Testing printed circuit boards of disk drives and servo track writers

• US 20060145721A1
• Filed: 12/31/2004
• Published: 07/06/2006
• Est. Priority Date: 12/31/2004
• Status: Abandoned Application

• Current Assignee: Riospring, Inc.
• Original Assignee: Riospring, Inc.
• Inventors: Ton-Churo, Huang
• Application Number:
  US11/026,229
• Publication Number:
  US 20060145721A1
• Time in Patent Office: Days
• US Class Current: 324/763.10
• CPC Class Codes: G01R 31/2803 by means of functional tests, e.g. logic-circuit-simulation or algorithms therefor testing electronic digital computers G06F11/00
• CPC Class Codes: G01R 31/31707 Test strategies methods for generation of test sequences G01R31/318371

Abstract

One embodiment of the present invention is method for testing a reading function of a printed circuit board of a disk drive or a servo track writer that includes: (a) providing a test pattern; (b) processing the test pattern to generate a digital signal series; (c) differentiating the digital signal series to provide a differentiated signal series; (d) applying the differentiated signal series as input to the printed circuit board; and (e) comparing an output from the printed circuit board with the test pattern.

Claims

1. A method for testing a reading function of a printed circuit board of a disk drive or a servo track writer that comprises:

providing a test pattern;

processing the test pattern to generate a digital signal series;

differentiating the digital signal series to provide a differentiated signal series;

applying the differentiated signal series as input to the printed circuit board; and

comparing an output from the printed circuit board with the test pattern.

2. The method of claim 1 wherein the step of processing comprises utilizing a pre-tested printed circuit board for processing.

3. The method of claim 1 wherein the step of processing comprises utilizing a field programmable gate array for processing.

4. The method of claim 1 wherein the printed circuit board is a servo track writer printed circuit board.

5. The method of claim 1 wherein the printed circuit board is a printed circuit board of a disk drive.

6. The method of claim 1 wherein the digital signal comprises time intervals between up pulses of 200 nanoseconds, 600 nanoseconds, and 1000 nanoseconds.

7. The method of claim 1 wherein the digital signal is generated utilizing a clock with a frequency of at least 20 megahertz

8. The method of claim 1 wherein the step of differentiating comprises utilizing an RC differentiator.

9. The method of claim 1 wherein the differentiated signal has a peak-to-peak amplitude in a range of about 100 millivolts to about 300 millivolts.

10. The method of claim 1 wherein a peak-to-peak amplitude of the differentiated signal may be adjusted by utilizing an AD835 or AD834 multiplier.

11. A method for testing a writing function of a printed circuit board of a disk drive or a servo track writer that comprises:

providing a test pattern;

applying the test pattern as input to the printed circuit board to generate a digital signal series;

differentiating the digital signal series to provide a differentiated signal series;

processing the differentiated signal series; and

comparing processed output from the step of processing with the test pattern.

12. The method of claim 11 wherein the printed circuit board is a servo track writer printed circuit board.

13. The method of claim 11 wherein the printed circuit board is a printed circuit board of a disk drive.

14. The method of claim 11 wherein the step of differentiating comprises utilizing an RC differentiator.

15. The method of claim 11 wherein the differentiated signal has a peak-to-peak amplitude in a range of about 100 millivolts to about 300 millivolts.

16. The method of claim 11 wherein a peak-to-peak amplitude of the differentiated signal may be adjusted by utilizing an AD835 or AD834 multiplier.

17. An apparatus for testing a reading function of a printed circuit board of a disk drive or a servo track writer that comprises:

a pattern generator that generates a test pattern;

a signal processor that processes the test pattern to generate a digital signal series;

a differentiator that differentiates the digital signal series to provide a differentiated signal series as input to the printed circuit board; and

a comparator that compares an output from the printed circuit board with the test pattern.

18. The apparatus of claim 17 wherein the signal processor comprises a pre-tested printed circuit board.

19. The apparatus of claim 17 wherein the comparator comprises a computer.

20. An apparatus for testing a writing function of a printed circuit board of a disk drive or a servo track writer that comprises:

a pattern generator that generates a test pattern as input to the printed circuit board, in response to which, the printed circuit board generates a digital signal series;

a differentiator that differentiates the digital signal series to provide a differentiated signal series;

a signal processor that processes the differentiated signal series to provide an output; and

a comparator that compares the output from the signal processor with the test pattern.