JP4080728B2 - Manufacturing method of surface mount type crystal unit - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface-mount type crystal resonator that can be mounted on the surface of a printed wiring board, for example, and in particular, a method for manufacturing a surface-mount type crystal resonator that is required to be miniaturized.
Is to provide.
[0002]
[Prior art]
In recent years, surface mount type crystal resonators are widely used in various electronic devices such as mobile communication devices.
FIG. 12 is a diagram showing the internal structure of a conventional surface-mount type crystal unit. FIG. 12A shows a top view of the crystal unit and FIG. 12B shows a cross-sectional view thereof. Are shown respectively. Note that the cross-sectional view shown in FIG. 5B is a view of the cross section when the crystal resonator is cut along the alternate long and short dash line shown in FIG.
[0003]
As shown in FIGS. 12A and 12B, a conventional surface-mounted crystal resonator (hereinafter simply referred to as a “crystal resonator”) includes a crystal piece inside an airtight container including a container body 100 and a lid 110. 10 is configured.
The container body 100 is made of, for example, ceramic, and has convex portions 102 and 103 on both sides of the bottom surface inside thereof.
[0004]
The convex portion 102 is a portion where an extraction electrode to which the excitation electrodes 10a and 10b attached to the crystal piece 10 are connected is formed, and is divided into two regions by a gap G provided in the central portion thereof. The extraction electrodes 104 and 105 are formed in the respective regions. Conductive adhesives 106a and 106b are used to connect the lead electrodes 104 and 105 to the electrodes 10a and 10b of the crystal piece 10.
[0005]
The protrusion 103 serves as a receiving surface that holds the other end of the crystal piece 10 that is not connected to the extraction electrodes 104 and 105 when connecting to the electrodes 10 a and 10 b of the crystal piece 10 and the extraction electrodes 104 and 105. Is provided.
Hereinafter, in this specification, the convex portion 102 on which the extraction electrode connected to the electrodes 10a and 10b of the crystal piece 10 is formed is referred to as “extraction electrode convex portion”, and the other end side of the crystal piece 10 is held. The convex portion 103 to be identified is described as “mounting convex portion”.
[0006]
On the outer bottom surface of the container main body 100, for example, four electrode terminals 111, 111... Are provided at the four corners, and of these four electrode terminals 111, 111. 111 is connected to the extraction electrodes 104 and 105 in the container main body 100 by conductive lines 112 and 112, respectively.
These four electrode terminals 111, 111... Are soldered to four lands 122, 122... Provided on a device-side substrate (hereinafter referred to as “mounting substrate”) 121. The crystal resonator can be mounted on the surface of the mounting substrate 121 by connecting by.
[0007]
By the way, when the electrodes 10a and 10b of the crystal piece 10 and the extraction electrodes 104 and 105 are connected in the manufacture of the conventional crystal unit as described above, conductive bonding is performed on the extraction electrodes 104 and 105, respectively. After applying the agents 106 a and 106 b, the crystal piece 10 is placed on the extraction electrodes 104 and 105 using the mounting convex portion 103. At this time, by placing the crystal piece 10 so that the electrodes 10a, 10b of the crystal piece 10 are positioned on the extraction electrodes 104, 105, the electrodes 10a, 10b of the crystal piece 10 are formed by the conductive adhesives 106a, 106b. 10b and the extraction electrodes 104 and 105 are electrically connected, and the crystal piece 10 is mechanically held therein.
[0008]
However, in this case, after the conductive adhesives 106a and 106b are cured, that is, after the connection between the extraction electrodes 104 and 105 and the electrodes 10a and 10b of the crystal piece 10, the projection 103 and a part of the crystal piece 10 come into contact with each other. It will be in the state.
For this reason, when a strain force is applied to the crystal resonator from the outside, the crystal piece 10 is stressed by the strain stress applied to the crystal piece 10 from the mounting convex portion 103, and the oscillation frequency changes. .
[0009]
FIG. 13 is a diagram showing the relationship between external pressure and frequency change in a conventional surface-mount type crystal resonator.
In the graph shown in FIG. 13, for example, among the electrode terminals 111, 111,... Provided at the four corners on the outer bottom surface of the crystal resonator, three electrode terminals 111,. The figure which showed the relationship between an external pressure and a frequency change at the time of giving pseudo-distortion force to a crystal oscillator by applying a weight above the electrode terminal 111 which is not connected to the attachment board | substrate 121 in the connected state. It is.
[0010]
FIG. 13 shows experimental results of three crystal resonators (No1 to No3) as experimental samples.
As can be seen from these experimental results, it can be seen that the oscillation frequency of any of the quartz crystal resonators (No1 to No3) changes greatly as the external weight (g) changes.
[0011]
[Problems to be solved by the invention]
In recent years, mobile communication devices using the above-described crystal resonators have been miniaturized and densified, and crystal resonators used in mobile communication devices and attachments to which the crystal resonators can be attached. The thickness of the substrate 121 is reduced.
For this reason, for example, the mounting substrate 121 is also distorted by pressure applied in a normal use state in which the user operates an operation button provided on the device main body. Further, it is conceivable that distortion of the crystal resonator is applied due to the distortion of the mounting substrate 121 and the oscillation frequency changes.
