JP3139284B2 - Component mounting method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a component mounting method capable of reducing tact time.

[0002]

2. Description of the Related Art A component mounting method is widely used for automatically mounting components on a substrate. Of these, there is a nozzle provided with a nozzle for sucking a component at a position eccentric from the rotation center of the transfer head, and rotating the nozzle around the rotation center so that the component forms a specified mounting angle on the substrate.

[0003]

However, in this method, the position of the nozzle is determined regardless of the amount of movement of the XY table for positioning the substrate with respect to the transfer head, and the amount of movement of the XY table is not sufficient. There is a problem that the tact time required for mounting increases as the number of necessities increases.

Accordingly, an object of the present invention is to provide a component mounting method capable of shortening the tact time.

[0005]

According to the present invention, a component mounting method of the present invention suctions a component with a nozzle located eccentrically from the center of rotation of a transfer head, and forms a specified mounting angle on a substrate. A component mounting method for moving a nozzle around a rotation center and mounting a component on a substrate, wherein the first position of the nozzle conforming to a designated mounting angle is point-symmetric with respect to the first position and the rotation center. The second position of the nozzle is determined, and the relative movement amount between the substrate and the transfer head when each of the first position and the second position is adopted is compared. A position having a smaller movement amount is selected from the two positions.

[0006]

According to the above arrangement, the first position and the second position of the nozzle suitable for the designated mounting angle are obtained, and the relative movement amount between the substrate and the transfer head when each position is adopted is determined. The positions are compared, and a position having a smaller movement amount is selected. Therefore, waste of relative movement between the substrate and the transfer head can be minimized, and as a result, the tact time required for mounting can be reduced.

[0007]

Next, an embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of an electronic component mounting apparatus according to one embodiment of the present invention, and FIG. 2 is a side view of the electronic component mounting apparatus according to one embodiment of the present invention. In FIG. 1, reference numeral 1 denotes a base, 2 is provided above the center of the base 1, and a rotary head which is index-rotated in the direction of arrow M by a driving means (not shown) is provided. A plurality of transfer heads 4 are nozzles provided downward in accordance with the type of component to be sucked on the circumferential portion of the transfer head 3. A is a component supply unit disposed at the rear of the base 1,
Among them, 5 is a parts feeder for supplying parts P of different types one by one, 6 is a moving table on which the parts feeder 5 is arranged side by side, 8 is screwed into a feed nut 7 provided at the rear of the moving table 6, A feed screw 9 extending in the X direction and rotatably supported by the base 1 is a drive motor 9 for rotating the feed screw 8. When the drive motor 9 is driven, the parts feeder 5 that supplies the required types of parts P can be positioned at the parts supply station S1 of the rotary head 2.

[0008] In step S2, the camera 10 provided below the rotary head 2 causes the positional deviations ΔX and ΔY of the component P sucked to the nozzle 3 and a mounting angle 0 (radian) to be described later.
This is a recognition station that measures an angle shift θR or the like with respect to. 11 and 12 are provided at the front of the base 1,
A board loading conveyor for loading the board 20 in the direction of the arrow N1;
Reference numerals 13 and 14 indicate the substrates 20 on which the components P have been mounted by arrows N.
This is a substrate unloading conveyor for unloading in two directions. Also 15
Denotes an X table provided on the base 1 and driven by an X motor 16; 17 denotes a Y table driven by a Y motor 18. On the Y table 17, a substrate holder 19 for holding a substrate 20 is provided. Have been. S3 is a component mounting station where the nozzle 3 mounts the component P on the substrate 20 positioned by the X table 15 and the Y table 17,
4 is a nozzle selection unit 21 for selecting the nozzle 3 to be used next time
Is a nozzle selection station provided. When the rotary head 2 rotates in the index direction in the direction of arrow M, the transfer head 3 is moved to the component supply station S.
1. Recognition station S2, component mounting station S
3. The nozzle selection station S4 is sequentially circulated.

In FIG. 2, reference numeral 22 denotes a disk-shaped rotary plate, which is index-rotated together with a rotary shaft 23 mounted on the center thereof. Reference numeral 24 denotes a transfer head rotation shaft fixed to the lower portion of the transfer head 3 and inserted into the circumferential portion of the rotating plate 22 so as to be able to move up and down and to rotate freely, and its axis coincides with the rotation center of the transfer head 3. Reference numeral 25 denotes a head motor for rotating the transfer head rotating shaft 24 via a timing pulley and a timing belt; 26, a block on which the upper end of the transfer head 24 is rotatably mounted so as not to be able to move up and down; It is a cam follower connected inside and outside.
The inner cam follower 28 is a non-rotating cylinder 2
9 comes in contact with the rib cam 29a protruding from the peripheral surface and moves up and down along the rib cam 29a. As a result, the nozzle 4 located below the transfer head 3 moves up and down according to the levels of the substrate 20 and the parts feeder 5. Reference numeral 30 denotes a cam receiver which engages with the outer cam follower 27 and guides the block 26 so as to be able to move up and down with respect to the top plate 31.

