Here you'll find insights into PCB design, tech trends, assembly issues, and trending topics
in the general news media as they relate to printed circuit board technology.
As experts in the manufacture and assembly of printed circuit boards, we work to make our blog a helpful resource on PCB topics and the industries that we work with, including automotive, consumer electronics, aerospace and many more.
As memory designs become more complex and compact, and data rates are increasing, the use of BGA probes to detect DDR DRAM is becoming more popular and has become a requirement. The DDR3 and DDR4 data rates have increased from 800 MT/s to approximately 3200 MT/s. Memory system designers are concerned about whether current BGA probe designs can meet high bandwidth requirements for optimal signal fidelity. Signal fidelity is important for accurate DDR conformance measurements based on JEDEC specifications. In addition, the memory designer needs to perform signal integrity measurements to complete the margin test. Moreover, the margin after eliminating the DDR BGA probe detection effect can be used to design components with lower tolerances. This article describes a new probe calibration method for scalable DDR BGA probe bandwidth to increase the margin of signal integrity testing and minimize errors caused by DDR BGA probes.
When a square wave of a signal is propelled forward by a high-level positive pressure signal in the signal line of the transmission line assembly, the theoretical reference layer (such as the ground layer) is theoretically necessary. The negative pressure signal induced by the electric field is accompanied by the forward path (equal to the return path of the positive pressure signal reverse path), so that the integral loop system can be completed. If the "signal" advances its flight time for a short period of time, it can be imagined that it suffers from the instantaneous impedance value (Instantanious Impedance) from the signal line, the dielectric layer and the reference layer. This is called "Characteristic impedance."
The abstract and complicated digital high-speed logic principle, how to transmit the square wave signal in the transmission line, and how to ensure its signal integrity (Signal Integrity), reduce the noise of its noise (Noise) and other professional expressions, if simple The example of life is explained, but instead of moving a bunch of mathematical formulas and difficult physics language, it is the inspiration and benefit for novices or interlocutors.
How to improve anti-interference ability and electromagnetic compatibility when developing electronic products with processors?
5-7 Measures taken to increase the system's ability of it.
1-4 Measures taken to increase the system's ability of it.
For the impact of the transmission line problem, we will talk about the ways to control these effects from the following aspects.
Based on the transmission line model, in summary, the transmission line will have the following effects on the overall circuit design.
High-speed circuit design is a very complex design process. There are several factors that need to be considered when designing a high speed circuit. These factors are sometimes opposite each other. Such as the high-speed device layout when the position is close, although the delay can be reduced, but crosstalk and significant thermal effects may occur. Therefore, in the design, we must weigh the various factors and make a comprehensive compromise; not only meet the design requirements, but also reduce the design complexity. The adoption of high-speed PCB design means the controllability of the design process. Only controllable is reliable.
In design, layout is an important part. The quality of the layout results will directly affect the effect of the wiring, so it can be considered that a reasonable layout is the first step in the success of PCB design.
In the PCB design, wiring is an important step to complete the product design. It can be said that the previous preparation work is done for it. In the whole PCB, the wiring design process is the highest, the trick is the finest, and the workload is the largest. The PCB wiring has single-sided wiring, double-sided wiring, and multilayer wiring. There are two ways to route: automatic routing and interactive wiring. Before automatic routing, you can use interactive pre-wired lines that require more stringent requirements. The edges of the input and output should avoid adjacent parallel to avoid reflection interference. If necessary, ground wire should be isolated. The wiring of two adjacent layers should be perpendicular to each other, and parasitic coupling is easy to occur in parallel.
Layer setting and power ground segmentation requirements; Power module requirements
Thermal design requirements for layout; Layout signal integrity requirements; EMC requirements
Flexible printed circuit boards can be classified according to the type of bending encountered during assembly and use. There are two design types, which are discussed below:
For digital circuit designers, the inductance of the via is more important than the capacitance. Each via has a parasitic mid-inductance. Because the physical structure of the via is small, its characteristics are very lumped lumped circuit components. The main effect of the series inductance of the via is to reduce the effectiveness of the power supply bypass capacitor, which will make the overall power supply filtering effect worse.
In circuit design, we are generally concerned about the quality of the signal, but sometimes we are often limited to the signal line for research, and the power and ground as the ideal situation to deal with, although this can simplify the problem, but in high-speed design This simplification is no longer feasible. Although the direct result of circuit design is manifested in signal integrity, we must not neglect the power integrity design. Because power integrity directly affects the signal integrity of the final PCB. Both power integrity and signal integrity are closely related, and in many cases, the main cause of signal distortion is the power system. For example, the ground bounce noise is too large, the design of the decoupling capacitor is not suitable, the loop effect is serious, the division of multiple power/ground planes is not good, the design of the ground layer is unreasonable, the current is not uniform, and the like.
Qualifications and main duties.