JP5435625B2 - Electronic component and electronic component manufacturing method - Google Patents

Description

  The present invention relates to an electronic component and a method for manufacturing an electronic component, and relates to, for example, a device that improves soldering and mounting quality with a circuit board.

For example, some electronic elements such as a crystal resonator and a semiconductor are provided in a package.
External electrodes are formed in these packages, and the electronic elements are electrically and physically connected to the circuit board together with the packages by soldering the external electrodes.

FIG. 6 is a diagram for explaining a conventional external electrode 8.
The external electrode 8 has a three-layer structure made of, for example, Cr, Ni, and Au.
The Cr layer is formed on the bottom surface of the base 3 because it has good adhesion to the glass constituting the base 3 of the package.
A Ni layer that forms an intermetallic compound with Sn, which is the main component of solder, is formed on the surface of the Cr layer, and an Au layer that prevents oxidation of Ni is further formed on the surface. Yes.

When the external electrode 8 configured in this way is soldered to the circuit board, the Au layer diffuses into the solder, and the Ni on which the Au layer has been formed constitutes the Sn and intermetallic compound layer, The Ni layer and the Cr layer that did not form the intermetallic compound with Sn are bonded to the circuit board via the intermetallic compound layer and the solder.
Techniques using Cr when the base material is glass are proposed in Patent Documents 1 and 2 below.

In patent document 1, when the base material is glass or the like, a Cr layer is formed as an adhesion layer.
Patent Document 2 proposes a technique of forming an external electrode on glass with two thin layers of Cr and Au or Cr and Ni alloy-Au.
In addition, when the base material is not glass, there are known those in which Ni is used as a base and Au for preventing oxidation is covered on the surface layer, and Cu is used as a base and Sn is formed thereon.

By the way, when heated by solder bonding, Sn and Cu or Ni in the solder (or in the electrode film) form an intermetallic compound layer, but since the intermetallic compound layer is more fragile than the base material, external force is reduced. When added, there was a problem that cracks were likely to occur.
In addition, when the temperature is increased, when the intermetallic compound layer grows and the Ni or Cu layer completely reacts, the strength is reduced, so that a certain thickness is required.
Thus, when the structure of Patent Document 2 is used to form a structure that does not include the Ni layer with a two-layer structure of Cr and Au thin films, there is a problem that the strength is not sufficient depending on the thickness of the Au layer.

Special Table 2007-528591 JP 2006-197278 A

  An object of this invention is to improve the soldering mounting quality of an electronic component and a circuit board.

In order to achieve the above object, according to the present invention, in the invention according to claim 1, an electronic device and a storage container formed of glass, which stores the electronic device in a hollow portion formed therein. the electron device electrically connected, a container electrode formed toward the outside from the inside of the container, the aforementioned container electrically connected to the electrodes, formed on the bottom surface of the container, mainly composed of Sn bonding the solder to, Cr, Ti, W, and bonding metal film is constituted by any one of Ta, and the oxide prevention film formed on a surface of the bonding metal film, in the electronic component provided with the The anti-oxidation film is composed of a plurality of gold layers and a metal layer formed between Cr, Ti, W, Ta formed between the gold layers, and 1000nm when the total thickness of the gold layer is 300nm or more A lower, to provide an electronic component, wherein a top surface of the gold layer is bonded to the bonding metal layer.
According to a second aspect of the present invention, there is provided the electronic component according to the first aspect, wherein the total thickness of the gold layers is not less than 300 nm and not more than 450 nm.
According to a third aspect of the present invention, there is provided the electronic component according to the first or second aspect, wherein the electronic element is a crystal resonator.
In the invention according to claim 4 , an electronic element installation step in which an electronic element and a container electrode for wiring electrically connected to the electronic element are installed on the base, and the electronic element and the container electrode are installed. A lid is attached to the base, and the electronic element is sealed in a storage container made of glass, which is composed of the base and the lid, and Sn is a main component on the bottom surface of the storage container. bonding the solder to, Cr, Ti, W, and the bonding metal layer forming step of forming a bonding metal film is constituted by any one of Ta, the surface of the bonding metal layer mentioned above is formed, a plurality of The metal layer is formed using a gold layer and a metal layer composed of any one of Cr, Ti, W, and Ta formed between the gold layers, and the total thickness of the gold layer is 300 nm or more. 1000 nm or less, An anti-oxidation film forming step of forming an anti-oxidation film in which an uppermost surface of a gold layer is bonded to the bonding metal film is provided.

