JPS63111695A - Method and apparatus for soldering multileaded electronic component - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention Technical Field The present invention relates to a method and apparatus for soldering a multi-lead electronic component such as a flat package which is a surface mount device (SMD). By skillfully utilizing capillary action, multi-lead electronic components that could previously only be soldered by hand can be soldered perfectly and extremely efficiently on one side without any bridge formation or poor solder adhesion. The present invention relates to an innovative soldering method and apparatus that allows soldering of all leads in one operation, either manually or automatically.

Conventional technology Conventionally, among various electronic components that are soldered to terminals on conductive circuits mounted on a printed wiring board, in a dual-in-package (DIP), the leads extend vertically in a line from both sides of the package. Therefore, each lead can be inserted into the through-hole provided on the board and the leads can be automatically soldered to the terminals on the bottom surface of the board using a normal dip-type solder bath or jet-type solder bath. Ta.

However, in a flat package, which is an example of a surface mount component, the leads come out in rows from each of the four sides of the package, and are only bent in a step-like manner, and each lead must be soldered on the bottom of the package. It extends horizontally at approximately the same height. For this reason, it is impossible to solder through through holes, and there is no place for the flux gas generated during automatic soldering to escape, and even in reflow soldering, if the amount of cream solder applied is too small, the solder will stick. This resulted in defects, and if too much cream solder was applied, bridging occurred frequently, making automatic soldering extremely difficult. In particular, recently the lead pitch of flat packages is 1.0.0.8.0.65.0.
．． As the number of fins gradually decreases to 5, the actual problem is that when the pitch becomes less than 0.65n+, conventional automatic soldering methods produce too many bridges, making it impossible to solder, making it difficult to solder by hand by skilled workers. Moreover, each lead must be soldered one by one using a tapered soldering iron, which not only significantly lowers work efficiency but also causes eye and nerve fatigue for the worker, making it difficult to solder. had drawbacks such as a high defect rate.

Purpose The present invention has been made in order to eliminate the drawbacks of the prior art described above, and its purpose is to provide a flat package, etc., which is held upward and in a substantially horizontal position together with a substrate, as in the prior art. Instead of applying a soldering iron from above the leads of a multi-lead electronic component and allowing the solder attached to the soldering iron to adhere to the gap between the lead and the terminal component on the board by its own weight, it is By placing a soldering iron on the side of the angled lead, a phenomenon in which molten solder flows back and forth between the soldering iron and the lead due to capillary action and the interaction of the molten solder's own weight is created, and the multi-lead electron If the component requires soldering, place the fixed board at a steep angle to the horizontal plane so that the leads are on the bottom, and if there is molten solder on the soldering iron, remove the soldering iron. Touch the tip of the soldering iron to the lead and heat it, and use capillary action to suck the molten solder into the gap between the bottom of the soldering iron and the surface of the terminal on the board and make it adhere. After that, while removing the soldering iron from the lead, the excess solder that has adhered to the lead due to the weight of the molten solder is returned to the soldering iron and removed from the lead, so that only the appropriate amount of solder is always attached to the lead. The purpose of soldering is to ensure that the solder adheres to the terminal to avoid solder adhesion defects and bridge formation.
Furthermore, this makes it possible to perform perfect automatic soldering even for multi-lead electronic components with a pitch of 0.65W or less, thereby dramatically improving production efficiency. Another purpose is that when cream solder is applied to the leads of a multi-lead electronic component, a soldering iron is brought into contact with the leads to heat the leads and melt the cream solder. By sucking the solder into the gap between the surface of the terminal and the surface of the terminal by capillary action, and then removing it from the lead by removing the soldering iron from the lead, the excess solder adhering to the lead is allowed to adhere to the soldering iron and removed from the lead. Similarly, an appropriate amount of cream solder adheres to the leads and solder terminals, allowing perfect and highly efficient automatic soldering with no solder adhesion defects or bridge formation.

Yet another purpose is to form an overhanging downward slope at the tip of the soldering iron, and cover the area other than the tip with a coating that does not adhere to solder, so that only the tip can be completely wetted with molten solder over its entire surface. In addition, when a soldering iron comes into contact with a lead, the molten solder flows upward due to capillary action very smoothly. The goal is to be able to absorb it.

