PCB Technical - Summary of PCB copper paving problems of PCB copy board

1. What is the effect of laying copper on the PCB circuit board?

Heat dissipation

Shielding anti-interference PCB board with parasitic capacitance;

Improve the strength of the board;

Beautiful

Increase the difficulty of copied boards, especially copper-clad + black oil.

2. PROTEL's irregular copper laying method:

1. First of all, you must know which area of the PCB to be coated with copper

2. Then determine the area where copper needs to be laid, and what kind of network copper should be laid (determine what power supply, or where, or what other network)

3. Click the tool for laying copper

4. Set the safe spacing and line width and grid spacing for copper paving

5. Set the copper paving method (positive and oblique grid)

Three, copper paving settings

1. Net Option option group: Set the network to be connected to the copper, mainly containing 3 options

Connect to net: Set the network name of the copper connection. If No Net is selected, the 2 options below the list are meaningless.

Pour Over Same: Cover the same network name, that is, if you choose GND as the copper connection, even if you draw some ground wires on the PCB board, these ground wires will be covered when the copper is laid. If you do not select this option, the already drawn ground wire will not be overwritten.

Remove Dead Copper: Remove dead copper. Some isolated copper that is not connected to the GND of the circuit is called dead copper or isolated copper. These coppers can only be used for decoration of the PCB and have no practical significance.

2. Hatching Style: Set the copper laying method, which are respectively 90 degrees, 45 degrees, vertical and horizontal copper film trace settings.

3.Plane Settings: Set the grid point interval of the copper film line

Grid Size: Set the spacing of the copper-laying polygons, that is, the copper-laying density

Trace Width: Set the width of the copper film line

Layer: Set the layer where the copper is laid

LockPrimitves: Lock all copper paving, generally select it.

If the line width is greater than the grid spacing, then the copper of the PCB board is a whole piece of copper.

4. Surround Pads With: Set the wrapping method between copper paving and pads, 8-sided or arc surrounding

5.Minimun Primitives Size: Set the shortest length of the copper film line, the larger the value, the faster the copper laying speed.

Note: When routing, the minimum track width (Track Width) cannot be less than 0.01, and the grid (Grid Size) cannot be less than 0.01. If you find a mistake during the copper paving process, you can press Backspace to delete the drawn shape.

If you want to keep more copper paving area, we generally don't set the removal of dead copper to be effective at the beginning of copper paving. In that case, you will see a large area after the paving, and a large area of free space has not been paved. So first lay it directly, and observe that those are dead copper after the paving, and see if you can connect through the upper and lower layers of copper as much as possible. If it is really difficult to connect in some places, see if you can optimize the PCB and try to save the dead copper through vias. Live. There is really no way, we choose to delete the dead copper item to resurface it again to make the board more tidy.

Sometimes the PCB factory wants to put the pad wires a little further away from the copper film line, we need to set the spacing distance in RULE first, if we increase the spacing distance, the system may prompt a lot of ERC detection errors, but it does not matter, etc. After we have finished laying the copper, we can set the spacing distance back.

Fourth, the deletion of protel99 copper paving

Shortcut key E+D, and then click the mouse on the cloth copper to be deleted. Or use the network selection method, select the network you want to delete, and then delete it.

Can protel99 delete part of the copper paving? Just cut off a piece of the existing copper paving. After I laid the wires and laid the copper, I found that there was a problem and needed to change the wiring, so that the copper should also be changed, but I don’t want to delete all of them and re-lay them, because it is irregular copper laying, which is more troublesome. Delete the copper paving of the place to be changed, and then pave it for operation after the change.

Five, the modification of protel99 copper paving

When you find that the PCB copper paving is not satisfactory, or you need to change the lower wiring, you'd better delete the copper paving first, and then place it again after the change. The method of deleting is to use the delete command under edit, and the mouse will be in In the delete command state, click the copper paving to delete it, which is much better than the adjustment copper paving effect introduced in some books.