In this paper, the key is to introduce PCB phosphorus copper ball in detail, the first detailed introduction of PCB electroplating copper need to use phosphorus containing copper ball, followed by the discussion of the use of phosphorus copper ball in PCB
in the design of PCB board, PCB anti-ESD design can be realized by layering, proper layout and wiring and installation. The PCB layout and wiring can be adjusted to prevent ESD.
Only under certain conditions can the 20H principle have obvious effects. 1. The power plane shall be located inside the PCB, and the upper and lower layers adjacent to it shall be 0V planes, and the distance between the two 0V planes shall be at least 20
The difference between them is that the core is thinner, the pp sheets of one or two layers and five or six layers are thinner, and there is a core board between the core board and the core board without copper foil on both sides, so generally this kind o
The characteristics of the gold process: the copper on the circuit board is mainly copper, copper solder in the air is easy to be oxidized, which will cause the electrical conductivity is to eat tin bad or bad contact, reduce the performance of the circui
The function of PCB design discharge teeth: in surge testing or ESD testing, the two ends of the common-mode inductor will produce high voltage, there will be a flying arc, if the distance is close to the surrounding devices, it may cause damage to the su
The role of PCB process edge: process edge is the part added on both sides or four sides of PCB board, mainly to assist the patch plug-in welding plate
Soft and hard combined board PCB design points: 1, flexible area line design requirements, 2, dimensional stability, 3, covering film window design, 4, rigid flexible transition zone design, 5, flexible zone design with air-gap requirements
The application of wave-crest welding technology and reflow welding technology are completely different in component layout design, PCB and pad graphic design and hole design.
Due to the different heat capacity and heating conditions of pad and pin, the temperature to which pad and pin are heated during reflow welding is also different. If the temperature difference is relatively large, it may cause poor welding.
The concept of DFM was first proposed in 1995 by the American Federation of Fittings Association and introduced into China in the late 1990s. "Circuit manufacturability design" is a new design concept put forward in 1998.
Basic principles of SMB design: layout, wiring, wire width, printed wire spacing, selection of components, selection of PCB substrate, PCB anti-electromagnetic interference, PCB heat dissipation, and arc Angle.
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