[0012]
In particular, in a mobile communication device capable of data communication, even if a slight frequency change of about 0.2 ppm, for example, there is a risk that normal data communication cannot be performed. The child preferably suppresses frequency changes due to external pressure as much as possible.
[0013]
Therefore, the present invention has been made in view of the above points, and in a surface-mount type crystal resonator, surface mount capable of suppressing frequency change due to pressure from the outside even when downsizing is required. An object of the present invention is to provide a method for manufacturing a quartz crystal resonator.
[0014]
[Means for Solving the Problems]
In order to achieve the above object, a method for manufacturing a surface-mounted crystal resonator according to the present invention includes:
A crystal piece to which an electrode part for excitation is attached;
A container set to a size that accommodates the crystal piece;
In the container, provided with an extraction electrode part for connecting to the electrode part extended to one end of the crystal piece accommodated,
The extraction electrode portion is at the same height with respect to the first electrode surface. Projecting second and third electrode surfaces Formed so that the connection surface with the electrode part of the crystal piece is concave,
At least, after applying a conductive and heat-shrinkable adhesive to the concave region, it extends to one end of the crystal piece across the second and third electrode surfaces Placed the electrode part,
To cure the heat-shrinkable adhesive Therefore, lift up until the other end of the crystal piece contacts the second and third electrode surfaces. The crystal piece is substantially horizontal with respect to the bottom surface of the container.
[0015]
According to the present invention, even when the surface-mount type crystal resonator is miniaturized, it is easy to lift one end of the crystal piece and support it in the container with a cantilever structure. Even if the container is distorted due to external pressure, the crystal piece connected to the extraction electrode in the container does not come into contact with any part other than the extraction electrode. Can be suppressed.
[0016]
In particular, in the method for manufacturing a surface-mounted crystal resonator according to the present invention, the crystal resonator element is reliably maintained in a substantially horizontal state in the container body, so that it is easy to cope with the miniaturization of the crystal resonator.
[0017]
Furthermore, in the method for manufacturing a surface-mounted crystal resonator according to the present invention, the extraction electrode portion may be formed above a convex portion disposed on the bottom surface of the container.
[0018]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the production method of the present invention Structure example of surface mount type crystal unit to explain Will be described.
1 to 3 are surface-mount type crystal units (hereinafter simply referred to as “crystal units”).
FIG. 1A is a top view, and FIG. 1B is a cross-sectional view. The cross-sectional view shown in FIG. 5B is a cross-sectional view of the crystal resonator taken along the alternate long and short dash line shown in FIG.
[0019]
The crystal resonator shown in FIG. 1 is configured by accommodating a crystal piece 10 in an airtight container including a container body 1 and a lid 11.
The container body 1 is formed of ceramic or the like, and forms an intermediate ceramic layer on both sides of the base ceramic layer that becomes the bottom plate 15, and forms an upper ceramic layer that serves as a side wall at the peripheral edge of the base ceramic layer that is laminated. It has a structure. That is, the container body 1 has a three-layer structure in which three ceramic layers, that is, a base ceramic layer, an intermediate ceramic layer, and an upper ceramic layer are laminated.
In this case, the internal shape of the container body 1 is a very shallow box shape that can accommodate the crystal piece 10.
[0020]
A metallized surface obtained by metallizing (metallizing) ceramic is formed on the upper edge of the container body 1 as a bonding surface 4 for bonding the lid 11. The joint surface 4 may be formed by brazing, for example, a metal seal ring or the like as a joint surface material.
[0021]
On both inner sides of the container body 1, a lead electrode convex portion 2 and a placement convex portion 3 are formed using the intermediate ceramic layer.
[0022]
The lead electrode projections 2 are portions for forming lead electrode portions 5 and 6 to which excitation electrode portions (hereinafter simply referred to as electrodes) 10a and 10b of the crystal piece 10 are connected. In this case, the lead electrode projection 2 is divided into two regions by a gap G provided at the center thereof, and lead electrode portions (hereinafter simply referred to as lead electrodes) 5 and 6 are formed in the respective regions. .
The extraction electrodes 5 and 6 and the electrodes 10a and 10b of the crystal piece 10 are connected by conductive adhesives 7a and 7b which are connecting members, and the extraction electrodes 5 and 6 and the electrodes 10a and 10b of the crystal piece 10 are electrically connected. And the crystal piece 10 is mechanically held therein. The structure of the extraction electrodes 5 and 6 will be described later.
The connection member is, for example, a heat shrink type, and a relatively soft silicon-based adhesive that can absorb an impact applied to the crystal piece 10 to be connected is used. Of course, if the extraction electrodes 5 and 6 and the electrodes 10a and 10b can be electrically and mechanically connected, an adhesive other than a silicon-based adhesive can be used as the connection member.
[0023]
The mounting convex portion 3 is provided to hold the other end side of the crystal piece 10 that is not connected to the extraction electrodes 5 and 6 when connecting to the electrodes 10a and 10b of the crystal piece 10 and the extraction electrodes 5 and 6; The crystal piece 10 functions as a receiving surface.
