JP7063695B2 - Optical module - Google Patents

Description

The present invention relates to an optical module.

Currently, most of the Internet and telephone networks are built by optical communication networks. Optical modules used as interfaces for routers / switches and transmission devices, which are optical communication devices, play an important role in converting electrical signals into optical signals.

TO-CAN (Transistor Outline-Can) optical modules used in optical communications generally have a stem that is electrically grounded and a lead pin that penetrates the stem and is isolated from the stem. .. Further, the stem and the cap attached to the stem constitute a housing for accommodating the optical semiconductor element. The lead pin and stem form a coaxial line. One end of the lead pin is connected to the optical semiconductor device. The other end of the lead pin is connected to a drive device that outputs a modulated electrical signal via a wiring board such as a flexible printed circuit board (FPC) that has a signal line and a ground formed along it. ..

Japanese Patent No. 5273600 Japanese Unexamined Patent Publication No. 2016-195217

In the structure of Patent Document 1, since a gap is created between the stem and the FPC, there is no characteristic impedance between the coaxial line composed of the lead pin and the stem and the microstrip line or the coplanar line configured on the FPC. Consistency occurs.

Patent Document 2 discloses a structure in which a carrier on which an optical semiconductor element is mounted is directly connected to an FPC by a bonding wire. However, there are problems such as difficulty in airtightness, cost increase due to thick gold plating for wire bonding, and a wide variety of FPC connectors being required in the assembly and inspection processes due to the absence of lead pins.

An object of the present invention is to avoid mismatch of characteristic impedance.

(1) The optical module according to the present invention has a conductive stem having first and second surfaces opposite to each other and having a through hole penetrating from the first surface to the second surface, and the stem. A photoelectric element fixed on the side of the first surface for converting an optical signal and an electric signal from at least one to the other, and the photoelectric element arranged inside the through hole in a non-contact manner with the stem. An electrically connected lead pin, an insulating substrate fixed to the stem on the side of the first surface and holding the lead pin outside the through hole, an insulating layer, and signal wiring and ground in close contact with the insulating layer. It has a substrate including a plane, the ground plane as a shield, and a transmission line having a characteristic impedance according to the dielectric constant of the insulating layer, and has an end portion of the insulating layer and an end portion of the signal wiring. Enters the through hole from the second surface, and the signal wiring is joined to the lead pin.

According to the present invention, since a part of the substrate enters the through hole of the stem, the characteristic impedance of the substrate is maintained outside the stem. This makes it possible to avoid the mismatch of the characteristic impedance.

(2) The optical module according to (1) may be characterized in that the signal wiring and the lead pin are continuously joined inside and outside the through hole.

(3) The optical module according to (1) or (2), which may further include a filler material including solder and a brazing material between the signal wiring and the lead pin.

(4) The optical module according to (3), wherein the substrate has a resist layer covering the signal wiring at least at a tip portion entering the through hole, and the resist layer is made of the filler metal. It may be characterized by being adjacently interposed between the signal wiring and the lead pin.

(5) The optical module according to any one of (1) to (4), wherein the substrate is in contact with the inner peripheral surface of the through hole on a surface opposite to the lead pin. It may be characterized by that.

(6) The optical module according to any one of (1) to (5), characterized in that there is no gap between the lead pin and the insulating layer at least outside the through hole. May be good.

(7) The optical module according to (6) may be characterized in that there is no void between the lead pin and the insulating layer even inside the through hole.

(8) In the optical module according to any one of (1) to (7), the lead pins are a pair of lead pins, and the signal wiring is a pair of lead pins joined to each other. It is a signal wiring, and the through hole may be characterized by being one through hole.

(9) The optical module according to any one of (1) to (8), wherein the insulating layer has a planar shape in which the end portion protrudes from the main body.

(10) The optical module according to any one of (1) to (9), wherein the ground plane does not enter the through hole.

(11) The optical module according to any one of (1) to (10), wherein the substrate may be a flexible substrate.