  According to the present invention, by limiting the total thickness of the gold layer in the antioxidant film, it is possible to improve the solder mounting quality of the electronic component and the circuit board.

It is the figure which showed sectional drawing etc. of an electronic component. It is a figure for demonstrating the various modifications of an antioxidant film | membrane. It is the figure which showed sectional drawing etc. of the electronic component at the time of joining to a circuit board. It is a figure showing the table | surface for demonstrating an experimental result, etc. It is a figure showing the table | surface for demonstrating an experimental result, etc. It is a figure for demonstrating a prior art example.

(1) Outline of Embodiment The electronic component 1 (FIG. 1A) is configured by disposing a crystal resonator 6 in a cavity 13 formed by a base 3 and a lid 2.
The base 3 is made of glass on which through electrodes 7 and 17 are formed. On the bottom surface of the base 3, an external electrode 8 that is electrically connected to the electrode of the crystal resonator 6 through the through electrodes 7 and 17 is formed. ing.

The external electrode 8 includes a bonding electrode film 31 formed of a Cr layer that is bonded to solder during soldering, and an antioxidant film 51 formed on the surface (the lower surface, that is, the side facing the bonding electrode film 31). Has been.
The antioxidant film 51 is configured by alternately stacking Au layers and Cr layers, and the uppermost surface of the Au layer is bonded to the bonding electrode film 31.

  The total thickness of the Au layers constituting the antioxidant film 51 is set to be 300 [nm] to 1000 [nm], preferably 300 [nm] to 450 [nm]. In addition, a thickness sufficient to effectively prevent the bonding electrode film 31 from being oxidized is ensured, and the solder is prevented from being weakened by the excessive amount of Au.

Since the oxidation preventing film 51 can effectively prevent the bonding electrode film 31 from being oxidized, the external electrode 8 can be soldered in the atmosphere to ensure a sufficient bonding strength.
Since the Au layer is directly formed on the bonding electrode film 31 made of Cr, it is not necessary to use a metal layer such as Ni that generates an intermetallic compound with solder.
In the example of FIG. 1C, the anti-oxidation film 51 has a multilayer structure composed of an Au layer and a Cr layer, but it can also be composed of a single Au layer.

(2) Details of Embodiment FIG. 1A shows an electronic component 1 according to this embodiment. When the electronic component 1 is bonded to a circuit board, the electronic component 1 is placed in a direction parallel to the surface of the circuit board. It is sectional drawing at the time of seeing.
However, in order to make the drawing easy to understand, the diameters of the through electrodes 7 and 17 are drawn larger in FIG. 1B than in FIG.
Hereinafter, the side facing the circuit board of the electronic component 1 at the time of mounting is referred to as a bottom surface side, and the side facing this is referred to as a top surface side.

The electronic component 1 includes a base 3, a lid 2, a support portion 5, a crystal resonator 6, internal electrodes 4 and 16, through electrodes 7 and 17, external electrodes 8 and 18, and the like.
The crystal resonator 6 is an electronic element constituted by, for example, a tuning fork type crystal resonator, and a tuning fork type base is held by the support portion 5.
Although not shown, an electrode is provided on the tuning fork arm of the crystal resonator 6, and the crystal resonator 6 can be oscillated at a predetermined frequency by supplying a predetermined pulse to the electrode.

The support unit 5 holds the crystal resonator 6 in a cantilever manner with respect to the base 3 so that the tuning fork arm of the crystal resonator 6 can vibrate in the cavity 13.
In this embodiment, the crystal resonator 6 is used as an example of an electronic element, but other electronic elements such as a semiconductor may be used.