[0024]
For example, four electrode terminals 13, 13... Are provided at the four corners of the outer bottom surface of the container body 1, and of these four electrode terminals 13, 13,. 13 are connected to the extraction electrodes 5 and 6 in the container body 1 by conductive lines 12 and 12, respectively.
And, by connecting these four electrode terminals 13, 13,... To the four lands 22, 22,... Provided on the device-side mounting substrate 21, by solder 23, 23,. A crystal resonator can be mounted on the surface of the mounting substrate 21.
[0025]
In the crystal resonator of this example, the lead electrodes 5 and 6 have the following structure, so that when the electrodes 10a and 10b of the crystal piece 10 are connected to the lead electrodes 5 and 6, the crystal piece 10 Does not come into contact with portions other than the extraction electrodes 5 and 6.
[0026]
Here, the structure of the extraction electrodes 5 and 6 of the crystal resonator shown in FIG. 1 will be described with reference to FIG.
2A shows a top view of the container body 1 shown in FIG. 1, and FIG. 2B shows a cross-sectional view thereof. The cross-sectional view shown in FIG. 2B is a view of the cross-section when the container main body is cut along the alternate long and short dash line shown in FIG.
[0027]
As shown in FIGS. 2A and 2B, the extraction electrode 5 includes a first electrode surface 5a and a second electrode surface 5b. In this case, the second electrode surface 5b is formed at a position from the mounting convex portion 3 on the first electrode surface 5a, and a step is provided between the first electrode surface 5a and the second electrode surface 5b. ing. That is, a step portion is provided on the surface of the extraction electrode 5.
[0028]
Similarly, the extraction electrode 6 includes a first electrode surface 6a and a second electrode surface 6b. Similar to the extraction electrode 5, the second electrode surface 6b is formed at a position from the mounting convex portion 3 on the first electrode surface 6a, and a step portion is formed between the first electrode surface 6a and the second electrode surface 6b. Is provided.
[0029]
In order to fabricate the extraction electrodes 5 and 6 as described above, the first electrode surfaces 5a and 6a of the extraction electrodes 5 and 6 are formed by metallizing (metalizing) the extraction electrode protrusions 2 made of ceramic, for example. When forming the second electrode surfaces 5b and 6b, a general conductive member such as tungsten or molybdenum manganese is applied so as to have a predetermined film thickness. can do. Although not shown, the surfaces of the extraction electrodes 5 and 6 are plated with gold or nickel. The manufacturing method of the extraction electrodes 5 and 6 described here is merely an example, and is not limited to such a manufacturing method. For example, the second electrode surfaces 5b and 6b may be formed of an insulating member. Conceivable.
[0030]
FIG. 3 is a diagram schematically showing a state where the crystal piece 10 is connected to the extraction electrode of the container body 1 shown in FIG.
In this case, as can be seen from FIG. 3A, the conductive adhesives 7a and 7b used for connecting the extraction electrodes 5 and 6 and the electrodes 10a and 10b of the crystal piece 10 are used as the first electrodes of the extraction electrodes 5 and 6. It is made to apply | coat on the surface 5a, 6a. That is, in this case, when the quartz piece 10 is placed on the extraction electrodes 5 and 6 using the placement convex portion 3, the first electrode surfaces 5 a and 6 a and the second electrodes of the extraction electrodes 5 and 6. Step portions formed between the surfaces 5b and 6b become application portions 9a and 9b for applying the conductive adhesives 7a and 7b.
[0031]
When the conductive adhesives 7a and 7b are applied to the application portions 9a and 9b, as shown in FIG. 3 (a), at the time before the conductive adhesives 7a and 7b are cured, The other end of the piece 10 is in contact with the mounting convex portion 3. Then, as the conductive adhesives 7a and 7b are cured, the conductive adhesives 7a and 7b contract, and the other end side of the crystal piece 10 is raised by the contraction force. That is, when the position of one end side of the crystal piece 10 connected to the extraction electrodes 5 and 6 is lowered by the conductive adhesives 7a and 7b, the second electrode surfaces 5b and 6b serve as fulcrums and The end side will be lifted.
As a result, when the conductive adhesive 7a is cured, as shown in FIG. 3B, the other end side of the crystal piece 10 is lifted, and the crystal piece 10 and the mounting convex portion 3 are separated by a distance t1. Thus, the crystal piece 10 does not come into contact with anything other than the extraction electrodes 5 and 6.
[0032]
Therefore, according to the crystal resonator according to this embodiment, the crystal piece 10 is placed on the mounting convex portion 3 in consideration of the lifting amount of the crystal piece 10 and the distortion force applied to the crystal resonator by the external pressure. If the distance t1 between the crystal piece 10 and the mounting convex portion 3 is set so as not to contact with the mounting convex portion 3, the crystal piece 10 does not come into contact with the mounting convex portion 3 due to a distortion force from the outside.
[0033]
Similarly, if the distance t2 between the crystal piece 10 and the lid 11 is set in consideration of the distortion force applied to the crystal resonator, the crystal piece 10 may be prevented from contacting the lid 11. it can.
