JP5714401B2 - X-ray inspection equipment - Google Patents

Description

  The present invention relates to an X-ray inspection apparatus, and more specifically, X-rays indicate the mounting state of electronic components such as BGA (Ball Grid Array) and CSP (Chip Scale Package), which are reduced in size and density, on a substrate (mounting substrate). The present invention relates to an X-ray inspection apparatus for inspection.

  There is a remarkable improvement in the performance of personal computers (PCs), portable terminals, video / audio devices, and the like. One of the cores and the driving force is to increase the density of the mounting substrate, which is the core part of these devices. In particular, in recent years, many IC packages, such as BGA and CSP, which are excellent in multi-terminal use have been adopted.

  However, packages such as BGA and CSP are very good at increasing the number of terminals, but due to their structure, when they are mounted on a printed circuit board, the joint between the package and the printed circuit board is hidden by the package body. It is difficult to confirm the quality of the bonded state by visual inspection as well as optical appearance inspection.

  In view of this, X-ray inspection, which has a strong property of transmitting through an object, is attracting attention. As an inspection apparatus using X-rays, an X-ray fluoroscopic apparatus that obtains a fluoroscopic image of the object by emitting X-rays to the object to be examined and detecting the X-ray transmitted through the object, or a printed circuit board There is an X-ray tomography apparatus that obtains a tomographic image that is sliced in a plane parallel to the main surface.

  When using an X-ray fluoroscopic apparatus (for example, see Patent Document 1 below), an internal shape that cannot be observed from the outside can be observed as a fluoroscopic image. It is effective in detecting relatively simple failure factors such as the presence or absence of solder voids (bubbles contained in the solder joints) and the presence or absence of solder debris. However, in the X-ray fluoroscopic apparatus, it is difficult to detect a failure factor such as an open solder ball portion (floating failure) and an excessive or excessive amount of solder.

  On the other hand, when an X-ray tomography apparatus is used, it is known that, in principle, it is effective in detecting a cause of defects such as opening of a solder ball portion, solder bridge, and excessive or excessive solder. However, it is actually very difficult to detect the opening of the solder ball part clearly. Even if the quality is detected, it is difficult to detect what kind of defective state it is.

  In view of this, the present inventor has previously proposed an X-ray inspection apparatus capable of accurately and inexpensively inspecting an electronic component such as a BGA or CSP mounted on a substrate by X-ray tomography. FIG. 15 is a block diagram schematically showing the main part of the X-ray inspection apparatus disclosed in the following Patent Document 2 invented by the present inventor. In the figure, Smp indicates a sample to be examined, and the sample Smp is placed on a sample stage 1 having a transmission plate 1a that transmits X-rays at the center.

  An X-ray detector 11 having an X-ray light receiving surface I and an X-ray generator 12 configured to include the X-ray focal point S1 are opposed to each other with the sample stage 1 interposed therebetween. X-rays emitted and transmitted through the transmission plate 1a and the sample Smp are detected on the X-ray light receiving surface I of the X-ray detector 11. In the figure, T1 indicates a plane including the intersection point O1 between the optical axis OA of the X-ray emitted from the X-ray focal point S1 and the axis L1 orthogonal to the mounting surface of the sample stage 1, and the plane T1 is a tomographic plane. It becomes the imaging surface FP.

  The X-ray detector 11 is connected to the image processing unit 2, and image data (video signal) corresponding to the X-ray detected by the X-ray detector 11 is output to the image processing unit 2. . The image processing unit 2 performs signal processing such as improving the image quality, and outputs the signal processed image data to a display (not shown) or the microcomputer 3.

  The circular moving mechanism 4 is driven by receiving the rotational force from the motor M1, and maintains two points on the X-ray receiving surface I while keeping the X-ray receiving surface I parallel to the mounting surface of the sample table 1. The X-ray detector 11 is moved around the axis L1 in a circle around the axis L1 while keeping the direction of the connecting straight line in a fixed direction.

On the other hand, the circular moving mechanism 5 is driven by receiving the rotational force from the motor M2, and keeps the X-ray emission surface 12a in parallel with the mounting surface of the sample table 1 and has 2 on the X-ray emission surface 12a. The X-ray generator 12 is moved in a circle around the axis L1 with the distance r from the axis L1 to the X-ray focal point S1 as the diameter while maintaining the direction of the straight line connecting the points in a constant direction (that is, The X-ray focal point S1 is rotated about the axis L1).
The motors M1 and M2 are controlled by the microcomputer 3, and the X-ray focal point S1 is controlled to rotate around the axis L1 with a phase difference of 180 ° in synchronization with the circular movement of the X-ray detector 11. It is like that.

  The horizontal movement mechanism 6 is driven by the rotational force from the motor M3, and moves the X-ray detector 11 in parallel with the mounting surface of the sample stage 1. The vertical movement mechanism 7 is a motor M4. The X-ray generator 12 is moved in the direction of the axis L1. These motors M3 and M4 are also controlled by the microcomputer 3. An operation unit 8 is connected to the microcomputer 3.

The movement of the X-ray detector 11 and the X-ray focal point s1 will be described in detail with reference to the schematic diagrams shown in FIGS. 16 is a perspective view, FIG. 17 is a front view, and FIG. 18 is a plan view. The X-ray detector 11 moves in a circle around the axis L1 around the axis L1 perpendicular to the mounting surface of the sample stage (not shown). For this reason, the X-ray detector 11 does not simply rotate about the axis L1, but connects the two points on the X-ray receiving surface I while maintaining the X-ray receiving surface I on a predetermined plane. While the direction of the straight line (for example, the direction of the straight line αβ connecting the point α and the point β) is maintained in a constant direction, the linear movement is performed, for example, from I _{1 to} I ₃ around the axis L1.

On the other hand, as shown in FIGS. 16 to 18, the X-ray focal point S1 has a phase difference of 180 ° in synchronization with the circular movement of the X-ray detector 11 and moves to S1 ₁ to S1 ₃ around the axis L1. It is designed to move circularly.
When the X-ray detector 11 and the X-ray focal point S1 are circularly moved as described above, the point O1 existing on the plane T1 (the intersection of the optical axis OA of the X-ray emitted from the X-ray focal point S1 and the axis L1). The detection position of the point P1 on the X-ray light receiving surface I is always the same position as the points O1 _{1 to} O1 ₃ and the points P1 _{1 to} P1 ₃ regardless of the circular movement. This is because the geometric relationship between the X-ray focal point S1 and the X-ray light receiving surface I is kept constant with respect to the point O1.

Further, if the distance from the X-ray focal point S1 to the point O1 on the surface T1 is D1, and the distance from the points O1 ₁ to O1 ₃ on the X-ray light receiving surface I to the point O1 is d1, ΔS1 ₁ O1 ₁ P1 _{For 1} , ΔS1 ₂ O1 ₂ P1 ₂ , and ΔS1 ₃ O1 ₃ P1 ₃ , the following formula is established.
O1 ₁ P1 ₁ = O1 ₂ P1 ₂ = O1 ₃ P1 ₃ = O1P1 (D1 + d1) / D1
Incidentally, (D1 + d1) / D1 is the geometric magnification of the tomographic image.

On the other hand, for the detection position on the X-ray light receiving surface I of the point Q1 that does not exist on the surface T1, for example, on another surface T1 ′ (see FIG. 16), the X-ray focal point S1 is set to S1 ₁ to S1 ₁ . When the X-ray receiving surface I is moved from I _{1 to} I ₃ to S 1 ₃ , the point changes to points Q _{1 1} to Q _{1 3} . That is, the input position of the image of the point Q1 changes, the image is blurred, and is no longer subject to visual recognition.

  As described above, when the X-ray detector 11 (X-ray light receiving surface I) and the X-ray focal point S1 are circularly moved as described above, the Xs of points (for example, the point O1 and the point P1) existing on the surface T1. While the detection position on the light receiving surface I is constantly the same position, the detection position on the X-ray light receiving surface I of a point that does not exist on the surface T1 (for example, the point Q1) changes. Therefore, by moving the X-ray detector 11 and the X-ray focal point S1 in a circular manner as described above, only an image existing on the surface T1 (that is, a tomographic image of the surface T1) can be acquired.

  Therefore, by using this X-ray inspection apparatus, a tomographic image of the sample Smp placed on the sample stage 1 can be acquired, and it is difficult to observe from the outside, such as opening of a solder ball portion or solder bridge. This makes it possible to accurately detect the cause of defects such as insufficient or excessive solder.

