KR20200131487A - 3D shape measuring system of both-sides mounting electronic components using 2D X-ray image - Google Patents

Abstract

The present invention relates to a three-dimensional shape measuring system for a double-sided surface mount electronic component using a two-dimensional X-ray image, which comprises: an X-ray generating unit for sequentially emitting an X-ray at different times; a detector for acquiring two-dimensional X-ray images of different phases at different positions; and a shape measuring device for acquiring a three-dimensional appearance shape for a double-sided-mounted electronic component. According to the present invention, a three-dimensional appearance shape for a corresponding double-sided-mounted electronic component can be measured more rapidly.

Description

3D shape measuring system of both-sides mounting electronic components using 2D X-ray image}

The present invention relates to a system for measuring the shape of an electronic component in a double-sided mounting type. In particular, X-rays in different directions are irradiated onto a double-sided mounting electronic component, and two-dimensional X-ray images of different phases collected from a detector are stereoscopically The present invention relates to a technology capable of measuring a three-dimensional external shape of the double-sided electronic component by vision treatment.

The modern technology industry is developing at a rapid pace with the trend of miniaturization. In particular, for electronic parts used in various technology industries, not only the production technology but also the inspection technology that can determine the defect of the produced product is also important. Until recently, inspection was performed using a two-dimensional plane inspection technology of electronic products using image information. Measurements have been made.

X-ray inspection devices are widely known as non-destructive inspection means for inspecting electronic products.

In general, the wavelength of X-rays is as small as an atomic size, forming a unique diffraction pattern for each crystal. In addition, since the energy is high, the fluorescence action on the material is strong and the material can be easily transmitted, and at this time, the material is ionized. In addition, during transmission, the transmittance varies depending on the density of the substance or the atom, and thus the energy impinging on the phosphor is different. X-ray inspection apparatuses using this principle are widely used as medical equipment for imaging the inside of a living body and non-destructive inspection equipment used in general industrial fields.

In addition, the X-ray inspection apparatus is composed of a stage, an X-ray tube, and a detector inside the case, and inspects the object to be measured by placing an object to be measured on the stage and irradiating an X-ray from the X-ray tube to image the detector. Is configured to

On the other hand, in recent years, more and more electronic components are also made of multi-layered products, and when inspecting the products, not only two-dimensional planar inspection but also three-dimensional three-dimensional inspection is required.

However, the conventional X-ray inspection apparatus described above does not have any problem with single-sided boards, but when products of double-sided or multi-layered boards are produced in the SMT process and inspected for defects, even the internal state is projected and imaged, so that solder defects and opposite sides are bonded. There is a limit to three-dimensional inspection using X-rays because the superimposed images of parts are not well distinguished.

Accordingly, industrial X-ray CT apparatuses have been developed and used that can acquire cross-sectional images of several samples using X-rays, create a three-dimensional three-dimensional image of the sample from the cross-sectional images and display them on a display.

Industrial X-ray CT apparatus uses 3D CT technology that takes multiple 2D X-ray images from various angles and then mathematically synthesizes them to form a 3D image. At this time, the 3D image is composed of 3D volume data, and the industrial X-ray CT apparatus utilizes it to visualize it so that we can recognize it well on a computer.

However, in order to use the 3D CT technology, a large amount of images are required for a sample, as well as a disadvantage that a large amount of time is required to reconstruct a large number of images.

1. Korean Patent Laid-Open Patent No. 10-2004-0020520 (Name: X-ray inspection device for obtaining 3D images) 2. Korean Patent Registration No. 10-0956873 (Name: Inspection device using X-ray)

Accordingly, the present invention was created in view of the above circumstances, from a detector that irradiates X-rays in different directions at different times and receives the X-rays passing through the double-sided electronic component moving in conjunction with the X-ray emission position. By stereo vision processing the collected 2D X-ray images of different phases, 3D shape measurement for double-sided mounted electronic parts using 2D X-ray images that can more quickly measure the 3D external shape of the corresponding double-sided mounted electronic component The technical purpose is to provide a system.

