JP2938328B2 - Soldering method and apparatus - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of soldering a wiring board by transporting the wiring board in a direction opposite to the direction of flow of the laminar solder and bringing the laminar solder into contact with the wiring board. It concerns the device.

[0002]

2. Description of the Related Art A conventional apparatus for performing soldering by bringing a laminar flow solder into contact with a wiring board will be described. In the following, the following seven publications will be used for the description of the related art.

The technology disclosed in Japanese Patent Application Laid-Open No. 55-16725 (known as Known Example 1) The technology described in Japanese Patent Publication No. 5-55228 (known as Known Example 2) The technology described in Japanese Utility Model Publication No. 4-42058 (known as Known Example 3) Japanese Patent Publication No. 58-56048 (known as a known example 4) Japanese Patent Application Laid-Open No. 63-80961 (known as a known example 5) Japanese Patent Publication No. 36-8713 (known as a known example 6) Japanese Utility Model Publication No. 56-3101 For example, the technique disclosed in Japanese Unexamined Patent Application Publication No. H11-115,086 can obtain a laminar flow of molten solder having a high surface flatness, and can increase the flow velocity. Therefore, the solder sufficiently flows into the minute and minute portions, and solder spots such as an unsoldered portion and a shortage of the solder amount are hardly generated. Also, the separation property of the solder is improved, and a bridging phenomenon and an icing phenomenon are hardly generated. There are advantages.

Further, the techniques of the prior arts 2 and 3 lose the above-mentioned advantages because the molten solder rises and the surface flow velocity is significantly reduced at a portion where the laminar flow of the molten solder comes into contact. It is a technology that reduces this.

[0005] That is, this is a technique in which a part of the laminar flow of the molten solder overflows from the side wall plate to reduce the swelling phenomenon of the molten solder and decrease in the surface flow velocity. Furthermore, the direction, angle and height of the opening control plate and the flat plate-like portion and the side wall plate of the channel-like flow passage which form the outlet for the molten solder,
It is a technique for adjusting the thickness of the molten solder to obtain the desired thickness and flow rate of the laminar flow.

The technique of the fourth prior art is a technique for increasing the thickness (height) of the jet solder wave while preventing the surface shape of the jet solder wave from being disturbed, and protrudes from the soldering surface of the wiring board. This is a technique in which restrictions on the lengths of terminals and lead wires of mounted electronic components are relaxed.

In other words, this is a technique in which "a jet portion for raising the solder wave high and a jet portion for generating the one-sided flow are separately provided to form a high-current one-sided flow as a whole". Next, the technique of the well-known example 5 will be described with reference to FIGS.

FIG. 9 (a) is a side sectional view, wherein 1 is a solder bath, in which a molten solder introduction passage 2 is provided, and a nozzle 3 is provided in communication therewith. It is ejected by a pump 4 composed of rotating blades. A curved portion 3 a is formed at the upper end of the nozzle 3. The waveformer 5 is formed by forming a lower waveformer member 5a at the lower end of the curved portion 3a, an upper waveformer member 5b at the upper portion, and a side wall plate 5c. In addition, a bypass passage 6 is provided on the rear side of the nozzle 3, and an opening 6 a is formed at a tip end. Also, P
Is a printed board.

[0009] FIG. 9 (b) in the side sectional view showing another example, the same reference numerals as FIG. 9 (a) shows the same parts, 7, 7a
Is an introduction passage, 8 is a nozzle, and 9 is a pump.

This technique is intended to achieve both the increase in the height (thickness) of the laminar flow of the molten solder and the increase in the speed of the laminar flow. The increase in the height of the laminar flow is the same as the reason disclosed in the conventional example 4, and
The purpose of increasing the speed of laminar flow is to ease the restrictions on the length of terminals and lead wires of mounted electronic components protruding from the soldering surface of the wiring board. It is to control. The technical principle is the same as that of the technique of the known example 4.

The technique of the known example 6 is designed to suppress the oxidation of the molten solder. An opening is provided in a part of a reflux pipe for refluxing the molten solder, and the flow is made higher than the opening. This is a technique of "soldering with molten solder." In other words, this is a technique in which the portion other than the opening is not in contact with the atmosphere.

The technique of the prior art 7 is a technique for suppressing soldering unevenness such as a solder bridge phenomenon and a non-solder phenomenon of a minute / fine part. In other words, on the "guide that guides the molten solder substantially horizontally", "a plurality of long wave-making projections having the same height are formed continuously" and "perpendicular to the flow of the solder", thereby forming the molten solder. A wave is formed in the laminar flow of the above to suppress the soldering unevenness.

[0013]

However, the conventional technique has the following problems.

