WO2024161500A1 - Optical modulation device and optical transmission apparatus using same - Google Patents

Optical modulation device and optical transmission apparatus using same Download PDF

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Publication number
WO2024161500A1
WO2024161500A1 PCT/JP2023/003041 JP2023003041W WO2024161500A1 WO 2024161500 A1 WO2024161500 A1 WO 2024161500A1 JP 2023003041 W JP2023003041 W JP 2023003041W WO 2024161500 A1 WO2024161500 A1 WO 2024161500A1
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WO
WIPO (PCT)
Prior art keywords
circuit board
optical modulation
housing
flexible circuit
modulation device
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PCT/JP2023/003041
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French (fr)
Japanese (ja)
Inventor
猛 坂井
恭平 長谷川
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住友大阪セメント株式会社
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Priority to PCT/JP2023/003041 priority Critical patent/WO2024161500A1/en
Publication of WO2024161500A1 publication Critical patent/WO2024161500A1/en

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    • G—PHYSICS
    • G02—OPTICS
    • G02F—OPTICAL DEVICES OR ARRANGEMENTS FOR THE CONTROL OF LIGHT BY MODIFICATION OF THE OPTICAL PROPERTIES OF THE MEDIA OF THE ELEMENTS INVOLVED THEREIN; NON-LINEAR OPTICS; FREQUENCY-CHANGING OF LIGHT; OPTICAL LOGIC ELEMENTS; OPTICAL ANALOGUE/DIGITAL CONVERTERS
    • G02F1/00—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics
    • G02F1/01—Devices or arrangements for the control of the intensity, colour, phase, polarisation or direction of light arriving from an independent light source, e.g. switching, gating or modulating; Non-linear optics for the control of the intensity, phase, polarisation or colour 

Definitions

  • the present invention relates to an optical modulation device and an optical transmission device using the same, and in particular to an optical modulation device that houses an optical modulation element in a housing, and that is disposed on an external circuit board and has a flexible circuit board that is electrically connected to an electrical line on the external circuit board.
  • optical modulation devices In the fields of optical communications and optical measurement, optical modulation devices are widely used, in which an optical waveguide is formed on a substrate with electro-optical effects such as lithium niobate (LN), and an optical modulation element equipped with a modulation electrode that modulates the light wave propagating through the optical waveguide is housed in a housing.
  • LN lithium niobate
  • FIG. 1 is a plan view showing an example of an optical modulation device.
  • An optical modulation element (not shown) is housed and hermetically sealed inside a housing CA.
  • a modulation signal and a DC bias voltage are introduced to the optical modulation element from outside the housing, and a monitor signal for monitoring the modulation state of the optical modulation element is output to the outside of the housing.
  • a flexible circuit board FPC is used in the housing of the optical modulation device in FIG. 1 as an RF input terminal for introducing a modulation signal. This is intended to improve the bandwidth of the optical modulator and match the line impedance.
  • An electrode terminal PIN is also provided for the DC bias and the monitor signal.
  • An optical fiber F is used to input and output light waves to and from the optical modulation element.
  • Figure 2 shows an example of a cross-sectional view taken along dashed line A-A' in Figure 1.
  • a modulated signal is introduced to the optical modulation element OME via a flexible circuit board FPC, lead pins LP arranged in glass bead GB, relay board RB, and wire bonding WB.
  • the optical modulation element OME is arranged in a housing CA, which is arranged and fixed on a printed circuit board PCB.
  • the flexible circuit board FPC is soldered to the printed circuit board PCB.
  • Figure 2 shows the state of the flexible circuit board before soldering. To solder the flexible circuit board FPC to the printed circuit board PCB, one end of the flexible circuit board is pressed against the printed circuit board.
  • Figure 3 illustrates the state in which the flexible circuit board FPC is in contact with the printed circuit board PCB.
  • the flexible circuit board FPC needs to be bent between the position where it is attached to the housing CA and the position where it is soldered onto the printed circuit board PCB.
  • Figure 3 employs a structure in which a protrusion CA1 is provided on part of the housing to mitigate the stress.
  • This configuration in which a protrusion is provided at the position where the flexible circuit board FPC contacts the housing is also disclosed in Patent Document 1, for example.
  • the protrusions CA1 bend the flexible circuit board FPC at a predetermined angle in advance, making it possible to reduce stress on the flexible circuit board at the part where the flexible circuit board is attached to the housing CA, particularly the lead pins LP, and on the solder fixing part on the printed circuit board PCB. In addition, because the flexible circuit board is bent in advance, it is easy to solder it to the printed circuit board.
  • the protrusion CA1 as shown in FIG. 3 is convenient in itself as described above, but on the other hand, it also causes the following problems.
  • the protrusion may damage the surface of the flexible circuit board FPC, and if the protrusion is located at a corner of the housing in particular, the flexible circuit board may be further damaged. As a result, the wiring of the flexible circuit board may short out.
  • the length of the flexible circuit board is made as short as possible to reduce electrical loss at high frequencies, so the bent part of the flexible circuit board needs to have a specific angle, and the precision of the protrusions becomes even more important, so it is difficult to form protrusions in a ceramic package.
  • the problem that the present invention aims to solve is to provide an optical modulation device that solves the problems described above, that is independent of the material of the housing, that allows the flexible circuit board to be bent with a simple configuration, and that reduces stress that occurs at the attachment points of the flexible circuit board to the housing or printed circuit board. It is also to provide an optical transmission device that uses this optical modulation device.
  • the optical modulation device and the optical transmission apparatus of the present invention have the following technical features.
  • An optical modulation device having an optical modulation element housed within a housing, the optical modulation device being disposed on an external circuit board and having a flexible circuit board electrically connected to an electrical line on the external circuit board, the optical modulation device being characterized in that a protrusion is formed on a surface of the flexible circuit board that contacts a surface of the housing, and the protrusion contacts the housing, thereby bending the flexible circuit board in the direction of the external circuit board.
  • the protrusion is made of insulating resin and is disposed at least on the top, both sides, or one side of the signal wiring on the flexible circuit board, or on the top of the ground wiring.
  • the protrusion is made of a conductive metal and is disposed on the ground wiring on the flexible circuit board.
  • the optical modulation device described in (1) above is characterized in that a step is formed on the bottom side of the housing, and when the optical modulation device is placed on the external circuit board, a part of the flexible circuit board is fixed within the surface of the step that is spaced apart from the external circuit board.
  • the optical modulation device according to any one of (1) to (5) above is characterized in that the housing includes a light source for inputting an optical wave to the optical modulation element, and an optical fiber for outputting the optical wave from the optical modulation element.
  • the optical modulation device described in (6) above is characterized in that it has an electronic circuit inside or outside the housing that amplifies the modulation signal input to the optical modulation element.
  • An optical transmitter comprising the optical modulation device described in (7) above and an electronic circuit that outputs a modulation signal that causes the optical modulation device to perform a modulation operation.
  • the present invention provides an optical modulation device that houses an optical modulation element in a housing, the optical modulation device being placed on an external circuit board and having a flexible circuit board that is electrically connected to an electrical line on the external circuit board, the flexible circuit board having a protrusion formed on the surface that contacts the surface of the housing, and the flexible circuit board is bent in the direction of the external circuit board when the protrusion contacts the housing, so that the flexible circuit board can be bent with a simple configuration without relying on the material of the housing, making it possible to provide an optical modulation device that alleviates stress generated at the attachment portion of the flexible circuit board to the housing or printed circuit board. It is also possible to provide an optical transmission device that uses an optical modulation device that has such an effect.
  • FIG. 1 is a plan view showing an example of a conventional optical modulation device (package).