FIG. 3 is a block diagram of a main part of an electronic component mounting apparatus according to one embodiment of the present invention. In FIG. 3, reference numeral 32 denotes a recognition unit that outputs the position shift ΔX, ΔY, angle shift θR, and the like of the component P based on an image acquired by the camera 10 at the recognition station S2, and 33 denotes a recognition unit shown in FIG. , Mount data storage unit for storing the mount data shown in FIG.
, A rotation angle temporary storage unit for temporarily storing the rotation angle β of the nozzle 4 in the component mounting station S3, and a positional deviation ΔX, ΔY and an angular deviation θR output by the recognition unit 32. Is a temporary storage unit for temporarily storing position shift, 39 is a control unit for controlling the whole, 3
7, the control unit 39 converts the position data X, Y into a positional deviation ΔX,
An XY table drive section for inputting correction position data X-ΔX and Y-ΔY corrected by ΔY and driving the X motor 16 and the Y motor 18 so as to match the data, It is a head motor drive unit that inputs and drives the head motor 25 so that the nozzle 4 rotates by this rotation angle β.

Next, the contents of the mount data will be described with reference to FIGS. 4 and 5 (explanatory diagrams of component mounting angles in one embodiment of the present invention). As shown in FIG.
The mount data includes information on mounting point coordinates x and y, mounting angle θ, and presence / absence of component polarity (“0” is absent and “1” is present) in numerical order. Mounting angle θ
Is the angle formed by the component P mounted on the board 20 with respect to the board 20, as shown in FIG. It is assumed that one of the components P has one electrode at the black end and the other electrode has a hatched portion. The mounting angle θ is determined by a circuit formed on the substrate 20, and is included in the mounting data as the specified mounting angle θ1.
Incidentally, some components P do not have polarity, such as resistors. In FIG. 4, the components P mounted in the numbers 1 to 4 have no polarity. In the component P having no polarity, the mounting angles θ = 0 and θ = ± π, and θ = π / 4 and θ = −3.
The result is the same regardless of which of the two mounting angles is symmetric with respect to the point F in FIG. 5, such as π / 4.

FIG. 6A is an explanatory view of the positional relationship between the transfer head rotating shaft and the nozzle in one embodiment of the present invention.
(B) is a correspondence diagram of the input coordinates of the XY table and the positional relationship between the nozzle centers in one embodiment of the present invention. Now, FIG.
In (a), the center of the transfer head rotation shaft 24 is the rotation center C of the transfer head 3 and also the rotation center of the nozzle 4. Here, in the electronic component mounting apparatus of this embodiment, when determining the mounting angle θ of the component P, instead of rotating the nozzle 4, the nozzle 4 is moved to the rotation center C of the transfer head 3.
Is rotated around a circle having a radius r. At the time of picking up the component P at the component supply station S1 and at the time of acquiring an image by the camera 10 at the recognition station S2, the nozzle 4 is set at a point where the absolute angle with respect to the rotation center C is 0 (radian). Here, at the time of the image acquisition, it is assumed that the component P has an angle deviation θR with respect to the absolute angle 0 (radian), and the designated mounting angle of the component P is θn. Then, if the nozzle 4 is rotated around the rotation center C of the transfer head 3 so that the absolute angle αA = θn−θR, the specified mounting angle θn for obtaining the component P can be obtained. Further, when the component P has no polarity, as described above, the absolute angle αA
Absolute angle αB = θn-θR + π advanced by (radian)
, The same designated mounting angle θn can be obtained. Therefore, hereinafter, the position of the nozzle 4 when the absolute angle αA is used is referred to as a first position, and the position of the nozzle 4 when the absolute angle αB is used is referred to as a second position.

The control unit 39 determines the mounting point coordinates x,
When y is given to the XY table driving section 37 as it is, the X motor 16 and the Y motor 18
substrate 20 so that y is positioned directly below the rotation center C of the transfer head 3 stopped at the component mounting station S3.
Position. However, as shown in FIG. 6A, the nozzle 4 does not exist on the rotation center C but exists on a circle having a radius r centered on the rotation center C. That is, the first
6B, if the input coordinates on the XY tables 15 and 17 are x and y, as shown in the pattern 1 in FIG. 6B, the center of the nozzle 4 (the position of the component P)
Is in x-rcosαA, y-rsinαA. Therefore, as in pattern 2, the input coordinates on the XY tables 15 and 17 are represented by X (= x + rcosαA) and Y (= y + rsi).
If the correction is performed as in the case of nαA), the center of the nozzle 4 is located at the mounting point coordinates x and y on the board 20 and the mounting angle of the component P coincides with the specified mounting angle θn. Similarly, at the second position, the input coordinates are X = x + rcosα
The corrected input coordinates may be given to B, Y = y + rsinαB.

