JP2002205163A - Soldering device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize high soldered quality and throughput even if a Pb free solder with a high melting point is used, in a soldering device for performing flow soldering. SOLUTION: The soldering device is equipped with a solder bath 12 in which a heater for melting solder is arranged and in which molten solder is stored, jet nozzles 26, 27 which are disposed in the solder bath 12 and which is for discharging molten solder and a jet pump 28 for jetting the molten solder. A first heater 29 is installed on the inner wall of the solder bath 12, and a second heater 30 is arranged near the flowing route of the molten solder in the solder bath 12 (the bottom center position of the solder bath 12), thereby uniformizing solder temperature in the solder bath 12.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering apparatus, and more particularly to a soldering apparatus for performing flow soldering.

[0002]

2. Description of the Related Art In general, various types of soldering apparatuses for performing a soldering process on an object to be soldered, such as a printed wiring board, are provided, and one of them is a flow soldering apparatus. In this flow soldering apparatus, the solder in a solder bath is heated by a heater to melt the solder, the molten solder is circulated by a jet pump, and discharged from a jet nozzle. For soldering. In this flow soldering apparatus, the molten solder is stirred by the jet pump, so that the distribution of the solder temperature can be made uniform and the production rate can be improved.

[0003] There are also various types of flow soldering equipment, specifically, a wave type, a flow dip type,
There is a dual wave type and the like. Of these, on a printed circuit board on which chip components are mounted, the chip components have no leads,
Because of the chip shape, in the wave type and the dual wave type having only one jet nozzle, the wraparound of the solder is not sufficient, and good soldering cannot be performed. For this reason, a dual wave type having two jet nozzles (one wave, two waves) is used for soldering a printed wiring board or the like on which chip components are mounted.

[0004]

Conventionally, solders containing tin (Sn) and lead (Pb) have been used. For example, Sn63-Pb37 solder has been widely used because its melting point is relatively low at 183 ° C. and its mechanical and electrical properties are good.

However, in recent years, toxicity of lead has become a problem, and severe restrictions have been imposed on the use of this lead and compositions containing lead. Further, it is necessary to prevent lead from being exposed due to discarding of electrical products and the like using solder containing lead. For this reason, lead-free solders have been developed, and in recent years, lead-free solders (Pb-free solders) have come into practical use.

For example, Pb-free solders in practical use include Sn-Cu, Sn-Cu-Ag,
There is a solder having a composition such as n-Cu-Ag-Bi. This solder has a higher melting point (220 ° C. to 230 ° C.) than the melting point of conventionally used lead-containing solder. As described above, it is desirable that even if a Pb-free solder having a high melting point is used, soldering can be performed using a conventional soldering apparatus as it is.

However, the conventional soldering device is
Since the melting point of the Sn—Pb solder was as low as 183 ° C., the temperature of the molten solder (molten solder) was controlled at about 250 ° C.
Had been implemented. In this case, there is a temperature difference of about 70 ° C. between the melting point of the solder (183 ° C.) and the control temperature (250 ° C.), and a temperature having a margin in the temperature range was implemented. (Non-uniformity) frequently did not result in a failure.

On the other hand, since the Pb-free solder has a high melting point as described above, if the temperature is to be controlled at the same control temperature as before, the melting point of the solder (220 ° C. to 230 ° C.) and the control temperature (250 ° C.) Between about 20 ° C to 30 ° C, and if the molten solder has uneven temperature,
There is a problem that a problem occurs in soldering. In this way, when temperature unevenness occurs in the molten solder,
This affects the solder quality and lowers the soldering yield.

Further, the jet pump for supplying the molten solder to the jet nozzle needs to be started after the solder in the solder bath is completely melted. However, if the temperature in the solder in the solder bath is uneven as described above, it is difficult to set the timing for starting the jet pump, and if the solder is not completely melted, the jet pump may be damaged, or However, if it does not start even though it is completely melted, there is a problem that the throughput of the soldering process is reduced.

The present invention has been made in view of the above points, and has as its object to provide a soldering apparatus which can realize high solder quality and throughput even when using a Pb-free solder having a high melting point.

[0011]

Means for Solving the Problems In order to solve the above-mentioned problems, the present invention is characterized by taking the following means.

According to the first aspect of the present invention, a heater for melting the solder is provided, and a solder bath for storing the molten solder is provided in the solder bath, and the molten solder is discharged. What is claimed is: 1. A soldering apparatus comprising: a jet nozzle; and a jet pump for supplying the molten solder to the jet nozzle, wherein the heater includes: a first heater provided on an inner wall of the solder tank; And a second heater disposed near the flow path of the molten solder.

According to the present invention, the second heater is provided near the flow path of the molten solder in addition to the first heater which has been conventionally provided, so that the temperature distribution of the solder in the solder bath can be reduced. Variation can be reduced, and good soldering processing can be performed.

According to a second aspect of the present invention, in the soldering apparatus according to the first aspect, the second heater is disposed at the center of the bottom of the solder bath.

According to the invention, the second heater is disposed at the center of the bottom of the solder bath where heat is easily radiated in the solder bath, that is, the temperature is easily lowered. Variation can be effectively reduced.

According to a third aspect of the present invention, in the soldering apparatus of the first or second aspect, a third heater is provided in the jet nozzle.

According to the invention, the third heater is provided in the jet nozzle, which tends to cause a temperature drop due to the discharge of the molten solder, so that the temperature of the molten solder in the jet nozzle can be suppressed from decreasing. And a good soldering process can be performed.

According to a fourth aspect of the present invention, in the soldering apparatus according to any one of the first to third aspects, a guide plate for guiding the flow of the molten solder is provided on the jet nozzle, and The length of the guide plate in the flow direction of the molten solder flowing over the nozzle is set to be equal to or less than the length of the jet nozzle in the flow direction of the molten solder.

