JP3377850B2 - Surface mount type crystal oscillator and manufacturing method thereof - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a computer and an AV machine.
Clock signal generation for communication devices and reference frequency generation for communication equipment
The present invention relates to a surface-mount type crystal oscillator for use. 2. Description of the Related Art A crystal oscillator is composed of a crystal oscillator, an IC element,
Passive electronic components such as capacitors and resistors as required
And the wiring circuit connecting each of these parts was formed
It is composed of an insulating substrate, an airtight case and the like. Conventionally, a crystal oscillator used for a crystal oscillator
And IC elements are individually enclosed in cases and packages.
Used in recent years.
Recently, both the crystal unit and IC element have been bare
Of these elements (bare chips), these elements are integrated
To ensure reliability by sealing in an airtight case
Parts. By doing this,
The crystal oscillator and the casing of the IC element itself can be omitted,
With the molding, the manufacturing cost can be reduced. [0004] Conventionally, as the above-mentioned airtight case, a metal case has
(Can case and stem board) were common
However, a collar for sealing is required,
The occupation area when mounting is large, the cost is high, etc.
There is a problem of sealing, considering the adaptability of the surface mount type
High reliability, compact and low cost ceramic
A crystal oscillator compatible with surface mounting using a case has been proposed.
(For example, JP-A-4-3609). [0005] Such a surface mount type crystal oscillator is one of them.
Of the housing-shaped ceramic substrate with the wiring pattern
Internally mounted crystal oscillator, IC bare chip, etc.
And further sealed by a lid.
You. In addition, the above-mentioned wiring is provided on the end face or the back face of the ceramic substrate.
A mounting terminal electrode electrically connected to the pattern is formed. Here, the wiring pattern and the terminal
The conductor layer of the pole is an underlayer such as tungsten metallization, N
Three-layer structure with i-plated layer and surface gold-plated layer
I have. This is because the wiring pattern and the mounting terminal electrode are the same
Since both are formed in a process, both have the same structure.
In the wiring pattern, the connection of the IC bare chip
In order to improve reliability, the surface should be
A key layer needs to be formed. When a metal member is used for the lid,
In addition to the wiring pattern and mounting terminal electrodes, the lid is air-tight.
A sealing conductor layer is formed on the ceramic substrate to be stopped.
It is needed. The configuration of this conductor layer is, for example, seam welding.
When performing, the underlying conductor layer such as tungsten metallization,
Ag brazing layer, metal ring such as Kovar, Ni plating
Layer and an Au plating layer. [0008] The surface mounting as described above
When mounting a crystal oscillator on a printed circuit board,
First, solder to the connection pads formed on the printed circuit board.
Apply paste and then mount the oscillator on the connection pad
And then passed through a reflow oven to
And the mounting terminal electrode are electrically and mechanically joined. At this time, it is the outermost surface layer of the mounting terminal electrode.
The gold plating layer forms a solid solution with the tin in the molten solder
Good solderability is obtained because a solder alloy layer is formed.
You. However, bonding to the printed circuit board in this way
The surface mount type crystal oscillator that has been
Temperature cycle test of 700 cycles from 40 ° C to + 90 ° C
Continuity failure is likely to occur when subjected to After various investigations on this conduction defect,
The junction between the surface mounted crystal oscillator and the printed wiring board
In the above, the mounting terminal electrode 4 of the surface mount type crystal oscillator
The gold plating layer on the outermost surface disappears and cracks occur at the solder joints
Was found to occur. That is, gold is a so-called “solder food”
And cause a complete solid solution in the solder.
The reason for this is that crystal oscillators have high operational reliability.
Requirements for reliability testing to meet
Connection pads of lint wiring board and the surface mount type crystal oscillation
Caused by the difference in the coefficient of thermal expansion with the terminal electrode of the vessel
Directly attached to the ceramic substrate of the surface-mount crystal oscillator
・ The difference in thermal expansion coefficient between the mounting terminal electrodes
Due to insufficient absorption of elasticity
Is concentrated on the joints, and the solder with gold
Because the layer becomes brittle and cannot withstand this concentrated stress.
