JP4363859B2 - Manufacturing method of crystal oscillator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a ceramic substrate suitable for manufacturing a crystal oscillator in which a crystal resonator (hereinafter, also referred to as a piezoelectric resonator) made of a piezoelectric element and an oscillation circuit are integrated, and a crystal oscillator using such a ceramic substrate. In particular , it relates to a method of manufacturing such a crystal oscillator.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, in an electronic device such as a mobile phone, a crystal oscillator using a crystal resonator such as a temperature compensated crystal oscillator (TCXO) is widely used.
[0003]
As a structure of the crystal oscillator, for example, an IC chip having an oscillation circuit is mounted in a shallow box-shaped container made of ceramic. A well-known example is one in which a quartz crystal component in which a quartz piece is accommodated and hermetically sealed is joined on the container (Patent Document 1).
[0004]
By the way, in the crystal oscillator having the structure described in the above-mentioned Patent Document 1, for the purpose of protecting and fixing the circuit surface of the IC chip mounted on the container, as a fixing reinforcing material between the IC chip and the container. It is necessary to fill a so-called underfill material. For this reason, the conventional container needs to have a structure in which an underfill material can be injected around the IC chip.
[0005]
FIG. 8 is a diagram showing an example of the structure of an oscillation circuit section of a conventional temperature compensated crystal oscillator (TCXO). FIG. 8A shows a top view of an oscillation circuit container, and FIG. A front view and a bottom view are shown in FIG.
[0006]
These conventional oscillating circuit containers 100 shown in FIG. 8 have a box shape, and the size is, for example, 3.2 mm × 2.5 mm.
Further, as shown in FIG. 8A, a notch 110 is formed in a part of the wall surface of the oscillation circuit container 100. Such a notch 110 provides an underfill material between the oscillation circuit container 100 and the IC chip 5 for protecting the circuit surface of the IC chip 5 accommodated in the container and for reinforcing and fixing the IC chip 5. It is formed to fill.
[0007]
Further, bonding surfaces 101, 101,... As shown in FIG. 8A are formed on the upper surface of the wall surface of the oscillation circuit container 100, and a quartz crystal (not shown) is formed on the bonding surfaces 101, 101,. The vibrator is joined.
Further, as shown in FIG. 8B, auxiliary electrode terminals 102 are formed on the wall surface of the oscillation circuit container 100. These auxiliary electrode terminals 102, 102,... Serve as data write terminals for writing temperature compensation data to the IC chip 5 at the time of manufacturing the TCXO, for example.
[0008]
8B and 8C, electrode terminals 103, 103,... Are formed from the bottom surface of the oscillation circuit container 100 to the four corners of the side surface. These electrode terminals 103, 103,... Are electrode terminals for mounting on the surface of the land provided on the equipment-side substrate on which the crystal oscillator is mounted.
[0009]
[Patent Document 1]
Japanese Patent Laid-Open No. 2000-315918
[Problems to be solved by the invention]
By the way, in recent years, with the miniaturization of various electronic devices, the size of surface mount components such as crystal oscillators is also required to be reduced. For example, the planar size (L × B) of TCXO is required to be reduced from the current size (3.2 mm × 2.5 mm) to a new size (2.5 mm × 2.0 mm). For this reason, development of a new size crystal oscillator has been actively conducted.
[0011]
However, when the crystal oscillator is downsized, it is necessary to change the equipment such as jigs used for manufacturing along with the size change. That is, along with the miniaturization of the crystal oscillator, it is necessary to remake equipment such as jigs, which has been one factor that increases the manufacturing cost of the crystal oscillator.
[0012]
Therefore, the present invention has been made in view of the above points, and a crystal oscillator using a ceramic substrate suitable for manufacturing a crystal oscillator having a reduced planar size, and such a crystal oscillator. An object is to provide a manufacturing method.