It is a perspective view of the optical module which concerns on 1st Embodiment. It is a perspective view which shows the optical module without a flexible substrate. It is a perspective view of the optical module with a cap removed. It is a top view of the optical module shown in FIG. FIG. 6 is a sectional view taken along line VV of the optical module shown in FIG. FIG. 6 is a sectional view taken along line VI-VI of the optical module shown in FIG. It is a figure which shows the 3rd surface of an insulating substrate. It is a figure which shows the 4th surface of an insulating substrate. FIG. 3 is a sectional view taken along line IX-IX of the optical module shown in FIG. It is a top view of a flexible substrate. It is a schematic diagram for demonstrating the details of the connection of a flexible substrate and a lead pin. It is a schematic diagram for demonstrating the modification of the connection of a flexible substrate and a lead pin. It is a front side perspective view of the optical module which concerns on 2nd Embodiment. It is a rear side perspective view of the optical module which concerns on 2nd Embodiment. It is a top view of the flexible substrate used in 2nd Embodiment. It is an XVI-XVI line cross section of the optical module shown in FIG. It is a perspective view of the optical module which concerns on 3rd Embodiment. It is the XVIII-XVIII line cross section of the optical module shown in FIG.

Hereinafter, embodiments of the present invention will be described in detail and in detail with reference to the drawings. Members with the same reference numerals in all the drawings have the same or equivalent functions, and the repeated description thereof will be omitted. The size of the figure does not always match the magnification.

[First Embodiment]
FIG. 1 is a perspective view of an optical module according to the first embodiment. The optical module is a TO-CAN (Transistor Outline-Can) type optical module, and is an optical transmission subassembly (TOSA: Transmitter Optical Sub-Assembly) including a light emitting element and an optical receiving subassembly (ROSA: Receiver Optical) including a light receiving element. It may be either a Sub-Assembly) or a bidirectional module (BOSA; Bidirectional Optical Sub-Assembly) including both a light emitting element and a light receiving element. The optical module has a housing composed of a stem 10 and a cap 12 attached to the stem 10, and has a flexible substrate 62 described later.

FIG. 2 is a perspective view showing an optical module without a flexible substrate 62. FIG. 3 is a perspective view of the optical module with the cap 12 removed. FIG. 4 is a plan view of the optical module shown in FIG. FIG. 5 is a sectional view taken along line VV of the optical module shown in FIG. FIG. 6 is a sectional view taken along line VI-VI of the optical module shown in FIG.

The optical module has a conductive stem 10. The stem 10 is electrically grounded. The stem 10 has a disk shape having a thickness of 0.5 mm or more, has a flange 14, and has a first surface 16 and a second surface 18 opposite to each other. The presence of the flange 14 makes the second surface 18 larger than the first surface 16. The stem 10 has a through hole 20 penetrating from the first surface 16 to the second surface 18. The through hole 20 has an inner peripheral surface 22. The inner peripheral surface 22 has a pair of surface regions 22a facing each other. The distance between the pair of surface regions 22a is 0.6 mm or more. If the opening of the through hole 20 is rectangular, the length of the side (for example, the short side) is 0.6 mm or more, and if the opening of the through hole 20 is circular, the diameter is 0.6 mm or more. The stem 10 can be miniaturized by reducing the through hole 20. A GND pin 24 for grounding is fixed to the stem 10 (for example, the second surface 18). A pair of GND pins 24 are provided on both sides of the through hole 20.

The optical module has one or more (eg, two) lead pins 26 for transmitting electrical signals (high frequency signals). The diameter of the lead pin 26 is 0.25 mm or more and less than 0.4 mm (for example, 0.3 mm). The pair of lead pins 26 are arranged in a direction along the pair of facing surface regions 22a. A pair of GND pins 24 are arranged on both sides of the pair of lead pins 26 in the arrangement direction.

The lead pin 26 is arranged inside the through hole 20 in a non-contact manner with the stem 10. The lead pin 26 penetrates the stem 10 and is insulated from the stem 10. A pair of lead pins 26 are arranged in one through hole 20. The lead pin 26 has an outer peripheral surface 28. The outer peripheral surface 28 and the inner peripheral surface 22 of the through hole 20 are separated by a gap (air). That is, there is no solid between the outer peripheral surface 28 and the inner peripheral surface 22, or even if a solid is present, the outer peripheral surface 28 and the inner peripheral surface 22 are not connected. The inner peripheral surface 22 and the outer peripheral surface 28 are not connected to each other in the facing region.

