KR100904658B1 - Pb free solder Composition for wave and deeping, electronic equipment and PCB with the same - Google Patents

Abstract

The present invention is to solve the problem that, when soldering by the conventional lead-free solder alloy, the molten solder is combined with oxygen to form an oxide, the soldering workability is lowered, the mechanical properties of the joint is reduced, Tin (Sn), The present invention relates to a lead-free solder composition for wave and dipping including copper (Cu), nickel (Ni), silicon (Si), phosphorus (P), and cobalt (Co), and more specifically, 0.1 to 2% by weight of copper, Lead-free solder composition for wave and dipping comprising 0.001 to 1.0% by weight of nickel, less than 0.001 to 0.05% of silicon, less than 0.001 to 0.01% by weight of cobalt, 0.001 to 0.2% by weight of phosphorus, and tin, and electronic devices using the same It relates to a printed circuit.

Therefore, the present invention not only continuously and effectively prevents the oxidation of the molten solder, but also maintains the conventional lead-free soldering temperature and wettability while adding a very small amount of silicon and cobalt elements, and prevents discoloration after soldering and printed circuit boards. It has an effect of providing a lead-free solder composition for wave and dipping and an electronic device and a printed circuit board using the same, which can improve soldering bonding properties such as copper pad erosion prevention.

Lead free solder compositions for pre-lead, wave and dipping, solder alloys.

Description

Pb free solder composition for wave and deeping, electronic equipment and PCB with the same}

1 is a schematic diagram showing the principle of the amount of oxide suppression of the lead-free solder composition according to the present invention.

FIG. 2 is an element analysis result diagram and a result table of an initial state with respect to the schematic diagram of FIG.

FIG. 3 is an element analysis result diagram and a result table after a 3-hour dross experiment for the schematic diagram of FIG. 1. FIG.

FIG. 4 is an Auger Si measurement peak for the schematic diagram of FIG. 1. FIG.

FIG. 5 is a peak of Auger SiO ₂ measurement for the schematic diagram of FIG. 1. FIG.

The present invention relates to a lead-free solder composition for wave and dipping, and an electronic device and a printed circuit using the same. More specifically, the present invention contains silicon (Si) and cobalt (Co) in a ternary composition consisting of tin (Sn), copper (Cu), nickel (Ni), and phosphorus (P) without containing lead that is harmful to the human body. By containing, the generation of oxide is continuously suppressed by the silicon to improve the soldering work efficiency, the addition of a small amount to maintain the conventional lead-free soldering temperature and wettability while preventing discoloration, the wettability is improved, cobalt The present invention relates to a lead-free solder composition for wave and dipping in which (O) is contained in a small amount together with silicon, and thus an oxide generation prevention, copper erosion prevention, and bond breaking load are greatly improved, and an electronic device and a printed circuit board using the same.

In the conventional case, lead-containing alloys have been used for a long time, and tin-lead-based flexible solders have been used as bonding materials in component mounting of printed circuit boards for a long time. More specifically, soldering is a bonding technique using soldering, and in particular, it is used as a bonding material for mounting small electronic components such as semiconductor chips and resistance chips on a printed circuit board (PCB). As a joining technique using such soldering, it is used as a bonding material for mounting small electronic components such as semiconductor chips and resistor chips, in particular on printed circuit boards.

Joining technology using such a solder is required to be more advanced because of the high density of component mounting in accordance with the recent miniaturization and high functionality of electronic products. On the other hand, as a soldering material, binary process alloys composed of tin (Sn) and lead (Pb) have been mainly used. However, when this is disposed of, lead is leaked, which causes environmental pollution. Reached. This is because lead has a fatal adverse effect on the human body following environmental pollution.

Therefore, in recent years, various environmentally friendly lead-free and lead-free solder compositions have been developed and attempted by regulating or excluding lead in the manufacture of solder alloys. However, the lead-free solder composition for wave and dipping according to the prior art has a higher melting point and lower wettability as compared to the flexible solder, and also causes severe oxidation of the molten solder during soldering, resulting in poor solderability. It has a problem of deterioration in quality and reliability.

