Preheating mechanism of jet welding device and jet welding device

Abstract

The invention provides a preheating mechanism of a jet welding device and the jet welding device, wherein the preheating mechanism can be efficiently heated to the upper part of a through hole of a substrate and can enable soft solder to reach the upper part of the through hole without solidification and wetting stopping. A preheating mechanism (50) for a jet welding device, which is attached to a soldering device for drawing up a molten solder from a jet nozzle (40) and soldering a portion of a soldering site (30) of a printed wiring board (10), the preheating mechanism (50) preheating the soldering site (30) and the periphery of the soldering site (30) of the printed wiring board (10), the preheating mechanism (50) being provided with at least: one or more electromagnetic coils (51); a mounting part (52) for mounting one or more electromagnetic coils (51) on the periphery of the jet nozzle (40); and an AC power supply and control unit (53) that causes an AC current to flow to the one or more electromagnetic coils (51) and performs on / off control of the AC current, in which the mounting unit (52) is disposed at a position at which it is possible to preheat the soldering site (30) of the printed wiring board (10) and the periphery thereof by electromagnetic induction heating using the one or more electromagnetic coils (51), and the mounting unit (52) is disposed at a position at which it is possible to preheat the soldering site (30) of the printed wiring board (10) and the periphery thereof by electromagnetic induction heating using the one or more electromagnetic coils (51). The heating time, the heating time, and the power applied to the one or more electromagnetic coils are controlled by an AC power supply and a control unit (53).

Description

Technical Field

[0001] The present invention relates to a preheating mechanism of a jet flow soldering device and a jet flow soldering device, wherein the preheating mechanism of the jet flow soldering device is attached to the following soldering device: molten solder is pumped up from a jet flow nozzle and soldered to a part of a soldering part of a printed wiring substrate, and the preheating mechanism of the jet flow soldering device preheats the soldering part of the printed wiring substrate and its surroundings. This application claims priority based on Japanese patent application No. 2023-43624 filed in Japan on March 17, 2023, and the application is cited in this application by reference to the application. Background Art

[0002] There is a local soldering device that performs soldering by ejecting molten solder from a cylindrical jet nozzle from a soldering surface (mainly the lower surface) when inserting a lead component into a through hole (plain hole) of a printed wiring board.

[0003] In the local soldering device, only a part of the printed wiring board is heated for local soldering, and the temperature rise of the periphery and the component surface (the upper surface of the substrate) is small. This has the advantage of less thermal stress on the surrounding components, but on the other hand, there is also the following disadvantage: due to the solidification of the solder, the wetting and spreading of the solder and the wetting climbing to the upper part of the through hole are poor.

[0004] As a countermeasure to the above, there is also the case of heating from the soldering surface (mainly the lower surface) by using hot air (heated air, heated nitrogen, etc.) or radiation heating (infrared heater, etc.), but the temperature of the surrounding substrate resin (base material) rises faster than the pattern to be soldered and the component electrodes.

[0005] Since local heating is used, the patterns and electrodes of components to be soldered have good thermal conductivity and are easy to dissipate heat to the surrounding areas. In addition, it takes time to heat patterns and electrodes with large heat capacity such as large components.

[0006] For example, Patent Documents 1 to 3 describe soldering by placing a high-frequency induction heating head at a soldering site, and Patent Document 4 describes soldering by induction heating a soldering target site using electromagnetic induction heating.

[0007] The inventions of Patent Documents 1 to 4 all aim to perform soldering by melting the solder using electromagnetic induction heating, rather than supplying molten solder using a jet nozzle. In addition, in the inventions of Patent Documents 1 to 3, the solder is melted by clamping the electrode using a high-frequency induction heating head or by bringing the high-frequency induction heating head close to the electrode, so that, for example, the following situation occurs: in the case of a plurality of rows of connector terminals, the solder cannot be clamped and cannot be melted.

[0008] Patent Document 5 describes a device for removing electronic components by electromagnetic induction heating, and Patent Documents 6 to 8 describe melting solder between two joined components by electromagnetic induction heating.

