IC socket

A plunger of the probe has a slider portion engaged with a plunger guide hole formed in a socket body, which is prevented from rotating, and first and second positioning surfaces having different vertical positions along a central axis of the probe by cutting two places of a rounded bar member in a radial direction. The probe receptacle has a first abutting protrusion on which the first positioning surface is abuttable and a second abutting protrusion on which the second positioning surface is abuttable when the probe is inserted in a correct posture. When the plunger is inserted in an erroneous posture, the first positioning surface abuts on the second abutting protrusion to prevent the plunger from projecting from the plunger guide hole or project the plunger by an amount less than the design dimension.

TECHNICAL FIELD

The present invention relates to an IC socket used in an electrical test for an electronic component.

BACKGROUND ART

For example, a QFP (Quad Flat Package), which is a type of semiconductor package for electronic components, has a square outer shape in many cases, and has a plurality of connection terminals protruding from all four sides, so that a pitch between the connection terminals has been reduced more and more.

FIG. 19is a diagram illustrating a Kelvin inspection IC socket101of the prior art used in an electrical test for such an electronic component100. Note thatFIG. 19Ais a diagram illustrating the Kelvin inspection IC socket101of the prior art to show a state of the electronic component100before the electric test. In addition,FIG. 19Bis a diagram illustrating a Kelvin inspection IC socket101of the prior art at the time of the electrical test for the electronic component100.

As illustrated inFIG. 19, in the Kelvin inspection IC socket101, a pair of probes103coining into contact with terminals102of the electronic component100are arranged as many as the number of terminals102, and the probes103are respectively housed in probe receptacles105provided in the socket body104formed of an insulating resin material. Note that one of the pair of probes103is a force contact probe for supplying an electric current, and the other probe103is a sense contact probe for monitoring a voltage.

As illustrated inFIG. 19, in the Kelvin inspection IC socket101of the prior art, in order to reliably connect a pair of probes103to small terminals102of the electronic component100(including electrodes formed of solder balls or the like), the pair of probes103are assembled to the probe receptacles105of the socket body104formed of an insulating material in a back-to-back manner such that vertex portions107(portions contacting the terminal102) of the plungers106of the pair of probes103are closest to each other while the pair of probes103are prevented from rotating with respect to the socket body104.

As illustrated inFIGS. 19 to 21, in the Kelvin inspection IC socket101of the prior art, a tip-side body portion108of the plunger106is offset with respect to a central axis105aof the probe receptacle105in order to prevent the pair of probes103from being assembled to the socket body104erroneously in the same posture (one of the pair of probes103placed back to back is rotated by 180° with respect to the other probe103).

Specifically, as illustrated inFIGS. 20B and 21, the tip-side body portion108of the plunger106has a substantially rectangular shape as seen in a plan view, and is engaged with a plunger guide hole110provided in the socket body104in a substantially rectangular shape when the probe103is assembled to the probe receptacle105of the socket body104in a correct posture. However, as illustrated inFIG. 22, when the probe103is assembled in an erroneous posture (in a posture rotated by 180° from the correct posture), the vertex portion107of the plunger106is caught in a stepped portion111between the probe receptacle105and the plunger guide hole110, and the plunger106cannot be engaged with the plunger guide hole110, so that the probe103is prevented from being erroneously assembled to the socket body104in advance (see Patent Document 1).

CITATION LIST

Patent Documents

SUMMARY OF INVENTION

Problems to be Solved by the Invention

However, in the Kelvin inspection IC socket101of the prior art, as illustrated inFIG. 20, when the tip-side body portion108of the plunger106is formed, three places of first to third regions of a rounded bar member113having the same diameter as that of a flange portion112of the plunger106are cut out through machining to form a pair of parallel side surfaces115and a side surface (flat surface)116perpendicular to the pair of parallel side surfaces115. Therefore, there are many machining places in the plunger106, and this increases a fabrication cost of the plunger106disadvantageously.

In this regard, an object of the present invention is to provide an IC socket capable of preventing the probe from being erroneously assembled to the socket body even when the fabrication workload for the side surface of the plunger is reduced.

