JP4634576B2 - Local soldering apparatus and local soldering method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a local soldering apparatus and a local soldering method characterized by a nozzle shape.
[0002]
[Prior art]
Although a double-sided reflow soldering substrate is used, a local soldering apparatus capable of local soldering is used when a lead part such as a connector is soldered to a part thereof. Since the board to be soldered by the local soldering apparatus has already been soldered for peripheral parts other than the lead parts such as connectors, it is necessary to solder only to the leads of the lead parts.
[0003]
Therefore, in the local soldering apparatus shown in FIG. 6, the substrate 1 is lowered as shown in FIG. 6A, and the soldered local part 2 such as a lead of the substrate 1 is moved to the soldered local part. 2 is inserted into a nozzle 4 having an opening 3 that is slightly larger than the region 2, and the molten solder 5 is raised in the nozzle 4 as shown in FIG. The soldering local area 2 is dipped to perform local soldering.
[0004]
As described above, in the conventional local soldering method, the opening 3 of the nozzle 4 is used to uniformly supply the molten solder to the entire opening in the region requiring local soldering on the substrate 1. Is kept horizontal.
[0005]
Then, the substrate 1 is lowered to the horizontal opening 3 of the nozzle 4 and the molten solder 5 is raised to the opening 3 of the nozzle 4, whereby the soldered local area 2 is formed in the molten solder 5. Local soldering is performed by dipping.
[0006]
After this local soldering, as shown in FIG. 6 (C), the solder surface in the nozzle of the molten solder 5 is lowered so as to be detached from the soldered local region 2, and after this separation is completed, As shown in FIG. 6 (D), the substrate 1 is raised and carried out.
[0007]
[Problems to be solved by the invention]
In this conventional immersion soldering apparatus and method, during soldering, the soldered local portion 2 on the substrate 1 and the opening 3 of the nozzle 4 for supplying the molten solder 5 are in contact with each other in a horizontal state. As shown in (C), when the solder is removed, the molten solder 5 approaches the center of the part to be soldered 2 due to surface tension, and finally a so-called bridge is cut at the center. For this reason, the last remaining molten solder 5a is pulled toward the substrate 1, and soldering defects such as so-called tsura are likely to occur.
[0008]
This invention is made in view of such a point, and it aims at providing the local soldering apparatus and local soldering method which reduce a soldering defect.
[0009]
[Means for Solving the Problems]
The invention described in claim 1 is provided with a solder bath containing molten solder, and supplied with molten solder from the solder bath, and tilted in the same direction as the soldering local area of the workpiece tilted on the solder bath. A nozzle having an inclined opening surface at the upper end that is opened and contacts the solder to be soldered locally, a partition plate that defines two flow paths on the molten solder supply side and discharge side inside the nozzle, and a partition plate A return port provided between the upper end and the inclined opening surface and communicating with the flow path on the molten solder supply side to the flow path on the discharge side, and the partition plate and the return port are on the discharge side on the higher side of the inclined opening surface Ru local soldering apparatus der provided at a position forming a flow path. Then, the molten solder supplied up to the inclined opening surface of the nozzle is soldered to the part to be soldered of the similarly inclined workpiece, and then starts to be detached from the highest end of the part to be soldered. Since the so-called bridge is cut at the lowest end, the so-called bridge can be cut reliably, so that poor soldering such as so-called tsura can be easily reduced, and the soldering quality can be improved. In addition, the solder flow that moves from the supply-side flow path partitioned by the partition plate to the discharge-side flow path through the return port can always supply fresh molten solder to the inclined opening, thereby reducing the temperature of the molten solder. And can improve soldering characteristics. Furthermore, the detachment of the molten solder from the workpiece can be started smoothly from the discharge-side flow path located on the higher side of the inclined opening surface.
[0010]
請 Motomeko 2 invention described in the in the local soldering apparatus according to claim 1 Symbol placement, good molten solder pull wettability soldering defects of the workpiece are arranged in the nozzle to face the easy part-generating Solder such as so-called tsura that is provided on the workpiece side by drawing the molten solder released from the workpiece to the nozzle side with a metal body having good wettability. Prevent improper attachment.