In addition, the lead-free solder according to the prior art is used in accordance with the improvement of the soldering process, such as replacement of the reflow oven without the development of near the melting point of 183 ℃ of the conventional solder (Sn37Pb) while satisfying the soldering bonding properties such as wettability. This is because only a very limited number of low melting point metals such as Cu, Ag, Zn, Bi, In, etc. are targeted as the melting point drop addition element.

In addition, the lead-free solder according to the prior art does not satisfy the melting point of 183 ° C of the conventional solder (Sn37Pb) while satisfying the soldering bonding properties such as wettability, corrosion resistance. And most lead-free solders have a small melting point by adding a small amount of low melting point metals such as Cu, Ag, Zn, Bi, In to Sn, but the development of lead-free solders with low melting point (low melting point) is no longer possible. No progress has been made and the limit has been reached.

Therefore, the Ag system of SnAgCu and the non-Ag system alloy of SnCu of melting | fusing point 220 degreeC-230 degreeC are the mainstream now. As described above, in terms of lowering the melting point of the solder, improvement has reached a limit, and development is mainly focused on improving soldering characteristics, improving workability, and improving quality and reliability.

In addition, lead-free solder has a higher melting point, more expensive dross due to the use of expensive raw materials and soldering oxidation, resulting in higher production costs, and increased oxides in the solder solder fillet of PCB Assey. ), The main cause of the deterioration of the quality and reliability of soldering assembly.

In order to solve the above problems, as described in KR 10-0327767, JP 3622788, and JP 3296289, a solder alloy in which an anti-oxidation element such as P, Ni, Ge, and Ga is added to SnAgCu and SnCu-based mother alloy solders has been developed. It is. However, in the case of Ge, Ga, and Ni, which are additional elements, the melting point is increased, and when exposed to thermal processing and thermal fatigue due to hardening, there is a concern that the reliability may be degraded, such as cracks in the solder portion, and thus it is used in a limited manner. .

In particular, when P is added in a large amount, the adverse effect of bridging the soldering portion due to hardening of the solder alloy occurs. In addition, P melts on the soldering surface to prevent oxidation of the molten solder. However, P has a high volatility to temporarily prevent generation of oxides at soldering temperatures around 260 ° C. However, wave soldering (Wave) In the case of soldering and dip soldering, hundreds of kilograms of solder are filled in the molten metal, followed by continuous use for several months by replenishing only a small amount of consumption. It only shows a short dross prevention effect and continuous oxidation has an unexpected problem.

Accordingly, the present invention is to solve the above problems, the object of the present invention has a mechanical property and workability comparable to Sn-Pb and Sn-Cu-P-Ni solder, and does not include Pb By containing silicon (Si) and cobalt (Co) in a quaternary composition consisting of tin (Sn), copper (Cu), nickel (Ni), and phosphorus (P), the oxidation of the molten solder can be prevented continuously and effectively. In addition, despite the addition of a very small amount of elements, lead-free soldering temperature and wettability while maintaining the conventional lead-free soldering, lead-free for wave and dipping that can improve the solderability of bonding, such as preventing discoloration after soldering, copper pad erosion of the printed circuit board It is to provide a solder composition and an electronic device and a printed circuit board using the same.

The present invention is a wave and di containing a balance of 0.1 to 2% by weight of copper, 0.001 to 1.0% by weight of nickel, less than 0.001 to 0.05% by weight of silicon, less than 0.001 to 0.01% by weight of cobalt, 0.001 to 0.2% by weight of phosphorus and tin. Provided is a lead-free solder composition for ping, and an electronic device and a printed circuit board using the same.

1 is a schematic diagram showing the principle of suppressing the amount of oxide generation of the lead-free solder composition according to the present invention.