Means for Solving the Problems

The present invention relates to an IC socket1used in an electrical test for an electronic component2. The IC socket1according to the present invention includes a probe4configured to contact a terminal3of the electronic component2and a socket body5having a probe receptacle6formed to house the probe4. The probe4includes a tube7housed in the probe receptacle6of the socket body5, and a plunger8assembled to one end side of the tube7and biased by a spring member11housed in the tube7such that a tip contacts the terminal3of the electronic component2. The plunger8has a slider portion16slidably engaged with a plunger guide hole15formed in the socket body5. The slider portion is prevented from rotating. The plunger guide hole15is formed in a plunger guide portion25placed to block one end side of the probe receptacle6to form a part of the probe receptacle6. The slider portion16has one side surface21formed by cutting a rounded bar member20from one end side of a radial direction toward a center side, the one side surface21extending from a tip23side of the plunger8along a central axis4aof the probe4, or a pair of side surfaces21formed by cutting the rounded bar member20from one end side of the radial direction and the other end side of the radial direction toward the center side, the pair of side surfaces21extending from a tip23side of the plunger8along the central axis4aof the probe4. The one side surface21of the slider portion16or the pair of side surfaces21of the slider portion16are engaged with the plunger guide hole15. In addition, the socket body5has a plunger projection amount restrictor25,26,27, and30that abuts on the plunger8to project the plunger8from the plunger guide hole15by a design dimension when the probe4is inserted into the probe receptacle6in the correct posture or abuts on the plunger8to prevent the plunger8from projecting from the plunger guide hole15or projects the plunger8by an amount less than the design dimension when the probe4is inserted into the probe receptacle6in an erroneous posture.

Advantageous Effects

The IC socket according to the present invention has one or two machining places on the side surface of the plunger, as compared with the example of the prior art in which three places are machined on the side surface of the plunger. Therefore, it is possible to prevent the probe from being erroneously assembled to the probe receptacle of the socket body even when the fabrication workload for the side surface of the plunger is reduced. Using the IC socket according to the present invention described above, the fabrication workload for the side surface of the plunger is reduced. As a result, it is possible to reduce the fabrication cost.

DESCRIPTION OF EMBODIMENTS

A Kelvin inspection IC socket according to embodiments of the present invention will now be described with reference to the accompanying drawings.

First Embodiment

FIG. 1is a diagram illustrating a Kelvin inspection IC socket1according to a first embodiment of the present invention. In addition,FIG. 2is a diagram illustrating a simplified relationship between the Kelvin inspection IC socket1according to the first embodiment of the present invention and an electronic component2. Note thatFIG. 1Ais a partial cross-sectional view illustrating the Kelvin inspection IC socket1(cross-sectional view taken along the line A1-A1ofFIG. 1B). In addition,FIG. 1Bis a partial front view illustrating the Kelvin inspection IC socket1by partially cutting it away. In addition,FIG. 1Cis a partial plan view of the Kelvin inspection IC socket1. In addition,FIG. 2Ais a partial cross-sectional view illustrating the Kelvin inspection IC socket1and the electronic component2(cross-sectional view taken along the line A2-A2ofFIG. 2B). In addition,FIG. 2Bis a partial front view illustrating the Kelvin inspection IC socket1and the electronic component2by partially cutting them away.

As illustrated inFIGS. 1 and 2, in the Kelvin inspection IC socket1, the pairs of probes4are arranged as many as the number of terminals3while coining into contact with the terminals3of the electronic component2, and the probes4are respectively housed in probe receptacles6provided in a socket body5formed of an insulating resin material. Note that, similar to the pair of probes103of the prior art, one of the pair of probes4according to the present embodiment is a force contact probe for supplying an electric current, and the other probe4is a sense contact probe for monitoring a voltage. In addition, the socket body5is formed by injection molding or the like.

As illustrated inFIGS. 1 and 2, in the Kelvin inspection IC socket1, a cylindrical tube7of the probe4is housed in the probe receptacle6of the socket body5, and a part of the plunger8placed in a tip side of the probe4(the upper end side as a terminal3side of the electronic component2) projects upward of the socket body5. Note that, although the socket body5has a first socket body block5A, a second socket body block5B, and a third socket body block5C by way of example, the invention is not limited thereto. Alternatively, the entire socket body5may also be divided into two blocks, four blocks, or more blocks.

As illustrated inFIGS. 1 to 3, the probe4has a cylindrical tube7formed of a conductive metal material, a plunger8formed of a conductive metal material and provided with a base end portion10assembled to one end side (upper end side) of the tube7, a coil spring (spring member)11that biases the plunger8and the tube7upward (to the terminal3side of the electronic component2) at all times, and an electrode contact member14formed of a conductive metal material and pressed to an electrode13on a board12by virtue of the spring force of the coil spring11.

