JPH1062480A - Board tester - Google Patents

Abstract

PROBLEM TO BE SOLVED: To perform the measurement and test of a printed wiring board more reliably by increasing the allowance of probing shift and to attain more reliable measurements. SOLUTION: When conductor parts 41, 42 are short-circuited in a conductor pattern arranged as shown at (A), designated probes 21a, 21b (hereinafter, referred to probe 21a or the like) are subjected to warp of a bare board or the like and touch not a measuring part P but a part P1 not present on the conductor part 41. At that time, the probes 21a are not conducted and not in contact with the conductor part 41 but when the probes 21a are conducted they are in contact with the conductor part 41. Furthermore, when the probes 21, 23 are conducted, a decision is made that the conductor parts 41, 42 are short- circuited. When the probe 21a touches the conductor part 41, the image of the center line of the probe 21 projected onto the X-Y coordinate projection plane starting from the touching point makes an angle of 35 deg. with respect to the X axis and the allowance is increased thus enlarging the touching range.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for automatically controlling the measurement and inspection of a conductor pattern or the like disposed on a printed wiring board, in particular, a printed wiring board alone (hereinafter, referred to as a bare board) without causing erroneous judgment. The present invention relates to a substrate inspection apparatus that can be performed by moving a probe.

[0002]

2. Description of the Related Art For example, in a bare board or the like, a measurement test for a short circuit (short circuit) and an open circuit (disconnection) of a conductor pattern is performed by moving a probe based on coordinate data of a measurement site inputted in advance and moving the tip of the probe. Inspection devices that perform the measurement by bringing the measurement site into contact are well known. Specifically, this type of inspection apparatus includes four heads that hold a probe that comes into contact with a bare board or the like to be inspected so as to be able to move up and down. Some are independently moved on an XY coordinate plane formed by the upper X axis and the Y axis orthogonal thereto, based on the XY coordinate data on the bare board with which the probe contacts. When performing a measurement test on such a short or open of a conductor pattern or the like, it is necessary that the probe surely comes into contact with a measurement site of the conductor pattern or the like to obtain a reliable measurement result without erroneous determination. Is required.

FIG. 11 is a schematic diagram schematically showing the positional relationship between each head and probes attached to each head in a conventionally known substrate inspection apparatus.
01 to 104 can move independently on the XY coordinate plane as described above.
Are attached with probes a to d at an angle to an axis perpendicular to the XY coordinate plane. The directions of the projected images formed on the XY coordinate projection planes of the probes a to d and the probes a to d
The probe a and the probes b and d are arranged so that the directions of the projection images formed on the projection surface are orthogonal to each other, for example, when the probe a is viewed, and the probes a to d Are arranged so that the direction of the projection image formed on the XY coordinate projection plane is at 45 degrees with respect to the X axis or the Y axis. Then, the probes a to d arranged as described above perform a measurement inspection regarding a short circuit and an open circuit pattern on the XY coordinate plane.

The conductor portion of the conductor pattern on the XY coordinate plane has a rectangular shape in the X-axis direction as shown in FIG. 12 or a rectangular shape in the Y-axis direction.
The smallest short side of such a conductor is about 0.1
mm and the minimum distance between the centers of both conductors is
It is about 0.2 mm, which is extremely small. Therefore, at the time of measurement and inspection, it is necessary to make sure that the probe is in contact with such a conductor portion, and to judge, for example, whether the conductor pattern is short or open.

[0005]

However, the conventional board inspection apparatus has a problem that the measurement and inspection cannot be reliably performed, and the above-described reliable determination as to whether the short circuit or the open circuit is acceptable cannot be performed. There was a problem. That is, when the quality of the conductor pattern on the XY coordinate plane is determined, for example, a predetermined probe a and c and a predetermined measurement site, that is, P2 of the conductor portions 105 and 106 of the conductor pattern are determined by a program. , Q2 (FIG. 12 (A))
Is specified, the bare board or the like on which the conductor pattern is arranged has a certain amount of warp, and is accompanied by deformation due to the contact of the probe, and is further affected by a positioning error in the head or the like. , C come into contact with a part outside the part without actually contacting the part. By the way, when the probes a and c make contact with the conductors 105 and 106, the allowable values of the so-called probing deviations are approximately the short sides of the conductor when converted into the direction of the probe which forms 45 degrees with respect to the X axis and the Y axis. / SIN
(45 °) or the short side of the conductor part / COS (45 °), and the shortest side is 0.1 mm when it is the smallest, so it is considered to be 0.14 mm at this time. However, the numerical value of such an allowable value is equal to the measurement error of .0 in each of the X-axis and Y-axis directions, which occurs during actual measurement.
It is clear that this is not enough when 1 mm and the wear and deterioration of the apparatus are taken into consideration. For this reason, the conductor may come in contact with the conductor part without coming into contact with the conductor part, and the measurement and inspection may not be performed reliably.

