JP3929714B2 - Surface-mount crystal oscillator - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a surface-mount type crystal oscillator (referred to as a surface-mount oscillator) as an industrial technical field, and more particularly to a surface-mount container in which a mounting area is increased to maintain strength.
[0002]
[Prior art]
BACKGROUND OF THE INVENTION Crystal oscillators are widely used in various electronic devices including communication devices as a frequency and time reference source. In particular, the surface-mounted oscillator is mainly used for portable devices because of its small size and light weight.
[0003]
(Example of Prior Art) FIG. 6 is a cross-sectional view of a surface mount oscillator for explaining one conventional example. The surface mount oscillator is configured by housing a crystal piece 4, an IC chip 5, and a circuit element 6 in a surface mount container 3 including a container body 1 and a cover 2. The container body 1 is made of a laminated ceramic, and has concave portions surrounded by side walls on the entire main surface sides. Normally, as shown in the basic assembly configuration diagram of FIG. 7, the upper and lower side walls in the form of a sheet having a plurality of openings 8 on both main surface sides of the bottom wall layer 7 in the form of a sheet. Layers 9 and 10 are laminated and fired, and then divided into individual container bodies 1.
[0004]
Then, the crystal piece 4 is accommodated in a concave portion (one concave portion) on one main surface side, and the IC chip 5 and the circuit element 6 are accommodated in a concave portion (other concave portion) on the other main surface side. The quartz crystal piece 4 (FIG. 9) is secured to the bottom surface of one concave portion by the conductive adhesive 13 on both sides of one end of the extraction electrode 12 (ab) extending from the excitation electrode 11 (ab) (FIG. 8). The IC chip 5 is fixed to the bottom surface of the other concave portion by the conductive adhesive 13 by ultrasonic thermocompression bonding or thermocompression bonding using bumps. And the mounting surface electrodes, such as a power supply, an output, and earth which are not shown in figure, are provided in the square surface of the other recessed part. Reference numeral 14 (ab) is a measurement terminal of the crystal resonator (crystal piece 4).
[0005]
[Problems to be solved by the invention]
(Problems of the prior art) However, the surface-mounted oscillator having the above-described configuration has a problem that the plate surface area is reduced as the miniaturization is rapidly promoted. Therefore, it has been considered to remove the side walls and form pedestals only at the squares to increase the plate area (not shown). However, in this case, since each pedestal is independent, there is a problem that it is difficult to form a sheet and the manufacturing is complicated.
[0006]
Further, when downsizing is required, especially when the height is lowered, the bottom wall layer 7 is also thinned, and the strength of the bottom wall layer 7 is reduced by only the square pedestals, so that the bottom wall layer 7 is easily bent. There was also a risk of peeling from the bottom or damaging the bottom wall layer 7 itself.
[0007]
(Object of the invention) An object of the present invention is to provide a surface-mount oscillator in which the plate surface area on the other main surface side of the container body is increased, the manufacture is facilitated, and the strength is maintained.
[0008]
[Means for Solving the Problems]
The basic solution of the present invention is to open a pair of opposing side walls that form recesses on the other main surface side of the surface mount container.
[0009]
[Action]
In the present invention, since the set of side walls on the other main surface side is opened, the plate surface area can be increased. Further, since the square portions are not independent, lamination is facilitated. And strength is raised by the other set of side walls facing each other. Hereinafter, an embodiment of the present invention will be described based on the manufacturing process.
[0010]
【Example】
1 and 2 are diagrams for explaining one embodiment of the present invention. FIG. 1 is a sectional view of a surface-mount oscillator, and FIG. 2 is a plan view of the other recess. In addition, the same number is attached | subjected to the same part as a prior art example figure, and the description is abbreviate | omitted or abbreviate | omitted.
As described above, the surface-mount oscillator accommodates the crystal piece 4 in one concave portion of the container body 1 made of laminated ceramic. In this embodiment, a part of a pair of side walls which are formed in the opposite short side direction and which forms the other concave portion is opened. In other words, a recess having an open end is formed by the other set of side walls P (1,2) in the long side direction and a part of the set of side walls.
[0011]
Then, the IC chip 5 is fixed to the center of the bottom surface of the other recess by, for example, ultrasonic thermocompression using a bump or thermocompression. In addition, the circuit element 6 is disposed on the bottom surface of the recess and the bottom surface where the side wall is partially open (referred to as the recess open bottom surface 15), and the crystal measurement terminal 14 (ab) is formed as necessary.
[0012]