FIGS. 10 (a) to 10 (c) are diagrams for explaining the problems of the prior art. FIG. 10 (a) is a sectional side view of a main part of the known example 1, and FIG. FIG. 10C is a side view illustrating the solder swelling phenomenon, and FIG. 10C is a plan view illustrating the solder swelling phenomenon, as viewed from above in FIG. FIG. 10C also shows the techniques of the known examples 2 and 3.

That is, in the technique of the known example 1, FIG.
As shown in (a), in order to increase the flow rate of the laminar flow 11a of the molten solder 11 and enhance its effect, it is necessary to increase the inclination angle θ of the solder flow plate (the term used in the known example 1) 12. There is. However, as a result, the thickness d of the laminar flow 11a of the molten solder 11 is reduced, and the length of the terminal or lead wire of the mounted electronic component protruding from the soldering surface of the wiring board 13 transported in the direction of arrow A is reduced. If it is long,
There is a problem that the protruding portion comes into contact with the solder flow plate 12 so that the soldering operation cannot be performed.

Further, as shown in FIG. 10 (b), a portion where the wiring board 13 and the laminar flow 11a of the molten solder 11 come into contact with each other forms a raised portion 11b of the solder, and the solder flow velocity in this portion is significantly reduced. There is. That is, due to this phenomenon, this type of soldering apparatus has a problem in that soldering defects such as a solder bridge phenomenon, a glazing phenomenon, and a non-solder phenomenon are easily generated.

In the techniques of the known examples 2 and 3, a part of the laminar flow 11a of the molten solder 11 overflows from the side wall plate 14 as shown in FIG. The reduction of the surface flow velocity is reduced. On the other hand, the direction, angle, height, etc. of the opening control plate forming the outlet of the molten solder 11 and the flat plate-like portion and the side wall plate of the channel-like flow passage are adjusted to obtain the desired thickness and thickness of the laminar flow of the molten solder. I'm trying to get the flow velocity.

However, the basic technology is the same as that of the prior art 1, and the increase in the thickness d of the laminar flow of the molten solder, the increase in the flow velocity, and the elimination of the solder bulge cannot be basically achieved at the same time.

According to the techniques of the known examples 4 and 5, the thickness (height) of the laminar flow of the molten solder can be increased, but it is fundamentally realizable that the laminar flow speed is also increased at the same time. Difficult.

That is, as shown in FIGS. 9 (a) and 9 (b), the movement and flow state of the molten solder in the opening 6a, which is the confluence of the molten solder ejected upward and the molten solder flowing in the horizontal direction, are as follows. There is no kinetic vector (kinetic energy) to flow in the horizontal direction in the molten solder ejected upward, but it flows in the horizontal direction by being pushed by the kinetic vector (kinetic energy) of the molten solder flowing in the horizontal direction. The kinetic energy or kinetic vector is given.

Therefore, at the merging portion of the opening 6a, a part of the kinetic energy of the laminar flow of the molten solder flowing in the horizontal direction into the merging portion is a kinetic energy for causing the molten solder ejected upward to flow in the horizontal direction. And the velocity of the laminar flow decreases. This increases the thickness (height) of the laminar flow at the junction. In other words, it is theoretically difficult to achieve both an increase in the thickness (height) of the laminar flow and an increase in the speed of the laminar flow.

In addition, since the direction of movement of the molten solder changes discontinuously in accordance with the merging of the molten solder, the surface shape of the laminar flow is disturbed if a large increase in the thickness (height) of the laminar flow is taken. It will be easier. Further, since the chamber structure becomes complicated, the manufacturing operation of the apparatus is difficult, and the cleaning operation of unnecessary deposits in the chamber generated during operation of the apparatus is extremely difficult.

In the technique of the known example 6, when the flowing speed of the molten solder is increased, the molten solder overflows from the opening. That is, in this technique, it is necessary to adjust and control the annular flow rate of the molten solder so as not to break the equilibrium point at which the molten solder does not overflow from the opening. In addition, the limit of the height of the molten solder flowing from the opening to a higher position is affected by the shape of the opening, but is basically determined by the surface tension of the molten solder and the material of the reflux tube member and the molten solder. It is defined by the interfacial tension beyond which the molten solder cannot be elevated.

That is, it is impossible to increase the thickness of the laminar flow of the molten solder and increase the speed at the same time.

In the technique of the prior art 7, the laminar flow speed of the molten solder is reduced by the wave-forming projections.
Increasing the thickness of the laminar flow and increasing the velocity cannot be compatible.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and an object of the present invention is to increase the thickness and speed of a laminar flow of a molten solder on a solder flow plate and obtain the stability of its surface shape. Accordingly, an object of the present invention is to provide a soldering method and apparatus capable of realizing a highly reliable soldering process of a wiring board which does not cause soldering defects.