As described above, the center-to-center distance between the conductors 105 and 106 is extremely small.
There is a case where a short circuit occurs as shown in FIG. However, the conventional device may not be able to detect this,
In some cases, reliable measurement results could not be obtained. That is, as described above, the P of the conductors 105 and 106
Even if 2 and Q2 are specified, the bare board or the like on which the conductor pattern is arranged has a certain amount of warp, is accompanied by deformation due to contact with the probe, and is further affected by positioning errors in the head and the like. , Probes a and c
Actually, for example, the probe a may come into contact with P3 which is not on the conductor portion 105 without actually contacting that portion. In such a case, in the conventional apparatus, there is no conduction between the probes a and c, even though the conductor is short-circuited. Therefore, "the conductor is not short-circuited", that is, "good".
And a reliable determination result could not be obtained.

Further, in addition to such a problem, an electric motor used as a driving means for driving four heads is
Even if the motor belongs to an electromagnetic motor, such as a commutator motor or a rotating magnetic field motor, the size of the apparatus itself may be increased, and as a result, the inspection efficiency may be reduced. That is, in such a commutator motor or a rotating magnetic field motor, the head cannot be directly driven to move on the XY coordinate plane, but is driven via a moving mechanism including a ball screw and a linear guide. Therefore, such a moving mechanism must be provided for each head. Therefore, as long as this type of motor is used, the size of the apparatus itself cannot be avoided, and the inspection efficiency may be reduced.

An object of the present invention relates to a measurement and inspection of a printed wiring board, and to provide a board inspection apparatus capable of performing more reliably by increasing an allowable value of a probing deviation and obtaining a reliable measurement result. It is in. Also,
It is an object of the present invention to provide a board inspection apparatus capable of improving the inspection efficiency by reducing the size of the apparatus itself, in addition to the above objects.

[0009]

In order to solve the above-mentioned problems, a board inspection apparatus according to the present invention comprises a pair of probes which can simultaneously contact a printed wiring board to be inspected and which are opposed to each other at a predetermined angle. A plurality of heads which are held so as to be able to move up and down, and these heads are independently arranged on an XY coordinate plane formed by an X axis on the apparatus main body and a Y axis orthogonal thereto, on a printed wiring board with which a probe is in contact. Driving means for moving based on the XY coordinate data of
In addition, the direction of the projection line formed on the XY coordinate projection plane of the center line of the probe, that is, the straight line bisecting the predetermined angle, and the X of the center line of the probe adjacent to the probe
-Each probe is arranged so that the direction of the projected image formed on the Y coordinate projection plane crosses each other at a predetermined angle, and these probes are inclined by a predetermined angle with respect to an axis perpendicular to the XY coordinate plane. In addition, each probe is held so as to protrude toward the probe facing the probe.

[0010] The probe provided in the head of this device is
A pair of probes arranged opposite to each other at a predetermined angle starting from a tip portion that comes into contact with a printed wiring board to be inspected, and can be simultaneously contacted with the board. Such a predetermined angle is
It is preferable to make the size as small as possible without interfering with each other, and it is necessary to determine the size in consideration of a manufacturing surface and an assembly surface. When each probe is constituted by a pair of probes in this way, when the probe constituted by the pair comes into contact with the substrate, whether or not the probe is in contact with the substrate depends on whether or not the probe is conducting. Therefore, it is possible to obtain a reliable determination result without causing an erroneous determination such as “the conductor part is short-circuited but not short-circuited” as described above. Then, the direction of the projected image formed on the XY coordinate projection plane of the center line of the probe constituted by such a pair, and the XY coordinate projection of the center line of the probe adjacent to the probe The direction of the projected image formed on the surface is arranged to cross each other at a predetermined angle. For example, when the number of heads is eight, the cross angle is 45 °, and the X of the center line of a certain probe is X. Assuming that the inclination angle with respect to the axis is θ, the inclination angle of the probe adjacent to the probe with respect to the X axis is
(45 ° −θ) or (45 ° + θ), and when there are six heads, the crossing angle is 60 °, and the inclination angle of the center line of a certain probe with respect to the X axis is θ. The inclination angle is (60 ° −θ) or (60 ° + θ),
Further, when there are four heads, the above-mentioned crossing angle is 90 °, and when the inclination angle of the center line of a certain probe with respect to the X axis is θ, the inclination angle is (90 ° −θ) or (90 °). +
θ). Therefore, in any case where the number of heads is 8, 6, or 4, whether the longitudinal direction of the object to be measured on the substrate, for example, the conductor portion of the conductor pattern is arranged in the X-axis direction,
Alternatively, by selecting an appropriate probe from among the probes attached to the head according to whether the probe is arranged in the Y-axis direction, the allowable value of the above-described probing deviation is increased, and the contact range can be expanded and the measurement can be reliably performed. . By the way, even in the case where the number of heads is two or three, it is possible to reliably measure the substrate having the arrangement state of the object to be measured by increasing the allowable value.

