JP2002076565A - Electronic component and mounted body thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve connection reliability between an electronic component and a conductive adhesive. SOLUTION: An electronic component comprises a lead terminal 4a and an external connection electrode 4b which is provided at the lead terminal 4a, electrically connected to a mounted member 1 through a conductive adhesive 3. Here, a connection surface 4c of the external connection electrode 4b comprises silver and copper, an electrode surface roughness R3 is 0.1 μm or more but less than 10 μm, the connection surface 4c is roughened, or through holes 10a-10e are formed. Thus, compared to a conventional electronic component, the connection reliability and adhesive strength to the conductive adhesive are significantly improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an external connection electrode electrically connected to a mounted member via a conductive adhesive,
The present invention relates to an electronic component having this external connection electrode and a lead terminal provided on the tip end side, and a packaged body thereof.

[0002]

2. Description of the Related Art Recently, awareness of environmental issues has increased,
In the field of electronics mounting, regulations on lead in solder alloys are about to be enforced, and there is an urgent need to establish a joining technology that does not use lead for mounting electronic components. Lead-free mounting technology mainly includes lead-free solder and conductive adhesives, but conductive adhesives that are expected to have advantages such as flexibility of joints and lower mounting temperature are
More attention.

A conventional conductive adhesive generally has a conductive filler dispersed in a resin-based adhesive component, and a connection between a connection terminal of an electronic component and a circuit board with the conductive adhesive interposed therebetween. After the connection with the terminal, the conductive adhesive is cured, and the conductive filler is brought into contact with each other to ensure conduction at the connection portion. Therefore, since the connection portion is bonded with resin, it can flexibly respond to deformation due to heat or external force, and has a merit that cracks are less likely to occur in the connection portion compared to solder in which the connection portion is an alloy. Therefore, it is expected as a substitute material for solder.

[0004]

However, when an electronic component having a solder plating electrode, which is currently generally supplied, is mounted on a circuit board by using a conductive adhesive, a sufficient adhesive strength cannot be obtained. There was a case that it could not be applied to the mounting form.

Although electronic components having tin-plated electrodes have been supplied along with the recent trend toward lead-free, the adhesive strength of the conductive adhesive to tin-plated electrodes is considerably lower than that of conventional solder connections. Has become.

[0006] As a result of examining the destruction modes in these cases, it was found that peeling occurred at the interface between the conductive adhesive and the solder and tin-plated electrodes. That is, most of the external electrode surfaces of currently supplied electronic components are smoothed so as to be suitable for solder connection. Therefore, when using the current conductive adhesive,
In many cases, sufficient adhesion strength between the solder and the tin-plated electrode cannot be obtained.

As described above, when an electronic component having a solder and a tin-plated electrode is mounted on a circuit board using a conductive adhesive instead of the solder, sufficient adhesive strength cannot be obtained.
In many cases, a conductive adhesive cannot be used as a solder substitute.

Further, when an electronic component having solder and tin-plated electrodes is mounted on a circuit board using a conductive adhesive, there is a danger that the electrical connection resistance increases and hinders the normal operation of the electronic device. there were. Specifically, in long-term use, a phenomenon occurs in which an insulating oxide grows on the surface of the solder and tin-plated electrodes and hinders conduction between the conductive adhesive and the electrodes. This phenomenon is particularly remarkable in a high-temperature and high-humidity environment.

[0009] The problem in the technique of connecting electronic components with the conductive adhesive described above is, in particular, an electronic component having an external connection electrode provided at the tip of a lead terminal, particularly, for example, a lead terminal such as a semiconductor package QFP or a connector component. It was remarkable in electronic components. Hereinafter, the reason will be described.

In order to achieve good electrical connection when an electronic component having solder and tin-plated electrodes is connected to a circuit board or the like using a conductive adhesive, a surface formed on the external connection electrode is required. It is better that the oxide layer is broken by silver filler or the like in the conductive adhesive so that the electrode metal and the silver filler are in direct contact.

However, in the case of an electronic component having a lead terminal, when the component is mounted on a conductive adhesive formed on an electrode of a circuit board by a mounting machine or the like, an external component is set in accordance with the setting of pushing of the mounting machine. It is inevitable that the connection electrode causes a springback phenomenon based on elastic deformation. However, when such a springback phenomenon occurs, a failure occurs in the contact state between the external connection electrode and the conductive adhesive when the electronic component is released from the mounting machine, and the contact between the electrode metal and the silver filler occurs. It is difficult to maintain direct contact.