[0034]
Thereby, in the crystal resonator as this embodiment, For the time being, The crystal piece 10 is in contact with a portion other than the extraction electrodes 5 and 6, for example, the mounting convex portion 3 and the lid 11 Not so A change in the oscillation frequency of the crystal resonator can be suppressed without applying stress in the longitudinal direction of the crystal piece 10.
[0035]
In this case, the distance t1 between the crystal piece 10 and the mounting convex portion 3 is such that the heights of the extraction electrode convex portion 2 and the mounting convex portion 3 are equal, and the film thicknesses of the first electrode surfaces 5a and 6a. If the thickness of the second electrode surfaces 5b and 6b is extremely thin, it changes depending on the height (film thickness) of the second electrode surfaces 5b and 6b and the shrinkage force of the heat shrinkable adhesive Will do .
[0036]
FIG. 4 is a diagram showing the relationship between the external pressure and the frequency change in the crystal unit shown in FIG.
In the graph shown in FIG. 4, the three electrode terminals 13,... Of the four electrode terminals 13, 13... Provided at the four corners of the outer bottom surface of the crystal unit shown in FIG. In the state of being connected to the lands 22 of the 21, the external pressure and frequency when applying a strain from the upper side of the electrode terminal 13 not connected to the mounting substrate 21 to give a pseudo strain to the crystal resonator. It is the figure which showed the relationship of a change.
[0037]
FIG. 4 shows experimental results of three crystal resonators (No1 to No3) as experimental samples.
As apparent from comparing the experimental results shown in FIG. 4 and the experimental results of the conventional crystal resonator shown in FIG. 13, the crystal resonator shown in FIG. It was confirmed that even if g) was changed, the change in the oscillation frequency was small.
[0038]
Therefore, if the crystal resonator shown in FIG. 1 is applied to a small mobile communication device, for example, the pressure applied when the user operates the operation button of the device main body causes distortion or the like on the mounting substrate 21, and the crystal Even if a distortion force is applied to the vibrator, a change in the oscillation frequency can be suppressed.
In particular, when such a crystal resonator is applied to a mobile communication device that performs data communication that is easily affected by a frequency change, good data communication can be performed.
However, the quartz crystal container body further When the size is reduced, it becomes difficult to reliably maintain the distance t1 for lifting one terminal of the crystal piece 10 as a gap.
[0039]
Accordingly, a crystal resonator according to an embodiment of the present invention in which this point is improved will be described.
5 (a) and 5 (b) Of the present invention It is the upper side figure and sectional view which showed the internal structure of the crystal oscillator as a form. Note that the cross-sectional view shown in FIG. 5B is a cross-sectional view of the crystal resonator taken along the alternate long and short dash line shown in FIG.
6 is a top view and a cross-sectional view for explaining the structure of the extraction electrode of the crystal resonator shown in FIG. The cross-sectional view shown in FIG. 6B is a view of the cross-section when the container main body is cut along the alternate long and short dash line shown in FIG. 6A from the arrow B′-B ′ direction.
5 and 6, the same parts as those in FIGS. As much as possible The same number is attached and detailed explanation is omitted.
[0040]
Of the present invention As shown in FIGS. 5 (a) and 5 (b), the crystal resonator as an embodiment also uses an intermediate ceramic layer, and has a lead electrode convex portion 2 and a mounting convex portion. 3, and the extraction electrodes 5 and 6 are formed on the extraction electrode convex portion 2.
[0041]
In this case, the extraction electrode 5 has a third electrode surface 5c formed on the first electrode surface 5a in addition to the first electrode surface and the second electrode surfaces 5a and 5b.
That is, the second electrode surface 5b is formed at a position on the first electrode surface 5a from the mounting convex portion 3, and the first electrode surface 5a is positioned at a position opposite to the second electrode surface 5b. A concave portion is formed on the surface of the extraction electrode by forming a three-electrode surface 5c and providing step portions between the first electrode surface 5a and the second electrode surface 5b and between the first electrode surface 5a and the third electrode surface 5c. To be formed.
[0042]
Similarly, the extraction electrode 6 forms the second electrode surface 6b on the first electrode surface 6a described above at a position from the mounting convex portion 3, and the second electrode surface on the first electrode surface 6a. A third electrode surface 6c is formed at a position opposite to 6b, and a step portion is formed between the first electrode surface 6a and the second electrode surface 6b and between the first electrode surface 6a and the third electrode surface 6c. A recess is formed on the upper surface of the extraction electrode portion.
[0043]
Therefore, in this case, the concave portion on the upper surface of the first electrode surface 5a located between the second electrode surface 5b of the extraction electrode 5 and the third electrode surface 5c has a coating portion 9a for applying the conductive adhesive 7a; The upper surface recess of the first electrode surface 6a located between the second electrode surface 6b of the extraction electrode 6 and the third electrode surface 6c becomes the application portion 9b for applying the conductive adhesive 7b.
The second electrode surfaces 5b and 6b and the third electrode surfaces 5c and 6c of the extraction electrodes 5 and 6 are preferably formed to have the same height.
