JPH09326595A - Part mounting method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a part mounting method which is capable of reducing a mounting head in descending movement to an irreducible minimum by a method wherein an XY table is moved in a vertical direction, where the descending movement of the mounting head is usually fixed with the height of a part. SOLUTION: A mounting equipment is equipped with an XY table movable in a vertical direction, the movement of an XY table 3 is calculated basing on the maximum height of an electronic part 5 mounted on a circuit board and the height of an electronic part 4 held by a part holder 1, and the XY table 3 is moved in a vertical direction by the above calculated movement so as to make the mounting movement of the part holder 1 minimum, and then the part holder 1 is actuated to carry out a mounting operation, so that a shock given to a mounting nozzle and an electronic part can be reduced to a minimum, and an electronic part is improved in mounting accuracy and reliability.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component mounter that holds an electronic component by a component holder and puts the electronic component at a predetermined position on a circuit board.

[0002]

2. Description of the Related Art FIG. 5 is an overall perspective view of an electronic component mounting machine.
Hereinafter, a conventional component mounting method will be described with reference to FIG. FIG.
In FIG. 1, reference numeral 11 is a rotatable rotary table, around which a plurality of mounting heads 12 are arranged at equal intervals so as to be able to move up and down, and suction nozzles 13 which are component holding portions for sucking electronic components at the tip of each mounting head 12. Is provided. A valve 14 for switching on / off of a vacuum circuit for each suction nozzle 13 is provided on the rotary table 11. Further, a plurality of component supply means 16 are arranged, and a component supply unit 15 for supplying a desired electronic component therein to the component suction position of the suction nozzle 13 is provided. On the other hand, the circuit board 17 on which the electronic components are mounted is fixed to the XY table 18, and the electronic component mounting position of the circuit board 17 is moved to the suction nozzle 13 by moving the XY table 18 in the X and Y directions.
Is configured to correspond to the component mounting position.

At the component mounting position, the mounting head 12 moves up and down for the mounting operation to mount a predetermined electronic component on the circuit board 17. At this time, during the lifting operation of the mounting head 12, the distance H between the tip of the suction nozzle 13 and the upper surface of the circuit board 17 when the mounting head 12 is at the highest rising point.
Is determined by adding the allowable distance σ to twice the height dimension h _MAX of the maximum component that can be mounted, as shown in FIG. 6A, and H = 2h _MAX + σ . A distance H between the tip of the suction nozzle 13 and the upper surface of the circuit board 17 when the mounting head 12 is at the highest position.
Is set as a fixed value for each machine.

As shown in FIG. 6 (b), the mounting movement amount H _ST that the mounting nozzle descends to mount an electronic component is, as shown in FIG. 6 (b), the tip of the suction nozzle 13 when the mounting head is at the highest point and the circuit. From the distance H to the upper surface of the substrate 17, the suction nozzle 13
It is determined by subtracting the thickness h of the electronic component 21 adsorbed on the substrate, and H _ST = H−h = 2h _MAX + σ−h.

[0005]

By the way, as described above, the distance between the tip of the suction nozzle 13 and the upper surface of the circuit board 17 when the mounting head is at the highest point is determined, and the mounting nozzle is determined based on the distance. Since the height of the highest rising point of the head does not change when is lowered, the mounting nozzle requires a large amount of downward movement when mounting a component having a small height.

Further, since the mounting operation is performed for a limited time, an increase in the mounting movement amount of the suction nozzle leads to an increase in the movement acceleration. Therefore, the impact value applied to the low-height electronic component 21 is larger than that of the high-height electronic component,
There is a possibility of causing a problem in the mounting accuracy and reliability of electronic components during high-speed operation, and when high-accuracy mounting is required, it was necessary to drop the tact and mount. In addition, the tip of the suction nozzle 13 at the point where the mounting head 12 is at the highest point,
When the value of the distance H between the upper surfaces of the circuit boards 17 is changed to reduce the amount of movement of the mounting head, there is a problem that the height of electronic components that can be mounted is limited due to interference with the components already mounted. .

