JP7558729B2 - Wiring member connection structure and optical device - Google Patents

Description

The present invention relates to a wiring member connection structure and an optical device.

Conventionally, optical devices are known that are connected to wiring members such as flexible printed wiring boards having multiple conductors (for example, Patent Document 1 and Patent Document 2). In this type of optical device, the spacing between adjacent conductors at the connection portion between the optical device and the wiring is narrowing due to an increase in the number of conductors accompanying an increase in communication capacity and the miniaturization of optical modules. The narrowing of the spacing is referred to as narrowing the pitch.

International Publication No. 2016/129277 International Publication No. 2016/129278

When the distance between adjacent conductors narrows at the connection between the optical device and the wiring member, the connecting material that electrically connects the conductors may come out of its designated position, electrically connecting conductors that should be electrically insulated, which can easily result in a short circuit.

Therefore, one of the objectives of the present invention is to obtain a novel wiring connection structure and optical device that can suppress short circuits, for example.

The connection structure of the wiring member of the present invention includes, for example, a wiring member having a first insulator having a plurality of through holes each extending across a first direction and penetrating the first direction, a plurality of first conductors each penetrating the first insulator along the through holes and electrically insulated via the first insulator, a base overlapping the wiring member in the first direction and having a second insulator and a plurality of second conductors each electrically connected to the first conductor and electrically insulated via the second insulator, and a plurality of connecting members each penetrating the first conductor in the first direction within the through holes and interposed between the first conductor and the second conductor to electrically connect the first conductor and the second conductor, at least one of the first conductors has a first extension portion extending in a direction away from other adjacent first conductors at intervals in a second direction intersecting the first direction on the opposite side of the base of the wiring member, and the connecting member electrically connected to the at least one first conductor extends in a direction away from the other first conductor along the first extension portion.

In the connection structure of the wiring member, for example, the first extension portion extends in a third direction that intersects the first direction and the second direction.

The connection structure of the wiring member of the present invention includes, for example, a wiring member having a first insulator extending across a first direction and a plurality of first conductors each electrically insulated via the first insulator, a base overlapping the wiring member in the first direction and having a second insulator and a plurality of second conductors each electrically connected to the first conductor and electrically insulated via the second insulator, and a plurality of connecting members interposed between the first conductor and the second conductor and electrically connecting the first conductor and the second conductor, and the second insulator has an opening that opens toward the wiring member on the opposite side to other second conductors adjacent to at least one of the second conductors at intervals in a second direction intersecting the first direction, and the at least one second conductor has a second extension along the inner surface of the opening, and a portion of the connecting member electrically connected to the at least one second conductor is accommodated in the opening along the second extension.

In the connection structure of the wiring member, for example, the opening is provided at a position shifted in a third direction intersecting the second direction with respect to the region of the base facing the first conductor in the first direction.

The connection structure of the wiring member of the present invention includes, for example, a wiring member having a first insulator extending across a first direction and a plurality of first conductors each electrically insulated via the first insulator, a base overlapping the wiring member in the first direction and having a second insulator and a plurality of second conductors each electrically connected to the first conductor and electrically insulated via the second insulator, and a plurality of connecting members interposed between the first conductor and the second conductor and electrically connecting the first conductor and the second conductor, and the second insulator has an opening extending in a direction away from the adjacent second conductors at intervals in a second direction intersecting the first direction for at least one of the second conductors and opening toward the wiring member, and the at least one second conductor has a second extension along the inner surface of the opening, and a portion of the connecting member electrically connected to the at least one second conductor is accommodated in the opening along the second extension.

In the connection structure of the wiring member, for example, the opening extends from a region of the base facing the first conductor in the first direction in a third direction intersecting the first direction and the second direction.

In the connection structure of the wiring member, for example, the wiring member is a flexible printed wiring board.

In the connection structure of the wiring member, for example, the connection material is solder.

In the connection structure of the wiring member, for example, the insulator is made of a synthetic resin material.

The optical device of the present invention also includes, for example, a housing having the base included in the connection structure of the wiring member, and an optical component housed within the housing.

The optical device includes, for example, at least one of a semiconductor laser element, a semiconductor modulator, a semiconductor optical amplifier, and a light receiving element as the optical component.

The optical device, for example, includes a wiring member that is included in a connection structure for the wiring member and fixed to the housing.

The present invention makes it possible to obtain, for example, a novel wiring connection structure and optical device that can suppress short circuits.

FIG. 1 is an exemplary schematic side view (partial cross-sectional view) illustrating the internal configuration of an optical device according to an embodiment. FIG. 2 is a cross-sectional view taken along line II-II of FIG. FIG. 3 is an exemplary schematic side view of the connection structure of the wiring member according to the embodiment. FIG. 4 is an illustrative schematic side view of a connection structure of a wiring member according to a first modified example. FIG. 5 is an illustrative schematic side view of a connection structure of a wiring member according to a second modified example. FIG. 6 is an exemplary schematic cross-sectional view of a wiring member connection structure according to a second embodiment, taken at the same position as in FIG. 2. In FIG. FIG. 7 is a cross-sectional view taken along line VII-VII of FIG. FIG. 8 is an exemplary schematic cross-sectional view of a wiring member connection structure according to a third embodiment, taken at the same position as in FIG. 2. In FIG. FIG. 9 is a cross-sectional view taken along line IX-IX of FIG.

Below, exemplary embodiments and variations of the present invention are disclosed. The configurations of the embodiments and variations shown below, and the actions and results (effects) brought about by said configurations, are merely examples. The present invention can also be realized by configurations other than those disclosed in the following embodiments and variations. Furthermore, according to the present invention, it is possible to obtain at least one of the various effects (including derivative effects) obtained by the configurations.

