JP7521614B2 - Probe Equipment - Google Patents

Description

The present disclosure relates to a probe apparatus, and more particularly to a probe apparatus for inspecting circuit characteristics of a circuit board.

Communication devices such as mobile terminals include circuit boards that handle high-frequency signals. For this type of circuit board, it is essential to inspect the circuit characteristics, such as high-frequency characteristics. A probe device with probe pins is used to inspect the circuit characteristics.

For example, International Publication No. 2020/110960 (Patent Document 1) discloses a conventional probe device. The conventional probe device includes, as main components, a flange, an external plunger arranged below the flange, a probe pin, a compression coil spring provided between the flange and the external plunger, and a coaxial cable.

The external plunger comprises a cylindrical main body with a bottom and a rectangular parallelepiped protrusion protruding from the bottom surface of the main body. A through hole is formed in the external plunger. This through hole penetrates from the internal space of the main body to the bottom surface of the protrusion. A probe pin is inserted into the through hole via an insulating sleeve and held by the external plunger, with the bottom end of the probe pin exposed on the bottom surface of the external plunger. A coaxial cable is electrically connected to the probe pin.

When inspecting a circuit board, the coaxial cable of the probe device is connected to a measuring instrument. The flange is attached to an elevator provided in the measuring instrument. The connector mounted on the circuit board to be inspected is placed below the external plunger. The elevator is operated to lower the flange. The external plunger descends together with the flange, and the protrusion of the external plunger engages with the connector on the circuit board. This causes the probe pin to come into contact with and be pressed against the terminal of the connector. In this state, the measuring instrument inputs and outputs signals to the circuit board through the probe device. This inspects the circuit characteristics of the circuit board.

WO 2020/110960

In many cases, when the flange begins to descend, the external plunger is slightly out of position relative to the connector on the circuit board. To accommodate this, the connector's mating portion has a sloped surface at the top, which serves as the entrance. In this case, as the flange descends, part of the periphery of the lower end surface of the external plunger (the lower surface of the protruding portion) comes into contact with the sloped surface of the connector. As the flange continues to descend, the external plunger is guided into the appropriate position on the connector while sliding against the sloped surface.

During this process, the external plunger receives a horizontal force from the inclined surface of the connector, causing it to tilt. This tilting of the external plunger causes the compression coil spring to elastically deform. As the flange continues to descend, the lower end of the tilted external plunger comes into contact with and is pressed against the bottom of the mating part of the connector. This causes the external plunger to stand up due to the elastic force of the compression coil spring and mate with the connector.

However, there is a risk that the external plunger will not rise sufficiently. If the external plunger does not rise sufficiently, the contact between the probe pin and the connector terminal will be insufficient. In this case, the accuracy of the test will not be stable.

The object of the present disclosure is to provide a probe device capable of accurately inspecting the circuit characteristics of a circuit board.

The probe device according to the present disclosure includes a flange, an external plunger, a connecting member, an elastic member, a coaxial cable, and a probe pin. The external plunger is disposed below the flange. A through hole penetrating the external plunger in the up-down direction is formed. The connecting member is fixed to the external plunger. The connecting member is supported so as to be capable of moving upward, moving horizontally, and swinging with respect to the flange. The elastic member is provided between the flange and the external plunger. The probe pin is inserted into the through hole via an insulating sleeve and held by the external plunger. The probe pin is electrically connected to the coaxial cable. The lower end of the probe pin is exposed on the lower surface of the external plunger. The external plunger includes, in order from the top to the bottom, a first cavity and a second cavity. The first cavity opens upward. The second cavity opens into the first cavity. The second cavity has a width smaller than the width of the first cavity. In the outer plunger, the through hole opens into the second cavity, and the lower end of the connecting member is inserted into the first cavity.

The probe device disclosed herein makes it possible to accurately inspect the circuit characteristics of a circuit board.

FIG. 1 is a perspective view showing the overall configuration of a probe apparatus according to a first embodiment. FIG. 2 is an enlarged side view of a portion of the probe apparatus shown in FIG. FIG. 3 is a perspective view of the external plunger of the first embodiment. FIG. 4 is a plan view of the external plunger shown in FIG. 3 as viewed from below. FIG. 5 is a cross-sectional view taken along line VV in FIG. FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. FIG. 7 is a perspective view of an external plunger of the second embodiment. FIG. 8 is a plan view of the external plunger shown in FIG. 7 as viewed from below. FIG. 9 is a cross-sectional view taken along line IX-IX in FIG.

Below, an embodiment of the present disclosure will be described. Note that in the following description, examples of the embodiment of the present disclosure will be described, but the present disclosure is not limited to the examples described below. In the following description, specific numerical values and specific materials may be exemplified, but the present disclosure is not limited to these examples.

