JP2001047225A - Method and device for flux application - Google Patents

Abstract

PROBLEM TO BE SOLVED: To apply a required quantity of flux to only a required place of a plate to be applied with flux. SOLUTION: A nozzle 29, which is supplied with flux and air for atomizing the flux, is provided opposite a substrate P of an object for flux application. The nozzle 29 is positioned at an optional location of a plane coordinates on the substrate P by moving the nozzle 29 and the substrate P with a coordinate mechanism 55. With an arithmetic operation controller 53, flux application from the nozzle 29 is controlled in a flux application condition inherent in each location where the nozzle 29 is positioned, linked with the coordinate mechanism 55 for the nozzle. The nozzle coordinate mechanism 55 is provided with a conveyor 21 which transfers the substrate P, and a nozzle transferring device 27 which moves the nozzle 29 in a direction crossing the transferring direction of the substrate P.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a flux applying method and a flux applying apparatus for applying a flux for soldering.

[0002]

2. Description of the Related Art As shown in FIG. 3, a printed wiring board (hereinafter simply referred to as a "board") P on which components are mounted is denoted by X.
A conveyor 1 for transporting in the direction is provided. The conveyor 1 is driven by a conveyor driving motor 2. A nozzle moving guide rail 3 is disposed below the conveyor 1 in a Y direction that is parallel to the lower surface of the substrate P and intersects at right angles to the direction in which the substrate P is transported. The nozzle 4 is provided so as to be able to reciprocate.

The nozzle 4 sprays a mist-like flux on the lower surface of the substrate P located above the upward spray hole 5 and is provided at one end of the nozzle moving guide rail 3 for reciprocating the nozzle. It is reciprocated by a feed mechanism such as a feed screw driven by the motor 6.

Further, a flux supply pipe 9 which sucks up a flux F stored in a flux storage tank 7 by a flux supply pump 9 driven by a pump drive motor 8 and discharges the flux F at a set flow rate according to the pump rotation speed. Is connected to the nozzle 4, and an air supply pipe 13 through a dial type regulator 12 for adjusting a set flow rate of the atomizing air from a pneumatic source 11 which is a source of the atomizing air is connected to the nozzle 4. Have been.

The nozzle 4 reciprocates along the nozzle moving guide rail 3 over the entire width of the substrate P while continuously spraying the flux on the substrate P conveyed by the conveyor 1, so that the conveyed substrate P Can be uniformly applied to the entire surface of the substrate.

[0006]

According to the conventional flux coating method, while the flux can be uniformly applied to the entire surface of the substrate P, the flux is also applied to unnecessary portions of the substrate P. Parts that do not need to be soldered need to be shielded with a masking plate or the like, and furthermore, sufficient cleaning after soldering is required.

Further, since the flux is uniformly applied,
The entire coating amount is adjusted to the portion requiring the most flux, and there is a portion where excessive flux is applied.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to apply a required amount of flux only to a required portion of a plate to be coated.

[0009]

According to a first aspect of the present invention, a nozzle is relatively moved with respect to a predetermined coordinate position of a plate to be coated with a flux, and a unique position is set for each coordinate position. Is a flux application method for applying the flux supplied from the nozzle under the flux application conditions to the plate to be applied.

[0010] Then, by selecting and setting a necessary amount and a necessary coating method for each part of the plate to be coated,
The required amount of flux is applied only where needed, preventing unnecessary flux application, realizing a high quality substrate manufacturing process, and addressing the environmental issues of the cleaning liquid required for cleaning after soldering.

According to a second aspect of the present invention, the supply of the flux from the nozzle to the plate to be coated is selected between a case where the flux is sprayed from the nozzle and a case where the flux is jetted from the same nozzle. Flux coating method.

When the flux application range is relatively wide, the atomizing flux is sprayed from a nozzle to uniformly apply the flux to the plate to be coated. On the other hand, when the flux application range is narrow, only the flux liquid is jetted from the nozzle and is appropriately applied to the plate to be applied.

According to a third aspect of the present invention, there is provided a nozzle which is provided opposite to a plate to be coated with a flux and receives a supply of the flux, and at least one of the nozzle and the plate to be coated is moved to be coated. A nozzle coordinate mechanism for positioning the nozzle at an arbitrary position in the plane coordinates of the plate, and a control unit for controlling the flux application from the nozzle with a unique flux application condition for each location where the nozzle is positioned in conjunction with the nozzle coordinate mechanism. And a flux coating device comprising:

The control unit controls the application of the flux from the nozzle in a specific flux application condition for each location where the nozzle is positioned in conjunction with the nozzle coordinate mechanism. The amount and the required application method are selected, and the required amount of flux is applied only to the required location, thereby preventing useless flux application.