The embodiments and modified examples shown below have similar configurations. According to the configuration of each embodiment and modified example, similar actions and effects based on the similar configurations can be obtained. Furthermore, below, the similar configurations are given the same reference numerals, and duplicate explanations may be omitted.

In this specification, ordinal numbers are used for convenience to distinguish between parts, portions, etc., and do not indicate priority or order.

In addition, in each figure, the X direction is represented by an arrow X, the Y direction is represented by an arrow Y, and the Z direction is represented by an arrow Z. The X direction, Y direction, and Z direction intersect with each other and are perpendicular to each other. The X direction can be referred to as the thickness direction or stacking direction of the wiring member, the Y direction can be referred to as the width direction of the wiring member, and the Z direction can be referred to as the extension direction of the wiring member.

[First embodiment]
Fig. 1 is a side view showing the internal configuration of the optical device 1 of the first embodiment. As shown in Fig. 1, the optical device 1 includes a housing 10 and components housed in the housing 10, such as a temperature control device 20, a light emitting element 41, a lens 42, a carrier 43, an optical isolator 51, a beam splitter 52, and a light receiving element 53. The light receiving element 53 is, for example, a photodiode.

The housing 10 has a bottom wall 11, a top wall 12, two end walls 13, and two side walls 14 as walls. The housing 10 has, for example, a rectangular parallelepiped and box-like shape. Within the housing 10, a storage chamber R is formed that is surrounded by the bottom wall 11, the top wall 12, the two side walls 14, and the two end walls 13.

The bottom wall 11 extends in a direction that intersects with the Z direction. In this embodiment, the bottom wall 11 extends in the X direction and the Y direction and is perpendicular to the Z direction.

In the accommodation chamber R, an optical component is attached on the bottom wall 11 via a temperature adjustment device 20. The optical component may be attached on the temperature adjustment device 20 via a base plate made of ceramic such as aluminum oxide (Al ₂ O ₃ ) or aluminum nitride (AlN). The bottom wall 11 may also be referred to as a support portion or a support wall.

The top wall 12 extends in a direction that intersects with the Z direction. In this embodiment, the top wall 12 extends in the X direction and the Y direction and is perpendicular to the Z direction.

The end walls 13 each extend in a direction that intersects with the X direction. In this embodiment, the end walls 13 extend in the Y direction and the Z direction and are perpendicular to the X direction. The end walls 13 are each located at the end of the housing 10 in the X direction (longitudinal direction).

An optical window 15 is provided in one of the end walls 13.

The other end wall 13, on which the optical window 15 is not provided, is provided with a feedthrough 16 that penetrates the end wall 13 in the thickness direction (X direction). The feedthrough 16 can also be said to constitute a part of the housing 10. The feedthrough 16 may also have a portion that penetrates the side wall 14.

The side walls 14 extend across the Y direction. In this embodiment, the side walls 14 extend in the X and Z directions and are perpendicular to the Y direction. The side walls 14 are located at the ends of the housing 10 in the width direction. The bottom wall 11, the top wall 12, and the side walls 14 may also be referred to as peripheral walls.

The bottom wall 11 may be made of a material with high thermal conductivity, such as copper tungsten (CuW), copper molybdenum (CuMo), copper (Cu), aluminum oxide (Al ₂ O ₃ ), or aluminum nitride (AlN). The top wall 12, end wall 13, and side wall 14 may be made of a material with low thermal expansion coefficient, such as an Fe-Ni-Co alloy, aluminum oxide (Al _{2 O 3 ), or aluminum nitride (AlN). The feedthrough 16 may be made of a ceramic, such as aluminum oxide (Al 2 O 3 )} , or aluminum nitride (AlN).

The temperature adjustment device 20 has an upper substrate 21U, a lower substrate 21L, and a number of thermoelectric elements 22. The upper substrate 21U and the lower substrate 21L are arranged along the bottom wall 11. The thermoelectric elements 22 are respectively interposed between the upper substrate 21U and the lower substrate 21L.

The upper substrate 21U extends across the Z direction. In this embodiment, the upper substrate 21U extends in the X and Y directions and is perpendicular to the Z direction. The upper substrate 21U has an upper surface 20a and a lower surface 21b on the back side of the upper surface 20a. The upper substrate 21U may be made of an insulating material with high thermal conductivity, such as ceramic. Optical components such as the light-emitting element 41, the lens 42, the optical isolator 51, the beam splitter 52, and the light-receiving element 53 are attached directly to the upper surface 20a or indirectly via other components such as a base plate. The upper substrate 21U may also be referred to as a first substrate or a mounting substrate, and the upper surface 20a may also be referred to as a mounting surface.

The lower substrate 21L extends across the Z direction. In this embodiment, the lower substrate 21L extends in the X and Y directions and is perpendicular to the Z direction. The lower substrate 21L has an upper surface 21a and a lower surface 20b on the reverse side of the upper surface 21a. The lower substrate 21L may be made of an insulating material with high thermal conductivity, such as ceramic. The lower substrate 21L is attached to the bottom wall 11 of the housing 10 in a state where it is thermally connected to the bottom wall 11. The lower substrate 21L may also be referred to as a second substrate or a mounting substrate, and the lower surface 20b may also be referred to as a contact surface or a mounting surface.

The thermoelectric element 22 is an example of a semiconductor element and can be made of a P-type semiconductor or an N-type semiconductor, such as a bismuth telluride-based semiconductor.

A wiring pattern (not shown) is provided on the lower surface 21b of the upper substrate 21U and the upper surface 21a of the lower substrate 21L. The thermoelectric elements 22 are each interposed between these two wiring patterns. The wiring pattern can be made of a highly conductive metal material, such as a copper-based metal.

