JP2011054667A - Photo-receiving module and photo-detector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a technology capable of improving frequency characteristics without damaging assembling workability in a light-receiving module. <P>SOLUTION: A base of a light-receiving module includes a stepped part connecting a lower-stage surface, a rising surface and an upper-stage surface in this order, and a width of a top face is shorter than that of an underside and film wiring for a reference voltage arranged extensively over the top face and a front and wiring for a signal voltage are positioned in a carrier disposing a photo-detector. The carrier is arranged along the lower-stage surface and the rising surface and a preamplifier is disposed on the upper-stage surface. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an optical receiver module and an optical receiver including the same, and more particularly to an optical receiver module that can operate in a high frequency region and an optical receiver including the optical receiver module.

  An optical receiving module mounted on an optical transceiver includes a light receiving element, a preamplifier circuit, a light receiving element bias circuit, an optical fiber, and optical parts such as a lens.

  The main performance of the optical receiver is determined by the input conversion noise and frequency response characteristics of the optical receiver module. Both the input conversion noise and the frequency response characteristic greatly depend on the frequency. When the optical receiver module is used at a high transmission rate, the influence of parasitic elements due to the mounting state of the light receiving element, the preamplifier circuit, the light receiving element bias circuit, and the like becomes particularly large.

  These parasitic elements in the optical receiver module include a parasitic inductance and a parasitic capacitance related to connection or mounting of a light receiving element, a preamplifier circuit, a light receiving element bias circuit, and the like. The resonance frequency of LC resonance based on the inductance (parasitic inductance) resulting from the connection between the light receiving element and the preamplifier circuit and the capacitance (parasitic capacity) such as the junction capacity of the light receiving element and the input terminal capacity of the preamplifier circuit is the transmission frequency band. It is necessary to make it high enough for.

  FIG. 6 is a perspective view of the main part of the optical receiver module according to the prior art. The carrier 2 on which the light receiving element is arranged and the preamplifier circuit 10 are separately arranged on the base part 7 of the optical receiving module. This is because the light receiving element 1 and the preamplifier circuit 10 are devices that tend to have variations in characteristics. The optical receiver module shown in FIG. 6 performs a characteristic inspection separately on the light receiving element 1 and the preamplifier circuit 10, selects elements that satisfy the characteristic criteria, and forms an optical receiver module using them. Therefore, the non-defective product rate of the optical receiver module can be greatly improved. Further, when the temperature dependency data of the light receiving element 1 is required, it is necessary to acquire the data by the light receiving element 1 alone. For example, when an avalanche amplification photodiode (Avalanche Photodiode: hereinafter referred to as APD) is used as the light receiving element 1, the temperature dependence of the breakdown voltage or dark current differs depending on each element. In consideration of the assembly workability of the optical receiving module, it is desirable that the light receiving element 1 is mounted on the carrier 2 and the preamplifier circuit 10 is mounted on the base portion 7.

JP 2003-134051 A US Pat. No. 5,200,612 JP 2000-58881 A

  The optical receiver module must satisfy the following specifications in order to satisfy a predetermined reception sensitivity.

  (1) The return loss of received light is suppressed to a certain value or less (for example, ITU-T: -27 dB or less of the international standard), and the coupling efficiency between the light receiving element and the optical fiber is increased as much as possible.

  (2) The input equivalent noise current density of the preamplifier circuit is made as low as possible.

  (3) In connection with the above (2), the junction capacitance of the light receiving element is made as low as possible.

  (4) The frequency response characteristic is optimized for the subsequent circuit. Here, the frequency response characteristics include S21 characteristics and S22 characteristics of the S parameter after photoelectric conversion. In the S21 characteristic and S22 characteristic, the optical signal input terminal is port 1 and the electrical signal output terminal is port 2.

  As S21 characteristics, there are specification items such as (A) 3 dB band and (B) in-band deviation, which depend on the characteristics of the subsequent circuit. In the case of a configuration in which a light receiving element is mounted on a carrier and a preamplifier circuit is mounted on a base portion, the above relationship is caused by the relationship between the parasitic inductance generated due to the connection between the two and other parasitic capacitances. The characteristics of (A) and (B) may be greatly affected.