[0027]

SUMMARY OF THE INVENTION According to the present invention, a high flow velocity of a molten solder and a laminar flow having a large thickness are obtained by temporarily flowing a molten solder downward to increase its flow velocity and thereafter ascending upward. The feature is that both a stable laminar surface shape and a stable laminar flow surface shape are achieved.

Therefore, according to the first aspect of the present invention, the molten solder is blown out from the blowing port, and the molten solder flows downward in the first flow guide portion, and flows upward in the first flow guide portion. Afterwards, the molten solder is guided in a substantially horizontal direction by a flow guide plate in which a rising portion that flows downward again is formed sequentially to form a laminar flow of the molten solder, while a direction opposite to the direction in which the laminar flow of the molten solder flows Then, the wiring board is transported, and the molten solder flowing through the rising portion is brought into contact with the wiring board to perform soldering.

According to a second aspect of the present invention, the molten solder is blown out from the blow port, and the molten solder flows downward, the second flow guide part flowing in a substantially horizontal direction, and the upward flow. Afterwards, the molten solder is guided in a substantially horizontal direction by a flow guide plate in which a rising portion that flows downward again is formed sequentially, and a laminar flow of the molten solder is formed, while the laminar flow of the molten solder flows in the opposite direction. The wiring board is transported in the direction, and the wiring board is brought into contact with the molten solder flowing through the rising portion to perform soldering.

Further, according to the third aspect of the present invention, the molten solder is blown out from the blowout port, and the second flowing portion for guiding the molten solder obliquely downward and the ascending flow which flows upward again after climbing upward. Part is guided by a flow guide plate sequentially formed to form a laminar flow of the molten solder, and, on the other hand, transports the wiring board in a direction opposite to a direction in which the laminar flow of the molten solder flows, and rises with the wiring board. The soldering is performed by contacting the molten solder flowing through the portion.

According to a fourth aspect of the present invention, there is provided a flow guide plate for guiding a flow of the molten solder in a substantially horizontal direction to form a laminar flow. In this configuration, a flow guide plate of a descending portion flowing downward and a flow guide plate of a rising portion flowing upward again after flowing upward are sequentially formed.

Further, the invention according to claim 5 is provided with a guide fluid for guiding the flow of the molten solder in a substantially horizontal direction to form a laminar flow, and a descending portion through which the molten solder flows downward through the flow guide plate. , A flow guide plate of a flow guide portion flowing in a substantially horizontal direction, and a flow guide plate of a rising portion which flows upward and then flows downward again are sequentially formed.

Further, the invention according to claim 6 is provided with a fluid-guiding fluid for guiding the flow of the molten solder to form a laminar flow,
The fluid guide is disposed obliquely downward and the flow guide plate of the rising portion where the molten solder flows upward after flowing upward again is provided downstream of the fluid guide.

Further, the invention according to claim 7 is characterized in that the lowering portion
Conductive flow plate, and is formed on either stepped or sloped shape or smooth curved.

Further, the invention according to claim 8, the rising portion of the guide flow plate, and is formed on either angled or smooth curved.

Further, according to the ninth aspect of the present invention, the flow guide plates of the descending portion and the rising portion are formed in any one of an inclined shape and a smooth curved shape, and are further flat on the top of the flow guide plate of the rising portion. Part is formed.

According to a tenth aspect of the present invention, the flow guide plate at the rising portion is formed in either an inclined shape or a smooth curved shape, and a flat portion is formed at the top of the flow guide plate at the rising portion. It was done.

In the eleventh aspect of the present invention, the fluid guide is formed by a plurality of dividable flow guide plates, and the relative positional relationship between the divided flow guide plates is fixed so as to be adjustable. A fixing means is provided.

Furthermore, in the twelfth aspect of the present invention, there is provided a fixing means for fixing the opening height of the blow-off port for jetting the molten solder into the conductive fluid so as to be adjustable.

[0040]

According to the first and fourth aspects of the present invention, the molten solder flowing down the descending portion increases its flow velocity and flows into the rising portion. At this time, since the molten solder is pooled between the descending part and the ascending part, the thickness of the laminar flow does not decrease due to the increased flow velocity in the descending part. As a result, a thick laminar flow of the molten solder can be quickly formed at the rising portion.

In the second and fifth aspects of the present invention, a standing wave is generated in the horizontal portion between the descending portion and the rising portion as the molten solder descends and rises. This standing wave is generated in alignment, and its wavelength becomes longer as approaching the rising part.
When the wiring board comes into contact with the ascending portion, this standing wave is generated between the contact portion and the descending portion. As a result, the contact pressure of the molten solder due to the standing wave on the wiring board further increases.