As shown in the figure, in the case of wave soldering using a solder alloy containing P and Si elements to suppress oxide generation in the SnAgCu master alloy, first, a part of the amount of the added P and Si elements is After being consumed in the deoxidation of the molten solder master alloy, it is dissolved in some molten solder master alloy, but P and Si are hardly dissolved in the molten Sn, and most of the added P and Si elements float on the surface due to the specific gravity difference. do. In addition, the phosphate and silicon oxide film blocks oxygen and molten solder in the atmosphere to suppress oxide generation of the lead-free solder.

However, in the case of P, a portion of the surface floating on the surface forms an oxide film, but a large portion of the surface is volatilized to the atmosphere, thereby degrading the continuous suppression of oxide generation on the surface of the molten solder. On the other hand, Si does not volatilize to the atmosphere and continuously forms silicon oxide on the surface of the molten solder, thereby suppressing the oxide generation effect. Experimental data on this can be seen through FIGS. 2 and 3.

지점별 성분 데이터를 통해 확인할 수 있다. FIG. 2 is a result of Auger element analysis of a solder alloy cross section by melting and casting a predetermined ingot by melting and casting as actual measurement data of the schematic diagram of FIG. Figure 3 is an Auger element analysis result when the Ingot produced by the same method for 3 hours Dross experiment (oxidation experiment) at 260 ℃. As shown in Fig. 2, in the initial state, phosphorus is floated on the surface of the ingot, and is mostly concentrated at 1.86% by mass at the top, and Si is distributed at the lower part of P.

This can be confirmed by point-specific component data.

지점에서도 P 보다는 Si이 더 잔존하고 있음을 알 수 있다. 또한, Auger의 Peak치를 보면, 상부에는 SiO₂로 간주되는 실리콘 산화물이 형성되어 있는 반면, 하부 방향 2, 3

지점에는 도4에서 알 수 있듯이 SiO₂ Peak치가 아닌 Si Peak가 나타나고 있다. As shown in Fig. 3, in the case of the dross experiment at 260 ° C. for 3 hours, P is 0.06% by mass and Si is 0.08% by mass, and Si remains relatively higher than P.

It can be seen that Si remains more than P at the point. In addition, the peak value of Auger shows that silicon oxide, which is regarded as SiO ₂ , is formed on the upper side, while the lower directions 2 and 3

As shown in FIG. 4, the Si peak is shown, not the SiO ₂ peak value.

From the above results, after P and Si were floated in the order of P. Si due to the specific gravity difference from the molten solder on the surface of the molten solder in the initial stage of melting, P was volatilized to a large extent and only a portion of the oxide film was formed by continuous contact with air. On the other hand, in the case of Si, most of the addition amount forms a silicon oxide film such as SiO ₂ to suppress oxidation of the molten solder.

Looking at the properties and uses of the composition of the lead-free solder composition according to the invention as follows.

The tin (Sn) is used as the base metal as an essential component of the lead-free solder.

Cu (copper) lowers the melting point slightly, improves the bonding strength of the bonded body, when added in less than 0.1% by weight, the effect is small and the addition of more than 2% by weight, the melting point is increased, 0.1 to 2% Addition in the% range is preferred.

Ni (nickel) is an additive element for preventing copper pad erosion and improving bonding strength. The addition of less than 0.001% by weight is not effective, and the addition of more than 1.0% by weight causes rapid melting point increase and overhardening, and thus, 0.001 ~. It is preferably included in 1.0% by weight.

The phosphorus is for suppressing the formation of oxide during soldering to improve the work of soldering. When added to less than 0.001% by weight, the effect does not occur, and when added to more than 0.2% by weight, the melting point is increased. The optimum content is 0.001 to 0.2% by weight.

Si (silicon) is a main additive element of the present invention, floating and non-volatile, a small amount added to the solder master alloy of Sn-Cu-Ni-P, while suppressing the generation of oxide, unlike the phosphorus (P) for a long time Even if the effect persists, not only does it show an excellent effect in preventing discoloration of the soldering part after soldering, but also improves the anti-corrosion effect.

Co (cobalt) is not floating, but addition with Si further suppresses the formation of oxides during soldering with a small amount of addition, and further improves soldering properties and workability such as discoloration and erosion prevention.