The base 3 is a plate-like member made of, for example, glass, and a crystal resonator 6 held by the support portion 5 is attached to the upper surface.
As a material of the base 3, for example, soda glass having any advantage that is inexpensive and capable of anodic bonding is used, and the thickness is, for example, 0.05 to 2 [mm], preferably 0.1 to 0.5. It is about [mm].
In addition to soda glass, borosilicate glass, alkali-free glass, crystallized glass (sometimes tempered) may be used.

Internal electrodes 4 and 16 that are electrically connected to the electrodes of the crystal resonator 6 are formed on the upper surface of the base 3.
The base 3 has a through hole penetrating from the upper surface portion to the bottom surface portion, and through electrodes 7 and 17 are formed in the through hole.
The internal electrode 4 and the through electrode 7 and the internal electrode 16 and the through electrode 17 are electrically connected to each other.

The lid (lid) 2 is formed of glass, metal, or the like, and a central portion of the surface facing the base 3 is removed to form a recess for housing the crystal resonator 6. In the case of a metal lid, it is desirable that the linear expansion coefficient is close to that of glass.
The amount of recess in the recess of the lid 2 is, for example, about 0.05 to 1.5 [mm], and can be processed by etching, sandblasting, hot pressing, laser, or the like.

The opening of the lid 2 is bonded to the base 3 using anodic bonding or a bonding material, and a cavity 13 for accommodating the crystal resonator 6 is formed by the upper surface of the base 3 and the concave portion of the lid 2.
In addition to anodic bonding, the base 3 and the lid 2 may be joined by direct bonding, metal bonding, low melting glass, brazing material, welding, high melting point soldering, or the like.
Further, an intermediate material may be used between the base 3 and the lid 2.

The cavity 13 is hermetically sealed by the lid 2 and the base 3 and shielded from the outside air. For example, the cavity 13 is hermetically sealed such that a vacuum is maintained or a predetermined gas is sealed.
In the electronic component 1, the recess 2 is provided in the lid 2 to form the cavity 13. However, the cavity 3 may be formed by providing the recess in the base 3 and joining the flat lid 2. The recess 2 may be formed on both the lid 2 and the base 3.

As described above, in the electronic component 1, the package by the glass case accommodates the electronic element by the base 3 and the lid 2.
When the package is made of glass, the material cost is low, and the crystal resonator 6 can be trimmed, bonded, and gettered by a laser from the outside on the lower surface side of the electronic component 1.
Here, gettering means that Al and surrounding air (oxygen) are reacted and consumed by irradiating and heating an Al pattern or the like placed in the space when vacuum sealing is performed. This is a technique for improving the degree of vacuum.

The external electrode 8 is a joint portion made of a metal film for electrically and mechanically joining the electrode land on the circuit board with solder or the like, and is formed on the bottom surface of the base 3. Conducted.
The external electrode 18 is configured similarly to the external electrode 8 and is electrically connected to the through electrode 17.

In the electronic component 1, the electrodes of the crystal unit 6 are electrically connected to the external electrodes 8 and 18 through the through electrodes 7 and 17. For example, the internal electrodes 4 and 16 connect the joint between the lid 2 and the base 3. The drawn internal electrodes 4 and 16 are further extended from the side surface to the bottom surface of the base 3, and the internal electrodes 4 and 16 are connected to the external electrode 8 on the bottom surface of the base 3. , 18 can also be configured to be electrically connected.
In this case, it is not necessary to form the through electrodes 7 and 17 in the base 3.

FIG. 1C is a diagram showing the configuration of the external electrode 8 in detail.
The external electrode 8 includes a bonding electrode film 31 formed on the surface of the base 3 and an antioxidant film 51 that protects the bonding electrode film 31 from oxidation.
The bonding electrode film 31 is made of a metal having good adhesion to glass, for example, Cr. In addition, Ti, W, Ta, or the like can be used as the material of the bonding electrode film 31.
The antioxidant film 51 is formed by alternately superposing three Au layers and two Cr layers, and the uppermost layer of the Au layer is bonded to the bonding electrode film 31.