The multiple thermoelectric elements 22 are connected in series to form a PN junction via the wiring pattern. The multiple thermoelectric elements 22 generate or absorb heat when power is supplied from outside the temperature control device 20 via the wiring pattern. The generation and absorption of heat in the thermoelectric elements 22 is switched depending on the direction of the current flowing through the multiple thermoelectric elements 22. The wiring pattern may also be referred to as a conductor or a conductor layer.

In this way, the temperature adjustment device 20 functions as a base for the optical components, and adjusts the temperature of the optical components by heating or cooling them. The temperature adjustment device 20 can also be called a Peltier module or a thermoelectric module.

The light-emitting element 41, which is an optical functional element, is, for example, a semiconductor laser element, and in this case, the optical device 1 is a wavelength-tunable laser module. In addition, the optical element may be an optical modulator element and the optical device may be an optical modulator module, the optical element may be a photodiode and the optical device may be an optical receiver module, or the optical device may be an integrated coherent-transmitter receiver optical sub-assembly (IC-TROSA) in which a semiconductor laser element, a photodiode element, and an optical modulator element are integrated. The light-emitting element 41 is mounted on the upper surface 20a of the temperature control device 20 via a carrier 43. The carrier 43 is made of an insulating material with a linear expansion coefficient close to that of the light-emitting element 41 or an insulating material with high thermal conductivity, and transmits heat generated by the light-emitting element 41 to the temperature control device 20. The carrier 43 may also be called a submount.

The light-emitting element 41 outputs laser light toward the lens 42. The wavelength of the laser light is, for example, 900 nm or more and 1650 nm or less, which is a suitable wavelength for optical communication. The element temperature of the light-emitting element 41 increases while the laser light is being output, and the light-emitting element 41 functions as a heating element. The light-emitting element 41 is, for example, a semiconductor laser element.

The lens 42 is attached to the carrier 43. The lens 42 collimates the laser light from the light emitting element 41 by applying a refractive index effect. The laser light output from the lens 42 is input to the optical isolator 51.

The optical isolator 51 has a magnet 51a and an optical element section 51b including a magneto-optical element and a polarizing plate. The optical isolator 51 polarizes the laser light from the optical element section 51b and exerts a magneto-optical effect on the laser light from the optical element section 51b. The laser light output from the optical isolator 51 is input to the beam splitter 52. The optical isolator 51 prevents the light from the beam splitter 52 from passing toward the light-emitting element 41.

The beam splitter 52 outputs the laser light from the optical isolator 51 outside the optical device 1, and also splits the laser light from the optical isolator 51 and inputs it to the light receiving element 53.

The housing 10 is hermetically sealed, which prevents air and water from acting on the optical components contained within the housing 10, such as the light-emitting element 41, lens 42, optical isolator 51, beam splitter 52, and light-receiving element 53. The optical device 1 is configured so that an inert gas, such as nitrogen gas, filled in the housing 10 during manufacture does not leak out of the housing 10.

As shown in FIG. 1, a flexible printed wiring board 30 is connected to the optical device 1. In this embodiment, the flexible printed wiring board 30 is fixed to the feedthrough 16. A fastener such as a screw (not shown) or an adhesive may be used to fix the flexible printed wiring board 30 to the feedthrough 16 or the housing 10.

Driving power and control signals are supplied from a higher-level device (not shown) to the light-emitting element 41 and the temperature adjustment device 20 via the conductors in the flexible printed wiring board 30. In addition, a detection signal is sent from a sensor (not shown) in the accommodation chamber R to the higher-level device via the conductors in the flexible printed wiring board 30.

Figure 2 is a cross-sectional view taken along line II-II in Figure 1. The connection structure 100A for wiring members (hereinafter simply referred to as the connection structure) has a flexible printed wiring board 30, a feedthrough 16, and a connection material 60. The flexible printed wiring board 30 is an example of a wiring member. The feedthrough 16 is an example of a base.

The flexible printed wiring board 30 has an insulating layer 31 and conductors 33, 34, and 35. The insulating layer 31 can be made of an insulating and flexible synthetic resin material, such as polyimide. The conductors 33, 34, and 35 can all be made of a conductive metal material, such as copper (copper-based metal). The conductors 33-1 (33), 34-1 (34), and 35-1 (35) are electrically connected to form a conductive path. The conductors 33-2 (33), 34-2 (34), and 35-2 (35) are electrically connected to form a conductive path. The conductors 33-1, 34-1, and 35-1 are electrically insulated from the conductors 33-2, 34-2, and 35-2 via the insulating layer 31. That is, the flexible printed wiring board 30 has a plurality of conductive paths (conductors) that are electrically insulated via the insulating layer 31. Although only two adjacent conductive paths are shown in FIG. 2, the flexible printed wiring board 30 includes three or more conductive paths that are insulated by the insulating layer 31. Each conductive path has a strip-shaped portion (not shown) that extends in parallel along the longitudinal direction of the flexible printed wiring board 30. The multiple conductive paths that are insulated from each other and that the flexible printed wiring board 30 has are an example of a plurality of first conductors. The insulating layer 31 is an example of a first insulator.

In the connection structure 100A, the insulating layer 31 spreads across the X direction and extends in the Y and Z directions. The X direction is the thickness direction of the insulating layer 31, the Y direction is the width direction of the insulating layer 31, and the Z direction is the longitudinal direction of the insulating layer 31. The insulating layer 31 has end faces 30b and 30c. The end face 30b is an end face in the opposite direction to the X direction and is located opposite the feed through 16. The end face 30c is an end face in the X direction and faces the feed through 16. The end faces 30b and 30c spread across the X direction and extend in the Y and Z directions. The insulating layer 31 also has a through hole 30a (30a1, 30a2) that penetrates in the X direction. The X direction is an example of a first direction.

A ring-shaped (tubular) conductor 33 (33-1, 33-2) is provided inside each of the through holes 30a (30a1, 30a2) along the inner circumference of the through hole 30a. As an example, the conductor 33 has a cylindrical shape.