[0009] However, the inventions of Patent Documents 5 to 8 are limited to local reflow and small parts.

[0010] Prior art literature

[0011] Patent Literature

[0012] Patent Document 1: Japanese Patent Application Publication No. 2022-059164

[0013] Patent Document 2: Japanese Patent Application Publication No. 2021-190295

[0014] Patent Document 3: Japanese Patent Application Publication No. 2022-122539

[0015] Patent Document 4: Japanese Patent Application Publication No. 2017-163015

[0016] Patent Document 5: Japanese Patent No. 7128994

[0017] Patent Document 6: International Publication No. 2019 / 073581

[0018] Patent Document 7: Japanese Patent No. 6915843

[0019] Patent Document 8: International Publication No. 2018 / 051475 Summary of the invention

[0020] Problem that the invention aims to solve

[0021] Therefore, in view of the actual situation of the above-mentioned prior art, the present invention aims to provide a preheating mechanism and a jet soldering device for a jet soldering device that can efficiently heat the upper part of the through hole of the substrate and enable the soft solder to reach the upper part of the hole without solidifying and stopping the wetting and climbing.

[0022] Solutions for solving problems

[0023] One form of the present invention for solving the above-mentioned problems is a preheating mechanism of a jet soldering device, which is attached to the following soldering device: molten solder is drawn up from a jet nozzle and soldering is performed locally on a soldering portion of a printed wiring substrate, the preheating mechanism of the jet soldering device preheats the soldering portion of the printed wiring substrate and its surroundings, the preheating mechanism of the jet soldering device comprises at least: one or more electromagnetic coils; a loading portion, which is used to set one or more electromagnetic coils around the jet nozzle; and an AC power supply and a control portion, which allow AC current to flow to the one or more electromagnetic coils and perform on / off control of the AC current, the loading portion is arranged at a position where the soldering portion of the printed wiring substrate and its surroundings can be preheated by electromagnetic induction heating using one or more electromagnetic coils, and the heating timing, heating time and applied power applied to the one or more electromagnetic coils are controlled by the AC power supply and the control portion.

[0024] At this time, in one aspect of the present invention, a core of a soft ferrite system may be provided to one or more electromagnetic coils.

[0025] Moreover, in one aspect of the present invention, the preheating mechanism may further include a heating gas supply mechanism that supplies heating gas to the printed wiring board.

[0026] In one aspect of the present invention, the Curie temperature of the soft ferrite core may be 200° C. or higher.

[0027] In one aspect of the present invention, the core of the soft ferrite system may be formed in a cylindrical shape so as to surround the jet nozzle, and the electromagnetic coil may be wound along the height direction of the cylindrical core.

[0028] In one aspect of the present invention, the soft ferrite core may be U-shaped, and the U-shaped core may be provided at one or more locations around the jet nozzle.

[0029] In one aspect of the present invention, a groove may be formed in the core of the soft ferrite system, and the electromagnetic coil may be wound in the groove so as to be buried in the groove.

[0030] Another aspect of the present invention is a jet welding device having the above-mentioned preheating mechanism, which comprises: a workpiece supporting component, which supports a workpiece with multiple soldering locations scattered thereon; a jet nozzle, which sprays molten solder toward the soldering locations; a preheating mechanism, which is arranged around the jet nozzle; and a positioning component, which reduces the distance from the jet nozzle to the multiple soldering locations during the automatic soldering process and increases the distance during the standby process.

[0031] Effects of the Invention

[0032] According to the present invention, the metal part (pattern, electrode) which is difficult to heat or heats slowly by hot air or radiation heating is self-heated by electromagnetic induction heating (IH: Induction Heating), so that the target part can be heated efficiently. In addition, the temperature of the upper part of the through hole can also be raised, so that the solder does not solidify but does not stop the wetting climb, and the molten solder easily reaches the upper part of the hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] [ Figure 1 ] Figure 1 It is a perspective view showing one embodiment of the jet welding device of the present invention.

[0034] [ Figure 2 ] Figure 2 It is a perspective view showing another embodiment of the jet welding device of the present invention.

