JPS63161700A - Method of correcting discrepancy of board - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a method for correcting positional deviation of a substrate applied to surface mounting of electronic components.

Conventional technology Conventionally, when correcting the positional deviation of a board, a through hole formed on the board surface as a feed hole of an XY table is optically detected, the deviation between the detected position and the standard position is calculated, and the mounting head and The correlation with the substrate is being adjusted. However, since the through hole is formed separately from the conductive pattern, it is likely to be misaligned with the conductive pattern. In view of this drawback, when printing and molding the conductive pattern on the board surface using a copper material, the positioning mark is also printed with the same material, and in order to prevent the positioning mark from oxidizing, it is recommended to solder plate the surface together with the conductive pattern. Proposed.

Problems to be Solved by the Invention With this positioning mark, the solder surface does not form a uniformly curved surface, so if only a single light source placed above irradiates the light beam, the reflected light will be diffused and the correct outline will be formed. cannot be imaged and cannot be used as control data for correcting the positional deviation of the board.

Means for Solving the Problems In the method for correcting positional deviation of a substrate according to the present invention, a light beam is irradiated over the entire surface of the positioning mark made of the same material as the conductive pattern on the substrate surface from the radial direction, and the reflection is detected. An optical image is randomly projected onto a TV screen using light through a camera, and the outer frame line and center point of the standard pattern corresponding to the positioning mark are set in advance at the center of the TV screen, and the image is projected onto the TV screen. The random optical image of the positioning mark is aligned with the outer frame line of the standard pattern by adjusting the binarization level up and down, and the center point of the optical line that matches this standard pattern is aligned with the center point set on the TV screen of the standard pattern. The positional deviation in the X and Y directions is detected using the coordinate axes of the television screen to adjust the correlation between the electronic component mounting head and the board position.

Function: In this method of correcting positional deviation of the board, a large amount of light is irradiated onto the positioning mark from the radial direction, a random optical image is projected on the TV screen, and the optical image is converted to a predetermined standard by adjusting the binarization level up and down. Since it is optically detected as a predetermined positioning mark by matching it with the outer frame line of the pattern, it becomes possible to accurately correct the correlation between the mounting head and the board even in accordance with the solder-plated positioning mark.

Embodiments will now be described with reference to the accompanying drawings.

This correction of positional deviation of the board is performed by adjusting the relative positional relationship between the printed circuit board placed on the XY table and the mounting head that surface-mounts electronic components on the board surface.
It is applied to attach electronic components to predetermined positions on a conductive pattern formed on a printed circuit board by moving along the direction and making corrections. In addition, to correct this positional deviation, we use a positioning mark printed and molded with copper along with a conductive pattern on the board surface of the printed circuit board, and when the positioning mark is irradiated with light, an optical image is obtained with reflected light and image processing is performed. This is used as head position correction data.

This image IA embedding is carried out by applying the system shown in FIG. In addition to irradiating a substantially central position of the positioning mark M formed in the positioning mark M, a plurality of LED lamps 14 connected to a power source 13 are irradiated with light beams. These LED lamps 14 are preferably arranged on the circumference of the center of the positioning mark M as shown in FIG. 3, and emit a large amount of light from the radiation direction including the incandescent bulb 11. The reflected light passes through the lens 15 to the camera projector 1.
6, and an image processing device 17 that is activated by operator operation.
is transmitted to the monitor television receiver 18 via. A numerical calculation controller 19 is connected to the image FI embedding device 17, and the television receiver 18 has a width corresponding to the positioning mark M printed and formed on the board surface of the printed circuit board P, as shown in FIG. The outer frame line F and center point O of W, , W2 are set in advance as a standard pattern in the XY direction.

In this image processing system, an optical image I formed by randomly captured reflected light of a reference mark on a board to be corrected by a camera projection m16 is converted to an arbitrary binarization level to a television receiver 18.
An image is displayed on the screen using electrical signals, and a numerical calculation controller 19 checks whether the optical image I'' matches the outer frame line F of the standard pattern.
This is determined based on screen recognition by the operator of the television receiver 18. If this optical image I'' extends beyond the outer frame line F of the standard pattern as shown in FIG.
The optical image I'' captured in step 6 is adjusted to lower the binarization level, and is gradually projected as images I' and I located within the outer frame line F of the standard pattern in both the X' and Y' force directions. On the contrary, when the randomly captured optical image I' appears smaller inside the outer frame line F of the standard pattern, as shown in Fig. 6, the binarization level is gradually increased and adjusted. , the optical rays are widened until they match the outer frame line F of the standard pattern in both the X' and Y' force directions to produce images I' and I.

Along with this, in any case, the outer frame line F of the standard pattern
The image I', which matches the image I', and the X' of I.

The center points o', o' where the Y' directions intersect are determined by the operator's operation on the screen of the television receiver 18 using the numerical calculation controller 19, and the center points o', o' (the center point O of the predetermined standard pattern and coordinate axis X I + X 2...Xn
,'/r+V2...'In, the screen processing device 17 operating as an image sensor and the numerical calculation controller 19 calculate the amount of positional deviation. After adjusting the positional relationship of the electronic component mounting head with the board placed on the XY table based on the positional deviation data, the mounting head is moved downward to place the electronic component held at the tip of the head onto the printed circuit board. If it is mounted on a PC, it will be possible to position it in a predetermined conductive pattern and fix it by soldering.

Effects of the Invention As described above, according to the method for correcting positional deviation of a board according to the present invention, the position of a mounted board placed on an XY table is determined using the positioning mark formed of the same material as the conductive pattern. Since positioning data can be obtained accurately, electronic components can be surface-mounted on printed circuit boards with extreme precision.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram of an optical processing system to which the positional deviation correction method according to the present invention is applied, Fig. 2 is an explanatory diagram showing a light irradiation process in the system, and Fig. 3 shows a light irradiation mechanism in the same process. An explanatory diagram, Fig. 4 is an explanatory diagram showing a standard pattern of a television projector used in the video processing process, each a of Figs. 5 and 6,
b and c are explanatory diagrams showing the screen processing process of the television projector, and FIG. 7 is an explanatory diagram showing the positional deviation data calculation process according to the coordinate axes of the television projector. P: Mounting board, M: Positioning mark, 10° 13 = light source, 16: Camera projector, 17 Two-image processing device, 18: Television receiver, 19: Numerical calculation controller, F: Outer frame line of standard pattern, 0 : Center point of standard pattern, ■: Image of standard pattern, I'. I'' Video to be binarized, o', o': Center point of binarized video, x, x2...xn,'
J1. 'j2...yn: Coordinate axis.

Claims (1)

[Claims] Positioning marks made of the same material as the conductive pattern on the board surface are irradiated with light from the radial direction, and the reflected light is used to randomly project optical images onto the TV screen via the camera. The outer frame line and center point of the standard pattern corresponding to the positioning mark are set in advance at the center position, and the random optical image of the positioning mark projected on the TV screen is adjusted to the outer frame of the standard pattern by adjusting the binarization level up and down. The center point of the optical line that matches this standard pattern is compared with the center point set on the TV screen of the standard pattern, and the positional deviation in the X and Y directions is detected using the coordinate axes of the TV screen. A method for correcting positional deviation of a board, characterized in that the correlation between the mounting head and the position of the board is adjusted.