JP7386102B2 - Support structure for electronic components and electronic clocks - Google Patents

Description

The present invention relates to a support structure for electronic components and an electronic timepiece.

Electronic watches measure internal time mainly based on the oscillation of a crystal oscillator, and display the measured time using a display means. Crystal resonators are susceptible to external factors. For example, if a load is applied to a crystal oscillator while it is mounted inside an electronic timepiece, there is a risk that the accuracy of the operation of the electronic timepiece will decrease.

Loads that act on electronic watches include mechanical loads and thermal loads. Mechanical loads are caused by impacts such as dropping the electronic watch or hitting it against other objects, and thermal loads are caused by crystal vibrations in addition to loads due to the operating temperature of the electronic watch. This occurs due to heating when fixing a crystal oscillator with an encapsulated crystal to a circuit board using a bonding member, and subsequent cooling.

The above-mentioned mechanical loads and thermal loads are not limited to the crystal oscillators of electronic watches, but can also occur in other electronic components used in electronic watches in the same way as the crystal oscillators.

In order to reduce the mechanical and thermal loads that act on electronic components, electronic components are printed on flexible circuit boards instead of being directly mounted on rigid circuit boards made of glass epoxy resin materials. A technique has been proposed in which a part of the board is bonded and an electronic component is mounted on a portion of the flexible printed board that is lifted from the circuit board (a portion that is not bonded to the circuit board) (for example, Patent Document 1).

According to this technology, shock and heat input to the circuit board are absorbed by the deformation of the flexible printed circuit board and are not directly transmitted from the circuit board to the electronic components. load can be reduced.

Japanese Patent Application Publication No. 6-013727

In the technique described in the above-mentioned prior art document, the flexible printed circuit board that absorbs the impact is greatly deformed, and this deformation can cause a mechanical load on the electronic component. Further, this technique has a problem in that the size of the circuit board in the thickness direction increases because the flexible printed circuit board is formed in a folded shape.

The present invention was made in view of the above circumstances, and reduces the mechanical load and thermal load that may be applied to electronic components mounted on a circuit board while suppressing the increase in the dimension in the thickness direction. It is an object of the present invention to provide an electronic component support structure and an electronic component support structure that can reduce the number of electronic components.

A first aspect of the present invention includes a circuit board that is not flexible, a flat flexible board that is flexible, a regulating member, and an electronic component, and the flexible board has one end. The electronic component is bonded to and supported by the circuit board at a portion of the flexible substrate, the electronic component is disposed bonded to a portion of the flexible substrate that is different from the portion bonded to the circuit board, and at least a portion of the regulating member is a support structure for an electronic component that is disposed in a portion of the flexible substrate where the distance from the electronic component to the electronic component is shorter than the distance from the portion joined to the circuit board to the electronic component.

A second aspect of the present invention is an electronic timepiece including the electronic component support structure according to the present invention.

According to the support structure for electronic components and the electronic timepiece according to the present invention, it is possible to prevent mechanical loads and thermal loads that may be applied to electronic components mounted on a circuit board while suppressing an increase in the dimension in the thickness direction. The load can be reduced.

1 is a plan view of an electronic timepiece equipped with an electronic component support structure according to Embodiment 1 of the present invention, viewed from the back cover side. 2 is a sectional view taken along line AA in FIG. 1. FIG. FIG. 3 is a plan view of an electronic watch equipped with an electronic component support structure according to a second embodiment, viewed from the back cover side. 4 is a sectional view taken along line BB in FIG. 3. FIG. FIG. 7 is a plan view of an electronic timepiece equipped with an electronic component support structure according to Embodiment 3, viewed from the back cover side. 6 is a sectional view taken along line CC in FIG. 5. FIG. FIG. 7 is a plan view of an electronic timepiece equipped with an electronic component support structure according to Embodiment 4, viewed from the back cover side. 8 is a sectional view taken along line DD in FIG. 7. FIG. FIG. 3 is a plan view showing an example of a portion of the FPC 30 whose displacement is regulated by a regulating member. FIG. 3 is a plan view showing the relationship between the longitudinal direction of the FPC and the longitudinal direction of the crystal oscillator. FIG. 8 is a sectional view corresponding to FIGS. 2 and 8, showing a solid pattern made of metal or ceramic fixed to the back surface of an FPC.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of an electronic component support structure and an electronic timepiece equipped with this electronic component support structure according to the present invention will be described with reference to the drawings.

<Embodiment 1>
FIG. 1 is a plan view of an electronic timepiece 100 equipped with an electronic component support structure according to Embodiment 1 of the present invention, viewed from the back cover side, and FIG. 2 is a sectional view taken along line AA in FIG. 1.

In FIG. 1, (12H) is the 12 o'clock direction on the dial of the electronic watch 100, (3H) is the 3 o'clock direction on the dial, (6H) is the 6 o'clock direction on the dial, and (9H) is the direction on the dial. Each shows the 9 o'clock direction.

Further, the direction connecting 3 o'clock and 9 o'clock is the X-axis direction, the direction connecting 12 o'clock and 6 o'clock is the Y-axis direction, and the direction is the thickness direction of the electronic watch 100 and is perpendicular to the X-axis direction and the Y-axis direction. is the Z-axis direction. Furthermore, a plan view is a diagram of a plane including the X-axis direction and the Y-axis direction (XY plane) viewed from the Z-axis direction. The same applies to other embodiments 2 to 4 below.

