JP2004226316A - Scanning head and appearance inspection apparatus available for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for accurately inspecting coating condition of cream solder on a substrate. <P>SOLUTION: A lighting unit 30 irradiates the substrate 1 with lateral light by a lateral lighting source 102 and slit light by a slit lighting source 103 which are alternately switched therebetween for every one line. Light from a plurality of LEDs (light emitting diodes) 120 of the lateral lighting source 102 is diffused by an acrylic sheet 104 and is projected onto a line 112 under inspection. A rotating tube 101 has a slit mask pattern. Light from a plurality of LEDs 120 of the slit lighting source 103 is projected onto the line 112 as a striped pattern. Reflected light from the line 112 is reflected by a half mirror 108 and enters a line sensor 34 through a lens 32. The coated area of the cream solder is judged through an appearance image of the substrate 1 by the lateral light, while the height of the coated area is measured by the striped pattern image. <P>COPYRIGHT: (C)2004,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a technology for inspecting the appearance of an object to be inspected. In particular, the present invention relates to a scanning head that scans an object to be inspected and obtains an image, and a visual inspection apparatus that can use the scanning head.
[0002]
[Prior art]
Chips such as ICs and LSIs are bonded to a substrate by soldering. This soldering is performed by applying cream solder to the electrodes of the substrate using a screen printing device, landing the chip leads on the cream solder, and then heating the cream solder using a reflow device. At this time, if the applied amount of the cream solder is not appropriate, the soldering is likely to be defective. Therefore, the inspection of the applied state of the cream solder is performed before the chip is mounted on the substrate by the chip mounter. In particular, in the case of BGA (Ball Grid Array), since input / output pads are arranged on the back surface of the package, it is not possible to judge the quality of soldering from the external appearance after bonding to the substrate. It is necessary to inspect the application state of the cream solder.
[0003]
In such a visual inspection apparatus for inspecting the application state of the cream solder, it is necessary to photograph the substrate with a very high resolution corresponding to the high-density mounting and to perform the defect detection with high accuracy. Therefore, the time required for the inspection tends to be long. The demand for integrated circuits is increasing and the speed of the mounting process is increasing. However, if the board inspection takes a long time, the shipment of products will be delayed, and it will not be possible to withstand the recent severe manufacturing competition. Further, once a defective product is found, extra work such as collection, repair, and re-shipment occurs, and the cost for that is not always covered by the sales profit of the product. Therefore, there is a strong need for a one-way logistics in which the inspection time can be shortened and the appearance of the inspection device with higher accuracy can minimize product defects and complaints about the product as much as possible.
[0004]
Here, the appearance inspection device has been performing inspection of the quality of the application state of the cream solder by measuring the application area of the cream solder. However, in order for the soldering of chips to be performed normally, it is necessary to apply an appropriate amount of cream solder. Inspection is not possible. Therefore, in order to perform a more precise inspection, it is becoming essential to measure the volume of the applied cream solder. For example, Patent Literature 1 discloses an apparatus that irradiates a line pattern onto a substrate by a slit light projector, captures an image of the substrate using a camera, and analyzes the shape of the solder paste.
[0005]
[Patent Document 1]
JP-A-5-187838 (Full text, Fig. 1-11)
[0006]
[Problems to be solved by the invention]
In the apparatus disclosed in Patent Literature 1, the substrate is moved in the X and Y directions to irradiate the solder paste in a specific area with a light cutting line, and an image is captured as a spot and inspected. In this case, even if a CCD (charge-coupled device) image sensor having 1 million pixels is used, if an image is captured at a pixel pitch of 20 to 30 micrometers, it is possible to capture an area of 2 to 3 cm in length and width at a time. Therefore, it takes a very long time to inspect the entire substrate. For example, on a motherboard of a notebook computer, there are 2,000 to 4,000 points of solder printing spots, but in such a visual inspection apparatus that moves an imaging spot in the XY directions, at most one hundred to two hundred points can be selectively selected. Just inspect. In order to put the motherboard on the production line, it is necessary to inspect the motherboard in 30 seconds or less, and if all the points are inspected, it will not be in time for production, but this will reduce the incidence of soldering defects. Not be able to do this, resulting in extremely poor production control.
