CN216354198U - Optical communication receiving module and optical communication module - Google Patents

Abstract

The utility model provides an optical communication receiving component and an optical communication module, which can improve the anti-electromagnetic crosstalk performance of the optical communication receiving component. The optical communication receiving assembly comprises a substrate, and a photoelectric receiver packaging structure and a photoelectric signal amplifier packaging structure which are arranged on the surface of one side of the substrate; the photoelectric receiver packaging structure is electrically connected with the photoelectric signal amplifier packaging structure, wherein an electromagnetic shielding structure is arranged on the photoelectric receiver packaging structure, the grounding end of the photoelectric signal amplifier packaging structure is electrically connected with the electromagnetic shielding structure, and the electromagnetic shielding structure is electrically connected with the grounding electrode on the substrate. By adopting the special anti-interference electromagnetic shielding structure, the influence of external electromagnetic crosstalk on the sensitivity of the optical communication receiving assembly is reduced.

Description

Optical communication receiving module and optical communication module

Technical Field

The present invention relates to the field of optical communications, and in particular, to an optical communication receiving module and an optical communication module having the same.

Background

In the high-speed optical communication module, the high-speed optical communication transmitting module comprises a high-speed optical communication transmitting component and a high-speed optical communication receiving component, the high-speed optical communication transmitting component comprises a DSP (Digital Signal Processing) chip and a CDR (Clock Data Recovery) chip, and after the high-speed electrical signals are processed by the DSP chip and the CDR chip in the optical communication transmitting component, the laser is driven by a driver. The optical communication receiving component comprises a photoelectric receiver and a trans-impedance amplifier, wherein the trans-impedance amplifier is used for amplifying a photoelectric signal output by the photoelectric receiver, and then the photoelectric signal is sent to a system after being processed by a DSP chip and a CDR chip. Since the signal driving the laser is typically a signal above 1.5V, while the photocurrent in the optical communication receiving component is relatively small (almost near its sensitive point), typically only a few tens of microamperes. In this case, if the photocurrent is disturbed by the outside, the performance of the entire optical communication receiving module is degraded. For high speed signals, radiation is highly likely to occur, and thus this form of crosstalk problem is persistent, and as the single channel rate increases, the impact of the crosstalk problem on the overall performance and sensitivity of the optical communications receiving component increases.

Since the optical communication receiving component is usually in a complicated electromagnetic radiation environment, electromagnetic crosstalk of the electromagnetic radiation to the communication signal of the optical communication receiving component cannot be ignored. How to reduce the electromagnetic crosstalk of the optical communication receiving assembly is a problem to be solved urgently in the industry.

SUMMERY OF THE UTILITY MODEL

In order to overcome the defects of the prior art, an object of the present invention is to provide an optical communication receiving assembly and an optical module having the same, so as to solve the problem that the optical communication receiving assembly in the prior art is easily interfered by an external electromagnetic field.

The purpose of the utility model is realized by adopting the following technical scheme:

the present invention provides an optical communication receiving module, comprising: the photoelectric signal amplifier comprises a substrate, and a photoelectric receiver packaging structure and a photoelectric signal amplifier packaging structure which are arranged on the surface of one side of the substrate; the photoelectric receiver packaging structure is electrically connected with the photoelectric signal amplifier packaging structure, wherein an electromagnetic shielding structure is arranged on the photoelectric receiver packaging structure, the grounding end of the photoelectric signal amplifier packaging structure is electrically connected with the electromagnetic shielding structure, and the electromagnetic shielding structure is electrically connected with the grounding electrode on the substrate.

Optionally, the optical receiver package includes a photodiode and the optical signal amplifier package includes a transimpedance amplifier having two cathode pins and one anode pin, the photodiode having a cathode and an anode, the cathode pin of the transimpedance amplifier being electrically connected to the cathode of the photodiode by a bonding wire, the anode pin of the transimpedance amplifier being electrically connected to the anode of the photodiode by a bonding wire.