  However, this type of X-ray inspection apparatus (inspecting the mounting state of an electronic component on a substrate using a tomographic image) has been difficult to perform tomography at high speed. Up to now, it has not been assumed to be used as an automatic inspection device, and is usually used in an inspection process or the like separate from an electronic component production line.

  On the other hand, in recent years, there has been a strong demand for an X-ray inspection apparatus that can be incorporated into an electronic component production line, that is, can be used as an inline automatic inspection apparatus, in order to further improve the productivity of electronic components. Investigations have also been made on speeding up of tomography, but a sufficiently fast inspection apparatus capable of in-line has not been realized.

  Therefore, the present inventor examined the speeding up of tomography, which has been difficult in the prior art, by using the above-described X-ray inspection apparatus. In the X-ray inspection apparatus described above, the X-ray focal point S1 of the X-ray generator 12 is controlled by controlling two motors, that is, the motor M1 that drives the circular moving mechanism 4 and the motor M2 that drives the circular moving mechanism 5. However, in synchronization with the circular movement of the X-ray detector 11, it is controlled so as to rotate with a phase difference of 180 °. Therefore, in order to increase the speed of tomography, the rotational force of the motors M1 and M2 is increased to control the circular movement of the X-ray detector 11 and the X-ray generator 12 to be faster. Can be considered.

In the X-ray inspection apparatus described above, the rotational force of the motors M1 and M2 is increased to speed up the circular movement between the X-ray detector 11 and the X-ray generator 12, thereby requiring one tomography. The time can be shortened to about 3 seconds.
However, in order to use the X-ray inspection apparatus as an in-line inspection apparatus, it is desirable that the time required for one tomography is about 1 second or less. Therefore, when the rotational force of the motors M1 and M2 is further increased to further increase the speed of the circular movement between the X-ray detector 11 and the X-ray generator 12, the circular movement between the X-ray detector 11 and the X-ray generator 12 is increased. As a result, blurring occurred and the synchronization was lost.

  In this phenomenon, as the circular movement speeds up, the difference in inertial force due to the mass difference between the X-ray detector 11 and the X-ray generator 12 becomes very large, and the rotational force generated by the two motors M1 and M2 This is probably because the adjustment control of (power) and sensitivity (gain) could not be performed well. If the circular movement between the X-ray detector 11 and the X-ray generator 12 is blurred and the synchronization is slightly shifted, the resolution of the tomographic image is lowered, and the image to be taken is blurred, and the tomographic image is highly accurate. It becomes difficult to obtain images.

  In conventional X-ray inspection apparatuses, the time required for one tomography is greatly reduced to a level desirable for an inline inspection apparatus (about 1 second or less) without reducing the accuracy (resolution) of tomographic images. However, it has been difficult to reduce the speed to a high-speed automatic inspection apparatus that can be inlined.

JP-A-10-239253 JP 2008-256441 A

Means for solving the problems and their effects

  The present invention has been made in view of the above problems, and can significantly reduce the time required for one tomography (less than about 1 second) without reducing the accuracy (resolution) of the tomography image. It is possible to inspect the mounting state of electronic parts such as BGAs and CSPs that are compact and high in density at high speed and with high accuracy, and can be constructed at low cost. (Mounting) An object is to provide an X-ray inspection apparatus that can be incorporated into a line.

In order to achieve the above object, an X-ray inspection apparatus (1) according to the present invention is such that an X-ray generator and an X-ray detector configured to include an X-ray focal point face each other across a sample placement surface. In the X-ray inspection apparatus, the X-ray detector is configured to detect X-rays emitted from the X-ray focal point and transmitted through the sample by the X-ray detector. The X-ray generator is mounted while the radiation surface is maintained parallel to the placement surface and the direction of a straight line connecting two points on the X-ray radiation surface is maintained in a fixed direction. A generator moving means for moving in a circle with a length from the axis to the X-ray focal point as a diameter around an axis orthogonal to the surface, and the X-ray receiving surface of the X-ray detector, While maintaining parallel, and keeping the direction of a straight line connecting two points on the X-ray receiving surface in a certain direction, The serial X-ray detector provided with a detector moving means for moving in a circular around the shaft around said axis and said detector moving means and said generator moving means, power from the drive source Are mechanically coupled via power transmission means for mechanically transmitting the power, and configured so that circular movement of the X-ray generator and the X-ray detector is performed synchronously by driving the power transmission means. And the power transmission means includes a first power transmission shaft mechanically connected to the generator moving means, a second power transmission shaft mechanically connected to the detector moving means, and the first power transmission shaft. And a third power transmission shaft that mechanically connects the first power transmission shaft and the second power transmission shaft, and the drive source is connected to any one of the first to third power transmission shafts. And the generator moving means is connected to the first power transmission shaft. A drive shaft having the shaft as an axis disposed in a support portion; a parallel shaft disposed in the support portion in parallel with the drive shaft; the drive shaft and the parallel shaft; and the X-ray generation. And a winding transmission means wound between the drive shaft and the parallel shaft, and the X-ray generator is connected via the coupling portion. The shafts such that the distance between the shaft fulcrums is the same as the distance between the shafts of the drive shaft and the parallel shaft at a position where the length is shifted in the same direction from the shaft centers of the drive shaft and the parallel shaft. It is characterized by being supported .

According to the X-ray inspection apparatus (1), the X-ray generator is a straight line connecting two points on the X-ray emission surface while maintaining the X-ray emission surface parallel to the placement surface. The X-ray focal point moves around the axis perpendicular to the placement surface while moving in a circle with the length from the axis to the X-ray focal point as a diameter. Rotate around.
On the other hand, the X-ray detector keeps the X-ray light receiving surface parallel to the placement surface and keeps the direction of a straight line connecting two points on the X-ray light receiving surface in a constant direction. , And moves around the axis in a circle around the axis.
The movements of the X-ray detector and the X-ray focal point are in principle the same as the movements of the X-ray detector 11 and the X-ray focal point S1 described with reference to FIGS. The X-ray focal point can be rotated around the axis in synchronization with a circular movement around the axis, and a tomographic image of the sample can be acquired.

Further, in the X-ray inspection apparatus (1), the generator moving means and the detector moving means for moving the X-ray detector and the X-ray focal point in a circle form the power from the drive source. And mechanically connected via a power transmission means for transmitting the power, and configured so that the circular movement of the generator movement means and the detector movement means is mechanically synchronized by driving the power transmission means. Has been. Therefore, even when the power of the drive source is increased to increase the speed of circular movement between the X-ray generator and the X-ray detector, the generator moving means and the detector moving means have the drive Since the power from the source is mechanically transmitted through the power transmission means, a synchronization shift (rotation blur) between the circular movement of the X-ray detector and the circular movement of the X-ray generator does not occur. can do.
As a result, high-accuracy tomographic images can be captured at high speed, and the time required to acquire one tomographic image can be significantly reduced to about 1 second or less, and the electronic component manufacturing (mounting) line can be obtained. A device that can be embedded (supported in-line) can be realized.

According to the X-ray inspection apparatus ( 1 ), the power transmission means is realized by a configuration in which the first, second, and third power transmission shafts are connected. A mechanism that can be mechanically transmitted to the generator moving means and the detector moving means can be realized at low cost and in a small space, and the apparatus cost can be greatly reduced.

According to the X-ray inspection apparatus ( 1 ), since the X-ray generator is pivotally supported at two different points, the movement path is specified as one. Further, since these shaft fulcrums are positions shifted in length in the same direction from the axis of each of the drive shaft and the parallel shaft, the X-ray generator is connected to the axis of the drive shaft (that is, the front axis). The length can be moved in a circle around an axis that is orthogonal to the placement surface.
Further, if the circular movement (parallel rotation) between the X-ray generator and the X-ray detector is accelerated, the influence of the dead point where no rotational force is generated cannot be ignored. Although there is a risk of blurring, according to the X-ray inspection apparatus ( 1 ), the winding transmission means is wound between the drive shaft and the parallel shaft. Rotational force) is transmitted to the parallel shaft via the winding transmission means, and the drive shaft and the parallel shaft can be driven complementarily. Therefore, it is possible to forcibly eliminate the influence of the dead point that occurs when the circular movement is speeded up, and it is possible to prevent the instantaneous rotational shake of the X-ray generator from occurring. A high tomographic image can be obtained reliably. The winding transmission means includes a rotating body (for example, a pulley member or a gear member) fixed to each of the drive shaft and the parallel shaft, and a winding member that is wound (strung) around the rotating body ( For example, a belt member or a chain member can be used.

