JP2913629B2 - Surface mount type crystal unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface mount type crystal unit, and more particularly to a support structure for a crystal plate.

[0002]

2. Description of the Related Art With the recent miniaturization of electronic equipment, electronic parts are required to be thin, low, and mounted on a printed wiring board at a high density on the surface thereof. This is not an exception in the field of crystal resonators, and recently, a thin surface-mount type crystal resonator has been invented, and as shown in FIGS. The quartz plate 6 on which the excitation electrode is formed is directly mounted on the upper surface of the electrode pad 33 of the lead terminal formed on the substrate without using the support that has been used, and is bonded with a conductive bonding material. Was. Further, a support base 44 for eliminating the inclination of the quartz plate according to the thickness of the electrode pad is provided at a portion facing the electrode pad 33. The base substrate 11 and the sealing lid are joined using, for example, low-melting glass, and are hermetically sealed.

[0003]

However, in the above configuration, the crystal plate is fixedly supported by a non-elastic supporting member such as an electrode pad and a ceramic laminate. In some cases, the crystal plate was greatly bent, and the quartz plate was damaged from the support portion. In addition, directly supporting the quartz plate with a support member having low elasticity and thermal expansion such as an electrode pad and a ceramic laminate requires a quartz crystal due to a difference between an expansion coefficient of the quartz plate due to a change in temperature and an expansion coefficient of the ceramic substrate. There has been a problem in reliability in terms of electrical characteristics of the quartz resonator, such as a strain stress applied to the plate and a change in CI value.

[0004] It is an object of the present invention to minimize damage to the quartz plate by minimizing strain stress on the quartz plate due to an external impact, and not to be affected by electrical differences due to the difference in thermal expansion between the quartz plate and the substrate. An object of the present invention is to provide a more reliable surface mount type crystal unit.

[0005]

In view of the above, a surface mount type crystal resonator according to the present invention forms an extraction electrode for leading out to the outside on an insulating substrate, and provides a support above the extraction electrode of the insulating substrate. In the surface mount type crystal unit, on which the excitation electrode and the lead electrode are formed on the front and back surfaces, and which are hermetically sealed by a lid, the insulating substrate Is formed in a state where two input / output electrode pads to which the support is joined are formed in parallel. The support is formed of two metal supports for input / output, and each support is made of quartz. It has two support portions for supporting both ends in the longitudinal direction of the plate, and a connecting portion for connecting the support portions, and a step is formed so that the position of the support portion is higher with respect to the connecting portion. And
And, the lead electrode connected to each excitation electrode of the quartz plate, which is formed so that the position height of each support portion at both ends is the same, to the end portion at one longitudinal end of the quartz plate, The two electrode pads of the insulating substrate, the two supports, and the respective lead electrode ends of the quartz plate, which are respectively drawn out, are arranged in parallel with each other, and the respective electrode pads and the respective supports are arranged in parallel. The coupling portion is electrically and mechanically joined, and only the support portion at one longitudinal end of each of the supports is electrically and mechanically joined to each of the lead electrodes at the end of the quartz plate. It is characterized by comprising.

[0006]

According to the present invention, there are provided two support portions for supporting both ends in the longitudinal direction of the quartz plate and a connecting portion for connecting the support portions, and the support portions at both ends are formed to have the same height. By holding the quartz plate cantilevered by using two metal supports, when joining the quartz plate to the support, one of the longitudinal end of the support or the other longitudinal end of the support is used. Can be electrically and mechanically joined to each other, and a highly productive holding structure that does not require directionality for mounting the quartz plate can be obtained. In addition, the supporting portion on the side that is not electrically and mechanically joined to the quartz plate always functions as a positioning piece, and a holding structure with high mounting accuracy that does not cause the quartz plate to tilt or the like can be obtained. In other words, it is possible to obtain a high level of productivity that does not require directionality for mounting the quartz plate, and to maintain the mounting plate with high mounting accuracy, so that the quartz plate can be reliably and easily mounted on the support.

[0007] Further, the connecting portion between the substrate and each of the supports is electrically and mechanically joined, and only the support portion on one end side in the longitudinal direction of each of the supports is electrically connected to each of the lead electrodes at the end of the quartz plate. Mechanically joined, the connection point with the quartz plate is separated from the connection point with the substrate, and the quartz plate is in a state where strain stress can be released at the support portion at the other end in the longitudinal direction of each support. Therefore, thermal mechanical impact on the quartz plate can be further reduced. Therefore, a mechanical shock such as a drop is released, and a change in distortion of the crystal plate caused by a difference in a coefficient of thermal expansion between the crystal plate and the insulating substrate due to a change in temperature is not given. Further, by forming a step so that the position height of the support portion with respect to the coupling portion is increased, the effect of mitigating thermal mechanical shock is further improved. In other words, dramatically improved impact resistance,
The adverse effect of electrical characteristics due to thermal stress on the quartz plate due to a change in temperature can be extremely reduced.