  FIG. 7 is a diagram illustrating S21 characteristics with respect to the frequency of the optical receiving module according to the related art illustrated in FIG. As shown in FIG. 7, since there is a resonance point of LC resonance in the vicinity of 25 GHz, for example, it is used as an optical reception module for a high-speed / wideband optical receiver that transmits a signal at a high transmission rate of 40 Gbps or higher. I can't. Therefore, it is necessary to further increase the resonance frequency of this LC resonance.

  In the prior art, for example, Patent Document 1 describes a technique for reducing a parasitic inductor by mounting a light receiving element and a preamplifier circuit on the same carrier. On the other hand, Patent Documents 2 and 3 describe a configuration in which the light receiving element is mounted on the carrier side and the preamplifier circuit is mounted on the base part side. Furthermore, Patent Document 3 describes a technique for reducing the parasitic inductance by providing an inductor on a carrier or a base.

  However, in the structure described in Patent Document 1, it is difficult to evaluate the light receiving element with a single chip, which is inappropriate. Further, in the technique described in Patent Document 1, a parasitic inductance is reduced by providing a light receiving element and an amplifier circuit on a carrier and shortening a connecting wire between the two, thereby improving these characteristics. . However, there is a limit to reducing parasitic inductance, and it does not become zero. Further, Patent Document 1 does not describe a countermeasure for a case where peaking or dip of the S21 characteristic occurs in a frequency band that affects the characteristics by causing LC resonance with the inductance and the capacitance.

  In the configuration described in Patent Document 2, no active element other than the light receiving element is mounted on the carrier. For this reason, the characteristic inspection of the light receiving element is possible. However, the length of the connecting wire between the light receiving element and the preamplifier circuit becomes long, and the parasitic inductance increases.

  In the technique described in Patent Document 3, a resistor or a resistance component is provided on at least one of the anode side and the cathode side of the light receiving element in any of the carrier, the base, and the preamplifier circuit. An impedance having a reactance component is connected. In addition, by connecting the bypass capacitor of the bias power supply for the light receiving element directly or through the series resistance or impedance to the ground side, the light receiving element and the preamplifier circuit are not provided on the carrier, and the parasitic elements are not reduced. Even in the optical receiver module, there is no peaking or dip, and a frequency characteristic of a necessary and sufficient band can be obtained.

  However, when the optical receiver module is operated at a high transmission rate of 40 Gbps or higher, the technique described in Patent Document 3 is not sufficient to reduce the parasitic inductance. Therefore, peaking or dip of the S21 characteristic occurs in the frequency band that affects the characteristics due to LC resonance caused by the inductance and the capacitance, so that it is impossible to satisfy the required frequency response characteristics. Furthermore, Patent Document 3 does not mention matching of characteristic impedance between the signal transmission line formed on the carrier and the preamplifier circuit on the substrate, and degradation of frequency response characteristics due to impedance mismatching also occurs. sell.

  In view of such problems, the present invention is to provide an optical receiver module capable of improving frequency characteristics without impairing assembly workability.

  (1) An optical receiver module according to the present invention includes a light receiving element that converts an input optical signal into an electrical signal, and a base portion having a stepped portion in which a lower step surface, a rising surface, and an upper step surface are connected in this order. A back surface disposed along the rising surface, a front surface located on the opposite side of the back surface, and a bottom surface extending between the lower edges of the back surface and the front surface and disposed along the lower surface. A carrier positioned on the opposite side of the bottom surface and having a top surface extending between upper edges of the back surface and the front surface, a preamplifier circuit disposed on the top surface and amplifying the electrical signal; The length of the carrier between the upper edge of each of the back surface and the front surface is shorter than the length between the bottom edge of each of the back surface and the front surface, and is used for a reference voltage. Membrane wiring Provided over the front surface and a part of the upper surface, and further, a signal voltage film-like wiring extends from the signal voltage terminal of the light receiving element, and extends over the front surface and a part of the upper surface, respectively. A reference voltage terminal and a signal voltage terminal provided in the preamplifier circuit, and a portion of the reference voltage film wiring and the signal voltage film wiring that are respectively located on a part of the upper surface. Are electrically connected to each other.

  (2) The optical receiver module according to (1), wherein the length between upper edges of the back surface and the front surface is determined by frequency response characteristics, and further, In addition, the length of the signal voltage film-like wiring and the interval between the reference voltage film-like wiring and the signal voltage film-like wiring match the impedance of the preamplifier circuit in the upper edge direction of the front surface. May be determined.

