JP2500107B2 - Heating tool cleaning Local soldering device without loss of time - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering apparatus for surface-mounting electronic parts, and more particularly, when the parts are difficult to handle or mount using an automatic mounting machine and are collectively soldered using a reflow soldering apparatus. Parts that are significantly adversely affected by heat, such as TCXO (temper control crystal oscillator), TAB (tape automated bonding) -IC, LCD
The present invention relates to a local soldering device for an electronic component such as a flexible wiring board with a (liquid crystal display) having an ultrathin narrow-pitch lead and having a bending structure.

[0002]

2. Description of the Related Art Conventionally, this type of soldering has been performed by locally heating. There are two typical methods of local soldering: a constant heating method and an instantaneous heating method. Generally, by heating this with a heating tool, the generated conductive heat is applied to the objects to be soldered, and an alloy layer (intermetallic compound) that is strong in connection with the interface with the bonding metal is generated. But,
In any of these methods, an alloy layer that strengthens the connection cannot be obtained only by heating, and an intermediation called flux is indispensable.

In the soldering work, it is a general principle that flux is always applied to the soldering site. The purpose is to (1) reduce the surface tension of the solder and to wet the solder. Improve spread,
(2) The oxide on the surface of the metal to be soldered is dissolved and removed to make it clean. (3) The surface of the solder being heated is covered to prevent oxidation (also to prevent contact with air and oxidation).

Although the flux plays an important role as described above during the soldering process, it becomes a useless long product after the soldering work is completed. Further, since it also adheres to the heating tool, if the portion is left as it is without being cleaned, carbonization accelerates and adheres to the tip of the heating tool over time. In this case, heat conduction from the heating tool to the soldered object is greatly hindered,
Optimal soldering heating conditions (solder melting temperature, +40 to 50 ° C.) cannot be obtained at the soldering site. As a result, defective soldering frequently occurs due to insufficient heat, and this has a serious influence on the joint quality.

Conventionally, in order to solve such a problem, the work is temporarily interrupted at a certain time interval, and the carbide generated at the soldering tip portion of the heating tool is cleaned and removed. Regardless of whether the cleaning means is manual or automatic, the flux carbide formed at the tip of the tool is removed using sandpaper, a steel brush, or a knife-shaped special tool.

Further, as an automatic soldering apparatus equipped with a cleaning means, there is one disclosed in Japanese Utility Model Laid-Open No. 2-38166. According to this publication, when cleaning the heating tool, the heating tool is moved from the soldering position to a point where the cleaning means is present, then the heating tool is cleaned, and the cleaning tool is cleaned after the cleaning is completed. It is designed to be returned to the soldering position again.

[0007]

In the above-mentioned conventional method for cleaning and removing carbides in the local soldering apparatus, the original soldering work must be interrupted for cleaning each time. In particular, in an automatic soldering device (for example, Japanese Utility Model Laid-Open No. 2-38166) that performs cleaning after moving the heating tool to a predetermined cleaning point, a large loss occurs in working time. Furthermore, since the cleaning is performed only for the time set in advance by the timer, there is also a drawback that the cleaning action ends there when the time is up even if the carbide cannot be removed well within the time. Also, as the heating tool material, a material such as molybdenum that does not cause thermal deformation and does not adhere to solder is usually used.
There is a fatal drawback that it is worn away by mechanical brushing cleaning such as a metal brush.

Particularly, in the cleaning means for rotating the heating tool or rotating the cleaning unit, the centrifugal separation action works from the center of rotation toward the outside, so that the degree of wear of the tool becomes large. Due to this wear, the heating tool cannot adhere closely to the objects to be soldered, the conduction heat is not sufficiently transmitted during crimping, part of the soldering part is not melted, and the joint strength is insufficient due to this, which causes serious soldering. It causes quality defects.

Similarly, in the manual cleaning action, since the cleaning state greatly varies and lacks compatibility, the same problem as described above occurs.

An object of the present invention is to eliminate the above-mentioned conventional drawbacks, and to efficiently remove flux carbides while moving a work (board) to a soldering work position without generating loss time. It is an object of the present invention to provide a local soldering device in which heating tool cleaning loss time does not occur.

[0011]

A local soldering apparatus of the present invention in which heating tool cleaning loss time does not occur is a heating method for heating a work (board) to be soldered and a soldering portion of a soldered object. A tool; first moving means for reciprocally moving a work table on which the work (substrate) and the object to be soldered are positioned and mounted in a predetermined region including the heating tool; Second moving means for moving in a direction in which the heating tool is moved toward and away from the bonded object; a cleaning unit mounted on the workbench to clean the tip of the heating tool; setting soldering conditions for the heating tool; A control unit for controlling an operation; the first moving means moves from a first position, which is a starting point of the work table, to a second position where soldering work is performed. The tip of the heating tool is cleaned by the cleaning unit during the forward movement of the work table and twice during the backward movement of the work table from the second position to the first position after the completion of the soldering work. It is configured to do.