Further, two electrode pads of the insulating substrate,
By simply adjusting the positions of the two supports and the end portions of the respective lead electrodes of the quartz plate, it is possible to obtain a surface-mount type crystal unit having extremely high production accuracy in which assembly displacement, mounting displacement, and the like hardly occur. In particular, each of the supports is formed integrally with a holding and conducting support portion that is electrically and mechanically joined by a conductive joining material and a positioning support portion that is not electrically and mechanically joined by the conductive joining material. And the support portions for holding and conducting the respective supports are arranged in parallel with the respective lead electrode end portions of the quartz plate. By simply doing so, it is possible to extremely easily eliminate the displacement of the support portion for positioning and achieve extremely high mounting accuracy.

[0009]

FIG. 1 shows a first embodiment of the present invention.
This will be described with reference to FIGS. FIG. 1 shows the first embodiment of the present invention.
FIG. 2 is an exploded perspective view showing an embodiment of the present invention, and FIG.
FIG. 6 is a perspective view showing the example of FIG. 1 in a state where the cap is seen through. FIG. 3 is a sectional view taken along line XX of FIG.

The substrate 1 is made of an insulating plate such as a ceramic.
Leader electrodes 2 and 3 for leading electrodes to the outside, and two input / output electrode pads 21 and 31 to which a support to be described later is joined are formed in parallel at the tip portion. The supports 4 and 5 are, for example, Cu-Ni-
The support portions 41a, 41b, and 5 made of a metal plate such as a Zn-based alloy and capable of supporting the quartz plate 6 at least at both ends in the longitudinal direction.
1a, 51b and connecting portions 42, 5 connecting the supporting portions
Consists of two. The supports 4 and 5 are integrally formed in steps from the connecting portions 42 and 52 to the supporting portions 41a and 51a and from the connecting portions 42 and 52 to the supporting portions 41b and 51b in a step-like shape. . In addition, one end side of the support was set to a. These supports are formed by, for example, press working. The quartz plate 6 is made of AT-cut rectangular quartz crystal, and has excitation electrodes 7 and 8 on its front and back surfaces.
And lead electrodes 71 and 81 are formed. And
The other end side connecting portion 42b of the support connecting portions 42, 52,
52b is arranged in parallel with the electrode pads 21 and 31 of the lead electrodes formed on the substrate 1, and the supports 4 and 5 are attached to the substrate 1 by performing electromechanical bonding with the conductive bonding material 9. . And support the crystal plate 6 4,
5 mounted on the support portions 41a, 41b, 51a, 51b,
The ends of the lead electrodes 71, 81 of the quartz plate are connected to the support support 41 at the other end facing the coupling portions 42b, 52b.
a, 51a, are arranged in parallel with each other, and are electrically and mechanically joined by a conductive joining material 9;
1b and 51b are arranged and attached without using a conductive bonding material. The substrate, the support, and the quartz plate configured as described above are hermetically sealed with the cap 10.

As in the embodiment of the present invention, it is possible to reduce the thermal and mechanical shock to the quartz plate by joining to the extraction electrode on the substrate at the other end of the support joining portion. The connection may be made at the center of the connection part or at one end side connection part (direction of one end side a). The joining means is not limited to the conductive joining material, but may be laser welding, spot welding, or the like. In addition, at the stage of forming the set of supports 4 and 5 by press working, the supports are integrally molded with the lead frame in advance, and are directly mounted on the substrate and joined, and then the lead frame portion is cut off and manufactured. The state can be maintained, and manufacturing with more improved support mounting accuracy can be performed.

Next, a second embodiment of the present invention will be described with reference to FIG.
This will be described with reference to FIG. FIG. 4 is an exploded perspective view showing a second embodiment of the present invention. Note that the same parts as those in the above embodiment are denoted by the same reference numerals.

