JPH1034323A - Method and device for iron soldering - Google Patents

Abstract

PROBLEM TO BE SOLVED: To achieve the non-cleaning or water-cleaning with little residue, to ensure excellent solder joining, and to improve penetration of the solder. SOLUTION: Soldering is performed by using a tip 6 made of the material which is not oxidized itself in the service condition and to which no solder is adhered, and by feeding the inert gas from an inert gas blowing nozzle 10 so that the area to be soldered including the molten part of the thread solder 12 to be fed is in the atmosphere of low oxygen concentration. The cleaning effect can be sufficiently demonstrated even when the thread solder 12 containing the flux capable of effecting the non-cleaning is used, the excellent soldering and non-cleaning is achieved, and penetration of the solder is improved by feeding the heated inert gas to increase the heat supply.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method and an apparatus for soldering electronic parts and the like using a soldering iron.

[0002]

2. Description of the Related Art In recent years, soldering apparatuses, such as flow and reflow, which collectively solder multiple points of solder at high quality have been developed. However, for soldering parts that cannot be processed by flow, reflow, etc., such as soldering of weak heat-resistant electronic components, point soldering by iron soldering is necessary, and many automatic point soldering machines using robots etc. It is used.

In such a point automatic soldering apparatus, copper having good heat conductivity is often used as a soldering iron. In addition, copper is consumed by erosion by molten solder, corrosion by flux, etc., so it is plated with a metal or alloy such as iron, nickel, chromium, etc., and the solder wet surface is soldered to ensure solder wettability. Is plated with solder.

As the supplied solder, a thread solder having a flux held at the center of a thin wire-shaped solder metal is used.
The flux melts faster than the solder metal and flows on the surface to be soldered, cleaning the surface to be soldered and reducing and removing metal oxides, and the surface of the soldering iron tip and the solder metal remaining there. And reduces oxidation of the molten solder. For this reason, a flux having strong activity is used.

Japanese Patent Application Laid-Open No. 4-309457 has a means for sending out an atmosphere gas to the tip of the tip and a means for heating the atmosphere gas in order to efficiently heat and cool the portion to be joined. A soldering apparatus is disclosed, and furthermore, it is disclosed that oxidation of solder can be prevented by using an inert gas as an atmosphere gas. Similar technical means are also disclosed in JP-A-6-315766 and JP-A-7-214371.

[0006]

However, in the conventional soldering apparatus, even if a means for sending out an inert gas to the solder joint is provided as disclosed in the above-mentioned publication, the soldering after the solder joint is completed. The tip moves to the atmosphere while the tip is still hot, and the molten solder adheres to the tip, so the tip and the attached solder are oxidized, and the flux of the thread solder prevents oxidation and wetting during the solder joining process. Since it is consumed to reduce the oxide of these solder tips and attached solder before contributing to ensuring the property, it is necessary to use a flux having a strong activity. However, flux with strong activity has many residues,
There is a problem that cleaning is necessary after soldering, which is not suitable for low residue and no cleaning. In recent years, there has been a strong demand for achieving no cleaning or water cleaning for environmental protection.

Further, since the molten solder adheres to the tip,
There is a possibility that the soldering amount may vary, and after soldering, the molten solder continues when the tip is separated from the joint, and when the tip is separated at high speed, the middle part is separated and the solder ball is separated. And scattered around to cause a short circuit.

In view of the above-mentioned conventional problems, the present invention can achieve no washing or water washing with a low residue, can stabilize the amount of soldering, does not generate solder balls, and has good solder penetration. It is an object to provide a soldering method and apparatus.

[0009]

SUMMARY OF THE INVENTION A soldering method according to the present invention uses a soldering iron having a tip made of a material which does not oxidize itself and does not adhere to solder in use, and a method of soldering. Soldering is performed while supplying an inert gas so that the soldering area including the melting point has a low oxygen concentration atmosphere, the tip does not oxidize, the solder does not adhere, and Oxidation of the molten solder and the heated solder joints can be prevented in an inert gas atmosphere, so even if a supplied solder containing a flux that does not require cleaning is used, the flux will only reduce the solder joints and ensure wettability. Therefore, the effect can be sufficiently exerted, and good solder bonding and no cleaning can be achieved. Further, since the solder does not adhere to the tip, even if the tip is moved away from the tip at a high speed after the solder joining, the solder balls do not scatter, and the amount of solder is stabilized, so that good solder joining is secured. On the other hand, the fact that solder does not adhere to the tip leads to poor solder penetration, but heating and supplying the inert gas increases the amount of heat supply and improves solder penetration. And can be soldered efficiently.

