JPS58218372A - Brazing device - Google Patents

Abstract

PURPOSE:To prevent the clogging of an ejection nozzle and the pouring of a brazing material on unnecessary parts in a device which ejects the molten brazing material by electromagnetic force and brazes printed substrates, etc., by changing the magnetic force according to the presence or absence of the work on the conveyance path above the storage tank for the brazing material. CONSTITUTION:The brazing material in a flow passage 58 extending from a storage tank 51 for a brazing material is fed forcibly by the electromagnetic force generated by the coil mechanism of an iron core 56, a stator core 74 and a stator coil 76, and is ejected toward the work which is conveyed by a conveyor 84. If a photoelectric switch 85 is provided in the midway of the conveyance route for the work and a signal for the presence of the work is emitted upon detecting the presence or absence of the work, the contact A operates to flow the electric current of the magnitude at which the injected brazing material draws an ordinary locus. Said current is inputted through a bidirectional thyristor 87 to a delay circuit 88 which supplies the electric current at which the normal ejection of the brazing material is accomplished to the coil 76. When the signal for absence is emitted on account of an interruption in the conveyance of the work, the contact B operates to flow small electric current so that the electric current at which the slight brazing material is emitted from the hole 60 is supplied to the coil 76 in the same manner as mentioned above.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field of the Invention] The present invention relates to a brazing device for brazing processed products, such as the back side of a printed circuit board, by spouting a brazing material such as molten solder.

[Technical background of the invention]

Generally, a device as shown in FIGS. 1 and 2 is used to braze lead wires of electrical components mounted on a printed circuit board to a circuit pattern.

That is, reference numeral 1 denotes a brazing needle reservoir, in which a brazing material 2 such as molten solder is stored. Then, the molten brazing material 2 in the brazing needle reservoir l is pumped by the electromagnetic pipe 3, and the slit-shaped waste 4 is also ejected into a thin film!
'L,! 1, structure it well and admonish it. Then, the printed circuit board 5 to be brazed is transported so that its back surface is in contact with the spouting brazing material 2, and the lead wires and circuit patterns protruding from the back surface 1 of the printed circuit board 5 are brazed by the spouting brazing material 2. It is configured so that

The electromagnetic pump 3 is constructed as follows.

Reference numeral 6 indicates a flow path through which the molten brazing filler metal 2 flows, and the reference numeral 7 denotes a Fi iron core, around which a coil 8 is wound. A part of the iron core 7 is cut out, and the flow path 6 is inserted through the cutout, and a magnetic field in a direction perpendicular to the axial direction of the flow path 6 is applied to the brazing material in the flow path 6. It is configured so that it can be added. Further, a pair of electrodes 9, 9 are attached to both sides of the flow path 60, and a current is configured to flow between the electrodes 9 in the axial direction of the flow path 6 and in a direction perpendicular to the direction of the magnetic field. has been done. Therefore, the brazing filler metal in the flow path 6 is transferred under pressure in the axial direction of the flow path 6 by the magnetic field and electrostatic force in directions perpendicular to each other, and is ejected from the air 4 (K11I□i"C). □）□Pa [Problems in background technology] However, in the conventional electromagnetic bomb, when the printed circuit board 5 is not being fed or is busy, the spouting of the brazing material from the nozzle 4 stops. At this time, air flows into the nozzle from the nozzle hole, which oxidizes the surface of the brazing material inside the nozzle, causing the nozzle to become warped. Materials may fly out and splash onto the surface of the board 50 being conveyed,
There was a problem in that the brazing filler metal was sprinkled on other unnecessary parts.

[Purpose of the invention]

In view of these points, the present invention prevents the oxidation of the brazing filler metal in the nozzle, prevents the nozzle from clogging, and prevents the brazing filler metal from being sprinkled on unnecessary parts of the workpiece at the beginning of the injection of the filler filler metal.
The purpose of the present invention is to provide a brazing device that does not require any additional brazing equipment.

[Embodiments of the invention]

Embodiments of the present invention will be described below with reference to FIGS. 3 to 8.

