JP5202112B2 - Soldering method and soldering apparatus - Google Patents

Description

  The present invention relates to a method and apparatus for performing soldering by mounting electronic components on a plate-like workpiece to be soldered, for example, a printed wiring board, and heating and melting the solder supplied in advance to the soldered portion.

  As a method of soldering an electronic component to a printed wiring board, there is a reflow soldering method in which solder (for example, cream solder) supplied in advance to a part to be soldered is heated and melted. By melting the solder, an intermetallic compound is formed in the soldered portion, so-called “wetting” of the solder is formed, and soldering is performed.

  As a means for heating the solder, there are a hot air heating method, a hot wire heating method, a steam heating method, and the like, and a hot air heating method that is excellent in usability as a whole is used as a main heating method.

  As a technique of a reflow soldering method employing a hot air heating method, there is a technique disclosed in Patent Document 1. In this document, there are a plurality of configurations in which the hot air blown from the nozzle blows on the printed wiring board and then flows back through gaps or holes provided around the nozzle as viewed from the width and length of the printed wiring board. The technique provided in is disclosed.

With this configuration, it is configured so that the flow of hot air does not “stagnate” in the valleys between the electronic components.
Japanese Patent Laid-Open No. 2-330374

  However, since the technology of Patent Document 1 is configured so that “the heat transfer coefficient is high” by “disturbing the flow” of the hot air on the printed wiring board, the flow speed is high on the printed wiring board. There is a problem that hot air cannot flow.

  In other words, it is configured so that `` the heat transfer coefficient is high '' by violently changing the wind speed and direction of hot air, so the heating temperature deviation Δt in each part of the printed wiring board tends to be large, and the heating temperature profile also has ripples. There are problems that are likely to occur. Further, since the resistance of the flow path through which the hot air flows is large, there is a problem that a large amount of energy is required for driving the air blowing means (fan) specifically for driving the means for flowing the hot air.

  An object of the present invention is to provide a high-speed flow of hot air on a printed wiring board so that it can be supplied with a small amount of energy. It is to be able to do it.

  The present invention is characterized in that hot air composed of a large number of swirling flows is blown and heated on a printed wiring board as a work to be soldered.

(1) The first invention of the present application is to blow a large number of swirling hot air giving a swirl vector in the plate surface direction to a plate-shaped soldered work in which solder is previously supplied to the soldered portion. The soldering method is configured to perform soldering by heating and melting the solder supplied to the soldered portion.

  With hot air that forms a swirl flow, the flow rate and direction of the hot air are extremely small, and the flow rate is high (at high speed) and the flow is aligned (wind speed and direction are aligned). Can be supplied and sprayed onto the workpiece. And since many such swirl-flow hot airs are arranged and supplied to the plate-like soldered workpiece, even if it is a plate-like soldered workpiece having a three-dimensional structure with electronic parts mounted on its surface It is possible to supply and blow hot air that is well-aligned at high speed to the fine parts.

  Therefore, it is possible to perform heating with a high heat transfer rate and a small heating temperature deviation Δt, and it is possible to uniformly solder each part of the plate-like workpiece to be soldered.

(2) The second invention of the present application is directed to a plate-shaped soldered work in which solder is supplied in advance to the soldered portion, and provides a turning vector in the plate surface direction of the plate-shaped soldered work. A swirl flow array generating plate-like member provided with a large number of swirl flow hot air generating means is provided. Then, the solder supplied to the soldered portion is heated and melted by blowing a large number of swirling hot air blown from the swirling flow array generating plate member onto the plate-like workpiece to be soldered and soldered. It is the soldering method comprised so that it might perform.

  A plurality of means for generating the swirling flow hot air are arranged on the plate-like member, and this plate-like member, that is, the swirling flow arrangement generating plate-like member is provided to face the plate-like workpiece to be soldered. A large number of swirling hot air can be uniformly supplied and blown to each part of the soldering work in an arrayed state.