[0007]
The present invention has been made in view of the above circumstances, and has as its object to provide a high-speed and high-precision appearance inspection technique suitable for being introduced into a substrate production line, which can inspect the solder application state of the substrate at high speed. In the offer.
[0008]
[Means for Solving the Problems]
One embodiment of the present invention relates to a head for scanning an object to be inspected. The scanning head includes a side illumination source that projects light obliquely to an inspection surface of the object to be inspected, a slit illumination source that emits slit light to the inspection surface obliquely, and vertically upward from the inspection surface. A one-dimensional sensor for detecting the reflected light traveling toward the side, and the side illumination source and the slit illumination source are configured to be selectively light-controlled.
[0009]
Here, “scan” refers to an operation in which the scanning head is driven in a direction perpendicular to the direction in which the imaging elements of the one-dimensional sensor are arranged, and the direction of the relative movement between the scanning head and the test object is referred to in this specification. Expressed as “driving direction” or “scanning direction”. On the other hand, detection of one line of reflected light by the scanning head is expressed as "imaging" to distinguish it from scanning.
[0010]
The side illumination source and the slit illumination source may each include a light emitting diode group arranged along an imaging line of the one-dimensional sensor. Since the light emitting diode group is turned on and off quickly enough and has a long life, it is advantageous as a side illumination source and a slit illumination source that are selectively turned on and off.
[0011]
The image processing apparatus may further include a short-focus imaging element array for projecting the slit light onto the inspection surface. The fringe pattern by the slit light can be efficiently projected along the imaging line by the short focus imaging element array.
[0012]
Another embodiment of the present invention relates to a visual inspection device for an object to be inspected. The apparatus includes a scanning head that scans the object to be inspected, and a main unit that comprehensively controls the entire apparatus including the scanning head. The scanning head includes a side illumination source that projects light from an oblique direction to an inspection surface of the object to be inspected, a slit illumination source that emits slit light to the inspection surface from an oblique direction, and vertically upward from the inspection surface. A one-dimensional sensor that detects reflected reflected light and generates image data, wherein the side illumination source and the slit illumination source are configured to be selectively light-controlled. A head control unit for controlling lighting of the scanning head and relative movement of the scanning head and the object to be inspected, an image for visual inspection of the inspection surface by the side illumination source, and the slit illumination source A memory control unit that loads the height measurement image into a memory, and an analysis unit that determines the quality of the solder application state using the appearance inspection image and the height measurement image.
[0013]
The head control unit repeats turning on and off the side illumination source and the slit illumination source alternately in accordance with the relative movement of the scanning head and the test object, and the memory control unit The image data generated by the original sensor may be selectively captured in accordance with a synchronization signal, and the image for visual inspection and the image for height measurement may be formed in the memory. The scanning head further includes an epi-illumination source for projecting light from above vertically to the inspection surface of the object to be inspected, and the epi-illumination source, the side illumination source, and the slit illumination source can be selectively turned on. It may be. In this case, the head control unit repeatedly turns on the epi-illumination source, the side illumination source, and the slit illumination source in accordance with the relative movement of the scanning head and the object to be inspected, and repeatedly turns on the illumination source. The memory control unit selectively captures image data generated by the one-dimensional sensor in accordance with a synchronization signal, an image for visual inspection by the epi-illumination source, and an image for visual inspection by the side illumination source, An image for height measurement by the slit illumination source may be formed in the memory.
[0014]
The analysis unit determines a solder application area photographed on the visual inspection image, and then determines a height of the solder application area based on a stripe pattern formed by slit light photographed on the height measurement image. By measuring the thickness, the quality of the applied state may be determined based on the volume of the solder. The position of the application area is specified by the visual inspection image, and it can be accurately associated with the stripe pattern of the height measurement image, so the area and height of the application area can be accurately determined, and the accuracy based on the volume of the solder The quality of the application state having a high value can be determined.
[0015]
A method, a system, and a computer program in which any combination of the above-described components and a device are expressed are also effective as embodiments of the present invention.
