JPH1093004A - Electronic component and method of manufacturing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic component and manufacture thereof, enabling the forming of a metal layer having good solderability, contg. no Pb, and having high mechanical strength and high bond reliability on electrode leads for external connections. SOLUTION: On electrode leads 5 for external connections, a metal layer 6 of an Sn alloy contg. Bi 4-15wt.% and Ag plus Cu 5wt.% or less is formed by the electroplating at a current density of 1.5A/dm<2> after forming an Ni or Cu base layer on the leads 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronic component such as a semiconductor device having an electrode lead wire for external connection which does not contain Pb, and a method of manufacturing the same.

[0002]

2. Description of the Related Art A lead-tin (Pb-Sn) -based solder layer is attached to electrode lead wires for external connection in a conventional semiconductor device in advance so that the semiconductor device can be easily mounted on a printed circuit board or a circuit board. Could be attached (soldered). Therefore, most semiconductor devices have
The portion of the external connection electrode lead wire contained Pb.
The Pb-Sn-based solder layer was formed by plating or dipping.

[0003] In recent years, a semiconductor device that does not require Pb and does not need to be soldered after assembling by previously attaching palladium (Pd), which is an easily solderable metal, to a lead frame has been introduced. (Eg, Nikkei Electronics no. 622, p17, 19)
94).

[0004]

SUMMARY OF THE INVENTION The present invention is intended to realize electronic parts such as semiconductor devices which eliminate Pb (Pb is reduced to an appropriate level in terms of environmental measures). The formed Pb-Sn based solder is replaced with P
does not contain b (Pb is reduced below the impurity level of the material)
An object of the present invention is to provide an electronic component that can be firmly soldered to a printed board or a circuit board when replaced with a metal layer, and that can obtain high reliability, and a method for manufacturing the same.

Another object of the present invention is to provide an electronic component which can be easily soldered and a method for manufacturing the same. Still another object of the present invention is to provide an electronic component with less change over time and a method for manufacturing the same.

[0006]

According to the electronic component of the present invention, Sn (mainly serving as an adhesive) replaces the conventional Pb-Sn-based solder as the outermost layer metal adhered to the external connection electrode lead wire. Sn-Bi mixed with bismuth (Bi) as a metal for lowering its melting point.
A system alloy was adopted. Further, Ag and Cu were selected as additive metals for facilitating soldering of the external connection electrode lead wires. That is, in the present invention, Ag and Cu are added as the outermost layer metal of the electrode lead wire for external connection of the electronic component using a Sn-Bi alloy. Note that Ag and C
With respect to u, either one of them may be added, or both may be added, or u may not be added. When added, Ag is more effective than Cu at the same amount.

The reason why the addition of Ag or Cu facilitates soldering is that Ag or Cu is easily dissolved in Sn. That is, Ag and Cu on this side (lead wire side) are easily dissolved in Sn in the solder paste at the time of soldering, and soldering is facilitated. Here, the content of Bi is set to 4 to 15% by weight. When the content is less than 4% by weight, the melting point is high (225 ° C.), and the temperature at the time of soldering to a printed circuit board or a circuit board is increased (260). C. or higher), making soldering difficult. If it exceeds 15% by weight, the mechanical strength of the alloy is significantly reduced. The Bi content is related to the reliability of the solder joint, and in order to solve this, for example, a total of 1 to 4% by weight of Ag or 1% by weight of Cu is used.
At least one of Ag and Cu was added within a range of 5% by weight. Also, for example, 1 to 5% by weight of Ag is added,
Cu may be 0% by weight, or 1 to 5% by weight of Cu may be added to make 0% by weight of Ag. As a combination when the total of Ag and Cu is 5% by weight, for example, Ag: 5% -Cu: 0%, Ag: 4.5%
-Cu: 0.5%, Ag: 4.0% -Cu: 1.0%,
‥‥‥, Ag: 0.5% -Cu: 4.5%, Ag: 0%
-Cu: 5% or the like is conceivable, but if the total amount of addition is the same, increasing the Ag is more effective, and the combination of Ag in the range of 5 to 3% by weight and Cu of 0 to 2% by weight is the best. is there.

