JP2013010127A - Soldering apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a soldering apparatus capable of suppressing insufficient wetting caused by a drop in temperature of a molten solder.SOLUTION: The soldering apparatus includes a solder storage tank 2 in which a molten solder is stored, a nozzle 20 which communicates with the solder storage tank 2 and performs soldering at a wanted portion of a substrate 30 above the solder storage tank 2 by using the molten solder fed from the solder storage tank 2, and an outer peripheral wall 11 which covers the periphery of the nozzle 20. Between the nozzle 20 and the outer peripheral wall 11, there is a passage communicating with the solder storage tank 2, in which the molten solder flows parallel to the nozzle 20.

Description

  The present invention relates to a soldering apparatus that performs soldering on a board (for example, a circuit board on which an electronic component is mounted).

  2. Description of the Related Art A conventional soldering apparatus that mounts a component on a substrate and performs soldering, and has a mounting portion having an opening at a position corresponding to the insertion portion of the component, and the side surface of the opening is mounted There is a taper surface in which the opening is widened downward from the partial placement surface (see Patent Document 1).

JP 2009-4527 A

  However, in the soldering apparatus of Patent Document 1, since only the nozzle protrudes from the solder storage tank and the nozzle is directly exposed to the atmosphere, heat is radiated from the nozzle to the atmosphere, causing the temperature of the molten solder in the nozzle to decrease, and the molten solder There is a problem of poor wetting.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a soldering apparatus that suppresses poor wetting due to a decrease in temperature of molten solder.

  The problem-solving means of the present invention includes a solder storage tank in which molten solder is stored, and a desired portion of the substrate above the solder storage tank in communication with the solder storage tank and with the molten solder sent from the solder storage tank. And a peripheral wall covering the periphery of the nozzle. The space between the nozzle and the peripheral wall communicates with the solder storage tank, and the molten solder is parallel to the nozzle. It was set as the composition which flows.

  The said structure WHEREIN: The upper end part of the said nozzle is good to set it as the structure located above the upper end part of the said outer peripheral wall.

  Moreover, it is good to set it as the structure which has the bottom face hole between the said nozzle and said outer peripheral wall on the plate which covered the upper surface of the said solder storage tank, and was provided with the said nozzle and the said outer peripheral wall.

  Moreover, it is good to have a structure which has a side hole in the said nozzle side surface.

  Moreover, the upper end part of the said nozzle is good in it being a taper shape extended in the outer side direction of the said nozzle.

  In the soldering apparatus of the present invention, since the nozzle can be covered with molten solder by providing an outer peripheral wall around the nozzle, the nozzle is not directly exposed to the atmosphere, and heat radiation from the nozzle to the atmosphere is suppressed to reduce the temperature of the molten solder. Can be suppressed, and poor solder wetting can be suppressed.

  In the soldering apparatus of the present invention, the upper end of the nozzle is positioned above the upper end of the outer peripheral wall, so that contact between the melted solder other than the desired portion of the substrate is suppressed, and solder balls, bridges, etc. Generation can be suppressed.

  Further, in the soldering apparatus of the present invention, by having a plate that covers the upper surface of the solder storage tank, the molten solder in the solder storage tank is not directly exposed to the atmosphere, and the temperature drop of the molten solder in the solder storage tank can be suppressed. .

  Further, in the soldering apparatus of the present invention, by having a side hole, the molten solder having a high temperature is always supplied to the molten solder pool between the nozzle and the outer peripheral wall. It is possible to prevent the temperature of the molten solder from being lowered, and to suppress poor solder wetting of the inserted part. Further, the molten solder flows out from the side hole, so that convection in the nozzle can be prevented and the jet pressure of the molten solder in the nozzle can be kept high.

  Further, in the soldering apparatus of the present invention, by providing a taper extending in the outer direction of the nozzle at the upper end of the nozzle, the contact area between the substrate and the molten solder is increased, and the temperature of the insertion component and the substrate is increased. It is possible to suppress poor solder wetting.

It is explanatory drawing which shows the structure of the soldering apparatus of this invention. It is AA sectional drawing of the soldering apparatus shown in FIG. 1, and shows the flow of molten solder.