A probe device according to an embodiment of the present disclosure includes a flange, an external plunger, a connecting member, an elastic member, a coaxial cable, and a probe pin. The external plunger is disposed below the flange. A through hole penetrating the external plunger in the up-down direction is formed. The connecting member is fixed to the external plunger. The connecting member is supported so as to be able to move upward, move horizontally, and swing with respect to the flange. The elastic member is provided between the flange and the external plunger. The probe pin is inserted into the through hole via an insulating sleeve and is held by the external plunger. The probe pin is electrically connected to the coaxial cable. The lower end of the probe pin is exposed on the lower surface of the external plunger. The external plunger includes, in order from the top to the bottom, a first cavity and a second cavity. The first cavity opens upward. The second cavity opens into the first cavity. The second cavity has a width smaller than the width of the first cavity. In the external plunger, the through hole opens into the second cavity, and the lower end of the connecting member is inserted into the first cavity (first configuration).

In a typical example, the elastic member provided between the flange and the external plunger is a compression coil spring. However, the elastic member may be, for example, rubber.

In conventional probe devices, the center of gravity of the external plunger is relatively high. This is because the inside of the external plunger is almost completely filled. As described above, when inspecting a circuit board, the external plunger tilts as the flange descends, and is raised by the elastic force of the compression coil spring provided between the flange and the external plunger. However, if the center of gravity of the external plunger is high, it is difficult for the tilted external plunger to rise.

In contrast, in the probe device of the first configuration, a first cavity and a second cavity are formed in the external plunger. The lower end of the connecting member is inserted into the first cavity, and the connecting member is fixed to the external plunger. The second cavity is continuous with the first cavity. The second cavity is located below the elastic member. This second cavity lowers the center of gravity of the external plunger. Therefore, during inspection of the circuit board, the external plunger, which has tilted as the flange descends, is likely to stand up. Then, when the external plunger fits into the mating portion of the connector, the external plunger stands up sufficiently, and the probe pin makes sufficient contact with the terminal of the connector. Therefore, the circuit characteristics of the circuit board can be inspected with high accuracy.

The probe device of the first configuration preferably includes the following configuration: A probe pin is inserted into an insulating sleeve, the insulating sleeve is inserted into a conductive cylindrical tube, and the cylindrical tube is inserted into a through hole. The cylindrical tube is exposed to a second cavity (second configuration).

In the second configuration, the cylindrical tube is exposed to the second cavity, so the length of the through hole holding the probe pin, insulating sleeve and cylindrical tube can be shortened.

A typical example of a probe device of the first or second configuration includes the following configuration: The external plunger comprises a cylindrical main body with a bottom having a central axis along the vertical direction, and a protrusion protruding from the underside of the main body. In the external plunger, the protrusion has a hole that opens into the internal space of the main body along the vertical direction. The internal space of the main body constitutes the first cavity. The hole constitutes the second cavity. A through hole penetrates from the bottom of the hole to the underside of the protrusion (third configuration).

In the third configuration, the external plunger includes a main body and a protrusion. The shape of the hole (second cavity) formed in the protrusion is not particularly limited. For example, the cross-sectional shape of the hole may be circular, rectangular, or another shape. Furthermore, the position of the hole formed in the protrusion is not particularly limited, as long as the through hole that holds the probe pin opens to the bottom of the hole. For example, the hole may be formed coaxially with the main body, or may be formed coaxially with the through hole. The outer shape of the protrusion is not particularly limited, as long as the protrusion can be fitted into the fitting portion of the connector.

In the probe device of the third configuration, preferably, the cross-sectional shape of the hole is circular (fourth configuration).

In the fourth configuration, the dimensions of the hole relative to the protrusion can be easily designed. Such a hole can be easily formed by machining using a lathe or the like.

A typical example of a probe device of the third or fourth configuration includes the following configuration. The protrusion has, from top to bottom, an intermediate portion and a tip portion. The intermediate portion is coaxial with the main body portion and has an outer diameter smaller than the outer diameter of the main body portion (fifth configuration).

In the fifth configuration, the protrusion has an intermediate portion and a tip portion. Since the intermediate portion is coaxial with the main body portion, it is easy to design the dimensions of the intermediate portion relative to the main body portion. It is possible to form a hole only in the intermediate portion. It is also possible to form holes in the intermediate portion and the tip portion. The shape of the hole (second cavity) formed at least in the intermediate portion is not particularly limited. For example, the cross-sectional shape of the hole may be circular, rectangular, or other shapes. In addition, the position of the hole formed at least in the intermediate portion is not particularly limited as long as the through hole that holds the probe pin opens to the bottom of the hole. For example, the hole may be formed coaxially with the intermediate portion or may be formed coaxially with the through hole. The outer shape of the tip portion is not particularly limited as long as the tip portion can be fitted into the fitting portion of the connector.

In the probe device of the fifth configuration, the hole is preferably arranged coaxially with the intermediate portion (sixth configuration).

In the sixth configuration, the dimensions of the hole in the middle portion can be easily designed. Such a hole can be easily formed by machining using a lathe or the like.