In view of the above conventional problems, the present invention determines the distance between the tip of the suction nozzle 13 and the upper surface of the circuit board 17, which is conventionally fixed, when the mounting head is at the highest point during operation. It is also an object of the present invention to provide a component mounting method that can minimize the amount of downward movement of the mounting head by freely changing the mounting head.

[0008]

In order to solve the above problems, the mounting method of the present invention is such that an electronic component is held by an electronic component supply unit and the electronic component is placed on an XY table which is vertically movable. In the electronic component mounting method of mounting on a circuit board that is arbitrarily positioned, based on the height of the electronic component held on the component holding portion and the height of the maximum electronic component already mounted on the circuit board, It is characterized in that the amount of downward movement of the component holder and the amount of vertical movement of the XY table are determined so that the amount of downward movement is minimized.

According to the electronic component mounting method of the present invention, the component holder is lowered based on the maximum height of the electronic component mounted on the circuit board and the height of the electronic component held in the component holder. By determining the amount of movement and the amount of vertical movement of the XY table and moving the XY table to the determined amount of movement, the amount of downward movement of the component holder can be minimized.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is to hold an electronic component from an electronic component supply unit by using a vertically movable component holding unit, and lower the electronic component from a predetermined height. In a component mounting method in an electronic component mounter for mounting the electronic component on a circuit board that is arbitrarily positioned on an XY table that can be moved in the vertical direction, the component is held by a component holder at each mounting operation at each mounting position. Based on the height of the electronic component and the maximum height of the electronic component already mounted on the circuit board, the downward movement amount of the component holding unit and the XY table are set so that the downward movement amount of the component holding unit is minimized. The vertical movement amount of the component holder is determined and the electronic component is mounted on the circuit board, and the lowering movement amount of the component holder is adjusted so that the mounting movement distance of the component holder is minimized. XY table lead Since the determination of movement amount, it is possible to minimize the impact value according to the mounting nozzle and the electronic component, it is possible to improve the reliability of the electronic component to be mounted accurate and mounting.

According to a second aspect of the invention, the lowering operation of the component holder for mounting the electronic component on the circuit board is XY.
This is performed after the movement of the table in the XY direction and the vertical direction is completed, and since the vertical movement of the XY table is completed by the time the component holding unit starts the lowering operation, the operation of the component holding unit is performed. There is no need to wait until the lifting / lowering operation of the XY table is completed.

The invention according to claim 3 is characterized in that the up and down movement amount of the XY table is moved by the relative movement amount from the position moved last time, and the XY table of each execution operation is moved. Since the ascending / descending operation is performed by the relative movement from the previously positioned position, the movement amount can be smaller than the absolute movement from the origin. According to a fourth aspect of the invention, the difference between the vertical movement amount of the XY table calculated by the method of the first aspect and the stepwise movement amount determined in advance according to the vertical movement amount of the XY table is calculated as The amount of vertical movement of the holding portion is used to change the amount of movement in stages according to the amount of vertical movement of the XY table. According to the calculated amount of vertical movement of the XY table, X
Since the movement amount of the Y table is performed in multiple stages, the mechanism of the XY table can be simpler than when the movement amount is arbitrarily set.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 4. (Embodiment 1) FIG. 1 is an embodiment of the present invention, and is an explanatory view of a suction nozzle movement amount and an XY table movement amount during a mounting operation of an electronic component mounting machine, and FIG. 2 is an embodiment of the present invention. 9 is a flowchart for calculating the suction nozzle movement amount and the XY table movement amount during the mounting operation of the electronic component mounting machine.