Further, in the X-ray inspection apparatus ( 2 ) according to the present invention, in the X-ray inspection apparatus ( 1 ), the coupling portion rotates around the swing shaft portion that rotates about the drive shaft and the parallel shaft. A swing shaft portion, and a rotation plate pivotally supported by the swing shaft portion at a position shifted in length in the same direction from the axis of each of the drive shaft and the parallel shaft, the rotation plate, It is characterized by being joined to linear motion guide means that allows movement in the X-axis direction and the Y-axis direction perpendicular to the drive shaft.

According to the X-ray inspection apparatus ( 2 ), the linear motion guide means for allowing the rotation plate supported by the swing shaft portion to move in the X-axis direction and the Y-axis direction orthogonal to the drive shaft; It is joined. When the rotating plate moves circularly as described above, the movement is restricted by the linear motion guide means, so that the rotating plate is forced not to deviate from the correct trajectory of the circular movement even when the circular moving speed is increased. The tomographic image with high resolution can be controlled, the rotational movement of the rotary plate and the X-ray generator can be prevented more reliably when the circular movement is accelerated. Can be obtained more reliably.

An X-ray inspection apparatus ( 3 ) according to the present invention further includes an attachment portion to which the X-ray generator is attached in the X-ray inspection apparatus ( 1 ) or ( 2 ), and the attachment portion includes the coupling portion. Thus, at a position where the length is shifted in the same direction from the axis of each of the drive shaft and the parallel shaft, the distance between the shaft support points is the same as the distance between the drive shaft and the parallel shaft. And an axial direction moving means for moving the mounting portion in the axial direction.

According to the X-ray inspection apparatus ( 3 ), the X-ray generator is moved in the axial direction because the X-ray generator is provided with the axial movement means for moving the mounting portion in the axial direction perpendicular to the placement surface. be able to. When the X-ray generator is moved in the axial direction, the X-ray focal point can be moved in the axial direction, so that the tomographic plane can be changed without changing the geometric magnification. Therefore, the tomographic image of the sample placed on the placement surface can be obtained on different surfaces and at the same magnification, so that a three-dimensional image of the sample can be obtained.

The X-ray inspection apparatus ( 4 ) according to the present invention is a state in which the detector moving means is connected to the second power transmission shaft in any of the X-ray inspection apparatuses ( 1 ) to ( 3 ). A drive shaft centered on the shaft, a parallel shaft disposed in parallel with the drive shaft, the drive shaft, the parallel shaft, and the X-ray. A coupling portion for coupling the detector, and winding transmission means wound between the drive shaft and the parallel shaft, and the X-ray detector is interposed via the coupling portion. The distance between the shaft fulcrums is the same as the distance between the axis of the drive shaft and the parallel shaft at a position away from the axis of each of the drive shaft and the parallel shaft by a predetermined length in the same direction. It is characterized by being pivotally supported.

According to the X-ray inspection apparatus ( 4 ), since the X-ray detector is pivotally supported at two different points, the movement path is specified as one. Further, since these shaft fulcrums are positions separated by the predetermined length in the same direction from the axis of each of the drive shaft and the parallel shaft, the X-ray detector is connected to the axis of the drive shaft (that is, The axis can be moved in a circle with the predetermined length as a diameter around an axis perpendicular to the placement surface. If the predetermined length is equal to or larger than the radius of the light receiving surface of the X-ray detector, the X-ray detector can be moved around the axis in a circle around the axis. .
Further, if the circular movement (parallel rotation) between the X-ray generator and the X-ray detector is accelerated, the influence of the dead point where no rotational force is generated cannot be ignored. However, according to the X-ray inspection apparatus ( 4 ), the winding transmission means is wound between the drive shaft and the parallel shaft. Power (rotational force) is transmitted to the parallel shaft via the winding transmission means, and the drive shaft and the parallel shaft can be complementarily driven. Therefore, it is possible to forcibly eliminate the influence of the dead point that occurs when the circular movement is speeded up, and it is possible to prevent instantaneous rotation blur of the X-ray detector from occurring. A high tomographic image can be obtained reliably. The winding transmission means includes a rotating body (for example, a pulley member or a gear member) fixed to each of the drive shaft and the parallel shaft, and a winding member (for example, stretched) that is wound (strung around) the rotating body. Belt member or chain member).

Further, in the X-ray inspection apparatus ( 5 ) according to the present invention, in the X-ray inspection apparatus ( 4 ), the coupling portion rotates about the swing shaft portion that rotates about the drive shaft and the parallel shaft. A swing shaft portion, and a rotating plate pivotally supported by the swing shaft portion at a position separated by a predetermined length from the axis of each of the drive shaft and the parallel shaft in the same direction, the rotating plate, It is characterized in that it is joined to a linear guide means that allows movement in the X-axis direction and the Y-axis direction orthogonal to the drive shaft.

According to the X-ray inspection apparatus ( 5 ), the linear motion guide means for allowing the rotary plate supported by the swing shaft portion to move in the X-axis direction and the Y-axis direction orthogonal to the drive shaft; It is joined. When the rotating plate moves circularly as described above, the movement is restricted by the linear motion guide means, so that the rotating plate is forced not to deviate from the correct trajectory of the circular movement even when the circular moving speed is increased. The tomographic image with high resolution can be controlled, the rotational movement of the rotating plate and the X-ray detector can be prevented more reliably when the circular movement is accelerated. Can be obtained more reliably.
In the X-ray inspection apparatus (6) according to the present invention, an X-ray generator configured to include an X-ray focal point and an X-ray detector are arranged to face each other across the sample mounting surface. In the X-ray inspection apparatus configured to detect the X-ray emitted from the X-ray focal point and transmitted through the sample by the X-ray detector, the X-ray emission surface of the X-ray generator is described above. The X-ray generator is placed on an axis perpendicular to the placement surface while maintaining parallel to the placement surface and keeping the direction of a straight line connecting two points on the X-ray emission surface in a fixed direction. At the center, the generator moving means for moving in a circle with the length from the axis to the X-ray focal point as a diameter, and the X-ray receiving surface of the X-ray detector, while maintaining parallel to the placement surface, In addition, the X-ray detector is connected to the front while the direction of a straight line connecting two points on the X-ray receiving surface is kept constant. Detector moving means for moving around the axis in a circle around the axis, and power transmission in which the generator moving means and the detector moving means mechanically transmit power from a driving source. The X-ray generator and the X-ray detector are synchronously moved by driving the power transmission means, and the power transmission means comprises: A first power transmission shaft mechanically connected to the generator moving means; a second power transmission shaft mechanically connected to the detector moving means; the first power transmission shaft; A third power transmission shaft that mechanically couples the power transmission shaft, the drive source is connected to one of the first to third power transmission shafts, and the detector moving means is The second power transmission shaft is connected to the support portion in a connected state. A drive shaft having the shaft as an axis; a parallel shaft arranged in parallel with the drive shaft; and a coupling for connecting the drive shaft, the parallel shaft, and the X-ray detector. And a winding transmission means wound between the drive shaft and the parallel shaft, and the X-ray detector is connected to the drive shaft and the parallel shaft via the coupling portion. The shaft is supported so that the distance between the shaft support points is the same as the distance between the drive shaft and the parallel shaft at a position that is a predetermined length away from each shaft in the same direction. Yes.
According to the X-ray inspection apparatus (6), the same effects as those of the X-ray inspection apparatuses (1) and (4) can be obtained.
Further, in the X-ray inspection apparatus (7) according to the present invention, in the X-ray inspection apparatus (6), the coupling portion rotates about a swing shaft portion that rotates about the drive shaft and the parallel shaft. A swing shaft portion, and a rotating plate pivotally supported by the swing shaft portion at a position separated by a predetermined length from the axis of each of the drive shaft and the parallel shaft in the same direction, the rotating plate, It is characterized in that it is joined to a linear guide means that allows movement in the X-axis direction and the Y-axis direction orthogonal to the drive shaft.
According to the X-ray inspection apparatus (7), the same effect as the X-ray inspection apparatus (5) can be obtained.

  Further, in any of the X-ray inspection apparatuses (1) to (7), transport for placing the sample between the X-ray generator and the X-ray detector and transporting the specimen into and out of the apparatus. A belt-type transporting means for transporting the sample on a belt disposed in parallel with the transport direction of the sample, and a direction orthogonal to the transport direction of the sample. An inspection position adjusting unit that moves the belt type conveying unit, and the belt type conveying unit may include a belt interval adjusting unit that adjusts an interval between the belts arranged in parallel. .

