CN214097892U - 400G LR4 light receiving subassembly structure - Google Patents

Abstract

The utility model relates to a 400G LR4 light reception subassembly structure, including the optical branching filter, can carry out array coupling lens, array photodiode, bonding gold wire, transimpedance amplifier and the assembly printed circuit board of setting for the angle reflection to light, the optical branching filter will close LR4 parallel light of restrainting together, divide into independent four ways parallel light, and four ways parallel light passes through array coupling lens, light are changeed the setting for the angle and are assembled array photodiode's photosurface, array photodiode turns into the light signal the signal of telecommunication, the signal of telecommunication passes through the bonding gold wire transmits transimpedance amplifier, transimpedance amplifier turns into the differential voltage signal with the undercurrent signal and exports assembly printed circuit board is last. This configuration not only facilitates signal optimization, but also simplifies the manufacturing process.

Description

400G LR4 light receiving subassembly structure

Technical Field

The utility model belongs to the fiber communication field, concretely relates to 400G LR4 light receiving subassembly structure.

Background

In the prior art, the light receiving sub-device mainly comprises an optical demultiplexer Demux, an Array coupling Lens Array, an Array photodiode PD Array, a gold bonding Wire Golden Wire, a photodiode pad PD Submount, a transimpedance amplifier TIA and an assembly printed circuit board PCBA, and the structure of the light receiving sub-device is shown in fig. 1. The problems existing in the prior art are as follows: based on 400G signal transmission, the signal bandwidth required to be transmitted by each channel is close to 53GHZ, and the electrical signal switching of PD Submount can introduce more parasitic capacitance and inductance, so that the signal bandwidth is reduced, noise is introduced, and the sensitivity of a corresponding receiving end is reduced.

Disclosure of Invention

An object of the utility model is to provide a 400G LR4 light-receiving subassembly structure, this structure not only is favorable to optimizing the signal, has simplified manufacturing process moreover.

In order to achieve the above object, the utility model adopts the following technical scheme: A400G LR4 light receiving subassembly structure comprises an optical splitter, an array coupling lens capable of reflecting light at a set angle, an array photodiode, a gold bonding wire, a transimpedance amplifier and an assembly printed circuit board, wherein the optical splitter divides combined LR4 parallel light into four independent paths of parallel light, the four paths of parallel light pass through the array coupling lens, the light passes through the set angle and is converged on a photosensitive surface of the array photodiode, the array photodiode converts an optical signal into an electrical signal, the electrical signal is transmitted to the transimpedance amplifier through the gold bonding wire, and the transimpedance amplifier converts a small current signal into a differential voltage signal and outputs the differential voltage signal to the assembly printed circuit board.

Furthermore, the array coupling lens is an array coupling lens capable of reflecting light by 90 degrees, and the array coupling lens couples four paths of parallel light into convergent light, reflects the convergent light by 90 degrees and emits the convergent light to the array photodiode.

Furthermore, the array coupling lens is of a right-angle triangular prism structure, the value range of the width L of the array coupling lens is 2.5-L < 4.5mm, the value range of the horizontal side length M is 1 mm-M < 2mm, the value range of the vertical side length N is 1 mm-N < 2mm, and the included angle between the inclined side and the horizontal plane is 1 mm-NβIs in the range of 40 DEG < (R) >β＜50°。

Further, the optical splitter splits the parallel light of four different wavelengths combined by LR4 into four parallel lights of independent wavelengths.

Furthermore, the wavelengths of the four paths of parallel light are 1295.56nm, 1300.05nm, 1304.58nm and 1309.14nm respectively, and the interval of the four paths of parallel light is 750 um.

Further, the array type photodiode converts the optical signal into a small current signal and outputs the small current signal through the bonding pad.

Furthermore, the gold bonding wire electrically connects the array type photodiode with the trans-impedance amplifier.

Compared with the prior art, the utility model discloses following beneficial effect has: the utility model discloses can reduce one step and paste the dress action, need not paste to become on COC pastes PCBA again, but direct PD is attached on PCBA, has reduced one step of gold wire welding action simultaneously, and PD lug weld is on TIA. The utility model discloses having reduced once electric switching, signal transmission's parasitic capacitance and inductance reduce, and the signal can be optimized more.

Drawings

Fig. 1 is a schematic view of a prior art structure.

Fig. 2 is a schematic structural diagram of an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of an array-type coupling lens according to an embodiment of the present invention.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 2, this embodiment provides a 400G LR4 optical subassembly structure, which includes an optical splitter 1, an array coupling lens 2 capable of reflecting light by 90 °, an array photodiode 3, a gold bonding wire 4, a transimpedance amplifier 5, and an assembly printed circuit board 6, where the optical splitter 1 splits LR4 parallel light bundled together into four independent parallel lights, the four parallel lights pass through the array coupling lens 2, turn by 90 ° and converge on a photosensitive surface of the array photodiode 3, the array photodiode 3 converts an optical signal into an electrical signal, the electrical signal is transmitted to the transimpedance amplifier 5 through the gold bonding wire 4, and the transimpedance amplifier 5 converts a small current signal into a differential voltage signal and outputs the differential voltage signal to the assembly printed circuit board 6.

