CAD to CAM - Computer Controlled Assistance in PCB Manufacturing
Computer-aided Design Engineers and Computer-aided Manufacturing Engineers are the two most important people in the design and manufacturing of a Printed Circuit Board (PCB). CAD Engineer to CAM Engineer relationship is an important one for PCB fabrication. Often CAD Engineers have the view of “No News is Good News” when it comes to communication with CAM engineers. This is the case because, when a CAM Engineer contacts the CAD Engineer, it is often to resolve a problem. It is important to have a working and an open line of communication between the two in order to resolve problems quickly and set precedence on how to handle future problems. CAM Engineer is the people responsible for fabricating the PCB and ensuring it will function as expected. At Bittele Electronics, we have knowledgeable and experienced CAM Engineers who are ready to assist and work with you on your projects. Bittele Electronics CAM Engineers have the extensive experience from years of PCB manufacturing and the know how to assist you in resolving any issue that may occur.
When sending files to our CAM Engineers, it is important to include artwork layers (Gerber 274X, ODB++), Drilling files, Fabrication drawings, and ReadMe files. Whatever software the designer used, it is important to generate Gerber or ODB++ files as these are the only files that Bittele is able to accept for manufacturing. Drilling files will need to be included upfront and will be reviewed in the CAM Engineers Design for Manufacturing (DFM) check before production. A fabrication schematic drawing is recommended so the CAM Engineer has a clear idea of the project and can help identify and resolve any complications that may come up. ReadMe files are not commonly used but should be. Attaching a ReadMe file with any important information will provide the CAM Engineer with simple and easy access to some vital information. This is also a great opportunity to ensure no mistakes or human error goes undetected. ReadMe file gives CAD Engineers an opportunity to summarize and prove key information to the CAM Engineer all in one place.
CAD Engineers used different software tools to create their board designs, different rules, different parameters, different expectation, and output data in different formats. This means most board designs and files CAM Engineers receive will be unique in some way. It is the responsibility of the CAM Engineer to turn all these files into boards. The CAM Engineer will need to review the files, understand the customer's requirements, and decide if it’s achievable and acceptable to move forward. The CAM Engineer will need to contact or have some sort of written instruction regarding just how much modification the CAM Engineer is allowed to make in order to ensure the board passes the DFM check. If all the information provided is good and the CAM Engineer is satisfied with the requirements, the project will move forward. The CAM Engineer may contact the CAM Engineer regarding any issues or question that may come up. The CAD Engineer will be hoping to for limited communication from the CAD Engineer as this would imply minimal issues or questions have come up.
Let’s take a quick look at exactly what the CAM Engineer does once, the initial inspection is complete, and files are accepted for fabrication. The first thing the CAM Engineer will need to do is organize the files for the project in methods that will make the fabrication process as efficient as possible. This is also a good time for the CAM Engineer to identify if any files are missing or to verify the formatting and setting of the files is interpretable. The CAM Engineer will then ensure all the artwork layers are aligned and the drill data matches the whole chart. Additional checks will also need to be completed to ensure the copper and silkscreen features are within the board outline. The design will also need to be checked to ensure the clearances and trace width are within the fabrication house limitations. The final step of the DFM check is to verify all the data meet whatever customized requirement is meet and to identify any potential errors that may occur in the fabrication process. This would be the final opportunity for either the CAM Engineer or CAD Engineer to make any modifications or corrections to the design before the files are handed over to the fabrication floor. Once the boards have been fabricated, the CAM Engineer will need to prepare and conduct electrical testing on the boards to detect any shorts or opens that may be present on the board. Visual inspection will be completed to ensure the board meets Class 2 Dedicated Service Electronic Products or Class 3 High-Reliability Electronic Products standards based on the clients request and requirements. The CAM Engineer will also conduct functional testing at this point if it was requested by the CAD Engineer.
Let's conclude by looking at how CAD Engineers can ensure they get the desired result and their board avoids any delays or issues. CAM Engineers want to provide the best possible printed circuit board to their customers. Bittele Electronics CAM Engineers receive files in different format and designs from CAD Engineers all over the world. They have the experience and know how to ensure the PCB is fabricated in the ideal condition. By using a ReadMe file inform the CAM Engineer what you require and desire as well detailed as possible. Also, include what is acceptable for the CAM Engineer to adjust or change himself. By giving the CAM Engineer the requirements and permissions, the CAD Engineer can limit the back and forth to essential matters. Ensure all your data is submitted. It is not uncommon to come across files that are missing artwork layers or drill files. Creating a separate layer for the PCB outline will ensure there is no confusion. Make sure to differentiate from un-plated and plated holes. Gerber 274X and ODB++ are used by almost all manufacturing houses. You can avoid any file format issues by outputting your design by both Gerber 274X or ODB++, if that is not possible then Gerber 274X is the way to go as it makes up 90% the PCB manufacturing based on data from 2016. The final and perhaps most important step is to have a look at your design before submitting it. There are many free Gerber 274X and ODB++ reader programs online, CAM Engineers strongly encourage CAD Engineers to take a moment to have a look at there output before submission, to catch any potential issues early on. After reviewing your board and if you are satisfied with what you see, send it in to Bittele Electronics, to see your board fabricated in the best quality possible.