PCB design copper precautions
Copper coating as an important part of PCB design, whether it is domestic PCB design software, or some Protel abroad, then how to apply copper? Next PCB design company -kinhford Electronics to introduce the PCB design copper precautions. What is copper coating?
The so-called copper coating is to use the idle space on the PCB board as the base level, and then fill with solid copper, these copper areas are also known as copper filling. The significance of copper coating is to reduce the ground impedance and improve the anti-interference ability. Reduce voltage drop, improve power efficiency; Connected with the ground wire, the loop area can also be reduced.
1. If the PCB board has more ground, such as SGND, AGND, GND, etc., it is necessary to use the most important "ground" as a reference reference to independently cover copper according to the different positions of the PCB board, and the digital ground and analog ground are separated to cover copper since it is not much to say. At the same time, before covering copper, first bold the corresponding power connection: 5.0V, 3.3V and so on, in this way, a number of different shapes of multi-deformation structure is formed.
2. For different single-point connections, the practice is to connect through 0 ohm resistance or magnetic beads or inductors.
3. The crystal oscillator in the circuit is a high-frequency emission source. The method is to apply copper around the crystal oscillator, and then ground the crystal shell separately.
4. The island (dead zone) problem, if you think it is big, then it does not take much to define a hole to add it.
5. At the beginning of the wiring, the ground line should be treated equally, and the ground line should be well walked when the line is wired, and the ground pin can not be eliminated by adding a hole after copper coating, which has a very bad effect.
6. It is best not to have a sharp Angle on the PCB board (=180 degrees), because from an electromagnetic point of view, this constitutes a transmitting antenna! For others, there will always be an impact on just big or small, I recommend the use of arc along the side.
7. Do not apply copper to the wiring open area of the middle layer of the multilayer board. Because it's hard to make this copper "well grounded."
8. The metal inside the equipment, such as metal radiators, metal reinforcement bars, etc., must be "well grounded".
9. The cooling metal block of the three-end regulator must be well grounded. The grounding isolation belt near the crystal oscillator must be well grounded. In short: the copper on the PCB board, if the grounding problem is handled well, it is certainly "more advantages than disadvantages", which can reduce the return area of the signal line and reduce the electromagnetic interference of the signal.
Maximum signal design rate: 10Gbps CML differential signal
Maximum PCB design layer: 40 layers
Minimum line width: 2.4mil
Minimum line spacing: 2.4mil
Minimum BGA PIN spacing: 0.4mm
Minimum mechanical hole diameter: 6mil
Minimum laser drilling diameter: 4mil
Maximum number of pins: 63000+
Maximum number of components: 3600
Maximum number of BGA: 48+
PCB design service flow
1. Customers provide schematics to consult PCB design;
2. Evaluate quotation according to schematic diagram and customer design requirements;
3. The customer confirms the quotation, signs the contract, and prepays the project deposit;
4. Received advance payment and arranged engineer design;
5. After the design is completed, provide the screenshot of the document to the customer for confirmation;