JP2016201469A - Local soldering nozzle, solder jet device using the same, and local soldering method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: a local soldering nozzle capable of performing high quality local soldering for an insertion mounting component even when a printed board has a thick board; a solder jet device using the local soldering nozzle; and a local soldering method.SOLUTION: A local soldering nozzle includes: a soldering nozzle having an opening through which molten solder is jetted; and a solder channel jetting molten solder to the inside of the soldering nozzle through an opening that has an opening diameter smaller than that of the soldering nozzle.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a local soldering nozzle that performs soldering by locally jetting molten solder onto a printed circuit board, a solder jet device using the nozzle, and a local soldering method.

  2. Description of the Related Art Conventionally, a local soldering apparatus has been used in which molten solder stored in a solder bath is jetted upward using a nozzle and soldered locally to a through hole provided in a printed circuit board.

  As background art related to this technical field, for example, JP 2009-262200 A (Patent Document 1), JP 2010-274286 A (Patent Document 2), JP 2011-35044 A (Patent Document 3). There is.

  In Patent Document 1, a receiving tray having an open end at a position higher than the upper end of the local soldering nozzle is provided on the outer periphery, and the molten solder is jetted from the local soldering nozzle so as to penetrate through the molten solder stored in the receiving tray. A technique for suppressing the spread of the molten solder that is jetted by the surface tension of the molten solder stored in the tray is disclosed.

  Patent Document 2 discloses a technique that can divide the internal flow path of a local soldering nozzle into two cylindrical flow paths on the tip side with a partition wall and perform good soldering at a plurality of points simultaneously. Has been.

  Furthermore, in Patent Document 3, a solder flow passage having a diameter smaller than that of the nozzle opening is provided inside the local soldering nozzle, and the molten solder that has been jetted flows into the flow passage so that solder is not soldered to unnecessary portions. A technique for suppressing the spread is disclosed.

JP 2009-262200 A JP 2010-274286 A JP 2011-35044 A

  In the local soldering method, in order to contact and supply molten solder from the lower surface of the printed circuit board, a flux is previously applied to the electrode portion to be soldered. Then, soldering is performed by the solder wets onto the surface of the electrode cleaned by the flux applied to the electrode portion by the heat of the molten solder.

  On the other hand, the number of layers of the printed circuit board has increased and the thickness of the printed circuit board has increased as the printed circuit board has a higher frequency circuit and a higher integrated circuit. Along with this, the length of the through hole becomes longer, and it is necessary to increase the flow rate of the molten solder necessary for fixing the insertion mounting component, but none of Patent Documents 1, 2, and 3 consider this point. .

  When the thickness of the printed circuit board is increased, the flux applied to the electrode part is scattered by the heat of the molten solder before the solder gets wet, and the cleaning of the electrode surface may be impaired. The problem is that wetting will not occur.

  In particular, in the local soldering method, when the solder is supplied to the adjacent through-hole part, the flux applied to the electrode part in the adjacent through-hole is scattered by the heat of the molten solder, and the solder wets up. Inhibiting is a challenge.

  As a method for increasing the flow rate of molten solder, it is conceivable to increase the nozzle opening diameter of the local soldering nozzle in order to increase the heat capacity of the molten solder. As a result, solder adheres unnecessarily to adjacent components such as surface-mounted components that are already mounted, causing a defect such as component separation, and restricting the design of the printed circuit board.

  Although a method of increasing the jet speed of the molten solder is also conceivable, there is a variation in the height of the molten solder jet, and this also causes the solder to adhere to unnecessary parts, which makes high-quality soldering impossible. Become.

  Further, although a method of increasing the jet time of the molten solder is conceivable, the production time becomes long, and the printed circuit board is eroded and damaged, resulting in damage to the circuit pattern.

  The present invention has been made in view of the above-mentioned problems, and the purpose of the present invention is to apply molten solder to a through-hole of a printed circuit board having a large number of layers and a large thickness when performing local soldering using a local soldering nozzle. It is an object to provide a local soldering nozzle that promotes flow-up performance and improves solder filling performance, a solder jet device using the same, and a local soldering method.