The thickness of each Au layer of the antioxidant film 51 is set so that the total value is 300 [nm] or more and 1000 [nm] or less, preferably 300 [nm] or more and 450 [nm] or less. ing.
In the example of the figure, the thickness of each Au layer is equal, but this need not be equal, and the total value of the thickness of the Au layer may be in the range of the value.

Cr has the property that it does not form an intermetallic compound with solder (Sn is the main component) and does not dissolve in the solder, and the Cr layer has such properties as Ti layer, W layer, Ta It can be replaced by layer.
On the other hand, Au has a property that when soldering, an intermetallic compound (alloy) such as AuSn ₂ or AuSn ₄ is generated and easily diffuses into the solder.

Each of these layers constituting the external electrode 8 can be formed, for example, by forming a film of these metal elements on the bottom surface of the base 3 by a sputtering method using sputtering.
That is, a bonding electrode film 31 made of Cr is formed on the bottom surface of the base 3, and then an Au film and a Cr film are alternately formed.
Alternatively, these layers can be formed by a plating method.

The electronic component 1 having the above configuration can be manufactured as follows.
A through hole is formed in the base 3, and the through electrodes 7 and 17 are formed in the through hole.
Then, the crystal resonator 6 is installed on the base 3 and connected to the through electrodes 7 and 17, and then the lid 2 is bonded to the base 3 by anodic bonding or the like to form a package.
Next, the external electrodes 8 and 18 are formed on the bottom surface of the base 3 by plating or the like by sputtering, and the electronic component 1 is completed.

It is also possible to change the process order, such as forming the external electrodes 8 and 18 on the base 3 and then bonding the lid 2 to the base 3.
Further, a wafer on which a large number of electronic components 1 are formed is formed by installing through electrodes 7 and 17 and a crystal resonator 6 on a base wafer on which a large number of bases 3 can be obtained, and bonding a lid wafer on which a large number of lids 2 can be obtained. After forming the external electrodes 8, 18, the external electrodes 8, 18 can be cut to take a large number of electronic components 1.

Each drawing in FIG. 2 is a diagram for explaining various modifications of the antioxidant film 51.
FIG. 2A shows an example in which one Cr layer is formed between two Au layers of the antioxidant film 51, and the thickness of the lower Au layer of the Cr layer is thicker than the thickness of the upper Au layer. This is an example.
The total thickness of these Au layers is set to be not less than 300 [nm] and not more than 1000 [nm], preferably not less than 300 [nm] and not more than 450 [nm].

FIG. 2B is also an example in which one Cr layer is formed between two Au layers of the antioxidant film 51, and the thickness of the lower Au layer of the Cr layer is made thinner than the thickness of the upper Au layer. It is an example.
The total thickness of these Au layers is set to be not less than 300 [nm] and not more than 1000 [nm], preferably not less than 300 [nm] and not more than 450 [nm].
In the example of FIGS. 2A and 2B, the thicknesses of the two Au layers are different, but the two Au layers may be formed to have the same thickness.

FIG. 2 (c), the anti-oxidation film 51 is an example in which a single Au layer, the thickness of the Au layer is a 300 [nm] or more 1000 [nm] or less, preferably, 300 [nm ] To 450 [nm] or less.

FIG. 3A is a cross-sectional view of the electronic component 1 joined to the circuit board 36 with solder.
As shown in the figure, the external electrode 8 is electrically and physically bonded to the substrate wiring 32 on the circuit board 36 via the solder 33, and the external electrode 18 is connected to the circuit board 36 via the solder 34. Thus, the electronic component 1 is electrically and physically bonded to the circuit board 36.

FIG. 3B is a diagram showing details of the joint surface of the external electrode 8 with the solder 33.
Since Cr in the electrode film for bonding 31 does not form an intermetallic compound with solder, it is bonded to the solder 33 while being bonded to the base 3.
On the other hand, the antioxidant film 51 is diffused in the solder 33 and is therefore not shown.
When the antioxidant film 51 includes a Cr layer, the Cr layer does not form an intermetallic compound with the solder. Therefore, when the Au layer diffuses, the Cr layer separates from the external electrode 8 and exists in any place of the solder 33.

