JP2009260126A - Optical communication device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical communication device which prevents a mismatching of an impedance by providing a spacer. <P>SOLUTION: In the optical communication device 1 in which a spacer 4 for adjusting a height of an optical element assembly (OSA) 2 is inserted into between a board 3 soldered to a pin of the OSA 2 and the OSA 2, the spacer 4 is provided with: a through-hole for an outside conductor 6 disposed at a plurality of portions surrounding a signal pin 5 of the OSA 2; a through-hole for a GND 8 soldered to a GND pin 7 of the OSA 2; and a GND wiring 9 for continuity between the through-hole for the GND 8 and the through-hole for the outside conductor 6. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an optical communication device for preventing impedance mismatch due to insertion of a spacer.

  Optical communication devices such as optical transceivers use optical element assemblies (OSA) such as TOSA (transmitting optical subassembly) and ROSA (receiving optical subassembly) in which optical elements such as light emitting elements and light receiving elements are accommodated in a housing. The

  In an optical communication device equipped with OSA, an optical position such as an optical axis and a focal point is designed so that an OSA mounted on a substrate and an optical component such as an optical waveguide or a lens are aligned with each other. Arrangement has been made.

  However, OSA has different dimensions depending on the type and manufacturer. Specifically, there is a difference in the height of the housing (the length from the bottom to the top). Due to the difference in OSA dimensions, the optical positions of the OSA and the optical component are shifted. In order to eliminate such a dimensional difference, a spacer is used.

  As shown in FIG. 4, in the optical communication device 41, the spacer 42 is a member that is sandwiched between the bottom of the housing of the OSA 2 and the substrate 3. At the bottom of the OSA2 housing, a pin 43 (also referred to as a lead) is provided as a support member for fixing the OSA2 to the substrate 3 and at the same time a power supply / GND and signal transmission member. The pins 43 are inserted into the mounting holes with conductors of the substrate 3 and soldered, whereby the OSA 2 is electrically connected to the substrate 3 and mounted. At this time, the distance from the substrate 3 to the bottom of the OSA 2 housing is adjusted by inserting or not inserting the spacer 42 between the bottom of the OSA 2 housing and the substrate 3 or by changing the thickness of the spacer 42. The distance from the substrate 3 to the top of the housing of the OSA 2 (OSA mounting height) can be made constant regardless of the size of the OSA 2.

  It should be noted that the pin 43 is formed sufficiently long when the OSA 2 is provided as a raw material. After the pins 43 are inserted into the substrate 3 and soldered, the extra length protruding to the opposite side of the substrate 3 is cut. The length of the pin 43 described below is the length after the extra length is cut.

JP 11-238916 A

  In recent years, the signal transmitted by the OSA 2 has increased in speed, and the frequency of the current flowing through the pin has increased accordingly. As described above, when the spacer 42 is inserted between the OSA 2 and the substrate 3, the distance from the substrate 3 to the OSA 2 becomes longer and the pins become longer. Even if the length of the pin is increased to this extent, the impedance of the pin becomes high at high frequencies, and the impedance does not match between the pin and the signal line on the substrate. Impedance mismatching causes waveform distortion and transmission loss due to signal reflection and the like, which hinders transmission.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide an optical communication device that solves the above-described problems and prevents impedance mismatch due to insertion of a spacer.

  In order to achieve the above object, the present invention provides an optical communication apparatus in which a spacer for adjusting the height of the optical element assembly is inserted between a substrate to which pins of the optical element assembly are soldered and the optical element assembly. The spacer includes through-holes for outer conductors arranged at a plurality of locations around the signal pins of the optical element assembly, GND through-holes soldered to the GND pins of the optical element assembly, and the GND through-holes. A GND wiring that conducts the hole and the outer conductor through-hole is provided.

  According to another aspect of the present invention, there is provided an optical communication device in which a spacer for adjusting the height of the optical element assembly is inserted between a substrate to which a pin of the optical element assembly is soldered and the optical element assembly. The metal spacer is soldered to the GND pin of the optical element assembly.

  According to another aspect of the present invention, there is provided an optical communication device in which a spacer for adjusting a height of the optical element assembly is inserted between a substrate to which a pin of the optical element assembly is soldered and the optical element assembly. It comprises a spacer substrate whose one surface is in contact with the GND pin of the optical element assembly and whose opposite surface is in contact with the signal pin of the optical element assembly. The one surface of the spacer substrate that is in contact with the GND pin is connected to the GND pin along the GND pin. A conductor film is formed, and a signal conductor film is formed along the signal pin on the opposite surface in contact with the signal pin of the spacer substrate.

  The present invention exhibits the following excellent effects.

  (1) Impedance mismatch due to insertion of a spacer can be prevented.

  Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIGS. 1 (a) and 1 (b), the optical communication device 1 according to this embodiment includes an optical element assembly (OSA) 2 and a substrate 3 to which pins of the OSA 2 are soldered. In the optical communication device 1 in which the spacer 4 for adjusting the height of the OSA 2 is inserted, a plurality of outer conductor through holes 6 are arranged around the signal pin 5 of the OSA 2 in the spacer 4, and the GND (ground) pin of the OSA 2 7 is provided with a GND through hole 8 to be soldered, and a GND wiring 9 for conducting the GND through hole 8 and the outer conductor through hole 6.

  FIG. 1 (a) does not strictly show the dimensions and ratios of each member such as the thickness and hole diameter, and there are some parts that are emphasized. In addition, a gap is formed between the members for easy viewing, but the members are actually in close contact.

  The OSA 2 has a housing (so-called CAN package) 10 made of metal and formed in a cylindrical shape. A top portion of the housing 10 (a surface facing the substrate 3) is a light incident / exit surface of an optical element built in the housing 10. A pin that connects the inside and outside of the housing is provided on the bottom of the housing 10 (the surface facing the substrate 3). The number of pins is four, for example, a power supply pin, a GND pin 7, and a signal pin 5 × 2, but is not limited to this, and may be any number. The signal pin 5 is a high-speed signal pin through which a high-frequency current of a high-speed signal (for example, 1 Gbps or higher) having a high transmission speed flows.

  The substrate 3 is, for example, a flexible substrate, but may be a rigid substrate. The substrate 3 is provided with predetermined holes (through holes or holes with lands) for inserting and soldering the pins of the OSA 2, and conductor patterns for transmitting power, GND, and signals are provided in these holes. Is provided.

  The spacer 4 is a member that is sandwiched between the bottom portion of the housing 10 of the OSA 2 and the substrate 3, and has a thickness set in accordance with a desired distance from the substrate 3 to the bottom portion of the housing 10. The spacer 4 is made of a material equivalent to a substrate such as glass epoxy, or a plastic that is an insulator (dielectric).

  For example, the spacer 4 is formed in a cylindrical shape having the same diameter as the OSA 2, but the diameter may be different from that of the OSA 2, and the shape is not limited to the cylindrical shape and is arbitrary.

  The spacer 4 is formed with a hole for inserting each pin of the OSA 2. In this embodiment, the signal pin insertion hole 11 through which the signal pin 5 is inserted is a through hole having no conductor film on the inner surface and no land around the opening. The hole through which the GND pin 7 is inserted is a through hole in which a conductor film is formed on the inner surface and a land which is connected to the conductor film on the inner surface is formed around the opening. This is the GND through hole 8. The power supply pin insertion hole 12 through which the power supply pin is inserted is not particularly limited to whether it is a through hole (non-conduction) or a through hole (conduction).

  The outer conductor through hole 6 is a through hole in which a conductor film is formed on the inner surface and a land that is connected to the conductor film on the inner surface is formed around the opening in the same manner as the GND through hole 8. Not a hole. The outer conductor through holes 6 are provided at predetermined angles along a circumference of a predetermined diameter so as to surround the signal pin insertion holes 11. Here, six outer conductor through holes 6 are provided at substantially equal angles from the center of the signal pin insertion hole 11 so as to surround the signal pin insertion hole 11.

  On one side or both sides of the spacer 4, a GND wiring 9 is formed for conducting the GND through hole 8 and the outer conductor through hole 6. The GND wiring 9 is wired so as to conduct the GND through hole 8 and all the outer conductor through holes 6.

  Next, a procedure for assembling the optical communication device 1 will be described.

  First, the spacer 4 is attached to the OSA 2. That is, the signal pin 5 is inserted into the signal pin insertion hole 11, the GND pin 7 is inserted into the GND through hole 8, the power supply pin is inserted into the power supply pin insertion hole 12, and the spacer 4 is inserted until it touches the bottom of the OSA 2, and in this state the GND pin 7 is soldered to the GND through hole 8 (soldering portion 13).

  In this way, the OSA 2 to which the spacer 4 is attached is attached to the substrate 3. That is, the OSA2 signal pin 5, the GND pin 7 and the power supply pin protruding from the spacer 4 are respectively inserted into predetermined holes of the substrate 3, and the OSA2 is inserted until the spacer 4 hits the substrate 3, and each pin is soldered in that state. (Soldering part 14). Thereafter, the extra length of each pin protruding from the substrate 3 is cut off.

  Next, the function and effect of the optical communication device 1 of this embodiment will be described.