Layered conductors 34 (34-1, 34-2) are provided on the end surface 30b near the edge of the through hole 30a. As an example, the conductors 34 have a circular or rectangular appearance when viewed in the X direction.

In addition, layered conductors 35 (35-1, 35-2) are provided on the end surface 30c near the edge of the through hole 30a. As an example, the conductors 35 have a circular or rectangular appearance when viewed in the X direction.

The feedthrough 16 and the flexible printed wiring board 30 overlap in the X direction. The feedthrough 16 has an insulating layer 16c and an electrode pad 17. The insulating layer 16c is made of multi-layered ceramic. An electric circuit pattern made of metal is formed in each ceramic layer, and the conductors of each ceramic layer are electrically connected by filling punched vias with metal paste, for example. The insulating layer 16c is an example of a second insulator.

As shown in FIG. 1, a metal pad 19 that serves as an electrical circuit end is formed on the Z-direction end face of the feedthrough 16. The metal pad 19 is electrically connected to terminals (not shown) of photoelectric components, electrical components, circuit boards, etc. in the accommodation chamber R via a conductor 18, such as a metal wire. Note that for simplicity, only one conductor 18 is shown in FIG. 1, but the optical device 1 also has other conductors 18 that are not shown.

The end face 16a of the feedthrough 16 on the opposite side of the X direction is exposed outside the housing 10. The end face 16a intersects with the X direction and extends in the Y direction and the Z direction. The end face 16a faces the insulating layer 31.

As shown in FIG. 2, layered electrode pads 17 (17-1, 17-2) are provided on the end surface 16a of the feedthrough 16. The electrode pads 17 are electrically connected to metal pads 19 via conductors (not shown) in the feedthrough 16. The electrode pads 17 are electrodes for connecting to an electrical circuit outside the module. As an example, the electrode pads 17 have a circular or rectangular appearance when viewed in the X direction. The electrode pads 17 are an example of a second conductor.

Electrode pad 17-1 faces conductor 35-1, and electrode pad 17-2 faces conductor 35-2.

The connection material 60 (60-1, 60-2) extends from between the electrode pad 17 and the conductor 35, through the through hole 30a (inside the cylindrical conductor 33), to a position where it contacts the conductor 34. The connection material 60 is heated and in a fluid state, and is injected into the through hole 30a1, for example, from the side opposite the feedthrough 16, and is solidified by cooling. The connection material 60 is, for example, solder.

When in a fluid state, the connecting material 60 has a higher affinity (wettability) with metal materials than with synthetic resin materials, so it selectively adheres to the surfaces of the electrode pad 17 and the conductors 33, 34, and 35 and flows along those surfaces.

The connection material 60-1 electrically connects the electrode pad 17-1 to the conductors 33-1, 34-1, and 35-1, thereby forming the connection part 100-1. The connection material 60-2 electrically connects the electrode pad 17-2 to the conductors 33-2, 34-2, and 35-2, thereby forming the connection part 100-2.

Figure 3 is a side view of the connection structure 100A as viewed in the X direction. Note that Figure 2 is a cross-sectional view taken along line II-II in Figure 3. As shown in Figures 2 and 3, in this embodiment, the positions of the electrode pad 17 and the conductors 33 and 34 are offset in the cross section along the X direction.

As shown in FIG. 2, the electrode pads 17 and conductors 35 corresponding to each other are generally aligned in the X direction. That is, the electrode pad 17-1 and conductor 35-1, which are electrically connected via the connection material 60-1, are generally aligned in the X direction, and the electrode pad 17-2 and conductor 35-2, which are electrically connected via the connection material 60-2, are generally aligned in the X direction. The electrode pads 17-1 and conductor 35-1, and the electrode pads 17-2 and conductor 35-2 are spaced apart in the Y direction. When the pitch is narrowed, the spacing between the electrode pads 17-1 and conductor 35-1 and the electrode pads 17-2 and conductor 35-2 is narrowed. The Y direction is an example of the second direction.

In addition, in this embodiment, the through hole 30a1 and the conductor 33-1 are positioned farther away from the conductor 35-1 than the conductor 35-2, and the through hole 30a2 and the conductor 33-2 are positioned farther away from the conductor 35-2 than the conductor 35-1.

Furthermore, in this embodiment, conductor 34-1 is provided at a position farther away from conductor 35-1 than conductor 35-2, and conductor 34-2 is provided at a position farther away from conductor 35-2 than conductor 35-1. Conductor 34-1 is a portion of conductors 33-1, 34-1, 35-1 that extends in a direction away from conductors 33-2, 34-2, 35-2 on the opposite side of feed-through 16, and conductor 34-2 is a portion of conductors 33-2, 34-2, 35-2 that extends in a direction away from conductors 33-1, 34-1, 35-1 on the opposite side of feed-through 16. Conductors 34-1 and 34-2 are examples of first extensions. Furthermore, conductors 33-2, 34-2, and 35-2 are examples of other first conductors compared to conductors 33-1, 34-1, and 35-1, and conductors 33-1, 34-1, and 35-1 are examples of other first conductors compared to conductors 33-2, 34-2, and 35-2.

As described above, the connecting material 60-1, in a fluid state, spreads along the conductors 33-1, 34-1, and 35-1. Here, in this embodiment, since the conductor 34-1 is provided as the first extension portion described above, the connecting material 60-1 having fluidity extends along the conductor 34-1. Therefore, the connecting material 60-1 having fluidity is subjected to interfacial tension in the direction in which the conductor 34-1 extends, that is, in the direction away from the conductors 33-2, 34-2, and 35-2. As a result, the connecting material 60-1 having fluidity in the portion between the conductor 35-1 and the electrode pad 17-1 is subjected to interfacial tension in the direction away from the electrode pad 17-2, the conductor 35-2, and the connecting material 60-2. Since the connecting material 60-1 is solidified in this state, contact between the connecting material 60-1 and the electrode pad 17-2, the conductor 35-2, or the connecting material 60-2, that is, a short circuit, is suppressed.

