CN101026952A - Electronic component mounting method and device - Google Patents

Abstract

The invention provides an electronic component installation method and device. Its object is to provide an electronic component mounting method and apparatus capable of reliably compensating for printing variations of solder, mounting electronic components with high precision, and improving productivity of substrates. As a solution, the substrate is transported to the device and fixed at a predetermined position (step S1), the camera is moved to the substrate mark formed on the substrate for identifying the substrate position (S2), and the substrate mark and Solder mark (S3) for identification of solder printing position printed nearby. The position of the center of gravity of the substrate mark and the solder mark is detected from the captured image (S4, S5), and the deviation amount n of the center of gravity position is calculated to obtain the printing deviation amount of the solder relative to the board (S6). Then, a component mounting position correction amount corresponding to solder printing deviation is calculated from the deviation amount n ( S10 ), and the component mounting position is corrected by combining this correction amount and other correction amounts to mount the component ( S11 ).

Description

Electronic component mounting method and device

technical field

The present invention relates to an electronic component mounting method and device for mounting electronic components on a circuit board on which solder is printed.

Background technique

Conventionally, in electronic component mounting devices, in order to mount electronic components on circuit boards (hereinafter simply referred to as substrates) with high precision, when the substrates are carried into the device, the substrates are fixed on the substrate to be mounted as a preliminary preparation for mounting. position, recognize the substrate mark printed on the substrate, detect the position deviation of the substrate, and correct the mounting position of the electronic component on the substrate (for example, refer to the following patent document 1).

However, in this structure, the variation in solder printing when solder paste is printed on each electrode on the substrate is not considered. Therefore, there is a problem that the mounted electronic components cannot be correctly positioned with respect to the solder printed on the electrodes, resulting in poor mounting.

In this regard, the following structure has been known, that is, the substrate on which the solder pattern is being printed is photographed, the respective positions of each electrode on the substrate and the solder printed thereon are detected, and the mounting position of each electronic component is corrected based on the detection result (see Patent Document 2).

However, in this configuration, all the electrodes on the board and the solder patterns printed on them are photographed and recognized, so depending on the number of parts mounted on the board and the number of electrodes on the board, it may take time for the recognition process and the tact of the board may become longer. question.

In contrast, Patent Document 3 describes a structure in which alignment marks are printed at a plurality of locations (for example, two locations) in the solder printing step of the substrate, deviations of the alignment marks are detected, and positional deviations of the printed patterns are obtained. This amount of deviation corrects the component mounting position.

In addition, Patent Document 4 describes a structure in which a solder mark (solder paste mark) for identifying a positional deviation of a solder pattern is printed on a board on which a board mark (pattern mark) is formed, and after the positional deviation of the board is recognized, , detect the position of the solder mark, calculate the position error amount of the solder mark when the board mark is used as a reference, and correct the mounting position based on the error amount and the board position deviation.

Patent Document 1 Japanese Patent Application Laid-Open No. 5-267899

Patent Document 2 Japanese Patent Laid-Open No. 2003-92496

Patent Document 3 Japanese Patent Publication No. 7-105635

Patent Document 4 Japanese Patent No. 3264395

However, in the structure of Patent Document 3, the position deviation of the printed pattern relative to the reference position is obtained, so the position deviation of the board is not considered. The problem.

In contrast, in the structure of Patent Document 4, although both the position deviation of the board and the printing deviation of the solder are considered, the imaging and recognition of the board mark for recognizing the board position and the solder mark for recognizing the solder printing position are separated front and rear. So when the camera is moved to the board mark and when it is moved to the solder mark, the positional relationship of the camera relative to each imaging position deviates due to mechanical errors, except that the amount of deviation is added to the error when correcting the mounting position In addition to the problem, there is an unnecessary time spent moving to the solder mark position after taking pictures of the board mark position.

Contents of the invention

The object of the present invention is to solve such problems and provide an electronic component mounting method and apparatus capable of compensating for solder printing position deviation, mounting electronic components with high precision in a short time, and improving substrate productivity.

In order to solve the above-mentioned problems, the electronic component mounting method of the present invention for mounting electronic components on a substrate printed with solder is characterized in that a substrate mark (51, 52, 53) for substrate position identification formed on the substrate or its Nearby, print solder marks (61, 62, 63) for identifying solder printing positions, photograph the board marks and solder marks at the same time, detect the positions of the board marks and solder marks from the captured images, and calculate the printed position of the solder relative to the board. The component is mounted by correcting the mounting position according to the calculated printing deviation amount.

