WO2010087374A1

WO2010087374A1 - Jet solder bath

Info

Publication number: WO2010087374A1
Application number: PCT/JP2010/051052
Authority: WO
Inventors: 市川広一; 細川晃一郎; 鈴木崇
Original assignee: 千住金属工業株式会社
Priority date: 2009-01-27
Filing date: 2010-01-27
Publication date: 2010-08-05
Also published as: CN102301839B; CN102301839A; JPWO2010087374A1

Abstract

Provided is a jet solder bath wherein the interval of a primary jet nozzle and a secondary jet nozzle can be adjusted easily. A jet solder bath (1) includes a solder bath body (2), a duct (6) for a secondary jet nozzle, a secondary jet nozzle (5), and a secondary jet nozzle tilting device (8) which tilts the secondary jet nozzle (5) toward the direction opposite from the conveyance direction of a printed board. The secondary jet nozzle tilting device (8) has two coupling members (8a) which are arranged, respectively, on two longitudinal walls (5d) of the secondary jet nozzle (5) and hooked, respectively, to two flanges (6a), and an installation height adjusting mechanism (11) which adjusts the installation height of the two coupling members (8a) individually with respect to the two longitudinal walls (5d). The installation height adjusting mechanism (11) has a fixing pin which penetrates both one of a plurality of through holes (8b) bored in the longitudinal walls (5d) of the two coupling members (8a) toward the horizontal direction, and one of a plurality of through holes (5e) bored in the two longitudinal walls (5d) of the secondary jet nozzle (5) toward the oblique upward direction.

Description

Jet solder bath

The present invention relates to a jet solder bath for soldering a printed circuit board by jetting molten solder.

Soldering of printed circuit boards incorporated in home appliances such as TV and video is generally more productive than other soldering because it can be soldered to the entire surface of the printed circuit board in one operation. This is done by the flow method. An automatic soldering apparatus that performs soldering in the flow method includes a processing device such as a fluxer, a pre-heater, a jet solder bath, and a cooler, and an endless conveyor disposed above these processing devices. The printed circuit board conveyed by the conveyor is soldered by this automatic soldering device, in which flux application by a fluxer, preheating by a preheater, solder adhesion by a jet solder bath, and cooling by a cooler are sequentially performed. .

Among these processing apparatuses, the most important one is a jet solder bath for performing soldering by bringing molten solder into contact with a printed circuit board. The jet solder tank is for causing molten solder pumped by a pump to flow into a jet nozzle through a duct and jet upward. As the jet nozzle, a primary jet nozzle that jets a rough wave and a secondary jet nozzle that jets a gentle wave are juxtaposed.

The rough waves jetted from the primary jet nozzle have the effect of preventing unsoldering by sufficiently infiltrating the molten solder into the inside of the through hole of the printed circuit board or, for example, the angular corner of the chip component. However, if the jet wave is rough, the state of solder adhesion to the soldering part will not be stable, and the solder will straddle between adjacent conductors, preventing the normal function of electronic equipment incorporating a printed circuit board. In addition, when the solder is attached to the tip of the lead of the electronic component in a square shape, a tsura that causes a discharge phenomenon from the tip of the tsura during use of the electronic device and causes the electronic device to fail occurs. Further, if the solder does not sufficiently wet into the through hole, the bonding strength between the lead of the discrete component and the printed circuit board is lowered.

Therefore, in order to prevent the bridge or tsura from remaining on the soldered part of the printed circuit board and to allow the solder to sufficiently wet up inside the through hole, the bridge and tsura are removed using a gentle wave jetted from the secondary jet nozzle. Correct the soldered parts by remelting.

However, if the primary jet nozzle and the secondary jet nozzle are arranged too close to each other, the molten solder jetted out from one jet nozzle flows into the molten solder jetted from the other jet nozzle, and the other jet nozzle By destroying the shape of the wave that jets from the nozzle, the unsoldering eliminating action in the primary jet nozzle and the bridge and wiggle correcting action in the secondary jet nozzle disappear. For this reason, in the conventional automatic soldering apparatus, the primary jet nozzle and the secondary jet nozzle are arranged apart from each other.

In conventional soldering of Sn—Pb solder, there is no problem even if the primary jet nozzle and the secondary jet nozzle are arranged apart from each other. Since Sn—Pb solder has a low melting point of 183 ° C., the primary jet nozzle and the secondary jet nozzle are arranged apart from each other, so that the secondary jet nozzle after the printed circuit board is soldered by the primary jet nozzle. Even if it takes time to reach the temperature and the temperature of the solder adhering to the primary jet nozzle drops, the adhering solder does not solidify and maintains its molten state. It is because it can be performed completely. Even if the bridge or tsura is solidified, the solidified bridge or tsura is at a temperature slightly lower than the melting point, so it can be easily remelted by contacting the molten solder with the secondary jet nozzle to correct the bridge or tsura. The In addition, when discrete components are soldered using Sn—Pb solder, the solder on the component surface side is sufficiently wet.