FIG. 4A summarizes the experimental results regarding the shear strength of the external electrode 8 in a table.
As shown in FIG. 2C, the antioxidant film 51 according to this experiment is composed of a single Au layer.
The item “electrode film configuration” is the film thickness of Cr (bonding electrode film 31) and Au (antioxidation film 51) expressed in [Å]. For example, “Cr600-Au750” is a bonding electrode. This shows a case where the thickness of the Cr layer of the film 31 is 600 [Å] (60 [nm]) and the thickness of the Au layer of the antioxidant film 51 is 750 [Å] (75 [nm]).
Moreover, the shear test method was based on JISZ3198-7, and the shear rate was 5 [mm / m].

The item “Au layer thickness” represents the thickness of the Au layer constituting the antioxidant film 51 in [nm].
The item “strength (index)” is an index representing the ratio of other shear strengths, where the shear strength is 1 when the thickness of the Au layer is 150 [nm].
FIG. 4B is a graph of this index.

As apparent from the table and graph, the shear strength is about 1 when the thickness of the Au layer is 75 to 150 [nm], whereas it is about 2 to 3 at 300 to 900 [nm]. It is a practical value.
Although there is no experimental value when the thickness of the Au layer is 1000 [nm], it is considered to be about the same as 900 [nm] from the continuity of data.
In general, it is known that as the amount of gold increases, the soldered portion becomes brittle. When the Au layer exceeds 1000 [nm], this vulnerability is considered to appear.
For this reason, the thickness of the gold layer is 300 [nm] or more and 1000 [nm] or less, which is a thickness suitable for practical use.
Moreover, since a peak appears at 450 [nm] according to the experimental results, a value of 300 [nm] to 450 [nm] is more preferable.

FIG. 5A is a table summarizing further experimental results relating to the shear strength of the external electrode 8, and FIG. 5B is a graph of this.
In this experiment, the thickness of the gold layer of the antioxidant film 51 is 150 [nm], single layer (one layer), two layers, and three layers. did.
When there are two or three Au layers, a Cr layer is formed between these Au layers.

  According to the experimental results, when the total thickness of the Au layer is 300 [nm] or more, that is, when the Au layer is two or three layers, the shear strength is 1.9 and 2.1, respectively. It is about 2 and is at a practical level.

FIG.5 (c) shows the experimental result showing the bending tolerance of a board | substrate as a table | surface.
The bending test method conforms to JEITA ET-7409 / 104, uses a glass epoxy circuit board with a thickness of 1.6 [mm], and determines the presence or absence of an external crack with an indentation amount of 1, 2, and 3 [mm]. Was done.
The item “electrode specification” is the specification of the electrode, the thickness of the Cr layer of the bonding electrode film 31 is 0.06 [μm] (600 [Å]), and the thickness of the Au layer of the antioxidant film 51 is When the Au layer is composed of three layers as 0.15 [μm] (1500 [Å]) (the external electrode 8 when the Au layer is composed of three layers), the thickness of the Cr layer is 0.06 [μm]. When the electrode is configured with the Cu layer thickness of 10.5 [μm], the Sn layer thickness of 10 [μm] (first comparative electrode), and the Cr layer thickness of 0.06 [μm] ], When the electrode is configured with the thickness of the Cu layer being 0.5 [μm], the thickness of the Ni layer being 2 [μm], and the thickness of the Sn layer being 10 [μm] (second comparative electrode) Show.

When these electrodes are formed on the electronic component 1 and bonded to the circuit board 36 and the circuit board is pushed in by a pushing mechanism, when the pushing amount is 1 [mm], the external electrode 8 is cracked 20 times. The number of occurrences was 0, and in the case of the first reference electrode, it was 1 out of 5 times, and in the case of the second comparison electrode, it was 0 times out of 5.
When the pushing amount is 2 [mm], it is 0 times in 20 times, 4 times in 5 times, 2 times in 5 times, respectively, and when the pushing amount is 3 [mm], each time is 0 times in 20 times. It was 4 out of 5 times and 4 out of 5 times.
In the external electrode 8, the total thickness of the Au layer is 450 [nm]. In this case, excellent bending resistance is realized.

