Printed circuit board development cycle using probe location automation and bead probe technology

• US 20060129955A1
• Filed: 12/10/2004
• Published: 06/15/2006
• Est. Priority Date: 12/10/2004
• Status: Abandoned Application

• Current Assignee: Agilent Technologies, Inc.
• Original Assignee: Agilent Technologies, Inc.
• Inventors: Parker, Kenneth P., Herczeg, John E., Jacobsen, Chris R.
• Application Number:
  US11/009,117
• Publication Number:
  US 20060129955A1
• Time in Patent Office: Days
• US Class Current: 324/750.160
• CPC Class Codes: H05K 1/0268 for electrical inspection or testing
• CPC Class Codes: H05K 2203/162 Testing a finished product, e.g. heat cycle testing of solder joints
• CPC Class Codes: H05K 3/0005 for designing circuits by computer

Abstract

Techniques for automating test pad insertion in a printed circuit board (PCB) design and fixture probes insertion in a PCB tester fixture are presented. A probe location algorithm predictably determines respective preferred probing locations from among respective sets of potential probing locations associated with a number of respective nets in a PCB design. Test pads, preferably in the form of bead probes, are added to the PCB design at the respective preferred probing locations along with, where feasible, one or more alternate probing locations chosen from among remaining ones of the respective sets of potential probing locations. During fixture design, nets with multiple test pads implemented in the PCB design are processed by the same probe location algorithm used during PCB design to determine the associated preferred probing location and any associated alternate probing locations for said respective nets. Fixture probes are preferably inserted in the PCB tester fixture design at respective preferred probing locations to exactly align with corresponding preferred test pads of a PCB implemented in accordance with the PCB design should the PCB be mounted in a printed circuit board tester fixture implemented in accordance with the PCB tester fixture design.

Claims

1. A method for improving a printed circuit board (PCB) development cycle, comprising:

executing a computerized test pad location algorithm to determine one or more test pad locations along one or more respective nets in a PCB design;

inserting one or more test pads into said PCB design at said one or more test pad locations to generate a modified PCB design.

2. A method in accordance with claim 1, further comprising:

fabricating a PCB according to said modified PCB design.

3. A method in accordance with claim 1, wherein:

said one or more test pads are inserted into said PCB design without necessitating rerouting of any nets of said PCB design.

4. A method in accordance with claim 2, wherein said one or more test pads comprise bead probes.

5. A method in accordance with claim 4, further comprising:

fabricating a PCB according to said modified PCB design.

6. A method in accordance with claim 1, further comprising:

extracting said one or more test pad locations from said modified PCB design based on locations of said one or more test pads in said modified PCB design; and

executing a fixture probe location algorithm that operates to determine one or more fixture probe locations in a fixture design based on said extracted one or more test pad locations such that if a PCB fabricated in accordance with said modified PCB design were mounted in a fixture fabricated with fixture probes inserted at said one or more fixture probe locations, respective tips of said inserted fixture probes would align with and contact said one or more test pads of said PCB fabricated in accordance with said modified PCB design at said one or more test pad locations.

7. A method in accordance with claim 6, further comprising:

inserting respective one or more fixture probes at said one or more fixture probe locations in said fixture design to generate a modified fixture design.

8. A method in accordance with claim 7, further comprising:

fabricating a fixture according to said modified fixture design.

9. A method in accordance with claim 8, further comprising:

testing a PCB fabricated in accordance with said modified PCB design and mounted in said fabricated fixture on a tester.

10. A method in accordance with claim 7, comprising:

executing a PCB balancing support location algorithm to determine PCB balancing support locations to optimize PCB flex based on said fixture probe locations; and

inserting one or more supports at said determined PCB balancing support locations in said modified fixture design.

11. A method in accordance with claim 10, further comprising:

fabricating a fixture according to said modified fixture design.

12. A method in accordance with claim 11, further comprising:

testing a PCB fabricated in accordance with said modified PCB design and mounted in said fabricated fixture on a tester.

13. A method in accordance with claim 1, wherein:

said computerized test pad location algorithm operates to determine at least one preferred test pad location and zero or more alternate test pad locations in said one or more test pad locations of said respective nets in said PCB design.

14. A method in accordance with claim 13, further comprising:

extracting said one or more test pad locations of said respective nets from said modified PCB design based on locations of said one or more test pads in said modified PCB design; and

executing a fixture probe location algorithm that operates to determine, from said extracted one more test pad locations of said respective nets, said at least one preferred test pad location and said zero or more alternate test pad locations of said respective nets in said PCB design, and to determine one or more fixture probe locations in a fixture design based on said determined at least one preferred test pad location and said zero or more alternate test pad locations of said respective nets such that if a PCB fabricated in accordance with said modified PCB design were mounted in a fixture fabricated with fixture probes inserted at said one or more fixture probe locations, respective tips of said inserted fixture probes would align with and contact corresponding one or more test pads of said PCB fabricated in accordance with said modified PCB design.

15. A method in accordance with claim 14, wherein:

said determined one or more fixture probe locations comprise respective at least one preferred fixture probe location and zero or more alternate fixture probe locations corresponding to each said respective nets, wherein if a PCB fabricated in accordance with said modified PCB design were mounted in a fixture fabricated with fixture probes inserted at said respective at least one preferred fixture probe locations and/or at said respective zero or more alternate fixture probe locations, respective tips of said inserted fixture probes would align with and contact corresponding preferred test pads and/or alternate test pads implemented at corresponding preferred test pad locations and/or alternate test pad locations on said PCB fabricated in accordance with said modified PCB design.

