JPH09148790A - Electronic device mounter - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a highly reliable electronic device mounter having simple structure. SOLUTION: The electronic device mounter lowers an electronic device 4 vertically while sucking and presses the electronic device 4 onto a board 3 thus bonding the electronic device 4. The electronic device mounter comprises a nozzle 8 for sucking the electronic device 4, and holder 9 for supporting the suction nozzle 8 from above, a nozzle base 7 for supporting the holder 9 slidingly up and down, a spring 10 interposed between the nozzle base 7 and suction nozzle 8 and urging the suction nozzle 8 downward, a unit 5 for elevating/lowering the nozzle base 7 with respect to the board 3, and a controller 22 for controlling the elevating/lowering unit 5 to lower the nozzle base 7. The controller 22 lowers the electronic device 4 at high speed to the vicinity of board 3 through the nozzle base 7 and then lowers the electronic device 4 at low speed to a bonding position.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to, for example, a QFP.
The present invention relates to an electronic component mounting apparatus that mounts an electronic component provided with (Quad Flat Package) on a substrate on which cream solder is printed by using a suction nozzle.

[0002]

2. Description of the Related Art Heretofore, as this type of electronic component mounting apparatus, one described in Japanese Patent Laid-Open No. 62-85490 has been known. This electronic component mounting apparatus has a mounting head that mounts electronic components on a substrate by moving up and down in the vertical direction. This mounting head includes a suction nozzle that sucks an electronic component, a holder that supports the suction nozzle from above, and a nozzle base that slidably supports the holder in the vertical direction. The holder is composed of an upper holder and a lower holder joined in a sheath tube form. Between the upper holder and the lower holder, the impact is absorbed when the electronic component is pressed against the substrate, and the electronic component for the substrate is absorbed. The coil spring that applies the pressing force is interposed. Further, above the holder, a stroke adjusting mechanism for adjusting the descending stroke of the holder according to the thickness of the electronic component and abutting against the holder to lower the stroke is provided.

In this case, when the holder is lowered after adjusting the descending stroke of the holder according to the thickness of the electronic component, the spring force of the coil spring acts on the electronic component from the stage where the electronic component contacts the substrate, The electronic component is bonded to the cream solder on the substrate with a desired pressing force. In this case, the holder is controlled by the stroke adjusting mechanism so as to descend at a low speed at first, gradually increase in speed, and finally descend at a low speed.

[0004]

In such a conventional electronic component mounting apparatus, a structure is adopted in which the pressing force of the electronic component is appropriately adjusted by directly pressing the holder by the stroke adjusting mechanism. However, since the stroke adjusting mechanism is composed of a complicated link mechanism, the structure is complicated as a whole, the number of parts is extremely large, and it is difficult to stably maintain good mounting accuracy. Further, the descending of the holder is controlled so that the speed is gradually increased at a low speed at the beginning and then becomes a low speed at the end, so that the pressing force of the electronic component to the substrate can be slowly applied, but the electronic component itself is Since it hits the substrate before the descending speed becomes slow, even if the coil spring acts as a cushion, there is a problem that the instantaneous impact is large and the electronic parts are damaged or the cream solder is scattered.

The present invention has been made to solve the above problems, and an object thereof is to provide an electronic component mounting apparatus having a simple structure and high reliability.

[0006]

According to another aspect of the present invention, there is provided an electronic component mounting apparatus, wherein an adsorbed electronic component is vertically lowered, and terminals of the electronic component are pressed against a cream solder or an adhesive coated on a substrate. In an electronic component mounting apparatus that adheres by adhesion, a suction nozzle that sucks an electronic component, a holder that supports the suction nozzle from above, a nozzle base that slidably supports the holder in the vertical direction, and a nozzle base and a suction nozzle. A spring interposed between them to urge the suction nozzle downward, and an elevating device for elevating the nozzle base relative to the substrate,
The control device controls the lifting device and lowers the nozzle base. The control device lowers the electronic component through the nozzle base at a high speed to a position closest to the substrate and then at a low speed to a bonding position to the cream solder. It is characterized by

