y* R8 v. p9 ]# w% C8 X! t8 k5 N# T) r6 h! N: I
From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>
& y6 d: _" g! @, mDate: Wed, 31 Oct 2012 21:33:48 +0000
8 n% L$ O# {7 j, ]+ d
* u% N+ ?$ u8 m
9 w) Z* U) h0 _  D  r3 C4 bI'm surprised at the tone of the responses to this posting (but perhaps I
0 O+ S0 ]2 g8 [; l8 Nshouldn't be, unfortunately); I don't see anything untoward in it.  I would
, j0 g+ R9 E" P8 _like to provide some context (with some assumptions on my part) for the message
9 z# h) f5 F! v9 p1 jlest other innocent postings meet with similar fates.  I'll also (eventually) 7 t) S4 I& K4 f
provide my answer to the question, as I understand it.( q/ A( x, g, N/ t6 a
# V! j+ r0 ~( F& |  `
9 [* x/ O1 U: W( m7 w" P4 q
There is a significant portion (majority?) of the industry which is extremely / Y. V; }  L! R& N2 L+ u
cost constrained.  For instance, to them rotating a design 10 degrees is
, R0 h" n5 L' X2 f$ z* iimpractical, much less 22 or 45 degrees.  Thus, they find other cost-effective 9 R( a' s1 W9 c4 Y- S
yet effective means of solving problems (such as zig-zag routing), even though ; @' d6 J4 O" b8 r5 ]
those don't appear efficient to others to whom cost is not an issue.( o3 J8 E4 p$ X: e4 |+ V, u, y  _

: ?8 W7 b+ ^' p$ T' u% K" q  g5 P7 V
" r+ p, x+ t% D: H2 W) Q; D
There are new pressures being applied to this segment - designers are now not
+ v* \* @* Y: Q! G, d! D7 vonly requiring impedance control, but are also insisting on insertion loss / j5 Y+ F5 k  @$ [/ v
control.  This is a HUGE paradigm shift, very similar to what we encountered
& L$ h1 G0 W1 D9 P! K* Rwhen traceable impedance control was first introduced.  That was a very
' s5 G; Z; W" ~% Z( achallenging evolution, and this will be also.
- K% _5 W+ k0 c) s; B3 D1 J0 V
# t3 o2 }9 ^2 i5 I( H
) Q1 V  [% o1 ?3 `0 r+ z
* J& t; b! E/ M: rAs an example, PCB vendors are now being advised to smooth their copper, after - N# I; }2 I. M4 |5 z
years of purposely roughening it for best mechanical integrity.  It should come
6 i! \: U0 t) z; p. `: tas no surprise that this is not a trivial change, considering the effort that % E! z, x, _8 a4 B3 D9 L
has gone into ensuring mechanically robust designs.
+ R& o2 x. a0 l! u+ l) b3 g! l# ?
# O6 w0 S" H" R# L
* Z9 O8 m$ s) s. v+ k. B, V
  m1 l; B( S- ^; l1 c( QLikewise, many other basic assumptions that we've been able to apply for years 4 S# _; K: j' o% s* r' T
are now being drawn into question, and PCB vendors are looking for help to ( t/ s# b6 A; \3 O7 m+ m, Z
intelligently and cost-effectively explore options - "How much effect does # X7 D* \( g: J- E# Y% V6 K
rougher copper have on insertion loss?".   I believe Terry is highlighting the
- [! z. _7 B" i' {( ~/ u" f  ?fact that, while there are many tools available for impedance prediction,
% C2 w0 G" C4 Dinsertion loss modeling is much less accessible.   I don't think it is   ^/ i( S' Y, Z4 w; o
inappropriate to ask if there are cost-effective, reliable tools available to
, ^+ f6 @4 M6 B% ]" U: B+ {0 [predict insertion loss based on a proposed stackup.
5 y# P% [2 k4 j4 V  P5 [9 d' K- H' X; L0 Q. t: C

