JPH0512068B2 - - Google Patents

Description

[Detailed Description of the Invention] [Object of the Invention] (Field of Industrial Application) The present invention relates to a jet soldering device,
It is particularly characterized by a nozzle that jets molten solder.

(Prior Art) As shown in FIGS. 6 and 7, in a conventional jet soldering device, molten solder, which is melted by a heater 12 and controlled at a constant temperature inside a solder bath 11, is pumped. 14 from the upper side of the partition plate 15 through the suction hole 16 to the lower side, and is further forced into the inside of the nozzle 18 attached around the nozzle attachment port 17 of the partition plate 15, and from this nozzle 18. It is jetted and further circulated to the suction hole 16 through the lower side of the plate member 19, which removes oxides from the solder surface.

Then, as shown in FIG. 7, the molten solder 13a, which is jetted from the inside of the nozzle at the upper end of the nozzle 18 to the side where the integrated circuit W as the object to be soldered is carried in and the side where it is carried out, is transferred to the molten solder 13a (not shown). The integrated circuit W held by the jig and the leads L are immersed, and a solder film is attached to the surface of the leads L. This coating serves to prevent the leads L from oxidizing.

The integrated circuit W includes a flat package type as shown in FIGS. 4 and 5. This type of integrated circuit W has J-shaped leads L projecting from the lower half of the entire circumference of the package P, as shown in FIG.

Therefore, in order to solder the entire surface of the lead L, the lower half of the package P must also be immersed in the molten solder jetted from the nozzle 18.

(Problem to be Solved by the Invention) However, the package P has a built-in circuit body that does not like the heat of molten solder, and this circuit body must be immersed in high-temperature solder as described above. There is a risk that the high heat conducted through the unobtainable package P may be adversely affected, reducing the reliability of soldering.

An object of the present invention is to provide a jet soldering device that can protect the internal circuit body from the heat of molten solder when soldering the leads of an integrated circuit as an object to be soldered. be.

[Structure of the invention]

(Means for Solving the Problems) The present invention is characterized in that molten solder S contained in a solder bath 21 is pumped to a nozzle 30 by a pump 24, and a jet solder wave is jetted from the nozzle 30.
In the jet soldering device in which the object W to be soldered is soldered by Sn, the nozzle 3
0 has a plurality of soldering object insertion holes 61 on the top surface.
The cover body 31 with the opening is inserted halfway into the molten solder S of the solder insertion, and the inside of this cover body 31 is divided into a plurality of sections corresponding to the insertion openings 61 by the vertical partition plate 34. A nozzle body 35 is provided in the center of each compartment, and a cylindrical solder ascending passage 39 communicating with the discharge side of the pump 24 is provided on the outer periphery of each nozzle body 35. , a solder spouting part 40 is provided at the upper end of this solder rising passage 39, a solder droplet 41 is provided at the center of this solder spouting part 40 and is inclined downwardly inward by the inclined surface part 38; A solder descending passage 42 is provided, and a lower end opening 43 of this solder descending passage 42 is communicated with the solder suction side of the pump 24 via a communication pipe 45 provided in the front solder ascending passage 39.

(Function) The present invention is arranged so that the jet solder wave Sn that is force-fed from the pump 24 to the nozzle 30 and ejected from the solder rising passage 39 to the solder spouting part 40 passes through the solder drop opening 41 and is rolled into the solder falling passage 42 around the outside. When an integrated circuit W as an object to be soldered is placed in the solder outlet 41, the molten solder Sn comes into contact with the leads L around the integrated circuit, but almost does not contact the package P. The circuit body inside the package is protected from heat. The molten solder dropped into the solder descending passage 42 is returned to the solder suction side of the pump 24 through the communication pipe 45.
In particular, the jet solder wave Sn, which has a centrally depressed shape clearly formed by the solder drop opening 41 having the inclined surface portion 38, efficiently contacts the leads that protrude from the outer peripheral surface of the object to be soldered to the lower surface thereof.
In addition, a communication pipe 45 that secures a path for returning the molten solder
As a result, the central depressed shape of the jet solder wave Sn is reliably maintained.

(Embodiments) Hereinafter, the present invention will be described in detail with reference to embodiments shown in FIGS. 1 to 3.

As shown in FIG. 1, a partition plate 22 is welded to the inside of the solder bath 21, and a suction port 23 formed in the partition plate 22 and a rotating centrifugal blade 24a of a pump 24 are arranged on the lower side. ing. This feather 24
The drive shaft 25 that rotates the tank a is rotatably held by a known bearing means as shown in FIG. 6, and is driven by an external motor via a rotation transmission mechanism using a belt.