  Therefore, it is possible to uniformly supply and blow hot air with a high flow rate to each part of the plate-like soldered workpiece, so that the heating temperature deviation of each part of the plate-like soldered workpiece is high. However, it is possible to perform heating with extremely small heating efficiency. As a result, it becomes possible to uniformly solder each part of the plate-like workpiece to be soldered.

(3) According to a third invention of the present application, in the soldering method described in (2) above, the swirling flow hot air generating means provided on the swirling flow array generating plate member has an angle on the hot air inlet side with respect to the hole axis. A cone-shaped hole whose angle changes is formed in at least two stages so as to be larger than the angle on the hot air outlet side, and a pressurized and compressed heated atmosphere is supplied to the hot air inlet side. In this soldering method, the swirling hot air generated by this configuration is supplied and blown to the plate-like workpiece to be soldered in an arrayed state.

  When the compressed heating atmosphere flows into the cone-shaped hole, a flow vector perpendicular to the hole axis, that is, a radial direction of the hole is given, and a swirling flow is generated by this vector component.

  Further, by configuring the cone opening angle to change in two or more steps along the hole axis direction, the hot air swirling motion, that is, the swirling speed is increased by the Coanda effect at each step of decreasing the angle. Become.

  And since a hot air flows by making the hole with which a swirl flow arrangement | sequence generation | occurrence | production plate-shaped member turns into a swirl flow, disturbance of a flow becomes very small. That is, since the energy spent for the flow disturbance is converted into the velocity energy of the swirling flow, it is possible to obtain the swirling flow hot air with less speed fluctuation and the same flow direction. Therefore, high-speed hot air can be generated even if the compression pressure of the heating atmosphere compressed and supplied to the hot air inlet side of the swirl flow array generating plate member is small.

  That is, it becomes possible to generate swirl flow hot air having a high flow rate and with low energy, and to generate a large number of swirl flow hot air arranged at the same time.

  As a result, it is possible to perform soldering of the soldered portions that exist in large numbers in the plate-like work to be soldered with uniform and less energy.

(4) In the fourth invention of the present application, a large number of holes for passing hot air are arranged in the plate-like member, and these holes are cone-shaped holes whose angle with respect to the hole axis changes in at least two stages. The swirl flow arrangement generating plate-like member is formed so that the angle of the hot air inlet side cone-shaped portion with respect to the hole axis is larger than the angle of the hot air outlet side cone shaped portion with respect to the hole axis. At the same time, the swirl flow array generating plate member is configured to have a compressed heating atmosphere supply means on the hot air inlet side.

  The swirl flow array generating plate is provided facing the plate-shaped soldered work in which solder is previously supplied to the soldered portion, and the plate-shaped soldered work is disposed on the swirl flow array generating plate. It is the soldering apparatus comprised so that it might comprise the conveyance means which conveys facing a shape member.

  As a result, a large number of swirling hot air that is generated at low speed and arranged at high speed is supplied and blown to the plate-like workpiece to be soldered in an arrayed state. And, since the plate-like soldered work is conveyed while facing the swirling flow arrangement generating plate-like member, the arranged swirling hot air flows uniformly in each part of the plate-like soldering work, Uniform soldering is performed at each part of the work to be soldered.

(5) In the fifth invention of the present application, a large number of holes for passing hot air are arranged in the plate-like member, and these holes are cone-shaped holes whose angle with respect to the hole axis changes in at least two steps. The angle of the hot air inlet side cone-shaped portion with respect to the hole axis is formed to be larger than the angle of the hot air outlet side cone-shaped portion with respect to the hole axis. A cylindrical hole is provided, and a ratio of the length of the cylindrical hole to the hole diameter is set to 1 to 4 or less to constitute a swirl flow array generating plate member, and the hot air flow of the swirl flow array generating plate member It is configured to have supply means for a compressed heating atmosphere on the inlet side.

