JPH0712530A - Soldering inspection apparatus - Google Patents

Abstract

PURPOSE:To perform an inspection with good accuracy by a method wherein the tip of a lead is detected, a precise inspection region is set by correcting its deviation or the like and a neuro-operation is performed. CONSTITUTION:A camera 4 changes the image of an electronic-circuit component 3 into a shading image signal (a), and a binary-coding circuit 5 outputs it as a binary-coded image signal (b). A region signal (c) which indicates the coordinates of a first inspection region 7 and the signal (b) are input to a deviation-amount detection circuit 10, and the detection circuit computes the deviation amount of the component 3 and outputs a deviation-amount signal (d). An inspection-region correction circuit 13 corrects the coordinates on the basis of the signal (d) and of a region signal (e) indicating the coordinates of a second inspection region 12 which is generated in a solder fillet part at the tip of a lead 9, it computes a soldering inspection region 14, and it outputs an inspection region signal (f). A neuro-operation circuit 15 generates the region 14 on the basis of the signal (a) and of the signal (b), it operates a neural network by using a load-data signal (g) on the basis of the signal (a), and it outputs an operated-result signal (h). A judgment circuit 17 can judge, on the basis of the signal (h), whether a soldering operation is good or not.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering inspection device, and more particularly to a soldering inspection device for inspecting the soldering condition of leads and pads of a surface mount IC soldered to a printed circuit board.

[0002]

2. Description of the Related Art A conventional soldering inspection apparatus is a lighting unit that irradiates a soldering portion with light at a constant angle, a camera that captures an image of the soldering portion, and an image that is captured by the camera is subjected to AD conversion to obtain a gray scale. An AD conversion circuit that outputs an image signal, an inspection area storage circuit that stores an inspection area, and a determination unit that determines the presence or absence of reflected light from the soldering unit are included. Next, a conventional soldering inspection apparatus will be described in detail with reference to the drawings.

FIG. 3 is a block diagram showing a conventional example. The lead 31 is soldered to the pad 33 on the printed circuit board 32 by the solder 34. The illumination 35 obliquely irradiates the soldered portion to be inspected. The camera 36 captures the image of the above-described soldering portion to be inspected and outputs the analog image signal i. The AD conversion circuit 37 inputs the analog image signal i, performs AD conversion, and outputs a grayscale image signal j. The inspection area generating circuit 38 inputs the grayscale image signal j, generates an inspection area set by the inspection area signal k stored in the inspection area storage circuit 39, and extracts only the grayscale image in the inspection area. The inner grayscale image signal 1 is output. In the judgment circuit 40, the grayscale image signal l in the inspection area
Is input, it is determined whether or not the specularly reflected light of the irradiation light is incident on the camera 6 depending on whether or not there is an extremely high brightness portion. If it is determined that the specularly reflected light is incident on the camera 6, it is normal. If not, it is judged as a defect. (As a conventional technique, for example, there is JP-A-3-068845).

The above-mentioned conventional soldering inspecting apparatus has inspected the soldering state from the image of the soldering portion at the tip of the lead. However, when the lead is misaligned, the inspection area is soldered. It is displaced from the attachment part,
Even if a misjudgment is made or the lead floating defect does not come into contact with the lead again, if the solder end under the lead is at the same position as the soldering part, specular reflection light from the solder end is incident on the camera. However, there was a drawback that it was judged as normal and some defects were overlooked.