, [" x/ V2 g- m- Z$ Q/ j
  T7 {& k3 z$ H7 Q9 T, M4 BUnfortunately, I believe the answer to the question is that there are no
' Z5 F" ^/ d: w. _8 s: e" z& f2 T3 mreliable, cheap (~free) modelers available to predict insertion loss.  And, the 7 L  Y3 w. v7 l, u
ones that are available require a great deal more knowledge about the stackup
' }$ I8 }4 H5 k2 v/ j8 }; Bthan impedance modeling does, and that information is not easily obtained.  
! I6 D- I3 x! Y: C  i  d. a! DThere are some of us working with a vendor to test their modeler against a * S6 S2 X0 W1 q9 l- G  V$ }
variety of stackups and we'll present results at DesignCon.  My personal goal
1 Y" f  A/ f: f) k; Dis not so much to test a specific modeler but to judge how effective a modeler
) q1 ~, t  v, b; t3 F: {can be given information that can reasonably be gleaned prior to building with 6 V% @6 t$ \) T
various materials, copper types, etc.8 t& @( Z8 g% b; a* L+ N- p! @
9 E+ j0 M$ f  Y

3 _$ ^- S: \' d( i: B2 j
6 w7 J0 C; ~2 r* x$ oIn the absence of a modeling tool, or in addition to one, I believe empirical 7 i0 r8 r; Q7 c+ t/ \
data is the best predictor of insertion loss.  To do this, however, you have to
& j/ g% h1 c) V- Qbuild a stackup representing the final design, and it's not clear at this point
% O, @* J' O8 I( qhow broadly you can extrapolate those results to other stackups.  But, I know , ~( g  [- r: ]! G- A
many material vendors and PCB shops are engaged in similar efforts.1 J. h$ M* Z! h& u
8 d* C2 y0 F$ g& C7 P9 q' e9 y
( s* c, Q) W' ^. @0 ]* i7 C+ v5 [, Q
% y. `! Z* A% V' @
I think this is very similar to what we went through with impedance control -
; k8 P. S4 V3 e& Uthe shops which most quickly were able to predict and control that ' @) l4 d9 l1 F  S% X9 V+ `
characteristic had an advantage.  I think successful PCB vendors will need
' y( d/ ^5 u, e* xreliable modeling software and empirical data on insertion loss for their
" [2 ~! }- ?) |( O0 n& h  ]! {/ gparticular choices of materials, etc. - they will be able to find the most cost
5 T# r" V  r; R& W5 p4 e" b) oeffective solution.
; k! T: d# @/ ?9 f; v# i; X' v# z5 h. h. V2 D$ s) B

9 [3 R) ^- A* t$ a
) m* J) E0 `5 T$ `* S' n4 E2 P' f+ t1 `Bottom line: I doubt a reliable modeling tool is going to be cheap, but is 8 d. `, r0 p9 c0 F; A6 q8 p/ Q
going to be necessary, and you'll want to compare any tool you do purchase
" S6 s% V* \, |( o! T; Hagainst empirical data before you trust it.
; Y6 z; G7 p; H3 i: ]! ~) b7 T6 w" u
6 ?& A) X1 ?1 `0 ?) e6 Z

6 x, A. P$ p# }+ J; XI hope this helps,- }' L! \* ~6 k! e
% L+ H9 z( M- `2 O1 \
Jeff Loyer2 }0 c, i* }5 s/ U  G

9 w  |  M0 f4 i6 m2 Q0 ^) t# ?3 q& P7 l2 O$ F, P* O8 Q" |" P
From: steve weir <weirsi@xxxxxxxxxx>
4 W- [6 Q9 @9 o6 ?Date: Wed, 31 Oct 2012 20:14:41 -0700  H! D( n( B8 Q$ O% j

