JP2689754B2 - Probing head - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a probing head, and in particular, when a surface mount component (SMD) is mounted on a printed circuit board, whether the surface mount component is correctly mounted at a predetermined position on the printed circuit board. The present invention relates to a probing head used for electrically inspecting.

[0002]

9 is a perspective view showing an example of a conventional probing head of this type, and FIG. 10 is a side view thereof.

The lead wire 103 of the surface mount component 111 is soldered to the pad 102 provided on the printed circuit board 100 at the soldering portion 101, and it is checked whether or not the soldering is correctly performed at a predetermined position. It shall be inspected by a probing head mainly composed of 110.

The body is an E-shaped yoke 1 made of a magnetic material.
53, the length of the E-shaped central projection and the projections on both sides of the E-shape are substantially equal, and the cross-sectional shape of each projection is square in the figure. The lower portion of the yoke 153 is fixed to the main body moving device 20 with the open end of the protrusion of the yoke 153 facing vertically upward. Further, the slide rail 102 whose longitudinal direction is parallel to the vertical line with the lower part of the main body 110
Is fixed to the yoke 153 on the opposite side of the probe 3 made of a rod-shaped conductive material. The slide portion 108 that can be displaced in the vertical direction by being guided by the slide rail 102 is the yoke 1 of the slide rail 102 described above.
It is attached to the 53 side.

The moving coil 104 wound around the central projection of the yoke 153 with a constant gap around an axis parallel to the vertical line is the yoke 15.
It is inserted with a gap in the outer periphery of the protrusion at the center of 3. A portion of the outer peripheral portion formed by the moving coil 104 near the slide portion 108 is fixed to the surface of the slide portion 108 facing the yoke side.

The moving coil 104 is connected to an external power source by moving coil lead wires 105 and 106.

One end of an arm 109 made of a conductive material is fixed to the outer peripheral portion of the moving coil 104, which is opposite to the outer peripheral portion fixed to the slide portion 108. The longitudinal direction of the arm 109 is parallel to the horizontal direction.

One surface of each of the rectangular parallelepiped permanent magnets 151 and 152 is fixedly attached to the surfaces of the yoke 153 on the opposite sides of the central projection of the yoke 153, which face the central projection, respectively. The surfaces of the permanent magnets 151 and 152 on the opposite side to the fixed surfaces face the side surfaces of the central projection of the yoke 153 described above with a gap between the permanent magnets 151 and 152 and the aforementioned moving coil.

The permanent magnets 151 and 152 are so arranged that the lines of magnetic force generated by these permanent magnets 151 and 152 are oriented so that they face the surface facing the permanent magnet 151 or 152 on the side surface of the central projection of the yoke 153. 1
It may be fixed to 53.

A rod-shaped probe 3 made of a conductive material having a longitudinal axis in the vertical direction and a tip portion below the arm 109 is fixed near the end of the arm 109 on the side opposite to the moving coil. Has been done. Further, a lead wire for measurement is electrically connected to the arm 109 described above.

The vertical extension force of the spring 112 inserted between the lower end of the slide portion 108 and the lower portion of the slide rail 102 is balanced with the gravity applied to the main body 110.

The surface mount component 11 is attached to the pad 102 described above.
When inspecting that 1 is properly soldered, first, the main body moving device 20 is displaced in the X direction, the Y direction, and the direction orthogonal to the paper surface to position the lower tip of the probe 3 directly above the inspection target point. Let Next, when a current in an appropriate direction is applied to the moving coil 104 by an external power source to displace the moving coil 104 vertically downward, the arm 109 is guided by the slide rail 102.
And the probe 3 also moves downward, and the tip of the probe 3 contacts the inspection target point. In this state, an electric resistance value between the measurement lead wire 107 and a predetermined measurement point reference point (not shown) on the printed circuit board 100 or electric power is supplied to an electric circuit on the printed circuit board to operate the circuit. At that time, an inspection is performed by measuring a potential difference between a reference point of a predetermined potential in the electric circuit on the printed circuit board 100 and the measurement lead wire 107 to determine whether the potential is normal. Was going on.

