阅读说明：本技术 一种50g pam4发射激光器同轴封装结构及方法 (Coaxial packaging structure and method for 50G PAM4 emission laser ) 是由 黃劲威 周书刚 赵永成 陈正刚 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50G PAM4发射激光器同轴封装结构及方法,该封装结构包括激光二极管芯片、汇聚耦合透镜帽、激光二极管垫片、片上芯片垫片、键合金丝、管座和高频柔性线路板,所述激光二极管芯片固定于激光二极管垫片上形成片上芯片,所述片上芯片固定于片上芯片垫片上,所述片上芯片垫片固定于管座上,所述高频柔性线路板穿设于管座上,所述激光二极管芯片通过键合金丝连接高频柔性线路板,所述汇聚耦合透镜帽固定于管座上；所述激光二极管芯片发射出高斯光束,高斯光束通过汇聚耦合透镜帽进行汇聚,汇聚光汇聚成与单光纤匹配的模式,入射到单模光纤中。该封装结构及方法有利于优化信号,并降低物料成本和封装成本。(The invention relates to a coaxial packaging structure and a method for a 50G PAM4 emitting laser, wherein the packaging structure comprises a laser diode chip, a convergence coupling lens cap, a laser diode gasket, an on-chip gasket, a gold bonding wire, a tube seat and a high-frequency flexible circuit board, the laser diode chip is fixed on the laser diode gasket to form an on-chip, the on-chip is fixed on the on-chip gasket, the on-chip gasket is fixed on the tube seat, the high-frequency flexible circuit board is arranged on the tube seat in a penetrating way, the laser diode chip is connected with the high-frequency flexible circuit board through the gold bonding wire, and the convergence coupling lens cap is fixed on the; the laser diode chip emits Gaussian beams, the Gaussian beams are converged through the converging coupling lens cap, the converged light is converged into a mode matched with a single optical fiber, and the mode is incident into a single mode optical fiber. The packaging structure and the packaging method are beneficial to optimizing signals, and reduce material cost and packaging cost.)

1. A50G PAM4 emission laser coaxial packaging structure is characterized by comprising a laser diode chip, a convergence coupling lens cap, a laser diode gasket, an on-chip gasket, a gold bonding wire, a tube seat and a high-frequency flexible circuit board, wherein the laser diode chip is fixed on the laser diode gasket to form an on-chip which is fixed on the on-chip gasket, the on-chip gasket is fixed on the tube seat, the high-frequency flexible circuit board is arranged on the tube seat in a penetrating manner, the laser diode chip is connected with the high-frequency flexible circuit board through the gold bonding wire, and the convergence coupling lens cap is fixed on the tube seat; the laser diode chip emits Gaussian beams, the Gaussian beams are converged through the converging coupling lens cap, the converged light is converged into a mode matched with a single optical fiber, and the mode is incident into a single mode optical fiber.

2. The coaxial packaging structure of 50G PAM4 transmitting laser as claimed in claim 1, wherein the converging coupling lens cap is a half-cap structure formed by converging coupling lenses, and the converging coupling lens cap is disposed at the outer side of the laser diode chip to converge Gaussian beams emitted from the laser diode chip.

3. The coaxial packaging structure of 50G PAM4 laser emitter according to claim 1, wherein the optical communication wavelength of the laser diode chip is 1310 nm.

4. The coaxial package structure of 50G PAM4 emitting laser according to claim 1, wherein the stem is made of Kovar and stainless steel.

5. The coaxial packaging structure of 50G PAM4 transmitting laser of claim 1, wherein the high frequency flexible circuit board is differential 100 ohm high frequency signal NRZ 25G Bps, PAM 450G Bps.

6. The coaxial packaging structure of the 50G PAM4 transmitting laser, according to claim 1, wherein the high frequency flexible circuit board and the driving circuit are connected together by welding.

7. The method for coaxial packaging of 50G PAM4 emitting lasers as claimed in any one of claims 1-6, comprising the steps of:

1) surface mounting: attaching the high-frequency flexible circuit board to the tube seat by using silver adhesive, and baking and fixing; fixing a laser diode chip on a laser diode gasket by high-temperature eutectic welding to obtain an on-chip, and fixing the on-chip on the on-chip gasket; then, using silver glue to attach the chip gasket on the chip to the tube seat and baking and fixing the chip gasket;

2) gold wire bonding: welding the laser diode gasket pad to the high-frequency flexible circuit board by using turnover routing and bonding gold wire welding;

3) and (4) capping: and the convergent coupling lens cap is welded on the tube seat by adopting a cap sealing machine in a resistance welding way.

