A circuit structure includes a semiconductor substrate, first and second metallic posts over the semiconductor substrate, an insulating layer over the semiconductor substrate and covering the first and second metallic posts, first and second bumps over the first and second metallic posts or over the insulating layer. The first and second metallic posts have a height of between 20 and 300 microns, with the ratio of the maximum horizontal dimension thereof to the height thereof being less than 4. The distance between the center of the first bump and the center of the second bump is between 10 and 250 microns.