JPH0851276A - Method and device for inspecting soldering of component mounted board - Google Patents

Abstract

PURPOSE:To improve inspection accuracy by performing response compensation of an X-ray transmission image of a one-sided mounted board or that of a double-sided mounted board based on the response characteristics of an image pick-up system and an image processing system including an X-ray detector. CONSTITUTION:A one-sided inspection part 2 inspects soldering of a board in one-sided board state where the mounting to one side of the board is completed by a one-sided mount board X-ray transmission image reading device 23, a response compensation device 22, and a one-sided mount defect judging device 7. The X-ray transmission image obtained by the one-sided mount board X-ray transmission image reading device 23 is subjected to compensation corresponding to the response characteristics of an X-ray detector 32 by the response compensation device 22. Then, an image is obtained, where the gain characteristics in a specific space frequency range are made constant. Soldering inspection according to the distribution of the amount of X-ray transmission is executed by the one-sided mount defect judging device 7 using the response-compensated image.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention irradiates a mounting board on which mounting components are mounted by soldering with X-rays,
The present invention relates to a soldering inspection method and apparatus for inspecting the quality of a soldering state from an X-ray transmission image.

[0002]

2. Description of the Related Art In order to inspect the quality of the soldered state of a mounting board on which mounting components are mounted by soldering,
When the mounting board is irradiated with X-rays and the amount of X-ray transmission that differs depending on the part of the mounting board is detected, an X-ray transmission image corresponding to the X-ray shielding degree can be obtained. From this X-ray transmission image, the shape of the soldering portion and the amount of solder can be detected from the X-ray transmission amount distribution of the soldering portion, and the quality of the soldering state can be determined. However, in the double-sided mounting substrate, the transmission images of the mounting components on both sides of the substrate overlap, so that the soldering inspection cannot be simply performed from the X-ray transmission image. In order to solve this problem, a soldering inspection method and device for the double-sided mounting substrate by an X-ray transmission image have been proposed. An outline of a conventional example of soldering inspection by an X-ray transmission image for a double-sided mounting substrate disclosed in JP-A-3-218409 and JP-A-5-99643 is shown below. According to the method disclosed in Japanese Unexamined Patent Publication No. 3-218409, the one-sided X-ray transmission image in which the member is mounted on one side of the double-sided mounting board is collected and stored, and the double-sided mounting is completed. In this state, a double-sided X-ray transmission image is collected, and an X-ray transmission image on the other side is obtained from the difference image between this image and the one-side X-ray transmission image. By this processing, X-ray transmission images of the one surface side and the other surface side are obtained, and the soldering inspection can be performed using the respective images. According to the method disclosed in the above-mentioned Japanese Patent Laid-Open No. 5-99643, the X-ray transmission image of only the mounted component on one side that interferes with the inspection is collected and stored in advance, and this image data and the inspection are stored. After aligning with the target image, the two-sided soldering inspection can be performed by subtracting the portion of the memory image mixed therein from the image of the soldering portion to be inspected.

[0003]

However, in the above-mentioned conventional method, images on both sides are obtained by the process of subtracting the X-ray transmission image of the double-sided mounting board mounted on only one side from the X-ray transmission image of the double-sided mounting substrate. However, in reality, due to the influence of the response characteristics of the X-ray detector and the like, it is not possible to accurately extract the image of only one side from the images of both sides mounted. The X-ray transmission image has an excellent feature that density information corresponding to the X-ray shielding degree of the subject is obtained, but the spatial frequency is high due to the response characteristic of the image pickup system including the X-ray detector and the transfer characteristic of the signal processing system. Since the gain characteristic in the part is reduced, the relationship between the density information at a high spatial frequency and the X-ray shielding degree of the subject becomes different from the relationship between the density information at a low spatial frequency and the X-ray shielding degree of the subject. This is a problem in performing an inspection conforming to the actual shape using an X-ray transmission image. Therefore, an object of the present invention is to perform a response correction on each of the one-sided mounting image and the two-sided mounting image of the double-sided mounting board, then obtain the other-side mounting image from the difference between the two images, and solder it. An object of the present invention is to provide a soldering inspection method and device that can improve inspection accuracy by performing inspection.