An electronic timepiece 100 according to the first embodiment of the present invention includes the electronic component support structure according to the first embodiment. As shown in FIGS. 1 and 2, the electronic component support structure of the first embodiment includes a circuit board 20, a flexible printed circuit board (an example of a flexible board, hereinafter referred to as FPC (Flexible Printed Circuits)) 30, , a base plate 10 and a substrate holder 50 as an example of a regulating member, and a crystal oscillator 40 as an example of an electronic component.

The main plate 10 supports a movement that includes a stepping motor 91 of the electronic watch 100, a gear train 92 that transmits the driving force generated by the stepping motor 91 to time display hands, etc., and a battery 93 that is a power source. It is a member.

The circuit board 20 is arranged between the base plate 10 and the back cover (not shown) of the electronic timepiece 100. The circuit board 20 is made of glass epoxy resin, for example, and is formed into a flat plate shape, and has no flexibility. A rectangular cutout 25 is formed near the 6 o'clock (6H) position of the circuit board 20 to avoid interference with an FPC 30, which will be described later. Specifically, this notch 25 is an area that at least overlaps in plan view with the range in which the FPC 30 is bent with one end 31 joined to the circuit board 20 as a fixed end.

Here, the term "the circuit board 20 does not have flexibility" means that it does not have flexibility (elasticity) compared to the FPC 30 described below on which the crystal oscillator 40 is mounted, and for example, it has more longitudinal elasticity than the FPC 30. It refers to a material and structure that has a large modulus (Young's modulus) and is more difficult to deform than FPC30.

On the circuit board 20, a control IC chip for controlling the driving of the stepping motor and the like of the electronic timepiece 100 and other electronic components are mounted. Note that the control IC chip and the like are mounted, for example, on the front surface (the surface closer to the base plate 10) 20A of the circuit board 20, but are mounted on the back surface (the surface closer to the back cover) 20B. Good too.

The FPC 30 has flexibility and is formed into, for example, a rectangular flat plate. The FPC 30 is fixed by joining the back surface (the surface near the back cover) 30B of one end 31 in the longitudinal direction (the left end in FIGS. 1 and 2) to the front surface 20A of the circuit board 20 with solder 60. ing. At this one end portion 31, the FPC 30 is supported substantially parallel to the circuit board 20 at a predetermined distance in the Z-axis direction of the circuit board 20.

Most of the FPC 30 except for one end 31 joined to the circuit board 20 is arranged within the notch 25 formed in the circuit board 20 in plan view (FIG. 1). A crystal oscillator 40 as an example of an electronic component is bonded and fixed to the front surface 30A of the FPC 30 using, for example, a conductive silicone adhesive 70.

The crystal oscillator 40 includes, for example, a crystal resonator 41 that is long in a predetermined direction and is enclosed inside a ceramic package. The crystal oscillator 40 vibrates at a predetermined vibration frequency and outputs an output signal corresponding to this vibration to a control IC chip or the like. The crystal oscillator 40 is arranged near the other end 32 of the FPC 30, which is the end opposite to the one end 31 of the FPC 30.

Here, the base plate 10 has a portion facing the front surface 30A of the other end 32, which is the end opposite to the one end 31 in the longitudinal direction of the FPC 30, at a predetermined distance from the front surface 30A. t1, and functions as a regulating section. The distance t1 between the portion of the base plate 10 facing the other end 32 and the FPC 30 is set to be shorter than the distance t2 between the crystal oscillator 40 fixed to the front surface 30A and the base plate 10.

Since one longitudinal end 31 of the FPC 30 is fixed to the circuit board 20, the vertical acceleration F shown in FIG. 2 acts on the FPC 30 (for example, when an external impact is applied to the electronic watch 100, Similar to a beam with one end 31 as a fixed end, the other end 32, which is the free end opposite to the one end 31, is the largest with respect to the center in the longitudinal direction L. bend.

When the FPC 30 is bent, the other end 32 hits the ground plate 10 before the crystal oscillator 40 hits the ground plate 10, so the FPC 30 stops bending and the crystal oscillator 40 can be prevented from hitting the ground plate 10.

Note that the distance from the other end 32 that first hits the base plate 10 when the FPC 30 is bent is shorter than the distance from the one end 31 of the FPC 30 to the crystal oscillator 40 . In other words, the area that functions as a regulating member on the base plate 10 is the distance from the part (one end 31) of the FPC 30, which is a flexible board, joined to the circuit board 20 to the crystal oscillator 40, which is an electronic component, in plan view. It is arranged facing the FPC 30 so as to overlap a portion where the distance L2 to the crystal oscillator 40 is shorter than L1.

In addition, in the first embodiment, the portion of the FPC 30 in which the region functioning as the regulating member for the base plate 10 is arranged opposite to the FPC 30 is the region on the opposite side of the one end portion 31 with respect to the center of the FPC 30 ( The end portion 32).

With such a configuration, when the FPC 30 is bent, stress concentrates on the fixed end 31 and its surroundings, so the crystal oscillator 40 is placed closer to the other end 32 than the fixed end 31. By keeping the crystal oscillator 40 away from the crystal oscillator 40, it is possible to suppress the influence of the generated stress on the crystal oscillator 40.

The board holder 50 is arranged on the back surface 20B side of the circuit board 20, and covers the circuit board 20, including the part where the notch 25 is formed, from the back cover side, thereby preventing the circuit board 20 from floating toward the back cover side. Hold down. It is preferable that the board holder 50 has no flexibility like the circuit board and has a rigidity equal to or greater than that of the circuit board 20.