Hereinafter, the function and effect of the composition composition range through the experimental data for a preferred embodiment of the lead-free solder composition for wave and dipping and the electronic device and the printed circuit board using the same will be described in detail.

The lead-free solder composition for wave and dipping according to the present invention comprises tin (Sn), copper (Cu), phosphorus (P), nickel (Ni), silicon (Si), and cobalt (Co).

Hereinafter, the antioxidant effect according to the composition range of the silicon and cobalt through the graph 1 will be described in detail.

The graph 1 below is experimental data of the amount of oxides generated, and selectively or simultaneously dissolves silicon and cobalt in a tin-copper and tin-copper-phosphorus master alloy to form a soldering composition, and the soldering composition has a diameter Heated to 260 ° C. using a hotplate in a 160 mm SUS crucible. Then, the resultant was stirred for 1 hour, 2 hours, and 3 hours at a rotational speed of 60 rpm using a stirrer having a diameter of 140 mm, and the amount of oxidation was measured by measuring the weight of oxides by time.

Graph 1.

As shown in Graph 1., Sn0.5Cu0.06Ni0.005P containing 0.5% by weight of Cu, 0.06% by weight of Ni, 0.005% by weight of P, and Sn was 134 (g), 2 after an hour of oxide generation. 2786 (g) after 3 hours and 384 (g) after 3 hours, total 786 (g) was generated, compared with 371 (g) after 2 hours, and 371 (g) after 2 hours 395 (g), 460 (g) after 3 hours, total 1,226 (g) was generated, and Sn0.5Cu0.005P containing 0.5% Cu, 0.005% P, and Sn by residual amount of oxide was 1 A total of 1,047 (g) was generated after lapse of 251 (g), after 2 hours of 356 (g), and after 3 hours of 440 (g). The reason why Sn0.5Cu0.06Ni0.005P has less oxide generation than Sn0.5Cu0.005P and Sn0.5Cu is because Ni and P play a role of reducing the amount of oxidation.

In the case of including 0.005% by weight of Si in the Sn0.5Cu0.06Ni0.005P, the amount of oxide generated is 110 (g) after 1 hour, 132 (g) after 2 hours, and 155 (g) after 3 hours. A total of 397 (g) was generated, and the amount of oxide generated was reduced compared to Sn0.5Cu, Sn0.5Cu0.005P and Sn0.5Cu0.06Ni0.005P.

From the above results, when 0.005% by weight of P was added, the occurrence of dross increased rapidly in the 3 hours, while when 0.005% by weight of Si was added, the oxidation rate was similar to that of 2 hours. It can be said to have a continuous antioxidant effect.

And, when it contains 0.05% by weight of Si, it can be seen that the oxide generation is further reduced.

In addition, when 0.01 wt% of Co is included in Sn0.5Cu0.005P0.06Ni0.05Si, the amount of oxide generated is 86 (g) after 1 hour, 103 (g) after 2 hours, and 119 (g after 3 hours). A total of 308 (g) was generated, it can be seen that the amount of oxide generation is reduced compared to the Sn0.5Cu0.005P and Sn0.5Cu0.06Ni0.005P0.005Si.

When the Sn 0.75Cu0.005P0.1Ni0.005Si is included 0.005% by weight of Co, it can be seen that the amount of oxide generated by the addition of a small amount of Si and Co compared to the comparative material.

Therefore, when a small amount of Si is added to the Sn-Cu-P-Ni master alloy, it can be confirmed that the amount of oxide generation is continuously prevented, compared to the conventional P-added soldering composition, and a small amount of Si and Co are simultaneously added. If it is, it can be confirmed that it is prevented more continuously and effectively.

Hereinafter, the wettability according to the component composition range of silicon and cobalt will be described in detail through Graph 2.

Graph 2 below is an experimental data on the wettability. In order to measure the wetting time of the soldering composition, the melting time after melting for 5 seconds was measured by melting the solder at 260 ° C. using a MalCom SP2 Wetting Tester.

Graph 2.