  In order to solve the above problems, for example, the configuration described in the claims is adopted. The present application includes a plurality of means for solving the above-mentioned problems. To give an example, a local soldering nozzle, a soldering nozzle in which molten solder jets from an opening, and an inside of the soldering nozzle are provided. A solder flow path for jetting molten solder with an opening diameter smaller than the opening diameter of the soldering nozzle is provided.

According to the present invention, local soldering can be performed with high quality even on a thick board / highly integrated printed circuit board having a large number of layers.

3 is a cross-sectional view of a local soldering nozzle in Example 1. FIG. 1 is an overall configuration diagram of a solder jet device using a local soldering nozzle in Embodiment 1. FIG. It is a fragmentary sectional view of the printed circuit board of the local soldering state in Example 1 of the local soldering nozzle and the insertion mounting component. FIG. 10 is a diagram illustrating a printed circuit board manufacturing process in Example 2. It is a fragmentary sectional view of a printed circuit board of a local soldering state of a local soldering nozzle for explaining a conventional example, and an insertion mounting part.

  Embodiments of the present invention will be described below with reference to the drawings.

  First of all, prior art will be described before explaining this embodiment. FIG. 5 is a view schematically showing a partial cross-sectional view of a conventional local soldering nozzle and a printed circuit board in a local soldering state of an insertion mounted component. In FIG. 5, 20 is a local soldering nozzle, 6 is a solder bath, 5 is molten solder, 15 is molten solder to be jetted, 10 is a printed circuit board, 9 is a substrate of the printed circuit board, 7 is a solder resist, and 8 is a land. , 12 is an insertion mounting component, 11 is a lead terminal of the insertion mounting component, and 13 is a through hole of the printed board. As shown in FIG. 5, the molten solder 5 stored in the solder bath 6 is jetted upward using a local soldering nozzle 20, and the molten solder 15 that is jetted is locally injected into the through hole 13 provided in the printed circuit board 10. Soldering.

  FIG. 5 shows a case where the thickness of the printed circuit board 10 is not thick. For example, since the total number of inner layers is 4 and the thickness is about 1.6 mm, the printed circuit board 10 is not damaged and the production time is increased. Without this, it was possible to find the jet condition of the local soldering nozzle 20 that jets the solder filling amount necessary for fixing the lead terminal 11 to the through hole 13. However, due to the high frequency circuit and high integration circuit of the printed circuit board, the total number of the printed circuit boards 10 is increased, and when the overall plate thickness is increased, the height of the through hole 13 is increased accordingly, and the volume is increased. It is necessary to increase the amount of filled solder for fixing the lead terminal 11 to the through hole 13.

  When the thickness of the printed board 10 is increased, the lead terminal 11 is shorter than the through hole 13 and the tip of the lead terminal 11 may not protrude from the lower end of the through hole 13. However, the thickness of the printed board 10 is increased. Even so, depending on the type of the insertion / mounting component 12, the length of the lead terminal 11 may be longer than the length of the through hole 13, and the leading end of the lead terminal 11 extends from the lower end of the through hole 13 as shown in FIG. Needless to say, it may protrude.

  In order to increase the amount of filled solder, methods such as increasing the jet flow rate, increasing the jet speed of the molten solder, and increasing the jet time will cause the solder to adhere to unnecessary parts as described above. In addition, there is a problem such as biting of the printed circuit board due to overheating, and it becomes difficult to manufacture a high quality printed circuit board as the thickness of the printed circuit board increases.

  Therefore, this embodiment for solving these problems will be described below. FIG. 1 is a sectional view of a local soldering nozzle in the present embodiment. As shown in FIG. 1, the local soldering nozzle 100 of the present embodiment includes a soldering nozzle 1 having a first solder flow path 2 and a needle having a second solder flow path 4, for example, A solder injection device 3 as a second soldering nozzle is provided. The soldering nozzle 1 and the solder injection device 3 are cylindrical metal members installed vertically upward from the solder tank 6, the solder flow path 2 is an internal path of the soldering nozzle 1, and the solder flow path 4 is This is an internal path of the solder injection device 3. That is, the local soldering nozzle 100 has a double structure in which the solder injection device 3 is included in the soldering nozzle 1. Moreover, the opening diameter of the opening 1a of the soldering nozzle 1 is larger than the opening diameter of the opening 3a of the solder injection device 3, for example, 7.6 mm larger, and the opening 1a is higher than the opening 3a. For example, 2 mm above.