The base end portion10of the plunger8is caulked and fixed in the tube7. In addition, the plunger8has a slider portion16slidably engaged with a plunger guide hole15formed in the socket body5, which is prevented from rotating, and first and second positioning surfaces17and18whose vertical positions along a central axis4aof the probe4are different.

By cutting a rounded bar member20from one end side of a radial direction toward the central axis4aside and cutting the rounded bar member20from the other end side of the radial direction toward the central axis4aside, a cross-sectional shape of the slider portion16of the plunger8perpendicular to the central axis4aof the probe4(as seen in plan views ofFIGS. 1C and 3D) is formed in a substantially rectangular shape, and a pair of side surfaces21extending from the tip side of the plunger8along the central axis4aof the probe4are formed. Note that the slider portion16has a pair of parallel side surfaces21and a pair of curved surfaces22(a part of the outer surfaces of the rounded bar member20) that connect the pair of parallel side surfaces21to each other.

The first positioning surface17of the plunger8is formed by cutting the rounded bar member20from one end side of the radial direction toward the central axis4aside, and is positioned in the lower end of the one of the pair of side surfaces21of the slider portion16. In addition, the second positioning surface18of the plunger8is formed by cutting the rounded bar member20from the other end side of the radial direction toward the central axis4aside, and is positioned in the other lower end of the pair of side surfaces21of the slider portion16. In addition, the second positioning surface18is placed farther from the tip23of the plunger8than the first positioning surface17.

A tip surface24(upper end surface inFIGS. 1 to 3) of the slider portion16is sloped such that its vertical position is gradually reduced from one end side of the longitudinal direction (one curved surface22side) having a substantially rectangular shape in a plan view toward the other end side of the longitudinal direction (the other curved surface22side). In addition, an upper end side of the sloped surface of the tip surface24of the slider portion16is sharpened in a triangular shape, and a sharp vertex of the triangular shape becomes the tip23of the plunger8. The tip23of the plunger8is placed at the upper edge of one curved surface22of the slider portion16in a central portion of the circumferential direction of the one curved surface22, and is offset from the central axis4aof the probe4.

The pair of probes4having such a configuration have the same shape, and, in a projected shape onto a virtual plane perpendicular to the central axis4aof the probe4, they are housed in the probe receptacles6while one of the probes4is rotated by 180° with respect to the other probe4. Therefore, the probes4are maintained in the correct posture in which the tips23of the plungers8are closest to each other (the tips23of the pair of plungers8are positioned back to back).

The plunger guide hole15of the socket body5is provided in the plunger guide portion25placed to block one end side of the probe receptacle6to form a part of the probe receptacle6. In addition, as illustrated inFIG. 1C, the plunger guide hole15has a substantially rectangular shape similar to that of the slider portion16of the plunger8as seen in a plan view.

The probe receptacle6of the socket body5has a first abutting protrusion26(plunger projection amount restrictor) on which the first positioning surface17is abuttable and a second abutting protrusion27(plunger projection amount restrictor) on which the second positioning surface18is abuttable when the probe4is inserted in the correct posture. In addition, as illustrated inFIG. 1, the probe receptacle6projects the plunger8from the plunger guide hole15by a design dimension when the probe4is inserted in the correct posture. In addition, as illustrated inFIG. 4, the probe receptacle6is formed such that, when the probe4is inserted in an erroneous posture (in which the tips23of the plunger8are not positioned back to back), the first positioning surface17abuts on the second abutting protrusion27, and the plunger8projects from the plunger guide hole15by an amount less than the design dimension. Note that, in the Kelvin inspection IC socket1according to the present embodiment, although the plunger8projects from the plunger guide hole15by an amount less than the design dimension when the probe4is inserted into the probe receptacle6in an erroneous posture by way of example as illustrated inFIG. 4, the invention is not limited thereto. Alternatively, the first and second positioning surfaces17and27may also be formed not to project the plunger8from the plunger guide hole15.