1 C; p) i# x: ~' l. C & f# d8 @, O: g8 F
Jeff, given that the only two responses were Scott and mine, I am 0 J$ T% c! r* v
surprised that you are disappointed with both.+ C' F  ?7 ?$ \+ Y) ?; q
8 Q7 u: ^$ m+ f9 I7 G
In a fabrication market filled with intense competition it is up to
: M* \0 T) R4 qindividual players to keep up with the technology requirements of the $ P/ J) ?" x  H% X
market or get left behind.  The task is not simple. Depending on how far 6 S7 a% d+ I9 H, |# {
up the frequency range one needs to go, dialing in cost effective
4 E2 J9 S7 B9 m# D: \process requires substantial skills, time, effort and serious money.  It 2 e6 d! l9 M9 p  _& d
represents competitive advantage to OEMs and their partner pcb fab : R. D! O/ F+ [, k  J( q( F% L8 P2 F2 M
houses alike.  Neither who have invested are likely to hand over that 5 U3 X; V( c% H) e5 f
kind of advantage especially when it is so costly to obtain.' ]# ?* e, O, |; c; N
+ {% `1 K6 n* m% r' x7 d
I don't mind that Terry is looking for a solution on the cheap or free.  
" B4 y, T, a" e7 Y4 Y. c  {If one could obtain such a sweet deal, one would be foolish not to take 9 j: v" A: S3 D
it.   I am troubled that in this day in age, his organization hopes to
: S2 e% ?# s/ b, i/ [. Q4 uaddress a sophisticated issue before his technical staff has a grip on # E; V7 E/ L1 `  p) t8 H$ A
the basics.   I fail to understand what you find inappropriate about
" s: x: V; ~4 H4 {+ ?that concern.  I would rather yell at someone headed for a cliff to stop
0 B# N$ G3 [( w0 z: K4 uthan smile and wave.( l4 s3 b  u: K/ B' \1 d, B
! l3 H: O% R- S* [; W0 s
Best Regards,6 M; o: J' Y/ m; _2 {" d  s# h
% r  n3 T, S; e& p9 ^5 f
( l* U# V" A/ I; Y* d& k0 A! {$ v
Steve.3 L8 U2 L' _5 s7 i5 X0 q+ @2 a

+ z! ~/ z( O0 l. \From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>& @% J. n' U. R4 P3 j6 N9 O  F
Date: Fri, 2 Nov 2012 15:37:46 +0000
: p( C  N. y: Y& G/ u" }1 B6 M* r9 z. U3 Z1 N

5 f, I- J: Q' i( G" f4 kI realized we hadn't answered the basic question - "why does a high resin
# _% ^* e; x1 k; Gprepreg give lower loss?"  The prediction of loss vs. resin content isn't
, U3 E8 A6 J, ^- ^trivial; as Steve said, a tool which allows you to model loss for the various   {( w" P& F; ?& |
scenarios should be on your Christmas wish list.  Here are the factors that I
& v2 r) d) A' h" yknow of (thanks to Richard Kunze for clarifying things for me, and I welcome " ?2 l" P6 H% R; p6 ]
others' data/opinions):1 R9 I- v! |' e$ T
* Resin has a lower Er than glass4 c; u) g5 B8 d

) K5 g) E4 t7 b     * loss is approximately proportional to Df * sqrt(Er), so lowering Er
" D& U( Z( k0 f9 xlowers loss6 ^7 q5 f4 G; N1 I( q" W2 j% N

' X2 i% N3 \" X$ f+ L3 t# {; F     * lower Er allows wider traces for the same impedance - this may decrease ( @  z" U) n" M$ j$ d
loss also3 ^* o0 n' [1 z& `
6 S- d% n+ O8 r, w
* But, resin is more lossy than glass, so Df may increase# c' l) m3 K6 Q