[0004]

In order to achieve the above object, a method adopted by the present invention is to irradiate a mounting board, which is mounted on a board by soldering, a member that does not completely shield X-rays with X-rays. Then, in the soldering inspection method of the mounting board, which determines the quality of the soldering state by detecting the X-ray transmission amount distribution of the soldering portion from the X-ray transmission image in which the transmitted X-rays are detected by the X-ray detector, A step of irradiating an X-ray onto the one-sided mounting board in which the above-mentioned member is mounted on one side of the board and performing a soldering inspection by detecting the X-ray transmission amount distribution; A step of irradiating a double-sided mounting board with the above-mentioned member mounted on the surface side with X-rays to detect an X-ray transmission image of the double-sided mounting board; X-ray transmission image of double-sided mounting board A step of the response corrected based on the response characteristics of the image pickup system and an image processing system including an X-ray detector, the response corrected double-sided mounting board X
A step of subtracting the response-corrected X-ray transmission image of the one-side mounting board from the X-ray transmission image to obtain the other-side X-ray transmission image, and the X-ray transmission amount using the other-side X-ray transmission image And a step of performing a soldering inspection by detecting a distribution.
The response correction corrects the X-ray transmission image so that the gain characteristic in the predetermined spatial frequency range becomes substantially constant.
When subtracting the X-ray transmission image of the one-side mounting board from the X-ray transmission image of the double-sided mounting board, the alignment amount from the reference mark is calculated for the X-ray transmission images of the one-side mounting board and the double-sided mounting board. , The displacement less than the pixel pitch is interpolated using the alignment amount, and the alignment is performed. Further, the X-ray transmission image of the one-side mounting board is compressed and encoded, and transferred to the step of obtaining the other-side X-ray transmission image.

The means adopted by the present invention is to irradiate an X-ray onto a mounting board formed by soldering a member that does not completely shield the X-ray, and detect the transmitted X-ray with an X-ray detector. In a soldering inspection device for a mounting board, which determines the quality of the soldering state by detecting the X-ray transmission amount distribution of the soldering portion from the X-ray transmission image, a state in which the member is mounted on one surface side of the board. X on one side mounting board
Based on the response characteristic of the X-ray detector, an X-ray transmission image of the one-sided mounting board inspecting means for irradiating a ray and performing a soldering inspection by detecting the X-ray transmission amount distribution is provided. The one-side mounted image correction means for response correction and the double-sided mounted board in which the above-mentioned members are mounted on the other side of the one-sided mounted board are irradiated with X-rays to detect an X-ray transmission image of the double-sided mounted board. A double-sided mounting image detecting means for performing the above-mentioned operation, a double-sided mounting image correcting means for correcting the X-ray transmission image of the double-sided mounting board based on the response characteristic of the X-ray detector, and the double-sided mounting image corrected for the response Another-side mounting image creating means for obtaining the other-side X-ray transmission image by subtracting the response-corrected one-side mounting image, and soldering by detecting the X-ray transmission amount distribution using the other-side mounting image It is configured as a soldering inspection device mounting board, characterized by comprising; and a second surface-side mounting board inspection means for inspecting. The one-side mounted image can be compressed and encoded and transferred to the other-side mounted image creating means by using a data transfer means. Further, it can be configured by including an image storage means for storing a plurality of the one-side mounted images that have been decoded and expanded.

[0006]