  According to such a configuration, the belt-type transport means can transport the sample into and out of the apparatus in a state where both end portions of the sample are placed on a belt disposed in parallel with the transport direction of the sample, and the X-ray A clearance in the tomographic range can be secured on the X-ray emission surface of the generator. Further, since the belt type conveying means is equipped with the belt interval adjusting means, the interval between these belts can be adjusted so as to match the size (width) of the sample to be inspected. Furthermore, since an inspection position adjusting means for moving the belt type conveying means in a direction orthogonal to the sample conveying direction is provided, the position of the belt type conveying means is set according to the inspection position of the sample. It can be moved, and various types of specimens can be inspected appropriately.

In addition, the electronic component is inspected in-line with the X-ray inspection apparatus (1) to (7), and the electronic component is inspected in-line, based on the tomographic image data obtained. An electronic component inspection method for determining whether a product is good or defective can be realized.
According to the electronic component inspection method, by using the X-ray inspection apparatus capable of greatly reducing the time required for one tomography to about 1 second or less, the bonding state of the solder joint portion of the electronic component However, the non-defective product and the defective product of the electronic component are determined based on the tomographic image data obtained by the in-line inspection.
Therefore, it is possible to realize high-speed automatic inspection for determining the quality of electronic components based on tomographic image data on a production (mounting) line, which could not be realized so far, and dramatically increase the production efficiency of electronic components. be able to.

In addition, any of the X-ray inspection apparatuses (1) to (7) can be implemented as an electronic component manufacturing system incorporated in an electronic component manufacturing line as an automatic inspection apparatus for solder joints of electronic components. .
According to the electronic component manufacturing system, any of the X-ray inspection apparatuses (1) to (7) is incorporated in an electronic component manufacturing (mounting) line as an automatic inspection apparatus for a solder joint portion of an electronic component. Therefore, in the production line, it is possible to realize an automatic inspection for determining whether or not the electronic component is good based on the tomographic image data, and it is possible to dramatically increase the production efficiency of the electronic component.

It is the block diagram which showed roughly the principal part of the X-ray inspection apparatus which concerns on embodiment of this invention. It is explanatory drawing for demonstrating the motion of the X-ray generator in the X-ray inspection apparatus which concerns on embodiment. It is explanatory drawing for demonstrating the movement range of the X-ray generator in the X-ray inspection apparatus which concerns on embodiment. It is the block diagram which showed roughly the principal part of the manufacturing system of the electronic component by which the X-ray inspection apparatus which concerns on embodiment was employ | adopted. It is the flowchart which showed the processing operation which the microcomputer of the X-ray inspection apparatus which concerns on embodiment performs. 1 is a partial transmission front view illustrating a main part of an X-ray inspection apparatus according to Embodiment 1. FIG. 1 is a partial transmission side view illustrating a main part of an X-ray inspection apparatus according to Embodiment 1. FIG. FIG. 8 is a partial transmission side view showing an upper part of the X-ray inspection apparatus in FIG. 7. FIG. 7 is a partial cross-sectional view taken along line IX-IX in FIG. 6. FIG. 8 is a partial transmission side view showing a main part on the lower side of the X-ray inspection apparatus in FIG. 7. It is the XI-XI line partial sectional view in FIG. FIG. 3 is a partial transmission plan view illustrating a main part of a transport mechanism in the X-ray inspection apparatus according to the first embodiment. It is the typical top view which showed the motion of the rotating plate in a circular moving mechanism. It is the typical top view which showed the motion of the rotating plate in a circular moving mechanism. It is the block diagram which showed roughly the principal part of the X-ray inspection apparatus which this inventor invented previously. It is a figure for demonstrating the motion of the X-ray light-receiving surface and X-ray focus in the X-ray inspection apparatus which this inventor invented previously. It is a figure for demonstrating the motion of the X-ray light-receiving surface and X-ray focus in the X-ray inspection apparatus which this inventor invented previously. It is a figure for demonstrating the motion of the X-ray light-receiving surface and X-ray focus in the X-ray inspection apparatus which this inventor invented previously.

  Embodiments of an X-ray inspection apparatus according to the present invention will be described below with reference to the drawings. FIG. 1 is a block diagram schematically showing a main part of an X-ray inspection apparatus according to an embodiment. However, the same components as those of the X-ray inspection apparatus shown in FIG.

  In the figure, Smp indicates a sample to be tested (for example, a substrate on which electronic components are mounted on one side or both sides), and the sample Smp is transported by the transport mechanism 21 to a predetermined inspection position inside the apparatus. It has become. An X-ray detector 11 having an X-ray light receiving surface I and an X-ray generator 12 including an X-ray focal point S1 are disposed to face each other with the transport mechanism 21 interposed therebetween. X-rays are emitted from the X-ray focal point S <b> 1 of the X-ray generator 12, and X-rays transmitted through the sample Smp are detected by the X-ray light receiving surface I of the X-ray detector 11. In the figure, T1 indicates a plane including the intersection point O1 between the optical axis OA of the X-ray emitted from the X-ray focal point S1 and the axis L1 orthogonal to the mounting surface T2 of the sample Smp. It becomes the imaging surface FP.

  The X-ray detector 11 is connected to the image processing unit 22, and image data (video signal) corresponding to the X-ray detected by the X-ray detector 11 is output to the image processing unit 22. . The image processing unit 22 performs signal processing such as improving the image quality, and outputs the signal-processed image data to a display (not shown) or to the microcomputer 23.

  The circular moving mechanism (generator moving means) 24 and the circular moving mechanism (detector moving means) 25 are mechanically connected via a power transmission mechanism 26 that transmits power (rotational force) from the motor M11. In response to the rotational force from the power transmission mechanism 26, it is driven synchronously. The power transmission mechanism 26 includes a plurality of power transmission shafts and mechanical elements such as gears that connect these power transmission shafts so as to transmit power.

  That is, the circular moving mechanism 24 is driven by receiving the rotational force from the power transmission mechanism 26, and maintains the X-ray light receiving surface I in parallel with the sample mounting surface T2 of the transport mechanism 21, and the X-ray light receiving surface. The X-ray detector 11 is moved around the axis L1 in a circle around the axis L1 while keeping the direction of a straight line connecting two points on I in a constant direction.

  Similarly to the circular movement mechanism 24, the circular movement mechanism 25 is driven by receiving the rotational force from the power transmission mechanism 26, while maintaining the X-ray emission surface 12 a parallel to the placement surface T <b> 2 and X-rays. The X-ray generator 12 is moved in a circle around the axis L1 with the distance r from the axis L1 to the X-ray focal point S1 as the diameter while keeping the direction of a straight line connecting two points on the radiation surface 12a constant. (That is, the X-ray focal point S1 is rotated about the axis L1). The movement of the X-ray detector 11 and the X-ray focal point S1 (principle capable of tomography) is the same as that described with reference to FIGS. 16 to 18 and will not be described here.

  The motor M11 connected to the power transmission mechanism 26 is controlled by the microcomputer 23, and the X-ray focal point S1 of the X-ray generator 12 maintains a 180 ° phase difference in synchronization with the circular movement of the X-ray detector 11. , Rotational movement about the axis L1. In other words, the rotational force of one motor M11 is mechanically transmitted to the circular moving mechanism 24 and the circular moving mechanism 25 via the power transmission mechanism 26 (without causing a synchronization shift), and therefore the rotational force of the motor M11. Thus, even when the circular movement of the X-ray detector 11 and the X-ray generator 12 is accelerated, these circular movements can be reliably synchronized.

The vertical movement mechanism 27 is driven by receiving the rotational force from the motor M12, and moves the X-ray generator 12 in the direction of the axis L1. The motor M12 is also controlled by the microcomputer 23.
The transport mechanism 21 is driven by receiving the rotational force from the motor M13, and a belt-type transport mechanism that transports the sample Smp on a belt disposed in parallel in the sample transport direction (X direction), and a sample transport mechanism. An inspection position adjusting mechanism for moving the belt-type conveyance unit in a direction (Y direction) orthogonal to the conveyance direction (X direction). The belt-type conveyance mechanism includes a belt arranged in parallel. A belt interval adjusting mechanism that adjusts the interval according to the size (width) of the sample is provided.

