KR102025370B1 - A component holding head for surface mounter - Google Patents

Abstract

According to an aspect of the present invention, a head body, a rotary head rotatably installed on the head body in an R direction around a vertical axis, a component holding mechanism arranged along the circumferential direction of the rotary head, and in the R direction And a reflective optical sensor that rotates to detect the component holding mechanism at a specific position, wherein the optical sensor includes: a light emitting unit for irradiating light toward the reflective surface of the component holding mechanism at the specific position; A light receiving portion for receiving the reflected light reflected from the slope, wherein the optical axis of the light irradiated from the light emitting portion is rotated in the R direction from the position on the vertical central axis of the component holding mechanism at the specific position among the portions of the reflective surface; To provide a component retaining head of the surface mounter that is offset to face a more rotated position in the direction.

Description

A component holding head for surface mounter

The present invention relates to a component holding head having a component holding mechanism for holding a component in a surface mounter for mounting components (electronic components) such as IC chips on a substrate.

In general, the surface mounter moves the component holding head above the component supplying part, performs a downward raising operation to the nozzle serving as the component holding mechanism provided in the component holding head, vacuum-adsorbs the component to the lower end of the nozzle, and After the next component holding head is moved above the substrate, the component is mounted at a predetermined coordinate position of the substrate by causing the nozzle to move up and down again from above the substrate.

As described above, when picking up a component by raising and lowering the nozzle, if the downward stroke of the nozzle is too large, the lower end of the nozzle strongly presses on the upper surface of the component to increase the risk of destruction of the component, and when the downward stroke of the nozzle is too small, the nozzle It can't land on the top of the part, preventing it from picking up the part.

The same applies to the case where the component is mounted on the substrate. In other words, if the downward stroke of the nozzle is too large, the component adsorbed on the lower end of the nozzle strongly presses the substrate, increasing the risk of the component being broken. If the downward stroke of the nozzle is too small, the component cannot land on the upper surface of the substrate, thereby mounting the component. You won't be able to. Therefore, the down stroke of the nozzle must be surely controlled.

As a method for reliably controlling the down stroke of a nozzle, a method using a detection means (a sensor for detecting a nozzle) for detecting the landing of a nozzle is disclosed in Japanese Patent No. 3553044. In addition, the applicant of the present application similarly proposed a method using a reflective optical sensor (optical fiber sensor) for the sensor detecting the nozzle in Japanese Patent Application No. 2013-212220 as a method for reliably controlling the down stroke of the nozzle. The optical fiber sensor has a light emitting portion that emits light toward the reflective surface of the nozzle outer periphery and a light receiving portion that receives the reflected light reflected from the reflective surface to detect the nozzle by a change in the amount of received light with respect to a predetermined threshold (threshold value).

As described above, when the nozzle is detected from the change in the amount of received light using a reflective optical sensor (optical fiber sensor), the amount of received light before detecting the nozzle is preferably as constant as possible in order to prevent false detection and improve detection accuracy. In this respect, the optical axis of the light emitted from the light emitting portion has been directed toward the central axis in the vertical direction of the detection target nozzle, but the detection accuracy was not necessarily sufficient.

According to one aspect of the present invention, the main problem is to improve the detection accuracy of the sensor for detecting the component holding mechanism (nozzle) in the component holding head of the surface mounter.

MEANS TO SOLVE THE PROBLEM In order to solve the said subject, when the inventors examined the arrangement | positioning of the sensor which detects a component retention mechanism (nozzle), etc., the direction of the optical axis of the light irradiated from the light-emitting part of the reflective optical sensor which detects a component retention mechanism is detected. When offset from the central axis in the vertical direction of the component storage and retention mechanism to the downstream side in the rotational direction (R direction) of the rotary head, it was found that the received amount of light before detecting the nozzle was stabilized at a high level.

Therefore, according to an aspect of the present invention, a head body; and a rotary head rotatably installed in an R direction around a vertical axis of the head body; and a component holding mechanism disposed along the circumferential direction of the rotary head; And a reflective optical sensor rotating in the R direction to detect the component holding mechanism at a specific position, wherein the optical sensor is configured to irradiate light toward the reflecting surface of the component holding mechanism at the specific position. And a light receiving unit for receiving the reflected light reflected from the reflecting surface, wherein the optical axis of the light irradiated from the light emitting unit is located in the R direction from the position on the vertical axis of the component holding mechanism at the specific position. A component holding head of a surface mounter is arranged to be offset so as to direct the position of the reflecting surface located at a further rotation in the rotational direction of the.