When the addition amount of Ag and Cu is set to 5% by weight or less, if the addition amount exceeds 5% by weight, precipitation is accelerated, and the surface becomes rough due to unevenness, and an electrical short failure occurs due to a migration phenomenon. This is because the effect of improving soldering becomes weaker. Here, the relationship between the reliability of the solder joint and the contents of Ag and Cu will be described. If the added amount of Bi is 4% or less, the oxidation of Sn proceeds remarkably, making it difficult to solder and lowering the reliability of the connection. Although the oxidation of Sn occurs to some extent even when the added amount of Bi is larger than that, when Ag and Cu are added at this time, soldering is easy because Ag and Cu are easily dissolved in Sn as described above. And reliability can be improved by reliably performing the soldering connection. In addition,
If the content of Bi exceeds 15% by weight, as described above, the mechanical strength decreases and the reliability of the soldered connection decreases. Therefore, the content of Bi is appropriately 4 to 15% by weight.

The electrode lead wire for external connection is made of Sn-B.
When the metal layer of i is formed by the dipping method (immersion method), the metal layer is easily oxidized at the time of adhesion formation.
And Cu are preferably added. However, when a metal layer is formed by electroplating, electroless plating, or the like, oxidation of the metal layer during adhesion formation is small, and addition of Ag and Cu may not be performed. . However, it is conceivable that oxidation may occur during connection with the substrate in a process that is left for a long time or in a subsequent process.
u is preferably added.

In addition, when forming on the electrode lead wire for external connection, not only does it adhere as a single alloy layer,
A metal layer having a multilayer structure such as a simple substance or an alloy of n, Bi, Ag, and Cu may be used. In this case, the metal layers are melted and mixed at the time of soldering the external connection electrode lead wires, so that a uniform composition is obtained. Before the metal layer is attached to the external connection electrode lead, Cu
Alternatively, by forming a base metal layer of Ni or the like and attaching and forming a metal layer on the base metal layer, it is possible to achieve a junction with little change with time. In other words, below the underlying metal layer (Ni or Cu) is generally an Fe / Ni alloy or Cu. This Fe / Ni alloy or Cu
During the process, the metal layer is deteriorated (formation or oxidation of the compound), the adhesion of the metal layer is deteriorated, and cracks may be generated in the joints due to aging, which may lead to disconnection. Such a problem can be avoided if a base metal layer is provided in advance.

[0011] Further, as a manufacturing method, the metal layer is electroplated under a condition of a current density of 1.5 A / dm ² or less to reduce the particle diameter of the particles constituting the metal layer adhered to the external connection electrode lead wire. As a result, the external connection electrode lead wire can be easily soldered. The above is summarized as follows. That is,
The present invention is based on the fact that a metal layer containing 4 to 15% by weight of Bi in Sn as an outermost metal layer is attached to an electrode lead wire for external connection, that is, covered. And
The metal layer containing 4 to 15% by weight of Bi in Sn further contains Ag in the range of 1 to 5% by weight, or Cu in the range of 1 to 5% by weight, or 1 to 5% in total. The invention containing Ag and Cu in the range of% is defined as the applied invention. In the above, the range is set to 1 to 5% by weight.
Ag or Cu or both of them may be contained in a range of not more than% by weight. In other words, the lower limit is set to 1% by weight in the sense that 0% by weight is excluded. However, even if the lower limit is less than 1% by weight, the effect can be obtained by the amount corresponding to the content.
It may be 0 to 5% by weight provided that 0% by weight is excluded.

Here, the action of the addition of Ag and Cu will be described. The structure of Ag + Cu solves the following three problems of Sn oxidation progress (in the order of steps) and the four problems of solderability after Sn oxidation. A: At the time of forming a coating layer A1: Dipping method (Sn is easily oxidized because it is immersed in a molten material) To prevent oxidation of Sn at this time, A
It is preferable to contain g + Cu at 5% by weight or less. Ag and C
u may be alone. The effect of preventing oxidation is higher for Ag if the amount is the same.

A2: Electroplating method (Sn is less oxidized) It is desirable that Ag + Cu be contained in consideration of a post-process. B: From the time the lead is manufactured until it is actually used,
In a test at 85 ° C. for 16 hours, which is equivalent to one year's worth of daily life in Japan, oxidation of Sn in the lead coating layer is observed for being left for about one year in a long case. To prevent its oxidation, Ag + C
It is preferable to contain 5% by weight or less of u. Ag and Cu are
Can be alone. In addition, the effect of oxidation prevention is as follows if the amount is the same.
g is higher.

