KR19990074198A - Square chip mounting and soldering test - Google Patents

Abstract

The present invention discloses a method of mounting and soldering a rectangular chip. The method includes a printed circuit board equipped with a square chip, a first light arranged on top of the printed circuit board and configured to have a ring shape for irradiating the substrate, and positioned between the first light and the printed circuit board to irradiate the substrate. A method of mounting and soldering a rectangular chip of a system having a second light having a ring shape larger than a first light, the method comprising: turning on a first light and turning off a second light to obtain a first image, the first light Turning off the second lighting, obtaining a second image, obtaining a difference image obtained by subtracting the second image from the first image, searching for searching the left and right ends of the rectangular chip from the difference image, and searching A first step of determining whether the deviation is less than the first reference value when the left and right ends are present, the distance between the detected positive electrode ends and the length of the square chip is determined; Determination step, if the determination result of the first determination step satisfies the second determination step of determining the deviation between the center of the detected positive electrode end and the center of the square chip, and determines whether the deviation is less than the second reference value, and the second determination If the step is satisfied, it is determined to be normal, and if the left or right end is not searched in the search step or if the first or second judgment step is not satisfied, it is determined to be bad. Therefore, mounting and soldering state can be judged correctly simultaneously.

Description

Square chip mounting and soldering test

The present invention relates to a method for mounting and soldering a rectangular chip, and more particularly, to a method for mounting and soldering a rectangular chip that can simultaneously check the mounting and soldering state of a rectangular chip.

In the conventional method for checking the mounting state of a rectangular chip, the mounting state is inspected by recognizing a color (contrast) of a part, a printed circuit board (PCB) or a specific character or mark printed on the part. By the way, the color, characters, and marks of the parts are different depending on the manufacturer, so it is very difficult to inspect them in a consistent manner, and many errors have occurred in determining good or bad.

In the conventional soldering state inspection method for the rectangular chip, the light and dark distribution of the fillet part was checked separately to determine good or bad.

That is, in the conventional inspection method, it was impossible to simultaneously inspect the mounting state and the soldering state of the chip, and the accuracy of the determination was not high.

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for testing a mounting and soldering state of a rectangular chip which can simultaneously inspect the mounting and soldering states of the rectangular chip and can increase the accuracy of the inspection.

The method of mounting and soldering a rectangular chip of the present invention for achieving the above object is to solder the left and right electrodes of the rectangular chip having left and right electrodes at both ends of the body to the pad of each electrode to solder the left and the right. A printed circuit board having a fillet portion formed thereon, the first lighting disposed above the printed circuit board and configured to have a ring shape to irradiate the substrate, and positioned between the first lighting and the printed circuit board to irradiate the substrate; A second illumination having a ring shape larger than one illumination, a camera for obtaining an image by the first illumination and a second illumination, and control means for controlling the first illumination, the second illumination, the camera and the printed circuit board. In the method for mounting and soldering a rectangular chip of a system, the first illumination is turned on and the second illumination is turned off. Obtaining a first image by turning off the first illumination and obtaining a second image by turning on the second illumination; obtaining a difference image obtained by subtracting the second image from the first image; A search step for searching the left and right ends of the rectangular chip, and if the left and right ends exist as a result of the search step, the deviation between the detected distance between the ends of the positive electrode and the length of the rectangular chip is obtained and the deviation is the first. A first determination step of determining whether the reference value is less than the reference value, and if the determination result of the first determination step is satisfied, the deviation between the center of the detected positive electrode ends and the center of the rectangular chip is calculated and the deviation is less than the second reference value. If it satisfies the second judging step and the second judging step, it is determined to be normal, and the left or right end is not searched in the search step, or the first or first If it does not satisfy the two determination step, characterized in that it comprises a step of determining that the defective.

1 is a block diagram of a device for mounting and soldering a rectangular chip of the present invention.

Figure 2 is a flow chart for explaining the mounting and soldering state inspection method of the square chip of the present invention.

3 shows a first image obtained by a camera.

4 shows a second image obtained by the camera.

5 illustrates a difference image obtained by subtracting the image of FIG. 4 from the image of FIG. 3.

6 is a difference image illustrating a search and determination method of the present invention.

Hereinafter, with reference to the accompanying drawings illustrating a mounting and soldering state inspection method of the rectangular chip of the present invention.

1 is a block diagram of the mounting and soldering state inspection device of the rectangular chip of the present invention, the control unit 10, the monitor 20, the camera 30, the first illumination 40, the second illumination 50, printing A circuit board (PCB) 60, square chips 72, 74, and 76, fillet portions 82 and 84, and pads 92 and 94 are formed.

The controller 10 controls the camera 30, the first light 40, and the second light 50. The monitor 20 displays the results obtained by the control of the controller 10. The first lighting 40 is configured by connecting a light emitting diode (LED) in a ring shape. The second lighting 50 has a ring shape at the lower side of the first lighting 40 similarly to the first lighting 40, and has a wider ring shape than the first lighting 40. Thus, the angle at which the first illumination 40 irradiates the chip is greater than the angle at which the second illumination 50 irradiates the chip so that the first illumination 40 irradiates the chip almost vertically and the second illumination 50 ) Scans the chip almost horizontally. In addition, when the first illumination and the second illumination are irradiated, a bright image is obtained in the case of a flat or inclined metal surface (solder surface, electrode surface, etc.). The left fillet 82 and the right fillet 84 are formed by soldering the left electrode 74 to the pad 92 on the PCB 60 and the right electrode 76 to the pad 94, respectively.