  The swirl flow array generating plate is provided facing the plate-shaped soldered work in which solder is previously supplied to the soldered portion, and the plate-shaped soldered work is disposed on the swirl flow array generating plate. It is the soldering apparatus comprised so that it might comprise the conveyance means which conveys facing a shape member.

  That is, in the configuration of the above (4), a cylindrical hole is provided on the front side of the hot air blowing side cone-shaped portion, and the ratio of the length of the cylindrical hole to the hole diameter is set to 1 to 4 or less. Attachment device.

  Thus, if the cylindrical hole is provided on the front side of the hot air blowing side cone-shaped part, the directivity of the swirling hot air blown out can be sharpened. However, since the cylindrical hole does not have an effect of increasing the swirling flow, the swirling flow is greatly attenuated when the length thereof is increased, and the swirling flow is eventually extinguished. Therefore, it is necessary to provide a ratio of the length of the cylindrical hole to the hole diameter of 1 to 4 or less.

  As a result, whirling hot air can be blown onto the plate-like workpiece to be soldered while maintaining the directivity of blowing without annihilating the swirling hot air. The hot air can be reliably blown to the soldered portion formed deep inside the lever.

  That is, even in a plate-like soldered workpiece having a complicated surface shape, the arranged swirl hot air flows uniformly in each part of the plate-like soldered workpiece, and in each part of the plate-like soldered workpiece Uniform soldering is performed.

  According to the present invention, a large number of arranged swirl flow hot air is supplied and blown to a printed wiring board which is a plate-like work to be soldered, and the solder is heated and melted by these arranged swirl flow hot air. And solder. And since it becomes possible to generate hot air with a high flow rate at a high speed in a compressed heating atmosphere at a lower pressure than before and to perform soldering, the heating temperature deviation Δt of each part of the printed wiring board is also reduced, and the printed wiring board It becomes possible to perform soldering of a large number of existing soldered portions uniformly and with less energy. Moreover, even a printed wiring board having a complicated surface shape can be uniformly soldered.

  Next, how the soldering method and the soldering apparatus of the present invention can be actually carried out will be described with reference to embodiments.

(1) Basic Principle FIG. 1 is a diagram for explaining the basic principle of the present invention. (A) is a cross-sectional view perpendicular to the surface of a printed wiring board, and (b) is an I- The blowout port of the swirl flow hot air is drawn with a broken line in the figure which looked at I cross section.

  That is, the swirl flow hot air is generated by the swirl flow hot air generation nozzle 102 of the swirl flow array generation plate-like member 101 and blown out radially from the outlet 103. A large number of swirl flow hot air generating nozzles 102 are arranged, and a large number of swirl flow hot air 104 generated from these nozzles is supplied and blown toward the printed wiring board 105.

  The swirling hot air 104 converts the energy spent in the flow turbulence (turbulent flow) into velocity energy in the swirling direction, and thus forms hot air having a high flow rate and high speed. Therefore, it becomes possible to supply hot air with a stable flow rate in the flow direction onto the surface of the printed wiring board 105, and stabilize the amount of heat supplied to the printed wiring board 105 and thus the solder of the soldered portion 107. Will be able to.

  In addition, since the swirling hot air 104 generates almost no turbulence in the flow, it becomes possible to supply hot air having a fixed swirling direction onto the surface of the printed wiring board 105 and from the hot air to the printed wiring board 105. The heat transfer coefficient is greatly improved. That is, the heating efficiency is greatly improved.

  The entire surface of the printed wiring board 105 is heated by the many swirling hot air 104 arranged, that is, by the large number of swirling hot air 104 having a small size, so that the electronic component 106 mounted on the surface of the printed wiring board 105 Even if the surface shape has a three-dimensional shape, hot air having a uniform flow direction can surely enter the soldered portion 107 existing in each part of the three-dimensional shape and can be heated uniformly.