Here, the amount of the offset may be set such that the change in the amount of received light of the light receiving portion is minimal with respect to the change in the amount of the offset.

Here, the optical sensor can detect the component holding mechanism by a change in the received light amount with respect to a predetermined threshold, and the threshold can be set based on the received light amount in the stable region of the received light amount by the light receiving unit.

According to one aspect of the present invention, in the reflective optical sensor that detects a component holding mechanism (nozzle), the light receiving amount before detecting the component holding mechanism is stabilized at a high level. As a result, the detection accuracy of the component holding mechanism by the sensor is improved, whereby the lowering stroke and the like of the component holding mechanism can be more reliably controlled.

1 is a perspective view showing the overall configuration of a component holding head according to an embodiment of the present invention.
FIG. 2 is a view showing a mechanism for elevating the spindle in the Z direction in the component holding head of FIG. 1, (a) is a front view, (b) is a left side view, and (c) and (d) are perspective views of a main part. .
It is explanatory drawing which shows the structure around the lifting member in the mechanism which raises and lowers the spindle of FIG.
FIG. 4 is a perspective view showing the main part of the optical fiber sensor used in the component holding head of FIG. 1 including its mounting state. FIG.
FIG. 5 is an enlarged perspective view of a cross section of a nozzle portion mounted at a lower end of a spindle in the component holding head of FIG. 1. FIG.
6 is a diagram schematically showing a change in the amount of received light of the optical fiber sensor when the nozzle according to the embodiment of the present invention is landed.
7 is a plan view conceptually showing an "offset" according to an embodiment of the present invention.
Fig. 8A is a diagram showing the result of measuring the light reception amount of the optical fiber sensor light receiving unit by changing the offset angle θ (offset amount d) according to the embodiment of the present invention (offset angle = -1.0 °).
FIG. 8B is a diagram showing the result of measuring the light reception amount of the optical fiber sensor light receiving unit by changing the offset angle θ (offset amount d) according to the embodiment of the present invention (offset angle θ = −0.5) ˚).
FIG. 8C is a diagram showing the result of measuring the light reception amount of the optical fiber sensor light receiving unit by changing the offset angle θ (offset amount d) according to the embodiment of the present invention (offset angle θ = 0.0 °). ).
8D is a diagram showing the result of measuring the light reception amount of the optical fiber sensor light-receiving unit by changing the offset angle θ (offset amount d) according to the embodiment of the present invention (offset angle θ = + 0). 5˚).
FIG. 8E is a diagram showing the result of measuring the light reception amount of the optical fiber sensor light receiving unit by changing the offset angle θ (offset amount d) according to the embodiment of the present invention (offset angle θ = + 1). 0).
FIG. 8F is a diagram showing the result of measuring the light reception amount of the optical fiber sensor light receiving unit by changing the offset angle θ (offset amount d) according to the embodiment of the present invention (offset angle θ = + 1). 5˚).
Fig. 8G is a diagram showing the result of measuring the light reception amount of the optical fiber sensor light-receiving unit by changing the offset angle θ (offset amount d) according to the embodiment of the present invention (offset angle θ = + 2). 0).
FIG. 9 is a diagram plotting the received light amount in each example with respect to the offset angle θ based on the results of FIGS. 8A to 8G.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. In addition, in this specification and drawing, duplication description is abbreviate | omitted by using the same code | symbol about the component which has substantially the same structure.

1 is a perspective view showing the overall configuration of a component holding head according to an embodiment of the present invention.

As shown in FIG. 1, the component holding head 10 is a rotary head type component holding head, which allows the rotary head 40 to be rotatable in the R direction around the vertical axis in the head body (main frame) 20. It is installed. In this rotary head 40, a plurality of spindles 41 are arranged at equal intervals along the circumferential direction, and a nozzle 42 is mounted as a part holding mechanism for sucking and holding parts at the lower ends of the spindles 41. .

The rotary head 40 can rotate in the R direction by driving the R servo motor 21 provided in the head main body 20. Moreover, each spindle 41 can rotate in the T direction around the axis line of each spindle 41 by the drive of the T servo motor 22 provided in the head main body 20.

In addition, the head main body 20 is arranged with a Z servo motor 23 for raising and lowering the spindle 41a (see FIG. 3) at a specific position in the Z direction, which is the axial direction. The mechanism for rotating the rotary head 40 in the R direction by driving the R servo motor 21, and the mechanism for rotating each spindle 41 in the T direction by driving the T servo motor 22 are well known. Its description will be omitted here. The mechanism for elevating the spindle 41a by the drive of the Z servo motor 23 will be described below.