Another purpose is to set the width of the tip of the soldering iron to a value that is equal to or greater than the collective width of the leads on one side of a multi-lead electronic component. The purpose is to enable soldering during work.

Still another object is to configure a work table on which a board mounted with multi-lead electronic components is fixed so that its inclination angle and rotational position are variable, thereby reducing the distance between the work table and the soldering iron. It is possible to arbitrarily control the movement of molten solder so that an appropriate amount of solder always adheres to the leads and solder terminals. Another object of the present invention is to rotate a multi-lead electronic component by 90 degrees with respect to a soldering iron so that the leads on all four sides can be easily soldered. Still another object is to provide a plurality of actuating devices and a control device for controlling these actuating devices, so that the soldering iron can be automatically moved horizontally, vertically, and toward or away from the substrate, respectively. With this configuration, it is possible to automatically solder even a plurality of multi-lead electronic components fixed to a board, thereby greatly improving work efficiency.

Configuration In short, the method of the present invention (specific invention) fixes a multi-lead electronic component to a board, and the board is tilted at a steep angle with respect to a horizontal plane with the leads facing downward when soldering the multi-lead electronic component. A heated soldering iron with an overhanging downward slope formed at the tip and molten solder attached only to the downward slope is brought close, and the tip of the soldering iron is brought into contact with the lead. The solder attached to the soldering iron is sucked into the gap between the bottom of the lead and the surface of the soldering terminal on the board by capillary action, and then the solder is heated. While detaching the soldering iron from the lead, remove excess solder adhering to the lead with the soldering iron, and soldering the lead to the soldering terminal of the board with an appropriate amount of solder. It is characterized by:

In addition, the method of the present invention (second invention) fixes a multi-lead electronic component to a board, and when soldering the multi-lead electronic component, the board is tilted at a steep angle with respect to a horizontal plane so that the leads are on the lower side. Apply cream solder to the leads required for soldering, bring a heated soldering iron with an overhang-like downward slope formed at the tip, and apply the soldering iron to the soldering iron. The cream solder attached to the lead is melted by contacting the lead and the solder on the board is sucked into the gap between the bottom surface of the lead and the surface of the terminal by capillary action. After that, while removing the soldering iron from the lead, remove the excess solder from the lead by using the soldering iron, and solder the lead to the board with an appropriate amount of solder. It is characterized by being soldered to the terminal.

The apparatus of the present invention (third invention) further includes a work table for mounting a substrate whose tilt angle and rotational position are variable, and a first actuator for changing the tilt angle and rotational position of the work table. and a soldering iron having an appropriate width and an overhanging downward sloping surface formed at the tip, and the other portions being covered with a film to which solder does not adhere so that the solder adheres only to the downward sloping surface. a second actuator that moves the soldering iron horizontally; a third actuator that moves the soldering iron vertically; and a multi-lead actuator that moves the soldering iron on a board fixed to the work table. The present invention is characterized by comprising a fourth actuating device that moves the electronic component toward or away from the electronic component, and a control device that controls these actuating devices.

The present invention will be explained below based on embodiments shown in the drawings. In order to enable high-quality and highly efficient soldering of multi-lead electronic components with very small lead pitches, the inventor of the present application
After many years of research, we have finally succeeded in developing the best soldering method.

Conventionally, as described above, a multi-lead electronic component is placed in a substantially horizontal or slightly inclined state together with a board, and a soldering iron is placed above the leads, and the leads are soldered by the weight of the molten solder from the soldering iron. Soldering on the bottom and the board was done by pouring molten solder into the gap between the surface of the terminal. However, with this method, if the amount of molten solder was too small, In order to avoid the disadvantages of poor solder adhesion and excessive solder, bridges are bound to occur and solder adheres to adjacent leads, there is also a way to easily remove this excess solder. As a result, it was not possible to increase the efficiency or automate the soldering of multi-lead electronic components.

In contrast, the inventor of the present invention has discovered that it is possible to perfectly solder the leads of a multi-lead electronic component using a theory that is completely different from the conventional soldering method described above. When soldering multi-lead electronic components, place the board at a steep angle to the horizontal plane with the leads facing down, and approach the soldering iron only from the side of the lead. The molten solder attached to the tip of the lead can be instantly raised and sucked between the bottom of the lead and the surface of the terminal by capillary action, and the excess solder is returned to the soldering iron by its own weight. They discovered that it was possible to completely remove bridges and the like.

