Having to make a change can be a frustrating process, as I found out recently when one of my household appliances abruptly failed. I had to invest time in research to find a suitable replacement. This research involved taking measurements, inspecting the new product, and eventually spending money I preferred not to spend. Unfortunately, changes like this are common occurrences that have to be dealt with, whether they involve a trip to the local big-box store or updating a printed circuit board design.
It would be ideal if electronic components never failed, never became obsolete, or were never too expensive or unavailable. Sadly, that is not the case. Any or all of those conditions can cause PCB design’s parts to need replacing. Since this problem is unavoidable, here are some different ways to find replacement electronic components and simplify that process.
Why Components Need Replacing
When a circuit board is designed, the components soldered to it are represented by schematic symbols and footprint models in the PCB design CAD system. Each schematic symbol type has a unique part number assigned to it to differentiate it from other similar symbols, as in two resistors with different values. This part number identifies the component’s type and value and is forwarded into the bill of materials (BOM) to purchase the correct parts for PCB assembly. When a component is replaced in the design, that schematic symbol must be updated with the new part number and device attributes. Simultaneously, the corresponding PCB footprint will be altered to model the new package if the physical part has changed.
Components are often swapped around during the design process until the final circuit configuration is decided. Once the design is completed, however, components are usually not replaced except for the following reasons:
- Design problems: Errors discovered during production may require the replacement of a part. Issues like these could be related to the performance of the board or in how it is manufactured. The replacement could be something as simple as changing the value of a capacitor or as complex as physically redesigning some critical circuitry layout.
- Unavailable parts: During production, a part may become unavailable for several reasons:
- Another OEM has bought out all the stock of a specialty part.
- The lead-time is too significant for the project’s needs.
- The component manufacturer is unable to keep up with demand.
- The part was phased out in favor of a more common component with similar functionality.
- The part was discovered to have a defect or design flaw.
- The manufacturer obsoleted the part due to other business reasons.
- Expense: Components may be replaced on a production circuit board to reduce manufacturing expenses. If a part begins to escalate in price, it’s sometimes more cost-effective to redesign the board. In some circumstances, a part will be replaced with less expensive components or redesigned circuitry. However, the savings must be compelling because the production of a new circuit board will require revalidating the design for the system that it operates in.
These are some of the reasons why a circuit board may have to have a part replaced on it. The next question is, where can replacement components be found?
Where to Find Replacement Electronic Components
The first place to look for replacement components is with the online manufacturer and distributor’s catalogs. These listings will provide you with up-to-date information on a wide range of parts along with their datasheets. One thing to be aware of is that while some of these listings will also include CAD models that you can download and use, many do not, and you will have to build symbols and footprints.
Another resource for components is to use a CAD part library service. These services typically offer online tools that tie directly into your PCB design system and provide native system data. Depending on the service and your system, you may have access to schematic symbols, PCB layout footprints, 3D STEP models, datasheets, illustrations, and more. These services can not only save you a lot of time, but they will also provide the most accurate data models possible—usually created by the manufacturer.
When replacing components in your design, it is crucial to consider the form, fit, and function of the new part concerning the rest of the design. Even a subtle difference in the part’s functionality could affect your circuitry, and a slight physical difference force changes to the layout. Here is where the help of seasoned component engineers and procurement specialists can be a big help. With their experience working with components, they can help you make the best choices for component replacements.
The Advantages of Using Component Procurement Specialists
The engineering and procurement specialists of a PCB contract manufacturer are set up to provide the component expertise that electronics OEMs seek. When it comes to questions about component replacements, their engineers can help with the following:
- Recommend direct component replacements.
- Find replacements that will offer similar functionality.
- Help with layout changes for new component packages.
- Recommend circuitry changes for new functionality.
At the same time, the PCB CMs procurement teams can offer the following resources:
- A far-reaching network of component manufacturers, distributors, and brokers.
- An alert system set up for advanced warning of component life-cycle changes.
- Knowledge of where to find available parts at the best prices.
- Experience in detecting and avoiding potential component counterfeits.
At VSE, our component engineers and procurement specialists have been helping our clients with part replacements for over 30 years. Our goal is to ensure that your board is built on time for the best price and highest quality level. To that end, our teams collaborate with you to make sure your component choices are the best for your printed circuit board’s life-cycle.