[0013]

In the above-mentioned conventional probing head, the lower end of the probe is displaced by the main body moving device to a position directly above the object to be measured, and then a current is applied to the moving coil in an appropriate direction to move the probe. Displace vertically downward. The part to be measured is convex in the soldering part, and the tip of the probe slides on the surface of this soldering part when the top end of the probe touches the top part of the soldering part. Part of the printed circuit board, such as when it stops in contact with another part of the printed circuit board, or when it contacts another circuit part on the printed circuit board adjacent to the target measurement part, making measurement impossible. Even if the tip contacts the target measurement point, there is a drawback that the probe bends and the side part of this probe contacts other adjacent mounting components, making it impossible to perform the target inspection. .

An object of the present invention is to dispose the lower tip of the probe slightly laterally and above the measuring object portion by the main body moving device, and then displace the tip of the probe slightly downward and horizontally. Accordingly, it is an object of the present invention to provide a probing head capable of reliably contacting a target measurement target portion.

[0015]

According to a first aspect of the present invention, there is provided a probing head in which a mounting surface of a printed circuit board having surface-mounted components mounted on a flat surface is fixed upward in parallel with a horizontal plane. The main body fixed to a main body moving device that moves in a plane parallel to this mounting surface and in a direction perpendicular to this mounting surface and a probe attached to this main body are moved by the main body moving device to move the probe. Position the tip of the probe in the vicinity of the inspection target position of the surface-mounted component mounted on the printed circuit board, and then finely move the probe with respect to the main body to bring the tip of the probe into contact with the inspection target point. , A potential between a measurement lead wire connected to the probe and a reference potential point on the printed circuit board or a reference point on the printed circuit board and the probe In a probing head used for measuring electrical resistance, one end is fixed below the bottom surface of the body, the direction of the longitudinal axis is parallel to the horizontal plane, and the longitudinal axis is orthogonal to the bottom surface of the body. A torsion bar having a rotation axis in the direction of the longitudinal axis, a bar-shaped arm made of a conductive material, which is made of a conductive material, and has one end fixed coaxially to the other end of the torsion bar, and an insulating material. With a thin plate-like outer shape having a semi-circular wide surface, the center of the semi-circular semi-circle coincides with the longitudinal axis of the arm in a state where the thin plate-like linear portion is positioned below and parallel to the horizontal plane, and A rotating substrate fixed to the middle of both ends of the arm in a state where the wide surface is orthogonal to the longitudinal axis of the arm, and an upper part fixed near the other end of the arm made of a conductive material and having a longitudinal axis The above A rod-shaped probe having a tip portion that is orthogonal to the longitudinal axis of and protrudes downward from the arm, and a plane along the wide surface at a position apart from the center of the semicircle on one wide surface of the rotating substrate. One or more spiral drive coils each having a hollow portion formed into a shape, the main body is made of a magnetic material, and the bottom surface has a dimension larger than that of the wide surface of the rotating substrate; and the bottom half of the bottom surface. A side plate which is fixed to the periphery except the part and is orthogonal to the bottom face and is provided on the rotary substrate side with respect to the bottom face and covers the rotary substrate, and the side plate of the main body on which the arm is located. One end is fixed to and the other end projects in parallel with at least one wide surface side of the rotating substrate toward the longitudinal axis of the arm, and when no current is flowing through the drive coil, the tip is located near the drive coil. Magnetic material And a maximum magnetic flux density when one end face is parallel to the plane formed by the spiral drive coil and a current is not flowing through the drive coil. The portion is coaxial with the center of the semi-circle of the rotary substrate from the center of the drive coil, and is located at a portion distant by a preset distance in the circumferential direction of the circle passing through the center of the coil. And a permanent magnet for generating magnetic field lines in a direction substantially orthogonal to the above, and a measurement lead wire electrically connected to the probe or the arm.