According to a fourth aspect of the present invention, the nozzle coordinate mechanism according to the third aspect moves a nozzle in a direction intersecting a conveyor for transporting the plate to be coated and a transport direction of the plate to be coated by the conveyor. And a nozzle moving device.

The nozzle is positioned at a predetermined plane coordinate of the plate to be applied by combining the transport distance of the plate to be coated by the conveyor and the moving distance of the nozzle by the nozzle moving device.

According to a fifth aspect of the present invention, there is provided the flux coating apparatus according to the fourth aspect, further comprising a stopper provided on the conveyor for locking and positioning the plate to be coated.

Then, the plate to be coated is positioned with high precision by the stopper, and the flux is applied to an accurate location.

According to a sixth aspect of the present invention, there is provided a flux coating apparatus according to any one of the third to fifth aspects,
The actuator is provided with an actuator for moving a nozzle in a direction far from or near the flux application surface of the plate to be applied.

Then, the nozzle is approached to the plate to be coated by the actuator, thereby coping with the flux application with a narrow application range.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS.

As shown in FIG. 1, reference numeral 21 denotes a conveyor, which is a fixed rail provided at a fixed position.
An endless chain (not shown) is provided so as to be freely rotatable along the movable rail 23 and the movable rail 23 whose interval can be adjusted while being parallel to the fixed rail 22. These endless chains are driven by a conveyor drive. Printed circuit board (hereinafter, referred to as a flux-applied plate) to be applied with flux, which is driven in rotation by the motor 24 for synchronization and is locked on both sides by pins (not shown) projecting from these endless chains. Simply "substrate"
P) is carried by the endless chain.

The conveyor driving motor 24 is a pulse motor, and the conveyor driving motor 24 is provided with a conveyor encoder 25 for detecting the number of pulses according to the rotation amount. The transport distance (position) of the substrate P can be measured from the number, and the transport speed at which the conveyor 21 transports the substrate P can be measured from the number of detection pulses per unit time.

The fixed rail 22 is a guide rail fixed at a fixed position, while the movable rail 23 is a fixed rail 22
The guide rails can be moved and adjusted in the width direction in accordance with the width of the substrate P by a conveyor width adjustment mechanism (not shown) while maintaining a parallel posture with respect to.

The fixed rail 22 and the movable rail 23
Are provided with stoppers 26 for positioning the substrate which can protrude inward and face each other. These stoppers 26 are projected from the fixed rail 22 and the movable rail 23 by an electric actuator or a fluid pressure actuator (not shown) to lock and position both sides of the substrate P at predetermined positions. To release the locking of the board P.

The position where the substrate 26 is locked by these stoppers 26 is defined as the origin of the X coordinate. The outer surface of the fixed rail 22 is defined as the origin of the Y coordinate.

Below the conveyor 21, a nozzle moving device 27 is provided.
Is provided. In the nozzle moving device 27, the nozzle moving guide rail 28 is parallel to the lower surface of the substrate P, and
The nozzle 29 is provided in a direction (Y-axis direction) that intersects at right angles to the conveyance direction (X-axis direction), and the nozzle 29 is reciprocally movable along the nozzle movement guide rail 28.

The nozzle 29 is a two-fluid spray nozzle for pulverizing and atomizing the flux by atomizing air as a gas for atomizing the flux, and is located upward from the upward orifice as shown in FIG. The atomizing flux f1 is sprayed on the lower surface of the substrate P using atomizing air, or only the flux liquid f2 is jetted without using the atomizing air.

As shown in FIG. 2, the mounting structure of the nozzle 29 is such that a nozzle vertical movement cylinder 31 as an actuator is mounted on a bracket 30 which is moved in the Y-axis direction by a nozzle moving device 27. 31
A nozzle 29 is attached to the tip of the piston rod 32, and the nozzle vertically moving cylinder 31 moves the nozzle 29 in a vertical direction perpendicular to the X-axis direction and the Y-axis direction. That is, the cylinder 31 for vertically moving the nozzle is
This is an actuator that moves and adjusts the nozzle 29 in the direction closer to the flux application surface.