According to the present invention, since the guide plate guides the flow of the molten solder, the flow of the molten solder on the jet nozzle can be stabilized. On the other hand, since this guide plate is in direct contact with the molten solder, it has a function similar to that of the heat sink, and there is a possibility that the temperature of the molten solder is reduced. However, the length of the guide plate is set to be shorter than the length of the jet nozzle with respect to the flow direction of the molten solder, and is set to the minimum length for guiding the flow of the molten solder. For this reason, the heat radiation area of the guide plate is minimized, and the heat radiation of the molten solder by the guide plate is suppressed to a small value, so that the flow of the molten solder can be stabilized and the temperature can be prevented from being reduced.

According to a fifth aspect of the present invention, there is provided a solder tank for storing molten solder, and a jet pump provided in the solder tank and supplied to a jet nozzle for discharging the molten solder. A soldering apparatus having temperature measuring means for measuring the temperature of solder in the solder bath, and control means for controlling the drive of the jet pump based on the solder temperature measured by the temperature measuring means,
The temperature measuring means comprises a plurality of temperature sensors,
Further, in the solder bath, the plurality of temperature sensors are configured so as to have different height positions for measuring the solder temperature.

According to the invention, a plurality of temperature sensors are provided in the solder bath and the height positions at which the temperature is measured are different from each other, so that the temperature at each height position in the solder bath can be reduced. You can know directly. Thereby, the molten state of the solder in the solder bath can be known with certainty, and it is possible to start another configuration for performing the soldering process such as a jet pump at an appropriate timing.

According to a sixth aspect of the present invention, there is provided a solder bath in which molten solder is stored, a jet nozzle provided in the solder bath for discharging the molten solder, A soldering device having a jet pump for supplying the jet nozzle, wherein a filter member for preventing intrusion of foreign matter is provided at an inlet of the molten solder of the jet pump.

According to the invention, since the filter member for preventing intrusion of foreign matter is provided at the inlet of the molten solder of the jet pump, it is possible to prevent the jet pump from being damaged by foreign matter intrusion.

According to a seventh aspect of the present invention, there is provided a solder bath in which molten solder is stored, a jet nozzle provided in the solder bath for discharging the molten solder, A soldering device having a jet pump for supplying the jet nozzle, wherein a moving device that moves an unnecessary material floating above the molten solder in the solder bath toward an unnecessary material removing position in the solder bath. It is characterized by having been provided.

According to the invention, the unnecessary material generated and floating above the molten solder is moved to the unnecessary material removing position in the solder bath by the moving device. Therefore, it is possible to prevent unnecessary substances from being accumulated at the position where the soldering process is performed, thereby preventing the occurrence of defective soldering. Further, since unnecessary materials are collected at the unnecessary material removing position, the unnecessary materials can be easily removed.

According to an eighth aspect of the present invention, there is provided the soldering apparatus according to the seventh aspect, wherein the unnecessary material collected at the unnecessary material removing position by the moving device is discharged to the outside of the solder bath. A device is provided.

According to the invention, the unnecessary objects collected at the unnecessary object removing position by the moving device are automatically discharged to the outside of the solder bath by the discharging device, so that the unnecessary objects can be removed without using manual operation. Can be.

According to a ninth aspect of the present invention, there is provided a solder bath in which molten solder is stored, a jet nozzle arranged in the solder bath for discharging the molten solder, A jet pump that supplies the jet nozzle, and a soldering device that has a transport device that transports the object to be soldered to the solder bath, wherein the transport device transports the object to be soldered to a transport center position. The center position of the jet nozzle with respect to the width direction is matched.

According to the present invention, the transfer device matches the center position of the jet nozzle with respect to the width direction of the jet nozzle, so that the object to be soldered is positioned with respect to the width direction of the jet nozzle. It moves around the center position and the soldering process is performed. The flow of the molten solder on the jet nozzle is not uniform over the entire width, and the flow velocity on both sides is lower than the flow velocity in the central part. In addition, focusing on the stability of the flow velocity, the flow velocity at the center of the jet nozzle is stable, while the flow velocity at both sides fluctuates and becomes unstable. Furthermore, the solderability is affected by the flow speed of the molten solder on the jet nozzle, and it is known that poor soldering occurs if the flow speed is not stable.

[0030] Therefore, by setting the transport center position at which the transport device transports the object to be soldered to the center position in the width direction of the jet nozzle, good soldering can be performed on the object to be soldered. Becomes

The invention described in claim 10 is the same as the ninth invention.
The soldering apparatus according to claim 1, wherein the transporting device includes a transporting claw portion on which the object to be soldered is mounted, an application device that applies a flux to the transporting claw portion, and an unnecessary device attached to the transporting claw portion. A removing brush for removing solder is provided.

According to the present invention, the flux is applied to the transport claw on which the object to be soldered is mounted by the coating device, thereby preventing the solder from adhering to the transport claw. In addition, since the unnecessary solder that has adhered is removed by the removing brush, the transport claw can be always kept clean.

[0033]

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

FIGS. 1 and 2 show the overall structure of a soldering apparatus according to one embodiment of the present invention. FIG. 1 is a plan view of the soldering apparatus 10, and FIG. 2 is a front view of the soldering apparatus 10. In this embodiment, the soldering device 1
A description will be given by taking a dual-wave type flow soldering apparatus as an example with 0 being used. The solder used in this embodiment is a so-called Pb-free solder (Sn96.5-Ag3.0-
(Having a composition of Cu0.5) and its solder melting point (2
20 ° C. to 230 ° C.), which is higher than that of the conventional Sn—Pb solder. Further, the control temperature of the molten solder (molten solder) in the present soldering apparatus 10 is set at around 250 ° C. as in the conventional case. Hereinafter, the configuration of the soldering apparatus 10 will be described.