Furthermore, each probe is inclined at a predetermined angle with respect to an axis perpendicular to the XY coordinate plane.
It is preferable that such an angle be as vertical as possible within a range that does not cause interference between the probes or the heads on which the probes are mounted. Further, each probe forms a required included angle with the probe facing each other,
It is projected from the head and held by the head. Such an included angle can prevent interference between the probe or the head as well as the measurement object even when performing a measurement inspection of a printed wiring board. It is preferable to make the size as small as possible in order to perform stable and reliable measurement and inspection. Here, the term "opposite" means opposing each other, and also includes a method of opposing the probes as in the case of three heads.

Further, the substrate inspection apparatus of the present invention includes four heads, and arranges probes mounted on these heads such that the directions of projected images of their center lines are orthogonal to each other. The direction of the projection image formed on the XY coordinate projection plane of each center line is 3 with respect to the X axis or the Y axis.
It is formed at 5 degrees or 55 degrees. When the center lines of the probes are arranged so as to form such an angle, the orientation of the projected image is arranged on the substrate as compared with the conventional one in which the direction of the projected image is formed at 45 degrees with respect to the X axis or the Y axis. In accordance with the determined arrangement state of the measurement target, the allowable value of the probing deviation is increased, so that the contact range can be expanded and the measurement can be reliably performed. Actually, when the conductor is formed at 35 degrees or 55 degrees, in the case of the above-described conductor, the allowable value is approximately the short side of the conductor / SIN (35 °) or the short side of the conductor / COS (5 °).
5 mm) and the short side of the conductor is 0.1 mm as described above.
Then, since it is 0.17 mm at this time, the contact range is increased by about 25% as compared with the above-mentioned conventional allowable value, and the measurement can be performed more reliably. Note that, when the tip portions of the paired probes come into contact with the conductor portion, strictly speaking, they do not come into contact with each other on the projected image formed on the XY coordinate projection plane of the center line of the probe. This is because the two end portions are coated with an insulating coating material and are held so that the two end portions come into contact with each other through the coating thickness. However, since the coating thickness is at most several tens of microns, the error can be regarded as infinitely small even if it is calculated as the contact on the projected image when calculating the allowable value.

Further, in the substrate inspection apparatus of the present invention, the driving means for moving the head electromagnetically engages the mover with the head mounted on the platen corresponding to the stator of the rotary motor, and moves on the platen surface. The motor is constituted by a planar motor. The planar motor referred to here is a linear DC motor or a linear pulse motor, which is obtained by cutting out a rotary motor and developing it in a plane. As a specific form, there is a linear three-phase surface motor belonging to a linear pulse motor. The basic configuration of such a motor is such that a platen corresponding to a stator of a rotary motor and a mover on which a head is mounted are electromagnetically engaged with each other. On the opposing mover, an X-direction movable yoke and a Y-direction movable yoke composed of one permanent magnet and a pair of yokes arranged on both sides of the permanent magnet are arranged orthogonal to each other, and wound around the yoke. When a three-phase pulse current is supplied to the coil, the movable yoke in the X direction and the movable yoke in the Y direction receive a force based on the so-called Fleming's left-hand rule, whereby the movable element moves on the XY coordinate plane of the platen surface. To do
At this time, high-pressure air acts against the suction force between the X-direction movable yoke or the Y-direction movable yoke and the platen so that the mover floats on the platen surface.

There is a linear surface motor as a planar motor. The linear surface motor is composed of a movable element facing the magnetic pole teeth group provided on the platen, one permanent magnet and yokes arranged on both sides of the permanent magnet. X-direction movable yoke and Y-direction movable yoke are arranged at right angles to each other,
By supplying a pulse current having a phase shift of 90 degrees to the coil wound around the yoke, the mover moves on the XY coordinate plane of the platen surface. A flat motor having a simple configuration may be used. The use of a planar motor that can directly drive the mover with the head mounted thereon eliminates the need for a moving mechanism composed of a ball screw, linear guide, etc., thereby reducing the size of the device itself and improving inspection efficiency. Can be. In addition, there is no mechanical wear, and a long mechanical life can be realized with a simple mechanical structure.