Accordingly, the present invention provides an electronic component using a conductive adhesive instead of solder and a package thereof, particularly an electronic component having lead terminals and a package thereof, to provide a sufficiently low connection resistance and connection strength for a long period of time. The purpose is to gain.

[0013]

In order to solve the above-mentioned problems, the present invention provides a lead terminal and the lead terminal, which is electrically connected to a mounted member via a conductive adhesive. An electronic component having an external connection electrode, wherein the surface portion of the external connection electrode that comes into contact with the conductive adhesive is silver, copper, or an alloy containing these metals as a main component,
Alternatively, it is composed of a mixture of these metals.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The invention according to claim 1 of the present invention provides a lead terminal and an external connection provided on the lead terminal and electrically connected to a mounted member via a conductive adhesive. An electronic component having an electrode, wherein a surface portion of the external connection electrode that is in contact with a conductive adhesive is silver,
It is characterized by being made of copper, an alloy containing these metals as a main component, or a mixture of these metals, thereby having the following effects.

That is, silver, copper, and alloys or mixtures of these metals are less likely to be oxidized than solder and tin, and are less expensive than gold, platinum, palladium and the like. Therefore, it is suitable for the electrode surface material of the present invention.

By using such an electronic component having an electrode surface specification, the connection resistance with the conductive adhesive becomes low and stable for a long time.

By using such an electronic component whose external connection electrode surface is roughened or roughened, the connection resistance with the conductive adhesive is low and stable, and the bonding strength is improved. A degree of connection is obtained.

According to a second aspect of the present invention, there is provided the electronic component according to the first aspect, wherein a surface portion of the external connection electrode in contact with the conductive adhesive is coated with an organic protection film. In particular, it has the following effects.

That is, silver and copper or an alloy or a mixture containing the metal as a main component are hardly oxidized as compared with solder and tin, but are slightly inferior in durability as compared with gold, so that the manufactured electronic parts can be used. In the case of storage for a long period of time, especially when stored in a high-humidity environment, oxidation proceeds slowly but gradually. When an organic protective film is formed, such a phenomenon can be suppressed to a level that does not pose a practical problem when connecting with a conductive adhesive.

According to a third aspect of the present invention, there is provided the electronic component according to the first aspect, wherein a surface portion of the external connection electrode that is in contact with the conductive adhesive is processed into an uneven shape. Which has the following effect.

That is, by processing the surface portion of the external connection electrode which is in contact with the conductive adhesive into an uneven shape, the bonding strength when mounting on the circuit board via the conductive adhesive is increased.

According to a fourth aspect of the present invention, there is provided the electronic component according to the first aspect, wherein the external connection electrode in contact with the conductive adhesive has a surface roughness R ₃ of 0.1 μm or more.
It is characterized in that it is set to less than μm, and thereby has the following effects.

That is, by setting the surface roughness of the uneven shape in this way, the bonding strength when mounting the member to the mounting member via the conductive adhesive is further increased.

According to a fifth aspect of the present invention, there is provided the electronic component according to the first aspect, wherein an external connection electrode forming portion of the lead terminal is provided along a direction substantially orthogonal to a connection surface of the external connection electrode. This is characterized in that the through hole is formed, and thereby has the following operation.

That is, by forming the through-hole, the electronic component is mounted on the member to be mounted in a state where the conductive adhesive fills or overflows the through-hole. Since the connection electrode is fixed to the mounted member (so-called anchor effect is generated), the bonding strength is further increased.

According to a sixth aspect of the present invention, in the electronic component according to the fifth aspect, the through hole has a shape whose diameter varies along an axial direction, and The diameter variation shape is characterized in that, at least in part thereof, the diameter on the side opposite to the axial direction of the hole is larger than the connection surface side of the external connection electrode, whereby the following It has such an effect.

That is, in the inside of the through hole, the region having a larger diameter than the region in the other hole is arranged above the connection surface side of the external connection electrode, that is, on the side away from the connection surface side. Become. Therefore, when the conductive adhesive is filled in the through-hole having such a shape, the conductive adhesive filled in the large-diameter region acts as a stopper to further increase the bonding strength. .

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

(Embodiment 1) FIGS. 1A and 1B show an electronic component mounted body according to Embodiment 1 of the present invention, and FIGS. 1A and 1B show lead terminals 4a. A QFP (Quad Flat Package) type semiconductor element (hereinafter, referred to as a QFP element) 5 having a tip of a lead terminal 4 a as an external connection electrode 4 b is connected to a connection electrode portion of the circuit board 1 via a conductive adhesive 3. 2 shows a state electrically connected.