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

  FIG. 1 is an explanatory view of a soldering apparatus 1 according to the present invention. The soldering apparatus 1 includes a solder storage tank 2 that stores molten solder, and a plate 10 that covers the upper surface of the solder storage tank 2. The plate 10 communicates with the solder storage tank 2 and protrudes upward from the plate 10. The plate 10 is soldered to a desired portion 30 a (see FIG. 2) of the substrate 30. The outer peripheral wall 11 is covered.

  In the solder storage tank 2, the molten solder is circulated and stored at a temperature 30 to 80 ° C. higher than the melting point of the solder. In addition, an insertion component 31 to be soldered and a plurality of mounting components 32 that are not soldered are attached to the substrate 30 to be soldered.

  FIG. 2 is an explanatory view showing the flow of molten solder in the AA section of the soldering apparatus 1 of the present invention. The plate 10 has a space 12 between the nozzle 20 and the outer peripheral wall 11 and filled with molten solder, and a bottom hole 13 that communicates the solder storage tank 2 and the space 12. The nozzle 20 has a side hole 21 that communicates the space 12 and the inside of the nozzle 20 at a position higher than the upper end 11a of the outer peripheral wall. The nozzle 20 has a taper 22 that extends in the nozzle 20 outer direction at the nozzle upper end 20a. Further, the height difference 14 between the nozzle 20 and the outer peripheral wall 11 is larger than the height difference 15 between the substrate 30 and the mounted component lower end portion 32a. Furthermore, the nozzle 20 and the outer peripheral wall 11 are manufactured by pressing a stainless material. The board 30 has a through hole 33 into which the insertion component lower end 31a of the insertion component 31 is inserted and soldered.

  The operation of the embodiment of the present invention will be described.

  The substrate 30 is attached to the insertion component 31 and the mounting component 32 in an assembly process (not shown), and then proceeds to a preheating process (not shown). The substrate 30, the insertion component 31, and the mounting component 32 are preheated in the preheating process, and then proceed to the soldering process illustrated in FIG. 1.

In the soldering process, a desired portion 30a of the substrate 30 around the insertion component lower end 31a is brought into contact with the nozzle upper end 20a, and the jet pressure of the molten solder toward the nozzle 20 and the outer peripheral wall 11 is increased. Molten solder is jetted to fill the through-hole 33 with molten solder, and the substrate 30 and the insert component 31 are soldered. At this time, the molten solder that has become excessive in the nozzle 20 flows into the space 12 from the side hole 21 and flows from the outer peripheral wall upper end portion 11 a to the upper surface of the plate 10 through the outer side of the outer peripheral wall 11. The molten solder that has flowed to the outside of the outer peripheral wall 11 and the upper surface of the plate 10 returns to the solder storage tank 2.

  Table 1 is a table showing the average value, maximum temperature, minimum temperature, average temperature difference, and peak temperature of the prior art and the solder of the present invention (molten solder) and the nozzle. From Table 1, the temperature of the molten solder is almost the same between the conventional technique and the present invention, but there is a difference in the nozzle temperature. In the conventional technique, the temperature difference between the molten solder and the nozzle is 8.0 ° C. on the average. In the invention, the temperature is 3.2 ° C., and it is understood that the heat release from the nozzle 20 to the atmosphere is suppressed and the temperature drop of the molten solder is suppressed. In addition, the land peak temperature (peak temperature of the substrate 30) is 215.2 ° C. in the conventional technique, and 218.5 ° C. in the present invention, which indicates that the temperature of the substrate 30 is high.

  The effect of the present invention will be described.

  In the soldering apparatus 1 of the present invention, by providing the outer peripheral wall 11 around the nozzle 20, the space 12 can be filled with the molten solder and the nozzle 20 can be covered with the molten solder, so the nozzle 20 is directly exposed to the atmosphere. Accordingly, heat radiation from the nozzle 20 to the atmosphere can be suppressed, and the temperature drop of the molten solder can be suppressed, and poor solder wetting can be suppressed.