On the outer periphery of the drive shaft 25 of the pump 24, a cylindrical enclosure body 26 having drive shaft insertion openings 26a on the upper and lower surfaces is provided to accommodate the molten solder S in the solder bath.
A closing plate 27 is inserted halfway inside and seals the upper opening of the solder bath 21 on the outer periphery of the enclosure 26.
A mounting plate 27a is integrally provided around the closing plate 27 and is airtightly attached to the opening edge 21a of the solder bath 21 via a packing 28. Further, a gas supply pipe 29 is welded to a part of the closing plate 27 for supplying an inert gas (nitrogen gas) to the sealed space below the closing plate 27, and a gas supply port 29a is provided in this pipe 29. It is being

Furthermore, the solder bath 21 is provided with a nozzle 30 that jets the molten solder pumped from the pump 24 together with the pump 24 . In this nozzle 30, a cover body 31 is inserted halfway into the molten solder S in the solder bath, and a closing plate 32 is welded to the outer periphery of the cover body 31 to seal the top opening of the solder bath. Closing plate 32
is attached to the opening edge 21a of the solder tank via a packing 33. Furthermore, the cover 3
1 is divided into eight sections by a vertical partition plate 34 as shown in FIG. 2, and a nozzle body 35 of the same structure is provided in the center of each section. Eight double structure cylindrical nozzles are formed by the eight outer cylinder structures formed by the cover body 31 and the partition plate 34 and the inner cylinder structure formed by the nozzle body 35 in each outer cylinder. do.

As shown in FIG. 1 or 3, this nozzle body 35 has an outer square tube section 36 and an inner corner tube section 37.
are integrally provided via the inclined surface portion 38 at the upper end, etc., and are formed into a rectangular tube shape when viewed as a whole.
A rectangular cylindrical solder rising passage 39 communicating with the discharge side of the pump 24 is provided on the outer circumference of the nozzle body 35, and a solder ejecting part 40 is provided at the upper end of this solder rising passage 39. A solder outlet 41 is provided in the center of 40,
A solder descending passage 42 communicating with the solder suction side of the pump 24 is provided below this solder drop opening 41, and an opening 4 at the lower end of this solder descending passage 42 is provided.
3 is inserted into the molten solder S in the solder bath.

Each of the solder descending passages 42 communicates with the pump suction side in the solder tank through the upper part of the receiving plate 44 provided opposite to them and the inside of the communication pipe 45 provided on the side surface of each nozzle body 35. ing. Left and right side plates 46 are provided at the bottom of the nozzle body 35.
between the receiving plate 44 as shown in FIG.
A V-shaped flow divider plate 47 in contact with is integrally provided,
As shown in FIG. 1, a solder supply port 48 provided along the side plate 46 connects the communication pipe 4.
The solder supply port 48a provided along the flow divider plate 47 communicates with the solder rising passage 39 on the other two sides through the outer periphery of the solder rising passage 39 on the other two sides as shown in FIG. is communicated with.

As shown in FIG. 1, each solder supply port 48 is provided with guide plates 51, 52, 53, and 54 that project downwardly as they move away from the pump 24 in an inclined manner. These guide plates are used for molten solder Sn spouted onto the upper side of each nozzle body 35.
This is to make the wave height uniform.

Each nozzle body 35 is provided on the upper surface of the cover 31.
A soldering object insertion port 61 corresponding to the solder drop port 41 is opened. And this insertion port 6
The top surface of the package of the integrated circuit W as the soldering object is vacuum-adsorbed to the lower end opening of the soldering object adsorption nozzle 62 which is moved up and down through the soldering object 1, and this integrated circuit W is placed directly above the solder droplet 41. Moved up and down.

A lower heater chamber 71 of the solder bath 21,
A heater (not shown) is inserted into this heater chamber 71. Further, a pump chamber 73 is defined above the heater chamber 71 by a partition plate 72.
Solder discharge port 74 on the nozzle side of this pump chamber 73
is opened.

The mounting portion 27a of the closing plate 27 having the surrounding body 26 is connected to the solder tank 21 by bolts 81.
The closing plate 32 of the cover body 31 is also detachably attached to the opening edge 21a of the cover body 31 using bolts 82, and at this time, an engagement plate 83 welded to the cover body 31 and the lower part in the form of a flange is attached. It engages with the partition plate 22. The closing plates 27 and 32 are removed when cleaning the inside of the solder bath 21, for example.

Next, the operation of this embodiment will be explained.

An inert gas such as nitrogen is supplied to the gas supply pipe 29 from an external gas tank or the like, and the solder bath sealed by the closing plates 27 and 32 is filled with the inert gas from the gas supply port 29a. This unconventional gas fills the upper part of the solder bath 21, except for the inside of the enclosure 26 and the inside of the cover 31, and comes into contact with the molten solder surface. Oxidation phenomena can be suppressed, and the amount of solder consumed due to oxidation can be reduced. Furthermore, by sealing the top opening of the solder bath 21 with the closing plates 27 and 32, there is a heat insulating effect that suppresses the heat released from the top opening to the outside, so that the power consumption of the heater in the bath can be saved. There is also.