In this embodiment, in the present embodiment, at least the conductive adhesive 3 on the surface of the external connection electrode 4b is provided.
(In this embodiment, the external connection electrode 4
b) was processed as follows. The electrode form is made of copper as the base material of the lead terminal 4a (see FIG. 1A). A silver plating layer 6A is formed on the surface of the external connection electrode 4b made of copper.
Is formed (see FIG. 1B). A conductive adhesive layer 6B formed by applying and drying a conductive adhesive containing silver filler is formed on the surface of the external connection electrode 4b made of copper (see FIG. 1B). A silver sintered layer 6C formed by applying and firing a sintered silver paste is formed on the surface of the external connection electrode 4b made of copper (FIG. 1).
(B)).

For comparison with the present embodiment, the surface of the external connection electrode 4b was processed as follows in the prior art. A solder plating layer is formed on the surface of the external connection electrode 4b.

The above five types of QFP elements 5 are manufactured,
The connection resistance was measured. That is, the prepared QFP element 5 was mounted on the circuit board 1 as a mounting member using the conductive adhesive 3 and cured in an oven at 150 ° C./1 hour. Then, each Q produced in this way
After the mounted body of the FP element 5 was put into a high-temperature and high-humidity environment test furnace at 85 ° C. and 85 RH, the electric resistance was measured. The results are shown in Table 1.

In this measurement, as the conductive adhesive 3, an epoxy resin-based conductive adhesive containing 80% by volume of silver filler was used. Further, a circuit board 1 made of glass epoxy is used as a mounting member on which the QFP element 5 is mounted.
As a copper electrode.

[0034]

[Table 1] As shown in Table 1, the surface specification of the external connection electrode 4b of the QFP element 5 according to the present embodiment is copper as is (the above configuration), silver-plated (the above configuration), and conductive containing silver filler. In the case where the adhesive was applied and dried (the above configuration) and the case where the sintered silver paste was applied and fired (the above configuration), the connection resistance hardly changed even after the high temperature and high humidity environment test. On the other hand, in the case of the prior art in which the surface of the external connection electrode 4b is solder-plated (the above configuration), the connection resistance is increased by about two digits as compared with the product of the present embodiment, and the advantage of the present invention is as follows. It is obvious.

(Embodiment 2) In this embodiment, FIG.
As shown in FIG. 5, in addition to the configuration of the first embodiment,
Organic protection film 7 on the surface of external connection electrode 4b of FP element 5
It is characterized by having formed.

In the present embodiment, similar to the first embodiment,
At least a surface portion of the surface of the external connection electrode 4b that is in contact with the conductive adhesive 3 (in the present embodiment, the entire external connection electrode 4b) was processed as follows. The electrode form is used as it is as the copper, which is the base material of the lead terminal 4a (see FIG. 2A). A silver plating layer 6A is formed on the surface of the external connection electrode 4b made of copper.
Is formed (see FIG. 2B). A conductive adhesive layer 6B formed by applying and drying a conductive adhesive containing silver filler is formed on the surface of the external connection electrode 4b made of copper (see FIG. 2B). A silver sintered layer 6C formed by applying and firing a sintered silver paste is formed on the surface of the external connection electrode made of copper (FIG. 2B).
reference).

For comparison with the present embodiment, a conventional product prepared by processing the surface of the external connection electrode 4b as follows is prepared. A solder plating layer is formed on the surface of the external connection electrode 4b.

After such processing is applied to the external connection electrode 4b, the present embodiment (-)
Further, an organic protective film 7 was formed on the external connection electrode 4b.

The organic protective film 7 was formed by spray-coating the external connection electrode 4b with an acrylic resin dissolved in an alcohol solvent and then drying it at 50 ° C. for 10 minutes. Since the acrylic resin is thermoplastic, it gels at the drying temperature of the conductive adhesive 3 and does not hinder the electrical connection between the silver filler contained in the conductive adhesive 3 and the external connection electrode 4b. . Therefore, in the present invention,
This is one of the materials that can be suitably used as the organic protective film 7.

As a comparative example, one having the above-mentioned electrode configuration but not forming the organic protective film 7 was prepared.

The connection resistance was measured for the above nine types of QFP elements having the electrode specifications. Table 2 shows the results.