Further, in the probing head of the second invention, the printed board on which the surface-mounted components are mounted on a plane is fixed at a fixed position so that the mounting surface on which the surface-mounted components are mounted is parallel to the horizontal plane and upward. The main body moving device includes a main body fixed to a main body moving device that moves above the printed circuit board in a plane parallel to the mounting surface and in a direction perpendicular to the mounting surface, and the probe attached to the main body. By moving the probe so that the tip of the probe is located in the vicinity of the inspection target point of the surface mount component mounted on the printed circuit board, and then the probe is finely moved with respect to the main body so that the tip of the probe is On the printed board, the potential between the measurement lead wire connected to the probe and the reference potential point on the printed board, which is brought into contact with the inspection target point In a probing head used to measure the electrical resistance between a reference point and the probe, one end is fixed below the bottom surface of the body, the longitudinal axis is parallel to the horizontal plane, and the longitudinal axis is orthogonal to the bottom surface. A torsion bar serving as a rotating shaft, a rod-shaped arm made of a conductive material, having a longitudinal axis coaxial with the longitudinal axis of the torsion bar, and having one end fixed to the other end of the torsion bar,
A rod-shaped probe which is made of a conductive material and has a longitudinal axis perpendicular to the longitudinal axis of the arm fixed to a portion near the other end of the arm and having the other end located below the arm; In the middle of both ends, in the plane orthogonal to the longitudinal axis of the arm, the longitudinal directions are different from each other by an acute angle with respect to the vertical line and an angle equal to the vertical line, and one end is fixed to the arm. Two rod-shaped bobbin mounting arms having a predetermined equal length, and a cylindrical bobbin mounting arm having a bottom surface at one end, the cylindrical surface being parallel to the longitudinal axis of the bobbin mounting arm, and an outer surface of the bottom surface. A bobbin fixed to the other end of the bobbin mounting arm, a moving coil wound on the circumference of the bobbin, an inner diameter larger than the outer shape of the moving coil and made of a magnetic material, and the axial length of the bobbin is approximately the same. A cylindrical portion having a length substantially equal to the axial length, a cylindrical portion coaxial with the cylindrical portion and having an outer diameter smaller than the inner diameter of the bobbin and an axial length shorter than the axial length of the cylindrical portion, and one end of the cylindrical portion. Two yokes, each of which is composed of a bottom portion that relatively fixes one end of the cylindrical portion, and the open end side of the cylindrical portion is coaxially inserted into each bobbin by a predetermined distance, and the bottom portion of the cylindrical portion. A columnar permanent magnet having an outer diameter equal to the outer diameter of the cylindrical portion, one end surface of which is coaxially fixed to the opposite end surface and the other end surface of which is substantially coincident with the end surface of the open end of the cylindrical portion of the yoke. The main body is fixed to the bottom surface and the side edges above the bottom surface, and the bottom portions of the two yokes are fixed to each other. When the moving coil is not energized, the open end of the cylindrical portion of the yoke is previously set in the bobbin. Insert the specified length coaxially with the bobbin. It becomes more side plates for fixing in position, and a lead wire for measuring electrically connected to the probe or the arm.

[0017]

Next, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view showing an embodiment of the probing head of the present invention, and FIG. 2 is a side view thereof.

As shown in FIG. 1, the probing head of the present invention has a main body 4 including a bottom surface portion 41 having a wide surface parallel to the vertical plane and a wide surface of the bottom surface portion 41 below the bottom surface portion 41. One end of the torsion bar 2 having a longitudinal axis orthogonal to the rotation axis B is fixed. The other end of the torsion bar 2 is coaxially fixed to one end of the arm 1 made of a rod-shaped conductive material having a longitudinal axis coaxial with the rotation axis B described above. Near the middle of both ends of the arm 1, the wide surface of the rotary substrate 8 having a semicircular wide surface made of an electrically insulating material is orthogonal to the rotation axis B, and the semicircular linear portion is parallel to the horizontal plane. The center of the semicircle is fixed to the arm 1 so that the center of the semicircle coincides with the rotation axis B. On the wide surface of the rotating substrate, there is provided a flat and hollow spiral drive coil 5 centered on the above-mentioned semicircular semicircle and concentric circles whose angular intervals are 90 degrees apart from each other. There is.

A rod-shaped probe 3 made of a conductive material having a longitudinal direction in the vertical direction is fixed near the end of the arm 1 farther from the torsion bar 2. The tip of the probe 3 is located below the arm 1. A measurement lead wire 107 is electrically connected to the arm 1.

From the periphery of the bottom surface 41 of the main body 4 excluding the lower side edges, there are left and right side walls having wide surfaces parallel to the vertical line, and upper side walls having wide surfaces parallel to the horizontal plane. The probe 3 is attached to the side where the probe 3 is present in a direction orthogonal to the wide surface of the bottom surface 41. Each of the side walls is made of a magnetic material.