  When the GND pin 7 of the OSA 2 is soldered to the substrate 3 by the soldering portion 14, the GND pin 7 becomes the GND potential. Since the GND through hole 8 of the spacer 4 is soldered to the GND pin 7 of the OSA 2 by the soldering portion 13, the GND through hole 8 is also at the GND potential. For this reason, all the through holes 6 for outer conductors are set to the GND potential via the GND wiring 9.

  The signal pin 5 is surrounded by the conductors of the outer conductor through-holes 6 having the GND potential at a plurality of peripheral positions over the entire length in the longitudinal direction. This means that the signal transmission line has a coaxial structure between the bottom of the housing 10 of the OSA 2 and the substrate 3. That is, it has the same structure as a coaxial cable in which a signal flows through the inner conductor and the outer conductor covering the inner conductor is kept at the GND potential. Thereby, the impedance of the signal pin 5 becomes low. Since the impedance of the signal pin 5 is lowered, the impedance can be matched between the signal pin 5 and the signal line on the substrate 3. When impedance is matched, waveform distortion and transmission loss do not occur.

  As described above, in the optical communication device 1 of the present embodiment, even when the spacer 4 is inserted in the optical communication device 1 that performs high-speed signal communication, the periphery of the signal pin 5 is surrounded by the through hole 6 for the outer conductor having the GND potential. With this configuration, an increase in impedance is prevented and transmission characteristics are improved.

  The position and number of the outer conductor through holes 6 may be selected according to the desired impedance.

  Hereinafter, other embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 2, the optical communication device 21 of the present embodiment is an optical communication device in which a spacer 22 for adjusting the height of the OSA 2 is inserted between the OSA 2 and the substrate 3 to which the pins of the OSA 2 are soldered. In the vessel 21, the spacer 22 is made of metal, and the metal spacer 22 is soldered to the GND pin 7 of the OSA 2.

  The OSA 2 and the substrate 3 are the same as those in FIG.

  The spacer 22 is a member sandwiched between the bottom of the housing 10 of the OSA 2 and the substrate 3, and has a thickness set in accordance with a desired distance from the substrate 3 to the bottom of the housing 10.

  For example, the spacer 22 is formed in a cylindrical shape having the same diameter as the OSA 2, but the diameter may be different from that of the OSA 2, and the shape is arbitrary.

  The spacer 22 is formed with a hole for inserting each pin of the OSA 2. In the present embodiment, the signal pin insertion hole 23 through which the signal pin 5 is inserted is a hole whose diameter is set so that the impedance of the signal pin 5 becomes a predetermined value. The GND pin insertion hole 24 through which the GND pin 7 is inserted is a hole having a diameter that can be easily soldered after the GND pin 7 is inserted. A power pin insertion hole (not shown) through which the power pin is inserted is a hole whose diameter is set so that contact with the power pin can be sufficiently avoided.

  The procedure for assembling the optical communication device 21 is almost the same as that of the optical communication device 1. First, in order to attach the spacer 22 to the OSA 2, the spacer 22 is inserted until it touches the bottom of the OSA 2, and the GND pin 7 is then inserted into the GND pin. It solders to the insertion hole 24 (soldering part 25). In this way, the OSA 2 to which the spacer 22 is attached is attached to the substrate 3. That is, the OSA2 signal pin 5, the GND pin 7 and the power supply pin protruding from the spacer 22 are inserted into predetermined holes of the substrate 3, respectively, and the OSA2 is inserted until the spacer 22 hits the substrate 3, and the pins are soldered in that state. (Soldering part 26). Next, the extra length portion of each pin protruding from the substrate 3 is cut off.

  The effect of the optical communication device 21 of this embodiment is demonstrated.

  The spacer 22 becomes a GND potential by being soldered to the GND pin 7 of the OSA 2.

  The signal pin 5 is surrounded by a metal conductor wall (signal pin insertion hole 23) having a GND potential over the entire length in the longitudinal direction. Therefore, the signal transmission line has a coaxial structure using air as a dielectric, and the impedance of the signal pin 5 is reduced. Since the impedance of the signal pin 5 is lowered, the impedance can be matched between the signal pin 5 and the signal line on the substrate 3. When impedance is matched, waveform distortion and transmission loss do not occur.

  As described above, the optical communication device 21 of the present embodiment is configured such that the signal pin 5 is surrounded by the metal conductor wall having the GND potential even when the spacer 22 is inserted into the optical communication device 21 that performs high-speed signal communication. As a result, an increase in impedance is prevented and transmission characteristics are improved.

  The diameter of the signal pin insertion hole 23 may be selected according to the desired impedance.

