Flex cable for a hard disk drive having an interrogation trace

1. A flex cable for a head stack assembly of a hard disk drive, said flex cable comprising:

a base film;

a first adhesive layer coupled with said base film;

at least one interrogation trace and at least one signal trace coupled with said first adhesive layer, wherein said interrogation trace is configured for probing to measure a deterioration of electrical conductivity;

a second adhesive layer coupled with said interrogation trace, said signal trace, and said first adhesive layer; and

a cover film coupled with said second adhesive layer.

2. The flex cable of claim 1 wherein said interrogation trace is between said at least one signal trace and an outermost edge which comprises the perimeter of said flex cable.

3. The flex cable of claim 1 wherein said interrogation trace coincides with an area of said flex cable that is to be subsequently bent.

4. The flex cable of claim 1 wherein said cover film comprising at least one via for facilitating access to electrically probe said interrogation trace.

5. The flex cable of claim 1 wherein said interrogation trace is selected from the group of non-copper conductors consisting of: aluminum, carbon, silver ink, INCONEL, and constantan.

6. The flex cable of claim 1 wherein said interrogation trace and said signal trace comprise copper.

7. The flex cable of claim 1 wherein said deterioration of electrical conductivity corresponds to a severity of damage of said flex cable.

8. A hard disk drive comprising:

a flex cable communicatively coupling an actuator assembly to a printed circuit board, said flex cable having:

a base film;

a first adhesive layer coupled with said base film;

at least one interrogation trace and at least one signal trace coupled with said first adhesive layer, wherein said interrogation trace is configured for probing to measure a deterioration of electrical conductivity;

a second adhesive layer coupled with said interrogation trace, said signal trace, and said first adhesive layer; and

a cover film coupled with said second adhesive layer.

9. The hard disk drive of claim 8 wherein said interrogation trace of said flex cable is between said at least one signal trace and an outermost edge which comprises the perimeter of said flex cable.

10. The hard disk drive of claim 8 wherein said interrogation trace of said flex cable coincides with an area of said flex cable that is bent.

11. The hard disk drive of claim 8 wherein said cover film of said flex cable comprises at least one via for facilitating access to electrically probe said interrogation trace.

12. The hard disk drive of claim 8 wherein said base film and said cover film of said flex cable are selected from the group of polymers consisting of: polyimide, UPILEX, KAPTON, polyester, and MYLAR.

13. The hard disk drive of claim 8 wherein said interrogation trace and said signal trace of said flex cable comprise copper.

14. The hard disk drive of claim 8 wherein said deterioration of electrical conductivity of said flex cable corresponds to a severity of damage of said flex cable.

15. A method of monitoring damage in a flex cable during the assembly of a hard drive, said method comprising:

providing a flex cable having:

a base film;

at least one interrogation trace and at least one signal trace; and

a cover film having at least one via for probing said interrogation trace, assembling said flex cable into a hard disk drive;

probing said interrogation trace after at least one process operation of said assembling of said flex cable; and

measuring electrical conductivity of said interrogation trace to monitor for damage in said flex cable.

16. The method as recited in claim 15 , further comprising:

determining a manufacturing disposition of said flex cable based upon a likelihood of said flex cable failing from damage at a subsequent level of assembly based on said electrical conductivity.

17. The method as recited in claim 15 wherein said providing said flex cable comprising:

designing said interrogation trace to be positioned between said signal trace and an outermost edge which comprises the perimeter of said flex cable.

18. The method as recited in claim 15 wherein said providing said flex cable comprising:

designing said interrogation trace to coincide with an area of said flex cable that is bent.

19. The method as recited in claim 16 wherein said determining a manufacturing disposition of said flex cable comprising:

allowing said flex cable to proceed further in the assembly of said hard disk drive when an electrical conductivity during said measuring is within an acceptable range.

20. The method as recited in claim 16 wherein said determining a manufacturing disposition of said flex cable comprising:

indicating said flex cable should be rejected for use in the assembly of said hard disk drive when an electrical conductivity threshold is exceeded during said measuring.