Rotating substrates 8 made of magnetic material and parallel to each other
The two protruding portions 42, which are parallel to each other and are parallel to each other, are fixed to the right side wall with the rotating substrate 8 sandwiched therebetween, and the other end, which is an open end, is located near the center of the right drive coil 5. ing. On the side of the open ends of these protrusions 42 facing the drive coil 5, permanent magnets 7a and 7b having magnetic flux lines in a direction substantially orthogonal to the plane formed by the drive coil 5 face each other at the maximum points of their magnetic flux densities. The drive coil 5 is fixed so as to be offset from the center thereof. These permanent magnets 7a and 7
The distance between the above-mentioned protrusions 42 facing each other is set in advance so that there is a gap between the surface of the drive coil 5 facing the drive coil 5 and the surface of the drive coil 5 or the surface of the rotary substrate 8.

Further, the permanent magnets 7a and 7b are fixed to the protrusion 42 so that the directions of the magnetic fields generated by the permanent magnets 7a and 7b are the same.

The two projections 42 forming such a pair and the permanent magnets 7a and 7b fixed to the open ends thereof are attached to the left side plate and the upper side plate of the main body 4 as described above. Has been.

The deviation between the drive coil 5 and the maximum magnetic flux density position of the permanent magnet 7a or 7b is set as described below in the state where no current is passed through the drive coil 5. Rotating substrate 8
The points at which the magnetic flux densities of the permanent magnets 7a and 7b are maximum are made to substantially coincide with each other on a circle passing through the center of the semicircle part of and passing through the center of the drive coil 5. However, the center of the drive coil 5 is set at an appropriate distance on the circle described above from the point of maximum magnetic flux density of the permanent magnets 7a and 7b.

FIGS. 3A, 3B, 3C and 3D
Is the current I when the current is applied to the drive coil 5.
1 or I2, the direction of the magnetic field H generated by the permanent magnet 7a or 7b, and the drive coil 5 and the rotating substrate on which the drive coil 5 is fixed by the interaction between the magnetic field H and the current I1 or I2. It is explanatory drawing of the relationship of the force F which 8 receives.

3 (A) to 3 (D) are all explanatory views when the permanent magnet 7a (or 7b) and the drive coil 5 are projected on a plane orthogonal to the rotation axis B. As shown in FIG.

It is assumed that the relationship between the permanent magnet 7a and the drive coil 5 is in the state shown in FIG. 4A when no current is flowing through the drive coil 5. Here, it is assumed that the maximum point of the magnetic flux density of the permanent magnet 7a is at the center of the permanent magnet 7a. The direction of the magnetic field H created by the permanent magnet 7a is assumed to be perpendicular to the back surface of the paper. Further, the center D of the drive coil 5 is separated from the center of the permanent magnet 7a.

When the current I1 is applied to the drive coil 5 in the clockwise direction, the left side portion of the drive coil 5 located substantially above the center of the permanent magnet 7a receives the leftward force F. On the other hand, since the magnetic flux density of the magnetic field H is weak in the right side portion of the drive coil 5, it receives almost no force from the magnetic field H.
The drive coil 5 and the rotary substrate 8 to which the drive coil 5 is fixed rotate about the rotation axis B in the counterclockwise direction. If the torsion bar 2 does not generate a reaction force that rotates the rotary substrate 8 in the clockwise direction with the rotation of the rotary substrate 8 described above, in the state where the current I1 is applied to the drive coil 5, The relative positional relationship between the magnet 7a and the drive coil 5 should be in the state shown in FIG. 3 (B). That is, in the state shown in FIG. 3B, the permanent magnet 7a
The right side portion of the drive coil 5 receives a force to the left with respect to the magnetic field H generated by, while the left side portion of the drive coil 5 receives a force to the right. The force received is almost zero.

However, when the rotary substrate 8 rotates counterclockwise, the torsion bar 2 generates a reaction force that tends to rotate the rotary substrate 8 clockwise. Therefore, when the current I1 is applied to the drive coil 5, the rotary substrate 8 rotates counterclockwise from the state shown in FIG.
It becomes stationary in the intermediate state shown in (A) and FIG. 3 (B).

