2020-09-25
1.1as receivedThe products submitted for acceptance have not been subjected to any condition treatment, and they are in ...
Because of the lack of a layer of dielectric and foil, the cost of raw materials for odd-numbered PCBs is slightly lower than that of even-numbered PCBs. However, the processing cost of odd-layer PCB is significantly higher than that of even-layer PCB. The processing cost of the inner layer is the same; but the foil/core structure obviously increases the processing cost of the outer layer.
2020-09-24
Shielding selection of different interference fields There are two main types of interference fields: electromagnetic interference and radio frequency interference. Electromagnetic interference (EMI) is mainly low-frequency interference. Motors, fluorescent lights, and power lines are common sources of electromagnetic interference. Radio frequency interference (RFI) refers to radio frequency interference, mainly high frequency interference. Radio, television broadcasting, radar and other wireless communications are common sources of radio frequency interference.
2020-09-23
There are four positioning holes on the four corners of the outer frame of the panel. The diameter of the hole is 4 mm (+0.01 mm). The strength of the holes should be moderate to ensure that there is no break between the upper and lower plates. The hole position has high precision, and the hole wall is smooth and free of burrs.
In the high speed PCB multilayer board, the signal transmission from one layer of interconnect to another needs to be connected through vias. When the frequency is lower than 1GHz, via can play a good role in connection, and its parasitic capacitance and inductance can be ignored.
2020-09-22
To learn high-speed PCB design, we must first know what transmission line is. The signal will be reflected because the wiring on the PCB has a certain impedance.
When the layer thickness is set, the thickness of the core plate between the ground plane layer and the power plane layer should not be too thick, so as to reduce the distributed impedance of the power supply and ground plane and ensure the plane capacitance filtering effect.
Solder mask: solder mask refers to the part of the board to be coated with green paint; because it is a negative output, the actual effect of the solder mask is not green, but tinned, silver white!
Oxidation resistance, tin spraying, lead-free HASL, gold deposition, tin deposition, silver deposition, hard gold plating, full plate gold plating, gold finger, nickel palladium OSP:
For PCB designers, we can not only consider the design and perfect requirements in the process of PCB design, there is a...
