JP2003179337A - Cooling device for soldering and soldering device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling device for soldering capable of coping with lead free solder and a soldering device using the cooling device. <P>SOLUTION: The soldering device is provided with a conveyor 11 carrying a work W, a jet type solder tank 12 for soldering arranged on the lower side of the conveyor 11 and the cooling device 13 for soldering arranged on the downstream side of the jet type solder tank 12. The cooling device 13 for soldering is provided with a lower side cooling means 16 cooling the work W soldered in the jet type solder tank 12 from the lower side and an upper side cooling means 17 capable of cooling the work W from an upper side on a soldering side more than the lower side cooling means 16. The lower side cooling means 16 and the upper side cooling means 17 are provided with a cold air supply source 21 generating temperature-adjusted cold air and cold air jetting devices 23 and 24 jetting the cold air supplied from the cold air supply source 21 to the work W. The cold air jetting device 24 of the upper side cooling means 17 is provided so as to be moved and adjusted parallelly to a work moving direction. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering cooling device and a soldering device for cooling a soldered work.

[0002]

2. Description of the Related Art As shown in FIG. 4, conventionally, a printed wiring board (hereinafter, this printed wiring board is simply referred to as "board") P is provided with an electronic component (hereinafter, this electronic component is simply referred to as "component"). Along the conveyor 1 that conveys the work W on which E is mounted, below the conveyor 1 is a preheater 2 that preheats the work W, and a jet solder bath 5 that has a primary nozzle 3 and a secondary nozzle 4. A cooling fan 6 for cooling the work W soldered by the jet solder bath 5 is sequentially arranged.

The work W conveyed by the conveyor 1 is preheated from the lower side by the radiant heat emitted from the preheater 2 to gradually raise the temperature of the work W and carried into the upper side of the jet solder bath 5. Substrate P of the processed work W
And the lead L of the component E mounted on the substrate P are soldered by the jet solder wave 3a jetted from the primary nozzle 3 of the jet solder bath 5 and the jet solder wave 4a jetted from the secondary nozzle 4. Then, the work W after soldering is cooled by the cooling fan 6.

Solid and dotted lines shown in FIG. 3 show the substrate surface temperature profile of the work W soldered by such a conventional soldering apparatus.

Recently, lead-free soldering that does not use lead has been performed due to environmental problems. Lead-free solder has a higher melting point than the conventional tin-lead solder, while the substrate is Each component mounted on has its own heat resistant temperature, and the melting point of lead-free solder is close to the heat resistant temperature of the component, so even when cooling after soldering,
More stringent conditions are required for cooling timing and the like.

[0006]

However, since the conventional cooling fan 6 is installed at a fixed position on the downstream side of the jet type solder bath 5, the work W cannot be cooled quickly and the secondary cooling fan 6 cannot be cooled. It takes time for the lead-free solder soldered to the work W by the jet solder wave 4a jetted from the nozzle 4 to be cooled until sufficient strength is obtained, causing troubles regarding the contraction timing of the lead-free solder. ing.

For example, as shown in FIG. 5, a so-called shrinkage cavity A is generated in a part of the solder joint portion S which is solidified by rising from the lower surface land portion a of the substrate P to the upper surface land portion b via the lead L. Lift-off B occurs in which the upper surface land portion b is peeled off or broken from the substrate surface.

Further, if the work W is not cooled quickly, there may be a problem in heat resistance depending on the board mounting parts.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a soldering cooling device capable of handling lead-free solder and a soldering device using this cooling device. .

[0010]

According to a first aspect of the present invention, there is provided a lower side cooling means for cooling the soldered work from the lower side, and a work side from the upper side on the soldering side of the lower side cooling means. A cooling device for soldering, comprising an upper cooling means capable of cooling, wherein an upper cooling means positioned on the soldering side of the lower cooling means before cooling the soldered work by the lower cooling means. By cooling the work from above, a cooling device for soldering that can handle high melting point lead-free solder is provided. That is, by quickly cooling the high melting point lead-free solder immediately after the completion of soldering with the upper side cooling means, it is possible to prevent the occurrence of troubles related to the solder shrinkage timing such as shrinkage cavities during lead-free solder cooling and lift-off, Do not impair the heat resistance of the parts.

According to a second aspect of the invention, there is provided a soldering cooling device in which the upper cooling means according to the first aspect is provided so as to be movable in parallel with the work moving direction. The cooling means is installed at a position where an optimum work surface temperature profile can be obtained. For example, even when the detachment point at which the work detaches from the jet solder wave is changed according to the work, the upper cooling means is moved and adjusted to be installed at an optimal position that can be dealt with.

