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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。! [+ [: a; D6 K: o: R$ A/ S
) d/ c, k& T" }$ q+ C
Date: Tue, 30 Oct 2012 08:52:23 +0800 (CST)
( F. Y1 h9 D' z9 {" L) @
5 f& c) g% v5 rHello experts,
5 g7 G; a3 s2 O& o* j>
8 g% \7 F3 m: D4 \> I'm from PCB house.  Recently we have producted some insertion loss test
3 r" K. `1 J- o  v2 n! T" p> boards(16L, SET2DIL coupon, IS415/IT150DA/I-Speed Mid/low loss material with
9 x) N0 V5 @0 ^+ \3 M+ D- L> RTF copper foil). We found that the multiply core and high resin PP will 4 R; ], W/ Q, P( k7 H, L! X
> result a lower loss result. It's a trouble to MI engineer.  I would like to 7 d; ^+ B9 @% I2 S4 K
> know how to predict the loss base on stackup. Please help to suggest (papers,
% J& o- _9 G* |- e, Y/ ]> script, free software etc ). Thanks a lot!; ?* K# `! h1 G8 ?& ^
>! _7 O' ]) g7 h7 X$ S9 f
>7 U1 r. z/ R+ l( _- @9 c
>
3 N3 f% v! u2 K0 R) y> Best regards,
/ y1 K! T7 v' g>
! _; w6 I4 A5 N" g> Terry Ho
8 M, q  R# z; q" y; O/ @
+ p4 w3 i+ M6 ~2 }7 s然后 Scott McMorrow ,steve weir,Loyer Jeff 这些活跃分子开始依次发表意见.
* V) ^% ]& n0 v3 N' K3 z
! r# y% j( W" O5 _3 oFrom: Scott McMorrow <scott@xxxxxxxxxxxxx>
0 c( g  ?. O" _  @Date: Mon, 29 Oct 2012 21:02:36 -0400% J( w6 O, r4 a6 i; ~+ i
4 {* H  }% B: x. _4 Z! F
Hmmm...  I'm in the middle of the middle of Hurricane Sandy.  Power is out.: ^) S$ S$ y8 m+ y. ]
Storm surge is causing the river across the street to rise to unprecedented
; s' ?* S# ^+ `levels.7 ]& ]$ [5 N4 M- a
... and this guy wants us to do his job and suggest free software.3 Z6 i( b' s) g& h6 P

1 g% ]0 h/ X0 O' q5 r/ ]' R2 b/ I( G7 a, ~
From: steve weir <weirsi@xxxxxxxxxx>: w2 X. k2 d" A# _4 s% K
Date: Mon, 29 Oct 2012 21:23:22 -0700/ q- [- t/ I" X5 A; U7 B+ Q
. _* ^/ l( T' _
As a PCB fabricator I think you need to develop in-house material ' }, a! _* ?: K* i% ]- g0 N1 f" Q
properties expertise.  Your competitors who understand the materials 0 M; K$ I/ ~$ K5 W
they use and their process limits are positioned to get higher yield
' s( I3 X) `, e. hpercentages at lower cost because of their knowledge., P& p+ p3 O% D; k. [* h  i; W
# X3 i9 n$ R3 [
I appreciate that you don't want to spend unnecessary money, but at
8 M1 i  {  v% G3 E2 x& b3 L: @least spend the time to learn about what you are using.  I am troubled
2 f6 g6 L4 j4 A( u; Q( Y; Othat your engineer knows so little about the materials you use that he
  t  b0 c8 [! }! X! P( _" M# r9 n) Tis surprised by common results.  Once your company understands materials
/ I+ ^6 c- ]: z  z4 a9 d( }5 ubetter you may well appreciate the value of commercial stack-up planning
' {1 d( _7 ]" k  D; T) }% l; B" Csoftware.
/ r3 r7 ]- Z1 ~$ W0 I+ T5 z) I8 T9 [, Z- Q
Steve.
7 g+ u3 e8 e# A, \8 o, f2 j" \' G% j8 E
From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>
1 T, I0 M) |+ l9 WDate: Wed, 31 Oct 2012 21:33:48 +0000+ D9 B) B1 J" g
/ F# [% L2 Q: K( h2 G