C: Problems when soldering electronic components to a board or the like C1: The solder paste and Sn of the lead coating layer are oxidized.
To prevent the oxidation, it is preferable that Ag + Cu contains 5% by weight or less. Ag and Cu may be used alone. The effect of preventing oxidation is higher for Ag if the amount is the same. C2: If Sn is oxidized, it is difficult to solder the electronic component with a solder paste, and the reliability is reduced. As a solution, it is preferable to contain Ag + Cu at 5% by weight or less. Ag and Cu may be used alone.

Ag + Cu acts as follows. That is, Ag + Cu in the lead coating layer dissolves in Sn in the solder paste, and even if Sn is oxidized, soldering becomes easy, the adhesion strength between the lead, the substrate and the solder paste is high, and the reliability is improved. . As described above, Ag + C
Although the effect of u is finally as described in the section of C2, the effect of preventing oxidation in the steps of A1, B and C1 in the middle stage is also combined. In other words, A, B,
Prevention of oxidation of Sn in each item of C means that soldering is easy, so that the bonding strength between the lead, the substrate, and the solder paste is high, and the reliability is improved.

[0016]

Embodiments of the present invention will be described below with reference to the drawings. Electrode leads for external connection of electronic components such as semiconductor devices are soldered to a printed circuit board or a circuit board by a flow method or a reflow method.
Therefore, it is necessary to correspond to each of the metals attached to the electrode lead wires of the electronic component.

In the electronic component according to the first aspect of the present invention, 4 to 15 Bi of Sn is used as the outermost metal in the electrode lead wire for external connection.
It is characterized in that a metal layer containing by weight is deposited and formed. With this configuration, the electronic components can be easily attached to the printed circuit board or circuit board by soldering at a low temperature, and the metal layer can have sufficient mechanical strength to improve the reliability of the solder joint. Can be higher.

In the electronic component according to the second aspect of the present invention, the outermost metal lead may include 5 to 12 Bi of Sn as the outermost layer metal.
It is characterized in that a metal layer containing by weight is deposited and formed. With such a configuration, electronic components can be easily attached to a printed circuit board or a circuit board at a lower temperature by soldering, and the metal layer can have more sufficient mechanical strength, and the reliability of the solder joint can be improved. Can be enhanced.

A metal layer containing 6 to 10% by weight of Bi in Sn as an outermost layer metal is formed on the electrode lead wire for external connection according to the third aspect of the present invention. With such a configuration, electronic components can be easily attached to a printed circuit board or a circuit board at a lower temperature by soldering, and the metal layer can have more sufficient mechanical strength, so that a solder joint portion can be provided. Reliability can be increased.

In the electronic component according to the fourth aspect, Bi is added to Sn as the outermost layer metal in the electrode lead wire for external connection.
A metal layer containing 1 to 5% by weight of Ag and Cu in total is deposited and formed. With such a configuration, electronic components can be more easily attached to a printed circuit board or a circuit board by soldering at a low temperature, and the metal layer can have sufficient mechanical strength, and the reliability of the solder joint portion can be improved. Can be higher.

In the electronic component according to the fifth aspect, Bi is contained in Sn as the outermost layer metal in the electrode lead wire for external connection.
A metal layer containing 2 to 5% by weight of Ag and Cu in total is deposited and formed. With such a configuration, the electronic components can be more easily attached to the printed circuit board or the circuit board at a lower temperature by soldering, and the metal layer can have more sufficient mechanical strength, so that the solder joint portion can be formed. Reliability can be increased.

In the electronic component according to the sixth aspect of the present invention, the outermost metal lead may include 5 to 10 Bi of Sn as the outermost metal.
A metal layer containing 2 to 4.5% by weight of Ag and Cu in total is deposited and formed. With such a configuration, the electronic components can be more easily attached to the printed circuit board or the circuit board at a lower temperature by soldering, and the metal layer can have more sufficient mechanical strength, so that the soldering can be performed. The reliability of the part can be increased.

According to a seventh aspect of the present invention, in the electronic component, a metal layer having a multilayer structure of a single or alloy of Sn, Bi, Ag, and Cu is attached to the external connection electrode lead wire, and the entire composition of the metal layer is formed. At 4-15% by weight of Bi, Ag and Cu
Is 1 to 5% by weight, and the balance is Sn. With such a configuration, the metal layer of the multilayer structure is melted at the time of soldering the electrode lead wires for external connection of the electronic component to a circuit board or a printed board, and has a uniform composition,
The operation as described in claim 4 is achieved.