As shown in FIG. 3, the container body 1 has a bottom wall layer 7 in the form of a sheet, an upper side wall layer 9 having a plurality of openings 8, and a row of openings 16 that are long in one direction. The divided side wall layer 17 on the lower surface is laminated and fired. Note that both end sides of the divided sidewall layer 17 are joined by the connecting portion 18. And after baking, it divides | segments into each container main body 1 which a part of one set of side wall which the other recessed part opposes opened. In addition, the outer area | region of a dashed-dotted line is excluded.
[0013]
With such a configuration, a part of the pair of side walls in the short side direction opposite to the other concave portion is opened to form the concave open bottom surface 15, so that the plate surface area is increased and enlarged. Therefore, it is possible to increase the number of circuit elements to be arranged and adapt to miniaturization.
[0014]
In addition, since there is another set of side walls P (1, 2) that open a part of one set of side walls, a sheet-like ceramic can be formed by the divided side wall layers 17 in which both ends are joined by the connecting portions 18. Therefore, the divided side wall layer 17 and the bottom wall layer 7 on the lower surface and the side wall layer 9 on the upper surface are laminated and fired, and then divided, thereby facilitating manufacture.
[0015]
In addition, a part of the pair of opposing side walls in the short side direction is opened, and the pair of opposing side walls P (1,2) in the longitudinal direction remains, so that compared with the case where only the square part is left. Maintain strength.
[0016]
[Other matters]
In the above embodiment, the side wall that is a part in the short side direction is opened, but the side wall that is a part in the long side direction may be opened. Even in this case, since a pair of opposing side walls in the short side direction remains, the strength is maintained as compared with the case where only the square portion is left. In any case, all the side walls except the corners where the mounting electrodes are formed may be opened.
[0017]
Moreover, although the center part of a pair of side wall which opposes a short side or a long side direction was open | released, there exists a possibility that curvature may generate | occur | produce in a short side or a long side direction in this case. Therefore, for example, as shown in FIG. 4, an open portion is provided on the opposite side of the pair of side walls P facing each other in the long side direction, and the center line XX crosses each side wall to prevent warpage. You may do it.
[0018]
Further, only the crystal piece 4 is accommodated in one concave portion of the container body. For example, the step is provided in one concave portion, the IC chip 5 is fixed to the bottom surface of the concave portion, and both ends of the crystal piece 4 are fixed to the step portion. Then, the circuit element 6 may be arranged in the recess having the other open portion (FIG. 5).
[0019]
【The invention's effect】
Since the present invention has opened a pair of opposing side walls that form the recesses on the other main surface side of the surface mount container, the plate surface area on the other main surface side of the container body is increased to facilitate manufacturing and increase strength. A maintained surface mount oscillator can be provided.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view of a surface-mount oscillator for explaining an embodiment of the present invention.
FIG. 2 is a plan view of the other concave portion in the surface mount oscillator for explaining an embodiment of the present invention.
FIG. 3 is an exploded view of a surface mount oscillator illustrating one embodiment of the present invention.
FIG. 4 is a plan view of the other concave portion in the surface mount oscillator for explaining another embodiment of the present invention.
FIG. 5 is a cross-sectional view of a surface mount oscillator for explaining still another embodiment of the present invention.
FIG. 6 is a cross-sectional view of a surface-mount oscillator for explaining a conventional example.
FIG. 7 is an exploded view of a surface mount oscillator for explaining a conventional example.
FIG. 8 is a plan view of the other concave portion in the surface-mount oscillator for explaining the conventional example.
FIG. 9 is a plan view of a crystal piece for explaining a conventional example.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Container body, 2 Cover, 3 Surface mount oscillator, 4 Crystal piece, 5 IC chip, 6 Circuit element, 7 Bottom wall layer, 8, 16 Opening part, 9, 10 Side wall layer, 11 Excitation electrode, 12 Extraction electrode, 13 Conductive adhesive, 14 crystal measuring terminal, 15 recess open bottom, 17 divided side wall layer, 18 connecting part.

Claims (1)

A concave portion surrounded by side walls is provided on both main surface sides of the surface mount container so that at least a crystal piece is accommodated in the concave portion on the one main surface side, and a circuit element is disposed in the concave portion on the other main surface side. In the surface-mount type crystal oscillator, a pair of opposing side walls on the other main surface side of the surface-mount container are opened, and a crystal measurement terminal is provided on the bottom surface of the recess that is opened on the side wall. A crystal oscillator.

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