Adjustments to Default CAD Settings to Ease Life as a PCB Designer
Most of the computing devices we use today have adjustable default settings on them. The default settings are usually adequate to get the job done, but you can enhance the use of your phone, tablet, or computer with some simple changes. For instance, changing the default keyboard on my phone really improved my ability to compose text messages. And if you don’t like those changes, you can usually reset them back to their default settings simply enough.
PCB design CAD tools also have default settings, and like any other device, these settings can be modified. Unlike our smart phones though, the default settings in our CAD tools aren’t merely for changing the background picture. These settings are designed to customize your work space and make you more productive on the tools by changing how objects are displayed, and how you can interact with the tools. Let’s take a quick look at some of the default CAD settings that you can enhance on your own PCB design system, and how that can make your life as a PCB designer easier.
Changing Your Grid, One of the First Default CAD Settings to Adjust
Your PCB design CAD system will come with different grid settings. Grids are very important in the CAD tools as they allow you to place objects, parts, traces, fills, and text on precise points in the design window. This is essential for maintaining the spacing you need, especially in instances where you need to place as many objects as possible side by side without violating a minimum spacing rule.
In the schematic capture tools, you will want to set up your grid to give you the best spacing between components and the nets that you will enter from pin to pin. You may also want to control your grid for placing the text for reference designators, part numbers, values, and net names. The default settings may not give you the spacing you need for this, so make sure to change it to a value that is appropriate for your schematic. Many companies will have designated grid values for schematic entry to ensure that the preferred spacing is maintained.
In the PCB layout tools, grids become even more important. As objects and layers may have different requirements for their spacing, it is very helpful to set your grids so that you can easily create or move objects to meet those spacing requirements. In the example below, you can see how this CAD system allows you to set up a grid for objects that are not metal (etch) such as component placement or drafting functions. You also have individual controls for different etch layers such as “TOP,” “GND,” and “INNER1.” By scrolling the menu down, you would find even more layer options. You can also turn the grid display on and off, as well as set up grid offsets.
This grid gives you a lot of control over changing the default settings. Note how all of the individual etch layers in the menu have an “X” value of “0.025.” This is because that value was entered into the “All Etch” value which propagated it to the individual etch layers. This is also an easy way to reset CAD settings to default for all the etch layers at once. At the same time, note how only the “TOP” layer has a “Y” value of “0.075” (highlighted in blue). This is because it was entered uniquely for that layer only.
The grid menu in a PCB design CAD system
Other PCB Design CAD Tool Settings to Change
There are also many other settings within a PCB design CAD tool system that you can change from their default settings. Here are some examples of those:
Units: Along with the grid, one of the first defaults you may change is the units. This will allow you to control your grids in units of inches, millimeters, mils, and centimeters.
Help: Many CAD systems will give you floating help or data tips while you work. You can often customize these tips to display in a way that will be most helpful to you.
Design parameters: Here you will be able to control the size, shape, and display of design data, text, and shapes.
User preferences: This will give you very specific control over tools like editors and wizards, zoom controls and how the display pans from side to side.
Design constraints: These settings control the rules for design objects on the board. For instance, you can set up constraints for common nets that will be routed at one width, while setting up a constraint for power and ground nets that will use a wider trace width. In addition, these rules allow you to control spacing, length, topologies, holes, and many other aspects of designing your board.
Colors: PCB design CAD tools come with a default color scheme that can usually be changed. For instance, I prefer to use blue and green for the top and bottom etch layers of the board layout, while the default colors are often green and red.
In today’s CAD tools you can find default settings to adjust for most every aspect of the tool’s operation. The key is to modify these settings so that the system works best for you.
The color menu in a PCB design CAD system
Working Within Your Design Tools
While older CAD systems only give you a minimal amount of control over your default settings, the more advanced tools of today give you a lot. You may find it helpful to not change everything at once in order to determine what changes work best. Many of these changes can also be written out so that you have access to them for new designs or if you want to recover your CAD settings after they are set back to default.
Another helpful tip is to work with a PCB design system that is designed to have its default settings customized and managed by the user for maximum productivity. OrCAD PCB Designer has the functionality that we’ve been describing to customize its different default settings. This will allow you to take your design from concept to manufacturing quicker and with fewer problems by making you more productive as you work with the tools. And in addition to its ability to be customized, OrCAD also gives you access to libraries, premier schematic capture and SPICE tools, and advanced PCB layout capabilities.
If you’re looking to learn more about how Cadence has the solution for you, talk to us and our team of experts.