The nozzle moving device 27 is driven by a nozzle feed mechanism 34 such as a feed screw driven by a nozzle reciprocating motor 33 serving as a nozzle reciprocating driving unit provided at one end of a nozzle moving guide rail 28. Reciprocate.

The nozzle reciprocating motor 33 is a pulse motor. The nozzle reciprocating motor 33 is provided with a nozzle encoder 35 for detecting the number of pulses corresponding to the operation amount, that is, the rotation amount. The moving distance of the nozzle 29 can be measured from the number of detected pulses of the encoder 35, and the reciprocating speed of the nozzle 29 can be measured from the number of detected pulses per unit time.

A flux supply means 36 for supplying a flux having a set flow rate to the nozzle 29 is provided, and a gas for supplying a gas for flux atomization having a set flow rate to the nozzle 29 is provided. Supply means 37 is provided.

The flux supply means 36 is driven by a pump driving motor 41 to supply a fixed amount of the flux F in the flux storage tank 42 at a set flow rate according to the rotation speed. It is connected to the.

The pump driving motor 41 is a pump driving means for driving the flux supply pump 44, and can adjust the motor rotation speed by an external control signal. It is also a flux flow rate adjusting means for variably controlling the rotation speed of the nozzle and variably adjusting the set flow rate of the flux supplied to the nozzle 29.

The gas supply means 37 adjusts a set flow rate of the atomizing air supplied from a pneumatic pressure source 46 as a gas supply source via a pressure gauge 46a for measuring its original pressure and a pneumatic pressure source valve 46b. An atomizing air flow rate adjusting device 48 is connected to the nozzle 29 by an air supply pipe 49.

In the atomizing air flow rate adjusting device 48, a plurality of orifices 51 having different opening areas so as to obtain different flow rates with respect to the same air pressure are connected in parallel with each other. On the other hand, a plurality of on / off type, ie, opening / closing type valves 52 are connected in series.

Each valve 52 controls the set flow rate of the fluid by a combination of the orifices 51 selected by the opening operation.
An electromagnetic valve having a solenoid and a return spring for electrically turning on and off each of these valve elements.

The atomizing air flow control device 48 includes a nozzle
An arbitrary valve 52 is selectively opened / closed by an on / off digital signal in accordance with an air setting flow value required in 29, and atomizing air is formed by a combination of an orifice 51 selected by the valve 52 that has been opened. Is controlled, and the particle diameter state of the atomization flux f1 is controlled.

The conveyor encoder 25 and the nozzle encoder 35 are connected to an input section of an arithmetic control section 53 as a control section.

The arithmetic control unit 53 has a central processing unit (CPU), a memory (ROM, RAM) and the like, and has a data input unit 54 such as a touch panel for inputting operation commands or data. The output unit of the control unit 53 is connected with the conveyor driving motor 24, the nozzle reciprocating motor 33, the pump driving motor 41, and the on / off valve 52, respectively.

The arithmetic control unit 53 is a control unit that controls the flux application from the nozzle 29 under a specific flux application condition for each location where the nozzle 29 is positioned on the plane coordinates of the substrate P.

That is, the arithmetic and control unit 53 controls the number of pulses of the conveyor driving motor 24 to control the X-axis coordinate of the nozzle 29 and controls the number of pulses of the nozzle reciprocating motor 33 to control the number of pulses of the nozzle 29. The Y axis coordinate is controlled, and the rotation speed of the pump driving motor 41 is controlled in conjunction with the X axis coordinate and the Y axis coordinate to control the flux supply pump 44.
By controlling the rotation speed of the flux setting flow rate supplied from the flux storage tank 42 to the nozzle 29 is controlled,
The set flow rate of the atomizing air is controlled by controlling the number of on / off type valves 52 in the open state of the atomizing air flow rate adjusting device 48.

The conveyor 21 for transporting the substrate P and the nozzle moving device 27 for moving the nozzle 29 in a direction intersecting with the direction of transport of the substrate P by the conveyor 21 include a nozzle at an arbitrary position in the plane coordinates of the substrate P. A nozzle coordinate mechanism 55 for positioning the nozzle 29 is formed.

That is, the conveyor 21 moves the substrate P in the X-axis direction, and the nozzle moving device 27 moves the nozzle 29 in the Y-axis direction to position the nozzle 29 at an arbitrary position in the plane coordinates of the substrate P. I do.