In the invention described in claim 3, the lower cooling means and the upper cooling means according to claim 1 or 2 are supplied from a cold air supply source for generating temperature adjusted cold air and a cold air supply source. Cooling device for soldering equipped with a cool air blower that blows cool air toward the work, and cools the work efficiently by blowing the temperature-controlled cool air from the cold air supply source to the work. To do.

According to a fourth aspect of the present invention, there is provided a conveyor for transporting a work, a soldering jet type solder bath arranged on the lower side of the conveyor, and a lower side of the conveyer downstream of the jet type solder bath. 4. The lower cooling means is arranged in the upper part, and the upper cooling means is arranged in the upper part of the conveyor.
Which is a soldering device comprising a soldering cooling device according to any one of 1 to 3, before the soldered work is cooled by the lower side cooling means, is positioned closer to the jet solder bath than the lower side cooling means. By cooling the work from the upper side by the upper side cooling means, it is possible to provide a soldering apparatus that can handle high melting point lead-free solder. That is, by quickly cooling the work immediately after it is separated from the jet solder wave in the jet solder bath, it is possible to prevent the occurrence of troubles related to the solder shrinkage timing such as shrinkage cavities and lift-off during lead-free solder cooling, and Do not impair the heat resistance of.

According to a fifth aspect of the present invention, there is provided a soldering device in which the lower cooling means according to the fourth aspect includes a cold air jet guide plate for jetting cold air in a direction opposite to the jet type solder bath. By blowing cold air in the direction opposite to the jet type solder bath by the cold air jet guide plate, the jet type solder bath and the molten solder jetted from this jet type solder bath are prevented from being cooled, and high melting point lead To be compatible with free solder.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will now be described in detail with reference to the embodiment shown in FIGS.

In FIG. 1, a conveyor 11 for conveying a work W is shown.
Along with, the soldering provided with a jet solder bath 12 for soldering arranged on the lower side of the conveyor 11, and a soldering cooling device 13 arranged on the downstream side of the jet solder bath 12. The device is shown.

The work W is a printed wiring board (hereinafter, this printed wiring board is simply referred to as a "substrate") on which electronic components (not shown, and hereinafter, this electronic component is simply referred to as "components") are mounted. .

The conveyor 11 synchronously runs a pair of endless chains along a pair of guide rails arranged in parallel, and the work W is driven by pins or claws protruding from these endless chains. Lock and transport.

The jet type solder bath 12 is a tin-type solder bath housed in the bath.
Lead-free solder such as silver solder is melted by an internal heater, and the primary nozzles 14 and 2 are heated by an electromagnetic induction pump.
Jet from the next nozzle 15 and these jet solder waves 14a, 1
5a is brought into contact with the work W conveyed by the conveyor 11 and the leads of the components inserted in the board are soldered to the board surface.

The soldering cooling device 13 sandwiches the conveyor 11 for conveying the work W, and below the conveyor 11,
Lower side cooling means 16 for cooling the soldered work W from the lower side is arranged, and upper side cooling means 17 for cooling the soldered work W from the upper side is arranged on the upper side of the conveyor 11.

The lower cooling means 16 and the upper cooling means 17 share a common cold air supply source 21 for generating a temperature-adjusted cold air, and a cold air supplied from the cold air supply source 21 via a duct 22 as a work W. It is provided with cold air blowers 23 and 24 for jetting from below and above, respectively.

The cold air supply source 21 sucks in the air whose temperature is adjusted by an air conditioner such as a built-in spot air conditioner or the air whose temperature is adjusted in the room, and supplies it to the lower and upper cold air ejectors 23 and 24. To do.

Cold air ejector of the lower side cooling means 16 from the duct 22
An opening adjusting plate 26 is movably provided at an inlet 25 to the 23, and a cool air ejector 24 of the upper cooling means 17 is provided from the duct 22.
An opening adjustment plate 28 is movably provided at the entrance 27 to
These opening adjustment plates 26 and 28 adjust the flow rate and flow ratio of the cold air supplied from the cold air supply source 21 to the cold air ejectors 23 and 24.

Inside the cold air blowers 23 and 24 of the lower side cooling means 16 and the upper side cooling means 17, the cold air supplied from the duct 22 is diffused over the entire area of the cold air blowers 23 and 24 to be ejected evenly. For this purpose, a plurality of stages of straightening vanes 29 are provided respectively.