Technical Field

The invention belongs to the field of optical fiber communication, and particularly relates to a coaxial packaging structure and method for a 50G PAM4 emission laser.

Background

The ever-increasing desire for data in today's society, not only is more and more data, but also the faster the data transmission speed, so that older modulation schemes based on NRZ type coding are increasingly inadequate. We need to acquire data from point a to point B as efficiently as possible, whether it be chips on a PC board or long distance fiber end to end. A modulation scheme that is favored in many respects is PAM 4.

The PAM4 signal employs 4 different signal levels for signal transmission, and each symbol period may represent 2 bits of logical information (0, 1, 2, 3). Because each symbol period of the PAM4 signal can transmit 2 bits of information, to achieve the same signal transmission capability, the symbol rate of the PAM4 signal only needs to reach half of that of the NRZ signal, and therefore loss caused by a transmission channel is greatly reduced. With the development of future technologies, the possibility of using more levels of PAM8 and even PAM16 signals for information transmission is not excluded.

To (transistor outline), i.e., the transistor outline. Early transistors mostly employed coaxial packages, which were later borrowed into optical communications, called TO packages, i.e., coaxial packages. The coaxiality is from the laser, the lens to the optical fiber, and the central lines of all the optical paths are on the same straight line. The TO packaged optical component is also called a coaxial package. Coaxial devices currently dominate the mainstream optical device market due to ease of manufacture and cost advantages. The TO-CAN, CAN is a jar, and the laser chip and the detector chip are contained in one jar. TO38, TO46, TO56, the numbers of which represent the diameters of the can base (TO base), 3.8mm, 4.6mm, 5.6mm, respectively, are common TO the optical communications industry. Butterfly Package (also called BOX Package), the casing is usually cuboid, the pipe case kovar, low temperature welding glass, high frequency ceramic sintering, the structure and realization function are usually complicated to can support the bonding wire of all above parts, the casing area is big, dispels the heat well, can be used for various speed and 80km long distance transmission.

In the prior art, the PAM4 coaxial package structure for emitting laser mainly comprises a laser diode Chip LD Chip, a converging coupling LENS, a BOX for loading and protecting optoelectronic components, a gasket COC Submount for supporting COC (Chip on Chip), a gasket LD Submount for supporting LD Chip, a laser and RF Circuit connection line Golden Wire, a high frequency flexible Printed Circuit (fpc), a high frequency Circuit pattern on high frequency Ceramic RF Circuit, and a high frequency Ceramic RF Ceramic, and the structure is shown in fig. 1. The principle of the light path is as follows: the LD chip emits divergent light, the divergent light is converged through the LENS, and the converged light is incident into the single mode fiber through the BOX window. The circuit principle is as follows: the FPC and the driving circuit are connected together by welding; the RF Circuit and the FPC are connected together through welding; the LD chip and the RF Circuit are bonded together through gold wires; the RF Circuit on RF Ceramic is a high frequency signal that is 100 ohms differential, NRZ 25G Bps, PAM 450G Bps. The problems existing in the prior art are as follows: the application of 50G PAM4 based on 5G base station is a huge application. At present, mass production can only be designed by using a BOX structure, the material cost is high, and the BOX packaging cost is high. Reviewing the coaxial packaging scheme used in the past for optical communication, the signal output mode used by the emission tube socket is differential by 50 ohms, and the signal output mode differential by 100 ohms can be realized for the tube socket, but the volume of the tube socket is increased, the volume of the tube socket is close to the diameter of 9mmmm, and the size of the module shell subspace is far exceeded.

Disclosure of Invention

The invention aims to provide a coaxial packaging structure and a coaxial packaging method for a 50G PAM4 emitting laser, which are beneficial to optimizing signals and reducing material cost and packaging cost.

In order to achieve the purpose, the invention adopts the technical scheme that: A50G PAM4 emission laser coaxial packaging structure comprises a laser diode chip, a convergence coupling lens cap, a laser diode gasket, an on-chip gasket, a gold bonding wire, a tube seat and a high-frequency flexible circuit board, wherein the laser diode chip is fixed on the laser diode gasket to form an on-chip which is fixed on the on-chip gasket, the on-chip gasket is fixed on the tube seat, the high-frequency flexible circuit board is arranged on the tube seat in a penetrating way, the laser diode chip is connected with the high-frequency flexible circuit board through the gold bonding wire, and the convergence coupling lens cap is fixed on the tube seat; the laser diode chip emits Gaussian beams, the Gaussian beams are converged through the converging coupling lens cap, the converged light is converged into a mode matched with a single optical fiber, and the mode is incident into a single mode optical fiber.