[0016]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiment 1
FIG. 1 shows a configuration of a visual inspection device 10 according to the first embodiment. This apparatus scans an inspection surface of an object to be inspected with a line sensor to form an image, and determines pass / fail of the application state of the cream solder by image recognition. By driving the scanning head perpendicular to the imaging line by the line sensor, images for each line are sequentially obtained, and the inspection is completed by one-dimensional movement of the scanning head.
[0017]
As shown in FIG. 1, the visual inspection device 10 includes a main unit 12 and a test unit 14. A support table 22 is provided below the test unit 14, and holds the substrate 1 as an object to be inspected. Above the test unit 14, a scanning head 16, a stepping motor 20 for driving the scanning head 16, and a guide 18 such as a linear guide for supporting the scanning head 16 are provided.
[0018]
The scanning head 16 has an illumination unit 30, a lens 32, and a line sensor. These members are fixed on a frame 36. The illumination unit 30 includes a side illumination source, a slit illumination source, and a half mirror, which will be described later. The light reflected vertically upward from the substrate 1 is guided to a lens 32 by a half mirror, passes through the lens 32, and is input to a line sensor 34 which is a one-dimensional CCD sensor. The line sensor 34 captures an image of the substrate 1 on a line-by-line basis and outputs image data 54 thereof.
[0019]
The main unit 12 comprehensively controls the entire apparatus, and can be realized in terms of hardware by using a CPU, a memory, or other LSI of any computer, and in terms of software, a visual inspection loaded into the memory. The functions are realized by a program having a function, and the functional blocks realized by their cooperation are illustrated here. Therefore, it is understood by those skilled in the art that these functional blocks can be realized in various forms by hardware only, software only, or a combination thereof.
[0020]
First, the head control unit 40 of the main unit 12 supplies an illumination control clock 50 (hereinafter, also referred to as a synchronization signal) to the illumination unit 30, and alternately switches the side illumination and the slit illumination for each line to light. The head control unit 40 further outputs a motor control signal 52 to the motor 20 and a test start signal 56 to the memory control unit 42. The step control of the motor 20 is performed by the motor control signal 52, and the scanning head 16 moves to the end of the substrate 1 at the start of the inspection. Hereinafter, this position is referred to as a “start position”. Thereafter, each time one line is imaged, the scanning head 16 advances by one line by the motor control signal 52. On the other hand, with reference to the test start signal 56, the memory control unit 42 controls the writing of the image data 54 to the memory 44, and thereafter, the image data 54 is recorded line by line. The image data 54 is selectively input for each line, the image captured when the surface is projected by the side illumination, and the image captured when the slit light is projected by the slit illumination. When the imaging of all lines is completed, an image for visual inspection by side illumination and an image for height measurement by slit illumination are formed in the memory 44. The internal configuration of the memory 44 and the arrangement of the image data 54 in the memory 44 have a degree of freedom in design, and various configurations are possible. For example, in the memory 44, two independent storage areas for separately storing the visual inspection image and the height measurement image are provided, and the memory control unit 42 divides each line into each storage area. Control may be performed such that the image data 54 is stored individually. Alternatively, a single storage area for storing the appearance inspection image and the height measurement image is provided in the memory 44, and the memory control unit 42 stores one image data 54 in the single storage area. Control may be performed such that the data is stored alternately line by line.
[0021]
The analysis unit 46 reads the image for the visual inspection and the image for the height measurement from the memory 44 in parallel with the scan or after the scan is completed, and reads the image for cream cream in accordance with the criteria previously recorded in the criteria memory 48. The pass / fail of the application state is determined. Based on the appearance inspection image, it is inspected whether the cream solder is applied to a correct position, and the area of the application area of the cream solder is measured. Based on the height measurement image, the height of the cream solder application area is measured, the volume of the cream solder is determined along with the previously measured area, and it is checked whether the application amount is appropriate. You.
[0022]
FIG. 2 is a perspective view of the test unit 14, and FIG. 3 is a schematic diagram of the test unit 14 as viewed from a direction 110 of an imaging line of the line sensor 34 (hereinafter simply referred to as an imaging direction). When image data for one line is taken in the state shown in FIG. 2 or FIG. 3, the scanning head 16 is sent out by one line in the driving direction 114 by the guide 18. Thereafter, by repeating the same processing, image data over the entire surface of the substrate 1 is obtained.