The substrate 1 is made of an insulating plate such as a ceramic.
Leader electrodes 2 and 3 for leading electrodes to the outside, and two input / output electrode pads 21 and 31 to which a support to be described later is joined are formed in parallel at the tip portion. The supports 41 and 51 are, for example, Cu-N
Support portions 411a, 41 made of a metal plate such as an i-Zn alloy and capable of supporting the quartz plate 6 at least at both ends in the longitudinal direction.
1b, 511a, and 511b, and connecting portions 421 and 521 connecting the supporting portions. This support 41,5
1 is a connecting portion 421, 521 to a supporting portion 411 when viewed from the side.
a, 511a, and from the coupling portions 421, 521 to the support portions 411b, 511b, are integrally formed with steps in a step shape. The support bonding portions 421 and 521 have slightly wider substrate bonding pads 421.
b, 521b. In addition, one end side of the support was set to a. These supports are formed by, for example, press working. The quartz plate 6 is made of AT-cut rectangular quartz crystal, and has excitation electrodes 7 and lead electrodes 7 on its front and back surfaces.
1 (only a part is shown). Then, the substrate bonding pads 421b and 521b are arranged in parallel with the electrode pads 21 and 31 of the lead electrodes formed on the substrate 1, and are electrically and mechanically bonded by laser welding to support the substrate 41. , 51 are attached. And
The crystal plate 6 is supported by the support portions 411a, 41 of the supports 41, 51.
1b, 511a, 511b, and the ends of the lead electrodes of the quartz plate are connected to the substrate bonding pads 421b, 521.
b at the other end opposite to b.
Are arranged in parallel with each other and electrically and mechanically joined by a conductive joining material.
1b is disposed and attached without using a conductive bonding material.
The substrate, the support, and the quartz plate configured as described above are hermetically sealed with the cap 10. In addition, at the stage where the set of supports 41 and 51 is formed by press working, they are integrally formed with a lead frame in advance, and are directly mounted on a substrate and joined, and thereafter, the lead frame portion is cut off and manufactured. The state can be maintained, and manufacturing with more improved support mounting accuracy can be performed.

FIGS. 5, 6, and 7 show other supporting embodiments of the present invention. FIG. 5 shows a structure in which substrate bonding pads are provided at both ends of a support connecting portion (third embodiment). FIG. 6 shows a configuration in which the support connecting portion is widened and a cutout is provided at the center (fourth embodiment). FIG. 7 shows a configuration in which the width of the support connecting portion is gradually increased from one end to the other end (fifth embodiment).

[0015]

According to the present invention, it is possible to obtain a high level of productivity that does not require a direction for mounting a quartz plate, and a holding that has a high mounting accuracy, and to reliably and easily mount the quartz plate on a support. Can be. Furthermore, since the impact resistance can be dramatically improved and the adverse effects of electrical characteristics due to thermal stress on the quartz plate due to temperature changes can be extremely reduced, in terms of impact resistance and environmental characteristics, An even more reliable crystal unit can be provided. Also, the surface mount type crystal with extremely high production accuracy, in which assembly displacement, mounting displacement, and the like are hardly generated simply by adjusting the arrangement of the two electrode pads of the insulating substrate, the two supports, and the respective lead electrode ends of the quartz plate. A vibrator is obtained.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a first embodiment of the present invention.

FIG. 2 shows the first embodiment of the present invention, and is a perspective view showing a state where a cap is seen through;

FIG. 3 is a sectional view taken along line XX of FIG. 2;

FIG. 4 is an exploded perspective view showing a second embodiment of the present invention.

FIG. 5 is a perspective view showing a third support embodiment of the present invention.

FIG. 6 is a perspective view showing a fourth support embodiment of the present invention.

FIG. 7 is a perspective view showing a fifth support embodiment of the present invention.

FIG. 8 is a plan view showing a conventional example.

FIG. 9 is a sectional view taken along the line YY of FIG. 4;

[Explanation of symbols]

 1, 11 ... base substrate 2, 3 ... lead-out electrodes 21, 31 ... electrode pads 4, 5 ... supports 41a, 41b, 51a, 51b ... support parts 42, 52 ... coupling Units 41, 51: Supports 411a, 411b, 511a, 511b: Supports 421, 521: Joining unit 6: Quartz plate 7, 8, Excitation electrodes 71, 81: Lead electrodes 9 Conductive bonding material 10 Cap 33 Electrode pad 44 Support

Claims (1)

(57) [Claims] An extraction electrode for leading out to the outside is formed on an insulating substrate, a support is provided above the extraction electrode of the insulating substrate, and a conductive bonding material is provided above the support via a conductive bonding material.
In a surface-mount type crystal resonator in which a quartz plate on which an excitation electrode and a lead electrode are formed on the front and back surfaces and hermetically sealed by a lid is provided, an extraction electrode on the insulating substrate has an input electrode to which the support is bonded. Two electrode pads for output are formed in parallel, the support comprises two metallic supports for input and output, and each support includes two supports for supporting both ends of the quartz plate in the longitudinal direction. And a connecting portion connecting the support portions, a step is formed so that the position height of the support portion is higher with respect to the connection portion, and the position height of each support portion at both ends is provided. The lead electrodes connected to the respective excitation electrodes of the quartz plate are drawn out to the ends on one longitudinal side of the quartz plate, respectively. Two electrode pads, the two supports G, the ends of the lead electrodes of the quartz plate are arranged in parallel with each other, and the connecting portions of the electrode pads and the supports are electrically and mechanically joined, and the longitudinal direction of each support is A surface-mounted crystal resonator, comprising: the above-mentioned structure, which is electrically and mechanically joined to each of the lead electrodes at the end of the crystal plate only by the support portion on one end side.