In the probe device of the fifth or sixth configuration, preferably, the above-mentioned hole is formed only in the middle portion (seventh configuration).

In the seventh configuration, the length of the through hole for holding the probe pin can be sufficiently secured.

In the probe device of the fifth or sixth configuration, the above-mentioned holes may be formed in the intermediate portion and the tip portion (eighth configuration).

In the eighth configuration, the second cavity in the external plunger expands downward. This lowers the center of gravity of the external plunger. This makes it easier for the external plunger to stand upright.

A typical example of the probe device of the third or fourth configuration includes the following configuration: The outer shape of the protrusion is symmetrical with respect to a plane including the central axis of the main body. The contour of the lower surface of the protrusion is substantially rectangular (ninth configuration).

In the ninth configuration, the connector on the circuit board to be tested has a mating portion that mates with the protrusion of the external plunger. The mating portion of the connector is, for example, an external conductor that surrounds the entire terminal. This mating portion has an inclined surface at the upper portion, which serves as the entrance. The inner peripheral shape of this mating portion is roughly rectangular. The contour of the lower surface of the protrusion of the external plunger is substantially rectangular so as to correspond to the inner peripheral shape of the mating portion of the connector. On the lower surface of this protrusion, the long side and short side are typically straight. However, the long side and short side are not limited to being strictly straight, and may include curved shapes that are slightly curved. For example, the long side may be an outwardly convex circular arc or elliptical arc. The short side may be an outwardly convex circular arc or elliptical arc.

The probe device of the ninth configuration preferably includes the following configuration: In the protruding portion, the long side of the lower surface is linear, and the short side of the lower surface is an arc-shaped protruding outward (tenth configuration).

In the case of the tenth configuration, when inspecting a circuit board, as the flange descends, part of the short side of the periphery of the lower end face (the lower face of the protrusion) of the external plunger comes into contact with the inclined surface of the connector. At this time, because the short side is an outwardly convex arc shape, the external plunger receives a horizontal force from the inclined surface of the connector toward the center of the connector. This makes it possible to reliably guide the external plunger to the appropriate position of the connector.

The probe device of the tenth configuration preferably includes the following configuration: A side surface of the protruding portion, including a short side of the lower surface, is continuously connected to the outer peripheral surface of the main body portion (eleventh configuration).

In the case of the eleventh configuration, in the external plunger, the short side of the underside of the protrusion is an outwardly convex arc shape, and the radius of the side of the protrusion including the short side (hereinafter also referred to as the "short side side") is the same as the radius of the outer circumferential surface of the main body. Such an outer circumferential surface of the main body and the short side side of the protrusion can be easily formed by machining using a lathe or the like.

A typical example of the probe device of any one of the fifth to eighth configurations includes the following configuration: The outer shape of the tip portion is symmetrical with respect to a plane including the central axis of the main body portion. The contour of the underside of the tip portion is substantially rectangular (twelfth configuration).

In the case of the twelfth configuration, the connector on the circuit board to be inspected has a mating portion that mates with the tip of the external plunger. The mating portion of the connector is, for example, an external conductor that surrounds the entire terminal. This mating portion has an inclined surface at the upper portion, which serves as the entrance. The inner peripheral shape of this mating portion is roughly rectangular. The contour of the underside of the tip of the external plunger is substantially rectangular so as to correspond to the inner peripheral shape of the mating portion of the connector. On the underside of this tip portion, the long and short sides are typically straight. However, the long and short sides are not limited to being strictly straight, and may include curved shapes that are slightly curved. For example, the long sides may be in the shape of a circular or elliptical arc that is convex outward. The short sides may be in the shape of a circular or elliptical arc that is convex outward.

The probe device of the twelfth configuration preferably includes the following configuration: At the tip, the long side of the lower surface is straight, and the short side of the lower surface is an outwardly convex arc (thirteenth configuration).

In the case of the thirteenth configuration, when inspecting a circuit board, as the flange descends, part of the short side of the periphery of the lower end face (the underside of the tip) of the external plunger comes into contact with the inclined surface of the connector. At this time, because the short side is an outwardly convex arc, the external plunger receives a horizontal force from the inclined surface of the connector toward the center of the connector. This makes it possible to reliably guide the external plunger to the appropriate position of the connector.

The probe device of the thirteenth configuration preferably includes the following configuration: A side surface of the tip portion, including a short side of the lower surface, is continuously connected to the outer peripheral surface of the middle portion (fourteenth configuration).

In the case of the fourteenth configuration, in the external plunger, the short side of the underside of the tip portion is an outwardly convex arc shape, and the radius of the side surface of the tip portion including the short side (hereinafter also referred to as the "short side surface") is the same as the radius of the outer circumferential surface of the middle portion. Such an outer circumferential surface of the middle portion and the short side surface of the tip portion can be easily formed by machining using a lathe or the like.

Below, a specific example of the probe device of this embodiment will be described with reference to the drawings. The same or corresponding parts in the drawings will be given the same reference numerals and their description will not be repeated.