A transmission line is configured in the optical module. In the transmission line, inside the through hole 20, the inner peripheral surface 22 is a shield surface, and the characteristic impedance (for example, 50 ohms) according to the dielectric constant of the medium (air) interposed between the inner peripheral surface 22 and the outer peripheral surface 28. ). The pair of surface regions 22a and the two lead pins 26 form a differential line. In other words, it constitutes a transmission line having a characteristic impedance uniquely determined by the dielectric constant of the inner peripheral surface 22 and the medium interposed therein. Further, this differential line constitutes a transmission line having an inner peripheral surface 22 as a ground potential. The inner peripheral surface 22 closer to the lead pin 26 is strongly electrically connected. If the distance between the inner peripheral surface 22 on the far side (for example, the inner peripheral surface in contact with the inner peripheral surface 22a in FIG. 1 in the perpendicular direction) and the lead pin 26 is large, a strip line (slab line) formed on the circuit board. Can be regarded as equivalent to.

According to the present embodiment, since the lead pin 26 and the stem 10 are separated by a gap (air), a desired characteristic impedance can be obtained according to a medium (air) having a low dielectric constant, and the characteristic impedance mismatch can be obtained. It can be avoided and miniaturized.

The stem 10 has a second through hole 30. Inside the second through hole 30, the second lead pin 34 is fixed by being insulated by a solid medium 32 such as glass. The second lead pin 34 is used for power supply (DC voltage) and the like, and does not require as high-precision characteristic impedance matching as the transmission of an electric signal.

The optical module has an insulating substrate 36. The insulating substrate 36 is fixed to the stem 10 on the side of the first surface 16. The insulating substrate 36 has a third surface 38 facing the first surface 16 and a fourth surface 40 vice versa. The third surface 38 of the insulating substrate 36 is fixed to the first surface 16 of the stem 10.

FIG. 7 is a diagram showing a third surface 38 of the insulating substrate 36. The insulating substrate 36 is made of ceramic and has a first conductive pad 42 on a third surface 38. The first conductive pad 42 is located at a position facing the through hole 20 and is not in contact with the stem 10, and is not shown in FIGS. 5 and 6 because it is a thin film. The first conductive pad 42 is connected to the first contact 44 penetrating the insulating substrate 36. The insulating substrate 36 further has a second conductive pad 46 on the third surface 38. The second conductive pad 46 is connected to a second contact 48 that penetrates the insulating substrate 36. The insulating substrate 36 and the stem 10 are fixed with solder 50 as shown in FIGS. 5 to 6. The solder 50 is interposed between the second conductive pad 46 and the stem 10 to electrically connect them, and fixes the insulating substrate 36 to the stem 10.

FIG. 8 is a diagram showing a fourth surface 40 of the insulating substrate 36. The insulating substrate 36 has a first electrode 52 connected to the first contact 44 on the fourth surface 40. The first conductive pad 42 and the first electrode 52 are electrically connected via the first contact 44. The insulating substrate 36 has a second electrode 54 connected to the second contact 48 on the fourth surface 40. The second conductive pad 46 and the second electrode 54 are electrically connected via the second contact 48.

As shown in FIGS. 5 and 6, the insulating substrate 36 holds one or a pair of lead pins 26 outside the through hole 20. The lead pin 26 is joined to the first conductive pad 42. One lead pin 26 is joined to one first conductive pad 42. Welding (eg, fusion welding) can be applied to the joints.

The optical module has a photoelectric element 56 for converting an optical signal and an electric signal from at least one to the other. The photoelectric element 56 is fixed to the stem 10 on the side of the first surface 16. Specifically, the insulating substrate 36 is fixed to the first surface 16 of the stem 10, and the photoelectric element 56 is mounted on the fourth surface 40 of the insulating substrate 36. The photoelectric element 56 is mounted so that light is input / output in a direction orthogonal to the first surface 16 (direction orthogonal to the mounting surface).