According to this structure, when the nozzle base is lowered by the elevating device, the electronic component sucked by the suction nozzle eventually comes into contact with the substrate and is almost stopped. Further, although the nozzle base descends, at that time, only the nozzle base continues to descend leaving the holder, and at the same time, the spring interposed between the nozzle base and the suction nozzle compresses the spring.
Then, the urging force of the spring presses the electronic component against the substrate, and when the pressing force reaches an appropriate value, that is, when the descending amount of the nozzle base reaches a predetermined amount, the electronic component is moved up and down via the control device. The device stops. in this case,
Since the control device controls the electronic parts to descend to the immediate vicinity of the board at a high speed through the nozzle base and then descends at a low speed to the bonding position to the cream solder, the electronic parts do not come in contact with the board. It descends at high speed and then contacts the substrate at low speed. Therefore, although a series of mounting operations of the electronic component are performed in a short time, the impact when the electronic component comes into contact with the substrate becomes sufficiently small.

In the electronic component mounting apparatus according to the first aspect, the control device has a memory for storing the descending amount of the nozzle base corresponding to the pressing force of various electronic components on the substrate due to the difference in the number of terminals, and the control device is It is preferable to control the descending amount of the nozzle base for each electronic component based on the descending amount stored in the memory.

According to this structure, even for electronic components having the same external shape, the pressing force of the electronic component with respect to the substrate can be adjusted according to the number of terminals of the electronic component. The electronic component can be properly mounted in relation to the cream solder.

In the electronic component mounting apparatus according to the first aspect, the holder has a stopper that abuts on the upper end of the nozzle base and restricts the lower limit of the sliding stroke of the holder against the biasing force of the spring. , A sensor for detecting the separation of the stopper from the upper end of the nozzle base and stopping the lifting device,
It is preferable to have a time adjusting means capable of adjusting the time from the input of the detection signal of the sensor to the stop of the lifting device.

According to the above arrangement, the amount of lowering of the nozzle base can be temporally adjusted by the time adjusting means after the sensor detects that the electronic component is in contact with the substrate.
This makes it possible to control the pressing force applied by the spring after the electronic component comes into contact with the substrate. Therefore, variations in products due to warpage of electronic components (packages) can be absorbed during the mounting operation.

In the electronic component mounting apparatus according to the first aspect, the holder has a stopper that abuts on the upper end of the nozzle base and restricts the lower limit of the sliding stroke of the holder against the biasing force of the spring. It is preferable to have a switch that detects that the stopper is separated from the nozzle base and stops the lifting device, and a position adjusting means that can adjust the mounting position of the switch in the vertical direction.

According to the above structure, the switch adjusts the amount of lowering of the nozzle base from the contact of the electronic component to the substrate to the stop of the nozzle base by adjusting the mounting position of the switch through the position adjusting means. , Can be controlled. Further, this fine adjustment can be achieved with a simple structure of the switch and the position adjusting means capable of moving and adjusting the mounting position of the switch. Such means is a particularly effective method when the substrate is warped or when the dimensions of the electronic components vary.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of the electronic component mounting apparatus of the present invention will be described in detail below with reference to the accompanying drawings. This electronic component mounting device is a device forming a main part of a so-called chip mounter, and is mainly for mounting an electronic component equipped with a QFP on the surface of a substrate.
FIG. 1 is a side view showing a main part of the electronic component mounting apparatus. As shown in the figure, the electronic component mounting apparatus 1 includes a mounting head 2 that mounts an electronic component 4 on a substrate 3 by moving up and down in the vertical direction, and a lifting device that lifts and lowers the mounting head 2 in the vertical direction. 5, the lifting device 5 and the mounting head 2
Is moved in the X-axis direction and the Y-axis direction in a horizontal plane.

The mounting head 2 is mounted on the substrate 3 by the lifting device 5.
A nozzle base 7 that moves up and down with respect to each other, a suction nozzle 8 that suctions the electronic component 4, and a holder 9 that holds the suction nozzle 8 from above and is slidably attached to the nozzle base 7 in the vertical direction. The base body 7a of the nozzle base 7 and the suction nozzle 8 are wound around the holder 9.
And a compression spring 10 interposed therebetween.

The holder 9 has a stem 11 which vertically penetrates the base body 7a of the nozzle base 7 and has a suction nozzle 8 at the lower end, and a block-shaped stopper 12 fixed to the upper end of the stem 11. Have
By mounting the stem 11 on the base body 7a via the thrust bearing 13, the stem 11 can be smoothly slid in the vertical direction with respect to the base body 7a. Further, in a steady state, the stopper 12 contacts the upper end 6c of the base body 6a by the urging force of the compression spring 10 to regulate the lowering (lower limit position) of the stem 11. Further, an air suction hole 11a is formed at the axis of the stem 11, and this air suction hole 11a communicates with the suction nozzle 8 and also with an air hose 14 fixed to the top of the stem 11.

The XY stage 6 is composed of an X stage 15 and a Y stage (not shown), and these stages are combined so as to be orthogonal to each other. X stage 15
It is linearly driven by a linear actuator 16 using a ball screw mechanism, and the Y stage has the same structure. After driving the XY stage 6 to cause the suction nozzle 8 to vacuum-suck the electronic component 4 at a predetermined location, the XY stage 6
By further driving the mounting head 2, the mounting head 2 is transported to a predetermined position on the substrate 3. That is, as shown in FIG. 1, by using the XY stage 6, the electronic component 4 can be positioned directly above the cream solder 3 a on the substrate 3.

The elevating device 5 is rotatably supported by a bracket 17 provided on the X stage 15 and has a ball screw 18 extending in the vertical direction, and a base portion 7b of the nozzle base 7 that is screwed into the ball screw 18. A support block 19 fixed to the upper end of the ball screw 18, an elevating motor 21 such as a servo motor connected to the upper end of the ball screw 18 via a coupling 20, and a controller 22 for controlling the forward / reverse rotation of the elevating motor 21. When the elevating motor 21 is normally or reversely rotated by a predetermined amount (step) by a control signal from the controller 22, the ball screw 18 is normally or reversely rotated by a predetermined amount, and the nozzle base 7 of the mounting head 2 is moved by the predetermined amount via the ball screw 18. Moves vertically in the vertical direction.

The controller 22 includes an input device (not shown) and RA.
It has a memory 22a composed of M and the like, and the descending stroke of the nozzle base 7 is stored in this memory 22a for each electronic component 4. This descending stroke depends not only on the thickness of the electronic component 4 but also on the same component (strictly speaking, the package having the same shape), the number of pins (the number of terminals), and the type of cream solder 3a. , Are different.

Specifically, the thickness of the electronic component 4 is L, the pushing amount of the electronic component 4 when mounting the electronic component 4 on the substrate 3 is H, the lower surface (suction surface) of the suction nozzle 8 and the substrate 3 When the distance from the surface is S, the descending stroke P of the nozzle base 7 is P = S-L + H. And the pushing amount H
Is determined in relation to the spring force of the compression spring 10 based on the number of pins of the electronic component 4 and the viscosity of the cream solder 3a. That is, for each electronic component 4 and for the cream solder 3
Electronic component 4 is mounted (installed) with the most appropriate pressing force for each a.
It is supposed to be.

Further, the controller 22 can control the descending stroke and the descending speed as described above. Specifically, the nozzle base 7 is lowered at a high speed until the electronic component 4 comes into close contact with the substrate, and then the nozzle base 7 is lowered at a low speed to a position where a predetermined lowering stroke is achieved. As a result, the impact when the electronic component 4 contacts the substrate can be reduced, and the time required for mounting can be shortened.

Next, the operation of the mounting head 2 described above will be described. First, the XY stage 6 is driven to move the electronic component 4 right above the predetermined cream solder 3 a on the substrate 3. Next, the lift motor 21 is driven according to the control signal of the controller 22, and the electronic component 4 is lowered at high speed via the nozzle base 7. When the electronic component 4 approaches the board,
The elevating motor 21 decelerates and lowers the electronic component 4 at a low speed. As the descent further proceeds, each pin 4a of the electronic component 4
Comes into contact with the substrate 3, but the nozzle base 7 further descends leaving the stem 11. When the electronic component 4 contacts the substrate 3, the stopper 12 relatively separates from the upper end 7c of the nozzle base 7, and the nozzle base 7 compresses the compression spring 10. As a result, the spring force of the compression spring 10 acts on the electronic component to press the electronic component 4 against the substrate 3. Then, when the pressing force of the compression spring 10 reaches a predetermined value, the lift motor 21 stops. Then, the vacuum suction is released, the elevating motor 21 is reversed, and the original state is restored.

When mounting the electronic component 4 on the substrate 3,
The compression spring 10 continues to contract from the moment when the pin 4a of the electronic component 4 hits the substrate 3. Therefore, the force of pressing the pin 4a against the substrate 3 by the compression spring 10 continues to increase in proportion to the pushing amount H of the electronic component 4. Therefore, the controller 22 controls the descending stroke P of the nozzle base 7 according to the type of the electronic component 4 and the adhesive force of the cream solder 3a.
By inputting into the above, it is possible to control the descending stroke P of the nozzle base 7 according to this value, and the compression amount of the compression spring 10, that is, the pushing amount H of the electronic component 4 is adjusted. As a result, the pressing force of the electronic component 4 against the substrate 3 can be made appropriate according to the type of the electronic component 4 and the adhesive force of the cream solder 3a.

By changing the descending speed of the nozzle base 7 from a high speed to a low speed, it is possible to reduce a collision impact of the electronic component 4 on the board 3 and to shorten an operation time of the mounting operation. . Therefore, the electronic component 4 can be mounted at high speed while effectively preventing the electronic component 4 from being damaged and the cream solder 3a from scattering. In addition, the rise of the nozzle base 7 after mounting the electronic component 4 is performed at high speed. On the other hand, the above-mentioned slow descending speed is the pushing amount H
It may be set so that the impact force when the electronic component 4 contacts the substrate 3 becomes smaller than the pressing force applied to the electronic component 4 when the electronic component 4 is pushed in by an amount.

Next, a second embodiment of the present invention will be described with reference to FIGS. In the electronic component mounting apparatus according to this embodiment, a sensor 30 is provided on the upper end 7c of the base body 7a of the nozzle base 7 to detect contact or release of contact between the surface of the upper end 7c of the base body 7a and the lower surface of the stopper 12. Has been. This sensor 30
Is composed of a touch sensor, a pressure sensor, etc.,
The detection end 31 is located on the surface of the upper end 7c. In such a configuration, the sensor 30 detects that the nozzle base 7 and the stopper 12 are separated from each other, and at the same time, detects that the electronic component 4 is in contact with the substrate 3.

The detection signal of the sensor 30 is output to the delay circuit (time adjusting means) 22b of the controller 22. Instead of the descending stroke P for each electronic component 4 described in the first embodiment, the controller 22 stores the drive time of the elevating motor 21 for each electronic component 4 corresponding to the pushing amount H. Therefore, the controller 22 delays the stop of the lift motor 21 by the delay circuit 22b after inputting the detection signal, and stops the lift motor 21 after the above drive time has elapsed. That is, after the electronic component 4 contacts the substrate 3, the lifting motor 21 is driven by an amount corresponding to the pushing amount H and then stopped.

In this configuration, the electronic component 4 is actually the substrate 3
Since the pressing amount H is controlled after the contact with, the method is particularly effective when the substrate 3 is warped or when the dimensions of the electronic component 4 vary. The sensor 30 may be provided on the stopper 12 side.

Next, a third embodiment of the present invention will be described with reference to FIG. In the electronic component mounting apparatus according to this embodiment, the limit switch 3 for detecting the relative amount of rise of the stopper 12 with respect to the nozzle base 7 and stopping the lowering of the nozzle base 7 on the base portion 7b of the nozzle base 7.
3 are provided. And this limit switch 3
By contacting the upper surface of the stopper 12, the switch 3 can perform a switching operation, and can be displaced in the vertical direction manually or automatically (for example, by screw feeding) via the slide base (position adjusting means) 34. Therefore, the pushing amount H can be directly adjusted by changing the position of the limit switch 33 in the vertical direction according to the type of the electronic component 4 and the type of the cream solder 3a.

In this configuration, the electronic component 4 is actually the substrate 3
The amount H of pushing can be adjusted with a very simple structure after the contact with the. Moreover, such a means is also effective when the substrate 3 is warped or when the dimensions of the electronic component 4 vary.

In this embodiment, the case where the electronic component is mounted on the cream solder of the board has been described.
In some cases, not only the cream solder but also the electronic component is mounted on an adhesive that temporarily fixes the substrate, and the present invention can be applied to such a case.

[0031]

As described above, according to the electronic component mounting apparatus of the present invention, the descending speed of the nozzle base 7 is changed from the high speed to the low speed immediately before the electronic component comes into contact with the substrate. The collision impact of the electronic component 4 on the substrate 3 can be reduced, and the operation time of the mounting operation can be shortened. Therefore, the electronic component 4 can be mounted at high speed while effectively preventing the damage of the electronic component 4 and the scattering of the cream solder 3a, and the electronic component mounting can be speeded up and reliability can be improved at the same time.

[Brief description of the drawings]

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

FIG. 2 is a side view showing a state in which electronic components are mounted on a board by the mounting head shown in FIG.

FIG. 3 is a side view showing a second embodiment of an electronic component mounting apparatus according to the present invention.

4 is a side view showing a state in which electronic components are mounted on a board by the mounting head shown in FIG.

FIG. 5 is a side view showing a third embodiment of an electronic component mounting apparatus according to the present invention.

[Explanation of symbols]

 1 Electronic Component Mounting Device 2 Mounting Head 3 Substrate 3a Cream Solder 4 Electronic Component 5 Lifting Device 7 Nozzle Base 8 Adsorption Nozzle 9 Holder 10 Compression Spring 11 Stem 12 Stopper 22 Controller 22a Memory 22b Delay Circuit 30 Sensor 33 Limit Switch 34 Slide Base

Claims (4)

[Claims] 1. A suction nozzle for sucking an electronic component in an electronic component mounting apparatus that lowers the sucked electronic component in the vertical direction and presses and bonds the terminals of the electronic component to cream solder or adhesive applied on a substrate. A holder that supports the suction nozzle from above, a nozzle base that slidably supports the holder in the up-down direction, and a suction base that is interposed between the nozzle base and the suction nozzle. A spring, a lifting device that raises and lowers the nozzle base relative to the substrate, and a control device that controls the lifting device and lowers the nozzle base. The electronic component mounting device is characterized in that the electronic component is lowered to the immediate vicinity of the substrate at a high speed and then to the bonding position to the cream solder at a low speed. 2. The control device has a memory for storing the amount of lowering of the nozzle base corresponding to the pressing force of various electronic components on the substrate due to the difference in the number of terminals, and the control device is provided for each electronic component. 2. The electronic component mounting apparatus according to claim 1, wherein the descending amount of the nozzle base is controlled based on the descending amount stored in the memory. 3. The holder has a stopper that abuts an upper end of the nozzle base and restricts a lower limit of a sliding stroke of the holder against an urging force of the spring, and the control means includes the stopper. A sensor for detecting the distance from the upper end of the nozzle base to stop the lifting device, and a time adjusting means capable of adjusting the time from the input of the detection signal of the sensor to the stop of the lifting device. The electronic component mounting apparatus according to claim 1, which is characterized in that. 4. The holder has a stopper that abuts an upper end of the nozzle base and restricts a lower limit of a sliding stroke of the holder against an urging force of the spring, and the control means includes the nozzle. The switch according to claim 1, further comprising a switch that detects that the stopper is separated from the base and stops the lifting device, and a position adjusting unit that can adjust the mounting position of the switch in the vertical direction. Electronic component mounting device.