Here, the board holder 50 is arranged such that a portion facing the back surface 30B of the other end 32, which is the end opposite to the one end 31 in the longitudinal direction of the FPC 30, is arranged with a predetermined distance from the back surface 30B. Functions as a regulating member. At least a part of the board holder 50 functions as a regulating member, and the region functioning as the regulating member is the distance from the part (one end 31) of the FPC 30 joined to the circuit board 20 to the crystal oscillator 40, which is an electronic component. It is configured to face the FPC 30 at a portion shorter than L1.

In FIG. 2, the board holder 50 has a flat plate shape and is arranged closer to the back cover than the circuit board 20, but the present invention is not limited to this embodiment. For example, the board holder 50 may have a convex portion on the front surface 50A in an area that overlaps the notch 25 and the FPC 30 in a plan view and is closer to the other end 32 than the one end 31. good.

This convex portion allows the distance between the substrate holder 50 and the back surface 30B of the FPC 30 to be shortened, so that the amount of displacement when the FPC 30 is bent can be suppressed. In particular, it is preferable that the convex portion be disposed within a range where the distance to the crystal oscillator 40, which is an electronic component, is shorter than the distance L1 in plan view, and in an area opposite to the one end portion 31 with respect to the center position of the FPC 30. It is preferable that they overlap at the other end 32.

According to the supporting structure of the crystal oscillator 40 and the electronic watch 100 of the first embodiment configured as described above, the crystal oscillator 40 is not directly fixed to the rigid circuit board 20, but has a flexible structure. It is fixed to the circuit board 20 via the FPC 30 having the FPC 30.

Therefore, even if an impact force (mechanical load) is input to the circuit board 20 by hitting the electronic watch 100 against another object, the FPC 30 interposed between the circuit board 20 and the crystal oscillator 40 By bending, the FPC 30 can absorb the input impact energy and prevent the impact force from being directly input to the crystal oscillator 40.

Further, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the first embodiment, the FPC 30 is bent by the impact force, and the other end 32 hits the base plate 10 due to the displacement due to the bending, so that the other end 32 is bent. Displacement can be regulated, and large displacements of the crystal oscillator 40 within the electronic timepiece 100 can be prevented.

In other words, the base plate 10 regulates the displacement of the FPC 30. As a result, the deflection of the FPC 30 can be reduced, and the mechanical load that may be generated on the crystal oscillator 40 due to the deflection of the FPC 30 can be reduced. Thereby, it is possible to suppress changes in characteristics (for example, accuracy of oscillation frequency; the same applies hereinafter) that may occur in the crystal resonator 41 inside the crystal oscillator 40.

Furthermore, according to the support structure for the crystal oscillator 40 and the electronic timepiece 100 of the first embodiment, the FPC 30 does not first bend downward (toward the dial side) in FIG. 2, the bent FPC 30 passes through the notch 25 and the back surface 30B of the other end 32 hits the front surface 50A of the board holder 50. This restricts the displacement of the other end portion 32.

Thereby, it is possible to prevent the crystal oscillator 40 from being largely displaced within the electronic timepiece 100. As a result, the deflection of the FPC 30 can be reduced, and the mechanical load that may be generated on the crystal oscillator 40 due to the deflection of the FPC 30 can be reduced.

Furthermore, changes in characteristics that may occur in the crystal resonator 41 inside the crystal oscillator 40 can be suppressed. Furthermore, by using the main plate 10 and the board holder 50 as regulating members, there is no need to add new parts, and it is possible to suppress the overall size and thickness of the electronic timepiece 100 from increasing.

Furthermore, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the first embodiment, since the FPC 30 is fixed to the circuit board 20 only at one end 31, the other end 32 is also fixed to the circuit board 20. It is possible to prevent or suppress the occurrence of thermal load on the FPC 30 compared to the case where the FPC 30 is not heated.

That is, even though the difference in physical properties between the circuit board 20 and the FPC 30 causes a difference in the amount of thermal expansion during heating and the amount of thermal contraction during cooling between the two, if one end 31 and the other end If the FPC 30 is fixed to the circuit board 20 at two or more locations with the section 32, distortion may occur between the two (FPC 30 and circuit board 20), causing the FPC 30 to become fixed to the FPC 30. Stress due to the strain generated in the FPC 30 also acts on the crystal oscillator 40, and a load (thermal load) is generated.

However, in the support structure of the crystal oscillator 40 and the electronic watch 100 of the first embodiment, since the FPC 30 is fixed to the circuit board 20 only at one end 31, the FPC 30 is subject to thermal expansion during heating and thermal contraction during cooling. Even if this happens, the other end 32 is only displaced due to expansion and contraction, and no thermal load (distortion) occurs on the FPC 30 that would otherwise occur if the other end 32 was also fixed. Therefore, it is possible to prevent or suppress thermal load from acting on the crystal oscillator 40 fixed to the FPC 30 as well. Thereby, changes in characteristics that may occur in the crystal resonator 41 inside the crystal oscillator 40 can be suppressed.

<Embodiment 2>
FIG. 3 is a plan view of an electronic timepiece 100 equipped with an electronic component support structure according to Embodiment 2 of the present invention, viewed from the back cover side, and FIG. 4 is a sectional view taken along line BB in FIG. 3.

An electronic timepiece 100 according to the second embodiment of the present invention includes the electronic component support structure according to the second embodiment. As in the first embodiment, the electronic component support structure and the electronic watch 100 of the second embodiment include a circuit board 20 having a notch 25, an FPC 30, and a regulating member as an example, as shown in FIGS. 3 and 4. It includes a base plate 10, a substrate holder 50, and a crystal oscillator 40 as an example of an electronic component.