[0011]
According to a third aspect of the present invention, in the local soldering apparatus according to the first or second aspect, the workpiece inclined at the same gradient as the inclined opening surface above the nozzle is soldered at the inclined opening surface of the nozzle. An approaching step for approaching to a position where it can be attached, a soldering step for soldering the soldered local part by bringing the molten solder raised to the entire surface of the inclined opening surface in the nozzle into contact with the soldered local part of the workpiece, The solder removal process in which the molten solder is released from the high position of the soldered portion inclined to the low position by lowering the solder surface of the molten solder in the nozzle, and the work after the solder removal is separated from the inclined opening surface. A local soldering method having a separation step, and the soldering method is also inclined by the molten solder raised to the entire surface of the inclined opening surface of the nozzle. After soldering the part to be soldered of the workpiece, the solder surface of the molten solder is lowered in the nozzle, so that the molten solder is smoothly detached from the high position of the inclined soldering target area toward the low position, Furthermore, a so-called bridge can be cut reliably at the lowest end of the part to be soldered, so that poor soldering during local soldering can be reduced and quality can be improved.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, referring to FIG. 1 and FIG. 2 for the premise technique of the local soldering apparatus according to the present invention , the second embodiment is further described with reference to FIG. 3 and FIG. 4 for the first embodiment of the present invention . This will be described with reference to FIG.
[0013]
FIG. 1 shows a local soldering apparatus, and a solder supply nozzle (hereinafter simply referred to as “nozzle”) 13 for local soldering is provided in a solder bath 12 in which molten solder 11 is accommodated.
[0014]
The nozzle 13 has a rectangular tube-shaped nozzle body 14 for raising the molten solder 11 supplied from a pump (not shown) installed in the solder bath 12, and an inclined opening at the upper end of the nozzle body 14. In addition, an inclined opening surface 17 that is slightly larger than the part to be soldered of the workpiece 15 is provided. The inclined opening surface 17 is opened to be inclined in the same direction as the part to be soldered of the work 15 carried in an inclined state on the solder bath 12.
[0015]
As shown in FIG. 2, the workpiece 15 is a printed wiring board having lead parts 16 _L, such as connectors, to be soldered local 16 is a lead group of the lead parts 16 _L.
[0016]
A transport mechanism (not shown) such as a robot that transports the workpiece 15 holds the workpiece 15 at the same inclination angle as the inclined opening surface 17 of the nozzle 13 with respect to the horizontal direction, and moves the workpiece 15 to a distance that can be soldered. 15 is lowered, and the soldered local part 16 of the work 15 is dipped at a predetermined inclination angle in the molten solder 11 that has risen due to the surface tension at the inclined opening surface 17 of the nozzle 13, and the soldered local part is melted by the molten solder 11. After 16 is locally soldered, the workpiece 15 is pulled up with its inclination angle.
[0017]
Next, a local soldering method using the nozzle 13 shown in FIG. 1 will be described with reference to FIG.
[0018]
FIG. 2A shows an approach process in which a workpiece 15 inclined at the same gradient as the inclined opening surface 17 of the nozzle 13 is approached to the position where soldering can be performed on the inclined opening surface 17 above the nozzle 13. This is the case when the workpiece 15 descends with a predetermined angle with respect to the nozzle 13.
[0019]
The predetermined position of the substrate as a work 15, is inserted a number of leads of previously read part 16 _L prior to soldering, the lead groups are inserted into the inclined opening surface 17 as an object to be soldered topical 16, substrate The nozzle 13 is stopped at a position almost in contact with the opening edge of the nozzle 13.
[0020]
FIG. 2B shows that the molten solder 11 raised to the inclined opening surface 17 in the nozzle 13 is brought into contact with the soldered local area 16 of the workpiece 15 while keeping the entire surface of the inclined opening surface 17 by surface tension. The soldering process for locally soldering the soldered local part 16 is shown, and the lower surface of the work 15 is substantially in contact with the inclined opening surface 17 of the nozzle 13, and the molten solder that is raised with respect to the soldered local part 16 on the lower surface of the work 15 is shown. It is a place where immersion soldering is performed.
[0021]
FIG. 2C shows a solder removal process in which the molten solder 11 is released from a high position to a low position in the inclined soldered local portion 16 by lowering the solder surface of the molten solder 11 in the nozzle 13. By stopping the solder pressure pump (not shown), the supply of the molten solder 11 is stopped, the solder surface in the nozzle is lowered, and the molten solder 11 is detached from the soldered local area 16 of the work 15. It represents the situation.
[0022]
Since the workpiece 15 and the nozzle 13 have a predetermined angle and are soldered at a predetermined angle, when the solder surface in the nozzle of the molten solder 11 is lowered, it is forcibly indicated by an arrow 18 from the left side to the right side in the drawing. As you can see, the so-called bridge is broken.
