Last Updated on October 4, 2022 by Olivia Anderson
There are several factors that affect the quality of PCB production. These factors include mechanical design, dielectric constant, and schematic design. However, these factors are only part of the equation. It’s critical to thoroughly evaluate all three elements of PCB design before proceeding to PCB production. Here are some tips to help you do a thorough evaluation.
Importance of thorough evaluation of outline design on PCB production
Before PCB production begins, it is important to thoroughly evaluate the outline design. This stage of the PCB layout process ensures maximum flexibility for revisions and maximizes the engineering team’s efforts. This step includes the definition of the board outline and footprint, component placement and routing, silkscreen cleanup, and DRC check. This stage is also necessary to generate the PCB production documents.
The design for manufacturing is critical to the final application. Any design feature that makes the PCB difficult to build increases the scrap rate and adds to the cost. PCB Design for Manufacturability is essential for PCBs that are particularly complex, as it helps identify manufacturing problems and optimize the design for trouble-free manufacturing.
Effect of mechanical design
Mechanical design plays an important role in producing PCBs. During the design phase, it is important to select components that will withstand the manufacturing process. Incorrect selection of components can lead to additional manufacturing problems. These problems can result in additional manufacturing costs and delays. In addition, poor mechanical design can lead to faulty components.
If the mechanical design does not incorporate a correct placement of PCBs, it may result in board warp. To overcome this, mechanical teams can also use a CAD program to make sure that the PCBA fits into the mechanical assembly. However, if a mechanical design involves an asymmetric laminate structure, it can lead to warping of the board. Using a symmetric laminate structure can improve assembly quality.
Effect of schematic design
Schematics are a key component of PCB design. They contain information about the circuits, components, and their properties. They are important business documents and must be accurate. These documents should also contain critical information, such as part numbers, names, copyright, and contact information. PCB production relies on electronic schematics to generate circuit boards, and errors in these documents can cause multiple manufacturing issues.
A circuit schematic describes the electrical implementation of each function on a PCB. In addition to this, it is important to create a realistic drawing of the final PCB dimensions, including areas designated for the circuit schematic blocks. A circuit schematic block is a collection of circuit components that are connected for specific electrical reasons.
Effect of dielectric constant
Dielectric constant refers to the properties of a material that governs its properties under certain conditions. Its values are expressed in parts per million and increase as the material temperature increases. For example, substrates have a higher CTE than copper, so a capacitor built with them will experience interconnection problems as the board heats up. The dielectric constant of a material is an important factor because it impacts signal integrity and impedance considerations. Most materials have a dielectric constant of 2.5 to 4.5.
The dielectric constant of a PCB material depends on its frequency, and it varies with the frequency. In the case of high-frequency devices, it is important to use a material with lower dielectric constant to avoid the possibility of causing delays in propagation. While a lower dielectric constant is advantageous from a propagation delay standpoint, it can negatively affect the characteristic impedance of traces. Therefore, careful modeling is needed to determine which dielectric constant is acceptable for a particular device.