[0013]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing a crystal oscillator of the present invention includes :
With respect to a sheet-like ceramic substrate in which the outer peripheral dimensions of a crystal oscillator container that is a finished product is larger than the area formed as a dividing line, the outer peripheral dimensions of the existing crystal oscillator are assembled as a plurality of ceramic substrates.
1, a mounting step of mounting and fixing an IC chip of a size to be a finished product in the area of each ceramic substrate;
2, a first dividing step of separating the area of each ceramic substrate on which the IC chip is mounted from the sheet-like ceramic substrate;
3, on each ceramic substrate separated in the first division step, a superposition step of superposing and integrating a quartz vibration portion of a finished product size, respectively,
4, a temperature data writing step of measuring temperature characteristics of the crystal oscillator formed by the polymerization step and writing temperature data so as to have a predetermined oscillation frequency;
Is constructed using the jig that was used to manufacture the existing crystal oscillator.
[0014]
Then, each ceramic substrate portion of each crystal oscillator for which the temperature data writing process has been completed is cut along the dividing line, and the size of the crystal oscillator to be completed is further reduced than the existing crystal oscillator. It is designed to be manufactured.
[0015]
In addition, in the crystal oscillator manufactured by the above-described manufacturing method, the mounted IC chip is fixed by an underfill material, and a hole having an electrode surface formed on the inner surface is arranged on the dividing line. It is preferable to provide a surface-mount crystal oscillator.
[0016]
As described above, according to the present invention, a part of the ceramic laminated plate can be separated by the dividing line formed on the ceramic laminated plate, so that a smaller surface-mount container can be taken out from the ceramic substrate. become.
Therefore, if a crystal oscillator is manufactured using such a ceramic substrate, even if the crystal oscillator is miniaturized, it oscillates with respect to the surface mount container in the state of the ceramic substrate having a larger planar size than the surface mount container. Circuit components and piezoelectric vibration components can be mounted.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below.
First, the structure of a crystal oscillator according to an embodiment of the present invention will be described with reference to FIGS. In the present embodiment, the crystal oscillator is assumed to be a temperature compensated crystal oscillator (TCXO).
[0018]
Perspective view of the crystal oscillator of the present embodiment having the finished product in FIG. 1, a bottom view in the front view, FIG. (B) in FIG. 2 (a) are illustrated, respectively.
FIG. 3 shows an example of the structure of a crystal vibrating component joined to a crystal oscillator.
[0019]
As shown in FIGS. 1 and 2, the crystal oscillator 1 includes an oscillation circuit unit 2 and a crystal vibrating component 10.
The oscillation circuit unit 2 is configured by mounting, for example, an IC chip 5 on an oscillation circuit container 3.
As shown in FIG. 2A, the oscillation circuit container 3 includes, for example, a rectangular plate-like base portion 3a, which is a first ceramic layer, and two opposing sides on the base portion 3a. The side wall part 3b which is a ceramic layer is laminated. In this case, the base portion 3a has a structure in which two ceramic layers are further laminated.
[0020]
In addition, as can be seen from FIGS. 2A and 2B, surface mounting electrode terminals 4, 4... Are formed on the oscillation circuit container 3 from the outer bottom surface to a part of the side surface of the base portion 3a. Yes. These electrode terminals 4, 4,... Are connected to the surface of an island electrode (land) provided on a mounting board (not shown) on the equipment side on which the crystal oscillator 1 is mounted.
[0021]
Further, on the base portion 3a inside the bottom surface of the oscillation circuit container 3, connection electrodes 8, 8,... To which the extraction electrodes 5a, 5a drawn from the IC chip 5 are connected are formed. And these connection electrodes 8, 8,... Are connected to electrode terminals 4, 4,... Outside the oscillation circuit container 3 through conductive paths (not shown) that form a required circuit pattern in the base 3a. .. Are electrically connected to the joint surfaces 7, 7... Formed on the upper surface of the side wall 3 b of the oscillation circuit container 3.