Conceivable. To solve the above problems,
After sealing with a lid, the surface of the gold plating layer of the mounting terminal electrode
A barrier layer that covers the
Thus, it is conceivable to prevent Au from being eroded by solder. I
However, when the inventor conducted experiments, it was found that N
The “solder erosion” phenomenon of gold is completely eliminated even with the i barrier layer
Cannot be controlled and reliability in temperature cycle test
I could not be satisfied. About nickel plating
After inspection, Ni plating was applied by barrel electrolytic plating.
When forming, mounting end including through-hole conductor
Plating media is sufficient and even on the sub-electrodes
Insufficient plating thickness, probably due to non-contact
It is. Also, if electroless plating is used, plating can be performed on unnecessary parts.
There was a problem of being formed. In addition, the terminal electrode is used in the case of surface mounting.
What is necessary is just to form a terminal electrode on the back of the mic substrate.
The use of through-hole conductors at the end
The mounting state of the solder and the terminal electrode can be confirmed when mounting
And fill it with solder fillet
To form a stronger joint by forming
You. The present invention has been devised in view of the above problems.
The purpose is to connect to the printed wiring board
The mounting reliability is high without causing conduction failure and connection failure.
Providing a method of manufacturing a surface mount type crystal oscillator with excellent work efficiency
Is to provide. [0014] The present invention provides a wiring pattern
On a ceramic substrate with
Mounting and connecting an IC bare chip for an oscillator circuit, and
At least the crystal unit and the IC bare chip
A lid is attached to the ceramic substrate so that it can be stored tightly
And at least the back surface of the ceramic substrate
Table with mounting terminal electrodes derived from the wiring pattern
A surface mount type crystal oscillator, wherein the wiring pattern is a base conductor
Layer electrode and surface gold plating layer
Indicates a layered structure of a base conductor layer and a surface solder plating layer.
This is a method for manufacturing a surface-mounted crystal oscillator. Specifically, a ceramic having a wiring pattern
At least a quartz oscillator and an oscillator circuit I
Mounting and connecting a C bare chip, and
The rotor and the IC bare chip for the oscillation circuit are stored in an airtight manner.
The lid is attached to the ceramic substrate,
At least on the back surface of the lamic substrate from the wiring pattern
Surface mount type crystal oscillation with derived mounting terminal electrodes
A method of manufacturing a vessel, comprising:
An under conductor layer serving as a pattern is provided on at least the back surface.
Base conductor that becomes the mounting terminal electrode derived from the wire pattern
Forming a layer, and gold plating on the surface of each of the underlying conductor layers.
A step of forming a metal layer and a predetermined surface of the ceramic substrate.
The wiring pattern should include at least a crystal oscillator and an oscillator circuit I
Mounting and connecting a C bare chip;
A plate is provided with the lid and at least the quartz oscillator, the oscillation circuit I
Step of attaching so that C bare chips are stored in an airtight manner
Dissolves and removes the gold plating layer on the surface of the mounting terminal electrode
And removing the gold plating layer of the mounting terminal electrode
The step of forming a solder plating layer on the exposed surface
This is a method for manufacturing a surface-mounted crystal oscillator. The above-mentioned underlying conductor layer is a ceramic base.
This refers to the metallized layer deposited on the board.
If necessary, add a Ni plating layer or silver plating layer
An interlayer may be provided. The surface mounted crystal oscillator according to the present invention has a wiring
The pattern has a gold plated layer on its surface,
Arranged with gold wire for wire bonding of C bare chip
High reliability of wire pattern connection and mounting terminal electrodes
Since no gold plating layer is interposed in the
No decrease in bonding strength due to solid solution
No. Therefore, temperature cycle tests under severe conditions after mounting
Does not cause conduction failure due to cracks in the joints
No. Specifically, a quartz oscillator, an IC chip,
After mounting and connecting the lid and hermetically sealing it with the lid,
Of the mounting terminal electrodes formed on at least the back side of the backing substrate.