0 U, N1 y9 `) [$ `I'm surprised at the tone of the responses to this posting (but perhaps I
8 f; o, q! y; O2 m$ k' `shouldn't be, unfortunately); I don't see anything untoward in it.  I would
; {( @: g& x/ ~' ]4 m+ P1 xlike to provide some context (with some assumptions on my part) for the message . J4 W/ Y3 `0 {% A0 r3 x! e* t6 n
lest other innocent postings meet with similar fates.  I'll also (eventually) 5 F! m+ r+ A3 r/ [( A: @
provide my answer to the question, as I understand it.
" g! |. ~2 v0 R1 s; G+ b5 C1 n& `
0 X2 l& o) u) o7 B
There is a significant portion (majority?) of the industry which is extremely
1 e( h% _5 K' R7 C2 _' Qcost constrained.  For instance, to them rotating a design 10 degrees is " s8 V; ?" I2 ]( ]" S( G7 {
impractical, much less 22 or 45 degrees.  Thus, they find other cost-effective 1 _0 [7 \. N+ ~+ o. f7 A/ r0 ]
yet effective means of solving problems (such as zig-zag routing), even though
& Y# x( f( O& m" E) @, Bthose don't appear efficient to others to whom cost is not an issue.- u+ R2 s" o' X8 t  ?
. e5 x6 j- N# o% t# U9 T
- \7 n9 `1 F- T; z- i7 m- O
: i& z+ f4 e# y8 e& Z3 X) N7 k
There are new pressures being applied to this segment - designers are now not $ L4 P# \8 ?# ?+ p/ _- Q5 C
only requiring impedance control, but are also insisting on insertion loss 9 e; ^9 G! x7 i: G$ ?9 o
control.  This is a HUGE paradigm shift, very similar to what we encountered
4 u4 O& W, r4 K. dwhen traceable impedance control was first introduced.  That was a very
. d: v& p: }* @! i8 p8 D$ Uchallenging evolution, and this will be also.
! t2 c8 k5 G) _* M* m: p6 ?# K+ w% g# P& Z) q
; @' J7 m/ u: G+ b! ^

+ O  Y1 R6 V& M0 `As an example, PCB vendors are now being advised to smooth their copper, after ; N! c& Q. b0 a% \7 q* r) G
years of purposely roughening it for best mechanical integrity.  It should come
2 j' q' O$ M7 E5 w/ {, b) pas no surprise that this is not a trivial change, considering the effort that ! \' ?" e* f4 T4 {
has gone into ensuring mechanically robust designs.  a) c. S: u0 O2 E4 H: U* l

% }3 ~* E, B; x/ |. C4 ?) P6 d8 P- {! G* M+ h. ?8 q* X
/ |9 k6 b6 E3 g- o/ x/ ^- d) d
Likewise, many other basic assumptions that we've been able to apply for years
2 x' r* C9 |1 w, K: d( ?6 m- B3 }are now being drawn into question, and PCB vendors are looking for help to . e7 D5 z) }; _4 u7 g! q" B# P( ?3 w& ?
intelligently and cost-effectively explore options - "How much effect does
! g/ @4 a. T* D3 n8 trougher copper have on insertion loss?".   I believe Terry is highlighting the 9 l$ o3 I, }) i1 o9 |
fact that, while there are many tools available for impedance prediction, " y% l5 H: W# v4 O! n
insertion loss modeling is much less accessible.   I don't think it is 8 D; L5 \8 h# Z4 j% v: _
inappropriate to ask if there are cost-effective, reliable tools available to
. B, e" B1 [7 h8 ]( \- r- ~predict insertion loss based on a proposed stackup.' J, n. E5 E0 Y3 E3 g! |

7 b8 z; O3 {$ f" p  C, Z" s
: Q+ V8 v# \5 |  G, \6 Z% f
! t: L0 E2 y+ R, S' ]Unfortunately, I believe the answer to the question is that there are no , H4 j. f; e4 Z! d
reliable, cheap (~free) modelers available to predict insertion loss.  And, the
$ K0 D8 m7 `/ S8 A; I& v4 Cones that are available require a great deal more knowledge about the stackup 5 U7 t9 x/ v. l$ p+ z/ j2 w
than impedance modeling does, and that information is not easily obtained.  6 A: _- s; J1 v$ z4 E
There are some of us working with a vendor to test their modeler against a
4 n/ c  O% F1 B4 f# c& S7 p- Tvariety of stackups and we'll present results at DesignCon.  My personal goal ( C; I# |& L6 [
is not so much to test a specific modeler but to judge how effective a modeler
/ o/ f2 U8 ?0 n7 a  k7 O$ \can be given information that can reasonably be gleaned prior to building with ! W! t: e( S; e8 a/ U2 k
various materials, copper types, etc.) ~0 _/ f* c( z
7 u6 {' s  y7 S3 H/ l: y) [. g