The present invention utilizes the surface tension and capillary phenomenon that act on molten solder discovered by the inventor of the present invention to allow molten solder to freely flow between the soldering iron and the lead and soldering terminal. A method has been developed for perfect soldering of multi-lead electronic components.

First, a method for soldering a multi-lead electronic component according to a specific invention will be explained with reference to FIGS. 1 to 9. First, as shown in FIG. 1, the multi-lead electronic component 1 is fixed to the board 2 by gluing or temporarily soldering a part of the leads 3, and the board is attached to the part of the multi-lead electronic component 1 that requires soldering. 3
The angle of inclination, for example, the angle of inclination θ, is set to be 60° or more, preferably about 70°, with respect to the horizontal plane so that the angle of inclination is on the lower side. In this case, there is always a slight gap C (exaggerated and wide in the drawing for illustrative purposes) between the bottom surface 3a of the lead 3 and the soldered surface 4a of the terminal 4 on the board 2. It turns out.

Then, an overhanging downwardly inclined surface 5b is formed at the tip 5a, and a heated soldering iron 5 with an amount of molten solder 6 attached to it that can be soldered several times is brought close to only this downwardly inclined surface, and the soldering iron 5 is brought close to the tip 5a. The steeply inclined surface 5C of the tip 5a of the iron is brought into contact with the tip 3b or the intermediate portion of the reed 3 to heat the reed.

This soldering iron 5 is arranged in a manner shown in FIGS. 6 to 8 so that solder adheres only to the overhanging downwardly inclined surface 5b of the tip 5a.
As shown in the figure, all other surfaces are coated with a coating 8 made of aluminum or the like to which solder does not adhere. Further, the downwardly inclined surface 5b has an angle β of 60° or more with respect to the horizontal plane, for example,
It preferably consists of a steeply sloped surface 5C formed at an angle of about 70°, and a gently sloped surface 5d formed below the steeply sloped surface continuously at an angle α of about 45° with respect to the horizontal plane. As shown in FIG. 9, the molten solder 6 adheres to the steeply sloped surface 5C to the extent that it simply wets the surface, and the molten solder 6 hangs on the surface of the gently sloped surface 5d in an amount that can be soldered several times. It is configured to adhere and accumulate under tension. In addition, the width of the soldering iron 5 is the width of one side of the multi-lead electronic component 1.
The soldering required for multi-lead electronic component 1 as shown in Fig. 4 is set to a value equal to or greater than the collective width of . .

As shown in FIG.
The lead is rapidly heated by contacting the tip 3b or the middle part of the lead, and the soldering temperature is reached by heating for about 1 second. Then, as shown in FIGS. 2 and 5, the molten solder 6 that had previously adhered to the downwardly inclined surface 5b of the soldering iron 5 is now connected to the bottom surface 3a of the lead 3 and the surface 4a of the terminal 4. It rapidly rises towards the gap C due to capillary action. Then, a portion 3 of the molten solder 6 that was attached to the soldering iron 5 for one batch and the solder adhere to the terminal 4, and also sufficiently adhere to the side surface 3C and top surface 3d of the lead 3. The molten solder 6 is attached in such a way as to cover the entire surface.

In such a case, as shown in FIG. 5, if the weight of the molten solder 6 is W, the force that acts perpendicularly to the surface of the terminal 4 during soldering and generates a frictional force is W sin
θ, and the force with which the solder tends to slide downward along the surface 4a of the terminal 4 is W cos θ. Therefore, in order for the molten solder 6 to stay in the gap C due to surface tension,
The upward holding force acting on the molten solder is the force Wcosθ
must be balanced. This force is balanced at the inclination angle θ of approximately 70° at the position of the gap C because the gap is very small and the upward holding force is large. However, since the distance between the leads 3 is much larger than the gap C, the lead 3 The upward holding force that acts on the molten solder 6 attached between them is the force W cos
It becomes smaller than θ and slides onto the soldering iron 5, so no bridging occurs at all. Therefore, in order to remove the excess molten solder 6 from the leads 3 and solder terminals 4, the soldering iron 5 is removed from the leads 3, and the excess solder attached to the leads 3 is attached to the soldering iron 5. Just let it happen. Further, if the tip 5a of the soldering iron 5 is in contact with the middle part of the lead 3, it is preferable to remove the soldering iron 5 while lowering it along the lead 3. In this case, the excess molten solder 6 is pulled back to the soldering iron 5 by the force of the tip 5a of the soldering iron 5 trying to tear off the molten solder 6 connected from the tip to the gap C, and by the weight of the molten solder 6. Become.