In the third and sixth aspects of the present invention, the laminar flow velocity of the molten solder is increased by inclining the conductive fluid obliquely. Since the rising portion is provided on the downstream side of the fluid guide, both the thickness and the speed of the laminar flow of the molten solder flowing through the rising portion can be achieved. Since the entirety of the fluid guide portion disposed obliquely forms a descending portion and no descending portion is provided locally, almost no standing wave is generated.

Further, by selecting various shapes of the flow guide plate in the descending portion and the rising portion as in the invention according to claims 7 to 10, the shape of the laminar flow can be generated without breaking the basic shape. Can be adjusted.

If the descending portion has a stepped shape, the kinetic energy of the molten solder in the descending direction increases, and the amplitude of the standing wave can be increased. Conversely, the amplitude of the standing wave can be reduced by making the shape of a slope or a smooth curve. That is, this makes it possible to adjust the laminar flow velocity and the acting force of the standing wave.

[0045] When the ascending section shall be the leaning slant and smooth curved
The laminar flow of the molten solder flowing through the rise forms a relatively gentle rounded shape.

If a flat portion is formed on the top of the rising portion, the contact time between the laminar flow of the molten solder and the wiring board can be increased.

Further, according to the eleventh aspect of the present invention, since the flow guide plate is divided into a plurality of portions, it is easy to replace each portion and adjust the relative positional relationship.
The laminar flow shape can be easily adjusted.

In the twelfth aspect of the present invention, the thickness and amount of the laminar flow of the molten solder spouted from the spout can be adjusted by adjusting the opening height of the spout. become. That is, the laminar flow shape can be adjusted.

[0049]

【Example】

[First Embodiment] FIG. 1 is a side sectional view showing a first embodiment of a soldering apparatus for carrying out the soldering method of the present invention, FIG. 2 is a plan view showing a main part of FIG. 1, and FIG. FIG. 2 is an explanatory diagram showing an aspect of a flow of molten solder in FIG. 1.

In these figures, reference numeral 21 denotes a main part of the soldering apparatus, and reference numeral 22 denotes a wiring board,
Is conveyed in the direction of arrow A. 24 is a molten solder,
It is housed in a solder bath (not shown). Reference numeral 25 denotes a jet tank, which blows molten solder 24 by a pump (not shown) into a jet port 2.
Eject from 6. Reference numeral 27 denotes a flow guide plate, and flow guide plates 27A to 27A.
C. Then, the flow of the molten solder 24 ejected from the outlet 26 of the jet tank 25 is guided in a substantially horizontal direction by the flow guide plate 27A, and the arrow B in the direction opposite to the transport direction of the wiring board 22 is guided.
A laminar flow 24a flowing in the direction is formed. The flow guide plate 27A
Forms a first flow guide portion 28, a descending portion 29 in which the molten solder 24 flows downward at the boundary between the flow guide plates 27A and 27B, and a second flow guide portion 30 which flows in a substantially horizontal direction by the flow guide plate 27B.
And an ascending part 31 composed of a flow guide plate 27C, which is formed again after the molten solder 24 flows upward and flows downward again. Reference numeral 32 denotes a side wall plate.

Further, the wiring board 22 is transported in the direction of arrow A opposite to the direction of the laminar flow 24a of the molten solder 24 (direction of arrow B), and the molten solder 24 flowing through the wiring board 22 and the rising portion 31 And soldering.

As described above, the molten solder 24 flowing down the descending portion 29 increases its flow velocity and flows into the rising portion 31. At this time, since the molten solder 24 is pooled between the descending portion 29 and the rising portion 31, the thickness of the laminar flow 24a does not decrease due to the increased flow velocity in the descending portion 29. As a result, as shown in FIG. 3, a thick laminar flow 24a (thickness d ₁ ) of the molten solder 24 can be formed on the rising portion 31 quickly.

Further, between the descending portion 29 and the rising portion 31, the standing wave 24 b
Occurs. The standing waves 24 b are generated in alignment as illustrated in FIG. 2, and their wavelength becomes longer as approaching the rising part 31. That is, the flow rate of the molten solder 24 is further increased in the rising portion 31. When the wiring board 22 comes into contact with the rising portion 31, the standing wave 24 b having the phase velocity υ ₃ comes into contact with the soldering surface of the wiring board 22 and is reflected. As a result, the standing wave 2
4b further increases the contact pressure of the molten solder 24.

