JP2019153673A - Optical module - Google Patents

Abstract

To meet the demand for miniaturization.SOLUTION: An optical module includes: a rigid substrate 14; a flexible substrate 16; a connector 44 that electrically connects the rigid substrate 14 and the flexible substrate 16 to each other; and an optical subassembly 10 that is electrically connected to at least one of the rigid substrate 14 and the flexible substrate 16 and converts an optical communication signal and an electrical communication signal from at least one to the other. The rigid substrate 14 has a first fixing region 52 to which the connector 44 is fixed, in at least one of the first front and back surfaces 14a and 14b. The flexible substrate 16 has a second fixing region 54 to which the connector 44 is fixed, in at least one of the second front and back surfaces 16a and 16b. The first fixing region 52 and the second fixing region 54 extend along the directions intersecting each other. The second fixing region 54 is outside the rigid substrate 14 in the direction along the first front and back surfaces 14a and 14b.SELECTED DRAWING: Figure 7

Description

  The present invention relates to an optical module.

  Optical modules used for optical communication have been reduced in size, functionality, and density. A plurality of integrated circuit chips are used for operation and control, and they are mounted on a printed circuit board (PCB) in the optical module. Further, in order to support a plurality of channels, it is known that a single PCB is not sufficient and a plurality of PCBs are used (Patent Documents 1 and 2).

JP 2012-244146 A JP 2014-67835 A

  Patent Documents 1 and 2 disclose a two-layer PCB. In connection with the upper and lower PCBs, a flexible printed circuit board (FPC) is used in Patent Document 1, and a connector is used in Patent Document 2. However, since the connection area with the FPC in the PCB or the mounting area of the connector is large, the demand for miniaturization has not been met.

  An object of the present invention is to meet the demand for miniaturization.

  (1) An optical module according to the present invention includes a rigid substrate having a first front and back surface, a flexible substrate having a second front and back surface, a connector for electrically connecting the rigid substrate and the flexible substrate, and the rigid substrate. And an optical subassembly that is electrically connected to at least one of the flexible substrates and converts at least one of the optical communication signal and the telecommunication signal from one to the other, and the rigid substrate has the connector fixed thereto A first fixing region on at least one of the first front and back surfaces, and the flexible substrate has a second fixing region on at least one of the second front and back surfaces to which the connector is fixed, The first fixed region and the second fixed region extend along a direction intersecting each other, and the second fixed region is in a direction along the first front and back surfaces. Characterized in that the outside of the rigid substrate.

  According to the present invention, since the second fixed region is outside the rigid board, the mounting area of the connector on the rigid board can be reduced, and the optical module can be downsized.

  (2) In the optical module according to (1), the connector may include a surface facing the first fixed region and a surface facing the second fixed region.

  (3) In the optical module according to (2), the rigid substrate has a first end surface on a peripheral edge of the first front and back surfaces, and the second fixing region is opposed to the first end surface, The connector may be opposed to the first end surface.

  (4) The optical module according to (3), wherein the flexible substrate has a portion that is bent and located at least one of an upper side and a lower side of the first front and back surfaces of the rigid substrate. Also good.

  (5) In the optical module according to (4), the rigid substrate may include the first fixing region on at least one of both sides opposite to each other.

  (6) In the optical module according to (5), the flexible substrate may include the second fixing region on at least one of both sides opposite to each other.

  (7) In the optical module according to (5), the flexible substrate may include the second fixing region between opposite sides.

  (8) In the optical module according to (5), the flexible substrate may include the second fixing region in at least one of both sides opposite to each other and between the both sides. .

  (9) In the optical module according to (4), the first fixed region of the rigid substrate includes a pair of first fixed regions, and the pair of first fixed regions are mutually connected to the rigid substrate. The second fixing region of the flexible substrate includes a pair of second fixing regions, and the pair of second fixing regions includes one of the opposite sides of the flexible substrate and the both sides of the flexible substrate. The connector may include a pair of connectors fixed to the pair of first fixing regions and the pair of second fixing regions, respectively.