  Hereinafter, other embodiments of the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 3, the optical communication device 31 of this embodiment is an optical communication device in which a spacer 32 for adjusting the height of the OSA 2 is inserted between the OSA 2 and the substrate 3 to which the pins of the OSA 2 are soldered. The spacer 32 is composed of a spacer substrate 33 that contacts one side of the GND pin 7 of the OSA 2 and the opposite surface of the signal pin 5 of the OSA 2, and the surface that contacts the GND pin 7 of the spacer substrate 33 extends along the GND pin 7. The GND conductor film 34 is formed, and the signal conductor film 35 is formed along the signal pin 5 on the surface of the spacer substrate 33 that contacts the signal pin 5.

  The OSA 2 and the substrate 3 are the same as those in FIG.

  The spacer 32 is a member that is sandwiched between the bottom of the housing 10 of the OSA 2 and the substrate 3. In the present embodiment, the spacer 32 is constituted by a spacer substrate 33. The spacer substrate 33 is a rigid substrate made of a material such as glass epoxy. The spacer substrate 33 contacts one side with the GND pin 7 of the OSA 2 and contacts the opposite surface with the signal pin 5 of the OSA 2. That is, the thickness of the spacer substrate 33 is substantially equal to the distance between the GND pin 7 and the signal pin 5. The width of the spacer substrate 33 is set according to a desired distance from the substrate 3 to the bottom of the housing 10. The spacer substrate 33 is mounted such that the substrate surface of the spacer substrate 33 stands at right angles to the substrate surface of the substrate 3.

  A conductor film is provided on the front and back substrate surfaces of the spacer substrate 33 by printing or the like. Specifically, a GND conductor film 34 is formed along the GND pin 7 on the substrate surface in contact with the GND pin 7. The GND pin 7 is soldered to the GND conductor film 34 over the entire length in contact with the GND conductor film 34.

  A signal conductor film 35 is formed along the signal pins 5 on the surface of the spacer substrate 33 in contact with the signal pins 5. The signal pin 5 is soldered to the signal conductor film 35 over the entire length in contact with the signal conductor film 35.

  According to the present embodiment, the GND conductor film 34 and the signal conductor film 35 formed on the respective surfaces of the spacer substrate 33 substantially increase the conductor cross-sectional areas of the GND pin 7 and the signal pin 5 and lower the impedance. It will be. In addition, since the spacer substrate 33 provided with the GND conductor film 34 and the signal conductor film 35 has a structure in which a conductor is placed on a dielectric, the structure is the same as that of the substrate 3. Easy to match.

  Further, according to the present embodiment, an arbitrary impedance can be obtained by a combination of the dielectric constant of the spacer substrate 33, the thicknesses of the conductor films 34 and 35, the conductor pattern width, and the like.

It is a figure of the optical communication device which shows one Embodiment of this invention, (a) is a sectional side view (b) is a bottom view of a spacer. It is a sectional side view of the optical communication device which shows other embodiment of this invention. It is a sectional side view of the optical communication device which shows other embodiment of this invention. In the prior art, it is the perspective view which mounted the optical element assembly on the board | substrate with the spacer.

Explanation of symbols

1, 21, 31 Optical communication device 2 Optical element assembly (OSA)
3 Substrate 4, 32 Spacer 5 Signal pin 6 Outer conductor through hole 7 GND pin 8 GND through hole 9 GND wiring 22 Metal spacer 23 Signal pin insertion hole 24 GND pin insertion hole 33 Spacer substrate 34 GND conductor film 35 Signal Conductor film

Claims (3)

  An optical communication device in which a spacer for adjusting a height of the optical element assembly is inserted between a substrate to which a pin of the optical element assembly is soldered and the optical element assembly, wherein the spacer includes a signal of the optical element assembly. The through hole for the outer conductor arranged at a plurality of locations around the pin, the GND through hole soldered to the GND pin of the optical element assembly, and the GND through hole and the outer conductor through hole are electrically connected. An optical communication device, characterized in that a GND wiring is provided.   In an optical communication device in which a spacer for adjusting the height of the optical element assembly is inserted between a substrate to which pins of the optical element assembly are soldered and the optical element assembly, the spacer is made of metal, and the metal An optical communication device characterized in that a spacer made of solder is soldered to a GND pin of the optical element assembly.   An optical communication device in which a spacer for adjusting a height of the optical element assembly is inserted between a substrate to which a pin of the optical element assembly is soldered and the optical element assembly, wherein the spacer is a GND pin of the optical element assembly. A spacer substrate in contact with the signal pin of the optical element assembly and an opposite surface in contact with the signal pin of the optical element assembly, and a GND conductor film is formed along the GND pin on the one surface of the spacer substrate in contact with the GND pin. An optical communication device, wherein a signal conductor film is formed along the signal pin on the opposite surface of the spacer substrate in contact with the signal pin.

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