By this phenomenon of the molten solder 6 flowing back and forth between the soldering iron 5 and the leads 3, the leads 3 can be perfectly soldered to the terminals 4 with just the right amount of solder 6, and the excess No solder bridge was formed and 10
0% complete soldering can be performed.

In addition, since the width of the soldering iron 5 is set on the collective width plate of the leads 3 of the multi-lead electronic component 1, soldering as described above can be done only once, and one piece of glue of the multi-lead electronic component 1 can be soldered. Soldering can be completed for all parts 3. Further, by supplying solder to the soldering iron 5 once, it is possible to perform the same soldering several times.

Next, the soldering method of the second invention will be explained with reference to FIGS. 1θ to 13. First, as shown in Figure 10,
The multi-lead electronic component 1 is fixed to a board 2, and the board is tilted at a steep angle, for example, at an angle θ of 60 degrees, with respect to a horizontal plane, with the soldering part 3 of the multi-lead electronic component 1 facing downward.
As described above, cream solder 9 is applied to the part 3 to be soldered, preferably set at about 706, and the downwardly inclined surface 5b has an overhanging shape on the tip 5a as in the above-mentioned specific invention.
As shown in FIG. 11, the soldering iron in a heated state where a 1
This heating is completed in seconds, melting the cream solder 9 adhering to the leads 3, and causing the solder on the bottom surface 3a of the leads 3 and the solder on the board 2 to be sucked into the gap C between the bottom surface 3a of the leads 3 and the surface 4a of the terminal 4 by capillary action. to attach it. The mechanical relationship in this case is exactly the same as the case shown in FIG. Excess solder 6 adhering to the lead 3 is removed by adhering it to a soldering iron 5 while being separated from the lead 3, and the lead 3 is soldered to the soldering terminal 4 of the board 2 with an appropriate amount of solder 6. In this case, the excess solder 6 is removed from the downwardly inclined surface 5b of the tip 5a of the soldering iron 5.
It adheres to the surface as shown in FIG.

When performing the next operation, if the amount of adhesion is large, the solder 6 may be removed from the soldering iron 5 by an appropriate means. In this way, the cream solder 9 is applied to the leads 3 of the multi-lead electronic component 1 before soldering work, while the soldering iron 5 is simply brought into contact with the leads 3 in a heated state by the method of the second invention. You can also perform perfect soldering.

Next, an apparatus 11 for soldering multi-lead electronic components according to the third invention will be explained with reference to FIG.

A device 11 for soldering multi-lead electronic components includes a work table 12, a first actuating device 21, a soldering iron 5, and a second soldering iron 5.
The actuating device 22, the third actuating device 23, the fourth actuating device 24, and the control device 13 are provided.

The work table 12 has a variable inclination angle θ and a variable rotational position, and fixes the board 2 by an appropriate method as shown in the figure, and performs soldering of the multi-lead electronic component 1 fixed on the board. It is configured so that soldering can be performed with a soldering iron 5 with the attached part 3 always facing downward.

The first actuating device 21 is configured to change the inclination angle θ and rotational direction position of the work table 12, that is, the substrate 2, and for example, the sprocket 21 of the pulse motor M1.
Wrap the toothed belt 21b around the belt l-21b.
is wound around a sprocket 21C provided behind the work table 12, so that the work table 12 can be rotated as appropriate. θ can also be changed by the pulse motor M. The soldering iron 5 has an appropriate width, has an overhanging downwardly inclined surface 5b formed at its tip 5a, and is covered with a coating 8 to which no solder adheres so that the solder 6 adheres only to the downwardly inclined surface. covered,
Since the explanations regarding these are the same as those explained in FIGS. 6 to 8, they will be omitted.