  (3) The optical receiver module according to (1) or (2), wherein the reference voltage film-like wiring is a portion of the reference voltage film-like wiring that is positioned on the front surface, The signal voltage film-like wiring may have an extension that extends the upper surface toward the signal voltage film-like wiring.

  (4) In the optical receiver module according to (3), the reference voltage film-shaped wiring and the signal voltage film-shaped wiring may be electrically insulated by cutting.

  (5) The optical receiver which concerns on this invention may be equipped with the optical receiver module in any one of said (1) thru | or (4).

  According to the present invention, there is provided an optical receiver module capable of improving frequency characteristics without impairing assembly workability.

1 is an overall perspective view of an optical receiver module according to an embodiment of the present invention. It is a schematic diagram which shows the structure of the optical receiver module which concerns on embodiment of this invention. It is a perspective view of the optical receiver module main part concerning the embodiment of the present invention. It is a figure which shows the S21 characteristic with respect to the frequency of the optical receiving module which concerns on embodiment of this invention. It is a contour map which shows the characteristic impedance with respect to the signal line | wire width in a coplanar transmission line, and the width | variety between a signal line | wire and a ground electrode. It is a perspective view of the optical receiver module principal part concerning a prior art. It is a figure which shows the S21 characteristic with respect to the frequency of the optical receiver module which concerns on a prior art.

  The optical receiver module 100 according to the embodiment of the present invention is provided in a high-speed / broadband optical receiver that transmits a signal at a high transmission rate of 43 Gbps, for example.

  FIG. 1 is an overall perspective view of an optical receiver module 100 according to an embodiment of the present invention. As shown in FIG. 1, on the base 7 of the optical receiving module 100, the carrier 2, in which the light receiving element 1 is disposed, the preamplifier circuit 10, the optical system component 25 such as a lens, and the light receiving element bias circuit 20 (see FIG. 1). Not shown), a light receiving element bias power source 21, a relay line 22, and the like. Further, an optical fiber is connected to the input side of the optical receiving module 100, and the optical input 30 is made as indicated by the arrows in the figure. An AGC amplifier circuit or the like is further connected to the output side of the optical receiving module 100, and then the amplified analog signal is converted into a digital signal.

  FIG. 2 is a schematic diagram showing a configuration of the optical receiving module 100 according to the embodiment of the present invention. The light receiving element 1 is, for example, an APD, and the input optical signal is detected by the light receiving element 1 as an analog electric signal. The light receiving element 1 is connected to a light receiving element bias power source 21 via a light receiving element bias circuit 20. The analog electric signal generated by the light receiving element 1 is amplified by the preamplifier circuit 10 and output via the relay line 22.

  FIG. 3 is a perspective view of the main part of the optical receiver module 100 according to the embodiment of the present invention. FIG. 3 is an enlarged view of a portion surrounded by a broken line III shown in FIG. As shown in FIG. 1, the base portion 7 has a stepped portion. The stepped portion is constituted by a lower step surface 7A, a rising surface 7B, and an upper step surface 7C. The base part 7 is formed of a conductive material such as metal.

  The carrier 2 on which the light receiving element 1 is disposed is formed of, for example, InP or the like, and has a columnar shape with a side surface having a trapezoidal shape as shown in FIG. The trapezoid has a lower side longer than the upper side, and one side is in contact with each of the upper side and the lower side at a right angle. That is, the trapezoid has a shape obtained by obliquely cutting a rectangle from the upper side to the lower side.

  The upper surface, the lower surface, the front surface, and the back surface, which are surfaces other than the two trapezoids of the carrier 2, each have a rectangular shape having the same extension length extending in the left-right direction in the drawing. The back surface is in contact with the upper surface and the lower surface at right angles, and the front surface is an inclined surface with respect to the upper surface and the lower surface. That is, the width of the lower surface (the lower side of the trapezoid) is longer than the width of the upper surface (the upper side of the trapezoid).

  The carrier 2 is disposed so that the lower surface is in contact with the lower surface 7 </ b> A of the base portion 7 and the back surface is in contact with the rising surface 7 </ b> B of the base portion 7. The upper surface of the carrier 2 is higher than the upper stage surface 7 </ b> C of the base portion 7.

  The upper surface of the carrier 2 is covered with a metal film, and the metal film is electrically insulated at three locations, and the upper left reference voltage film-like wiring in the extending length direction from the left in the figure. 4A, upper surface signal voltage film wiring 8A, upper surface bias voltage film wiring 9A, and upper surface right reference voltage film wiring 3A.