  • FIG. 2 is a cross-sectional view taken along dashed line A-A' in FIG.
  • FIG. 1 is a diagram illustrating an example of a conventional optical modulation device, in which a protrusion is provided on a part of a housing.
  • FIG. 2 is a plan view showing an example of an optical modulation device of the present invention, illustrating a state in which a lid of a housing is removed.
  • FIG. 5 illustrates a cross-sectional view of the optical modulation device of FIG. 4.
  • FIG. 4 is a cross-sectional view showing another example of an optical modulation device of the present invention.
  • 1A to 1C are diagrams showing examples of protrusions applied to a flexible circuit board used in an optical modulation device of the present invention.
  • 8A and 8B are diagrams illustrating a state in which a flexible circuit board using the protrusions shown in FIG. 7D is disposed.
  • 8A is a diagram illustrating a state in which a flexible circuit board using the protrusion portion shown in FIG. 7E is disposed.
  • 1A to 1C are diagrams illustrating an example in which protrusions made of insulating resin are arranged on a flexible circuit board.
  • 1A and 1B are diagrams illustrating an example in which conductive metal protrusions are arranged on a flexible circuit board.
  • 1 is a plan view showing an optical modulation device and an optical transmission device according to the present invention;
  • the present invention is an optical modulation device in which an optical modulation element OME is housed in a housing CA, and the optical modulation device is arranged on an external circuit board PCB and has a flexible circuit board FPC that is electrically connected to an electrical line on the external circuit board, and is characterized in that a protrusion B is formed on the surface of the flexible circuit board FPC that contacts the surface of the housing, and the flexible circuit board is bent in the direction of the external circuit board by the protrusion contacting the housing.
  • An example of an optical modulation element is an optical waveguide formed on a substrate such as lithium niobate (LN), lithium tantalate (LT), or PLZT (lead lanthanum zirconate titanate), or a substrate made of various materials such as semiconductor materials and organic materials. Modulation electrodes and DC bias electrodes are formed along the optical waveguide, and the light waves propagating through the optical waveguide are modulated and controlled.
  • Optical modulation elements are not limited to those using a substrate on which an optical waveguide is formed, and elements that are housed in a housing and are modulated and driven by introducing a high-frequency signal from outside fall under this category of optical modulation elements.
  • light sources such as semiconductor lasers and light-emitting diodes are also covered by the present invention.
  • light sources such as semiconductor lasers and light-emitting diodes are also covered by the present invention.
  • Figure 4 is a plan view of the optical modulation device, illustrating the state when the lid of the housing is open.
  • Figure 5 is a diagram illustrating the state when cut along dashed line C in Figure 4.
  • the optical modulation device uses a flexible circuit board FPC for the RF input terminal.
  • the flexible circuit board FPC is configured so that it can be bent to make it easy to solder the tip of the flexible circuit board to the printed circuit board PCB, which is an external circuit board.
  • a protrusion B is arranged on the surface of the flexible circuit board FPC in order to bend the flexible circuit board to give it an angle.
  • the protrusion B formed on the flexible circuit board is positioned in a position that contacts the surface of the housing CA.
  • a step is formed on the bottom side of the housing CA, and when the optical modulation device is placed on the external circuit board PCB, a part of the flexible circuit board FPC is fixed within a surface CA2 of the step that is spaced apart from the external circuit board.
  • the wiring formed on the flexible circuit board FPC and the lead pins LP are soldered to be electrically connected to the flexible circuit board.
  • a driver circuit DRV for driving the optical modulation element
  • a flexible circuit board FPC for transmitting a modulation signal to the driver circuit
  • lead pins LP lead pins LP
  • a relay board RB relay board
  • wire bonding WB wire bonding WB
  • the driver circuit DRV and the optical modulation element OME are also electrically connected by, for example, wire bonding WB.
  • an optical block OB that guides light waves input to and output from the optical modulation element, and an optical fiber F that introduces light waves into the housing CA (or leads light waves out from within the housing).
  • the optical modulation element OME, driver circuit DRV, etc. are mounted on the bottom side of the housing CA, and this bottom surface is placed on the printed circuit board PCB, and a configuration is described in which the flexible circuit board FPC and the printed circuit board PCB are electrically connected.
  • the optical modulation element OME, driver circuit DRV, etc. may be mounted on the top side of the housing CA, and the bottom side of the housing (the side opposite the top surface) may be placed on the printed circuit board PCB.
  • a hybrid housing configuration may be used in which a wiring board CE such as ceramics on which electrical signal wiring is formed to extract electrical signals to the outside of the housing CA is bonded to the housing metal, as shown in Figure 6.
  • the ceramic wiring board CE can be formed of a single layer or multiple layers of ceramics.
  • the flexible circuit board FPC is fixed to the surface of the ceramic wiring board facing the printed circuit board PCB, and is electrically connected to the wiring of the ceramic wiring board.
  • FIG. 7A and 7B are diagrams for explaining variations of protrusions provided on the flexible circuit board FPC.
  • Fig. 7A shows the flexible circuit board used in Fig. 5 or 6, in which a protrusion B is disposed in the portion that contacts the housing CA.
  • 7B shows an example in which the protrusion in the portion in contact with the housing CA is composed of two protrusions B1 and B2.
  • the protrusions distribute stress, and the protrusions themselves are prevented from being significantly deformed.
  • FIG. 7C shows a projection B3 having a wedge (tapered) shape, which is configured to support the curved portion of the flexible circuit board continuously in a planar manner.
  • 7(D) shows a flexible circuit board having projections (B3, B4) formed on both sides thereof similar to those in FIG. 7(C). As shown in FIG. 8, this flexible circuit board can be used in such a way that projections are disposed not only between the flexible circuit board FPC and the housing CA, but also between the flexible circuit board FPC and the printed circuit board PCB to assist bending of the flexible circuit board.
  • Figure 7(E) not only has protrusions B5 and B6 that help the flexible circuit board FPC bend, but also, as shown in Figure 9, protrusion B7 is provided to support the flexible circuit board by pressing it against the housing from the printed circuit board side when the flexible circuit board is fixed to the housing CA and the housing CA is placed on the printed circuit board PCB.
  • the material for forming the protrusion is not particularly limited as long as it can be attached to the flexible circuit board and has a mechanical strength sufficient to withstand bending of the flexible circuit board.
  • the protrusion may be formed directly on the flexible circuit board FPC to form an integrated type.
  • the protrusion can be made of insulating resin, and as shown in FIG. 10(A), the protrusion BR may be arranged so as to continuously cross the signal wiring S and ground wiring G that are wired on the surface of the flexible circuit board.
  • the protrusion BR may be placed only on the top of the ground wiring G as in FIG. 10(B), or, taking advantage of its electrically insulating properties, it can be placed on the top of the signal wiring S as in FIGS. 10(A) and (C). Therefore, when the protrusion is made of insulating resin, it can be placed at least on the top, both sides, or one side of the signal wiring on the flexible circuit board, or on the top of the ground wiring.
  • FIG 11 (A) shows a metal protrusion BM placed on top of the ground wiring G, and it is possible to take advantage of the electrical conductivity to ground the ground wiring on the flexible circuit board to the housing CA. This makes it possible to make the wiring resistant to noise.
  • the protrusions arranged on the ground wiring G are not limited to being continuous as in FIG. 11(A), but can also be arranged in a discrete or staggered pattern.
  • the protrusions BM are formed in separate parts, and compared to the configuration in FIG. 11(A), the housing CA and the protrusions BM can be fixed more stably.
  • a metal protrusion BM and a resin protrusion BR are used for the protrusions, and it is possible to arrange the protrusion BM on the ground wiring G and the protrusion BR on the signal wiring S, or separately on either side or both sides of the signal wiring S.