In addition, the electronic component mounting device for mounting electronic components on a substrate printed with solder according to the present invention is characterized in that the electronic component mounting device includes: an imaging unit (17) that simultaneously captures images of substrate marks and positions on the substrate. A solder mark (61, 62, 63) for identifying a solder printing position printed in or near the substrate mark (51, 52, 53); a calculation unit (27, S4-S6), which according to the The position of the substrate mark and the solder mark is detected by the image of the substrate, and the amount of printing deviation of the solder relative to the substrate is calculated; and the control unit (20, S10-S11) performs mounting position correction corresponding to the calculated printing deviation amount, thereby Carry parts.

In the present invention, the amount of deviation in printing of the solder relative to the board is detected and the component mounting position is corrected, so it is possible to reliably compensate for the deviation in the printing position of the solder that occurs when printing the solder on the board. In addition, in the present invention, the board mark and the solder mark are located in the same field of view of the imaging unit and can be photographed at the same time, so it is possible to obtain the amount of positional deviation of the board and the position of the solder relative to the board with high precision in a short time. The effect of printing offset.

Description of drawings

FIG. 1 is a perspective view showing an overall schematic configuration of an electronic component mounting apparatus according to the present invention.

FIG. 2 is a block diagram showing the configuration of a control system of the device.

3 is a plan view showing an example of a stencil used for solder printing on a circuit board.

FIG. 4 is a plan view showing a circuit board printed with solder using the stencil.

Fig. 5 is a flow chart showing the component mounting flow of the present invention.

6 is an explanatory view showing images of a board mark and a solder mark captured by a board recognition camera.

FIG. 7 is another example of an image of a board mark and a solder mark captured using a board recognition camera.

FIG. 8 is another example of an image of a board mark and a solder mark captured using a board recognition camera.

Detailed ways

Hereinafter, an embodiment of the best mode for carrying out the present invention will be described with reference to the drawings.

【Example】

FIG. 1 is a diagram schematically showing an electronic component mounting apparatus according to an embodiment of the present invention. As shown in this figure, the electronic component mounting apparatus 1 has: a circuit board conveyance path 15 extending toward the left-right direction (X-axis direction) after the central part; The lower side shown) provides electronic components (hereinafter simply referred to as components) to be mounted on the substrate 10; and an X-axis moving mechanism 11 and a Y-axis moving mechanism 12 arranged above them.

The X-axis moving mechanism 11 moves the suction head 13 having the suction nozzle 13 a of the suction member in the X-axis direction, and the Y-axis moving mechanism 12 moves the X-axis moving mechanism 11 and the suction head 13 in the Y-axis direction. In addition, although the suction head 13 is not shown in FIG. 1, it has a Z-axis moving mechanism that moves the suction nozzle 13a vertically (Z-axis direction) up and down, and makes the suction nozzle rotate with the suction nozzle axis (suction axis). ) is a θ-axis moving mechanism that rotates around the center.

In addition, a substrate recognition camera 17 as an imaging unit and an unillustrated illumination unit for illuminating the substrate 10 are attached to the suction head 13 , and the camera 17 captures a substrate mark formed on the substrate 10 for substrate position recognition.

Moreover, the component recognition camera 16 which images the component sucked by the suction nozzle 13a from below is provided in the side part of the component supply part 14. As shown in FIG. In addition, an illuminating unit (not shown) for illuminating the absorbed component is provided together with the component recognition camera 16 . In addition, although not shown in order to avoid complication, a laser unit is attached to the suction head 13 to recognize parts that do not require high-precision recognition.

In addition, an operation monitor 18 for displaying the operation status of the device and the like is provided on the upper front portion of the electronic component mounting device 1 . In addition, a control unit 19 that performs overall control of the device, image processing, and the like is provided in the main body.

FIG. 2 shows the configuration of the control system of the electronic component mounting apparatus 1 . The control unit 19 in FIG. 1 is composed of the controller 20 in FIG. 2 , the image processing device 27 , the storage device 30 and the like.

The controller 20 is composed of a microcomputer (CPU) for controlling the entire apparatus, RAM, ROM, and the like. The following structures 21 to 31 are connected to the controller 20 .

The X-axis motor 21 is a driving source of the X-axis moving mechanism 11 and moves the suction head 13 in the X-axis direction. The Y-axis motor 22 is the driving source of the Y-axis moving mechanism 12, and moves the X-axis moving mechanism 11 and the suction head 13 in the Y-axis direction, so that the suction head 13 can move in the X-axis direction and the Y-axis direction .

