Confused about what is the difference between Gerber and CAD files? Well, the understanding of these file formats can become tricky, at least for beginners in PCB designing. Fear not, though, as this article will guide you through what each kind of file does.
By the end, you will know what are Gerber and CAD files and when to use each, and we’ll make it simple and clear so that you can start your projects with your PCB confidently.
So let us begin.
What is a Gerber File
A Gerber file is a standard format used in the electronics industry to describe printed circuit board designs. In other words, it is the literal blueprint to making a printed circuit board but in a way that gets all the necessary information across for it to be fabricated.
Definition of Gerber Format
The Gerber format is an international language for sending designs for fabrication. It was developed by the Gerber Systems Corporation but is now in the possession of Ucamco. It guarantees that different machines and software will interpret the design specifications similarly.
Purpose of Gerber Files in PCB Production
Gerber files are the most vital part of the production of PCBs. They contain the instructions on how the board is to be made, with every possible piece of information—elements such as copper layer layout, solder mask, legend, and almost everything else with respect to it—specified in detail. Manufacturers use these files to produce boards that meet a designer’s specifications.
Key Components of a Gerber File
- Layers: Each Gerber file would represent a single layer of the PCB, such as a top copper layer, bottom copper layer, solder mask, and silkscreen.
- Apertures: Holes that create the shapes and dimensions for the features on the PCB—pads and tracks.
- Coordinates: They define the exact location where each feature will appear on the board.
Gerber File Extensions and Variations
These files usually have either .GBR or .GBO extensions. Some of the variants are RS-274D, which is the old format, and RS-274X, which is an extended version that provides a lot more detail about the design.
Advantages and Limitations of Gerber Files
Advantages:
- Standardization:Agreed upon in the industry as a whole to ensure compatibility.
- Precision: It provides detailed and precise instructions to manufacture an actual Printed Circuit Board.
- Flexibility: Suitable for fabricating various PCB layers and components.
Limitations:
- Complexity: It wants very lengthy files to represent just one PCB. Its management becomes a heck of a job.
- Impressively: If the files do not exactly interpret the Gerber files on the manufacturing equipment, then mistakes can easily be made.
What is a CAD File?
A CAD file is a digital document created using Computer-Aided Design (CAD) software, which is widely used in various engineering and architectural fields, including PCB design.
CAD files convey very minute details of the apparatus being built within the design and layout, hence being able to create and change complex designs.
Definition of CAD (Computer-Aided Design)
Computer-aided design is the use of computer systems to assist in the creation, modification, analysis, or optimization of a design. The work aims to allow designers to work with more comfortable attitudes, both two and three-dimensional, into the detailing.
Role of CAD Software in PCB Design
In PCB design, CAD software plays a crucial role by allowing designers to create intricate and precise layouts of electronic circuits. This includes layout instructions such as component placements for wiring routes, among other most critical components of the design.
Therefore, CAD software allows one to simulate and clearly view the outcome of circuit functionality prior to the manufacturing process of a circuit.
Key Features of CAD Software Relevant to PCB Design
- Schematic Capture: The function allows designers to create very comprehensive schematics of the electronic circuit.
- Layout Design: It enables precise placement of components and routing of simple paths on the PCB.
- 3D Visualization: It enables a 3D view of the PCB design to allow the identification of possible problems.
- Simulation and Testing: It offers tools to design for simulating and then testing the performance of the circuit even before it goes into production.
Advantages and Limitations of CAD Files
Advantages:
- Precision and Detail: With these CAD files, high accuracy is needed for such complex designs in the case of a printed circuit board.
- Flexibility: Easily editable, allowing for quick changes and iterations.
- Integration: Integrates with other design tools and software to provide a better design process overall.
Limitations:
- Complexity: Special Knowledge and Training is required to operate it properly.
- Cost: The CAD software is very expensive and will call for hefty investments from small business people or even dabblers.
- Compatibility: In some circumstances, compatibility among them does not work because different CAD software uses different file formats.
Now let’s discuss the differences between Gerber and CAD files in detail.
Gerber Vs. CAD: Key Differences
Understanding the differences between Gerber and CAD files is essential for anyone involved in PCB design and manufacturing.