FIG. 7 is an explanatory diagram of the positional relationship between the substrate and the nozzle in one embodiment of the present invention. In FIG. 7, X _n−1 , Y
_n-1 is the input coordinate of the component mounted on the board 20 immediately before, X
_n and Y _n are input coordinates of the component P mounted on the board 20 this time. As described above, when the component P has no polarity, two candidates for the position of the nozzle 4 are the first position and the second position. In FIG. 7, the broken lines indicate the positions of the board 20 and the component P when the first position is adopted,
The chain line indicates the substrate 20 and the component P when the second position is adopted.
Position. Then, the position vectors when the substrate 20 moves from the state before the movement (solid line position) to the positions indicated by the broken lines and the chain lines are denoted by v1 and v2.

FIGS. 8A and 8B are explanatory diagrams of the position vector of the substrate in one embodiment of the present invention. FIG. 8A shows the position vector v1, and FIG. 8B shows the length of a component obtained by decomposing the position vector v2 in the X and Y directions. FIG.
In (a), it is the role of the X motor 16 to realize the movement of the substrate 20 having the length | X _nA −X _n−1 |, and the length | Y _nA −
The movement of the length of Y _n-1 | depends on the operation of the Y motor 18.
Here, if the X motor 16 and the Y motor 18 can be driven in parallel and have the same performance,
It is the length |
_{XnA- Xn-1} | and the length | _YnA- Yn _-1 |, which is the longer one (the length | _{XnA- Xn-1} | in FIG. 8A). Similarly, in the case of FIG. 8B, the lengths | X _nB −X _n−1 | and |
The longer _{one of} | _YnB- Yn _-1 | (| _YnB- Yn _-1 |) determines the time until the movement is completed. Therefore, these longer lengths are compared with each other, and a position provided with a shorter one of them (in the example of FIG. 8, | X _nA -X _n-1 | <| Y _nB -Y
_n-1 | first position), the XY table 1
It is possible to further reduce the travel time of the fifth and the 17th, and to shorten the tact time accordingly.

Next, the operation of the electronic component mounting apparatus of this embodiment will be described with reference to FIGS. FIG. 9 is an operation flowchart as viewed from components of the electronic component mounting apparatus according to one embodiment of the present invention, and FIGS. 10 to 11 are flowcharts of a component mounting method according to one embodiment of the present invention.

As shown in FIG. 9, first, the component P is picked up from the parts feeder 5 by the nozzle 4 of the transfer head 3 at the component supply station S1 (step 1). Then, when the transfer head 3 reaches the recognition station S2, the image acquisition and recognition unit 32 by the camera 10
Is performed, and the positional deviations ΔX, ΔY and the angular deviation θR are output to the control unit 39, and the positional deviation temporary storage unit 36
(Step 2). Next, as will be described later, the control unit 39 calculates position data X _n and Y _n and a rotation angle β _n by calculation (step 3), and the XY table driving unit 37.
To output the corrected position data X _n -ΔX, Y _n -ΔY,
The X-motor 16 and the Y-motor 18 position the mounting point of the substrate 20 directly below the nozzle 4. A rotation angle β _n is given to the head motor drive unit 38, and the head motor 25 rotates the nozzle 4 by the rotation angle β _n , so that the component P sucked by the nozzle 4 has a designated mounting angle with respect to the substrate 20. Thus, the component P lands on the board 20 and the mounting of the component P is completed (step 4).

Next, regarding step 3 in FIG. 9, FIGS.
This will be described with reference to FIG. First, in step 31, the control unit 39 checks the number of the component P of interest and refers to the mount data storage unit 33 to check whether there is a polarity. If there is polarity, the second position described above cannot be adopted and must be set to the first position.
n = θn−θR (step 32), and the position data X
_n, the _{Y n X n = x n +} rcosαn, Y n = y n + r
and Sinarufaenu, the position data X _n, and registers the Y _n and the position data temporary storage unit 34 (step 34).

On the other hand, if the component P has no polarity, absolute angles αA and αB are obtained for the first position and the second position (step 35), and the input coordinates X _nA and Y _nA corresponding to the absolute angles are obtained.
And input coordinates X _nB and Y _nB are obtained (step 36). The longer one of the lengths | X _nA -X _n-1 | and | Y _nA -Y _n-1 | is _defined as the first length LA, and the length | X _nB -X _n-1 | The longer one of | Y _nB −Y _n-1 | is set as the second length LB (step 37).