On the other hand, in the electronic equipment industry, so-called lead-free solder containing no Pb is used instead of Sn-Pb solder, which has been used since ancient times, as part of countermeasures against lead pollution, which has been regarded as a problem in recent years. It has become. Lead-free solder contains Sn as a main component and appropriately contains Ag, Cu, Sb, In, Bi, Zn, Ni, Cr, Mo, Fe, Co, P, Ge, Ga and the like. . Currently, the composition of lead-free solder that is widely used in the electronic industry is Sn-3.5Ag and Sn-3.0Ag-0.5Cu, and the melting point of these lead-free solders is about 220 ° C. or higher. On the other hand, the upper limit of the temperature of the molten solder in the jet solder bath in the immersion method (hereinafter referred to as “working temperature in the solder bath”) is determined to be about 240 to 250 ° C. from the heat resistance of the electronic components. For this reason, the difference between the melting point of the conventional Pb—Sn solder and the working temperature in the solder bath was about 60 ° C., whereas the difference between Sn-3.5Ag and Sn-3.0Ag-0.5Cu With a lead-free solder having a composition, only about 20-30 ° C. can be secured.

In this way, the conventional automatic soldering device in which the primary jet nozzle and the secondary jet nozzle are arranged apart from each other in the lead-free solder that can ensure the difference between the melting point and the working temperature in the solder bath only about 20-30 ° C. When applied to, the occurrence of bridges and wiggles increases as compared with the case of applying conventional Pb—Sn solder, and the shortage of wetting into the through holes also increases. In other words, since lead-free solder has a high melting point, the temperature of the lead-free solder that adheres to the printed circuit board after reaching the secondary jet nozzle a little away after soldering with the primary jet nozzle is much higher than its melting point. The molten solder adhering to the printed circuit board by the primary jet nozzle is completely solidified, and unavoidably, the bridge and tsura generated on the printed circuit board and the solder inside the through hole are also solidified. Even if it comes into contact with the molten solder jetted from the nozzle, the solder on the board, the bridge, the tsura, and the solder inside the through hole cannot be completely melted, and the bridge and tsura remain, or the wetting and spreading inside the through hole. Is lacking.

In recent years, lead-free solder having a composition of Sn-3.0Ag-0.5Cu has excellent temperature cycle resistance, but it is hard and has a problem of drop impact resistance. Depending on the specifications, Sn-3.5Ag, Sn-3.0Ag-0.5Cu composition is not lead-free solder, but Sn-Cu or the same Sn-Ag-Cu-based lead-free solder can be used as low silver. A lead-free solder such as Sn-0.7Cu-0.3Ag is also used.

However, Sn-Cu-based lead-free solder and low-silver Sn-Cu-Ag-based lead-free solder have a melting point of about 230 ° C and a composition of Sn-3.5Ag and Sn-3.0Ag-0.5Cu. About 10 ° C higher than lead-free solder. In addition, since the heat resistance temperature of the electronic parts is only guaranteed at 260 ° C. at the maximum, the working temperature in the solder bath can be increased only to around 255 ° C. with a margin. For this reason, soldering is performed under a severe condition where the difference between the melting point of the solder and the working temperature in the solder bath is 20 to 25 ° C. The molten solder adhering to the printed circuit board by the primary jet nozzle is transferred to the secondary jet nozzle. It was easy to solidify completely before reaching.

In order to solve such problems associated with the expanded adoption of lead-free solder, the present applicant has installed a large number of cylindrical jet ports above the primary jet nozzle and arranged in parallel on the exit side according to Patent Document 1. An invention relating to an automatic soldering apparatus in which a secondary jet nozzle is installed by placing an entry-side former of a secondary jet nozzle in close proximity to the jet port formed is disclosed.

Further, FIG. 8 of Patent Document 2 discloses an invention in which a partition wall is disposed between the primary jet solder and the secondary jet solder so that the distance between them is reduced.

JP 2004-356161 A JP 2002-11593 A

Even according to the inventions disclosed in Patent Documents 1 and 2, the melting point of lead-free solder such as Sn-Cu-based lead-free solder and Sn-0.7Cu-0.3Ag is particularly high at about 230 ° C. It cannot be surely solved that the molten solder adhered to the printed circuit board by the primary jet nozzle solidifies before transferring to the secondary jet nozzle.

