JPH01265144A - Lead deformation checking method for packaging parts - Google Patents

Abstract

PURPOSE:To use the pattern recognition in common for detecting the shift quantity of a parts adsorbing position of an absorbing head by confirming whether a lead deformation of longitudinal bending exists or not, based on a shift from the reference in the lead length direction of a lead tip. CONSTITUTION:A (b) dimension of packaging parts being an object and an (h) dimension of a longitudinal bending failure are stored in advance in a memory. In such a state, from a camera 10 of a chip laser, an image (projection image) of the mounting parts being an object is inputted. This input image is binarized and a plane image is obtained. Subsequently, in the plane image, the center of gravity and the moment by an image processing are derived. Next, the tip of each lead is derived, and from these data, when many lead tips come on a line being parallel to the moment is regarded as a normal lead, and by setting it as a reference position, an l dimension is derived. When the lead being different from the l dimension exists, it becomes an l' dimension, therefore, this lead whose tip position is shifted is the lead which has generated a longitudinal bending deformation althrough there is a difference of its degree.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a component mounting machine that mounts electrical components whose electrodes are formed by leads onto a circuit board. This invention relates to a method for checking lead deformation of a mounted component to be confirmed.

[Summary of the Invention] The present invention is a method for checking lead deformation of a mounted component in a component mounting machine. By determining the tip position and determining the presence or absence of vertical bending lead deformation of the holding component based on the deviation from the standard in the lead length direction, this method eliminates the cause of mounting defects without increasing the cost of the component mounter. It is designed to automatically check for defects in vertically bent leads of mounted components.

[Prior Art] Chip placers have been known as devices for automatically mounting surface-mounted electrical components on circuit boards and the like. - Boat fishing chip placer - is equipped with a suction nozzle as a mounting head, and it suctions and holds various parts from the percassette of the parts supply section, and places them on a predetermined position on a circuit board positioned with an X-Y table, etc. Move to position and mount the suction nozzle holding part. In the above process,
Generally, the position of the component picked up by the suction nozzle has a positional shift in the plane direction, so as shown in the configuration diagram of the prior art in FIG. Place it on top of the vision sensor, and in this position, insert part 2.
The pattern recognition unit 4 performs pattern recognition on the planar image of , detects the component position, corrects positional deviations if necessary, and performs the above-described component mounting.

FIGS. 7(a) and 7(b) are a plan view (a) and a side view (b) showing a flat package IC, which is an example of a mounted component. A typical electrical component has a lead such as lead 2λ of a flat package IC (integrated circuit) 2. Even if the displacement of the holding component is corrected by the above-mentioned pattern recognition, if the leads themselves are deformed as shown in leads 2b and 2c, this may cause mounting defects. This lead deformation mainly includes horizontal bending deformation in the pitch direction (plane direction) (lead 2b) and vertical bending deformation in the direction perpendicular to the plane (lead 2c), but in the past, only the horizontal bending deformation was checked. I was worried.

FIG. 8 is an explanatory diagram of a conventional lead deformation checking method. 2d is an image obtained by pattern recognition and binarization of part 2 in FIG. In the conventional lead deformation check method, an arbitrary line is drawn that passes through the lead portions 2a, .

If there is no lateral bend, the pitches will all be the same p, but if there is a lateral bend like the lead 2b, the pitch of that part will be Q+r, which is different from p. Conventionally, when this change in pitch is larger than a certain specified value, the device automatically determines that a horizontal bend has occurred in the component lead.

[Problems to be Solved by the Invention] However, the conventional lead deformation checking method described above has the problem that it is not possible to confirm lead deformation such as vertical bending, and many of the causes of poor attachment cannot be eliminated. It remained. Horizontal bending lead deformation may cause a bridge between rounds on the board as a mounting defect, but abnormal phenomena caused by this bridge can be easily detected and repaired during the inspection process, and are relatively minor defects. and occurs with respect to that lead. On the other hand, vertically bent lead deformation may lead to poor soldering (refloat state) not only to the lead but also to multiple adjacent leads.In addition, no abnormal phenomenon appears during the inspection process, and it may take 2 to 3 years. There is a risk that a contact failure will appear after this process, resulting in a serious failure that is difficult to detect.Moreover, the reality is that vertically bent lead failures are more common than horizontally bent ones.