The soldering apparatus 10 is generally composed of a housing 11, a solder bath 12, a transfer device 13, and the like. An object to be soldered, such as a printed wiring board, is mounted on the transfer device 13 from the left side position in the figure (the carry-in position indicated by the arrow A in the figure), transferred into the housing 11, and subjected to a predetermined soldering process in the housing 11. Is performed, the right position in the figure (the carry-out position indicated by arrow B in the figure)
It is configured to be taken out.

The housing 11 has a solder bath 12,
It has a preheater 15, a nail cleaning device 16, a cooling fan 18, etc., and a control device 19, a power supply device 20,
An operation panel 21, an exhaust flange 22, and the like are provided. The details of the solder bath 12 and the nail cleaning device 16 will be described later for convenience of description.

The preheater 15 is provided between the carry-in position A and the position where the solder bath 12 is provided. The preheating sensor 15 preheats the object to be soldered in a process in which the object to be soldered mounted on the transfer device 13 is transferred to the solder tank 12 at the loading position A. Thereby, when the soldering process is performed in the solder bath 12, the object to be soldered is heated to the predetermined temperature, so that the soldering process can be performed well.

The cooling fan 18 is arranged near the carry-out position B so as to face the transfer device 13. The cooling fan 18 has a function of cooling the object to be soldered by being heated to a high temperature by performing the soldering process in the solder bath 12. Thus, the object to be soldered at the unloading position B can be easily taken out of the transfer device 13.

The control device 19 is composed of, for example, a sequencer device, and controls the driving of each component of the soldering device 10. In addition, the start-up control of the jet pump 28 described later is also performed by the control device 19. The power supply device 20 supplies power to each component of the soldering device 10.

Next, the configuration of the solder bath 12 will be described mainly with reference to FIGS. 3 is an exploded perspective view of the solder bath 12, FIG. 4 is a plan view of the solder bath 12, and FIG. 5 is a cross-sectional view of the solder bath 12. Solder bath 12
Is roughly the solder tank body 25, the first jet nozzle 2
6 (first wave), second jet nozzle 27 (second wave), jet pump 28, first heater 29, second heater 30, first temperature sensor 31, second temperature sensor 32, etc. It consists of.

The solder bath main body 25 has a rectangular shape with an opening at the top and a bottom, in which first and second jet nozzles 26 and 27, a jet pump 28, and first and second heaters 29 are provided. , 30, first and second temperature sensors 31, 32
Is arranged. The solder bath main body 25 stores molten solder therein. Therefore, the solder tank body 2
The first heater 29 is disposed on both side walls of the second heater 5, and the second heater 30 is disposed at the center bottom (see FIG. 5). The solder loaded in the solder bath main body 25 is melted by the first and second heaters 29 and 30. The first jet nozzle 26 serving as the first wave and the second jet nozzle 27 serving as the second wave are disposed in the solder tank main body 25 in a side-by-side state (see FIGS. 4 and 5). Each jet nozzle 2
6 and 27 have nozzle housings 37 and 38 at the lower part. A jet pump 28 is provided at an inflow port 51 (see FIGS. 3 and 6) formed in the nozzle housings 37 and 38.
Are connected respectively.

As described later, the jet pump 28 supplies the molten solder in the solder bath main body 25 to the first and second jet nozzles 26 and 27 (nozzle housings 37 and 38).
The supplied molten solder rises in the nozzle housings 37 and 38 and is discharged from the solder discharge portions 33 and 34.

The molten solder discharged from the solder discharge portions 33 and 34 flows as shown by the broken arrow in FIG. 4 and returns to the solder bath main body 25 again. And, this solder discharge part 3
In the process of being discharged from 3, 34 and returning to the solder bath main body 25, a soldering process is performed on the soldered object. In this soldering process, the object to be soldered is as shown in FIG.
Move from right to left in. The first jet nozzle 26 serving as the first wave is provided mainly for removing the flux gas from the soldering object and improving the flow of the solder around the chip component. Also, the second
The jet nozzle 27 performs finish soldering on the object to be soldered.

Here, attention is paid to the second jet nozzle 27. As shown in FIG. 4, the molten solder discharged from the solder discharge part 34 flows on the upper plate 35 provided in the second jet nozzle 27 as shown by a broken arrow in FIG. Form a return flow. At this time, since the upper plate 35 has a relatively long distance in the flow direction of the molten solder, the temperature of the molten solder on the upper plate 35 may decrease. When the temperature of the molten solder decreases, there is a possibility that high quality soldering cannot be performed.

Therefore, in this embodiment, as shown in FIG.
The third heater 39 is provided in the second jet nozzle 27. The third heater 39 is connected to the upper plate 35
, And is configured to directly heat the upper plate 35. Also, upper plate 3
A third temperature sensor 40 is provided at a position directly below the fifth heater 5 in addition to the third heater 39. The temperature of the molten solder flowing on the upper plate 35 can be measured by the third temperature sensor 40. Therefore, the third
By controlling the third heater 39 based on the output of the temperature sensor 40, the temperature of the molten solder flowing on the upper plate 35 can be kept constant. This allows
Since the temperature of the molten solder in the second jet nozzle 27 can be suppressed from decreasing, and can be maintained at a constant temperature, it is possible to perform a good soldering process. The control process of the third heater 39 based on the output of the third temperature sensor 40 is performed by the control device 19.

Guide plates 36 are provided on both upper sides of the second jet nozzle 27 (both sides in a direction perpendicular to the direction in which the molten solder flows). The guide plate 36 is provided to guide the flow of the molten solder flowing through the upper plate 35. In this embodiment, the length of the guide plate 36 in the flow direction of the molten solder is set to be smaller than the length of the second jet nozzle 27 in the same direction. This configuration will be described with reference to FIG.