  An operation unit 28 is connected to the microcomputer 23 so that various input settings for a desired inspection can be performed. The microcomputer 23 includes a CPU, a RAM, and a ROM. The ROM stores a program for determining pass / fail of the solder joint portion based on the tomographic image, a program for driving and controlling each portion, and the like. ing. The microcomputer 23 is connected to a storage unit (not shown) for storing inspection data and the like. The X-ray inspection apparatus 10 according to the embodiment is configured as described above.

According to the X-ray inspection apparatus 10 according to the above-described embodiment, the X-ray detector 11 maintains the X-ray light receiving surface I in parallel with the placement surface T2 of the transport mechanism 21 and is on the X-ray light receiving surface I. While the direction of the straight line connecting the two points is maintained in a constant direction, it moves around the axis L1 in a circle around the axis L1.
On the other hand, the X-ray generator 12 maintains the X-ray emission surface 12a parallel to the placement surface T2 of the transport mechanism 21, and the direction of a straight line connecting two points on the X-ray emission surface 12a is set to a fixed direction. While keeping the axis L1, the distance from the axis L1 to the X-ray focal point S1 moves in a circle around the axis L1, so that the X-ray focal point S1 rotates around the axis L1. The X-ray focal point S1 rotates about the axis L1 with a phase difference of 180 ° in synchronization with the circular movement of the X-ray detector 11.

  Further, in the X-ray inspection apparatus 10, circular movement mechanisms 24 and 25 for circular movement of the X-ray detector 11 and the X-ray focal point S1 of the X-ray generator 12 mechanically transmit the power from the motor M11. The power transmission mechanism 26 is mechanically coupled, and the circular movement of the X-ray detector 11 and the X-ray focal point S1 by the circular movement mechanisms 24 and 25 is mechanically synchronized by driving the power transmission mechanism 26. Is configured to do.

Therefore, even when the power (rotational force) of the motor M11 is increased to increase the speed of the circular movement between the X-ray detector 11 and the X-ray generator 12, the circular movement mechanisms 24 and 25 receive power from the motor M11. Can be mechanically transmitted via the power transmission mechanism 26, so that a synchronization shift (such as rotation blur) between the circular movement of the X-ray detector 11 and the circular movement of the X-ray generator 12 can be prevented.
Therefore, even when the circular movement is speeded up, only an image existing on the surface T1 (that is, a tomographic image of the surface T1) is based on the same principle as described with reference to FIGS. ) Can be obtained with high accuracy, and a tomographic image of the sample Smp placed on the placement surface T2 of the transport mechanism 21 can be obtained in a short time (about 0.5 to 1 second per tomographic image). Therefore, it is possible to accurately and quickly detect the cause of defects such as solder ball opening, solder bridging, solder deficiency and excess, which are difficult to observe from the outside, to the electronic component manufacturing (mounting) line. A device that can be embedded (supported in-line) can be realized.

  In addition, according to the X-ray inspection apparatus 10 according to the above-described embodiment, it is possible to acquire not only a tomographic image of the sample Smp but also a fluoroscopic image. Furthermore, the X-ray generator 12 can be moved in the direction of the axis L1 by the vertical movement mechanism 27, and the X-ray focal point S1 can be moved in the direction of the axis L1. When the X-ray focal point S1 is moved in the direction of the axis L1, the tomographic plane FP can be changed without changing the geometric magnification.

  Accordingly, since the tomographic image of the sample Smp placed on the placement surface T2 of the transport mechanism 21 can be acquired at different speeds and at the same magnification rate, the three-dimensional image of the sample Smp can be obtained at high speed. Can be obtained at. Thereby, the mounting state of the electronic component on the substrate can be inspected in more detail and at a high speed.

The X-ray generator 12 moves in a circle around the axis L1 with a distance r from the axis L1 to the X-ray focal point S1 as a diameter (see FIGS. 2 and 3). Further, as shown in FIG. 3, the movement range of the X-ray generator 12 is within the area E, the length of the x-axis direction of the X-ray generator 12 and x _12, the length of the y-axis direction y ₁₂ , it can be seen that the X-ray generator 12 moves in the range of x ₁₂ + 2r in the x-axis direction and moves in the range of y ₁₂ + 2r in the y-axis direction. It is also clear that the X-ray generator 12 does not rotate. Therefore, a tomographic image can be acquired without rotating the X-ray generator 12. Further, as apparent from FIG. 3, the moving range of the X-ray generator 12 can be minimized, and a power cable (not shown) connected to the X-ray generator 12 is twisted. Can not be.

FIG. 4 is a block diagram schematically showing an electronic component manufacturing system (surface mounting system) in which the X-ray inspection apparatus 10 according to the embodiment is incorporated.
The electronic component manufacturing system according to the embodiment includes a cream solder printer (also referred to as a screen printer) 200, a chip mounter (surface mounter) 300, a reflow device 400, and the X-ray inspection device 10 described above. Between these apparatuses, a loader (automatic feeder), an unloader (automatic unloader) and the like for transporting a substrate as a sample are appropriately arranged to automate the manufacturing process.

  The cream solder printing machine 200 is an apparatus for applying cream solder (the solder is added with a flux to have an appropriate viscosity) on the pads of the printed circuit board. The chip mounter 300 mounts (mounts) an electronic component such as BGA or CSP at a predetermined position on the printed circuit board after the solder is applied by the cream solder printing machine 200. For example, a component supply device (not shown) The electronic components supplied from the are picked up by a nozzle and mounted on a predetermined position of the substrate.

  The reflow device 400 is a device for applying a predetermined heat to the printed circuit board after the electronic component is positioned and mounted by the chip mounter 300 to melt the solder and fixing the electronic component to the printed circuit board. The X-ray inspection apparatus 10 performs tomography of the solder joint portion of the mounting board that has passed through the reflow apparatus 400 at a high speed (within 0.5 to 1 second per cross section) to determine the joining state, and Is determined, and is carried out.

FIG. 5 is a flowchart showing an inspection processing operation performed by the microcomputer 23 in the X-ray inspection apparatus 10 according to the embodiment. This processing operation is repeatedly executed at a predetermined time interval based on the tact time of the designed production line.
First, in step 1, signals are exchanged with a loader disposed on the substrate carry-in side of the apparatus, the substrate carry-in opening is opened at a predetermined timing, and the mounting board that has passed through the reflow device 400 is transferred to the transfer mechanism 21. Control (driving control of the motor M13 etc.) for placing on the mounting surface (on the belt) and transporting it to a predetermined inspection position is performed. Note that control may be performed so that signals are exchanged with an unloader arranged on the substrate carry-out side of the apparatus at approximately the same timing as carry-in, the substrate carry-out port is opened, and the inspected mounting board is carried out. .

  In step 2, the inspection number corresponding to the mounted substrate that has been carried in is counted and stored in the storage unit as inspection data. In step 3, the mounting substrate is positioned. Positioning of the mounting board is detected at the edge of the board, and processing for alignment correction of positional deviation and inclination is performed.

  In the next step 4, the mounting substrate distortion is detected and corrected. The distortion of the mounting substrate is detected at a predetermined position and automatically corrected for the tomographic height. In the next step 5, tomographic processing of the solder joint portion of the mounting board is performed. By driving the motor M11, circular movement of the X-ray detector 11 and the X-ray generator is performed at high speed, and tomography can be performed for one section in about 0.5 seconds to 1 second. Based on the number and size of electronic components mounted on the substrate, tomography is executed as many times as necessary for determining the joining state.

  In step 6, based on the photographed cross-sectional image, for example, the photographed cross-sectional image is compared with a pre-registered good product cross-sectional image, and automatic determination of good / bad solder joints is performed. Examples of the defective state of the solder joint detected by the X-ray inspection apparatus 10 include states such as solder ball floating, solder ball misalignment, and insufficient solder.

  In step 7, the inspection (image, pass / fail judgment) data is stored in the storage unit in association with the inspection number stored in step S <b> 2, and then in step 8, the mounted substrate that has been inspected is carried out. For exchanging signals with the unloader arranged on the substrate unloading side of the device, opening the substrate unloading port at a predetermined timing, transporting the mounted substrate after inspection to the exit, and transporting to the unloader Control (drive control of the motor M13 and the like) is performed, and then the process ends.