  Both ends of the front surface of the carrier 2 are covered with a metal film in the extending length direction, and a front left reference voltage pattern 4B and a front right reference voltage pattern 3B are formed, respectively. The upper left reference voltage film wiring 4A and the front left reference voltage pattern 4B constitute the left reference voltage film wiring 4, and similarly, the upper right reference voltage film wiring 3A and the front right reference. The voltage pattern 3B constitutes the film wiring 3 for the right reference voltage.

  Here, the base portion 7 serves as a reference voltage, and the left reference voltage film-like wiring 4 and the right reference voltage film-like wiring 3 are each electrically connected to the base portion 7. When the base unit 7 is grounded, the reference voltage is 0V. Further, the upper left reference voltage film-like wiring 4A includes an upper left wiring extension 4C and an upper left wiring connection 4D. The upper surface left wiring connection portion 4D is electrically connected to the front surface left reference voltage pattern 4B, and is connected to the reference voltage electrode 6 provided on the upper surface 7C of the base portion 7 via the pattern connection wire 14. Electrically connected. Further, the front left reference voltage pattern 4B does not exist in the front surface portion of the upper surface of the carrier 2 where the upper surface left wiring extension 4C contacts. Therefore, the left reference voltage film-like wiring 4 is extended in the extending length direction with respect to the upper surface voltage film-like wiring 8A by the upper surface left wiring extension 4C. A place where the light receiving element 1 is arranged on the front surface can be secured by the upper left wiring extension 4C. Therefore, even if the light receiving element 1 has a relatively large size with respect to the carrier 2, the light receiving element 1 can be mounted on the carrier 2. In addition, the carrier 2 can be reduced in size.

  A cathode electrode pattern 8B and an anode electrode pattern 9B are formed on the front surface in order to be electrically connected to the light receiving element 1 in the vicinity of the center of the front surface of the carrier 2 in the drawing. The width of the cathode electrode pattern 8B decreases from the upper surface side end toward the center. The anode electrode pattern 9B extends in contact with the upper surface bias voltage film-like wiring 9A in the extending length direction. The anode electrode pattern 9B extends further from the end on the cathode electrode pattern 8B side toward the center. Then, the light receiving element 1 is disposed on the front surface of the carrier 2 so as to be connected to the cathode electrode and the anode electrode of the light receiving element 1 at the tip portions of the cathode electrode pattern 8B and the anode electrode pattern 9B.

  Furthermore, the signal voltage film wiring 8 is configured by the upper signal voltage film wiring 8A and the cathode electrode pattern 8B. Similarly, the upper bias voltage film wiring 9A and the anode electrode pattern 9B The bias voltage film wiring 9 is configured. The signal voltage film wiring 8 electrically connects the light receiving element 1 and the preamplifier circuit 10. The bias voltage film wiring 9 electrically connects the light receiving element 1 and the light receiving element bias power source 21.

  On the upper surface 7C of the base portion 7, the bias power source electrode 5, the preamplifier circuit 10, and the above-described reference voltage electrode 6 are arranged from the right side in the drawing near the end on the rising surface 7B side. . The preamplifier circuit 10 is provided with a reference voltage terminal 12 and a signal voltage terminal 11. The upper left wiring extension 4C described above extends to the vicinity of the reference voltage terminal 12, and the tip of the upper left wiring extension 4C and the reference voltage terminal 12 are electrically connected by the pattern connection wire 15. Has been. In addition, the upper surface signal voltage film-like wiring 8 </ b> A is located in the vicinity of the signal voltage terminal 11 and is electrically connected by the pattern connection wire 16.

  Next to the preamplifier circuit 10, a bias power supply electrode 5 is arranged, and the end of the upper surface bias voltage film wiring 9A on the upper surface right reference voltage film wiring 3A side and the bias power supply electrode 5 are connected in a pattern. It is electrically connected by a wire 17 for use. As described above, the upper surface of the carrier 2 is higher than the upper stage surface 7C of the base unit 7. This is because the thickness of the preamplifier circuit 10 and the bias power supply electrode 5 is taken into account, and the upper surface signal voltage is considered. The distance between the film-like wiring 8A and the signal electrode terminal 11, the distance between the upper-surface signal voltage film-like wiring 8A, and the distance between the upper-surface bias voltage film-like wiring 9A and the bias power supply electrode 5 are shortened. .