  Therefore, it is possible to uniformly heat the solder of the soldered portions 107 existing on the printed wiring board 105 and to perform heating with a small heating temperature deviation Δt. Since the printed wiring board 105 is conveyed in the direction of arrow A by the conveyor 108, it is heated by the array group of the swirling hot air 104 while being conveyed, and heating with a smaller heating temperature deviation is possible. .

  Note that the interval between the swirling hot air generating nozzles 102 is preferably determined so that the swirling hot air 104 that blows out from the blowout port 103 reaches the board surface of the printed wiring board 105 before greatly interfering with each other. The compressed heating atmosphere 100 is a hot air source.

(2) Means for generating high-speed swirling hot air in a low-pressure compression heating atmosphere FIG. 2 is a diagram for explaining the configuration of a nozzle that generates swirling hot air swirling from a pressurized heating atmosphere. FIG. 5B is a diagram illustrating only one swirling hot air generating nozzle cut out and seen through, and FIG. 7B is an end view of the section II-II in FIG.

  The swirling flow hot air generating nozzle is formed with a hole axis perpendicular to the plate surface of the swirling flow array generating plate member 201, has two cone-shaped hole portions 202 and 203, and is compressed under pressure. An angle θ1 formed by the side surface of the inlet-side cone to which the heating atmosphere is supplied with respect to the hole axis is larger than an angle θ2 formed by the side surface of the outlet-side cone with respect to the hole axis (θ1> θ2). It is configured.

  As shown in FIG. 2, the first cone-shaped hole 202 has a dish shape, and the size of θ <b> 1 is configured to be about 60 ° to 90 °. The second cone-shaped hole 203 is formed in a shape with θ2 of about 15 ° to 60 ° (preferably 15 ° to 45 °).

  Further, a cylindrical hole 204 is provided on the tip side of the second cone-shaped hole 203, and the hole diameter φ2 is the same as the tip diameter of the second cone-shaped hole 203. Then, assuming that the diameter of the second cone-shaped hole 203 on the large diameter side is φ1, the ratio is φ2: φ1 = 1: 1.5 to 1: 3.

  The ratio of the hole diameter φ2 of the cylindrical hole 204 to its length is set to 1: 4 or less. That is, since the cylindrical hole has no effect of increasing the swirling flow, if this ratio exceeds 1: 4, the swirling flow is attenuated and eventually disappears. More preferably, it is preferable to select in the range of 1: 1 to 1: 2 in order to maintain the directivity and prevent large attenuation.

  When a compressed and heated atmosphere is supplied, it is possible to generate a swirling flow using only the second cone-shaped hole 203. However, when the first cone-shaped hole 202 is used in combination, the swirling flow is enhanced. The effect can be obtained.

  The swirling flow is generated by applying a flow vector in a direction perpendicular to the hole axis, that is, in the radial direction of the hole, when the pressurized compressed heating atmosphere flows through the cone-shaped hole.

  In the first cone-shaped hole 202, a flow is generated such that the flow velocity (component force) in the radial direction is larger than the flow velocity in the hole axial direction due to the compressed heating atmosphere pressurized near the hole surface. As a result, a swirl flow 206 is generated. The swirling hot air flows into the second cone-shaped hole 203 due to the Coanda effect, the flow velocity is increased, and the swirling flow is enhanced. Therefore, although it is possible to generate the swirl flow hot air 207 with only the second cone-shaped hole 203, it is more preferable to use the first cone-shaped hole 202 together.

  A cylindrical hole 204 provided on the distal end side of the second cone-shaped hole 203 is provided in order to improve the directivity of the swirling hot air 207 blown out from the blowout port. Further, the Coanda effect can be strengthened by a columnar 205 hole between the first cone-shaped hole 202 and the second cone-shaped hole 203, and a pressure increasing action can be obtained.