As described above, the first length LA determines the completion time of the movement of the XY tables 15, 17 when the first position is adopted, and the second length is the same as that of the second position. To decide. Therefore, the control unit 39 compares the first length LA and the second length LB in step 38, and if the first length LA is shorter than the second length LB, the input coordinate X relating to the first position. _nA, the Y _nA position data X _n, and Y _n, taking the absolute angle .alpha.A (step 39). Otherwise, the second
Input coordinates X _nB, position Y _nB data X _n, Y according to the position
_The absolute angle αB is set as _n (step 40). Then, registration in step 34 is performed.

FIG. 11 shows a flow for determining and registering the rotation angle βn. When the absolute value of the absolute angle αn exceeds π, it is more likely that the transfer head 3 is rotated in the negative direction (clockwise) in FIG.
This process focuses on the fact that the rotation amount of No. 5 can be reduced and the tact time can be further reduced. That is, the control unit 39
If the absolute value of the absolute angle αn is not more than π, the absolute angle αn is registered as it is as the rotation angle βn (steps 41 and 4).
2, 46). If the absolute value of the absolute angle αn exceeds π and the absolute angle αn is positive, the rotation angle βn = αn−2π
(Steps 41, 43, 45, 46).
The absolute value of the absolute angle αn exceeds π, and the absolute angle α
If n is negative or zero, the rotation angle is registered as βn = αn + 2π (steps 41, 43, 44, 46).

[0022]

The component mounting method of the present invention uses a nozzle which is located at a position eccentric from the rotation center of the transfer head, sucks the component, and forms the specified mounting angle on the substrate. Is mounted around the center of rotation, and the component is mounted on the substrate. The first position of the nozzle conforming to the designated mounting angle is point-symmetric with respect to the first position and the center of rotation. The second position of the nozzle is obtained, and the relative movement amount between the substrate and the transfer head when adopting each of the first position and the second position is compared. Since the position with the smaller movement amount is selected from the positions (1) and (2), the relative movement amount between the substrate and the transfer head can be reduced as much as possible, and the tact time for mounting can be reduced.

[Brief description of the drawings]

FIG. 1 is a plan view of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 2 is a side view of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 3 is a main block diagram of an electronic component mounting apparatus according to an embodiment of the present invention.

FIG. 4 is a configuration diagram of mount data according to an embodiment of the present invention;

FIG. 5 is an explanatory view of a component mounting angle in one embodiment of the present invention.

6A is a diagram illustrating a positional relationship between a transfer head rotation axis and a nozzle according to an embodiment of the present invention. FIG. 6B is a diagram illustrating a positional relationship between input coordinates of an XY table and a nozzle center according to an embodiment of the present invention. Correspondence diagram

FIG. 7 is an explanatory diagram of a positional relationship between a substrate and a nozzle in one embodiment of the present invention.

8A is an explanatory diagram of a position vector of a substrate according to an embodiment of the present invention. FIG. 8B is an explanatory diagram of a position vector of a substrate according to an embodiment of the present invention.

FIG. 9 is an operation flowchart as viewed from components of the electronic component mounting apparatus according to the embodiment of the present invention;

FIG. 10 is a flowchart of a component mounting method according to an embodiment of the present invention.

FIG. 11 is a flowchart of a component mounting method according to an embodiment of the present invention.

[Explanation of symbols]

 3 Transfer head 4 Nozzle 15 X table 17 Y table 20 Board P Component C Rotation center θ Designated mounting angle

Claims (3)

(57) [Claims] A nozzle located at a position eccentric from the rotation center of the transfer head sucks a component, and moves the nozzle around the rotation center so that the component forms a specified mounting angle on a substrate; A component mounting method for mounting a component on a substrate, comprising: a first position of the nozzle that matches the designated mounting angle; and a second position of the nozzle that is point-symmetric with respect to the first position and the rotation center. A relative position between the substrate and the transfer head when adopting each of the first position and the second position; and comparing the first position with the second position. A component mounting method characterized by selecting a position having a smaller amount of movement from among the positions. 2. The method according to claim 1, wherein the substrate is positioned with respect to the transfer head with an X table and a Y table, and a larger one of the X table and the Y table when the first position is adopted. Comparing the larger amount of movement of the X table and the larger amount of movement of the Y table when the second position is adopted, and comparing the larger amount of movement between the first position and the second position. 2. The component mounting method according to claim 1, wherein a position having a smaller amount is selected. 3. The component mounting method according to claim 1, wherein the presence or absence of polarity of the component is determined before the comparison.