In this embodiment, the optical module is a ROSA and has an integrated circuit chip 58. The integrated circuit chip 58 includes a TIA (Trance Impedance Amplifier) that converts the photoelectric element 56 and its small signal into an impedance, amplifies and outputs it as a voltage signal, and a CDR (Clock Data Recovery) that demolishes data from a clock signal synchronized with the data signal. Etc. are integrated. The integrated circuit chip 58 is mounted on the insulating substrate 36, the back surface of the integrated circuit chip 58 is electrically connected to the second electrode 54 (ground potential), and the stem is via the second contact 48 and the second conductive pad 46. It is electrically connected to 10. An electronic component 60 such as a capacitor is also mounted on the stem 10. The electronic component 60 is not mounted on the insulating substrate 36, but is mounted directly on the first surface 16 of the stem 10.

The integrated circuit chip 58 is connected to the first electrode 52 by the wire W1 and is connected to the photoelectric element 56 by the wire W2. The photoelectric element 56 is connected to the first electrode 52 via the integrated circuit chip 58. The lead pin 26 is electrically connected to the photoelectric element 56. The integrated circuit chip 58 is also connected to the electronic component 60 by the wire W3. The electronic component 60 is connected to the second lead pin 34 by the wire W4. The integrated circuit chip 58 is connected to another second lead pin 34 by a wire W5.

FIG. 9 is a sectional view taken along line IX-IX of the optical module shown in FIG. FIG. 10 is a plan view of the flexible substrate 62. FIG. 11 is a schematic view for explaining the details of joining the flexible substrate 62 and the lead pin.

The flexible substrate 62 includes an insulating layer 64. The insulating layer 64 has a planar shape in which the end portion 64E protrudes from the main body. For example, the end 64E projects from the center of the short side of the rectangular body. The flexible substrate 62 includes a pair of signal wirings 66. The pair of signal lines 66 are differential transmission lines. The signal wiring 66 is in close contact with the insulating layer 64, and there is no gap between the two. The signal line 66 has a signal terminal 66T wider than the transmission line. The pair of signal lines 66 have a signal terminal 66T extending from the transmission line in a direction away from each other. The pair of signal terminals 66T of the pair of signal wirings 66 are arranged next to each other so as to reach one end 64E of the insulating layer 64. The signal wiring 66 is covered with a first resist layer 68 (see FIG. 11), which is not shown in FIG. However, the first resist layer 68 avoids the signal wiring 66 in the junction region (signal terminal 66T) with the lead pin 26.

The flexible substrate 62 includes a ground plane 70. The ground plane 70 is in close contact with the insulating layer 64, and there is no gap between the two. A signal wiring 66 and a ground plane 70 are formed on opposite surfaces of the insulating layer 64, respectively. The insulating layer 64 is provided with a GND terminal 72 that is electrically connected to the ground plane 70 on the same side as the signal wiring 66. The ground plane 70 and the GND terminal 72 are electrically connected by a via 74 penetrating the insulating layer 64. The ground plane 70 is entirely covered with the second resist layer 76. A transmission line is configured on the flexible substrate 62. The transmission line has a characteristic impedance (for example, 50 ohms) according to the dielectric constant of the insulating layer 64 with the ground plane 70 as a shield. The lead pin 26 and the signal wiring 66 have the same characteristic impedance.

The end portion 64E of the insulating layer 64 enters the through hole 20 from the second surface 18. The end portion (signal terminal 66T) of the signal wiring 66 enters the through hole 20 from the second surface 18. The first resist layer 68 does not exist inside the through hole 20. The ground plane 70 does not enter the through hole 20. The flexible substrate 62 is in contact with the inner peripheral surface 22 of the through hole 20 on the surface opposite to the lead pin 26. Specifically, the second resist layer 76 covering the ground plane 70 is in contact with the inner peripheral surface 22. As a result, the flexible substrate 62 is supported by the stem 10 (through hole 20).