According to the present invention, when performing a soldering inspection by X-ray transmission of a double-sided mounting board, an X-ray transmission image is detected in a state of being mounted on one side of the board, and this one-side mounting image is used. Conduct soldering inspection on one side. Then,
After detecting the X-ray transmission image in the state that it is mounted on the other side of the one-sided mounting board and becomes a double-sided mounting board, and after performing the response correction of the one-sided mounting image and the two-sided mounting image respectively, Extract the other-side mounted image. By the above response correction, the response characteristics of the one-side mounting image and the two-side mounting image having different spatial frequencies with respect to the spatial frequency can be made uniform within a predetermined spatial frequency range, so that an accurate other-side mounting image can be extracted and inspected. The accuracy can be improved. When the difference image between the one-side mounted image and the two-side mounted image is obtained, the displacement less than the pixel pitch is interpolated and aligned, so that the other-side mounted image can be more accurately extracted. Further, when the one-side mounted image is transferred to the other-side image extracting step, the transfer speed is improved by compressing, encoding and transferring the one-side image. The transferred images are sequentially stored in a plurality of image storage means, taken out in accordance with the detection process of the double-sided mounting image, and the other-side mounted image is extracted from the difference image. With this configuration, the soldering inspection for one surface side mounting and the soldering inspection for the other surface side mounting can be performed in parallel, and the one surface side mounting image of the next board can be prepared during the inspection of one board. The soldering inspection can be carried out according to the manufacturing process of the mounting board.

[0007]

Embodiments of the present invention will be described below with reference to the accompanying drawings for the understanding of the present invention. The following embodiments are examples embodying the present invention and do not limit the technical scope of the present invention. 1 is a block diagram showing the configuration of a soldering inspection apparatus to which the soldering inspection method according to the present invention is applied, FIG. 2 is a schematic diagram showing the schematic configuration of an X-ray transmission image reading apparatus, and FIG. 3 is one surface side. FIG. 4 is a schematic diagram illustrating a state of alignment between a mounting image and a mounting image on the other surface side that is less than a pixel pitch, FIG. 4 is a graph showing an example of response characteristics of an X-ray detector, and FIG. 5 is a double-sided mounting example (a) And FIG. 6 is a graph showing an example of X-ray transmission amount distribution, FIG. 6 is an example of mounting on one surface side (a) and a graph showing an example of X-ray transmission amount distribution (b), and FIG. 7 is an example of mounting on the other surface side. FIG. 6A is a graph showing an example of the X-ray transmission amount distribution and the X-ray transmission amount distribution obtained from the difference between the one-side mounting and the double-sided mounting. FIG. In FIG. 1, the soldering inspection apparatus 1 according to the present embodiment is configured so that a soldering inspection line is provided during a manufacturing process of a mounting board so that a soldering inspection of a single-sided mounting board and a double-sided mounting board can be performed. There is. If the mounting board to be inspected is a double-sided mounting board, the double-sided mounting board mounts components on one surface side of the board, and then mounts components on the other surface side as well. In order to correspond to the soldering inspection, the soldering inspection device 1 is provided with the one surface side inspection unit 2 and the other surface side inspection unit 3, and during that time, the image data is transferred from the one surface side inspection unit 2 to the other surface side inspection unit 3. They are connected by a transmission line 4. One side inspection section 2
Is a single-sided mounting board that mounts components on one side of the board. The other-side inspection unit 3 mounts components on the other side of the one-sided board to form a double-sided board. It is placed in the substrate manufacturing process. When the mounting board to be inspected is a single-sided mounting board, the soldering inspection can be performed only by the one-side inspection section 2.

The one-side inspection unit 2 determines the one-side mounted substrate X-ray transmission image reading device 23, the response correction device 22, and the one-side mounting defect determination for the one-side mounted substrate that has been completely mounted on the one side. The device (single-sided mounting board inspecting means) 7 performs soldering inspection, and the X-ray transmission image of the single-sided mounting board obtained by the X-ray transmission image reading apparatus 23 is image-compressed by the image compression apparatus 24 and encoded. The image is encoded by the device 25 and stored in the memory 5, and the stored image can be transmitted from the image transmitter (data transfer means) 6 to the other-side inspection section 3 through the transmission path 4. The one-side mounting board X-ray transmission image reading device 23 and the double-sided mounting board X-ray transmission image reading device 17 described later irradiate the mounting board 30 with X-rays as shown in FIG. The X-ray detector 32 detects the X-rays transmitted through the substrate 30.
The X-ray transmission image of the mounting substrate 30 can be read by the detection. By detecting the X-ray transmission amount distribution of the soldering portion to be inspected from this X-ray transmission image, the shape of the soldering portion and the amount of solder can be measured, and the quality of soldering can be inspected. . The X-ray transmission image obtained by the X-ray transmission image reading device 23 for the one-side mounting board conforms to the actual shape because the gain characteristic in the high spatial frequency portion is lowered due to the influence of the response characteristic of the X-ray detector 32. There is a problem that the X-ray transmission image cannot be obtained accurately. Therefore, the response correction device (one-side mounted image correction means) 22 corrects the X-ray transmission image corresponding to the response characteristic of the X-ray detector 32, and an image with a constant gain characteristic in a predetermined spatial frequency range is obtained. To get The soldering inspection based on the X-ray transmission amount distribution is performed by the one-side mounting defect determination device 7 using the response-corrected image as described above.