[0023]
The illumination unit 30 includes a side illumination source 102 provided with an acrylic sheet 104 below, a slit illumination source 103 surrounded by a rotating cylinder 101, and a half mirror 108.
[0024]
As shown in FIG. 3, each of the two side illumination sources 102 has an LED (light emitting diode) group 120 and is inclined to efficiently emit side light to the line 112 under inspection. The acrylic sheet 104 has a function of diffusing side light from the side illumination source 102. Since the side illumination source 102 is an aggregate of LEDs that are point light sources, if there is no diffusion effect, there is a concern that spot-like light will be reflected in image data and adversely affect inspection accuracy.
[0025]
The slit illumination source 103 also has an LED group 120 as a light source. Slit light is generated by a slit mask pattern provided on the outer peripheral surface of the rotating cylinder 101, condensed by the short focus imaging element array 105, and the substrate 1 is formed as a stripe pattern. Are projected onto the line 112 on the inspection plane of the. Light reflected from the line 112 is reflected by the half mirror 108 and enters the line sensor 34 via the lens 32.
[0026]
As an example of the short focus imaging element array 105, a Selfoc (registered trademark) lens array (SLA) is used to realize the projection of a stripe pattern in a small space. In addition, the rotating cylinder 101 is configured to be able to control the rotation at the same time as the driving of the scanning head 16, so that the continuity of the stripe pattern can be ensured by the rotation, the interval between the stripe patterns can be narrowed, and the resolution of the height measurement can be increased. be able to.
[0027]
FIGS. 4A and 4B are diagrams illustrating a slit mask pattern provided on the surface of the rotary cylinder 101. FIG. Chips such as ICs and LSIs are generally arranged along the vertical or horizontal direction of the substrate 1, and are rarely arranged diagonally. From this, the stripe pattern by the slit light is formed at an angle of 45 degrees with respect to the cream solder application area, so that the solder application area is set regardless of whether the chips are arranged vertically or horizontally. It is more preferable that the number of stripe patterns with respect to is sufficiently obtained. Therefore, in FIG. 4A, a slit mask pattern having a 45-degree inclination is formed on the surface of the rotary cylinder 101. However, as shown in FIG. 4B, a slit mask pattern may be provided so that a stripe pattern is generated in parallel to the imaging direction 110 of the line sensor 34.
[0028]
FIG. 5 is a diagram illustrating the substrate 1 on which cream solder is applied. A cream solder 3 is applied to the electrode 2 of the substrate 1. A portion of the substrate 1 other than the electrode 2 is coated with a translucent solder resist film 4, and even if the cream solder 3 is applied thereon, it is not melted by reflow. This figure shows a defective solder application state.
[0029]
FIGS. 6A and 6B are diagrams illustrating a stripe pattern formed by irradiating the substrate 1 coated with such cream solder with slit light. FIGS. 6A and 6B are stripe patterns when slit light is irradiated by the slit mask patterns of FIGS. 4A and 4B, respectively.
[0030]
6A and 6B, the long side of the cream solder application area 5 is formed parallel to the imaging direction 110 of the line sensor 34, and the imaging direction shown in FIG. When a slit mask pattern parallel to 110 is used, the stripe pattern is formed in the long side direction of the solder application area 5 as shown in FIG. The number is limited. When the long side of the coating area 5 is formed perpendicular to the imaging direction 110, the number of stripes projected on the coating area 5 increases.
[0031]
On the other hand, when a slit mask pattern having an inclination of 45 degrees with respect to the imaging direction 110 shown in FIG. 4A is used, the stripe pattern is oblique to the coating area 5 as shown in FIG. Since it is formed, a sufficient number of stripes can be secured regardless of whether the long side direction of the application area 5 is perpendicular or parallel to the imaging direction 110, and the resolution can be increased. .
