JPH01121788A - Mounting inspecting device for chip component - Google Patents

Abstract

PURPOSE:To enable inspection after soldering by performing the inspection by comparing an image passed through a filter which does not pass the wavelength of the color of a solder surface with an image which is not passed. CONSTITUTION:The image signal (a) of a chip component to be inspected which is photographed by a camera 1 is binarized 2. The binary signal (b) is inputted to an outward appearance coordinate inspecting circuit 3 to find pad outward shape coordinates and a pat outward shape coordinate signal (c) is outputted to an absolute position detecting circuit 4. The image signal a' of the chip component to be inspected which is photographed by the camera 6 through the filter 5 is binarized 7 into a binary signal b', which is inputted to an elec trode outward shape coordinate detecting circuit 8, so that an electrode outward shape signal (d) is outputted to the absolute position detecting circuit 4. The filter 5 is a filter which does not pass the half wave of the color of the solder surface. The absolute position detecting circuit 4 detects the relative position between a pat and the chip component and outputs a relative position signal (e). A position shift deciding circuit 8 decides whether or not the chip component is in a normal mount state from the input signal (e).

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a chip component mounting inspection device, and in particular a chip component inspection device for inspecting the presence or absence of chip components on a printed circuit board after the mounting and soldering process is completed. The present invention relates to a device inspection device for parts.

[Technological environment]

In recent years, electronic devices such as home appliances and 0AJI products have become smaller and lighter in size and weight due to space-saving portability and resource conservation. Chip parts are increasingly being used in

It is difficult to manually mount these chip components onto a printed circuit board, and when mass production is carried out, all of this is done by machine, but the mounting condition cannot be said to be 100% satisfactory.

When chip components are mounted on a printed circuit board, mounting problems occur, such as the chip component not being in the correct location, or even if the chip component is mounted, it is misaligned and the circuit does not operate properly.

For this reason, it is necessary to inspect the quality of the mounting state of the chip components, but even if the inspection after the actual device is performed to determine the quality and corrections are made, the components may sometimes become misaligned during the next process of soldering. .

Therefore, after the mounting and soldering of components, an inspection is required to determine whether the mounting state is good or bad.

[Conventional technology]

As a conventional technique, for example, Japanese Patent Publication No. 58-13594
As shown in Japanese Patent No. 1, there is a chip component mounting inspection device.

A conventional chip component mounting inspection device illuminates a printed circuit board on which chip components are mounted diagonally from above in a predetermined direction.
, a lighting device that emits light, a television camera that photographs the shadow formed by the chip component, a reference pattern memory that stores the reference shadow position in advance, and a binary image that captures the image captured from the television camera. A signal processing circuit that
The device includes a comparison circuit that compares the output of the signal processing circuit and the output of the reference pattern memory to determine the mounting state of the chip component, and a result display circuit that displays the determination result.

Next, a conventional chip component mounting inspection device will be described in detail with reference to the drawings.

FIG. 3 is a block diagram showing an example of a conventional chip component mounting inspection device.

The chip component mounting inspection apparatus shown in FIG. 3 includes an illumination device 30 that irradiates a printed circuit board on which chip components are mounted with illumination ft from diagonally above in a predetermined direction, and a television that photographs shadows formed by the chip components. A camera 31, a reference pattern memory 32 that stores reference shadow positions in advance, a signal processing circuit 33 that binarizes the image captured from the television camera 31, an output of the signal processing circuit 33, and the reference pattern memory 32 that stores reference shadow positions in advance. It also includes a result display circuit 35 that compares the outputs of the pattern memory 32 and displays the tick determination result.

Here, the illumination device 30 forms a shadow on the chip component to be inspected, and the shadow is photographed by the television camera 31.

This apparatus must store the reference shadow position in the reference pattern memory 32 in advance before starting the inspection. The reference shadow position is generated from an image taken using a printed circuit board with a chip component attached at a normal position, and is stored in the reference pattern grid 32.

The image of the shadow of the chip component to be inspected taken by the television camera 11 is binarized by the signal processing circuit 33.

The binarized signal and the output of the reference pattern memory 32 are input to a comparison circuit 34 to determine the mounting state of the chip component to be inspected. The determination result is input to the result display circuit 35, and the determination result is displayed.

FIGS. 4(a) to 4(C) are pattern diagrams for explaining a method for determining the mounting state of a chip component in a conventional chip component mounting inspection apparatus.

FIG. 4(a) is a pattern diagram showing the reference shadow positions stored in the reference pattern memory 32, and the reference shadow position pattern 40 shows the reference positions of the shadows of each chip component.

FIG. 4(b) is a pattern diagram showing the position of the shadow of the chip component outputted from the signal processing circuit 33, and the chip component shadow position pattern 41 shows the position of the shadow generated by the chip component to be inspected. -ru.