A nozzle coordinate mechanism (not shown) that moves only one of the nozzle 29 and the substrate P in the X-axis direction and the Y-axis direction may be used.

Next, the operation of the flux coating device shown in FIGS. 1 and 2 will be described.

The user operates the data input unit 54 before operating the apparatus.
Thus, the X coordinate of the substrate transfer direction by the conveyor 21 with the origin position at the tip end position of the substrate P, the Y coordinate of the nozzle movement direction by the nozzle moving device 27, and the flux application condition Z of how to spray are defined by the flux. Enter the required number of points corresponding to the application location.

Each time the nozzle 29 is relatively moved to a preset coordinate position of the substrate P, the nozzle 29 is moved from the nozzle 29 under the specific flux application condition Z for each coordinate position.
Apply flux.

The flux application conditions Z include Za1, Z
State parameters such as a2, Zb1, and Zb2 are used in combination.

For example, the state parameter Za1 is determined by the nozzle 29
Is a parameter for ejecting the flux while moving the set distance in the Y-axis direction at the set speed, and the state parameter Za2 is a parameter for stopping the predetermined position for a predetermined time and ejecting the flux while waiting for the movement. Parameter.

The state parameter Zb1 is a parameter for spraying the atomizing flux f1 at a predetermined flow rate of the atomizing air adjusted by opening and closing the valve 52 of the atomizing air flow rate adjusting device 48. This is a parameter related to the particle size state (coarse or fine) of f1.

Further, the state parameter Zb2 is determined by using the nozzle vertical movement cylinder 31 shown in FIG. 2 without using the atomizing flux f1 for applying the flux having a narrow application range.
The nozzle 29 is brought closer to the substrate P, and all the valves 52 of the atomizing air flow rate adjusting device 48 are closed to reduce the flow rate of the atomizing air to zero, so that only the flux liquid f2 is jetted from the nozzle. This is a parameter for performing flux application with the flux liquid f2.

These state parameters Za1, Za2, Zb
The conditions Z1, Z2, Z3... Created for each flux application location by combining 1, Zb2, etc. are input from the data input unit 54.

As a form of data input, a data file created by a terminal device such as another personal computer may be transferred to a recording medium such as a floppy disk or a network such as a LAN for data input.

When the data input is completed, an operation command is input to the data input unit 54 or the arithmetic control unit 53. Thus, the conveyor driving motor 24 for transporting the substrate P operates.

When a board detection sensor (not shown) at a fixed position detects that the board P has been loaded into the conveyor 21, the arithmetic control unit 53 determines the relative positional relationship between the board P and the nozzle 29 for the conveyor. It can be grasped by the encoder 25 and the nozzle encoder 35.

When the flux-coated portion of the substrate P reaches the position of the coordinate X1 from the origin where the substrate positioning stopper 26 is located, the conveyor driving motor 24 stops, and the nozzle reciprocating motor 33 When the nozzle 29 moves in the Y-axis direction by the driven nozzle feed mechanism 34 and moves to the position of the coordinate Y1, the nozzle reciprocating motor 33
Stops, and the nozzle 29 also stops at that position.

At these coordinates (X1, Y1), the flux application sequence operation by spraying or jet flow is performed under the first condition Z1 combined with the above-mentioned state parameters Za1, Za2, Zb1, Zb2 and the like.

At this time, the number of rotations of the pump driving motor 41 of the flux supply pump 44 is controlled to supply a required flux flow rate from the flux storage tank 42 to the nozzle 29, and the particle size state of the atomized flux f1 is controlled. For this purpose, the necessary air flow for atomization is supplied to the nozzle 29 by the air flow adjusting device 48 for atomization.

After the operation under the first condition Z1 is completed, the nozzle 29 moves to the position of the preset coordinates (X1, Y2), and the flux application operation is performed under the second condition Z2.

When the control at the last set coordinates (Xn, Ym) is performed in this way, the flux application is completed.

As described above, conventionally, the flux is uniformly applied to the substrate. However, in the present method and apparatus, the position of the transfer substrate in the X direction is controlled.
By adjusting the position of the nozzle 29 in the Y direction and applying the flux under the application condition Z, that is, for each part of the substrate, the necessary flux flow rate and air flow rate and the required application method are selected and set. By doing so, it is possible to apply a required amount of flux only to a necessary place, it is possible to apply flux without waste, and a high-quality substrate manufacturing process can be realized.