The soldering apparatus of the present invention feeds a soldering iron having a soldering tip made of a material which does not oxidize itself and does not adhere to solder in use, and a thread solder toward a soldering position. A solder supply guide, and an inert gas blowing nozzle for blowing an inert gas toward the soldering location,
Preferably, a heating means for heating the inert gas supplied to the inert gas blowing nozzle is provided so that the above-mentioned soldering method can be performed.

Further, when the heating means is constituted by a heat exchanger arranged near the heater of the soldering iron, the inert gas can be heated with high efficiency by utilizing the heat of the heater of the soldering iron. In addition, a compact configuration can be achieved.

[0012] Further, by arranging the extension of the inert gas blowing nozzle toward the soldering portion in substantially the same direction as the extension of the solder supply guide, the thread solder can be heated by the heated inert gas. In addition, it is possible to improve solder penetration while preventing oxidation of molten solder.

In addition, if the tip is made of a material having an affinity for flux, preferably graphite, if it does not adhere to the solder at the tip, heat conduction to the solder becomes poor and the meltability deteriorates. On the other hand, when the flux has an affinity, the wettability of the soldering tip with respect to the solder can be obtained through the flux and the penetration can be ensured, while preventing the solder from adhering to the tip. Solder penetration can be improved.

Further, the tip is made of sheet-like or block-like graphite having heat conduction anisotropy, and the surface having high thermal conductivity is arranged along the direction from the tip attachment part to the solder wet part. Then, the heat conduction efficiency is high, and the penetration of the solder can be further improved.

[0015]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A soldering apparatus according to an embodiment of the present invention will be described below with reference to FIGS.

In FIGS. 1 and 2, a movable plate 2 is vertically movably provided at a distal end portion 1 of a robot arm, and is configured to be vertically movable by a cylinder device 3. 4 are attached. In the soldering iron unit 4, a copper iron body 5 is held inside a heater 7 for heating the soldering iron, and a tip 6 is integrally attached to a tip of the iron body 5. . Around the heater 7, an inert gas supply pipe 8 whose base end is connected to an inert gas supply source (not shown) is spirally wound to form a heat exchanger 9, and the inert gas supply pipe is provided. The tip of the nozzle 8 is formed in an inert gas blowing nozzle 10, and is configured to blow out the inert gas heated by the heater 7 toward the tip of the tip 7. Reference numeral 11 denotes a soldering iron holder that holds the soldering iron body 5 and surrounds the heat exchanger 9.

Numeral 12 is a thread solder containing a flux corresponding to no cleaning at the center, and the tip of the tip 6 along a direction substantially the same as the blowing direction of the inert gas blowing nozzle 10 by the solder supply guide 13. The solder is melted by an inert gas supplied toward the portion and heated in a state of being surrounded by an inert gas atmosphere. Reference numeral 14 denotes a guide holder that supports the solder supply guide 13. In FIG. 1, 15 is a surface to be soldered, 16 is an object to be soldered, 17 is a heated inert gas, and 18 is a molten solder.

As shown in FIG. 3 (a), the soldering tip 6 is provided around a strength holding member 19 made of isotropic carbon or the like to which no solder is attached and which is not oxidized in use. The sheet-like graphite 20 which does not adhere and does not oxidize in use and has heat conduction anisotropy is wound tightly, and the strength holding material 19 and the end of the sheet and between the sheets have a heat resistance of 400 ° C. or more. Are integrally bonded by an adhesive such as glassy carbon having properties. The sheet-like graphite 20 is formed so that its high heat conduction direction is along the direction from the mounting portion of the tip 6 to the solder wetted portion 6a. The solder wetted portion 6a at the tip of the tip 6 is formed by polishing. As a specific numerical example of the tip 6, the strength retaining material 19 has a diameter of 2 mm and a length of 50 m.
m, the thickness of the graphite sheet 20 is 0.1 mm
The sheet-like graphite 20 is wound until the outer diameter of the iron tip 6 becomes 5 mm.

