JP3816614B2 - Dispenser in component mounting system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a dispenser in a component mounting system that applies a coating liquid such as an adhesive or cream solder for mounting components on a printed board.
[0002]
[Prior art]
Conventionally, a component mounting system has been known in which a printed circuit board is transported along a conveyor and small pieces of components such as ICs are sequentially mounted on the printed circuit board while applying a coating liquid such as an adhesive to the printed circuit board. ing.
[0003]
In this type of system, for example, a dispenser head that can move in the X and Y directions is disposed on a transport path of a printed circuit board by a conveyor, and a coating liquid is applied to an arbitrary position on the printed circuit board by the dispenser head. Has been done.
[0004]
The dispenser head is equipped with, for example, a syringe equipped with a nozzle for discharging a coating liquid at the tip and an elevating drive mechanism for moving the syringe up and down integrally, and supplies air into the syringe via a switching valve. Thus, the coating liquid stored in the syringe is applied to the printed circuit board while being pushed out to the tip of the nozzle.
[0005]
Specifically, while the dispenser head is moved above the printed circuit board, the coating liquid S is pushed out to the tip of the nozzle 80 by air pressure as shown in FIG. Is reached, the syringe is lowered and the coating liquid S pushed out to the tip of the nozzle is pressed against the surface of the printed circuit board 81 (FIG. 5B). After that, the application liquid is separated from the tip of the nozzle by raising the syringe, and a predetermined amount of application liquid is applied onto the printed circuit board (FIGS. 5C and 5D).
[0006]
[Problems to be solved by the invention]
However, in the above-described conventional dispenser that applies the coating liquid S pushed out to the nozzle tip onto the printed circuit board while raising and lowering the syringe, the viscosity of the coating liquid S or the coating liquid is applied after the coating liquid S is pressed against the surface of the printed circuit board 81. There is a problem that it is difficult to properly apply the coating liquid S unless the syringe is raised at an appropriate speed according to the amount.
[0007]
For example, when a relatively high viscosity coating solution is applied, when the syringe is raised at a relatively slow speed suitable for the viscosity, the coating solution is substantially hemispherical on the printed circuit board surface as shown in FIG. When the syringe is raised at a speed faster than that speed, the coating liquid spreads to the periphery due to the stringing phenomenon of the coating liquid (FIG. 6 (b)) or is separated (FIG. 6 (c)). ) Etc. In such a case, the application liquid may adhere to other component mounting positions close to the application position and cause a conduction failure.
[0008]
For this reason, usually, the syringe is moved up and down at a speed somewhat slower than the moving up and down speed according to the viscosity of the coating solution, and the occurrence of the above situation is surely avoided. It is a hindrance to improvement.
[0009]
The present invention has been made to solve the above-described problem, and an object thereof is to provide a dispenser in a component mounting system that can efficiently and appropriately apply a coating liquid such as an adhesive to a printed circuit board. Yes.
[0010]
[Means for Solving the Problems]
The present invention includes a syringe for storing a coating liquid and a nozzle member for deriving the coating liquid toward a target position, and is configured to apply the coating liquid in the syringe while extruding the tip of the nozzle member. In the dispenser, the nozzle member is attached to a nozzle holder that is held at a certain height with respect to the target position, and a liquid passage communicating with the inside of the nozzle member is formed in the nozzle holder. A frame that is connected to the outlet tube extending from the lower portion of the syringe and that supports the syringe above the lower portion of the syringe from which the outlet tube is extended is provided on the nozzle holder, and covers the nozzle member A nozzle cap that forms an air passage between the nozzle member and the air passage and the outside formed at the tip of the nozzle cap. A discharge hole through which the air is supplied, and an air supply means for supplying air to the air passage, and as an opening and closing means for opening and closing the nozzle hole of the nozzle member, the nozzle member is supported so as to be vertically movable and lowered. A shaft body that closes the nozzle hole with its tip closely contacting the peripheral edge of the nozzle hole at the end position and an air cylinder for moving the nozzle up and down are provided. The air cylinder is a base end of the shaft body. The piston is coupled to the inside, and the space in the air cylinder is partitioned into two chambers by this piston, and the air is selectively supplied to and discharged from each chamber. The dispenser in the component mounting system is characterized in that the nozzle hole is opened and closed by moving the shaft up and down.