[0035] [ Figure 3 ] Figure 3 A is a cross-sectional view showing a state where an electronic component mounted on a printed wiring board is soldered using a jet nozzle and a preheating mechanism of one embodiment of the present invention arranged around the jet nozzle. Figure 3 B is a cross-sectional view showing a preheating mechanism according to another embodiment of the present invention.

[0036] [ Figure 4 ] Figure 4 A is a diagram showing an arrangement of an electromagnetic coil including a core of a soft ferrite system related to a preheating mechanism according to one embodiment of the present invention. Figure 4 B means from Figure 4 Figure A shows the state where the electromagnetic coil is removed.

[0037] [ Figure 5 ] Figure 5 This is a diagram showing an arrangement of an electromagnetic coil including a core of a soft ferrite system in accordance with another embodiment of a preheating mechanism according to the present invention.

[0038] [ Figure 6 ] Figure 6 A is a diagram showing a state viewed from the component surface side when a component lead is soldered to a through hole by conventional jet welding. Figure 6 B is a view showing a state viewed from the component surface side when the component lead is soldered to the through hole by jet welding to which the preheating mechanism of the present invention is applied. DETAILED DESCRIPTION

[0039] Hereinafter, the preheating mechanism of the jet flow welding device and the jet flow welding device of the present invention will be described in detail with reference to the drawings. In addition, the present invention is not limited to the following examples, and can be arbitrarily changed within the scope of the gist of the present invention.

[0040] One aspect of the present invention is attached to a soldering device that draws molten solder from a jet nozzle and solders a portion of a soldering portion of a printed wiring board. First, a jet nozzle type soldering device to which the present invention is applied is described, and then the structure of the preheating mechanism of the present invention is described.

[0041] Figure 1 This is a perspective view showing one form of the jet soldering device of the present invention, showing a situation where a printed wiring board with electronic components mounted thereon is conveyed to a predetermined position by a roller conveyor and soldered by a jet nozzle. Figure 1 As shown, one form of the present invention is a jet soldering device 100 having a preheating mechanism 50 to be discussed later, which comprises: a workpiece supporting component 20, which supports a workpiece (printed wiring substrate 10) with multiple soldering locations scattered thereon; a jet nozzle 40, which sprays molten solder 1 toward the soldering location 30; a preheating mechanism 50, which is arranged around the jet nozzle 40; and a positioning component 60, which reduces the distance from the jet nozzle 40 to the multiple soldering locations 30 during the automatic soldering process, and increases the distance during the standby process.

[0042] exist Figure 1 In the jet welding device 100, the workpiece support member 20 also serves as a workpiece conveying member, and as an example, is a roller conveyor, such as Figure 1 As shown, vertical five-axis rollers 21 to 25 are arranged in a row to clamp both sides of the workpiece (printed wiring board 10), and are rotated in a unified manner in a conveying direction 27 by a hook chain 26, thereby fulfilling the function of conveying the workpiece in the conveying direction 27 (arrow).

[0043] The workpiece support member (workpiece conveying member) 20 conveys the printed wiring substrate 10 according to the progress of the soldering process. The printed wiring substrate 10 put into the jet soldering device 100 reaches the position where the soldering process is to be performed by using the workpiece support member 20. As long as the jet soldering device 100 is in operation, the jet nozzle 40 always sprays the molten solder 1, and sprays the molten solder 1 in a manner that the molten solder 1 reaches the portion 30 of the printed wiring substrate 10 to be soldered. The positioning member 60 (nozzle driving unit) is a driving mechanism that can move the jet nozzle 40 in the XYZ direction in a manner that the jet nozzle 40 approaches the soldering portion 30. The drive control of the workpiece support member 20 (workpiece conveying member) and the positioning member 60 (nozzle driving unit) is uniformly controlled by, for example, a control device 61.

[0044] In the present invention, the workpiece is mainly the printed wiring board 10 , but the preheating mechanism of the present invention can be applied to workpieces other than the printed wiring board 10 as long as the soldering portion is preferably preheated.