In addition, since the composition of lead-free solder that can obtain all the characteristics obtained by conventional Sn-Pb solder having a composition in the vicinity of Sn-37Pb and its vicinity is not present, for example, even a video board has Sn on the main board. Uses lead-free solder with a composition of -3.5Ag, Sn-3.0Ag-0.5Cu, and has a low silver resistance such as Sn-0.7Cu-0.3Ag, which has high drop impact resistance for handheld remote control It is necessary to change the solder composition, such as using lead-free solder. For this reason, when many solders with different melting temperatures are used in the flow method, it is necessary to adjust the interval between the primary jet nozzle and the secondary jet nozzle according to the type of solder. There is no known means for easily adjusting the distance between the primary jet nozzle and the secondary jet nozzle in accordance with the melting point of the solder.

The present invention has been made in view of the above-described problems of the prior art, and the distance between the primary jet nozzle and the secondary jet nozzle can be easily adjusted. It is an object to provide a jet solder bath that can surely prevent the molten solder attached to a printed circuit board by a primary jet nozzle from solidifying before transferring to the secondary jet nozzle, regardless of fluctuations in the melting point.

As a result of intensive studies to solve the above-described problems,
(A) A jet nozzle tilting device that can change the jet nozzle arranged in communication with the duct arranged inside the jet solder bath from the normal vertically upward state to the inclined state is newly added. This makes it possible to easily adjust the distance between the primary jet nozzle and the secondary jet nozzle, and the molten solder adhering to the printed circuit board by the primary jet nozzle can It is possible to surely prevent solidification before moving to the jet nozzle, and (b) the nozzle base portion of the secondary jet nozzle is tilted in the direction opposite to the direction of conveyance of the printed circuit board by the jet nozzle tilting device. In this case, the retraction side former for guiding the molten solder ejected by being arranged on the side of the secondary jet nozzle is adjusted to adjust the inclination angle with respect to the jet nozzle. By adding additional side former tilting device, and found that enable stable soldering regardless inclined arrangement of the secondary jet nozzle, and have completed the present invention by overlapping a further study.

The present invention includes (i) a solder bath main body on which a printed board is transported in a predetermined transport direction, and (ii) a pump that is disposed inside the solder bath main body and sends molten solder made of lead-free solder. In addition to guiding the molten solder to be sent, a duct having an opening formed on the upper surface formed by two flanges spaced upward in the conveying direction and an upper surface extending between the two flanges is arranged. Two combinations of jet nozzles that communicate with the duct through the opening, guide the molten solder supplied through the duct and jet upward, and (iii) of the two jet nozzles A jet characterized by comprising a jet nozzle tilting device for tilting at least one jet nozzle toward the transport direction or the direction opposite to the transport direction. It is a tank.

In the jet solder bath according to the present invention, (I) the jet nozzle is a primary jet nozzle, and the jet nozzle tilting device is arranged so that the primary jet nozzle is tilted toward the transport direction, or (II) the jet nozzle is It is a secondary jet nozzle, and the jet nozzle tilting device is arranged such that the secondary jet nozzle is tilted in the direction opposite to the transport direction, and the exit-side former is disposed in the secondary jet nozzle in the transport direction. It is desirable to provide an exit-side former tilting device for adjusting the tilt angle with respect to the jet nozzle.

In these jet soldering baths according to the present invention, the jet nozzle tilting device is installed on the two vertical wall portions of the jet nozzle that are separated from each other in the transport direction, and two connecting members that are respectively hooked on the two flanges. It is desirable to have an installation height adjusting mechanism for individually adjusting the installation heights of the two connecting members with respect to the two vertical wall portions.

In the jet solder bath according to the present invention, the installation height adjustment mechanism includes one of a plurality of through holes drilled in the horizontal direction in the respective vertical wall portions of the two connecting members, and the jet flow. It is desirable to have a fixing pin that penetrates any one of a plurality of through holes formed in the two vertical wall portions of the nozzle in an obliquely upward direction.

Furthermore, in these jet soldering baths according to the present invention, the exit-side former tilting device moves up and down the shaft support mechanism provided on the secondary jet nozzle and rotatably supporting the exit-side former, and the lower surface of the exit-side former. It is desirable to have a plate cam mechanism.

According to the jet soldering bath according to the present invention, the interval between the primary jet nozzle and the secondary jet nozzle can be easily adjusted, so that regardless of the type of lead-free solder used, the primary jet nozzle can be used as a printed circuit board. It is possible to reliably prevent the molten solder adhering to the solidification before transferring to the secondary jet nozzle.