  • a protrusion BR is formed, so compared to the configuration in FIG. 11(B), it is possible to reduce distortion of the flexible circuit board FPC, especially of the signal wiring S, due to bending, and to reduce distortion of the entire flexible circuit board FPC.
  • the protrusions by constructing the protrusions from a material (low hardness material, elastic body) that is softer than the housing and printed circuit board, it is possible to make the surface of the flexible circuit board less susceptible to damage. Furthermore, if the housing and protrusions are both made of metal, there is a possibility that shavings will be produced and cause a short circuit between the signal wiring S and the ground wiring G, so it is preferable to solder, screw, or glue the housing CA and protrusions B (B1-B3, etc.). This also makes it possible for the protrusions to support the stress that occurs in the bent parts of the flexible circuit board, preventing the stress from affecting other parts.
  • the optical modulation device of the present invention accommodates an optical modulation element (a chip having a substrate 1 and an optical waveguide 2) in a housing CA made of metal or the like, and connects the outside of the housing to the optical modulation element with an optical fiber F, thereby providing a compact optical modulation device MD.
  • an optical modulation element a chip having a substrate 1 and an optical waveguide 2
  • a housing CA made of metal or the like
  • connects the outside of the housing to the optical modulation element with an optical fiber F thereby providing a compact optical modulation device MD.
  • a light source such as a semiconductor laser inside the housing CA and omit the optical fiber for input. Lin indicates the input light, and Lout indicates the output light.
  • An electronic circuit that outputs a modulation signal S0 that causes the optical modulation device MD to perform a modulation operation can be connected to the optical modulation device MD to configure an optical transmission device OTA. Since the modulation signal S to be applied to the optical waveguide element needs to be amplified, a driver circuit DRV is used.
  • the driver circuit DRV and the digital signal processor DSP can be arranged outside the housing CA, but can also be arranged inside the housing CA. In particular, by arranging the driver circuit DRV inside the housing, it is possible to further reduce the propagation loss of the modulation signal from the driver circuit.
  • an optical modulation device that can bend a flexible circuit board with a simple configuration, regardless of the material of the housing, and that reduces stress generated at the attachment portion of the flexible circuit board to the housing or printed circuit board. It is also possible to provide an optical transmission device that uses this optical modulation device.

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  • Physics & Mathematics (AREA)
  • Nonlinear Science (AREA)
  • General Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Structure Of Printed Boards (AREA)

Abstract

The purpose of the present invention is to provide an optical modulation device in which a flexible circuit substrate can be bent by a simple configuration independently of the material of a housing thereof, and stress that occurs in the housing of the flexible circuit substrate or a part for attachment to a printed substrate is alleviated.　The present invention is an optical modulation device in which an optical modulation element OME is accommodated in a housing CA, the optical modulation device being disposed on an external circuit substrate PCB, and the optical modulation device having a flexible circuit substrate FPC that is electrically connected to an electric line on the external circuit substrate, wherein the optical modulation device is characterized in that a protruding part B is formed on a surface of the flexible circuit substrate FPC that is in contact with the surface of the housing, and the flexible circuit substrate is bent toward the external circuit substrate by contact of the protruding part with the housing.

Description

光変調デバイス及びそれを用いた光送信装置Optical modulation device and optical transmitter using same
　本発明は、光変調デバイス及びそれを用いた光送信装置に関し、特に、光変調素子を筐体内に収容した光変調デバイスであり、該光変調デバイスは外部回路基板上に配置されると共に、該外部回路基板上の電気線路と電気的に接続するフレキシブル回路基板を有する光変調デバイスに関する。 The present invention relates to an optical modulation device and an optical transmission device using the same, and in particular to an optical modulation device that houses an optical modulation element in a housing, and that is disposed on an external circuit board and has a flexible circuit board that is electrically connected to an electrical line on the external circuit board.
　光通信分野や光計測分野において、ニオブ酸リチウム（ＬＮ）などの電気光学効果を有する基板に光導波路を形成し、光導波路を伝搬する光波を変調する変調電極を備えた光変調素子などを筐体内に収容した光変調デバイスが多用されている。 In the fields of optical communications and optical measurement, optical modulation devices are widely used, in which an optical waveguide is formed on a substrate with electro-optical effects such as lithium niobate (LN), and an optical modulation element equipped with a modulation electrode that modulates the light wave propagating through the optical waveguide is housed in a housing.
　図１は、光変調デバイスの一例を示す平面図である。筐体ＣＡ内には、不図示の光変調素子が収容され、気密封止されている。光変調素子には、筐体の外部から変調信号やＤＣバイアス電圧が導入されると共に、光変調素子の変調状態をモニタするモニタ信号が筐体の外部に導出される。図１の光変調デバイスの筐体には、変調信号を導入するためのＲＦ入力端子としてフレキシブル回路基板ＦＰＣが利用されている。これは、光変調器の帯域改善及び線路インピーダンス整合を目的としている。またＤＣバイアスやモニタ信号のための電極端子ＰＩＮが設けられる。また、光ファイバＦにより光変調素子への光波の入出力が行われる。 FIG. 1 is a plan view showing an example of an optical modulation device. An optical modulation element (not shown) is housed and hermetically sealed inside a housing CA. A modulation signal and a DC bias voltage are introduced to the optical modulation element from outside the housing, and a monitor signal for monitoring the modulation state of the optical modulation element is output to the outside of the housing. A flexible circuit board FPC is used in the housing of the optical modulation device in FIG. 1 as an RF input terminal for introducing a modulation signal. This is intended to improve the bandwidth of the optical modulator and match the line impedance. An electrode terminal PIN is also provided for the DC bias and the monitor signal. An optical fiber F is used to input and output light waves to and from the optical modulation element.
　図２は、図１の一点鎖線Ａ－Ａ’における断面図の一例を示す。光変調素子ＯＭＥには、フレキシブル回路基板ＦＰＣ、ガラスビードＧＢ内に配置されるリードピンＬＰ，中継基板ＲＢ、さらにワイヤーボンディングＷＢを介して、変調信号が導入される。光変調素子ＯＭＥは筐体ＣＡ内に配置され、筐体はプリント基板ＰＣＢ上に配置固定される。また、フレキシブル回路基板ＦＰＣは、プリント基板ＰＣＢに半田付される。図２は、半田付け前のフレキシブル回路基板の状態を示している。フレキシブル回路基板ＦＰＣをプリント基板ＰＣＢに半田付けするには、フレキシブル回路基板の一端をプリント基板側に押し付けて作業を行うこととなる。 Figure 2 shows an example of a cross-sectional view taken along dashed line A-A' in Figure 1. A modulated signal is introduced to the optical modulation element OME via a flexible circuit board FPC, lead pins LP arranged in glass bead GB, relay board RB, and wire bonding WB. The optical modulation element OME is arranged in a housing CA, which is arranged and fixed on a printed circuit board PCB. The flexible circuit board FPC is soldered to the printed circuit board PCB. Figure 2 shows the state of the flexible circuit board before soldering. To solder the flexible circuit board FPC to the printed circuit board PCB, one end of the flexible circuit board is pressed against the printed circuit board.
