Open-circuit testing system and method

• US 7,612,568 B2
• Filed: 05/02/2007
• Issued: 11/03/2009
• Est. Priority Date: 03/08/2007
• Status: Active Grant

• Current Assignee: Test Research Incorporated
• Original Assignee: Test Research Incorporated
• Inventors: Chen, Chien-Wei, Chen, Chia-Ming
• Primary Examiner(s): Dole; Timothy J
• Assistant Examiner(s): HOQUE, FARHANA AKHTER
• Application Number:
  US11/743,641
• Publication Number:
  US 20080218175A1
• Time in Patent Office: 916 Days
• Field of Search: 324/538, 439/54, 439/169, 439/219, 439/482
• US Class Current: 324/538
• CPC Class Codes: G01R 31/304 of printed or hybrid circuits G01R31/305 - G01R31/315 take precedence
• CPC Class Codes: G01R 31/312 by capacitive methods
• CPC Class Codes: G01R 31/70 Testing of connections between components and printed circuit boards G01R31/68 takes precedence

Abstract

The invention discloses a testing system and method suitable for determining the connection state of an electronic component in an electronic device assembly. In an embodiment, the testing system comprises a signal sensing unit configured to provide a sensed signal induced by capacitive coupling in response to the output of a testing signal passing through a tested pin, a signal processor unit configured to filter and over-sample the sensed signal to obtain a digital signal, and an analyzer unit configured to compute the digital signal for determining a connection state of the test pin.

Claims

1. A testing method for determining a connection state of an electronic component in an electronic device assembly, the method comprising:

obtaining a sensed signal induced by capacitive coupling in response to the output of a testing signal passing through a tested pin of the electronic component;

applying a signal processing sequence on the sensed signal, the processing sequence including;

filtering and over-sampling the sensed signal to obtain a digital signal; and

applying a validation test on the digital signal to determine whether the sensed signal is an acceptable measure, wherein the validation test is applied by computing the digital signal to determine a correspondence with a predetermined capacitive coupling reference;

when a result of the validation test finds no correspondence with the predetermined capacitive coupling reference from the digital signal, raising a frequency and/or amplitude of the testing signal;

when a correspondence with the predetermined capacitive coupling reference is found, converting the digital signal into frequency-domain spectrum data; and

determining the connection state of the tested pin based on the frequency-domain spectrum data.

2. The method according to claim 1, wherein the signal processing sequence includes amplifying the sensed signal before filtering the sensed signal.

3. The method according to claim 1, wherein the signal processing sequence includes processing the sensed signal through an anti-alias filter before over-sampling the sensed signal.

4. The method according to claim 1, wherein the signal processing sequence includes processing the digital signal through a digital filter after over-sampling the sensed signal.

5. The method according to claim 4, wherein the digital filter includes a finite impulse response filter.

6. The method according to claim 1, further comprising:

obtaining a new sensed signal corresponding to the testing signal of raised frequency and/or amplitude; and

applying the signal processing sequence for the new sensed signal.

7. The method according to claim 1, wherein converting the digital signal into frequency-domain spectrum data includes applying a Fast Fourier Transform to convert the digital signal into a frequency-domain spectrum data, and determining the connection state of the tested pin includes comparing the frequency-domain spectrum data against a range of reference values.

8. A testing system suitable for determining a connection state of an electronic component in an electronic device assembly, the testing system comprising:

a signal sensing unit providing a sensed signal induced by capacitive coupling in response to the output of a testing signal passing through a tested pin of the electronic component;

a signal processor unit filtering and over-sampling the sensed signal to obtain a digital signal;

an analyzer unit applying a processing sequence on the sensed signal, wherein the processing sequence comprises;

determining whether the sensed signal is an acceptable measure by computing the digital signal to determine a correspondence with a predetermined capacitive coupling reference; and

when a correspondence with the predetermined capacitive coupling reference is found, computing frequency-domain spectrum data from the digital signal for determining a connection state of the tested pin; and

a controller raising a frequency and/or amplitude of the testing signal when no correspondence with the predetermined capacitive coupling reference is found from the digital signal.

9. The system according to claim 8, wherein the signal processor unit includes an anti-alias filter through which the sensed signal is processed before being over-sampled.

10. The system according to claim 8, wherein the signal processor unit includes a digital filter through which the digital signal is processed before being converted into frequency-domain spectrum data.

11. The system according to claim 10, wherein the digital filter includes a finite impulse response filter.

12. The system according to claim 8, wherein the analyzer unit applies a Fast Fourier Transform to convert the digital signal into frequency-domain spectrum data, and compares the frequency-domain spectrum data against a range of reference values for determining the connection state of the tested pin.

13. The system according to claim 8, wherein the testing signal has a frequency of about 100 kHz or higher.