[First embodiment]
A probe device 1 according to a first embodiment will be described with reference to FIGS.

Figure 1 is a perspective view showing the overall configuration of the probe device 1 of the first embodiment. Figure 2 is an enlarged side view of a portion of the probe device 1 shown in Figure 1. Figure 1 shows the probe device 1 as viewed from diagonally above. To facilitate understanding of the configuration, Figure 1 shows a connector 8 mounted on a circuit board to be inspected. Note that in this specification, the vertical and horizontal directions are used to explain the configuration of the probe device 1. However, when the probe device 1 is actually used to inspect a circuit board, the vertical direction does not have to strictly match the vertical direction, and the horizontal direction does not have to strictly match the horizontal direction.

1 and 2, the probe device 1 includes, as main components, a flange 2, an external plunger 3, a probe pin 4, an elastic member 5, and a coaxial cable 6. Furthermore, the probe device 1 includes a connecting member 7.

In this embodiment, the connector 8 on the circuit board to be inspected is a multi-pole connector and has multiple terminals. The probe pins 4 are arranged at positions corresponding to the terminals of the connector 8. The probe device 1 has two probe pins 4, and a coaxial cable 6 is connected to each of the two probe pins 4. In inspecting the circuit board, the two probe pins 4 each come into contact with two of the terminals of the connector 8. However, the number of probe pins 4 may be one, or three or more.

The external plunger 3 is disposed below the flange 2. In this embodiment, the external plunger 3 comprises, in order from top to bottom, a main body portion 31 and a protruding portion 32. The protruding portion 32 protrudes from the underside of the main body portion 31. The protruding portion 32 comprises, in order from top to bottom, an intermediate portion 33 and a tip portion 34. In other words, the external plunger 3 is composed of the main body portion 31, the intermediate portion 33 and the tip portion 34. The external plunger 3 is conductive. For example, the material of the external plunger 3 is a metal. This metal is, for example, stainless steel.

The main body 31 is cylindrical with a bottom and has a central axis A along the vertical direction. The intermediate portion 33 is coaxial with the main body 31 and has an outer diameter smaller than the outer diameter of the main body 31. The tip 34 is roughly rectangular, and the outer shape of the tip 34 is symmetrical with respect to a plane including the central axis A of the main body 31. The lower surface 34a of the tip 34 corresponds to the lower surface of the external plunger 3. From another perspective, the lower surface 34a of the tip 34 corresponds to the lower surface of the protrusion 32.

Referring to FIG. 2, the probe pin 4 is arranged in the vertical direction. The probe pin 4 is held by the external plunger 3, details of which will be described later. The lower end 41 of the probe pin 4 protrudes downward from the lower surface 34a of the tip 34 of the external plunger 3. The probe pin 4 includes the lower end 41 and a barrel portion. The lower end 41 is allowed to move upward while being given a downward elastic force by an elastic body built into the barrel portion. In other words, the lower end 41 of the probe pin 4 is held so as to allow upward movement relative to the external plunger 3. However, the probe pin 4 is electrically insulated from the external plunger 3.

A coaxial cable 6 is connected to the upper end of the probe pin 4 (see FIG. 6 described later). The coaxial cable 6 is connected to a measuring instrument (e.g., a network analyzer). For example, the inner conductor (core wire) of the coaxial cable 6 is connected to the upper end of the probe pin 4. The outer conductor (ground conductor) of this coaxial cable 6 is electrically connected to the external plunger 3. As long as the probe pin 4 is conductive, its material is not particularly limited. For example, the material of the probe pin 4 is a metal. This metal is, for example, beryllium copper.

1 and 2, the connecting member 7 has a generally cylindrical shape. The coaxial cable 6 is inserted through the connecting member 7. The upper end 71 of the connecting member 7 protrudes in a flange shape.

The flange 2 has a generally rectangular parallelepiped shape and extends horizontally. A through hole 21 is formed in the flange 2 along the up-down direction. The through hole 21 includes a tapered surface 22 that expands toward the top and a step surface 23 that continues to the bottom end of the tapered surface 22. The connecting member 7 is inserted into the through hole 21 of the flange 2 from above the flange 2, and the upper end 71 of the connecting member 7 is caught on the step surface 23 of the through hole 21. This prevents the connecting member 7 from falling out downward.

The main body 31 is cylindrical with a bottom, and has an internal space that opens upward. This internal space forms a first cavity that opens upward. The lower end of the connecting member 7 is fitted inside the main body 31 of the external plunger 3. In other words, the lower end of the connecting member 7 is inserted into the first space of the external plunger 3. This connects the connecting member 7 to the main body 31 of the external plunger 3. In other words, the external plunger 3 is integrated with the connecting member 7. The connecting member 7 and the external plunger 3 may be connected to each other by bonding with an adhesive or by welding.