FIG. 11A shows a conventional second jet nozzle 27A. On the other hand, FIG.
Shows a second jet nozzle 27 according to the present embodiment. As shown in FIG. 11 (A), the guide plate 36A is provided in the second jet nozzle 27A in the related art, but the length of the guide plate 36A with respect to the flow direction of the molten solder (the left-right direction in the figure) is as follows. , The second jet nozzle 27
The length is set to be longer than the length of the molten solder A in the flow direction (in the example shown in FIG. 11A, it is longer by the amount indicated by the arrow W in the figure). Thus, the guide plate 3
It is considered that the reason why the length of 6A is set long is that the flow of the molten solder is more reliably guided.

However, the guide plates 36, 36A
Since is a plate-shaped member and has a large area in contact with the outside air, it functions not only as a guide for the molten solder but also as a heat radiating plate for absorbing and radiating the temperature of the molten solder. When Sn-Pb solder having a low melting point is used as in the prior art, the control temperature (250 ° C.) of the molten solder is higher than the melting point (183 ° C.) of the solder with a margin. Even with a slight cooling, the solder did not reach the melting point (183 ° C.) and good soldering could be performed.

On the other hand, in the case where a Pb-free solder having a high melting point is used, when the above-described cooling is performed on the guide plate 36A, the temperature near the guide plate 36A decreases, and accordingly, the molten solder at the both side positions is particularly reduced. Since the viscosity changes, the flow rate of the molten solder decreases. For this reason, there is a possibility that good soldering cannot be performed at both sides of the second jet nozzle 27 (positions where the guide plate 36A is provided).

On the other hand, in the present embodiment, FIG.
As shown in (2), the length of the guide plate 36 is substantially equal to the length of the second jet nozzle 27. Thus, the heat radiation area of the guide plate 36 can be reduced, and a decrease in the temperature of the molten solder due to the guide plate 36 is suppressed, so that good soldering processing can be performed.

The length of the guide plate 36 does not necessarily have to be equal to the length of the second jet nozzle 27, and if the molten solder can be properly guided, the length of the guide plate 36 is equal to the second length. A configuration in which the length is set shorter than the length of the jet nozzle 27 may be used. This makes it possible to both stabilize the flow of the molten solder on the second jet nozzle 27 and prevent the temperature from decreasing.

Next, the jet pump 28 will be described mainly with reference to FIGS. 3, 4, and 6. FIG. As described above, the jet pump 28 is provided corresponding to the first jet nozzle 26 and the second jet nozzle 27, and has a function of supplying the molten solder to the nozzles 26, 27. The jet pump 28 is roughly similar to the pump housing 4.
1, a rotary shaft 42, a jet screw 43, a drive motor 54, and the like. The pump housing 41 is fixed to the solder bath main body 25. The pump housing 41 is provided with an ejection port 50, and a fixing plate 45 is disposed on an upper portion thereof. Spout 50
Are connected to inflow ports 51 formed in the nozzles 26 and 27, as shown in FIG.

The fixed plate 45 is provided with a support mechanism 46 on which the rotary shaft 42 is rotatably supported. A drive pulley 44 is attached to the upper end of the rotating shaft 42, and this drive pulley 44 is connected to a drive motor 54 via a drive belt 56 as shown in FIG.
The drive motor 54 is attached to a motor fixing bracket 55 disposed on the solder bath main body 25. Further, a cover 53 is attached to the upper portions of the fixed plate 45 and the drive motor 54 so as to cover them.

On the other hand, a jet screw 43 is provided at the lower end of the rotary shaft 42. The aforementioned drive motor 54
When the rotary shaft 42 rotates via the drive belt 56, the jet screw 43 also rotates. And
As the jet screw 43 rotates, the molten solder in the solder bath main body 25 is sucked through an opening 49 a formed in the mounting member 49. The sucked molten solder is supplied from the ejection port 50 of the pump housing 41 to the inflow ports 51 of the nozzles 26 and 27. 6 indicate the flow of the molten solder by the jet pump 28.

As described above, the soldering apparatus 10 according to the present embodiment uses Pb-free solder as the solder, but the Pb-free solder has a higher melting point and a lower specific gravity than the conventional Sn-Pb solder. It is getting smaller. As described above, when the specific gravity of the solder is small, foreign matter is likely to be mixed into the jet pump 28. That is, a hexagon wrench used for maintenance of the soldering apparatus 10, a stainless steel screw for fixing the nozzles 26 and 27, etc.
These may be referred to as foreign matters) and fall into the solder bath 12 by mistake. Sn-Pb with large specific gravity as before
In the case of the solder, even if the foreign matter falls into the solder bath main body 25, the foreign matter floats on the molten solder due to its small specific gravity, and is easily collected.

However, when a Pb-free solder having a small specific gravity is used, when foreign matter falls into the solder bath main body 25, the foreign matter sinks into the molten solder and cannot be collected. Then, the sunk foreign matter is injected into the jet pump 2
8, the jet screw 43 may be damaged or stopped.

Therefore, in the present embodiment, the filter plate 47 is provided at a position where the molten solder of the jet pump 28 is sucked. The filter plate 47 is a metal plate in which a large number of small holes 48 are formed as shown in an enlarged manner in FIG. And this filter plate 47
As shown in FIG. 3 and FIG. 6, the mounting member 49 is mounted on the lower surface of the pump housing 41 serving as a suction port for molten solder. By arranging the filter plate 47 in the jet pump 28 in this way, it is possible to prevent the jet pump 28 from being damaged by foreign matter intrusion, and to improve the reliability of the soldering apparatus 10.

Next, the second heater 30 and the first and second heaters 30
The configuration of the temperature sensors 31 and 32 will be described.