According to one aspect of the present invention for achieving the above object, a transfer means for transferring a double-sided electronic component for measuring a three-dimensional shape, and a phase angle that is positioned above the transfer means to emit X-rays, but perpendicular to the center point An X-ray generator that sequentially emits X-rays at different times in a direction of 0° and a direction having at least one phase difference with respect to both sides based on the phase angle of 0°, and the zero surface mounted electronic component under the transfer means A detector that is disposed at the same position as and receives X-rays that have passed through the double-sided electronic component while moving at the same speed as the transfer means, thereby acquiring 2D X-ray images of different phases at different locations, and the transfer of the transfer means In response to the speed, at least three different phases of X-rays are emitted to the double-sided electronic component through the X-ray generator, and the transfer means and the detector are controlled to move, and collected at different times from the detector. Including a shape measuring device that obtains a three-dimensional external shape of the double-sided electronic component by calculating a height value for each feature point by stereo vision processing a 2D X-ray image of different phases of the double-sided electronic component. A three-dimensional shape measuring system for double-sided electronic components using a two-dimensional X-ray image is provided.

In addition, the shape measuring device includes x-rays on both sides of the center point so that the larger the maximum height value is based on the maximum height value for the reference surface that divides both sides of the double-sided electronic component, the smaller the phase difference from the center point of the x-ray generator. Using a two-dimensional X-ray image, characterized in that each phase angle is set, and X-rays are respectively emitted in a direction having a phase angle of both sides and an output phase angle of 0° perpendicular to the center point at different times through the X-ray generator. A three-dimensional shape measurement system for double-sided electronic components is provided.

In addition, the shape measuring apparatus includes a vertical image at a position perpendicular to the center point of the x-ray generator and a first side image at a position having a preset phase difference relative to the center point of the x-ray generator, and a second direction relative to the center point of the x-ray generator. Collects a second side image at a position with a preset phase difference, generates a first disparity map for the vertical image and the first side image, and generates a second disparity map for the vertical image and the second side image By mapping the feature points in the first disparity map and the second disparity map based on the feature points of the vertical image, the disparity between the feature points of the first disparity map and the second disparity map is calculated, and the calculated disparity is averaged. There is provided a three-dimensional shape measuring system for a double-sided electronic component using a two-dimensional X-ray image, which is configured to determine a height value for a feature point.

In addition, the shape measuring device sets an area having the same distance value at the edge of the double-sided electronic component in a vertical image at a position perpendicular to the center point of the X-ray generator as a reference plane, and extracts the height value of the reference plane of the double-sided electronic component. And, there is provided a three-dimensional shape measurement system for a double-sided electronic component using a two-dimensional X-ray image, characterized in that the upper and lower appearances of the shape are separated and shaped using the extracted reference height value.

According to the present invention, stereo vision processing is performed on the double-sided electronic component by using at least three or more 2D X-ray images of different phases, so that the double-sided electronic component is applied using the minimum 2D X-ray image. It is possible to more quickly measure the three-dimensional appearance shape for the.

1 is a diagram showing a schematic configuration of a three-dimensional shape measuring system for a double-sided electronic component using a two-dimensional X-ray image according to a first embodiment of the present invention.
FIG. 2 is a diagram illustrating an arrangement structure of the X-ray generator 100 and the detector 200 shown in FIG. 1.
FIG. 3 is a diagram illustrating the shape of the double-sided electronic component 1 shown in FIG. 1;
FIG. 4 is a diagram illustrating a process of processing a stereo vision in the shape measuring apparatus 300 shown in FIG. 1.
5 is a view for explaining the operation of the three-dimensional shape measuring system for a double-sided mounted electronic component using a two-dimensional X-ray image shown in FIG.
6 is a view for explaining in more detail a process (ST500) of measuring a three-dimensional external shape of the double-sided electronic component 1 in FIG. 5;

Since the embodiments described in the present invention and the configurations shown in the drawings are only preferred embodiments of the present invention, and do not represent all the technical spirit of the present invention, the scope of the present invention is limited to the embodiments and drawings described in the text. Should not be construed as limited by That is, since the embodiments can be variously changed and have various forms, the scope of the present invention should be understood to include equivalents capable of realizing the technical idea. In addition, since the object or effect presented in the present invention does not mean that a specific embodiment should include all of them or only those effects, the scope of the present invention should not be understood as being limited thereto.

