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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
+ M9 t0 n+ Q) J: ~test information can be represented. In the simplest of forms, this means it must be able to store
6 G7 E8 V, z( D' `! znetlist information along with XY coordinates, and even reference designators and pin numbers
, ^" F/ V6 E. G, l: c(if they exist). I feel like ending this article here before it gets unmanageable, but then Pete
% j9 H9 ^% {7 Q( e! _Waddell wouldn’t be happy, so let’s proceed. If all the information that a test system would
5 W% }8 Y$ @0 g) rneed to know to verify and test a bare board could be represented in a single file, it would bring
$ u, A# w$ m: H# R# O9 h- |/ Zconsistency 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, field9 T5 \- K _7 {) _) k7 T6 j% p/ ~
parameters 5 U! D5 O- J8 S# O( [" h
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 about* I5 G( J( q- U7 J' [0 a
the problem of testing the PCB before it is stuffed with parts. Therefore, most CAD packages
+ ?6 Z5 X M1 i( @do not even provide the option of exporting a coordinate based netlist in this format. CAM
8 W8 g% l# h& ]8 {8 O$ G) s: \- j/ wsoftware is the common source of this information. Net connectivity is computed from the
0 Z1 D3 p* |2 cGerber data and the file is exported. Nets are numbered because the original CAD netlist was
3 N, W+ S/ _$ y) E7 | R. onot used. The RefDes/Pin# fields are also not filled in because this information does not exist in$ J% W. W+ e) @6 W2 @
the Gerber data. The IPC-D-356 file is then read by the bare board test system. The net
7 R8 A/ c6 Y2 {/ w8 c' N' Rinformation replaces the need for the old “golden board” technique. This process is the way the
2 ?% ~9 o9 W2 u; Pmajority of the industry is working today.
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