An elastic member 5 is provided between the external plunger 3 and the flange 2. Therefore, the external plunger 3 integrated with the connecting member 7 is supported by the flange 2 while being given a downward elastic force by the elastic member 5 with respect to the flange 2. In this embodiment, a compression coil spring is used as the elastic member 5.

The upper end 71 of the connecting member 7 is caught on the step surface 23 of the flange 2. Therefore, the external plunger 3 integrated with the connecting member 7 is allowed to move upward relative to the flange 2. Furthermore, as the connecting member 7 moves upward, the upper end 71 of the connecting member 7 is released from the engagement between the upper end 71 of the connecting member 7 and the step surface 23 of the flange 2, and the upper end 71 of the connecting member 7 enters the range of the tapered surface 22 of the flange 2. This allows the external plunger 3 integrated with the connecting member 7 to move further in the horizontal direction, and also allows it to tilt and stand up from the tilt.

In this way, the external plunger 3 is allowed to move upward relative to the flange 2 while being subjected to a downward elastic force by the elastic member 5. Furthermore, the external plunger 3 is allowed to move within the horizontal plane due to the elastic deformation of the elastic member 5, and is also allowed to tilt and stand up from the tilt. In other words, the connecting member 7 and the external plunger 3 are supported relative to the flange 2 so as to be able to move upward, move horizontally, and swing.

During the inspection of the circuit board, the connecting member 7 and external plunger 3 descend as the flange 2 descends. As a result, the external plunger 3 comes into contact with and is pressed against the connector 8. This causes the connecting member 7 and external plunger 3 to move upward and horizontally relative to the flange 2 and further oscillate. The circuit board is then inspected. After the inspection, the flange 2 rises. At this time, the connecting member 7 is subjected to the restoring force of the elastic member 5. As a result, the upper end 71 of the connecting member 7 becomes caught on the step surface 23 of the flange 2. In other words, it easily returns to its original state after the inspection is completed.

In the above example, the cross-sectional shape of the upper end 71 of the connecting member 7 is circular. In this case, the cross-sectional shapes of the tapered surface 22 and the step surface 23 in the through hole 21 of the flange 2 are circular to correspond to the cross-sectional shape of the upper end 71 of the connecting member 7. However, the cross-sectional shape of the upper end 71 may be polygonal, such as a rectangle. In this case, the cross-sectional shapes of the tapered surface 22 and the step surface 23 in the through hole 21 of the flange 2 are polygonal. In this way, unexpected rotation of the connecting member 7 relative to the flange 2 can be suppressed.

When the cross-sectional shape of the upper end 71 of the connecting member 7 is circular, a convex portion may be provided on the step surface 23 in the through hole 21 of the flange 2, and a concave portion that engages with this convex portion may be provided on the underside of the upper end 71 of the connecting member 7. Conversely, a concave portion may be provided on the step surface 23 of the flange 2, and a convex portion that engages with this concave portion may be provided on the underside of the upper end 71 of the connecting member 7. The engagement of these convex portions and concave portions can suppress unexpected rotation of the connecting member 7 relative to the flange 2.

The flange 2 supports the external plunger 3, probe pin 4, coaxial cable 6, connecting member 7, and elastic member 5. The flange 2 is attached to an elevator (not shown) provided in the measuring instrument by bolts. The flange 2 is lowered by operating the elevator. As the flange 2 descends, the external plunger 3 and probe pin 4 move toward the connector 8.

Figure 3 is an oblique view of the external plunger 3 of the first embodiment. Figure 3 shows the external plunger 3 when viewed from diagonally below. Figure 4 is a plan view of the external plunger 3 shown in Figure 3 when viewed from below. Figure 4 shows the underside. Figure 5 is a cross-sectional view taken along line V-V in Figure 4. Figure 5 shows a cross-section including the central axis A of the main body 31. Figure 6 is a cross-sectional view taken along line VI-VI in Figure 4. Figure 6 shows a cross-section including the central axis of the through hole 36.

3 to 6, as described above, the external plunger 3 is composed of a bottomed cylindrical main body portion 31, an intermediate portion 33, and a tip portion 34. The main body portion 31, the intermediate portion 33, and the tip portion 34 are arranged in order from the upper side to the lower side along the central axis A of the main body portion 31.

The intermediate portion 33 is coaxial with the main body portion 31 and has an outer diameter smaller than the outer diameter of the main body portion 31. In other words, the intermediate portion 33 has a cylindrical outer circumferential surface. The central axis of the intermediate portion 33 coincides with the central axis A of the main body portion 31.

The tip 34 is generally rectangular, and the outer shape of the tip 34 is symmetrical with respect to a plane including the central axis A of the main body 31. Referring to FIG. 4, the contour of the lower surface 34a of the tip 34 is substantially rectangular. Specifically, in the tip 34, the long side 34al of the lower surface 34a is straight, and the short side 34as of the lower surface 34a is arc-shaped. The center of the arc of the short side 34as is on the central axis A. The radius of the side (short side side) including the short side 34as of the tip 34 is the same as the radius of the outer peripheral surface of the intermediate portion 33. Therefore, the short side side of the tip 34 is continuously connected to the outer peripheral surface of the intermediate portion 33. However, the center of the arc of the short side 34as may be located at a position shifted from the central axis A.