Similarly, when the connecting material 60-2 has fluidity, it spreads along the conductors 33-2, 34-2, and 35-2. Here, in this embodiment, since the conductor 34-2 is provided as the first extension portion described above, the connecting material 60-2 having fluidity extends along the conductor 34-2. Therefore, the connecting material 60-2 having fluidity is subjected to interfacial tension in the direction in which the conductor 34-2 extends, that is, in the direction away from the conductors 33-1, 34-1, and 35-1. As a result, the connecting material 60-2 having fluidity in the portion between the conductor 35-2 and the electrode pad 17-2 is subjected to interfacial tension in the direction away from the electrode pad 17-1, the conductor 35-1, and the connecting material 60-1. Since the connecting material 60-2 is solidified in this state, contact between the connecting material 60-2 and the electrode pad 17-1, the conductor 35-1, or the connecting material 60-1, that is, a short circuit, is suppressed.

Also, as shown in Figures 2 and 3, the conductors 33, 35 and the electrode pad 17 are each aligned in the Y direction. That is, the connection parts 100-1, 100-2 are approximately aligned in the Y direction. Also, as shown in Figure 3, the conductor 34-1 extends in the D1 direction between the Y direction and the opposite direction to the Z direction, and the conductor 34-2 extends in the D2 direction between the opposite direction to the Y direction and the Z direction. The D1 direction and the D2 direction are both directions that intersect with the Y direction and are examples of a third direction. If the conductor 34 extends along the Y direction in the Y direction or in the opposite direction to the Y direction, the length of the connection parts 100-1, 100-2 in the Y direction will be long, and the gap between the connection parts 100-1, 100-2 will be small, making it difficult to set the pitch (installation interval) of the connection parts 100-1, 100-2 in the Y direction narrow. In this embodiment, the conductor 34 extends in the D1 or D2 direction that intersects with the Y direction, so the length of the connection parts 100-1 and 100-2 in the Y direction can be made shorter. This allows the pitch of the connection parts 100-1 and 100-2 in the Y direction to be narrowed, making it easier to accommodate narrower pitches.

As described above, in this embodiment, the conductor 34-1 (first extension) extends in a direction away from the conductors 33-2, 34-2, and 35-2 (other first conductors) on the opposite side of the feedthrough 16 (base) of the flexible printed wiring board 30 (wiring member). In addition, the connection material 60-1 electrically connected to the conductors 33-1, 34-1, and 35-1 (first conductors) extends along the conductor 34-1 in a direction away from the conductors 33-2, 34-2, and 35-2.

The conductor 34-2 (first extension) extends in a direction away from the conductors 33-1, 34-1, and 35-1 (other first conductors) on the opposite side of the feedthrough 16 of the flexible printed wiring board 30. The connecting material 60-2 electrically connected to the conductors 33-2, 34-2, and 35-2 (first conductors) extends along the conductor 34-2 in a direction away from the conductors 33-1, 34-1, and 35-1.

According to this configuration, the connection material 60-1 can be solidified in a state where interfacial tension acts in a direction away from the electrode pad 17-2, the conductor 35-2, and the connection material 60-2, and the connection material 60-2 can be solidified in a state where interfacial tension acts in a direction away from the electrode pad 17-1, the conductor 35-1, and the connection material 60-1. Therefore, it is possible to suppress a short circuit caused by contact between the connection material 60-1 and the electrode pad 17-2, the conductor 35-2, or the connection material 60-2, and it is possible to suppress a short circuit caused by contact between the connection material 60-2 and the electrode pad 17-1, the conductor 35-1, or the connection material 60-1. Therefore, even if the spacing between the multiple conductive paths (conductors 33, 34, 35) and the spacing between the multiple electrode pads 17 is narrowed by so-called narrow pitch, it is possible to suppress a short circuit through the connection material 60. In addition, the conductor 34 only needs to be provided where necessary, and it is not necessary to provide a conductor 34 for each of the multiple conductors 33 and 35.

[First Modification]
4 is a side view of a portion of the connection structure 100A-1 of the first modified example. As shown in FIG. 4, in this modified example, the connection portion 100-1 and the connection portion 100-2 are offset from each other in the Z direction and are arranged in a staggered, i.e., zigzag, pattern in the Y direction. With this arrangement, the electrode pads 17 and the conductors 33, 34, 35 can be arranged more densely in the Y direction, making it easier to further miniaturize the connection structure 100A-1, and thus the flexible printed wiring board 30 and the optical device 1, in the Y direction.

[Second Modification]
5 is a side view of a portion of the connection structure 100A-2 of the second modified example. As shown in FIG. 5, in this modified example, a row in which the connection portions 100-1 are aligned in the Y direction and a row in which the connection portions 100-2 are aligned in the Y direction are arranged at intervals in the Z direction. With this arrangement, the electrode pads 17 and the conductors 33, 34, 35 can be arranged more densely in the Y direction, making it easier to further miniaturize the connection structure 100A-1, and thus the flexible printed wiring board 30 and the optical device 1, in the Y direction.

[Second embodiment]
Fig. 6 is a cross-sectional view of a connection structure 100B of the second embodiment taken at the same position as in Fig. 2, and Fig. 7 is a cross-sectional view taken along line VII-VII in Fig. 6. Fig. 6 is a cross-sectional view taken along line VI-VI in Fig. 7.

As shown in FIG. 6, the connection structure 100B includes a feedthrough 16B and a flexible printed wiring board 30B. However, in this embodiment, the flexible printed wiring board 30B does not have a through hole 30a (see FIG. 2) in the insulating layer 31 as in the first embodiment, and does not have conductors 33 and 34. In this embodiment, only the conductor 35 is an example of a first conductor.