It is a perspective view showing the whole jet soldering bath concerning the present invention. It is a perspective view which shows the jet solder tank of the state cut | disconnected by A cross section of FIG. It is a perspective view which shows the state of the secondary jet nozzle which comprises the jet solder tank which concerns on this invention. It is a perspective view which shows the state of the secondary jet nozzle which comprises the jet solder tank which concerns on this invention.

Hereinafter, the form for implementing the jet soldering bath concerning the present invention is explained in detail, referring to an accompanying drawing.
FIG. 1 is a perspective view showing the entire jet solder bath 1 according to the present invention. FIG. 2 is a perspective view showing the jet solder tank 1 in a state cut along a cross section A in FIG. 3 and 4 are perspective views showing the secondary jet nozzle 5 constituting the jet solder tank 1 according to the present invention in a cut state.

As shown in FIGS. 1 to 4, the jet solder bath 1 includes a solder bath main body 2, a primary jet nozzle 3, a primary jet nozzle duct 4, a primary jet nozzle pump (not shown), and a secondary jet nozzle. 5. Since the secondary jet nozzle duct 6 and the secondary jet nozzle pump (not shown), the primary jet nozzle tilting device 7, the secondary jet nozzle tilting device 8, and the exit-side former tilting device 9 are provided. These components will be described sequentially.

[Solder tank body 2]
The solder tank main body 2 is a rectangular parallelepiped container having an upper opening, and contains lead-free solder molten solder. The solder tank body 2 is preferably made of stainless steel in order to prevent erosion of lead-free solder, and more preferably nitriding the whole.

A heater (not shown) is mounted inside or outside the solder bath body 2 in order to melt the solder and maintain a constant temperature.
Although not shown, a transport conveyor for transporting the printed circuit board to be soldered is disposed above the solder bath body 2, and the printed circuit board is transported with the direction of the white arrow in FIG. 1 as the transport direction.
Since this solder tank main body 2 is well-known and commonly used by those skilled in the art, further explanation is omitted.

[Primary jet nozzle 3, primary jet nozzle duct 4 and primary jet nozzle pump (not shown)]
A primary jet nozzle 3, a primary jet nozzle duct 4, and a primary jet nozzle pump (not shown) are disposed inside the jet solder bath body 2.

The primary jet nozzle pump is disposed inside the solder bath main body 2 and at a predetermined position facing one end of a primary jet nozzle duct 4 to be described later, while being completely immersed in the molten solder. The primary jet nozzle pump supplies molten solder made of lead-free solder accommodated in the solder bath main body 2 to the primary jet nozzle duct 4. The primary jet nozzle pump need only be capable of sending molten solder and need not be limited to a specific type, but has few pulsations during constant speed rotation and rapid convergence during shifting. From this point of view, it is desirable to use a screw pump.

The molten solder sent by the primary jet nozzle pump is supplied to the primary jet nozzle duct 4. The primary jet nozzle duct 4 is disposed in the solder tank main body 2 and in the vicinity of the bottom, and has an opening 4b formed by two flanges 4a that are spaced upward in the printed board conveyance direction. On top. The primary jet nozzle duct 4 guides the molten solder sent by the primary jet nozzle pump arranged facing one end to the other end.

The primary jet nozzle 3 having an opening on the upper surface of the other end of the primary jet nozzle duct 4 is installed. The primary jet nozzle 3 communicates with the primary jet nozzle duct 4 by extending upward between the two flanges 4a of the primary jet nozzle duct 4 so that the primary jet nozzle duct 4 is connected to the primary jet nozzle duct 4. The molten solder supplied through the pipe is guided and jetted upward. The primary jet nozzle 3 extends substantially vertically upward, and is configured such that the upper cross-sectional area is smaller than the lower cross-sectional area. Further, as will be described later, the two flanges 4a of the primary jet nozzle duct 4 are formed in a space formed by the vertical wall portion 3d of the primary jet nozzle 3 and a connecting member 7a attached to the vertical wall portion 3d with a fixing pin or the like. The primary jet nozzle 3 is positioned with respect to the primary jet nozzle duct 4 and is detachably installed by engaging the two connecting members 7a with the two flanges 4a. The Therefore, the primary jet nozzle 3 can be pulled out from the primary jet nozzle duct 4 during maintenance.

On the upper part of the primary jet nozzle 3, a wave-making plate 3b having a large number of holes 3a is provided, and the molten solder sent upward in the primary jet nozzle 3 is moved upward as a rough wave. To jet.

Note that, as shown in FIG. 2, known rectifying plates 3 c are arranged in multiple stages inside the primary jet nozzle 3.