[0011]
According to this dispenser, the nozzle member is attached to the nozzle holder that is held at a certain height with respect to the target position, and when the coating liquid in the syringe is pushed out to the tip of the nozzle member, the nozzle cap and the nozzle member Since the coating liquid is separated from the nozzle tip by the pressure of the airflow flowing through the air passage between the nozzle member and the nozzle member, the nozzle member is held at a certain height above the target position, such as a printed circuit board, and applied to the target position in this state A liquid can be applied. As a result, the occurrence of the stringing phenomenon of the coating liquid in the application operation like this type of conventional dispenser is eliminated, and the cycle time is shortened by not moving the nozzle member up and down compared to this type of conventional dispenser. This can effectively increase the mounting efficiency.
[0015]
In the dispenser of the present invention as described above, the nozzle member is attached to the nozzle holder, a liquid passage communicating with the inside of the nozzle member is formed in the nozzle holder, and the liquid passage extends from the lower portion of the syringe. The nozzle holder is preferably provided with a frame that is connected to the outlet tube and supports the syringe above the lower portion of the syringe from which the outlet tube extends . By doing so, the positional relationship between the nozzle member and the syringe can be freely set, the degree of freedom in design can be increased, and a layout that is advantageous for maintenance and the like can be selected.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the drawings.
[0018]
1 and 2 schematically show a dispenser according to the present invention. As shown in the figure, a conveyor 2 for conveying a printed circuit board is disposed on a base 1 of the dispenser, and the printed circuit board 3 is conveyed on the conveyor 2 to a predetermined work position (position shown in the figure). It is designed to be positioned.
[0019]
Above the conveyor 2, a dispenser head 4 for applying a component mounting application liquid to the printed circuit board 3 is provided. The dispenser head 4 is arranged in the X-axis direction (direction of the conveyor 2) and the Y-axis direction ( It is supported so as to be movable in a direction perpendicular to the X axis on a horizontal plane.
[0020]
That is, a pair of fixed rails 5 extending in the Y-axis direction and a ball screw shaft 6 driven to rotate by a Y-axis servo motor 7 are disposed on the base 1, and a head unit is disposed on the fixed rail 5. A support member 8 is disposed, and a nut portion 9 provided on the support member 8 is screwed onto the ball screw shaft 6. The support member 8 is provided with a guide member 10 extending in the X-axis direction and a ball screw shaft 11 driven by an X-axis servo motor 12 so that the dispenser head 4 can move to the guide member 10. A nut portion 13 that is held and provided on the dispenser head 4 is screwed onto the ball screw shaft 11. Then, the ball screw shaft 6 is rotated by the operation of the Y-axis servo motor 7 and the support member 8 is moved in the Y-axis direction, and the ball screw shaft 11 is rotated by the operation of the X-axis servo motor 12 to thereby dispense the dispenser head. 4 moves in the X-axis direction with respect to the support member 8.
[0021]
The dispenser head 4 is equipped with a plurality of dispenser main bodies 15 for applying different types of coating liquids to the printed circuit board 3, and in the illustrated example, two dispenser main bodies 15 are mounted.
[0022]
FIG. 3 shows a specific configuration of the dispenser body 15. As shown in this figure, the dispenser body 15 is applied from a syringe 20 for storing a coating liquid, a nozzle (nozzle member) 21 for deriving the coating liquid in the syringe 20 toward a target position, and a tip of the nozzle 21. And various means for discharging the liquid.
