EDA365欢迎您!
您需要 登录 才可以下载或查看,没有帐号?注册
x
IPC网表和相应软件的操作 什么是ipc网表文件? 准确的说应该是IPC-D-356网表文件,大家简称ipc网表文件。 它是一种特定格式的记录设计文件各逻辑关系的网络集合文件。 详细见以下英文描述(翻译水平有限就不翻译了) The IPC-D-356 format was designed to define a standard netlist format by which bare board
1 u* W3 b$ O" a; ktest information can be represented. In the simplest of forms, this means it must be able to store# t* P8 ]; I( A) Y) K n( l2 y. V2 S
netlist information along with XY coordinates, and even reference designators and pin numbers
: S$ y- W/ a$ o* R( p2 j9 J(if they exist). I feel like ending this article here before it gets unmanageable, but then Pete) h2 @$ f% A- l' n `
Waddell wouldn’t be happy, so let’s proceed. If all the information that a test system would
, x8 q/ x3 ]: \, I `need to know to verify and test a bare board could be represented in a single file, it would bring
5 c% r% ]% g: K* y( e/ b$ Hconsistency to the testing world. IPC-D-356 does just that. The IPC-D-356 format can carry a lot of information such as comments, format specifiers, field
' ^+ x$ K9 D- L: tparameters
6 s- y6 N; E- H- c% i9 z2 [) c( u
为什么要网表对比操作?主要是以下2点 1,pcb软件输出的光绘文件,有时会变异,会造成开短路,通过对比能保证网络一致性(概率很小) 2,工厂端通常要修改设计文件以便符合生产,修改当中就可能会造成开短路,通过对比可以保证网络一致性(作用主要是此点,保障工厂修改完的文件网络没有问题) Since testing bare boards is a manufacturing process, the design engineer seldom thinks about5 S [/ h U& y9 [2 V+ j+ @* L/ H
the problem of testing the PCB before it is stuffed with parts. Therefore, most CAD packages: ^6 e& l1 Y" Y2 J: G9 v+ z/ x
do not even provide the option of exporting a coordinate based netlist in this format. CAM
3 L% H( v! _) esoftware is the common source of this information. Net connectivity is computed from the0 Y- [; V% k$ Y
Gerber data and the file is exported. Nets are numbered because the original CAD netlist was
2 h4 g: o" ^3 `9 G; w. Qnot used. The RefDes/Pin# fields are also not filled in because this information does not exist in c( g* p3 N$ L3 h
the Gerber data. The IPC-D-356 file is then read by the bare board test system. The net
! ?/ v9 k \ y! e5 [ ^4 @5 V ]2 dinformation replaces the need for the old “golden board” technique. This process is the way the; A9 `2 ?: V% I7 L0 C0 R
majority of the industry is working today.
5 Y# G: N1 A6 f: N+ [) s# V0 a" T
% H; c7 N. e' B' a- d
: I+ y: z% Y [! \$ K* L7 k
4 d3 V* C- D. E$ h& X5 o1 R" N U1 O; K: U% A
|