Optionally, the electromagnetic shielding structure is electrically insulated from both the cathode and the anode of the photodiode.

Optionally, the electromagnetic shielding structure is a metal layer disposed in the same layer as the cathode and the anode of the photodiode, and a gap is provided between the electromagnetic shielding structure and the cathode and the anode of the photodiode.

Optionally, the electromagnetic shielding structure is a U-shaped metal layer, and the U-shaped metal layer surrounds the cathode and the anode of the photodiode.

Optionally, the electromagnetic shielding structure is a metal layer disposed in a different layer from the cathode and the anode of the photodiode, wherein, in a direction perpendicular to the substrate surface, the metal layer constituting the electromagnetic shielding structure has an overlapping region with the cathode and/or the anode of the photodiode, and an insulating layer is disposed between the metal layer and the cathode and/or the anode.

Optionally, the electromagnetic shielding structure is electrically connected to the ground electrode on the substrate through a bonding wire to form a ground loop.

Optionally, the optoelectronic receiver package structure includes a plurality of through holes penetrating through the optoelectronic receiver package structure, conductive materials are filled in the plurality of through holes, and the electromagnetic shielding structure is connected to the plurality of through holes and electrically connected to the ground electrode on the substrate through the conductive materials in the plurality of through holes.

Optionally, the gap between the electromagnetic shielding structure and the cathode and the anode of the photodiode is less than a predetermined threshold.

On the other hand, the embodiment of the utility model also provides an optical communication module, which comprises a light emitting unit and a light receiving unit, wherein the light receiving unit comprises any one of the optical communication receiving assemblies.

Compared with the prior art, the optical communication receiving assembly and the optical communication module with the same provided by the embodiment of the utility model have the advantages that the special anti-interference electromagnetic shielding structure is adopted, so that the grounding electrode can absorb an external electromagnetic field, the signal interference of the external electromagnetic field on the cathode and the anode of the photoelectric receiver is avoided, and the influence of external electromagnetic crosstalk on the sensitivity of the optical communication receiving assembly is reduced.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a top view of an optical communication receiving module provided in the prior art;

fig. 2 is a schematic circuit diagram of an optical communication receiving module according to an embodiment of the present invention;

fig. 3 is a top view of an optical communication receiving module according to an embodiment of the present invention;

fig. 4 is an enlarged schematic view of a package structure of the optical receiver in fig. 3;

FIG. 5 is a schematic cross-sectional view taken along line A-A' of FIG. 4;

fig. 6 is an enlarged schematic view of a further optoelectronic receiver package;

FIG. 7 is a schematic cross-sectional view taken along line B-B' of FIG. 6;

FIG. 8 is a schematic view of a further cross-sectional configuration taken along line B-B' of FIG. 6;

FIG. 9 is a schematic view of a further cross-sectional configuration taken along line B-B' of FIG. 6;

fig. 10 is a top view of another optical communication receiving module provided in an embodiment of the present invention;

FIG. 11 is a schematic cross-sectional view taken along line C-C' of FIG. 10;

fig. 12 is a schematic structural diagram of an optical communication module according to an embodiment of the present invention.

Detailed Description

The foregoing description is only an overview of the technical solutions of the present invention, and in order to make the technical means of the present invention more clearly understood, the present invention may be implemented in accordance with the content of the description, and in order to make the above and other objects, features, and advantages of the present invention more clearly understood, the following preferred embodiments are described in detail with reference to the accompanying drawings.

Fig. 1 is a top view of an optical communication receiving module provided in the prior art. As shown in fig. 1, an optical communication receiving component in the prior art includes an optical receiver 101, a transimpedance amplifier 102, and a backplane 104 for carrying the optical receiver 101 and the transimpedance amplifier 102. The photoelectric receiver 101 is configured to convert an optical signal into an electrical signal, an anode of the photoelectric receiver 101 is electrically connected to an input end of the transimpedance amplifier 102 through a connection lead, a cathode of the photoelectric receiver 101 is configured to be connected to a bias power supply VPD, the transimpedance amplifier 102 is configured to amplify the electrical signal output by the photoelectric receiver 101, and a ground terminal on the transimpedance amplifier 102 is electrically connected to a ground electrode GND on the bottom plate 104 through a connection lead.