[0012]

Next, the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view of a local soldering apparatus according to an embodiment of the present invention, FIG. 2 is an enlarged perspective view showing a cleaning unit in this embodiment, and FIG. 3 is a workbench and a heating tool in this embodiment. A plan view showing a relative positional relationship of (fixed),
4 and 5 are flowcharts showing the operation of this embodiment.

The local soldering apparatus of this embodiment solders the soldered article 23 to the work (substrate) 28, and is roughly divided into the following four units.

That is, (1) work (board) positioning and conveying system unit, (2) heating tool and its descending / ascending system unit, (3) heating tool cleaning system unit, (4) soldering condition setting and operation control system A unit.

(1) The work (substrate) positioning and conveying system unit is a unit for reciprocating the work (substrate) 28 and the article to be soldered 23 in a predetermined region, and reciprocating means constituted on the base plate 1. Consists of. Two guide rails 2, 3 laid on the base plate 1
And a movable table 6 with a handle 29 mounted on the guide rails 2 and 3 and horizontally reciprocally movable by guide rollers 4 and 5 in an area including a heating tool 15 described later, and the movable table 6. Two workbench positioning pins 9 mounted on the top and diagonally facing each other, positioned by the guide holes thereof, and a workbench 10 with a handle mounted detachably with one touch, and mounted on the workbench 10. And an arbitrary number of work (substrate) positioning pins 11. The moving table 6 has a starting position (A) that abuts the starting point position stopper 7 and a soldering work position (B) that abuts the work position stopper 8 shown in FIG.
And reciprocally move between and as shown by arrow F. The heating tool 15 is held and fixed between the positions (A) and (B). The work (substrate) 28 and the object to be soldered 23
Is positioned and fixed at an arbitrary position by a work positioning pin 11 on the workbench 10. Workpiece positioning pin 1
1 is fixed to an arbitrary position on the workbench 10 with an adhesive or the like, and the position can be freely changed.

(2) The heating tool and its descending / ascending system unit hold the heating tool 15 for heating the article to be soldered 23, and the direction in which the tool is brought into contact with and separated from the article to be soldered 23, in this embodiment. Is a means for moving in the vertical direction, and four guide posts 1 are provided on the base plate 1.
As the ascending / descending means attached to the guide plate 13 provided with the guide plates 13 and 14 and the heating tool 15 installed upright at 2 so as to cover the moving path of the transport system unit of (1) from above. Slide bearing 16,
The heating tool 1 is attached to the slide bearing 16 on the movable side of 17.
5 is fixed and held, and an air cylinder 18 for vertically moving the slide bearing 16 to move the heating tool 15 toward and away from the work table 10 is provided on the guide plate 14. That is, the heating tool 15 is provided at a position corresponding to the soldering work position (B) and does not move in the horizontal direction indicated by the arrow F in FIG. 3 but only moves up and down. The main body of the heating tool 15 is made of stainless steel, and in order to prevent wear, the tip chip 15a is made of a carbonized sintered alloy (superhard metal) which has excellent wear resistance and whose hardness does not drop even at high temperatures. The tip 15a is screwed and fixed so that it can be freely attached to and detached from the tool body.

(3) The heating tool cleaning system unit is for cleaning and removing flux carbides generated and attached to the soldering portion of the tip 15a of the heating tool 15 by brushing, and as shown in FIG. A cleaning unit 19 mounted on an end of the workbench 10 in the direction of the heating tool 15, a brass brush 20 as a cleaning means incorporated in the cleaning unit 19, a position adjusting means and an abrasion dimension adjusting means. To be done. The position adjusting means is used in the horizontal direction of the movable table 6 and the workbench 10 (see FIG.
When moving in the direction of arrow F), the cleaning unit position adjusting screw 21a is loosened to adjust the relative position so that the brass brush 20 is on the moving path corresponding to the heating tool 15, and on the workbench 10. The mounting position of the cleaning unit 19 is adjusted in the direction of arrow G in FIG. Further, the wear dimension adjusting means loosens the height adjusting screw 21b so that the contact state between the brass brush 20 worn by mechanical brushing cleaning and the tip 15a of the heating tool is almost constant at all times, and the height adjusting screw 21b is loosened. The height is indicated by the arrow H in Fig. 2.
It is to adjust in the direction. In this embodiment, the brass material of the brass brush 20 has a diameter of 0.15 per brush.
mm, which is extremely thin and soft, is used to minimize damage to the tip chip 15a of the opponent.