The array coupling lens 2 couples the four paths of parallel light into convergent light, reflects the convergent light by 90 degrees and emits the convergent light to the array photodiode 3. As shown in fig. 3, the array-type coupling lens 2 is a right-angled triangular prism structure, the width L of the array-type coupling lens is in a range of 2.5 < L < 4.5mm, the horizontal side length M is in a range of 1mm < M < 2mm, the vertical side length N is in a range of 1mm < N < 2mm, and an included angle between the oblique side and the horizontal plane isβIs in the range of 40 DEG < (R) >β< 50 deg. The value ranges of the parameters of the mirror circle 21 butted by the array coupling lens 2 and the array photodiode 3 are as follows: radius < 0.5 mm < 0.6mm, Thickness < 0.14mm < 0.13 mm, Index < 1.51 < 1.52, -Concic < 0.49 mm.

The optical splitter 1 splits parallel lights of four different wavelengths, which are combined together by LR4, into four parallel lights of independent wavelengths. In this embodiment, the wavelengths of the four parallel lights are 1295.56nm, 1300.05nm, 1304.58nm and 1309.14nm, respectively, and the interval of the four parallel lights is 750 um.

The array type photodiode 3 converts the optical signal into a small current signal and outputs the small current signal through a bonding pad.

The gold bonding wire 4 electrically connects the array photodiode 3 with the transimpedance amplifier 5.

The utility model discloses a manufacturing approach of 400G LR4 light-receiving subassembly structure does: 1) surface mounting: attaching the array type photodiode to the assembly printed circuit board by using silver adhesive, and baking and fixing the array type photodiode in an oven; the trans-impedance amplifier is attached to the printed circuit board by silver glue and then is put into an oven to be baked and fixed. 2) Gold wire bonding: welding a trans-impedance amplifier bonding pad from an array type photodiode bonding pad by using overturning routing and bonding gold wire welding; and welding the chip from the trans-impedance amplifier pad to a mounting printed circuit board pad by using gold bonding wire welding. 3) Array coupling lens coupling: the array type coupling lens couples the four paths of parallel light, the four paths of light are balanced and coupled to the maximum during coupling, and then the array type coupling lens is fixed by glue.

Above is the utility model discloses a preferred embodiment, all rely on the utility model discloses the change that technical scheme made, produced functional action does not surpass the utility model discloses during technical scheme's scope, all belong to the utility model discloses a protection scope.

Claims (7)

1. A400G LR4 light receiving subassembly structure is characterized by comprising an optical splitter, an array coupling lens capable of reflecting light at a set angle, an array photodiode, a gold bonding wire, a transimpedance amplifier and an assembly printed circuit board, wherein the optical splitter divides combined LR4 parallel light into four independent parallel lights, the four parallel lights pass through the array coupling lens, the light passes through the set angle and is converged on a photosensitive surface of the array photodiode, the array photodiode converts an optical signal into an electrical signal, the electrical signal is transmitted to the transimpedance amplifier through the gold bonding wire, and the transimpedance amplifier converts a small current signal into a differential voltage signal and outputs the differential voltage signal to the assembly printed circuit board.

2. The structure of claim 1, wherein the arrayed coupling lens is an arrayed coupling lens capable of reflecting light by 90 °, and the arrayed coupling lens couples four parallel lights into a converging light, and reflects the converging light by 90 ° to be incident on the arrayed photodiode.

3. The structure of claim 1, wherein the array-type coupling lens is a right-angled triangular prism, the width L of the array-type coupling lens ranges from 2.5 < L < 4.5mm, the length M of the horizontal side ranges from 1mm < M < 2mm, the length N of the vertical side ranges from 1mm < N < 2mm, and the included angle between the oblique side and the horizontal plane is 1mm < N < 2mmβIs in the range of 40 DEG < (R) >β＜50°。

4. The structure of claim 1, wherein the optical splitter splits parallel light of four different wavelengths into four independent wavelengths, wherein the four independent wavelengths are parallel light of LR 4.

5. The structure of claim 4, wherein the wavelengths of the four parallel lights are 1295.56nm, 1300.05nm, 1304.58nm and 1309.14nm, and the interval of the four parallel lights is 750 um.

6. The structure of claim 1, wherein the arrayed photodiode array converts light signals into low current signals for output via the bonding pads.

7. The structure of claim 1, wherein the gold bonding wires electrically connect the arrayed photodiode to the transimpedance amplifier.

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