When the mounting board to be inspected is a single-sided mounting board, the soldering inspection is completed by the above processing, but in order to correspond to the case where the mounting board to be inspected is a double-sided mounting board, It has the following configuration. The one-side mounting image obtained by the one-side mounting substrate X-ray transmission image reading device 23 is image-compressed by the image compression device 24 and encoded by the encoding device 25.
It is stored in the memory 5. The image stored in the memory 5 is transferred by the image transmitter 6 to the other-side inspection section 3 through the transmission path 4. Since this transmitted image is image-compressed and coded, the transfer time can be shortened, the speed of the manufacturing process of the mounting board can be responded to, and the soldering inspection can be performed in-line during the manufacturing process. In the other-side inspection section 3, the transferred image is received by the image receiver 8, decoded by the decoding device 9, and the one-side mounted image is reproduced by the image expansion device 10. This image is appropriately switched and stored in the two memories 12 and 13 by the switch 11. By preparing a plurality of memories 12 and 13 in this way, the transferred one-side mounting image can be temporarily held in order, taken out in accordance with the flow of the manufacturing process of the mounting board, and post-processing can be executed. ， For processing extraction of soldering inspection image,
The next image (mounting image on one side) can be prepared and put on standby. In the manufacturing process of the double-sided mounting substrate, the double-sided mounting is performed by mounting the one-sided mounting on the other side of the substrate. An X-ray transmission image is sampled by the double-sided mounting substrate X-ray transmission image reading device 17 from the double-sided mounting substrate that has completed double-sided mounting, and a response correction device (double-sided mounting image correction means)
The gain characteristic in a predetermined spatial frequency range is corrected by 18 so as to be constant. The response-corrected image is input to the difference device (other-side X-ray transmission image creating means) 20 and the alignment calculation device 19.

On the other hand, from the one-side mounting image stored in the above two memories 12 and 13, an image of the one-side mounting substrate, which is the source of the double-side mounting substrate currently in processing operation, is selected by the switching unit 14. It is selected and taken out, and response correction is performed by the response correction device 15 in the same manner as above.
The response-corrected image is input to the difference calculation device 20 and the alignment calculation device 16.
The alignment calculators 16 and 19 calculate the alignment amount based on the information about the alignment mark of the substrate given in advance and the position of the alignment mark read from the image, and input it to the difference device 20. The difference device 20 interpolates a shift of one pixel or less of each image based on the response-corrected double-sided mounting image and its alignment amount, and the response-corrected one-sided mounting image and its alignment amount, Positioning is performed to obtain the difference image between the two images, and the other-side mounted image is obtained. Using this other-side mounting image, the other-side mounting defect determination device (other-side mounting board inspection means) 21 performs a soldering inspection.

As described above, in this configuration, when the difference image between the one-side mounting image and the two-side mounting image is obtained, the alignment is performed with an accuracy less than the pixel pitch. The X-ray transmission image discretizes the analog signal detected by the X-ray detector at a predetermined time interval using an A / D converter. This time interval corresponds to the pixel pitch of the image. Therefore, when the difference image is obtained, if the difference is obtained without performing the alignment with an accuracy of less than the pixel pitch, an error due to a deviation of less than one pixel occurs in the obtained image, which causes a false determination in the soldering inspection. .
Therefore, in the present embodiment, the gray level (X-ray transmission level) of the pixel at the desired position is two-dimensionally interpolated,
Elimination of erroneous determination factors. For example, it is assumed that a two-dimensional matrix Ya [j, k] representing the gray level of the image is given. Here, j is in the range of 1 to m, and k is a natural number in the range of 1 to n. In addition to this, an array x1a of length m and an array x2a of length n are also given. From these values, the gray level value can be expressed by the following equation (1). Ya [j, k] = y (x1a [j], x2a [k]) (1) Here, Ya represents a gray level value discretized on a plane, and y represents a continuous gray level value.