The second actuating device 22 is configured to move the soldering iron 5 in the horizontal direction, and is, for example, a pulse motor M2.
A toothed belt 22b is attached to the sprocket 22a.
, the toothed belt is wound around another sprocket 22C, and a horizontal moving table 14 is attached to a part of the toothed belt, and the horizontal moving table is guided in the horizontal direction by two guide rods 15, Both ends of the guide rod are fixed to a pair of vertically movable tables 16. The vertically movable table 16 is guided by a guide rod 18 so as to be movable in the vertical direction.

The third actuating device 23 is configured to move the soldering iron 5 in the vertical direction, and is, for example, a pulse motor M3.
A toothed belt 23b is wound around the sprocket 23a, and the toothed belt is wound around another sprocket 23c, and a vertically moving table 16 is attached to a part of the toothed belt 23b. The soldering iron 5 is configured to be able to be moved in the vertical direction together with the horizontal moving table 14.

The fourth actuating device 24 moves the soldering iron 5 onto the work table 1.
For example, an air cylinder 19 is used, and a soldering iron 5 is attached to a piston rod 19a of the multi-lead electronic component 1 fixed on a board 2. Fix the piston rod 1
The reciprocating movement of the soldering iron 9a allows the soldering iron 5 to approach and move away from the leads 3 of the multi-lead electronic component 1.

Note that this fourth actuating device 24 is also not limited to the air cylinder 19, and can of course be replaced with a pulse motor (not shown) or the like. A solder supply device 20 is disposed on the right side of the soldering iron 5 in the figure, and a flux supply device 25 having a nozzle 25a and a brush 25b is disposed above the soldering iron 5.

The control device 13 is composed of, for example, a microcomputer, and includes air cylinders 19 of a first actuating device 21, a second actuating device 22, a third actuating device 23, and a fourth actuating device 24. A solenoid valve (not shown) is connected, and all these actuators are controlled by a specific program to control the four-side part 3 of the multi-lead electronic component 1.
Also, a plurality of multi-lead electronic components 1 fixed to various parts of the board 2 can be automatically soldered.

Function The present invention is constructed as described above, and its function will be explained below. In the method of the specific invention shown in FIGS. 1 to 4, molten solder 6 is attached to a steeply sloped surface 5C and a gently sloped surface 5d formed at the tip 5a of the soldering iron 5,
The molten solder is simply applied to the steeply sloped surface 5C to the extent that it is wetted, and the molten solder 6 in an amount necessary for several solderings is attached to the gently sloped surface 5d in a hanging state as shown in FIG. Using such a soldering iron 5, the tip 3a or the middle of the lead 3 of the multi-lead electronic component 1 is set and arranged at a steep angle with respect to the horizontal plane so that the soldering part 3 is on the lower side. By contacting and heating the molten solder 6 on the soldering iron 5, heating of the lead 3 is completed in just about 1 second, and instantaneously, the bottom surface 3a of the lead 3 and the solder are bonded together by capillary action. It is sucked up by the gap C between it and the surface 4a of the terminal 4, and rises to the upper surface 3d of the lead 3.
The molten solder 6 adheres to the leads 3 and the terminals 4 while wrapping the leads 3 and the side surfaces 3c, and by separating the soldering iron 5 from the leads 3, all excess molten solder 6 is removed by the soldering iron. It will return to 5.

Furthermore, the adhesion force of the molten solder 6 to the leads 3 and the soldering terminals 4 is determined by the inclination angle θ of the multi-lead electronic component 1 or the board 2 with respect to the horizontal plane. Therefore, by changing the inclination angle θ, the molten solder 6 can be freely soldered. It is possible to move the soldering iron 5 back and forth between the soldering iron 5 and the gap C, and the amount of solder deposited is also very easy to control, allowing perfect soldering to be performed.