The Z-axis motor 23 is a drive source of the Z-axis driving mechanism of the suction nozzle 13a, and moves the suction nozzle 13a up and down in the Z-axis direction (height direction). The θ-axis motor 24 is a drive source of the θ-axis rotation mechanism of the suction nozzle 13a, and rotates the suction nozzle 13a around its nozzle center axis (suction axis).

The image processing device 27 is composed of an A/D converter 27a, a memory 27b and a CPU 27c, and the analog image signal of the part 2 taken by the part recognition camera 16 is converted into a digital signal by the A/D converter 27a and stored in the memory 27b, The CPU 27c recognizes the position deviation of the component center and the deviation of the suction angle with respect to the suction center of the suctioned component 2 from the component image data.

Further, the image processing device 27 (computing unit) converts the images of the board mark for board position recognition and the solder mark for solder printing position recognition captured by the board recognition camera (imaging unit) 17 through the A/D converter 27a into The digital signal is stored in the memory 27b, and the CPU 27c detects the position of the board mark and the solder mark based on the image data, and obtains the position deviation of the board and the printing deviation of the solder as described later. Then, the controller 20 (control unit) corrects the mounting position of the component 2 based on the respective deviations obtained from the captured images of the cameras 16 and 17 , and mounts the component 2 at the correct mounting position on the substrate 10 .

The keyboard 28 and the mouse 29 are used to input data such as parts data.

The storage device 30 is composed of a flash memory or the like, and stores component data input through the keyboard 28 and the mouse 29, component data supplied from a host computer not shown, and the like.

The display device (monitor) 31 displays component data, calculation data, an image of the component 2 captured by the component recognition camera 16 , and images of board marks and solder marks captured by the board recognition camera 17 on a screen 31 a.

FIG. 3 shows an example of a stencil for printing solder on the electrodes of the substrate. A plurality of holes 33 are respectively formed on the stencil 32 at positions corresponding to the respective electrodes, for printing solder on the electrodes on the substrate connecting component terminals. Further, holes 41 to 43 for printing solder marks for identifying solder printing positions on the board are respectively formed at predetermined positions of the three corners of the stencil 32 . One solder mark may be used, but usually a plurality (2 to 4) is printed in order to improve accuracy, so holes corresponding to the number are formed on the stencil.

FIG. 4 shows the substrate 10 on which solder printing was performed using the stencil 32 of FIG. 3 . On the substrate 10 , substrate marks 51 to 53 for substrate position identification are printed in advance at predetermined positions. Solder 64 is printed on each electrode of the substrate 10 through the electrode holes 33 of the stencil 32 , and solder marks 61 to 63 are printed through the solder mark holes 41 to 43 . Here, the respective positions of the solder mark holes 41 to 43 correspond to the respective positions of the board marks 51 to 53, and the respective solder marks 61 to 63 are printed on the respective board marks 51 to 53 so that the center (center of gravity) positions thereof are aligned with the positions of the board marks 51 to 53. The center positions of the respective substrate marks 51 to 53 coincide. Furthermore, since the holes 41 to 43 are smaller than the board marks 51 to 53 , the solder marks 61 to 63 are printed on the board marks 51 to 53 smaller than the board marks, respectively.

In fact, when printing solder, the stencil 32 and the substrate 10 will have a positional deviation, so correspondingly, the solder marks 61-63 will be printed with a positional deviation relative to the substrate marks 51-53, and the solder on the electrode will also have a positional deviation relative to the electrode. is printed. In FIG. 4 , the solder 64 on the electrodes is shown in a state where there is no positional deviation in order to avoid confusion.

Hereinafter, the component mounting operation will be described according to the flow chart shown in FIG. 5 .

Before the mounting operation, solder printing is performed on the substrate 10 using the stencil 32 shown in FIG. 3 , and solder 64 and solder marks 61 to 63 are printed on the electrodes of the substrate 10 as shown in FIG. 4 .

In step S1 , the substrate 10 on which solder has been printed is conveyed on the substrate conveyance path 15 shown in FIG. 1 , and fixed at a predetermined position.

In step S2 , the suction head 13 is moved in the X and Y axis directions by the X-axis moving mechanism 11 and the Y-axis moving mechanism 12 , and the substrate recognition camera 17 is moved to a predetermined position facing the first substrate mark 51 .

In step S3, the substrate mark 51 and the solder mark 61 printed thereon are photographed simultaneously by the substrate recognition camera 17, and the photographed images are stored in the memory 27b. FIG. 6 shows captured images of the board mark 51 and the solder mark 61 .