The present invention was devised to solve the above-mentioned problems, and allows a component mounting machine to automatically correct vertically bent lead deformation of components, which causes mounting defects, without increasing equipment manufacturing costs. It is an object of the present invention to provide a method for checking lead deformation of a mounted component, which can confirm the deformation of a lead in a mounted component.

[Means for Solving the Problems] The structure of the method for checking lead deformation of a mounted component according to the present invention to achieve the above object is as follows: A component is held in a mounting head, and the position of the held component is recognized using a planar image. When mounting on a circuit board, there is a process of determining the lead tip position of the holding component from the planar image, and a vertically bent lead deformation of the holding component based on the deviation of the lead tip position from the standard in the lead length direction. and a process of determining the presence or absence of.

[Effects] If a mounted component has a vertically bent lead deformation, the lead tip will be shorter and longer in the lead length direction on a planar image than when the lead tip is normal. According to the present invention, the presence or absence of lead deformation such as vertical bending is confirmed based on the deviation of the lead tip from the standard in the lead length direction. The image of the mounted component required above uses a plane image obtained by pattern recognition, which is conventionally performed to check the position of the component held in the mounting head, so there is no need to add any special hardware. This does not result in an increase in device manufacturing costs.

[Example] Hereinafter, an example of the present invention will be described in detail based on the drawings.

FIG. 1 is a schematic external view of a chip placer to which an embodiment of the method for checking lead deformation of a mounted component according to the present invention is applied. This chip placer includes a rotary head 6 equipped with a plurality of suction nozzles 5, a component supply section 7 that supplies components to the suction nozzles 5, a substrate 8 that is fixed, and the component mounting location of the suction nozzle 5 is fixed. an X-Y table 9 for positioning in the X and Y directions relative to the suction nozzle 5; a video camera 10 for checking the positional deviation of the suction of the component and deformation of the lead of the component before the suction nozzle 5 mounts the component; It includes four actuators 11, 12, 13, and 14 that rotate the direction of the suction nozzle 4 by a predetermined amount at a given position.

In the rotary head 6, a plurality of suction nozzles 5 are arranged movably up and down at equal intervals on the periphery of a base 6a on a disc, and each suction nozzle 5 is moved to a station where the suction nozzles are stopped by a base drive unit 6b. are incremented sequentially.

The parts supply section 7 is equipped with a plurality of parts cassettes 15 for storing taped parts according to the type of mounted parts, and equipped with a Z-axis circumferential DC servo motor 7a equipped with an encoder, and transported to a station where the cassettes 15 for taping are performed in the rotary head 6 for suction. A predetermined parts cassette 15 is positioned so that parts can be supplied.

The encoder of the DC servo motor 7a is used for servo control for positioning.

The X-Y table 9 has a table 9b that is positioned in the X direction by an X-axis circumferential DC servo motor 9a.
It is positioned in the Y direction by a table 9d equipped with a servo motor 9c. The board 8 on which the components are mounted is fixed onto a table 9b using suitable fixing means such as screws, and the X-Y table 9 moves the mounting location of a predetermined component on the board 6 to a mounting station in the rotary head 6. be done.

The four actuators 11, 12, 13, and 14 are fixed corresponding to predetermined stations on the rotary head 6. The θ rotation actuator 11 is provided corresponding to a station after the suction station, and rotates the direction of the suction nozzle 5 that has been advanced to that station by θ angle, so that the suctioned parts are placed on the substrate 8 in a predetermined position. so that it is mounted in the direction of △θ rotation actuator 1
Reference numeral 2 denotes a pre-mounting station, which is provided corresponding to the station after the station where the video camera IO detects suction displacement. This actuator 12 rotates the suction nozzle 5 by an angular deviation Δθ in the nozzle direction (θ direction) among the detected suction deviations of the component, thereby correcting the direction of the component. - (to θ+8) rotation actuator 13 is provided corresponding to the station after mounting, and is for returning the direction of suction nozzle 5 to the origin (initial state). Actuator 1 for setting suction direction
4 is provided corresponding to the station after the above-mentioned station and before the component suction.