[0032]
6A and 6B, at the boundary of the cream solder application area 5, a stripe pattern shift occurs according to the height of the application area. Therefore, the height of the application area 5 can be obtained by measuring the amount of deviation of the stripe pattern and performing an inverse calculation.
[0033]
FIG. 7 is a flowchart showing an inspection procedure of the visual inspection device 10 having the above configuration. The lighting of the side light and the lighting of the slit light are selected and performed in accordance with the synchronization signal, and both the image for the visual inspection and the image for the height measurement are simultaneously performed while the scanning head 16 moves once on the substrate 1. Form. Here, an inspection procedure by a switching scanning method in which an odd-numbered line including the first line, which is a start position, is set for visual inspection, and an even-numbered line is set for height measurement.
[0034]
First, the appearance inspection mode, which is the first mode, is selected, and the scanning head 16 is sent to the start position (S50). With the selection of the appearance inspection mode, the side illumination source 102 is turned on and the slit illumination source 103 is turned off by the head control unit 40. Under the side light, the first line is imaged by the line sensor 34 (S52), and the image data 54 is written to the memory 44 (S54).
[0035]
Subsequently, the scanning head 16 is moved by one line in the driving direction by the head control unit 40 (S56), and the position is determined at the scanning end position, that is, at the end end of the substrate 1, in accordance with the information regarding the substrate 1 that has been input in advance. It is determined whether or not there is (S58). If it is not the end position (N in S58), the mode is switched to the height measurement mode (S60). With the selection of the height measurement mode, the side illumination source 102 is turned off and the slit illumination source 103 is turned on by the head control unit 40. Under the slit light, imaging of the second line by the line sensor 34, writing of the image data 54 to the memory 44, and advance of the scanning head 16 (S52, S54, S56) are performed. Until the scanning head 16 reaches the end position, the processing from S52 to S60 is repeated, and the image of the odd line is formed by the side light, while the image of the even line is formed by the slit light.
[0036]
When the scanning head 16 comes to the end position, the process proceeds from Y in S58 to S60. In step S60, the analysis unit 46 reads out the image for the appearance inspection by the side light from the memory 44, determines whether or not the application area of the cream solder is applied to the inspection location, and then reads out the image for the height measurement by the slit light. The height of the application area is measured. That is, for each inspection point, whether the application position of the cream solder is correct is inspected, and the volume of the cream solder is calculated from the area and height of the application area of the cream solder, and whether or not the application amount is appropriate is determined. Will be inspected. Pass / fail judgment criteria for the solder application state inspection and other information are read from the judgment reference storage unit 48 and used. When the inspection is completed, the result is displayed (S62), and a series of processing is completed. The pass / fail may be recorded in the memory 44 as well as the display.
[0037]
As described above, in the appearance inspection apparatus 10 of the present embodiment, the image for the appearance inspection and the image for the height measurement on which the stripe pattern is projected are obtained at a time by switching the illumination, and the application of the solder is performed using the image for the appearance inspection. After the area is accurately determined, the height of the application area can be measured by associating the stripe pattern with the image for height measurement. Since the side light and slit light are switched for each line and the substrate is photographed, the displacement of the application area can be minimized, and the volume of the applied solder can be accurately calculated to achieve high-precision application. A pass / fail determination of the quantity can be made.
[0038]
Embodiment 2
In the present embodiment, the illumination unit 30 of the test unit 14 of the visual inspection apparatus 10 according to Embodiment 1 further includes the epi-illumination illumination source 100, and captures an image for visual inspection using epi-illumination light. Here, a configuration and an operation different from the first embodiment will be described.
[0039]
FIG. 8 is a perspective view of the test unit 14 of the appearance inspection apparatus 10 according to the second embodiment, and FIG. 9 is a schematic view of the test unit 14 of FIG. A lenticular sheet 106 is provided between the epi-illumination source 100 and the half mirror 108, and the epi-illumination light from the epi-illumination source 100 passes through the lenticular sheet 106 and the half mirror 108 and has an incidence angle of almost zero on the inspection surface of the substrate 1. Thrown. The lenticular sheet 106 acts to narrow incident light to a component perpendicular to the substrate 1 when viewed in the imaging direction 110 due to refraction of light.