FIG. 3C is an explanatory view showing the moment when the current I2 is passed through the drive coil 5 in a state where no current is passed through the drive coil 5. The current I2 is a current in the opposite direction to the current I1 shown in FIG. When the current I2 flows through the drive coil 5 in this manner, the magnetic field H causes the drive coil 5 to move.
The left side portion of the drive coil 5 receives the rightward force F2, and the right side portion of the drive coil 5 has a small magnetic field generated by the permanent magnet 7a.
Rotate clockwise around. However, since the torsion bar 2 is twisted by the rotation of the rotating substrate 8, a reaction force against this force, that is, a force for rotating the rotating substrate 8 in the counterclockwise direction is generated. Therefore, the rotational force caused by the current I2 and the torsion bar 2 are generated. The rotating substrate 8 stands still in a state in which the reaction force generated is balanced, that is, in the state shown in FIG.

As is clear from the above description, by reversing the direction of the current flowing through the drive coil 5, the rotation axis B
Around it, the probe 3 can be rotated clockwise and counterclockwise around the axis of rotation B.

FIG. 4 shows the probe 3 when inspecting the state of the soldering portion 101 of the surface mount component 111 soldered by the soldering portion 101 to the pad 102 of the printed circuit board 100 by the probing head shown in FIG. FIG. 6 is an explanatory diagram showing a relationship between the rotary board 8 and the soldered portion 101 on the printed board 100.

That is, by the main body moving device 20 fixing the main body 4 shown in FIG. 1, the probe 3 is located slightly above the soldering portion 101 to be inspected and laterally beyond the target portion. Position the tip of the. Next, a current is applied to the drive coil 5 in a predetermined direction to rotate the tip of the probe 3 around the rotation axis B in the rotation direction R to bring it into contact with the soldered portion 101 to be inspected. An inspection similar to the conventional probing head of this type shown in FIG. 9 is performed.

In FIG. 1, the drive coil 5 is provided on the rotary substrate 8 at three places, but it may be provided at one place. Further, the number of the two protrusions facing each other and attached to the side plates of the main body 4 with the rotary substrate 8 sandwiched therebetween may be one. Therefore, the permanent magnet fixed to the tip of the two protrusions is also attached to one drive coil 5. It may be one.

FIG. 5 is a perspective view showing another embodiment of the present invention, and FIG. 6 is a side view thereof. One end of the torsion bar 12 having a longitudinal axis parallel to the horizontal plane is fixed below the bottom surface portion 141 of the main body 14 having a wide surface parallel to the vertical line.

One end of a rod-shaped arm 11 made of a conductive material and having a longitudinal axis coaxial with the longitudinal axis of the torsion bar 12 is fixed to the other end of the torsion bar 12. A rod-shaped probe 3 is fixed near the other end of the arm 11 in parallel with a vertical line made of a conductive material and having a tip located below the arm 11. A measurement lead wire 107 is electrically connected to the arm 11.

The arm 1 is located near the middle of both ends of the arm 11.
A rod shape that forms an acute angle with respect to the vertical line in the plane orthogonal to the longitudinal axis of 1 and one is on the left side and the other is on the right side and the longitudinal directions are equal to each other with respect to the vertical line. One end of each bobbin mounting arm 19 is fixed to the arm 11. At the other end of the bobbin mounting arm 19, the bottom surface of the bobbin 16 made of a cylindrical electrically insulating material having a bottom surface at one end is coaxial with the cylindrical axis of the bobbin 16 and the longitudinal axis of the bobbin mounting arm 19. It is fixed. Bobbin 1
A moving coil 15 is fixedly attached to the outer circumference of 6.

The yoke 17 is made of a magnetic material and has a cylindrical portion whose inner diameter is larger than the outer diameter of the moving coil 15 described above and a length shorter than the length of this cylindrical portion, and the outer diameter is smaller than the inner diameter of the bobbin described above. In addition, it is composed of a central protrusion on a cylinder arranged coaxially with the above-mentioned cylindrical portion, and a bottom portion that relatively fixes the ends of the cylindrical portion and the central protrusion on the same side. A cylindrical permanent magnet 18 having an outer diameter equal to the outer diameter of the central protrusion is fixed to the open end of the central protrusion. The open end surface of the cylindrical permanent magnet is substantially flush with the open end surface of the cylindrical portion.

Most of the magnetic lines of force generated by the permanent magnet 18 are orthogonal to the inner surface of the cylindrical portion described above and are directed from the center of the cylindrical portion to the outside or from the outside. Each of the two yokes 17 having the above-described shape has an open end face of the cylindrical portion facing each of the two bobbins 16, and a central protrusion of the yoke 17 is coaxial with the inside of the bobbin 16 by a predetermined distance. The bottom portion of the yoke 17 is fixed to the side plate that is partially fixed to the wide surface of the bottom surface of the main body 14 in the inserted state.