[0045] Figure 2 2 is a perspective view showing another embodiment of the jet welding device of the present invention. Figure 2 As shown, the jet soldering device 200 includes: a fixed solder tank 15; a table X-axis drive unit (also called "X-axis drive guide") 33X, which is located above the solder tank 15; a table support 33YZ; and a workpiece fixing table (hereinafter referred to as "table") 31, which can move in the X direction on the table support 33YZ. In addition, the workpiece (printed wiring board 10) is fixed to the table 31 in a freely detachable manner. In addition, Figure 2 In the jet welding device 200, the workpiece fixing table 31 corresponds to the workpiece supporting member, and the table X-axis driving portion 33X (X-axis driving guide) and the table support column 33YZ correspond to the positioning member.

[0046] The jet nozzle 40 ejects the molten solder 1 toward the soldering position. The positioning member 33 reduces the distance from the jet nozzle 40 to the plurality of soldering positions during the automatic soldering process, and increases the distance during the standby process. The positioning member 33 can move the workpiece (printed wiring substrate 10) supported by the workpiece support member (workpiece fixing table 31) relative to the jet nozzle 40 in the XYZ direction.

[0047] Figure 1 The jet welding device 100 shown in FIG. Figure 2 The main difference between the jet welding device 200 shown is that in the positioning operation between the jet nozzle and the soldering part, the jet welding device 100 ( Figure 1 ) is the nozzle side movement, in the jet welding device 200 ( Figure 2 ) is the workpiece side movement. The preheating mechanism 50 of the jet welding device of the present invention can be applied to any of the jet welding devices 100 and 200.

[0048] Next, the preheating mechanism of the jet flow welding device of the present invention will be described. Figure 3 A. Figure 3 B is a cross-sectional view showing a situation where an electronic component mounted on a printed wiring board is soldered using a jet nozzle and a preheating mechanism of one embodiment of the present invention arranged around the jet nozzle. Figure 3 A indicates the following discussion Figure 4 A. Figure 4 The shape of B is shown in the figure. Figure 3 B is for the following discussion Figure 5Diagram of the shape. One form of the present invention is a preheating mechanism 50 of a jet soldering device, which is attached to the following soldering device: molten solder 1 is sucked up from a jet nozzle 40 and soldered to a part of a soldering portion 30 of a printed wiring substrate 10, and the preheating mechanism 50 of the jet soldering device preheats the soldering portion 30 of the printed wiring substrate 10 and its surroundings, wherein the preheating mechanism 50 at least includes: one or more electromagnetic coils 51; a loading portion 52, which is used to set the one or more electromagnetic coils 51 around the jet nozzle 40; and an AC power supply and a control portion 53, which allows an AC current to flow to the one or more electromagnetic coils 51 and performs on / off control of the AC current, and the loading portion 52 is arranged at a position where the soldering portion 30 of the printed wiring substrate 10 and its surroundings can be preheated by electromagnetic induction heating using the one or more electromagnetic coils 51, and the heating timing, heating time and applied power applied to the one or more electromagnetic coils are controlled by the AC power supply and the control portion 53.

[0049] As an example, a printed wiring board 10 to which a soldering process is performed by the jet soldering device 100 of the present invention is configured as follows: a predetermined circuit pattern and a conductor portion such as a pad 11 are printed on a main surface, and electronic components are assembled on a main surface of a substrate 13 having a plurality of through holes 12 formed thereon by passing pins 14 through the through holes 12. In the printed wiring board 10, the pins 14 passing through the through holes 12 and the pads 11 are soldered to mount the electronic components on the substrate 13 in a manner that is electrically and mechanically connected to the substrate 13.

[0050] For example, Figure 3 A. Figure 3 As shown in FIG. 1B , the pin 14 of the electronic component penetrates from the component surface (upper surface) of the printed wiring board 10 to the solder surface (lower surface), and the through hole 12 exposed from the copper foil to the solder surface protrudes in a relatively short state. On the other hand, in the jet soldering device 100, the control device 61 controls the nozzle driving unit 60 to make the jet nozzle 40 approach the soldering part 30. In this way, if the jet nozzle 40 approaches the soldering part 30 while ejecting the solder 1, the pin 14 is soldered to the pad 11.