[0024] In the electronic component according to the present invention, a metal layer having a multilayer structure of a simple substance or an alloy of Sn, Bi, Ag and Cu is formed on the electrode lead wire for external connection by adhesion. With 5 to 12% by weight of Bi, Ag and Cu
Is 2 to 5% by weight, and the balance is Sn. With such a configuration, the metal layer of the multilayer structure is melted at the time of soldering the electrode lead wires for external connection of the electronic component to a circuit board or a printed board, and has a uniform composition,
The operation as described in claim 5 is provided.

According to a ninth aspect of the present invention, in the electronic component, a metal layer having a multilayer structure of a simple substance or an alloy of Sn, Bi, Ag, and Cu is formed on the external connection electrode lead wire. With 6 to 10% by weight of Bi, Ag and Cu
Is 2 to 4.5% by weight, and the balance is Sn. With such a configuration, the metal layer having a multilayer structure is melted at the time of soldering the electrode lead wires for external connection of the electronic component to a circuit board or a printed board, so that a uniform composition is obtained. It works like this.

An electronic component according to a tenth aspect is the first aspect.
2. The electronic component according to 2, 3, 4, 5, 6, 7, 8, or 9, wherein the metal layer attached to the external connection electrode lead wire is formed on a base metal layer made of Cu or Ni. Features. As described above, by forming the metal layer on the underlying metal layer made of Cu or Ni, it becomes possible to obtain a junction with little change over time.

[0027] According to a eleventh aspect of the invention, there is provided a method of manufacturing an electronic component.
An electronic component manufacturing method for manufacturing an electronic component according to claim 1, 2, 3, 4, 5, 6, 7, 8, or 9, wherein a current density is 1.5 A / dm ² or less. The method is characterized in that a metal layer is deposited and formed by a method. According to this method, the particle diameter adhering to the external connection electrode lead wire can be reduced, and the external connection electrode lead wire can be easily attached to a circuit board or a printed board by soldering.

FIG. 1 is a sectional view of an external connection electrode lead wire of a semiconductor device which is one of electronic components. In the drawing, 1 is a semiconductor element, 2 is a metal wire, 3 is a die bonding agent, 4 is a molding resin, 5 is an electrode lead wire for external connection, 6 is a metal for facilitating attachment to a printed circuit board or a circuit board. Show layers. Hereinafter, a description will be given with some embodiments.

[0029]

【Example】

 [Example 1] A semiconductor element was mounted on a copper lead frame.
Is bonded, wiring to external electrodes is performed, and
And electrode lead wires of semiconductor devices after lead processing
After forming an underlying Ni plating film having a thickness of 1 to 3 μm,
Current density of 1.0 A / dm on top ^TwoContaining 10% by weight of Bi
A Sn—Bi alloy film was formed to a thickness of 10 μm.

Example 2 A 1-2 μm underlayer Cu plating film was formed on an iron-nickel electrode lead wire which had been subjected to resin encapsulation and lead processing in the same manner as described above. A 4 wt% Sn-Bi alloy film of dm ² and Bi was deposited to a thickness of 12 μm. Example 3 A copper-based electrode lead wire that has been subjected to resin encapsulation and lead processing in the same manner as described above was used to form a base Ni film, and then heated to 280 ° C. by Sn-Bi-Ag.
(85-10-5% by weight), and a metal layer was deposited to a thickness of 20 μm.

Embodiment 4 First, Sn-Bi (80-20% by weight) having a thickness of 10 μm is formed by plating on an electrode lead made of a copper material which has been subjected to resin sealing and lead processing in the same manner as described above. And then heated to 280 ° C.
-Dipped in Ag (96-4% by weight). The composition of the metal layer on the electrode lead wire is Sn-Bi-Ag (85-11).
-4% by weight).

