There is provided a test apparatus that tests an electronic device. The test apparatus includes a socket board in which a socket for mounting thereon the electronic device is provided, and a test head that detachably holds the socket board and transmits source power to the electronic device via the socket board, the test head includes a first source power transmission line that transmits the source power to the socket board, a first bypass capacitor that is provided between the first source power transmission line and ground potential, and a switch that switches whether the first bypass capacitor is connected between the first source power transmission line and the ground potential, and the socket board includes a second source power transmission line that transmits the source power to the electronic device, and a second bypass capacitor that is fixedly connected between the second source power transmission line and the ground potential.
1. A test apparatus that tests an electronic device, comprising:
a socket board in which a socket for mounting thereon the electronic device is provided; and
a test head that detachably holds the socket board and transmits source power to the electronic device via the socket board,
the test head comprising:
a first source power transmission line that transmits the source power to the socket board;
a first bypass capacitor that is provided between the first source power transmission line and ground potential; and
a switch that switches whether the first bypass capacitor is connected between the first source power transmission line and the ground potential, and
the socket board comprising:
a second source power transmission line that transmits the source power to the electronic device; and
a second bypass capacitor that is fixedly connected between the second source power transmission line and the ground potential.
2. The test apparatus as claimed in claim 1 , wherein a capacity of the first bypass capacitor is larger than a capacity of the second bypass, capacitor.
3. The test apparatus as claimed in claim 2 , wherein
the test apparatus further comprises a mainframe that generates the source power, and
electric power transmission distance between the mainframe and the test head is larger than electric power transmission distance between the test head and the electronic device.
4. The test apparatus as claimed in claim 3 , wherein the first bypass capacitor has a capacity according to the electric power transmission distance between the mainframe and the test head.
5. The test apparatus as claimed in claim 1 , wherein the first bypass capacitor has a capacity according to operating frequency of the electronic device.
6. The test apparatus as claimed in claim 1 , wherein the first bypass capacitor has a capacity according to the size of fluctuation of power supply currents supplied to the electronic device when a state of the electronic device transits from a quiescent state to an operating state.
7. The test apparatus as claimed in claim 1 , wherein the first bypass capacitor further comprises first bypass capacitors with different capacities, and the switch selects which one of the plurality of first bypass capacitors is connected between the first source power transmission line and the ground potential.
8. The test apparatus as claimed in claim 7 , further comprising a relay control section that makes the switch select one of the plurality of first bypass capacitors with a capacity according to an operating frequency of the electronic device.
9. The test apparatus as claimed in claim 7 , further comprising a relay control section that makes the switch select one of the plurality of first bypass capacitors with a capacity according to the size of fluctuation of power supply currents supplied to the electronic device when a state of the electronic device transits from a quiescent state to an operating state.