As shown in Graph 2., the wettability of Sn0.5Cu0.06Ni0.005P containing 0.5% by weight of Cu, 0.06% by weight of Ni, 0.005% by weight of P and Sn by balance is 2.07 sec, and compared with 0.5 weight of Cu. Wetting time of Sn0.5Cu0.005P containing%, P 0.005% by weight and Sn as remainder is 1.88 sec, compared to that of Sn0.5Cu containing 0.5% by weight of Cu and Sn as remainder is 1.67 sec. sec.

In addition, when the Sn0.5Cu0.06Ni0.005P contains 0.005% by weight of Si, the wetting time is 1.85 sec, and when the 0.05% by weight Si is included, the wet time is 2.09 sec. It was confirmed that the increase compared to the wet time.

In addition, in the case of including 0.01 wt% of Co in Sn0.5Cu0.06Ni0.005P0.05Si, the wetting time is 2.18sec, and in the case of including Sn 0.005 wt% Co in Sn0.75Cu0.1Ni0.005P0.005Si, the wet time is 1.92 sec.

Therefore, when 0.005% by weight of Si is added to the Sn-Cu-N-P master alloy, the wettability is slightly improved, but when the weight is 0.05% by weight or more, the wettability can be confirmed. The wettability is slightly improved by removing oxygen in the molten master alloy solder (SnAgCu) by adding a very small amount of Si to 0.005% by weight, but when added by 0.05% by weight or more, it is melted by excess Si with an increase in melting point. It is considered that the wettability of solder is poor. In addition, when Si and Co are added in small amounts simultaneously, the wettability is further improved, but when Co is added in a large amount, for example, 0.01 wt% or more, the wettability is lowered.

Hereinafter, the copper erosion according to the composition range of the silicon and cobalt through the graph 3 will be described in detail.

The following graph 3 is experimental data on copper erosion amount, in order to measure copper erosion amount, the solder is melted and maintained at 260 ° C., and copper wire having a diameter of 0.8 mm is immersed in a molten solder at a depth of 30 mm for 60 seconds, and then The copper wire was taken out and the weight before and after dipping was measured to obtain the erosion rate (%), and the average value of five samples was calculated.

Graph 3.

As shown in Graph 3, the copper erosion amount of Sn0.5Cu0.06Ni0.005P is 47.1%, in comparison, the copper erosion amount of Sn0.5Cu is 53.6%, and the copper erosion amount of Sn0.5Cu0.005P is 52.7%.

And, when the Sn0.5Cu0.06Ni0.005P contains 0.005% by weight of Si, the copper erosion amount is 45%, when containing 0.05% by weight of Si, copper erosion amount is 44.7%, Sn0.5Cu, Sn0.5Cu0 It can be seen that the erosion amount of .005P and Sn0.5Cu0.06Ni0.005P was reduced.

In addition, when the Sn 0.5 Cu 0.06 Ni 0.005 P 0.05 Si is included 0.01% by weight of Co, it can be seen that the copper erosion was significantly reduced to 11.8%.

Therefore, when a small amount of Si is added to the Sn-Cu-P-Ni master alloy, it is confirmed that copper erosion amount is reduced, and when Si and Co are added in small amounts at the same time, the amount of copper erosion is greatly reduced.

Hereinafter, referring to Table 1, the amount of oxide generation, melting point, discoloration, wetting time, copper erosion rate, and bonding strength according to the composition range of silicon and cobalt are described in detail, and thus included in the Sn-Cu-P-Ni mother alloy. The optimum content of silicon and cobalt to be described is described.

Table 1 is a comprehensive experimental data for each composition range of silicon and cobalt including the above-described graphs 1,2 and 3, and adding test data of melting point, discoloration and bonding strength.

Table 1.

First, as shown in the melting point data of Table 1, the melting point of Sn0.5Cu0.06Ni0.005P is 233 ° C, and the melting point of Sn0.5Cu0.005P containing 0.5% by weight of Cu, 0.005% by weight of P and Sn as the remainder is The melting point of Sn 0.5 Cu, which is 231 ° C. and 0.5% by weight of Cu, 0.005% by weight of P, and Sn, is 230 ° C.