Further, in the substrate inspection apparatus of the present invention, the platens are arranged at predetermined intervals and face each other in parallel. The platen corresponds to the stator as described above, and is formed of a rectangular plate made of iron or the like having a flat disk shape and having a high magnetic permeability, and the magnetic pole teeth are engraved on the rectangular plate surface. I have. Such a pair of platens, for example, are arranged such that the surfaces on which the teeth are engraved face each other, and the two surfaces are separated by a predetermined distance and arranged in parallel with each other, and a head is provided on each surface. If the movers with the armatures are engaged with each other so that they can move on each surface, measurement inspection can be performed from both sides of the substrate, further improving the inspection efficiency. Can be achieved.

[0016]

FIG. 1 shows an example of an embodiment of the present invention.
This will be described with reference to FIGS. The board inspection apparatus 1 according to the present embodiment is configured such that the four heads 2 to 5 are mounted on a base 1a of the apparatus main body.
It has a driving means for independently moving on an XY coordinate plane formed by the upper X axis and a Y axis orthogonal thereto, and the driving means comprises arms 6 to 6 for supporting the respective heads 2 to 5 respectively. 9 for moving the arms 6 to 9 along the linear guides 10a and 11a, and drive motors 12 to 15 and arms for driving the arms 6 to 9 in the X-axis direction. 6 to 9 are respectively driven in the Y-axis direction. The rotation of the drive motors 12 to 19 is controlled by the arms 6 through ball screws and the like provided on the moving mechanisms 10 and 11.
-9, so that each head 2-5 has X
It can move in the axial direction or the Y-axis direction, respectively.
However, when the transport device places a bare board (not shown), which is an object to be measured, and carries it to the measurement position on the base 1a, the heads 2 to 5 are driven by the driving means, and
Probes 21 and 2 attached to heads 2 to 5, respectively
4 is moved to the measurement site of the bare board based on the previously programmed XY coordinate data on the bare board by the respective motors (for example, the motor 26 for the probe 21 in FIG. Is performed. By the way, the drive motors 12 to 19 of the drive means
Is a DC motor belonging to a commutator motor or a step motor belonging to a rotating magnetic field motor, and moves each of the heads 2 to 5 to a predetermined measurement site by performing pulse control or the like by a semiconductor switching device.

FIG. 2 shows the positional relationship between the heads 2 to 5 and the probes 21 to 2 provided in these heads 2 to 5, respectively.
4 is enlarged and shown on the XY coordinate projection plane. As described above, the heads 2 to 5 are respectively moved in directions orthogonal to each other on the XY coordinate plane, but as shown in FIG. Are arranged at right angles to the center lines of the heads 2 to 5 adjacent to the head 2. Of these heads 2 to 5, for example, when the head 2 is viewed, the center line is 35 degrees with respect to the X axis. , 55 degrees with respect to the Y axis. On the other hand, the probes 21 to 24 provided in the heads 2 to 5, respectively,
A pair of probes referred to as a so-called twin probe, for example, the probe 21 is composed of probes 21a and 21b, and the pair of probes 21a and 21b has its tip as a starting point, as described later in detail. A predetermined angle, that is, 30 degrees, is arranged opposite to each other, and the center line thereof, that is, a straight line bisecting the 30 degrees, is arranged in a plane including the center line of the head 2. . Therefore, the directions of the projected images formed on the projection plane of the center lines of the probes 21 to 24 and the probes 21 to
The orientation of the projection image formed on this projection plane at the center line of 24 is arranged so as to be orthogonal to each other, and the projection image formed on this projection plane at the center line of the probe 21, for example. Is 35 degrees with respect to the X axis and 55 degrees with respect to the Y axis.

FIG. 3A is a side view showing a state in which the probe 21 is mounted on the head 2 of the heads 2 to 5. The head 2 is provided with probes 21a and 2a in a housing 25 attached to the tip of the arm 6 (FIG. 1).
1b, a pulley 2 driven through a timing belt 27 by the motor 26
8 and 29 are accommodated, and an LM guide 30 is attached along the right housing side surface 25a in the figure. A bracket 31 is fixed to a belt 27a between the pulleys 28 and 29, and one end of the bracket 31 is attached. Protruding from a slit (not shown) provided on the right housing side surface 25a,
It is locked to 2. A probe mounting body 33 on which the probes 21a and 21b are mounted is mounted on the holder 32 (only the probe 21a is shown in the figure), and the holder 32 is provided perpendicular to the XY coordinate plane. By sliding on the guide rail 30,
The probes 21a and 21b move up and down.