Further, as shown in FIG. 1, a part of the connection electrodes 8, 8,... Is also connected to the auxiliary electrode terminals 6, 6 ... formed on the side wall portion 3b of the oscillation circuit container 3. Yes. These auxiliary electrode terminals 6, 6... And the joint surfaces 7, 7... Are not electrically connected directly.
[0022]
The auxiliary electrode terminals 6, 6,... Are terminals for writing compensation data for temperature compensation that differs for each crystal oscillator into a memory (not shown) in the IC chip 5 when manufacturing the crystal oscillator.
[0023]
The IC chip 5 is formed with a temperature compensation circuit, a memory circuit, an oscillation circuit, and the like for constituting the temperature compensated crystal oscillator. The lead electrodes 5a, 5a,... Drawn from the IC chip 5 are connected to the connection electrodes 8, 8... Formed on the inside of the bottom surface of the oscillation circuit container 3 described above.
In this case, the IC chip 5 is connected by a flip chip method, and bumps (protrusions) are provided on an external electrode extraction pad (bonding pad) (not shown) of the IC chip 5 so that the extraction electrodes 5a, 5a ... is formed.
[0024]
Then, ultrasonic vibration is applied in a state where the extraction electrodes 5a, 5a,... And the connection electrodes 8, 8,. They are connected or connected using a conductive member such as solder or conductive adhesive.
In this case, in the gap between the IC chip 5 and the bottom surface of the oscillation circuit container 3, in order to protect the circuit surface of the IC chip 5 and to strengthen the connection between the IC chip 5 and the oscillation circuit container 3, For example, an epoxy adhesive or the like is injected as the underfill material 9.
[0025]
In this embodiment, the oscillation circuit is formed by the IC chip 5, but this is only an example. For example, a so-called chip size package IC (chip scale package IC) in which the IC chip is packaged in a chip size is used. Can also be used. In that case, it is not necessary to inject an underfill material.
[0026]
As shown in FIG. 3, the crystal vibrating component 10 houses a crystal piece 14 in, for example, a shallow box-shaped ceramic resonator container 11 and hermetically seals the inside with a lid 12. .
In this case, the crystal piece 14 accommodated in the vibrator container 11 is a rectangular thin plate, and metal electrodes are formed on both surfaces by vapor deposition or the like.
Such a metal electrode of the crystal piece 14 is connected to an electrode lead portion (not shown) formed in the container by the conductive adhesives 15 and 15. The electrode lead-out portion is connected to connection electrodes 13 and 13 provided on the bottom surface of the vibrator container 11 through a through hole, an inner layer pattern, and the like. And these connection electrodes 13 and 13 join with the joint surfaces 7, 7,... Of the oscillation circuit container 3, whereby the oscillation circuit and the crystal resonator are electrically connected. In this case, the connection electrodes 13 and 13 of the crystal vibrating component 10 and the bonding surfaces 7 and 7 of the oscillation circuit container 3 are bonded using, for example, a conductive member such as solder or a conductive adhesive.
[0027]
By the way, in the crystal oscillator 1 having the above configuration, when the planar size (L × B) is reduced from, for example, 3.2 mm × 2.5 mm to 2.5 mm × 2.0 mm, Equipment such as jigs used for manufacturing needs to be changed. For example, it was necessary to reassemble the jigs used for assembling the crystal oscillator and measuring the temperature characteristics, etc., down to the size of the crystal oscillator.
[0028]
Therefore, in the present embodiment, in manufacturing the crystal oscillator 1 as described above, even when the shape size of the crystal oscillator is reduced, the crystal oscillator is manufactured using the manufacturing equipment up to that point. There is a feature.
Hereinafter, a manufacturing method of the crystal oscillator according to the present embodiment will be described. Before explaining the manufacturing method, a ceramic substrate used in manufacturing the crystal oscillator and an oscillation circuit container that can be taken out from such a ceramic substrate The structure will be described with reference to FIGS.