In addition, the melting point of the Sn 0.5 Cu 0.06 Ni 0.005P 0.1% by weight of Si rises slightly to 237 ℃.

In addition, the melting point slightly increased to 236 ° C. when 0.01 wt% of Co was included in Sn 0.5 Cu 0.06 Ni 0.005 P 0.05 Si. From the above results, when a small amount of Si having a high melting point of 1400 ° C. or higher is added to the low melting point Sn alloy in the state of metal alloy state, the melting point increases rapidly, but the melting point rise is insignificant compared to the amount of Si added. This is probably due to the surface of the molten solder.

Next, in order to measure the discoloration of the alloy composition, the color change data of Table 1 was made by depositing an oxygen-free copper (99.99%) of 25X31X0.3mm at 420 ° C for 3 seconds to make a specimen, and then heating the specimen at 250 ° C for 10 minutes. The degree of discoloration was measured using a chromatic aberration meter of the Minolta CM3700B model.

As shown in Table 1, the discoloration degree of Sn0.5Cu0.006Ni0.005P is 13.5, in comparison, the discoloration degree of Sn0.5Cu0.005P is 14.71, and the discoloration degree of Sn0.5Cu is 15.81.

And, when the Sn0.5Cu0.006Ni0.005P containing 0.005% by weight of Si, the discoloration degree is 12.7, when including 0.05% by weight of Si, the discoloration is significantly reduced to 11.3, Sn0.5Cu and Sn0.5Cu0. It can be seen that the decrease compared to the degree of discoloration of 005P.

In the case of including 0.005% by weight of Co in Sn0.5Cu0.006Ni0.005P0.005Si, the degree of discoloration is 8.33, and the degree of discoloration is 4 when Sn0.5Cu0.006Ni0.005P0.05Si is included in 0.01% by weight of Co. It can be seen that the decrease significantly.

Therefore, when a small amount of Si is added to the Sn-Cu-P-Ni master alloy, it is confirmed that the discoloration is reduced, and when the Si and Co are added in small amounts at the same time, the discoloration is greatly reduced.

Next, the bond breaking load (kgf) data of Table 1 is a tensile tester after making a specimen by vertically inserting a wire of 2mm diameter plated with tin-bismuth into the hole of the PCB substrate to measure the bond breaking load. The bond breaking load (kgf) was measured.

As shown in Table 1, Sn0.5Cu0.006Ni0.005P has a bond breaking load of 85kgf, compared with Sn0.5Cu0.005P, a bond breaking load of 87kgf and Sn0.5Cu of a bond breaking load of 83kgf.

In addition, when the Sn0.5Cu0.006Ni0.005P contains 0.005% by weight of Si, the bond breaking load is 90kgf, and when Si 0.05% by weight, the Sn0.5Cu0.006Ni0.005P is significantly improved to 96kgf, the Sn0.5Cu and Sn0 It can be seen that it is improved compared to the junction break load of .5Cu0.005P.

In addition, in case of including 0.005% by weight of Co in Sn0.5Cu0.006Ni0.005P0.005Si, the bond breaking load is 93kgf. It can be seen that the significantly improved to 99kgf.

Therefore, when a small amount of Si is added to the Sn-Cu-P-Ni master alloy, it can be confirmed that the bond breaking load is improved. When Si and Co are added in small amounts at the same time, the bond breaking strength is significantly improved.

As described above, the lead-free solder composition for wave and dipping according to the present invention maintains the conventional lead-free soldering temperature and wettability by adding a small amount of Si to the Sn-Cu-P-Ni master alloy, and the amount of oxide generation is continuously maintained. Decreases, copper erosion decreases, discoloration decreases, and bond breaking strength increases.

In addition, when a small amount of Co is added to the Sn-Cu-P-Ni master alloy containing a small amount of Si, the amount of oxides is continuously reduced, copper erosion is reduced and discoloration degree is reduced. Reduced, and the junction break load is increased.