FIG. 4 is an exploded perspective view showing the probe mounting body 33 and the probes 21a and 21b mounted on the mounting body 33. As shown in the figure, the probes 21a and 21b are respectively composed of T-shaped base members 34a and 34b and end members 35a and 35b bent down from the base members 34a and 34b and hanging downward. ing. Then, the base member 34 a is the first member of the probe mounting body 33.
The base member 34b is fitted to the slot formed by the probe guide 36 and the second probe guide 37 and the slot formed by the first probe guide 36 and the third probe guide 38 with a predetermined fitting tolerance. It is loosely inserted and slidably held along these slots.
However, in the present embodiment, both the slot portions are formed so as to have a taper angle of 30 degrees.
1a and 21b, as shown in FIG.
5a and 35b are arranged at an angle of 30 degrees with respect to each other starting from the tips of the tips, and their tips are arranged so as to intersect at the center line, that is, at a point on a straight line bisecting the 30 degrees. Is done. However, FIG. 3B is a sectional view taken along line WW of FIG. 3A. However, actually, the tip portion formed sharply at a taper angle of 30 degrees similar to the slot portion is coated with an insulating coating material so that both tip portions come into contact with each other via the coating film. , The two tips are separated by their coating thickness, ie, approximately 15 microns, and do not intersect at a point on the centerline.

The probe 21 includes a probe 21a,
The end members 35a and 35b of the probe 21b are held so as to protrude from those (not shown) of the probes 23a and 23b of the probe 23 facing the probe 21, and the end members 35a and 35b -Formed substantially perpendicular to the axis perpendicular to the Y coordinate plane. This aspect is exactly the same for the other probes 22 to 24, and therefore, the included angle formed between each of the probes 21 to 24 and each of the probes 21 to 24 facing each other. In the present embodiment, for example, The included angle between the end member 35a of the probe 21a and that of the probe 23a or between the end member 35b of the probe 21b and that of the probe 23b is substantially zero degree. By the way, a spring 39 for urging the probes 21a, 21b in the protruding direction is attached to the upper ends of the base members 34a, 34b by a spring retainer 40, whereby the tips of the end members 35a, 35b are measured. The object is reliably brought into contact with the object, and when the object comes into contact with the object, a force exceeding a certain level is not applied to the object.

Next, a case where a measurement inspection is performed using the present apparatus will be described with reference to the drawings. First, on the bare board, as shown in FIG. 5A, a conductor pattern in which the longitudinal direction of the conductor portions 41, 42 is arranged in the X-axis direction is short-circuited to the conductor portions 41, 42 constituting the conductor pattern. A description will be given of the measurement inspection in the case where there is an existing part. When the bare board on which such a conductor pattern is arranged is carried into a predetermined position on the base 1a by the carrier, the measurement sites P and Q programmed in advance, that is, the conductor portion 4
Based on the XY coordinate data of the first and second X-Y coordinates, the heads 2 and 4 having the probes 21 and 23 mounted thereon are designated by the driving means, and the probes 21 and 23 are further moved by the motor 26 and the like to the above-mentioned parts. , And a measurement inspection regarding the quality of the conductor pattern is performed. At this time,
The tips of the probes 21a and 21b constituting the probe 21 and the probes 23a and 23b constituting the probe 23 should come into contact with P and Q, respectively, as described above. And so on, for example, the probes 21a and 21a
b may come in contact with P1 not on the conductor portion 41. However, it is assumed that the probes 23a and 23b are in contact with Q.

In such a case, the probes 21a and 21b
Since there is no continuity between the probes, it is determined that the probes 21a and 21b are not in contact with the conductor portion 41, and the measurement site P + ΔP in which the error due to the influence of the warp or the like is considered is specified again, and The correction of P + ΔP is repeated until contact with the conductor portion 41, that is, until conduction between the probes 21a and 21b is detected. After the correction is repeated, when the probes 21a and 21b come into contact with the conductor portion 41, there is continuity between them, so it is determined that the probe has contacted the conductor portion 41, and there is a short-circuited portion in the conductor portions 41 and 42. And probes 21 and 23 as well as between probes 21a and 21b and between probes 23a and 23b.
Since continuity is detected even between them, it is determined that there is a short-circuited portion in the conductor portions 41 and 42.

When the probes 21a and 21b and the probes 23a and 23b come into contact with the conductor portions 41 and 42, the contact points formed on the XY coordinate projection plane of the center lines of the probes 21 and 23 are set. The directions of the projection images as starting points are both 35 degrees with respect to the X axis. Therefore, the above tolerance is approximately equal to the short side of the conductor / SIN (3
5 °) or the short side of the conductor / COS (55 °),
Since the direction of the projection image can be made larger than that of the related art in which the direction of the projected image is 45 degrees, the probes 21a and 21b and the probe 23
a and 23b can be reliably brought into contact with the conductor, and, as described above, even when it is determined that the conductor 41 is not in contact and the correction of P + ΔP is repeated,
The probe 21a, 2
1b can be brought into contact with the conductor portion 41, so that the efficiency of measurement and inspection can be improved.