In such a solder bath 21, the pump 24
The molten solder sent out from the discharge port 74 by the rotating centrifugal blade 24a of each nozzle unit ascends through the rectangular tube-shaped ascending passage 39 from the four supply ports 48, 48a, and reaches the upper end of the double structure rectangular tube nozzle. At the spouting part 40, the solder flows uniformly from all sides through the slope part 38 into the central droplet 41, flows down the descending passage 42 under its own weight, returns to the inside of the solder bath 21, and then passes through the communication pipe 45 and the like from the suction port 23. It is sucked into the centrifugal blade 24a.

In such a circulation system for molten solder, when the suction nozzle 62 is lowered by an air cylinder or the like (not shown) and the integrated circuit W, which is vacuum-adsorbed by the nozzle 62, is lowered to the drop port 41, the integrated circuit W is lowered to the drop port 41. The leads L arranged on the four sides of the package P of the integrated circuit W flow into the solder outlet 41 from all sides through the inclined surface part 38 at the upper end of the double structure cylindrical nozzle in an inclined manner, and a jet stream having a concave shape is formed in the center. The entire surface of each lead L is soldered by being immersed in the solder wave Sn. At this time, since there are few high-temperature jet solder waves Sn that come into contact with the package P, the heat of the molten solder does not have an adverse effect on the circuit body inside the package P. This integrated circuit W
Immediately after this soldering, it is raised and taken out above the insertion opening 61.

In the above embodiments, a flat package type integrated circuit was exemplified as an object to be soldered, but the present invention is not limited to this. For example, a rectangular dual-in-line type package integrated circuit, and furthermore, It can be anything.

Further, in the above embodiment, the planar shape of the nozzle body 35 was formed into a square to match the flat package type integrated circuit, but the present invention is not limited to this shape, and may be modified depending on the shape of the object to be soldered, for example. It may be rectangular, circular, etc.

〔Effect of the invention〕

According to the present invention, a plurality of double-structured cylindrical nozzles can be easily formed by the cover, the vertical partition plate that divides the inside of the cover into a plurality of sections, and the nozzle body in each section, and each of the cylindrical nozzles The molten solder that spews out from all sides flows into the solder drop opening that has a sloped surface formed at the center of the solder spouting part, and a jet solder wave with a drop-down shape in the center is clearly formed. It is possible to efficiently bring molten solder into contact with the leads protruding from the outer peripheral surface of the attachment to the lower surface. Since a communication pipe provided through a part of the cylindrical solder ascending passage can secure a return path for the molten solder, the central part of the jet solder wave formed along the slope at the solder drop port falls. The shape is reliably maintained. As a result, the integrated circuit as a soldering object supplied from the soldering object insertion port of the cover to the solder drop port can be soldered in all directions with respect to the leads on the circumferential surface of the package without allowing the molten solder to come into contact with the package. At the same time, the molten solder flowing down from the package allows efficient soldering, and the circuit body inside the package can be effectively protected from the heat of the molten solder.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing an embodiment of the jet soldering apparatus of the present invention, Fig. 2 is a plan view thereof, Fig. 3 is a sectional view taken along the line - - of Fig. 1, and Fig. 4 is a front view of an integrated circuit. 5 is a plan view, FIG. 6 is a sectional view showing a conventional jet soldering device, and FIG.
It is a sectional view taken along the line - in the figure. S...molten solder, Sn...jet solder wave, W
...Integrated circuit as an object to be soldered, 21...
Solder bath, 24...Pump, 30...Nozzle, 3
DESCRIPTION OF SYMBOLS 1... Cover body, 34... Vertical partition plate, 35... Nozzle main body, 38... Inclined surface part, 39... Solder rising passage, 40... Solder spouting part, 41... Solder drop port, 42... Solder Descending passage, 43...Descent opening, 45...Communication pipe, 61...Soldering object insertion port.

Claims (1)

[Claims] 1. A jet type in which molten solder contained in a solder tank is forced into a nozzle by a pump, and objects to be soldered are soldered by jet solder waves jetted by the nozzle. In the soldering device, the nozzle inserts a cover body having a plurality of soldering object insertion openings in the upper surface partway into molten solder in a soldering bath, and inserts the inside of the cover body into a vertical partition plate. Therefore, it is divided into a plurality of sections corresponding to the insertion ports, and a cylindrical nozzle body is provided in the center of each section, and the discharge side of the pump is provided on the outer periphery of each nozzle body. A cylindrical solder rising passage communicating with the solder rising passage is provided, a solder spouting part is provided at the upper end of the solder rising passage, and a solder droplet is provided in the center of the solder spouting part and is inclined downwardly inward by an inclined surface part. A jet soldering method characterized in that a solder descending passage is provided below the mouth, and a lower end opening of the solder descending passage is communicated with the solder suction side of the pump via a communication pipe provided in the solder ascending passage. Device.