JP3122366B2 - Solder chip and manufacturing method thereof - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a soldering chip such as an electric soldering iron chip and an automatic machine chip, and a method of manufacturing the same. And a method for manufacturing the same.

[0002]

2. Description of the Related Art Solder chips are required to have good heat conduction and excellent solder wettability, and copper is usually used as a material satisfying these requirements. However, copper has a drawback that it has poor corrosion resistance to solder and flux.If the entire tip is made of copper only, in a continuous soldering operation, the erosion effect of solder and flux causes early There is a problem that the number of tips is reduced and the life is extremely short.
This problem was particularly noticeable in a precision soldering tip having a tip diameter of 1 mm or less.
Therefore, an iron film having excellent corrosion resistance and good solder wettability is applied to the entire surface of the copper base by an electroplating method to a thickness of 50 to 500.
Solder chips formed with a thickness of about μm have been generally used. In manufacturing the solder chip, first, the copper base A is formed into a chip shape (FIG. 7).
(A)) Then, after an iron plating layer is formed on the entire surface (FIG. 7 (b)), the raised portion B 'of the iron plating layer at a corner such as the tip of the tip is turned by turning using a lathe or the like. The product is removed as shown in FIG. 7C by surface finishing. The raised portion B 'of the iron plating layer
Is caused as a result of an increase in the current density at the corners of the copper base A due to the fact that the iron plating treatment is performed for a long time in the electrolytic treatment. It had to be removed because it was undesirable. However, in such a manufacturing method, since the thickness of the iron plating layer B cannot be confirmed from the outside, even if the surface contour is formed into a desired shape by the surface finishing by the machining as described above, the iron plating layer B is formed. There is a problem that the thickness of B varies, which makes it impossible to impart uniform corrosion resistance to the product. When manufacturing a small-diameter chip having a tip diameter of 1 mm or less, such as a soldering tip for precision soldering, for example, an iron plating layer B having a thickness of 250 μm is used.
, The tip diameter of the copper base A is 0.5
However, it is extremely difficult to manufacture the copper base end A having such a small tip end diameter by machining, so that mass production was practically impossible.

In this regard, recently, first, FIG.
As shown in FIG. 7, after forming a round bar-shaped copper base body A whose tip is processed into a spherical surface, an iron plating layer B is formed on this surface to obtain a chip base material as shown in FIG. A method has been developed in which the chip base material is formed into a desired product shape as shown in FIG. 7 (f) by forging (swaging and pressing) (for example, Japanese Patent Publication No. 59-59).
No. 11386). According to this method, since the tip portion of the copper base A, which is the tip end of the chip, has a spherical shape, the iron plating layer B having a uniform thickness can be formed.
The thickness of the iron plating layer B after the forming and finishing is made uniform to some extent, and a small-diameter chip having a tip diameter of 1 mm or less can be easily manufactured. Further, as shown in FIG. 8A, a round bar-shaped copper base A whose tip is machined into a spherical shape.
Is formed, a thin chip member C made of iron or the like is integrally and integrally fixed to the surface of the front end portion in a covering shape, and the front end portion of the base A to which the chip member C is fixed is formed by forging processing as shown in FIG. A method of forming the product into an expected product shape as shown in c) has also been developed (for example, Japanese Patent Application Laid-Open No. 4-17974).
According to this method, the same effect can be obtained while omitting the plating work as compared with the method of FIG. 7, and the manufacturing cost and the like can be greatly reduced, and the pollution to the worker by harmful gas and the like accompanying the plating work can be achieved. , As well as air and river pollution.

[0004]

First, Japanese Patent Publication No. Sho 59-1
In the manufacturing method described in Japanese Patent No. 1386, a plating step is indispensable for forming an iron film, and it has been a major problem to remove the following four problems caused by the plating step. First, a plating process of about 60 hours was required to obtain a 500 μm iron film by the plating method, resulting in poor productivity. Second, when electroplating is performed for a long time, plating is applied to an unnecessary portion, and much labor is required to remove the portion. Third, the plating operation involves handling hazardous materials and poisons, which is harmful to humans and the environment. Fourth, the metals that can be plated are limited to Ni, Cr, Cu, Au, Fe, and the like, and plating of other metals and alloys is very difficult or impossible. Next, the manufacturing method described in Japanese Unexamined Patent Publication No. 4-17974 in consideration of these drawbacks has a problem that not only is it difficult to manufacture the chip member C, but also it is difficult to join the base member A and the chip member C. there were. Further, in connection with this point, there is a problem that the effect of reducing the manufacturing time and the manufacturing cost is not sufficient. The present invention has been made in view of these problems, and can provide an iron film without using a plating method, is easy to manufacture, has high productivity, and has a good yield. And a method for producing the same.