FIG. 2 is an operation flowchart for explaining a mounting and soldering state inspection method of a rectangular chip according to the present invention. First, the controller 10 turns on the first light 40 and turns off the second light 50 ( Step 100). The first image is obtained using the camera 30 under the control of the controller 10 (operation 110). 3 shows a first image obtained by the camera 30. When the first illumination is turned on and the second illumination is turned off, the fillets 82 and 84 composed of the inclined surfaces appear as negative (dark) regions (white portions in FIG. 3) by the reflection characteristics of the light, and are composed of the horizontal surfaces. Assuming that lead is almost flat on the electrodes and the distal ends of the pads 92 and 94, the distal ends of the pads appear as positive (bright) areas (hatched in FIG. 3). In addition, the numeral 105 printed with the paint having the diffuse reflection characteristic, the letters A and B, and the body 72 made of plastic material are displayed with similar brightness regardless of lighting or turning off. Next, the first lighting is turned off and the second lighting is turned on by the control of the controller 10 (step 120). Under the control of the controller 10, the camera 30 obtains a second image and transmits the second image to the controller 10 (operation 130). 4 shows an image obtained by the camera 30. In this case, the fillets 82, 84 appear as positive regions (hatched portions in FIG. 4), numbers, letters and plastic portions appear as shown in FIG. 3, and other portions are negative regions (in FIG. White part). Next, the controller 10 obtains a difference image obtained by subtracting the brightness of the second image from the brightness of the first image (step 140). 5 shows a difference image obtained by the controller 10. The ends of the electrodes 74 and 76 and the pads 92 and 94 are shown as positive regions (hatched portions in FIG. 5), the body 72, the fillets 82 and 84, and the numerals, letters, and plastic parts It appears as a negative area (white part in FIG. 5). That is, obtaining the difference image by the operation of step 140 is to obtain the result of FIG. 5. Inspection using this result can improve the accuracy of the good and bad judgment of the mounting state and the soldering state of the parts irrespective of the color, letters, or marks printed on the parts. Next, the controller 10 searches for the end of the left electrode from the difference image (step 150). FIG. 6 illustrates the difference image of FIG. 5. The search region a is searched using the template X to find a dotted line having the same image as X. FIG. If step 150 is satisfied, the controller 10 searches for an end of the right electrode from the difference image (step 160). The search area b is searched using the template Y shown in FIG. 6 to find a dotted line with the same image as Y. FIG. If step 160 is satisfied, it is determined whether the deviation between the detected distance between the positive electrode ends and the part length is less than the reference value (step 170). That is, it is determined whether the difference value between the distance l shown in FIG. 6 and the length of the original part is less than the reference value. If step 170 is satisfied, it is determined whether the deviation between the center of the detected positive electrode end and the center of the component is less than the reference value (step 180). That is, it is determined whether the difference value between the coordinates (x, y) shown in FIG. 6 and the coordinates of the original part center is less than the reference value. If step 180 is satisfied, it is determined that the mounting and soldering state is normal (step 190). If the 150, 160, 170, 180 step is not satisfied, it is determined that the mounting and soldering state is bad (step 200).

Therefore, the method for checking the mounting and soldering state of the square chip of the present invention obtains a difference image using the first light and the second light, and simultaneously uses the difference image to accurately determine whether the component is mounted and the soldering state is good or bad. Can be.

Claims (3)

A printed circuit board having left and right solder fillets formed by soldering the left and right electrodes of the square chip having left and right electrodes at both ends of the body to pads of the electrodes; First illumination mounted above the printed circuit board and configured to have a ring shape to irradiate the substrate; A second illumination located between the first illumination and the printed circuit board and configured to be larger than the first illumination to illuminate the substrate; A camera for obtaining an image by the first illumination and the second illumination; And A method of mounting and soldering a rectangular chip of a system having a control means for controlling the first light, the second light, the camera and the printed circuit board, Turning on the first light and turning off the second light to obtain a first image; Turning off the first illumination and turning on the second illumination to obtain a second image; Obtaining a difference image obtained by subtracting a second image from the first image; A search step of searching for left and right ends of the rectangular chip from the difference image; A first determination step of determining a deviation between the distance between the detected positive electrode ends and the length of the rectangular chip if the left and right ends exist as a result of the searching in the searching step and determining whether the deviation is less than a first reference value; A second determination step of determining a deviation between the center between the detected positive electrode ends and the center of the rectangular chip if the determination result of the first determination step is satisfied and determining whether the deviation is less than a second reference value; And Determining that it is normal if the second determination step is satisfied, and determining that the left or right end is not searched in the search step or that it is defective if the first or second determination step is not satisfied. Method of checking the mounting and soldering condition of the square chip. The rectangular chip of claim 1, wherein the first fill image includes a solder fillet formed of the inclined surface and a body of the chip as a negative region, and a terminal portion of the electrode and the pad as a positive region. How to check the mounting and soldering status. The method of claim 1, wherein the solder fillet part is represented by a positive region, and the body and the electrode of the chip and the distal end of the pad are represented by a negative region. Way.