Cold air jet guide plates 30 for jetting cold air are provided on the opening surfaces of the lower air cooling means 16 and the upper air cooling means 17 that face each other, respectively. The cold air jetting guide plate 30 of the lower cooling means 16 is a louver for jetting cold air in the direction opposite to the jet solder bath 12, but the cold air jetting guide plate 30 of the upper cooling means 17 is
A variable louver or the like may be used to blow cold air to the jet solder bath 12 side.

Further, the cold air ejector 24 of the upper side cooling means 17 is
It is arranged on the left side in FIG. 1 so that the work W can be cooled from the upper side on the soldering side, that is, on the jet type solder bath 12 side of the cold air blower 23 of the lower side cooling means 16.

Further, the cool air blower of the upper side cooling means 17
24 is provided so as to be movable and adjustable in parallel with the work moving direction.

That is, the upper cold air blower 24 is moved and adjusted in the perspective direction with respect to the secondary nozzle 15 of the jet type solder bath 12 by a guide rail (not shown) arranged in parallel with the conveyor 11. It is provided so that you can.

For this reason, the duct 22 connected to the upper cool air blower 24 is provided so as to be extendable and flexible so as to accommodate the movement adjustment of the upper cool air blower 24.

Next, the function and effect of the embodiment shown in FIG. 1 will be described with reference to FIGS. 2 and 3.

The work W is conveyed by the conveyor 11 onto the jet solder waves 14a and 15a of the lead-free solder jetted from the primary nozzle 14 and the secondary nozzle 15 of the jet solder bath 12, and these jet solder waves are carried. When 14a and 15a come into contact with the land part on the bottom surface of the board and the component lead protruding from the land part on the bottom surface of the board, the lead-free solder wets and spreads over the entire land part on the bottom surface of the board and the part lead, and the part lead is inserted. It goes up to the land portion on the upper surface of the substrate through the through holes and via holes, and spreads over the entire land portion on the upper surface of the substrate.

In this way, the workpiece W soldered with the high melting point lead-free solder jetted from the primary nozzle 14 and the secondary nozzle 15 of the jet type solder bath 12 is jetted by the jet solder wave of the secondary nozzle 15. After being separated from 15a, the temperature-controlled cold air supplied from the cold air supply source 21 of the soldering cooling device 13 is ejected from the upper cold air ejector 24 onto the work W as soon as possible, so that the work W To quickly and efficiently forcibly cool.

That is, the soldered work W is
Before cooling with the cold air ejected from the cold air ejector 23 of the lower side cooling means 16 in the fixed position, the upper side cooling means located on the jet type solder bath 12 side of the cold air ejector 23 of this lower side cooling means 16
By cooling the work W from the upper side by the cool air blown from the cold air blower 24 of 17, the work W after soldering is immediately and forcibly cooled, and high melting point lead-free solder is dealt with.

For example, when the cool air blower 24 of the upper side cooling means 17 is placed at the standard position shown by the chain double-dashed line in FIG. 1, the upper surface of the substrate is cooled relatively gently as shown in the upper side of FIG. On the other hand, the cold air ejector 24 of the upper side cooling means 17 is shown in FIG.
Moving to the left by 50 mm indicated by the solid line, the start of cooling is accelerated, and the upper surface of the substrate is rapidly cooled as shown in the lower side of FIG.

Further, when the cold air blower 24 of the upper side cooling means 17 is moved leftward from the position shown in FIG. 1 and brought closer to the secondary nozzle 15 of the jet type solder bath 12, it is shown in FIG. As described above, it is possible to start the upper surface cooling by the upper cool air from the separation point where the work W separates from the jet solder wave 15a of the secondary nozzle 15, and the substrate upper surface temperature profile as shown in FIG. 3 is obtained.

Furthermore, the jet solder wave from the secondary nozzle 15
Work W is the departure point where Work W leaves from 15a.
Even if the temperature is changed according to the above, by moving and adjusting the cool air blower 24 of the upper side cooling means 17, it can be installed at a position where an optimum substrate upper surface temperature profile that can cope with the change of the leaving point can be obtained.

In this way, the jet solder wave of the secondary nozzle 15
By cooling the work W separated from 15a as quickly as possible, it is possible to prevent problems related to solder shrinkage timing such as shrinkage cavities and lift-off when cooling lead-free solder, and not to impair the heat resistance of parts. .