[0023]
Thus, after soldering the soldered local part 16 of the similarly inclined workpiece 15 with the molten solder 11 raised to the entire surface of the inclined opening surface 17 of the nozzle 13, the solder of the molten solder 11 in the nozzle 13 By lowering the surface, detachment starts from the highest end of the inclined soldered local part 16, the detachment point smoothly transitions to the lower end, and the so-called bridge is easily cut at the lowest end.
[0024]
As a result, a so-called bridge can be surely cut at the lowest end of the soldered local portion 16, soldering defects during local soldering can be reduced, and quality can be improved.
[0025]
FIG. 2 (D) shows a separation process for separating the workpiece 15 after the solder removal from the inclined opening surface 17, and the supply of the molten solder 11 is completely stopped, and the molten solder 11 is completely detached from the soldered local area 16. By the way, the workpiece 15 is raised by the transport mechanism, and after cooling, the immersion soldering is completed.
[0026]
When local soldering only lead group of the lead component 16 _L on the workpiece 15 by the above process through the step of FIG. 2 (C), the momentum of the bridge breakage moved to the lead located in the lowest end Also, the last bridge break is easily made, and it becomes possible to reduce soldering defects such as so-called tsura. As a result, the occurrence of so-called bridging defects in the conventional local soldering apparatus can be easily solved.
[0027]
In addition, after the local soldering, the work 15 is not lifted and transported while the molten solder 11 is supplied, but the supply of the molten solder 11 into the nozzle 13 is stopped first, and the solder surface of the molten solder 11 in the nozzle It is also effective in preventing the occurrence of a so-called bridging failure that the so-called bridge is cut by the detachment accompanying the lowering and then the workpiece 15 is transported.
[0028]
Next, FIGS. 3 and 4 show an internal circulation type nozzle 13 which is a first embodiment based on the premise technology of FIGS. 1 and 2, and as shown in FIG. A partition plate 23 for partitioning and forming the molten solder supply side flow path 21 and the molten solder discharge side flow path 22 is provided between the upper end of the partition plate 23 and the inclined opening surface 17; Is provided with a return port 24 that communicates the flow channel 21 with the flow channel 22 on the discharge side.
[0029]
The flow path 21 on the molten solder supply side is fitted to a guide cylinder member 25 that guides the molten solder 11 discharged from the pump in the solder tank 12 upward, and the flow path 22 on the molten solder discharge side is a nozzle. The projecting cylindrical portion 26 projecting from one lower part of the main body 14 extends below the molten solder surface in the solder bath 12, so that the molten solder 11 is returned to the solder bath 12 in the nozzle 13. Just make it smooth.
[0030]
Thus, the nozzle 13 having a two-layer structure inside the nozzle 13 by the partition plate 23 and provided with the two flow paths 21 and 22 on the supply side and the discharge side is located inside the nozzle 13 during local soldering. The molten solder 11 is given a flow that moves from the supply-side flow path 21 partitioned by the partition plate 23 to the discharge-side flow path 22 through the turn-back port 24, and the fresh molten solder 11 is applied to the inclined opening surface 17. Since it can always be supplied, temperature drop of the molten solder 11 can be prevented.
[0031]
Next, FIG. 4 shows the local soldering action using the nozzle 13 shown in FIG.
[0032]
FIG. 4A shows the same state as that shown in FIG. However, a partition plate 23 for forcibly creating a flow in the nozzle 13 is attached inside the nozzle 13 to which molten solder is supplied. The nozzle 13 is divided into two layers by the partition plate 23.
[0033]
In FIG. 4B, the lower surface of the work 15 is substantially in contact with the inclined opening surface 17 of the nozzle 13, and the soldered local portion 16 on the lower surface of the work 15 is in contact with the molten solder 11 and is subjected to immersion soldering.
[0034]
In this figure, the molten solder 11 in the nozzle 13 moves upward from the lower side of the drawing, and then is forced to flow in the direction of the arrow 27 while hitting the lower surface of the workpiece at the inclined opening surface 17 of the nozzle 13, After passing through 24, the partition plate 23 flows into the discharge-side flow path 22 formed in the nozzle 13, and returns to the solder bath 12 as indicated by an arrow 28.