This actuator 14 is connected to a predetermined parts cassette 15.
This is used to set the direction of the suction nozzle when picking up parts from the ground. Each actuator 11 to 14 has a lever 11a=14a (14
a (not shown), which contacts the rotating shaft of the suction nozzle 5 at the station to rotate it.

FIG. 2 is a block diagram showing the configuration of the control circuit of the chip placer. 16 is a CPU (central processing unit) that controls each drive section of the chip placer, 17 is a CPU
This memory is connected to the 16 buses and stores programs indicating the above-mentioned control procedures and data necessary for the control.

The CPU 16 and the memory 17 constitute functional means for checking the presence or absence of lead deformation of the suction component in this embodiment from pattern recognition data to be described later. 18a, 18b.

18c are Z-axis circumferential DC servo motors 7a, X
Shaft circumference DC servo motor 9a, Y-axis circumference DC servo motor 9
It is a drive unit that performs servo control for each of c on the basis of the control amount given from cpute, and
a, 19b, 19c.

Each of 19d is a θ rotation actuator 11.6
0 rotation actuator 12. - (to θ+8) rotation actuator 13. Actuator 14 for setting suction direction
a drive unit 20 that controls the rotation angle of each of the rotation angles based on the angle control amount given from the CPU 16;
is a drive unit that controls the advancement of the base drive unit according to instructions from the CPU 16. Reference numeral 21 denotes a pattern recognition unit, which binarizes the signal from the video camera 10 to obtain a planar image of the component in order to detect the displacement of the component by the suction nozzle 5, and recognizes the pattern to determine the amount of displacement (X',
Y', Δθ), the center of gravity and moment are determined by image processing using the plane image, the position of the lead tip of the component is determined, and these pattern recognition data are sent to the CPU 16. In cpu l 6, Δθ of the above-mentioned deviation amount is corrected by the 60 rotation actuator 14, deviations tlX' and Y' are simultaneously corrected when positioning the mounting point of the board, and the lead tip position Based on this data and the data in the memory 17, it is determined whether or not there is at least vertical lead deformation.

An embodiment of the method for checking lead deformation of vertical bending of a mounted component according to the present invention, which is applied to the chip placer having the above structure, will be described below. FIG. 3 is a flowchart of one embodiment. In this example, the mounted components are flat packages tC.
Let us take as an example the case where . In this example, vertical lead deformation is detected by measuring the lead tip position (corresponding to length) using pattern recognition, and this pattern recognition is also used to detect the amount of deviation in the component suction position of the suction head. It is characterized by being shared. When the mounted component has a vertically bent lead deformation (lead 2c) as shown in FIG. 7, the lead tip position is at a different position from other normal leads. Therefore, the planar projection map of the component input from the video camera 10 shown in FIG. 1 is as shown in FIG. 8, and the lead length of the component that has vertically bent lead deformation is the normal lead length. are different. Therefore, in this embodiment, vertical bending is detected based on the lead length. Generally, in the case of vertical lead deformation, as shown in FIG. 4, the entire lead is often deformed from near the root, so this embodiment will be described using this case as an example. Fourth
In the figure, & is the plane projection dimension from the root to the bent part, b is the height dimension of the bending part of the lead, C is the plane projection dimension from the bending part to the lead tip, θ is the vertical bending deformation angle, and h is the vertical bending. Q is the height dimension of the lead tip of the deformed lead, Q is the planar projection dimension of the lead from the root to the lead tip, and Q' is the planar projection dimension of the vertically bent deformed lead. In this embodiment, a vertical bending defect in a lead of a mounted component is detected by the following procedure.

(1) The five dimensions of the target mounted component and the h dimension that is considered to be a vertical bending defect are stored in advance in a memory (memory 17 in FIG. 2).

(2) An image (projected image) of the target mounted component is input from the camera IO of the chip placer shown in FIG.

(3) Binarize the input image in (2) to obtain a planar image as shown in FIG.

(4) Find the center of gravity and moment using image processing in the plane image of (3).

(5) Find the tip position of each lead.

(6) From the data in (4) and (5), a case where many lead tips are on a line parallel to the moment is considered to be a normal lead, and this is used as a reference position to determine the 0 dimension.

(7) If there is a lead that differs from the 0 dimension, use the Q' dimension.

This lead whose tip position has shifted is a lead that has undergone vertical bending deformation to varying degrees.