FIG. 2 is a view showing a mechanism for elevating the spindle 41a in the Z direction in the component holding head 10 of FIG. 1, (a) is a front view, (b) a left side view, (c), ( d) is a perspective view of a main part.

The motor shaft of the Z servo motor 23 is connected to the screw shaft 24 of the ball screw mechanism, and the nut of the ball screw mechanism is attached to the screw shaft 24. In addition, the lifting member 25 is fastened to the nut.

Moreover, the upper spline shaft 26 is attached to the elevating member 25 for rotation stop and elevating guide. And the press part 25a is integrally connected with this lifting member 25. As shown in FIG. Therefore, the pressurizing part 25a moves in the Z direction with the lifting member 25 by the drive of the Z servo motor 23.

Only one lifting member 25 and one pressing portion 25a are provided on the head main body 20 side. When lowering the spindle 41, the spindle 41 (the spindle 41a at the specific position) that is lowered by moving the spindle 41 relative to the pressing portion 25a is selected and the pressing portion 25a is selected. By lowering, the spindle 41a and the nozzle 42a attached to the lower end thereof are lowered.

 In this embodiment, as shown in FIG. 3, the rotary head 40 is rotated in the R direction to move the spindle 41 relative to the pressing portion 25a relative to the pressing portion 25a so that the spindle 41 to be lowered is placed under the pressing portion 25a. Position it. Then, the pressing portion 25a is lowered to lower the spindle 41a directly below the pressing portion 25a. Here, two or more specific positions may be provided.

As shown in FIG. 2, a part of the arm member 28 is connected to the lifting member 25 to which the pressing portion 25a is connected, with the adapter member 27 interposed therebetween, and the end of the arm member 28 is connected. The optical fiber sensor 30 is connected as a sensor which detects a nozzle with the sensor holder member 29 on the side.

In addition, the lower spline shaft 31 is attached to the end side of the arm member 28 to guide the lifting and lowering of the arm member 28 according to the lifting and lowering of the lifting member 25. The lower spline shaft 31 is fixed to the head body 20 with the fixing member 32 interposed therebetween.

The said adapter member 27 is an XY direction position adjustment member for adjusting the position of the XY direction of the optical fiber sensor 30 here. In other words, the adapter member 27 is connected to the lifting member 25 in a XY direction in a horizontal plane perpendicular to the Z direction. Thereby, the position in the XY direction of the arm member 28 integral with the adapter member 27 can be adjusted, and as a result, the position in the XY direction of the optical fiber sensor 30 connected to the arm member 28 can be adjusted.

In addition, the sensor holder member 29 is a Z direction positioning member for adjusting the position of the optical fiber sensor 30 in the Z direction. That is, the sensor holder member 29 is connected to the arm member 28 so that the position can be adjusted in the Z direction. As a result, the position in the Z direction of the optical fiber sensor 30 that is integrally connected to (maintained) the sensor holder member 29 is adjusted.

In this way, the optical fiber sensor 30 is connected to the elevating member 25 with the adapter member 27, the arm member 28 and the sensor holder member 29 interposed therebetween, and the adapter member 27 and the sensor holder member ( After the position adjustment by 29 is made, it is integrated with the elevating member 25 and the press part 25a. Therefore, when the pressurizing part 25a moves to Z direction by the drive of the Z servo motor 23, the optical fiber sensor 30 will move to Z direction in conjunction with this. That is, the optical fiber sensor 30 moves in the Z direction in synchronism with the movement in the Z direction of the spindle 41a by the lifting and lowering of the pressurizing portion 25a. In addition, the spindle 41 is always elastically pressurized toward the upper initial position by the ballistic body 41b (refer FIG. 1) which consists of two coil springs.

The optical fiber sensor 30 is a structure in which a light emitting portion and a light receiving portion are sandwiched together with an optical fiber or a lens, and the structure itself is well known. 4 is a perspective view showing the main part of the optical fiber sensor 30 used in the present embodiment, including its mounting state.

As described above, the optical fiber sensor 30 is connected to the arm member 28 with the sensor holder member 29 interposed therebetween. The optical fiber sensor 30 of this embodiment has an eccentric collar 30a as an optical axis direction adjusting means for adjusting the optical axis direction. That is, the eccentric collar 30a is attached to the lens 30b of the optical fiber sensor 30, and the optical axis direction of the optical fiber sensor 30 is adjusted by rotating this eccentric collar 30a with respect to the lens 30b.

Next, the basic function of the sensor function of the optical fiber sensor 30 will be described.