FIG. 5is a diagram illustrating an assembled state of the Kelvin inspection IC socket1, in which one of the pair of probes4is inserted into the probe receptacle6in an erroneous posture. As illustrated inFIG. 5, after the second socket body block5B is assembled onto the first socket body block5A, the pair of probes4are inserted into the probe receptacles6from the upper side of the second socket body block5B. In this case, when one of the pair of probes4is inserted into the probe receptacle6of the second and first socket body blocks5B and5A in an erroneous posture with respect to the other probe4, one of the tips23of the pair of probes4does not project from the probe receptacle6, or the projection amount from the probe receptacle6becomes small. As a result, at the time of assembling the Kelvin inspection IC socket1, one of the rear ends of the pair of probes4(electrode contact member14) projects from the second socket body block5B to be higher than the other rear end of the pair of probes4(electrode contact member14), so that it is possible to make an operator recognize that one of the pair of probes4is inserted into the probe receptacle6in an erroneous posture and prevent the probe4from being erroneously assembled to the first and second socket body blocks5A and5B. In addition, in the Kelvin inspection IC socket1, after all of the probes4are inserted into the probe receptacles6of the first and second socket body blocks5A and5B, the third socket body block5C is assembled to the second socket body block5B, so that the entire assembling work is completed. After the assembling is completed, the Kelvin inspection IC socket1is turned upside down and is installed on the board12for use (refer toFIG. 1).

In the Kelvin inspection IC socket1according to the present embodiment having the aforementioned configuration, as compared with an example of the prior art in which three side surfaces115,115, and116of the plunger106are machined (refer toFIG. 20), two side surfaces21of the plunger8are machined. In addition, it is possible to prevent the probe4from being assembled to the probe receptacle6of the socket body5in an erroneous posture even when a fabrication workload for the side surface21of the plunger8is reduced. In this manner, in the Kelvin inspection IC socket1according to the present embodiment, since the fabrication workload for the side surface21of the plunger8is reduced as compared with the example of the prior art, it is possible to reduce the fabrication cost as compared with the example of the prior art.

Second Embodiment

FIG. 6is a diagram illustrating a Kelvin inspection IC socket1according to a second embodiment of the present invention in contrast withFIG. 1.FIG. 7is a diagram illustrating a probe4of the Kelvin inspection IC socket1according to the second embodiment of the present invention in contrast withFIG. 3. Note that, in the drawings illustrating the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 1that shows the Kelvin inspection IC socket1of the first embodiment, and they will not be described repeatedly. In addition, in the drawings illustrating the probe4of the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 3that shows the probe4of the Kelvin inspection IC socket1of the first embodiment, and they will not be described repeatedly.

As illustrated inFIGS. 6 and 7, in the Kelvin inspection IC socket1according to the present embodiment, the plunger8has a slider portion16slidably engaged with a plunger guide hole15provided in the socket body5, which is prevented from rotating, and a pair of positioning slope surfaces28whose vertical positions along the central axis4aof the probe4change.

By cutting a rounded bar member20from one end side of the radial direction toward the central axis4aside and cutting the rounded bar member20from the other end side of the radial direction toward the central axis4aside, a cross-sectional shape of the slider portion16of the plunger8perpendicular to the central axis4aof the probe4is formed in a substantially rectangular shape, and a pair of side surfaces21extending from the tip23side of the plunger8along the central axis4aof the probe4are formed. Note that the slider portion16has a pair of parallel side surfaces21and a pair of curved surfaces22(a part of the outer surfaces of the rounded bar member20) that connect the pair of parallel side surfaces21to each other.

One of the pair of positioning slope surfaces28of the plunger8is formed by cutting the rounded bar member20from one end side of the radial direction toward the central axis4aside, and is positioned in the lower end of one of the pair of side surfaces21of the slider portion16. In addition, the other positioning slope surface28is formed by cutting the rounded bar member20from the other end side of the radial direction toward the central axis4aside, and is positioned in the lower end of the other side surface21of the slider portion16.

A tip surface24(upper end surface inFIG. 6) of the slider portion16is sloped such that its vertical position is gradually reduced from one end side of the longitudinal direction (one curved surface22side) having a substantially rectangular shape in a plan view toward the other end side of the longitudinal direction (the other curved surface22side). In addition, a vertex of the sloped surface of the tip surface24of the slider portion16becomes the tip23of the plunger8. The tip23of the plunger8is placed at the upper edge of one curved surface22of the slider portion16in a central portion of the circumferential direction of the one curved surface22, and is offset from the central axis4aof the probe4.

The pair of probes4having such a configuration have the same shape, and, in a projected shape onto a virtual plane perpendicular to the central axis4aof the probe4, they are housed in the probe receptacles6while one of the probes4is rotated by 180° with respect to the other probe4. Therefore, the probes4are maintained in the correct posture in which the tips23of the plungers8are closest to each other (the tips23of the pair of plungers8are positioned back to back).

The plunger guide hole15of the socket body5is provided in the plunger guide portion25placed to block one end side of the probe receptacle6to form a part of the probe receptacle6. In addition, as illustrated inFIG. 6C, the plunger guide hole15has a substantially rectangular shape similar to that of the slider portion16of the plunger8as seen in a plan view.