Although not shown in the figure, the connector 8 to be inspected has a mating portion that mates with the tip 34 of the external plunger 3. The mating portion of the connector 8 is an external conductor that surrounds the entire connector terminal. This mating portion has an inclined surface at the upper part, which serves as the entrance. The inner peripheral shape of this mating portion is roughly rectangular. The outline of the underside 34a of the tip 34 of the external plunger 3 is substantially rectangular to correspond to the inner peripheral shape of the mating portion of the connector 8.

In this embodiment, a pair of protrusions 35 are formed on the underside 34a of the tip 34. The protrusions 35 are formed near the short side 34as of the underside 34a of the tip 34. When the external plunger 3 is mated with the mating portion of the connector 8 during inspection of the circuit board, the protrusions 35 are mated with the recesses of the connector 8.

As described above, the main body 31 has an internal space (first cavity) that opens upward. The intermediate portion 33 has a hole 37 along the vertical direction. This hole 37 opens into the internal space of the main body 31, i.e., the first cavity. The cross-sectional shape of the hole 37 is circular. The diameter of the hole 37 is smaller than the inner diameter of the main body 31. The hole 37 is provided coaxially with the intermediate portion 33. In other words, the central axis of the hole 37 coincides with the central axis of the intermediate portion 33, i.e., the central axis A of the main body 31. The hole 37 is formed close to the lower surface 33a of the intermediate portion 33. The hole 37 does not penetrate the lower surface 33a of the intermediate portion 33 and does not reach the tip portion 34. The hole 37 forms a second cavity in the external plunger 3. Since the diameter of the hole 37 is smaller than the inner diameter of the main body 31, the width of the second cavity is smaller than the width of the first cavity. In this way, the external plunger 3 includes, in order from the top to the bottom, the first cavity and the second cavity. In this case, the distance from the bottom 37a of the hole 37 to the lower surface 34a of the tip portion 34 in the vertical direction is 1/100 or more of the length of the second cavity. In other words, this distance is 1/100 or more of the depth of the hole 37.

The hole 37 forming the second cavity is formed at least in the upper part of the external plunger 3. In this specification, the upper part of the external plunger 3 means the part above the center in the vertical direction of the external plunger 3. However, as long as the hole 37 is formed in the upper part of the external plunger 3, the hole 37 may extend below the center in the vertical direction of the external plunger 3.

The external plunger 3 has a through hole 36 formed along the vertical direction to hold the probe pin 4. In this embodiment, since the probe device 1 has two probe pins 4, two through holes 36 are formed in the external plunger 3. The through hole 36 penetrates from the bottom 37a of the hole 37 to the lower surface 34a of the tip 34. In other words, the through hole 36 opens into the second cavity of the external plunger 3. The probe pin 4 is inserted into the through hole 36 via the insulating sleeve 12 and is held by the external plunger 3.

With reference to Figure 6, an example of a structure for holding the probe pin 4 by the external plunger 3 will be described. The probe pin 4 includes a lower end 41, a barrel portion 42, and an upper end 43. The lower end 41 protrudes downward from the barrel portion 42. The lower end 41 can advance and retreat relative to the barrel portion 42. An elastic body (e.g., a compression coil spring) is built into the barrel portion 42. The lower end 41 is allowed to move upward while being given a downward elastic force by the elastic body against the barrel portion 42. The upper end 43 protrudes upward from the barrel portion 42. The lower end 41, the barrel portion 42, and the upper end 43 are conductive with each other.

The coaxial cable 6 comprises, from the center, an inner conductor 61 (core wire), an insulating coating 62, an outer conductor 63 (ground conductor), and an outer sheath 64. At the lower end of the coaxial cable 6, the inner conductor 61, the insulating coating 62, and the outer conductor 63 are exposed in that order.

The lower end of the coaxial cable 6 is inserted into a conductive cylindrical tube 11 together with the probe pin 4. In particular, an insulating sleeve 12 is inserted into the lower end of the cylindrical tube 11, and the probe pin 4 passes through the insulating sleeve 12. In other words, the probe pin 4 is held insulated from the cylindrical tube 11 by the insulating sleeve 12.

The inner conductor 61 inserted into the cylindrical tube 11 is electrically connected to the upper end 43 of the probe pin 4 by soldering or the like. This connection is insulated from the cylindrical tube 11 by the auxiliary insulating sleeve 13. The outer conductor 63 inserted into the cylindrical tube 11 is electrically connected to the cylindrical tube 11 by soldering or the like.

The insulating sleeve 12 and the auxiliary insulating sleeve 13 are made of a material such as a resin. This resin is, for example, a fluororesin (e.g., PTFE). The cylindrical tube 11 is made of a material such as a metal. This metal is, for example, a copper alloy, phosphor bronze, etc.