According to the method for inspecting an electronic component according to the above-described embodiment, by using the X-ray inspection apparatus 10 that can greatly reduce the time required for one tomography to about 1 second or less, the solder for the electronic component is used. The joining state of the joining part is automatically in-line tested, and the non-defective product and the defective product of the electronic component are determined based on the obtained tomographic image data.
Therefore, it is possible to realize high-speed automatic inspection for determining the quality of electronic components based on tomographic image data in the production (mounting) line, which could not be realized until now, and fully automatic inspection with the required tact time And the production efficiency of electronic parts can be dramatically improved.

  In addition, according to the electronic component manufacturing system according to the embodiment, the X-ray inspection apparatus 10 is incorporated in an electronic component manufacturing (mounting) line as an in-line inspection apparatus for an electronic component solder joint. In the production line, high-speed automatic inspection for determining the quality of electronic parts based on tomographic image data can be realized, and the production efficiency of electronic parts can be dramatically increased.

  FIG. 6 is a partially transparent front view illustrating the main part of the X-ray inspection apparatus according to the first embodiment. FIG. 7 is a partially transparent side view showing the main part of the X-ray inspection apparatus according to the first embodiment. FIG. 8 is a partially transparent side view showing the main part on the upper side of the X-ray inspection apparatus in FIG. 7, and FIG. 9 is a partial sectional view taken along the line IX-IX in FIG. 10 is a partially transparent side view showing the main part of the lower side of the X-ray inspection apparatus in FIG. 7, and FIG. 11 is a partial sectional view taken along the line XI-XI in FIG. FIG. 12 is a partially transparent plan view showing the periphery of the transport mechanism.

In the figure, reference numeral 21 denotes a transport mechanism on which the sample Smp is placed and transports the sample Smp in and out of the apparatus (X direction). The transport mechanism 21 is sandwiched between the X-ray detector 11 and the X-ray generator 12. Are arranged so as to face each other, X-rays are emitted from the X-ray generator 12, and X-rays transmitted through the sample are detected by the X-ray detector 11.
A circular moving mechanism 24 is coupled above the X-ray detector 11, and a vertical moving mechanism 27 and a circular moving mechanism 25 are coupled below the X-ray generator 12, and the circular moving mechanism 24 and the circular moving mechanism are coupled. 25 is connected via a power transmission mechanism 26 (see FIG. 7) that mechanically transmits power from the motor M11.

  The power transmission mechanism 26 is connected to the motor M11 at one end side, and has a first power transmission shaft 26a horizontally disposed in the horizontal direction, and a lower end side via the other end side of the first power transmission shaft 26a and bevel gears 29a and 29b. The third power transmission shaft 26c that is connected and is erected in the vertical direction, and the second power transmission that is connected to the upper end side of the third power transmission shaft 26c via the bevel gears 29c and 29d and laterally installed in the horizontal direction. And a shaft 26b.

  The first power transmission shaft 26a is connected to the drive shaft 81 of the circular movement mechanism 25 via bevel gears 29e and 29f, and the second power transmission shaft 26b is driven to the circular movement mechanism 24 via bevel gears 29g and 29h. The shaft 41 is connected. The first power transmission shaft 26a is rotatably supported by the support base 85 of the circular moving mechanism 25 via the bearing holders 30a, 30b, and the second and third power transmission shafts 26b, 26c are bearings. It is supported in a rotatable state by a support frame 32 fixed in the apparatus housing 31 via holders 30c to 30i and the like. In addition, about the bevel gears 29a-29h, the attachment state is adjusted so that the backlash (gap) between the gears which mutually mesh may be eliminated.

Next, the configuration of the circular moving mechanism 24 will be described. In the figure, reference numeral 41 denotes a drive shaft having the axis L1 as an axis, and the upper end of the drive shaft 41 is connected to the second power transmission shaft 26b via bevel gears (bevel gears) 29h and 29g. 41 is rotationally driven in response to the rotational force from the second power transmission shaft 26b.
The drive shaft 41 is held by bearings 42 and 43, a holding portion 44, and a holding plate 45, and is supported by the support frame body 32 via a fixture 46. A rotary boss 47 is fastened to the lower end of the drive shaft 41, and the rotary boss 47 also rotates around the axis L1 based on the rotation of the second power transmission shaft 26b.

  A swing shaft 48 (with the axis L2 as an axis) is joined to the rotary boss 47, and the swing shaft 48 also rotates around the axis L1 based on the rotation of the power transmission mechanism 26. Yes. The swing shaft 48 is pivotally supported by the rotary plate 50 via a bearing 49 at a position (axis L2) away from the axis (axis L1) of the drive shaft 41 by a distance R.

Further, a parallel shaft 51 parallel to the drive shaft 41 (with the axis L3 as an axis) is supported by the holding plate 45 by bearings 52 and 53 and a holding portion 54, and the holding plate 45 is supported by a support frame via a fixture 46. It is supported by the body 32. A rotating boss 55 is fastened to the lower end of the parallel shaft 51, and a swing shaft 56 (with the axis L4 as an axis) is joined to the rotating boss 55.
The swing shaft 56 is located at a position (axis L4) that is a distance R away from the axis (axis L3) of the parallel shaft 51, and the distance between the shaft support points is the same as the distance between the axes of the drive shaft 41 and the parallel shaft 51. Further, it is pivotally supported on the rotary plate 50 via a bearing 57.

  Timing pulleys (hereinafter referred to as pulleys) 58 and 59 are respectively attached to the drive shaft 41 and the parallel shaft 51, and a timing belt (hereinafter referred to as belt) 60 is stretched between the pulleys 58 and 59. Thus, the rotational force of the drive shaft 41 is transmitted to the parallel shaft 51 via the pulleys 58 and 59 and the belt 60. The X-ray detector 11 is fixed to the rotating plate 50 via a fixture 61. The X-ray detector 11 is connected to a cable (not shown) for transmitting image data.

  Further, a linear guide mechanism 70 is disposed between the rotating plate 50 and the holding plate 45. As shown in FIG. 9 (in FIG. 9, the description of the drive shaft 41 and the parallel shaft 51 is omitted for ease of explanation), the upper surface 4 of the rotating plate 50 having a substantially rectangular shape. A linear bush (bearing cylinder member) 63 into which Y-direction linear guides (guide shafts) 62a and 62b are inserted is joined to the corner. Connection plates 64a and 64b are joined to both end surfaces of the Y-direction linear guides 62a and 62b inserted through the linear bushes 63, respectively. X-direction linear guides 65a and 65b are connected to both ends of the connection plates 64a and 64b. The linear bush 66 to be inserted is joined. Connecting plates 67a and 67b are joined to both end faces of the X-direction linear guides 65a and 65b inserted through the linear bushing 66, and the connecting plates 67a and 67b are connected to the holding plate 45 via a support tool 68. . A linear motion guide mechanism 70 is configured including the Y-direction linear guides 62a and 62b, the linear bush 63, the X-direction linear guides 65a and 65b, the linear bush 66, and the like.

  FIG. 13 is a schematic plan view showing the movements of the shaft centers L2 and L4 of the swing shafts 48 and 56 and the rotating plate 50 based on the rotation of the power transmission mechanism 26 driven by receiving the power from the motor M1. is there. As shown in FIGS. 13A to 13C, based on the rotation of the motor M1, the rotating plate 50 moves in a circle around the axis (axis L1) of the drive shaft 41 with the distance R as the diameter. To do.

  Since the X-ray detector 11 is attached to the rotating plate 50 via the fixture 61, the X-ray detector 11 moves in the same manner as the rotating plate 50 in conjunction with the rotating plate 50. That is, the X-ray detector 11 moves in a circle around the axis L <b> 1 with the distance R as a diameter based on the rotation of the power transmission mechanism 26. Therefore, the X-ray detector 11 keeps the X-ray light receiving surface I parallel to the mounting surface orthogonal to the axis L1, and the direction of a straight line connecting two points on the X-ray light receiving surface I is set to a fixed direction. While being held, it moves around the axis L1 in a circle around the axis L1.

Next, the configuration of the circular moving mechanism 25 will be described. In the figure, 81 (see FIG. 10) is a drive shaft having the axis L1 as an axis, and the lower end of the drive shaft 81 is connected to the first power transmission shaft 26a via bevel gears (bevel gears) 29f and 29e. The drive shaft 81 is rotationally driven in response to the rotational force from the first power transmission shaft 26a.
The drive shaft 81 is supported on the support base 85 by bearings 82 and 83 and a holding portion 84. A rotating boss 86 is coupled to the upper end of the drive shaft 81, and the rotating boss 86 is also rotated around the axis L1 based on the rotation of the first power transmission shaft 26a.