[0035]
Thus, since the molten solder 11 is always flowing after being supplied to the inclined opening surface 17 by the partition plate 23, the temperature of the molten solder 11 on the soldering surface is not reduced during the immersion soldering. ,rare.
[0036]
Further, since the discharge-side flow path 22 extends below the molten solder surface in the solder bath 12 by the protruding cylindrical portion 26, the molten solder is applied to the molten solder surface in the solder bath 12 during local soldering. 11 is not dropped and the molten solder 11 is prevented from being scattered and oxidized.
[0037]
FIGS. 4C and 4D show a state where the supply of the molten solder 11 is stopped and the molten solder 11 is detached. Since the work 15 and the nozzle 13 have a predetermined inclination angle and are soldered at a predetermined inclination angle, the solder supply from the pump into the nozzle 13 is stopped and the solder surface in the nozzle of the molten solder 11 is lowered. Then, the so-called bridge is forcibly cut in the direction of the arrow 29, that is, from the left side to the lower right side in the drawing.
[0038]
In particular, since the partition plate 23 and the folding opening 24 are provided at positions where the discharge-side flow path 22 is formed on the higher side of the inclined opening surface 17, the detachment of the molten solder 11 from the work 15 It starts smoothly on the discharge-side flow path 22 located on the higher side of 17.
[0039]
That is, when the supply of the molten solder 11 is stopped, the molten solder 11 is first positioned in the discharge-side flow path 22 which is located at the higher side of the inclined opening surface 17 and is directly opened in the solder bath and has a small solder flow resistance. Then, the molten solder 11 starts to be detached from the soldered local portion 16 on the discharge-side flow path 22, and then is connected to the pump to increase the flow resistance of the supply side. Since the solder surface in the nozzle descends in the path 21, a so-called bridge can be cut more reliably at the end of the lead component by a synergistic effect with the inclined opening surface 17 of the nozzle 13.
[0040]
As shown in FIG. 4 (E), when the supply of the molten solder 11 is stopped, when the solder is completely detached from the work 15, the work 15 is raised in an inclined state by a transport mechanism such as a transport robot (not shown). After cooling, the local soldering process ends.
[0041]
Thus, by using the nozzle 13 having the partition plate 23, when the soldering is performed, the partition plate 23 gives a flow to the solder in the nozzle 13 and circulates in the inside, thereby the inclined opening surface 17 Therefore, it is possible to prevent the molten solder 11 in the nozzle 13 from overflowing and dripping out of the nozzle 13 during local soldering, thereby preventing the molten solder 11 from being scattered or oxidized.
[0042]
Furthermore, by forming the discharge-side flow path 22 on the higher side of the inclined opening surface 17 by the partition plate 23, it is possible to easily create a trigger for solder breakage on the discharge-side flow path 22. When the solder is removed, a so-called bridge can be smoothly cut from the end on the higher level side (left end in the drawing) of the soldered portion 16.
[0043]
Next, FIG. 5 shows an internal circulation and bridge reduction type nozzle 13 which is a second embodiment based on the premise technology of FIGS. 1 and 2, and in this nozzle 13, molten solder drawing having good wettability is shown. A metal body 31 for shifting is disposed.
[0044]
This metal body 31 is made of, for example, a nickel plate having good solder wettability or a nickel-plated plate, and is opposed to a portion where a soldering failure such as a so-called bridge between the leads of the work 15 is likely to occur during local soldering. Since the molten solder 11 is attracted by wettability to enhance the solder breakage action, it has a function of reducing poor soldering such as so-called tsura.
[0045]
Then, as shown in FIG. 5 (D), the molten solder drawing with good wettability in the nozzle 13 is opposed to the portion where the soldering failure of the work 15 is likely to occur, that is, the position where the final solder removal is expected. By placing the metal body 31 for shifting, the molten solder 11 that is released from the work 15 is finally pulled to the nozzle 13 side by the metal body 31 with good wettability, and is generated on the work 15 side during local soldering. This prevents soldering defects such as so-called wigs.
[0046]
5 (A), (B), (C), (D), and (E) correspond to FIGS. 4 (A), (B), (C), (D), and (E), respectively. Therefore, description of operations other than the above FIG.
[0047]
As described above, the soldering surface is inclined by inclining the opening surface of the nozzle for supplying the molten solder at a predetermined angle, and further, the work having the soldered local part is also inclined at the predetermined angle for soldering. As a result, as shown in FIG. 2C, a so-called bridge can be smoothly cut at the lower end of the part to be soldered. That is, by inclining the upper end opening of the nozzle for supplying solder and the work by a predetermined angle, it is possible to reduce soldering defects such as so-called tsura and improve the quality.