All terms used herein have the same meaning as commonly understood by one of ordinary skill in the field to which the present invention belongs, unless otherwise defined. Terms defined in a commonly used dictionary should be construed as having the meaning of the related technology in context, and cannot be interpreted as having an ideal or excessively formal meaning that is not clearly defined in the present invention.

1 is a diagram showing a schematic configuration of a three-dimensional shape measuring system for a double-sided electronic component using a two-dimensional X-ray image according to a first embodiment of the present invention.

Referring to FIG. 1, a 3D shape measurement system for a double-sided electronic component using a 2D X-ray image according to the present invention includes an X-ray generator 100, a detector 200, and a shape measurement device 300. .

The X-ray generator 100 is disposed on a transfer means 10 on which a double-sided electronic component 1 is placed in a form in which electronic devices, etc. are mounted on both sides, for example, is disposed on the upper side of a conveyor belt, and is at a certain level toward the transfer means 10 Emits an x-ray of

In addition, a plurality of detectors 200 are disposed under the transfer means 10 to receive X-rays transmitted through the object to be inspected 1 to obtain a two-dimensional X-ray image of the double-sided electronic component 1. .

At this time, the X-ray generation unit 100 emits X-rays in a predetermined period in response to the moving speed of the transfer means 10, and as shown in FIG. 2, the center point C of the X-ray generation unit 100 is referenced. At different times, X-rays are emitted in different directions to have an arbitrary phase angle. To this end, the separation distance of the double-sided electronic component 1 disposed on the transfer means 10 is also appropriately set in consideration of the transfer speed of the transfer means 10 to satisfy this.

In FIG. 2, a direction having a phase difference (-60°) of 60° downward (0°) perpendicular to the center point (C) of the X-ray generator 100 and a phase difference (-60°) in the right direction based on the center point (C), and the left side. A diagram that emits X-rays in a direction having a phase difference (+60°) of 60° in the direction is illustrated. That is, X-rays of -60° phase are emitted at time T1, X-rays of 0° phase are emitted at time T2, and X-rays of +60° phase are respectively emitted at time T3.

When the x-ray generator 100 emits X-rays to have the same phase difference in different directions as shown in FIG. 2, the shape measurement device 300 then shapes the three-dimensional appearance of the double-sided electronic component 1 It can be simpler than this. In the present invention, in some cases, it is possible to emit X-rays so as to have a different phase difference in each direction based on the central point C of the X-ray generator 100. For example, X-rays may be emitted to have a phase difference of 30° to the right and 45° to the left.

In addition, in FIG. 2, the X-ray generator 1000 is shown to emit X-rays so as to have one phase difference in each direction with respect to the center point C, but is implemented to emit two or more X-rays having a different phase difference in each direction. For example, it is possible to have a phase difference of 60° and 30° in the right direction with respect to each direction based on the center point C of the X-ray generator 100 and a phase difference of 30° and 45° in the left direction. Can emit X-rays.

In addition, referring to FIG. 2, the detector 200 is moved to be located at a position corresponding to a corresponding X-ray emission position at a time when an X-ray is emitted from the X-ray generator 100. At this time, the detector 200 is located on the lower surface of the transfer means 10 at the same position as the double-sided electronic component 1 located on the upper surface of the transfer means 10, and is moved at the same speed as the transfer means 10. I can.

That is, the X-ray generator 100 emits X-rays to at least one or more different phase positions in different directions, including a 0° phase position perpendicular to the center point C, and emits X-rays corresponding thereto. The transfer means 10 and the detector 200 are moved and controlled so that the double-sided electronic component 1 and the detector 200 are positioned at the position.