Further, the cold air jetting device 23 on the lower side ejects cold air in the direction opposite to the jet type solder bath 12 by means of the cold air jet guide plate 30, so that the jet type solder bath 12 and the jet type solder bath 12 Jetted molten solder Jet solder waves 14a, 1
Prevents the possibility that 5a will be cooled, and makes it possible to handle high melting point lead-free solder.

[0039]

According to the invention described in claim 1, before the soldered work is cooled by the lower side cooling means, the work is cooled by the upper side cooling means located on the soldering side of the lower side cooling means. By cooling from the upper side, it is possible to provide a soldering cooling device that can handle high melting point lead-free solder. That is, by rapidly cooling the high melting point lead-free solder immediately after the completion of soldering with the upper side cooling means, it is possible to prevent the occurrence of troubles related to solder shrinkage timing such as shrinkage cavities during lead-free solder cooling and lift-off, The heat resistance of parts can be secured.

According to the second aspect of the present invention, the upper cooling means can be installed at a position where an optimum work top surface temperature profile can be obtained according to the work. For example, even when the detachment point at which the work is detached from the jet solder wave is changed according to the work, the upper cooling means can be moved and adjusted to be installed at the optimal position.

According to the third aspect of the invention, the work can be efficiently cooled by ejecting the temperature-controlled cold air from the cold air supply source onto the work from the cold air ejector.

According to the fourth aspect of the invention, before the soldered work is cooled by the lower side cooling means, the work is cooled by the upper side cooling means located on the jet type solder bath side of the lower side cooling means. By cooling from the upper side, it is possible to provide a soldering device that can handle high melting point lead-free solder. That is, by quickly cooling the work immediately after it is separated from the jet solder wave of the jet type solder bath, it is possible to prevent the occurrence of troubles related to the solder shrinkage timing such as shrinkage cavities and lift-off at the time of cooling the lead-free solder. The heat resistance of can be secured.

According to the fifth aspect of the present invention, the lower side cooling means ejects the cold air in the direction opposite to the jet type solder bath by the cold air jet guide plate, thereby forming the jet type solder bath and the jet type solder bath. It is possible to prevent the molten solder jetted from from cooling and to cope with high melting point lead-free solder.

[Brief description of drawings]

FIG. 1 is a sectional view showing an embodiment of a soldering cooling device and a soldering device according to the present invention.

FIG. 2 is a characteristic diagram showing a substrate upper surface temperature profile of a work cooled by the same cooling device.

FIG. 3 is a characteristic diagram showing a substrate surface temperature profile of a work to be soldered by a soldering device.

FIG. 4 is a schematic view of a soldering device including a conventional cooling fan.

FIG. 5 is an enlarged cross-sectional view of a problem occurrence portion of a work cooled by a conventional cooling fan.

[Explanation of symbols]

W work 11 conveyor 12 Jet solder bath 13 Cooling device for soldering 16 Lower cooling means 17 Upper cooling means 21 Cold air supply source 23, 24 Cold air blower 30 Cold air blowout guide plate

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Masataka Iijima             11 shares, 591 Kamihirose, Sayama-shi, Saitama             Company Tamura FA System F-term (reference) 4E080 AA01 AB03 AB06                 5E319 AA01 AC01 CC24 CC58 CD35                       CD47 GG03 GG15

Claims (5)

[Claims] 1. A lower cooling means for cooling the soldered work from the lower side, and an upper cooling means capable of cooling the work from the upper side on the soldering side of the lower cooling means. Cooling device for soldering. 2. The cooling device for soldering according to claim 1, wherein the upper side cooling means is provided so as to be movable and adjustable in parallel to the work moving direction. 3. The lower side cooling means and the upper side cooling means are provided with a cold air supply source for generating temperature adjusted cold air, and a cold air ejector for ejecting the cool air supplied from the cold air supply source toward a work. Claim 1 characterized by the above.
Alternatively, the cooling device for soldering according to the item 2. 4. A conveyor for transporting a work, a soldering jet type soldering tank arranged on the lower side of the conveyor, and a lower cooling means on the lower side of the conveyor downstream of the jetting type soldering tank. A soldering device comprising: the cooling device for soldering according to any one of claims 1 to 3, further comprising an upper cooling means arranged on an upper side of the conveyor. 5. The soldering device according to claim 4, wherein the lower cooling means includes a cold air jet guide plate for jetting cold air in a direction opposite to the jet type solder bath.