Semiconductor chip and test method

• US 8,667,353 B2
• Filed: 05/17/2012
• Issued: 03/04/2014
• Est. Priority Date: 05/18/2011
• Status: Active Grant

• Current Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Original Assignee: LAPIS Semiconductor Co., Ltd. (ROHM Co., Ltd.)
• Inventors: Taya, Takashi
• Primary Examiner(s): Bhatia, Ajay
• Assistant Examiner(s): GANDHI, DIPAKKUMAR B
• Application Number:
  US13/474,675
• Publication Number:
  US 20120297263A1
• Time in Patent Office: 656 Days
• Field of Search: None
• US Class Current: 714/733
• CPC Class Codes: G01R 31/2884 using dedicated test connectors, test elements or test circuits on the IC under test G01R31/2855 takes precedence
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

A semiconductor chip having a functional block that performs a communication function includes an input circuit that supplies an oscillating test signal to the functional block, and a test circuit that detects the strength of an oscillating signal which the functional block outputs in response. A strength signal indicating the detected strength is output from the test circuit through an external terminal of the semiconductor chip to a test device. The test device evaluates the strength signal to decide whether an operating characteristic of the functional block is within a specified range. The strength information indicated by the strength signal is not affected by impedance on the signal transmission line between the semiconductor chip and the test device, so the test is not affected by impedance loss.

Claims

1. A semiconductor chip comprising:

a functional block for generating an oscillating output signal to perform a communication function;

an input circuit for selectively supplying a first oscillating test signal supplied from a test device to test the functional block during testing of the functional block and a modulated communication signal during normal operation of the semiconductor chip to the functional block, thereby causing the functional block to generate the oscillating output signal;

a first test line through which the first oscillating test signal is supplied from the test device to the input circuit;

a test circuit for detecting a first strength, the first strength being a strength of the oscillating output signal, and generating a strength signal indicating the first strength;

a signal line for electrically connecting the functional block and the test circuit, thereby causing the oscillating output signal to be supplied from the functional block to the test circuit;

a first external terminal for external output of the strength signal;

a second external terminal for external output of the oscillating output signal; and

a second test line for receiving a second oscillating test signal supplied from the test device and supplying the received second oscillating test signal to the test circuit without passing the input circuit and the functional block, wherein;

the test circuit detects the first strength of the oscillating output signal supplied via the signal line and outputs the strength signal indicating the detected first strength to the first external terminal during the testing of the functional block,

the test circuit detects a second strength, the second strength being a strength of the second oscillating test signal, generates other strength signal indicating the second strength and outputs the other strength signal to the first external terminal, and

the functional block outputs the oscillating output signal to the second external terminal during the normal operation of the semiconductor chip.

2. The semiconductor chip of claim 1, wherein the strength signal and the other strength signal are direct-current signals.

3. The semiconductor chip of claim 1, wherein the strength signal and the other strength signal are direct-current voltage signals.

4. The semiconductor chip of claim 1, wherein the strength signal and the other strength signal are digital signals.

5. The semiconductor chip of claim 1, further comprising a third external terminal for external input of the first oscillating test signal.

6. The semiconductor chip of claim 5, wherein:

the first oscillating test signal is input through the third external terminal to the functional block when the test circuit detects the first signal strength; and

the second oscillating test signal is input through the second external terminal to the test circuit when the test circuit detects the second signal strength.

7. The semiconductor chip of claim 5, wherein the test circuit receives the first oscillating test signal via the third external terminal.

8. The semiconductor chip of claim 7, further comprising

a first switch connected to the functional block, for selectively supplying the test circuit with the first oscillating test signal input to the functional block and the oscillating output signal output from the functional block.

9. The semiconductor chip of claim 1, further comprising:

a fourth external terminal for external input of an adjustment signal; and

an adjustment circuit for storing information provided by the adjustment signal and adjusting the functional block according to the stored information.

10. The semiconductor chip of claim 9, wherein the stored information corresponds to a difference between the first strength and the second strength.

11. The semiconductor chip of claim 1, wherein the functional block is a radio-frequency transmitting amplifier.

12. The semiconductor chip of claim 1, wherein the functional block includes at least one of a receiving low-noise amplifier, a mixer, and an intermediate-frequency filter.

13. The semiconductor chip of claim 1, wherein the first oscillating test signal is identical to the second oscillating test signal.

14. A method of testing a semiconductor chip including a functional block that generates an oscillating output signal to perform a communication function and outputs the oscillating output signal from the semiconductor chip during normal operation of the semiconductor chip, the method comprising:

supplying a first oscillating test signal from an input circuit disposed in the semiconductor chip to the functional block, thereby causing the functional block to generate the oscillating output signal, the input circuit supplying the functional block with the first oscillating test signal to test the functional block during the testing of the semiconductor chip and with a modulated communication signal during the normal operation of the semiconductor chip, the first oscillating test signal being supplied from a test device to the input circuit through a first test line disposed in the semiconductor chip;

supplying the oscillating output signal to a test circuit disposed in the semiconductor chip via a signal line disposed in the semiconductor chip, the signal line electrically connecting the functional block and the test circuit, thereby causing the oscillating output signal to be supplied from the functional block to the test circuit;

detecting a first strength, the first strength being a strength of the oscillating output signal, by using the test circuit, the test circuit also generating a strength signal indicating the first strength;

outputting the strength signal from the semiconductor chip to the test device;

supplying a second oscillating test signal supplied from the test device to the test circuit through a second test line disposed in the semiconductor chip without passing the input circuit and the functional block;

detecting a second strength, the second strength being a strength of the second oscillating test signal, by using the test circuit, the test circuit also generating other strength signal indicating the second strength;

outputting the other strength signal from the semiconductor chip to the test device; and

evaluating the strength signal and the other strength signal in the test device to decide whether the functional block has an operating characteristic that falls within a specified range.

15. The method of claim 14, wherein

evaluating the strength signal and the other strength signal includes taking a difference between the first strength and the second strength.

16. The method of claim 14, further comprising adjusting the operating characteristic of the functional block if the operating characteristic does not fall within the specified range but falls within an adjustable range.

17. The method of claim 16, wherein adjusting the operating characteristic further comprises:

sending an adjustment signal from the test device to the semiconductor chip;

storing information provided by the adjustment signal in the semiconductor chip; and

using an adjustment circuit disposed in the semiconductor chip to adjust the functional block according to the stored information.

18. The method of claim 17, wherein the stored information corresponds to a difference between the first strength and the second strength.

19. The method of claim 14, wherein the method is repeated to test mutually identical functional blocks in each of a plurality of semiconductor chips on a semiconductor wafer.

20. The method of claim 14, wherein the first oscillating test signal is identical to the second oscillating test signal.