Similar to the first embodiment, the cutout 25 is formed in a region that at least overlaps in plan view with the range in which the FPC 30 is bent with one end 31 joined to the circuit board 20 as a fixed end.

In the electronic component support structure and electronic watch 100 of the second embodiment, unlike the first embodiment, a crystal oscillator 40 is bonded and fixed to the back surface 30B of the FPC 30. With this configuration, compared to the first embodiment, the thickness of the electronic timepiece 100 in the Z-axis direction due to the mounting of the board 20, FPC 30, and crystal oscillator 40 can be made thinner. Note that the crystal oscillator 40 is arranged at a position closer to the other end 32 than to the one end 31, similarly to the first embodiment.

The substrate holder 50 has a portion facing the back surface 30B of the other end 32, which is the end opposite to the one end 31 in the longitudinal direction of the FPC 30, arranged at a predetermined distance from the back surface 30B. In this embodiment, a notch 55 is formed in the substrate holder 50 to allow the crystal oscillator 40 to pass therethrough when the FPC 30 is bent upward in FIG.

The distance t3 between the part of the substrate holder 50 facing the other end 32 and the FPC 30 is defined by a member (not shown) that faces the crystal oscillator 40 fixed to the back surface 30B and the notch 55 of the substrate holder 50; The dimension is set to be shorter than the distance t4 between the surfaces of the opposing members (indicated by broken lines in FIG. 4).

The base plate 10 is arranged such that a portion of the other end 32, which is an end opposite to the one end 31, facing the front surface 30A in the longitudinal direction of the FPC 30 is arranged at a predetermined distance from the front surface 30A. ing.

As shown in FIG. 4, at least a portion of each of the board holder 50 and the base plate 10, which function as regulating members, is larger than the distance L1 from one end 31 of the FPC 30 fixed to the circuit board 20 to the crystal oscillator 40. The distance L2 from the region that hits the substrate holder 50 or the base plate 10 (in the second embodiment, the other end 32) to the crystal oscillator 40 when the crystal oscillator 40 is bent is configured to be shorter.

According to the support structure for the crystal oscillator 40 and the electronic watch 100 of the second embodiment configured as described above, if the electronic watch 100 is bumped against another object, an impact force (mechanical load) is applied to the circuit board 20. ) is also input, the FPC 30 interposed between the circuit board 20 and the crystal oscillator 40 bends, so that the FPC 30 absorbs the input impact energy, and the impact force is not directly input to the crystal oscillator 40. You can prevent this from happening.

Further, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the second embodiment, the FPC 30 is bent by the impact force, and the other end 32 hits the main plate 10 due to the displacement due to the bending, so that the other end 32 is bent. Displacement can be regulated, and the mechanical load that may be generated on the crystal oscillator 40 due to the bending of the FPC 30 can be reduced.

Further, according to the support structure of the crystal oscillator 40 and the electronic watch 100 of the second embodiment, when the FPC 30 is first bent upward in FIG. 4 due to the input of impact force, the bent FPC 30 is cut out. 25, and the back surface 30B of the other end 32 comes into contact with the front surface 50A of the substrate holder 50, thereby regulating the displacement of the other end 32. At this time, the crystal oscillator 40 passes through the notch 55 of the substrate holder 50, thereby preventing the crystal oscillator 40 from interfering with the substrate holder 50.

Thereby, it is possible to prevent the crystal oscillator 40 from being largely displaced within the electronic timepiece 100. As a result, the deflection of the FPC 30 can be reduced, and the mechanical load that may be generated on the crystal oscillator 40 due to the deflection of the FPC 30 can be reduced.

Further, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the second embodiment, since the FPC 30 is fixed to the circuit board 20 only at one end 31, the other end 32 is also fixed to the circuit board 20. It is possible to prevent or suppress the occurrence of thermal load on the FPC 30 compared to the case where the FPC 30 is not heated.

In the second embodiment, the substrate holder 50 has a notch 55 through which the crystal oscillator 40 can be inserted, but the present invention is not limited to this embodiment, and when the FPC 30 is displaced, Any configuration may be used as long as the region facing the regulating member hits the crystal oscillator 40 before the FPC 30 and is regulated so that the FPC 30 is not displaced any further.

For example, when the thickness of the substrate holder 50 is sufficiently larger than the interval t3, what is formed in the substrate holder 50 may be a recess that does not penetrate, instead of the notch 55 penetrating in the Z-axis direction. In this way, the substrate holder 50 in which the recessed portion is formed can have higher rigidity than the substrate holder 50 in which the notch 55 is formed.

Further, a convex portion may be provided on the front surface 50A of the substrate holder 50. As a result, the distance t3 between the convex portion and the FPC 30 can be further reduced, the amount of displacement of the FPC 30 can be further suppressed, and the depth of the concave portion can be made shallow, so that the rigidity of the substrate holder 50 can be reduced. Further improvements can be made.

<Embodiment 3>
FIG. 5 is a plan view of an electronic timepiece 100 equipped with an electronic component support structure according to Embodiment 3 of the present invention, viewed from the back cover side, and FIG. 6 is a sectional view taken along line CC in FIG. 5.

An electronic timepiece 100 according to the third embodiment of the present invention includes the electronic component support structure according to the third embodiment. As in the first and second embodiments, the support structure for electronic components and the electronic watch 100 of the third embodiment include a circuit board 20 having a notch 25, an FPC 30, and an example of a regulating member, as shown in FIGS. It includes a base plate 10 and a substrate holder 50 as an example of an electronic component, and a crystal oscillator 40 as an example of an electronic component.

