Common Operations in Allegro PCB#
Information:
Creating Mechanical Mounting Holes in Allegro:
https://blog.csdn.net/jiangchao3392/article/details/82415270
1. Batch Update Packages#
Select the packages that need to be updated, click Refresh to complete the update.
2. Board Frame Chamfering#
Draw a 2mm rounded corner.
3. Draw Route Keepin Area#
Select the Route KeepIn area, choose inward shrink, 20mil.
4. Add Different Colors for Different Nets#
Only check Net.
Select color and click on the pin.
5. Configure Area Rules#
6. Import Gerber Configuration#
Open the previously created Gerber project, select file-->Export-->Parameters.
Select select all.
Choose the save path and name.
Click save.
In the new project, select file--->Import--->Parameters.
Select the path of the saved prm file.
Click import.
You can see that the import was successful.
7. Delete Dimensions#
Enter the Allegro software, select manufacturer-dimension environment or directly select the Dimension Edit icon.
Right-click, select delete dimensions.
Click on the dimension that needs to be deleted. Complete the dimension deletion.
8. Create Hollow Silk Screen#
8.1 Use BMP Image to Create Hollow Silk Screen#
Software used: RATA-Raster-(BMP)To-Allegro(IPF).exe
Download link: https://wwlx.lanzoul.com/ix78413rf1zi
Password: d34r
- Select BMP file.
- Set both Line Thick and Scale to 1 for clearer silk screen without ghosting.
- Pick Color to white, move the mouse to the white area of the image and click.
- Make out plt to complete.
Import plt file into Allegro:
After making out plt, an out.plt will be generated (usually on the desktop).
Open ALLEGRO.
Select the generated out.plt.
It defaults to Drillguide, right-click to change it to the silk screen layer.
8.2 Use Copper Layer in ANDNOT Form to Create Hollow Silk Screen (Recommended)#
When designing silk screens in PCB, you may need to draw hollow silk screens. Allegro upgraded to version 172 allows for hollow silk screens, as shown below.
Specific operations are as follows:
Select Shape Add Rect command.
In Options, select the layer to draw on, such as Silkscreen TOP layer.
Click Add Text command to add silk screen text.
Select the layer and silk screen font.
Write the silk screen in the area of the drawn silk screen frame.
The completed silk screen is shown below.
Click Shape-Shape Operations.
Select ANDNOT.
Find will default to check Clines, Lines, Text.
First, click on the square copper.
Then click on the silk screen text.
The effect is shown below.
Right-click and select Done.
You will get the hollow silk screen.
9. Modify Allegro Copper Pour Non-Avoidance Issue#
10. Solution for Inability to ZCOPY After Importing DXF#
Sometimes when we import the DXF border, it may not be able to use the Z-COPY command because it is not composed of a closed line shape. Here I summarize a method based on the requirement that it must be a closed shape to use this command:
- Click the menu shape——compose shape.
- In options, set active class to BOARD GEOMETRY and subclass to outline.
-
Click on any border of the imported DXF, and a shape composed of lines will be generated inside this border, matching the size of your import.
-
At this point, you can delete the previously imported DXF. Note to only select lines during the deletion process, not the shape. The remaining shape will be composed of lines, allowing for ZCOPY operations.
11. Merge Copper#
Enter the command “shape merge shapes” in the command bar, then click on the copper areas (copper 1, copper 2) that need to be merged.
12. BOM Export Format#
Header:
item\tvalue\treference\tfootprint\tquantity\t
Combined property string:
{Item}\t{Value}\t{Reference}\t{pcb footprint}\t{Quantity}\t\t
13. Modify Outline Line Width#
When using Allegro for layout, do not use the default line width set to 0 for drawing the board frame; it is better to change it to 5mil. Allegro supports a line width of 0, but this will result in the board frame not being visible after generating the photoplot files. PCB manufacturers will definitely contact you about this.
Solution 1: Directly Modify Line Width#
Select Edit->change.
In Options, select Outline, check Line width, and set the width; here I set it to 5mil.
Select Outline to change the board frame to 5mil.
Method 2: Solve the Issue of No Outline in Allegro Output Photoplot Files#
After exporting photoplot files from Allegro and sending them to the board factory, they always say there is no outline, but our original data clearly has OUTLINE. What is the reason?
This is because the default line width is 0 when generating photoplot files, so when sent to the manufacturer, there is no outline.
A simple modification method is to change the default 0 to an appropriate line width in each layer of the photoplot files.
This way, when sending photoplot files to the board factory, there will be no issues.