In the present embodiment, the connection resistance was measured as follows. That is, each of the prepared QFP elements 5 was first subjected to an accelerated test of electrode surface deterioration during storage after manufacturing of the QFP element 5. This is 85 ° C
10 QFP element 5 in a high temperature / high humidity environment test furnace of / 85RH
This was carried out by feeding for 00 hours.

Further, each of the QFP elements 5 on which the acceleration test of the electrode surface deterioration was performed was mounted on the circuit board 1 using the conductive adhesive 3. And 15 in the oven
Cured at 0 ° C./1 hour. Furthermore, the mounted body of the QFP element 5 having the different electrode specifications is again replaced with 85 ° C / 85RH.
1000 hours into the high temperature and high humidity environment test furnace
Finally, the electric resistance was measured.

[0044]

[Table 2] As shown in Table 2, in each of the products of the present embodiment in which the organic protective film 7 was formed on the surface of the external connection electrode 4b of the QFP element 5, the initial resistance was small and the connection resistance was high even after the high temperature and high humidity environment test. Almost unchanged. However, in the case where the organic protective film 7 was not formed and the conventional example in which the solder plating layer was formed on the surface of the external connection electrode 4b, the connection resistance was about several times as large as that of the embodiment. It has increased to about two digits. In addition, the comparative example product having the solder plating layer is insulated, and the superiority of the present invention is obvious.

(Embodiment 3) FIG. 3 shows a mounted electronic component according to Embodiment 3 of the present invention. In FIG. 3, the same components as those in the first embodiment (FIG. 1) are denoted by the same reference numerals. Here, in FIG. 3A, the connection surface 4c (the surface with which the conductive adhesive 3 contacts) of the external connection electrode 4b is roughened to a desired surface roughness. In the case of FIG. 3B, the unevenness 8 is further increased by forming unevenness so that the connection surface 4c of the external connection electrode 4b is formed.
(The surface on which the conductive adhesive 3 contacts). Although not shown in any configuration of the present embodiment, it goes without saying that the silver plating layer 6A is formed on the surface of the external connection electrode 4a.

The method for roughening the connection surface 4c of the external connection electrode 4b is not limited, but may be, for example, etching, sandblasting, or the conductive adhesive layer 6.
A method of applying and drying B, or a method of applying and firing the silver sintered layer 6C can be preferably used. The surface roughness of the conductive adhesive layer 6B and the silver sintered layer 6C is rougher than that of solder plating or the like, and is suitable for electrical connection via the conductive adhesive 3. In addition, as a method of forming the uneven shape 8 on the surface of the external connection electrode 4b, a method of pressing a mold having a transfer pattern formed on the surface is practical.

Table 3 shows the results of measuring the adhesive strength of the external connection electrode 4b in the mounting body in which the QFP element 5 is mounted on the circuit board 1 as described above. Here, the adhesive strength was defined as follows. That is, the lead terminal 4a is set to 1
The force at the time of pulling one by one and peeling from the connection electrode part 2 of the circuit board 1 was defined as the adhesive strength.

Table 3 shows the measurement results. In this embodiment, obtained by changing the surface roughness lead frame by etching conditions, and the lead frame for those with different surface roughness depending on the condition of sandblasting, their surface roughness R ₃ a stylus type The results measured using a surface roughness meter are also shown in Table 3.

[0049]

[Table 3] As shown in Table 3, it can be seen that the rougher the connection surface 4c of the external connection electrode 4b, the higher the adhesive strength. As shown in this example, if the surface roughness R ₃ is less than 0.1 μm, sufficient bonding strength cannot be obtained in mounting using the conductive adhesive 3, and it is often not suitable for practical use. On the other hand, the surface roughness R
_{When 3} was 12.0 μm, the adhesive strength was reduced due to the effect that the contact area between the conductive adhesive 3 and the external connection electrode 4b was reduced. These phenomena are caused when the surface roughness R ₃ is 1
It occurred remarkably when it was 0 μm or more.

The adhesive strength of the external connection electrode 4b formed with the irregularities 8 is much higher than that of the comparative example (the surface of the external connection electrode 4b is not roughened). Has improved.

Based on the above findings, according to the present invention, the surface roughness R ₃ of the external connection electrode 4b is set to 0.1 μm or more and less than 10 μm, or
By forming the concavo-convex shape 8 on the surface b, the bonding strength between the external connection electrode 4b and the connection electrode portion 2 of the circuit board 1 is increased.