[0040]
As shown in FIG. 9, the epi-illumination source 100 is divided into two sub-substrates 100a and 100b from the center, and each has an LED group 120 in the scanning direction 110. These sub-boards 100a and 100b are connected so that they face slightly inward, and the respective LED groups 120 are arranged to efficiently project incident light to the line 112 under inspection. Note that the diffusing action on the incident light is realized by the lenticular sheet 106.
[0041]
The illumination unit 30 sequentially turns on and off the epi-illumination, the side illumination, and the slit illumination for each line. While the scanning head 16 moves once on the substrate 1, the image for the appearance inspection by the epi-illumination, An image for visual inspection by side light and an image for height measurement by slit light are acquired at a time.
[0042]
FIG. 10 is a sectional view of the substrate 1 to which the cream solder has been applied. A cream solder 3 is applied to the electrodes 2 of the substrate 1, and a portion of the substrate 1 other than the electrodes 2 is coated with a translucent solder resist film 4. The substrate 1 is irradiated with incident light from directly above by the incident illumination source 100 and is imaged by the line sensor 34.
[0043]
The cream solder 3 is an aggregate of fine spherical solder particles, and the surface thereof is a rough surface having irregularities. Therefore, the incident light L1 applied to the cream solder 3 is scattered, and a part of the scattered light Then, the light enters the line sensor 34. Therefore, the cream solder 3 is imaged in slightly light gray. The electrode 2 is formed of a metal such as a copper foil, and the surface thereof is a mirror surface. Therefore, the incident light L2 applied to the electrode 2 is vertically and regularly reflected, and sufficiently enters the line sensor 34. Therefore, the electrode 2 is imaged in bright white. The incident light L3 applied to the translucent solder resist film 4 is transmitted to the substrate 1, but since the surface of the substrate 1 is a dark color such as dark green, the incident light L3 is absorbed and the substrate 1 becomes black. The image is taken.
[0044]
FIG. 11 is a diagram illustrating an image of the substrate 1 on which cream solder is applied, which is imaged under incident light. The electrode 2 of the substrate 1 is imaged white, and the portion of the substrate 1 other than the electrode 2 covered with the solder resist film 4 is imaged black, so that the position of the electrode 2 can be clearly recognized. Since the electrode 2 is imaged white and the cream solder 3 is imaged gray, the boundary between the cream solder 3 and the electrode 2 is clear, and the shape of the cream solder 3 can be clearly recognized.
[0045]
As described above, it is possible to identify whether or not the surface is a mirror surface by imaging the reflected light under the incident light. Therefore, the electrode 2 and the cream solder are determined based on the image captured under the side light. Even when it is difficult to identify 3 from the color information, accurate identification can be achieved by using an image by incident light. Therefore, it is possible to more accurately determine whether or not the cream solder 3 is applied to the electrode 2 at a correct position and whether or not the applied area is appropriate by using the image for the visual inspection by the incident light. And the inspection accuracy can be further improved.
[0046]
The present invention has been described based on some embodiments. These embodiments are exemplifications, and it is understood by those skilled in the art that various modifications can be made to the combination of each component and each processing process, and such modifications are also within the scope of the present invention. By the way. Some such modified examples will be given.
[0047]
In the above embodiment, since the scanning head 16 moves only once on the substrate 1 to obtain the image for the visual inspection and the image for the height measurement, the visual inspection device 10 is incorporated into the production line. It is also advantageous. In this case, for example, the substrate 1 flowing through the production line can be inspected as it is by setting the scanning head 16 side to a fixed type and using the support base 22 of the substrate 1 as a conveyor.
[0048]
Further, although the main unit 12 and the test unit 14 are illustrated integrally in FIG. 1, they may exist in different places. For example, the test unit 14 may be built into a factory production line, and the main unit 12 may be located at an analysis center or other organization that is connected to the test unit 14 by any network. The test unit 14 is placed on the user side, the main unit 12 is placed on the analysis center, and a business model in which the user undertakes analysis work is established.