! @, Q. O& Q, h/ F% q6 o9 f2 N/ C0 c0 m
In the absence of a modeling tool, or in addition to one, I believe empirical ; F0 |0 ]9 f& t# o) ^  V
data is the best predictor of insertion loss.  To do this, however, you have to . \- y" A$ ?, x
build a stackup representing the final design, and it's not clear at this point & \- D' b# [! u$ P5 M# {* f
how broadly you can extrapolate those results to other stackups.  But, I know
2 D, B) ?9 q9 {1 lmany material vendors and PCB shops are engaged in similar efforts.8 }. h! u, j$ ~4 E. f7 N" ~

* t' A8 h3 G) K: ~, k+ b8 g4 x. Z- G1 g/ Z6 n, W) v

, z& ?4 T" v2 wI think this is very similar to what we went through with impedance control -
* ?. u1 g# c$ y! ?* X7 h& v8 I5 ]the shops which most quickly were able to predict and control that
% B/ b6 m  ~7 A( Tcharacteristic had an advantage.  I think successful PCB vendors will need
0 w0 c5 V. ~  D& l3 `4 C! p. Ireliable modeling software and empirical data on insertion loss for their 0 m5 O2 r% @/ @5 T3 _. H0 ]# B6 z2 I# P
particular choices of materials, etc. - they will be able to find the most cost
4 O4 U8 h6 J$ i0 feffective solution.7 _) N+ n6 T- |+ u
9 W0 k; V  K9 k% d- ~" ]; l
! ~3 {2 r, S3 s7 V+ \1 w

4 G( H. ^. [; Q$ B- SBottom line: I doubt a reliable modeling tool is going to be cheap, but is , p6 W- z0 _' a+ p. }: K8 O
going to be necessary, and you'll want to compare any tool you do purchase
( r# B. L4 p4 H# xagainst empirical data before you trust it.
# L: P% h: X/ m- u" j2 H1 m2 {2 j: v. ~9 ~
: P# i' G: X1 Z4 u
% `/ ]# b2 P% d/ v
I hope this helps,+ e* h8 e1 U5 _( O  H# i9 y4 n

5 `4 \  J3 E3 D5 m5 R! IJeff Loyer( r  g8 L4 H! J4 ]5 t
8 {3 p' u, B- ~/ G( k
4 d( ~+ j% w6 u" j/ a+ ^% S
From: steve weir <weirsi@xxxxxxxxxx>
$ g0 j' z& N$ ~$ eDate: Wed, 31 Oct 2012 20:14:41 -0700
# w+ `- P, f/ I7 R% p" N" v7 H" W8 x+ V2 R* b7 N
. |0 ?5 l+ f5 s8 @/ o
Jeff, given that the only two responses were Scott and mine, I am
% N4 p8 d* p) T8 ]1 p- rsurprised that you are disappointed with both.
: Y; v# X/ R2 o( d0 z8 z; b" r6 r# ?3 L" h
In a fabrication market filled with intense competition it is up to
# L, z! W1 w# W8 g) }individual players to keep up with the technology requirements of the ' o% \( X& e- V/ I" h# I& n
market or get left behind.  The task is not simple. Depending on how far 0 y2 P" T+ }: C% v
up the frequency range one needs to go, dialing in cost effective * C4 W; M* Q5 Q1 x5 J; u7 T$ _2 ^
process requires substantial skills, time, effort and serious money.  It * i9 F  x6 z) f( ?. z- u% ^% g8 ^
represents competitive advantage to OEMs and their partner pcb fab
  E. i* q1 U9 ^, d$ H, V8 ]houses alike.  Neither who have invested are likely to hand over that 9 \* n1 w  v* H
kind of advantage especially when it is so costly to obtain.0 P& Y- S% [5 [$ K1 l- e2 {

" x; H9 h; X* i) \( g! a. eI don't mind that Terry is looking for a solution on the cheap or free.  
2 i5 V1 Y  b' OIf one could obtain such a sweet deal, one would be foolish not to take 7 Y, [5 N: P+ i( P% m) S
it.   I am troubled that in this day in age, his organization hopes to / C4 @" y# ^7 W/ {  W- i
address a sophisticated issue before his technical staff has a grip on
. r% a: p- x! e8 \/ d+ tthe basics.   I fail to understand what you find inappropriate about
0 x6 U3 {9 w* k% p& j8 R7 p+ R8 \) uthat concern.  I would rather yell at someone headed for a cliff to stop
) K; U; r# ~$ z9 Q+ u3 M' ~0 d5 ythan smile and wave.9 {% h. s6 c4 C2 c) M7 t& q. Z* p