(4) The soldering condition setting and operation control system unit is configured to set the descending pressure bonding pressure of the heating tool 15 to the work (substrate) 28 and the object to be soldered 23, the soldering contact time, and the soldering temperature. And the control unit 22 for controlling the operation of each unit system of (1) to (3) described above. The control unit 22 is provided with a temperature controller 24, a timer controller 25, an air pressure controller 26, a solderable temperature reaching display lamp 27, a soldering work end buzzer 31, a power switch 32, an air stopper 33 and a work position confirmation lamp 34. Has been. An operation start button 30 and an emergency stop switch 35 are provided on the base plate 1.

In the local soldering apparatus of the present embodiment having the above-mentioned structure, as shown in FIG. 3, the moving table 6 and the workbench 10 on which the work (substrate) 28 and the article to be soldered 23 are mounted and set. A moving table 6 is provided between the starting position (A) and the soldering work position (B).
And when the workbench 10 reciprocates as indicated by arrow F,
The brushing cleaning of the tip 15a of the heating tool by the cleaning unit 19 is performed twice, the forward path and the return path, without causing a special cleaning loss time such as temporarily interrupting the work for cleaning.

The operation of this embodiment will be described below with reference to the flow charts of FIGS.

After the power is turned on by the power switch 32 (step S1, the following steps are omitted) and the air for the air cylinder 18 is turned on by the air plug 33 (S2), the soldering conditions are set (S3). As the soldering conditions, the saturation point temperature of the heating tool 15 and the contact pressure and contact time with the soldered article 23 are set in advance by the control unit 22. That is, the saturation point temperature of the heating tool 15 is set to the temperature controller 24 in the unit so that the heating temperature of the cartridge heater incorporated in the heating tool 15 becomes +40 to 50 ° C., which is the melting temperature of the solder of the soldered article 23. Set by. Similarly, the contact time is set by the timer controller 25 in the unit. Further, as the downward pressure, the air pressure of the air cylinder 18 is set by the air pressure controller 26 in the unit.

When the power of the apparatus is turned on, the heating tool 15 starts heating (S4), and after reaching the set temperature, the solderable temperature reached display lamp 27 is turned on (S5), and the temperature range where soldering can be performed is reached. Tell what you have done. This temperature is constantly maintained and controlled by the temperature controller 24. The workbench 10 on the moving table 6 stands by at a position in contact with the start-point stopper 7, and the worker stands on the workbench 1
The work (substrate) 28 and the article to be soldered 23 are set on the work positioning pin 11 on 0 (S6, S7), and flux is applied to the soldering site with a writing pen (S8). After that, the workbench 10 is manually moved by the handle 29 of the moving table 6, the guide rollers 4, 5 and the guide rails 2, 3 of the moving means until it hits the soldering position, that is, the work position stopper 8 (S9).

During the course of this forward movement, the brass brush 20 in the cleaning unit 19 attached to the tip portion of the workbench 10 shown in FIG. 2 removes the flux residue, the carbide, etc. attached to the bottom surface of the tip 15a of the heating tool 15. The brushing is removed (S10). This brass brush 20 is closely and linearly planted, and the heating tool 15 is positionally positioned.
The cleaning unit 19 is adjusted in the arrow G direction by the cleaning unit position adjusting screw 21a so that the cleaning unit 19 comes to the movement path corresponding to the tip 15a of the above. Further, by moving the brass brush height adjusting screw 21b in the direction of the arrow H, it is possible to appropriately adjust the amount of wear due to brushing.

When the moving table 6 hits the working position stopper 8 (S11), the soldering preparation completion lamp 34
Lights up (S12). If it does not light, the heating tool 15 does not descend because the preparation is not completed. After that, by pressing the operation start button 30 (S13), the air cylinder 18 for vertical movement of the heating tool 15 is operated (S1).
4) The soldering timer is activated, the heating tool 15 is lowered by the slide bearings 16 and 17 which are the descending means (S15), and the soldering object 23 is pressure-bonded at a preset pressure and time by the conduction heat. Soldering is performed (S16).

After the time is up (S17), the air cylinder 18 for vertical movement is operated to raise the heating tool 15 and stop at the top dead center (S18), and then the buzzer 13 for finishing the soldering work is sounded. Handle 2 of moving table 6
At 9, the work table 10 is pulled back by the guide rollers 4 and 5 and the guide rails 2 and 3 of the moving means until it abuts on the starting point position stopper 7 (S19). The brass brush 2 in the cleaning unit 19 is in the middle of this returning and returning movement.
0 again brushes and cleans the flux adhered to the bottom surface soldering portion of the tip 15a of the heating tool 15 before solidifying (S20). When the workbench 10 hits the starting point position stopper 7 (S21), one cycle of work is completed, and the work (substrate) 28 is removed from the work positioning pin 11 (S22).