Similar to the first embodiment, the cutout 25 is formed in a region that at least overlaps in plan view in a range where the FPC 30 is bent with one end 31 joined to the circuit board 20 as a fixed end.

In the electronic component support structure and electronic watch 100 of the third embodiment, unlike the first and second embodiments, the front surface 30A of the FPC 30 is bonded and fixed to the back surface 20B of the circuit board 20. As in the first embodiment, the crystal oscillator 40 is bonded and fixed to the front surface 30A of the FPC 30.

With this configuration, the thickness of the electronic timepiece 100 in the Z-axis direction due to the mounting of the board 20, FPC 30, and crystal oscillator 40 can be made thinner than in the first embodiment or the fourth embodiment described later. Further, as in the first and second embodiments, the crystal oscillator 40 is placed closer to the other end 32 than to the one end 31.

The base plate 10 is arranged such that a portion of the other end 32 which is the end opposite to the one end 31 in the longitudinal direction of the FPC 30 and which faces the front surface 30A is spaced apart from the front surface 30A by a predetermined distance t5. has been done. This interval t5 is set to be shorter than the interval t6 in the Z-axis direction between the crystal oscillator 40 fixed to the front surface 30A and the base plate 10.

The substrate holder 50 has a portion facing the back surface 30B of the other end 32, which is the end opposite to the one end 31 in the longitudinal direction of the FPC 30, arranged at a predetermined distance from the back surface 30B.

As shown in FIG. 6, at least a portion of each of the base plate 10 and the board holder 50, which function as regulating members, is larger than the distance L1 from one end 31 of the FPC 30 fixed to the circuit board 20 to the crystal oscillator 40. The distance L2 from the region that hits the substrate holder 50 or the base plate 10 (the other end 32 in the third embodiment) to the crystal oscillator 40 when the crystal oscillator 40 is bent is configured to be shorter.

According to the supporting structure of the crystal oscillator 40 and the electronic watch 100 of the third embodiment configured as described above, if the electronic watch 100 is bumped against another object, an impact force (mechanical load) is applied to the circuit board 20. ) is also input, the FPC 30 interposed between the circuit board 20 and the crystal oscillator 40 bends, so that the FPC 30 absorbs the input impact energy, and the impact force is not directly input to the crystal oscillator 40. You can prevent this from happening.

Further, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the third embodiment, the FPC 30 is bent by the impact force, and the other end 32 hits the base plate 10 due to the displacement due to the bending, so that the other end 32 is bent. Displacement can be regulated, and the mechanical load that may be generated on the crystal oscillator 40 due to the bending of the FPC 30 can be reduced.

Further, according to the support structure of the crystal oscillator 40 and the electronic watch 100 of the third embodiment, when the FPC 30 is first bent upward in FIG. 6 due to the input of impact force, the bent FPC 30 is The displacement of the other end portion 32 is regulated by contacting the front surface 50A.

Thereby, it is possible to prevent the crystal oscillator 40 from being largely displaced within the electronic timepiece 100. As a result, the deflection of the FPC 30 can be reduced, and the mechanical load that may be generated on the crystal oscillator 40 due to the deflection of the FPC 30 can be reduced.

Furthermore, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the third embodiment, since the FPC 30 is fixed to the circuit board 20 only at one end 31, the other end 32 is also fixed to the circuit board 20. It is possible to prevent or suppress the occurrence of thermal load on the FPC 30 compared to the case where the FPC 30 is not heated.

<Embodiment 4>
7 is a plan view of an electronic timepiece 100 equipped with an electronic component support structure according to Embodiment 4 of the present invention, viewed from the back cover side, and FIG. 8 is a sectional view taken along line DD in FIG. 7.

An electronic timepiece 100 according to the fourth embodiment of the present invention includes the electronic component support structure according to the fourth embodiment. As in Embodiments 1 to 3, the support structure for electronic components and the electronic watch 100 of the fourth embodiment include a circuit board 20 having a notch 25, an FPC 30, and an example of a regulating member, as shown in FIGS. It includes a base plate 10 and a substrate holder 50 as an example of an electronic component, and a crystal oscillator 40 as an example of an electronic component.

Similar to the first embodiment, the cutout 25 is formed in a region that at least overlaps in plan view in a range where the FPC 30 is bent with one end 31 joined to the circuit board 20 as a fixed end.

In the electronic component support structure and electronic watch 100 of the fourth embodiment, the crystal oscillator 40 is bonded and fixed to the back surface 30B of the FPC 30, as in the second embodiment, and the FPC 30 is attached to the substrate holder 50 in the upper direction in FIG. A notch 55 is formed for passing the crystal oscillator 40 in the bent state. Further, as in the first to third embodiments, the crystal oscillator 40 is placed closer to the other end 32 than the one end 31.

Further, in the support structure for electronic components and the electronic watch 100 of the fourth embodiment, the front surface 30A of the FPC 30 is bonded and fixed to the back surface 20B of the circuit board 20, as in the third embodiment.

At least a part of the board holder 50 is arranged such that a portion facing the back surface 30B of the other end 32, which is the end opposite to the one end 31 in the longitudinal direction of the FPC 30, is arranged with a predetermined distance t7 from the back surface 30B. ing. The distance t7 between the part of the board holder 50 facing the other end 32 and the FPC 30 is defined by the crystal oscillator 40 fixed to the back surface 30B and a member (not shown; The dimension is set to be shorter than the distance t8 from the surface of the member shown by the broken line in FIG.