[Secondary jet nozzle 5, secondary jet nozzle duct 6 and secondary jet nozzle pump (not shown)]
A secondary jet nozzle 5, a secondary jet nozzle duct 6, and a secondary jet nozzle pump (not shown) are disposed inside the jet solder tank body 2.

The secondary jet nozzle pump is disposed inside the solder bath main body 2 and at a predetermined position facing one end of a secondary jet nozzle duct 6 described later, in a state of being completely immersed in the molten solder. The secondary jet nozzle pump supplies molten solder made of lead-free solder accommodated in the solder bath body 2 to the secondary jet nozzle duct 6. The secondary jet nozzle pump need only be capable of sending molten solder and need not be limited to a specific type, but has few pulsations during constant speed rotation and rapid convergence during shifting. From the viewpoint of safety, it is desirable to use a screw pump.

The molten solder sent by the secondary jet nozzle pump is supplied to the secondary jet nozzle duct 6. The secondary jet nozzle duct 6 is disposed inside the solder bath main body 2 and in the vicinity of the bottom, and is an opening 6b formed by two flanges 6a that are spaced upward in the printed board conveyance direction. On the top surface. The secondary jet nozzle duct 6 guides the molten solder sent by the secondary jet nozzle pump disposed at one end thereof to the other end.

A secondary jet nozzle 5 having an opening on the upper surface of the other end of the secondary jet nozzle duct 6 is installed. The secondary jet nozzle 5 communicates with the secondary jet nozzle duct 6 by extending upward between the two flanges 6 a of the secondary jet nozzle duct 6, and is connected to the secondary jet nozzle duct 6. The molten solder supplied through the duct 6 is guided and jetted upward. The secondary jet nozzle 5 extends vertically upward and is configured such that the upper cross-sectional area is smaller than the lower cross-sectional area, and the interior of the secondary jet nozzle 5 is sent upward. The resulting molten solder is jetted upward as a gentle wave. Further, as will be described later, two flanges 6a of the secondary jet nozzle duct 6 are made of a vertical wall portion 5d of the secondary jet nozzle 5 and a connecting member 8a attached to the vertical wall portion 5d with a fixing pin or the like. The secondary jet nozzle 5 is positioned with respect to the secondary jet nozzle duct 6 by being fitted into the space, in other words, the two connecting members 8a are hooked on the two flanges 6a, and is attached and detached. Installed freely. Therefore, the secondary jet nozzle 5 can be pulled out from the secondary jet nozzle duct 6 during maintenance.

As shown in FIG. 2, a known rectifying plate 5 c is arranged in multiple stages inside the secondary jet nozzle 5.

[Primary jet nozzle tilting device 7]
As shown in FIG. 2, the primary jet nozzle 3 is provided with a primary jet nozzle tilting device 7 for arranging the primary jet nozzle 3 so as to be tilted toward the conveyance direction of the printed circuit board.

The primary jet nozzle tilting device 7 is installed on the two vertical wall portions 3d of the primary jet nozzle 3 that are separated in the transport direction of the printed circuit board, and is connected to two flanges 4a, respectively, and two connecting members 7a. An installation height adjusting mechanism 10 is provided for individually adjusting the installation height of the two connecting members 7a with respect to the two vertical wall portions 3d.

The installation height adjusting mechanism 10 includes one of a plurality of through holes 7b drilled horizontally in the respective vertical wall portions 3d of the two connecting members 7a and two of the primary jet nozzle 3. It has a fixing pin (not shown) that penetrates any one of the plurality of through holes 3e formed in the vertical wall portion 3d obliquely upward.

By appropriately selecting the two through holes 7b and 3e through which the fixing pin in the installation height adjusting mechanism 10 passes, the installation height of the two connecting members 7a with respect to the two vertical wall portions 3d can be individually adjusted. . When the primary jet nozzle 3 is inclined in the transport direction, the two through holes 7b and 3e into which the fixing pins are inserted are appropriately provided so that the left vertical wall 3d is positioned higher than the right vertical wall 3d. select. For example, the front through hole 3e drilled at the lowest position in the left vertical wall 3d is selected, and the front through hole 7b is selected in the left connecting member 7a, and these selected through holes are selected. A fixing pin is inserted into each of 3e and 7b. On the other hand, in the right vertical wall portion 3d, the middle (or back side drilled at the highest position) through hole 3e is selected, and in the right connecting member 7a, the middle (or back side) through hole 7b is selected. And a fixing pin is inserted into each of the selected through holes 3e and 7b. As a result, the left vertical wall portion 3d constituting the primary jet nozzle 3 is shifted to a position higher than the right vertical wall portion 3d, and the primary jet nozzle 3 as a whole is inclined toward the conveyance direction of the printed circuit board. Can be arranged.