The cylindrical tube 11 with the coaxial cable 6, the probe pin 4, the insulating sleeve 12, etc. inserted in this manner is inserted into the through hole 36 of the external plunger 3. As a result, the probe pin 4 is held by the external plunger 3 via the insulating sleeve 12. In this state, the lower end 41 of the probe pin 4 is exposed to the lower surface of the external plunger 3, i.e., the lower surface 34a of the external plunger 3. The upper part of the cylindrical tube 11 is exposed to the hole 37 (second cavity). The lower end 41 of the probe pin 4 is allowed to move upward while being given a downward elastic force against the external plunger 3. In addition, by inserting the cylindrical tube 11 into the through hole 36 of the external plunger 3, the cylindrical tube 11 and the external plunger 3 are mutually conductive. As a result, the outer conductor 63 of the coaxial cable 6 is electrically connected to the external plunger 3 via the cylindrical tube 11.

In the probe device 1 of this embodiment configured as described above, a second cavity is formed in the external plunger 3 by a hole 37 formed in the middle part 33 of the external plunger 3. This second cavity (hole 37) lowers the center of gravity of the external plunger 3. In the inspection of the circuit board, the external plunger 3 tilted with the descent of the flange 2 stands up by the elastic force of the elastic member 5 provided between the flange 2 and the external plunger 3. In this embodiment, since the center of gravity of the external plunger 3 is low, the tilted external plunger 3 is easy to stand up. Then, when the external plunger 3 is fitted into the fitting part of the connector 8, the external plunger 3 stands up sufficiently, and the probe pin 4 is in sufficient contact with the connector terminal. Therefore, the circuit characteristics of the circuit board can be inspected with high accuracy.

Moreover, because the external plunger 3 is easy to stand up, the burden on the elastic member 5 provided between the flange 2 and the external plunger 3 is also reduced. Therefore, unexpected damage to the elastic member 5 can be suppressed.

After the inspection is completed, the flange 2 rises, and the connecting member 7 is subjected to the restoring force of the elastic member 5. This causes the upper end 71 of the connecting member 7 to be caught on the step surface 23 of the flange 2. In other words, after the inspection is completed, it returns to its original state with high precision and ease. Therefore, another inspection can be performed with high precision.

In this embodiment, in the external plunger 3, the intermediate portion 33 is coaxial with the main body portion 31. This makes it easy to design the dimensions of the intermediate portion 33 relative to the main body portion 31. In this case, the main body portion 31 and the intermediate portion 33 can be easily formed by machining using a lathe or the like.

In addition, in the external plunger 3, the cross-sectional shape of the hole 37 is circular, and the hole 37 is provided coaxially with the intermediate portion 33. This makes it easy to design the dimensions of the hole 37 relative to the intermediate portion 33. In this case, the hole 37 can be easily formed by machining using a lathe or the like.

Furthermore, in the external plunger 3, the short side 34as of the underside 34a of the tip portion 34 is an outwardly convex arc shape, and the short side surface of the tip portion 34 is continuously connected to the outer circumferential surface of the intermediate portion 33. Therefore, the radius of the short side surface of the tip portion 34 is the same as the radius of the outer circumferential surface of the intermediate portion 33. In this case, the outer circumferential surface of the intermediate portion 33 and the short side surface of the tip portion 34 can be easily formed by machining using a lathe or the like.

In the external plunger 3, the through hole 36 that holds the probe pin 4 can be formed by drilling using a drill tool.

The external plunger 3 can be easily formed by machining. However, the method of forming the external plunger 3 is not limited to machining. The rough shape of the external plunger 3 may be formed by casting, and the finishing process may be left to machining.

In addition, during inspection of the circuit board, as the flange 2 descends, part of the short side 34as of the periphery of the lower end face (lower surface 34a of the tip 34) of the external plunger 3 comes into contact with the inclined surface of the connector 8. At this time, because the short side 34as is an outwardly convex arc shape, the external plunger 3 receives a horizontal force from the inclined surface of the connector 8 toward the center of the connector 8. This makes it possible to reliably guide the external plunger 3 to the appropriate position on the connector 8.

[Second embodiment]
A probe device 1 according to a second embodiment will be described with reference to Figures 7 to 9. The probe device 1 according to the second embodiment is obtained by modifying the shape of the external plunger 3 in the probe device 1 according to the first embodiment.

Figure 7 is an oblique view of the external plunger 3 of the second embodiment. Like Figure 3, Figure 7 shows the external plunger 3 when viewed from diagonally below. Figure 8 is a plan view of the external plunger 3 shown in Figure 7 when viewed from below. Like Figure 4, Figure 8 shows the underside. Figure 9 is a cross-sectional view taken along line IX-IX in Figure 8. Like Figure 5, Figure 9 shows a cross-section including the central axis A of the main body portion 31.

