阅读说明：本技术 一种400g lr4光接收次组件结构及其制造方法 (400G LR4 light receiving subassembly structure and manufacturing method thereof ) 是由 黃劲威 周书刚 陈正刚 赵永成 黄敏华 陈斌 于 2021-01-30 设计创作，主要内容包括：本发明涉及一种400G LR4光接收次组件结构及其制造方法,该结构包括光分波器、可对光进行设定角度反射的阵列式耦合透镜、阵列式光电二极管、键合金丝、跨阻放大器和装配印刷电路板,所述光分波器将合束在一起的LR4平行光,分为独立的四路平行光,四路平行光经过所述阵列式耦合透镜,光转过设定角度并汇聚到所述阵列式光电二极管的光敏面,所述阵列式光电二极管将光信号转化为电信号,所述电信号通过所述键合金丝传输到所述跨阻放大器,所述跨阻放大器将小电流信号转化为差分电压信号输出到所述装配印刷电路板上。该结构不仅有利于优化信号,而且简化了制造过程。(The invention relates to a 400G LR4 light receiving subassembly structure and a manufacturing method thereof, the structure comprises an optical branching filter, 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 branching filter divides LR4 parallel light bundled together 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 to be output to the assembly printed circuit board. This configuration not only facilitates signal optimization, but also simplifies the manufacturing process.)

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.

8. The method of any of claims 1-7, wherein the method comprises the steps of:

1) surface mounting: attaching the array type photodiode to an assembly printed circuit board by using silver adhesive, and baking and fixing; attaching the transimpedance amplifier to the assembly printed circuit board by using silver adhesive, and baking and fixing;

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; welding the transresistance amplifier pad to a pad of the assembly printed circuit board 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.

Technical Field

The invention belongs to the field of optical fiber communication, and particularly relates to a 400G LR4 optical receiving subassembly structure and a manufacturing method thereof.

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

The invention aims to provide a 400G LR4 light receiving sub-assembly structure and a manufacturing method thereof, wherein the structure is not only beneficial to optimizing signals, but also simplifies the manufacturing process.

In order to achieve the purpose, the invention adopts the technical scheme that: 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.

The invention also provides a manufacturing method of the 400G LR4 light receiving sub-assembly structure, which comprises the following steps:

1) surface mounting: attaching the array type photodiode to an assembly printed circuit board by using silver adhesive, and baking and fixing; attaching the transimpedance amplifier to the assembly printed circuit board by using silver adhesive, and baking and fixing;

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; welding the transresistance amplifier pad to a pad of the assembly printed circuit board 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.

Compared with the prior art, the invention has the following beneficial effects: the invention reduces one-step mounting action, the PD is directly attached on the PCBA instead of being attached on the PCBA after being attached into the COC, and meanwhile, one-step gold wire welding action is reduced, and the PD is directly welded on the TIA. The invention reduces one-time electrical switching, reduces the parasitic capacitance and inductance of signal transmission and optimizes signals.

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 in an embodiment of the invention.

Detailed Description

The invention is described in further detail below with reference to the figures and the 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 ranges from 2.5 to 4.5mm, the length M of the horizontal side ranges from 1mm to 2mm, and the vertical sideThe length N is 1mm < N < 2mm, and the included angle between the bevel edge and the horizontal planeβIs 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 invention also provides a manufacturing method of the 400G LR4 light receiving sub-assembly structure, which comprises the following steps:

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.

The above are preferred embodiments of the present invention, and all changes made according to the technical scheme of the present invention that produce functional effects do not exceed the scope of the technical scheme of the present invention belong to the protection scope of the present invention.