[0051] In the present invention, one or more electromagnetic coils 51 are arranged around the jet nozzle 40. By passing an alternating current through the electromagnetic coil 51, magnetic lines of force F (alternating magnetic field) are generated, and eddy currents are generated in the pins 14 and the pads 11 in the through hole 12 of the printed wiring substrate 10 due to the magnetic lines of force F, causing electromagnetic induction heating (IH) due to heat generated by resistance. As a result, the through hole 12 of the printed wiring substrate 10 can be preheated, so that when soldering is performed using the jet nozzle 40 of the jet soldering device 100, the solder will not solidify in the middle of the through hole 12, but the solder can be spread from the lower part of the through hole 12 to the entire upper part.

[0052] The placement part 52 is provided for placing one or more electromagnetic coils 51 around the jet nozzle 40. In the jet soldering device 100, when soldering is performed, solder is supplied from the jet nozzle 40, and the remaining solder flows back along the outer wall of the jet nozzle 40. Therefore, the placement part 52 is provided around the jet nozzle 40 in a manner not to hinder the flow of the jet solder. In addition, it is desirable to adjust the position so that electromagnetic induction heating (IH) performed by one or more electromagnetic coils 51 is efficiently generated at the soldering part 30 of the printed wiring substrate 10. As an example, one or more electromagnetic coils 51 are arranged at a position 10 mm to 40 mm away from the center of the nozzle in the horizontal direction according to the diameter of the jet nozzle 40 of 2 mm to 20 mm. It is desirable that one or more electromagnetic coils 51 are close to the jet nozzle within a range that does not hinder the reflow of the remaining jet solder and the path of the heating gas. The placement portion 52 may be provided at a fixed position relative to the jet nozzle 40 , or may be provided so that the position and angle of one or more electromagnetic coils 51 are movable.

[0053] The AC power supply and the control unit 53 allow an AC current to flow to one or more electromagnetic coils 51, and perform on / off control of the AC current. Thus, the timing and amount of electromagnetic induction heating of the soldering part 30 can be controlled by using time and the applied power applied to the electromagnetic coil 51. For example, the applied power can be controlled by switching the power adjustment of the applied voltage. In the case of having a plurality of electromagnetic coils 51, it can also be set to be able to perform on / off control for each individual electromagnetic coil. In addition, in the present invention, the preheating mechanism 50 used as the jet welding device 100 using the molten solder 1 does not need to heat the soldering part 30 to above the melting point of the solder as in the above-mentioned prior art documents (patent documents 1 to 4). Therefore, in the present invention, the preheating temperature of the preheating mechanism 50 can be set to below the melting point of the solder.

[0054] In one aspect of the present invention, one or more electromagnetic coils 51 are preferably provided with a core 54 of a soft ferrite system. Soft ferrite is a ferrite that acts as a magnet when a current flows through the electromagnetic coil and a magnetic field is generated, and returns to its original state without magnetism when a current does not flow through the electromagnetic coil and the magnetic field disappears. It is a type of ceramic with iron oxide as the main raw material. By using a core of a soft ferrite system, the magnetic flux generated from the electromagnetic coil can be efficiently irradiated to the soldering part 30 of the printed wiring board 10 to cause electromagnetic induction heating (IH), and the timing and heating amount of electromagnetic induction heating can be controlled in conjunction with the on / off control of the AC power supply and the control unit 53.

[0055] In one aspect of the present invention, the preheating mechanism 50 may further include a heating gas supply mechanism 56 for supplying a heating gas H to the printed wiring substrate 10. As an example, a mechanism for supplying heated nitrogen gas from below toward the periphery of the nozzle opening of the jet nozzle 40 is provided. By so configuring, the soldering portion 30 of the printed wiring substrate 10 can be heated, and the periphery of the nozzle opening of the jet nozzle 40 can be made into a nitrogen atmosphere to suppress oxidation of the molten solder 1.