　図３は、フレキシブル回路基板ＦＰＣをプリント基板ＰＣＢに接触させた状態を図示したものである。フレキシブル回路基板ＦＰＣを筐体ＣＡに取り付けた位置から、プリント基板ＰＣＢ上に半田固定する位置までの間で、フレキシブル回路基板ＦＰＣを曲げる必要がある。この曲げに係る応力の影響を緩和するため、図３では、筐体の一部に突起部ＣＡ１を設け、応力を緩和する構造を採用している。このようにフレキシブル回路基板ＦＰＣが筐体に接触する位置に突起部を設ける構成は、例えば、特許文献１にも開示されている。 Figure 3 illustrates the state in which the flexible circuit board FPC is in contact with the printed circuit board PCB. The flexible circuit board FPC needs to be bent between the position where it is attached to the housing CA and the position where it is soldered onto the printed circuit board PCB. To mitigate the effects of stress associated with this bending, Figure 3 employs a structure in which a protrusion CA1 is provided on part of the housing to mitigate the stress. This configuration in which a protrusion is provided at the position where the flexible circuit board FPC contacts the housing is also disclosed in Patent Document 1, for example.
　突起部ＣＡ１により、フレキシブル回路基板ＦＰＣが予め所定の角度を持って曲げられているため、フレキシブル回路基板を筐体ＣＡ，特にリードピンＬＰに取り付けた部分や、プリント基板ＰＣＢ上の半田固定部へのフレキブル回路基板による応力を緩和することが可能となる。また、予めフレキシブル回路基板が曲げられているため、プリント基板への半田付け作業が容易になっている。 The protrusions CA1 bend the flexible circuit board FPC at a predetermined angle in advance, making it possible to reduce stress on the flexible circuit board at the part where the flexible circuit board is attached to the housing CA, particularly the lead pins LP, and on the solder fixing part on the printed circuit board PCB. In addition, because the flexible circuit board is bent in advance, it is easy to solder it to the printed circuit board.
　図３のような突起部ＣＡ１は、それ自体が上述したように利便性があるが、その一方で、以下のような不具合も生じる。
（Ａ）筐体ＣＡに突起部ＣＡ１が設けられている場合には、突起部がフレキシブル回路基板ＦＰＣの表面を傷つける可能性があり、特に筐体の角に突起部が配置されると、よりフレキシブル回路基板が傷つけられる可能性がある。その結果、フレキシブル回路基板の配線がショートする可能性がある。 The protrusion CA1 as shown in FIG. 3 is convenient in itself as described above, but on the other hand, it also causes the following problems.
(A) If the housing CA is provided with a protrusion CA1, the protrusion may damage the surface of the flexible circuit board FPC, and if the protrusion is located at a corner of the housing in particular, the flexible circuit board may be further damaged. As a result, the wiring of the flexible circuit board may short out.
（Ｂ）筐体ＣＡに突起部ＣＡ１を設ける場合は、従来は金属製のパッケージが利用されていたため、削り出しで突起部のみを残す等の作製が容易であった。しかしながら、近年では、ＨＢ－ＣＤＭ（Ｈｉｇｈ　Ｂａｎｄｗｉｄｔｈ　Ｃｏｈｅｒｅｎｔ　Ｄｒｉｖｅｒ　Ｍｏｄｕｌａｔｏｒ）のようなドライバ集積型変調器では、セラミックパッケージが用いられるようになっている。セラミックパッケージでは、焼結で作製するため、筐体に付けられた突起部のエッジの仕上がり状況を管理する必要があるため加工費が上がることとなる。特に、フレキシブル回路基板をＲＦ信号ラインに設ける場合には、高周波での電気損失を減らすために、フレキシブル回路基板の長さはなるべく短くするため、フレキシブル回路基板の曲げ部分には、特定の角度を持たせる必要があり、より突起部の精度が重要になるため、セラミックパッケージでは突起部の形成が難しい。 (B) When providing a protrusion CA1 on the housing CA, a metal package was used in the past, and it was easy to manufacture it by cutting out only the protrusion. However, in recent years, ceramic packages have come to be used for driver integrated modulators such as HB-CDM (High Bandwidth Coherent Driver Modulator). Since ceramic packages are manufactured by sintering, it is necessary to manage the finish of the edges of the protrusions attached to the housing, which increases the processing cost. In particular, when a flexible circuit board is installed on an RF signal line, the length of the flexible circuit board is made as short as possible to reduce electrical loss at high frequencies, so the bent part of the flexible circuit board needs to have a specific angle, and the precision of the protrusions becomes even more important, so it is difficult to form protrusions in a ceramic package.
（Ｃ）突起部でフレキシブル回路基板を曲げた状態に維持するため、フレキシブル回路基板を筐体に取り付けた部分に応力が掛かり続け、長時間の使用中にフレキシブル回路基板が外れる可能性がある。 (C) Because the protrusions keep the flexible circuit board in a bent state, stress is constantly being applied to the part where the flexible circuit board is attached to the housing, which may cause the flexible circuit board to come loose during extended use.
特開２０１８－１０３１３号公報JP 2018-10313 A
　本発明が解決しようとする課題は、上述したような問題を解決し、筐体の素材に依存せず、フレキシブル回路基板を簡単な構成で曲げることが可能であり、フレキシブル回路基板の筐体やプリント基板への取り付け部に発生する応力を緩和した光変調デバイスを提供することである。また、この光変調デバイスを用いた光送信装置を提供することである。 The problem that the present invention aims to solve is to provide an optical modulation device that solves the problems described above, that is independent of the material of the housing, that allows the flexible circuit board to be bent with a simple configuration, and that reduces stress that occurs at the attachment points of the flexible circuit board to the housing or printed circuit board. It is also to provide an optical transmission device that uses this optical modulation device.
　上記課題を解決するため、本発明の光変調デバイス及び光送信装置は、以下のような技術的特徴を有する。
（１）　光変調素子を筐体内に収容した光変調デバイスであり、該光変調デバイスは外部回路基板上に配置されると共に、該外部回路基板上の電気線路と電気的に接続するフレキシブル回路基板を有する光変調デバイスにおいて、該フレキシブル回路基板には、該筐体の表面と接する面に突起部が形成され、該突起部が該筐体に接することにより、該フレキシブル回路基板が該外部回路基板の方向に曲げられていることを特徴とする。 In order to solve the above problems, the optical modulation device and the optical transmission apparatus of the present invention have the following technical features.
(1) An optical modulation device having an optical modulation element housed within a housing, the optical modulation device being disposed on an external circuit board and having a flexible circuit board electrically connected to an electrical line on the external circuit board, the optical modulation device being characterized in that a protrusion is formed on a surface of the flexible circuit board that contacts a surface of the housing, and the protrusion contacts the housing, thereby bending the flexible circuit board in the direction of the external circuit board.
（２）　上記（１）に記載の光変調デバイスにおいて、突起部が絶縁性樹脂又は導電性金属で構成されていることを特徴とする光変調デバイス。 (2) An optical modulation device according to the above (1), characterized in that the protrusion is made of insulating resin or conductive metal.
（３）　上記（２）に記載の光変調デバイスにおいて、該突起部は、絶縁性樹脂で構成され、該フレキシブル回路基板上の信号配線の上部、両脇、片側、又は接地配線の上部の少なくともいずれかに配置されていることを特徴とする。 (3) In the optical modulation device described in (2) above, the protrusion is made of insulating resin and is disposed at least on the top, both sides, or one side of the signal wiring on the flexible circuit board, or on the top of the ground wiring.
（４）　上記（２）に記載の光変調デバイスにおいて、該突起部は、導電性金属で構成され、該フレキシブル回路基板上の接地配線上に配置されていることを特徴とする。 (4) In the optical modulation device described in (2) above, the protrusion is made of a conductive metal and is disposed on the ground wiring on the flexible circuit board.
（５）　上記（１）に記載の光変調デバイスにおいて、該筐体の底面側に段差部が形成され、該光変調デバイスを該外部回路基板上に配置した際に、該段差部の該外部回路基板から離間した面内に該フレキシブル回路基板の一部が固定されていることを特徴とする。 (5) The optical modulation device described in (1) above is characterized in that a step is formed on the bottom side of the housing, and when the optical modulation device is placed on the external circuit board, a part of the flexible circuit board is fixed within the surface of the step that is spaced apart from the external circuit board.