  The above is the configuration of the main part of the optical receiver module 100 according to the present invention.

  As described above, the parasitic inductance is generated by the signal voltage film-like wiring 8 and the left reference voltage film-like wiring 4 that connect the light receiving element 1 and the preamplifier circuit 10. In the carrier 2 in the prior art, due to the rectangular parallelepiped shape, the connection wiring length between the light receiving element 1 and the preamplifier circuit 10 becomes long and the parasitic inductance cannot be reduced. The carrier 2 according to the embodiment of the present invention is Since the width of the upper surface is shorter than the width of the lower surface, the connection wiring length between the light receiving element 1 and the preamplifier circuit 10 can be shortened, and the parasitic impedance can be reduced. In addition, since the width of the lower surface can be made longer than the width of the upper surface, the strength and stability of the carrier 2 itself as a housing can be ensured. In addition, since the width of the lower surface is longer than the width of the upper surface, the front surface on which the light receiving element 1 is disposed is an inclined surface with respect to the lower step surface 7A of the base portion 7 and the like. That is, since the light receiving surface of the light receiving element 1 is not perpendicular to the optical axis of the input light, the input light is reflected by the light receiving surface of the light receiving element 1 and is again disposed on the input side. The reflection to the optical fiber is suppressed.

  Furthermore, the length of the upper surface width is determined by determining the parasitic impedance to be reduced for the desired frequency. In the light receiving element 1 and the carrier 2 according to the present embodiment, when the width of the upper surface of the carrier 2, that is, the connection wiring length L is changed, the S21 characteristic which is one of the frequency response characteristics is changed by computer simulation. It can be obtained by performing.

  FIG. 4 is a diagram illustrating S21 characteristics with respect to frequency when the width of the upper surface of the carrier 2, that is, the connection wiring length L, is different in the optical receiver module 100 according to the embodiment of the present invention. The four curves are the width of the upper surface of the carrier 2, that is, the connection wiring length is L, and in the four curves shown in the figure, L is 0.1 mm, 0.15 mm, 0.2 mm, and 0, respectively. It shows the case of 3 mm.

  In the optical receiver module 100 according to the embodiment of the present invention, unlike the S characteristic of the optical receiver module according to the prior art shown in FIG. 7, the S21 characteristic maintains a stable characteristic up to a higher frequency.

  Here, when L is 0.3 mm, due to an increase in the inductance component resulting from the length L of the signal line, peaking of the S21 characteristic is caused in the vicinity of 32 GHz where L is a frequency lower than 0.1 mm or 0.2 mm. In addition, the 3 dB bandwidth is about 40 GHz. As a frequency characteristic of an optical receiver module for a high-speed / broadband optical receiver that transmits a signal at a transmission speed of 40 Gbps or higher, it is desirable that at least L be 0.3 mm or less.

  Further, the upper surface signal voltage film wiring 8A is formed on the upper surface of the carrier 2 and the upper left reference voltage film wiring 4A and the upper right reference voltage film wiring 3A located on both sides, and is used for high frequency transmission. The structure approximates that of a coplanar transmission line, which is one of the lines. Thus, from the viewpoint of the high-frequency transmission line, the carrier 2 can be designed so as to achieve impedance matching with the preamplifier circuit 10 in the subsequent stage.

  In other words, the coplanar transmission line approximated by the upper-surface signal voltage film-like wiring 8A and the upper-surface left reference voltage film-like wiring 4A formed on the upper surface of the carrier 2 according to the embodiment of the present invention The length D1 of the upper signal voltage film-like wiring 8A, which is impedance-matched with the amplifier circuit 10, in the extending length direction, and the upper signal voltage film wiring 8A and the upper left reference voltage film wiring 4A. The width D2 can be obtained.

  FIG. 5 is a contour diagram showing the characteristic impedance with respect to the signal line width D1 and the width D2 between the signal line and the ground electrode in the coplanar transmission line. The curve shown at the center in the hatched area in FIG. 5 is a contour line with a characteristic impedance of 50Ω, and becomes a contour line in which the characteristic impedance increases in order of 5Ω as it goes to the upper left in the figure. That is, the area indicated by hatching in FIG. 5 is an area where the characteristic impedance is 50 ± 5Ω.