For example, it is possible to apply a flux only to the land portion of the printed wiring board, and it is suitable for a fluxless method which is being promoted from the viewpoint of environmental protection.

The present flux applying method and apparatus are desirably used in a local soldering pretreatment step of soldering a part of a substrate through a local nozzle or a mask.

[0065]

According to the first aspect of the present invention, the nozzle is relatively moved with respect to a predetermined coordinate position of the plate to be coated, and supplied from the nozzle under a specific flux application condition for each coordinate position. Since the required flux is applied to the plate to be applied, the required amount of flux can be applied only to the necessary places by appropriate methods, preventing unnecessary flux application, realizing a high quality substrate manufacturing process, and The cleaning liquid required for cleaning after attaching can also be minimized, and the environmental problem of the cleaning liquid can be dealt with.

According to the second aspect of the present invention, by spraying the atomized flux from the nozzle, the flux can be uniformly applied to a relatively wide flux application area of the plate to be coated, and only the flux liquid is jetted from the nozzle. By doing so, it is possible to appropriately apply the flux to the narrow flux application range of the plate to be applied.

According to the third aspect of the present invention, the control unit controls the flux application from the nozzle under the specific flux application condition for each location where the nozzle is positioned in cooperation with the nozzle coordinate mechanism. The required amount and the required application method are selected for each part, and the required amount of flux can be appropriately applied only to the required location, thereby preventing unnecessary flux application.

According to the fourth aspect of the present invention, the coating distance of the plate to be coated by the conveyor and the moving distance of the nozzle by the nozzle moving device in a direction intersecting the conveying direction of the conveyor are combined. The nozzle can be easily positioned at a predetermined plane coordinate of the plate.

According to the fifth aspect of the present invention, the applied plate can be positioned with high accuracy by the stopper provided on the conveyor, and the flux can be applied to an accurate location.

According to the sixth aspect of the present invention, it is possible to cope with flux application with a narrow application range by bringing the nozzle closer to the plate to be applied by the actuator.

[Brief description of the drawings]

FIG. 1 is a plan view and a circuit diagram showing an embodiment of a flux coating device according to the present invention.

FIG. 2 is a front view showing a nozzle portion of the coating apparatus.

FIG. 3 is a plan view showing a conventional flux coating device.

[Explanation of symbols]

 P Substrate as a substrate to be coated F Flux 21 Conveyor 26 Stopper 27 Nozzle moving device 29 Nozzle 31 Cylinder for vertical movement of nozzle as actuator 53 Arithmetic control unit as control unit 55 Nozzle coordinate mechanism

Continued on the front page (72) Inventor Hidekazu Imai 591-11, Kamihirose, Oaza, Sayama-shi, Saitama F-term in Tamura FA System Co., Ltd. 4F035 AA04 CB13 CD02 CD03 CD05 CD18 CD19 5E319 CD22

Claims (6)

[Claims] A nozzle is relatively moved with respect to a predetermined coordinate position of a plate to be coated with a flux, and a flux supplied from the nozzle is coated with a flux applying condition specific to each coordinate position. A flux coating method characterized by coating on a plate. 2. The flux application according to claim 1, wherein the flux supply from the nozzle to the plate to be coated is selected from a case where the flux is sprayed from the nozzle and a case where the flux is jetted from the same nozzle. Method. 3. A nozzle provided to face a plate to be coated with a flux and receiving a supply of a flux, and at least one of the nozzle and the plate to be coated is moved to an arbitrary position on the plane coordinates of the plate to be coated. A nozzle coordinate mechanism for positioning the nozzles, and a control unit for controlling the flux application from the nozzles in a unique flux application condition for each location where the nozzle is positioned in conjunction with the nozzle coordinate mechanism. Flux coating equipment. 4. A nozzle coordinate mechanism comprising: a conveyor for conveying a plate to be coated; and a nozzle moving device for moving a nozzle in a direction intersecting the direction of conveyance of the plate by the conveyor. The flux coating device according to claim 3. 5. The flux coating apparatus according to claim 4, further comprising a stopper provided on the conveyor for locking and positioning the plate to be coated. 6. The flux coating apparatus according to claim 3, further comprising an actuator for moving a nozzle in a direction far from or near a flux application surface of the plate to be coated.