Therefore, according to the method of the specific invention, it is possible to perform automatic soldering even when the pitch of some parts 3 is 0.65 m or less, which was previously considered impossible, and moreover, the width of the soldering iron 5 has a large number of leads. Since the width is set to be equal to or greater than the collective width of the leads 3 of the electronic component 1, one soldering process is enough to complete the soldering of all parts 3 of one side of the multi-lead electronic component 1. Can be done. Therefore lead 3 on all sides
It is possible to complete soldering of the multi-lead electronic component 1 with the exposed parts in four steps. If necessary, the width of the soldering iron 5 can be made to match the width of one part 3 to solder each lead one by one, or to correct defective soldering such as bridges. is also possible.

Next, in the method of the second invention, since the cream solder 9 is already attached to the soldering part 3, there is no need to attach the molten solder 6 to the soldering iron 5, and the soldering iron 5 is simply heated. Place the soldering iron on the tip 3 of the lead 3 as shown in Figure 11.
Just by contacting the terminal b or the intermediate part, the cream solder 9 melts and becomes molten solder 6, and due to capillary action, the lead 3 and solder are similarly sucked into the gap C between the terminal 4 and wrap the lead 3 there. By removing the soldering iron 5 from the lead 3, the excess solder is removed from the 12th lead.
As shown in the figure, good soldering with no excess or deficiency is achieved on each soldering iron 5, and as a result, there is no formation of bridges or poor solder adhesion. becomes.

Next, soldering of multi-lead electronic components shown in Fig. 14 is carried out using the device 1.
The effect of No. 1 will be explained. The operator fixes the board 2 on which the multi-lead electronic component 1 is fixed by adhesive or temporary soldering to the work table 12, turns on the power to the soldering iron 5, and operates the solder supply device 20 and flux application device 25. Then, the brush 25b formed at the tip of the nozzle 25a applies flux to the soldering pad 3, and the solder supply device 20 causes the required amount of molten solder 6 to adhere to the downwardly inclined surface 5b of the soldering iron 5. . All of these are automatically controlled by the control device 13.

When the application of flux and the supply of solder 6 have been completed in this way and the soldering iron 5 has been heated to a predetermined temperature, the first actuating device 21 is configured to control the direction of rotation and tilt of the work table 12. The work table is fixed by setting the angle θ to a predetermined value. Then, the second actuating device 22 and the third actuating device 23 move the horizontal moving table 14 and the vertical moving table 16 left and right and up and down, respectively, to change the position of the soldering iron 5 relative to the soldering board 3. Then, the fourth actuating device 24 is activated to move the soldering iron 5 forward, and the tip 5 of the soldering iron 5 is moved forward.
a comes into contact with the lead 3 and soldering is performed using capillary action in the same way as in the method described above, and then the fourth actuating device 24 moves the soldering iron 5 backward to separate it from the lead 3, thereby removing the excess soldering iron 5. All the solder is removed from the lead 3 and an appropriate amount of solder 6 is applied to the lead 3 and soldered to the terminal 4.
perfect soldering is done automatically. All the parts from the first actuating device 21 to the fourth actuating device 24 are automatically controlled by the control device 13.
The soldering process is completed.

When the soldering of the required soldering part 3 on one side of the multi-lead electronic component 1 is completed in this way, the first actuating device 21 is activated to rotate the work table 12 by 90 degrees and move the soldering part 3 on the other side. Soldering is performed on the soldering portion 3, and such soldering operations are repeated one after another to complete soldering on the leads 3 on the four sides of one multi-lead electronic component 1.

Then, the soldering iron 5 is moved to the position of another multi-lead electronic component 1 fixed on the board 2 by the operation of each actuator, and the same operation is automatically performed, and the soldering iron 5 is moved to the position of another multi-lead electronic component 1 fixed on the board 2. Soldering is performed on a plurality of multi-lead electronic components 1. Note that the operation of soldering itself is the same as that explained in the specific invention and the second invention, so the explanation thereof will be omitted.