In this embodiment, the optical fiber sensor 30 is arrange | positioned obliquely above the nozzle 42 (nozzle 42a in the said specific position) attached to the lower end of the spindle 41 as shown in FIG. And the light emitting part of the optical fiber sensor 30 irradiates light P obliquely downward toward the reflecting surface 42b of the outer periphery upper surface of the nozzle 42a shown in FIG. The irradiated light P is reflected by the reflecting surface 42b, and the reflected reflected light is received by the light receiving portion of the optical fiber sensor 30.

Here, the nozzle 42 is attached to the lower end of the spindle 41 via the coil spring 43 (elastic body) as shown in FIG. Therefore, when the spindle 41a at the specific position is lowered and the nozzle 42a is landed, the coil spring 43 is compressed to change the relative position of the nozzle 42a with respect to the spindle 41a in the vertical direction. Specifically, the nozzle 42a moves relatively toward the lower end side of the spindle 41a.

On the other hand, the light P irradiated from the light emitting portion of the optical fiber sensor 30 is reflected by the lens 30b shown in FIG. 4 to the reflecting surface 42b when the nozzle 42a is not in the initial state. Focus is on. Therefore, when the nozzle 42a is landed and the position of the nozzle 42a with respect to the spindle 41a in the up-down direction is changed, the amount of reflected light reflected by the reflecting surface 42b is reduced, so that the light receiving portion of the optical fiber sensor 30 The amount of light received by the light is reduced (see FIG. 6). In this embodiment, the decrease in the amount of received light is detected by a sensor unit (not shown) of the optical fiber sensor 30. Then, the sensor unit determines that the nozzle 42a has landed when the received amount of light decreases by a predetermined amount, for example, when it is equal to or less than the threshold A shown in FIG. 6, and generates a 'landing detection signal'.

Here, the expression that the nozzle 42a has been 'ground' means that a force is applied from below the nozzle 42a, in which case the nozzle 42a moves downward in the pick-up process of the part, and then the nozzle 42a The case where the lower end part lands on the upper surface of a component, and the component adsorbed-held by the lower end part of the nozzle 42a in the component mounting process land on the upper surface of a board | substrate.

Referring again to FIG. 6, it is preferable that the amount of received light before the nozzle 42a at a specific position lands is as stable as possible in time order.

 This is because if the temporal change in the amount of received light before the nozzle 42a is landed is large, the amount of received light becomes less than the threshold A even when the nozzle 42a is not landed, and the ground detection signal is accidentally issued. Moreover, it is preferable that the light reception amount before landing of the nozzle 42a is a level as high as possible. This is because when the light receiving amount before the nozzle 42a is landed is at a high level, the degree of freedom in setting the threshold A is increased, so that the landing of the nozzle 42a can be detected more reliably.

In the present invention, in order to stabilize the light reception amount before the nozzle 42a is landed at a high level, the optical axis direction of the light irradiated from the light emitting portion of the optical fiber sensor 30 is offset in a specific direction.

7 is a plan view conceptually showing this offset. In the same figure, the optical fiber sensor 30 detects the landing of the nozzle 42a which arrived at the specific position by the above-mentioned method. In the present invention, the optical axis of the light P emitted from the light emitting portion of the optical fiber sensor 30 is the rotary head from the position of the reflecting surface 42b on the vertical central axis C of the nozzle 42a at the specific position. The optical fiber sensor 30 is disposed to be offset so as to direct the position of the reflecting surface 42b located further in the rotational direction (R direction) of the 40. In other words, the optical axis direction of the light irradiated from the light emitting portion of the optical fiber sensor 30 which detects the nozzle 42a at a specific position is determined by the rotational direction of the rotary head (in the vertical axis C) of the nozzle 42a. The offset amount d is determined and offset to a position further rotated in the R direction).

8A to 8G show the results of measuring the light reception amount of the light receiving portion of the optical fiber sensor 30 by changing the offset amount d of FIG. 7 as a test for verifying the effect of the present embodiment. In the test, the offset amount d at the specific position was changed by changing the offset angle θ in the R direction of the rotary head with the specific position as a reference (zero). The relationship between the offset angle θ and the offset amount d is shown in Table 1 below, and the direction in which the optical axis direction of the light emitting portion of the optical fiber sensor 30 is offset in the R direction is opposite to the positive (+) and R directions and offset. The direction to become was negative (-). In the test, for each example set in the offset angles θ (offset amount d) of Nos. A to G in Table 1, the rotary head was rotated in the R direction by mimicking the operation of the actual rotary head. The change over time of the light reception amount of the light receiving part of the optical fiber sensor 30 from the time point before a nozzle arrives at the said specific position to the said specific position was measured. Nos. A, B, C, D, E, F, and G in Table 1 correspond to the results shown in FIGS. 8A, 8B, 8C, 8D, 8E, 8F, and 8G, respectively.

