The printed circuit board (PCB) manufacturing and assembly involves various steps, which are carried out in a specified manner to achieve desired results. Nowadays, automated equipment is used for PCB manufacturing and assembly, and this helps minimize design and manufacturing errors, production costs, product recalls, as well as accelerates the time-to-market. The success of any PCB assembly depends on various factors such as design, placement of components, testing and inspection, and so on. Although a lot has been discussed about these factors, there is one commonly overlooked factor - the selection of the right components. This post discusses component selection in detail and analyzes the common mistakes performed by designers.
Component Selection – Know About the Different Steps Involved
Although component selection may sound simple, this process involves several considerations. For gaining a clear insight, this process can be divided into three steps:
- Selection of Components: This is the most important step in PCB manufacturing and assembly. A PCB assembly utilizes various active and passive components. Vacuum valves, triodes, transistors, and tunnel diodes are a few active components. These components carry power to the circuit and can amplify the signals. Active components derive power from the power source. Passive components are the components that cannot induce power in the circuit and they do not depend on any type of power source. Inductors, transformers, capacitors, and resistors are a few examples of passive components.
- Buying Components: This relates to buying or purchasing components for the assembly. Component purchasing or sourcing cycles may be longer than expected due to various factors such as shortage of supplies, high prices, unavailability of desired components, and so on.
- Placement of Components: The above two steps culminate in the placement of components, which is a key step in PCB manufacturing and assembly. Although largely automated, this process also involves several considerations. The performance and success of a PCB largely depend on this stage.
Common Mistakes Made by PCB Designers During Component Selection, Sourcing, and Placement Discussed in Detail
Each of the above-discussed steps involves several sub-steps, which need to be performed in a certain way. However, PCB designers tend to make the following mistakes in each phase:
Component Selection: A PCB may use one or more active components and a few passive components. Although calculations have a great role to play in their selection, designers may fail if they overlook the following:
Functionality of the Component: They must check if the component meets all the requirements of the application. For instance, if the power supply IC meets the current and voltage requirements of the application.
- Power Consumption: Most designers depend on CAD libraries for power rating. However, they fail to replace it with the required power rating, which often leads to the failure of passive components.
- Voltage and Current Ratings: Many times, designers fail to address the maximum and minimum voltage and current ratings of the circuit. Buying components with a higher voltage rating than required may lead to bulkier circuits. Similarly, buying components with low current ratings than required may lead to failure due to melting.
- Requirements of Operating Environment: How the PCB will be operated? The components are usually specified for operating at certain temperature as well as humidity range. They are identified as industrial grade, commercial-grade, and military-grade depend on the operating environment.
- Regulatory Requirements: Failure to comply with regulatory requirements may not immediately lead to circuit failure, but it may definitely lead to product recalls if you are shipping PCBs outside the US.
- Components Purchase: This stage offers more challenges than any other phase. The shortage of components is one of the key challenges faced by many PCB assembly. Although many PCB designers suggest alternate components, sometimes finding them can be challenging as well. Due to shortage, many times, electronics manufacturers may settle for low-quality alternatives or may even fall for cheap marketing gimmicks adopted by untrustworthy sources selling products. To avoid all these, it is always better to partner with PCB assembly and manufacturing services that offer turnkey PCB services.
- Component Placement: Nowadays, component placement is conducted using automated placement machines, then how could PCB designers go wrong? This is quite an obvious question. However, to perform, these machines require suitable input in the form of Gerber data. Along with the Gerber data, fabricators need to focus on specifics like appropriate panel sizes, panel handling strips, fiducial marks, and so on. These features help minimize placement errors and build a quality product.
As the component selection and common mistakes made by fabricators is well introduced here, it is important that you partner with the trusted PCB assembly and manufacturing services. Today, it is easy to find several service providers in your area; however, not all may be equally qualified and experienced to meet your requirements. PCBHERO is one of the well-known and trusted PCB manufacturing and assembly services in the China, which offers end-to-end solutions from prototype to production runs.