Probe card for testing integrated circuit chips

An apparatus for testing integrated circuit chips on a wafer, comprising:

• a prober (16) having an integrated circuit probe-card (22) at an upper surface thereof, said probe-card having a plurality of probe-pins for contacting corresponding pads of a chip on a wafer under test, said probe-card (22) comprising a plurality of pegs (27) protruding from the upper surface of said prober (16);
• and
• a test head (12) disposed above said prober (16), and comprising at a bottom surface thereof a test card (28) contacting said pegs (27);
• wherein the probe-card comprises a base mothercard (30) and a removable daughtercard, said daughtercard (32) plugged in said mothercard, said probe-card further comprising a maintaining ring (38) for releasably maintaining said daughtercard plugged into said mothercard,
• said maintaining ring including a recess for accommodating said daughtercard and engaging means for engaging said daughtercard while releasing said daughtercard from the mothercard.

In an apparatus for testing integrated circuit chips on a wafer, the improvement comprising means for reducing a number of connections and withdrawals of conductive pegs from an integrated circuit probe-card to and from a test card, including:

• a base mothercard of said integrated circuit probe card connected by said conductive pegs to said test card;
• said mothercard including socket means;
• a removable daughtercard including plugs for plugging connecting to said socket means of said mothercard and probe pins for connecting to a wafer under test in said prober;
• and
• a maintaining ring including a recess for accommodating said daughtercard and engaging means for maintaining said daughtercard in said recess thereby releasing said daughtercard from the mothercard.

A method for releasing a removable daughtercard from a base mothercard of an interacted circuit probe card by manipulation of a maintaining ring, the maintaining ring including threaded means for engaging the base mothercard, a recess for accommodating the removable daughtercard and engaging means for engaging the removable daughtercard while releasing the removable daughtercard from the base mothercard, the engaging means including a plurality of rotatable portions each respectively mounted on a respective rod for rotating about a respective axis of the rod between a first position, wherein the rotatable portion at least partially covers the recess while maintaining the removable daughtercard int eh recess, and a second position wherein the rotatable portion does not maintain the removable daughtercard in the recess, the engaging means further including a plurality of keys forming stops for the rotatable portions to define the first and second positions thereof, the rotatable portions being mounted on respective first ends of corresponding rods, each rod having a corresponding manipulating means on an opposing end thereof for moving the rotatable portions between the first and second positions thereof, comprising the steps of:

• moving the engaging means to said first position thereby partially covering the recess and the removable daughtercard therein, and
• rotating the maintaining ring for threadedly disengaging said maintaining ring from said removable daughtercard, thereby causing said engaging means to engage the removable daughtercard for retaining the removable daughtercard in said recess for unplugging the removable daughtercard from the base card.