On the other hand, in FIG. 3, when the wiring board 22 comes into contact with the molten solder 24 of the rising portion 31, the molten solder 2
The flow velocity υ ₀ of 4 comes into contact with the wiring board 22 and flows away with υ ₁ in the horizontal direction and υ ₂ in the vertical direction. That is, the motion vector of the molten solder 24 pressed against the surface of the wiring board 22;
The motion vector flowing away along the surface of the wiring board 22 can be given to the soldering surface of the wiring board 22. Therefore, the solderability to the fine and minute portions is improved, and the separating property of the molten solder 24 is also improved. On the other hand, the molten solder 24 flowing down the descending portion 29 and having a height D ₂ is
It rises to a height D ₁ at elevated portion 31.

The portion where the laminar flow of the molten solder 24 contacts the wiring board 22 is the laminar flow 2 of the rising portion 31 having the height D _1.
4a at the top and in the vicinity thereof, the lower part 24c of FIG.
There is no swelling of the solder in the portion where is formed. That is, the laminar flow velocity does not decrease in the portion where the laminar flow 24a and the wiring board 22 are in contact.

As described above, a laminar flow of the thick molten solder 24 quickly and a laminar flow 24a generated so as to be inserted into the soldering surface of the wiring board 22 (flow velocity υ ₀ = υ ₁ + υ ₂ ) are obtained. A contact portion that does not cause solder swelling, that is, a contact portion that does not cause a decrease in laminar flow velocity, and an increase in the contact pressure of the molten solder 24 due to the standing wave 24b cause a long lead wire or the like. Can be applied to the wiring board 22 having a long length, and no unsoldered or solder-deficient portions are generated in fine and minute portions.
In addition, the solder bridge phenomenon and the glaring phenomenon do not occur. [Second Embodiment] A soldering device is formed by removing the second flow guide portion 30 between the descending portion 29 and the rising portion 31 shown in FIG. Is configured.
In this case, the same operation and effect as described above can be obtained. [Third Embodiment] FIG. 4 is a side sectional view showing a shape when the main part of FIG. 1 is formed so as to be adjustable. FIG. 5 is FIG.
It is a perspective view which shows the whole view of. In these figures, the same reference numerals as those in FIG. 1 indicate the same parts, that is, the molten solder 2 blown up from the chamber 41 by a pump (not shown).
4 is guided by the guide plate and blows out from the blow port 26. On the other hand, the fluid guide 27 is composed of three parts, that is, a flow guide plate 27A that forms the descending portion 29, a flow guide plate 27B that forms a substantially horizontal portion and a part of the rise portion 31, and a rise portion 31. Are formed in three parts of the flow guide plate 27C. These components are fixed by screws 44 through the elongated holes 43 so that the dimensions of the components can be easily adjusted and exchanged.

The molten solder ejected from the outlet 26 is guided by the flow guide plate 27A, and forms a target laminar flow 24a with a descending movement and an ascending movement.

Further, a guide plate 42 for forming the blowing port 26 is provided.
Is inserted into the chamber 41 through a slot (not shown) and the screw 44
And the height of the opening can be adjusted. That is, by adjusting the opening height and the sending power of the pump mechanism, it is possible to adjust the thickness, the speed, and the amount of the molten solder 24 ejected from the outlet 26.
As a result, the thickness and speed of the laminar flow 24a can also be adjusted.

Incidentally, the head of the descending part 29 is 1 to 10 m.
m is optimal, and if an extremely large step is provided, the
The standing wave 24b shown in FIG. On the other hand, if it is extremely small, the function of the descending portion 29 will be small, and a sufficient effect cannot be expected. The head of the rising part 31 may have a value equal to that of the falling part 29, but may be small. When it is extremely large, the laminar flow velocity of the molten solder 24 flowing through the rising portion 31 tends to decrease.

In FIG. 4, the flow guide plate 27B except for the descending portion 29 and the rising portion 31 is disposed so as to be substantially horizontal, but the molten solder 24 flows through the entire flow guide plate 27. It is also effective to adopt a configuration that is slightly inclined downward toward the downstream side. That is, the laminar flow velocity can be increased by the descending slope. In this case, it is possible to make the head of the rising part 31 larger than the head of the falling part 29 by the amount of the inclination, and to adjust the laminar flow 24a.
The range of selection can be widened. [Fourth Embodiment] FIG. 6 is a side sectional view showing a fourth embodiment of the present invention.