On the other hand, in the feedthrough 16B, a bottomed cylindrical opening 16b (16b1, 16b2) is provided on the end face 16a toward the flexible printed wiring board 30B, and bottomed cylindrical conductors 18 (18-1, 18-2) are provided along the inner surface of the opening 16b. The conductors 18 are adjacent to and electrically connected to the electrode pad 17. The conductor 18-1 is adjacent to and electrically connected to the electrode pad 17-1, and the conductor 18-2 is adjacent to and electrically connected to the electrode pad 17-2. In this embodiment, the electrode pad 17 and the conductor 18 are an example of a second conductor. Furthermore, the electrode pad 17-2 and the conductor 18-2 are an example of another second conductor with respect to the electrode pad 17-1 and the conductor 18-1, and the electrode pad 17-1 and the conductor 18-1 are an example of another second conductor with respect to the electrode pad 17-2 and the conductor 18-2. The opening 16b and the conductor 18 have a cylindrical shape with a bottom, but are not limited to this. The opening 16b can also be called a recess.

As shown in Figures 6 and 7, in this embodiment, the positions of the electrode pad 17 and the conductor 18 (opening 16b) are offset in the cross section along the X direction.

As shown in FIG. 6, in this embodiment, the corresponding electrode pads 17 and conductors 35 are also aligned approximately in the X direction. That is, the electrode pad 17-1 and conductor 35-1, which are electrically connected via a connection material 60-1, are aligned approximately in the X direction, and the electrode pad 17-2 and conductor 35-2, which are electrically connected via a connection material 60-2, are aligned approximately in the X direction. The electrode pad 17-1 and conductor 35-1, and the electrode pad 17-2 and conductor 35-2 are spaced apart in the Y direction.

In addition, in this embodiment, opening 16b1 is provided offset from electrode pad 17-1 to the opposite side of electrode pad 17-2, and opening 16b2 is provided offset from electrode pad 17-2 to the opposite side of electrode pad 17-1. Electrode pad 17-1 is an example of an opposing region in the X direction to conductor 35-1, and electrode pad 17-2 is an example of an opposing region in the X direction to conductor 35-2. Furthermore, conductor 18-1 along the inner surface of opening 16b1 and conductor 18-2 along the inner surface of opening 16b2 are examples of second extensions.

In this embodiment, when the connecting material 60-1 has fluidity, it spreads along the electrode pad 17-1 and the conductor 18-1 and enters the opening 16b1. Therefore, the connecting material 60-1 having fluidity is subjected to interfacial tension in the direction in which the conductor 18-1 exists relative to the electrode pad 17-1, in other words, in the direction in which the conductor 18-1 extends relative to the electrode pad 17-1. The direction in which the conductor 18-1 extends relative to the electrode pad 17-1 is also the direction away from the electrode pad 17-2. Therefore, in the portion of the connecting material 60-1 having fluidity that exists between the conductor 35-1 and the electrode pad 17-1, interfacial tension acts in the direction away from the electrode pad 17-2, the conductor 35-2, and the connecting material 60-2. Since the connecting material 60-1 is solidified in this state, contact between the connecting material 60-1 and the electrode pad 17-2, the conductor 35-2, or the connecting material 60-2, i.e., a short circuit, is suppressed. In addition, in the solidified state, a portion of the connection material 60-1 is housed within the opening 16b1 along the conductor 18-1.

Similarly, when the connecting material 60-2 has fluidity, it spreads along the electrode pad 17-2 and the conductor 18-2 and enters the opening 16b2. Therefore, the connecting material 60-2 having fluidity is subjected to interfacial tension in the direction in which the conductor 18-2 exists relative to the electrode pad 17-2, in other words, in the direction in which the conductor 18-2 extends relative to the electrode pad 17-2. The direction in which the conductor 18-2 extends relative to the electrode pad 17-2 is also the direction away from the electrode pad 17-1. Therefore, the portion of the connecting material 60-2 having fluidity that exists between the conductor 35-2 and the electrode pad 17-2 is subjected to interfacial tension in the direction away from the electrode pad 17-1, the conductor 35-1, and the connecting material 60-1. Since the connecting material 60-2 is solidified in this state, contact between the connecting material 60-2 and the electrode pad 17-1, the conductor 35-1, or the connecting material 60-1, i.e., a short circuit, is suppressed. In addition, in the solidified state, a portion of the connection material 60-2 is housed within the opening 16b2 along the conductor 18-2.

As shown in Figures 6 and 7, the conductor 35 and electrode pad 17 are aligned in the Y direction. That is, the connection portions 100-1, 100-2 are approximately aligned in the Y direction. In contrast, as shown in Figure 7, the opening 16b1 and the conductor 18-1 are positioned offset in the D1 direction between the Y direction and the opposite direction to the Z direction with respect to the electrode pad 17-1, and the opening 16b2 and the conductor 18-2 are positioned offset in the D2 direction between the opposite direction to the Y direction and the Z direction with respect to the electrode pad 17-2. The D1 direction and the D2 direction are both directions that intersect with the Y direction and are examples of a third direction. If the opening 16b and the conductor 18 were offset in the Y direction or in the opposite direction to the Y direction relative to the electrode pad 17, the length of the connection parts 100-1 and 100-2 in the Y direction would be longer, and the gap between the connection parts 100-1 and 100-2 would be smaller, making it difficult to set the pitch (installation interval) of the connection parts 100-1 and 100-2 in the Y direction narrower. In this embodiment, the opening 16b and the conductor 18 are offset in the D1 direction or D2 direction intersecting the Y direction relative to the electrode pad 17, so the length of the connection parts 100-1 and 100-2 in the Y direction can be made shorter. Therefore, the pitch of the connection parts 100-1 and 100-2 in the Y direction can be narrowed, making it easier to accommodate narrower pitches.