In the prior art, the package of the photoreceiver 101 and the transimpedance amplifier 102 in the optical communication receiving component generally adopts a package manner of a wire bonding technology, and usually, the ground terminals 1021 on both sides of the transimpedance amplifier 102 are connected to the ground electrode on the bottom board 104 through connecting wires (gold wires), so that the transimpedance amplifier 102 is connected to the external ground, and the inductance of the optical communication receiving component is reduced and the GND potential is stabilized. However, in the package method using the wire bonding technology, both the electrodes on the optoelectronic receiver 101 and the connecting wires (gold wires) are very susceptible to the electromagnetic field interference of the external environment, and the longer the length of the connecting wires (gold wires), the higher the signal interference strength. If the problem of the interference is to be completely improved, the length of the gold wire needs to be shortened by using a flip-chip bonding technique, however, the flip-chip bonding technique is complicated and needs to be implemented by providing a matching external bonding pad on the optical receiver 101. Therefore, it has been a challenge to design an optical communication receiving module to reduce crosstalk of external electromagnetic field interference in the optical communication module to the optical communication receiving module.

In order to solve the problems, the utility model provides a scheme of an anti-electromagnetic crosstalk optical communication receiving assembly, and the influence of external electromagnetic crosstalk on the sensitivity of the optical communication receiving assembly is reduced by adopting a special anti-interference electromagnetic shielding structure.

Fig. 2 is a schematic circuit diagram of an optical communication receiving module according to an embodiment of the present invention. As shown in fig. 2, an optical communication receiving component 100 according to an embodiment of the present invention includes a photo-electric receiver 1 and a transimpedance amplifier 2 that are electrically connected to each other, a negative electrode of the photo-electric receiver 1 is electrically connected to a pin terminal of the transimpedance amplifier 2, a positive electrode of the photo-electric receiver 1 is electrically connected to a pin terminal of the transimpedance amplifier 2, and the photo-electric receiver 1 is configured to perform photoelectric conversion and generate an electrical signal. Because the current signal output by the photoelectric receiver 1 is weak, the electrical signal output by the photoelectric receiver 1 needs to be amplified by the transimpedance amplifier 2, and the transimpedance amplifier 2 outputs the amplified electrical signal.

Fig. 3 is a top view of an optical communication receiving module according to an embodiment of the present invention. As shown in fig. 2 and 3, in the present embodiment, the optical communication receiving module includes: the photoelectric signal amplifier comprises a substrate, and a photoelectric receiver packaging structure and a photoelectric signal amplifier packaging structure which are arranged on the surface of one side of the substrate; the photoelectric receiver packaging structure is electrically connected with the photoelectric signal amplifier packaging structure, wherein an electromagnetic shielding structure is arranged on the photoelectric receiver packaging structure, the grounding end of the photoelectric signal amplifier packaging structure is electrically connected with the electromagnetic shielding structure, and the electromagnetic shielding structure is electrically connected with the grounding electrode on the substrate.

Specifically, the photo receiver and the transimpedance amplifier may be a PD chip 10 (i.e., a photo receiver package) and a TIA chip 20 (i.e., a photo signal amplifier package), respectively, and exemplarily, the TIA chip 20 includes two cathode pins (denoted by PINK in the figure) and one anode pin (denoted by PINA in the figure), the PD chip 10 includes two cathodes 11, one anode 12, and a light sensing portion 13, the two cathode pins PINK of the transimpedance amplifier are electrically connected to the two cathodes 11 of the photodiode through bonding wires, respectively, the anode pin PINA of the transimpedance amplifier is electrically connected to the anode 12 of the photodiode through bonding wires, in other embodiments, the TIA chip 20 may also include one cathode pin and one anode pin, which is not limited in this respect. The optical communication receiving assembly 100 further includes a substrate 40 for carrying the PD chip 10 and the TIA chip 20, and a conductive layer 41 disposed on the substrate 40, wherein the conductive layer 41 can be used as a ground electrode. The PD chip 10 and the TIA chip 20 are both fixed on the surface of the same side of the substrate 40.