In this embodiment, the hole 37 provided in the external plunger 3 opens into the internal space of the main body 31 and is formed close to the underside 34a of the tip 34. The hole 37 penetrates the underside 33a of the intermediate portion 33 and reaches into the tip 34. In this case, the distance from the bottom 37a of the hole 37 to the underside 34a of the tip 34 in the vertical direction is 1/100 or more of the length of the second cavity. In other words, the distance is 1/100 or more of the depth of the hole 37. This is to ensure the length of the through hole 36 that holds the probe pin 4.

According to the probe device 1 of this embodiment, the hole 37 formed in the external plunger 3 reaches into the tip 34. In this case, the cavity formed by the hole 37 in the external plunger 3 expands downward. This makes the center of gravity of the external plunger 3 lower. This makes it easier for the external plunger 3 to stand up.

In addition, the present disclosure is not limited to the above-described embodiment, and various modifications are possible within the scope of the present disclosure. For example, in the tip portion 34, the long side 34al and the short side 34as of the lower surface 34a may both be straight. In this case, the outline of the lower surface 34a of the tip portion 34 is a strict rectangle.

In the above embodiment, the protrusion 32 is composed of the middle portion 33 and the tip portion 34, but the protrusion 32 itself may be a single part. In this case, the protrusion 32 fits into the fitting portion of the connector 8. The lower surface 34a of the tip portion 34 corresponds to the lower surface of the protrusion 32.

1: Probe device 2: Flange 3: External plunger 31: Main body 32: Protruding portion 33: Middle portion 33a: Lower surface 34: Tip portion 34a: Lower surface 36: Through hole 37: Hole (cavity)
37a: Bottom 4: Probe pin 5: Elastic member (compression coil spring)
6: Coaxial cable 8: Connector 11: Cylindrical tube 12: Insulating sleeve A: Central axis

Claims (14)

A flange;
an external plunger disposed below the flange, the external plunger having a through hole extending vertically therethrough;
a connecting member fixed to the external plunger and supported so as to be movable upward, horizontally, and oscillate with respect to the flange;
an elastic member provided between the flange and the external plunger;
A coaxial cable,
a probe pin that is inserted into the through hole via an insulating sleeve and held by the outer plunger, the probe pin being electrically connected to the coaxial cable, and a lower end portion of the probe pin being exposed on a lower surface of the outer plunger;
The external plunger includes, in order from the top to the bottom, a first cavity that opens upward, and a second cavity that opens into the first cavity and has a width smaller than a width of the first cavity,
A probe device, wherein the through hole of the external plunger opens into the second cavity, and a lower end of the connecting member is inserted into the first cavity and coupled to the external plunger . 2. The probe device according to claim 1,
the probe pin is inserted into the insulating sleeve, the insulating sleeve is inserted into a conductive cylindrical tube, and the cylindrical tube is inserted into the through hole;
The cylindrical tube is exposed to the second cavity. 3. The probe device according to claim 1,
The external plunger includes a cylindrical main body having a bottom and a central axis along a vertical direction, and a protrusion protruding from a bottom surface of the main body,
In the external plunger,
The protrusion has a hole that opens into an internal space of the main body along a vertical direction,
the internal space of the body portion constitutes the first cavity;
the hole constitutes the second cavity;
A probe device, wherein the through hole extends from the bottom of the hole to the underside of the protrusion. 4. The probe device according to claim 3,
A probe device, wherein the bore has a circular cross-sectional shape. The probe device according to claim 3 or 4,
The protrusion includes, from top to bottom, an intermediate portion that is coaxial with the main body portion and has an outer diameter smaller than that of the main body portion, and a tip portion. 6. The probe device according to claim 5,
A probe device, wherein the hole is disposed coaxially with the intermediate portion. The probe device according to claim 5 or 6,
A probe device, wherein the hole is formed only in the middle portion. The probe device according to claim 5 or 6,
A probe apparatus, the holes being formed in the intermediate portion and the tip portion. The probe device according to claim 3 or 4,
A probe device, wherein an outer shape of the protrusion is symmetrical with respect to a plane including the central axis of the main body, and a contour of the lower surface of the protrusion is substantially rectangular. 10. The probe device according to claim 9,
A probe device, wherein the long side of the lower surface of the protrusion is linear, and the short side of the lower surface is arc-shaped and convex outward. The probe device according to claim 10,
A probe device, wherein a side surface of the protrusion, which includes the short side of the lower surface, is continuously connected to an outer peripheral surface of the main body. The probe device according to any one of claims 5 to 8,
A probe device, wherein an outer shape of the tip portion is symmetrical with respect to a plane including the central axis of the main body portion, and a contour of the lower surface of the tip portion is substantially rectangular. The probe device according to claim 12,
A probe device, wherein at the tip portion, the longer side of the lower surface is linear, and the shorter side of the lower surface is arc-shaped and convex outward. 14. The probe device according to claim 13,
A probe device, wherein a side surface of the tip portion, which includes the short side of the lower surface, is continuously connected to an outer peripheral surface of the intermediate portion.

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