The base plate 10 is arranged such that a portion of the other end 32, which is an end opposite to the one end 31, facing the front surface 30A in the longitudinal direction of the FPC 30 is arranged at a predetermined distance from the front surface 30A. ing.

Note that in FIG. 8, the surface of the base plate 10 facing the FPC 30 is a flat surface, but the present invention is not limited to this embodiment. For example, the base plate 10 may have a convex portion that protrudes toward a surface of a region closer to the other end 32 than the one end 31 in a region overlapping with the notch 25 and the FPC 30 in a plan view.

This convex portion allows the distance between the base plate 10 and the front surface 30A of the FPC 30 to be shortened, so that the amount of displacement when the FPC 30 is bent can be suppressed. In particular, it is preferable that the convex portion be disposed within a range where the distance to the crystal oscillator 40, which is an electronic component, is shorter than the distance L1 in plan view, and in an area opposite to the one end portion 31 with respect to the center position of the FPC 30. It is preferable that they overlap at the other end 32.

As shown in FIG. 8, at least a portion of each of the base plate 10 and the board holder 50, which function as regulating members, has a distance L1 from one end 31 of the FPC 30 fixed to the circuit board 20 to the crystal oscillator 40. The distance L2 from the region that hits the substrate holder 50 or the base plate 10 (the other end 32 in the fourth embodiment) to the crystal oscillator 40 when the crystal oscillator 40 is bent is configured to be shorter.

According to the support structure for the crystal oscillator 40 and the electronic timepiece 100 of the fourth embodiment configured as described above, if the electronic timepiece 100 is bumped against another object, an impact force (mechanical load) is applied to the circuit board 20. ) is also input, the FPC 30 interposed between the circuit board 20 and the crystal oscillator 40 bends, so that the FPC 30 absorbs the input impact energy, and the impact force is not directly input to the crystal oscillator 40. You can prevent this from happening.

Further, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the fourth embodiment, the FPC 30 is bent by the impact force, the bent FPC 30 passes through the notch 25, and the other end 32 is displaced by the bending. By hitting the base plate 10, the displacement of the other end portion 32 can be restricted, and the mechanical load that may be generated on the crystal oscillator 40 due to the bending of the FPC 30 can be reduced.

Further, according to the support structure of the crystal oscillator 40 and the electronic watch 100 of the fourth embodiment, when the FPC 30 is first bent upward in FIG. 8 due to the input of impact force, the other end of the bent FPC 30 is The rear surface 30B of the portion 32 comes into contact with the front surface 50A of the substrate holder 50, thereby regulating the displacement of the other end portion 32. At this time, the crystal oscillator 40 passes through the notch 55 of the substrate holder 50, thereby preventing the crystal oscillator 40 from interfering with the substrate holder 50.

Thereby, it is possible to prevent the crystal oscillator 40 from being largely displaced within the electronic timepiece 100. As a result, the deflection of the FPC 30 can be reduced, and the mechanical load that may be generated on the crystal oscillator 40 due to the deflection of the FPC 30 can be reduced.

Further, according to the support structure for the crystal oscillator 40 and the electronic watch 100 of the fourth embodiment, since the FPC 30 is fixed to the circuit board 20 only at one end 31, the other end 32 is also fixed to the circuit board 20. Compared to the case, generation of thermal load on the FPC 30 can be prevented or suppressed.

<Other embodiments>
In the electronic component support structure and electronic watch 100 of each of the first to fourth embodiments described above, one end 31 of the FPC 30 in the longitudinal direction L is joined to the circuit board 20, and the other end 32 of the FPC 30 in the longitudinal direction L is connected to the base plate 10 or the substrate. Displacement is regulated by a regulating member such as a presser foot 50.

However, in the electronic timepiece support structure and electronic timepiece according to the present invention, the portion of the flexible substrate whose displacement is regulated by the regulating member is located on the opposite side from one end in the longitudinal direction of the flexible member. It is not limited to the other end.

FIG. 9 is a plan view showing an example of a portion of the FPC 30 whose displacement is regulated by a regulating member. In the electronic timepiece support structure and electronic timepiece according to the present invention, the portion of the flexible substrate whose displacement is regulated by the regulating member is smaller than the distance from the portion of the flexible substrate bonded to the circuit board to the electronic component. Also, it is sufficient if the distance to the electronic component is short.

Therefore, in the electronic timepiece support structure and the electronic timepiece 100 of this embodiment, the portion of the FPC 30 whose displacement is regulated by the restriction member is not only the other end 32 in the longitudinal direction L, for example, as shown in FIG. , both ends 33, 34 in the width direction W of the FPC 30 in the vicinity of the crystal oscillator 40 (in the range where the distance from the crystal oscillator 40 is closer than the end part 31 (the part fixed to the circuit board with the solder 60)) etc.

FIG. 10 is a plan view showing the relationship between the longitudinal direction L of the FPC 30 and the longitudinal direction of the crystal oscillator 40. The electronic timepiece support structure and the electronic timepiece 100 of each of the embodiments described above use a crystal oscillator 40 as an electronic component, but the longitudinal direction of the crystal oscillator 40 is set to the longitudinal direction of the FPC 30 as shown in FIG. It is preferable to have a structure in which they are arranged along the width direction W perpendicular to L.

The FPC 30 is less likely to bend in the width direction W than in the longitudinal direction L. Therefore, according to a structure in which the longitudinal direction of the crystal oscillator 40 is arranged in a posture along the width direction W of the FPC 30, a mechanical load due to the deflection along the longitudinal direction L of the FPC 30 acts on the crystal oscillator 40. Therefore, the influence on the characteristics of the crystal oscillator 40 can be further reduced.