This embodiment as described above can also suppress short circuits caused by contact between the connection material 60-1 and the electrode pad 17-2, the conductor 35-2, or the connection material 60-2, and can also suppress short circuits caused by contact between the connection material 60-2 and the electrode pad 17-1, the conductor 35-1, or the connection material 60-1. Therefore, even if the spacing between the multiple conductive paths (conductors 35) and the spacing between the multiple electrode pads 17 is narrowed by so-called narrow pitch, it is possible to suppress short circuits through the connection material 60. Note that the openings 16b and the conductors 18 only need to be provided where necessary, and it is not necessary to provide openings 16b and conductors 18 corresponding to all of the multiple electrode pads 17.

[Third embodiment]
Fig. 8 is a cross-sectional view of a connection structure 100C of the third embodiment taken at the same position as in Fig. 2, and Fig. 9 is a cross-sectional view taken along line IX-IX in Fig. 8. Fig. 8 is a cross-sectional view taken along line VIII-VIII in Fig. 9.

As is clear from comparing FIG. 8 with FIG. 6, the connection structure 100C of this embodiment has a similar configuration to the connection structure 100B of the second embodiment. However, in this embodiment, the arrangement and shape of the opening 16b, the electrode pad 17, and the conductor 18 are different from those of the second embodiment. The configuration of the flexible printed wiring board 30C is similar to that of the flexible printed wiring board 30B of the second embodiment.

The opening 16b1 extends from the region on the end face 16a facing the conductor 35-1 in a direction away from the electrode pad 17-2, and the opening 16b2 extends from the region on the end face 16a facing the conductor 35-2 in a direction away from the electrode pad 17-1. The conductor 18-1 extends along the inner surface of the opening 16b1 from the region facing the conductor 35-1 in a direction away from the electrode pad 17-2, and the conductor 18-1 extends along the inner surface of the opening 16b1 from the region facing the conductor 35-2 in a direction away from the electrode pad 17-1. As shown in FIG. 9, the shapes of the opening 16b and the conductor 18 are, for example, elliptical (long hole-like), but are not limited thereto.

In this embodiment, the connecting material 60-1, when in a fluid state, spreads along the electrode pad 17-1 and the conductor 18-1 and enters the opening 16b1. Therefore, interfacial tension acts on the connecting material 60-1 with fluidity in the direction in which the conductor 18-1 extends. The direction in which the conductor 18-1 extends is the direction away from the electrode pad 17-2. Therefore, the interfacial tension acts on the part of the connecting material 60-1 with fluidity that exists between the conductor 35-1 and the electrode pad 17-1 in the direction away from the electrode pad 17-2, the conductor 35-2, and the connecting material 60-2. Since the connecting material 60-1 is solidified in this state, contact between the connecting material 60-1 and the electrode pad 17-2, the conductor 35-2, or the connecting material 60-2, i.e., a short circuit, is suppressed. In the solidified state, a part of the connecting material 60-1 is accommodated in the opening 16b1 along the conductor 18-1.

Similarly, when the connecting material 60-2 has fluidity, it spreads along the electrode pad 17-2 and the conductor 18-2 and enters the opening 16b2. Therefore, the connecting material 60-2 has fluidity, and an interfacial tension acts in the direction in which the conductor 18-2 extends. The direction in which the conductor 18-2 extends is the direction away from the electrode pad 17-1. Therefore, the portion of the connecting material 60-2 that has fluidity and exists between the conductor 35-2 and the electrode pad 17-2 has interfacial tension acting in the direction away from the electrode pad 17-1, the conductor 35-1, and the connecting material 60-1. Since the connecting material 60-2 is solidified in this state, contact between the connecting material 60-2 and the electrode pad 17-1, the conductor 35-1, or the connecting material 60-1, i.e., a short circuit, is suppressed. In addition, in the solidified state, a portion of the connection material 60-2 is housed within the opening 16b2 along the conductor 18-2.

Also, as shown in Figures 8 and 9, the conductors 35 are aligned in the Y direction. That is, the connection portions 100-1 and 100-2 are substantially aligned in the Y direction. In contrast, as shown in Figure 9, the opening 16b1 and the conductor 18-1 extend in the D1 direction between the Y direction and the opposite direction to the Z direction from the facing region in the X direction with the conductor 35-1 of the feedthrough 16C, and the opening 16b2 and the conductor 18-2 extend in the D2 direction between the opposite direction to the Y direction and the Z direction from the facing region in the X direction with the conductor 35-2 of the feedthrough 16C. The D1 direction and the D2 direction are both directions that intersect with the Y direction and are examples of a third direction. If the opening 16b and the conductor 18 extend in the Y direction or in the opposite direction to the Y direction along the Y direction relative to the electrode pad 17, the length of the connection parts 100-1 and 100-2 in the Y direction will be long, and the gap between the connection parts 100-1 and 100-2 will be small, making it difficult to set the pitch (installation interval) of the connection parts 100-1 and 100-2 in the Y direction narrow. In this embodiment, the opening 16b and the conductor 18 extend in the D1 direction or D2 direction that intersects with the Y direction, so the length of the connection parts 100-1 and 100-2 in the Y direction can be made shorter. Therefore, the pitch of the connection parts 100-1 and 100-2 in the Y direction can be narrowed, making it easier to accommodate narrower pitches.

Although the above describes the embodiments and variations of the present invention, the above embodiments and variations are merely examples and are not intended to limit the scope of the invention. The above embodiments and variations can be implemented in various other forms, and various omissions, substitutions, combinations, and modifications can be made without departing from the spirit of the invention. Furthermore, the specifications of each configuration, shape, etc. (structure, type, direction, model, size, length, width, thickness, height, number, arrangement, position, material, etc.) can be modified as appropriate.