% P" ?! H7 Q) E  oBest Regards,; l9 C4 g1 _6 i% c1 z, q

& R% @3 S6 Q6 W7 `0 R, d, O- `) W" Y+ D1 s) O( l6 f8 v
Steve.
- ~3 n1 [- H' [3 ~8 O% B. R' @& T# u; W; l
From: "Loyer, Jeff" <jeff.loyer@xxxxxxxxx>' f" h% B& d' p0 u
Date: Fri, 2 Nov 2012 15:37:46 +00008 d" z1 H7 ^5 H, M! u

7 g$ ]) R3 x' ], q  }! Z % \2 l5 D* T" V
I realized we hadn't answered the basic question - "why does a high resin
% z% T' V( r5 f1 m1 m$ Wprepreg give lower loss?"  The prediction of loss vs. resin content isn't
( a" P$ I+ F, Ytrivial; as Steve said, a tool which allows you to model loss for the various $ d! t# i2 \+ j) k
scenarios should be on your Christmas wish list.  Here are the factors that I
$ w' J3 J: r! Lknow of (thanks to Richard Kunze for clarifying things for me, and I welcome : a% C6 o/ h' W7 o8 L) g  c$ P
others' data/opinions):
3 a" P8 [, z5 o6 x- r* Resin has a lower Er than glass
5 M1 `) j- d% c6 e: y9 z6 I6 b% k; F
/ R9 U9 ~* c7 h     * loss is approximately proportional to Df * sqrt(Er), so lowering Er 9 D% b4 K2 @. a7 K4 l1 w
lowers loss
, b4 B- o$ `  @& n: r5 }6 @
. |. k2 w: Z! E! w& F- Y: N; `     * lower Er allows wider traces for the same impedance - this may decrease
. E' g9 i' j' T! p4 p; q6 Uloss also
8 p8 |+ K: D! k% d" M% ]" @  S
5 }, t" W8 l5 j* But, resin is more lossy than glass, so Df may increase+ ]  X( p2 I) t
# f7 E1 ^5 g+ X# i- d- q; @! U
     * for standard FR4 constructions, this is especially true.  The data sheet ! L: p- Z1 G! c+ h# [' j8 [/ h
for IS370HR, for instance, shows Df varying from 0.0177 to 0.0247 (1GHz), . E. ~  E9 Q- _; I6 ^4 @0 k
depending on the resin content' W* E/ ?: x- y
: |) b% B3 x# e6 w% {
     * for low loss materials, this doesn't hold.  The data sheet for Meg6
6 z/ A  V) \$ U- ?5 }" X8 [shows Df constant (0.002 @ 1GHz) for all its flavors of prepreg
5 K" z5 \1 b4 J, b1 j) {
& O8 |- ?% l$ I: J: {% C8 u6 L! K* Where the factors dominate will depend on your relative conductor vs. 8 W2 m; H: _3 ]* Q
dielectric loss effects: for FR4, dielectric loss dominates at >~1GHz; for
; t* ~, [* b$ o5 ^low-loss materials, conductor loss dominates up to much higher frequencies (as * S" X* ]; ~! H# \2 a
much as 10GHz).
' f/ j7 a4 \/ @7 W" N% F
! c* d) l, }# ^4 ~/ E
; Y! C7 S1 D$ v9 Q# v. e0 Q% @( \, ^0 s2 y
In your particular (low loss) case, the lower Er of the resin-rich case is % G% X3 O5 I: O7 R  I# Y( G! t
trumping the Df change (or lack of) so you get lower loss.
- J, F+ T6 v$ q, \. k, y+ ^6 U/ E' [+ C$ @
" {" m! F, c2 ^; F* y- H

* \5 A# x/ M  aOnly a tool which takes into account the properties of the specific material
4 C& F) Q1 w5 u) R- |1 dunder consideration can be expected to give an accurate prediction of insertion
$ j; a8 F2 H3 k  f1 b' }loss for various resin contents.5 D4 ~$ j# @5 h* R5 G9 O- m