As illustrated inFIGS. 6 and 8, the probe receptacle6is provided with a pair of abutting protrusions (plunger projection amount restrictor)30having abutting slope surfaces30ahaving the same slope angles as those of the pair of positioning slope surfaces28when the probe4is inserted in the correct posture. In addition, as illustrated inFIG. 6, the probe receptacle6is formed to project the plunger8from the plunger guide hole15by a design dimension when the probe4is inserted in the correct posture. In addition, as illustrated inFIG. 9, the probe receptacle6is formed such that the slope angles of the pair of positioning slope surfaces28become opposite to those of the abutting slope surfaces30awhen the probe4is inserted in an erroneous posture (in which the tips23of the plunger8are not positioned back to back), and, assuming that a position of the pair of positioning slope surfaces28closest to the tip23of the plunger8is the highest position of the pair of positioning slope surfaces28, the highest position of the pair of positioning slope surfaces28abuts on the lowest position of the abutting slope surfaces30aof the pair of abutting protrusions30to project the plunger8from the plunger guide hole15by an amount less than the design dimension. Note that, in the Kelvin inspection IC socket1according to the present embodiment, although the plunger8projects from the plunger guide hole15by an amount less than the design dimension when the probe4is inserted into the probe receptacle6in an erroneous posture by way of example as illustrated inFIG. 9, the invention is not limited thereto. Alternatively, the pair of positioning slope surfaces8and28and the pair of abutting protrusions30may also be formed not to project the plunger8from the plunger guide hole15.

In the Kelvin inspection IC socket1according to the present embodiment described above, similar to the assembled state of the Kelvin inspection IC socket1according to the first embodiment illustrated inFIG. 5, when one of the pair of probes4is inserted into the probe receptacle6of the second and first socket body blocks5B and5A in an erroneous posture with respect to the other probe4, one of the tips23of the pair of probes4does not project from the probe receptacle6, or the projection amount from the probe receptacle6becomes small. As a result, at the time of assembling the Kelvin inspection IC socket1, one of the rear ends of the pair of probes4(electrode contact member14) projects from the second socket body block5B to be higher than the other rear end of the pair of probes4(electrode contact member14), so that it is possible to make an operator recognize that one of the pair of probes4is inserted into the probe receptacle6in an erroneous posture and prevent the probe4from being erroneously assembled to the first and second socket body blocks5A and5B.

In the Kelvin inspection IC socket1according to the present embodiment having the aforementioned configuration, as compared with an example of the prior art in which three side surfaces115,115, and116of the plunger106are machined (refer toFIG. 20), two side surfaces21of the plunger8are machined. In addition, it is possible to prevent the probe4from being assembled to the probe receptacle6of the socket body5in an erroneous posture even when a fabrication workload for the side surface21of the plunger8is reduced. In this manner, in the Kelvin inspection IC socket1according to the present embodiment, since the fabrication workload for the side surface21of the plunger8is reduced as compared with the example of the prior art, it is possible to reduce a fabrication cost as compared with the example of the prior art.

Third Embodiment

FIG. 10is a diagram illustrating a Kelvin inspection IC socket1according to a third embodiment of the present invention in contrast withFIG. 1.FIG. 11is a diagram illustrating a probe4of the Kelvin inspection IC socket1according to the third embodiment of the present invention in contrast withFIG. 3. Note that, in the drawings illustrating the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 1that shows the Kelvin inspection IC socket1of the first embodiment, and they will not be described repeatedly. In addition, in the drawings illustrating the probe4of the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 3that shows the probe4of the Kelvin inspection IC socket1of the first embodiment, and they will not be described repeatedly.

As illustrated inFIGS. 10 and 11, in the Kelvin inspection IC socket1according to the present embodiment, the plunger8has a slider portion16slidably engaged with a plunger guide hole15formed in the socket body5, which is prevented from rotating, and a pair of positioning surfaces31that determine a projection amount of the probe4from the plunger guide hole15.

By cutting a rounded bar member20from one end side of the radial direction toward the central axis4aside and cutting the rounded bar member20from the other end side of the radial direction toward the central axis4aside, a cross-sectional shape of the slider portion16of the plunger8perpendicular to the central axis4aof the probe4is formed in a substantially rectangular shape, and a pair of side surfaces21extending from the tip23side of the plunger8along the central axis4aof the probe4are formed. Note that the slider portion16has a pair of side surfaces21and a pair of curved surfaces22aand22b(a part of the outer surfaces of the rounded bar member20) that connect the pair of side surfaces21to each other.