(Embodiment 4) FIG. 4 shows a mounted electronic component according to Embodiment 4 of the present invention. In FIG. 4, the same components as those in the first embodiment (FIG. 1) are denoted by the same reference numerals. Here, in FIG. 4A, a through-hole 10A is formed in the external connection electrode forming portion of the lead terminal 4a. The through hole 10A is formed to have the same diameter along a direction substantially perpendicular to the connection surface 4c of the external connection electrode 4b. Also in FIG. 4B, although a through-hole 10B similar to the above-described through-hole 10A is formed,
The through hole 10B has a so-called drum shape in which the diameter at the axial center position is smaller than the diameter at both end positions. 4C, a through hole 10C similar to the through hole 10A is formed. However, the diameter of the through hole 10C at the axial center position is larger than the diameter at both end positions. It has a so-called abacus bead-shaped cross-section note. In FIG. 4D, although a through-hole 10D similar to the above-described through-hole 10A is formed, the inner peripheral surface 11 of the through-hole 10D has a female screw-like uneven shape. In FIG. 4E, although a through hole 10E similar to the through hole 10A is formed, the inner peripheral surface 12 of the through hole 10E is
It has been roughened.

Although not shown in any configuration of the present embodiment, it goes without saying that the silver plating layer 6A is formed on the surface of the external connection electrode 4a.

The lead terminals 4a have through holes 10A-1A.
As a method of forming 0E, since it can be formed by etching in the manufacturing process of the lead frame of the QFP element 5, it is practical and hard to increase the cost. In order to form the drum-shaped through hole 10B, for example, it can be easily formed by performing double-sided etching in the etching step. In order to form the abacus bead-shaped through-hole 10C, for example, a lead frame having a tapered shape by one-sided etching is used.
It can be formed by preparing a plurality of sheets and bonding together a surface having a large opening area of each lead frame. Further, in order to form the female screw-shaped through-hole 10D, the through-hole 10D can be formed by, for example, tapping a predetermined position of the lead frame with a tap. Further, in order to form the through hole 10E whose inner peripheral surface is roughened, for example, after masking a lead frame portion other than the inner peripheral surface of the through hole 10E, etching for roughening different from the formation of the through hole is performed. It can be formed by dipping in a liquid.

In a mounted body in which the electronic component (QFP element 5) having the lead terminals 4a is mounted on the circuit board 1, the force when the lead terminals 4a are pulled one by one and peeled off from the connection electrode portion 2 is reduced. It was defined and measured as adhesive strength. Table 4 shows the results.

The lead terminal 4 having the through hole 10A
In a, the conductive adhesive 3 is formed by the following two types of structures.
Was provided, the above-mentioned adhesive strength was measured. First
In the structure of (1), the conductive adhesive 3 disposed between the external connection electrode 4b and the connection electrode portion 2 is filled up to the inside of the through hole 10A, and a part of the filled conductive adhesive 3 is penetrated. It overflows from the upper opening of the hole 10A. At this time, the conductive adhesive 3 covers the upper opening but overflows to the extent that it does not overflow from the lead terminal 4a. The conductive adhesive 3 provided in this manner is cured, and the external connection electrode 4 is cured.
b and the connection electrode portion 2 were electrically connected.

Second, in the structure, although the conductive adhesive 3 is filled in the through hole 10A, the conductive adhesive 3 does not overflow from the upper opening of the through hole 10A. Was cured, and the external connection electrode 4b and the connection electrode portion 2 were electrically connected.

[0058]

[Table 4] As shown in Table 4, it was confirmed that the formation of the through holes 10A to 10E significantly improved the adhesive strength. This is presumed to be the result of the so-called anchor effect caused by the conductive adhesive 3 filling the through holes 10A to 10E. Also, the conductive adhesive 3 is applied to the through hole 10.
It was also confirmed that the portion protruding from the upper opening of A increased the anchor effect and further improved the adhesive strength. Furthermore, it was also confirmed that by processing the inside of the hole as in the through holes 10B to 10E, the adhesive strength was further improved. This is presumed to be due to the following reasons.

That is, the common feature of the through holes 10B to 10E is that at least a part of the inner peripheral surface of the through holes 10B to 10E is opposite to the connection surface 4c side in the axial direction of the holes 10B to 10E. (Upper opening side)
That is, there is a region having a large diameter. The same can be said for the through hole 10E in which the inner peripheral surface 12 is roughened.