In this embodiment, in addition to the first heater 29,
The configuration is such that a second heater 30 is provided. The first heater 29 is also provided in a conventional soldering apparatus, and is disposed on a side wall of the solder bath main body 25. When Sn-Pb solder having a low melting point is used as in the prior art, the control temperature (250 ° C.) of the molten solder is higher than the melting point (183 ° C.) of the solder with a margin.
Even with the configuration in which only the first heater 29 was provided in the solder bath main body 25, the temperature of the molten solder in the solder bath main body 25 could be maintained uniformly.

On the other hand, when a Pb-free solder having a high melting point is used, the melting point of the molten solder is 220 ° C. to 230 ° C.
And Sn-Pb solder, so that the solder bath body 2
5, only the first heater 29 disposed on the side wall 5 has a melting point of 220 ° C.
There were places below ℃. Specifically, the temperature is likely to decrease at the bottom center of the solder bath main body 25.

The center of the bottom of the solder bath body 25 is
Since it is separated from the first heater 29 and has high heat dissipation, it is considered that the temperature tends to decrease. This position is located in the flow path through which the molten solder flows by the jet pump 28. Therefore, when the temperature of the molten solder decreases in this flow path, the fluidity of the solder decreases, which may adversely affect the driving of the jet pump 28.

For this reason, in this embodiment, as shown in FIGS. 4 and 5, in addition to the conventional first heater 29, the vicinity of the flow path through which the molten solder flows, The second heater 30 was disposed at the center of the bottom.

With this configuration, the solder in the solder bath main body 25 is supplied to the second heater 30 provided near the flow path of the molten solder in addition to the first heater 29 provided conventionally. Therefore, variation in the temperature distribution of the solder in the solder bath main body 25 can be reduced, and good soldering processing can be performed. For the same reason, the jet pump 2
8 can be prevented from being adversely affected.

On the other hand, the first and second temperature sensors 31,
Reference numeral 32 is mounted on the solder holder main body 25 after being mounted on the sensor holder 52. These temperature sensors 31, 32
Is provided to determine the start timing of the jet pump 28 described above. That is, if the jet pump 28 is started in a state where the solder is not completely melted, the jet screw 43 may not be rotated and the jet pump 28 may be damaged. Therefore, the solder temperature in the solder bath main body 25 is measured, and when the solder is completely melted, the jet pump 28
Is started. For this reason, the solder bath main body 25 is provided with first and second temperature sensors 31 and 32 for measuring the temperature of the solder. By the way, in the conventional soldering apparatus, only one temperature sensor for measuring the temperature of the molten solder is provided, and the temperature measurement position is the upper position in the solder bath main body 25. This is because the melting point of the Sn-Pb solder was low in the past and the temperature of the molten solder in the solder bath body was substantially uniform, so that the temperature was measured at any position in the solder bath body. This is because it is equivalent to measuring the temperature at all positions in the solder bath body.

However, when Pb-free solder having a high melting point is used, the temperature distribution in the solder bath body 25 tends to be non-uniform as described above. Therefore, in order to determine whether the solder in the solder bath main body 25 is completely melted, in this embodiment, two temperature sensors 31 and 3 are used.
2 is provided. As shown in FIG. 5, the first temperature sensor 31 is set longer than the second temperature sensor 32, and is configured to measure the solder temperature near the bottom of the solder bath main body 25. In contrast, the second
The temperature sensor 32 is short and configured to measure the solder temperature at the upper position of the solder bath main body 25.

As described above, the central portion at the bottom of the solder bath main body 25 is a portion where heat radiation is likely to occur, and a position where molten solder is sucked into the jet pump 28. Therefore,
In order to prevent the jet pump 28 from being damaged, it is necessary to confirm that the temperature at the bottom center position is surely higher than the melting temperature of the solder. For this reason, in the present embodiment, the first temperature sensor 31 is configured to measure the temperature at the center of the bottom of the solder bath main body 25.

FIG. 9 is a block diagram of a control system for starting and controlling the jet pump 28, and FIG.
5 is a flowchart of a start-up control process performed by the device. FIG.
As shown in (1), the temperature at a predetermined position in the solder bath main body 25 detected by the first temperature sensor 31 and the second temperature sensor 32 is sent to the control device 19. Then, the control device 19 performs the startup control process shown in FIG. 10 to perform the startup process of the jet pump 28.

The startup control process of the jet pump 28 shown in FIG. 10 is started when the soldering apparatus 10 is started. When the activation control process of the jet pump 28 is activated, first, in step 10 (step is abbreviated as S in the figure), the first temperature sensor 31 is activated, and the temperature at the bottom center of the solder bath main body 25 is increased. Perform the measurement. The temperature information measured by the first temperature sensor 31 is transmitted to the control device 19.

In the following step 11, the control device 19 determines whether or not the temperature at the bottom center of the solder bath main body 25 measured by the first temperature sensor 31 has reached the melting point of the solder. The processing of steps 10 and 11
The process is repeatedly performed until the temperature at the bottom center of the solder bath main body 25 becomes equal to or higher than the melting point of the solder.

Then, in step 11, when control device 19 determines that the temperature at the bottom center of solder bath main body 25 has become equal to or higher than the melting point of the solder (YES in step 11), the process proceeds to step 12, and control device 19 proceeds to step 12. The temperature sensor is switched from the first temperature sensor 31 to the second temperature sensor 32. Therefore, after this switching process,
The temperature of the upper part of the solder bath main body 25 measured by the second temperature sensor 32 is sent to the control device 19 (step 13).

In the following step 14, the control device 19
It is determined whether the temperature of the upper part of the solder bath main body 25 measured by the second temperature sensor 32 has reached the melting point of the solder. Steps 13 and 14 are repeatedly performed until the temperature of the upper part of the solder bath main body 25 becomes equal to or higher than the melting point of the solder.