（６）　上記（１）乃至（５）のいずれかに記載の光変調デバイスにおいて、該筐体内には、該光変調素子に光波を入力する光源と、該光変調素子から光波を出力光ファイバとを備えることを特徴とする。 (6) The optical modulation device according to any one of (1) to (5) above is characterized in that the housing includes a light source for inputting an optical wave to the optical modulation element, and an optical fiber for outputting the optical wave from the optical modulation element.
（７）　上記（６）に記載の光変調デバイスにおいて、該光変調素子に入力する変調信号を増幅する電子回路を該筐体の内部又は外部に有することを特徴とする。 (7) The optical modulation device described in (6) above is characterized in that it has an electronic circuit inside or outside the housing that amplifies the modulation signal input to the optical modulation element.
（８）　上記（７）に記載の光変調デバイスと、該光変調デバイスに変調動作を行わせる変調信号を出力する電子回路とを有することを特徴とする光送信装置である。 (8) An optical transmitter comprising the optical modulation device described in (7) above and an electronic circuit that outputs a modulation signal that causes the optical modulation device to perform a modulation operation.
　本発明により、光変調素子を筐体内に収容した光変調デバイスであり、該光変調デバイスは外部回路基板上に配置されると共に、該外部回路基板上の電気線路と電気的に接続するフレキシブル回路基板を有する光変調デバイスにおいて、該フレキシブル回路基板には、該筐体の表面と接する面に突起部が形成され、該突起部が該筐体に接することにより、該フレキシブル回路基板が該外部回路基板の方向に曲げられているため、筐体の素材に依存せずに、簡単な構成でフレキシブル回路基板を曲げることが可能であり、フレキシブル回路基板の筐体やプリント基板への取り付け部に発生する応力を緩和した光変調デバイスを提供することが可能となる。また、そのような効果を有する光変調デバイスを用いた光送信装置を提供することも可能となる。 The present invention provides an optical modulation device that houses an optical modulation element in a housing, the optical modulation device being placed on an external circuit board and having a flexible circuit board that is electrically connected to an electrical line on the external circuit board, the flexible circuit board having a protrusion formed on the surface that contacts the surface of the housing, and the flexible circuit board is bent in the direction of the external circuit board when the protrusion contacts the housing, so that the flexible circuit board can be bent with a simple configuration without relying on the material of the housing, making it possible to provide an optical modulation device that alleviates stress generated at the attachment portion of the flexible circuit board to the housing or printed circuit board. It is also possible to provide an optical transmission device that uses an optical modulation device that has such an effect.
従来の光変調デバイス（パッケージ）の一例を示す平面図である。FIG. 1 is a plan view showing an example of a conventional optical modulation device (package). 図１の一点鎖線Ａ－Ａ’における断面図を示す図である。FIG. 2 is a cross-sectional view taken along dashed line A-A' in FIG. 従来の光変調デバイスの一例であり、筐体の一部に突起部を備えた例を説明する図である。FIG. 1 is a diagram illustrating an example of a conventional optical modulation device, in which a protrusion is provided on a part of a housing. 本発明の光変調デバイスの一例を示す平面図であり、筐体の蓋を外した状態を説明する図である。FIG. 2 is a plan view showing an example of an optical modulation device of the present invention, illustrating a state in which a lid of a housing is removed. 図４の光変調デバイスの断面図を示す図である。FIG. 5 illustrates a cross-sectional view of the optical modulation device of FIG. 4. 本発明の光変調デバイスの他の例を示す断面図である。FIG. 4 is a cross-sectional view showing another example of an optical modulation device of the present invention. 本発明の光変調デバイスに用いられるフレキシブル回路基板に適用される突起部の例を示す図である。1A to 1C are diagrams showing examples of protrusions applied to a flexible circuit board used in an optical modulation device of the present invention. 図７（Ｄ）に示す突起部を用いたフレキシブル回路基板を配置した様子を説明する図である。8A and 8B are diagrams illustrating a state in which a flexible circuit board using the protrusions shown in FIG. 7D is disposed. 図７（Ｅ）に示す突起部を用いたフレキシブル回路基板を配置した様子を説明する図である。8A is a diagram illustrating a state in which a flexible circuit board using the protrusion portion shown in FIG. 7E is disposed. フレキシブル回路基板に絶縁性樹脂の突起部を配置した例を説明する図である。1A to 1C are diagrams illustrating an example in which protrusions made of insulating resin are arranged on a flexible circuit board. フレキシブル回路基板に導電性金属の突起部を配置した例を説明する図である。1A and 1B are diagrams illustrating an example in which conductive metal protrusions are arranged on a flexible circuit board. 本発明に係る光変調デバイスと光送信装置を示す平面図である。1 is a plan view showing an optical modulation device and an optical transmission device according to the present invention;
　以下、本発明について好適例を用いて詳細に説明する。
　本発明は、図４及び図５に示すように、光変調素子ＯＭＥを筐体ＣＡ内に収容した光変調デバイスであり、該光変調デバイスは外部回路基板ＰＣＢ上に配置されると共に、該外部回路基板上の電気線路と電気的に接続するフレキシブル回路基板ＦＰＣを有する光変調デバイスにおいて、該フレキシブル回路基板ＦＰＣには、該筐体の表面と接する面に突起部Ｂが形成され、該突起部が該筐体に接することにより、該フレキシブル回路基板が該外部回路基板の方向に曲げられていることを特徴とする。 The present invention will now be described in detail with reference to preferred embodiments.
As shown in Figures 4 and 5, the present invention is an optical modulation device in which an optical modulation element OME is housed in a housing CA, and the optical modulation device is arranged on an external circuit board PCB and has a flexible circuit board FPC that is electrically connected to an electrical line on the external circuit board, and is characterized in that a protrusion B is formed on the surface of the flexible circuit board FPC that contacts the surface of the housing, and the flexible circuit board is bent in the direction of the external circuit board by the protrusion contacting the housing.
　光変調素子（チップ）の一例としては、ニオブ酸リチウム（ＬＮ）やタンタル酸リチウム（ＬＴ）、ＰＬＺＴ（ジルコン酸チタン酸鉛ランタン）などの基板や、半導体材料や有機材料など種々の材料で構成される基板上に光導波路を形成したものである。光導波路に沿って変調電極やＤＣバイアス電極が形成され、光導波路を伝搬する光波を変調等の制御を行うものである。光変調素子は、光導波路を形成した基板を用いたものに限定されず、筐体内に収容され、高周波信号を外部から導入して変調駆動される素子は、この光変調素子に該当する。例えば、半導体レーザーや発光ダイオードなどの光源も本発明の対象となる。光変調素子を高周波信号によって駆動するためには、筐体の外部から高周波信号を導入する必要があり、ＲＦ入力端子としてフレキシブル回路基板を用いるものは、本発明の対象となり得る。 An example of an optical modulation element (chip) is an optical waveguide formed on a substrate such as lithium niobate (LN), lithium tantalate (LT), or PLZT (lead lanthanum zirconate titanate), or a substrate made of various materials such as semiconductor materials and organic materials. Modulation electrodes and DC bias electrodes are formed along the optical waveguide, and the light waves propagating through the optical waveguide are modulated and controlled. Optical modulation elements are not limited to those using a substrate on which an optical waveguide is formed, and elements that are housed in a housing and are modulated and driven by introducing a high-frequency signal from outside fall under this category of optical modulation elements. For example, light sources such as semiconductor lasers and light-emitting diodes are also covered by the present invention. In order to drive an optical modulation element with a high-frequency signal, it is necessary to introduce the high-frequency signal from outside the housing, and those that use a flexible circuit board as an RF input terminal can be covered by the present invention.
