I found this on old CPU motherboard circuit and find its interesting. What is the purpose of that pattern? is it only for aesthetic or is there something else? I only seen the same pattern on bluetooth module rf antenna.
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.