Only the gold plating layer is dissolved and removed. Therefore, the above arrangement
Mounting terminals without affecting the wire pattern
Only the gold plating layer of the electrode is selectively removed by etching.
Since the solder layer is formed on the surface from which
No problem occurs, and surface mounting by soldering becomes possible, and
In addition, these selective etching and re-plating
Work efficiency can be achieved by processing the crystal oscillator at once.
And the manufacturing process is simplified. DESCRIPTION OF THE PREFERRED EMBODIMENTS The surface mount type crystal oscillator of the present invention
The manufacturing method will be described with reference to the drawings. FIG. 1 shows a surface-mounted crystal according to the present invention.
FIG. 2 is an external perspective view of the oscillator, and FIG. 2 shows a cross-sectional structure thereof.
FIG. 4 is a plan view of FIG. 3 excluding a lid, and FIG.
To explain the layer configuration of wiring patterns and mounting terminal electrodes
FIG. In FIG. 1, reference numeral 1 denotes a ceramic substrate.
2 is a lid, 3 is a quartz oscillator, 4 is an IC bare chip
In addition, 5 is a wiring pattern, and 6 is a mounting terminal electrode.
The mounting terminal electrode 6 is located on one end face of the ceramic substrate 1.
With the terminal electrode on the back surface
Consists of The ceramic substrate 1 is formed, for example, in a housing shape.
Inside, both ends of the crystal unit 3 are placed and electric
Steps 11a, 11 having connection patterns to be connected
b is formed, and a predetermined wiring is provided on the surface of the inner bottom portion.
Pattern 5 is formed. Also, the ceramic substrate 1
Some of the outer surface of the
An electrode 6 is formed. Further, around the surface of the ceramic substrate 1,
Has a conductor layer 13 for sealing. Such a ceramic substrate 1 is made of, for example, 3
It has a multi-layer structure with each layer having a predetermined shape.
You. For example, the lower layer 1c has a flat plate shape in plan view,
Is an end surface conduction through hole which becomes a part of the mounting terminal electrode 6.
A depression is formed so that a
The wiring pattern 5 has a mounting terminal on the back surface and the recess.
Electrodes 6 are respectively formed. The intermediate layer 1b is made of quartz
To form steps 11a and 11b on which the child 3 is placed.
It has a ring shape in plan view. Of the surface of the intermediate layer 1b
Some parts, that is, the steps 11a and 11b,
Connection patterns 12a and 12b for joining with the
Conductor layer is formed. In addition, the upper layer 1a is
Around the surface, that is, around the opening
It becomes a hermetically sealed portion with the lid 2. Such a lower layer 1
c, by laminating the intermediate layer 1b and the upper layer 1a,
Is achieved. In addition,
There are no connection patterns and locations on the steps 11a and 11b.
The constant wiring pattern 5 is a via penetrating through the thickness direction of the intermediate layer 1b.
Using the holes and the end faces of the steps 11a and 11b,
Connected. In addition, the wiring pattern 5 is
lead to the mounting terminal electrode 6 using the interface between c and the intermediate layer 1b.
Through. Such a ceramic substrate 1 is made of ceramic.
Press molding method for green sheet, on green sheet
Metallization forming method, using green sheet lamination technology
And can be easily achieved by integrally firing. A quartz oscillator is provided inside the ceramic substrate 1.
3. Oscillation circuit IC bare chip 4, various electronic components (illustration
Without). The IC bare chip 4 is provided with an IC necessary for an oscillation circuit.
Converters, resistors, etc.
Die bonding on the inner surface of the plate 1, ie, the surface of the lower layer 1c
Then, a gold bonding wire is
They are electrically connected by ears 10. The quartz oscillator 3 has a predetermined vibration mode and a predetermined frequency.
A rectangular crystal piece defined to oscillate at the wave number;
Vibrating electrodes extending in different end face directions on both main surfaces of the
And both ends thereof are connected to the connection pattern 1 of the steps 11a and 11b.