What is desired to be estimated by the interpolation is the value of y at the points (x1, x2) not included in this. Now, consider four points surrounding the point (x1, x2) as shown in FIG. The square at each point in FIG. 3 indicates each pixel.
J and k are determined by the following equations (2) and (3), and x1a [j] ≦ x1 ≦ x1a [j + 1] ... (2) x2a [k] ≦ x2 ≦ x2a [k + 1] ... (3) Light and shade of each point The levels are set as the following equations (4), (5), (6) and (7). y1 = Ya [j, k] ... (4) y2 = Ya [j + 1, k] ... (5) y3 = Ya [j + 1, k + 1] ... (6) y4 = Ya [j, k + 1] ... (7) Two-dimensional The simplest interpolation is with the following equations (8) and (9)
Obtaining t and u, t = (x1-x1a [j] / (x1a [j + 1] -x1a [j]) ... (8) u = (x2-x2a [k] / (x2a [k + 1] -x2a [k ] (9) Further, the gray level at the point (x1, x2) is obtained by the following equation (10): y (x1, x2) = (1-t) (1-u) y1 + t (1-u) y2 + Tuy3 + (1-t) uy4 (10) The above expression (10) can be regarded as weighting the gray level at a desired position by the area ratio of a plurality of pixels in the vicinity thereof, and the sum is calculated. By doing so, interpolation is performed.

To further improve the accuracy of interpolation,
Select an m × n block that includes the point (x1, x2) for which the interpolation value is to be calculated, perform one-dimensional interpolation using m pixels in the x2 direction, and then perform one-dimensional interpolation using n pixels in the x1 direction. It can be performed. As one-dimensional interpolation, interpolation by polynomial such as Lagrange's formula, interpolation by rational function, interpolation by spline function can be used. The one-side mounting image and the both-side mounting image input to the difference device are images that have been response-corrected as described above. An X-ray detector for obtaining an X-ray transmission image is shown in FIG.
As shown in the example of the image intensifier which is a kind of X-ray detector, the response to the spatial frequency is not constant. Therefore, even if the one-sided mounting image and the two-sided mounting image that are in different mounting states and have different spatial frequencies are difference-corrected without response correction and the other-side mounting image is obtained, the other-side mounting image and the one-side mounting image are obtained. The sum of and does not become a double-sided mounting image. Therefore, it is possible to obtain a highly accurate other-side mounted image by extracting the difference image using the images in which the responses are corrected for both images and the responses to the spatial frequencies are aligned. The above-mentioned response correction is X by the analog signal detected by the X-ray detector.
By digitally converting the line-transmissive image, obtaining the spatial frequency component from this digital image, multiplying by a correction coefficient that corrects so that the predetermined spatial frequency range becomes substantially constant, and inversely transforming the multiplication result, This is a process of correcting an image so that the response characteristic becomes constant in a predetermined spatial frequency range. The correction coefficient can be set by previously obtaining a correction coefficient that makes the value of each spatial frequency of the digital image of the subject having a predetermined spatial frequency constant.