Even when the primary jet nozzle 3 is inclined, the molten solder can be surely prevented from leaking by appropriately setting the vertical dimension of the connecting member 7a.

[Secondary jet nozzle tilting device 8]
As shown in FIG. 2, the secondary jet nozzle 5 is provided with a secondary jet nozzle tilting device 8 for tilting the secondary jet nozzle 5 in a direction opposite to the direction of conveyance of the printed circuit board. ing.

The secondary jet nozzle tilting device 8 is installed on the two vertical wall portions 5d of the secondary jet nozzle 5 that are separated from each other in the transport direction of the printed circuit board, and two connecting members 8a that are respectively hooked on the two flanges 6a. And an installation height adjusting mechanism 11 for individually adjusting the installation height of the two connecting members 8a with respect to the two vertical wall portions 5d.

The installation height adjusting mechanism 11 includes one of a plurality of through holes 8b drilled horizontally in the respective vertical wall portions 5d of the two connecting members 8a, and the second of the secondary jet nozzle 5. Each of the vertical wall portions 5d has a fixing pin (not shown) that passes through one of the plurality of through holes 5e that are drilled obliquely upward.

The installation height of the two connecting members 8a with respect to the two vertical wall portions 5d can be individually adjusted by appropriately selecting the two through holes 8b and 5e through which the fixing pin in the installation height adjusting mechanism 11 passes. . When the secondary jet nozzle 5 is inclined in the direction opposite to the conveying direction, the two penetrations into which the fixing pins are inserted are arranged such that the right vertical wall 5d is higher than the left vertical wall 5d. The holes 8b and 5e are selected as appropriate. For example, as shown in FIG. 2, the front through hole 5e drilled at the lowest position in the right vertical wall 5d is selected, and the front through hole 8b is selected in the right connecting member 8a. Then, a fixing pin is inserted into each of the selected through holes 5e and 8b. On the other hand, in the left vertical wall portion 5d, the middle (or the back side drilled at the highest position) through hole 5e is selected, and in the left connecting member 8a, the middle (or back side) through hole is selected. 8b is selected, and a fixing pin is inserted into each of the selected through holes 5e and 8b. As a result, the right vertical wall portion 5d constituting the secondary jet nozzle 5 is shifted to a position higher than the left vertical wall portion 5d, and the secondary jet nozzle 5 as a whole is opposite to the conveyance direction of the printed circuit board. It can be arranged inclined toward the direction.

Even when the secondary jet nozzle 5 is inclined, the leakage of molten solder can be reliably prevented by appropriately setting the vertical dimension of the connecting member 8a to be large.

[Exit-side former tilting device 9]
In the jet solder bath 1, the exit-side former tilting device for adjusting the tilt angle of the exit-side former 12 arranged in the upper part of the secondary jet nozzle 5 in the printed board conveying direction with respect to the secondary jet nozzle 5. 9 is provided.

The exit-side former tilting device 9 includes a shaft support mechanism 9a provided on the secondary jet nozzle 5 and rotatably supporting the exit-side former 12, and a plate cam mechanism 9b that moves the lower surface of the exit-side former 12 up and down. . As shown in FIGS. 3 and 4, a handle 13 for operating the plate cam mechanism 9b is mounted. As shown in FIGS. 3 and 4, by operating the handle 13, the inclination angle of the exit-side former 12 with respect to the secondary jet nozzle 5 can be adjusted.

According to the present invention, when the primary jet nozzle 3 and the secondary jet nozzle 5 are inclined inward in the respective directions, the jet angle of the molten solder changes, and the molten solder from the primary jet nozzle 3 is moved to the secondary jet nozzle 5 side. The molten solder from the secondary jet nozzle 5 is jetted to the primary jet nozzle 3 side. At this time, since the outlet-side former 12 is attached to the secondary jet nozzle 5, the outlet-side former 12 is also inclined toward the primary jet nozzle 3 side with the inclination of the secondary jet nozzle 5. In particular, the secondary jet nozzle 5 needs to jet a gentle wave that can correct bridges and wiggles of the printed circuit board soldered by the rough wave jetted from the primary jet nozzle 3. 5 and the exit former 12 are inclined, the molten solder jet from the secondary jet nozzle 5 is inclined and the height of the secondary jet is not aligned. There is sex.