In FIGS. 3 to 7, a brazing needle reservoir 51 for storing solder markings, etc. has a wide portion 51 having a wide end.
a'l' (formed, and the other end is a narrow part 51 with a narrow width)
b □, and the overall planar shape is approximately T-shaped. This brazing needle reservoir 51 is composed of a thick bottom plate 52 and side plates &. The bottom plate 52 is formed with a passage forming part 8 cut out in an elongated shape from the narrow part 51b to the wide part 51a.
Steps are formed on the upper side and the lower side of both sides of the □ (sixth
(Fig.), a thin partition plate 55 is fitted into the lower step, and left and right friction flange portions 5 between the elongated iron cores are fitted into the upper step.
6a and 56a are fitted through the back plate 100, and these are integrally attached to the y-bottom plate 52 by bolts 57, 57, . . . 57. A brazing force feeding channel 58 is formed between the partition plate 55 and the lower surface (bottom surface) of the iron core 56, and the coil mechanism 0 is provided on the T side of this channel 58. reactor,
One end between the brazing force feeding channels communicates with the inside of the brazing needle reservoir 51 at the tip of the narrow portion 5113. In addition, a nozzle 59 is erected at the end of the wide part 51a of the soldering needle reservoir 51, and this nozzle 59 is an elongated book that spans the entire width of the wide part 51a. A slit-shaped nozzle hole ω is provided over the entire area, and this nozzle hole ω is oriented obliquely upward, and the other end between the brazing force feeding channels communicates with the inside of this nozzle 59. The nozzle hole 60KG is provided with an oil supply pipe 61 for preventing oxidation of the brazing material, and this oil supply [61-Ab Iz oil is supplied little by little through a guide plate 6 provided at an angle near the bottom of the oil supply pipe 61.
2 and drips onto the upper surface of the brazing filler metal, forming an oil surface B there. Inside the nozzle 59, pressure adjustment plates 64 in the form of elongated plates are provided in two stages, upper and lower. A large number of orifice holes 64a, 64a...64a are formed in the pressure adjustment plate 64 in the width direction Kffi, and these orifice holes 64SL have a diameter of It is small, and it is ordered that the diameter be larger on the outside. Therefore, the wax is supplied to the central part of the nozzle body from the wax blowing pressure sending channel side.
□ The soldering filler metal passes through this pressure adjustment plate: This makes the pressure uniform across the width, and the soldering filler metal passes through this pressure adjustment plate. □The material shines evenly in the width direction from the nozzle hole ω.5K
A stone made of m.・・″Place: 1□1:
:.

Incidentally, bar heaters 65, 65 are embedded in the straight wall of the nozzle device.

Approximately half of the storage tank 51 on the side opposite to the nozzle device is closed with an inclined tank cover 6, and the inside of the tank /(-6
Three rod heaters 67, 672>E are installed in the tank below the tank in the longitudinal direction KG (in the flow direction Ka of the brazing material), and the nozzle side of the rod heater 67 is attached to a hanger hanging from the tank cover 66iIb. It is suspended by holding members 68, 68, 68, and the opposite side is supported by a cypress cover 66. t7? :, A brazing material receiving plate 69 is attached to the nozzle side end of the tank cover, and this receiving plate is used to return the remaining brazing material that was ejected from the nozzle hole 6o and did not adhere to the substrate into the tank. A dam plate 7° with an angular cross section is provided across the narrow part 51b of the KFi soldering needle reservoir 51 below the curved brazing material receiving plate 69 that is gently inclined toward the nozzle. The solder metal passes over the front plate 70IIL of this dam plate 7o and flows through the small hole formed in the rear plate 70b.Therefore, the solder oxidizes. ..Clogging of the nozzle 9 is prevented by mixing the brazing filler metal inside □□oo1♂:: 7゜yoyo, □□, 0rek.

A discharge lower 1 for regulating the uppermost position of the oil level 8 is formed at one corner of the wide part 51a of the tank, and when the oil level becomes higher than one centimeter, the flow of the discharge lower 1 passes through the lower lower 1a. It seems like the oil is being drained out. In addition, the wax needle reservoir tank 5
A drain hole 72 for extracting the used brazing filler metal from the tank is formed at a position outside the core at the tip of the narrow part 1, and this drain hole 72 is connected to a discharge device (not shown) that can be opened and closed. There is.

A thin heat insulating plate 7 is provided on the bottom surface of the bottom plate 52 and the partition plate 55.
3 is attached. This heat insulating plate 73 is the wax needle storage tank 5.
1 is placed and supported on the upper surface of the mating shaft B, and this gold plate B
Inside, the coil machine #a is provided corresponding to between the brazing pressure sending channels. This coil mechanism O has a stator core 74, which is formed into a block by laminating thin steel plates, and the width of the stator core 740 is approximately equal to the width between the brazing pressure channels. , t, and its length is formed to be approximately equal to the length between the brazing force feeding channels. On the upper surface of the stator core 74, there are a plurality of coil housing grooves 75, 75...7 in the axial direction between the brazing pressure feed channels and in the direct firing direction.
5 is formed (Fig. 3, Fig. 7). The plurality of coil accommodation grooves 75ii are arranged at predetermined intervals in the axial direction of the brazing force feeding passage piece, and these coil accommodation grooves 75
Stator coils 76, 76, . . . , 76 are housed diagonally within the groove so as to span every other groove.