[0044]
Further, when producing the extraction electrodes 5 and 6, for example, when the first electrode surfaces 5 a and 6 a are formed by metallizing the extraction electrode projection 2, the second electrode surfaces 5 b and 6 b and the third electrode surfaces 3 are formed. For example, a general conductive member such as tungsten or molybdenum manganese is applied to the portions where the electrode surfaces 5c and 6c are to be formed so as to have a predetermined film thickness. For example, the second electrode surfaces 5b and 6b and the third electrode surfaces 5c and 6c can be formed using an insulating member.
[0045]
When the crystal oscillator shown in FIG. 5 is manufactured, when the lead electrodes 5 and 6 and the extended portions of the electrodes 10a and 10b of the crystal piece 10 are connected by the conductive adhesives 7a and 7b, the first electrode surface is used. After applying conductive adhesives 7a and 7b to the application portions 9a and 9b formed on 5a, respectively, the quartz piece 10 is placed on the extraction electrodes 5 and 6 by using the mounting convex portions 3. To be done. At this time, as shown in FIG. 5, the second electrode surface 5b (second electrode surface 6b) on the extraction electrodes 5 and 6 and the third electrode surface 5c (third electrode surface 6c). ), The electrodes 10a, 10b extending on one side of the crystal piece 10 are placed and placed on the crystal piece 10, so that the conductive adhesives 7a, 7b The extraction electrodes 5 and 6 are electrically connected, and the crystal piece 10 is mechanically held therein.
[0046]
In this case as well, if the conductive adhesives 7a and 7b are applied to the application portions 9a and 9b that are concave portions, a crystal piece is obtained before the conductive adhesives 7a and 7b are cured. The other end side of 10 is in contact with the mounting convex portion 3, but the conductive adhesives 7a and 7b contract as they harden, and the other end side of the crystal piece 10 rises due to the contraction force, The second electrode surfaces 5 b and 6 b serve as fulcrums, and the other end side of the crystal piece 10 is separated from the mounting convex portion 3.
When the other end side of the crystal piece 10 is lifted to a horizontal position, the crystal piece 10 comes into contact with the third electrode surfaces 5c and 6c, and the lifting is restricted.
As a result, when the conductive adhesive 7a is cured, the other end of the crystal piece 10 is lifted to a substantially horizontal position, and the crystal piece 10 and the mounting convex portion 3 are separated by a distance t1, and the crystal piece 10 Does not come into contact with anything other than the extraction electrodes 5 and 6.
Further, as shown in FIG. 5, the crystal vibrating piece 10 is in a substantially horizontal state, so that the distance t2 with the lid 11 can be set to a predetermined gap, and even when the container body is downsized. Easy to maintain cantilever structure.
[0047]
Therefore, even when the surface-mount type crystal resonator manufactured in this embodiment is miniaturized, the crystal piece 10 is placed on the convex projection in consideration of the distortion force applied to the crystal resonator by external pressure. Since it becomes easy to set the distance t1 between the crystal piece 10 and the mounting convex portion 3 and the distance t2 with the lid so that the crystal piece 10 does not come into contact with the portion 3, the crystal piece 10 is caused by the external distortion force. Contact with the mounting convex portion 3 is eliminated, and a change in the oscillation frequency of the crystal resonator can be reliably prevented.
[0048]
Thus, in this case, since the crystal piece 10 can be kept almost horizontal by forming the third electrode surfaces 5c and 6c on the extraction electrodes 5 and 6, the crystal piece 10 and the lid 11 If the distance t <b> 2 is reliably maintained, it is easy to manufacture so that the crystal piece 10 does not contact the lid 11 reliably.
[0049]
Next, a crystal resonator as another embodiment of the present invention will be described with reference to FIGS.
FIGS. 7A and 7B are a top view and a cross-sectional view showing the internal structure of the crystal resonator. Note that the cross-sectional view shown in FIG. 5B is a cross-sectional view of the crystal resonator taken along the alternate long and short dash line shown in FIG.
8A is a top view for explaining the structure of the crystal resonator shown in FIG. 7, and FIG. 8B is a sectional view thereof. In addition, the cross-sectional view shown in FIG. 8B is a view of the cross section when the container main body is cut along the alternate long and short dash line shown in FIG. 8A from the arrow C′-C ′ direction. The same parts as those in FIGS. 5 and 6 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0050]
In the crystal resonator as the embodiment shown in FIG. 7, as shown in FIGS. 7A and 7B, only the lead electrode convex portion 2 is formed using the intermediate ceramic layer. The lead electrode projections 2 are divided by gaps G, and lead electrodes 5 and 6 are formed in the respective regions.
Also in this case, the extraction electrodes 5 and 6 form the second electrode surfaces 5b and 6b and the third electrode surfaces 5c and 6c on the first electrode surfaces 5a and 6a, respectively.
In this case as well, it is preferable that the electrode surfaces of the extraction electrodes 5 and 6 are all formed to have the same height.