[0023]
The syringe 20 is a tapered cylindrical container having a liquid inlet at the upper end, and is detachably attached to the frame 16 of the dispenser head 4. The syringe 20 contains the application liquid such as an adhesive or cream solder for mounting components, and a syringe cap 23 is attached to the upper end of the syringe to close the liquid introduction port, thereby preventing the outside air. Stored in a blocked state.
[0024]
In the syringe 20, a piston 22 is inserted in an upper part of the stored coating liquid so as to be movable up and down, and air of a constant pressure is supplied via an air introduction tube 24 attached to the syringe cap 23. It is always supplied above the piston 22. In this way, by supplying air at a constant pressure and pressing the coating liquid in the syringe 20 downward by the piston 22, the nozzle is connected via the outlet tube 25 connected to the tip of the syringe 20 (the lower end in FIG. 3). The coating liquid is pushed out toward 21.
[0025]
The nozzle 21 has an outflow hole (nozzle hole) 21a at the tip (lower end in FIG. 3) and is a cylindrical nozzle in which the inside and outside of the tip are tapered, and a nozzle holder 26 fixed to the frame 16. The nozzle cap 30 described later is mounted integrally with the lower end of the nozzle. The nozzle holder 26 is formed in a hollow shape as shown in the figure, and with the nozzle 21 mounted, the hollow portion communicates with the inside of the nozzle 21 to form a liquid passage 28 extending in the vertical direction. The liquid passage 28 is connected to the outlet pipe 25 through a port 27 formed in the nozzle holder 26.
[0026]
The nozzle cap 30 is a cylindrical member having a discharge hole 30a at the tip (lower end in FIG. 3) and tapered at the inside and outside of the tip, and the discharge hole 30a is positioned coaxially with the outflow hole 21a. The nozzle 21 is attached to the nozzle holder 26 so as to cover the nozzle 21.
[0027]
A cylindrical spacer 31 is disposed between the nozzle cap 30 and the nozzle 21, thereby forming a passage 32 extending in the vertical direction between the nozzle cap 30 and the nozzle 21 and having a tapered tip. In addition, the passage 32 is connected to the air supply pipe 33 via a port 30 b formed in the side portion of the nozzle cap 30. The air supply pipe 33 is connected to an air supply source via, for example, a pressure adjusting means such as a pressure reducing valve and a flow rate adjusting valve. When the dispenser body 15 is operated, the air supply pipe 33 is connected to the passage 32 via the air supply pipe 33. As a result of the supply of air, a laminar flow (indicated by an arrow in FIG. 3) is formed by the air that flows downward along the periphery of the nozzle 21 and converges at the tip of the nozzle 21 and flows out of the discharge hole 30a. It has become so.
[0028]
On the other hand, above the nozzle holder 26, a needle (shaft body) 43 and an air cylinder 35 for vertically moving the needle 43 are provided as opening / closing means for opening / closing the outflow hole 21a of the nozzle 21.
[0029]
The needle 43 is a cylindrical member having an outer diameter smaller than the inner diameter of the nozzle 21 and larger than the outflow hole 21a and having a tapered portion corresponding to the inner tip shape of the nozzle 21 at the tip. It enters the liquid passage 28 and is arranged coaxially with the outflow hole 21a.
[0030]
The air cylinder 35 includes a piston 36 inside, and has pressure chambers 37 and 38 above and below the piston 36, and these pressure chambers 37 and 38 are connected to the air supply / discharge system via ports 39 and 40. It is configured to be connected to the passages 41, 42, and the piston 36 descends when air is discharged from the lower pressure chamber 32 while air is supplied to the upper pressure chamber 37. The piston 36 is raised when air is discharged from the upper pressure chamber 31 while air is supplied to the pressure chamber 32.
[0031]
When the proximal end portion of the needle 43 is screwed to the piston 36 of the air cylinder 35 and the piston 36 is lowered as described above, the tip of the needle 43 comes into close contact with the inner tip of the nozzle 21 and flows out. While the hole 21a is closed, the outflow hole 21a is opened when the piston 36 is raised.