FIG. 7 is a partial sectional view showing a state in which the yoke 17 is inserted in the bobbin 16. By means of the main body moving device 20 for fixing the main body of the probing head of the present invention described in FIG. Position the tip. FIG. 8 is an explanatory diagram showing a state in which the tip of the probe 3 of the probing head shown in FIG. 5 is thus positioned at the inspection target portion.

The moving coil 15 on the right side in FIG.
This moving coil 15
Moving coil 15 from the yoke inserted in
Direction, the tip of the probe 3 is displaced in the a1 direction and the inspection target portion (soldered portion 101 in FIG. 8)
Contact In this state, the mounting state of the surface-mounted component already mounted on the printed board is tested in the same manner as in the conventional probing head of this type shown in FIG.

The left moving coil 15 is moved by passing an electric current through the left moving coil 15 of the moving coils shown in FIG. 8 in an appropriate direction.
Yoke 17 inserted in (not shown in FIG. 8)
The moving coil on the left side is displaced in the b direction in response to the force from, and the tip of the probe 3 is accordingly displaced in the b direction.

[0044]

As described above, according to the probing head of the present invention, the tip of the probe is once positioned slightly above and to the side of the object to be inspected, and then in the horizontal direction and slightly in the vertical direction. By displacing and contacting the tip of the probe with the portion to be inspected, there is an effect that the tip of the probe can be surely brought into contact with the portion to be inspected such as the soldered portion without deforming the probe.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embodiment of a probing head of the present invention.

FIG. 2 is a side view of FIG.

FIG. 3 is an explanatory diagram showing the relationship between the current flowing in the drive coil, the direction of the magnetic field generated by the permanent magnet, and the force received by the coil.

FIG. 4 is an explanatory diagram showing a state when the probe of the probing head shown in FIG. 1 is brought into contact with a portion to be inspected.

FIG. 5 is a perspective view showing another embodiment of the present invention.

FIG. 6 is a side view of FIG. 5;

FIG. 7 is a partial sectional view of FIG. 5;

FIG. 8 is an explanatory diagram showing a state when the probe of the probing head of FIG. 5 is brought into contact with an inspection target portion.

FIG. 9 is a perspective view showing an example of a conventional probing head of this type.

FIG. 10 is a side view of FIG. 9;

[Explanation of symbols]

 1 Arm 2 Torsion Bar 3 Probe 4 Main Body 5 Drive Coil 8 Rotating Substrate 11 Arm 12 Torsion Bar 14 Main Body 15 Moving Coil 16 Bobbin 17 Yoke

Claims (2)