[0051]
Accordingly, when the extraction electrodes 5 and 6 and the electrode of the crystal piece 10 are connected by the conductive adhesives 7a and 7b at the time of manufacturing the crystal resonator shown in FIG. 7, the first electrode surfaces 5a and 5b are connected. Before the conductive adhesives 7a and 7b are cured by applying the conductive adhesives 7a and 7b to the application portions 9a and 9b between the second electrode surfaces 5b and 6b and the third electrode surfaces 5c and 6c. At this point, the other end side of the crystal piece 10 is in contact with the bottom plate 15 of the container body 1, but as the conductive adhesives 7a and 7b are cured, the other end of the crystal piece 10 is contracted by the contraction force. The side will be lifted.
When the other end side of the crystal piece 10 is raised to a horizontal position, the crystal piece 10 comes into contact with the third electrode surfaces 5c and 6c, and the lift is restricted, so that the conductive adhesives 7a and 7b are cured. At this point, the crystal piece 10 becomes almost horizontal, and the crystal piece 10 does not come into contact with anything other than the extraction electrodes 5 and 6.
[0052]
Therefore, the quartz crystal resonator according to this embodiment also does not come into contact with the bottom plate 15 or the lid 11 even when a distortion force is applied from the outside, and the oscillation frequency of the quartz crystal resonator is reliably changed. It becomes possible to suppress.
[0053]
In particular, in this case, since the placement convex portion 3 is not provided in the container body 31, a sufficient distance t 1 between the crystal piece 10 and the container body 31 can be ensured accordingly, and thus the crystal piece 10. Therefore, it is possible to reliably suppress the change in the oscillation frequency due to the contact.
[0054]
The shapes of the second electrode surfaces 5b and 5c and the third electrode surfaces 6b and 6c of the extraction electrodes 5 and 6 described in the embodiments described so far and the positions thereof are merely examples. The shape of the electrode surface and the position thereof are not limited by the drawings.
[0055]
FIG. 9 illustrates the internal structure of a crystal resonator as another embodiment for reducing the size of the container body. Note that the cross-sectional view shown in FIG. 6B is a cross-sectional view of the crystal resonator taken along the alternate long and short dash line shown in FIG. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0056]
The crystal resonator according to the embodiment shown in FIG. 9 includes a container body 41 in the container body 31 without forming the extraction electrode projections 2 and the placement projections 3 using an intermediate ceramic layer. The extraction electrodes 5 and 6 are formed directly on the bottom plate 15.
[0057]
Also in this case, by providing a stepped portion on the surface of the extraction electrodes 5 and 6, the crystal piece at the time before the conductive adhesives 7a and 7b connecting the extraction electrodes 5 and 6 and the electrode of the crystal piece 10 are cured. 10 has the other end in contact with the bottom plate 15 of the container body 41, but after the conductive adhesives 7a and 7b are cured, the crystal piece 10 is separated from the bottom plate 15 of the container body 41 by a distance t1. It becomes.
[0058]
Accordingly, even in such a configuration, it is possible to suppress a change in the oscillation frequency by a distortion force applied from the outside.
Further, in this case, since the height of the container body 41 can be reduced by the amount that the extraction electrode protrusions 2 and the placement protrusions 3 are not formed in the container body 41, the thickness of the crystal resonator is reduced. Can
Further, if the crystal resonator having such a configuration is applied to a mobile communication device, there is an advantage that the device can be further reduced in size and thickness.
[0059]
Note that the shapes of the second electrode surfaces 5b and 6b and the third electrode surfaces 5c and 6c of the extraction electrodes 5 and 6 described in the above embodiments and the formation positions thereof are merely examples, and the first embodiment of the present invention is as follows. The shapes of the second and third electrode surfaces are not limited to these shapes and positions.
[0060]
In short, when connecting the crystal piece 10 to the connection surface (first electrode surface) of the extraction electrodes 5 and 6, a surface or a point (second electrode surface) is used as a fulcrum for lifting the other end of the crystal piece 10 ), And in addition to the second electrode surface, a surface or a point (third electrode surface) that restricts the lifting of the crystal piece 10 is provided, the shape and the arrangement position are particularly limited. It is not something. For example, the second and third electrode surfaces can be formed by a plurality of surfaces or points.
[0061]
In the present embodiment, the second electrode surfaces 5b and 6b and the third electrode surfaces 5c and 6c of the extraction electrodes 5 and 6 are formed on the first electrode surfaces 5a and 6a. Enables the crystal resonator to be supported in a substantially horizontal direction, and by providing the second electrode surface and the third electrode surface projecting at the same height with respect to the first electrode surface, A concave portion to which a shrinkable resin can be applied can also be formed.
[0062]
By the way, the present applicants have conducted extensive studies in order to suppress the frequency change due to the external pressure of the crystal resonator, and as a result, the conductive adhesive applied when connecting the extraction electrodes 5 and 6 and the crystal piece 10. It was found that if the distance between 7a and 7b is narrowed, the frequency change due to the external pressure of the crystal resonator can be further suppressed.
[0063]
This is because the crystal resonator according to the embodiment described so far prevents the crystal piece 10 from coming into contact with the mounting convex portion 3, so that the distortion of the crystal piece 10 is mainly out of the distortion force applied to the crystal piece 10. While the influence of the strain stress applied in the longitudinal direction is suppressed, if the distance between the conductive adhesives 7a and 7b connecting the extraction electrodes 5 and 6 and the crystal piece 10 is narrowed, the crystal piece 10 becomes short. This is because the influence of strain stress applied in the hand direction can be suppressed.
