Circuit Layout Design
Almost every electronic device uses a printed circuit board (PCB). A PCB provides a physical base for all electronic and electrical components used in the device. It facilitates their connections by means of conductive tracks etched from sheet layers of copper and soldering. In addition to electronic devices, PCBs are also used for electrical products, such as passive switch boxes.
PCB design and layout
Days when PCBs were designed manually by creating a photomask on a clear mylar sheet are long over. Today, specialized layout software is used for designing and laying out PCBs.
Let us check what are the steps involved in PCB design and layout:
1. An EDA tool is used to schematically capture the circuit design.
2. What sizes the card and the template would be are decided, according to the circuitry and PCB case.
3. Next the position of the modules along with heat sinks is determined. Heat sinks gets rid of the heat generated by the PCB components.
4. Based on the complexity of the circuit, the layers of the PCB are decided that can be from one to tens of layers. Ground and power planes are also decided. Signal interconnections are traced on signal planes, both on the outer and inner layers.
5. Line impedance is evaluated by means of different parameters like copper thickness.
6. It is now that the components are placed in their designated places. This placement takes into account thermal factors along with geometry. At this step, vias and lands are also marked.
7. Routing of signal traces takes place.
8. In the final step, Gerber files need to be created for manufacturing.
Tips for flawless PCB designing
There are certain practical aspects that need to be kept in mind to design an error-free PCB. Let us see what they are:
● Before designing the PCB, ensure points to be used for troubleshooting in case something is not working in the circuit. Aim for test points that form a loop.
● Leave adequate space for routing of wires by placing the components at appropriate distances. As a thumb rule, the more pins a component has, more space it will need. This will also facilitate soldering.
● Pin numbering on components is important. It should not be haphazard. #1 should start from the upper left corner. This will help when soldering or inspecting the components.
● The print out of the layout is now taken after laying out all the components at their respective places. This placement is done by laying out the components on the layout paper.
● Now the wiring of lines is made by drawing both vertical and horizontal traces in such a way that it facilitates cross overs without any confusion. Avoid ninety-degree angles with traces, since this makes it difficult to keep the width constant. Better is the forty-five-degree approach.
● Compare the schematic and layout to ensure that both are matching.
Doxals’ edge
Doxals Engineering, a Singapore-based electronic engineering solutions company, fine-tunes the PCB design and layout by using sophisticated technology and software. It is also ensured that there is no compromise on quality.