[0004]

A soldering inspection apparatus according to the present invention comprises an illumination for irradiating a soldering portion to be inspected with light,
The camera mounted above that captures the image of the soldering part to be inspected and outputs the grayscale image signal, and the part that is brighter than a predetermined value by inputting the grayscale image signal to "1",
The dark portion is a binarization circuit for converting it into a binary image of "0", a first inspection area storage circuit for storing the first inspection area, and a binary image signal output from the binarization circuit. And a displacement amount detection circuit for generating an inspection region stored in the first inspection region storage circuit and calculating displacement amounts in the Y direction and the X direction of the lead tip, and storing a second inspection region. A second inspection area storage circuit, an inspection area correction circuit for correcting the coordinates of the second inspection area based on the deviation amount signal output from the deviation amount detection circuit, and load data used for the calculation of the neural network. A weight data storage circuit for storing the data, a neuro operation circuit for inputting the gray image signal and performing a neural network operation using the weight data from the gray image signal only in the corrected inspection region, and a neuro operation. Configured to include a determination circuit for determining the type of neuro-operation signal output from the circuit test results.

[0005]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to the drawings.

FIGS. 1A and 1B are a block diagram and a top view showing an embodiment of the present invention. The illumination 1 illuminates the inspection target electric circuit component 3 mounted on the printed circuit board 2 from above. The camera 4 captures an image of the electric circuit component 3 to be inspected from above and outputs a grayscale image signal a. The binarization circuit 5 inputs the grayscale image signal a, and outputs a binarized image signal b converted into “1” for a brighter part and “0” for a darker part than a predetermined value. First inspection area storage circuit 6
Stores the coordinates of the first inspection area 7 for detecting the amount of deviation of the electric circuit component 3, and outputs the first inspection area signal c. The coordinates of the first inspection area 7 are set such that the Y direction of the lead 9 (longitudinal direction) becomes the center of the Y direction of the tip 9 of the lead 9 when the electric circuit component 3 is normally mounted. The X direction (direction perpendicular to the longitudinal direction) is stored in advance so that the center of the lead 9 becomes the center of the X direction.

The shift amount detecting circuit 10 receives the first inspection area signal c and the binarized image signal b, and detects the binarized image in the first inspection area 7 from the binarized image in the X direction and the Y direction of the electric circuit component 3. The deviation amount in each direction is calculated, and the deviation amount signal d is output. The second inspection area storage circuit 11 stores in advance a second inspection area 12 to be generated in the solder fillet portion at the tip of the lead 9 when the electric circuit component 3 is normally mounted. The inspection area signal e is output. The inspection area correction circuit 13 inputs the deviation amount signal d and the second inspection area signal e, corrects the coordinates of the second inspection area 12 based on the deviation amount, and calculates the soldering inspection area 14. ,
The soldering inspection area signal f is output.

The load data storage circuit 16 stores the load data used for the calculation of the neural network in advance and outputs the load data signal g. The load data is created in advance by classifying good products and defect types into categories and learning. Neuro arithmetic circuit 15
Is the input of the grayscale image signal a, generates the soldering inspection region 14 based on the soldering inspection region signal f, and uses the load data signal g to generate a neural image based on the grayscale image signal a in the soldering inspection region 14. The network is calculated and the calculation result signal h is output. The determination circuit 17 receives the operation result signal h, and determines that the output value to the defect category is a defect if it is larger than a preset reference value.

Next, the principle of the present invention will be described with reference to FIG. FIG. 2 is a pattern diagram for explaining the principle of deviation amount detection. The deviation amount detection circuit 10 projects the number of “1” s in the Y direction of the binarized image in the first inspection region 7 and outputs the number “1” s of the number 20 which is a preset threshold Th.
Center X of the X-direction lead range 21, which is a range greater than n1
Find c. Since the binarization level is set in advance in the binarization circuit 5 so that the lead portion becomes "1",
Xc can be the center of the lead tip in the X direction,
Xc-Xo is calculated as an X-direction displacement amount from the center coordinate Xo in the X direction of the lead tip when the electric circuit component 3 is normally mounted.

In the range 22 in which the number of "1" s out of the result 22 obtained by projecting the number of "1s" in the X direction of the binarized image in the first inspection area 7 is larger than the preset threshold Th2. End Y of a certain Y-direction lead range 23 on the side away from the lead side
Find e. Ye indicates the tip of the lead. Therefore, Ye-Yo is calculated as the deviation amount in the Y direction from the Y coordinate in the Y direction of the lead tip when the electric circuit component 3 is normally mounted.