Meanwhile, in FIG. 1, the shape measuring apparatus 300 controls to emit X-rays of different phases through the X-ray generator 100, and the transfer means 10 and the detector 200 are By controlling the moving speed and calculating the height value for each feature point by stereo vision processing the two-dimensional X-ray images of different phases for the double-sided electronic component 1 collected at different positions from the detector 200, A three-dimensional external shape of the double-sided electronic component 1 is obtained.

At this time, the shape measuring apparatus 300 is configured to measure a single double-sided electronic component 1 in different directions based on a vertical image at a position perpendicular to the center point C of the X-ray generator 100 and the vertical image. The three-dimensional external shape of the double-sided electronic component 1 is measured using at least two phase difference images having a set phase difference.

In the present invention, in the double-sided electronic component 1, as shown in FIG. 3, the electronic device U is mounted on the upper surface of the PCB substrate and the electronic device D is mounted on the lower surface of the PCB substrate. As a component, the electronic device U on the upper surface and the electronic device D on the lower surface may have different external shapes.

Accordingly, the shape measuring apparatus 300 extracts an area that has the same height value of the edge portion of the double-sided electronic component 1 from the vertical image and divides it into a reference plane that divides both sides of the double-sided electronic component 1, that is, a PCB substrate. Can be set to Through this, the height of the electronic device (U) formed on the upper surface of the PCB substrate and the height of the electronic device (D) formed on the lower surface of the PCB substrate can be divided and shaped.

That is, the shape measuring apparatus 300 classifies a distance value lower than the reference plane as an upper surface and a distance value greater than the reference plane as a lower surface, and the lower the distance value for the upper surface, the higher the corresponding position height, and the higher the distance value for the lower surface, Shape it so that the height of the location is high.

In addition, the shape measuring device 300 selects an x-ray phase angle corresponding to the height value based on basic information including the height value of the double-sided electronic component 1, and generates an x-ray in response to the selected x-ray phase angle. Drive control the unit 100, the transfer means 10, and the detector 200. In addition, the shape measurement device 300 includes a two-dimensional X-ray image collected by the detector 200 at a selected phase angle position and a position perpendicular to the center point C of the x-ray generator 100. The shape of the double-sided electronic component 1 may be measured using a 2D X-ray image.

In this case, the basic information on the double-sided electronic component 1 includes a maximum height value of the upper surface of the PCB substrate, a maximum height value of the PCB substrate, and may further include a thickness of the PCB.

In addition, the shape measuring device 300 stores X-ray phase angle information for each height value range of the double-sided electronic component 1 in advance, and based on a higher height value among the maximum height value of the upper surface based on the PCB and the maximum height value based on the PCB. The x-ray phase angle can be determined by.

In this case, the X-ray phase angle information for each height value range is set to have an X-ray phase angle having a smaller phase difference from the center point C of the X-ray generator 100 as the height value of the double-sided electronic component 1 increases. For example, an X-ray phase angle corresponding to ±30° is selected for a height value of 10 mm of the double-sided electronic component 1, and an X-ray phase angle corresponding to ±60° for a height value of 5 mm of the double-sided electronic component 1 Can be chosen.

In addition, the shape measuring apparatus 300 performs stereo vision processing to calculate the height of the corresponding feature point by using the disparity between the matched feature points in two X-ray images having different phases, and thus, the double-sided electronic component 1 Shape in three dimensions. The stereo vision processing algorithm generates a sine graph using the detection values (parallax) of the feature points detected in images of different phases, inversely transforms it into an equation, and recognizes the dense part of the 3D value as a boundary surface. By calculating the value, various algorithms such as obtaining an approximate three-dimensional shape can be applied.

4 illustrates a stereo vision processing process for X-ray images of different phases.

Referring to FIG. 4, as shown in (A), 2D X-ray images of different phases appear as brightness values corresponding to distances to specific feature points. (B) shows images corresponding to -30°, 0°, and +30° for the same sample, respectively, and images of different phases have different brightness values at the same position (feature point) corresponding to the height difference. You can see that it has. That is, stereo vision is to obtain a height image as shown in (C) by calculating a difference in brightness values at the same location in images of different phases.