Illustratively, the TIA chip 20 includes two ground terminals 21, an electromagnetic shielding structure 30 is disposed on a surface of the PD chip 10 on a side away from the substrate 40, the electromagnetic shielding structure 30 is a conductive metal film layer, and the metal film layer may be copper (Cu) or gold (Au), but is not limited thereto. The two ground terminals 21 on the TIA chip 20 are electrically connected to the electromagnetic shielding structure 30 through connecting leads (bonding wires), and the electromagnetic shielding structure 30 is further electrically connected to the ground electrode on the substrate 40. Therefore, in this embodiment, the path of the ground signal is the ground terminal 21- > the electromagnetic shielding structure 30- > the ground electrode of the TIA chip 20, and this embodiment can provide a complete signal ground loop, which is beneficial to the absorption of the ground electrode to the external electromagnetic field, not only avoiding the signal interference of the external electromagnetic field to the cathode 11 and the anode 12 on the PD chip 10, but also isolating and absorbing the electromagnetic crosstalk originating from the ground electrode (the substrate GND) or the transimpedance amplifier of the substrate 40, and improving the performance of resisting the electromagnetic crosstalk.

Further, in order to avoid crosstalk of the electromagnetic shielding structure 30 to signals on the cathode 11 and the anode 12 of the PD chip 10, the electromagnetic shielding structure 30 is electrically insulated from both the cathode 11 and the anode 12 of the photodiode.

Fig. 4 is an enlarged schematic view of a package structure of the optical receiver in fig. 3, and fig. 5 is a schematic view of a cross-sectional view taken along a-a' in fig. 4. Alternatively, as shown in fig. 4-5, in one embodiment, the electromagnetic shielding structure 30 is a metal layer disposed in the same layer as the cathode 11 and the anode 12 of the photodiode, i.e., the electromagnetic shielding structure 30 and the cathode 11 and the anode 12 may be disposed on the same substrate film layer. In order to maintain electrical insulation, the electromagnetic shielding structure 30 is spaced apart from the cathode 11 and the anode 12. For example, for simplification of the manufacturing process, the same film layer manufacturing process may be used as the cathode 11 and the anode 12, and the required electromagnetic shielding structure 30 is obtained by patterning and etching, and optionally, the gap between the electromagnetic shielding structure and the cathode and the anode of the photodiode is smaller than a predetermined threshold, which may be set in combination with the actual process.

Alternatively, the electromagnetic shielding structure 30 may be U-shaped, and the electromagnetic shielding structure 30 is disposed around the cathode 11 and the anode 12 in the photoelectric receiver to form a semi-enclosed wrapping structure, so as to isolate the cathode 11 and the anode 12 in the photoelectric receiver from an external electromagnetic field, and at the same time, the electromagnetic shielding structure 30 is electrically connected to the ground electrode on the substrate 40 to provide ground connection, and serves as a ground bridge to electrically connect the ground terminal of the transimpedance amplifier to the ground electrode on the substrate 40.

Fig. 6 is an enlarged schematic view of another photoelectric receiver package structure, fig. 7 is a schematic view of a cross-sectional structure taken along B-B ' in fig. 6, fig. 8 is a schematic view of another cross-sectional structure taken along B-B ' in fig. 6, and fig. 9 is a schematic view of another cross-sectional structure taken along B-B ' in fig. 6. As shown in fig. 6 to 9, in another embodiment, the electromagnetic shielding structure 30 is a metal layer disposed in a different layer from the cathode 11 and the anode 12 of the photodiode, and an insulating layer 15 is disposed between the metal layer and the cathode 11 and the anode 12. As shown in fig. 7-9, an insulating layer 15 is disposed between the electromagnetic shielding structure 30 and the cathode 11 and the anode 12 of the photodiode, so that the electromagnetic shielding structure 30 overlaps with the cathode 11 and/or the anode 12 of the photodiode in a direction perpendicular to the substrate, so as to better shield the interference of external electromagnetic signals on the cathode 11 and the signals of the photoelectric receiver.