It is a perspective view of the optical module which concerns on embodiment of this invention. It is the schematic of the II-II sectional view of the optical module shown in FIG. It is a top view which shows the surface side of a rigid board | substrate. It is a top view which shows the back surface side of a rigid board | substrate. It is a top view of an optical subassembly. It is an expanded view which shows the bending inner surface of a flexible substrate. It is an enlarged view of the VII-VII line cross section of the optical module shown in FIG. It is an enlarged view of the VIII-VIII line cross section of the optical module shown in FIG. It is an enlarged view of the IX-IX line cross section of the optical module shown in FIG. It is an enlarged view of the XX line cross section of the optical module shown in FIG. It is a perspective view of the optical module which concerns on the modification 1 of embodiment. It is the schematic of the optical module which concerns on the modification 2 of embodiment. It is the schematic of the optical module which concerns on the modification 3 of embodiment. It is the schematic of the optical module which concerns on the modification 4 of embodiment.

  Embodiments of the present invention will be described below with reference to the drawings. In addition, about drawing, the same code | symbol is attached | subjected to the same or equivalent element, and the overlapping description is abbreviate | omitted.

  FIG. 1 is a perspective view of an optical module according to an embodiment of the present invention. The optical module has an optical subassembly 10. The optical subassembly 10 converts an optical communication signal and an electric communication signal from at least one to the other. The optical module is a transceiver (optical transceiver module) including an optical sub-assembly (TOSA) 10A having an optical transmission function and an optical sub-assembly (ROSA) 10B having an optical reception function. It is.

  The optical module exchanges telecommunication signals (high frequency signals) with an external host device. An electrical communication signal input from the host device is subjected to signal conversion processing, input to an optical subassembly (TOSA) 10A, converted into an optical communication signal, and output through a receptacle 12A optically connected to an optical fiber. The On the other hand, an optical communication signal input from a receptacle 12B optically connected to an optical fiber is input to an optical subassembly (ROSA) 10B, converted into an electric communication signal, subjected to processing such as amplification, and an external host. Output to the device. The optical subassembly 10 is electrically connected to at least one (for example, both) of the rigid substrate 14 and the flexible substrate 16.

  2 is a schematic view of a cross section taken along line II-II of the optical module shown in FIG. The optical module has a rigid substrate 14. The rigid substrate 14 is a multilayer substrate having a plurality of wiring layers as inner layers on a base made of glass epoxy. The rigid substrate 14 has first front and back surfaces 14a and 14b. The rigid substrate 14 has a first end surface 14c on the periphery of the first front and back surfaces 14a and 14b so as to surround them.

  FIG. 3 is a plan view showing the first surface 14 a side of the rigid substrate 14. FIG. 4 is a plan view showing the first back surface 14 b side of the rigid substrate 14. The rigid substrate 14 has a first wiring pattern 18. The first wiring pattern 18 is composed of multiple layers, and vias (not shown) are used to connect different layers. The first wiring pattern 18 includes an inner layer wiring and may include a surface layer wiring, and these are shown in FIG. 3 and FIG. 4 without distinction.

The optical subassembly 10 shown in FIG. 1 is electrically connected to at least the first wiring pattern 18. Communication wirings 20 for transmitting electrical communication signals are included in the first wiring pattern 18. The first wiring pattern 18 includes a first terminal 22 and a second terminal 24. The first terminal 22 and the second terminal 24 are located at both ends of the rigid substrate 14 opposite to each other in the length direction. The first terminal 22 is a part of the communication wiring 20 and is connected to the optical subassembly 10. The second terminal 24 is another part of the communication wiring 20 and is used for external input / output of telecommunication signals, and is included in the plurality of external terminals T _out .

  A first integrated circuit chip 26 is mounted on the rigid substrate 14 (for example, the first surface 14a thereof). The first integrated circuit chip 26 is for processing input / output telecommunication signals. For example, a digital signal processor. The first integrated circuit chip 26 is electrically connected to the communication wiring 20 between the first terminal 22 and the second terminal 24. A heat sink 28 is attached to the first integrated circuit chip 26.