  In FIG. 2, the schematic diagram of the whole block diagram of the solder jet apparatus 200 using the local soldering nozzle 100 of a present Example is shown. The molten solder 5 is stored in the solder bath 6, heated by a heat source (not shown), pressurized by the pressure feeding device 210, and the molten solder 5 from the solder bath 6 is sent from the solder feeding portion 220 to the solder flow path 2. And 4 are jetted upward.

  FIG. 3 is a diagram schematically showing a partial cross-sectional view of a local soldering nozzle and a printed circuit board in a locally soldered state of an insertion mounted component in the present embodiment.

  As shown in FIG. 3, the jetted molten solder reaches a lower portion of a through hole 13 that is a soldering portion of a printed circuit board 10 that is a soldered body, and fixes the lead terminal 11 to the through hole 13. When the molten solder is pumped from the solder bath 6, the pressure per unit area applied to the soldering nozzle 1 and the solder spraying device 3 is the same, so the difference in the opening diameter between the opening 1a and the opening 3a The flow rate of the molten solder passing through the path 4 is larger than the flow rate of the molten solder passing through the solder flow path 2. Therefore, from the opening 1a having a large opening diameter of the soldering nozzle 1, molten solder having a large jet area and a low jet height at the illustrated wave height C is jetted, while the solder injection apparatus 3 has a small opening diameter. From the part 3a, a molten solder having a small jet area and a high jet height of the wave height D shown in the figure is jetted. Therefore, the molten solder jetted from the entire local soldering nozzle by the molten solder jetted from the opening 3a having a small opening diameter is higher than the jet height of the molten solder jetted from the conventional local soldering nozzle. And the solder filling of through-holes in a thick printed circuit board is promoted. Further, the molten solder jetted from the opening 1a has a heat capacity secured by the size of the jet area, and high-quality soldering is possible. That is, the molten solder jetted from the soldering nozzle 1 and the solder injection device 3 simultaneously jets molten solder having different jet heights, and solders the same soldered portion of the soldered body, thereby achieving high quality. Can be soldered.

  As described above, in this embodiment, in the local soldering nozzle, the nozzle for jetting molten solder from the upper end includes a solder flow path having an opening diameter smaller than the opening diameter of the nozzle, and two solder jet paths Is provided.

  In addition, when molten solder is jetted from a solder tank in which molten solder is stored, the jet velocity of the solder flow path having a small opening diameter contained therein is larger than the jet velocity of the soldering nozzle having a large opening diameter. Molten solders having different jet speeds are jetted simultaneously from two solder jet paths.

  Moreover, since the molten solder jetted from the solder flow path having a small opening diameter has a high jet velocity, the jet height is higher than the jet height of the molten solder jetted from the soldering nozzle having a large opening diameter. A molten solder having a jet height can be simultaneously jetted to a predetermined soldering location.

  In addition, since the upper end of the solder flow path with a small opening diameter contained is in a position lower than the upper end of the soldering nozzle with a large opening diameter, the heat capacity of the molten solder can be secured in the soldering nozzle with a large opening diameter, and Therefore, high-quality local soldering can be performed without soldering unnecessary portions.

  Therefore, the local soldering nozzle and the local soldering method in the present embodiment are the same as the solder solder that can maintain a stable jet height with a large opening diameter, and a solder flow path that has a higher jet height than the solder path. Since the jet height to the predetermined soldering location can be stably increased by jetting, a predetermined amount of solder can be filled even in a through hole of a thick printed board having a large number of layers. .

  For example, when fixing a lead terminal (for example, lead terminal diameter: 0.8 mm) to a through hole (for example, through hole diameter: 1.2 mm) of a printed board having a plate thickness of 3.2 mm, the local soldering in FIG. The jet height is, for example, 7 mm, which is, for example, 4 mm higher than the jet height of the conventional local soldering nozzle, and the through hole can be filled with solder. Therefore, the printed circuit board provided with the to-be-soldered body soldered with high quality by the local soldering nozzle of the present embodiment can be provided.

