JP2001168594A - Installation apparatus for surface mounting component - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a correction man-hour after a soldering operation in a process in which a surface mounting component is installed on a circuit board. SOLUTION: After the surface mounting component is installed on the circuit board and before a reflow soldering operation is performed, the lead of the surface mounting component and a solder paste are imaged by an image recognition device. The central position of the lead and that of the solder paste are found. When the central position is deviated by a prescribed size or more, the central position is detected as the deviation of a mounting position. The solder paste is imaged after the surface mounting component is installed. When the solder paste has a prescribed area or more, it is detected as the crush of the solder paste. When it is corrected before the reflow soldering operation is performed, the correction man-hour after the soldering operation is reduced.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount component mounting apparatus for automatically mounting electronic components on a circuit board, and mainly to print pad positions or solder paste in order to eliminate mounting position deviation of narrow pitch lead components. A surface that corrects the mounting by judging the mounting state by recognizing the position deviation from the center of the mounted component lead and the crushed shape of the solder paste or adhesive after mounting the electronic component on the circuit board, and judging the mounting state The present invention relates to a mounting component mounting apparatus.

[0002]

2. Description of the Related Art Conventional surface mount component mounting apparatuses include:
As shown in JP-A-5-41598 and JP-A-8-16279, the upper surface of an electronic component is vacuum-sucked by a suction nozzle to mount the electronic component at a predetermined position on a circuit board. At that time, narrow pitch lead parts (0.5 mm pitch QF
P, etc.) to improve the mounting accuracy, take a photograph of the lead part of the electronic component sucked by the suction nozzle with a camera, measure the outermost dimension including the lead of the electronic component, calculate the component center position, and The correction for the mounting position (XY axis direction) is corrected by moving the suction head or the substrate mounting table. The camera also recognizes a shift in the rotation direction (θ direction) of the electronic component with respect to the circuit board, calculates the inclination of the component, and corrects the rotation angle.

However, even when the mounting position is corrected in this manner, actually, warpage of the circuit board and dimensional variation of the electronic components, particularly, the thickness of the components such as coils and transformer components, etc.
The external dimensions and the dimensions of the surface on which the components are to be picked up vary depending on the component lot, and there are positional shifts that must be corrected manually after mounting electronic components due to fluctuations in the mechanical mounting accuracy of the device. There is.

According to the present invention, in order to further improve the mounting accuracy, the positional relationship between the lead portion of the component and the solder paste and the degree of crushing of the solder paste in a state where the electronic component is mounted on the circuit board are improved in the present invention. This is an electronic component automatic mounting apparatus that performs photographing with a camera and corrects the mounting position (the XY axis direction, the rotation direction, and the height direction) of the electronic component.

[0005]

When mounting a surface mount component on a circuit board, a defect such as a component displacement or a solder short is detected by a visual inspection device after completion of soldering. In general, a method of detecting by visual inspection is used, but there is a problem that the repair of the defect of the surface-mounted component after the soldering is largely dependent on human labor and requires a lot of man-hours.

An object of the present invention is to check the mounting quality of surface-mounted components before reflow or before curing an adhesive and to solder only non-defective products, thereby reducing the number of man-hours for repairing defects after soldering. I have.

[0007]

According to the present invention, in order to achieve the above object, after mounting a surface mount component on a circuit board and before reflow or curing of an adhesive, the center of the lead is connected to a solder paste or pad by an image recognition device. The center position is determined, and if a deviation exceeding a specified dimension occurs, the position where the deviation has occurred is detected and a correction is performed. Similarly, the area of the solder paste after mounting the surface-mounted components is measured, and if the area is equal to or larger than the specified area, the area is detected as a solder crush and repair is performed. Furthermore, by performing mounting while self-correcting the mounting position coordinates and mounting data in the mounting height direction based on the obtained displacement dimensions and solder area, the number of correction steps after soldering can be reduced.

