1. Schematic diagram and common mistakes:
Pin (1) the ERC report no access signal:
A. create the wrapping to pin define I/O properties;
B. create components or modified the inconsistent place component when the grid properties, pin and line not connected;
C. create component pin direction reverse, must not pin name end connection.
(2) components to drawing out: no create component in the center of the element libraries chart paper.
(3) to create a project file network table only partially transferred to PCB: have no choice for global generate netlist.
(4) when using the create element composed of several parts, don't use annotate.
2. PCB in common mistakes:
(1) when the network load NODE report not found:
A. principle diagram of the components using the PCB library without encapsulation;
B. used in components of the schematic diagram is inconsistent with the PCB library name encapsulation;
C. schematic diagram of the components using the PCB library pin number is not consistent with the packaging. As triode: pin in the SCH
Number of e, b, c, and for 1, 2, 3 in PCB.
(2) when the printing is always can't printed on a sheet of paper:
A. create a PCB library at the origin;
B. move and rotate the components for many times, PCB out hidden characters. Select show all hidden characters, narrow
PCB, and then move the character to the boundary.
(3) the DRC report network is divided into several parts:
Indicates that the network is not CONNECTED, see report files, use select CONNECTED COPPER lookup.
In addition to remind friends try to use WIN2000, decreases the chance of blue screen. More than a few times the export file, make the new DDB file,
To reduce file size and PROTEL zombie. If a more complicated design, try not to use the automatic wiring.
In PCB design, wiring is an important step to complete the product design, can say in front of the preparation work for it,
In the whole PCB, in order to limit the highest, wiring design process skills the finest and the biggest effort. PCB wiring has a jersey
Line, double wiring and multilayer wiring. The wiring way also has two kinds: automatic wiring and interactive wiring, in the automatic wiring
Before, you can use the interactive prior to wiring requirements more stringent line, input and output side edges should be avoided
Parallel, lest produce reflection interference. Should add ground isolation when necessary, two adjacent layers of wiring to perpendicular to each other, parallel easily
Produce spurious coupling.
Completion rate of automatic wiring, depends on good layout, wiring rules can be set in advance, including linear bending times,
Guide hole, step, etc. The number of the number of warp to explore type cloth first commonly, the short line connected quickly and then
Labyrinth wiring, the cloth first attachment the wiring path of global optimization, it can disconnect has cloth line according to need.
And try to resume the wiring, in order to improve the overall effect.
For the high density PCB design has been felt not adapted to the through hole, it wasted a lot of valuable wiring channel, for the solution
This contradiction, the blind and buried hole technology, it not only completed the guide hole, also save many wiring channel
Make a wiring process more convenient, more smooth, more perfect, the PCB design process is a complex and simple
Process, to master it well, still need the electronic engineering design personnel to their experience, to get the true
Truths.
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