Test apparatus
View Patent ↗The test apparatus tests a wafer under test on which devices under test each including magnetoresistive memory or a magnetic sensor are formed. In a test process, the wafer under test is mounted on a stage. A test probe card is configured such that it can make probe contact with the wafer under test in the test process. A wafer connection HiFix is arranged between the test probe card and a test head. A magnetic field application apparatus is provided to the wafer connection HiFix. In the test process, the magnetic field application apparatus applies a magnetic field B EX to the wafer under test.
1. A test apparatus structured to test a wafer under test on which devices under test each comprising magnetoresistive memory or a magnetic sensor are formed, the test apparatus comprising:
a test head;
a stage on which the wafer under test is to be mounted in a test process;
a connection unit structured to be coupled to the test head;
a test probe card structured to be detachably coupled to the connection unit and to make probe contact with the wafer under test in the test process; and
a magnetic field application apparatus provided to the connection unit and structured to apply a magnetic field to the wafer under test through the test probe card in the test process.
2. The test apparatus according to claim 1 , wherein the magnetic field application apparatus comprises:
a core;
a coil wound on the core; and
a driving circuit structured to drive the coil,
and wherein the connection unit further comprises an interface circuit structured to receive a control signal for the driving circuit from the test head, and wherein the interface circuit is an existing interface.
3. The test apparatus according to claim 1 , wherein the magnetic field application apparatus comprises:
a core; and
a coil wound on the core,
and wherein a driving circuit structured to drive the coil is provided as an external component of the connection unit.
4. The test apparatus according to claim 1 , further comprising:
a diagnostic wafer structured to be mounted on the stage instead of the wafer under test in a diagnostic process of the test apparatus, wherein a plurality of magnetization detection units are formed on the diagnostic wafer, and the diagnostic wafer is structured to measure a magnetic field generated by the magnetic field application apparatus by means of each magnetization detection unit in the diagnostic process; and
a diagnostic probe card to be used in the diagnostic process instead of the test probe card, and structured to make probe contact with the diagnostic wafer.