A power supply IC chip 30 is mounted on the rigid substrate 14 (for example, the first back surface 14b). Power IC chip 30 is for supplying a predetermined power supply voltage, is connected to the wiring I _pw extending from the external terminal T _out. The power supply IC chip 30 is not connected to the first integrated circuit chip 26, but is connected to other components (for example, the second integrated circuit chip 32 and the processor chip 34 shown in FIG. 2). The power supply IC chip 30 and the first integrated circuit chip 26 may be connected. Although the power supply IC chip 30 is described as a single chip here, it may be a circuit composed of a plurality of ICs or electronic components having equivalent functions.

  The 1st wiring pattern 18 contains the 3rd terminal 38 for electrically connecting to the 2nd wiring pattern 36 (FIG. 6) mentioned later. The third terminals 38 are on at least one side (for example, both sides) of both sides in the direction (width direction) orthogonal to the direction between the both ends (length direction), avoiding both ends in the length direction of the rigid substrate 14. . For example, the third terminal 38A connected to the first integrated circuit chip 26 and the third terminals 38B and 38C connected to the power supply IC chip 30 are electrically connected to the second wiring pattern 36 (FIG. 6). The third terminal 38 includes a pair of pads on the first front and back surfaces 14a and 14b of the rigid board 14, and both are connected by vias (see FIGS. 7 to 9).

  FIG. 5 is a plan view of the optical subassembly 10. The optical module has a flexible substrate 16. The flexible substrate 16 is a multilayer substrate having flexibility and having a plurality of wiring layers as inner layers on a base made of resin such as polyimide resin. The flexible substrate 16 is bent as shown in FIG. 2, and has a portion located on at least one (for example, both) above and below the first front and back surfaces 14 a and 14 b of the rigid substrate 14. The flexible substrate 16 has second front and back surfaces 16a and 16b. The flexible substrate 16 has a hole 40 (FIGS. 1 and 5) for avoiding the heat sink 28 attached to the first integrated circuit chip 26.

  FIG. 6 is a development view showing the bent inner surface (second back surface 16 b) of the flexible substrate 16. The flexible substrate 16 has a second wiring pattern 36. The second wiring pattern 36 includes an inner layer wiring and may include a surface layer wiring, and these are shown in FIG. 6 without distinction. The optical subassembly 10 is also electrically connected to the second wiring pattern 36 (see FIG. 1). The second wiring pattern 36 includes the control wiring 42 for transmitting the control signal of the optical subassembly 10, but does not include the wiring for transmitting the telecommunication signal. That is, neither the telecommunication signal converted from the optical communication signal nor the telecommunication signal for converting to the optical communication signal passes through the flexible substrate 16 (second wiring pattern 36). Therefore, since the wiring for transmitting the telecommunication signal does not become long, the deterioration of the high frequency characteristics can be suppressed.

A second integrated circuit chip 32 is mounted on the flexible substrate 16 (for example, the second back surface 16b). The second integrated circuit chip 32 is for controlling the optical subassembly 10. The second integrated circuit chip 32 is electrically connected to the control wiring 42. The optical subassembly 10 is electrically connected to the terminal of the control wiring 42. A processor chip 34 is mounted on the flexible substrate 16 (for example, the second surface 16a). The processor chip 34 has a function as a microcomputer. The processor chip 34 is connected to and controls the second integrated circuit chip 32. The connection is made by the wiring I _α of the second wiring pattern 36.

  The flexible substrate 16 is fixed and electrically connected to the rigid substrate 14. That is, the second wiring pattern 36 is electrically connected to the first wiring pattern 18. A connector 44 is used for fixing and electrical connection (FIG. 2).

The processor chip 34 is connected to and controls the first integrated circuit chip 26 (FIG. 3). Therefore, the wiring I _X ′ connected to the processor chip 34 has a terminal T ₁ . Terminal _{T 1} is connected via the connector 44A to the third terminal 38A (FIG. 3).

