JPS6219264B2 - - Google Patents

Description

[Detailed description of the invention]

This invention has high strength and high thermal conductivity,
The present invention relates to a soldering iron chip that also has excellent solder wettability and molten solder erosion resistance. In general, soldering iron tips for soldering include
Because its intended use requires high strength and high thermal conductivity, precipitation-hardening Cu alloys containing approximately 1.2% by weight or less of Cr are usually used, and their surfaces have excellent solderability and resistance to molten solder corrosion. Fe plating is applied for the purpose of giving sex. It is true that this Cr-containing precipitation-hardening Cu alloy has relatively high strength, but it does not have a sufficiently high strength, so the tip of the soldering iron tip must be processed into a very fine shape, for example, to a diameter of 1.5 mm or less. It is impossible to do this, and the molten solder corrosion resistance is also poor, so the Fe plating applied to the tip end of the chip must be 0.25 to 0.5 mm thick, or even thicker. Since it is necessary to thicken the tip end of the chip in this way, the current situation is that productivity is inevitably low and costs are high. On the other hand, in today's electronics industry, electrical products are becoming smaller and more highly packaged, and as a result, electrical circuits tend to become more and more precise. In order to efficiently and reliably solder components, the soldering iron chips used therein are also required to be small, that is, to have an extremely thin shape. Therefore, from the above-mentioned viewpoint, the present inventors conducted research in order to develop a soldering iron chip with high strength capable of ultra-fine processing and excellent resistance to molten solder erosion at a low cost. As a result, Cr:
Contains more than 2% 17.0%, Zr: 0.03 to 1.2%, further contains P: 0.005 to 0.25% as necessary, and the rest
Composition consisting of Cu and unavoidable impurities (more than % by weight,
(The following % indication means weight %)
When the alloy is used to manufacture soldering iron chips, it has high strength that allows the tip to be processed into an ultra-fine shape, and high thermal conductivity (high electrical conductivity) required for soldering iron chips. At least the tip surface of the Cu alloy soldering iron chip having the above composition contains at least one of Ni and Co as a main alloy component, preferably 10 to 50%.
By forming one or more Sn alloy plated layers of Sn alloy, the resulting soldering iron chip has excellent molten solder erosion resistance and solderability, and if necessary, When the plating layer is formed through one or more intermediate plating layers made of one or more of Fe, Ni, Co, Cr, and alloys containing these components as main components, the above-mentioned
The adhesion strength of the Sn alloy plating layer is further increased, and the diffusion of the Sn alloy plating layer into the chip body is suppressed.
This led to the discovery that the service life could be further extended. This invention has been made based on the above knowledge, and the reason why the range of the component composition of the chip is limited as described above will be explained below. (a) Cr The Cr component has the effect of increasing strength and improving oxidation resistance and molten solder erosion resistance, but if its content is less than 2%, the desired effect cannot be obtained. On the other hand, if the content exceeds 17%, the thermal conductivity (electroconductivity) decreases, so the content was set at more than 2% to 17%. (b) Zr The Zr component has the effect of imparting high-temperature ductility, high-temperature creep strength, and high-temperature strength, but if its content is less than 0.03%, the desired effect of improving each of the above properties cannot be obtained. On the other hand, if the content exceeds 1.2%, no further improvement effect will be obtained, and on the contrary, the plastic workability will deteriorate, so the content should be
It was set at 0.03-1.2%. (c) P The P component has the effect of suppressing ingot segregation during ingot making, uniformly and finely dispersing Cr that crystallizes as primary crystals, and further improving strength and elongation. It is included as necessary when properties are required, but if the content is less than 0.005%, the desired effect of improving the above function cannot be obtained; on the other hand, 0.25%
Even if it is contained in excess of
It was set at 0.005-0.25%. In addition, in the chip of this invention, unavoidable impurities include C of 0.1% or less and C of 0.5% or less.
Even if Fe, Ni, Co, Cd, and Sn are contained, the above characteristics are not impaired in any way. In addition, in the chip of this invention, Al, Mg,
Each contains one or more of Ti, Si, Be, B, Ag, In, Hf, and Mitsushi metal.
When Ca is contained in a range of 0.5% or less, heat resistance and/or molten solder corrosion resistance are further improved, and Ca is added as a deoxidizing agent.
and 0.2 each of one or two of Li.
It is also possible to clean the ingot and improve its properties by including it in a range of % or less. Furthermore, when manufacturing the soldering iron chip of the present invention, the Sn alloy plating layer is Sn-Ni based, Sn-Co
Dry plating method such as chemical vapor deposition method or physical vapor deposition method is applied to Sn alloys such as Sn-Ni-Co-based, Sn-Ni-Co-based, and Sn alloys containing one or more of Cu, W, and Mo. wet plating methods such as melt plating method, electroless plating method, and electroplating method (electroplating method is the most desirable from a cost standpoint)
The layer thickness is preferably 5 to 50 μm. The reason why this Sn alloy plated layer exhibits excellent molten solder erosion resistance is thought to be due to the presence of an intermetallic compound of SnNi or SnCo formed in the Sn alloy plated layer. Further, the intermediate plating layer can be similarly formed by a dry or wet plating method, and in this case, the layer thickness is preferably 1 to 10 μm. Furthermore, the entire surface of the chip body other than the chip tip is coated with a Cr plating layer to prevent surface oxidation of the heat transfer area, as well as to prevent solder wetting and remove solder from the chip tip. It is preferable to suppress the lifting phenomenon. Next, the soldering iron chip of the present invention will be specifically explained using examples. Examples Each of the ingredients had the composition shown in Table 1.
Cu alloy round bar (dimensions: diameter 10mmφ x length 70mm)
Adjust this round bar, the length of the tip is 3mm, the diameter is 0.8mmφ x the diameter of the main body is 7mmφ x the overall length is:
This was then cut to a size of 55 mm, and a layer having the composition and layer thickness also shown in Table 1 was used.
The Sn alloy plating layer and the intermediate plating layer are plated using a normal electroplating method, and the length of the tip of the chip is 2 mm.
By forming chips 1 to 1 of the present invention,
20 were produced each. Next, chips 1 to 20 of the present invention obtained as a result