Therefore, in the present invention, for the sake of completeness, the inclination of the molten solder jet generated by arranging the secondary jet nozzle 5 at an inclination is lowered by changing the inclination angle of the exit-side former 12 with respect to the secondary jet nozzle 5. Thus, the angle of the molten solder jet from the secondary jet nozzle 5 is returned to the horizontal. Specifically, as shown in FIG. 3, with the inclination of the secondary jet nozzle 5 toward the primary jet nozzle 3, the downstream end in the transport direction of the exit-side former 12 rises above the horizontal position. 4, the handle 13 is rotated counterclockwise to a predetermined position to actuate the plate cam mechanism 9b as shown in FIG. As a result, the downstream end of the exit-side former 12 returns to the horizontal position or slightly below the horizontal position, so that the exit-side former 12 can be arranged in the horizontal direction.

Thus, by appropriately adjusting the inclination angle of the exit-side former 12 with respect to the secondary jet nozzle 5 by the exit-side former tilting device 9, the secondary jet nozzle tilting device 8 causes the secondary jet nozzle 5 to be placed on the printed circuit board. Even in the case where the exit-side former 12 is inclined toward the direction opposite to the conveyance direction, the exit-side former 12 can be arranged toward the horizontal direction.

Here, in order to prevent soldering failure due to carbonization of the pine resin component of the flux or oxidation of the molten solder, the jet solder bath 1 is formed inside a case that constitutes a chamber filled with nitrogen gas having a lower oxygen concentration than the atmosphere. Is housed. Therefore, as described above, when the inclination angle of the exit-side former 12 is adjusted, the opening / closing door provided in the case is opened and the handle 13 in the chamber is operated to adjust the inclination angle of the exit-side former 12. Had to do. Therefore, the jet solder bath 1 according to the present invention is provided with an operation portion (handle) 14 that allows the handle 13 to be operated indirectly from the outside of the chamber.

The operation unit 14 is connected to the handle 13 via a coupling mechanism (not shown) provided between the operation unit 14 and the handle 13, and is rotatably attached to the outer surface of the case. When the operation unit 14 is rotated by the operator, as shown in FIGS. 3 and 4, the handle 13 rotates clockwise or counterclockwise via the coupling mechanism in accordance with the rotation operation amount of the operation unit 14. To do. As a result, the plate cam mechanism 9b is operated, and the inclination angle of the exit-side former 12 is finely adjusted. Thus, by providing the operation part 14 for operating the handle 13 in the case outside the case, the inclination angle of the exit-side former 12 can be finely adjusted without opening the case. As a result, it is possible to reduce the work time and work load of the worker.

The jet solder bath 1 according to the present invention is configured as described above. The jet solder bath 1 is provided with a primary jet nozzle tilting device 7 for the primary jet nozzle 3 and a secondary jet nozzle tilting device 8 for the secondary jet nozzle 5, so that it communicates with the duct 4 for the primary jet nozzle. From the state in which the primary jet nozzle 3 and the secondary jet nozzle 5 arranged in communication with the secondary jet nozzle duct 6 are directed upward in the normal vertical direction, respectively, the transport direction of the printed circuit board, this transport, respectively. It can change to the state inclined in the direction opposite to the direction.

For this reason, this jet solder tank 1 can adjust the space | interval of the primary jet nozzle 3 and the secondary jet nozzle 5 in the conveyance direction of a printed circuit board very simply, and the melting | fusing point of the lead-free solder to be used can be adjusted. Regardless of the fluctuation, it is possible to reliably prevent the molten solder attached to the printed circuit board by the primary jet nozzle 3 from solidifying before transferring to the secondary jet nozzle 5.

Further, since the jet solder tank 1 includes the exit-side former tilting device 9, the secondary jet nozzle tilting device 8 tilts the secondary jet nozzle 5 in the direction opposite to the conveyance direction of the printed circuit board. Even in this case, it is possible to adjust the inclination angle of the exit-side former 12 provided for the secondary jet nozzle 5 for guiding the molten solder ejected with respect to the secondary jet nozzle 5 in an appropriate direction. Stable soldering can be performed regardless of the inclined arrangement of 5.

In this manner, according to the jet solder tank 1 according to the present invention, the interval between the primary jet nozzle 3 and the secondary jet nozzle 5 can be easily adjusted. Therefore, it is possible to reliably prevent the molten solder attached to the printed circuit board by the primary jet nozzle 3 from solidifying before transferring to the secondary jet nozzle 5.