Furthermore, the converging coupling lens cap is a half-cap structure formed by converging coupling lenses, and the converging coupling lens cap is arranged at the outer side part of the laser diode chip so as to converge Gaussian beams emitted by the laser diode chip.

Further, the optical communication wavelength of the laser diode chip is 1310 nm.

Further, the tube seat is made of kovar and stainless steel.

Further, the high-frequency flexible circuit board is a high-frequency signal with the difference of 100 ohms, NRZ 25G Bps, PAM 450G Bps.

Further, the high-frequency flexible circuit board and the driving circuit are connected together through welding.

The invention also provides a coaxial packaging method of the 50G PAM4 emitting laser, which comprises the following steps:

1) surface mounting: attaching the high-frequency flexible circuit board to the tube seat by using silver adhesive, and baking and fixing; fixing a laser diode chip on a laser diode gasket by high-temperature eutectic welding to obtain an on-chip, and fixing the on-chip on the on-chip gasket; then, using silver glue to attach the chip gasket on the chip to the tube seat and baking and fixing the chip gasket;

2) gold wire bonding: welding the laser diode gasket pad to the high-frequency flexible circuit board by using turnover routing and bonding gold wire welding;

3) and (4) capping: and the convergent coupling lens cap is welded on the tube seat by adopting a cap sealing machine in a resistance welding way.

Compared with the prior art, the invention has the following beneficial effects: the invention reduces one-step electrical connection, and the high-frequency flexible circuit board is directly connected with the laser diode gasket through the gold bonding wire, so that not only can the high-frequency signal be better, but also the material cost and the packaging cost are reduced.

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 diagram of the construction of a convergent coupling lens cap and socket 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, the embodiment provides a 50G PAM4 emission laser coaxial packaging structure, which includes a laser diode chip 1, a converging coupling lens cap 2, a laser diode pad 3, an on-chip pad 4, a gold bonding wire 5, a tube seat 6 and a high-frequency flexible circuit board 7, wherein the laser diode chip 1 is fixed on the laser diode pad 3 to form an on-chip, the on-chip is fixed on the on-chip pad 4, the on-chip pad 4 is fixed on the tube seat 6, the high-frequency flexible circuit board 7 is arranged on the tube seat 6 in a penetrating manner, the laser diode chip 3 is connected with the high-frequency flexible circuit board 7 through the gold bonding wire 5, and the converging coupling lens cap 2 is fixed on the tube; the laser diode chip 1 emits Gaussian beams, the Gaussian beams are converged through the converging coupling lens cap 2, the converged light is converged into a mode matched with a single optical fiber, and the mode is incident into a single mode optical fiber.

The optical communication wavelength of the laser diode chip is 1310 nm.

As shown in fig. 3, in the present embodiment, the converging coupling lens cap 2 is a half-cap structure formed by converging coupling lenses, and the converging coupling lens cap 2 is covered on the outer side of the laser diode chip 1 to converge the gaussian beam emitted by the laser diode chip 1.

The tube seat 6 is made of kovar and stainless steel.

In this embodiment, the range of values of the dimensional parameters of the convergent-coupled lens cap 2 and the tube seat 6 is as follows:

3.3＜A＜7mm，0.5＜B＜6mm，0＜C＜3mm，0＜D＜5mm，1＜E＜6mm，0.1＜F＜7mm，0.5＜G＜7mm，0.5＜H＜7mm。

the high-frequency flexible circuit board is a high-frequency signal with the difference of 100 ohms, NRZ 25G Bps and PAM 450G Bps. The high-frequency flexible circuit board is connected with the driving circuit through welding.

The invention also provides a 50G PAM4 emitting laser coaxial packaging method for realizing the packaging structure, which comprises the following steps:

1) surface mounting: attaching the high-frequency flexible circuit board to the tube seat by using silver adhesive, and baking and fixing; fixing a laser diode chip on a laser diode gasket by high-temperature eutectic welding to obtain an on-chip, and fixing the on-chip on the on-chip gasket; then, using silver glue to attach the chip gasket on the chip to the tube seat and baking and fixing the chip gasket;

2) gold wire bonding: welding the laser diode gasket pad to the high-frequency flexible circuit board by using turnover routing and bonding gold wire welding;

3) and (4) capping: and the convergent coupling lens cap is welded on the tube seat by adopting a cap sealing machine in a resistance welding way.

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.