That is, in this embodiment, the conventional jet nozzle 51 is provided with the fluid guide 27 as a foam-forming plate of the molten solder 24. In this example, the fluid guide plate 27B is provided with a fluid guide 27 as the foam-forming plate of the molten solder 24. This is an example in which a flow plate 27C is attached, and the fluid guide 27 is an example of a two-part configuration.
That is, it is composed of two parts, a descending portion 29, a flow guiding plate 27B forming a part of the second flow guiding portion 30 and a part of the rising portion 31, and a flow guiding plate 27C forming the rising portion 31. It is fixed with screws 44.

In this configuration, the jet nozzle 51 of the conventional apparatus is used.
There are advantages that can be used. That is, it can be implemented by providing the guide fluid 42 and the guide plate 42 for guiding the molten solder 24 ejected from the jet nozzle 51 to the flow guide plate 27A side at the tip of the jet nozzle. The guide plate 42 is also fixed by screws 44 through the elongated holes. [Fifth Embodiment] FIG. 7 is a side sectional view showing a fifth embodiment of the present invention.

That is, in this example, instead of providing the descending portion 29 of FIG. 6, the flow guide plate 27B is disposed in the second flow guide portion 30 at an angle, and the molten solder 24 blown out from the blow port 26 is provided.
Of the laminar flow 24a is increased by this inclination,
In this configuration, the laminar flow is raised while increasing the thickness of the laminar flow in the concave portion immediately below / directly below, ie, the pool portion 24d, so that the laminar flow velocity can be secured. In this example, the standing wave 24b of FIG. 1 hardly occurs.

By the way, the flow guide plate 27B is composed of two parts, a downwardly inclined part, a part forming a part of the rising part 31, and a part forming the rising part 31.

FIG. 8 is a side view showing various modified shapes of the fluid guide 27 shown in FIG. 1. The basic shape is as shown in FIG. FIGS. 8A to 8E are diagrams illustrating deformation of the descending portion 29 and the rising portion 31. FIG.

In FIG. 1 showing the basic shape, a stepped lowering portion 29 and a smooth curved rising portion 31 are combined.

Next, FIG. 8A shows an example in which the rising surface of the rising portion 31 is formed in an inclined shape 61, FIG. 8B shows an example in which a flat portion 62 is formed on the top of the rising portion 31, and FIG. c) is the descending part 2
9 is formed in an inclined shape 63, and FIG.
Is formed in a smooth curved shape 64. FIG.
(E) is an example in which the descending portion 29 and the ascending portion 31 are continuously formed in a smoothly curved curved shape 65.

That is, the details of the laminar flow shape can be adjusted without changing the basic type of the laminar flow 24a by such variations. In the example of FIG. 8E, the standing wave 24b of FIG. 1 hardly occurs.

For example, if the descending portion 29 is formed in a stepped shape, the kinetic energy of the molten solder 24 in the descending direction increases, and the rate of increase of the laminar velocity and the amplitude of the standing wave 24b can be increased. Conversely, if the shape is a slope or a smooth curve, the amplitude of the standing wave 24b can be reduced without changing the rate of increase of the laminar velocity. That is, by these, the laminar velocity can be adjusted and the acting force of the standing wave 24b can be adjusted.

Of course, the magnitude of the head of the descending portion 29 affects the rate of increase of the laminar velocity and the amplitude of the standing wave 24b.

On the other hand, the rising portion 31 is formed into an inclined shape or a smooth curve.
In this case, the laminar flow 2 of the molten solder 24 flowing through the rising portion 31
4a forms a shape tinged relative to gentle rounded.
These shapes are selected according to the unevenness ratio of the soldering surface of the wiring board 22 even if the wiring board 22 has the same fine pitch (the area of the soldering land is small and the interval between the soldering lands is small). Good to do.

[0072] For example, when the wiring board surface mount mounting height of the electronic components are aligned small, that is, if irregularities ratio is smaller wiring board 22 selects the inclined or curved shape. That is, a relatively stable laminar flow can provide uniform solder wettability as compared with the case of the stepped shape.

If the flat portion 62 is formed on the top of the rising portion 31, the laminar flow 24a of the molten solder 24 and the wiring board 22
Contact time can be increased. This is for example
This is effective when the (statistical) deviation of the heat capacity of each electronic component mounted on the wiring board 22 is large. That is, when there is an electronic component having a solder terminal or a lead wire having a large deviation and a large heat capacity, a long contact time between the laminar flow 24a and the wiring board 22 provides a sufficient heating time for the component. That you can do
Therefore, good solder wettability can be obtained also in the component.