4 s/ m! G$ B1 x/ s! e2 j     * for standard FR4 constructions, this is especially true.  The data sheet ' _. R" U4 ?6 P+ b5 W. h9 t5 c/ {
for IS370HR, for instance, shows Df varying from 0.0177 to 0.0247 (1GHz),
( j: |  j) B7 J# o3 i7 Hdepending on the resin content' w% d$ \) n6 P% z. w

; e! A* F1 L" Y1 y  p8 x     * for low loss materials, this doesn't hold.  The data sheet for Meg6 / A9 L0 }3 j: P% l$ f. [$ ?! E9 U
shows Df constant (0.002 @ 1GHz) for all its flavors of prepreg( [8 b6 k4 {: F$ J
1 q" I  W: Y; Z' l
* Where the factors dominate will depend on your relative conductor vs.
" O( D6 G7 W  F5 s- ndielectric loss effects: for FR4, dielectric loss dominates at >~1GHz; for 5 I. w' s$ d3 q1 c/ N1 }
low-loss materials, conductor loss dominates up to much higher frequencies (as ; Q# ?: }& c$ n! S" g8 w) D9 k
much as 10GHz).
: L9 M1 ]* M2 e$ L" l9 X5 X
$ ?6 V# a7 {& H# D+ J1 n) j
8 ]0 {9 [! ]) t# l. C! `7 u+ X6 g" E
In your particular (low loss) case, the lower Er of the resin-rich case is : E- j" w- \+ A5 {
trumping the Df change (or lack of) so you get lower loss.7 z1 M1 k3 R, |/ \

3 l/ f! e! v5 E- U' P
& k( ^% N8 @& N; l$ S8 d' J/ R& a0 a
Only a tool which takes into account the properties of the specific material $ a" F6 A; r# e, C: l+ T
under consideration can be expected to give an accurate prediction of insertion ! F  A0 S. S( T9 P" W
loss for various resin contents.
" ~5 w! }/ P) U# k9 k7 D. ~; F

  k" E8 ^7 y+ q% l( @- r* t% k3 k6 M- _  t* J
There are also environmental effects (I haven't heard or seen these stressed at / M5 Z& {+ h5 [9 ?  \( v7 ^; M
this point, though that may change soon):/ |5 V/ ]9 _# j! C' ~; h, i( j

9 ~. r; F. ^6 `, q2 ?& I* Higher resin content will absorb more moisture, and thus your loss will be
5 M- f1 ?0 c, D, rmore susceptible to humidity effects* a/ g: Q& h3 ?
  r1 E+ H1 a, W/ u
* There's a difference in how the various materials' Df changes w/ temperature 5 I3 F& t* _. r" f. w0 |4 R
- more at DesignCon
; X7 o6 x: A/ L8 \: C% O
2 k0 l, S& A: r: k+ r3 c+ E( P9 [

4 \/ M0 X* p; t: t# \+ M8 r- CI hope this helps,( B' @: U$ v. @7 W
, u, Y4 S5 J" d* }- U: [: z. g9 h
Jeff Loyer. ~! G4 B& P( o

: \" q, b. o' o/ q( W9 Y, N! J# NFrom: Scott McMorrow <scott@xxxxxxxxxxxxx>0 o, J3 C, V- [
Date: Thu, 8 Nov 2012 09:12:46 -0500; k, @% c2 o' Y3 `$ ~
& f7 F' x8 ^# N5 r1 B- b% J
+ o! `5 W: k4 q7 Z- {" \% D) S
Jeff8 D7 d% e6 U2 o7 t( {8 Q$ ~
A few quick comments.  Although the tanD of Meg 6 is stated to be flat, it1 b( U( E+ L* q1 N
is not if you measure it.  The manufacturer reported characterization in. p: z5 B1 {) P- t' ~- t& U
the data sheet is not correct.  Causality is violated when tanD is flat.+ [7 @1 \, z0 O' |- x" x8 f

