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 and click Refresh to complete the update.
2. Chamfering the Board Frame#
Draw a 2mm rounded corner.
3. Drawing Route Keepin Area#
Select the Route KeepIn area, choose inward shrink, 20mil.
4. Assign Different Colors to Different Nets#
Only check Net.
Select a 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 path and name to save.
Click save.
In the new project, select file--->Import--->Parameters.
Select the path of the recently saved prm file.
Click import.
You can see that the import was successful.
7. Delete Annotations#
Enter the Allegro software, select manufacturer-dimension environment or directly select the Dimension Edit icon.
Right-click and select delete dimensions.
Click on the annotations that need to be deleted. The annotation deletion is complete.
8. Creating Hollow Silkscreen#
8.1 Creating Hollow Silkscreen Using BMP Images#
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 silkscreen without ghosting.
- Pick Color to white, move the mouse to the white area of the image and click.
- Make out plt to complete.
Importing 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; we can right-click to change it to the silkscreen layer.
8.2 Creating Hollow Silkscreen Using Silkscreen Layer Copper in ANDNOT Form (Recommended)#
When designing PCB silkscreens, you may need to draw hollow silkscreens. Allegro upgraded to version 172, allowing for hollow silkscreen drawing, 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 silkscreen text.
Select the layer and silkscreen font.
Write the silkscreen in the area of the drawn silkscreen frame.
The completed silkscreen 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 silkscreen text.
The effect is shown below.
Right-click and select Done.
You will get a hollow silkscreen.
9. Modifying 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 a closed line shape, preventing the use of the Z-COPY command. Here’s a summary of a method: since it must be a closed shape to use this command, we can operate as follows:
- 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. What remains is the shape composed of lines, allowing for ZCOPY operations.
11. Merging 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. Modifying 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 make the board frame invisible 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: Solving 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 for this?
That is because the default line width during photoplot file generation is 0, so when sent to the manufacturer, there is no border.
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 the photoplot files to the board factory, there will be no issues.