Cantilever-type probe card for high frequency application

• US 20080191726A1
• Filed: 02/13/2007
• Published: 08/14/2008
• Est. Priority Date: 02/13/2007
• Status: Active Grant

• Current Assignee: Mpi Corporation
• Original Assignee: MJC Probe Incorporation
• Inventors: Ku, Wei-Cheng, Ho, Chih-Hao, Lin, Shu-Kan
• Granted Patent: US 7,595,651 B2
• Time in Patent Office: Days
• US Class Current: 324/755.07
• CPC Class Codes: G01R 1/06772 High frequency probes
• CPC Class Codes: G01R 1/07342 the body of the probe being at an angle other than perpendicular to test object, e.g. probe card

Abstract

A cantilever-type probe card includes a circuit board, a grounding block electrically connected to a zero potential, signal probes, and at least one grounding probe connected to the grounding block. Each signal probe has a probing tip, a connection portion affixed to the circuit board, and a front arm defined between the connection portion and the probing tip. The front arm of each of the signal probes is suspended in the grounding block and spaced from the grounding block at a predetermined pitch.

Claims

1. A cantilever-type probe card comprising:

a circuit board arranged thereon with a plurality of signal lines and a grounding block, said grounding block being a metal block electrically connected to a zero potential; and

a plurality of signal probes and at least one grounding probe made of a conducting metal material, said signal probes being respectively electrically connected to said signal lines, said at least one grounding probe being electrically connected to said grounding block, said at least one grounding probe having a connection portion, a probing tip, and a front arm defined between said connection portion and said probing tip, each of said signal probes having at least one connection portion, at least one probing tip, and at least one front arm defined between said connection portion and said probing tip, the connection portions of said signal probes and said at least one grounding probe being fastened to said circuit board, the front arms of said signal probes being suspended in said grounding block and spaced from said grounding block at a predetermined pitch.

2. The cantilever-type probe card as claimed in claim 1, which said circuit board has two opposite surfaces;

said signal lines are coaxial transmission lines extended to the two opposite surfaces of said circuit board, each having a coaxial metal shield electrically connected to said grounding block.

3. The cantilever-type probe card as claimed in claim 1, wherein said circuit board has a probe holder mounted thereon, said probe holder having a recess;

the connection portions of said signal probes and said at least one grounding probe are affixed to said probe holder adjacent to the recess of said probe holder;

said grounding block is mounted in the recess of said probe holder.

4. The cantilever-type probe card as claimed in claim 3, wherein said probe holder has a grounding plane made of a conducting metal material and electrically connected to said grounding block.

5. The cantilever-type probe card as claimed in claim 4, wherein said probe holder is made of a conducting metal material, having an outer surface that constitutes said grounding plane.

6. The cantilever-type probe card as claimed in claim 4, wherein each said signal probe has two distal ends respectively terminating in an endpiece and the probing tip, and is surrounded by a dielectric layer between the respective endpiece and the respective connection portion and a grounding layer around the dielectric layer, said grounding layer being formed of a conducting metal material and electrically connected to said grounding plane of said probe holder.

7. The cantilever-type probe card as claimed in claim 1, wherein said grounding block has a center through hole and a plurality of grooves radially arranged around said center through hole;

the front arms of said signal probes and said at least one grounding probe are suspended in the grooves of said grounding block to support the respective probing tips protruding outside said grounding block.

8. The cantilever-type probe card as claimed in claim 7, wherein said signal probes are respectively inserted through the grooves of said grounding block.

9. The cantilever-type probe card as claimed in claim 7, wherein said signal probes are respectively arranged in the grooves of said grounding block in such a manner that each said signal probe is adjacent to said grounding block and said at least one grounding probe.

15. The cantilever-type probe card as claimed in claim 1, wherein each of said signal probes comprises two bared needles, each of the bared needles having said at least one connection portion, said at least one probing tip, and said at least one front arm, each of said bared needles having two distal ends respectively terminating in an endpiece and the probing tip, said two endpieces of each said signal probe being connected with said signal lines respectively.

16. The cantilever-type probe card as claimed in claim 15, wherein each of said signal lines is a differential transmission line for transmitting differential signal, a grounding layer coaxially surrounding each of said differential transmission lines and made of electrically conductive metal and electrically connected with said grounding block.

17. The cantilever-type probe card as claimed in claim 16 further comprising a dielectric layer coaxially surrounding between said endpiece and said connection portion of each said signal probe, said grounding layer surrounding said two dielectric layers of said signal probes.

18. The cantilever-type probe card as claimed in claim 17 further comprising a protective layer surrounding said grounding layer of each said signal probe, said protective layer being made of insulated material and affixed to said circuit board.

10. A cantilever-type probe card comprising:

a circuit board arranged thereon with a plurality of differential transmission lines and a grounding block, said grounding block being a metal block electrically connected to a zero potential; and

a plurality of differential probes and at least one grounding probe, said differential probes each having two bared needles suspended in said grounding block and kept a predetermined space from said grounding block and electrically connected to each of said differential transmission lines, said differential probes each further having a grounding layer surrounding the respective two bared needles and spaced from the two bared needles at a predetermined pitch corresponding to the predetermined space between the two respective bared needles and said grounding block, said at least one grounding probe and said grounding layers of said differential probes being electrically connected to said grounding block.

11. The cantilever-type probe card as claimed in claim 10, wherein said differential probes each further having a protective layer surrounding the respective grounding layer and affixed to said circuit board.

12. A cantilever-type probe card comprising:

a circuit board arranged thereon with a plurality of signal lines and a grounding block, said grounding block being a metal block electrically connected to a zero potential and having a plurality of grooves, said grooves each having a predetermined depth; and

a plurality of signal probes and at least one grounding probe made of a conducting metal material, said signal probes being respectively electrically connected to said signal lines, said at least one grounding probe being electrically connected to said grounding block, said signal probes and said at least one grounding probe each having a connection portion, a probing tip, and a front arm defined between said connection portion and said probing tip, the connection portions of said signal probes and said at least one grounding probe being fastened to said circuit board, the front arms of said signal probes and said at least one grounding probe being suspended in said grooves of said grounding block, the front arm of each of said signal probes being kept a predetermined space transversely from said grounding block and flexible longitudinally along the respective depth of each of said grooves, the probing tips of said signal probes and said at least one grounding probe being protruded out of said grounding block.

13. The cantilever-type probe card as claimed in claim 12, wherein said circuit board has a probe holder mounted thereon, said probe holder having a recess;

the connection portions of said signal probes and said at least one grounding probe are affixed to said probe holder adjacent to the recess of said probe holder;

said grounding block is mounted in the recess of said probe holder.

14. The cantilever-type probe card as claimed in claim 13, wherein said probe holder has a grounding plane made of a conducting metal material and electrically connected to said grounding block.