As described above, when the thickness of the Au layer constituting the antioxidant film 51 is not less than 300 [nm] and not more than 1000 [nm], the shear strength of the external electrode 8 is improved. This is because the Au layer is thick. This is presumably because the ability of the bonding electrode film 31 to prevent oxidation of Cr is improved.
Further, when the Au layer of the antioxidant film 51 is multilayered, it is considered that the strength and the like are further improved by the Cr layer sandwiched between these Au layers becoming fine and mixed or included in the solder. It is done.

  When the Au layer is a thin film, it may be difficult to solder the Cr layer in the atmosphere. However, when the thickness of the Au layer is 300 [nm] or more, the antioxidant function of the Cr layer is improved. Therefore, it is possible to perform soldering (reflow) in the air, it is not necessary to prepare a special atmosphere for soldering, and the soldering cost can be reduced.

  According to the present embodiment described above, an electronic element (for example, a crystal resonator 6 and a semiconductor is also possible) and a storage container (lid 2) that stores the electronic element in a hollow portion (cavity portion 13) formed therein. And a base 3), a container electrode (internal electrodes 4, 16, and penetrating electrodes 7, 17 and the like) electrically connected to the electronic element and formed from the inside to the outside of the storage container, and a container electrode A metal film for bonding (bonding electrode film 31) that is electrically connected to the solder and formed on the bottom surface of the storage container, and an antioxidant film (antioxidant film 51) formed on the surface of the bonding metal film. The antioxidant film is formed using one or more gold layers (Au layers) having a total thickness of 300 [nm] or more and 1000 [nm] or less. The top layer of the antioxidant film 51 is Because it is composed of u layers, the uppermost surface of the gold layer is bonded to the bonding metal layer.

The total thickness of the Au layer of the antioxidant film 51 is preferably 300 [nm] or more and 450 [
nm] or less.
When there are a plurality of Au layers in the antioxidant film 51, a Cr layer or the like, for example, a metal layer that does not dissolve in solder can be formed between them. Therefore, the antioxidant film includes a plurality of gold layers and the gold layers. The predetermined metal layer can be formed of a metal that does not dissolve in the solder.
In addition, the Au layer can be a single layer. In this case, the antioxidant film is composed of a single-layer gold layer.
Furthermore, the base 3 can be comprised with glass, and the storage container of an electronic component is formed using glass in this case .

  The electronic component 1 is bonded to the circuit board 36 to form an oscillation circuit together with other electronic elements such as a capacitor and a coil, and the computer acquires the operation timing by the oscillation, and the timepiece measures the time. Therefore, various types of oscillators including an oscillation unit (oscillation circuit) that oscillates using electronic components and an operation unit (CPU (Central Processing Unit), etc.) that operates by acquiring operation timing by oscillation of the oscillation unit are used. The electronic device can be provided.

  In this case, an electronic element (such as a crystal resonator 6), a storage container (a package including the lid 2 and the base 3) that stores the electronic element in a hollow portion formed inside, and the electronic element are electrically connected. A container electrode (through electrodes 7, 17, etc.) formed from the inside to the outside of the storage container, a bonding electrode film 31 electrically connected to the container electrode, formed on the bottom surface of the storage container, and bonded to solder; And an electronic device including a circuit board (circuit board 36) which is bonded to the connection metal film via solder and provided with other electronic elements.

  Also, an electronic device is installed on the base (base 3) with an electronic device (such as a crystal resonator 6) and a container electrode for wiring (such as through electrodes 7 and 17) electrically connected to the electronic device. A process, a sealing step in which the electronic element is sealed in a storage container composed of the base and the lid by bonding a lid (lid 2) to the base on which the electronic element and the container electrode are installed; and a sputtering method on the bottom surface of the storage container The bonding metal film forming step for forming the bonding metal film (bonding electrode film 31) to be bonded to the solder by the method, and the surface of the formed bonding metal film has a total thickness of 300 [nm] or more and 1000 Oxidation that forms an anti-oxidation film (anti-oxidation film 51) composed of one or more gold layers (Au) of [nm] or less, with the uppermost surface of the gold layer being bonded to the bonding metal film Using a protective film forming step, Made electronic component manufacturing method can be provided.