Add conductive powder to polyimide resin etc. for 2a, 12b
Electrically and mechanically connected with the heat-resistant conductive paste 8 added.
Have been. That is, the crystal unit 3 is
It is arranged so as to lie above. Therefore, the step 11
a, 11b, that is, the thickness of the intermediate layer 1b,
Considering the thickness of the chip 4, furthermore, the bonding wire
It is necessary to consider so that the
You. For example, the thickness of the IC bare chip 4 is
When the thickness is thicker, the IC bare chip 4
A cavity that is deep enough to accommodate all or some
It may be formed. In this case, the lower layer 1c has a two-layer structure.
And a four-layer structure as a whole. In addition, this
With such a structure, the wiring pattern 5 and the IC bare chip 4
Since the step with the surface is reduced, the bonding wire
The shorter the distance, the higher the bonding reliability
Become. The lid 2 is made of, for example, a metal member or a ceramic material.
And the crystal oscillator housed inside the ceramic substrate 1
In order to accommodate the moving element 3 and the IC bare chip 4
It is attached around the opening of the lamic substrate 1. As an example of the sealing structure, a metal
When a member is used, it is sealed around the opening of the ceramic substrate 1.
Metal layer 13 is formed, and lid 2 is joined by seam welding
I do. The sealing metal layer 13 is made of molybdenum, tungsten, or the like.
Metal such as Kovar on the metallized underlayer
The metal ring 7 is brazed, and the surface is further coated with Ni.
It has a laminated structure in which plating and Au plating are performed. One lid
The body 2 is Ni-plated at least on the sealing portion. In addition, a metal ring body such as the above-mentioned Kovar etc.
7, the ceramic substrate 1 and the lid are simply formed by high-temperature soldering.
2 may be joined. Here, the lid 2 is made of a metal member.
And has an electromagnetic wave shielding effect to prevent unnecessary radiation.
Stopped. The inside of the ceramic substrate 1 is nitrogen
And inert gas such as argon to change the element over time.
It is desirable to prevent the formation. Further, a ceramic member is used for the lid 2.
In this case, a low melting point glass layer is formed instead of the sealing metal layer 13.
With the lid 2 placed on the low-melting glass layer
Then, the glass layer may be melted and both may be hermetically sealed. In the above structure, the printed wiring board
Considering the cleanability after surface mounting on the board,
A protrusion is formed at the center of the mounting terminal electrode 6 on the back surface of the substrate 1
It does not matter. The mounting terminal electrode 6 has a temperature cycle after bonding.
In the test, the effect of stress applied due to the difference
To increase the bonding strength and the joint strength,
The maximum distance between the poles 6 ... is 20 mm or less, and one end
The area of the secondary electrode 6 is 0.5 mm ^Two The above is preferred. Next, using the partial sectional view of FIG.
Of the predetermined wiring pattern 5 and the mounting terminal electrode of the
The layer configuration of the conductor layer will be described. The configuration of the conductor layer of the predetermined wiring pattern 5 is
Of metallization such as Ngustene, molybdenum and manganese
The base conductor layer 14, the intermediate Ni plating layer 15, and the gold
Basically, it has a three-layer structure in which the hook layers 16 are stacked.
On the other hand, the configuration of the conductor layer of the mounting terminal electrode 6 is
Metallized base conductor such as molybdenum and manganese
Layer 14, intermediate Ni plating layer 15, silver plating layer 17,
Basically, a four-layer structure in which the surface solder plating layer 18 is laminated
It is made. Note that the wiring pattern 5 and the
Metallized base conductor layers 14, which constitute conductor layers, intermediate
Ni plating layers 15 are simultaneously deposited in the same process.
Is what is done. The wiring pattern 5 and the mounting terminal electrode 6
Lower layer 1c, intermediate layer 1b of ceramic substrate 1 connecting
The conductor layer formed at the interface with
Single layer structure with only metallized layer such as manganese
You. Therefore, bonding with the IC bare chip 4
The predetermined wiring pattern 5 connected via the wire is
Is firmly and reliably because the surface of the
Can be joined. Further, as shown in FIG.