FIG. 2 shows the measurement results of the change of the relative bonding strength and the change of the melting point of the Sn—Bi alloy due to the change of the Bi content (% by weight) in the Sn—Bi alloy.
In the figure, the Bi content (% by weight) is plotted on the horizontal axis, the relative bonding strength (kg) is plotted on the left side of the vertical axis, and the melting point (° C.) is plotted on the right side of the vertical axis. In the figure, the curve with a white circle is
It is a curve showing the relationship between the Bi content (% by weight) and the relative bonding strength (kg), and the curve with a black circle is the curve showing the relationship between the Bi content (% by weight) and the melting point (° C.). , Bi
When the content (% by weight) of Ni is less than 4%, the melting point sharply rises, and when the content (% by weight) of Bi exceeds 15%, the relative bonding strength decreases sharply. Recognize.

Further, the reason why the current density is set to 1.5 A / dm ² or less in the electroplating is because the particle size changes depending on the current density, and the solderability deteriorates. In other words, when the current density is large, the particle diameter increases, and the solderability deteriorates. FIG. 3 shows the solderability (the relationship between the zero cross time and the current density) by a meniscograph. In the figure, when the current density exceeds 1.5 A / dm ² , the zero cross time exceeds about 3 seconds, which indicates that a soldering failure occurs. The zero-clock time in a meniscograph refers to the following time. That is, when the sample piece is inserted into the molten solder bath, the solder surface around the sample piece temporarily drops, but after a certain period of time, the sample piece and the solder blend together and the solder surface returns along the surface of the sample piece. Will rise above the height of
At this time, the time from the insertion of the sample piece until the solder surface returns to the original height is referred to as zero black time.

According to the embodiment of the present invention, it is possible to provide an electronic component having an external connection electrode lead wire that does not use lead. In addition, the adhesion and formation of the external connection electrode lead wire is made of Sn-Bi with little deterioration due to thermal fatigue.
It becomes an alloy solder and can be a highly reliable solder.
Table 1 shows, as examples of the present invention, electrode lead wires for external connection of Examples 1 to 4 and, as a conventional example, Pb-Sn solder (40 to 60% by weight) for external connection formed by plating or dipping. The electrode lead wire is connected by the flow method (Sn
-Bi solder, 80-20% by weight) and reflow method (S
n-Bi-Ag solder, manufactured by Tanaka Kikinzoku Co., Ltd. (trade name: Alloy H: composition Sn-90%, Bi-7.5%, Ag-
(2%, Cu-0.5%) showed a change in the adhesive strength due to the thermal shock cycle when bonded to the printed circuit board (thermal shock: -55 ° C. →→ 150 ° C., 30 minutes each). The reason why the Sn-Bi solder (80-20% by weight) was used in the flow method was that the working temperature (230 ° C.
(240 ° C.).

[0035]

[Table 1]

As can be seen from Table 1, in the conventional example, 300
Although a defect occurred by one thermal shock cycle, in this example, no defective product was generated even when the thermal shock cycle was repeated the same number of times. Therefore, it is clear that the reliability of the electronic component obtained by the present invention is high.

[0037]

According to the electronic component according to the first aspect, the electronic component can be easily attached to a printed board or a circuit board at a low temperature by soldering, and the metal layer has sufficient mechanical strength. Therefore, there is little deterioration with respect to thermal fatigue, and the reliability of the solder joint can be increased.

According to the electronic component of the second aspect, the electronic component can be easily attached to a printed board or a circuit board at a lower temperature by soldering.
The metal layer can be provided with more sufficient mechanical strength, less deteriorated against thermal fatigue, and the reliability of the solder joint can be increased. According to the electronic component according to the third aspect, the electronic component can be easily attached to a printed board or a circuit board at a still lower temperature by soldering, and the metal layer can have more sufficient mechanical strength. Thus, there is little deterioration with respect to thermal fatigue, and the reliability of the solder joint can be increased.

According to the electronic component of the fourth aspect, the electronic component can be more easily attached to a printed board or a circuit board by soldering at a low temperature, and the metal layer can have sufficient mechanical strength. Thus, there is little deterioration with respect to thermal fatigue, and the reliability of the solder joint can be increased. According to the electronic component of the fifth aspect,
At lower temperatures, electronic components can be more easily attached to printed circuit boards and circuit boards by soldering, and the metal layer can have more sufficient mechanical strength, with less deterioration against thermal fatigue. The reliability of the solder joint can be increased.