　図４は、光変調デバイスの平面図であり、筐体の蓋を開けた状態を図示したものである。また、図５は、図４の一点鎖線Ｃで切断した状態を示す図である。光変調デバイスは、ＲＦ入力端子にフレキシブル回路基板ＦＰＣを用いている。フレキシブル回路基板ＦＰＣを曲げて、フレキシブル回路基板の先端を外部回路基板であるプリント基板ＰＣＢに半田付けし易いように構成している。フレキシブル回路基板を曲げて、角度を持たせるために、フレキシブル回路基板ＦＰＣの表面には、突起部Ｂを配置している。 Figure 4 is a plan view of the optical modulation device, illustrating the state when the lid of the housing is open. Figure 5 is a diagram illustrating the state when cut along dashed line C in Figure 4. The optical modulation device uses a flexible circuit board FPC for the RF input terminal. The flexible circuit board FPC is configured so that it can be bent to make it easy to solder the tip of the flexible circuit board to the printed circuit board PCB, which is an external circuit board. A protrusion B is arranged on the surface of the flexible circuit board FPC in order to bend the flexible circuit board to give it an angle.
　フレキシブル回路基板に形成する突起部Ｂは、筐体ＣＡの表面と接する位置に配置される。特に、図５に示すように、筐体ＣＡの底面側に段差部が形成され、光変調デバイスを外部回路基板ＰＣＢ上に配置した際に、該段差部の該外部回路基板から離間した面ＣＡ２内に該フレキシブル回路基板ＦＰＣの一部が固定されている。フレキシブル回路基板ＦＰＣに形成される配線と、リードピンＬＰとはハンダ固定されフレキシブル回路基板と電気的接続が行われている。 The protrusion B formed on the flexible circuit board is positioned in a position that contacts the surface of the housing CA. In particular, as shown in FIG. 5, a step is formed on the bottom side of the housing CA, and when the optical modulation device is placed on the external circuit board PCB, a part of the flexible circuit board FPC is fixed within a surface CA2 of the step that is spaced apart from the external circuit board. The wiring formed on the flexible circuit board FPC and the lead pins LP are soldered to be electrically connected to the flexible circuit board.
　図４や図５及び図６では、光変調素子ＯＭＥの外に、光変調素子を駆動するためのドライバ回路ＤＲＶ，ドライバ回路に変調信号を伝送するための、フレキシブル回路基板ＦＰＣ、リードピンＬＰ，中継基板ＲＢ，及びワイヤーボンディングＷＢが、互いに電気的に接続されている。また、ドライバ回路ＤＲＶと光変調素子ＯＭＥとの間も、例えば、ワイヤーボンディングＷＢ等で電気的に接続される。
　また、図４には、光変調素子に入出力する光波を案内する光学ブロックＯＢや筐体ＣＡ内に光波を導入する（又は筐体内から光波を導出する）光ファイバＦが設けられている。 4, 5 and 6, in addition to the optical modulation element OME, a driver circuit DRV for driving the optical modulation element, a flexible circuit board FPC for transmitting a modulation signal to the driver circuit, lead pins LP, a relay board RB, and wire bonding WB are electrically connected to each other. The driver circuit DRV and the optical modulation element OME are also electrically connected by, for example, wire bonding WB.
Also, in FIG. 4, there are provided an optical block OB that guides light waves input to and output from the optical modulation element, and an optical fiber F that introduces light waves into the housing CA (or leads light waves out from within the housing).
　図４や図５では、筐体ＣＡの底面側に光変調素子ＯＭＥやドライバ回路ＤＲＶなどを搭載し、この底面側の面をプリント基板ＰＣＢ上に配置し、フレキシブル回路基板ＦＰＣとプリント基板ＰＣＢが電気的に接続される構成を説明した。一方、図６のように筐体ＣＡの上面側に光変調素子ＯＭＥやドライバ回路ＤＲＶなどを搭載し、該筐体の底面側（上面と反対側）をプリント基板ＰＣＢ上に配置する構成としてもよい。 In Figures 4 and 5, the optical modulation element OME, driver circuit DRV, etc. are mounted on the bottom side of the housing CA, and this bottom surface is placed on the printed circuit board PCB, and a configuration is described in which the flexible circuit board FPC and the printed circuit board PCB are electrically connected. On the other hand, as shown in Figure 6, the optical modulation element OME, driver circuit DRV, etc. may be mounted on the top side of the housing CA, and the bottom side of the housing (the side opposite the top surface) may be placed on the printed circuit board PCB.
　また図５の筐体ＣＡでは従来のように金属製のパッケージを利用しているが、図６のように筐体ＣＡの外部へ電気信号を取り出す電気信号配線が形成されたセラミックスなどの配線基板ＣＥと筐体金属とが接合したハイブリッドな筐体構成としてもよい。この場合、セラミックス配線基板ＣＥはセラミックスを単層や多層で形成できる。そしてフレキシブル回路基板ＦＰＣは、セラミックス配線基板のプリント基板ＰＣＢ側の面に固定され、セラミック配線基板の配線と電気的に接続される。 In addition, while the housing CA in Figure 5 uses a metal package as in the past, a hybrid housing configuration may be used in which a wiring board CE such as ceramics on which electrical signal wiring is formed to extract electrical signals to the outside of the housing CA is bonded to the housing metal, as shown in Figure 6. In this case, the ceramic wiring board CE can be formed of a single layer or multiple layers of ceramics. The flexible circuit board FPC is fixed to the surface of the ceramic wiring board facing the printed circuit board PCB, and is electrically connected to the wiring of the ceramic wiring board.
　図７はフレキシブル回路基板ＦＰＣに設ける突起部のバリエーションを説明する図である。図７（Ａ）は、図５又は図６に使用されるフレキシブル回路基板を示し、筐体ＣＡに接する部分に突起部Ｂを配置している。
　図７（Ｂ）は、筐体ＣＡに接する部分の突起部を２つの突起部Ｂ１，Ｂ２で構成した例を示す。このように、複数の突起部を並べて配置することで、安定してフレキシブル回路基板を曲げることが可能となる。また曲げに際して、突起部で応力を分散し、突起部自体が大きく変形することも抑制される。さらに、並べて配置した突起部の高さをフレキシブル回路基板の曲がりに合わせて変え、突起部でフレキシブル回路基板を支えるよう構成することも可能である。 7A and 7B are diagrams for explaining variations of protrusions provided on the flexible circuit board FPC. Fig. 7A shows the flexible circuit board used in Fig. 5 or 6, in which a protrusion B is disposed in the portion that contacts the housing CA.
7B shows an example in which the protrusion in the portion in contact with the housing CA is composed of two protrusions B1 and B2. In this way, by arranging a plurality of protrusions side by side, it becomes possible to stably bend the flexible circuit board. In addition, when bending, the protrusions distribute stress, and the protrusions themselves are prevented from being significantly deformed. Furthermore, it is also possible to change the height of the protrusions arranged side by side according to the bending of the flexible circuit board, and to configure the flexible circuit board to be supported by the protrusions.
　図７（Ｃ）は、突起部Ｂ３の形状を楔状（テーパー状）に形成したものであり、フレキシブル回路基板の曲がり部を面的に連続して支持するよう構成している。
　また、図７（Ｄ）は、フレキシブル回路基板の両面のそれぞれに図７（Ｃ）と同様な突起部（Ｂ３，Ｂ４）を形成したものである。このフレキシブル回路基板の使用方法は、図８に示すように、フレキシブル回路基板ＦＰＣと筐体ＣＡとの間だけでなく、フレキシブル回路基板ＦＰＣとプリント基板ＰＣＢとの間にも突起部を配置し、フレキシブル回路基板の曲がりを補助するように構成することが可能である。 FIG. 7C shows a projection B3 having a wedge (tapered) shape, which is configured to support the curved portion of the flexible circuit board continuously in a planar manner.