Next, as shown in FIG.
44 is a conductor pattern in which the longitudinal direction is arranged in the Y-axis direction,
A case where there is a short-circuited portion in the conductor portions 43 and 44 constituting such a conductor pattern will be described. In this case, for example, the designated probes 22, 24 move to the measurement sites R and S, respectively, and the tips of the probes 22a, 22b constituting the probe 22 and the probes 24a, 24b constituting the probe 24 are R and S should come into contact with each other, but for the above-mentioned reason, for example, the probes 22a and 22b may come into contact with each other at R1 which is not on the conductor 43, and in this case, the probe 2
Since there is no continuity between the probes 22a and 22b,
2b is determined not to be in contact with the conductor 43, and correction of R + ΔR is performed until the probes 22a and 22b contact the conductor 43, that is, until conduction between the probes 22a and 22b is detected, as described above. repeat.

After the correction is repeated, the probes 22a, 22
When the conductor 2b comes into contact with the conductor 43, it is determined that the conductor has contacted the conductor 43 because there is continuity therebetween.
If there is a short-circuit at 3, 44, the probe 2
Since conduction is detected not only between the probes 2a and 22b and between the probes 24a and 24b, but also between the probes 22 and 24, it is determined that there is a short-circuited portion in the conductor portions 43 and 44. Then, the probes 22a and 22b and the probe 2
When the conductors 4a and 24b make contact with the conductors 43 and 44, the directions of the projection images of the center lines of the probes 22 and 24 starting from the contact point formed on the XY coordinate projection plane are both set. Since the angle is 55 degrees with respect to the X axis, the above-mentioned allowable value is approximately the short side of the conductor portion / SIN (35 °) or the short side of the conductor portion / COS (55 °). Since the direction is larger than that at 45 degrees, the probe 22
a, 22b and the probes 24a, 24b can be surely brought into contact with the conductor, and the probe 22a, 22b can be brought into contact with the conductor 43 by rough correction, so that the efficiency of the measurement and inspection can be improved. .

In the above embodiment, the case where a DC motor or a step motor is used as the drive motors 12 to 19 of the drive means has been described. In the following embodiment, a case where a linear three-phase surface motor (plane motor) is used instead of such a DC motor and the like and the heads 2 to 5 are moved by such a motor will be described with reference to FIGS. . 6 to 10, FIGS.
The same reference numerals are given to the same components as those described above, and the description thereof is omitted. As shown in FIG. 6, in the present apparatus 50, a pair of platens 51 and 52 made of a flat plate and made of a rectangular plate made of iron or the like having a high magnetic permeability.
The magnetic pole teeth (not shown) engraved on both the lower surface 51a of the platen 51 and the upper surface 52a of the platen 52 face each other, and the lower surface 51a and the upper surface 52a are separated by a predetermined distance. The movers 61a to 61 are arranged in parallel, and the heads 53 to 56 are mounted on the lower surface 51a.
64a, and movers 65a to 68a having heads 57 to 60 mounted on the upper surface 52a are electromagnetically engaged with each other, and between the movers 61a to 68a and each of the surfaces 51a, 52a. The three linear three-phase surface motors 61 to 68 are configured. In the apparatus 50, a bare board (not shown), which is an object to be measured, is carried by the transfer device between the lower surface 51a and the upper surface 52a separated by a predetermined distance, that is, between the heads 53 to 56 and the heads 57 to 60. It is supposed to be.

Here, the structure and operation of the motors 61 to 68 will be described with reference to FIGS. In the following description, the description is made for the motor 61, but the same applies to the other motors 62 to 68. Mover 61a
In FIG. 9, two sets of an X-direction movable yoke 69 and a Y-direction movable yoke 70 are arranged in a manner as shown in FIG. 9 so as to face the magnetic pole teeth group formed on the lower surface 51 a of the platen 51. Each of the X-direction movable yoke 69 and the Y-direction movable yoke 70 is composed of one permanent magnet 71 and a pair of yokes 72, 73 arranged on both sides of the permanent magnet 71. Also, the yokes 72 and 73 are
Three legs 72a-72c and 73a-73c are provided,
These legs are spaced apart from each other by a predetermined distance and are opposed to the magnetic pole teeth group.
J2 direction (X-axis direction) and K1-K2 direction (Y-axis direction)
Is substantially the same size as each tooth width of the magnetic pole teeth group.

By the way, the legs 72a to 72c have U
A phase coil 74, a V-phase coil 75, and a W-phase coil 76 are wound, and these coils have a phase of 12
A three-phase current shifted by 0 degrees is supplied. Also, the legs 73a
73c include a U-phase coil 77, a V-phase coil 78 and a W-phase coil 78.
Each of the phase coils 79 is wound, and a similar three-phase current is supplied to these coils. The arrangement pitch of the legs 72a to 72c is shifted by a predetermined amount with respect to the tooth pitch of the magnetic pole teeth group in accordance with the phase shift of the three-phase current. The arrangement pitch is also shifted by a predetermined amount from the tooth pitch of the magnetic pole teeth group. Moreover, the respective currents supplied to the three-phase coils 74 to 76 are shifted by 180 degrees in phase angle corresponding to the respective currents supplied to the respective three-phase coils 77 to 79.