Effects The present invention has the advantage of applying a soldering iron from above the leads of a multi-lead electronic component such as a flat package that is held with a board in an upward and substantially horizontal state as in the past, and removing the solder attached to the soldering iron from the leads. Soldering on the board is not simply done by its own weight in the gap between the terminals, but rather by placing the soldering iron on the side of the steeply sloped leads as shown above. This causes a movement of molten solder due to the interaction of capillarity and the weight of the molten solder.
When soldering multi-lead electronic components, place the fixed board at a steep angle with respect to the horizontal plane so that the leads are on the bottom, and if molten solder is attached to the soldering iron,
Bringing the tip of the soldering iron into contact with the lead and heating it,
To solder the solder on the board and the bottom of the lead from the soldering iron, the molten solder is sucked into the gap between the bottom surface of the terminal and the surface of the terminal by capillary action, and then the soldering iron is removed from the lead. Excess solder that adhered to the leads due to the solder's own weight was returned to the soldering iron and removed from the leads, ensuring that only the appropriate amount of solder adhered to the leads and terminals at all times, thereby preventing poor solder adhesion. The revolutionary effect of completely eliminating the formation of bridges is obtained.
Further, as a result, perfect automatic soldering is possible even for multi-lead electronic components with a pitch of 0.651 m or less, which has the effect of dramatically improving production efficiency.

In addition, when cream solder is applied to the leads of multi-lead electronic components, a soldering iron is brought into contact with the tip of the lead to heat the lead and melt the cream solder. The soldering iron is sucked into the gap between the lead and attached by capillary action, and then the soldering iron is removed from the lead, and the excess solder attached to the lead is allowed to adhere to the soldering iron and removed from the lead.
Similarly, an appropriate amount of cream solder adheres to the leads and the solder terminals, making it possible to perform perfect and highly efficient automatic soldering with no solder adhesion defects or bridge formation.

Furthermore, an overhanging downward sloping surface is formed at the tip of the soldering iron, and the area other than the tip is covered with a film that does not adhere to solder, so that only the tip is completely wet with molten solder. Furthermore, the molten solder accumulates at the bottom of the slope in a hanging state due to moderate surface tension, and as a result, when the soldering iron comes into contact with the lead, the molten solder is drawn upwards by capillary action very smoothly. . In addition, the width of the tip of the soldering iron is set to a value that is equal to or greater than the collective width of the leads on one side of a multi-lead electronic component, making it possible, for example, to solder all the leads on one side of a flat package in one operation. effective.

Furthermore, the work table on which the board mounted with multi-lead electronic components is fixed is configured so that its inclination angle and rotational position are variable, so that the flow of molten solder between it and a part of the soldering iron is reduced. This allows the phenomenon to be controlled arbitrarily, and has the effect of ensuring that an appropriate amount of solder always adheres to the leads and solder terminals. Furthermore, since the multi-lead electronic component can be rotated by 90 degrees with respect to the soldering iron, it is possible to easily solder the leads on all four sides. Furthermore, a plurality of actuating devices and a control device for controlling these actuating devices are provided, and the soldering iron is configured to be able to automatically move horizontally, vertically, and toward or away from the substrate, respectively. Therefore, it is possible to automatically solder a plurality of multi-lead electronic components fixed to the board, and it is possible to achieve the effect of greatly improving work efficiency.

[Brief explanation of the drawing]