  A swing shaft 87 (centered on the axis L5) is joined to the rotary boss 86, and the swing shaft 87 also rotates around the axis L1 based on the rotation of the first power transmission shaft 26a. It has become. The swing shaft 87 is a bearing 88 at a position (axis L5) away from the axis (axis L1) of the drive shaft 81 by a distance r (length from the axis L1 to the X-ray focal point S1 of the X-ray generator 12). Is rotatably supported by the rotating plate 89 via

In addition, a parallel shaft 91 that is parallel to the drive shaft 81 (with the axis L6 as an axis) is supported on the support base 85 by bearings 92 and 93 and a holding portion 94. A rotating boss 95 is joined to the upper end of the parallel shaft 91, and a swing shaft 96 (with the axis L7 as an axis) is joined to the rotating boss 95.
The swing shaft 96 is located at a position (axis L7) that is a distance r away from the axis (axis L6) of the parallel shaft 91, and the distance between the shaft support points is the same as the distance between the axes of the drive shaft 81 and the parallel shaft 91. Further, it is rotatably supported on the rotary plate 89 via a bearing 97.

  Further, pulleys 98 and 99 are coupled to the drive shaft 81 and the parallel shaft 91, respectively, and a belt 100 is stretched between the pulleys 98 and 99. 99 and the belt 100 are transmitted to the parallel shaft 91.

  Further, a vertical moving mechanism 27 is disposed on the rotating plate 89. Drive shafts 102 are rotatably mounted on both sides of the rotating plate 89 via bearings 101. A bevel gear 103 is joined to the lower end of the drive shaft 102, and the bevel gear 103 meshes with a bevel gear 105 (FIG. 6) joined to the drive shaft 104 driven by the rotational force from the motor M12 (FIG. 6). The drive shaft 102 is rotationally driven by the rotational force of the drive shaft 104 driven by the motor M12.

  Further, guide shafts 106 and 107 are erected on the upper surface of the rotating plate 89 in parallel with the drive shaft 102, and bearing members 108 and 109 sliding on the shaft are inserted into the guide shafts 106 and 107. ing. A cylindrical mounting portion 110 is screwed onto the screw-shaped drive shaft 102, and the mounting portion 110 and the bearing members 108 and 109 are coupled to an installation plate 111 on which the X-ray generator 12 is installed. The X-ray generator 12 is fixed to the installation plate 111 with a fixture or the like.

  The mounting portion 110 moves in the axial direction of the drive shaft 102 based on the rotation of the motor M12. That is, the X-ray generator 12 attached to the installation plate 111 moves in the axial direction (vertical direction) of the drive shaft 102 based on the rotational drive of the motor M12. A power cable (not shown) is connected to the X-ray generator 12.

  A linear motion guide mechanism 120 is provided between the rotating plate 89 and the support base 85. As shown in FIG. 11 (in FIG. 11, the main part of the linear motion guide mechanism 120 is shown for ease of explanation), the four corners on the upper surface of the substantially rectangular rotating plate 89 are A linear bushing (bearing cylinder member) 122 into which the Y-direction linear guides (guide shafts) 121a and 121b are inserted is coupled. Connection plates 123a and 123b are coupled to both end surfaces of the Y-direction linear guides 121a and 121b inserted through the linear bushes 122, respectively, and X-direction linear guides 124a and 124b are coupled to both ends of the connection plates 123a and 123b. The linear bush 125 to be inserted is coupled. Connecting plates 126a and 126b are coupled to both end faces of the X-direction linear guides 124a and 124b inserted through the linear bush 125, and the coupling plates 126a and 126b are coupled to a support base 85 via a support 127. . The guide mechanism 120 includes the Y-direction linear guides 121a and 121b, the linear bush 122, the X-direction linear guides 124a and 124b, the linear bush 125, and the like.

FIG. 14 is a schematic plan view showing the movements of the shaft centers L5 and L7 of the swing shafts 87 and 96 and the rotating plate 89 based on the rotation of the power transmission mechanism 26 driven by receiving the power from the motor M1. is there. As shown in FIGS. 14A to 14C, based on the rotation of the motor M1, the rotary plate 89 moves in a circle around the axis (axis L1) of the drive shaft 81 with the distance r as the diameter. To do.
Since the X-ray generator 12 is attached to the rotating plate 89 via the installation plate 111 and the drive shaft 102, the X-ray generator 12 moves in the same manner as the rotating plate 89 in conjunction with the rotating plate 89. That is, based on the rotation of the motor M1, it moves in a circle around the axis L1 with the distance r as the diameter. Therefore, the X-ray focal point S1 rotates around the axis L1.

  Next, the configuration of the transport mechanism 21 will be described. FIG. 12 is a partially transparent plan view showing the periphery of the transport mechanism 21. The transport mechanism 21 is driven in response to the rotational force from the motor M13, and a belt-type transport mechanism 130 that transports the sample Smp in the sample transport direction (X-axis direction) and the sample transport direction (X-axis direction). And an inspection position adjusting mechanism 131 (see FIG. 7) that moves the belt-type transport mechanism 130 in a direction (Y-axis direction) orthogonal to each other. The belt-type transport mechanism 130 is equipped with a belt interval adjusting mechanism 132 that adjusts the interval between the belts arranged in parallel according to the size (width) of the sample.

  The inspection position adjusting mechanism 131 shown in FIG. 7 is disposed on a bracket (supporting means) 140, and includes a motor M14 that is driven and controlled by the microcomputer 23, a drive shaft 141 connected to the motor M14, and a drive shaft 141. Bearing holders 142 and 143 that are rotatably held, and a shifter (tubular member) 144 that is inserted so as to be capable of screwing along a drive shaft 141 on which a screw thread is formed. By rotating the drive shaft by the motor M14, the shifter 144 can be reciprocated in the Y-axis direction.

  The shifter 144 is joined to a transport table 145 on which the belt-type transport mechanism 130 is disposed. The belt-type transport mechanism 130 disposed on the transport table 145 includes a belt driving motor M13, a belt driving shaft 146 connected to the motor M13, a belt driven shaft 147, a belt driving shaft 146, and tips of the belt driven shaft 147. Pulleys 148 and 149 attached to the respective parts, a conveyor belt 150 (see FIG. 7) stretched between these pulleys, a belt drive shaft 146 and a belt holder 151 to 154 for rotatably holding a belt driven shaft 147 are provided. These bearing holders are joined to the transport table 145.

  The belt-type transport mechanism 130 includes cylindrical bearing members (including spline nuts, bearing holders, and the like) 155 and 156 that are slidably inserted into the belt drive shaft 146 and the belt driven shaft 147, respectively. Pulleys 157 and 158 provided, a conveyor belt 159 having a predetermined width stretched between these pulleys (see FIG. 7), and a shift plate 160 joined between these cylindrical bearing members are provided.

  In addition, idle pulleys 161 and 162 are disposed between the pulleys 148 and 149 (in the middle of the conveyor belt 150) to push the return side of the conveyor belt 150 upward and bias the idle belt 161 and 162. It is coupled to the transport table 145 via tools 163 and 164. In addition, idle pulleys 165 and 166 are also provided between the pulleys 157 and 158 (in the middle of the conveyor belt 159) so as to face the idle pulleys 161 and 162, and the shaft portions 167 and 168 of the idle pulleys 165 and 166 are shifted. It is joined to the plate 160.

  The belt interval adjustment mechanism 132 includes a belt interval adjustment motor M15, a drive shaft 169 connected to the motor M15, bearing holders 170 and 171 that rotatably hold the drive shaft 169, and a drive shaft 169 formed with a screw thread. A shifter (cylindrical member) 172 inserted so as to be capable of being screwed along is provided, and the shifter 172 is joined to the shift plate 160. Further, auxiliary shafts (shafts) 175 and 176 into which cylindrical members 173 and 174 joined to the shift plate 160 are slidably inserted are disposed between the belt drive shaft 146 and the belt driven shaft 147. Yes. Therefore, by rotating the drive shaft 169 by the motor M15, the shift plate 160 joined to the shifter 172 can be reciprocated in the Y direction together with the transport belt 159, and transported in accordance with the size of the sample. The distance between the belts 150 and 159 can be adjusted as appropriate.