Further, as shown in FIG. 10, the longitudinal direction of the crystal resonator 41 disposed inside the crystal oscillator 40 may also be disposed in a posture along the width direction W orthogonal to the longitudinal direction L of the FPC 30. preferable. That is, it is preferable that the crystal oscillator 41 is arranged such that the longitudinal direction of the crystal oscillator 41 is along the longitudinal direction of the crystal oscillator 40.

With such a configuration, mechanical load due to deflection along the longitudinal direction L of the FPC 30 is less likely to act on the crystal resonator 41, and the influence on the characteristics of the crystal resonator 41 can be further reduced.

The electronic timepiece support structure and the electronic timepiece 100 of each of the embodiments described above are such that the base plate 10 and the board holder 50 are disposed facing the FPC 30 with a predetermined distance therebetween. It functions as a regulating member that regulates the displacement of the FPC 30 to a predetermined dimension.

However, the support structure of the electronic timepiece and the regulating member in the electronic timepiece of the present invention are not limited to the base plate 10 and the board holder 50, but are used to suppress the influence of external magnetic fields on electronic components such as the step motor 91. It is also possible to apply, as a regulating member, a magnetic shield plate, a gear train holding member used to define the position of the gear train 92, etc., a battery holding member used to hold the position of the battery 93, etc. .

Further, when the electronic timepiece 100 is a photovoltaic timepiece having a solar cell, a support frame for the solar cell or the like can be used as a regulating member.

Note that the support structure of the electronic timepiece and the regulating member in the electronic timepiece of the present invention are separate members from the circuit board to which the flexible substrate is bonded, and the regulating member does not include the circuit board.

The electronic timepiece support structure and electronic timepiece 100 of each of the embodiments described above use solder 60 as a joining member for joining the FPC 30 to the circuit board 20, and conductive silicone adhesive as the joining member for joining the crystal oscillator 40 to the FPC 30. 70 is applied.

Here, since the conductive silicone adhesive 70 has a softer hardness after bonding than the solder 60, even if the FPC 30 is firmly fixed to the circuit board 20 with the solder 60, the mechanical The load can be absorbed by the deformation of the soft conductive silicone adhesive 70, and the mechanical load acting on the crystal oscillator 40 can be further reduced.

Note that the electronic timepiece support structure and electronic timepiece of the present invention are not limited to joining the flexible board and the circuit board by soldering, and can be joined by various joining structures. The bonding between the flexible substrate and the flexible substrate is not limited to bonding using a conductive silicone adhesive, and various bonding structures may be used.

In the present invention, the flexible substrate and the circuit board and the electronic component and the flexible substrate are both bonded using a thermosetting bonding member. It is preferable to use a material in which the temperature at which the first joining member that joins the electronic component and the flexible substrate is hardened is lower than the temperature at which the second joining member that joins the electronic component and the flexible substrate is hardened.

In the process of manufacturing the electronic component support structure according to the present invention, for example, the electronic component may be bonded to the flexible substrate prior to bonding the flexible substrate to the circuit board. In this step, when the electronic component is bonded to the flexible substrate with the second bonding member, the second bonding member is heated to harden and bond, and then cooled. Through this step, the electronic component is bonded and fixed to the flexible substrate.

Thereafter, when the flexible substrate to which the electronic component is fixed is bonded to the circuit board using the first bonding member, the first bonding member is heated and the first bonding member is cured and bonded. If the temperature at which the second bonding member is cured is higher than the temperature at which the second bonding member is cured, the second bonding member will be cured again by the temperature at which the first bonding member is cured. As a result, the hardening of the second bonding member progresses, and the second bonding member may lose its softness when the electronic component is bonded to the flexible substrate.

However, if the temperature at which the first bonding member is cured is lower than the temperature at which the second bonding member is cured, the flexible substrate to which the electronic component is fixed is bonded to the circuit board by the first bonding member. The heating temperature at which the second bonding member is cured can be lower than the temperature at which the second bonding member hardens, thereby preventing the second bonding member from curing again and maintaining the softness of the second bonding member. be able to.

In addition, in the electronic component support structure and electronic watch according to the present invention, the flexible board and the circuit board may be joined using an adhesive or solder, or may be joined using a mechanical member such as a connector. It's okay. Bonding using a mechanical member is preferable because it does not impose thermal loads such as heating and cooling when bonding the flexible substrate and the circuit board. Preferably, this mechanical member is provided with wiring that electrically connects the flexible board and the circuit board.

Furthermore, mechanical members can also be used for bonding the electronic component and the flexible substrate, but bonding using an adhesive or the like is preferable from the viewpoint of obtaining the effect of absorbing mechanical loads.

FIG. 11 is a sectional view corresponding to FIGS. 2 and 8, showing a solid pattern 80 made of metal or ceramic fixed to the back surface 30B of the FPC 30. As shown in FIG. 11, the electronic timepiece support structure and the electronic timepiece 100 of each embodiment described above have metal or ceramic on one surface of the FPC 30 (for example, the back surface 30B in contact with the solder 60 bonded to the circuit board 20). A solid pattern (pattern of a surface uniformly formed over the entire surface without cutouts or holes) 80 may be fixed.

In this way, even if the FPC 30 with the solid pattern 80 formed on one side expands due to heating or contracts due to cooling, the solid pattern 80 made of metal or ceramic, which has a smaller coefficient of linear expansion than the FPC 30, will not expand or contract the FPC 30. Therefore, the thermal load on the crystal oscillator 40 can be reduced.