Next, the operation of the motor 61 will be described. In this embodiment, a pulse train proportional to the amount of movement of the housing 61a (motor 61) is input to the drive control device 80 to drive the housing 61a. That is, the drive control device 80 calculates the amount of movement, the direction of movement, and the speed of movement from the pulse train input to move the mover 61a to a desired position, and performs a three-phase shift according to the results of these calculations. Output waveform. However, the current having this waveform is supplied to the three-phase coil 74.
When the current is supplied to the coils 74 to 79, pulse width modulation (PWM) proportional to the current to be supplied to each of the coils 74 to 79 is performed. The switch circuit is controlled by the PWM on / off signal, and the power loss of each of the three-phase coils 74 to 79 is suppressed. At this time, the switch circuit is controlled to be turned on / off by PWM corresponding to the supplied current deviation, thereby preventing an overcurrent from flowing through the coils 74 to 79. The current controlled in this way is supplied to each of the coils 74 to 7.
6 and simultaneously to each of the coils 77-79.
Then, a force based on the so-called Fleming's left-hand rule acts between the legs 72a to 72c and the magnetic pole teeth group and between the legs 73a to 73c and the magnetic pole teeth group. 8 receives the force in the J1-J2 direction in FIG. 8, and the Y-direction movable yoke 70 receives the force in the K1-K2 direction in FIG.
Move on the XY coordinate plane formed on the lower surface 51a of the platen 51, and at this time, the space between the X-direction movable yoke 69 and the platen 51 or the Y-direction movable yoke 70
High-pressure air acts between the plate and the platen 51 against the magnetic attraction force, thereby causing the housing 61a to slightly float from the lower surface 51a. However, since the current supplied to the coils 74 to 76 and the current supplied to the coils 77 to 79 are shifted by 180 degrees in phase angle as described above, the X-direction movable yoke 69 and the Y-direction movable yoke 70 The above forces are not offset within. Further, switching of the moving direction of the mover 61a, that is, moving in the J1 direction in FIG.
When switching to two-direction movement or switching from the K1 direction movement to the K2 direction movement in the drawing, any two of the coils 74 to 76 are selected and the current supplied to them is selected. And replace the coil 77
Select the one corresponding to this exchange from ~ 79,
What is necessary is just to replace the electric current supplied to them.

The legs 72a provided on the yokes 72 and 73 for the purpose of increasing the driving force for moving the mover 61a.
Needless to say, a linear three-phase surface motor in which the width of the magnetic pole teeth group is reduced in accordance with the division of the magnetic pole teeth groups 72c and 73a to 73c. As described above, when the linear three-phase surface motors 61 to 68 are used as the driving means, a moving mechanism including a ball screw, a linear guide and the like is not required. Since the device can be moved upward, the size of the device 50 itself can be reduced, and as a result, the inspection efficiency can be improved. In addition, there is no mechanical wear, and a long mechanical life can be realized with a simple mechanical structure. Further, in the present apparatus 50, the platens 51 and 52
Since the configuration in which the bare board is disposed therebetween is employed, measurement and inspection can be performed from both sides of the bare board, and the inspection efficiency can be further improved.

The heads 53 to 56 mounted on the movers 61a to 64a and the heads 57 to 60 mounted on the movers 65a to 68a are configured to be mounted on the movers 61a to 68a. Except for the above heads 2-5
Therefore, for example, as shown in FIG. 10, the center line of the head 53 mounted on the mover 61 a on the XY coordinate plane of the lower surface 51 a of the platen 51 is 35 ° with respect to the X axis. The mover 62 is set at 55 degrees with respect to the Y axis and at 55 degrees with respect to the X axis and 35 degrees with respect to the Y axis.
a, 64a, respectively, so that the center line of the head 53 and that of the heads 54 and 56 are arranged to be orthogonal to each other. In addition, in the same figure, the cable bears 81-84 whose one ends are respectively fixed to the movers 61a-64a are flexible pipes arranged so as to be able to follow the movement of the movers 61a-64a. Houses a cable for supplying current to the coil and an air hose for supplying high-pressure air. As described above, the probes 21 to 24 attached to the heads 53 to 56, respectively,
The above-mentioned center line, that is, a straight line bisecting a predetermined angle of 30 degrees is mounted in a plane including the center lines of ~ 56, and the X of the center line of the probes 21 to 24 is set. -The direction of the projection image formed on the Y coordinate projection plane and the direction of the projection image formed on this projection plane of the center line of the probes 21 to 24 adjacent thereto are arranged so as to be orthogonal to each other. Also, in the probes 21 to 24 attached to the heads 57 to 60, the projection images are arranged in the same manner on the XY coordinate plane of the upper surface 52a of the platen 52 so that the directions of the projection images are orthogonal to each other. Is done. Thus, in the present device 50, similarly to the above-described device 1, for example, in a measurement inspection when there is a short-circuited portion in the conductor portions 41, 42 or 43, 44 configuring the conductor pattern as shown in FIG. In addition, the allowable range of the probing deviation can be increased to broaden the contact range, more reliably perform the measurement, and obtain a reliable measurement result.