As shown in FIG. 3 (b), the iron tip 6 has a sheet-like graphite 20 wound tightly around a core 21 made of isotropic carbon or the like, and a carbon ceramic coating layer or A reinforcement layer 22 such as a metal plating layer having poor solder wettability and not oxidizing may be formed.

Further, as shown in FIG.
It is composed of prismatic graphite 23 made of single crystal like graphite. Further, as shown by a virtual line in FIG. 4, a reinforcing layer 24 made of a heat-resistant adhesive or coating material such as glassy carbon is provided on a surface perpendicular to the high heat conducting surface, The configuration may be such that the graphite 23 that is easily peeled in the direction is prevented from peeling and the strength of the tip 6 is secured.

Next, the operation of soldering the object 16 to be soldered to the surface 15 to be soldered by the soldering iron unit 4 in the above configuration will be described.

First, the soldering iron unit 4 is lowered to the surface 15 to be soldered by the cylinder device 3 and transferred from the tip of the iron body 6 heated by the heater 7 to the surface 15 to be soldered. Get heated. At the same time, the inert gas heated by the heat exchanger 9 from the inert nozzle blowing nozzle 10 is blown onto the surface of the soldering tip 6 and the surface 15 to be soldered, thereby performing non-contact heating. At this time, the heat transfer due to the contact heating of the soldering tip 6 is transmitted faster to the surface 15 to be soldered, and the surface 15 to be soldered is heated by the non-contact heating by the heated inert gas. The molten solder 18 that has reached the solder wetting surface 6a and melted quickly and stably flows to the surface 15 to be soldered, and
8, an alloy layer is formed between the surface 15 to be soldered and the object 16 to be soldered, and soldered. At this time, since the molten solder 18 does not adhere to the soldering tip 6, even if the soldering tip 6 is moved away at a high speed after soldering, the solder ball does not scatter,
In addition, since the amount of solder is stabilized, good solder bonding is ensured.

Further, since the extension of the inert gas blowing nozzle 10 toward the soldering point is directed substantially in the same direction as the extension of the solder supply guide 13, the heated inert gas cannot be soldered as described above. The thread solder 1 sprayed on the attachment surface 15 and sent out from the solder supply guide 13
Since the solder 2 is heated, it is easy to melt the thread solder 12 on the solder wetted surface 6a, and it is possible to improve the meltability of the solder while preventing the oxidation of the molten solder 18, and to use the tip 6 to which the solder does not adhere. Therefore, the deterioration of the solder penetration can be eliminated. Also, scattering of solder balls and the like caused by the temperature difference between the solder wet surface 6a and the thread solder 12 is reduced.

In addition, since the tip 6 is made of graphite, the tip 6 is not oxidized in use and does not adhere to the molten solder 18, and the periphery of the surface 15 to be soldered is set to an inert gas atmosphere. Since the oxidation of the soldering surface 15 is suppressed, even if the thread solder 12 containing a flux corresponding to no-cleaning is used, the flux only needs to act on the reduction of the solder joint and the securing of the wettability. To demonstrate its effect enough. Therefore, good solder bonding and no cleaning can be achieved at the same time.

Further, since the tip 6 is made of graphite and has an affinity for the flux, if the molten solder 18 does not adhere to the tip 6 as described above, the meltability of the solder deteriorates. In addition, it is possible to ensure the penetration of the solder through the flux, and to improve the penetration of the solder while preventing the adhesion of the solder to the tip 6. The tip 6 is made of sheet or block graphite having heat conduction anisotropy, and the surface having high thermal conductivity is directed from the mounting portion of the tip 6 toward the solder wet portion 6a. Since they are aligned, the heat conduction efficiency is high, and the meltability of the solder can be further improved.

In this embodiment, since the inert gas is heated by the heat exchanger 9 disposed around the heater 7, the heat of the heater 7 for heating the soldering iron is used. The inert gas can be heated with high thermal efficiency and a compact configuration can be achieved.