At this time, the shape measurement device 300 generates a parallax map by comparing a vertical image having a phase difference of 0° and a 2D X-ray image having a different phase difference collected by the detector perpendicular to the center point C of the X-ray generator 100. Then, a map is generated using the parallax average value for the feature points between each parallax map.

For example, the shape measuring apparatus 300 generates a right parallax map by comparing an X-ray image of -30° phase with an X-ray image of 0° phase, and compares the X-ray image of +30° phase with the X-ray image of 0° phase. A left parallax map is created, and by mapping feature points in the right parallax map and the left parallax map, the parallax between the feature points of the right parallax map and the left parallax map is calculated. In addition, by calculating the average value of the parallax between the feature points of the right parallax map and the left parallax map, that is, "parallax/2", a height value for the double-sided electronic component 1 can be obtained.

At this time, by setting a pair of feature points between the right parallax map and the left parallax map based on an X-ray image of 0° phase, it is possible to map more accurately. That is, as shown in Fig. 3, when there is a difference between the upper or lower height on the right and the upper or lower height on the left, the upper and lower feature points overlap, making it difficult to accurately distinguish the feature points. As such, the present invention maps a pair of feature points based on an X-ray image of 0° phase, so that even in such a situation, the feature points can be more accurately determined.

Next, an operation of a three-dimensional shape measuring system for a double-sided electronic component using a two-dimensional X-ray image according to the present invention will be described with reference to FIG. 5.

First, the X-ray generating unit 100 is positioned at a position spaced a predetermined distance above the transfer means 10, and on the upper surface of the transfer means 10, a double-sided electronic component 1 as a measurement object is disposed, and the transfer means ( The detector 200 is disposed below 10) at the same position as the double-sided electronic component 1.

In the above-described state, when basic information including a height value for the double-sided electronic component 1 is provided to the shape measuring device 300 (ST100), the shape measuring device 300 is The x-ray phase angle corresponding to the height value is determined (ST200). For example, the x-ray phase angle of -30°, 0°, and +30° for the electronic component 1 with a height of 10 mm may be determined.

In addition, the shape measurement device 300 generates an x-ray so that the double-sided electronic component 1 and the detector 200 are present at the position where the x-ray of the phase angle determined in step ST200 is emitted in consideration of the moving speed of the transfer unit 10 The unit 100 generates an X-ray generation signal in the form of a pulse for generating X-rays.

In addition, the shape measuring apparatus 300 provides an X-ray generation signal to the X-ray generator 100 to control to emit X-rays of different phase angles at different times, and the transfer means 10 and the detector 200 Is controlled to move at the same speed (ST300).

In the process of the ST300, the shape measuring apparatus 300 collects 2D X-ray images of different phases from the detector 200 at different viewpoints (ST400).

At this time, the shape measuring apparatus 300 calculates a height value for the double-sided electronic component 1 by performing stereo vision processing using two-dimensional X-ray images of different phases, and uses the two-dimensional X-ray images to calculate a height value of Acquire (ST500).

That is, the shape measurement apparatus 300 extracts and maps feature points corresponding to the same location from different 2D X-ray images, calculates the parallax between the mapped feature point pairs, and applies the calculated parallax to a preset stereo vision algorithm. , It is possible to calculate the height value of the corresponding location (feature point). Then, by generating a map for the height value, the external shape of the double-sided electronic component 1 is completed.

Meanwhile, FIG. 6 is a view for explaining in more detail a process (ST500) of measuring a three-dimensional external shape of the double-sided electronic component 1 in FIG. 5. 6, a vertical image photographed from the detector at a position perpendicular to the central point C of the x-ray generator 100, and a predetermined phase difference in the right direction from the central point C of the x-ray generating unit 100 prior to the vertical image. A first phase difference image photographed from the detector 200 at a position, and a second phase difference image photographed from the detector 200 at a position having a constant phase difference in the left direction from the center point C of the X-ray generator 100 after the vertical image A process of measuring the three-dimensional external shape of the double-sided electronic component 1 by using is illustrated.