Below is a feature comparison, allowing you to understand the biggest differences between the two file types.
|
Feature
|
Gerber Files
|
CAD Files
|
|---|---|---|
|
Purpose
|
Used primarily for PCB manufacturing
|
Used for designing and visualizing PCBs
|
|
File Format
|
Standardized (RS-274D, RS-274X)
|
Proprietary formats (e.g., .dxf, .dwg)
|
|
Content
|
Contains layer-specific information
|
Contains comprehensive design details
|
|
Usage
|
Instructions for PCB fabrication
|
Design and simulation of PCBs
|
|
Detail Level
|
High precision for manufacturing
|
High detail for design and editing
|
|
File Count
|
Multiple files for different layers
|
Single file with various design elements
|
|
Software Compatibility
|
Widely compatible with manufacturing tools
|
Specific to CAD software used
|
|
Editability
|
Not easily editable
|
Easily editable and modifiable
|
When to Use Gerber Vs. CAD?
Use Gerber Files When:
- You need to send your design to a manufacturer for PCB fabrication.
- Manufacturing proceeds adequately with general information, level-specific.
- Various manufacturing tools have to agree upon standardized formats.
Use CAD Files When:
- You are now in the design and development section for the PCB project.
- You’re going to have to make a lot of changes in the design, quite frequently.
- Before being built, the PCB has to be simulated and tested.
File Conversion Between Gerber and CAD
It becomes necessary at times to convert between Gerber and CAD files during the whole process of PCB design and manufacture. Besides, the CAD software usually adopts integrated tools to export the design into Gerber format.
Essentially, this conversion maps detailed CAD file design information to the particular manufacturing instructions in a Gerber file.
Conversely, converting Gerber files back into CAD format is more complex and less common, often requiring specialized software to interpret the manufacturing data into a usable design file.
Knowing the key differences and when to utilize each type of file sets you up nicely for making sure your PCB projects all go smoothly from concept to production.
The Relationship Between Gerber and CAD
Gerber is very much an integral relationship with CAD files in a PCB design and manufacturing process. These functions work in tandem, but are quite different from each other, with the main task being to explain the board from concept to reality.
How CAD Files Are Used to Generate Gerber Files?
Here’s how CAD files are used to generate Gerber files:
1.Design Creation:
This is done by first designing a PCB with the CAD software. Designers, assisted by CAD tools, can draw schematics, layout components, and route traces on the printed circuit board.
2.Design Finalization:
After the design is completed and reviewed, it needs to be translated or be in a format that is processable for manufacturing. That is where the Gerber files come in.
3.Exporting Gerber Files:
CAD software typically includes functionality to export the design into Gerber format. Lastly, all CAD software will usually also have the ability to export the design into Gerber format. This process will encode all minute details of the design like layers, traces, and components into the exact command it is to follow for being manufactured.
Each PCB layer—top copper, bottom copper, solder mask, and silkscreen—is individually exported as a Gerber. This produces the drill file, which describes all the holes these layers contain, among others.
Gerber File Verification Process
1.Design Rule Check (DRC):
Run a Design Rule Check (DRC) inside your CAD software before you export. This shows if your design meets manufacturing constraints and industry standards.
2.Gerber File Generation:
The CAD software generates Gerber files for all the layers of a PCB, plus any drill files and other ancillary files that might be necessary.
3.Gerber File Review:
The Gerber files are then cross-checked through Gerber file-viewer software to check if all elements in the design are translated and no error or omission was made.
4.Manufacturing Readiness:
Once verified, the Gerber files are ready to be sent to the PCB manufacturer. The manufacturer uses these files as precise instructions for fabricating the PCB, ensuring the final product matches the original design.
Summary of the Relationship
The CAD file is really reflective of the design, creative, and developmental phase of PCB—a transformation of ideas into elaborated, editable designs. Gerber files, on the other hand, represent the transition from the phase of designing to the production of the product, providing standardized quality along with detailed, precise manufacturing instructions.
Together, they take care that the eloquent idea of the designer is transferred onto reality correctly and perfectly in order to achieve the making of the perfect kind of high-quality PCB.