[0064]
Therefore, as an embodiment of the present invention, a crystal resonator capable of suppressing strain stress applied in the short direction of the crystal piece 10 will be described.
FIG. 10 is a top view and a cross-sectional view for explaining the internal structure of the crystal resonator. Note that the cross-sectional view shown in FIG. 10B is a view of the cross section when the crystal unit is cut along the alternate long and short dash line in FIG. The same parts as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.
[0065]
The crystal resonator shown in FIG. 10 is made such that the crystal piece 10 and the mounting convex portion 3 do not come into contact with each other, and further, conductive adhesives 7a and 7b for connecting the crystal piece 10 and the extraction electrodes 5 and 6 to each other. The distance L1 between them is configured to be narrower than before.
For example, in the crystal resonator shown in FIG. 1, the distance L1 between the conductive adhesives 7a and 7b is about 1.6 mm, whereas in the crystal resonator shown in FIG. The example which narrowed to about 1.0 mm is shown.
[0066]
FIG. 11 is a diagram showing the relationship between the external pressure and the frequency change in the crystal unit shown in FIG.
The graph shown in FIG. 11 also shows that the three electrode terminals 13... Are connected to the lands 22... Of the mounting substrate 21 among the four electrode terminals 13, 13. FIG. 6 is a diagram showing the relationship between the external pressure and the frequency change when applying a weight from above the electrode terminal 13 not connected to the mounting substrate 21 to give a pseudo strain to the crystal resonator.
[0067]
The experimental results of three crystal resonators (No1 to No3) are shown as the experimental samples shown in FIG. 11. Compare the experimental results shown in FIG. 11 with the experimental results shown in FIG. Obviously, as in the crystal resonator shown in FIG. 10, when the distance L1 between the conductive adhesives 7a and 7b connecting the crystal piece 10 and the extraction electrodes 5 and 6 is narrowed, the oscillation frequency changes more. It was confirmed that it can be suppressed.
[0068]
Therefore, when the crystal unit shown in FIG. 10 is applied to a small and thin mobile communication device, even if distortion or the like occurs in the mounting substrate 21 on the device side and a distortion force is applied to the crystal unit, the oscillation is generated. The change in frequency can be made smaller.
[0069]
In the crystal resonator shown in FIG. 10, the case where the distance L1 between the conductive adhesives 7a and 7b is narrowed to about 1.0 mm has been described as an example. As the distance L1 between the adhesives 7a and 7b is reduced, the strain stress applied in the short direction of the crystal piece 10 can be suppressed.
[0070]
Note that the distance L1 between the conductive adhesives 7a and 7b is a frequency deviation until it is considered that there is no practical problem in the mobile communication device when the crystal resonator shown in FIG. 10 is used as a clock generator. What is necessary is just to set the distance between the conductive adhesives 7a and 7b so that it may be suppressed. Therefore, the distance between the conductive adhesives 7a and 7b does not need to be uniquely determined. For example, the distance between the conductive adhesives 7a and 7b may be set as appropriate so as to obtain the frequency system required by the device on which the crystal resonator is mounted. It is.
For example, as shown in FIG. 10, if the crystal resonator is configured such that the crystal piece 10 and the mounting convex portion 3 are not in contact with each other, the conductive adhesives 7 a and 7 b are applied in the vicinity of the gap G. It can be set to.
[0071]
Further, in the crystal resonator of the form shown in FIG. 10, the extraction electrodes 5 and 6 are configured as in the embodiment shown in FIG. 1, and the crystal piece 10 and the mounting convex part 3 are not in contact with each other. In addition, the case where the distance between the conductive adhesives 7a and 7b that connect the crystal piece 10 and the extraction electrodes 5 and 6 is narrowed is described as an example, but this is only an example, Needless to say, the present invention can also be applied to the crystal resonators as the embodiments exemplified above.
[0072]
Further, in addition to the crystal resonator as the embodiment exemplified so far, if the crystal resonator is configured by connecting the electrodes 10a and 10b of the crystal piece 10 to the extraction electrode provided in the container body, it is simply Since the strain stress applied in the short direction of the crystal piece 10 can be suppressed only by reducing the distance between the conductive adhesives 7a and 7b connecting the crystal piece 10 and the extraction electrodes 5 and 6, the crystal resonator It is possible to suppress changes in the oscillation frequency. In that case, when the crystal resonator is used as a clock generator, the distance between the conductive adhesives 7a and 7b is set so that the frequency shift is suppressed until there is no practical problem in the mobile communication device. You only need to set it.
[0073]
In the present embodiment, as the connection member, for example, a heat shrink type and a relatively soft silicon-based adhesive that can absorb an impact applied to the crystal piece 10 that is a connection target is used as an example. However, this is merely an example, and other types of conductive adhesives can be used as long as they are contraction types.