[0029]
FIG. 4 is a diagram showing the structure of a sheet-like ceramic substrate used when manufacturing the crystal oscillator according to the present embodiment.
The sheet-like ceramic substrate 21 shown in FIG. 4 is formed by arranging a plurality of ceramic substrates 31, 31,.
.. Are formed on such a sheet-like ceramic substrate 21. By dividing the sheet-like ceramic substrate 21 by these division lines A, A... The substrate 21 is configured to be separated into a plurality of ceramic substrates 31. Moreover, the position of the dividing line B is also illustrated as will be described later.
[0030]
FIG. 5 is a view showing the structure of a ceramic substrate obtained by dividing the sheet-like ceramic substrate as described above, wherein FIG. 5 (a) is a top view, FIG. 5 (b) is a front view, FIG. A bottom view is shown in c), and a side view is shown in FIG. FIG. 6 is a diagram showing the structure of the oscillation circuit container taken out from the ceramic substrate shown in FIG. 5, wherein FIG. 6 (a) is a top view, FIG. 6 (b) is a front view, and FIG. (C) is a bottom view and FIG. (D) is a side view.
[0031]
The ceramic substrate 31 shown in FIGS. 5A and 5B has a plane size larger than that of the oscillation circuit container 3 and the same plane size as the oscillation circuit container of the crystal oscillator that has been manufactured previously. Is done.
For example, if the plane size of the crystal oscillator 1 of the present embodiment is 2.5 mm × 2.0 mm and the plane size of the conventional crystal oscillator is 3.2 mm × 2.5 mm, for example, the plane size of the ceramic substrate 31 (L1) × B1) is 3.2 mm × 2.5 mm, and the planar size (L2 × B2) of the oscillation circuit container 3 is 2.5 mm × 2.0 mm.
[0032]
In the present embodiment, for example, dividing lines B and B as shown in the figure are also formed on such a ceramic substrate 31, and these dividing lines B, B... By separating 32, an oscillation circuit container 3 having a structure as shown in FIG. 6 is formed.
In this case, an elliptical hole 33 as shown in the figure is formed on the dividing lines B and B of the ceramic substrate 31, and an electrode is formed on the inner surface of the hole 33, so that the ceramic substrate is formed. When 31 is divided by the dividing lines B and B, the electrode terminals 4 for surface mounting are formed on the side surfaces of the oscillation circuit container 3.
Further, in such a ceramic substrate 31, as shown in FIG. 5 (b), the electrode terminals 4 are extended and formed also on both side portions 32, 32 thereof. That is, an electrode terminal having the same size as the electrode terminal 4 formed outside the bottom surface of the conventional crystal oscillator is also formed on the bottom surface of the ceramic substrate 31.
[0033]
In the present embodiment, the crystal oscillator is manufactured using the ceramic substrate 31 of the existing size as described above. That is, for example, the plane size of the ceramic substrate 31 is set to the same size as that of the previous crystal oscillator, and a new crystal oscillator is assembled and temperature characteristics are measured in the state of the ceramic substrate 31. I am doing so. In this way, it becomes possible to manufacture a new miniaturized crystal oscillator using the jig used for manufacturing the previous crystal oscillator, and a jig for manufacturing a new crystal oscillator. There is no need to make.
[0034]
FIG. 7 is a diagram showing a manufacturing procedure of the crystal oscillator according to the present embodiment.
In this case, first, in step S1, a sheet-like ceramic substrate 21 having a structure as shown in FIG. 4 is produced.
Next, in step S2, IC chips 5, 5,... Are mounted at required positions of the sheet-like ceramic substrate 21 produced in step S1.
In the next step S3, the underfill material 9 is injected between the sheet-like ceramic substrate 21 and the IC chips 5 and 5.
