During the process of printed circuit board designing, there are the three main steps – component selection, component sourcing, and component placement that have the power of influencing the efficiency and functionality of the final product. Any mistake in one step or more can lead to major project issues and complications. It can result in malfunctioning or even non-functioning final products that further result in delays and holds – which is a major loss for any company in the electrical and electronics industry. Thus, when you place an order for PCB prototype or PCBs, it is critical that you choose experienced and skilled Circuit Board Manufacturers.
In this post, we will focus on the first step – component selection and discuss the common factors that naive and amateur designers often overlook.
Component Selection
A designer usually creates the foundation of circuit board design on the basis of one or more active components. Typically, the working of these components depends on the value and rating of passive components. Even though designers calculate these values carefully for the passive components, they can easily overlook the following parameters.
• Power Rating of resistor
• Voltage Rating of capacitor
• Current Rating of inductor
• Footprint Pattern for passive as well as active components
• Obsolescence of components
1. Power Rating of Resistor: Many naive designers and amateurs miss to consider the power ratings for resistors. The selection of the power rating of a resistor is based on the maximum current that can pass through it. Since CAD libraries often use standard rating when a designer calls for a component, it is essential to double-check if the power rating is correct or not. Otherwise, it can lead to a burnt resistor or non-functioning board.
2. Voltage Rating of Capacitor: While choosing a capacitor, a designer needs to specify various parameters, including capacitance value, temperature characteristics, and voltage rating. The capacitance value and temperature characteristics directly affect the working of a circuit. However, the voltage rating depends on the operating voltage of the circuit itself. While selecting a higher voltage rating than required may mean in a bulkier circuit board, selecting a lower voltage rating can blow up the capacitor.
3. Current Rating of an Inductor: Even though the primary parameter in case of an inductor is the inductance value, not paying attention to the maximum current flowing through it can also lead the circuit to operate at a higher temperature or even melt during operation.
4. Footprint Pattern for Passive and Active Components: You may be surprised to know but it is common that designers sometimes can get the wrong footprint pattern for not only passive components but also active components. The problem is that different component manufacturers offer different packages for the same type of components and PCB CAD libraries have multiple footprint patterns to match the various packages from the manufacturers. Besides, component manufacturers identify different packages of the same component with unique type numbers.
Thus, Circuit Board Manufacturers and designers must be careful while deciding the proper footprint from the library by matching the chosen package and parameters, including calculated power, voltage, and current rating of the components. Plus, they should decide beforehand whether the power component will need a separate heat sink or require a copper pattern for effective heat removal.
5. Obsolescence of Components: Last but not the least thing to make sure is that the components used in the circuit boards must be available for significant time and they must not become obsolete soon. Based on the application, the parts and components should be available for not only the lifetime of the circuit board and the product in which it will be used but also for some years beyond that time.
All these criteria are very important for Circuit Board Manufacturer and designers. Since this is the early stage of a circuit board design, one can easily make changes and the cost effect is low. So, it is always better to make things right in the first stage.