  To increase the flow rate of the molten solder passing through the solder flow path 4 by increasing the area of the opening 1a within a range not adhering to adjacent parts to further increase the heat capacity and reducing the area of the opening 3a. As a result, the lead terminal of the insertion mounted component can be soldered with high quality even through a through-hole in a thick printed board.

  In this embodiment, the local soldering nozzle has a double structure, but a plurality of structures such as a triple structure may be used. In addition, since it is only necessary to spray molten solder having different jet heights, instead of the local soldering nozzle having the second soldering nozzle such as a needle included in the soldering nozzle 1 described above, for example, A plurality of protrusions are provided in the vicinity of the opening of the soldering nozzle 1 so as to partially block the jet flow from the soldering nozzle 1 so that the jet heights from the first and second soldering nozzles are different. Also good.

  In other words, this embodiment is a local soldering nozzle, and a soldering nozzle in which molten solder jets from the opening, and an opening diameter smaller than the opening diameter of the soldering nozzle inside the soldering nozzle. A solder flow path for jetting molten solder is provided.

  Moreover, it is a local soldering nozzle which the molten solder jets from an opening part, Comprising: It comprises two solder jet paths, and it is comprised so that the solder of different jet height may be jetted from each jet path.

  Further, the solder jet device has the above-described local soldering nozzle, and further includes a solder tank in which the molten solder is stored, a pressure feeding device that pressurizes, and a pressure feeding unit that pumps the molten solder by the pressure from the pressure feeding device. The molten solder is jetted through the local soldering nozzle by the pumping unit.

  Moreover, it is a local soldering method for locally soldering a soldered portion of a body to be soldered, and jets when the jetted molten solder reaches the lower part of the soldered portion of the body to be soldered. The soldering part of a to-be-soldered body is soldered by two jets from which the molten solder jet height differs.

  As described above, according to the present embodiment, it is possible to perform local soldering with high quality even on a thick board / highly integrated printed circuit board having a large number of layers.

  FIG. 4 shows a process for manufacturing a printed circuit board on which the surface mounting component and the insertion mounting component are mounted in this embodiment. Steps 101 to 104 show the surface mounting component soldering process, and steps 105 and after show the insertion mounting component soldering process.

  Through holes and lands are formed in the printed circuit board, and the copper electrode wiring is protected by an insulating layer such as a solder resist. Therefore, the level | step difference by the land, the copper electrode wiring, and the solder resist has arisen. The unevenness of the glass epoxy in the printed circuit board, the variation in the plating thickness of the copper electrode, the variation in the coating thickness of the solder resist, and the like are also causes of the surface unevenness of the printed circuit board.

  In FIG. 4, in step 101, in the printing machine, a metal mask is brought into contact with the printed board, and a solder paste is formed using a squeegee at a position where a surface mount component of the printed board is mounted from the opening of the metal mask. Transcript to. Since the metal mask has an organic layer that can absorb the land on the printed circuit board, copper electrode wiring, and solder resist, the printed circuit board and the metal mask can be in close contact with each other. Therefore, the solder paste does not bleed into the gap between the printed board and the metal mask. In step 102, it is confirmed by a printing inspection machine that no defect such as a bridge (solder short) or a solder ball has occurred.

  In step 103, the surface mount component is mounted by the mounter device in accordance with the position where the solder paste is transferred to the land of the printed circuit board. In step 104, the surface-mounted component is fixed to the land of the printed board by passing the printed board through a reflow furnace. In this way, the surface mount component can be soldered by the reflow method.

  Subsequently, in step 105, the lead terminal of the insertion mounted component is inserted into the through hole of the printed board, and flux is applied to the through hole and the lead terminal with a fluxer. In step 106, the printed circuit board on which the insertion mounting component is mounted is heated using a preheater, and in step 107, the lead terminals inserted into the through holes by the local soldering apparatus described in the first embodiment are soldered. . In step 108, the entire printed circuit board is confirmed by an inspection machine. As described above, the local soldering method according to the present embodiment can fill a predetermined amount of solder even on a thick printed board without increasing the manufacturing time of the printed board.