[0035]
Next, in step S4, the sheet-like ceramic substrate 21 is divided by dividing lines A, A... And separated into ceramic substrates 31 having the same plane size as the conventional crystal oscillator.
In the next step S <b> 5, the separately produced crystal vibrating component 10 is attached to the ceramic substrate 31. That is, the crystal vibrating component 10 is bonded to the bonding surfaces 7, 7,... Of the ceramic substrate 31 shown in FIG.
[0036]
In the next step S6, the temperature characteristics are measured in units of the ceramic substrate 31 to which the crystal vibration component 10 is bonded. Based on the temperature characteristic measurement result, the ceramic substrate 31 is mounted on the ceramic substrate 31 in the next step S7. Temperature compensation data is written into the IC chip 5.
[0037]
Thereafter, in step S8, the crystal oscillator 1 as shown in FIG. 1 is manufactured by separating and removing both side portions 32, 32 from the ceramic substrate 31 at the dividing lines B, B formed on the ceramic substrate 31. can do.
[0038]
In the manufacturing process of the crystal oscillator as described above, for example, when the chip size package IC is used instead of the IC chip 5 as the oscillation circuit component, the step S3 of injecting the underfill material 9 is not necessary. For example, when a crystal oscillator other than TCXO is manufactured, steps S6 and S7 may be unnecessary.
[0039]
Therefore, if the crystal oscillator is manufactured in this way, in the above-described steps S1 to S7, a new crystal oscillator can be manufactured by using the equipment for manufacturing a conventional crystal oscillator, that is, a jig as it is. Therefore, it is not necessary to manufacture a new jig, and the manufacturing cost of the crystal oscillator can be reduced accordingly.
[0040]
The above-described manufacturing process of the crystal oscillator according to the present embodiment is merely an example. At least a process of mounting an oscillation circuit component such as an IC chip on a ceramic substrate, a step of bonding a piezoelectric vibration component to the ceramic substrate 31, and If the temperature data writing process or the like is performed before the ceramic substrate 31 is divided by the dividing lines B and B, the conventional quartz crystal can be obtained by using the equipment used for manufacturing the crystal oscillator of the conventional size. The crystal oscillator according to the present embodiment having a plane size smaller than that of the oscillator can be manufactured.
[0041]
In addition, the structure of the ceramic substrate 31 illustrated in the present embodiment is merely an example, and the structure of the ceramic substrate as the present invention is not limited to the structure of the ceramic substrate 31 described in the present embodiment. . The point is that the oscillation circuit container of the new size can be taken out when the ceramic substrate is divided by the dividing line with the same size as the oscillation circuit container of the crystal oscillator that has been manufactured so far. Any structure may be used as long as the structure is a ceramic substrate.
[0042]
Further, in the embodiment of FIG. 6, the length of the short side direction B1 is set to be the length of the long side L2 of the oscillation circuit container 3 miniaturized ceramic substrate 31, on both sides of the ceramic substrate 31 each dividing line B, to form a B, the dividing line B, and separated both side portions 32, 32 of the container oscillation circuit is to eject the new oscillator container 3 Suyo by B.
[0043]
Further, in the present embodiment, the side wall 3b of the oscillation circuit container 3 is formed with respect to two short sides on the base 3a. However, this is merely an example, for example, on the base 3a. It is also possible to form it on two long sides. Further, the side wall portion 3b of the oscillation circuit container 3 may be formed on three sides on the base portion 3a, or may be formed only on one side of the base portion 3a if strength is possible. Further, for example, it is possible to form columnar shapes at four corners on the base portion 3a.
[0044]
Furthermore, in the present embodiment, the temperature-compensated crystal oscillator (TCXO) has been described as an example of the crystal oscillator 1, but for example, a crystal oscillation such as a voltage controlled crystal oscillator (VCXO). It can be applied to various crystal oscillators using a child.
Further, it is applicable not only to a crystal oscillator but also to a piezoelectric oscillator using a piezoelectric element such as a resonator.