$ @" ]& [* N8 ~% N, k# `" ~6 _' e
# }0 y+ C4 l; Q9 K4 R
There are also environmental effects (I haven't heard or seen these stressed at
4 V$ |" \/ f9 j2 k( H/ uthis point, though that may change soon):8 R( }6 l6 z: \; z. `; d
/ o3 W3 }1 K8 Z+ l5 q, U: L, g7 {
* Higher resin content will absorb more moisture, and thus your loss will be
6 [) Z" G0 m, U0 Y6 w2 i4 v+ nmore susceptible to humidity effects
2 C2 E* b9 t4 R; ]$ o  K! l
( ?% f; h/ ^- {4 m* There's a difference in how the various materials' Df changes w/ temperature
. T6 Y/ n/ a! N2 W6 @- more at DesignCon
* o6 w% Y, O/ V6 S! }3 t* t' a+ K# L' ]/ J
/ k% i0 d- h! n  f" Q6 X
5 }8 `# [) ~7 P; ~" C
I hope this helps,
" \# v7 X5 i, P2 ?6 K
, [  M' y, Y2 [$ k2 {& y% PJeff Loyer& t1 X" }9 }( ~/ K/ v
- {: m/ k; \* V. r* _5 x
From: Scott McMorrow <scott@xxxxxxxxxxxxx>
# `: T9 u6 y5 gDate: Thu, 8 Nov 2012 09:12:46 -0500# ~. }8 `3 w6 _0 p6 K9 p. h1 @

! ?, W$ ^: v" J/ \2 Z6 { $ a1 k9 N8 }, |3 B: z7 |; ]
Jeff
5 }3 k: ]" C2 w" D- Y$ sA few quick comments.  Although the tanD of Meg 6 is stated to be flat, it
. v$ {% t/ _# |4 m; L& mis not if you measure it.  The manufacturer reported characterization in
+ s7 n3 z) x, I" I3 lthe data sheet is not correct.  Causality is violated when tanD is flat.6 z9 g. V' d. ]: i
3 k1 z" N7 }! v, k0 H/ x
Loss is generally due to molecular dipole losses in the material.  It can
, d3 B  D  R1 \% S2 X+ B/ Fbe low for high Er, as is the case with ceramic.
* J+ p6 f& {2 y) i( F2 J3 N& k0 a: Q- s. h9 \% S3 X
Hygroscopic loss is due to molecular polarity. Polar molecules "glom" on to
  [# S& q5 t+ ]& Q% X+ ~water molecules, which are also polar. Same property makes the material" e  F& V# _1 Z3 n# E: p
extremely "sticky."* O5 l3 M' W* q3 k5 q
  F* \& o3 _0 f# C
The paper that Jason Miller of Oracle and I wrote for DesignCon last year
9 V  s& A, j3 b+ {6 I' _* ncovers some of the impact of temperature and humidity on measured losses.
1 ^, s! E% k4 F. | I don't have access to my storage server right now, otherwise I'd give a
1 r4 N3 a8 {( o' I3 Bpaper citation./ e* L- a0 C8 W5 [- o
- S, C+ R# c0 W* O7 p' V# d2 n" i+ ~* u
regards,; C2 N3 B: o' m  g( c1 g

4 `% V+ A4 _1 }; a' ?  S* qScott
- [$ ~: ]/ t" w1 K1 m4 N5 W$ _7 F# Z* u; b
From: Kirby Goulet <kgoulet@xxxxxxxx>
. g. H  l3 e7 a) _( h) U, nDate: Fri, 9 Nov 2012 11:08:49 -0800 (PST)' ]& f9 \+ y2 g% n2 |+ _% r1 Y