One of the pair of positioning surfaces31of the plunger8is formed by cutting the rounded bar member20from one end side of the radial direction toward the central axis4aside, and is positioned in the lower end of one of the pair of side surfaces21of the slider portion16. In addition, the other positioning surface31is formed by cutting the rounded bar member20from the other end side of the radial direction toward the central axis4aside, and is positioned in the lower end of the other side surface21of the slider portion16.

A tip surface24(upper end surface inFIG. 10) of the slider portion16is sloped such that its vertical position is gradually reduced from one end side of the longitudinal direction (one curved surface22aside) having a substantially rectangular shape in a plan view toward the other end side of the longitudinal direction (the other curved surface22bside). In addition, a vertex of the sloped surface of the tip surface24of the slider portion16becomes the tip23of the plunger8. The tip23of the plunger8is placed at the upper edge of one curved surface22aof the slider portion16in a central portion of the circumferential direction of the one curved surface22a, and is offset from the central axis4aof the probe4.

The pair of probes4having such a configuration have the same shape, and, in a projected shape onto a virtual plane perpendicular to the central axis4aof the probe4, the probes4are housed in the probe receptacles6while one of the probes4is rotated by 180° with respect to the other probe4. Therefore, the probes4are maintained in the correct posture in which the tips23of the plungers8are closest to each other (the tips23of the pair of plungers8are positioned back to back).

The plunger guide hole15of the socket body5is provided in the plunger guide portion25placed to block one end side of the probe receptacle6to form a part of the probe receptacle6. In addition, as illustrated inFIG. 10C, the plunger guide hole15has a substantially triangular shape similar to that of the slider portion16of the plunger8as seen in a plan view.

As illustrated inFIG. 10, the probe receptacle6is formed such that, when the probe4is inserted in the correct posture, the pair of positioning surfaces31abut on the plunger guide portions (plunger projection amount restrictor)25to project the plunger8from the plunger guide hole15by a design dimension. In addition, as illustrated inFIG. 12, the probe receptacle6is formed such that, when the probe4is inserted in an erroneous posture (in which the tips23of the plunger8are not positioned back to back), the tip23side of the plunger8abuts on the plunger guide portion (plunger projection amount restrictor)25to project the plunger8from the plunger guide hole15by an amount less than the design dimension. Note that, althoughFIG. 12shows a configuration in which the plunger8projects from the plunger guide hole15by an amount less than the design dimension when the probe4is inserted into the probe receptacle6in an erroneous posture by way of example, the invention is not limited thereto. Alternatively, the thickness of the plunger guide portion25(the thickness along the central axis4aof the probe4) may also be set not to project the plunger8from the plunger guide hole15.

In the Kelvin inspection IC socket1according to the present embodiment described above, similar to the assembled state of the Kelvin inspection IC socket1according to the first embodiment illustrated inFIG. 5, when one of the pair of probes4is inserted into the probe receptacle6of the second and first socket body blocks5B and5A in an erroneous posture with respect to the other probe4, one of the tips23of the pair of probes4does not project from the probe receptacle6, or the projection amount from the probe receptacle6becomes small. As a result, at the time of assembling the Kelvin inspection IC socket1, one of the rear ends of the pair of probes4(electrode contact member14) projects from the second socket body block5B to be higher than the other rear end of the pair of probes4(electrode contact member14), so that it is possible to make an operator recognize that one of the pair of probes4is inserted into the probe receptacle6in an erroneous posture and prevent the probe4from being erroneously assembled to the first and second socket body blocks5A and5B.

In the Kelvin inspection IC socket1according to the present embodiment having the aforementioned configuration, as compared with an example of the prior art in which three side surfaces115,115, and116of the plunger106are machined (refer toFIG. 20), two side surfaces21of the plunger8are machined. In addition, it is possible to prevent the probe4from being assembled to the probe receptacle6of the socket body5in an erroneous posture even when a fabrication workload for the side surface21of the plunger8is reduced. In this manner, in the Kelvin inspection IC socket1according to the present embodiment, since the fabrication workload for the side surface21of the plunger8is reduced as compared with the example of the prior art, it is possible to reduce a fabrication cost as compared with the example of the prior art.