[Table] After heating in the air at a temperature of 400℃ for 24 hours, the tip of the chip was placed in molten solder (with a composition of Sn: 60% and Pb: 40%) at a bath temperature of 230℃ for 1 second. When the solder wettability of the chips was observed under immersion conditions, all chips showed extremely good solder wettability. In addition, when chips 1 to 20 of the present invention were subjected to a continuous soldering durability test under the conditions of chip tip holding temperature: 400°C, pressing load: 150 g, and 1 cycle: 3 seconds, all chips were tested 50,000 times. No abnormalities were observed in the appearance even after the test, showing excellent resistance to molten solder corrosion and good solder wettability, indicating that it can be used for a long period of time. . Furthermore, Table 1 shows the tensile properties of the chip bodies of chips 1 to 20 of the present invention at 500°C and 100°C at 280°C.
The time creep rapture life and electrical conductivity are also shown, and it is clear from these results that the chip of the present invention has high strength and high electrical conductivity, that is, high thermal conductivity. As mentioned above, the soldering iron tip of the present invention has high strength, so the tip end of the tip can be processed into an extremely thin shape that is sufficiently durable for practical use, making it possible to apply it to precision soldering. In addition, it has excellent molten solder erosion resistance and solder wettability required for soldering iron chips, and has high thermal conductivity, so it has industrially useful properties such as exhibiting excellent soldering performance over a long period of time. It has.

Claims (1)

[Claims] 1. At least a Cu alloy soldering chip having a composition (weight %) containing 1 Cr: more than 2% to 17.0%, Zr: 0.03 to 1.2%, and the remainder consisting of Cu and unavoidable impurities. The surface of the tip is coated with one or more Sn alloy plating layers of Sn alloy containing at least one of Ni and Co as the main alloy component to improve solder wettability and molten solder erosion resistance. Excellent high strength and high thermal conductivity soldering iron chip. 2 Made of a Cu alloy containing Cr: more than 2% to 17.0%, Zr: 0.03 to 1.2%, further containing P: 0.005 to 0.25%, and the remainder consisting of Cu and unavoidable impurities (weight %) At least the surface of the tip of the soldering tip is made of Sn containing at least one of Ni and Co as the main alloy component.
A high-strength, high-thermal conductive soldering iron chip that is coated with one or more Sn alloy plating layers and has excellent solder wettability and molten solder erosion resistance. 3. At least the surface of the tip of a soldering iron tip made of a Cu alloy having a composition (weight %) containing Cr: more than 2% to 17.0%, Zr: 0.03 to 1.2%, and the remainder consisting of Cu and unavoidable impurities, Fe, Ni, Co,
Through one or more intermediate plating layers consisting of one or more of Cr and alloys containing these components as main components, at least Ni is added as the main alloy component.
A high-strength, high-thermal-conductivity soldering iron chip with excellent solder wettability and molten solder erosion resistance, which is coated with one or more Sn alloy plating layers made of a Sn alloy containing one or more of Co and Co. 4 Made of a Cu alloy containing Cr: more than 2% to 17.0%, Zr: 0.03 to 1.2%, further containing P: 0.005 to 0.25%, and the remainder consisting of Cu and unavoidable impurities (weight %) At least the tip of the soldering iron chip is coated with the main alloy through one or more intermediate plating layers made of one or more of Fe, Ni, Co, Cr, and alloys containing these components as main components. High strength and high thermal conductivity with excellent solderability and molten solder erosion resistance, made by coating with one or more Sn alloy plating layers of Sn alloy containing at least one of Ni and Co as a component. Soldering iron chip.