handle revisions in a printed circuit prototype
When a printed circuit board prototype is first assembled, a number of tests must be performed to ensure the final product will function as intended. These include visual inspection of the entire assembled PCB to make sure all components are correctly placed and soldered and powering it up to evaluate performance metrics such as signal integrity, current distribution, and thermal characteristics. It is also important to take this opportunity to look for any design improvements and apply them to the schematics, layout, and BOM.
As you can imagine, a proper revision control system is essential for keeping track of all these changes. The most straightforward way to document a part’s revision level is within the engineering drawing that the component is associated with. The revision level is usually indicated in the title block with either an alphanumeric code or a numeric code and is the most accurate way to reflect the part’s status.
Unfortunately, even with a solid revision control system in place it is still possible that mistakes will be made. One of the most common errors is a short or open in the board, and both can severely affect the functionality of the finished product.
How do you handle revisions in a printed circuit prototype?
To avoid these problems, a printed circuit prototype should be tested at each milestone in the development process. The first test is to verify the physical integrity of the board by visually inspecting it and making note of any anomalies such as unintended connections. The next step is to perform functional testing using a variety of testing equipment such as oscilloscopes and multimeters to ensure that the circuitry is working as expected.
Once the PCB has been deemed to be functioning as intended, it is then ready to proceed to full-spec production. During this stage, the PCB will be manufactured using high-end materials and will have all of the necessary features needed for the final product to function. This is also a great time to evaluate the effectiveness of the design and determine any changes that may be needed before the board moves forward into the production phase.
If any significant issues are found during the functional testing phase, a new revision is created. These changes can be minor, but they must still represent a non-negligible change in functionality. This change will then be reflected in the layout, schematic, and BOM, moving the project to its new revision number.
It is critical to have a well-documented revision control system in place to reduce the risk of error, improve productivity, and increase the quality of the finished product. Having a clear system for documenting each version of the PCB, schematics, and BOM will allow you to easily and quickly identify which version is being referenced and will greatly reduce the chances of incorrect parts being ordered. Moreover, an effective revision control system will greatly simplify product development by providing immediate access to historical data on each part’s history. This will save a tremendous amount of time when it comes to re-ordering obsolete or no longer available parts.