No. Offset angle θ (˚) Offset amount d (mm) A -1.0 -0.27 B -0.5 -0.13 C 0.0 0 D +0.5 0.14 E +1.0 0.27 F +1.5 0.41 G +2.0 0.55

8A to 8G, the offset angle θ (offset amount d) is positive, that is, the optical axis direction of the light irradiated from the light emitting portion of the optical fiber sensor 30 is rotated at the central axis C in the vertical direction of the nozzle. When offset in the rotational direction (R direction) of the head, it can be seen that the change over time of the light receiving amount of the light receiving portion of the optical fiber sensor 30 is suppressed over time, and the light receiving amount is stabilized.

 Here, the upper limit of offset angle (theta) (offset amount d) is necessarily determined from the precondition that the optical fiber sensor 30 detects a nozzle. Specifically, since it is a necessary condition that the optical axis direction of the light irradiated from the light emitting portion of the optical fiber sensor 30 is within the range of the reflecting surface 42b of the nozzle 42a described in FIG. 5, the offset angle? ) (The upper limit of the offset amount d) is determined.

Here, the threshold A described in FIG. 6 is set based on the light reception amount in the stable region of the light reception amount in the change over time of the light reception amount in the present embodiment shown in FIGS. 8D to 8G. The stable region of the light receiving amount is a region excluding the rising region and the falling region of the light receiving amount in FIGS. 8D to 8G. Thus, by setting the threshold value based on the received light amount in the stable region of the received light amount, a certain threshold can be set, thereby improving the detection accuracy of the optical fiber sensor 30.

FIG. 9 plots the average amount of received light in each example with respect to the offset angle θ based on the results of FIGS. 8A to 8G. 9, it can be seen that in the present embodiment, when the offset angle θ is + 1.0 °, the light reception amount becomes maximum and the change in the light reception amount with respect to the change in the offset angle θ becomes minimal. The small change in the received light amount with respect to the change in the offset angle θ means that a stable light received amount can be obtained even if the offset angle θ (offset amount d) changes slightly due to an error or the like, so that the detection accuracy of the optical fiber sensor 30 is reduced. It is preferable for improvement and stabilization. Therefore, in the present embodiment, the offset angle θ is + 1.0 °. In addition, although the value of the optimum offset angle (theta) (offset amount d) changes with a structure, a dimension, etc. of a rotary head, it can obtain | require by carrying out the test like FIG.

Adjustment of this offset angle (theta) (offset amount d) is carried out by the adapter member 27 (XY-direction positioning member) and sensor holder member 29 (Z-direction positioning member) demonstrated in FIG. This is performed using the eccentric collar 30a (optical axis direction adjusting means) described in 4.

While aspects of the present invention have been described with reference to the embodiments shown in the accompanying drawings, this is merely exemplary, and various modifications and equivalent other embodiments are possible from those skilled in the art. You will understand the point. Accordingly, the true scope of protection of the invention should be defined only by the appended claims.

The present invention can be used in the manufacture and operation of component mounters.

10: parts retaining head 20: head body
30: optical fiber sensor 40: rotary head

Claims (3)

Head body;
A rotary head rotatably installed in an R direction around a vertical axis of the head body;
A component holding mechanism disposed along the circumferential direction of the rotary head; And
And a reflective optical sensor rotating in the R direction to detect the component holding mechanism at a specific position.
The optical sensor,
A light emitting portion for irradiating light toward the reflective surface of the component holding mechanism at the specific position; And
And a light receiving unit for receiving the reflected light reflected from the reflective surface.
The optical axis of the light irradiated from the light emitting portion is arranged to be offset so as to direct the position of the reflective surface located further in the rotational direction in the R direction from the position on the vertical central axis of the component holding mechanism at the specific position. Component Retention Head in Surface Mounter. The method of claim 1,
The component holding head of the surface mounter is set such that the amount of the offset is such that the change in the amount of received light of the light receiving portion is minimum with respect to the change in the amount of the offset. The method of claim 1,
The optical sensor detects the component holding mechanism by a change in the amount of received light with respect to a predetermined threshold,
The said threshold value is a component holding head of the surface mounter set based on the light reception amount in the stable area of the light reception amount by the said light reception part.

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