The electronic component mounting machine of the present invention is different from the conventional example described in FIG. 5 in that the XY table 18 is also movable in the vertical direction, and other configurations are different from the conventional example. Since they are the same, the description thereof will be omitted here, and the calculation method and the operation of the vertical movement amount of the suction nozzle and the XY table which are the component holding units will be described below. In FIG. 1, 1 is a suction nozzle, 2 is a circuit board installed and fixed on an XY table, and 3 is an XY table which can be arbitrarily moved in the XY direction and the vertical direction. Reference numeral 4 is an electronic component that is sucked by the suction nozzle 1 and mounted on the circuit board 2, and 5 is an electronic component of the maximum height that is already mounted on the circuit board 2. Here, the maximum height dimension of the electronic component 4 attracted to the suction nozzle 1 is L, the height dimension of the already mounted electronic component 5 having the maximum height is L _MAX , and the suction nozzle 1 located at the maximum lift limit. The distance between the tip of the and the circuit board 2 at the origin in the vertical direction is H
_MAX, adsorbed to have the lifting movement of the suction nozzle 1 when mounting the electronic component 4 on the circuit board 2 H _ST, and the moving amount of the XY table T _STO from the vertical direction of the origin.

The relationship between the raising / lowering operation of the suction nozzle 1 and the movable period of the XY table 3 is as shown in FIG. 3, and the cam for raising / lowering the suction nozzle 1 makes one rotation in one mounting operation. . The XY table is movable when the XY table movable period signal is ON, and the lifting operation of the suction nozzle 1 is performed after the XY table 3 is moved in the XY direction and vertically moved.

Next, when the sucked electronic component 4 is mounted on the circuit board 2, the vertical movement distance H of the suction nozzle 1 is set.
_A method of calculating _ST and the vertical movement distance T _STO from the origin of the XY table that can move vertically in the vertical direction will be described with reference to FIG. First, in step 1, the height L _MAX of the electronic component 5 having the maximum height mounted on the circuit board 2 is read on the XY table. Here, by acquiring the component data mounted in the previous stage from the host computer system, L
Determine _MAX .

In step 2, the height L of the sucked electronic component 4 is read from the component information data of the mounting machine itself. In step 3, the vertical movement amount H _ST of the suction nozzle 1 is maintained while maintaining the distance σ of the allowable space so that the electronic component 5 mounted on the circuit board and the electronic component 4 suctioned by the suction nozzle do not interfere with each other. H _ST is determined so that The moving amount is H _ST = L _MAX + σ from FIG. 1 (b). Next, the vertical movement amount T _STO from the origin of the XY table that can move vertically is calculated. The movement amount is T _STO = H _MAX −L−H _ST = H _MAX −L−L _MAX −σ from FIG. Here, T _STO is the amount of movement from the origin, and the actual amount of movement is the relative distance from the previous positioning position of the XY table. Letting T _ST be the relative amount of movement of the XY table, T _ST = T _STO −T _OLD . Here, T _OLD is the distance from the origin of the positioning position immediately before the XY table. Based on this result,
The XY table 3 is moved a distance T _ST from the previous positioning position, and after the XY table movement is completed, the suction nozzle 1 is moved a distance H _ST downward to move the sucked electronic component 4 to the circuit board 2.
Attach on top.

In step 4, the heights of the electronic component 4 mounted in step 3 and the maximum mounted electronic component 5 already mounted are compared. When the comparison result is L _MAX <L, L is set to L _MAX, and in other cases, L _MAX is not changed. Also, the amount of movement T of the XY table from the origin
_STO is necessary to calculate the relative movement amount at the time of positioning the XY table in the vertical direction next time, and is stored as T _OLD .

In step 5, it is judged whether or not there is an NC program step to be executed.
Repeat step 5. In the above embodiment, an example in which the vertical movement amount H _ST of the suction nozzle 1 and the vertical movement amount T _ST of the XY table that can move vertically in the vertical direction are set arbitrarily is calculated. The difference between the vertical movement amount of the XY table and the stepwise movement amount that is predetermined according to the vertical movement amount of the XY table is used as the vertical movement amount of the component holding unit to move the vertical movement of the XY table. Each movement amount may be changed stepwise according to the amount. (Embodiment 2) In this embodiment, in step 1 of FIG. 2, the maximum height L _MAX of the electronic component mounted on the circuit board is set.
The step of reading in is performed by a sensor installed in the substrate transfer section, which is a previous step of the XY table. The configuration of this embodiment will be described with reference to FIG. 6 is an XY table, 7 is a board transfer unit, 8 is an electronic component height detection sensor,
Reference numeral 10 is a circuit board on which the electronic component 9 is mounted. The circuit board 10 conveyed from the right side reads the dimension of the maximum height component mounted on the circuit board 10 by the electronic component height detection sensor 8. Hereinafter, the processes from step 2 onward are the same as those in the first embodiment, and the description thereof will be omitted.