Bonded with a predetermined connection pad 21 of No. 0 via solder 22
The mounting terminal electrode 6 has a solder plating layer 18 on the surface.
When the reflow process is performed, the solder 22
And the solder plating layer 18 are diffused to ensure a strong and reliable
Can be joined to At this time, the solder 22 is
Conductive through not only the back surface but also the end surface of the ceramic substrate 1
The solder 22 rises up to the hole, further strengthening
Solid bonding is possible, and the bonding state can be easily and visually checked.
Therefore, it can be confirmed. In particular, the mounting terminal electrode 6 has gold on the lower layer side.
No plating layer exists, and solder plating layer 18 is formed on the surface
Therefore, as in the conventional case, gold and tin in the solder 22
Solid bonding strength is maintained without solid solution
Wear. Also, for temperature cycle tests under severe conditions after mounting
A strong Au-Sn alloy layer is formed
The printed circuit board 20 and the ceramic base
Even if stress is generated due to the difference in the coefficient of thermal expansion from
Not enough to cause cracks as in
Is completely eliminated. Next, the manufacture of the surface mount type crystal oscillator of the present invention will be described.
The fabrication method will be described in order according to the process diagram of FIG. Step of Forming Ceramic Substrate First, the ceramic substrate 1 is formed. Ceramic substrate 1
Indicates the wiring pattern 5, the mounting terminal electrode 6,
The conductor film which becomes the connection patterns 12a and 12b is formed by printing.
Laminated ceramic green sheets of a predetermined shape are fired
It is formed by doing. Specifically, each of the layers 1a to 1c has a thickness
For example, press molding a 350μm green sheet
More ring-shaped, hollow at the end, and via-hole conductor
The required through holes are formed as shown in the figure and necessary for each green sheet.
Depending on the surface, or both sides, and even through holes
Wiring pattern 5, mounting terminal electrode 6, connection on end face, etc.
The conductor film to be the patterns 12a and 12b is
And print it. Multiple green sheets like this
Laminate, trim, and extract multiple substrates
And firing in a reducing atmosphere. Wiring pattern 5, mounting terminal electrode 6, connection
The patterns 12a and 12b are made of an underlying conductor layer of tungsten.
14 only. The height of the whole oscillator is usually
Is about 300 to 10000 μm in consideration of
If each layer is green so that it does not interfere with electrical
Sheets may be stacked. Thereafter, a Ni plating layer is formed on the underlying conductor layer 14.
15, a gold plating layer 16 is sequentially formed. Ni plating layer 1
The thickness of 5 is 2 in order to enhance the adhesion to the underlying conductor layer 14.
The thickness of the gold plating layer 16 is preferably
0.75-2 μm to increase ear bonding strength
Is preferable. It is to be noted that a metal member is used for the
In the case of contact, sealing around the opening of the ceramic substrate 1
The conductor layer 13 is formed. Specifically, the above-described underlying conductor layer
At the same time as 14, the underlayer conductor layer of tongue-tatin is formed.
Ag metal brazing on the underlying conductor layer
A coating 7 is applied, and the surface thereof is coated with the above-described Ni plating layer and gold.
At the same time as the formation of the plating layer, the Ni plating layer and the gold plating layer
Form sequentially. Further, a glass substrate is used as a ceramic substrate material.
When using low-temperature firing materials such as lamic, the inner conductor layer
Silver or copper to reduce wiring resistance, but other
The basic procedure is almost the same as described above. Device for mounting a crystal unit and an IC bare chip
Next, an IC bare chip is placed at a predetermined position in the ceramic substrate 1.
4 and gold wiring for electrical connection with the wiring pattern 5
By wire bonding. The crystal unit 3 is
The connection pattern of the steps 11a and 11b inside the
Turns 12a and 12b are electrically connected with heat-resistant conductive paste 8
Make a mechanical connection simultaneously with the connection. When mounting other electronic parts,
Is mounted and connected to the wiring pattern 5 by a known method. Here, the IC bare chip 4 is a wire bonder.