Due to the presence of such a large-diameter region, the region having a larger diameter than the other in-hole region is located above the connection surface 4c side of the lead terminal 4a, that is, on the side away from the connection surface 4c side. Will be placed. Therefore, the conductive adhesive 3 is filled in the through holes 10B to 10E having such a shape (the conductive adhesive 3 is provided between the connection surface 4c and the connection electrode surface 2 so that the conductive adhesive 3 naturally penetrates). Hole 10B-10
E), the conductive adhesive 3 filled in the large-diameter region acts as a stopper, and the anchor effect is enhanced, resulting in further improvement in adhesive strength. .

The cross-sectional shape of the through-hole may be other than the above shape, for example, a mortar-shaped one having an opening area on the side in contact with the conductive adhesive 3 smaller than the opening area on the opposite side. . Also, the number of the through holes 10A to 10E is not specified.

In the embodiment of the present invention, a case where a QFP element is used as an electronic component has been described.
The type is not limited as long as it is generally used as an electronic component such as a semiconductor package such as a lead and a connector, and a connector.

[0063]

As described above, according to the present invention, the surface is made of silver, copper,
Or an electronic component having an external electrode of an alloy or a mixture of these metals, and an electronic component having a specified surface roughness or shape, and in connection with a conductive adhesive, the reliability of the connection resistance and the adhesive strength. Can be improved.

Further, according to the present invention, it is possible to realize lead-free electronic components and electronic component mounted bodies, which is useful for environmental problems that have recently attracted attention.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view showing a structure of a mounted body of a QFP element according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view illustrating a structure of a mounted body of a QFP element according to a second embodiment of the present invention.

FIG. 3 is an enlarged view of a main part showing a structure of a connection portion of a mounting body according to a third embodiment of the present invention.

FIG. 4 is an enlarged view of a main part showing a structure of a connection portion of a mounting structure according to a fourth embodiment of the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Circuit board 2 Connection electrode part 3 Conductive adhesive 4a Lead terminal 4b External connection electrode 4c Connection surface 5 QFP element 6A Silver plating layer 6B Conductive adhesive layer
6C Silver sintering layer 7 Organic protective film 8 Uneven shape
10A-10E Through hole

Continued on the front page (72) Inventor Yukihiro Ishimaru 1006 Kazuma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (72) Inventor Takashi Kitae 1006 Okadoma Kadoma Kadoma City, Osaka Matsushita Electric Industrial Co., Ltd. (72) Invention Person Yasuhiro Suzuki 4-3-1 Tsunashima Higashi, Kohoku-ku, Yokohama-shi, Kanagawa Prefecture F-term in Matsushita Communication Industrial Co., Ltd. 5E319 AA03 AA07 AB01 BB11 5E336 AA04 BB01 CC08 DD19 EE08 GG16

Claims (8)

[Claims] An electronic component, comprising: a lead terminal; and an external connection electrode provided on the lead terminal and electrically connected to a mounting member via a conductive adhesive. An electronic component, wherein a surface portion of the external connection electrode which is in contact with the metal is made of silver, copper, an alloy mainly containing these metals, or a mixture of these metals. 2. The electronic component according to claim 1, wherein a surface portion of the external connection electrode that contacts the conductive adhesive is covered with an organic protection film. 3. The electronic component according to claim 1, wherein a surface portion of the external connection electrode that is in contact with the conductive adhesive is processed into an uneven shape. 4. The electronic component according to claim 1, wherein a surface roughness R ₃ of a surface portion of the external connection electrode in contact with the conductive adhesive is set to 0.1 μm or more and less than 10 μm. Electronic components featured. 5. The electronic component according to claim 1, wherein a through-hole is formed in the external connection electrode forming portion of the lead terminal along a direction substantially orthogonal to a connection surface of the external connection electrode. And electronic components. 6. The electronic component according to claim 5, wherein the through hole has a shape whose diameter varies along an axial direction, and the diameter variation shape is at least a part thereof. 3. The electronic component according to claim 1, wherein the diameter of the hole on the side opposite to the axial direction of the hole is larger than that on the connection surface side of the external connection electrode. 7. The electronic component package according to claim 1, wherein the electronic component according to claim 1 is electrically connected to an electrode of a mounted member via a conductive adhesive. . 8. The electronic component according to claim 5, which is connected to an electrode of a mounted member via a conductive adhesive, and is cured in a state where the conductive adhesive overflows from the through hole. A packaged electronic component, characterized in that: