JP2570508B2 - Soldering inspection equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering inspection apparatus and, more particularly, to a soldering inspection apparatus for inspecting a soldering state of a lead wire of an IC (integrated circuit) soldered to a printed circuit board and surface-mounted.

[0002]

2. Description of the Related Art A conventional soldering inspection apparatus includes a light source for irradiating a soldering portion with light at a fixed angle, a camera for capturing and outputting an image of the soldering portion, and a soldering inspection based on an image output from the camera. And a determining unit that determines whether or not there is light reflected from the unit.

Next, a conventional soldering inspection apparatus will be described in detail with reference to the drawings.

FIG. 3 is a block diagram showing an example of this type of conventional soldering inspection apparatus.

The lead wire 2 of the integrated circuit component shown in FIG. 3 is soldered to a pad 4 fixed to a printed circuit board 3. Irradiation light a is incident on the soldering part 5 from the light source 6. The camera 7 captures an image including the soldered portion 5 and outputs an image signal c having a level proportional to the intensity of reflected light from the target point to the determination unit 24. The determination unit 24 receives the image signal c and determines whether or not the specularly reflected light of the irradiation light a is incident on the camera 23 depending on whether or not there is an extremely high luminance portion. If it is determined that there is a defect, it is determined to be normal;

When the camera 7 takes an image of the soldered portion 5 of the integrated circuit component to be inspected, the camera 7 and the light source 6 are relatively fixed, for example, and the soldered portion 5 to be inspected is fixed. The printed circuit board 3 is moved in parallel in the horizontal direction, and the pads 4 fixed to the printed circuit board 3 on which the soldered portions 5 to be inspected are located at predetermined positions with respect to the camera 7 and the light source 6 described above. After that, the object is imaged by the camera 7 described above.

[0007]

The above-described conventional soldering inspection apparatus is based on the fact that the irradiation light from the light source incident on the soldered portion is specularly reflected by the soldered portion and is present in the image picked up by the camera. Inspection of the soldering state was performed, but if there is a misalignment between the lead wire and the pad of the part to be inspected, the camera will take an image of the part that is not soldered and the soldered part will be inspected accurately. There was a disadvantage that it could not be done.

[0008]

SUMMARY OF THE INVENTION A soldering inspection apparatus according to the present invention comprises a soldering portion of an integrated circuit component having a lead wire soldered to a predetermined position on a printed circuit board placed and fixed in parallel with a horizontal plane. The integrated circuit adjacent to the soldered portion, the lead wire, and the lead wire illuminated with a light beam from a light source placed at a predetermined oblique position above the soldered portion with respect to the soldered portion, and illuminated by the irradiation light An image of a part including a part of the molded part of the component is taken from a predetermined position above the soldered part, and a level is proportional to the intensity of reflected light from each point of the object, and one side is the lead. The quality of the soldered portion is determined based on the output of a camera that outputs an image signal of a rectangular area substantially parallel to the longitudinal direction of the line and whose side perpendicular to the line is substantially parallel to the side edge of the mold portion, and outputs the result. In the soldering inspection apparatus, a level of the image signal which is equal to or higher than a predetermined level is converted to a predetermined first level, and the level of the image signal which does not reach the predetermined level is determined. A binarizing circuit that converts the signal to a predetermined second level and outputs the binarized image signal as a binarized image signal; and a side including the lead wire and the mold portion adjacent to the lead wire, one side of which is parallel to a longitudinal direction of the lead wire. A first inspection area storage circuit for storing a first inspection area defining a predetermined image boundary line having a rectangular boundary area, and outputting the first inspection area signal as a first inspection area signal; A first signal for inputting a signal and the first inspection area signal, extracting only the binarized image signal component in an area defined by the first inspection area signal, and outputting the extracted signal as an in-window binary image; A window generating circuit, a center line parallel to the longitudinal direction of the image portion of the lead wire and an image parallel to the center line, which receives the binarized image in the window as an input, and The two outer peripheries are divided into two equal parts, and a difference from a straight line parallel to the longitudinal direction is detected as a first displacement amount, and the lead wire is adjacent to the lead wire in the binarized image in the window. A straight line parallel to the direction of these two outer perimeters is obtained by bisecting a straight line formed by the side edge of the image of the mold portion orthogonal to the longitudinal direction and two outer peripheries of the image substantially parallel to this straight line. A positional deviation amount detection circuit for detecting a difference between the two as a second positional deviation amount and outputting the first and second positional deviation amounts, and soldering the lead wire in an image taken by the camera. The area that should contain the partial image A second inspection area storage circuit that stores in advance a signal defining a boundary line of a boundary area of an image included therein and outputs the signal as a second inspection area signal; and inputs the second inspection area signal and the image signal. An area defined by the corrected second inspection area signal from an image generated by the image signal by correcting the position of the second inspection area signal based on the first and second positional deviation amounts; A second window generating circuit for extracting and outputting image components in the image, an integrating circuit for integrating the level of the output from the second window generating circuit over the entire image component area, and outputting the result, The output level of the circuit is compared with a predetermined reference level, and when the output level of the line segment circuit is higher than the reference level, it is determined that the state of the soldered portion is acceptable, and the output of the integration circuit is determined. Lebe There has been configured and a judgment circuit for outputting the result determined failed when not reach the reference level.