In the inspection area correction circuit 13, assuming that the center coordinates of the area stored in the second inspection area are (Xk, Yk), the soldering inspection area 14 is calculated from the deviation amount output from the deviation amount detection circuit 10. The center coordinates of (Xk + Xc−X
o, Yk + Ye−Yo). Therefore, according to the present invention, the leading end of the lead of the inspection target component is detected and the inspection area is generated according to the displacement amount in the X and Y directions. Therefore, the mounting displacement of the inspection target component and the variation of the lead length of each component are caused. It can be seen that the inspection can be performed accurately without being affected by.

[0012]

According to the soldering inspection apparatus of the present invention, an inspection area is generated at the calculated lead tip portion, and instead of judging whether the product is a good product or a defect by the presence or absence of strong reflected light in the inspection area, it is taken in. The lead tip portion is accurately detected from the pattern, and the neuron is calculated from the image data of the lead tip portion to determine the difference in the pattern shape of the reflected light, so that there is an effect that the inspection can be performed accurately.

[Brief description of drawings]

1A and 1B are a block diagram and a top view showing an embodiment of the present invention.

FIG. 2 is a pattern diagram showing an embodiment of the present invention.

FIG. 3 is a block diagram showing a conventional example.

[Explanation of symbols]

 1 Lighting 2 Printed Circuit Board 3 Electric Circuit Parts 4 Camera 5 Binarization Circuit 6 First Inspection Area Storage Circuit 7 First Inspection Area 8 Mold Section 9 Lead 10 Deviation Detection Circuit 11 Second Inspection Area Storage Circuit 12 Second Second inspection area 13 Inspection area correction circuit 14 Soldering inspection area 15 Neuro arithmetic circuit 16 Load data storage circuit 17 Judgment circuit 20 Y direction projection result 21 X direction lead range 22 X direction projection result 23 Y direction lead range a Gray image signal b binarized image signal c first inspection area signal d deviation amount signal e second inspection area signal f soldering inspection area signal g load data signal h neuro operation result signal i analog image signal j grayscale image signal k inspection area Signal l Grayscale image signal in the inspection area

Claims (3)

[Claims] 1. A lighting device for irradiating a soldering portion to be inspected with light, a camera mounted above which captures an image of the soldering portion to be inspected and outputs a gray-scale image signal, and a gray-scale image signal is input to be predetermined. The binarization circuit for converting into a binarized image of "1" for a brighter part and "0" for a darker part, a first inspection region storage circuit for storing a first inspection region, and a binary The inspection area stored in the first inspection area storage circuit is generated in the binarized image signal output from the digitizing circuit, and the longitudinal direction (hereinafter referred to as Y direction) of the lead at the tip of the lead and the direction perpendicular to the lead. (Hereinafter referred to as X direction)
A deviation amount detection circuit for calculating the deviation amount in each direction, a second inspection area storage circuit for storing a second inspection area, and a second deviation amount signal output from the deviation amount detection circuit. The inspection area correction circuit for correcting the coordinates of the inspection area, the load data storage circuit for storing the load data used in the calculation of the neural network, and the grayscale only in the corrected examination area by inputting the grayscale image signal. Soldering characterized in that it includes a neuro arithmetic circuit for performing a neural network operation by using weight data with an image signal and a determination circuit for inputting a neuro arithmetic signal output from the neuro arithmetic circuit to determine an inspection result Inspection device. 2. The soldering inspection apparatus according to claim 1, wherein the load data is created by previously classifying good products and defect types into categories and learning. 3. A means for detecting a deviation amount of a tip of a lead to be inspected with respect to a coordinate of a lead tip portion when an electric circuit component is normally mounted, and a soldering inspection area for inspecting the soldering inspection area based on the deviation amount. A soldering inspection device comprising means for setting each time.