(57) [Claims] 1. A mounting surface of a printed circuit board on which surface-mounted components are mounted on a flat surface is fixed upward in parallel with a horizontal plane, and above the printed circuit board and in a surface parallel to the mounting surface and the mounting surface. A surface-mounted component in which a main body fixed to a main body moving device that moves in a direction perpendicular to the main body and a probe attached to the main body are moved by the main body moving device so that the tip of the probe is mounted on the printed circuit board. Position of the probe in the vicinity of the inspection target position, and thereafter, the probe is finely moved with respect to the main body to bring the tip of the probe into contact with the inspection target point, and the measurement lead wire connected to the probe and A probing probe used to measure the electric potential between a reference potential point on the printed circuit board or the electrical resistance between the reference point on the printed circuit board and the probe. In the head, one end is fixed below the bottom surface of the main body, the direction of the longitudinal axis is parallel to the horizontal plane, the longitudinal axis is orthogonal to the bottom surface of the body, and the torsion bar has the rotational axis in the direction of the longitudinal axis. And a rod-shaped arm made of a conductive material, which is made of a conductive material and whose longitudinal axis is coaxially fixed to the other end of the torsion bar, and a semi-circular wide surface made of an insulating material. With the thin plate-shaped straight portion positioned below and parallel to the horizontal plane, the center of the semicircular semicircle coincides with the longitudinal axis of the arm and the wide surface is orthogonal to the longitudinal axis of the arm. The rotating substrate fixed in the middle of both ends of the arm in the state of being made, and the vicinity of the upper part is fixed near the other end of the arm made of a conductive material, and the longitudinal axis is orthogonal to the longitudinal axis of the arm. Tip protruding downward One or more spiral-shaped drives having a rod-shaped probe and a hollow portion formed in a flat shape along the wide surface at a position apart from the center of the semicircle on one wide surface of the rotating substrate. The coil and the body are made of a magnetic material, and the dimension of the bottom surface is larger than the dimension of the wide surface of the rotating substrate. It is formed of a side plate provided on the rotary substrate side with respect to the bottom surface and covering the rotary substrate, one end of which is fixed to a side of the side plate of the main body on which the arm is provided, and at least one wide surface side of the rotary substrate. In parallel with the longitudinal axis of the arm, the other end protrudes, and when the electric current does not flow in the drive coil, the tip portion is located near the drive coil and is formed of a magnetic material. Partly stuck One of the end faces is parallel to the plane formed by the spiral drive coil, and the portion having the maximum magnetic flux density when no current flows in the drive coil is coaxial with the center of the rotary substrate from the center of the drive coil. A permanent magnet that is located in a portion that is separated by a preset distance in the circumferential direction of a circle that passes through the center of the coil, and that generates magnetic force lines in a direction that is substantially orthogonal to the wide surface of the rotating substrate; Alternatively, a probing head having a lead wire for measurement electrically connected to the arm. 2. A printed board on which surface-mounted components are mounted on a plane is fixed at a fixed position so that a mounting surface on which the surface-mounted components are mounted is parallel and upward with respect to a horizontal plane, and above the printed board. A body fixed to a body moving device that moves in a plane parallel to the mounting surface and a direction perpendicular to the mounting surface and a probe attached to the body are moved by the body moving device to move the tip of the probe The probe is positioned in the vicinity of the inspection target point of the surface mount component mounted on the printed circuit board, and then the probe is finely moved with respect to the main body to bring the tip of the probe into contact with the inspection target point, The electric potential between the connected measurement lead wire and the reference potential point on the printed circuit board or the electric resistance between the reference point on the printed circuit board and the probe is measured. Probing used for
In the head, one end is fixed below the bottom surface of the main body, the longitudinal axis is parallel to the horizontal plane and is orthogonal to the bottom surface, and the longitudinal axis is the rotation axis, and the longitudinal direction of the torsion bar is made of a conductive material. A rod-shaped arm having a longitudinal axis coaxial with the axis and having one end fixed to the other end of the torsion bar, and a portion made of a conductive material near the other end of the arm and fixed to a portion close to the one end of the arm. A rod-shaped probe having a longitudinal axis orthogonal to the axis and the other end located below the arm, and an acute angle with respect to the vertical line in a plane orthogonal to the longitudinal axis of the arm at the middle of both ends of the arm. Two rod-shaped bobbin mounting arms, which have longitudinal directions in directions different from each other by an equal angle with respect to a vertical line and have one end fixed to the arm and have a predetermined equal length, and a cylindrical shape. A bobbin in which the cylindrical surface has a bottom outer surface of the bottom surface is parallel to the longitudinal axis of the bobbin mounting arm is fixed to the other end of the bobbin mounting arm to the end,
A moving coil wound around the circumference of the bobbin, a cylindrical portion made of a magnetic material, having an inner diameter larger than the outer shape of the moving coil, and an axial length substantially equal to the axial length of the bobbin; A cylindrical portion having an outer diameter smaller than the inner diameter of the bobbin and an axial length shorter than the axial length of the cylindrical portion, one end of the cylindrical portion, and a bottom portion that relatively fixes one end of the cylindrical portion. Two yokes into which the open ends of the cylinders are coaxially inserted into the respective bobbins by a predetermined distance, and one of the end faces is coaxially fixed to the end face opposite to the bottom of the cylinders. A columnar permanent magnet having an outer diameter equal to the outer diameter of the cylindrical portion whose end surface substantially coincides with the end surface of the open end of the cylindrical portion of the yoke, and the main body includes the bottom surface and the upper edge of the bottom surface. Fixed to the bottom of the two yokes Note that when the moving coil is not energized, it comprises a side plate that fixes the open end of the cylindrical portion of the yoke at a position inserted coaxially with the bobbin by a predetermined length in the bobbin, the probe or the side plate. A probing head having a measurement lead wire electrically connected to the arm.