Probe card and space transformer thereof

The present disclosure relates to a probe card and a space transformer thereof. The space transformer includes a main space transforming unit and at least one sub-space transforming unit. A top surface of the main space transforming unit includes a first test area and a second test area. The first test area has a plurality of first top contacts formed on it. The second test area has at least one recess formed on it. A bottom surface of the at least one recess has a plurality of first inter-contacts formed on it. A bottom surface of the main space transforming unit has a plurality of first bottom contacts and a plurality of second bottom contacts, the first bottom contacts electrically connect to the first top contacts, the second bottom contacts electrically connect to the first inter-contacts. The sub-space transforming unit is disposed in the recess. The top surface has a plurality of second top contacts formed on it, and the bottom surface has a plurality of second inter-contacts. The second top contacts e