  As the shape of the cone-shaped hole, it is possible to ensure a good generation state of the swirling hot air 207 under the above-described conditions. The swirl flow hot air 207 converts the energy spent for the flow disturbance into the velocity energy of the swirl direction flow, so that the flow disturbance is reduced and the flow is arranged at high speed even in a low pressure compression heating atmosphere. A swirling hot air can be generated.

(3) Configuration Example of Soldering Device Next, a configuration example of the soldering device of the present invention using the swirling flow array generating plate member having a plurality of swirling flow hot air generating nozzles will be described.

  FIG. 3 is a diagram illustrating a configuration example of the reflow soldering apparatus, and is a diagram illustrating a cross section with respect to the transport direction of the transport conveyor 308. Note that FIG. 3 shows only the heating furnace 306 portion on the upper side of the transport conveyor 308, but the heating furnace is also formed in a symmetrical shape on the lower side of the transport conveyor.

  The printed wiring board 307 is held by pins 309 of the conveyor 308 and is conveyed in a direction perpendicular to the drawing.

Further, the circulation flow path forming plate 302 forms an atmospheric circulation flow path in the furnace body 300. A fan 305 driven by a motor 304 is provided in the furnace of the heating furnace 306, and the atmosphere is compressed and supplied by the fan 305 to circulate through the circulation channel.

  In addition, a heater 303 is provided in the circulation path of the atmosphere, and heating is performed in the circulation process of the atmosphere. And the electric power supplied to the said heater is adjusted with the temperature control apparatus and temperature sensor which are not shown in figure, and the temperature of a furnace interior atmosphere temperature and by extension, the temperature of a swirling hot air are controlled.

  On the other hand, a swirl flow array generating plate member 301 is provided facing the printed wiring board 307 conveyed by the conveyer 308, and the swirl flow array generating plate member 301 is compressed by a fan 305. A heated atmosphere is supplied. The swirl flow array generating plate-like member 301 is provided with a large number of swirl flow hot air generating nozzles shown in FIG. 2, for example, as illustrated in FIG. 1 (b).

  Therefore, a large number of swirling hot air 310 generated by the swirling flow array generating plate member 301 is supplied and blown to the printed wiring board 307 conveyed by the conveying conveyor 308, and the printed wiring board 307 is soldered. Soldering is performed by heating and melting the solder supplied in advance to the part.

  Then, the swirling hot air blown to the printed wiring board 307 returns to the fan 305 through the circulation flow path, is pressurized, heated by the heater 303, and then supplied again to the swirling flow array generating plate member 301. Is done.

  If a pipe (heat exchanging means) through which a refrigerant is passed is provided instead of the heater in FIG. 3, it can be applied as means for cooling the printed wiring board after soldering.

  The hot air blowing port has the same diameter and the conventional hot air blowing means composed of a simple cylindrical hole and the swirl flow hot air generating nozzle having two cone-shaped holes of the present invention were used. The case was compared.

  As a result, in the swirl flow hot air generating nozzle of the present invention, hot air having the same wind speed as that of the prior art can be obtained on the printed wiring board even if the rotational speed of the fan is halved. Moreover, the magnitude of the temporal fluctuation of the wind speed is also 1/5 or less of the conventional, and has an excellent turbulent flow conversion action. Further, the heating temperature deviation Δt in each part of the printed wiring board is also halved, and almost no ripple is generated on the heating temperature profile of the printed wiring board.

  Furthermore, despite the high-speed hot air, there was no possibility that fine and lightweight electronic components were peeled off during heating. This is because the flow of hot air on the printed wiring board is a swirling flow and the wind speed is uniformly distributed.

  The soldering method and the soldering apparatus according to the present invention are used for printed wiring boards that are workpieces to be soldered, such as printed wiring boards on which large-sized electronic components are mounted and printed wiring boards on which fine and lightweight electronic components are densely mounted. Since the same heating temperature profile can be obtained even if the types are different, it can be used as a reflow soldering apparatus having extremely high versatility.