FIG. 4(C) shows a comparison pattern for inputting the reference shadow position pattern 40 and the chip component shadow position pattern 41 into the comparison circuit 34, superimposing them, and detecting their matching state. Therefore, the comparison circuit 34 determines that the mounting position is incorrect when there is a shadow that does not match the reference shadow position pattern 40, such as the shadow pattern 42 of a chip component that is misaligned.

[Problem that the invention seeks to solve]

The above-mentioned conventional chip component mounting inspection device photographs the shadow formed by the chip component to be inspected and performs the inspection using this image. μ is applied to the chip components after soldering.
However, since shadows are less likely to occur, the reliability of the test is reduced.

In addition, since the chip parts to be tested are tested by comparing them with the values in the memory that has already been loaded, the accuracy of the position of the stage that moves the board on which the chip part to be tested is mounted, and the mounting of the board on the stage are subject to change. There is a drawback that the accuracy etc. may be detected as a position error.9.

[Means for deciding issues]

The chip component mounting inspection device of the present invention includes: a first camera that captures an image a't of a chip component to be inspected; a first binarization circuit that binarizes the image signal t captured from the first camera; a pad outer shape coordinate detection circuit that calculates the coordinates of the pad outer shape from the binarized signal output from the first binarization circuit;
a second camera that passes through the filter and captures an image of the chip component to be inspected; and a second camera that binarizes the image signal captured from the second camera. a binary conversion circuit, an electrode contour coordinate detection circuit for determining the coordinates of the contour of the electrode of the chip component from the binary signal output from the second binary conversion circuit, and a pad contour coordinate detection circuit input from the pad contour coordinate detection circuit. A relative position detection circuit that detects the relative positional relationship between the pad and the chip component from the external coordinates and the electrode external coordinates input from the electrode external coordinate detection circuit, and a mounting state inspection based on the relative positional relationship signal output from the relative position detection circuit. and a mounting state determination circuit that determines the result.

〔Example〕

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

FIG. 1 is a block diagram showing an embodiment of the present invention. A conversion signal C is inputted to a pad outer coordinate detection circuit 3, the pad outer coordinates are determined, and a putt outer coordinate signal C is outputted to a relative position detection circuit 4. .

The image signal a' of the chip component to be inspected, which has passed through the filter 5 and is photographed by the camera 2, is input to the binarization circuit 7 and is binarized. The second binarized signal b' output from the binarization circuit 7 is input to the electrode outline coordinate detection circuit 8 to determine the electrode outline coordinates, and the electrode outline coordinate signal d is outputted to the relative position detection circuit 4. Ru.

The relative position detection circuit 4 detects the relative positional relationship between the pad and the chip component from the pad outer shape correction signal C and the electrode outer shape coordinate signal d, and outputs a relative position signal e'fI to the positional deviation determination circuit 9.

The positional deviation determination circuit 9 determines the quality of the mounting state of the chip component to be inspected based on the input relative position signal e.

FIGS. 2(a) to 2(C) are pattern diagrams illustrating in more detail the process of determining whether the mounting state of chip components is good or bad.

FIG. 2(a) is a pattern diagram of image signal a.
A chip component 23 that also includes an electrode 21 and a body part 22 is placed on top of the chip component 23.
has been implemented.

Figure 2 (baFi picture signal a is sent to the binarization circuit 2) 2
FIG. 3 is a pattern diagram of a binarized signal.

Reflections from pads 20 and electrodes 21 A part where the brightness is higher than the light reflected from the body part 22, lower than the brightness of the light reflected from the body part 20 and the electrode 21, and higher than the brightness of the light reflected from the body part 22. By setting the binarization level to , only the pads 20 and electrodes 21 are extracted, and a nine-binarization signal is obtained.

The binarized signal is input to the pad outer shape coordinate detection circuit 3. In the pad outer coordinate detection circuit 3, the binarized signal 2
one putt and horizontal direction t-xs.

Assuming that the direction perpendicular to the two pads is the y-axis, the maximum and minimum values of the extracted pad 20 and electrode 21 in the x- and y-axes are determined. The maximum value x12 and the minimum value xo in the X-axis direction are the maximum value y in the vertical external coordinates t-y axis of the putt! 2 and the minimum value 11 ri represent the outer coordinates of the putt in the horizontal direction.

FIG. 2C is a pattern diagram of an image signal a''k of a chip component to be inspected passed through a filter 5t and photographed by a camera 6, and a binary signal b' converted into a binary signal by a binary conversion circuit 7.

In carrying out the present invention, the solder surface of the chip component to be inspected must have one color that does not pass through the filter 5t. For example, when using a filter 5 that does not transmit green color, the solder surface can be made green by soldering using green 7lux (for example, Senju Metal's Spark Solder Color Record), and the solder surface can be colored green. The reflected light does not reach the second camera 6.