The signal wiring 66 is joined to the lead pin 26. A pair of signal wirings 66 are joined to the pair of lead pins 26, respectively. The signal wiring 66 and the lead pin 26 are continuously joined inside and outside the through hole 20. A filler material 78 containing solder and a brazing material is interposed between the signal wiring 66 and the lead pin 26. There is no void (air) between the lead pin 26 and the insulating layer 64 at least outside the through hole 20. Even inside the through hole 20, there is no gap (air) between the lead pin 26 and the insulating layer 64.

According to the present embodiment, since a part of the flexible substrate 62 enters the through hole 20 of the stem 10 and is connected to the lead pin 26, there is no gap between the flexible substrate 62 and the stem 10. Therefore, in the vicinity of the connection portion between the signal wiring 66 and the lead pin 26, there is no state where there is no ground potential around the lead pin 26, and impedance mismatch in the connection portion can be avoided.

Further, according to the present embodiment, since the characteristic impedances of the lead pin 26 and the signal wiring 66 are made equal to each other, it is possible to construct an excellent transmission line without impedance mismatch. As shown in FIG. 9, the GND pin 24 is joined to the GND terminal 72 adjacent to the stem 10. A filler 78 containing solder and a brazing material is also used for the joining. Further, in the present embodiment, the example using a flexible substrate having flexibility has been described, but the effect of the present invention can be obtained even with a rigid substrate having no flexibility (for example, PCB: Printed Circuit Board).

FIG. 12 is a schematic view for explaining a modified example of joining a flexible substrate and a lead pin. In this example, the flexible substrate 162 has a first resist layer 168 that covers the signal wiring 166 at least at the tip portion that enters the through hole 120. The first resist layer 168 is located next to the filler material 178 and between the signal wiring 166 and the lead pin 126. The first resist layer 168 serves as a flow stop for the molten filler material 178.

[Second Embodiment]
FIG. 13 is a front perspective view of the optical module according to the second embodiment. FIG. 14 is a rear perspective view of the optical module according to the second embodiment. In this embodiment, the optical module is TOSA.

The stem 210 includes a disc-shaped eyelet 280 having a thickness of 0.5 mm or more. The eyelet 280 has a plurality of (eg, two) through holes 220. The opening of the through hole 220 is circular. A GND pin 224 is fixed to the eyelet 280 between the two through holes 220, as shown in FIG. Further, the eyelet 280 has a second through hole 230.

The stem 210 has a pedestal 282 protruding from the first surface 216. The pedestal 282 has a pedestal surface 284 that rises from the first surface 216. The pedestal surface 284 is a ceramic substrate on which a spacer 286 is mounted and a photoelectric element 256 is mounted on the spacer 286. A wiring pattern 288 is formed on the upper surface of the spacer 286. The insulating substrate 236 is fixed to the pedestal surface 284. The insulating substrate 236 has an electrode pattern 290. The electrode pattern 290 is formed on a surface opposite to the pedestal surface 284. A photoelectric element 256 is electrically connected to the electrode pattern 290 by wires W6 and W7. Specifically, the photoelectric element 256 and the wiring pattern 288 are connected by the wire W6, and the wiring pattern 288 and the electrode pattern 290 are connected by the wire W7. The photoelectric element 256 is mounted so that light is input / output in a direction orthogonal to the first surface 216 (a direction parallel to the mounting surface).

The lead pin 226 is joined to the electrode pattern 290. The joining is made by a filler 278 containing solder and a brazing material at a protrusion 226a from the first surface 216. The inner peripheral surface 222 of the through hole 220 and one lead pin 226 form a coaxial line. The medium between the inner peripheral surface 222 and the lead pin 226 is air. Inside the second through hole 230, the second lead pin 234 is fixed by being insulated by a solid medium 232 such as glass.