The processor chip 34 is connected to the power supply IC chip 30 (FIG. 4) to obtain power. Therefore, the wiring I _Y ′ connected to the processor chip 34 has a terminal T ₂ . Terminal _{T 2} are, are connected via a connector 44B to the third terminal 38B (Fig. 4).

The second integrated circuit chip 32 is connected to the power supply IC chip 30 (FIG. 4) to obtain power. Therefore, the wiring I _Z ′ connected to the second integrated circuit chip 32 has a terminal T ₃ . Terminal _{T 3} is connected via a connector 44A to the third terminal 38C (FIG. 4).

  FIG. 7 is an enlarged view of a cross section taken along line VII-VII of the optical module shown in FIG. FIG. 8 is an enlarged view of a cross section taken along line VIII-VIII of the optical module shown in FIG. FIG. 9 is an enlarged view of a cross section taken along line IX-IX of the optical module shown in FIG. FIG. 10 is an enlarged view of a cross section taken along line XX of the optical module shown in FIG.

The base of the connector 44 is made of resin. A third wiring pattern 46 is provided on the base along its outer shape. The metal film constituting the third wiring pattern 46 does not cover the entire surface of the base. The connector 44 has a recess 48 to be inserted and held at the end of the rigid board 14. The connector 44 is flat on the opposite side of the recess 48. The third wiring pattern 46 includes a plurality of wirings I ₁ , I ₂ , I ₃ extending from the inside of the recess 48 to the opposite side of the recess 48.

7, the wiring I ₁ for connecting the third terminal 38A and the terminal T ₁ is shown for connection of the first integrated circuit chip 26 and the processor chip 34. Wire _{I X} of the first wiring pattern 18 is connected to the first integrated circuit chip 26, it is connected to the wiring _{I 1} at the third terminal 38A. The wiring I _X ′ of the second wiring pattern 36 is connected to the processor chip 34 and is connected to the wiring I ₁ at the terminal T ₁ . Solder 50 is used for connection.

Figure 8 is a wiring _{I 2} for connecting the third terminal 38B and the terminal _{T 2} is shown for connection of the power supply IC chip 30 and the processor chip 34. The wiring I _Y of the first wiring pattern 18 is connected to the power supply IC chip 30 and is connected to the wiring I ₂ at the third terminal 38B. The wiring I _Y ′ of the second wiring pattern 36 is connected to the processor chip 34 and is connected to the wiring I ₂ at the terminal T ₂ . Solder 50 is used for connection.

9 shows the wiring _{I 3} for connecting the third terminal 38C and the terminal _{T 3} is shown for connection of the power supply IC chip 30 and the second integrated circuit chip 32. Wire _{I Z} of the first wiring pattern 18 is connected to the power supply IC chip 30 is connected to the wiring _{I 3} at the third terminal 38C. The wiring I _Z ′ of the second wiring pattern 36 is connected to the second integrated circuit chip 32 and is connected to the wiring I ₃ at the terminal T ₃ . Solder 50 is used for connection. In FIG. 10, the wiring Iα (see FIGS. 5 and 6) of the second wiring pattern 36 connects the upper and lower components (the second integrated circuit chip 34 and the processor chip 32) without using the connector 44. It is shown.

  A connector 44 is fixed to the rigid board 14. The first fixing region 52 to which the connector 44 is fixed is on at least one of the first front and back surfaces 14a and 14b. The first fixing region 52 is on at least one of the opposite sides of the rigid substrate 14. A pair of first fixing regions 52 </ b> A and 52 </ b> B are provided on both sides of the rigid substrate 14 opposite to each other. A pair of connectors 44A and 44B are fixed to the pair of first fixing regions 52A and 52B, respectively. The connector 44 has a surface facing the first fixed region 52. The connector 44 faces the first end face 14c.