Then, the controller 19 controls the solder bath main body 25.
If it is determined that the temperature at the top of the solder has become equal to or higher than the melting point of the solder (YES in step 14), the process proceeds to step 15, and the control device 19 starts the jet pump 28. That is,
When the controller 19 determines from the outputs from the first temperature sensor 31 and the second temperature sensor 32 that both the bottom center and the top of the solder bath main body 25 have a melting point or higher, the whole of the solder bath main body 25 is It is determined that the solder is melted, and the jet pump 28 is started. At this time, in order to further complete the processing, after the affirmative determination is made in step 14, the processing of step 15 is carried out after waiting for a predetermined time to elapse. By performing the above-described startup control processing, the jet pump 28 can be started at an appropriate timing. Therefore, it is possible to prevent the jet pump 28 from being damaged, and to prevent a decrease in throughput due to an unnecessarily long waiting time until startup.

In this embodiment, two temperature sensors 3
The number of the temperature sensors is not limited to two, but may be three or more (the temperature measurement positions of the temperature sensors are different). . With this configuration, the temperature distribution in the solder bath main body 25 can be known more accurately, and the startup control of the jet pump 28 can be performed more accurately.

Further, in the above embodiment, the example in which the activation of the jet pump 28 is controlled by the outputs from the two temperature sensors 31 and 32 has been described, but the activation processing for the other components constituting the soldering apparatus 10 has been described. May be similarly performed.

Subsequently, the transfer device 13 provided in the soldering device 10 will be described mainly with reference to FIGS. 1, 2, 8 and 11. As shown in FIG. 1 and FIG. 2, the transport device 13 is configured by transport conveyors 13A and 13B. This transport conveyor 13A, 13
A conveyor drive motor 17 is provided at each of the carry-in position A and the carry-out position B of B. A conveyor chain (not shown) provided on each of the conveyors 13A and 13B is driven by the conveyor drive motor 17 to move from the carry-in position A to the carry-out position B.

The conveyor chains provided on each of the conveyors 13A and 13B are provided with a plurality of conveyor claws 60, which are enlarged in FIG. 8, and are arranged opposite to the conveyors 13A and 13B. An object to be soldered, such as a printed wiring board, is mounted between the pair of transport conveyor claws 60. More specifically, a mounting portion 61 is formed on each of the conveyor claws 60, and an object to be soldered is conveyed while being locked by the mounting portion 61.

Incidentally, the size of the object to be soldered is not uniform, and there are various sizes. Therefore, the distance between the transport conveyor 13A and the transport conveyor 13B constituting the transport device 13 is configured to be variable so that the objects to be soldered having various sizes can be transported. here,
Regarding the structure of the conventional conveyors 13A and 13B,
This will be described with reference to FIG.

In the transfer device provided in the conventional soldering apparatus, the transfer conveyor 13A is fixed, and the transfer conveyor 13B can be moved in the direction of the arrow with respect to the transfer conveyor 13A. And it was. That is, in the related art, a dashed line indicated by an arrow C1 in FIG.
By moving the conveyor 13B with respect to the above, the configuration is adapted to accommodate objects of various sizes.

However, it has been found that in the transfer device having the conventional configuration, soldering defects are likely to occur frequently on the object to be soldered particularly at a position close to the reference position C1. This poor soldering is considered to occur for the following reasons. That is, the upper plate 35 of the second jet nozzle 27A
Looking at the flow of the molten solder above, FIG.
As shown by the solid arrows in FIG. 3A, the flow of the molten solder on the upper plate 35 is not uniform over the entire width, and at a position close to the guide plate 36A, the flow speed of the molten solder is low and the flow direction is also low. Not linear. This is because, as described above, the temperature near the guide plate 36A is likely to decrease, and the guide plate 36A functions as a flow resistance.

Conventionally, since the reference position C1 is provided at a side position where the flow of the molten solder is unstable, the object to be soldered necessarily passes through the position where the flow of the molten solder is unstable. It had been. It is known that the flow state of molten solder greatly affects the quality of soldering, and that if the flow is unstable, the quality of soldering deteriorates. For this reason, soldering failure has conventionally occurred.

However, as shown in FIG. 11A, the flow of the molten solder at the center of the upper plate 35 is uniform and stable. Therefore, in the present embodiment, the reference position for positioning the conveyors 13A and 13B of the conveyor 13 is set at the center position on the upper plate 35.

That is, the reference positions of the conveyors 13A and 13B were set to the positions indicated by the dashed line indicated by the arrow C2 in FIG. 11B. The reference position C2 is a center position of the jet nozzle 27 in the width direction.

When setting the separation distance between the conveyors 13A and 13B according to the size of the object to be soldered,
The setting is made by moving each of the conveyors 13A and 13B in the direction of the arrow in the figure around the reference position C1.

With this configuration, the transport device 13
When conveying the object to be soldered, the center of conveyance of the object to be soldered coincides with the reference position C2. Therefore, the material to be soldered is subjected to soldering at a position where the flow of the molten solder is uniform and stable, and high quality soldering can be performed.

Further, as shown in FIG.
Is provided with a claw cleaning device 16 to oppose the conveyors 13A and 13B. This nail cleaning device 16
As shown in FIG. 8 in an enlarged manner, it is provided so as to face a conveyor claw 60 provided on the conveyor chain. The nail cleaning device 16 is provided with the conveyor nail 6.
It is composed of a flux injection nozzle 63 for applying a flux to 0, and a brush 62 for removing unnecessary solder attached to the conveyor claw 60.

Since the conveyer claw 60 performs the soldering process in the solder bath 12 with the object to be soldered mounted thereon, the solder is likely to adhere. However,
By providing the nail cleaning device 16, the mounting portion 61 to which the object to be soldered is mounted by the flux injection nozzle 63.
A flux for preventing the adhesion of solder is applied in the vicinity. Therefore, it is possible to prevent the solder from adhering to the conveyor nail 60. In addition, since the unnecessary solder that has adhered is removed by the brush 62,
The conveyor claw 60 can always be kept clean.

