Semiconductor device and test method of semiconductor device

A packaged semiconductor device, comprising:

• a wiring substrate;
• a first semiconductor chip on the wiring substrate;
• a second semiconductor chip on the wiring substrate;
• a first pad on the first semiconductor chip and electrically connected to a node between a power supply pad and a ground pad on the first semiconductor chip;
• a second pad on the second semiconductor chip;
• a third pad on the second semiconductor chip;
• an internal wiring connecting the first pad to the second pad;
• a power supply circuit on the second semiconductor chip configured to supply a current to the second pad;
• a switch on the second semiconductor chip between the second pad and the power supply circuit to connect or disconnect the second pad from the power supply circuit;
• a control circuit on the second semiconductor chip configured to output:
• a first control signal for controlling ON and OFF states of the switch in response to a test signal supplied to the third pad, and
• a second control signal to the power supply circuit to cause the power supply circuit to output current;
• and
• a sealing resin covering the first and second semiconductor chips, the internal wiring, and a first surface of the wiring substrate.

A test method for a packaged semiconductor device including an internal wiring connecting a first pad on a first semiconductor chip to a second pad on a second semiconductor chip, the test method comprising:

• receiving a test signal at a third pad on the second semiconductor chip, the third pad being electrically connected to a control circuit on the second semiconductor chip;
• outputting a first control signal from the control circuit to a power supply circuit on the second semiconductor chip in response to the receiving of the test signal at the third pad, the first control signal causing the power supply circuit to output a current to a wiring connected to the second pad;
• outputting a second control signal from the control circuit to a switch in response to the receiving of the test signal at the third pad, the switch being on the wiring connecting the second pad and the power supply circuit and controlling whether current from the power supply circuit reaches the internal wiring via the second pad;
• measuring a voltage between a power supply pad and a ground pad, the first pad being electrically connected to a node between the power supply pad and the ground pad;
• and
• detecting a connection state of the internal wiring based on the measuring of the voltage.