Figures 1 to 9 relate to embodiments of the specific invention, and Figure 1 is a partial vertical cross-section showing a state before a soldering iron with molten solder comes into contact with a multi-lead electronic component fixed to a board. 2 is a partial longitudinal sectional view showing the state in which the soldering iron contacts the lead from the state shown in FIG. 1 and molten solder is sucked up to the lead by capillary action; 4 is a partial vertical cross-sectional view showing a state in which soldering has been completed with the wire detached from the lead; FIG. 4 is a front view of the structure shown in FIG.
Figure 5 is an enlarged vertical cross-sectional view of a portion of the soldering iron showing that the molten solder adhered to the soldering iron is sucked up into the gap between the lead and the solder terminal due to capillary action, and Figure 6 is an enlarged partial view of the soldering iron. A perspective view, FIG. 7 is a partially enlarged vertical sectional view of the soldering iron,
Figure 8 is a right side view of the thing shown in Figure 7, and Figure 9 is a partially enlarged side view showing the state of molten solder hanging down on the steeply sloped surface and gently sloped surface formed at the tip of the soldering iron. , FIG. 10 to FIG. 13 relate to an embodiment of the second invention, FIG. 10 is a partial vertical sectional view similar to FIG. 1, and FIG.
12 is a partial longitudinal sectional view similar to that shown in FIG. 3, FIG. 13 is a front view taken along the xm arrow in FIG. 10, and FIG. FIG. 2 is a perspective view of the device. 1 is a multi-lead electronic component, 2 is a board, 3 is a lead, 3a is a bottom surface, 3b is a tip, 4 is a terminal for soldering, 4a is a surface, 5
1 is a soldering iron, 5a is a tip, 5b is a downwardly sloped surface, 5c is a steeply sloped surface, 5d is a gently sloped surface, 6 is molten solder, 8 is a coating that does not adhere to solder, 9 is cream solder, 11 is a multi-lead electronic A device is used for soldering parts, 12 is a work table, 13 is a control device, 21 is a first actuating device, 22 is a second actuating device, 23 is a third actuating device, 24 is a fourth actuating device, C
is the gap between the bottom surface of the lead and the surface of the soldered terminal, and θ is the inclination angle of the board, multi-lead electronic component, or work table. Figure 6 and Figure 8 Figure 7 Figure 10 Figure 12 Figure 6]b Figure 11 5I Figure 13 Procedural amendment (voluntary) 1.44 p O$ 16 Meno 9βCr (l i2,
Title of the invention Method and apparatus for soldering multi-lead electronic components 3 Relationship with the case of the person making the amendment Patent applicant 4, agent Address: 193 Telephone (0426) (24)
) 1137 Address: 98, 1-33 Hatachi, Motohachioji-cho, Hachioji-shi, Tokyo Contents of amendment: The drawings in this application are amended in the attached document.

Claims (1)

[Scope of Claims] 1. A multi-lead electronic component is fixed to a board, and the board is set and arranged at a steep angle with respect to a horizontal plane so that the soldering leads of the multi-lead electronic component are on the lower side, A heated soldering iron with an overhanging downward slope formed at the tip and molten solder adhered only to the downward slope is brought close, and the tip of the soldering iron is brought into contact with the lead to remove the lead. The solder attached to the soldering iron is sucked into the gap between the bottom surface of the lead and the surface of the soldering terminal on the board by capillary action and adhered thereto, and then the soldering iron is attached to the soldering iron. A multi-lead electronic device characterized in that while removing the lead from the lead, excess solder adhering to the lead is removed by adhering to the soldering iron, and the lead is soldered to the soldering terminal of the board with an appropriate amount of solder. How to solder parts. 2. Fix the multi-lead electronic component to a board, place the board at a steep angle with respect to a horizontal plane so that the soldering leads of the multi-lead electronic component are on the lower side, and attach the soldering leads to the multi-lead electronic component. Applying cream solder, bringing a heated soldering iron with an overhanging downward slope formed at the tip and bringing the tip of the soldering iron into contact with the lead to heat the lead, The cream solder adhering to the lead is melted and is sucked into the gap between the bottom surface of the lead and the surface of the soldering terminal on the board by capillary action, and then adhered to the lead. A multi-lead electronic component characterized in that surplus solder adhering to the leads is removed by adhering to the soldering iron while the leads are separated from the lead, and the leads are soldered to the soldering terminals of the board with an appropriate amount of solder. How to solder. 3. A work table for mounting a board having a variable inclination angle and rotational position, a first actuating device for changing the inclination angle and rotational position of the worktable, and a A soldering iron is formed with an overhanging downward slope, and the other parts are covered with a film that does not adhere to solder so that solder adheres only to the downward slope, and a soldering iron that moves the soldering iron horizontally a third actuating device for moving the soldering iron in the vertical direction; 1. A soldering device for multi-lead electronic components, characterized by comprising a fourth actuating device for movement and a control device for controlling these actuating devices. 4. The downwardly inclined surface at the tip of the soldering iron has a steeply inclined surface formed at an angle of approximately 70° with respect to the horizontal surface, and a steeply sloped surface formed at an angle of approximately 45° with respect to the horizontal surface continuously below the steeply sloped surface. 4. The soldering device for multi-lead electronic components according to claim 3, characterized in that the soldering device comprises a gently sloped surface formed at an angle. 5. The multi-lead device according to claim 3, wherein the width of the tip of the soldering iron is set to a value equal to or greater than the collective width of the leads on one side of the multi-lead electronic component. Electronic component soldering equipment.