According to the electronic component according to the sixth aspect, the electronic component can be more easily attached to the printed board or the circuit board by soldering at a still lower temperature, and the mechanical strength is further enhanced to the metal layer. , And less deterioration with respect to thermal fatigue, so that the reliability of the solder joint can be increased. According to the electronic component according to the seventh aspect, the electronic component can be more easily attached to a printed board or a circuit board by soldering at a low temperature, and the metal layer can have sufficient mechanical strength. There is little deterioration with respect to fatigue, and the reliability of the solder joint can be increased.

According to the electronic component of the eighth aspect, the electronic component can be more easily attached to a printed board or a circuit board by soldering at a lower temperature, and the metal layer has more sufficient mechanical strength. Therefore, there is little deterioration with respect to thermal fatigue, and the reliability of the solder joint can be increased. According to the electronic component according to the ninth aspect, the electronic component can be more easily attached to a printed circuit board or a circuit board at a lower temperature by soldering, and the metal layer has more sufficient mechanical strength. Therefore, there is little deterioration with respect to thermal fatigue, and the reliability of the solder joint can be increased.

According to the electronic component of the tenth aspect, it is possible to obtain a junction with little change with time. Claim 11
According to the method for manufacturing an electronic component described above, the particle diameter attached to the external connection electrode lead can be reduced, and the external connection electrode lead can be easily attached to a circuit board or a printed board by soldering. it can.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an external connection electrode lead wire of a semiconductor device according to an embodiment of the present invention.

FIG. 2 is a characteristic diagram showing a relationship between a Bi content in a Sn—Bi alloy, a bonding strength, and a melting point.

FIG. 3 is a characteristic diagram showing a relationship between solderability (zero crossing time in a meniscograph test) and current density during plating.

[Explanation of symbols]

 Reference Signs List 1 semiconductor layer element 2 metal wire 3 die bonding material 4 resin for molding and sealing 5 electrode lead wire for external connection 6 metal layer

Continuation of front page (72) Inventor Ryoji Sawada 1-1, Sachimachi, Takatsuki-shi, Osaka Matsushita Electronics Corporation

Claims (11)

[Claims] 1. An electronic component, wherein a metal layer containing 4 to 15% by weight of Bi in Sn as an outermost layer metal is formed on an electrode lead wire for external connection. 2. An electronic component, wherein a metal layer containing 5 to 12% by weight of Bi in Sn as an outermost layer metal is formed on an electrode lead wire for external connection. 3. An electronic component, wherein a metal layer containing 6 to 10% by weight of Bi in Sn as an outermost layer metal is attached to an electrode lead wire for external connection. 4. A metal layer containing 4 to 15% by weight of Bi and a total of 1 to 5% by weight of Ag and Cu in Sn as an outermost layer metal on an electrode lead wire for external connection. And electronic components. 5. An electrode lead wire for external connection, wherein a metal layer containing 5 to 12% by weight of Bi in Sn and 2 to 5% by weight of Ag and Cu in total as an outermost layer metal is adhered and formed. And electronic components. 6. A metal layer containing Sn as an outermost layer metal containing 5 to 10% by weight of Bi and a total of 2 to 4.5% by weight of Ag and Cu as an outermost layer metal. Electronic components characterized by the following. 7. An electrode lead wire for external connection, wherein Sn, B
A metal layer having a multilayer structure of a simple substance or an alloy of i, Ag, and Cu is adhered and formed.
i is 4 to 15% by weight, and the total of Ag and Cu is 1 to 5% by weight
Wherein the balance is Sn. 8. An electrode lead wire for external connection, wherein Sn, B
A metal layer having a multilayer structure of a simple substance or an alloy of i, Ag, and Cu is adhered and formed.
i is 5 to 12% by weight, and the total of Ag and Cu is 2 to 5% by weight
Wherein the balance is Sn. 9. An external connection electrode lead wire comprising Sn, B
A metal layer having a multilayer structure of a simple substance or an alloy of i, Ag, and Cu is adhered and formed.
An electronic component, wherein i is 6 to 10% by weight, the total of Ag and Cu is 2 to 4.5% by weight, and the balance is Sn. 10. The method according to claim 1, wherein the metal layer attached to the external connection electrode lead wire is formed on a base metal layer made of Cu or Ni.
The electronic component according to 5, 6, 7, 8 or 9. 11. The method of claim 1, 2, 3, 4, 5, 6, 7,
10. A method for manufacturing an electronic component according to 8 or 9, wherein the metal layer is formed by an electroplating method at a current density of 1.5 A / dm ² or less. Manufacturing method.