[0009]

Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 1 is a block diagram showing one embodiment of the present invention. The integrated circuit component 1 to be inspected is a mold 1
6 and a lead wire 2, and the lead wire 2 is soldered to a pad 4 fixed on the printed circuit board 3 by a soldering portion 5.

A light source 6 emits and irradiates the integrated circuit component 1 and its surroundings with illumination light a from diagonally above.
Are positioned above and fixed to the integrated circuit component 1 in a direction in which the reflected light b is reflected by the soldered portion 5, and the integrated circuit component adjacent to the soldering portion 5 and the lead wire 2 that has taken in the reflected light b from the integrated circuit component 1 An image signal c including a part of one mold section 16, that is, an image signal having a level proportional to the light intensity is output. The binarization circuit 8 receives the image signal c and converts a level corresponding to a level portion higher than a predetermined binarization level into a value, for example, "1", and a level lower than the binarization level, that is, a dark portion. Is converted to a value, for example, "0".
Is output. The first window generation circuit 9 receives the binary image signal d, generates an inspection window set by the first inspection area signal e stored in the first inspection area storage circuit 10, and generates a first inspection window. And outputs a binarized image signal f in the window obtained by extracting only the binarized image in the inspection window defined by the inspection region signal e. The first inspection area storage circuit 10 generates a first inspection area signal e that defines an area including the lead 2 of the integrated circuit component 1 of the printed circuit board 3 and a part of the mold portion 16 adjacent to the lead 2. Occur.

The image area generated by the first inspection area storage circuit 10 is rectangular, and two parallel sides thereof are the camera 7.
Is set so as to coincide with the longitudinal direction of the lead wire image in the image generated by the image signal c output from the image processing device.

The position shift amount detection circuit 11 receives the in-window binary image signal f and detects the position shift amount of the lead wire. In detecting the amount of displacement, the reflected light from the lead enters the camera 7, whereas the reflected light from the mold portion 16 of the integrated circuit component 1, the surface of the printed circuit board 3, and the surface of the pad 4 is mostly transmitted to the camera 7 Utilizing the fact that the light does not enter, a shift amount in a direction perpendicular to the lead wire (hereinafter referred to as X direction) is detected from the boundary between the lead wire 2 and the upper surface of the printed circuit board 3, and the molding of the lead wire 2 and the integrated circuit component 1 is performed. Part 1
From the boundary of No. 6, it is possible to detect the amount of displacement of the lead wire 2 in the longitudinal direction (hereinafter referred to as the Y direction). The position shift amount detection circuit 11 outputs a signal g proportional to the two types of position shift amounts described above.
Is output to the second window generating circuit 12.

The second window generating circuit 12 converts the image area set by the second inspection area signal h stored in the second inspection area storage circuit 13 into a displacement amount indicated by the displacement amount signal g. The position shift is corrected and generated according to.

The image area defined by the second inspection area signal h is set in advance so that the image of the soldered portion 5 of the image of the image signal c output by the camera 7 is mostly used. Therefore, even if the component is displaced, the inspection window can be a window that defines an area including the soldered portion 5 to be inspected. Further, the second window generating circuit 12 receives the image signal c, and outputs an in-window image signal j obtained by extracting only the image in the inspection window generated by correcting according to the positional deviation amount.

The integrator circuit 14 receives the in-window image signal j, integrates the output level in the window area, and outputs an integrated signal k proportional to the integrated result to the decision circuit 15. The determination circuit 15 compares a preset reference level with the level of the input integrated signal k,
If the level of the integration signal k is higher, the soldering inspection is passed and a pass / fail signal is output with the result being, for example, a value "1". If the value of the integration signal k is less than the reference level, it is rejected, and for example, a value “0” is output as a pass / fail signal.

FIG. 2 is an explanatory diagram showing a method of detecting a displacement amount. Hereinafter, a method of detecting the amount of displacement will be described with reference to FIG. When the integrated circuit component 1 is mounted at a normal position, the first window generation circuit 9 generates a first inspection area, that is, a first inspection window 90, with the following relationship. That is, the center line X0 of the window 90 in the X direction, which is the center line of the window 90 in the X direction, coincides with the center line 20c of the lead wire 2 in the longitudinal direction of the lead wire, and the center line Y0 of the window 90 in the Y direction is the center line of the window 90 in the Y direction. It is generated at a position that coincides with the mold part binarized image boundary line 16a indicating the boundary between the lead wire 2 and the mold part.

An image generated by the in-window binarized image signal d input to the position shift amount detection circuit 11 is a mold section 16 generated in an internal area of the inspection window 90.
And a lead line binarized image boundary line 20a and 20b, which is a binarized image boundary line 16a corresponding to the side edge adjacent to the lead wire 2 of FIG.