[0008]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 shows the appearance of an electronic component mounting apparatus having a mounting position correcting function according to the present invention.
Shows a basic operation flow relating to the present invention. An outline of the operation will be described with reference to FIGS. First, the circuit board 1 is transported from the previous process by the transport conveyor 15 and is positioned and fixed on the XY table 12 in the apparatus. A board position recognition mark (a copper pattern having a diameter of about 1.0 mm) is arranged at a diagonal position of the circuit board 1, and a camera 5 installed next to the component mounting hand 6 photographs the recognition mark and performs image processing. The data is converted into binary image data or multivalued image data by the device 14 to detect the center position of the mark. By detecting the positions of the two marks arranged at diagonal positions on this substrate,
The relative displacement and inclination of the substrate with respect to the XY table 12 are recognized. Next, the component mounting hand 6 is moved to the component pick-up position of the component supply unit 11 by the direct-type robots 7, 8, and 9, and the electronic component 2 is suction-held therefrom by the suction nozzle 10 attached to the tip of the hand. Thereafter, the component mounting hand 6 moves above the electronic component lead detection camera 13. This camera captures all the leads of the component and converts the lead shape into binary or multi-valued image data by the image processing device 14. Next, the center position of the component is finally determined by determining the outermost dimensions of the component including the leads.
At the same time, the inclination angle of the rotation direction with respect to the component mounting hand 6 is also recognized. As described above, by recognizing the relative displacement and inclination of the circuit board 1 with respect to the XY table 12 and the relative displacement and inclination angle of the electronic component 2 with respect to the component mounting hand 6, the electronic component with respect to the circuit board 1 is recognized. The correction values of the relative displacement and the inclination angle of the electronic component 2 are calculated, and the component mounting position data corrected for the component mounting hand 6 and the orthogonal robots 7 and 8 are fed back to the electronic component 2.
At a predetermined position on the circuit board 1. Then camera 5
Moves above the component mounting position of the circuit board 1, and photographs the component mounting state before soldering. With this, it is possible to recognize lot-like board warpage and component dimensional variation, as well as misalignment of component mounting caused by fluctuations in the mechanical mounting accuracy of the device, and use this misalignment data to mount the next component. By feeding back to the position data, mounting of components with higher accuracy is performed. Next, FIG. 3 shows a top view (I) and a cross-sectional view (II) in a state where the electronic component 2 is mounted on the circuit board 1, and FIG. 4 is an enlarged view of the lead portion 3 after mounting the component. This shows a state in which the component lead 3 is displaced (Y) with respect to the solder paste 4. In particular, even in the case of a narrow-pitch lead component (0.5 mm pitch QFP, etc.), even if the misalignment is corrected as described above, the mounting position may vary due to the lot-like warpage of the board 1 and the dimensional variation of the electronic component 2 and the mounting accuracy of the device. Deviation has occurred. Therefore, conventionally, after the components are mounted, the mounting position is manually corrected. FIG. 5 shows a system configuration diagram of an apparatus for performing the position shift correction. In the present invention, in order to abolish the manual position correction described above, the state in which the electronic component 2 is mounted on the circuit board 1 is taken by the camera 5. The position deviation of the lead 3 of the electronic component 2 with respect to the solder paste 4 is detected by image processing, and the deviation amount (y) is fed back to the driving units 7 and 8 of the mounting hand 6 to correct the position deviation. Thereby, the mounting accuracy can be improved.

<Embodiment 2> FIG. 6I is a top view of the lead portion 3 after the electronic component 2 is mounted on the circuit board 1. Shows a state where it is spread. In such a case, when soldering is performed in the reflow process, a solder bridge defect may occur. Therefore, the amount of crushing when the solder paste 4 is crushed is standardized, and the amount of movement of the mounting hand 6 in the height direction is changed when the threshold value at which the solder bridge failure occurs is exceeded, so that no solder bridge is generated. This is to perform good component mounting. This solder paste 4
As a threshold value of the amount of crushing of the solder paste, the amount of crushing of the solder paste 4 is about the dimension (x) between the adjacent pads 16 based on the relationship between the amount of movement of the mounting hand and the amount of crushing of the solder paste 4 in FIG. If it exceeds １ ／, it becomes a dangerous area where a solder bridge occurs. Therefore, as the control of the movement amount of the mounting hand 6,
First, after detecting the crush amount (c) of the solder paste 4 with a camera, if the crush amount exceeds the threshold, the amount of movement of the mounting hand 6 by the dimension (b) is compared with the initial movement amount (a) of the mounting hand 6. Make it shorter. This is fed back to the mounting height data of the next component to correct the amount of crushing of the solder paste 4.