However, in the case of containing a large amount of Si, that is, containing 0.05% by weight or more, the melting point is slightly increased, and considering the inferior wettability to the joined object, the optimum content of Si is less than 0.001 to 0.05% by weight. to be.

In addition, when Co is contained in a large amount, that is, when it is contained in 0.01 weight% or more, wettability is inferior. In addition, with a small amount of 0.05% by weight of Si, even when the addition of a very small amount shows excellent effects, the optimum content of Co is 0.001 to less than 0.01% by weight.

In addition, Cu (copper) in the Sn-Cu-P-Ni master alloy lowers the melting point slightly, improves the bonding strength of the bonded body, the addition of less than 0.1% by weight is less effective and the addition of more than 2% by weight As it is raised, the optimum content of copper is 0.1 to 2% by weight, and the nickel is alloyed to increase the strength and toughness of the solder itself, not only to prevent erosion, but also to suppress oxide generation and to promote intermetallic compound growth on the joint surface. The optimum content for this is 0.001 to 1.0% by weight. This is because the melting point increases as the nickel content increases, and the wettability and spreading rate decrease. The phosphorus is for improving the work of soldering by suppressing the formation of oxide during soldering, and has an optimum content of 0.001 to 0.2% by weight. Sn (tin) is used as the base metal as an essential component of lead-free solders.

In addition, the lead-free solder composition for wave and dipping according to the present invention can be used in the form of Bar, Wire, and is implemented as an electronic device including a plurality of electronic components are fixed by the lead-free solder alloy. The electronic device is applied to various products such as a computer, a digital video camcorder, a digital television, a digital camera, a mobile communication terminal, and the like.

In addition, the present invention is a printed circuit board bonded by a lead-free solder alloy, copper 0.1 ~ 2% by weight, nickel 0.001 ~ 1.0% by weight, silicon 0.001 ~ less than 0.05% by weight, cobalt 0.001 ~ less than 0.01% by weight, phosphorus 0.001 ~ It is implemented as a printed circuit board containing 0.2% by weight, and tin as the remainder.

The present invention described above is not limited to the above-described embodiments, and various permutations, modifications, and changes can be made without departing from the technical spirit of the present invention. It will be obvious to him.

As described above, the present invention has mechanical properties and workability comparable to those of Sn-Pb and Sn-Cu-P-Ni solders, and does not include Pb, but also include tin (Sn), copper (Cu), And by containing silicon (Si) and cobalt (Co) in a ternary composition made of nickel (Ni), it is possible to continuously and effectively prevent oxidation of the molten solder, and in spite of adding an extremely small amount of element, Provides lead-free solder compositions for wave and dipping that can improve solderability, such as preventing discoloration and wettability after soldering, and preventing copper pad erosion of printed circuit boards while maintaining soldering temperature and wettability, and electronic devices and printed circuit boards using the same. Has the effect.

Claims (7)

Lead-free solder composition for wave and dipping comprising 0.5 to 2% by weight of copper, 0.001 to 1.0% by weight of nickel, 0.001 to 0.2% by weight of less than 0.001 to 0.05% of silicon, 0.001 to 0.01% by weight of cobalt and tin. delete An electronic device comprising a plurality of electronic components fixed by a lead-free solder composition for wave and dipping, The lead-free solder composition for wave and dipping is copper 0.5-2% by weight, nickel 0.001-1.0% by weight, silicon 0.001-0.05% by weight, phosphorus 0.001-0.2% by weight, cobalt 0.001-0.01% by weight and tin Containing Electronics. delete The method of claim 3, The electronic device is one of a computer, a digital video camcorder, a digital television, a digital camera, and a mobile communication terminal. Electronics. A printed circuit board fixed by a lead-free solder composition for wave and dipping, The lead-free solder composition for wave and dipping is copper 0.5-2% by weight, nickel 0.001-1.0% by weight, silicon 0.001-0.05% by weight, phosphorus 0.001-0.2% by weight, cobalt 0.001-0.01% by weight and tin Containing Printed circuit board. delete

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