(8) Find the amount of vertical bending of the lead using the following formula.

h=b+IT-17"-1η...■This formula is derived from the formulas ■, ■, and ■ shown in FIG.

a cos θ + b sin θ + 'CCo1t θ = Q' ・
・・■1)+asinθ−b coso+csinθ=
h −...■Y+c−Q...■ If the h dimension value obtained here is larger than the h dimension value stored in the memory in (1) that is determined to be defective, the mounted component It is determined that a vertical bending defect has occurred in the lead.

Note that, as is clear from Equation 0, with projection mapping from only one direction, it is not clear whether the lead is deforming upward or downward. Therefore, as shown in the explanatory diagram of the application example in FIG.
By comparing the differences in dimensions, it is possible to determine which direction (up or down) the object is bent. For example, if the value of +Q-Q'l of an image taken from an oblique direction is smaller than the value when the video camera 10 is installed vertically, it can be determined that the lead is deformed upward.

In addition, in the above embodiment, the vertical bending defect of the component lead is detected based on the h dimension, but the +Q
- Store the value of Q'l in memory and calculate the actual IQ-
If Q'l is greater than the value of lQl'1 in memory, then
The mounted component may be determined to have a vertical lead bending defect. The value of IQ-12'l in the memory in this case can also be determined by considering cases of deformation other than vertical bending by θ from the root.

Furthermore, the vertical bending deformation of the lead is the amount of lead deformation +
It is learned from Q-Q'l, but this IL-12'
The value of l is actually a small value (for example, about 0.5 mm in the above embodiment). On the other hand, when the entire part is photographed with a camera, the resolution (minimum discernible dimension) on the pattern recognition unit side is coarse.

Therefore, it may not be possible to accurately measure the amount of lead deformation. In such cases, when taking a picture of the entire part, roughly verify the position of the lead tip, and if there is a suspicious part, change the magnification of the camera lens, input an enlarged image of that part, and save the data. The amount of lead deformation may be accurately calculated using the method.

It goes without saying that the present invention can be carried out together with the conventional horizontal bending lead deformation check method and can be applied to component mounting machines with various configurations. You can also do that.

As described above, the present invention can be applied in various ways in accordance with its gist and can take various embodiments.

[Effects of the Invention] As is clear from the above description, the method for checking lead deformation of a mounted component according to the present invention provides the following effects.

(1) Pattern recognition information input to detect the position of a component held by a mounting head can be used as is to automatically check for vertical bending deformation of component leads that may cause serious defects.

(2) Since vertical bending of component leads is checked using only the data processing method, there is no need to add new hardware and there is no increase in device manufacturing (assembly) costs.

(3) There is no need to move the component held by the mounting head to a sensor specially installed at a different location to check for vertical bending of the component lead, and there is no time loss due to such movement, so the component mounting tact time is reduced. Vertical bending of component leads can be checked with almost no effect on time.

[Brief explanation of the drawing]

FIG. 1 shows a chip placer to which an embodiment of the present invention is applied.
2 is a block diagram of the control circuit of the chip placer, FIG. 3 is a flowchart showing an embodiment of the method for checking vertical bending deformation of leads in mounted components according to the present invention, and FIG. 4 is a block diagram of the control circuit of the chip placer. An explanatory diagram of vertical bending lead deformation, Fig. 5 is an explanatory diagram of an application example, Fig. 6 is a configuration diagram of the prior art, and Fig. 7 (
a). (b) is a diagram showing an example of a mounted component, and FIG. 8 is an explanatory diagram of the prior art. 2... Parts, 5... Suction nozzle, 8... Board, 1
0...Video camera, 16...CPU. 17...Memory, 21...Pattern recognition unit. -Large 1 fix 4 ri J's 70-~- and Figure 3 Figure 4 Figure 5

Claims (1)

[Claims] (1) The process of determining the lead tip position of the holding component from the planar image when holding the component in the mounting head and mounting it on the circuit board by recognizing the position of the holding component using a planar image; and the process of determining the lead tip position of the holding component from the planar image. A method for checking lead deformation of a mounted component, comprising the step of determining whether or not there is a vertically bent lead deformation in the holding component based on a deviation from a standard in the lead length direction.