[0011]

As described above, according to the present invention, the relative positional relationship between the electronic component and the solder paste and the amount of crushing of the solder paste are recognized, and this is corrected for the mounting position data. The position correction work after component mounting, which has been performed, can be eliminated, and electronic components can be mounted on a circuit board automatically with high precision.

[Brief description of the drawings]

FIG. 1 is a perspective view showing an automatic mounting device for an imposition component according to the present invention.

FIG. 2 is a diagram showing an operation flow of the automatic component mounting apparatus according to the present invention.

FIG. 3 shows a top view (I) and a cross-sectional view (II) in a state where electronic components are automatically mounted on a circuit board.

FIG. 4 is an enlarged view of a lead portion after components are automatically mounted on a circuit board, showing a state in which a positional shift between a solder paste and component leads has occurred.

FIG. 5 is a diagram showing a system configuration of an apparatus for correcting misregistration according to the present invention.

FIG. 6 is an enlarged view of a lead portion after electronic components are mounted on a circuit board. FIG. 6 (I) is a diagram showing a state in which a large amount of pressing is performed at the time of mounting components, the solder paste is crushed, and the solder paste is spread horizontally. Between Transfer of Solder and Destruction of Solder Paste (II)
FIG.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Circuit board, 2 ... Electronic component, 3 ... Component lead, 4 ... Solder paste, 5 ... Camera, 6 ... Component mounting hand, 7 ...
Mounted hand drive (Y-axis), 8 ... Mounted hand drive (X
9) Mounting hand drive unit (Z axis), 10 ... Component suction pad, 11 ... XY table, 12 ... Component supply unit, 13 ... Electronic component lead detection camera, 14 ... Image processing device, 15 ... Substrate transport conveyor, 16 ... imposition pads.

 ──────────────────────────────────────────────────の Continuing from the front page (72) Inventor Hideki Ono 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Inside the Communication Systems Division of Hitachi, Ltd. (72) Inventor Tomoyuki Omura 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Address Co., Ltd.Hitachi, Ltd.Communication System Division (72) Inventor Yuzo Kato216, Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture Co., Ltd.Communication System Division, Hitachi Ltd. (72) Inventor Tomoharu Horii Totsuka, Yokohama-shi, Kanagawa Prefecture 216 Totsuka-cho, Toku-ku, Hitachi, Ltd. Communication Systems Division of Hitachi, Ltd. (72) Inventor Mitsuhiro Zhang, 216 Totsuka-cho, Totsuka-ku, Yokohama-shi, Kanagawa Prefecture F-term (Reference) 5E313 AA02 AA11 EE03 FF03

Claims (3)

[Claims] 1. After automatically mounting a surface mount component on a circuit board on which solder paste is printed, the surface mount component lead and the solder paste are imaged by an image recognition device, and the center of the surface mount component lead is determined from the obtained image data. Value and the center value of the solder paste, and if the center value of the surface mount component lead deviates from the specified value with respect to the center value of the solder paste, the surface mount component has a function to detect the position shift as a displacement. Onboard equipment. 2. A solder paste is imaged by an image recognition device in a state where the surface mount components are automatically mounted, and an area of the solder paste is obtained based on the obtained image, as in claim 1.
A surface mount component mounting device having a function of detecting a solder paste being crushed when the area is equal to or larger than a specified area. 3. In the case of detecting a mounting position shift based on the mounting shift amount and the crushing amount of the solder paste obtained in the above-described claims, the shift amount is calculated based on mounting position coordinate data for mounting on the next circuit board and thereafter. A surface mount component mounting device that has a function to automatically correct and mount components in the height direction of components to be mounted after the next circuit board in the event of solder paste collapse.