Next, a description will be given of a solder bath 65 which is a modification of the solder bath 12 described above. FIG. 12 is a schematic configuration diagram illustrating the solder bath 65. In FIG. 12,
The same components as those of the solder bath 12 described with reference to FIGS. 3 to 5 are denoted by the same reference numerals, and description thereof will be omitted.

Since the soldering apparatus 10 has a configuration in which molten solder is discharged from the first and second jet nozzles 26 and 27 to perform a soldering process on an object to be soldered.
Oxide (dross) is likely to be generated on the upper part of the molten solder stored in the solder bath main body 25. This dross is unnecessary for the soldering process, and if deposited in a large amount, has a bad influence on the solder quality.

Therefore, it is necessary to remove the dross floating in the molten solder, but conventionally, the dross was manually and periodically removed. However, it is troublesome to remove dross manually, and it is dangerous because dross floating in the molten solder is removed.

Therefore, in the solder bath 65 shown in FIG.
Dross generated in molten solder is automatically collected in one place,
It is configured to be able to automatically remove the collected dross. Hereinafter, the configuration of the solder bath 65 will be described.

The solder bath 65 is provided with an unnecessary solder moving device 70.
And an unnecessary solder discharging device 75. The unnecessary solder moving device 70 is generally constituted by an unnecessary solder moving screw 71 and a drive motor 74. The unnecessary solder transfer screw 71 is provided between the inner wall of the solder bath main body 25 and the first jet nozzle 26, between the first jet nozzle 26 and the second jet nozzle 27, and between the second jet nozzle 27 and the second jet nozzle 27. They are respectively arranged between the solder tank main body 25 and the inner wall.

A pulley 72 is attached to an end of the screw 71 for transferring unnecessary solder. Each pulley 72 is connected to a drive motor 7 via a drive belt 73.
4 is connected. Accordingly, the drive motor 74 is driven to rotate the respective unnecessary solder moving screws 71.

The direction of rotation of the unnecessary solder transfer screw 71 is determined by the dross generated above the molten solder stored in the solder bath main body 25 at an unnecessary object removing position below the figure (the position indicated by arrow D in the figure). ). Therefore, dross (unnecessary matter) generated above the molten solder is collected by the moving device 70 at the unnecessary matter removing position D in the solder bath 12.

The unnecessary solder discharging device 75 is connected to the solder bath 12.
Is disposed at the unnecessary object removing position D. Solder bath body 2
A discharge opening 76 is formed at the unnecessary material removing position D of No. 5, and the dross collected at the unnecessary material removing position D is sucked into the unnecessary solder discharging device 75 through the discharge opening 76. ing. The dross sucked into the unnecessary solder discharging device 75 is sent to a drain for discarding the dross.

As described above, the solder bath 6 according to this modification is
In 5, the dross is collected at the unnecessary object removing position D in the solder bath 12 by the unnecessary solder moving device 70, and thereafter is removed from the solder bath 12 to the outside by the unnecessary solder discharging device 75. Therefore, the process of removing dross from the solder bath 12 can be easily performed without using any manual operation, and a high-quality soldering process can always be performed.

In the above embodiment, a dual wave type flow soldering device has been described as an example of the soldering device. However, the application of the present invention is not limited to this. The present invention can be applied to various soldering devices to be used.

[0097]

According to the present invention as described above, the following various effects can be realized.

According to the first aspect of the present invention, in addition to the first heater conventionally provided, the second heater is provided in the vicinity of the flow path of the molten solder. Of the temperature distribution can be reduced, and good soldering processing can be performed.

According to the second aspect of the present invention, the second
By disposing the heater at the center of the bottom of the solder bath where heat is likely to be radiated in the solder bath, that is, the temperature tends to be low, the variation in the temperature distribution of the solder in the solder bath can be effectively reduced.

According to the third aspect of the present invention, the temperature of the molten solder in the jet nozzle is reduced by arranging the third heater in the jet nozzle where the temperature is likely to decrease due to the discharge of the molten solder. Can be suppressed, and good soldering processing can be performed.

According to the fourth aspect of the present invention, the guide plate guides the flow of the molten solder, and since the heat radiation of the molten solder by the guide plate is suppressed to a small level, the flow of the molten solder can be stabilized. Prevention of temperature reduction can be realized together.

Further, according to the fifth aspect of the present invention, the molten state of the solder in the solder bath can be surely known, and another configuration for performing a soldering process such as a jet pump can be properly adjusted at an appropriate timing. It is possible to start.

According to the sixth aspect of the present invention, since the filter member for preventing foreign matter from entering is provided at the molten solder inlet of the jet pump, it is possible to prevent the jet pump from being damaged by foreign matter entering. can do.

According to the seventh aspect of the present invention, it is possible to prevent an unnecessary object from being accumulated at a position where the soldering process is performed, thereby preventing a defective soldering. In addition, since unnecessary materials are collected at the unnecessary material removal position,
Unnecessary substances can be easily removed.

According to the eighth aspect of the present invention, the unnecessary objects collected at the unnecessary object removing position by the moving device are automatically discharged to the outside of the solder bath by the discharging device, so that the unnecessary devices are unnecessary without using any manual operation. An object can be removed.

According to the ninth aspect of the present invention, the soldering process can be performed on the object to be soldered at a position where the flow speed of the molten solder is stable. Can be attached.

According to the tenth aspect of the present invention, by applying a flux to the transport claw by the coating device, it is possible to prevent the solder from being attached to the transport claw, and it is also possible to prevent the solder from being unnecessarily attached. Since the solder is removed by the removing brush, the transport claw can be always kept clean.