1 t# s, J4 X8 O+ C4 ]/ sLoss is generally due to molecular dipole losses in the material.  It can: e# ?% e0 x0 G4 B
be low for high Er, as is the case with ceramic.) L1 C; @  u/ k' a+ `* W6 s, E

5 V) {" W7 Z% J2 ZHygroscopic loss is due to molecular polarity. Polar molecules "glom" on to
' f( l2 ]5 y& x1 z; Cwater molecules, which are also polar. Same property makes the material, Z6 i: F; n& f
extremely "sticky.". F- d# a6 V5 {4 T1 G0 i4 {' E) l9 S
( w  Q) g% I8 ^
The paper that Jason Miller of Oracle and I wrote for DesignCon last year7 T7 M! U7 `9 E6 C5 z+ J8 ]/ E
covers some of the impact of temperature and humidity on measured losses.  \9 ~/ {* N) u$ ?( d
I don't have access to my storage server right now, otherwise I'd give a' R6 s) z0 F/ O/ V9 H
paper citation.3 R5 c, l" R, B% d2 a
# a( b- H/ c  K, S9 e7 R7 B
regards,
* H1 L3 K0 X6 I' a
6 c7 Q8 ~1 P  B2 E$ k3 E# E! ]Scott2 G3 D: X) ^( w
$ L0 P8 _, T, d9 t
From: Kirby Goulet <kgoulet@xxxxxxxx>; }; j$ X4 f+ q+ S4 C- q; p
Date: Fri, 9 Nov 2012 11:08:49 -0800 (PST)% U0 y$ H, ]0 ^$ c: V" B" A$ Q

& X* L3 s& W8 H! c9 V5 G 3 O3 X# F6 m; h* t) A, }/ O7 _
It's not production quality software but you could try the mdtlc calculator to
4 |3 ^2 _% ]1 dexperiment.  I tried Jeff's example and it seems to point to an explanation. $ s! |7 b4 v7 _: `* E- k
The source code is available so you might extend it to do what you want if you
$ E7 I6 ~) p7 }: L4 p  C: mhave more time than money.( s) F" E" j, b
It looks like a race between loss due to increasing loss due to resin and
4 i$ w0 m# o9 J" A- u1 ldecreasing loss due to wider traces.  There is a bigger increase in the resin 1 N( j  d' l8 g& a9 S$ _: P/ n
content for the IS370 case over the IS415 case.  Not only that, but the IS370 7 `. `$ o# D2 V4 o# _
resin is lossier: 0.0169 versus 0.02984 so the winner is increasing loss.  
5 s2 B- \- U7 p9 o6 g* R8 S, S" L6 B) w
From the field solver,
5 B7 ]1 t9 ?# F0 G9 r4 D9 d' l% C6 @
! O9 l- Z  M. X7 XIS370: the effective dielectric loss went up 14.7%.  The perimeter of the ) _5 r- {1 e' g+ T
conductor went up 3.6%.  ( R* a: r' n0 \
IS415: the effective dielectric loss went up 6.7%. The perimeter of the 7 [7 c1 f8 h- W( _% k( R5 |
conductor went up 5.7%.
6 @8 [* f8 w& E8 W
# V9 K' p# g' tIn the second case, overall dielectric loss is a smaller fraction than the & o% U! K8 {5 Y& b: {# N# n
first case.  The missing bit of information you need to add is the conductor
& r9 T7 u+ I; d' Z" aloss.7 N% Q$ Y3 j8 ~9 c" u