[0027]

According to the soldering method of the present invention, as is apparent from the above description, the soldering iron having a soldering tip made of a material which does not oxidize itself and does not adhere to solder in use. , And soldering is performed while supplying an inert gas so that the soldering area has a low oxygen concentration atmosphere, so even if a supplied solder containing a flux compatible with no cleaning is used, the flux is Since it only needs to act to reduce the solder joints and ensure the wettability, it exerts its effects sufficiently, achieves good solder joints and no cleaning, and since the molten solder does not adhere to the tip, Even if the tip is moved away at a high speed, the solder balls do not scatter, and the amount of solder is stabilized, so that good solder bonding can be ensured.

Further, by heating and supplying the inert gas, the amount of heat supplied is increased, and the penetration of the solder is improved, so that the soldering can be performed efficiently.

Further, according to the soldering apparatus of the present invention, a soldering iron having a tip made of a material which does not oxidize itself and does not adhere to solder in a use state, and a thread which is directed toward a soldering position A heating means for heating the inert gas to be supplied to the solder supply guide for feeding the solder and an inert gas blowing nozzle for blowing an inert gas toward the soldering location; The effect can be obtained by implementing the above-mentioned soldering method.

Further, when the heating means is constituted by a heat exchanger disposed in the vicinity of the heater of the soldering iron, the inert gas can be efficiently heated by utilizing the heat of the heater of the soldering iron. In addition, a compact configuration can be achieved.

Also, by arranging the extension of the inert gas blowing nozzle toward the soldering point in substantially the same direction as the extension of the solder supply guide, the thread solder can be heated by the heated inert gas. In addition, it is possible to improve solder penetration while preventing oxidation of molten solder.

In addition, when the tip is made of a material having an affinity for the flux, preferably graphite, the solderability generally deteriorates directly with the solder because the solder does not generally adhere to the tip. Since the flux has an affinity, the meltability can be ensured, and the solder meltability can be improved while preventing the solder from adhering to the tip.

Further, the tip is made of sheet-like or block-like graphite having heat conduction anisotropy, and the surface having high thermal conductivity is arranged along the direction from the tip mounting part to the solder wet part. Then, the heat conduction efficiency is high, and the penetration of the solder can be further improved.

[Brief description of the drawings]

FIG. 1 is a front view showing a configuration of an embodiment of a soldering apparatus of the present invention.

FIG. 2 is a partial cross-sectional front view of a main part of the embodiment.

FIG. 3 shows a configuration example of a tip in the embodiment;
(A) is a vertical front view of one structural example, and (b) is a vertical front view of another structural example.

FIGS. 4A and 4B show still another configuration example of the tip in the embodiment, wherein FIG. 4A is a front view and FIG. 4B is a bottom view.

[Explanation of symbols]

 Reference Signs List 4 soldering iron unit 6 iron tip 7 heater 9 heat exchanger (heating means) 10 inert gas blowing nozzle 12 thread solder (supply solder) 13 solder supply guide 20 sheet graphite 23 prismatic graphite

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication // C04B 35/52 C04B 35/54 E

Claims (9)

[Claims] 1. A soldering iron having a tip made of a material that does not oxidize itself and does not adhere to solder in a use state,
A soldering method characterized in that the soldering is performed while supplying an inert gas so that the soldering area including the melting point of the supplied solder has a low oxygen concentration atmosphere. 2. The soldering method according to claim 1, wherein the inert gas is supplied by heating. 3. A soldering iron having a tip made of a material which does not oxidize and does not adhere to solder in a use state, a solder supply guide for feeding thread solder toward a soldering position,
An inert gas blowing nozzle for blowing an inert gas toward a soldering location. 4. The soldering apparatus according to claim 3, further comprising heating means for heating the inert gas supplied to the inert gas blowing nozzle. 5. The soldering apparatus according to claim 4, wherein the heating means comprises a heat exchanger disposed near the heater of the soldering iron. 6. The soldering apparatus according to claim 4, wherein an extension of the inert gas blowing nozzle toward the soldering point is directed substantially in the same direction as an extension of the solder supply guide. 7. The soldering apparatus according to claim 3, wherein the tip is made of a material having an affinity for flux. 8. The soldering apparatus according to claim 7, wherein the tip is made of graphite. 9. The tip is made of sheet-like or block-like graphite having heat conduction anisotropy, and the surface having high thermal conductivity is oriented along the direction from the tip mounting part to the solder wet part. 9. The soldering device according to claim 8, wherein the soldering device is configured.