If the camera 7 is in a predetermined positional relationship with respect to the integrated circuit component 1, the upper and lower horizontal boundaries of the image in the inspection window 90 are bisected and parallel to the horizontal boundaries. Window horizontal center line Y0 that is a straight line
And the mold portion binarized image boundary line 16a coincide with each other as described above, and further divide the left and right vertical boundary lines of the inspection window 90 into two equal parts, and a window vertical center line X0 parallel to these vertical lines. , Lead line binarized image boundary line 20
a and 20b are bisected, and the center line 20c in the longitudinal direction of the lead wire parallel to the boundary line of the binarized image of the lead wire coincides with the lead wire. In general, the lead wire 2 is soldered to the printed circuit board 3. In the case of FIG. 2, a displacement occurs in the vertical direction and the horizontal direction due to the positional displacement in the case of FIG.

The displacement detecting circuit 11 detects the displacement in these two directions and outputs a signal having a level proportional to each displacement.

[0021]

According to the soldering inspection apparatus of the present invention, the position deviation of a component is first determined, the image area is corrected according to the position deviation, and the inspection of the soldering state is performed. There is an effect that the inspection can be performed with high accuracy without being affected by the displacement of the lead wire of the integrated circuit component with respect to the predetermined position.

[Brief description of the drawings]

FIG. 1 is a block diagram showing one embodiment of a soldering inspection apparatus of the present invention.

FIG. 2 is an explanatory diagram illustrating a method for detecting a displacement amount.

FIG. 3 is a block diagram showing an example of this type of conventional soldering inspection apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Integrated circuit component 2 Lead wire 3 Printed board 5 Solder part 8 Binarization circuit 9 First window generation circuit 10 First inspection area storage circuit 11 Position shift amount detection circuit 12 Second window generation circuit 13 Second Inspection area storage circuit 14 Integrator circuit 15 Judgment circuit

Claims (1)

(57) [Claims] 1. A state of a soldered portion of an integrated circuit component having a lead wire soldered to a predetermined position on a printed circuit board placed and fixed in parallel with a horizontal plane with a predetermined inclination with respect to the soldered portion. A part including a part of the molded part of the integrated circuit component adjacent to the lead wire and the lead wire and the soldered portion illuminated with the light beam by irradiating a light beam with a light source placed at an upper position is soldered. An image is taken from a predetermined position above the attached portion and has a level proportional to the intensity of reflected light from each point of the object, and one side is substantially parallel to the longitudinal direction of the lead wire and is a side orthogonal to the longitudinal direction of the lead wire. In a soldering inspection device that determines the acceptability of the soldered portion based on the output of a camera that outputs an image signal of a rectangular area substantially parallel to the side edge of the mold portion, and outputs the result, The level of the image signal higher than the level is converted to a predetermined first level, and the level of the image signal not reaching the predetermined level is converted to a predetermined second level. A binarizing circuit that outputs the image as a binarized image signal, a predetermined portion including the lead wire and the mold portion adjacent to the lead wire, one side of which is parallel to a longitudinal direction of the lead wire, and a boundary region is rectangular; A first inspection area storage circuit that stores a first inspection area that defines a boundary line of the obtained image and outputs the first inspection area signal as a first inspection area signal, and stores the binary image signal and the first inspection area signal. A first window generation circuit for inputting and extracting only the binarized image signal component in an area defined by the first inspection area signal and outputting the extracted signal as a binarized image in a window; An image is input, and a bisecting is made between a center line parallel to the longitudinal direction of the image portion of the lead line and the two outer peripheries of the image parallel to the center line in the boundary side of the binarized image in the window. Detecting a difference from a straight line parallel to the longitudinal direction as a first positional deviation amount; and an image of the mold portion adjacent to the lead wire and orthogonal to the longitudinal direction of the lead wire in the binarized image in the window. The distance between the straight line formed by the side edge of the image and the two outer perimeters of the image substantially parallel to this straight line is bisected, and the difference between the straight line parallel to the direction of these two outer perimeters is defined as a second displacement amount. And a position shift amount detection circuit that outputs the first and second position shift amounts, and an area in which an image of the soldered portion of the lead wire should be included in an image captured by the camera. Specifies the border of the boundary area of the containing image A second inspection area storage circuit that stores a signal in advance and outputs the second inspection area signal as a second inspection area signal; A second window for correcting the position of the second inspection area signal and extracting and outputting an image component in an area defined by the corrected second inspection area signal from an image generated by the image signal A generation circuit, an integration circuit that integrates the level of the output from the second window generation circuit over the entire image component area and outputs the result, and an output level of the integration circuit and a predetermined reference level. When the output level of the integrating circuit is higher than the reference level, it is determined that the state of the soldered portion is acceptable, and when the output level of the integrating circuit does not reach the reference level, it is determined as failed. And a determination circuit for outputting the result.