Probe head for wafer-level burn-in test (WLBI) and probe card comprising said probe head

A probe head for wafer-level burn-in test, comprising:

• a first and a second alignment plates arranged parallel to each other and provided with a plurality of passage holes;
• at least one spacing element interposed between the first and the second alignment plates and designated for keeping them in a prefixed spaced apart relationship;
• a plurality of probes housed between the passage holes of the alignment plates;
• said probes comprising a stem, an input contact and an output contact at the opposite ends of said stem, wherein the input contact passes through the second alignment plate to electrically connect to a corresponding testing channel of a probe card and the output contact comes out of the first alignment plate and is designed to contact a termination of a wafer to be tested;
• and
• a spacer made of dielectric material surrounded by said spacing element and also interposed between the first and the second alignment plates, said spacer being provided with a plurality of through holes for housing said probes;
• said output contact being retractable into the stem in opposition to first counteracting elastic element;
• wherein said input contact is retractable into the stem in opposition to a second counteracting elastic element.