JPH0244234A - Soldering inspecting device - Google Patents

Abstract

PURPOSE:To obtain an inexpensive inspecting device by irradiating a soldered part of an object to be inspected askew to judge the propriety thereof based on the quantity of reflected light of an illumination light. CONSTITUTION:A soldered part 4 of an electrode 3 is irradiated askew from a lighting section 5. A camera 6 picks up an image in a range containing the part 4 and outputs an analog image signal (a) to an A/D conversion circuit 7, which converts the signal (a) into a digital image signal (b) of a multi-value contrast to be outputted into a masking circuit 8. The circuit 8 outputs a mask image signal (c) having density values of parts other than the soldered part 4 as object to be inspected as the darkest level. An addition circuit 9 adds the density values of the signal (c) to be inputted into a judging circuit 10. The circuit 10 compares an added value with a reference value preset and the larger the added value is, a soldering is determined to be pass an examination thereby producing an inexpensive inspecting device with a simple construction.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a soldering inspection device, particularly a soldering inspection device for inspecting the soldering condition of surface-mounted components such as chip components, SOPs, and QFPs mounted on printed circuit boards. Regarding inspection equipment.

[Conventional technology]

As a conventional technique, for example, Japanese Patent Publication No. 61-241641
As shown in the publication, there is an inspection device for soldering.

Conventional soldering inspection equipment has a heating part that heats the soldering part, a temperature measuring part that measures the temperature rise of the soldering part, and a judgment of the quality of the soldering part based on the temperature change measured by the temperature measuring part. The configuration includes a determination unit that performs the following operations.

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

FIG. 3 is a side view showing the principle of a conventional soldering inspection device.

The soldering inspection device shown in FIG.
The terminal portion 33 of the FIC 32 mounted on the heating device 3
4 to an appropriate temperature.

The heat generated by the terminal portion 33 is transferred to the solder portion 35 through contact with the solder portion 35, and the solder portion 35 is warmed.

The temperature of the solder portion 35 is measured by an infrared detector 36.

At this time, if the contact between the terminal part 33 and the solder part 35 is insufficient, that is, if the thermal conductivity between the terminal part 33 and the solder part 35 is poor, the temperature of the solder part 35 can be suppressed to a low temperature although it takes time to rise. .

Therefore, by measuring the temperature change of the solder portion 35 over time, the quality of soldering is determined.

[Problem to be solved by the invention]

The conventional soldering inspection equipment described above has to apply heat to multiple inspection points and measure the temperature rise, which takes time to inspect each location, and requires the printed circuit board to be moved by the number of inspection points. This has the drawback that the stage on which the printed circuit board is mounted must be moved many times, and the total inspection time becomes longer.

Furthermore, the conventional soldering inspection apparatus described above has the disadvantage of being expensive because it uses a heating device and an infrared detector.

[Means to solve the problem]

The soldering inspection device of the present invention includes an illumination section that illuminates the soldered portion of the component to be inspected from an oblique direction, and an illumination section that is installed at an angle that allows the most reflected light from the illumination section to be incident from the fillet portion of the soldered section. A camera that inputs an image of a 1-inch portion of solder, an AD conversion circuit that performs AD conversion on the image input from the camera, and a mask circuit that extracts only the portion to be inspected from the image data input from the AD conversion circuit. , an adder circuit that adds all the grayscale values of the image of the portion extracted by the mask circuit, and a determination circuit that determines the test result based on the added value output from the adder circuit.

〔Example〕

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.

An example will be explained in which a soldering test is performed on the electrodes 3 of the FIC 2 mounted on the printed circuit board 1.

In this description, the parts to be inspected are not limited to FICs, but surface-mounted parts such as chip parts are to be inspected.

The lighting section 5 is an electric f! The soldered portion 4 of No. 3 is irradiated obliquely. The camera 6 captures an image of the range including the soldered portion 4 and outputs an analog image signal a to the AD conversion circuit 7.

The AD conversion circuit 7 inputs the analog image signal a, converts it into a multi-level gradation digital image signal, and sends it to the mask circuit 8.
Output to. In the mask circuit 8, in order to obtain information only on the soldered portion 4 to be inspected, the gradation value of the portion other than the soldered portion 4 is set to the darkest 0, and the mask image signal C is outputted to the addition circuit 9. The adder circuit 9 adds up all the grayscale values of the input mask image signal C to obtain an added value. The addition value signal d is input to the determination circuit 10. Judgment circuit 10
Then, the preset reference value and the input added value are compared, and if the added value is larger, it is determined that the soldering test has passed.

FIGS. 2(a) to 2(c) are side views for explaining the present invention in detail. In Fig. 2, 21 is a printed circuit board;
2 is a pad portion, 23 is a component electrode, and 24 is a soldered portion.

FIG. 2(a) shows a case where soldering is performed normally. When soldering is performed normally, the illumination light e irradiated onto the soldered portion is regularly reflected on the mirror-like fillet surface. The camera is installed in the direction of the reflected light f,
The soldered area shines brightly in the camera image.

Figure 2 (b) shows the case where there is insufficient solder or no solder, and since there is no fillet, the illumination light e irradiated to the soldered part is diffusely reflected on the pad or electrode side surface, and the reflected light f is scattered, so it is not visible in the camera image. The soldered area will be dark.

Figure 2 (c) shows a case where there is too much solder, and the illumination light e irradiated on the soldered part is regularly reflected by the solder part and some light enters the camera, but due to too much solder, the surface of the soldered part is convex. It has a curved surface, and most of the reflected light is scattered, so in the camera image, only a part of the soldered area is bright, but the whole is dark.

From the above explanation, it can be seen that if the shading values of only the soldered parts are added, the following order will be obtained.

(Normal)〉(Too much solder)〉(No solder/Too much solder) Therefore,
By setting a reference value used in the determination circuit between the added value in the normal case and the added value in the case of excessive solder, it is possible to distinguish between the normal case and other cases.

〔Effect of the invention〕

The soldering inspection device of the present invention performs pass/fail inspection based on the amount of reflected light of the illumination light applied to the soldering part, so inspection can be performed at high speed, and since the component parts are inexpensive, the device is also inexpensive. There is an effect.

FIGS. 2(a) to (C) are side views for explaining the present invention in detail, and FIG. 3 is a side view showing an example of the prior art.

DESCRIPTION OF SYMBOLS 1... Printed circuit board, 2... FIC13... Electrode, 4... Soldering part, 5... Lighting part, 6... Camera, 7... AD conversion circuit, 8... Mask circuit, 9.
... Addition circuit, 10... Judgment circuit, 21... Printed circuit board, 22... Pad portion, 23... Component electrode, 2
4...Soldering part, 31...Printed circuit board, 32.
...FIC133...terminal part, 34...heating device,
35...Solder part, 36...Infrared detector, a...Analog image signal, b...Digital image signal, C...Mask image signal, d...Addition value signal, e
...Illumination light, f...Reflected light.

Claims (1)

[Claims] a lighting section that illuminates the soldered portion of the component to be inspected from an oblique direction;
a camera that inputs an image of the soldering part installed at an angle where the most reflected light of the illumination part from the fillet part of the soldering part is incident; and an AD conversion circuit that converts the image input from the camera into an AD converter; , a mask circuit that extracts only the portion to be inspected from the image data input from the AD conversion circuit, an adder circuit that adds all the grayscale values of the portion of the image extracted by the mask circuit, and an output from the adder circuit. 1. A soldering inspection device comprising: a determination circuit that determines an inspection result based on an added value.