[0048]
In particular, through the steps of FIGS. 4C and 4D, a so-called bridge is cut from the end of the lead, and it becomes possible to further reduce soldering defects such as so-called tsura. Furthermore, through the steps of FIGS. 5C and 5D, it is possible to further reliably prevent the occurrence of defective soldering in the conventional local immersion soldering apparatus.
[0049]
【The invention's effect】
According to the first aspect of the present invention, the molten solder supplied up to the inclined opening surface of the nozzle is soldered to the soldering area of the similarly inclined workpiece, and then from the highest end of the soldering area. The separation starts, the separation point moves to the lower end, so-called bridge is cut at the lowest end, so-called bridge can be surely cut, soldering defects such as so-called tsura can be easily reduced, The soldering quality can be improved. In addition, the solder flow that moves from the supply-side flow path partitioned by the partition plate to the discharge-side flow path through the return port can always supply fresh molten solder to the inclined opening, thereby reducing the temperature of the molten solder. And can improve soldering characteristics. Furthermore, the detachment of the molten solder from the workpiece can be started smoothly from the discharge-side flow path located on the higher side of the inclined opening surface.
[0050]
According to the invention 請 Motomeko 2, wherein the molten solder to leave from the work, that that draws on the nozzle side by the end wettable metal body, generated by the work side, the soldering defects such as so-called icicle Can be prevented.
[0051]
According to invention of Claim 3 , after soldering the soldering local part of the similarly inclined workpiece | work with the molten solder raised to the whole surface of the inclined opening surface of a nozzle, the solder surface of molten solder within a nozzle By lowering, it is possible to smoothly release the molten solder from a high position of the inclined soldered local area toward a low position, and further, it is possible to reliably cut a so-called bridge at the lowest end of the soldered local area, It is possible to reduce soldering defects such as so-called tsura and improve quality.
[Brief description of the drawings]
FIG. 1 is a perspective view showing a prerequisite technique of a local soldering apparatus according to the present invention.
FIG. 2 is a sectional view showing a local soldering method using a nozzle of the soldering apparatus.
FIG. 3 is a perspective view showing a first embodiment (internal circulation type) of a nozzle of a local soldering apparatus according to the present invention.
4 is a cross-sectional view showing a local soldering method using the nozzle of FIG. 3;
FIG. 5 is a cross-sectional view showing a local soldering method using the second embodiment (internal circulation bridge reduction type) of the nozzle of the local soldering apparatus according to the present invention.
FIG. 6 is a cross-sectional view showing a local soldering method using a conventional nozzle.
[Explanation of symbols]
11 Molten solder
12 Solder bath
13 nozzles
15 work
16 Local soldering
17 Inclined aperture
21 Flow path on the molten solder supply side
22 Flow path on molten solder discharge side
23 Partition plate
24 Turnaround
31 Metal body with good wettability

Claims (3)

A solder bath containing molten solder;
In addition to receiving molten solder from the solder bath, the upper end is an inclined opening surface that opens in the same direction as the soldering area of the workpiece that is tilted on the solder tank and that contacts the solder to be soldered locally. A nozzle having ,
A partition plate that partitions and forms two flow paths on the molten solder supply side and discharge side inside the nozzle;
A folding opening provided between the upper end of the partition plate and the inclined opening surface and communicating the flow path on the molten solder supply side with the flow path on the discharge side ;
The local soldering apparatus, wherein the partition plate and the folding opening are provided at positions where a flow path on the discharge side is formed on a higher side of the inclined opening surface . Soldering defects is characterized by comprising a metal body for good molten solder pull pulling a disposed wettability in the nozzle to face the easy part occurs claim 1 Symbol placement of local soldering device of a work . In the local soldering apparatus of Claim 1 or 2 ,
An approaching step of bringing the workpiece soldering area close to the position where soldering can be performed at the same gradient as the inclined opening surface of the nozzle above the nozzle,
A soldering process of soldering the soldered local area by bringing the molten solder raised to the entire surface of the inclined opening surface within the nozzle into contact with the local area to be soldered;
A solder removal step of releasing the molten solder from the high position of the soldered local area inclined by lowering the solder surface of the molten solder within the nozzle;
A local soldering method comprising: a separation step of separating the workpiece after the solder removal from the inclined opening surface.

Images