7(D) shows a flexible circuit board having projections (B3, B4) formed on both sides thereof similar to those in FIG. 7(C). As shown in FIG. 8, this flexible circuit board can be used in such a way that projections are disposed not only between the flexible circuit board FPC and the housing CA, but also between the flexible circuit board FPC and the printed circuit board PCB to assist bending of the flexible circuit board.
　図７（Ｅ）は、フレキシブル回路基板ＦＰＣの曲がりを助ける突起部Ｂ５及びＢ６だけでなく、図９に示すように、フレキシブル回路基板が筐体ＣＡに固定され、該筐体ＣＡがプリント基板ＰＣＢ上に配置された際に、プリント基板側からフレキシブル回路基板を筐体側に押し付けるように支持するための突起部Ｂ７を備えている。 Figure 7(E) not only has protrusions B5 and B6 that help the flexible circuit board FPC bend, but also, as shown in Figure 9, protrusion B7 is provided to support the flexible circuit board by pressing it against the housing from the printed circuit board side when the flexible circuit board is fixed to the housing CA and the housing CA is placed on the printed circuit board PCB.
　突起部を構成する材料は、フレキシブル回路基板に接着可能であり、フレキシブル回路基板の曲げに耐える機械的強度を有するものであれば、特に制限されない。また、フレキシブル回路基板ＦＰＣに直接、突起部を形成した一体型としてもよい。
　例えば、絶縁性樹脂で突起部を構成することが可能であり、図１０（Ａ）に示すように、フレキシブル回路基板の表面に配線されている信号配線Ｓや接地配線Ｇに対して、これらを連続的に横切るように突起部ＢＲを配置しても良い。 The material for forming the protrusion is not particularly limited as long as it can be attached to the flexible circuit board and has a mechanical strength sufficient to withstand bending of the flexible circuit board. In addition, the protrusion may be formed directly on the flexible circuit board FPC to form an integrated type.
For example, the protrusion can be made of insulating resin, and as shown in FIG. 10(A), the protrusion BR may be arranged so as to continuously cross the signal wiring S and ground wiring G that are wired on the surface of the flexible circuit board.
　また、図１０（Ｂ）のように接地配線Ｇの上部のみに突起部ＢＲを配置しても良いし、電気的に絶縁性を有する特性を活かして、図１０（Ａ）及び（Ｃ）のように、信号配線Ｓの上部に配置することも可能である。したがって、突起部を絶縁性樹脂で構成する場合は、突起部をフレキシブル回路基板上における信号配線の上部、両脇、片側、又は接地配線の上部の少なくともいずれかに配置することが可能である。 Furthermore, the protrusion BR may be placed only on the top of the ground wiring G as in FIG. 10(B), or, taking advantage of its electrically insulating properties, it can be placed on the top of the signal wiring S as in FIGS. 10(A) and (C). Therefore, when the protrusion is made of insulating resin, it can be placed at least on the top, both sides, or one side of the signal wiring on the flexible circuit board, or on the top of the ground wiring.
　また、突起部を構成する材料として、導電性金属を使用することも可能である。図１１（Ａ）は接地配線Ｇの上部に金属製の突起部ＢＭを配置するものであり、導電性を活かしてフレキシブル回路基板上の接地配線と筐体ＣＡとの接地を行うことも可能である。これによりノイズに強い配線が可能となる。 In addition, conductive metals can also be used as the material that makes up the protrusions. Figure 11 (A) shows a metal protrusion BM placed on top of the ground wiring G, and it is possible to take advantage of the electrical conductivity to ground the ground wiring on the flexible circuit board to the housing CA. This makes it possible to make the wiring resistant to noise.
　図１１（Ｂ）に示すように、接地配線Ｇ上に配置する突起部は、図１１（Ａ）のように連続的なものに限らず、離散的に又は千鳥状などのパターンを形成して配置することも可能である。これにより突起部ＢＭが分割して形成されているため、図１１（Ａ）の構成と比較し、筐体ＣＡと突起部ＢＭとをより安定して固定することができる。 As shown in FIG. 11(B), the protrusions arranged on the ground wiring G are not limited to being continuous as in FIG. 11(A), but can also be arranged in a discrete or staggered pattern. As a result, the protrusions BM are formed in separate parts, and compared to the configuration in FIG. 11(A), the housing CA and the protrusions BM can be fixed more stably.
　図１１（Ｃ）は、突起部に金属製の突起部ＢＭと樹脂製の突起部ＢＲとを使用し、突起部ＢＭは接地配線Ｇ上に、突起部ＢＲは信号配線Ｓ上、または信号配線Ｓの両脇や片側に各々分けて配置することも可能である。これにより図１１（Ｂ）の突起部ＢＭに加え、突起部ＢＲが形成されているため、図１１（Ｂ）の構成と比較し、フレキシブル回路基板ＦＰＣの曲げによる特に信号配線Ｓの基板の歪を低減することができ、フレキシブル回路基板ＦＰＣ全体の歪を低減することができる。 In FIG. 11(C), a metal protrusion BM and a resin protrusion BR are used for the protrusions, and it is possible to arrange the protrusion BM on the ground wiring G and the protrusion BR on the signal wiring S, or separately on either side or both sides of the signal wiring S. In this way, in addition to the protrusion BM in FIG. 11(B), a protrusion BR is formed, so compared to the configuration in FIG. 11(B), it is possible to reduce distortion of the flexible circuit board FPC, especially of the signal wiring S, due to bending, and to reduce distortion of the entire flexible circuit board FPC.
　また、突起部を筐体やプリント基板より柔らかい素材（硬度が低い材料、弾性体）で構成することで、フレキシブル回路基板の表面が傷つき難くすることが可能となる。また、筐体と突起部が両方とも金属の場合には、削りカスが出て信号配線Ｓと接地配線Ｇとがショートする可能性もあるため、筐体ＣＡと突起部Ｂ（Ｂ１～Ｂ３等）を半田付けやネジ固定や接着固定することが好ましい。またこれにより、フレキシブル回路基板の曲がり部分に発生する応力を突起部が支え、他の部分に当該応力が影響を与えるのを抑制することも可能となる。 Furthermore, by constructing the protrusions from a material (low hardness material, elastic body) that is softer than the housing and printed circuit board, it is possible to make the surface of the flexible circuit board less susceptible to damage. Furthermore, if the housing and protrusions are both made of metal, there is a possibility that shavings will be produced and cause a short circuit between the signal wiring S and the ground wiring G, so it is preferable to solder, screw, or glue the housing CA and protrusions B (B1-B3, etc.). This also makes it possible for the protrusions to support the stress that occurs in the bent parts of the flexible circuit board, preventing the stress from affecting other parts.
　図１２に示すように、本発明の光変調デバイスは、光変調素子（基板１、光導波路２を有するチップ）を金属等の筐体ＣＡ内に収容し、筐体の外部と光変調素子とを光ファイバＦで接続することで、コンパクトな光変調デバイスＭＤを提供することができる。当然、基板１の光導波路の入射部又は出射部に光ファイバを直接接続するだけでなく、空間光学系を介して光学的に接続することも可能である。また、半導体レーザーなどの光源を筐体ＣＡ内に配置し、入射用の光ファイバを省略することも可能である。Ｌｉｎは入射光、Ｌｏｕｔは出射光を示す。 As shown in FIG. 12, the optical modulation device of the present invention accommodates an optical modulation element (a chip having a substrate 1 and an optical waveguide 2) in a housing CA made of metal or the like, and connects the outside of the housing to the optical modulation element with an optical fiber F, thereby providing a compact optical modulation device MD. Naturally, it is possible not only to directly connect an optical fiber to the input or output part of the optical waveguide of the substrate 1, but also to optically connect via a spatial optical system. It is also possible to place a light source such as a semiconductor laser inside the housing CA and omit the optical fiber for input. Lin indicates the input light, and Lout indicates the output light.