Diagram for explaining the basic principle of the present invention The figure explaining the structure of the nozzle which generate | occur | produces the swirling flow hot air used for this invention The figure explaining the structure of the reflow soldering apparatus of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Compression heating atmosphere 101 Swirling flow arrangement | sequence generation plate-shaped member 102 Swirling flow hot air generation nozzle 103 Outlet 104 Swirling flow hot air 105 Printed wiring board 106 Electronic component 107 Soldering part 108 Conveyor 201 Swirling flow arrangement generation plate-shaped member 202 1st 1 cone-shaped hole 203 2nd cone-shaped hole 204 cylindrical hole 205 cylindrical hole 206 swirl flow 207 swirl flow hot air 300 furnace body 301 swirl flow array generating plate member 302 circulation flow path forming plate 303 heater 304 Motor 305 Fan 306 Heating furnace 307 Printed wiring board 308 Conveyor 309 Pin 310 Swirling hot air

Claims (5)

It faces a plate-like workpiece to be soldered with solder supplied to the part to be soldered in advance, and a rotation vector in the direction of the plate surface is given , and each has an independent rotation axis coordinate in its outlet and rotates. A large number of swirl flow hot air outlets for movement are arranged, and each swirl flow hot air is blown from the large number of blow openings to the plate-like workpiece to be soldered to be supplied to the soldered portion. Heating and melting the solder to perform soldering;
Soldering method characterized by Facing the work to be soldered beforehand solder is plate-like, which is supplied to the portion to be soldered, the rotary axis coordinate the turning vector plate surface direction of the plate-shaped work to be soldered are each given an independent the balloon swirl flow sequence generation plate-like member the outlet of the swirling flow hot air at which the rotation movement is provided by a number sequence has a mouth provided, a number of the orbiting blown from the swirl flow sequence generating plate-like member Performing soldering by heating and melting the solder supplied to the soldered part by blowing a flowing hot air on the plate-like workpiece to be soldered;
Soldering method characterized by 3. The soldering method according to claim 2, wherein the swirling flow hot air generating means provided on the swirling flow array generating plate member is formed such that the angle on the hot air inlet side with respect to the hole axis is larger than the angle on the hot air outlet side. A cone-shaped hole having an angle change in at least two stages, and a hot and compressed heating atmosphere is supplied to the hot air inlet side.
Soldering method characterized by A large number of holes for passing hot air through the plate-like member are arranged, and these holes are provided with cone-shaped holes whose angle with respect to the hole axis changes in at least two stages. The swirl flow array generating plate member is configured so that the angle of the portion with respect to the hole axis is larger than the angle with respect to the hole axis of the hot air outlet side cone-shaped portion, and the swirl flow array generating plate member A heating air supply means compressed on the hot air inlet side of the
On the other hand, the swirl flow arrangement generating plate-like member is provided facing the plate-like soldered work in which solder is previously supplied to the soldered portion, and the plate-like soldered work is generated by the swirling flow arrangement generating. Comprising transport means for transporting facing the plate-like member;
Soldering device characterized by A large number of holes for passing hot air through the plate-like member are arranged, and these holes are provided with cone-shaped holes whose angle with respect to the hole axis changes in at least two stages. The angle of the part with respect to the hole axis is formed to be larger than the angle with respect to the hole axis of the hot air outlet side cone-shaped part, and a cylindrical hole is provided on the front side of the hot air outlet side cone-shaped part. A swirl flow array generating plate member configured by providing a ratio of the length of the cylindrical holes to the hole diameter of 1 to 4 or less, and a heated atmosphere compressed on the hot air inlet side of the swirl flow array generating plate member Supply means,
On the other hand, the swirl flow arrangement generating plate-like member is provided facing the plate-like soldered work in which solder is previously supplied to the soldered portion, and the plate-like soldered work is generated by the swirling flow arrangement generating. Comprising transport means for transporting facing the plate-like member;
Soldering device characterized by

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