[0074]
【The invention's effect】
As described above, the surface-mounted crystal resonator of the present invention Production method Since the crystal piece is configured so that it does not come into contact with any part other than the extraction electrode when the electrode of the crystal piece and the extraction electrode are connected by the connecting member, the stress is applied even if a strain force is applied from the outside. Can be prevented from being applied to the crystal piece.
[0075]
That is, if the extraction electrode is formed by the first electrode surface and the second electrode surface, a step portion is provided between the first electrode surface and the second electrode surface, and at least the connecting member is applied to the step portion, the second Since the electrode surface becomes a fulcrum and the other end of the crystal piece is lifted as the connecting member is hardened, the crystal piece does not contact any part other than the extraction electrode. Become .
[0076]
In particular, in the method for manufacturing a surface-mount type crystal resonator according to the present invention, the extraction electrode portion is formed by forming the first electrode surface, the second electrode surface and the third electrode surface on the first electrode surface, The second and third electrode surfaces protrude at the same height relative to the first electrode surface. , At least after applying a conductive heat-shrink connecting agent to the recess formed on the first electrode surface,
By placing the electrode portion of the crystal piece across the second and third electrode surfaces, After the adhesive is cured, when the other end of the crystal piece is lifted, the lifting amount is restricted on the second and third electrode surfaces, so that it can be kept almost horizontal, Even when the surface-mount type crystal resonator container is downsized, it is possible to easily prevent the other end of the crystal piece from coming into contact with the inside of the container.
[0077]
In addition, the surface mount type crystal resonator of the present invention sets the distance between the connecting members that connect the crystal piece and the extraction electrode so that the stress applied in the short direction of the crystal piece is suppressed below the required level. Then outside Even if a strain force is applied from the portion, it is possible to suppress the stress from being applied to the crystal piece.
[0078]
Therefore, if such a crystal resonator of the present invention is applied to a small and thin mobile communication device, even if distortion is applied to the crystal resonator due to pressure from the device side, the change in the oscillation frequency is suppressed. Therefore, stable communication with good quality can be performed.
In particular, if the present invention is applied to a mobile communication device that performs data communication, good data communication can be reliably performed.
[Brief description of the drawings]
FIGS. 1A and 1B are a top view and a cross-sectional view for explaining an internal structure of a crystal resonator according to a first embodiment.
2 is a top view and a cross-sectional view showing the internal structure of the container shown in FIG. 1. FIG.
FIG. 3 is a diagram schematically showing a state of adhesion between an electrode of a crystal piece and an extraction electrode.
4 is a diagram showing a relationship between an external pressure and a frequency change in the crystal unit shown in FIG. 1. FIG.
FIGS. 5A and 5B are a top view and a cross-sectional view for explaining an internal structure of a crystal resonator according to a second embodiment. FIGS.
6 is a top view and a cross-sectional view showing the internal structure of the container shown in FIG. 5. FIG.
FIGS. 7A and 7B are a top view and a cross-sectional view for explaining an internal structure of a crystal resonator according to a third embodiment. FIGS.
8 is a diagram showing the relationship between external pressure and frequency change in the crystal unit shown in FIG.
FIGS. 9A and 9B are a top view and a cross-sectional view for explaining an internal structure of a crystal resonator according to a fourth embodiment. FIGS.
FIGS. 10A and 10B are a top view and a cross-sectional view for explaining an internal structure of a crystal resonator according to a fifth embodiment. FIGS.
11 is a diagram showing the relationship between external pressure and frequency change in the crystal unit shown in FIG.
12A and 12B are a top view and a cross-sectional view for explaining an internal structure of a conventional crystal unit.
13 is a diagram showing the relationship between external pressure and frequency change in the conventional crystal unit shown in FIG.
[Explanation of symbols]
1 31 41 Container body, 2 extraction electrode convex portion, 3 mounting convex portion, 4 joint surface, 5 6 extraction electrode, 5a 6a first electrode surface, 5b 6b second electrode surface, 5c 6c third electrode surface, 7a 7b conductive adhesive, 9a 9b coating part, 10 crystal piece, 10a, 10b electrode, 11 lid, 12 conductive line, 13 electrode terminal, 21 mounting substrate, 22 land

Claims (2)

A crystal piece to which an electrode part for excitation is attached;
A container set to a size that accommodates the crystal piece;
In the container, provided with an extraction electrode part for connecting to the electrode part extended to one end of the crystal piece accommodated,
The extraction electrode portion is formed by second and third electrode surfaces protruding at the same height with respect to the first electrode surface, and is concave on the connection surface with the electrode portion of the crystal piece. Forming a region,
At least, after applying a conductive heat-shrinkable adhesive to the concave region, an electrode portion extending on one end of the crystal piece is placed across the second and third electrode surfaces. Place
Thereafter, by curing the heat-shrinkable adhesive, the other end of the crystal piece is lifted, and the electrode portion abuts and adheres to both the second and third electrode surfaces. A method for manufacturing a surface-mounted crystal resonator, wherein the crystal piece is horizontal with respect to the bottom surface of the container.   2. The method for manufacturing a surface-mount type crystal resonator according to claim 1, wherein the extraction electrode portion is provided above a convex portion provided on a bottom surface in the container.

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