What is the use of zigzag pattern on PCB board
Some electronic devices such as DDR memories transmit data at very high speed and traces that carry those signals are critical. The only point of that routing technique (leaving antennas and RF stuff apart) is to achieve the exact similar trace lengths in all of those signals. The zig zag allows to gain some millimeters when the straight path is too short for the target length. Same length in all of the data traces allows the data to arrive at almost the same time to the data pins and so, achieve better transmission rates and performance.