  Therefore, when the impedance of the preamplifier circuit 10 in the subsequent stage is 50Ω, the signal transmission line width D1 included in the region indicated by the oblique line and the signal transmission line and the ground electrode are included in the region indicated by the oblique line. The value of the width D2 is selected, and the value of D1 is set to the length in the extending direction of the upper-surface signal voltage film-like wiring 8A, and the upper-surface signal voltage film-like wiring 8A and upper surface are set to the value of D2. The carrier 2 may be formed such that the width of the left reference voltage film-like wiring 4A is the same.

  As shown in FIG. 5, for example, the values of D1 and D2 may be selected so that D1 is 0.2 mm and D2 is 0.08 mm. The length of D1 and D2 is set to such a length by first forming a metal film on the entire upper surface of the carrier 2 and then electrically cutting between each film-like wiring by dicing (cutting). Further, it is desirable to form the film-like wiring so that the length in the extending direction becomes a desired length.

  As described above, even if a light receiving element including a parasitic element is used, the optical receiving module has sufficient response characteristics for a higher transmission speed and realizes impedance matching with a preamplifier circuit in the subsequent stage. Is in the provision of.

  In the present embodiment, it has been described that the wiring connecting the light receiving element and the preamplifier circuit is designed to approximate the coplanar transmission line so as to be impedance matched with the preamplifier circuit in the subsequent stage. In this way, from the viewpoint of a high-frequency transmission line, when it is designed to have sufficient response characteristics for a higher transmission speed, and to perform impedance matching with a preamplifier circuit in the subsequent stage. Good. Examples of the high-frequency transmission line include a strip transmission line, in addition to the coplanar transmission line.

  In this embodiment, the optical receiver module provided in the optical receiver that transmits a signal at a transmission rate of 40 Gbps such as 43 Gbps has been described, but it goes without saying that the transmission rate is not limited to the 40 Gbps band. Further, the transmission code format is not limited to any one. As described in Patent Document 3, resistance and impedance may be further connected on the carrier.

  DESCRIPTION OF SYMBOLS 1 Light receiving element, 2 carrier, 3 Film wiring for right reference voltage, 4 Film wiring for left reference voltage, 5 Bias power supply electrode, 6 Reference voltage electrode, 7 Base part, 8 Film wiring for signal voltage, 9 Bias Film wiring for voltage, 10 preamplifier circuit, 11 signal voltage terminal, 12 reference voltage terminal, 14, 15, 16, 17 pattern connection wire, 20 light receiving element bias circuit, 21 light receiving element bias power supply, 22 relay Line, 25 Optical system parts, 30 optical input, 100 optical receiving module.

Claims (5)

A light receiving element that converts an input optical signal into an electrical signal;
A base portion having a stepped portion in which the lower step surface, the rising surface and the upper step surface are connected in this order;
A back surface disposed along the rising surface, a front surface located on the opposite side of the back surface, and a bottom surface extending between the lower edges of the back surface and the front surface and disposed along the lower surface, A carrier located on the opposite side of the bottom surface and having a top surface extending between upper edges of the back surface and the front surface;
A preamplifier circuit disposed on the upper surface and amplifying the electrical signal;
An optical receiver module comprising:
The length between the upper edge of each of the back surface and the front surface of the carrier is shorter than the length between the lower edge of each of the back surface and the front surface,
Reference voltage membrane wiring is provided across each of the front surface and the top surface,
Further, a signal voltage film-like wiring extends from the signal voltage terminal of the light receiving element, and is provided across each of the front surface and the upper surface,
Of the reference voltage film-like wiring and the signal voltage film-like wiring, a part located on a part of the upper surface, respectively, and a reference voltage terminal and a signal voltage terminal provided in the preamplifier circuit, Each electrically connected,
An optical receiver module. The optical receiver module according to claim 1,
The length between the upper edge of each of the back surface and the front surface is determined by a frequency response characteristic;
Further, on the upper surface, the length of the signal voltage film-like wiring and the interval between the reference voltage film-like wiring and the signal voltage film-like wiring are about the back edge and the upper edge direction of the front surface. Determined to match the impedance of the preamplifier circuit,
An optical receiver module. The optical receiver module according to claim 1 or 2, wherein
The reference voltage film-like wiring extends to the signal voltage film-like wiring side with respect to a portion of the reference voltage film-like wiring located on the front surface. Having an extension,
An optical receiver module. The optical receiver module according to claim 3, wherein
The reference voltage film wiring and the signal voltage film wiring are electrically insulated by cutting.
An optical receiver module.   An optical receiver comprising the optical receiver module according to claim 1.

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