[0074]

As described above, according to the first aspect of the present invention, molten solder is blown out from a blow port.
The molten solder is guided in a substantially horizontal direction by a flow guide plate in which a descending portion in which the molten solder flows downward in the first flow guide portion and a rising portion in which the molten solder flows upward again after flowing upward are sequentially formed. A laminar flow of molten solder is formed, and on the other hand, the wiring board is transported in the direction opposite to the direction in which the laminar flow of the molten solder flows, and the wiring board is brought into contact with the molten solder flowing through the rising portion so that soldering is performed. Therefore, the molten solder is pooled between the descending portion and the ascending portion, so that the thickness of the laminar flow does not decrease due to the increased flow velocity in the descending portion. As a result, a thick laminar flow of the molten solder can be quickly formed at the rising portion. Solderability to fine and minute parts is improved, and separation of molten solder is also improved.

According to a second aspect of the present invention, the molten solder is blown out from the blowout port, and the molten solder flows downward, the second flow guide part flowing in a substantially horizontal direction, and the upward flow. Afterwards, the molten solder is guided in a substantially horizontal direction by a flow guide plate in which a rising portion that flows downward again is formed sequentially, and a laminar flow of the molten solder is formed, while the laminar flow of the molten solder flows in the opposite direction. The wiring board is conveyed in the direction, and the molten solder flowing in the rising portion is brought into contact with the wiring board to perform soldering, so that a standing wave is generated as the molten solder descends and rises, This standing wave further increases the contact pressure of the molten solder.

Further, according to the present invention, the molten solder is blown out from the blowing port, and the second flowing portion for guiding the molten solder obliquely downward and ascending upward and flowing again after flowing upward. The laminar flow of the molten solder is guided by the flow guide plate formed sequentially with the wiring board, and the wiring board is transported in a direction opposite to the direction in which the laminar flow of the molten solder flows, and the wiring board is lifted. Since the soldering is performed by contacting the molten solder flowing in the rising part, the molten solder is pooled immediately before the rising part, and the thickness and speed of the laminar flow of the molten solder flowing in the rising part are increased. Can be compatible.

The invention described in claim 4 can realize the soldering method according to the invention described in claim 1.

Further, the invention described in claim 5 can realize the soldering method according to the invention described in claim 2.

The invention according to claim 6 can realize the soldering method according to claim 3.

Further, according to the invention described in claim 7, the lowering portion
The flow guide plate is formed in any one of a stepped shape, an inclined shape, and a smooth curved shape. By selecting various shapes of the descending portion and the rising portion, the laminar flow can be performed without breaking the basic shape. Can be adjusted.

[0081] Further, the invention according to claim 8, since the rise of the guide flow plate formed either inclined slant or smooth curved, by selecting various shapes of the rising portion, the base It is possible to adjust the shape of the laminar flow without breaking the typical pattern.

According to the ninth aspect of the present invention, the flow guide plates of the descending portion and the rising portion are formed in an inclined shape or a smooth curved shape, and a flat portion is formed on the top of the rising portion. Compared to the average heat capacity of the electronic components mounted on the fine pitch wiring board, it is effective when there is an electronic component with solder terminals or lead wires having a large heat capacity by far, and even in such a portion, sufficient. Solder wettability can be obtained.

According to a tenth aspect of the present invention, the flow guide plate in the rising portion is formed in either an inclined shape or a smooth curved shape, and a flat portion is formed on the top of the flow guide plate in the rising portion. Therefore, compared to the average heat capacity of the electronic components mounted on the fine pitch wiring board, it is effective when there is an electronic component with solder terminals or lead wires that have a large heat capacity by far, and in that part, Thus, sufficient solder wettability can be obtained.

Further, in the invention according to the eleventh aspect, the fluid guide fluid is formed so as to be dividable, and a fixing means for adjusting the relative positional relationship between the divided flow guide plates is provided. Therefore, by adopting a configuration in which the fluid guiding fluid is divided into a plurality of parts, it is easy to exchange each part and adjust the relative positional relationship, and it is easy to adjust the laminar flow shape. That is, an optimum laminar flow can be formed with respect to wiring boards having different characteristics.

According to the twelfth aspect of the present invention, since the height of the opening for blowing the molten solder to the flow guide plate can be adjusted, the height of the opening of the blowing port can be adjusted.
The thickness and amount of the laminar flow of the molten solder ejected from the outlet can be adjusted. That is, the laminar flow shape can be adjusted.

As described above, according to the present invention, it is possible to solder a terminal of a mounted electronic component or a wiring board having a long protruding length of a lead wire on a soldering surface side. It has various advantages, such as realizing a highly reliable soldering process of a wiring board which does not cause soldering defects such as insufficient wettability, bridge phenomenon, and glazing phenomenon.

[Brief description of the drawings]

FIG. 1 is a side sectional view showing a first embodiment of the present invention.

FIG. 2 is a plan view showing a main part of FIG.