[0005]

In order to achieve the above object, according to the first aspect of the present invention, a tip portion of a solder chip after forging is determined outside a cylindrical second pipe having a length of L2.
As to polymerize a cylindrical first pipe length L2 + A which is determined in correspondence with their thickness, subjected to a first forging machining while forming a non-overlapping portion of the length A to the tip of both, After the heat treatment, the distal end of the cylindrical second pipe is fixed and closed, and the distal end of the cylindrical first pipe is also fixed and closed so as to cover it.
The forging process is further performed on the distal ends of the two pipes. In the invention according to claim 2, in the state where a metal pipe for corrosion prevention is interposed outside the cylindrical second pipe having the length L2, the tip of the soldering tip after forging is determined.
As to polymerize a cylindrical first pipe length L2 + A which is determined in correspondence to their thickness, in a state of forming a non-overlapping portion of the length A to the tip of the first pipe and the second pipe first After the forging process is performed and the heat treatment is performed, the tip of the cylindrical second pipe is fixed and closed, and the tip of the cylindrical first pipe is also fixed so as to cover the tip. Further, forging is performed on the distal ends of the two pipes so that the pipes are closed.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in more detail based on embodiments. First Embodiment FIG. 1 is an illustration of an example of the material of the solder tip according to the present invention, the length L _1, the inner diameter X
i ₁ , iron pipe 1 with outer diameter Xo ₁ , length L ₂ , inner diameter Xi
₂ shows a copper pipe 2 having an outer diameter Xo ₂ . Although the dimensions of each of the materials 1 and 2 can be appropriately changed in design, in this embodiment, after the copper pipe 2 is inserted into the iron pipe 1 and the soldering chip is manufactured by forging processing, the size of the iron pipe 1 is reduced. The copper pipe 2 has a relationship of Xi ₁ ＬXo ₂ and L ₁ > L ₂ . In order to manufacture a solder chip, first, as shown in FIG. 2, a copper pipe 2 is inserted into an iron pipe 1 for positioning. Due to this positioning, a non-overlapping portion having a length of L ₁ -L ₂ = A is formed at the tip of the pipe. The length A of the non-overlapping portion and the thickness Xo ₁ -Xi _{1 of the} iron pipe are obtained.
= T determines the state of the tip of the soldering chip after forging. When the positioning of the iron pipe 1 and the copper pipe 2 is completed, next, the saging (rotaryswagin)
g) Reduce the diameter of both pipes 1 and 2 by a fixed amount. Thereafter, the vicinity of the non-polymerized portion is further subjected to a serging process, and the distal ends of both the pipes 1 and 2 are formed into the state shown in FIG. 3 (first stage serging). Next, heat treatment is performed at a temperature exceeding the transformation point of iron to sufficiently anneal. This heat treatment removes the work hardening and residual stress of the material due to the previous saging,
This is for facilitating the next saging process.
Note that this heat treatment is desirably performed in an inert atmosphere. When the heat treatment is performed in a normal heat treatment furnace, oxidized scale is generated. Therefore, the generated scale is removed (including washing with water, neutralization, and drying) by hydrochloric acid treatment or the like.

After that, the ends of the two pipes 1 and 2 are further processed to form the state shown in FIGS. 4 (a) and 4 (b) (second-stage aging). By this processing, copper pipe 2
The tip 2a of the iron pipe 1 is also fixed and closed so as to cover the tip 2a.
After that, if necessary processing such as engraving of a character or Cr plating or solder plating of the tip of the tip is completed, the manufacture of the solder chip is completed. In the above-described embodiment, the solder chip is manufactured by the two-stage saging process.
If the degree of molding is large depending on the final shape, a third-stage or higher-stage saging treatment may be performed. Further, the tip portion 1b may be flattened like a screwdriver by using press working together (FIG. 4C). As described above, the method of forming an iron film on a copper pipe substrate by a saging process has been described. However, compared to an iron film formed by plating, it was confirmed that a dense iron layer without pinholes was obtained. I have. Further, since the soldering chip is manufactured by the saging process, the material is not limited as in the case of the plating method, and the manufacturing time is short and the manufacturing cost can be reduced. by the way,
In the above description, after the copper pipe 2 is inserted into the iron pipe 1, both pipes are reduced in diameter. However, by pressing the copper pipe 2 into the iron pipe 1, the diameter reduction processing can be omitted. good. Although the copper pipe 2 is described as having a bottomless cylindrical shape, a bottomed cylindrical copper pipe 2A having a bottom only on the tip side may be used. FIG. 4D shows a soldering chip when such a copper pipe 2A is used. The bottom is not limited to the disk-shaped bottom, but may be a ring-shaped bottom, and the ring may be inclined in the axial direction as necessary.

