Talking about how to learn PCB layout? Release time: 2018-01-30 0 Based on your own work experience, you need to master at least a few points to learn PCB Layout: (1) Basic principles of circuits, you can refer to 'Basics of Circuit Analysis'. (2) Choose the Design tool and recommend cadence. I have also used AD. I personally feel that Cadence is more powerful and handy. And you want to take a circuit board with cutting-edge technology. I don’t know how to define cutting-edge. In fact, the most challenging part of a PCB is the contradiction between design and cost Fab ability. The 24th layer), small pin pitch, narrow wiring space, demanding signal quality requirements, cumbersome wiring constraints, and a series of inspections after completion, and I believe that it will be more convenient and easy to use Cadence to complete these tasks. (3) It is very important to use cadence to draw schematic diagrams. If you don’t know the circuit principle, it’s actually difficult for you to make a good Placement (I don’t know if this term is common, so I’ll explain: the components of the schematic diagram are on the PCB. Actual layout), I think a good Placement actually completes more than half of a PCB design. (4) According to the schematic diagram, make good use of the PCB space and make reasonable placement to ensure the best signal path and the largest signal routing space. After finishing the Placement, adjust the silk. This is the face made by the final board. (5) Will design the PCB stackup, a reasonable and optimal (without sacrificing signal quality, taking into account the cost and wiring complexity, because it is certain that the more layers, the better the line, but the higher the cost). Design routing constraint rules, and then complete the layout. (I personally think that Layout is the easiest in this complete process, because under constraints, only a little experience can complete the final layout work) (6) Know the actual Fab capabilities of the Fab manufacturer, of course you have to know you Can the manufacturer produce it (if you design a 100-layer board (even if it is estimated to be a sky-high price)), I don’t know which manufacturer can produce it. I currently know that the most Fab around me is only 60 layers (40x60cm 10 More than W US dollars), I have not heard of 70 layers) (7) Will make a quotation, know the charges for each Fab, stacking, blind holes, buried holes, plug holes, back drilling, processing accuracy, drilling ratio requirements, Line width, etc., can estimate the quotation at the beginning of the schematic, and even take the cost into consideration during the design, so that the final product is price competitive. (8) The PCB will be checked after the completion of the PCB, including impedance matching and other long line width inspection, power line load capacity inspection, repeated wiring inspection, short circuit and open circuit inspection, signal return path inspection, etc., signal inspection, and actual Fab capability inspection , Line width inspection, line spacing, line hole spacing and so on. (9) Generate Fab files and deliver them to Fab manufacturers. (10) One point is missing from the above. Regarding the BOM option, according to the schematic diagram, considering the cost and delivery cycle of the device, the impact on Placement (if they are all resistors with the same parameters, I am willing to choose a small size in most cases, because Can save PCB board space) Choose the most suitable device.