FIG. 15 is a plan view of the flexible substrate 262 used in the second embodiment. The insulating layer 264 of the flexible substrate 262 has a planar shape in which a pair of end portions 264E project from the main body. For example, a pair of ends 264E project at intervals at the center of one side (short side) of the rectangular body. The flexible substrate 262 includes a pair of signal wirings 266 that are in close contact with the insulating layer 264. The end of one signal wiring 266 (signal terminal 266T) leads to one end of the insulating layer 264, 264E. The flexible substrate 262 includes a ground plane 270 that is in close contact with the insulating layer 264. On the same side as the signal wiring 266, the insulating layer 264 is provided with a GND terminal 272 that is electrically connected to the ground plane 270 by a via 274. The GND terminal 272 is located between the pair of signal terminals 266T.

FIG. 16 is an XVI-XVI line cross section of the optical module shown in FIG. The signal wiring 266 is joined to the lead pin 226. A filler 278 containing solder and brazing filler metal is used for the joining. There is no void between the lead pin 226 and the insulating layer 264 at least outside the through hole 220. Even inside the through hole 220, there is no gap between the lead pin 226 and the insulating layer 264.

According to the present embodiment, since a part of the flexible substrate 262 enters the through hole 220 of the stem 210, the characteristic impedance of the flexible substrate 262 is maintained outside the stem 210. This makes it possible to avoid the mismatch of the characteristic impedance. Other details correspond to the contents described in the first embodiment.

[Third Embodiment]
FIG. 17 is a perspective view of the optical module according to the third embodiment. The first insulating substrate 336 is fixed to the stem 310. The first insulating substrate 336 has a third surface 338 facing the first surface 316 of the stem 310, and the third surface 338 is fixed to the first surface 316.

The stem 310 has a through hole 320, and a lead pin 326 is arranged inside the through hole 320. The inner peripheral surface 322 of the through hole 320 and one lead pin 326 form a coaxial line. The lead pin 326 penetrates the first insulating substrate 336 and is fixed to the first insulating substrate 336. A filler material 378 containing solder and a brazing material may be used for fixing. The lead pin 326 protrudes from the fourth surface 340 of the first insulating substrate 336.

The stem 310 has a pedestal 382 protruding from the first surface 316. The pedestal 382 has a pedestal surface 384 that rises from the first surface 316. The optical module has a second insulating substrate 392. The second insulating substrate 392 is mounted on the pedestal surface 384.

The lead pin 326 has a protrusion 326a protruding from the fourth surface 340. The lead pin 326 (protruding portion 326a) is joined to the electrode pattern 390. The joint is made at the protrusion 326a by a filler 378 containing solder and brazing filler metal. That is, the lead pin 326 is also fixed to the second insulating substrate 392.

A spacer 386 is mounted on the pedestal 382 (pedestal surface 384), and a photoelectric element 356 is mounted on the spacer 386. A wiring pattern 388 is formed on the upper surface of the spacer 386. The wiring pattern 388 and the photoelectric element 356 are electrically connected by a wire W8. The wiring pattern 388 and the electrode pattern 390 are connected by a wire W9. Through these, the photoelectric element 356 and the lead pin 326 are electrically connected.

FIG. 18 is a XVIII-XVIII line cross section of the optical module shown in FIG. The signal wiring 366 is joined to the lead pin 326. A filler material 378 containing solder and brazing material is used for the joining. There is no void between the lead pin 326 and the insulating layer 364 at least outside the through hole 320. Even inside the through hole 320, there is no gap between the lead pin 326 and the insulating layer 364.

According to the present embodiment, since a part of the flexible substrate 362 enters the through hole 320 of the stem 310 and is connected to the lead pin 326, there is no gap between the flexible substrate 362 and the stem 310. Therefore, in the vicinity of the connection portion between the signal wiring 366 and the lead pin 326, there is no state where there is no ground potential around the lead pin 326, and impedance mismatch at the connection portion can be avoided.
Other details correspond to the contents described in the first embodiment.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, the configurations described in the embodiments can be replaced with substantially the same configuration, a configuration that exhibits the same action and effect, or a configuration that can achieve the same purpose.