FIG. 5 schematically shows a manufacturing method according to a second embodiment, in which a metal pipe 3 for preventing corrosion is provided between an iron pipe 1 and a copper pipe 2. Is shown. Although the material of the metal pipe 3 is not particularly limited, for example, stainless steel such as SUS is preferable. The method of manufacturing the soldering chip is the same as that of the first embodiment, in which the metal pipe 3 is inserted into the iron pipe 1,
Further, after the copper pipe 2 is inserted therein, a soldering chip is manufactured by forging such as saging. As described above, according to the present invention, a multilayer film can be formed at a time by appropriately combining two or more kinds of different metal pipes. Providing the bad layer can extend the life of the solder chip. Further, since the soldering chip is manufactured by forging, there is no limitation on the selection of the material as in the case where the plating is performed.

[Third Embodiment] FIG. 6 shows an embodiment in which a cylindrical copper rod 2B is inserted into an iron pipe 1. The method of manufacturing the solder chip is the same as that of the first embodiment. After the copper rod 2B is inserted into the iron pipe 1, the solder chip is manufactured by forging. And FIG.
The soldering chip formed in the state of (b) is used by inserting it into a cylindrical heater.

[0010]

As described above, according to the present invention, in the manufacture of a soldering chip such as a soldering iron tip, iron or the like is formed on a substrate such as copper without using plating and other coating methods. Alternatively, a thin film of another metal is formed by forging. Therefore, as compared with the method described in JP-B-59-11386, the manufacturing process can be largely omitted, the manufacturing time can be shortened, and the manufacturing cost can be significantly reduced. Moreover, depending on the thickness of the outermost pipe and the difference between the length of the base and the length of other pipes,
Since the thickness of the protective film of the solder chip can be set appropriately,
Compared to the method described in Japanese Patent Application Laid-Open No. 4-17974, the production is easier, the productivity is higher, and the yield is better. Further, in the present invention, since the soldering chip is manufactured by forging such as saging, the material to be used is not particularly limited, and by an appropriate combination of pipe materials,
Multiple layers can be formed at once. For example, when a stainless steel pipe and an iron pipe are provided on the outer periphery of a copper base and forging processing is performed, even if the iron coating part is corroded and worn by solder, the stainless steel film covers the copper base. A longer life can be achieved.

[Brief description of the drawings]

FIG. 1 illustrates an example of a material for a solder chip according to a first embodiment.

FIG. 2 illustrates a state in which an iron pipe and a copper pipe are positioned.

FIG. 3 is a diagram illustrating a state after a first-stage saging process.

FIG. 4 is a diagram illustrating states (a) and (b) after the second-stage saging process, together with cases (c) and (d) of another embodiment.

FIG. 5 illustrates a solder chip according to a second embodiment.

FIG. 6 illustrates a solder chip according to a third embodiment.

FIG. 7 is a diagram illustrating a conventional technique.

FIG. 8 is a diagram illustrating another conventional technique.

[Explanation of symbols]

 1 Iron pipe 2 Copper pipe 3 Stainless steel pipe

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) B23K 3/02 B21C 37/06 B21K 5/00

Claims (2)

(57) [Claims] 1. A forging outside a cylindrical second pipe having a length of L2.
In order to determine the tip of the soldering tip after pressing, the cylindrical first pipe of length L2 + A determined according to its own thickness is superimposed , and a non-overlapping portion of length A is formed at both ends. After performing the first forging process in the state where it has been
The distal ends of the two cylindrical pipes are so fixed that the distal ends of the cylindrical second pipes are fixed and closed, and the distal ends of the cylindrical first pipes are also fixed and closed so as to cover them. And a method for manufacturing a solder chip in which forging is further performed. 2. A forging process in which a metal pipe for corrosion prevention is interposed outside a cylindrical second pipe having a length L2.
Of the cylindrical first pipe having a length L2 + A determined according to its own thickness so that the tip of the soldering chip is determined , and a non-polymerized length A is formed at the tips of the first pipe and the second pipe. After the first forging process is performed in a state where the portion is formed, and the heat treatment is performed, the distal end of the cylindrical second pipe is fixed and closed, and the cylindrical first pipe is formed so as to cover it. A method for manufacturing a solder chip, wherein the tip portions of both pipes are further forged so that the tip portions of the pipes are also fixed and closed.