铜填充是PCB上铜被完好无损的地方，而不是被蚀刻出来。我们看到Arduino Uno克隆的背面有一个铜填充区域的例子。 铜填充(也被称为“铜倒”)通常用于创建一个接地面(以及5v或3.3V的平面)，作为一个更好的方式来分配地面水平周围的板(相对于使用布线)。敷铜的另一个原因是为了减少从原始板上去除铜所需的蚀刻化学物质的数量，并改善最终PCB的电气和无线电干扰特性。

敷铜有不同的类型。大多数设计师倾向于选择固体铜浇注，也可以创建包含格子图案的铜填充，。

In Part 3, you learned about copper fills, which is the fifth step of the PCB layout process. In this recipe, you will learn how to create a copper fill in KiCad. We’ll be using the breadboard power supply board project for this demonstration. Before you create a copper fill, you must complete the routing of your board. In Figure 25.1, you can see the example board fully routed. The next step is to create a copper fill for the ground level (also known as 'ground plane'). Figure 25.1:The fully routed board. In Pcbnew, follow this process: 1. From the left toolbar, click on the 'Show filled areas in zones' button . This will allow you to see the filled zone you are about to create. If this button is not pressed, the filled zones will be invisible. This is a useful option to use when you want to examine your board by reducing the amount of visual clutter. 2. From the right toolbar, click on the 'Add filled zones' button . In this example, you will create a ground plane. From the Layers Manager, click on 'B.Cu'.

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Figure 25.2: Select the back copper layer. 3. To start drawing the outline of the copper fill, place the cursor on the board location where you would like the first corner to be, and click. I am starting my drawing on the top left corner of the J2 connector. Figure 25.3: Click at the position you want to start drawing a copper fill. 4. The Copper Zone Properties window will appear. Most of the defaults are appropriate for this project. Draw your attention to selecting the correct layer ('B.Cu' since we want to create a ground plane in the bottom layer), the connected Net (in his example, the Ground net name is 'V-'), and the clearance of the copper fill to other nets (0.508 mm). Click 'Ok' to accept these settings, and continue drawing the outline of the copper fill.

Figure 25.4: Connect the copper fill to a net.

5. Draw the outline of the copper fill. Click to create an edge, and try to draw each edge of the polygon as close as you can to the border to the board. To complete the outline, double-click on the exact location where you started the drawing. Figure 25.5 shows my example board on completion of the ground plane. 331

Figure 25.5: The completed ground plane in the bottom layer. You can use the 3D viewer to inspect the new copper fill. Zoom in to one of the ground pads and notice that it is connected to the ground plane using thermals (Figure 25.6). Figure 25.6: A partial 3D view of the ground plane, showing thermal traces between pads and ground plane.

If you want to re-create a copper fill, right click on the zone’s border and click 'delete' from the context menu.

You can make the copper fill disappear (but not deleted) by clicking on the 'Do not show filled areas in zones' button from the right toolbar ( ).