  A connector 44 is fixed to the flexible substrate 16. The second fixing region 54 to which the connector 44 is fixed is on at least one of the second front and back surfaces 16a and 16b (for example, the inner surface of the bend). The second fixed region 54 extends along a direction intersecting the first fixed region 52. The second fixed region 54 is outside the rigid substrate 14 in the direction along the first front and back surfaces 14a and 14b. The second fixed region 54 faces the first end surface 14c.

  As shown in FIG. 6, there is a second fixing region 54 </ b> A on at least one (for example, only one) of both sides of the flexible substrate 16 opposite to each other. There is also a second fixed region 54B between the opposite sides of the flexible substrate 16. The flexible substrate 16 includes a pair of second fixing regions 54A and 54B. The pair of second fixing regions 54 </ b> A and 54 </ b> B is located at one of the opposite sides of the flexible substrate 16 and between the both sides. The pair of connectors 44A and 44B are fixed to the pair of second fixing regions 54A and 54B, respectively. The connector 44 has a surface facing the second fixed region 54.

  According to this embodiment, as shown in FIGS. 7 to 9, since the second fixing region 54 is outside the rigid board 14, the mounting area of the connector 44 on the rigid board 14 can be reduced, and the rigid board 14. More ICs, electronic parts, and wiring patterns can be provided on the top, and high-density mounting can be realized. Therefore, the optical module can be downsized.

  The connector 44 is attached as follows. The flexible substrate 16 is prepared in the unfolded state as shown in FIG. A pair of connectors 44 </ b> A and 44 </ b> B are fixed to the flexible substrate 16. For fixing, solder 50 may be used and a reflow method may be applied. And the one side of the rigid board | substrate 14 is fixed to the connector 44A attached to the one side of the flexible substrate 16 (FIG. 7 or FIG. 8). Solder 50 is used for fixing, and a tool such as a soldering iron is used. Next, the flexible substrate 16 is bent, and the connector 44B attached to the center (between both sides) of the flexible substrate 16 is fixed to the other side of the rigid substrate 14 (FIG. 9). Solder 50 is used for fixing, and a tool such as a soldering iron is used. As shown in FIG. 9, since the first surface 14a side of the rigid substrate 14 is covered with the flexible substrate 16 and the soldering iron does not enter, the soldering 50 is performed only on the first back surface 14b side.

[Modification 1]
FIG. 11 is a perspective view of an optical module according to Modification 1 of the embodiment. In the first modification, no heat sink is attached to the first integrated circuit chip 126. Therefore, the flexible substrate 116 does not have a hole for avoiding the heat sink. Other contents correspond to the contents of the embodiment.

[Modification 2]
FIG. 12 is a schematic diagram of an optical module according to Modification 2 of the embodiment. In the second modification, the rigid substrate 214 has a first fixed region 252 on one side. The flexible substrate 216 has a second fixed region 254 on one side. One connector 244 fixes and electrically connects the rigid board 214 and the flexible board 216. Other contents correspond to the contents of the embodiment.

[Modification 3]
FIG. 13 is a schematic diagram of an optical module according to Modification 3 of the embodiment. In the third modification, the rigid substrate 314 has first fixing regions 352 on both sides opposite to each other. A pair of connectors 344A and 344B are attached to the pair of first fixing regions 352A and 352B, respectively. Separate flexible boards 316A and 316B are attached to the connectors 344A and 344B, respectively. That is, a pair of flexible substrates 316A and 316B is used. The flexible substrate 316 has a second fixed region 354 on one side. A connector 344 fixes and electrically connects the rigid board 314 and the flexible board 316. Other contents correspond to the contents of the embodiment.

[Modification 4]
FIG. 14 is a schematic diagram of an optical module according to Modification 4 of the embodiment. In the modified example 4, the rigid substrate 414 has a first fixing region 452 on one side. The flexible substrate 416 has a second fixing region 454 at the opposite center (between both sides). One connector 444 fixes and electrically connects the rigid board 414 and the flexible board 416. Other contents correspond to the contents of the embodiment.

