Inspection probe and an IC socket with the same

1. An inspection probe comprising:

a first plunger formed from a copper alloy material, and having a contact point configured to selectively come into contact with an electrode portion of an object to be inspected;

a second plunger formed from the copper alloy material, and having a contact point configured to selectively come into contact with an electrode portion of a wiring board;

a spring portion formed integrally with one end of the first plunger and a first end of the second plunger, the spring portion being configured to bias the first plunger and the second plunger in a direction away from each other; and

a support stem formed into a cylindrical shape integrally with the contact point of a second end of the second plunger, the second end being opposite to the first end, the support stem extending from the second end and being folded back toward the first end in such a manner as to be disposed inside the spring portion with a predetermined clearance in between, and configured to slidably guide the spring portion, wherein

when the contact point of the first plunger comes into contact with the electrode portion of the object to be inspected, one end of the support stem inserted into an inner peripheral portion of the first plunger comes into sliding contact with the inner peripheral portion of the first plunger.

2. The inspection probe according to claim 1 , wherein another end of the support stem having a pair of elastic contact pieces on the one end of the support stem, forms the contact point of the second plunger.

3. The inspection probe according to claim 2 , wherein the contact point of the second plunger is spherical.

4. The inspection probe according to claim 1 , wherein the predetermined clearance between an inner peripheral portion of the spring portion and an outer peripheral portion of the support stem is set in such a manner as to retain straight advancing property of the spring portion.

5. The inspection probe according to claim 1 , wherein a cross-sectional shape of the spring portion along a longitudinal section of the support stem is formed into a rectangular shape.

6. The inspection probe according to claim 1 , wherein the contact point of the first plunger comprises at least three projections located on a common circumference.

7. The inspection probe according to claim 1 , wherein the first plunger, the second plunger, the spring portion, and the support stem are formed by subjecting a common plate-shaped blank to bending work.

8. An IC socket comprising:

a plurality of the inspection probes according to claim 1 ; and

a housing being disposed on a wiring board to be electrically connected to the inspection probes, having

a probe accommodating portion configured to accommodate the inspection probes, and

a semiconductor device mounting portion configured to attachably and detachably accommodate a semiconductor device provided with a plurality of the electrode portions with which the contact points of the inspection probes come into contact.

9. An inspection probe comprising:

a first plunger formed from a copper alloy material, and including a contact point configured to selectively come into contact with an electrode portion of an object to be inspected;

a second plunger formed from the copper alloy material, and having a contact point configured to selectively come into contact with an electrode portion of a wiring board;

a spring portion formed integrally with one end of the first plunger and a first end of the second plunger, the spring portion being configured to bias the first plunger and the second plunger in a direction away from each other; and

a support stem formed into a cylindrical shape integrally with the contact point of a second end of the second plunger, the second end being opposite to the first end, the support stem extending from the second end and being folded back toward the first end in such a manner as to be disposed inside the spring portion with a predetermined clearance in between, and configured to slidably guide the spring portion, wherein

when the contact point of the first plunger comes into contact with the electrode portion of the object to be inspected, one end of the support stem inserted into an inner peripheral portion of the first plunger comes into sliding contact with the inner peripheral portion of the first plunger, and

the first plunger, the second plunger, and the spring portion are shaped by subjecting a common plate-shaped blank made of the copper alloy to bending work and then to a plating process with a non-magnetic metal.

10. The inspection probe according to claim 9 , wherein the non-magnetic metal includes at least gold or copper.

11. The inspection probe according to claim 9 , wherein the plating process is performed in such a way as to form a first layer of copper in a film thickness of 0.05 to 1 μm on a surface of a base metal made of the copper alloy, and then to stack a second layer of gold in a film thickness of 0.1 to 5 μm on the first layer.

12. The inspection probe according to claim 9 , wherein the plating process is performed in such a way as to form only a single layer of gold in a film thickness of 0.1 to 5 μm on a surface of a base metal made of the copper alloy.

13. An IC socket comprising:

a plurality of the inspection probes according to claim 9 ; and

a housing being disposed on a wiring board to be electrically connected to the inspection probes, having

a probe accommodating portion configured to accommodate the inspection probes, and

a semiconductor device mounting portion configured to attachably and detachably accommodate a semiconductor device provided with a plurality of the electrode portions with which the contact points of the inspection probes come into contact.