These stator coils 76 have a substantially oval shape, and their height is formed to be lower than the depth of the coil housing #75, and there are cooling gaps 77 between the stator coils 76 and the partition plate group.
77...77 are formed. The stator coil 76 is configured to be supplied with alternating currents whose phases are sequentially shifted from the narrow portion 511) side to the wide portion 51a side. Therefore, the magnetic field generated by these stator coils 76 passes through the stator core 74 and the core group, and crosses the brazing pressure sending channel 58 from the narrow portion 51b to the wide portion 5.
A stone moving towards 1allK. Therefore, due to this moving magnetic field, the brazing material in the brazing pressure feeding channel egg is moved to the wide portion 51a (III
K, the pressure is increased to a predetermined pressure, and the pressure is increased to the nozzle 5.
A cooling fan 78 is provided to reduce the side pressure of the shaft B that supports the wax needle reservoir 51.

78 sends cooling air to the coil mechanism (Fig. 6). In addition, at the four corners of the lower frame 79, there are adjustment support devices 83, 83 for adjusting the installation height of the filter 2 attachment device.
, 83 are provided, and the stator core 74 is fixed by fixing screws 81 between the presser member marks KA and 80 on the lower frame 79 of metal phase B.

The jetting of the brazing material hits the printed circuit board that is being sent on the workpiece conveyance device 84, and is sprayed at an appropriate position on the conveyance path of the workpiece of the conveyance device (in this embodiment, on the diagram of the brazing device). On the left side), a photoelectric switch δ is provided which serves as a detection member for detecting whether or not a printed circuit board is being conveyed. While being transported (l
When the photoelectric switch issues a signal indicating that there is a workpiece present (1), the A contact operates and a current of a magnitude that causes the injected brazing metal to draw a normal work pattern flows, and this current is bidirectional and connects the thyristor 87f.
: Then, the delay circuit 88 is manually powered, and a current is supplied to the stator coil of the coil (→ structure) such that the injection of normal brazing material is similar to that of normal brazing material injection. Since there is a certain distance between the injection position and the injection position, this is to delay the change in the electromagnetic force of the stator coil for a certain period of time based on the relationship between that distance and the conveyance speed of the workpiece.

In addition, when the conveyance of the processed product is stopped and the signal 'No processed product 1' is issued, the B contact is activated and a small current flows, and this small current is input to the delay circuit section through the thyristor 87, and the stator A current is supplied to the coil so that the brazing metal slightly comes out from the nozzle hole ω.

Note that an inverter 89 (indicated by a chain line in the figure) for setting the frequency is provided in place of the bidirectional thyristor 870, and the stator coil 76 is adjusted according to signals from each contact point A and B.
The degree of injection of the brazing filler metal may be adjusted by setting two types of frequencies of the current applied to the brazing material. In this way, regardless of whether or not processed products such as prints and circuit boards are being transported, if the solder material is always jetted out, the saccharification of the solder material in the nozzle hole (A) can be effectively prevented, and the nozzle!・The hole is hard to get clogged.1. Furthermore, if the injection is restarted after the injection has been stopped, the brazing material will not spray out with force at the beginning, and the brazing material will not be applied to the front side of the printed circuit board.

Furthermore, depending on the length of the lead wires to be incorporated into the board, it is necessary to move the entire brazing apparatus up and down by adjusting the VA node support device 83 to prevent the lead wires from colliding with the nozzle. In such a case, the speed of injection must be changed depending on the distance between the nozzle hole ω and the conveying device 84. This injection speed adjusting device has a bracket provided at the upper end of the tank cover mark, and a height detector 91 is attached to the image straight part 90a.
A is always urged upward by a spring K (not shown). This height detector 9] is connected to 80H, and this BO
A current is passed through R to the stator coil 76.

For example, if the entire brazing apparatus is lowered; the height detector 91 is lowered. Therefore, the contactor 91a has risen relative to the height detector 91, and this rising signal is greater than the current before the EIORK input and the brazing device descends into the stator coil. A current is applied, and the magnetic force of the coil is adjusted so that the ejected wax hitting force reaches exactly the print T4 board. If the brazing device is raised, the ejection velocity will be reduced by the opposite action. In this way, even if the distance between the workpiece conveyance device 84 and the nozzle hole ω changes, uniform brazing is possible if the ejection speed of the brazing material is automatically changed accordingly.