　光変調デバイスＭＤに変調動作を行わせる変調信号Ｓ０を出力する電子回路（デジタル信号プロセッサーＤＳＰ）を、光変調デバイスＭＤに接続することにより、光送信装置ＯＴＡを構成することが可能である。光導波路素子に印加する変調信号Ｓは増幅する必要があるため、ドライバ回路ＤＲＶが使用される。ドライバ回路ＤＲＶやデジタル信号プロセッサーＤＳＰは、筐体ＣＡの外部に配置することも可能であるが、筐体ＣＡ内に配置することも可能である。特に、ドライバ回路ＤＲＶを筐体内に配置することで、ドライバ回路からの変調信号の伝搬損失をより低減することが可能となる。 An electronic circuit (digital signal processor DSP) that outputs a modulation signal S0 that causes the optical modulation device MD to perform a modulation operation can be connected to the optical modulation device MD to configure an optical transmission device OTA. Since the modulation signal S to be applied to the optical waveguide element needs to be amplified, a driver circuit DRV is used. The driver circuit DRV and the digital signal processor DSP can be arranged outside the housing CA, but can also be arranged inside the housing CA. In particular, by arranging the driver circuit DRV inside the housing, it is possible to further reduce the propagation loss of the modulation signal from the driver circuit.
　以上のように、本発明によれば、筐体の素材に依存せず、フレキシブル回路基板を簡単な構成で曲げることが可能であり、フレキシブル回路基板の筐体やプリント基板への取り付け部に発生する応力を緩和した光変調デバイスを提供することが可能となる。また、この光変調デバイスを用いた光送信装置を提供することも可能となる。 As described above, according to the present invention, it is possible to provide an optical modulation device that can bend a flexible circuit board with a simple configuration, regardless of the material of the housing, and that reduces stress generated at the attachment portion of the flexible circuit board to the housing or printed circuit board. It is also possible to provide an optical transmission device that uses this optical modulation device.
　ＯＭＥ　光変調素子
　ＤＲＶ　ドライバ回路
　ＷＢ　ワイヤーボンディング（ワイヤー）
　ＲＢ　中継基板
　ＬＰ　リードピン
　ＦＰＣ　フレキシブル回路基板
　Ｂ、Ｂ１～Ｂ７　突起部
　ＢＲ　樹脂製の突起部
　ＢＭ　金属製の突起部
　ＰＣＢ　プリント基板（外部回路基板） OME Light modulation element DRV Driver circuit WB Wire bonding (wire)
RB Relay board LP Lead pin FPC Flexible circuit board B, B1 to B7 Protrusions BR Resin protrusions BM Metal protrusions PCB Printed circuit board (external circuit board)

Claims (8)

  1. 　光変調素子を筐体内に収容した光変調デバイスであり、該光変調デバイスは外部回路基板上に配置されると共に、該外部回路基板上の電気線路と電気的に接続するフレキシブル回路基板を有する光変調デバイスにおいて、
    　該フレキシブル回路基板には、該筐体の表面と接する面に突起部が形成され、該突起部が該筐体に接することにより、該フレキシブル回路基板が該外部回路基板の方向に曲げられていることを特徴とする光変調デバイス。     An optical modulation device having an optical modulation element housed in a housing, the optical modulation device being disposed on an external circuit board and having a flexible circuit board electrically connected to an electric line on the external circuit board,
    An optical modulation device characterized in that a protrusion is formed on the surface of the flexible circuit board that contacts the surface of the housing, and the flexible circuit board is bent in the direction of the external circuit board by the protrusion contacting the housing.
  2. 　請求項１に記載の光変調デバイスにおいて、突起部が絶縁性樹脂又は導電性金属で構成されていることを特徴とする光変調デバイス。 The optical modulation device according to claim 1, characterized in that the protrusion is made of insulating resin or conductive metal.
  3. 　請求項２に記載の光変調デバイスにおいて、該突起部は、絶縁性樹脂で構成され、該フレキシブル回路基板上における信号配線の上部、両脇、片側、又は接地配線の上部の少なくともいずれかに配置されていることを特徴とする光変調デバイス。 The optical modulation device according to claim 2, characterized in that the protrusion is made of insulating resin and is disposed at least one of the above, both sides, or one side of the signal wiring on the flexible circuit board, or above the ground wiring.
  4. 　請求項２に記載の光変調デバイスにおいて、該突起部は、導電性金属で構成され、該フレキシブル回路基板上の接地配線上に配置されていることを特徴とする光変調デバイス。 The optical modulation device according to claim 2, characterized in that the protrusion is made of a conductive metal and is disposed on the ground wiring on the flexible circuit board.
  5. 　請求項１に記載の光変調デバイスにおいて、該筐体の底面側に段差部が形成され、該光変調デバイスを該外部回路基板上に配置した際に、該段差部の該外部回路基板から離間した面内に該フレキシブル回路基板の一部が固定されていることを特徴とする光変調デバイス。 The optical modulation device according to claim 1, characterized in that a step is formed on the bottom side of the housing, and when the optical modulation device is placed on the external circuit board, a part of the flexible circuit board is fixed within the surface of the step that is spaced apart from the external circuit board.
  6. 　請求項１乃至５のいずれかに記載の光変調デバイスにおいて、該筐体内には、該光変調素子に光波を入力する光源と、該光変調素子から光波を出力光ファイバとを備えることを特徴とする光変調デバイス。 The optical modulation device according to any one of claims 1 to 5, characterized in that the housing includes a light source for inputting a light wave to the optical modulation element, and an optical fiber for outputting the light wave from the optical modulation element.
  7. 　請求項６に記載の光変調デバイスにおいて、該光変調素子に入力する変調信号を増幅する電子回路を該筐体の内部又は外部に有することを特徴とする光変調デバイス。 The optical modulation device according to claim 6, characterized in that it has an electronic circuit inside or outside the housing that amplifies the modulation signal input to the optical modulation element.
  8. 　請求項７に記載の光変調デバイスと、該光変調デバイスに変調動作を行わせる変調信号を出力する電子回路とを有することを特徴とする光送信装置。 An optical transmitter comprising the optical modulation device according to claim 7 and an electronic circuit that outputs a modulation signal that causes the optical modulation device to perform a modulation operation.
PCT/JP2023/003041 2023-01-31 2023-01-31 Optical modulation device and optical transmission apparatus using same WO2024161500A1 (en)

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JP2020086389A (en) * 2018-11-30 2020-06-04 富士通株式会社 Optical component, and optical module using the same

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20040240036A1 (en) * 2001-10-03 2004-12-02 Henri Porte Electro-optic modulator, the production method therefor and the block for implementing same
JP2005128440A (en) * 2003-10-27 2005-05-19 Fujitsu Ltd Optical waveguide module with built-in electric circuit, and its manufacturing method
JP2010199277A (en) * 2009-02-25 2010-09-09 Kyocera Corp Connecting device, package for housing semiconductor element with flexible substrate, and semiconductor device with flexible substrate
JP2017067981A (en) * 2015-09-30 2017-04-06 住友大阪セメント株式会社 Optical modulator
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