For example, the optical device may include, as optical components, a semiconductor laser element, a light receiving element, a semiconductor modulator, a semiconductor optical amplifier, etc. The optical device may include, as optical components, at least one of the semiconductor laser element, the light receiving element, the semiconductor modulator, and the semiconductor optical amplifier.

The optical device may also be configured as an assembly including a wiring member. In other words, the optical device may include a wiring member as a component thereof.

1...Optical device 10...Housing 11...Bottom wall 12...Top wall 13...End wall 14...Side wall 15...Optical window 16, 16B, 16C...Feed-through (base, housing)
16a: End surface 16b, 16b1, 16b2: Opening 16c: Insulating layer (second insulator)
17, 17-1, 17-2...electrode pads (second conductor, opposing area)
18, 18-1, 18-2...conductor (second conductor, second extension)
19... Metal pad 20... Temperature adjustment device 20a... Upper surface 20b... Lower surface 21U... Upper substrate 21L... Lower substrate 21a... Upper surface 21b... Lower surface 22... Thermoelectric element 30, 30B, 30C... Flexible printed wiring board (wiring member)
31: Insulating layer 30a, 30a1, 30a2: Through hole 30b: End surface 30c: End surface 33, 33-1, 33-2: Conductor (first conductor)
34, 34-1, 34-2...conductor (first conductor, first extension)
35, 35-1, 35-2...conductor (first conductor)
41...Light emitting element 42...Lens 43...Carrier 51...Optical isolator 51a...Magnet 51b...Optical element portion 52...Beam splitter 53...Light receiving element 60, 60-1, 60-2...Connecting material 100-1, 100-2...Connecting portion 100A, 100A-1, 100A-2, 100B, 100C...Connecting structure D1, D2...Direction (third direction)
R...accommodation chamber X...direction (first direction)
Y direction (second direction)
Z...direction

Claims (12)

a wiring member including a first insulator having a plurality of through holes extending across a first direction and penetrating the first direction, and a plurality of first conductors penetrating the first insulator along the through holes and electrically insulated via the first insulator;
a base overlapping the wiring member in the first direction, the base including a second insulator and a plurality of second conductors each electrically connected to the first conductor and electrically insulated from the second insulator;
a plurality of connection members each penetrating the first conductor in the first direction within the through hole and interposed between the first conductor and the second conductor to electrically connect the first conductor and the second conductor;
two adjacent first conductors among the plurality of first conductors spaced apart in a second direction intersecting the first direction each have a first extension portion extending in a direction away from the other one of the two first conductors on an opposite side of the wiring member from the base,
A connection structure of a wiring member, wherein the connection material electrically connected to each of the two first conductors extends along the first extension portion in a direction away from the other first conductor. The wiring member connection structure according to claim 1, wherein the first extension portion extends in a third direction intersecting the first direction and the second direction. a wiring member including a first insulator extending across a first direction and a plurality of first conductors each electrically insulated via the first insulator;
a base overlapping the wiring member in the first direction, the base including a second insulator and a plurality of second conductors each electrically connected to the first conductor and electrically insulated from the second insulator;
a plurality of connecting members each interposed between the first conductor and the second conductor to electrically connect the first conductor and the second conductor;
the second insulator is provided with an opening that is open toward the wiring member on a side opposite to another second conductor adjacent to at least one of the plurality of second conductors in a second direction intersecting the first direction,
the at least one second conductor has a second extension along an inner surface of the opening;
A portion of the connection material electrically connected to the at least one second conductor is received in the opening along the second extension portion ,
the wiring member has a surface that faces the base and extends in a direction intersecting with the first direction,
A wiring member connection structure , in which the first conductor is provided at a position away from the end of the surface in the second direction and the end in the direction opposite to the second direction . The wiring member connection structure according to claim 3, wherein the opening is provided at a position shifted in a third direction intersecting the second direction with respect to a region of the base facing the first conductor in the first direction. a wiring member including a first insulator extending across a first direction and a plurality of first conductors each electrically insulated via the first insulator;
a base overlapping the wiring member in the first direction, the base including a second insulator and a plurality of second conductors each electrically connected to the first conductor and electrically insulated from the second insulator;
a plurality of connecting members each interposed between the first conductor and the second conductor to electrically connect the first conductor and the second conductor;
the second insulator is provided with an opening that extends in a direction away from another second conductor adjacent to at least one of the plurality of second conductors in a second direction intersecting with the first direction and that opens toward the wiring member , and at least a portion of the opening is positioned offset from the first conductor in the first direction ;
the at least one second conductor has a second extension along an inner surface of the opening;
A portion of the connection material electrically connected to the at least one second conductor is received in the opening along the second extension portion ,
the wiring member has a surface that faces the base and extends in a direction intersecting with the first direction,
A wiring member connection structure , in which the first conductor is provided at a position away from the end of the surface in the second direction and the end in the direction opposite to the second direction . The wiring member connection structure according to claim 5, wherein the opening extends from a region of the base facing the first conductor in the first direction in a third direction intersecting the first direction and the second direction. The wiring member connection structure according to any one of claims 1 to 6, wherein the wiring member is a flexible printed wiring board. The connection structure of the wiring member according to any one of claims 1 to 7, wherein the connection material is solder. The wiring member connection structure according to any one of claims 1 to 8, wherein the first insulator is made of a synthetic resin material. A housing having the base included in the wiring member connection structure according to any one of claims 1 to 9;
an optical component contained within the housing;
An optical device comprising: The optical device according to claim 10, comprising at least one of a semiconductor laser element, a semiconductor modulator, a semiconductor optical amplifier, and a light receiving element as the optical component. The optical device according to claim 10 or 11, comprising a wiring member included in a connection structure for the wiring member and fixed to the housing.

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