This invention relates to an inner connection structure suitable for welding pad region of a base, which already includes a semiconductor circuit and a welding pad corresponding to the welding pad region, the inner connection structure includes a first dielectric layer, multiple dielectric window plugs, a second dielectric and multiple contact window plugs , the pattern conductor layer includes an assistant layer and multiple first leads, the assistant layer has multiple gaps and the first lead is matched between the assistant layers and passes through the welding pad region via the gaps, the first dielectric layer is matched between the pattern conductor layer and the pad and covers the conductor layer, the dielectric window plugs are matched in the first dielectric layer for connecting to the assistant layers and the pad, the second dielectric layer is set between the base and the pattern conductor layer and covers the semiconductor circuit, the contact window plugs are set in the second dielectric layer for connecting the semiconductor circuit and the first lead. |