Referring to FIG. 6, the shape measuring apparatus 300 performs stereo vision processing on a vertical image and a first phase difference image to generate a first parallax map, and stereo vision processing the vertical image and a second phase difference image to obtain a second parallax map. Generate (ST510, ST520).

In addition, the shape measuring apparatus 300 performs stereo vision processing on the first disparity map and the second disparity map to calculate disparity for each feature point (ST530). In this case, the shape measuring apparatus 300 maps the feature points between the first disparity map and the second disparity map based on the feature points of the vertical image. For example, when "Y" is mapped in the first disparity map and "Z" is mapped in the second disparity map with respect to the feature point "X" of the vertical image, "Y" and "Z" are mapped.

Subsequently, the shape measuring apparatus 300 determines a height value for the corresponding feature point by calculating the average of the parallax calculated in step ST530 (ST540).

At this time, the shape measuring device 300 extracts the height value of the reference surface of the double-sided electronic component 1 from the vertical image, and uses the extracted reference surface height value to determine the top and bottom appearances of the double-sided electronic component 1 It can be implemented to separate and shape. Here, the reference surface of the double-sided electronic component 1 may be set as an area having the same distance value from the outer portion of the double-sided electronic component 1.

100: X-ray generator, 200: detector,
300: shape measuring device,
1: double-sided electronic component, 10: transfer means.

Claims (4)

A transfer means for transferring the double-sided electronic component for measuring a three-dimensional shape;
It is positioned above the conveying means to emit X-rays, but at different times in a direction having a phase angle of 0° perpendicular to the center point and a direction having at least one phase difference for both sides based on the phase angle of 0°. An x-ray generator that sequentially emits,
Two-dimensional X-ray images of different phases at different positions by receiving X-rays that are disposed under the transport means at the same position as the permanently mounted electronic component, and while moving at the same speed as the transport means, passing through the double-sided electronic component A detector that acquires and,
In response to the transfer speed of the transfer means, control to emit at least three or more different phases of X-rays to the double-sided electronic component through the X-ray generator, and control to move the transfer means and the detector, and A shape that obtains a three-dimensional appearance of the double-sided electronic component by calculating the height value for each feature point by stereo vision processing 2D X-ray images of different phases of the double-sided electronic component collected at different times. A three-dimensional shape measuring system for a double-sided electronic component using a two-dimensional X-ray image, comprising a measuring device.
The method of claim 1,
The shape measuring device includes an x-ray phase angle for both sides of the center point to have a smaller phase difference from the center point of the x-ray generator as the maximum height value increases based on a maximum height value for a reference surface that divides both sides of a double-sided electronic component. Double-sided mounting using a two-dimensional X-ray image, characterized in that each is set and controlled to emit X-rays respectively in a direction having a phase angle of both sides and an output phase angle of 0° perpendicular to the center point at different times through the X-ray generator. 3D shape measurement system for electronic parts.
The method of claim 1,
The shape measuring apparatus includes a vertical image at a position perpendicular to the center point of the x-ray generator, a first side image at a position having a preset phase difference in a first direction with respect to the center point of the x-ray generator, and a second direction with respect to the center point of the x-ray generator. Collecting a second side image at a position having a phase difference, generating a first disparity map for the vertical image and the first side image, and generating a second disparity map for the vertical image and the second side image, By mapping the feature points in the first disparity map and the second disparity map based on the feature points of the vertical image, the disparity between the feature points of the first disparity map and the second disparity map is calculated, and the calculated disparity is averaged to the corresponding feature point. A three-dimensional shape measurement system for a double-sided electronic component using a two-dimensional X-ray image, characterized in that configured to determine a height value for the.
The method according to any one of claims 1 to 3,
The shape measuring device sets an area having the same distance value at the edge of the double-sided electronic component in a vertical image at a position perpendicular to the center point of the X-ray generator as a reference plane, and extracts a height value with respect to the reference plane of the double-sided electronic component, A three-dimensional shape measurement system for a double-sided electronic component using a two-dimensional X-ray image, characterized in that the upper and lower appearances of the shape are separated and shaped using the extracted reference surface height value.

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