The support structure for electronic components and the electronic timepiece 100 of each of the embodiments described above apply the crystal oscillator 40 as an electronic component fixed to the FPC 30, but the support structure for electronic components and the electronic timepiece according to the present invention are However, the electronic component supported on the flexible substrate is not limited to a crystal oscillator. Therefore, in the electronic component support structure and electronic timepiece according to the present invention, control IC chips and other electronic components other than the crystal oscillator can be used as the electronic components supported on the flexible substrate.

Further, in the electronic component support structure and the electronic watch 100 of each embodiment, the FPC 30 is used as a flexible substrate to which the electronic component is fixed, but the material of the FPC 30 is not limited to a specific substance. Furthermore, the shape of the FPC 30 is not limited to that of the embodiment described above. Therefore, the flexible substrate in the electronic component support structure and electronic watch according to the present invention may have a shape other than a rectangle, such as a square, other polygons, or a circle, as long as it has the physical property of flexibility. , an ellipse, and various other shapes.

Furthermore, in the electronic component support structure and the electronic watch 100 of each embodiment, the FPC 30 is provided with an electrical contact that electrically connects a test device for testing the operating characteristics of the crystal oscillator 40 fixed to the FPC 30. It is preferable that

Since the characteristics of the crystal oscillator 40 can be inspected with inspection equipment while being fixed to the FPC 30, it is possible to select in advance crystal oscillators 40 with good characteristics while being fixed to the FPC 30. The yield of the electronic timepiece 100 can be improved compared to the case where the characteristics of the crystal oscillator 40 can only be inspected after the FPC 30 to which is fixed is fixed to the circuit board 20.

Although the electronic timepiece 100 of each embodiment is assumed to be a wristwatch that is mainly worn on the wrist, the electronic timepiece according to the present invention is not limited to a wristwatch, and can be used as a portable watch such as a pocket watch or a wristwatch. It may be a clock that is worn, a table clock, or a wall clock.

10 Main plate (an example of regulating member)
20 Circuit board 30 FPC (flexible board)
31 One end 32 Other end 40 Crystal oscillator (an example of electronic component)
50 Board holder (an example of a regulating member)
60 Solder (an example of joining material)
70 Conductive silicone adhesive (an example of bonding member)
100 Electronic watch L Longitudinal direction W Width direction

Claims (10)

Comprising a circuit board that is not flexible, a flat flexible board that is flexible, a regulating member, and an electronic component,
the flexible substrate is joined to and supported by the circuit board at one end;
The electronic component is arranged to be bonded to a portion of the flexible substrate that is different from a portion bonded to the circuit board,
At least a portion of the regulating member is disposed in a portion of the flexible substrate where the distance to the electronic component is shorter than the distance from the portion bonded to the circuit board to the electronic component ,
The regulating member is arranged at a distance from the electronic component and the flexible substrate when the flexible substrate is not bent, and is spaced apart from the electronic component and the flexible substrate when the flexible substrate is bent. A support structure for an electronic component, wherein the other end of the flexible substrate is arranged so as to hit the restriction member before hitting the restriction member, thereby preventing the electronic component from hitting the restriction member. The distance between the surface of the flexible substrate on which the electronic component is arranged and the surface of the restriction member facing the flexible substrate is greater than the distance between the electronic component and the restriction member. 2. The electronic component support structure according to claim 1 , wherein the support structure for electronic components is also set to be short. 3. The electronic component according to claim 1 , wherein the circuit board is cut out in a region that at least overlaps in plan view with a range in which the flexible board is bent with the part joined to the circuit board as a fixed end. Support structure. The portion of the flexible substrate where the regulating member is disposed facing the flexible substrate is located on the opposite side of the center of the flexible substrate from the portion bonded to the circuit board. The support structure for an electronic component according to any one of claims 1 to 3, wherein the support structure is a region. A first bonding member for bonding the flexible substrate and the circuit board is cured at a lower temperature than a second bonding member for bonding the electronic component and the flexible substrate. A support structure for an electronic component according to any one of items 1 to 4 . The second joining member that joins the electronic component and the flexible board has a softer hardness after joining than the first joining member that joins the flexible board and the circuit board. A support structure for an electronic component according to any one of claims 1 to 5 . The electronic component is a crystal oscillator having a crystal oscillator, and the longitudinal direction of the crystal oscillator is perpendicular to the longitudinal direction of the flexible substrate in which the flexible substrate is bent with the portion joined to the circuit board as a fixed end. The support structure for electronic components according to any one of claims 1 to 6, wherein the electronic component support structure is arranged in a posture. 8. The electronic device according to claim 7, wherein the longitudinal direction of the crystal resonator is orthogonal to the longitudinal direction of the flexible substrate in which the flexible substrate is bent with the portion joined to the circuit board as a fixed end. Support structure for parts. An electronic timepiece comprising the electronic component support structure according to any one of claims 1 to 8. Comprising a circuit board that is not flexible, a flat flexible board that is flexible, a regulating member, and an electronic component,
the flexible substrate is joined to and supported by the circuit board at one end;
The electronic component is arranged to be bonded to a portion of the flexible substrate that is different from a portion bonded to the circuit board,
At least a portion of the regulating member is disposed in a portion of the flexible substrate where the distance to the electronic component is shorter than the distance from the portion bonded to the circuit board to the electronic component ,
A region of the flexible substrate opposite to the surface to which the electronic component is bonded, which overlaps the region to which the electronic component is bonded in plan view, has a coefficient of linear expansion smaller than that of the flexible substrate. A support structure for electronic components to which solid metal or ceramic patterns are fixed .