Optionally, in order to better shield the interference of the external electromagnetic signal on the signal of the photoelectric receiver, on the PD chip 10, regions except for the connection terminal exposing the cathode 11, the connection terminal exposing the anode 12, and the light sensing portion 13 of the photoelectric receiver may be covered with the metal layer, and the metal layer is electrically connected to the ground electrode on the substrate 40.

Illustratively, as shown in fig. 7, in a direction perpendicular to the plane of the substrate 40, the metal layer constituting the electromagnetic shielding structure 30 overlaps both the cathode 11 and the anode 12 of the photoreceiver; as shown in fig. 8, in a direction perpendicular to the plane of the substrate 40, the metal layer constituting the electromagnetic shielding structure 30 overlaps only the cathode 11 of the photoreceiver; as shown in fig. 9, the metal layer constituting the electromagnetic shielding structure 30 overlaps with part of the cathode 11 of the photoreceiver and overlaps with the anode 12 in a direction perpendicular to the plane of the substrate 40. Of course, other embodiments are possible as long as the connection terminal of the cathode 11, the connection terminal of the anode 12, and the region where the light sensing section 13 is located can be exposed. The embodiments of the utility model are not limited thereto.

Fig. 10 is a top view of another optical communication receiving assembly according to an embodiment of the present invention, and fig. 11 is a schematic cross-sectional view taken along line C-C' in fig. 10. As shown in fig. 10 to fig. 11, in the present embodiment, the package of the PD chip 10 is implemented by a Through Silicon Via (TSV) technology, and the TSV technology implements vertical electrical interconnection of the TSV by filling conductive substances such as copper, tungsten, and polysilicon.

Illustratively, the PD chip 10 includes a plurality of vias 14 penetrating through the PD chip 10, and the plurality of vias 14 are filled with a conductive material, which may be a conductive substance such as copper, tungsten, polysilicon, or the like. The electromagnetic shielding structure 30 covers the plurality of through holes 14, and the electromagnetic shielding structure 30 is connected to the plurality of through holes 14 and electrically connected to the ground electrode on the substrate 40 through the conductive material in the plurality of through holes 14. By adopting the through silicon via technology, the through silicon via can be directly electrically connected with the grounding electrode on the substrate 40 through vertical interconnection, the connecting lead between the electromagnetic shielding structure 30 and the substrate 40 can be eliminated, the signal delay caused by the arrangement of the connecting lead is reduced, the capacitance/inductance is reduced, the low power consumption and high-speed communication of the PD chip 10 are realized, the bandwidth is increased, and the integration miniaturization of the device is realized.

Specifically, a plurality of through holes 14 penetrating through the PD chip 10 may be formed in the PD chip 10 so as to avoid an electrode area of the photo receiver, the through holes 14 may be formed by laser etching and deep reactive ion etching, any one or a combination of conductive materials such as polysilicon, copper, tungsten, and a polymer conductor is filled in the through holes 14, and the conductive materials are filled in the through holes 14 by processes such as electroplating, sputtering, chemical vapor deposition, and polymer coating, so as to achieve vertical electrical interconnection of the through holes 14. Illustratively, as shown in fig. 11, a conductive layer 41 may be provided on the substrate 40 as a ground electrode, and the ground electrode may be connected to the outside through a specific pin.

In addition, the optical receiver in the optical communication receiving component provided by the embodiment of the utility model can be applied to an ordinary optical receiver by using the photodiode, and can also be applied to an optical receiver requiring low noise by using the avalanche photodiode.

Fig. 12 is a schematic structural diagram of an optical communication module according to an embodiment of the present invention. As shown in fig. 12, the optical communication module 1000 includes a light emitting unit and a light receiving unit, and the light receiving unit includes the optical communication receiving assembly 100 disclosed in any of the above embodiments.