8 {! ?2 S7 @; z& r" C6 S % f( R6 L8 x7 L  |$ s2 d2 c4 @  j- Q# z
It's not production quality software but you could try the mdtlc calculator to 1 N0 T5 c% e! J# ^
experiment.  I tried Jeff's example and it seems to point to an explanation.
6 b# v% E, m4 _0 E: y The source code is available so you might extend it to do what you want if you
# f8 O) m7 V- V( Y* R- shave more time than money.
; [" C, _; j# n  SIt looks like a race between loss due to increasing loss due to resin and - K8 f  `/ a+ r- j9 w: i" a# A
decreasing loss due to wider traces.  There is a bigger increase in the resin $ J& E* @- }" L3 Q) A
content for the IS370 case over the IS415 case.  Not only that, but the IS370
! U) d6 A, t8 \4 U$ _& {% qresin is lossier: 0.0169 versus 0.02984 so the winner is increasing loss.  : y8 z' C. g7 Y
6 a& t6 K+ Q8 ~- G  r( s
From the field solver,
' h2 @" W* K; q4 O$ M$ L5 e6 G
/ Q  C8 b! v6 f8 p) j( JIS370: the effective dielectric loss went up 14.7%.  The perimeter of the
2 e$ }$ X4 d5 E, e! c& J. \conductor went up 3.6%.  . R/ \) d+ T6 s6 k
IS415: the effective dielectric loss went up 6.7%. The perimeter of the ' ~# M; U4 |9 q
conductor went up 5.7%.
! @* n$ G$ c' p; u" `5 y: d
8 S: C- {* c/ C: TIn the second case, overall dielectric loss is a smaller fraction than the : ?) f' |0 k$ }
first case.  The missing bit of information you need to add is the conductor
8 \8 A' s1 L) Bloss.
1 j; T. h- k* J* w7 L2 f2 Z
/ @# J. ]- i" }INPUT PARAMETERS:
  a! I5 `- U0 {: U* W$ [ 1 F% a! Z( B' p/ p, X# g3 _' B4 v
      Layer             Thick   Specifications 3 l+ ~, b4 G4 D8 c$ V( W
      Copper Plane Top   1.30    Opening w=0.0  offset=0.0* v/ V% S! J. C/ r
      Laminate Layer 1   3.90    Resin Content  57.0% 3.4-4.9
5 Q  n7 U2 {" b# _5 u' t6 H& c        Signal Layer 1   1.20  4.3-7.2-4.3  Etchback=0.00
' o" w! _( p5 o: T. ^      Laminate Layer 2   3.90    Resin Content  57.0% 3.4-4.9 / P' ]; J9 O8 N8 C! v& u
   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0
. b" l. G5 \4 H , i0 z4 [. |/ J- _1 S/ d2 b9 S
      Layer             Thick   Er    Loss Tangent5 |6 u7 I1 c/ `% U' {9 V& c; @! L$ t
      Copper Plane Top   1.30  3.20   ' z: H$ W+ ]$ \0 ^
      Laminate Layer 1   3.90  4.02    0.02100 4 K: g1 J( Z# k
        Signal Layer 1   1.20  3.38    0.02984
- x5 \9 k4 b% `5 c% f( V" ^      Laminate Layer 2   3.90  4.02    0.02100! \. m$ X7 K" x
   Copper Plane Bottom   1.30  3.20
3 ]9 t2 S. h  D4 F  P
/ f  l! Z/ W7 O7 e, Y$ T1 p+ X6 \ DC resistance by dimensions:
1 y. V4 H% J' V, L# C! o4 j6 r Rdc_trace_1= 131.53      Rdc_trace_2 = 131.53  milliohms/in 20C
3 y6 |: C- o8 ^  E) V+ \ + g8 W3 t; m5 Y
DC resistance by pixel count:
* Q% D$ Y% W2 ~ Rdc_trace_1= 131.531     Rdc_trace_2 = 131.531 milliohm/in5 A. U, V! Z2 }. O- S
C_odd      =   4.221 pF/in    C_even =   3.968 pF/in9 g1 ^4 \7 X8 B6 e9 f! Q3 {
Er_odd     =   3.923         Er_even =   3.947( y: B& w1 t2 V8 e
Loss_tan_o = 0.02212     Loss_tan_e  = 0.02184  5 A# Y3 ^& \% D2 _1 d+ l( x5 r4 p
Delay_odd  = 167.801      Delay_even = 168.314  ps/in.* M. M; x: e0 v6 H6 a9 W
Z_diff     =  79.501  ohms   Z_comm  =  21.209  ohms0 U& C6 O. \  U2 I; V! H