[Brief description of the drawings]

FIG. 1 is a plan view showing the overall configuration of a soldering apparatus according to one embodiment of the present invention.

FIG. 2 is a front view showing an overall configuration of a soldering apparatus according to one embodiment of the present invention.

FIG. 3 is an exploded perspective view of a solder bath provided in the soldering apparatus according to one embodiment of the present invention.

FIG. 4 is a plan view of a solder bath provided in the soldering apparatus according to one embodiment of the present invention.

FIG. 5 is a cross-sectional view (a cross-sectional view along line XX in FIG. 4) of a solder bath provided in the soldering apparatus according to one embodiment of the present invention;

FIG. 6 is a sectional view showing a jet pump provided in a soldering apparatus according to one embodiment of the present invention.

FIG. 7 is a perspective view showing a filter plate provided in the jet pump.

FIG. 8 is a diagram for explaining a nail cleaning device provided in the soldering device according to one embodiment of the present invention.

FIG. 9 is a block diagram of a control system that performs startup control of a jet pump in the soldering apparatus according to one embodiment of the present invention.

FIG. 10 is a flowchart showing a jet pump startup control process performed by the control device.

FIG. 11 is a diagram for explaining a transfer device provided in the soldering device according to one embodiment of the present invention.

FIG. 12 is a view for explaining a solder bath having an unnecessary solder moving device.

[Explanation of symbols]

 Reference Signs List 10 soldering device 11 housing 12, 65 solder bath 13 transfer device 13A, 13A transfer conveyor 16 claw cleaning device 19 control device 25 solder bath main body 26 first jet nozzle 27, 27A second jet nozzle 28 jet pump 29 first Heater 30 second heater 31 first temperature sensor 32 second temperature sensor 36 guide plate 37, 38 nozzle housing 39 third heater 40 third temperature sensor 41 pump housing 42 rotating shaft 43 jet screw 47 filter plate 48 Small hole 54 Drive motor 60 Conveyor claw 61 Mounting part 62 Brush 63 Flux injection nozzle 70 Unnecessary solder transfer device 71 Unnecessary solder transfer screw 75 Unnecessary solder discharge device

Continued on the front page (72) Inventor Yasuhiko Kajitani 32-1, Senju Asahi-cho, Adachi-ku, Tokyo Hiroteru, Inc. (72) Inventor Masayoshi Nishi 10-7-6 Tajima, Urawa-shi, Saitama Prefecture (72) Inventor Naoshi Ishigaki 1601 Sakai, Atsugi-shi, Kanagawa Prefecture Mitsumi Electric Co., Ltd.Atsugi Office (72) Inventor Etsuhisa Ikeda 1601, Sakai, Atsugi-shi, Kanagawa Prefecture Mitsumi Electric Co., Ltd.Atsugi Office F-term (reference) 4E080 AA01 AB03 AB07 BA09 BA14 CB04 DA02 DA04 5E319 AA01 AC01 BB01 CC24 CC28 CC58 CD21 CD22 CD23 CD28 CD31 CD35 CD42 GG07

Claims (10)

[Claims] 1. A solder bath for disposing a heater for melting solder and storing the molten solder, a jet nozzle disposed in the solder bath for discharging the molten solder, and What is claimed is: 1. A soldering apparatus having a jet pump for supplying solder to a jet nozzle, comprising: a first heater provided on an inner wall of the solder tank; and a flow path of the molten solder in the solder tank. A soldering device comprising a second heater disposed in the vicinity. 2. The soldering apparatus according to claim 1, wherein the second heater is disposed at the center of the bottom of the solder bath. 3. The soldering apparatus according to claim 1, wherein a third heater is provided in the jet nozzle. 4. The soldering apparatus according to claim 1, wherein a guide plate for guiding the flow of the molten solder is provided in the jet nozzle, and the guide plate for guiding the molten solder flowing on the jet nozzle is provided. The length of the guide plate with respect to the flow direction is set to be equal to or less than the length of the jet nozzle with respect to the flow direction of the molten solder. 5. A solder bath in which molten solder is stored, a jet pump provided in the solder bath and supplied to a jet nozzle for discharging the molten solder, What is claimed is: 1. A soldering apparatus comprising: temperature measuring means for measuring a temperature; and control means for controlling driving of the jet pump based on a solder temperature measured by the temperature measuring means. And wherein the height positions at which the plurality of temperature sensors measure the solder temperature are different from each other in the solder bath. 6. A solder bath for storing molten solder, a jet nozzle disposed in the solder bath for discharging the molten solder, and a jet pump for supplying the molten solder to the jet nozzle. And a filter member for preventing intrusion of foreign matter is provided at an inlet of the molten solder of the jet pump. 7. A solder tank in which molten solder is stored, a jet nozzle disposed in the solder tank for discharging the molten solder, and a jet pump for supplying the molten solder to the jet nozzle A soldering device having a moving device for moving an undesired material floating above the molten solder in the solder bath toward an unnecessary material removing position in the solder bath. Mounting device. 8. The soldering apparatus according to claim 7, further comprising a discharge device that discharges the unnecessary objects collected at the unnecessary object removal position by the moving device to the outside of the solder bath. Soldering equipment. 9. A solder bath in which molten solder is stored, a jet nozzle disposed in the solder bath, for discharging the molten solder, and a jet pump for supplying the molten solder to the jet nozzle. And a transfer device for transferring the object to be soldered to the solder tank, wherein the transfer center position at which the transfer device conveys the object to be soldered is set at the center in the width direction of the jet nozzle. A soldering device characterized by matching the position. 10. The soldering device according to claim 9, wherein the transport device includes a transport claw portion on which the object to be soldered is mounted, a coating device that applies a flux to the transport claw portion, A soldering device, comprising: a removing brush for removing unnecessary solder attached to a transport claw portion.