16. A method in accordance with claim 15, further comprising:

inserting respective one or more fixture probes at said determined respective at least one preferred fixture probe location and/or said zero or more alternate fixture probe locations in said fixture design to generate a modified fixture design.

17. A method in accordance with claim 16, further comprising:

fabricating a fixture according to said modified fixture design.

18. A method in accordance with claim 17, further comprising:

testing a PCB fabricated in accordance with said modified PCB design and mounted in said fabricated fixture on a tester.

19. A method in accordance with claim 16, comprising:

executing a PCB balancing support location algorithm to determine PCB balancing support locations to optimize PCB flex based on said fixture probe locations; and

inserting one or more supports at said determined PCB balancing support locations in said modified fixture design.

20. A method in accordance with claim 19, further comprising:

testing a PCB fabricated in accordance with said modified PCB design and mounted in said fabricated fixture on a tester.

21. A method for automatically inserting test pads into a PCB design, comprising:

executing a computerized test pad location algorithm to determine one or more test pad locations along one or more respective nets in a PCB design;

inserting one or more test pads into said PCB design at said one or more test pad locations to generate a modified PCB design.

22. A method in accordance with claim 21, wherein:

said one or more test pads are inserted into said PCB design without necessitating rerouting of any nets of said PCB design.

23. A method in accordance with claim 22, wherein said one or more test pads comprise bead probes.

24. A computer readable storage medium tangibly embodying program instructions implementing a method for automatically inserting test pads into a PCB design, said method comprising the steps of:

determining one or more test pad locations along one or more respective nets in said PCB design;

inserting one or more test pads into said PCB design at said one or more test pad locations to generate a modified PCB design.

25. A computer readable storage medium in accordance with claim 24, wherein:

said one or more test pads are inserted into said PCB design without necessitating rerouting of any nets of said PCB design.

26. A computer readable storage medium in accordance with claim 25, wherein said one or more test pads comprise bead probes.

27. An apparatus for automatically inserting test pads into a PCB design, comprising:

a computerized test pad location function which determines one or more test pad locations along one or more respective nets in a PCB design;

a test pad insertion function which inserts one or more test pads into said PCB design at said one or more test pad locations to generate a modified PCB design.

28. An apparatus in accordance with claim 27, wherein:

said test pad insertion function inserts said one or more test pads into said PCB design without necessitating rerouting of any nets of said PCB design.

29. An apparatus in accordance with claim 28, wherein said one or more test pads comprise bead probes.

30. A method for automatically inserting fixture probes into a PCB tester fixture design, comprising:

extracting one or more test pad locations from a PCB design; and

executing a fixture probe location algorithm that operates to determine one or more fixture probe locations in said PCB tester fixture design based on said extracted one or more test pad locations such that if a PCB fabricated in accordance with said PCB design were mounted in a fixture fabricated with fixture probes inserted at said one or more fixture probe locations, respective tips of said inserted fixture probes would align with and contact one or more test pads of said PCB fabricated in accordance with said PCB design at said one or more test pad locations.

31. A method in accordance with claim 30, further comprising:

inserting respective one or more fixture probes at said one or more fixture probe locations in said fixture design to generate a modified PCB tester fixture design.

32. A method in accordance with claim 31, comprising:

executing a PCB balancing support location algorithm to determine PCB balancing support locations to optimize PCB flex based on said fixture probe locations; and

inserting one or more supports at said determined PCB balancing support locations in said modified PCB tester fixture design.

33. A computer readable storage medium tangibly embodying program instructions implementing a method for automatically inserting fixture probes into a PCB tester fixture design, said method comprising the steps of:

extracting one or more test pad locations from a PCB design; and

executing a fixture probe location algorithm that operates to determine one or more fixture probe locations in said PCB tester fixture design based on said extracted one or more test pad locations such that if a PCB fabricated in accordance with said PCB design were mounted in a fixture fabricated with fixture probes inserted at said one or more fixture probe locations, respective tips of said inserted fixture probes would align with and contact one or more test pads of said PCB fabricated in accordance with said PCB design at said one or more test pad locations.

34. A computer readable storage medium in accordance with claim 33, said method further comprising the steps of:

inserting respective one or more fixture probes at said one or more fixture probe locations in said fixture design to generate a modified PCB tester fixture design.

35. A computer readable storage medium in accordance with claim 34, said method further comprising the steps of:

executing a PCB balancing support location algorithm to determine PCB balancing support locations to optimize PCB flex based on said fixture probe locations; and

inserting one or more supports at said determined PCB balancing support locations in said modified PCB tester fixture design.

36. An apparatus for automatically inserting fixture probes into a PCB tester fixture design, comprising:

a test pad location extraction function which extracts one or more test pad locations from a PCB design; and

a fixture probe location function which determines one or more fixture probe locations in said PCB tester fixture design based on said extracted one or more test pad locations such that if a PCB fabricated in accordance with said PCB design were mounted in a fixture fabricated with fixture probes inserted at said one or more fixture probe locations, respective tips of said inserted fixture probes would align with and contact one or more test pads of said PCB fabricated in accordance with said PCB design at said one or more test pad locations.

37. An apparatus in accordance with claim 36, further comprising:

a fixture probe insertion function which inserts respective one or more fixture probes at said one or more fixture probe locations in said fixture design to generate a modified PCB tester fixture design.

38. An apparatus in accordance with claim 37, comprising:

a PCB balancing support location function which determines PCB balancing support locations to optimize PCB flex based on said fixture probe locations; and

a balancing support insertion function which inserts one or more supports at said determined PCB balancing support locations in said modified PCB tester fixture design.