Further, an automatic brazing material supply device 92 for supplying brazing material into the storage tank is provided near the bracket 90,
As shown in FIG. 4, this supply device 92 has a float 93 made of, for example, titanium, which floats on the surface of the brazing material. It is slidably attached to the tank cover 6, and its upper end projects above the tank cover 6.

A light emitting element and a light receiving element 95 are provided on both sides of the protrusion of the shaft 93a, and when the brazing material is sufficiently stored in the tank, the light from the light emitting element 94 is blocked by the protrusion. However, when the brazing material decreases and the float 93 lowers, the light receiving element 9
5 senses the light and opens the brazing material supply pipe 97 connected to the brazing material preliminary tank via the electromagnetic valve 96, thereby supplying the brazing material into the storage tank. In this way, if an automatic brazing material supply device is installed, -Q brazing material will always be supplied into the storage tank, making it easier to control the temperature of the brazing material and achieving uniform brazing. There is no need to interrupt the brazing and sealing work.

In addition, it is appropriate that the thickness tl on the side of the pressure-feeding channel is approximately 4 mm.
For this thickness tl, the core dimensions W, (width) Xb, (length) are (20t1~80t 1)X (30t, 1
~120t, ) is desirable, and the nozzle width W is 20t1
~150t is preferable, and the nozzle gap t3 is approximately 1
The u position is preferable (Figure #48).

〔Effect of the invention〕

As explained above, the present invention provides a detection member for detecting the presence or absence of a processed product in the middle of the conveyance path of the processed product, and operates the control coil mechanism according to the presence/absence signal of the processed product from the detection member. Actuation circuit that changes the electromagnetic force of the coil (contact point: East bidirectional thyristor,
',',',Ill,',',1 87, delay circuit 88, i, nhani 1 89) is operated, and this operating circuit operates when the brazing material is in the normal state by the signal 'Processed product present 1'. A current is passed through the coil so that it ejects, and 1
Since the current is passed through the coil so that a small amount of jet is emitted from the nozzle hole of the nozzle, the oxidation of the brazing filler metal in the nozzle is eliminated, the nozzle is no longer clogged, and the nozzle is free from the nozzle hole. This has the effect of preventing unstable injection.

[Brief explanation of the drawing]

Fig. 1 is a schematic diagram of a conventional electromagnetic pump, Fig. 2 is a perspective view thereof, Fig. 3 is a vertical sectional view of a brazing device of the present invention, Fig. 4 is a schematic diagram of an automatic brazing material supply device, and Fig. 5 is a plan view of the brazing device of the present invention, FIG. 6 is a sectional view taken along the line Vl-M in FIG. be. 51... Waxing needle reservoir, 5... Partition plate, 56...
Iron core, 58... Brazing pressure sending channel, 59... Nozzle,
U... Nozzle hole, 67... Rod heater, 72... Drain hole, 74... Stator core 1.75... Coil collection groove, 76... Stator coil, 84... Processed product conveyance device, 11', ... photoelectric switch, 87... bidirectional 1,. thyristor, vane...delay circuit, 89...inverter, 91...height detector, 92...brazing material automatic supply device. Applicant's agent Kiyoshi Inomata IRT document of the drawings (no change in content) 1st drawing procedure amendment (method) 1981 Director of the Japan Patent Office Kazuo Sugi 1. Indication of the case 1988 Patent application No. 101642 2. Name of the invention Brazing device 3. Person making the amendment Relationship to the case η4 Applicant, (1 other person) Power of attorney, specification, and drawings. 8. Contents of amendment (1) Amend the power of attorney as shown in the attached sheet. (2) The specification and drawings will be reprinted to match the damage (no changes to the contents).

Claims (1)

[Claims] A brazing material channel is extended from a brazing needle reservoir that stores molten brazing material, and a force is applied to the brazing material in this channel in the direction of extension of the channel by electromagnetic force from a coil mechanism. A sizzle is provided to spray the brazing material pressure-fed to the end of the flow path onto the workpiece, and during the brazing process, the workpiece is conveyed through the brazing needle storage tank upper leg by a conveying device. In the attached device, a detection member for detecting the presence or absence of the processed product is provided in the middle of the conveyance path of the processed product, and the electromagnetic force of the coil of the coil mechanism is adjusted according to the presence/absence signal of the processed product from the detection member. The actuating circuit operates the actuating circuit that changes the state of the workpiece by applying a current to the coil that is strong enough to eject the brazing material in a normal state according to the signal indicating that there is a workpiece. A brazing device characterized in that a current of a magnitude such that a small jet is generated from a nozzle hole of a nozzle is passed through a coil in response to a non-seismic signal.