Probe card

A probe card, comprising:

• a circuit board;
• a transformer disposed on the circuit board, and including:
• a body having a first surface and a second surface, wherein the first surface is located between the circuit board and the second surface;
• a plurality of first solder balls disposed on the first surface;
• and
• a plurality of first contact points disposed on the second surface;
• a probe head disposed on the second surface, wherein the probe head is electrically connected to the first contact points, and is electrically connected to the circuit board through the first solder balls;
• and
• a reinforcement structure disposed between the probe head and the circuit board, wherein the first solder balls are connected between the first surface and the circuit board, the reinforcement structure includes an encapsulant disposed on the first surface and the encapsulant only covers the first solder balls, a thickness of the encapsulant measured from the first surface is greater than half of a height of each of the first solder balls measured from the first surface, and the thickness of the encapsulant measured from the first surface is less than the height of each of the first solder balls measured from the first surface, and
• wherein the first contact points are a plurality of bumps protruding from the second surface, the body has a plurality of openings, a trace of the transformer is disposed in each of the plurality of openings, and each of the first contact points fills in the corresponding opening and is connected to the corresponding trace.