By applying this height detection method,
It is possible to use the component mounting method according to the present invention even in an electronic component mounting machine that is not connected to a host computer system.

[0021]

According to the electronic component mounting method of the present invention, based on the maximum height of the electronic component mounted on the circuit board and the height of the electronic component held in the component holding portion, Since the amount of downward movement of the component holder and the amount of vertical movement of the XY table are determined so that the mounting movement distance is minimized, the impact value applied to the mounting nozzle and the electronic component can be minimized, and the mounting accuracy can be reduced. Also, the reliability of the mounted electronic component can be improved.

Further, since the vertical movement of the XY table is completed by the time the component holder starts the lowering operation,
Since it is not necessary to wait for the operation of the component holding unit to complete the lifting / lowering operation of the XY table, the tact time can be improved. Furthermore, since the raising / lowering operation of the XY table for each execution operation is performed by the relative movement from the previously positioned position, the movement amount can be smaller than the absolute movement from the origin.

Further, since the movement amount of the XY table is carried out in multiple stages according to the calculated vertical movement amount of the XY table, the mechanism of the XY table can be simplified as compared with the case where the movement amount is arbitrarily set. You can

[Brief description of drawings]

FIG. 1 is an explanatory diagram of a suction nozzle movement amount and an XY table movement amount during a mounting operation of an electronic component mounting machine according to an embodiment of the present invention.

FIG. 2 is a flowchart for calculating a suction nozzle movement amount and an XY table movement amount during a mounting operation of an electronic component mounting machine according to an embodiment of the present invention.

FIG. 3 is a timing chart of a lifting / lowering operation of a suction nozzle and an XY table movable period signal.

FIG. 4 is a structural explanatory view of a method using a height detection sensor.

FIG. 5 is an overall perspective view of an electronic component mounting machine.

FIG. 6 is an explanatory diagram of a method for determining the distance between the tip of the nozzle and the upper surface of the circuit board at the highest position in the conventional example.

[Explanation of symbols]

 1 suction nozzle 2 circuit board 3 XY table 4 electronic parts 5 electronic parts with maximum height

Claims (4)

[Claims] 1. An XY table on which an electronic component can be vertically moved by holding the electronic component from an electronic component supply unit using a vertically movable component holding unit and lowering the electronic component from a predetermined height. In the component mounting method in the electronic component mounting machine to be mounted on the circuit board arbitrarily positioned in,
For each mounting operation at each mounting position, the minimum amount of downward movement of the component holder is based on the height of the electronic component held in the component holder and the height of the maximum electronic component already mounted on the circuit board. As described above, the amount of downward movement of the component holder and the amount of vertical movement of the XY table are determined, and the electronic component is mounted on the circuit board. 2. The lowering operation of the component holder, which is performed to mount the electronic component on the circuit board, is performed by the X of the XY table.
The electronic component mounting method according to claim 1, wherein the electronic component mounting method is completed after the movement in the Y direction and the vertical direction is completed. 3. The electronic component mounting method according to claim 1, wherein the XY table is moved up and down by a relative movement amount from a position where the XY table is moved last time. 4. The difference between the ascending and descending movement amount of the XY table calculated by the method of claim 1 and the stepwise moving amount which is predetermined according to the ascending and descending movement amount of the XY table The electronic component mounting method according to claim 1, 2 or 3, wherein the movement amount is changed stepwise according to a vertical movement amount of the XY table.