FIG. 3 is an explanatory view showing an aspect of a flow of molten solder in FIG. 1;

FIG. 4 is a side sectional view showing a shape when a main part of FIG. 1 is formed so as to be adjustable.

FIG. 5 is a perspective view showing the entire contents of FIG. 4;

FIG. 6 is a side sectional view showing a second embodiment of the present invention.

FIG. 7 is a side sectional view showing a third embodiment of the present invention.

FIG. 8 is a side view showing the shape of the flow guide plate of FIG.

FIG. 9 is a side view showing an example of a conventional soldering apparatus.

FIG. 10 is a side view showing another example of the conventional soldering apparatus.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 21 Soldering apparatus 22 Wiring board 23 Conveyor 24 Melted solder 24a Laminar flow 24b Standing wave 25 Jet tank 26 Blow outlet 27 Fluid guide 27A Flow guide 27B Flow guide 27C Flow guide 28 First flow guide 29 Downward Part 30 second flow guiding part 31 rising part

Claims (12)

(57) [Claims] 1. A laminar flow of a molten solder is guided in a substantially horizontal direction by a conductive fluid to form a laminar flow of the molten solder, and the laminar flow of the molten solder is lowered by the conductive fluid. Part, and then flows upward again at the rising part of the fluid guide, and then flows downward again.On the other hand, the wiring board is transported in a direction opposite to the direction in which the laminar flow of the molten solder flows. Soldering by contacting the molten solder flowing in the rising portion with the solder. 2. The method according to claim 1, wherein the molten solder ejected from the outlet is guided in a substantially horizontal direction with a conductive fluid to form a laminar flow of the molten solder and soldering is performed. Part, and then flow in a substantially horizontal direction at the horizontal part of the conductive fluid, then flow upward again at the rising part of the conductive fluid, and then flow downward again, while laminar flow of the molten solder flows Soldering by carrying the wiring board in a direction opposite to the direction, and bringing the wiring board into contact with the molten solder flowing through the rising portion. 3. A method for forming a laminar flow of the molten solder by guiding the molten solder spouted from the blowing port in a substantially horizontal direction with a conductive fluid and performing soldering. After flowing obliquely downward in the inclined portion, after flowing upward in the rising portion of the fluid guide, it flows downward again, while, on the other hand, transports the wiring board in a direction opposite to the direction in which the laminar flow of the molten solder flows, Soldering by bringing the wiring board into contact with the molten solder flowing through the rising portion. 4. A soldering apparatus provided with a fluid-guiding fluid for guiding a flow of molten solder in a substantially horizontal direction to form a laminar flow, wherein the fluid-guiding fluid is guided by a descending portion through which the molten solder flows downward. A soldering apparatus, wherein a flow plate and a flow guide plate of a rising portion which flows upward and then flows downward again are sequentially formed. 5. A soldering apparatus provided with a conductive fluid for guiding a flow of molten solder in a substantially horizontal direction to form a laminar flow, wherein the conductive fluid is provided in a descending portion where the molten solder flows downward. A flow guide plate, a flow guide plate of a flow guide portion flowing in a substantially horizontal direction, and a flow guide plate of a rising portion flowing upward and then flowing downward again are sequentially formed. Soldering equipment. 6. A soldering apparatus provided with a fluid guide for guiding a flow of a molten solder in a substantially horizontal direction to form a laminar flow, wherein the fluid guide is disposed obliquely downward and inclined, The soldering device according to claim 1, wherein a flow guide plate of a rising portion in which the molten solder flows upward after flowing upward again is provided on a downstream side of the conductive fluid. 7. The soldering apparatus according to claim 4, wherein the flow guide plate in the descending portion is formed in any one of a stepped shape, an inclined shape, and a smooth curved shape. . 8. ascender guide flow plate, soldering apparatus according to claim 6, characterized in that formed on either of the inclined slant or smooth curved. 9. The flow guide plate of the descending portion and the rising portion is formed in any one of an inclined shape and a smooth curved shape, and a flat portion is formed on the top of the flow guide plate of the rising portion. The soldering apparatus according to claim 4 or 5, wherein 10. The flow guide plate of the rising portion is formed in one of an inclined shape and a smooth curved shape, and a flat portion is formed on the top of the flow guide plate of the rising portion. 7. The soldering apparatus according to 6. 11. The fluid guide is formed of a plurality of dividable flow guide plates, and fixing means for adjusting the relative positional relationship between the divided flow guide plates is provided. The soldering apparatus according to any one of claims 4 to 10, wherein: 12. The soldering apparatus according to claim 4, wherein the outlet for ejecting the molten solder to the fluid guide side is formed such that the opening height thereof is adjustable. .