In steps S4 and S5, the CPU 27c of the image processing device 27 processes the captured image, for example, by pattern matching or edge detection, to detect the position (X1, Y1) of the center of gravity of the substrate mark 51a and the position (X2, Y1) of the center of gravity of the solder mark 61a (X2, Y2), in step S6, calculate the deviation n of the two center of gravity positions. The amount of deviation n indicates the amount of printing deviation (error amount) of the solder with respect to the substrate 10 .

In step S7, when it is determined that the value of the deviation amount n is greater than the predetermined allowable limit value m, it is determined that the solder printing is defective, the processing operation of FIG. 5 is terminated, and the mounting operation of components on the substrate is prohibited. In addition, at this time, a message warning the user of poor solder printing is output.

Only one board mark and the solder mark printed on it can also be used to obtain the printing deviation of the solder relative to the board, but in order to improve the accuracy, the camera 17 is moved to the positions of other board marks 52 and 53 in sequence, and step S3 is repeated. ~S7 processing.

After finishing the process of marking all the boards (step S8), the amount of printing deviation of the solder with respect to the board is finally obtained. For example, when only one set of board marks and solder marks is used, the amount of printing misalignment is obtained as the difference between the X-coordinates and the Y-coordinates of the centroid positions of the two marks. In addition, in the case of using two sets of board marks and solder marks, since tilt correction can be performed, the average value of the difference between the barycentric coordinates (X, Y) of the two sets of board marks and solder marks after tilt correction is used as the printing value. In addition, in the case of using three sets of substrate marks and solder marks, since two tilts can be obtained, the average value is used for tilt correction, and the center of gravity coordinates of the three sets of substrate marks and solder marks after tilt correction ( The average value of the difference between X and Y) is used as the printing deviation.

After the amount of printing misalignment is obtained in this way, the amount of printing misalignment is multiplied by a weighting coefficient (correction coefficient) k to obtain a loading correction amount (step S10). The weighting coefficient can be determined according to the type of the component, for example, 0.5. If the component requires loading accuracy, the weighting coefficient is set to a value greater than 0.5. Then, the mounting position is corrected using the correction amount obtained in this way, and the component is mounted on the substrate (step S11 ).

In addition, when correcting the mounting position, if there are suction deviations of components and positional deviations of the substrate from the reference position, these deviation amounts are also corrected. The center position and suction angle of the component can be detected by image processing of the component 2 captured by the component recognition camera 16 to obtain the suction deviation of the component. In addition, the position of the substrate can be obtained by detecting the positions of the substrate marks 51 to 53 deviation. In this embodiment, the board mark and the solder mark are photographed at the same time, and the position of each mark is detected, so there is an advantage that the printing deviation of the solder relative to the board and the position deviation of the board relative to the reference position can be obtained in a short time .

In addition, in the above embodiment, the printing position of the solder mark is set on the board mark, but as shown in FIG. As shown in FIG. 8, if the substrate mark 91 and the solder mark 99 can be captured in the same field of view 98 of the substrate recognition camera 17 and photographed simultaneously, the solder mark can also be printed near the substrate mark.

Claims (4)

1. an electronic component mounting method that carries electronic unit on the substrate that has printed scolding tin is characterized in that,

Near the scolding tin mark of print solder printing position identification usefulness in the base plate mark of substrate position on being formed at substrate identification usefulness or it,

Take described base plate mark and scolding tin mark simultaneously,

According to the position of image detection base plate mark that photographs and scolding tin mark, calculate the printing deviation amount of scolding tin with respect to substrate,

Carry out and the described corresponding mounting position correcting of printing deviation amount that calculates, thus boarded parts.

2. electronic component mounting method according to claim 1 is characterized in that, multiply by weight coefficient to the printing deviation amount of the described scolding tin that calculates, and carries out and the corresponding mounting position correcting of printing deviation amount that multiply by behind the weight coefficient.

3. electronic component mounting method according to claim 1 and 2 is characterized in that, when the printing deviation amount of described scolding tin surpasses the tolerance limit value of regulation, forbids carrying action.

4. electronic component mounting apparatus that carries electronic unit on the substrate that has printed scolding tin is characterized in that this electronic component mounting apparatus has:

Image unit, it takes base plate mark and in the base plate mark of substrate position identification usefulness or near the scolding tin mark used of the solder printing location recognition of printing it simultaneously;

Computing unit, it calculates the printing deviation amount of scolding tin with respect to substrate according to the image detection base plate mark that photographs by described image unit and the position of scolding tin mark; And

Control unit, it carries out and the described corresponding mounting position correcting of printing deviation amount that calculates, thus boarded parts.

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