The following effects can be obtained by the present embodiment described above.
(1) It is difficult to oxidize the bonding electrode film 31 by constituting the total thickness of the Au layer on the bonding electrode film 31 within a predetermined range, and solder due to too much Au. The weakening can be suppressed, and the mounting strength of the electronic component 1 is increased.
(2) Since the function of preventing oxidation of the Au layer is high, the electronic component 1 can be soldered in the atmosphere.
(3) The Au layer diffuses uniformly in the solder, and the joint interface of the external electrode 8 becomes Cr and Sn. However, Cr and Sn form an alloy in the temperature range (up to 260 ° C.) of reflow and high temperature tests.・ There is almost no growth and excellent heat resistance and impact resistance.
(4) Since there is no growth of the alloy by Cr and solder, it is not necessary to form a thick Cr layer, and the film stress can be kept small, so that the substrate bending resistance is excellent.
(5) When Cr—Au is used for the internal electrodes 4, 16, etc., the apparatus can also be used for forming the external electrodes 8, 18. Furthermore, if the film thickness of each layer is made the same inside and outside, it is not necessary to change the conditions of the apparatus, and the capital investment can be suppressed and the productivity can be increased.
(6) It is brittle and low in strength compared to ceramics, but it is possible to adopt a transparent glass package at a low cost.
(7) When a step portion exists in the formation region of the external electrode 8, the risk of disconnection can be reduced by laminating the Cr layer and the Au layer.
(8) Since the external electrode 8 can be formed by a sputtering method, a metal layer can be formed in a dry atmosphere, thereby preventing elution of the through electrode 7 and the like.

DESCRIPTION OF SYMBOLS 1 Electronic component 2 Lid 3 Base 4 Internal electrode 5 Support part 6 Crystal oscillator 7 Through electrode 8 External electrode 13 Hollow part 16 Internal electrode 17 Through electrode 18 External electrode 31 Electrode film for joining 32 Substrate wiring 33 Solder 34 Solder 35 Substrate wiring 36 Circuit board 51 Antioxidation film

Claims (4)

An electronic element;
A storage container formed of glass, storing the electronic element in a hollow portion formed inside;
A container electrode electrically connected to the electronic element and formed from the inside of the storage container to the outside;
A joining metal film composed of any one of Cr, Ti, W, and Ta, which is electrically connected to the container electrode and is joined to a solder composed mainly of Sn, which is formed on the bottom surface of the storage container. When,
An antioxidant film formed on the surface of the bonding metal film;
An electronic component comprising:
The antioxidant film is composed of a plurality of gold layers and a metal layer formed of any one of Cr, Ti, W, and Ta formed between the gold layers. An electronic component having a total thickness of 300 nm or more and 1000 nm or less, and an uppermost surface of the gold layer being bonded to the bonding metal film.   2. The electronic component according to claim 1, wherein the total thickness of the gold layer is 300 nm or more and 450 nm or less. The electronic elements, electronic component according to claim 1 or claim 2 characterized in that it is a crystal oscillator. An electronic element installation step of installing an electronic element and a container electrode for wiring electrically connected to the electronic element on a base;
An enclosing step of enclosing the electronic element in a storage container made of glass , comprising the base and the lid, by bonding a lid to the base on which the electronic element and the container electrode are installed;
A joining metal film forming step of forming a joining metal film composed of any one of Cr, Ti, W, and Ta, which is joined to solder containing Sn as a main component on the bottom surface of the storage container;
On the surface of the formed bonding metal film, using a plurality of gold layers and a metal layer made of any of Cr, Ti, W, Ta formed between the gold layers An anti-oxidation film forming step of forming an anti-oxidation film in which the total thickness of the gold layer is 300 nm or more and 1000 nm or less, and an uppermost surface of the gold layer is bonded to the bonding metal film;
Electronic component manufacturing method configured using

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