[0032]
Next, the application | coating operation | movement of the coating liquid by the dispenser comprised as mentioned above is demonstrated using FIG.
[0033]
When the application operation of the application liquid is started in the dispenser, first, the printed circuit board 3 is conveyed along the conveyor 2 to a predetermined work position.
[0034]
At this time, the dispenser head 4 is set at a predetermined standby position, and in each dispenser body 15, the needle 43 is held at the lowered end position, the outflow hole 21a of the nozzle 21 is closed, and the nozzle cap Air is supplied to the passage 32 between the nozzle 30 and the nozzle 21, and the laminar flow is formed by the air. In addition, by applying pressure into the syringe 20 through the piston 22, the coating liquid in the syringe 20 is filled up to the nozzle tip through the outlet tube 25 and the liquid passage 28 (FIG. 4A).
[0035]
When the printed circuit board 3 is set at the working position, the dispenser head 4 is moved to apply the coating liquid to the first application position (target position P) on the printed circuit board 3, and the dispenser head 4 is moved to the target position P. When approaching, the outflow hole 21 a of the nozzle 21 is temporarily opened by the vertical movement of the needle 43. As a result, the coating liquid in the liquid passage 28 is pushed out to the nozzle tip through the outflow hole 21a (FIG. 4B).
[0036]
That is, since the coating liquid is constantly pressurized toward the nozzle tip, the coating liquid is pushed out to the nozzle tip by temporarily opening the outflow hole 21a as described above, and the needle 43 is further closed. The coating solution is also extruded. At this time, the amount of the coating liquid pushed out to the nozzle tip is controlled by controlling the air supply / discharge switching time in the air cylinder 35, although it varies depending on the viscosity of the coating liquid, the pressure value, and the like.
[0037]
When the coating liquid is pushed out to the nozzle tip in this way, the coating liquid is separated into particles from the nozzle tip by the pressure of the airflow formed in the passage 32 between the nozzle cap 30 and the nozzle 21 as described above. The liquid is discharged to the outside from the discharge hole 30a by the air current and applied to the target position P on the printed circuit board 3 (FIGS. 4C and 4D). At this time, as described above, the airflow flows downward along the periphery of the nozzle 21, converges at the center of the tip of the nozzle 21, and forms a laminar flow that flows out from the discharge hole 30 a of the nozzle cap 30. A uniform pressure acts on the applied coating liquid from its surroundings. For this reason, the coating liquid separated from the nozzle tip is formed into a substantially spherical shape and appropriately discharged from the discharge hole 30a, whereby the coating liquid is formed into a substantially hemispherical shape at the target position P as shown in FIG. Will be applied.
[0038]
Thereafter, the same operation as described above is repeated while the dispenser head 4 is moved, so that the coating liquid is sequentially applied to predetermined positions on the printed circuit board 3. At this time, if possible, both the dispenser bodies 15 are actuated to apply the coating solution at two locations simultaneously.
[0039]
In addition, although the opening / closing timing of the outflow hole 21a of the nozzle 21 is not described in detail, the timing is such that the coating liquid discharged during the movement of the dispenser head 4 is appropriately applied to the target position P. Further, it is set in consideration of various conditions such as the moving speed of the dispenser head 4 and the distance between the nozzle 21 and the printed circuit board 3.
[0040]
As described above, in the dispenser of the above embodiment, the coating liquid is applied by being ejected toward the target position P on the printed circuit board 3, so that the nozzle 21 can be held at a certain height above the printed circuit board. A coating solution can be applied to the printed circuit board 3. Therefore, as compared with this type of conventional dispenser, the cycle time can be shortened because the nozzle member does not need to be moved up and down, thereby effectively increasing the mounting efficiency.
[0041]
Moreover, in the dispenser, since the coating liquid pushed out to the nozzle tip is separated and discharged by the pressure of the airflow, there is no threading of the coating liquid (occurrence of stringing phenomenon) as in the conventional case. Therefore, it is possible to reliably avoid the occurrence of application failure due to the stringing phenomenon, and in this respect, the application liquid can be more appropriately applied to the printed circuit board 3 than a conventional dispenser.
[0042]
In addition, since the stringing phenomenon does not occur, there is no need to change the nozzle lifting speed according to the type of coating liquid, in other words, the time required for the coating operation is not affected by the type of coating liquid. Therefore, there is also a feature that the coating liquid can be applied to the printed circuit board 3 with high efficiency regardless of the type of the coating liquid.
[0043]
In the dispenser, there is a slight time difference between the time required to push the coating liquid to the nozzle tip and the time required to separate and discharge the coating liquid pushed to the nozzle tip due to the difference in the viscosity of the coating liquid. However, in the configuration of the dispenser, the time difference as described above is eliminated by setting the air pressure supplied to the syringe 20, the opening / closing timing of the outflow hole 21a, the air pressure of the airflow, or the like according to the viscosity of the coating liquid. Is sufficiently possible and does not affect the coating efficiency.
[0044]
Further, according to the dispenser, it is not necessary to move the nozzle member up and down as described above, so that various drive mechanisms for raising and lowering the nozzle are unnecessary. Therefore, as compared with a conventional dispenser of this type, there is an advantage that the configuration of the dispenser head can be simplified because such a drive mechanism is unnecessary.
[0045]
In addition, the said dispenser main body 15 is an example of the dispenser which concerns on this invention, The concrete structure can be suitably changed in the range which does not deviate from the summary of this invention.
[0046]
For example, in the dispenser of the above embodiment, the syringe 20 and the nozzle 21 are arranged apart from each other, and the coating liquid in the syringe 20 is discharged while being guided to the nozzle 21 through the outlet tube 25. You may comprise so that the nozzle 21 may be integrally provided in a front-end | tip part. In this case, the needle 43 is arranged inside the syringe 20 so as to move up and down. In this way, since the dispenser component is integrated with the syringe 20, there is an advantage that the dispenser can be made compact. On the other hand, when configured as in the above embodiment, the positional relationship between the nozzle holder 26 and the syringe 20 can be set freely, which is advantageous in terms of design freedom.
[0047]
In the dispenser main body 15, as a means for opening and closing the outflow hole 21a, a needle 43 is provided inside the nozzle 21, and this is moved up and down by the air cylinder 35. You may make it employ | adopt the structure which opens and closes the outflow hole 21a like a shutter. However, according to the configuration of the dispenser main body 15, it is possible to increase the degree of freedom of the shape of the passage 32 formed between the nozzle cap 30 and the nozzle 21 and form an optimal air flow for discharging the coating liquid. There is an advantage that can be. That is, when the mechanism for opening / closing the outflow hole 21a is arranged outside the nozzle 21, a restriction is imposed on the shape of the passage 32 to form an air flow suitable for discharging the coating liquid. May be difficult to do. However, according to the configuration of the dispenser main body 15, since the mechanism for opening and closing the outflow hole 21a is arranged in the nozzle, there is little restriction on the shape of the passage 32, and therefore an optimal air flow is formed. Thus, the coating liquid can be appropriately discharged.
[0048]
Furthermore, in the dispenser body 15, a laminar flow is formed as an air flow, but the air flow is not necessarily a laminar flow and may be a turbulent flow. However, in the case of turbulent flow, it becomes difficult to control the direction when the coating liquid is discharged. Therefore, it is preferable to form a laminar flow to discharge the coating liquid in order to increase the coating accuracy.
[0049]
In the above dispenser, the application liquid is discharged on the printed circuit board 3 while the dispenser head 4 is moving. Of course, the application liquid is discharged after the dispenser head 4 reaches the target position. It may be.
[0050]
【The invention's effect】
As described above, in the dispenser of the present invention, the nozzle member is attached to the nozzle holder that is held at a certain height with respect to the target position , the coating liquid is pushed out to the tip of the nozzle member, and the coating liquid is discharged. The nozzle member is separated from the nozzle tip by the airflow formed in the air passage between the nozzle cap and the nozzle member, and discharged and applied toward the target position such as a printed circuit board through the discharge hole of the nozzle cap. The coating liquid can be applied to the printed circuit board while maintaining the position at a certain height. Therefore, as compared with the conventional dispenser of this type, the cycle time can be shortened by the amount that the nozzle member is not moved up and down, thereby effectively increasing the mounting efficiency.
[0051]
Moreover, since the coating liquid pushed out to the nozzle tip is separated and discharged by the pressure of the airflow, there is no stringing of the coating liquid as in the prior art, and it is possible to reliably avoid the occurrence of coating defects due to the stringing phenomenon. . Therefore, in this respect, the coating liquid can be applied more appropriately as compared with the conventional dispenser.
[0055]
In the dispenser of the present invention as described above, the nozzle member is attached to the nozzle holder, a liquid passage communicating with the inside of the nozzle member is formed in the nozzle holder, and the liquid passage extends from the lower portion of the syringe. It is preferable that the nozzle holder is provided with a frame that is connected to the outlet pipe and that supports the syringe above the lower portion of the syringe from which the outlet pipe extends . If it does in this way, the positional relationship of a nozzle member and a syringe can be set freely, a design freedom can be raised, and a layout advantageous for a maintenance etc. can be selected. Note that the nozzle member may be provided integrally with the syringe, and in this way, the dispenser can have a compact configuration.
[Brief description of the drawings]
FIG. 1 is a schematic plan view of a dispenser according to an embodiment of the present invention.
FIG. 2 is a front view of the same.
FIG. 3 is a cross-sectional view of a main part showing a dispenser main body mounted on the dispenser head.
FIGS. 4A to 4D are cross-sectional views of a main part of a dispenser main body for explaining a coating liquid coating operation by the dispenser. FIGS.
FIGS. 5A to 5D are cross-sectional views of a nozzle tip for explaining a coating liquid coating operation by a conventional dispenser.
FIGS. 6A to 6C are diagrams showing examples of application states of the application liquid.
[Explanation of symbols]
4 Dispenser head 15 Dispenser main body 20 Syringe 21 Nozzle 21a Outflow hole 22 Piston 25 Outlet pipe 30 Nozzle cap 30a Discharge hole 32a Passage 33 Air supply pipe 35 Air cylinder 43 Needle

Claims (1)

In a dispenser that has a syringe for storing a coating liquid and a nozzle member for deriving the coating liquid toward a target position, and that is configured to apply the coating liquid in the syringe while pushing it to the tip of the nozzle member.
The nozzle member is attached to a nozzle holder that is held at a certain height with respect to the target position, and a liquid passage that communicates with the inside of the nozzle member is formed in the nozzle holder. The nozzle holder is provided with a frame that is connected to the outlet tube extending from the lower portion and supports the syringe above the lower portion of the syringe from which the outlet tube is extended,
A nozzle cap that is covered by the nozzle member and forms an air passage between the nozzle member, a discharge hole that is formed at a tip of the nozzle cap and communicates the air passage and the outside, and the air passage. Air supply means for supplying air, and
As an opening / closing means for opening and closing the nozzle hole of the nozzle member, a shaft body that is supported so as to be vertically movable in the nozzle axis direction, and whose tip is in close contact with the peripheral edge of the nozzle hole at the descending end position; And an air cylinder for moving this up and down,
The air cylinder includes a piston coupled to a base end portion of the shaft body, and the piston divides a space in the air cylinder into two chambers, which are selectively supplied from an air supply source to each chamber. A dispenser in a component mounting system, wherein the nozzle hole is opened and closed by vertically moving a piston and a shaft by supplying and discharging air.

Images