A specific example of extracting the other-side mounted image from the difference image using the response-corrected image is shown below. As shown in FIG. 5A, one surface side 26 a of the substrate 26
The X-ray transmission amount distribution of the double-sided mounting substrate 35 in which the chip component 27 mounted by soldering to the soldering land 28a formed on the above and the lead 33 of the component mounted on the other surface side 26b overlap each other and are mounted are shown. The gray level shown is as shown in FIG. The gray level of the one-sided mounting substrate 36 (FIG. 6a) before this double-sided mounting is as shown in FIG.
It becomes like (b). FIG. 7B shows the difference between the two X-ray transmission amount distributions without response correction and with response correction. Further, in FIG. 7B, as shown in FIG. 7A, the X in the state of being mounted only on the other surface side is shown.
The X-ray transmission amount distribution obtained by response-correcting the line transmission image is shown as comparison data. Although an X-ray transmission image in this state cannot be obtained by an actual inspection, how a response-corrected difference image between the one-side mounting image and the two-side mounting image can be approximated to the ideal other-side mounting image. It is for verifying whether it can be done. As shown in FIG. 7B, it can be seen that the difference image after the response correction is close to the other-side mounted image in the ideal state. In this example, the difference between the other-side mounted image and the image in the ideal state, which is the difference image without response correction, is 3.8% on average and 12.1% at maximum.
Therefore, by correcting the response, the average is 1.2.
%, The maximum is 4.0%. By performing the response correction in this way, the mounting image on the other side can be accurately extracted from the mounting image on both sides, and the soldering inspection can be performed accurately. Further, since the one-side mounting image and the both-side mounting image are both corrected so that the response characteristics are the same, the soldering inspection can be performed based on the same inspection standard.

[0015]

As described above, according to the present invention, when performing a soldering inspection by X-ray transmission of a double-sided mounting board, an X-ray transmission image is detected in a state of being mounted on one surface side of the board, A soldering inspection on one surface side is performed using this one surface side mounting image. Then, the X-ray transmission image is detected in a state where it is mounted on the other surface side of the one-side mounting board to become a double-sided mounting board, and the response correction of each of the one-side mounting image and the double-sided mounting image is performed. The other-side mounted image is extracted from the difference. By the above response correction, the response characteristics of the one-side mounting image and the two-side mounting image having different spatial frequencies with respect to the spatial frequency can be made uniform within a predetermined spatial frequency range, so that an accurate other-side mounting image can be extracted and inspected. The accuracy can be improved. When the difference image between the one-side mounted image and the two-side mounted image is obtained, the displacement less than the pixel pitch is interpolated and aligned, so that the other-side mounted image can be more accurately extracted.
Further, when the one-side mounted image is transferred to the other-side image extracting step, the transfer speed is improved by compressing, encoding and transferring the one-side image. The transferred images are sequentially stored in a plurality of image storage means, taken out in accordance with the detection process of the double-sided mounting image, and the other-side mounted image is extracted from the difference image. With this configuration, the soldering inspection for one surface side mounting and the soldering inspection for the other surface side mounting can be performed in parallel, and the one surface side mounting image of the next board can be prepared during the inspection of one board. The soldering inspection can be carried out according to the manufacturing process of the mounting board.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a soldering inspection apparatus according to an embodiment of the present invention.

FIG. 2 is a schematic diagram showing a schematic configuration of an X-ray transmission image reading device.

FIG. 3 is a schematic diagram illustrating a state of alignment between the one-side mounted image and the other-side mounted image that is less than a pixel pitch.

FIG. 4 is a graph showing an example of response characteristics of an X-ray detector.

FIG. 5 is a graph (b) showing an example of double-sided mounting (a) and an example of an X-ray transmission amount distribution.

FIG. 6 is a graph (b) showing an example of one-side mounting (a) and an example of an X-ray transmission amount distribution.

FIG. 7 is a graph (b) showing an example of mounting on the other side (a) and an X-ray transmission amount distribution thereof and an example of an X-ray transmission amount distribution obtained from the difference between the one-side mounting and the double-sided mounting.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Soldering inspection device 2 ... One surface side inspection part 3 ... Other surface side inspection part 4 ... Transmission path (data transfer means) 6 ... Image transmitter (data transfer means) 7 ... Defect determination device (one surface side mounting board inspection means) ) 8 ... Image receiver (data transfer means) 9 ... Decoding device 10 ... Image decompression device 12, 13 ... Memory (image storage means) 15 ... Response correction device (one-side mounted image correction means) 16, 19 ... Alignment calculation device Reference numeral 17 ... Double-sided mounting board X-ray transmission image reading device 18 ... Response correction device (double-sided mounting image correction means) 20 ... Difference device (other-side mounting image creation means) 21 ... Defect determination device (other-side mounting board inspection means) 22 ... Response correction device (one-side mounted image correction means) 23 ... One-side mounted substrate X-ray transmission image reading device 24 ... Image compression device 30 ... Mounting substrate 31 ... X-ray source 32 ... X-ray detector