( J! c) l8 r% i$ WINPUT PARAMETERS:
: U6 ]4 Z" C1 Z8 H0 Z
3 n  M: u6 ^+ R/ `- f      Layer             Thick   Specifications 8 p8 I$ S. @1 l( i$ L$ x( g
      Copper Plane Top   1.30    Opening w=0.0  offset=0.0/ w2 _) O  k8 h  f( F
      Laminate Layer 1   3.90    Resin Content  57.0% 3.4-4.9
6 ]7 I* a) H% Y( X& U        Signal Layer 1   1.20  4.3-7.2-4.3  Etchback=0.00
* W: X" t; p1 d2 x. z+ f      Laminate Layer 2   3.90    Resin Content  57.0% 3.4-4.9 ( Z, }" v1 s6 v: e  a0 R
   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0
& L; S# P% k8 |# S ) w" w1 U' e) \0 n) |
      Layer             Thick   Er    Loss Tangent& z& q7 \4 k0 {8 `- }$ w9 g* L$ _
      Copper Plane Top   1.30  3.20   
& z: r) g6 d! a$ \' {" ?8 B      Laminate Layer 1   3.90  4.02    0.02100
' m" }+ }9 a; f9 t$ J6 D, R        Signal Layer 1   1.20  3.38    0.02984- N* ~: o- u7 k2 N8 z" K: R
      Laminate Layer 2   3.90  4.02    0.02100
$ W- N5 H& v  v( ]   Copper Plane Bottom   1.30  3.20+ n, E% P) i4 H8 G7 ~. ]
7 I+ T. Y/ c8 l" ]
DC resistance by dimensions:3 B: T1 _* m0 `0 e6 k8 J5 h/ v' K
Rdc_trace_1= 131.53      Rdc_trace_2 = 131.53  milliohms/in 20C2 C! w9 k3 {/ j

9 I  i9 q: W; e) ~8 I8 x DC resistance by pixel count:
' i9 b4 e' C7 m' ? Rdc_trace_1= 131.531     Rdc_trace_2 = 131.531 milliohm/in  F: G# j+ F0 i$ W
C_odd      =   4.221 pF/in    C_even =   3.968 pF/in4 t+ `. J: a( z. t
Er_odd     =   3.923         Er_even =   3.947
: c7 J7 Z1 E6 R! e$ J' `, G$ Y' J1 q Loss_tan_o = 0.02212     Loss_tan_e  = 0.02184  & w. n5 |  [, |; j, N
Delay_odd  = 167.801      Delay_even = 168.314  ps/in.) u7 ]% k7 _' C2 s3 e/ N
Z_diff     =  79.501  ohms   Z_comm  =  21.209  ohms6 p) V9 u8 S, A- u9 |% i. T

5 u: P+ `1 J) s6 \2 R% H/ mSimulation pix map 122 pixels high by 800 pixels wide.4 u, B6 K5 L; B  @3 }# g  Q! Y  I
293824 bytes allocated for bmp., |- p9 r4 ^0 K# J, y
, _# j- |' e% _
INPUT PARAMETERS:
* o$ L# T: _  H+ o; Z. Q4 D $ S- z& q: E. Q9 d
      Layer             Thick   Specifications * f/ W; [( [9 M! z- a: M
      Copper Plane Top   1.30    Opening w=0.0  offset=0.0
0 y2 j' J1 y0 N2 S5 }      Laminate Layer 1   4.20    Resin Content  75.0% 3.4-4.9
8 K6 M1 E" Q, z  \; R        Signal Layer 1   1.20  4.5-7.0-4.5  Etchback=0.00
, C4 N+ Z! ?' W$ O' t      Laminate Layer 2   4.20    Resin Content  75.0% 3.4-4.9
& `' G" ~" {2 l8 q   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.01 `  b" ?* D$ {2 R
; c4 [* S) N- y/ {. E
      Layer             Thick   Er    Loss Tangent
2 s- @; G: l1 b$ n      Copper Plane Top   1.30  3.20   
$ m. K4 g: J9 H7 G. A      Laminate Layer 1   4.20  3.75    0.02470 ' T7 M# W( w: j4 {  T  S
        Signal Layer 1   1.20  3.38    0.029840 [2 @- i0 n( F* R6 H
      Laminate Layer 2   4.20  3.75    0.02470+ m) h6 h/ s/ D
   Copper Plane Bottom   1.30  3.205 Q* S, R3 |% u- u1 w3 D2 S: R