[0056] In one embodiment of the present invention, the soft ferrite core 54 preferably has a Curie temperature of 200° C. or higher. The soft ferrite core 54 is also heated by the heating gas H supplied from the heating gas supply mechanism 56, so in order to prevent the loss of magnetic force and the inability to perform electromagnetic induction heating, it is preferable to use a raw material with a Curie temperature of 200° C. or higher.

[0057] Figure 4 A is a diagram showing an arrangement of an electromagnetic coil including a core of a soft ferrite system related to a preheating mechanism according to one embodiment of the present invention. Figure 4 B means from Figure 4 Figure A is a diagram of a state where the electromagnetic coil is removed. In one embodiment of the present invention, Figure 4 As shown in FIG. 4A , the core 54 of the soft ferrite system is formed into a cylindrical shape so as to surround the jet nozzle 40, and the electromagnetic coil 51 can be wound along the height direction of the cylindrical core 54. Figure 4 As shown in B, the structure can be as follows: a groove portion 55 is formed in the core 54 of the soft ferrite system, and the electromagnetic coil 51 is wound in the groove portion 55 in such a manner that the electromagnetic coil 51 is buried in the groove portion 55. By setting it in this way, the electromagnetic coil 51 is buried in the core 54 of the soft ferrite system, and the position of the electromagnetic coil 51 can be fixed so that it does not deviate during the operation of the jet welding device 100. In addition, for the groove portion 55 of the core 54 of the soft ferrite system, a method of winding the electromagnetic coil 51 along one groove can be used, or a winding method in which a plurality of slits are formed in the wall of the groove and the electromagnetic coil 51 is returned to the outside or the inside respectively. Figure 4A. Figure 4 In B, the electromagnetic coil 51 has a copper wire in a glass tube, but is not limited to this form, and the material, thickness, number of turns of the coil, etc. may be appropriately selected according to the degree of preheating, the preheating location, etc.

[0058] Figure 5 1 is a diagram showing the configuration of an electromagnetic coil including a core of a soft ferrite system related to another embodiment of the preheating mechanism of the present invention. In another embodiment of the present invention, the core 54 of the soft ferrite system may be U-shaped, and the U-shaped core 54 may be disposed at one or more locations around the jet nozzle 40. For example, Figure 3 In B, the electromagnetic coils 51A, 51B and the cores 54A, 54B of the soft ferrite system are arranged at two locations across the jet nozzle 40, but they can also be arranged at four locations in the front, back, left, and right of the jet nozzle 40, or more. (In addition, in Figure 3 In A, the electromagnetic coil 51 and the core 54 of the soft ferrite system are also shown on the left and right sides of the jet nozzle 40, but Figure 3 In the embodiment of A, the core 54 of the soft ferrite system is cylindrical, so the left and right electromagnetic coils 51 and the core 54 of the soft ferrite system are connected to form a ring.) If each electromagnetic coil 51A, 51B is connected to the AC power supply and the control unit 53 separately, it is also possible to perform on / off control for each of the electromagnetic coils 51A, 51B. Figure 5 In the embodiment, the material, thickness, number of turns of the electromagnetic coil 51 may be appropriately selected according to the degree of preheating, the preheating location, etc.

[0059] Example

[0060] The present invention will be described in further detail using the following examples, but the present invention is not limited to these examples.

[0061] Figure 6 A is a diagram showing a state viewed from the component surface side when a component lead is soldered to a through hole by conventional jet welding (comparative example). Figure 6 B is a diagram showing a state viewed from the component surface side when the component lead is soldered to the through hole by jet welding to which the preheating mechanism of the present invention is applied (Example).

[0062] exist Figure 6 In the comparative example A (conventional example), it can be seen that a void is generated in the through hole observed from the component surface side, and it can be seen that the solder does not climb to the upper part of the through hole. Figure 6 In Example B (the present invention), it can be seen that the solder fills the upper portion of the through hole when viewed from the component surface side.

