1. Right angle routing (three aspects) 2. Differential traces ("equal length, equidistant, reference plane") 3. Serpentine line (adjustment delay)
As early as the 1970s, there was already a literature report on BUM technology, but it was not until the early 1990s that the Japanese company (Yasu) developed a coating of photosensitive resin on the core board to form conductive micropores by photo-induced method. Even after the new method of manufacturing a high-density circuit board by the new method of addition, the high-density circuit board was successfully used in a Thinkpad type notebook computer, and the new technology was first published in 1991. It is called Surface Laminar Circuit, SLC (Surface Laminated Circuit Board). Since this technology has created an unprecedented high-density Interconnect, HDI (High-density Interconnect) new ideas, Japanese electronics manufacturers have developed and unveiled The BUM era in the history of PCB development.
Since the printed circuit board is not a general end product, the definition of the name is slightly confusing. For example, the motherboard for the personal computer is called the motherboard and cannot be directly called the circuit board. Although there is a circuit board in the motherboard, It's not the same, so when you evaluate the industry, you can't say the same thing. For example, because there are integrated circuit parts on the board, the news media called him an IC board, but in fact he is not equivalent to a printed circuit board.
When the signal propagates on the transmission line, the transient impedance sensed by the signal is related to the capacitance per unit length and the dielectric constant of the material.
In high-speed circuit design, the traditional approach to locating signal integrity problems is to use hardware triggers to isolate events and/or to capture events using deep acquisition storage techniques before looking for problems. As the speed and complexity of high-performance circuit systems continue to increase, the limitations of using oscilloscopes to locate signal integrity problems are becoming more prominent.