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

DESCRIPTION OF SYMBOLS 10 Optical subassembly, 10A optical subassembly, 10B optical subassembly, 12A receptacle, 12B receptacle, 14 Rigid board | substrate, 14a 1st surface, 14b 1st back surface, 14c 1st end surface, 16 Flexible substrate, 16a 2nd surface, 16b 2nd back surface, 18 1st wiring pattern, 20 communication wiring, 22 1st terminal, 24 2nd terminal, 26 1st integrated circuit chip, 28 heat sink, 30 power supply IC chip, 32 2nd integrated circuit chip, 34 processor chip 36, second wiring pattern, 38 third terminal, 38A third terminal, 38B third terminal, 38C third terminal, 40 holes, 42 control wiring, 44 connector, 44A connector, 44B connector, 46 third wiring pattern, 48 Recess, 50 solder, 52 first fixed area, 52A first fixed area, 52B first fixed area Fixed region, 54 Second fixed region, 54A Second fixed region, 54B Second fixed region, 116 Flexible substrate, 126 First integrated circuit chip, 214 Rigid substrate, 216 Flexible substrate, 244 Connector, 252 First fixed region, 254 Second Fixed Area, 314 Rigid Board, 316 Flexible Board, 316A Flexible Board, 316B Flexible Board, 344 Connector, 344A Connector, 344B Connector, 352 First Fixed Area, 352A First Fixed Area, 352B First Fixed Area, 354 First 2 fixed region, 414 rigid substrate, 416 flexible substrate, 444 connector, 452 first fixed region, 454 second fixed region, I _α wiring, I ₁ wiring, I ₂ wiring, I ₃ wiring, I _X wiring, I _Y wiring , _{I Z} wire, _{I X} 'lines, _{I Y'} line, _{Z 'lines, I pw} wiring, _{T 1} terminal, _{T 2} terminal, _{T 3 terminal, T out} external terminal.

Claims (9)

A rigid substrate having a first front surface and a back surface;
A flexible substrate having a second front and back surface;
A connector for electrically connecting the rigid substrate and the flexible substrate;
An optical subassembly that is electrically connected to at least one of the rigid board and the flexible board to convert an optical communication signal and an electric communication signal from at least one to the other;
Have
The rigid board has a first fixing region to which the connector is fixed on at least one of the first front and back surfaces,
The flexible substrate has a second fixing region to which the connector is fixed on at least one of the second front and back surfaces,
The first fixed region and the second fixed region extend along directions intersecting each other,
The optical module, wherein the second fixed region is outside the rigid substrate in a direction along the first front and back surfaces. The optical module according to claim 1,
The optical module has a surface facing the first fixed region and a surface facing the second fixed region. The optical module according to claim 2,
The rigid substrate has a first end surface at a periphery of the first front and back surfaces;
The second fixed region is opposed to the first end surface,
The optical module, wherein the connector faces the first end face. The optical module according to claim 3,
The optical module according to claim 1, wherein the flexible substrate has a portion that is bent and located at least above and below the first front and back surfaces of the rigid substrate. The optical module according to claim 4,
The optical module, wherein the rigid substrate has the first fixed region on at least one of opposite sides. The optical module according to claim 5,
The optical module, wherein the flexible substrate has the second fixing region on at least one of opposite sides. The optical module according to claim 5,
The optical module, wherein the flexible substrate has the second fixed region between opposite sides. The optical module according to claim 5,
The optical module is characterized in that the flexible substrate has the second fixing region in at least one of both sides opposite to each other and between the both sides. The optical module according to claim 4,
The first fixed region of the rigid substrate includes a pair of first fixed regions,
The pair of first fixing regions are on opposite sides of the rigid substrate,
The second fixing region of the flexible substrate includes a pair of second fixing regions,
The pair of second fixing regions are located at one of the opposite sides of the flexible substrate and between the both sides.
The optical module includes a pair of connectors fixed to the pair of first fixing regions and the pair of second fixing regions, respectively.

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