Other than flip-chip connection. this
At this time, a solder bump is used for the joint of the IC bare chip 4
And gold bumps are usually used,
Performing with pastes based on heat-resistant resin such as amide resin
Therefore, even when flip-chip connection is used,
It is preferable that the surface layer of the wire 5 be a gold plating layer 16.
You. Attaching Step of Lid Next, as described above, the ceramic containing each element 3, 4
The lid 2 is attached to the substrate 1. For example, a metal member such as Kovar
Ni plating is applied to at least the joint portion of the
Cover 2 on ceramic substrate 1 so as to cover the opening.
Placed, seam welded and hermetically sealed. This work
Perform in an inert gas atmosphere such as nitrogen or argon and seal
After that, make sure that these inert gases are filled in the enclosed space.
You. In this sealing step, low melting glass sealing or high melting point
Hot solder sealing can also be applied. Low melting glass sealing
In the case of, the metal ring as described above is unnecessary and the lid 2 is
Mic member, but about 400 ° C.
Up to the maximum temperature, the thermal effects on the IC must be considered.
No. On the other hand, in high-temperature solder sealing,
Heat is reduced to below 300 ° C. Next, the layer configuration of the mounting terminal electrode 6 was changed to the lower conductor layer 14,
Intermediate Ni plating layer 15, silver plating layer 17, surface solder
In order to form the plating layer 18, the plating layer 18
The gold plating layer 16 is removed. Specifically, the lid 2 is airtight.
Sodium cyanide water
Immerse in the solution. Thereby, the surface of the ceramic substrate 1
Only the gold plating layer of the mounting terminal electrodes 6 exposed at the
Will be left. After that, use a sulfuric acid solution to mount
A negative voltage is applied to the portion to be the terminal electrode 6 for
Electrolytic cleaning by adsorbing hydrogen ions on the surface
You. This is a case in which a large number of lids 2 are hermetically sealed.
The lamic substrate 1 is put into a barrel device, and a positive electrode is applied to the electrode.
Pressure and applying a negative voltage to the mesh drum.
Do more. The purpose of this electrolytic cleaning is to
Removes surface oxide film and increases the adhesion strength of plating in the next process
That's because. Thus, the surface of the mounting terminal electrode 6 is
The Ni plating layer 15 is exposed. After the plating step, the exposed surface of the mounting terminal electrode 6 is coated with the Ni plating layer 15.
The ceramic substrate 1 hermetically sealed with the lid 2 is treated with an acid.
Then, the silver plating layer 17 and the solder
The plating layers 18 are sequentially formed. As a result, the lid 2
Ag-solder plating layer on exposed parts, mounting terminal electrodes 6, etc.
Is formed. As a result, the mounting terminal electrode 6 is
A Ni plating layer 15, a silver plating layer 17, and a half
It has a layer configuration in which the field plating layers 18 are sequentially formed. here
The thickness of the silver plating layer 17 is preferably in the range of 2 to 5 μm.
No. If the thickness is less than 2 μm, the adhesion strength of the solder plating layer 18 is insufficient.
I do. Further, the semi-glossy solder (S
n: Pb = 9: 1), and the preferred layer thickness is 4 to
It is in the range of 10 μm. The reason for forming the silver plating layer 17 is as follows.
The affinity with the solder plating layer 18 is improved,
Of the solder plating layer 18
It is to improve. In the crystal oscillator of the above embodiment, the
Alumina is used as the material of the
Although the underlying conductor layer 14 is formed by metallization or the like,
Instead of this, glass-ceramic etc.
Under the wiring pattern 5 etc.
A silver or copper conductor layer is formed on the ground conductor layer by thick film printing, and the conductor layer
A gold plating layer may be formed on the partial surface. This place
In this case, the firing temperature is low, making it possible to reduce the cost of the substrate.
You. Further, on the underlying conductor layer of the mounting terminal electrode 6,
Both the Ni plating layer 15 and the silver plating layer 17 to be formed are half.