, b$ H* {& _. a, b1 y DC resistance by dimensions:# R5 Q, y) }+ j: l* b: t7 @; M9 Q
Rdc_trace_1= 125.69      Rdc_trace_2 = 125.69  milliohms/in 20C3 D* d, X3 S4 \# r# s
3 s, z8 c3 y" i) e* o) Z7 I
DC resistance by pixel count:5 O2 K9 J- y6 K& V' R* Q# H
Rdc_trace_1= 125.685     Rdc_trace_2 = 125.685 milliohm/in
& o4 [9 |0 f8 S- M: _& f0 _ C_odd      =   3.929 pF/in    C_even =   3.624 pF/in- `4 W9 j: q; a8 b
Er_odd     =   3.694         Er_even =   3.710
& E0 H$ ]) ?9 F) E  T/ P! P1 ? Loss_tan_o = 0.02537     Loss_tan_e  = 0.02518  
! _0 y4 }$ j+ v8 L9 @% C. j; J) R% z. w Delay_odd  = 162.844      Delay_even = 163.195  ps/in.% N  u, _4 a/ ~2 p$ y, S% w% z+ C3 G
Z_diff     =  82.900  ohms   Z_comm  =  22.519  ohms% A6 a. R- b0 P$ b2 [" _

4 I, m  Y2 H$ V5 k% rLog file save name:6 n  F9 Q# {8 [9 Q) Y( Q4 Z, S
mdtlc_12100946383.txt
  _$ t% x) [+ {! V+ [0 K
" D7 f+ D4 }/ k3 vSimulation pix map 118 pixels high by 780 pixels wide.9 m2 z8 ^( n& v$ @
277144 bytes allocated for bmp.
: B2 U0 z+ I% Y
, r; F8 u' N6 ZINPUT PARAMETERS:
% Y& a" y9 e+ b7 f3 G6 C/ V
# U1 K7 x  S, X% A+ P2 |$ g  i      Layer             Thick   Specifications ) y7 r+ g4 P% j: M; ?
      Copper Plane Top   1.30    Opening w=0.0  offset=0.0
/ `& E; D: W( Z& T      Laminate Layer 1   4.00    Resin Content  45.0% 2.6-5.1
- \1 }+ ~/ D; i- s1 |        Signal Layer 1   1.20  4.1-7.4-4.1  Etchback=0.007 D( Z1 m9 C" P4 a3 c
      Laminate Layer 2   4.00    Resin Content  45.0% 2.6-5.1
# x0 s6 m+ m3 S   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.06 n) b3 S9 G: m2 I0 }6 M6 D* G  f

# q0 {" F9 Q: F      Layer             Thick   Er    Loss Tangent
; i: x9 G. t. [- P3 u4 g      Copper Plane Top   1.30  3.20   # V6 O) a3 D9 j
      Laminate Layer 1   4.00  3.98    0.01140
% C! I* s4 l5 V, X        Signal Layer 1   1.20  2.64    0.016906 {% G1 B$ p8 d+ K/ f/ m
      Laminate Layer 2   4.00  3.98    0.011408 [1 M- S* x, T4 a. y  h0 e7 ]
   Copper Plane Bottom   1.30  3.20
, i* B9 Y" V5 W 9 T& ^6 Q4 S) j0 Q& B1 R
DC resistance by dimensions:
+ a7 c$ [. n' R. ^ Rdc_trace_1= 137.95      Rdc_trace_2 = 137.95  milliohms/in 20C% W. O$ T9 r$ `; J1 {4 R