  Further, in the soldering apparatus 1 of the present invention, the nozzle upper end portion 20a is positioned above the outer peripheral wall upper end portion 11a, so that contact between the melted solder other than the insertion component 31 is suppressed, and solder balls, bridges, etc. are generated. Can be suppressed.

  Moreover, in the soldering apparatus 1 of the present invention, by having the plate 10 that covers the upper surface of the solder storage tank 2, the molten solder in the solder storage tank 2 is not directly exposed to the atmosphere, and the molten solder in the solder storage tank 2 is not exposed. Temperature drop can be suppressed.

  Further, in the soldering apparatus 1 of the present invention, the temperature of the nozzle 20 can be increased by always supplying a high temperature molten solder to the molten solder pool between the nozzle 20 and the outer peripheral wall 11 by having the side holes 21. The drop and the temperature drop of the molten solder in the nozzle 20 can be prevented, and the solder wettability of the insertion part 31 can be suppressed. Furthermore, the molten solder flows out from the side hole 21 to prevent convection in the nozzle 20 and keep the molten solder jet pressure in the nozzle 20 in a high state.

  Further, in the soldering apparatus 1 of the present invention, the contact area between the substrate 30 and the molten solder is increased by providing the nozzle upper end portion 20 a with a taper 22 that extends in the outer direction of the nozzle 20. It is possible to increase the temperature and suppress solder wetting failure of the insertion component 31.

  Further, in the soldering apparatus 1 of the present invention, the difference in height between the nozzle 20 and the outer peripheral wall 11 is made larger than the difference in height between the substrate 30 and the mounting component 32, so that the molten solder of the mounting component 32 can be reduced. Can be prevented and generation of solder balls and bridges can be suppressed.

  Moreover, in the soldering apparatus 1 of this invention, by using stainless steel for the nozzle 20 and the outer peripheral wall 11, manufacturing cost can be suppressed by manufacturing by press, bending, and welding.

  In addition, this invention is not limited to the said embodiment, You may change into the aspect shown below.

-The nozzle does not need to be attached to the plate, for example, the nozzle, the outer peripheral wall, and the small solder storage tank may be integrated. In that case, the soldering apparatus can be reduced in size.

-You may use metals, such as titanium, for a nozzle and an outer peripheral wall. In that case, like stainless steel, it can be manufactured by pressing, bending, and welding, and the manufacturing cost can be suppressed.

-You may use material with low heat conductivity, such as fine ceramics, for a nozzle and an outer peripheral wall. In that case, the temperature drop of the molten solder in the nozzle 20 can be prevented, and the solder wettability of the insertion part 31 can be suppressed.

-The side opening need not necessarily be at a position higher than the upper end of the outer peripheral wall, as long as the nozzle communicates with the space.

DESCRIPTION OF SYMBOLS 1 Soldering apparatus 2 Solder storage tank 10 Plate 11 Outer peripheral wall 12 Space 13 Bottom hole 14 Height difference 20 Nozzle 21 Side hole 22 Taper 30 Substrate 31 Insertion part 32 Mounting part 33 Through hole

Claims (5)

A solder storage tank storing molten solder;
A nozzle that communicates with the solder storage tank and solders to a desired portion of the substrate above the solder storage tank with the molten solder sent from the solder storage tank;
An outer peripheral wall covering the periphery of the nozzle,
A soldering device that communicates with the solder storage tank between the nozzle and the outer peripheral wall and allows the molten solder to flow in parallel with the nozzle.   The soldering apparatus according to claim 1, wherein an upper end portion of the nozzle is positioned above an upper end portion of the outer peripheral wall. A plate that covers the upper surface of the solder storage tank and is provided with the nozzle and the outer peripheral wall;
The soldering apparatus according to claim 1, wherein a bottom hole is provided between the nozzle on the plate and the outer peripheral wall.   The soldering apparatus according to claim 1, further comprising a side hole on a side surface of the nozzle.   5. The soldering apparatus according to claim 1, wherein an upper end portion of the nozzle has a tapered shape extending in an outer direction of the nozzle.

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