[0063] As described above, it has been confirmed that the present invention can realize a preheating mechanism of a flow soldering device that can efficiently heat the upper portion of a through hole of a substrate and allow the solder to reach the upper portion of the hole without solidifying and stopping the wetting climb.

[0064] In addition, although one embodiment and each example of the present invention have been described in detail as described above, many modifications can be made without substantially departing from the scope and effect of the present invention, which should be easily understood by those skilled in the art. Therefore, all such modifications are included in the scope of the present invention.

[0065] For example, in the specification or drawings, a term that is described at least once together with a different term having a broader meaning or a synonym may be replaced with the different term at any location in the specification or drawings. In addition, the preheating mechanism of the jet flow welding device and the structure of the jet flow welding device are not limited to the forms described in one embodiment and each example of the present invention, and various modifications may be implemented.

[0066] Description of Reference Numerals

[0067] 1. molten solder; 10. printed wiring board; 11. pad; 12. through hole; 13. substrate; 14. pin; 15. solder groove; 20. workpiece support member; 21-25. rollers; 26. chain; 27. conveying direction; 30. soldering part; 31. workpiece fixing table; 33. positioning member; 33X, shaft drive unit; 33YZ, table support; 40. jet nozzle; 50. preheating mechanism; 51, 51A, 51B, electromagnetic coil; 52, loading unit; 53, AC power supply and control unit; 54, 54A, 54B, core of soft ferrite system; 55, groove; 56, heating gas supply mechanism; 60, positioning member (nozzle drive unit); 61. control device; 100, 200, jet welding device; F, magnetic lines of force; H, heating gas.

Claims

1. A preheating mechanism for a jet welding device, characterized in that: It is attached to the following soldering device: molten solder is sucked up from a jet nozzle to solder a part of the soldering part of the printed wiring board, and the preheating mechanism of the jet soldering device preheats the soldering part of the printed wiring board and its surroundings. The preheating mechanism of the jet welding device at least comprises: 1 or more electromagnetic coils; a mounting portion for placing the one or more electromagnetic coils around the jet nozzle; and an AC power source and a control unit, which allows an AC current to flow to the one or more electromagnetic coils and performs on / off control of the AC current, The mounting portion is arranged at a position where the soldering portion of the printed wiring board and its surroundings can be preheated by electromagnetic induction heating using the one or more electromagnetic coils, and the heating timing, heating time and applied power to the one or more electromagnetic coils are controlled by the AC power supply and the control unit.

2. The preheating mechanism of the jet welding device according to claim 1, characterized in that: A soft ferrite core is provided to the one or more electromagnetic coils.

3. The preheating mechanism of the jet welding device according to claim 1 is characterized in that: The preheating mechanism further includes a heating gas supply mechanism for supplying a heating gas to the printed wiring board.

4. The preheating mechanism of the jet welding device according to claim 2, characterized in that: The Curie temperature of the soft ferrite core is above 200°C.

5. The preheating mechanism of the jet welding device according to claim 4, characterized in that: The soft ferrite core is formed in a cylindrical shape so as to surround the jet nozzle, and the electromagnetic coil is wound along the height direction of the cylindrical core.

6. The preheating mechanism of the jet welding device according to claim 4, characterized in that: The core of the soft ferrite system is U-shaped, and the U-shaped core is provided at one or more locations around the jet nozzle.

7. The preheating mechanism of the jet welding device according to claim 5, characterized in that: A groove portion is formed in the core of the soft ferrite system, and the electromagnetic coil is wound in the groove portion so as to be buried in the groove portion.

8. A jet welding device, characterized in that: The present invention is a jet flow welding device having a preheating mechanism according to any one of claims 1 to 7, comprising: A workpiece support member that supports a workpiece having a plurality of soldering locations dispersed therein; A jet nozzle that sprays molten solder toward the soldering site; A preheating mechanism, which is arranged around the jet nozzle; as well as A positioning member that reduces the distances from the jet nozzle to the plurality of soldering locations during automatic soldering and increases the distances during a standby period.

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