(1) For fundamental circuit principles, please refer to “Basics of Circuit Analysis.”
(2) Select a design tool; I recommend Cadence. While I’ve also used Altium Designer (AD), I find Cadence to be more powerful and user-friendly. If you’re aiming for cutting-edge technology in circuit boards, it’s important to note that “cutting-edge” can be subjective. The most challenging aspect of PCB design often lies in balancing design requirements with manufacturing capabilities. Considerations like 24-layer boards, small pin pitches, narrow routing spaces, stringent signal quality standards, complex routing constraints, and extensive post-completion inspections make Cadence a more effective choice for these tasks.
(3) Utilizing Cadence for schematic capture is crucial. Without a solid understanding of circuit principles, creating an effective Placement (the arrangement of schematic components on the PCB) can be quite challenging. A well-executed Placement can account for over half of a successful PCB design.
(4) We will effectively utilize the PCB space as outlined in the schematic diagram, ensuring optimal placement to achieve the best signal path and maximum routing area. After completing the placement, we will adjust the silkscreen. This will represent the final board’s face.
(5) We will design the PCB stackup to be reasonable and optimal, maintaining signal quality while considering cost and wiring complexity. More layers improve signal quality, but they also increase expenses. Next, we will establish wiring constraint rules and finalize the layout. (Personally, I find the layout stage the simplest in this process, as it only requires a bit of experience within the given constraints to complete the final layout.)
(6) It is crucial to understand the actual fabrication capabilities of the manufacturer. You must confirm that your PCB can be produced and whether the manufacturer has the capacity to make it. For instance, designing a 100-layer board may be costly and impractical; currently, the most capable fabs near me handle up to 60 layers (40x60cm for over $10). I have yet to hear of any capable of producing a 70-layer board.
(7) We will obtain quotes, understanding the costs associated with each fab, including stacking, blind and buried holes, plug holes, back drilling, machining accuracy, drilling ratios, and line widths. This estimation can begin early in the schematic phase, allowing us to consider costs in the design to ensure a competitive final product price.
(8) Once the PCB is completed, we will conduct thorough inspections, including checks for impedance matching, power line load capacity, repetitive wiring, short circuits, open circuits, signal return paths, signal integrity, and actual fab capabilities, as well as line width, spacing, and hole spacing inspections.
(9) We will generate fab files and deliver them to the manufacturers.
(10) One key point is regarding the BOM selection based on the schematic. Considering the cost and delivery times for components, as well as their impact on placement, I prefer smaller sizes for resistors with the same parameters to optimize PCB space. The aim is to choose the most suitable components.