[0032]

According to the board inspection apparatus of the present invention, the measurement and inspection of a printed wiring board can be performed more reliably by increasing the allowable value of the probing deviation, and a reliable measurement result can be obtained. Further, according to the substrate inspection apparatus of the present invention, the apparatus itself can be reduced in size and the inspection efficiency can be improved, and further, there is no mechanical wear portion,
Long service life can be realized with a simple mechanical structure.

[Brief description of the drawings]

FIG. 1 is a plan view schematically showing a substrate inspection apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged view showing an arrangement relationship of four heads in FIG. 1 on an XY coordinate projection plane.

FIG. 3 is a side view showing a state where a flow is mounted on the head of FIG. 1;

FIG. 4 is an exploded perspective view showing a state where a flow is mounted on the holder of FIG. 3;

FIG. 5 is an explanatory diagram of a case where a conductor pattern is measured and inspected using the apparatus of FIG. 1;

FIG. 6 is a front view schematically showing a substrate inspection apparatus according to another embodiment of the present invention.

FIG. 7 is a schematic configuration diagram of the linear three-phase surface motor of FIG. 6;

8 is a perspective view showing a state in which the X-direction movable yoke and the Y-direction movable yoke of FIG. 7 are arranged on a platen surface.

FIG. 9 is a perspective view showing an arrangement state of an X-direction movable yoke and a Y-direction movable yoke of FIG. 7;

FIG. 10 is a schematic view of the arrangement relationship of four heads, as viewed in the direction of arrows ZZ in FIG. 6;

FIG. 11 is a schematic diagram illustrating an arrangement relationship between a conventional head and a probe mounted thereon on an XY coordinate projection plane.

FIG. 12 is an explanatory diagram of a case where a conductor pattern is measured and inspected using a conventional apparatus.

[Explanation of symbols]

1,50 Board inspection apparatus 2-5, 53-60 Head 21-24 Probe 21a, 21b A pair of probes 22a, 22b A pair of probes 23a, 23b A pair of probes 24a, 24b A pair of probes 51, 52 Platen 51a Lower surface (platen) 52a Upper surface (of platen) 61-68 Linear three-phase surface motor (plane motor) 61a-68a Mover

Claims (4)

[Claims] A plurality of heads for holding a probe for contacting a printed wiring board to be inspected so as to be able to move up and down;
The head is independently moved on an XY coordinate plane formed by an X axis on the apparatus main body and a Y axis orthogonal thereto, based on XY coordinate data on a printed wiring board with which the probe contacts. In the board inspection apparatus provided with driving means for causing the probe, the probe can be simultaneously contacted with the printed wiring board, and is configured by a pair of probes facing each other at a predetermined angle. X of a straight line bisecting (hereinafter referred to as a center line)
-Each probe so that the direction of the projection image formed on the Y coordinate projection plane and the direction of the projection image formed on the projection plane of the center line of the probe adjacent to this probe intersect each other at a predetermined angle. And each probe is referred to as the XY
A substrate inspection apparatus characterized by being inclined by a predetermined angle with respect to an axis perpendicular to a coordinate plane, and holding each probe so as to protrude toward a probe facing the same. 2. The apparatus according to claim 1, further comprising a plurality of said heads, wherein said probes are arranged such that the directions of projected images of their center lines are orthogonal to each other, and are formed on said XY coordinate projection plane of said respective center lines. Direction of the projected image is 35 with respect to the X axis or the Y axis.
The substrate inspection apparatus according to claim 1, wherein the substrate inspection apparatus is formed at an angle of 55 degrees. 3. A planar motor comprising: a driving means for moving the head, wherein a movable element on which the head is mounted is electromagnetically engaged with a platen corresponding to a stator of a rotary motor, and is moved on the platen surface. The substrate inspection apparatus according to claim 1, wherein: 4. The substrate inspection apparatus according to claim 3, wherein the platens are arranged at predetermined intervals and face each other in parallel.