. x5 Z# ?3 r' I; D" QSimulation pix map 122 pixels high by 800 pixels wide." t, v; d6 \% w* J4 w1 ~# ]) F* K
293824 bytes allocated for bmp.( H6 f+ Q9 H/ ]  @. }+ y. ]
' s1 Z  C+ v8 v; u1 J$ m
INPUT PARAMETERS:$ S! J4 G) B$ t
9 n4 c& o( _! V' P8 c
      Layer             Thick   Specifications
$ R8 a7 K: `) l      Copper Plane Top   1.30    Opening w=0.0  offset=0.0
2 a% |0 P/ ]+ b8 `/ ?2 Z      Laminate Layer 1   4.20    Resin Content  75.0% 3.4-4.9
6 u' w- w. T; s6 c% K6 w8 i        Signal Layer 1   1.20  4.5-7.0-4.5  Etchback=0.00
8 Y1 x5 R! v) e& L      Laminate Layer 2   4.20    Resin Content  75.0% 3.4-4.9 : ~% `/ N+ T; D# X0 J( i
   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0$ E5 Z% c* O* [. ~' A
2 T+ w/ G3 o" S2 ]# w3 p7 h6 a
      Layer             Thick   Er    Loss Tangent* q. L6 }& k, a# v
      Copper Plane Top   1.30  3.20   ; u1 X. t5 W  |" }5 c" ]1 a
      Laminate Layer 1   4.20  3.75    0.02470
+ _. T: {6 `, _        Signal Layer 1   1.20  3.38    0.02984
3 A2 f) q4 j* R+ K      Laminate Layer 2   4.20  3.75    0.02470
& A% ]5 E% C0 L4 j) }2 M# y. |  [& o5 m   Copper Plane Bottom   1.30  3.20& Z( ~1 v" h5 D+ r9 T6 _) c  _8 U/ N
/ \/ Q3 h6 _  m) Y/ r* b
DC resistance by dimensions:8 B* e3 m% V9 f# w
Rdc_trace_1= 125.69      Rdc_trace_2 = 125.69  milliohms/in 20C2 k3 r% m9 [+ {; g7 o# `( n% g
7 \8 O& x) }1 t, o: m2 a4 k) H9 c
DC resistance by pixel count:
! l" @' c3 z+ m Rdc_trace_1= 125.685     Rdc_trace_2 = 125.685 milliohm/in) B8 c1 P: j& W/ K7 x
C_odd      =   3.929 pF/in    C_even =   3.624 pF/in: a0 H+ g9 Y  u$ T* x
Er_odd     =   3.694         Er_even =   3.710
5 S8 Y% o' i' M) W$ r- P) t) w, [  c/ u Loss_tan_o = 0.02537     Loss_tan_e  = 0.02518  " E8 q/ o; I+ l3 X% d4 s. z; t
Delay_odd  = 162.844      Delay_even = 163.195  ps/in.
$ K3 `; d. k6 W6 H) c  K Z_diff     =  82.900  ohms   Z_comm  =  22.519  ohms0 _2 f' z8 R: |3 B: g
) _% I9 d7 X( l# e
Log file save name:
; H4 |$ l' x' {1 umdtlc_12100946383.txt9 B1 O+ {3 f# `; D' S# y
( S1 |% z5 |' d/ ~
Simulation pix map 118 pixels high by 780 pixels wide.# ^3 J' k# {* f; e3 K: q6 _  g. ^
277144 bytes allocated for bmp.
2 i6 x7 m1 S2 |; n, O# v % z4 N# u! U8 H: ]6 ^* ?$ K
INPUT PARAMETERS:# h" G8 _; @+ g2 n
" R* k" d1 e+ s, C3 F
      Layer             Thick   Specifications
: E3 V$ f4 u: g3 y* _* d      Copper Plane Top   1.30    Opening w=0.0  offset=0.0/ {# z6 }: y/ F+ f) ]% ~7 {
      Laminate Layer 1   4.00    Resin Content  45.0% 2.6-5.1
: ?# B% E) n3 _6 q& J        Signal Layer 1   1.20  4.1-7.4-4.1  Etchback=0.00
$ \) f- g4 X' R6 {4 Y8 F7 v      Laminate Layer 2   4.00    Resin Content  45.0% 2.6-5.1
) g$ R( o7 B" }; R: o$ o   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.0
4 |  D5 l6 P" u6 ]8 `; E 7 D8 r' K3 F5 p9 k$ l
      Layer             Thick   Er    Loss Tangent8 Z/ X  @6 e8 Z# F. g- I
      Copper Plane Top   1.30  3.20   
* m5 h: b$ p, @- Z% r5 v! q! L      Laminate Layer 1   4.00  3.98    0.01140   h9 ^, q0 A; y0 J+ b) c5 O. A6 u* N
        Signal Layer 1   1.20  2.64    0.01690
& W8 g3 _$ L! C      Laminate Layer 2   4.00  3.98    0.011402 |% \0 D& T% l6 ^