  In the X-ray inspection apparatus according to the first embodiment, power transmission in which the circular moving mechanisms 24 and 25 for circularly moving the X-ray detector 11 and the X-ray focal point S1 mechanically transmit the power from the motor M11. A mechanism that is mechanically coupled via a mechanism 26 (first to third power transmission shafts 26a to 26c) and mechanically transmits power from the motor M11 to the circular moving mechanisms 24 and 25 is inexpensive and space-saving. By driving the power transmission mechanism 26, the circular movement of the X-ray detector 11 and the X-ray focal point S1 by the circular movement mechanisms 24 and 25 is configured to be mechanically synchronized.

Therefore, even when the power (rotational force) of the motor M11 is increased to increase the speed of the circular movement between the X-ray detector 11 and the X-ray generator 12, the circular movement mechanisms 24 and 25 receive power from the motor M11. Is mechanically transmitted via the power transmission mechanism 26 so that the synchronous movement (the rotational angle difference, rotational vibration, etc.) between the circular movement of the X-ray detector 11 and the circular movement of the X-ray generator 12 does not occur. Can be.
Therefore, even when the circular movement is speeded up, only an image existing on the surface T1 (that is, a tomographic image of the surface T1) can be acquired with high accuracy, and the placement surface T2 of the transport mechanism 21 can be obtained. A tomographic image of the placed sample Smp can be acquired in a short time (about 0.5 to 1 second per tomographic image), and it is difficult to observe from the outside. Therefore, it is possible to accurately and quickly detect the cause of defects such as insufficient or excessive solder, and to realize an apparatus that can be incorporated into an electronic component manufacturing (mounting) line (inline compatible).

DESCRIPTION OF SYMBOLS 10 X-ray inspection apparatus 11 X-ray detector 12 X-ray generator 22 Image processing part 23 Microcomputer 24, 25 Circular movement mechanism 26 Power transmission mechanism 26a-26c 1st-3rd power transmission shaft 27 Vertical movement mechanism 41, 81 Drive Axis 51, 91 Parallel axis 47, 55, 86, 95 Rotating boss 48, 56, 87, 96 Swing axis I X-ray receiving surface L1-L7 Axis M11-M15 Motor S1 X-ray focus

Claims (7)

An X-ray generator configured to include an X-ray focal point and an X-ray detector are arranged opposite to each other across the sample placement surface, and is emitted from the X-ray focal point and transmitted through the sample. In the X-ray inspection apparatus configured to be detected by the X-ray detector,
While maintaining the X-ray emission surface of the X-ray generator parallel to the placement surface, and maintaining the direction of a straight line connecting two points on the X-ray emission surface in a constant direction,
Generator moving means for moving the X-ray generator in a circle around the axis orthogonal to the placement surface as described above, with a length from the axis to the X-ray focal point as a diameter;
While maintaining the X-ray receiving surface of the X-ray detector parallel to the placement surface, and maintaining the direction of a straight line connecting two points on the X-ray receiving surface in a constant direction,
Detector moving means for moving the X-ray detector around the axis in a circle around the axis; and
The generator moving means and the detector moving means are mechanically coupled via power transmission means for mechanically transmitting power from a drive source, and the X-ray generator is driven by driving the power transmission means. And a circular movement of the X-ray detector are performed synchronously ,
The power transmission means is
A first power transmission shaft mechanically coupled to the generator moving means;
A second power transmission shaft mechanically coupled to the detector moving means;
A third power transmission shaft that mechanically connects the first power transmission shaft and the second power transmission shaft, and the drive source is any one of the first to third power transmission shafts. Concatenated with
The generator moving means is
A drive shaft having the shaft as an axis disposed in a support portion in a state of being connected to the first power transmission shaft;
A parallel shaft disposed in parallel with the drive shaft disposed on the support;
A coupling portion for coupling the drive shaft and the parallel shaft to the X-ray generator;
A winding transmission means wound between the drive shaft and the parallel shaft;
The X-ray generator is located at a position where the length is shifted in the same direction from the axis of each of the drive shaft and the parallel shaft via the coupling portion, and the distance between the shaft fulcrums is the drive shaft and the parallel shaft. The X-ray inspection apparatus is characterized in that it is axially supported so as to be the same as the distance between the axes . The coupling portion has a swing shaft portion that rotates about the drive shaft, a swing shaft portion that rotates about the parallel shaft, and the length of the drive shaft and the parallel shaft in the same direction from the respective axis. Including a rotating plate pivotally supported by these swing shafts at a shifted position,
The rotary plate, X-rays inspection apparatus according to claim 1, characterized in that it is joined to the linear guide means for allowing the movement of the X-axis direction and the Y-axis direction orthogonal to the drive shaft. An attachment portion to which the X-ray generator is attached;
The mounting portion is located at a position where the length is shifted in the same direction from the axis of each of the drive shaft and the parallel shaft via the coupling portion, and the distance between the shaft support points is between the drive shaft and the parallel shaft. It is pivotally supported to be the same as the distance between shaft centers,
X-ray examination apparatus as claimed in claim 1 or claim 2, wherein further comprising an axial movement means for moving the mounting portion in the axial direction. The detector moving means is
A drive shaft centered on the shaft, disposed on a support portion in a state of being connected to the second power transmission shaft;
A parallel shaft disposed in parallel with the drive shaft disposed on the support;
A coupling portion for coupling the drive shaft and the parallel shaft to the X-ray detector;
A winding transmission means wound between the drive shaft and the parallel shaft;
When the X-ray detector is located at a predetermined distance away from the axis of each of the drive shaft and the parallel shaft in the same direction via the coupling portion, the distance between the shaft fulcrums is the drive shaft and the parallel shaft. The X-ray inspection apparatus according to claim 1 , wherein the X-ray inspection apparatus is axially supported so as to be equal to a distance between the axial centers of the two. The coupling portion includes a swing shaft portion that rotates about the drive shaft, a swing shaft portion that rotates about the parallel shaft, and the predetermined length in the same direction from the axis of each of the drive shaft and the parallel shaft. Including a rotating plate pivotally supported by these swing shafts at a position apart from each other,
The X-ray inspection apparatus according to claim 4 , wherein the rotary plate is joined to linear motion guide means that allows movement in the X-axis direction and the Y-axis direction orthogonal to the drive shaft. An X-ray generator configured to include an X-ray focal point and an X-ray detector are arranged opposite to each other across the sample placement surface, and is emitted from the X-ray focal point and transmitted through the sample. In the X-ray inspection apparatus configured to be detected by the X-ray detector,
While maintaining the X-ray emission surface of the X-ray generator parallel to the placement surface, and maintaining the direction of a straight line connecting two points on the X-ray emission surface in a constant direction,
Generator moving means for moving the X-ray generator in a circle around the axis orthogonal to the placement surface as described above, with a length from the axis to the X-ray focal point as a diameter;
While maintaining the X-ray receiving surface of the X-ray detector parallel to the placement surface, and maintaining the direction of a straight line connecting two points on the X-ray receiving surface in a constant direction,
Detector moving means for moving the X-ray detector around the axis in a circle around the axis; and
The generator moving means and the detector moving means are mechanically coupled via power transmission means for mechanically transmitting power from a drive source, and the X-ray generator is driven by driving the power transmission means. And a circular movement of the X-ray detector are performed synchronously,
The power transmission means is
A first power transmission shaft mechanically coupled to the generator moving means;
A second power transmission shaft mechanically coupled to the detector moving means;
A third power transmission shaft that mechanically connects the first power transmission shaft and the second power transmission shaft, and the drive source is any one of the first to third power transmission shafts. Concatenated with
The detector moving means is
A drive shaft centered on the shaft, disposed on a support portion in a state of being connected to the second power transmission shaft;
A parallel shaft disposed in parallel with the drive shaft disposed on the support;
A coupling portion for coupling the drive shaft and the parallel shaft to the X-ray detector;
A winding transmission means wound between the drive shaft and the parallel shaft;
When the X-ray detector is located at a predetermined distance away from the axis of each of the drive shaft and the parallel shaft in the same direction via the coupling portion, the distance between the shaft fulcrums is the drive shaft and the parallel shaft. The X-ray inspection apparatus is characterized in that it is axially supported so as to be the same as the distance between the axes. The coupling portion includes a swing shaft portion that rotates about the drive shaft, a swing shaft portion that rotates about the parallel shaft, and the predetermined length in the same direction from the axis of each of the drive shaft and the parallel shaft. Including a rotating plate pivotally supported by these swing shafts at a position apart from each other,
The X-ray inspection apparatus according to claim 6, wherein the rotating plate is joined to linear motion guide means that allows movement in the X-axis direction and the Y-axis direction orthogonal to the drive shaft.

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