As can be seen from the above, in the optical communication receiving assembly and the optical communication module having the same provided in the embodiments of the present invention, the optical receiver packaging structure is provided with the electromagnetic shielding structure, the ground terminal of the optical-electrical signal amplifier packaging structure is electrically connected to the electromagnetic shielding structure, and the electromagnetic shielding structure is electrically connected to the ground electrode on the substrate. The photoelectric receiver is beneficial to the absorption of the grounding electrode to an external electromagnetic field, and avoids the signal interference of the external electromagnetic field to the cathode and the anode on the photoelectric receiver, so that the sensitivity of the optical communication receiving assembly is improved.

It should be understood that although the present description refers to embodiments, not every embodiment contains only a single technical solution, and such description is for clarity only, and those skilled in the art should make the description as a whole, and the technical solutions in the embodiments can also be combined appropriately to form other embodiments understood by those skilled in the art.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not intended to limit the scope of the present invention, which is defined by the appended claims.

Claims (10)

1. An optical communication receiving assembly, comprising: the photoelectric signal amplifier comprises a substrate, and a photoelectric receiver packaging structure and a photoelectric signal amplifier packaging structure which are arranged on the surface of one side of the substrate;

the photoelectric receiver packaging structure is electrically connected with the photoelectric signal amplifier packaging structure, wherein an electromagnetic shielding structure is arranged on the photoelectric receiver packaging structure, the grounding end of the photoelectric signal amplifier packaging structure is electrically connected with the electromagnetic shielding structure, and the electromagnetic shielding structure is electrically connected with the grounding electrode on the substrate.

2. The optical communication receiving component of claim 1, wherein the photoreceiver package comprises a photodiode and the optoelectronic signal amplifier package comprises a transimpedance amplifier having a cathode pin and an anode pin, the photodiode having a cathode and an anode, the cathode pin of the transimpedance amplifier being electrically connected to the cathode of the photodiode by a bonding wire, the anode pin of the transimpedance amplifier being electrically connected to the anode of the photodiode by a bonding wire.

3. The optical communication receiving module of claim 2,

the electromagnetic shielding structure is electrically insulated from both the cathode and the anode of the photodiode.

4. The optical communication receiving module of claim 3, wherein the electromagnetic shielding structure is a metal layer disposed in a same layer as the cathode and the anode of the photodiode, and wherein the electromagnetic shielding structure has a gap with the cathode and the anode of the photodiode.

5. The optical communication receiving module of claim 4, wherein the electromagnetic shielding structure is a U-shaped metal layer, and the U-shaped metal layer surrounds the cathode and the anode of the photodiode.

6. The optical communication receiving module according to claim 3, wherein the electromagnetic shielding structure is a metal layer provided as a separate layer from the cathode and the anode of the photodiode, wherein the metal layer constituting the electromagnetic shielding structure has an overlapping region with the cathode and/or the anode of the photodiode in a direction perpendicular to the upper surface of the substrate, and an insulating layer is provided between the metal layer and the cathode and/or the anode.

7. The optical communication receiving module as claimed in any one of claims 1-6, wherein the electromagnetic shielding structure is electrically connected to a ground electrode on the substrate by a bonding wire to form a ground loop.

8. The optical communication receiving assembly of any one of claims 1-6, wherein the optical receiver package structure comprises a plurality of vias extending through the optical receiver package structure, the plurality of vias being filled with a conductive material, the electromagnetic shielding structure being connected to the plurality of vias and electrically connected to a ground electrode on the substrate through the conductive material in the plurality of vias.

9. The optical communication receiving assembly of claim 4, wherein the gap between the electromagnetic shielding structure and the cathode and the anode of the photodiode is less than a predetermined threshold.

10. An optical communication module comprising a light emitting unit and a light receiving unit, wherein the light receiving unit comprises the optical communication receiving assembly according to any one of claims 1 to 9.

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