10 stem, 12 cap, 14 flange, 16 1st surface, 18 2nd surface, 20 through hole, 22 inner peripheral surface, 22a surface area, 24 GND pin, 26 lead pin, 28 outer peripheral surface, 30 2nd through hole, 32 Medium, 34 2nd lead pin, 36 Insulated substrate, 38 3rd surface, 40 4th surface, 42 1st conductive pad, 44 1st contact, 46 2nd conductive pad, 48 2nd contact, 50 solder, 52 1st electrode , 54 2nd electrode, 56 photoelectric element, 58 integrated circuit chip, 60 electronic component, 62 flexible substrate, 64 insulation layer, 64E end, 66 signal line, 66T signal terminal, 68 first resist layer, 70 ground plane, 72 GND terminal, 74 via, 76 second resist layer, 78 filler material, 120 through hole, 126 lead pin, 162 flexible board, 166 signal wiring, 168 first resist layer, 178 filler metal, 210 stem, 216 first surface , 220 through hole, 222 inner peripheral surface, 224 GND pin, 226 lead pin, 226a protrusion, 230 second through hole, 232 medium, 234 second lead pin, 236 insulating substrate, 256 photoelectric element, 262 flexible substrate, 264 insulating layer , 264E end, 266 signal wiring, 266T signal terminal, 270 ground plane, 272 GND terminal, 274 via, 278 filler material, 280 eyelets, 282 pedestal, 284 pedestal surface, 286 spacer, 288 wiring pattern, 290 electrode pattern, 310 stem, 316 first surface, 320 through hole, 322 inner peripheral surface, 326 lead pin, 326a protrusion, 336 first insulating substrate, 338 third surface, 340 fourth surface, 356 photoelectric element, 362 flexible substrate, 364 insulation Layers, 366 signal wiring, 378 filler material, 382 pedestal, 384 pedestal surface, 386 spacer, 388 wiring pattern, 390 electrode pattern, 392 second insulating substrate, W1 to W9 wires.

Claims (11)

A conductive stem having first and second surfaces opposite to each other and having through holes penetrating from the first surface to the second surface.
A photoelectric element fixed to the stem on the side of the first surface and for converting an optical signal and an electric signal from at least one to the other.
A lead pin arranged inside the through hole in a non-contact manner with the stem and electrically connected to the photoelectric element,
An insulating substrate that is fixed to the stem on the side of the first surface and holds the lead pin outside the through hole.
A substrate including an insulating layer, signal wiring and a ground plane in close contact with the insulating layer, and a transmission line having a characteristic impedance according to the dielectric constant of the insulating layer with the ground plane as a shield.
Have,
The end of the insulating layer and the end of the signal wiring enter the through hole from the second surface.
An optical module characterized in that the signal wiring is joined to the lead pin. The optical module according to claim 1.
An optical module characterized in that the signal wiring and the lead pin are continuously joined inside and outside the through hole. The optical module according to claim 1 or 2.
An optical module further comprising a filler material containing solder and a brazing material between the signal wiring and the lead pin. The optical module according to claim 3.
The substrate has a resist layer covering the signal wiring at least at the tip portion entering the through hole.
An optical module characterized in that the resist layer is interposed between the signal wiring and the lead pin next to the filler material. The optical module according to any one of claims 1 to 4.
The optical module is characterized in that the substrate is in contact with the inner peripheral surface of the through hole on a surface opposite to the lead pin. The optical module according to any one of claims 1 to 5.
An optical module characterized in that there is no void between the lead pin and the insulating layer at least outside the through hole. The optical module according to claim 6.
An optical module characterized in that there is no gap between the lead pin and the insulating layer even inside the through hole. The optical module according to any one of claims 1 to 7.
The lead pin is a pair of lead pins.
The signal wiring is a pair of signal wirings joined to a pair of lead pins, respectively.
The optical module is characterized in that the through hole is one through hole. The optical module according to any one of claims 1 to 8.
The insulating layer is an optical module having a planar shape in which the end portion protrudes from the main body. The optical module according to any one of claims 1 to 9.
The ground plane is an optical module characterized in that it does not enter the through hole. The optical module according to any one of claims 1 to 10.
The substrate is an optical module characterized by being a flexible substrate.

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