Therefore, when soldering a printed circuit board using this jet solder bath 1, for example, for a main board, soldering of lead-free solder having a composition of Sn-3.5Ag and Sn-3.0Ag-0.5Cu However, it is possible to change the lead-free solder to the remote control that is a hand-held device, as in the case of using a low silver lead-free solder such as Sn-0.7Cu-0.3Ag, which has a strong drop impact. Even when necessary, the distance between the primary jet nozzle 3 and the secondary jet nozzle 5 can be adjusted easily, and any lead-free solder with any composition can be left with a bridge or tsura, or even through. Soldering with good quality and high reliability can be performed without causing insufficient wetting and spreading inside the hole.

Here, due to the primary jet nozzle 3 and the secondary jet nozzle 5 being too close to each other, the molten solder jetted out from the respective jet nozzles 3 and 5 is jetted from the other jet nozzle. The phenomenon of flowing into the molten solder occurs near the ducts of the jet nozzles 3 and 5. The jet soldering bath 1 according to the present invention is configured to incline the primary jet nozzle 3 and the secondary jet nozzle 5 so that the distance between the nozzles 3 and the secondary jet nozzle 5 is close. The primary jet nozzle duct 4 and the secondary jet nozzle duct 6 Since the installation position is not close, the wave flowing from the jet nozzles 3 and 5 into which the molten solder has flowed is deformed and the action at the jet nozzle, that is, the unsolder elimination action at the primary jet nozzle 3 and the secondary jet nozzle. The phenomenon that the correction action of the bridge and icicle 5 in 5 is not performed does not occur at all.

The jet solder bath 1 according to the present invention can pull out the primary jet nozzle 3 from the primary jet nozzle duct 4 and pull out the secondary jet nozzle 5 from the secondary jet nozzle duct 6 together. Can do. For this reason, the maintainability of the primary jet nozzle 3 and the secondary jet nozzle 5 which are required during operation is also improved.

DESCRIPTION OF SYMBOLS 1 Jet solder bath 2 according to the present invention Solder bath body 3 Primary jet nozzle 3a Hole 3b Wave plate 3c Rectifying plate 3d Vertical wall 3e Through hole 4 Primary jet nozzle duct 4a Flange 4b Opening 5 Secondary jet nozzle 5c Rectification Plate 5d Vertical wall portion 5e Through hole 6 Duct for secondary jet nozzle 6a Flange 6b Opening portion 7 Primary jet nozzle tilting device 7a Connecting member 7b Through hole 8 Secondary jet nozzle tilting device 8a Connecting member 8b Through hole 9 Retracting-side former tilting Device 9a Shaft support mechanism 9b Plate cam mechanism 10 Installation height adjustment mechanism 11 Installation height adjustment mechanism 12 Exit side former 14 Operation section

Claims

A solder bath body over which the printed circuit board is conveyed in a predetermined conveyance direction; and
An opening formed by two flanges that are arranged inside the solder bath main body and guide the molten solder sent by a pump that sends molten solder made of lead-free solder and that are spaced upward in the conveying direction and provided upward A duct having an upper surface thereof, and a molten solder supplied through the duct, the duct being arranged to extend upward between the two flanges so as to communicate with the duct through the opening. Two combinations of jet nozzles that guide and jet upwards,
A jet solder tank, comprising: a jet nozzle tilting device for tilting at least one of the two jet nozzles toward the transport direction or the direction opposite to the transport direction.
2. The jet solder bath according to claim 1, wherein the jet nozzle is a primary jet nozzle, and the jet nozzle tilting device is arranged to tilt the primary jet nozzle toward the transport direction.
The jet nozzle is a secondary jet nozzle, and the jet nozzle tilting device is arranged to incline the secondary jet nozzle in a direction opposite to the transport direction and to the secondary jet nozzle in the transport direction. The jet solder bath according to claim 1, further comprising a withdrawal-side former tilting device for adjusting an inclination angle of the withdrawal-side former arranged with respect to the jet nozzle.
The jet nozzle tilting device is installed in two vertical wall portions of the jet nozzle that are separated in the transport direction, and is connected to the two flanges, and the two vertical wall portions. The jet solder bath according to any one of claims 1 to 3, further comprising an installation height adjusting mechanism for individually adjusting an installation height of the two connecting members with respect to the inner surface.
The installation height adjusting mechanism includes one of a plurality of through holes formed in the vertical wall portions of the two connecting members in the horizontal direction and the two vertical walls of the jet nozzle. The jet solder bath according to claim 4, further comprising a fixing pin penetrating through one of a plurality of through holes drilled in a diagonally upward direction.
The said exit side former | tilt apparatus has a shaft support mechanism provided in the said secondary jet nozzle, and rotatably supporting the said exit side former, and a plate cam mechanism which raises / lowers the lower surface of the said exit side former. A jet solder bath according to any one of claims 1 to 5.