Fourth Embodiment

FIG. 13is a diagram illustrating a Kelvin inspection IC socket1according to a fourth embodiment of the present invention in contrast withFIG. 1.FIG. 14is a diagram illustrating a probe4of the Kelvin inspection IC socket1according to the fourth embodiment of the present invention in contrast withFIG. 3. Note that, in the drawings illustrating the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 1that shows the Kelvin inspection IC socket1of the first embodiment, and they will not be described repeatedly. In addition, in the drawings illustrating the probe4of the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 3that shows the probe4of the Kelvin inspection IC socket1of the first embodiment, and they will not be described repeatedly.

As illustrated inFIGS. 13 and 14, in the Kelvin inspection IC socket1according to the present embodiment, the plunger8has a slider portion16slidably engaged with a plunger guide hole15formed in the socket body5, which is prevented from rotating, and a positioning surface32that determines a projection amount of the probe4from the plunger guide hole15.

By cutting a rounded bar member20from one end side of the radial direction to the central axis4a, a cross-sectional shape of the slider portion16of the plunger8perpendicular to the central axis4aof the probe4is formed in a semicircular shape, and a side surface (flat surface)21extending from the tip23side of the plunger8along the central axis4aof the probe4is formed. Note that the slider portion16has a side surface (flat surface)21and a curved surface22(obtained by bisecting an outer circumferential surface of the rounded bar member20along the circumferential direction).

The positioning surface32of the plunger8is formed in the lower end side of the side surface21to be perpendicular to the central axis4aof the probe4by cutting the rounded bar member20from one end side of the radial direction to the central axis4a, and has a semicircular shape as seen in a plan view.

A tip surface24(upper end surface inFIG. 13) of the slider portion16is sloped such that its vertical position is gradually reduced from one end side of the radial direction having a semicircular shape in a plan view toward the other end side of the radial direction. In addition, a vertex of the sloped surface of the tip surface24of the slider portion16becomes the tip23of the plunger8. The tip23of the plunger8is placed at one end side of the radial direction of the tip surface24having a semicircular shape in a plan view, and is offset from the central axis4aof the probe4.

The pair of probes4having such a configuration have the same shape, and, in a projected shape onto a virtual plane perpendicular to the central axis4aof the probe4, the probes4are housed in the probe receptacles6while one of the probes4is rotated by 180° with respect to the other probe4. Therefore, the probes4are maintained in the correct posture in which the tips23of the plungers8are closest to each other (the tips23of the pair of plungers8are positioned back to back).

The plunger guide hole15of the socket body5is provided in the plunger guide portion25placed to block one end side of the probe receptacle6to form a part of the probe receptacle6. In addition, as illustrated inFIG. 13C, the plunger guide hole15has a semicircular shape similar to that of the slider portion16of the plunger8as seen in a plan view.

As illustrated inFIG. 13, the probe receptacle6is formed such that the positioning surface32of the plunger8abuts on the plunger guide portion (plunger projection amount restrictor)25, and the plunger8projects from the plunger guide hole15by a design dimension when the probe4is inserted in the correct posture. In addition, as illustrated inFIG. 15, the probe receptacle6is formed such that, when the probe4is inserted in an erroneous posture (in which the tips23of the plunger8are not positioned back to back), the tip23side of the plunger8abuts on the plunger guide portion (plunger projection amount restrictor)25to prevent the plunger8from projecting from the plunger guide hole15.

In the Kelvin inspection IC socket1according to the present embodiment described above, similar to the assembled state of the Kelvin inspection IC socket1according to the first embodiment illustrated inFIG. 5, when one of the pair of probes4is inserted into the probe receptacle6of the second and first socket body blocks5B and5A in an erroneous posture with respect to the other probe4, one of the tips23of the pair of probes4does not project from the probe receptacle6. As a result, at the time of assembling the Kelvin inspection IC socket1, one of the rear ends of the pair of probes4(electrode contact member14) projects from the second socket body block5B to be higher than the other rear end of the pair of probes4(electrode contact member14), so that it is possible to make an operator recognize that one of the pair of probes4is inserted into the probe receptacle6in an erroneous posture and prevent the probe4from being erroneously assembled to the first and second socket body blocks5A and5B.

In the Kelvin inspection IC socket1according to the present embodiment having the aforementioned configuration, as compared with an example of the prior art in which three side surfaces115,115, and116of the plunger106are machined (refer toFIG. 20), one side surface21of the plunger8is machined. In addition, it is possible to prevent the probe4from being assembled to the probe receptacle6of the socket body5in an erroneous posture even when a fabrication workload for the side surface21of the plunger8is reduced. In this manner, in the Kelvin inspection IC socket1according to the present embodiment, since the fabrication workload for the side surface21of the plunger8is reduced as compared with the example of the prior art, it is possible to reduce a fabrication cost as compared with the example of the prior art.