Therefore, among the reflected light reaching the camera 6, the luminance of the reflected light from the electrode 21 is strong, and when it is binarized by the binarization circuit 7, the extracted binary value of the electrode 21 shown in FIG. A converted signal b' is obtained. Binary signal 4. b/ is input to the electrode outline coordinate detection circuit 8. - Electrode outline coordinate detection circuit 8
Now, from the binarized signal b', find the maximum and minimum values. The maximum value x21 and the minimum value x21 in the axial direction represent the external coordinates of the electrode 21 in the vertical direction, that is, the external coordinates of the chip component 23 in the vertical direction. Further, the maximum value 'Iu and the minimum value Yzx in the y-axis direction represent the lateral outline coordinates of the electrode 21, that is, the lateral outline coordinates of the chip component 23.

The relative position detection circuit 4 calculates the pad external coordinate signal C output from the pad external coordinate detection circuit 3 and the electrode external coordinate signal dt output from the electrode external coordinate detection circuit 8.
The amount of positional deviation of the electrode 21, that is, the chip component 23 relative to the pad 20 is detected. Relative displacement amount IX of the pad and chip parts in the vertical and horizontal directions
, ly are respectively expressed by equations (1) and (2) in the second case.

It is output to the mounting state determination circuit 9 as a gold relative position signal e.

The mounting state judgment circuit 9 is pre-registered with the permissible amount dxdy of the amount of deviation in the vertical and horizontal directions between the pad and the chip component, and the comparison circuit comprising the judgment circuit 9't determines the amount of deviation dxdy. Allowable amounts dx, dy and relative deviation amount tx input
, i, are compared and the formula (when both 3 and 41 are satisfied,
The mounting of the chip components is determined to be normal.

dx≧lz −...(3) dy
≧ly...(4) Also, if the electrode 21 is not detected by the electrode outer coordinate detection circuit 8, the detection circuit 8 generates an error code in the electrode outer coordinate signal d, and the error code is determined based on the relative position. Detection circuit 4t
- is input to the mounting state determination circuit 9. When the mounting state determination circuit 9 receives the error code, it determines that the chip component is not mounted.

Inspection is performed by comparing images that pass through a filter that does not pass the wavelength of the color of the surface and images that do not pass through, so inspection can be performed after soldering, and positional deviations of chip components can be checked based on their relative relationship with pads. Since the positional accuracy of the stage and the mounting accuracy of the substrate on the stage are determined without being affected by the accuracy, there is an effect that positional deviation inspection can be performed.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention, and FIG. 2 (
a) is a pattern diagram of the image signal a shown in Fig. 1, and Fig. 2 (
b) and (C) are the binary signals b shown in Fig. 1, respectively.
, b', FIG. 3 is a block diagram showing a conventional example, FIG. 4(a) is a pattern diagram stored in the reference pattern memory 32 shown in FIG. 3, and FIG. 4(b) is a pattern diagram of A pattern diagram output from the signal processing circuit 33 shown in FIG. 3, and FIG. 4 (CJ is a comparison pattern diagram in the comparison circuit 34 shown in FIG. 3. 1... first camera, 2... first binarization circuit, 3
. . . Pad outer coordinate detection circuit, 4. Relative position detection circuit, 5. Filter, 6. Second camera, 7.
. . . Second binarization circuit, 8 . . . Electrode outer shape coordinate detection circuit, 9 . . . Mounting state determination circuit, 20 .
... Electrode, 22 ... Body part, 23 ... Chip component, 30 ... Lighting device, 31 ... Television camera, 32
-...Reference pattern memory, 33... Signal processing circuit,
34...Comparison circuit, Engineering...Result display circuit, 40...
・Reference shadow position pattern, 41... Chip component shadow position pattern, 42... Shade pattern of misaligned chip component a, a' ---first image signal, b, b'--first
2m conversion signal, C... Pad external coordinate signal, d...
Electrode outline coordinate signal, e-...relative position signal.

Claims (1)

[Claims] A first camera that captures an image of the chip component to be inspected; a first binarization circuit that binarizes the image signal captured from the first camera;
a pad contour coordinate detection circuit that determines the coordinates of the pad contour from a value signal; a filter that does not pass light having a wavelength in a specific band; a second camera that captures an image of the chip component to be inspected that has passed through the filter; a second binarization circuit that binarizes the image signal captured from the second camera; and an electrode outline for determining the coordinates of the outline of the electrode of the chip component from the binarization signal output from the second binarization circuit. A coordinate detection circuit, a relative position detection circuit that detects the relative positional relationship between the pad and the chip component from the electrode external coordinates input from the pad external coordinate detection circuit, and a relative positional relationship signal output from the relative position detection circuit. A mounting inspection device for chip components, comprising: a mounting state determination circuit for determining a state inspection result.