[0049]
Further, in the first embodiment, instead of the side illumination source, the epi-illumination source described in the second embodiment is used, and the appearance inspection image by the incident light and the height measurement image by the slit light are used. An inspection may be performed.
[0050]
【The invention's effect】
According to the present invention, a highly accurate appearance inspection can be efficiently performed.
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram of a visual inspection device according to a first embodiment.
FIG. 2 is a detailed perspective view of the test unit of FIG.
FIG. 3 is a schematic diagram of a scanning unit including the illumination unit of FIG.
FIG. 4 is an explanatory diagram of a slit mask pattern of a rotating cylinder used for the slit illumination source of FIG. 3;
FIG. 5 is an explanatory diagram of a substrate on which cream solder is applied.
FIG. 6 is an explanatory diagram of a stripe pattern formed by irradiating slit light to a substrate to which cream solder has been applied.
FIG. 7 is a flowchart showing a visual inspection procedure according to the first embodiment;
FIG. 8 is a perspective view of a test unit of the appearance inspection device according to the second embodiment.
FIG. 9 is a schematic diagram of the test unit of FIG.
FIG. 10 is a cross-sectional view of a substrate to which cream solder has been applied.
FIG. 11 is an explanatory diagram of a captured image of the substrate on which the cream solder is applied by the incident light.
[Explanation of symbols]
1 board, 3 cream solder, 10 appearance inspection device, 12 main unit, 14 test unit, 16 scan head, 30 illumination unit, 32 lens, 34 line sensor, 40 head control unit, 42 memory control unit, 44 memory, 46 analysis Unit, 48 criteria storage unit, 54 image data, 100 epi-illumination source, 102 side illumination source, 104 acrylic sheet, 106 lenticular sheet, 108 half mirror, 110 imaging direction, 114 driving direction, 120 LED group.

Claims (7)

A head for scanning an object to be inspected,
A side illumination source that projects light from an oblique direction to an inspection surface of the inspection object,
A slit illumination source for projecting slit light from an oblique direction to the inspection surface,
A one-dimensional sensor that detects reflected light going vertically upward from the inspection surface,
A scanning head, wherein the side illumination source and the slit illumination source are configured to be selectively light-controllable. The scanning head according to claim 1, wherein each of the side illumination source and the slit illumination source includes a light emitting diode group arranged along an imaging line of the one-dimensional sensor. The scanning head according to claim 1, further comprising a short-focus imaging element array for projecting the slit light onto the inspection surface. An epi-illumination source for projecting light from above vertically to the inspection surface of the object to be inspected, the epi-illumination source, the side illumination source, and the slit illumination source are configured to be selectively lit. The scanning head according to claim 1, wherein: A device for inspecting the appearance of an object to be inspected,
A scanning head for scanning the inspection object,
A main unit that comprehensively controls the entire apparatus including the scanning head,
The scanning head comprises:
A side illumination source that projects light from an oblique direction to an inspection surface of the inspection object,
A slit illumination source for projecting slit light from an oblique direction to the inspection surface,
Including a one-dimensional sensor that detects reflected light going vertically upward from the inspection surface and generates image data,
The side illumination source and the slit illumination source are configured to be selectively light-controllable,
The main unit includes:
A head control unit for controlling lighting of the scanning head, and relative movement of the scanning head and the test object,
A memory control unit that captures an image for visual inspection of the inspection surface by the side illumination source and an image for height measurement by the slit illumination source into a memory,
An appearance inspection apparatus, comprising: an analysis unit that determines the quality of a solder application state by using the appearance inspection image and the height measurement image. The head control unit repeats lighting by alternately switching the side illumination source and the slit illumination source in accordance with the relative movement of the scanning head and the inspection object,
The memory control unit selectively captures image data generated by the one-dimensional sensor in accordance with a synchronization signal, and forms the visual inspection image and the height measurement image in the memory. The visual inspection device according to claim 5, wherein The analysis unit determines a solder application area photographed on the visual inspection image, and then determines a height of the solder application area based on a stripe pattern formed by slit light photographed on the height measurement image. The appearance inspection apparatus according to claim 5, wherein the quality of the applied state is determined based on the volume of the solder by measuring the thickness.

Images