   Copper Plane Bottom   1.30  3.20) V1 _( d) j4 W; h
5 y1 Q0 U1 s3 \6 f& ?1 B/ y
DC resistance by dimensions:3 B! M6 t# i6 ^# t1 S. e0 ]
Rdc_trace_1= 137.95      Rdc_trace_2 = 137.95  milliohms/in 20C
: f7 V. E) m- h, j/ Q* { 0 o0 j+ M, E) R" }) Y
DC resistance by pixel count:# {; x' d1 @; M! P2 E
Rdc_trace_1= 137.947     Rdc_trace_2 = 137.947 milliohm/in9 ?: e5 e% G6 w, I, k1 m1 E4 \
C_odd      =   3.910 pF/in    C_even =   3.695 pF/in5 W/ n/ {6 y# W' F. v8 N
Er_odd     =   3.769         Er_even =   3.817
. W( C  u3 }0 m1 B/ I' g$ u Loss_tan_o = 0.01202     Loss_tan_e  = 0.01189  * p* Z; h' N2 V
Delay_odd  = 164.490      Delay_even = 165.524  ps/in.
, S$ X" h7 Q# O! a2 ~8 L Z_diff     =  84.134  ohms   Z_comm  =  22.396  ohms
* {' O4 c2 C# C0 X. o% T, W% y. G. |
3 p* U7 f' d: k- a1 L! R+ w# PSimulation pix map 118 pixels high by 795 pixels wide.; R& n8 E8 u# s. u0 f
282454 bytes allocated for bmp.
, U9 L$ n0 A6 `9 W . O: t1 P7 F5 _$ ~$ b
INPUT PARAMETERS:1 h) D( Y; }* ?1 z' u2 r3 Y
5 |* l2 W( y# q: g
      Layer             Thick   Specifications $ i& I" v$ a4 G4 [- }% V0 r2 W3 o6 i
      Copper Plane Top   1.30    Opening w=0.0  offset=0.0, Q/ q0 I5 d; P  y& P- {
      Laminate Layer 1   4.00    Resin Content  54.0% 2.6-5.1
; J* T1 }0 j5 A$ \/ b        Signal Layer 1   1.20  4.4-7.1-4.4  Etchback=0.00# T7 S/ o. T1 S0 U
      Laminate Layer 2   4.00    Resin Content  54.0% 2.6-5.1
- t( l" {- s6 Q$ c4 V4 i9 H   Copper Plane Bottom   1.30    Opening w=0.0  offset=0.00 n6 ]5 y# D  c0 |5 R# q; B1 h
$ {# E8 F, ~- j
      Layer             Thick   Er    Loss Tangent
& h9 S! q% ]0 x4 M; Q      Copper Plane Top   1.30  3.20   
7 u+ i0 \( \* I3 R7 H% V' S8 ?8 ~      Laminate Layer 1   4.00  3.76    0.01230
% L$ V7 \% n/ T9 F# m- ^6 p        Signal Layer 1   1.20  2.64    0.01690) D/ v' y& P6 W6 k1 t. a2 m9 m
      Laminate Layer 2   4.00  3.76    0.01230
& @9 ?# D0 Y' b: q7 U4 B   Copper Plane Bottom   1.30  3.204 N9 t9 ~; a! Q: S& J
+ f1 E5 @* o. Y3 x5 Q
DC resistance by dimensions:
0 ?" [2 ~  w3 I" [0 E0 ?0 A; Y7 P Rdc_trace_1= 128.54      Rdc_trace_2 = 128.54  milliohms/in 20C
1 J: ^: a/ d' G6 Y8 g
' |* f& t' ~- X0 m# K8 [3 y" { DC resistance by pixel count:
' j. I9 D( B4 H/ @% q) j Rdc_trace_1= 128.542     Rdc_trace_2 = 128.542 milliohm/in  p" C$ U4 _% k& S4 y
C_odd      =   3.865 pF/in    C_even =   3.623 pF/in% j& e& X  l  {2 l5 Y: P
Er_odd     =   3.588         Er_even =   3.631
) e: B; S9 Y5 Q# H8 L# R Loss_tan_o = 0.01283     Loss_tan_e  = 0.01270  
: m2 _6 L" `4 p2 g Delay_odd  = 160.480      Delay_even = 161.455  ps/in.$ N. O' ]8 ]; g% l
Z_diff     =  83.041  ohms   Z_comm  =  22.280  ohms$ K/ I( ]& j$ |7 a

) Y7 @6 g  z+ l. z9 R4 @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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2#
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!5 Z1 K0 `  Y& \0 e( q0 f
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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3#
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!
5 b1 B: z9 W5 p6 R$ O汗!!!{:soso_e110:}
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