[0045]
【The invention's effect】
As can be understood from the above description, the present invention is a ceramic substrate in which a smaller-sized surface mounting container can be taken out by separating a part of the ceramic laminated plate by a dividing line formed on the ceramic laminated plate. Is used to manufacture crystal oscillators. In this case, at least the oscillation circuit component and the crystal vibration component are mounted on the surface mounting container in the state of the ceramic substrate, and then the ceramic substrate is divided by the dividing line.
[0046]
In this way, even when the crystal oscillator is downsized, the oscillation circuit component and the crystal vibration component can be mounted on the surface mounting container in a state of a ceramic substrate having a larger planar size than the surface mounting container.
Therefore, for example, if the plane size of the ceramic substrate is set to the same plane size as that of the previously manufactured crystal oscillator, it is possible to divert the jig used in the manufacture of the previous crystal oscillator, Since it is not necessary to manufacture the crystal oscillator, the manufacturing cost of the crystal oscillator can be reduced accordingly.
[Brief description of the drawings]
FIG. 1 is a perspective view showing the structure of a crystal oscillator according to an embodiment of the present invention.
2A and 2B are a side view and a bottom view of the crystal oscillator according to the present embodiment.
FIG. 3 is an explanatory diagram of the structure of a crystal vibrating part.
FIG. 4 is a diagram showing the structure of a sheet-like ceramic substrate used in the manufacturing process of the crystal oscillator of the present embodiment.
FIG. 5 is a diagram showing the structure of a ceramic substrate used in the manufacturing process of the crystal oscillator of the present embodiment.
FIG. 6 is a diagram showing a structure of an oscillation circuit container according to the present embodiment.
FIG. 7 is a diagram showing a manufacturing procedure of the crystal oscillator of the present embodiment.
FIG. 8 is a diagram showing a structure of an oscillation circuit container of a conventional crystal oscillator.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Crystal oscillator, 2 Oscillator circuit part, 3a Base part, 3b Side wall part, 3 Oscillator circuit container, 4 Electrode terminal, 5a Lead electrode, 5 IC chip, 6 Auxiliary electrode terminal, 7 Joint surface, 8 Connection electrode, 9 Under Fill material, 10 Quartz vibration component, 11 Vibrator container, 12 Lid, 13 Connection electrode, 14 Quartz piece, 15 Conductive adhesive, 21 Sheet ceramic substrate, 31 Ceramic substrate, 32 Both sides, 33 holes

Claims (3)

With respect to a sheet-like ceramic substrate in which the outer peripheral dimensions of a crystal oscillator container that is a finished product is larger than the area formed as a dividing line, the outer peripheral dimensions of the existing crystal oscillator are assembled as a plurality of ceramic substrates.
1, a mounting step of mounting and fixing an IC chip of a size to be a finished product in the area of each ceramic substrate;
2, a first dividing step of separating the area of each ceramic substrate on which the IC chip is mounted from the sheet-like ceramic substrate;
3, on each ceramic substrate separated in the first division step, a superposition step of superposing and integrating a quartz vibration portion of a finished product size, respectively,
4, a temperature data writing step of measuring temperature characteristics of the crystal oscillator formed by the polymerization step and writing temperature data so as to have a predetermined oscillation frequency;
The size of the crystal oscillator that will be the finished product by using the jig that was used to manufacture the existing crystal oscillator, and then completing the ceramic substrate part of each crystal oscillator that has completed the temperature data writing process. A second dividing step of cutting along the dividing line so that
To manufacture a crystal oscillator that is smaller than an existing crystal oscillator. 2. The method of manufacturing a crystal oscillator according to claim 1, wherein the IC chip is fixed by an underfill material. 2. The method for manufacturing a crystal oscillator according to claim 1, wherein a hole having an electrode surface formed on an inner surface is disposed on the dividing line.

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