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Eiji Yoshida 2-3-1, Niihama, Arai-cho, Takasago-shi, Hyogo Kobe Steel Works Takasago Works

Claims (7)

[Claims] 1. A X-ray transmission image obtained by irradiating an X-ray onto a mounting board, which is a member that is not completely shielded from X-rays and is attached to the board by soldering, and the transmitted X-ray is detected by an X-ray detector. In a soldering inspection method for a mounting board, which determines the quality of a soldering state by detecting an X-ray transmission amount distribution of a soldering part, in a mounting board on one side in a state where the member is mounted on one side of the board. A step of irradiating an X-ray and performing a soldering inspection by detecting the above-mentioned X-ray transmission amount distribution, and irradiating the double-sided mounting board with the above-mentioned member mounted on the other surface side of the one-sided mounting board with the X-ray. And a step of detecting an X-ray transmission image of the double-sided mounting board, and an image capturing system including the X-ray detector for the X-ray transmission image of the one-side mounting board and / or the X-ray transmission image of the double-sided mounting board, Based on the response characteristics of the image processing system And a response correction step, and a step of subtracting the response-corrected X-ray transmission image of the one-side mounting board from the response-corrected X-ray transmission image of the response-corrected double-side mounting board to obtain the other-side X-ray transmission image. A mounting board soldering inspection method, which comprises a step of performing a soldering inspection by detecting the X-ray transmission amount distribution using the other-side X-ray transmission image. 2. The mounting board soldering inspection method according to claim 1, wherein the response correction corrects the X-ray transmission image so that a gain characteristic in a predetermined spatial frequency range becomes substantially constant. 3. When the X-ray transmission image of the one-side mounting board is subtracted from the X-ray transmission image of the two-side mounting board, the X-ray transmission images of the one-side mounting board and the double-side mounting board are aligned from the reference mark. 2. The mounting board soldering inspection method according to claim 1, wherein the amount is obtained, and the displacement less than the pixel pitch is interpolated and aligned by using the alignment amount. 4. The soldering inspection method for a double-sided mounting board according to claim 1, wherein the X-ray transmission image of the first-side mounting board is compressed and encoded and transferred to a step of obtaining the second-side X-ray transmission image. . 5. An X-ray transmission image obtained by irradiating an X-ray on a mounting board, which is a member that is not completely shielded from X-rays and is attached to the board by soldering, and the transmitted X-ray is detected by an X-ray detector. In a soldering inspection apparatus for a mounting board, which determines the quality of a soldering state by detecting an X-ray transmission amount distribution of a soldering part, a mounting board on one side in which the member is mounted on one side of the board Based on the response characteristics of the X-ray detector, one-sided mounting board inspection means for irradiating X-rays and performing a soldering inspection by detecting the above-mentioned X-ray transmission amount distribution, and an X-ray transmission image of the one-sided mounting board. And the X-ray transmission image of the double-sided mounting board by irradiating the double-sided mounting board with the member mounted on the other side of the one-sided mounting board with X-rays. Double-sided mounting image for detection Detecting means and X of the double-sided mounting board
Double-sided mounting image correction means for response-correcting a line-transmission image based on the response characteristics of the X-ray detector, and the other-sided side by subtracting the response-corrected one-sided mounting image from the response-corrected double-sided mounting image It is provided with another-side mounting image creating means for obtaining an X-ray transmission image, and another-side mounting board inspection means for performing a soldering inspection by detecting the X-ray transmission amount distribution using the other-side mounting image. A soldering inspection device for a mounting board, characterized in that 6. The soldering inspection apparatus according to claim 5, wherein the one-side mounting image is compressed and encoded, and is transferred to a double-sided mounting board inspection side by using a data transfer means. 7. The soldering inspection apparatus according to claim 5, further comprising image storage means for storing a plurality of the one-side mounted images that have been decoded and expanded.