Fifth Embodiment

FIG. 16is a diagram illustrating a Kelvin inspection IC socket1according to a fifth embodiment of the present invention, which is a modification of the Kelvin inspection IC socket1ofFIG. 13.FIG. 17is a diagram illustrating a probe4of the Kelvin inspection IC socket1according to the fifth embodiment of the present invention, which is a modification of the probe4of the Kelvin inspection IC socket1ofFIG. 14. Note that, in the drawings illustrating the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 13that shows the Kelvin inspection IC socket1of the fourth embodiment, and they will not be described repeatedly. In addition, in the drawings illustrating the probe4of the Kelvin inspection IC socket1according to the present embodiment, like reference symbols denote like elements as inFIG. 14that shows the probe4of the Kelvin inspection IC socket1of the fourth embodiment, and they will not be described repeatedly.

A tip surface24(upper end surface inFIG. 16) of the slider portion16is sloped such that its vertical position is gradually reduced from a central position of the circumferential direction having a semicircular shape in a plan view toward the central axis4aof the probe4. In addition, a vertex of the sloped surface of the tip surface24of the slider portion16becomes the tip23of the plunger8. The tip23of the plunger8is placed in the center of the circumferential direction of the tip surface24having a semicircular shape in a plan view, and is offset from the central axis4aof the probe4.

The pair of probes4having such a configuration have the same shape, and, in a projected shape onto a virtual plane perpendicular to the central axis4aof the probe4, the probes4are housed in the probe receptacles6while one of the probes4is rotated by 180° with respect to the other probe4. Therefore, the probes4are maintained in the correct posture in which the tips23of the plungers8are closest to each other (the tips23of the pair of plungers8are positioned back to back).

The plunger guide hole15of the socket body5is provided in the plunger guide portion25placed to block one end side of the probe receptacle6to form a part of the probe receptacle6. In addition, as illustrated inFIG. 16C, the plunger guide hole15has a semicircular shape similar to that of the slider portion16of the plunger8as seen in a plan view.

As illustrated inFIG. 16, the probe receptacle6is formed such that, when the probe4is inserted in the correct posture, the positioning surface33abuts on the plunger guide portion (plunger projection amount restrictor)25to project the plunger8from the plunger guide hole15by a design dimension. In addition, as illustrated inFIG. 18, the probe receptacle6is formed such that, when the probe4is inserted in an erroneous posture (in which the tips23of the plunger8are not positioned back to back), the tip23side of the plunger8abuts on the plunger guide portion (plunger projection amount restrictor)25to prevent the plunger8from projecting from the plunger guide hole15.

In the Kelvin inspection IC socket1according to the present embodiment described above, similar to the assembled state of the Kelvin inspection IC socket1according to the first embodiment illustrated inFIG. 5, when one of the pair of probes4is inserted into the probe receptacle6of the second and first socket body blocks5B and5A in an erroneous posture with respect to the other probe4, one of the tips23of the pair of probes4does not project from the probe receptacle6. As a result, at the time of assembling the Kelvin inspection IC socket1, one of the rear ends of the pair of probes4(electrode contact member14) projects from the second socket body block5B to be higher than the other rear end of the pair of probes4(electrode contact member14), so that it is possible to make an operator recognize that one of the pair of probes4is inserted into the probe receptacle6in an erroneous posture and prevent the probe4from being erroneously assembled to the first and second socket body blocks5A and5B.

In the Kelvin inspection IC socket1according to the present embodiment having the aforementioned configuration, as compared with an example of the prior art in which three side surfaces115,115, and116of the plunger106are machined (refer toFIG. 20), one side surface21of the plunger8is machined. In addition, it is possible to prevent the probe4from being erroneously assembled to the probe receptacle6of the socket body5even when a fabrication workload for the side surface21of the plunger8is reduced. In this manner, in the Kelvin inspection IC socket1according to the present embodiment, since the fabrication workload for the side surface21of the plunger8is reduced as compared with the example of the prior art, it is possible to reduce a fabrication cost as compared with the example of the prior art.

Other Embodiments

While the Kelvin inspection IC socket has been described by way of example, the IC socket according to the present invention is not limited to the Kelvin inspection IC socket. Alternatively, one probe may be arranged for each terminal of the electronic component for a general burn-in test of the electronic component.

REFERENCE SIGNS AND NUMERALS