  In addition, when this manufacturing process was implemented with the board thickness of 3.2 mm of a printed circuit board, it could fully endure reliability tests (practical use test), such as a temperature cycle.

  Although the present invention has been specifically described above based on the embodiments, it is needless to say that the present invention is not limited to the above embodiments and can be variously modified without departing from the gist thereof. The above-described embodiments have been described in detail for easy understanding of the present invention, and are not necessarily limited to those having all the configurations described.

  In the local soldering nozzle of the present invention, it is only necessary that the soldering nozzle having a large opening diameter includes a solder injection path having a small opening diameter, and each opening diameter and shape is limited to the configuration shown in the figure. In addition, the configuration of the insertion mounting component and the printed circuit board which are the solder material and the member to be soldered to be used is arbitrary.

DESCRIPTION OF SYMBOLS 1 ... Soldering nozzle, 1a, 3a ... Opening part, 2 ... 1st solder flow path, 3 ... Solder injection apparatus, 4 ... 2nd solder flow path, 5 ... Molten solder, 6 ... Solder tank, 7 ... Solder Resist, 8 ... Land, 9 ... Base, 10 ... Printed circuit board, 11 ... Lead terminal, 12 ... Inserted mounting component, 13 ... Through hole, 15 ... Mold solder to be jetted, 20,100 ... Local soldering nozzle, 200 ... Solder jet device, 210 ... Pressure feeding device, 220 ... Pressure feeding section

Claims (12)

A soldering nozzle through which molten solder jets from the opening;
A local soldering nozzle comprising a solder flow path for jetting molten solder with an opening diameter smaller than the opening diameter of the soldering nozzle inside the soldering nozzle. The local soldering nozzle according to claim 1,
The said solder flow path is comprised with the 2nd soldering nozzle included in the said soldering nozzle, The local soldering nozzle characterized by the above-mentioned. The local soldering nozzle according to claim 2,
The local soldering nozzle, wherein an opening of the soldering nozzle is positioned higher than an opening of the second soldering nozzle. The local soldering nozzle according to claim 3,
The local soldering nozzle characterized by soldering the same soldering part of a to-be-soldered body with the molten solder jetted from the said soldering nozzle, and the molten solder jetted from the said 2nd soldering nozzle.   A local soldering nozzle for jetting molten solder from an opening, the soldering nozzle having two solder jet paths, and jetting solder of different jet heights from the respective jet paths. The local soldering nozzle according to claim 5,
The two solder jet passages are solder jet passages each composed of a first soldering nozzle and a second soldering nozzle contained in the first soldering nozzle, respectively. . The local soldering nozzle according to claim 6,
The opening diameter of the second soldering nozzle is smaller than that of the first soldering nozzle,
The local soldering nozzle, wherein a jet height of the molten solder jetted from the opening of the second soldering nozzle is higher than a jet height of the molten solder jetted from the opening of the first soldering nozzle. The local soldering nozzle according to claim 7,
The local soldering nozzle, wherein an opening of the first soldering nozzle is positioned higher than an opening of the second soldering nozzle. The local soldering nozzle according to claim 8,
A local soldering nozzle characterized by jetting solder of different jet heights simultaneously. The local soldering nozzle according to claim 1,
A solder bath in which molten solder is stored;
A pressure feeding device for pressurization;
A pumping unit that pumps the molten solder by pressure from the pumping device, and causes the molten solder to jet through the soldering nozzle and the solder flow path of the local soldering nozzle by the pumping unit. Solder jet device characterized by. The local soldering nozzle according to claim 5,
A solder bath in which molten solder is stored;
A pressure feeding device for pressurization;
A pumping unit that pumps the molten solder by pressure from the pumping device; and the jetting unit causes the molten solder to jet through the two solder jet paths of the local soldering nozzle. Solder jet device. A local soldering method for locally soldering a soldered portion of a body to be soldered,
When the jetted molten solder reaches the lower part of the soldered portion of the soldered body, the soldered portion of the soldered body is moved by two jets having different jet heights of the molten solder to be jetted. A local soldering method characterized by soldering.

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