" q( S  ~/ z+ @2 [/ }% Q; d DC resistance by pixel count:
% |( u9 G9 W' y2 h6 T/ h Rdc_trace_1= 137.947     Rdc_trace_2 = 137.947 milliohm/in' G' J  @6 q: J
C_odd      =   3.910 pF/in    C_even =   3.695 pF/in3 E: S+ p& Y3 \9 k9 l
Er_odd     =   3.769         Er_even =   3.817
/ k  W' Z- y4 l+ } Loss_tan_o = 0.01202     Loss_tan_e  = 0.01189  
$ p" X  g& M! a1 g/ | Delay_odd  = 164.490      Delay_even = 165.524  ps/in.$ D9 ?0 {8 G* U! L1 Z
Z_diff     =  84.134  ohms   Z_comm  =  22.396  ohms0 ~# Q5 _) I# p0 M) |0 l( `) P9 H

5 X9 L4 `9 l% X/ u+ N- x  ^Simulation pix map 118 pixels high by 795 pixels wide.+ ^9 S' e- u$ Q
282454 bytes allocated for bmp.; I/ ^& {$ W) {$ T0 u8 t1 V
; a6 L( |5 V8 b8 [6 V
INPUT PARAMETERS:4 h0 N, C# C) |

! s7 G8 L. b0 l! ?+ S# R      Layer             Thick   Specifications
9 g4 ]- s# F& m9 U9 `; p) ~      Copper Plane Top   1.30    Opening w=0.0  offset=0.0
) a2 n4 U: d+ E! s      Laminate Layer 1   4.00    Resin Content  54.0% 2.6-5.1
- _6 g) q0 j. q        Signal Layer 1   1.20  4.4-7.1-4.4  Etchback=0.007 w3 d# L' w! ~) L# T6 k+ b
      Laminate Layer 2   4.00    Resin Content  54.0% 2.6-5.1 / g4 y! K; }- g7 ~6 d% @1 p9 Q* K2 j
   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0  P% I. {- S7 d, ?& N
# ^; K( Y9 i6 g, K5 q
      Layer             Thick   Er    Loss Tangent
& _0 t! B! C" z; p- N, O      Copper Plane Top   1.30  3.20   ; i! i: |2 Q# [9 O0 Q
      Laminate Layer 1   4.00  3.76    0.01230
, f8 \6 p3 ^' j        Signal Layer 1   1.20  2.64    0.01690% r' ~* z6 R0 [
      Laminate Layer 2   4.00  3.76    0.01230  a0 ~  c2 {; V6 X; o
   Copper Plane Bottom   1.30  3.20
" E6 [2 h  K9 B6 k1 q  l
! h) e+ |* r  L9 y. D4 |; | DC resistance by dimensions:* H1 f& Z. P7 O5 t; U2 h
Rdc_trace_1= 128.54      Rdc_trace_2 = 128.54  milliohms/in 20C
& X5 p  R( @3 u1 o* I* B% L 9 _+ S5 r7 P6 d0 j/ C9 E$ q% |
DC resistance by pixel count:
, U0 X' G9 C' T9 K, x% |% U) K: r Rdc_trace_1= 128.542     Rdc_trace_2 = 128.542 milliohm/in# g6 G/ |" p# D3 L
C_odd      =   3.865 pF/in    C_even =   3.623 pF/in
  `6 s5 {5 x/ s) C, O0 ^2 K2 H Er_odd     =   3.588         Er_even =   3.631
9 Z" T( V# p) ? Loss_tan_o = 0.01283     Loss_tan_e  = 0.01270  
& _+ M% O: A! @3 k4 @( |+ e Delay_odd  = 160.480      Delay_even = 161.455  ps/in.9 I4 {8 v/ Z5 O- ]8 D4 e1 m) K
Z_diff     =  83.041  ohms   Z_comm  =  22.280  ohms
% X1 D$ _& w1 E$ Y* M% c& l6 p: Y* @. E$ d7 R- t
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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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!0 l7 `. p) h/ P. p5 A9 ]
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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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!+ R# l# k: {3 |: B
汗!!!{:soso_e110:}
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