The apparatus of this embodiment is premised on that the soldering position of the work (substrate) 28 basically does not greatly change with respect to the position of the heating tool 15. Therefore, when changing the work from the first work (board) to the second work (board) or changing the soldering position, the work table 10 itself is detached from the moving table 6 with one touch, and the second work (board) is removed. The workbench for) is set on the moving table 6 in the above-mentioned manner to deal with it.

The tip 15a of the heating tool 15 is also used.
There are various shapes and variations of the heating tool 15
It can be freely replaced depending on the mounting condition of the workpiece and the influence of surrounding parts.
Further, since the tip 15a is made of a super hard metal, it has very high wear resistance and can be used semipermanently. On the other hand, since the brass brush 20 is soft and is worn away by brushing, the distance between the tip 15a and the tip tip 15a, that is, the contact state, is appropriately adjusted by the brass brush height adjusting screw 21b as an abrasion size adjusting means.

[0029]

As described above, according to the present invention, the flux carbide and the residue thereof which are generated at the soldering portion of the heating tool and solidify and increase in the soldering work step of one cycle, immediately before the start of work and immediately after the end of work. For two times,
It can be cleaned and removed at an effective timing when it is not completely fixed.

Further, since this cleaning cleaning is carried out during the movement of the work (substrate), there is an effect that the loss time which is specially spent for this cleaning and impaired is not generated. Further, as for the wear of the heating tool due to the brushing, the material is changed to the super hard metal, so that the wear resistance is remarkably improved, and stable, high-quality and highly compatible soldering joints can be obtained.

[Brief description of drawings]

FIG. 1 is a perspective view of a local soldering apparatus according to an embodiment of the present invention.

FIG. 2 is an enlarged perspective view showing a cleaning unit according to an embodiment of the present invention.

FIG. 3 is a plan view showing a relative positional relationship between a workbench and a heating tool according to an embodiment of the present invention.

FIG. 4 is a flowchart showing the operation of the embodiment of the present invention.

FIG. 5 is a flowchart showing the operation of one embodiment of the present invention.

[Explanation of symbols]

 1 Base Plate 2, 3 Guide Rail 4, 5 Guide Roller 6 Moving Table 7 Starting Point Position Stopper 8 Working Position Stopper 9 Working Platform Positioning Pin 10 Working Platform 11 Work (Substrate) Positioning Pin 12 Guide Post 13, 14 Guide Plate 15 Heating Tool 15a Tip tip 16,17 Slide bearing 18 Air cylinder 19 Cleaning unit 20 Brass brush 21a Cleaning unit position adjusting screw 21b Brass brush height adjusting screw 22 Control unit 23 Soldered joint 24 Temperature controller 25 Timer controller 26 Air pressure controller 27 Soldering Possible temperature indicator lamp 28 Work (board) 29 Handle 30 Operation start button 31 Finishing soldering work Buzzer 32 Power switch 33 Air stopper 34 Ready for work Pump 35 emergency stop switch

Claims (7)

(57) [Claims] 1. A heating tool for heating a work (board) to be soldered and a soldering portion of a product to be soldered; a work table on which the work (board) and the product to be soldered are positioned and mounted. A first moving means for reciprocating in a predetermined area including the heating tool; a second moving means for holding the heating tool and moving it in a direction in which the heating tool is moved toward and away from the object to be soldered; A cleaning unit mounted on the work table for cleaning the tip of the tool; and a control unit for setting soldering conditions and controlling the operation of the heating tool;
Moving means to move the work table from the first position, which is the starting point of the work table, to the second position where the soldering work is performed, and the second position after the completion of the soldering work.
The cleaning tool is configured to clean the tip of the heating tool twice during the return path for moving the work table from the position to the first position. No heating tool cleaning loss time occurs. Local soldering equipment. 2. The local soldering apparatus according to claim 1, wherein the workbench is removably mounted on a moving table constituting the first moving means via a guide member. 3. The local soldering device according to claim 1, wherein the second moving means is configured to move a slide bearing holding the heating tool by an air cylinder. 4. The local soldering device according to claim 1, wherein the cleaning means in the cleaning unit is brushing cleaning with a brass brush. 5. The heating tool cleaning loss time-free local according to claim 1, wherein the relative position of the cleaning unit with respect to the heating tool and the spacing of the tip of the heating tool can be adjusted freely. Soldering equipment. 6. The local soldering apparatus according to claim 1, wherein the material of the tip of the heating tool is a carbonized sintered alloy (carbide metal). 7. The local soldering device according to claim 1, wherein the tip of the heating tool is detachably fixed to the main body of the heating tool.