The adhesion between the plating layer 18 and the underlying conductor layer 14 is improved.
For this purpose, but this combination is limited
It is not essential to the present invention. The inventor
According to the experiment, the copper plating layer was used instead of the silver plating layer.
However, a sufficiently practical adhesion strength was obtained. Also, the above low
When using a hot-fired substrate, the nickel plating layer 15 is also omitted.
A solder plating layer directly on the underlying conductor layer 14.
18 can be formed. Further, the shape of the ceramic substrate 1 is changed to a housing shape.
From the flat plate to the housing.
I do not care. The surface mount type crystal oscillator of the present invention has a wiring
Since the conductor surface layer of the pattern is a gold plated layer,
In addition, bonding with an IC bare chip, for example, wire bonding
Connection reliability of bonding and flip chip bonding
No. At the same time, the conductor surface layer of the mounting terminal electrode
A gold plating layer does not intervene on the base side and becomes a solder plating layer
Is reflow soldered to the printed circuit board.
When surface mounted, poor continuity even after temperature cycling
Does not occur, and the joining reliability is increased. Further, the surface mount type crystal oscillator of the present invention was manufactured.
In the fabrication method, in order to achieve the above-mentioned structure,
As with the wiring pattern, a temporary gold plating
What forms a gold layer, after sealing with a lid, gold plating layer
Is removed and a solder plating layer is formed.
One layer of mounting terminal electrodes without a gold plating layer
It can be configured. Therefore, work efficiency is high and
The manufacturing process is simplified. As a result, reliable miniaturization
Surface-mounted crystal oscillators at low cost.
Wear. [0066]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an external perspective view of a surface-mounted crystal oscillator according to the present invention. FIG. 2 is a cross-sectional view of the surface mount type crystal oscillator of the present invention. FIG. 3 is a plan view of the surface-mounted crystal oscillator according to the present invention, excluding a cover. FIG. 4 is a partial cross-sectional view of a ceramic substrate of the surface-mounted crystal oscillator according to the present invention. FIG. 5 is a partial cross-sectional view showing a state of being surface-mounted on a printed wiring board. FIG. 6 is a process diagram illustrating a method for manufacturing a surface-mounted crystal oscillator according to the present invention. [Description of Signs] 1 ... Ceramic substrate 2 ... Cover 3 ... Crystal vibrator 4 ... IC bare chip 5 ... Wiring pattern 6 ... For mounting Terminal electrode 7 Metal ring body 8 Heat-resistant conductive paste 14 Base conductor layer 15 Ni plating layer 16 Gold plating layer 17 Silver plating layer 18 Solder plating layer

Claims (1)

(57) Claims 1. At least a quartz oscillator and an IC bare chip for an oscillation circuit are mounted and connected on a ceramic substrate having a wiring pattern, and the at least quartz oscillator and an IC bare chip for an oscillation circuit are provided. A method of manufacturing a surface-mounted crystal oscillator, wherein a lid is attached to the ceramic substrate and a mounting terminal electrode derived from the wiring pattern is formed on at least the back surface of the ceramic substrate so that the ceramic substrate is hermetically stored. Forming a base conductor layer serving as a wiring pattern on the surface of the ceramic substrate, and forming a base conductor layer serving as a mounting terminal electrode derived from the wiring pattern on at least the back surface, and forming a gold plating layer on the surface of each base conductor layer. Forming, and providing at least a quartz oscillator and an IC circuit for an oscillation circuit on a predetermined wiring pattern on the surface of the ceramic substrate. A step of mounting and connecting a lid, a step of attaching a lid to the ceramic substrate so that the at least the crystal unit and the IC bare chip for an oscillation circuit are stored in an airtight manner, and gold plating on a surface of the mounting terminal electrode. A method for manufacturing a surface-mounted crystal oscillator, comprising sequentially performing a step of dissolving and removing a layer and a step of forming a solder plating layer on the exposed surface of the mounting terminal electrode from which the gold plating layer has been removed.