CN112987198A

CN112987198A - High-reliability optical transceiving integrated circuit

Info

Publication number: CN112987198A
Application number: CN202110217366.4A
Authority: CN
Inventors: 苏妍妍; 牛士敏; 孙程程; 高苏芳; 郑东飞
Original assignee: Xian Microelectronics Technology Institute
Current assignee: Xian Microelectronics Technology Institute
Priority date: 2021-02-26
Filing date: 2021-02-26
Publication date: 2021-06-18

Abstract

The invention discloses a high-reliability optical transceiving integrated circuit, and belongs to the field of hybrid integrated optical transceiving design. The high-reliability optical transceiver integrated circuit is based on a high-temperature co-fired ceramic (HTCC) process, has a structure that an open through cavity is combined with a stepped radiating boss of a metal base plate, and solves the problem of heat radiation in a photoelectric transceiver circuit module; the stepped radiating boss of the metal base plate provides a coplanar reference for light coupling, can realize horizontal bonding of the bonding wire of the high-speed signal channel, and solves the problem of poor signal quality caused by high-speed signal loss and reflection. Meanwhile, the circuit structure bonds the multi-path high-speed differential wires with the leading-out end of the shell, and through the design of a ground network between the differential pins, the reflection and the loss caused by the bonding of the internal chip and the external pins are reduced, the series winding between the differential wires is reduced, and the signal quality of the high-speed differential wires is improved.

Description

High-reliability optical transceiving integrated circuit

Technical Field

The invention belongs to the field of hybrid integrated optical transceiving design, and particularly relates to a high-reliability optical transceiving integrated circuit.

Background

With the progress of science and technology and the coming of the information era, diversified information transmission technologies have greatly pushed the world to enter the big data era. The demand for signal bandwidth and speed in the field of communications is increasing. Large capacity, high speed optical fiber communication has become a necessary trend for the development of the information age. As a core device in a communication network, a conventional transceiver module has defects in transmission rate, transmission capacity, transmission distance, signal quality, energy loss, and the like.

With the development of the optical transceiver module towards high speed, high bandwidth and miniaturization, the design difficulty is increased accordingly. It is desirable to integrate optical transmission, optical reception, and digital control circuitry on a small circuit board while taking full account of the signal quality and signal integrity of high speed signals. The high-speed photoelectric module (device/circuit) applied in the market at present is incompatible with the modern microelectronic process and the hybrid integration process, so that the high-speed photoelectric module is high in price, large in size, difficult to integrate, difficult to meet the increasing speed transmission requirement and becoming the bottleneck of high-speed data transmission and exchange.

Disclosure of Invention

The invention aims to overcome the defect that the existing high-speed photoelectric module is difficult to meet the increasing speed transmission requirement, and provides a high-reliability optical transceiving integrated circuit.

In order to achieve the purpose, the invention adopts the following technical scheme to realize the purpose:

a high-reliability light receiving and transmitting integrated circuit comprises a metal base plate, wherein a stepped radiating boss and an HTCC base plate are arranged on the metal base plate, a U-shaped stepped desktop through cavity is arranged on the HTCC base plate, and the stepped radiating boss is positioned in the U-shaped stepped desktop through cavity;

a Kovar frame is arranged on the periphery of the HTCC substrate, an external lead is arranged on the back of the HTCC substrate, and an optical fiber sealing frame is arranged on the other end face of the Kovar frame;

a control circuit, a power management circuit, a monitoring circuit and a plurality of paths of high-speed differential signal wiring are arranged in an open cavity of the HTCC substrate;

and the light transceiving device on the stepped radiating boss is connected with the high-speed differential wiring through a gold bonding wire.

Furthermore, the metal bottom plate, the HTCC substrate and the kovar frame cover plate are integrated by adopting a sintering process.

Furthermore, the optical fiber sealing frame adopts local welding to realize the sealing of the optical fiber and the Kovar frame.

Furthermore, the multi-path high-speed differential signal routing is distributed on the HTCC substrate in a 6-layer wiring mode.

Further, the high-speed differential signal path comprises bonding fingers from the optical transceiver chip positioned on the stepped heat dissipation boss to the surface layer of the HTCC substrate;

a routing wire from the bonding finger to the edge of the surface layer of the HTCC substrate;

from the edge of the substrate skin to the high speed pins at the bottom of the HTCC substrate.

Furthermore, the light receiving and transmitting chip is connected with the bonding fingers through gold bonding wires.

Compared with the prior art, the invention has the following beneficial effects:

the high-reliability optical transceiver integrated circuit is based on a high-temperature co-fired ceramic (HTCC) process and has a structure of combining an open through cavity and a stepped radiating boss of a metal base plate, and the problem of heat dissipation in the photoelectric transceiver integrated circuit module is solved; the stepped radiating boss of the metal base plate provides a coplanar reference for light coupling, horizontal bonding of the bonding wire on the high-speed signal path can be realized, and the problem of poor signal quality caused by high-speed signal loss and reflection is solved. Meanwhile, the circuit structure directly bonds the multi-path high-speed differential wires with the leading-out end of the shell, and through the design of a ground network among the differential pins, the reflection and the loss caused by the bonding of the internal chip and the external pins are reduced, the series winding among the differential wires is reduced, and the signal quality of the high-speed differential wires is improved.

Drawings

FIG. 1 is a block diagram of a highly reliable optical transceiver integrated circuit module housing;

FIG. 2 is an exploded view of a highly reliable optical transceiver integrated circuit module housing;

FIG. 3 is a wiring diagram of the bottom surface of an open cavity of an HTCC substrate;

FIG. 4 is a schematic view of a chip-to-HTCC open cavity surface bond wire on a stepped heat dissipating boss;

fig. 5 is a partial enlarged view of the differential path.

Wherein: the optical fiber connector comprises a metal base plate 1, a stepped radiating boss 2, a Kovar frame 3, an external lead 4, an HTCC substrate 5 and an optical fiber sealing frame 6.

Detailed Description

In order to make the technical solutions of the present invention better understood, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

It should be noted that the terms "first," "second," and the like in the description and claims of the present invention and in the drawings described above are used for distinguishing between similar elements and not necessarily for describing a particular sequential or chronological order. It is to be understood that the data so used is interchangeable under appropriate circumstances such that the embodiments of the invention described herein are capable of operation in sequences other than those illustrated or described herein. Furthermore, the terms "comprises," "comprising," and "having," and any variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, system, article, or apparatus that comprises a list of steps or elements is not necessarily limited to those steps or elements expressly listed, but may include other steps or elements not expressly listed or inherent to such process, method, article, or apparatus.

The hybrid integrated photoelectric technology combines the hybrid integrated technology with the light receiving/generating circuit, effectively improves the assembly density of photoelectric devices/components, and makes the miniaturization and integration of modules possible. Therefore, hybrid integrated photovoltaic technology is a new development in the field of photovoltaic conversion. Miniaturization and integration of photoelectric products are the basic trend, and the photoelectric products are increasingly used as the core support technology of high-tech weaponry.

The invention is described in further detail below with reference to the accompanying drawings:

1. high-reliability integrated circuit structure design

Referring to fig. 1, fig. 1 is a structural diagram of a housing of a high-reliability optical transceiver integrated circuit, the high-reliability optical transceiver integrated circuit includes a metal base plate 1, a stepped heat dissipation platform 2 and an HTCC substrate 5 are arranged on the metal base plate 1, the stepped heat dissipation platform 2 is located in a U-shaped open through cavity of the HTCC substrate 5, and the stepped heat dissipation platform 2 serves as a heat dissipation platform; the periphery of the HTCC substrate 5 is provided with a Kovar frame 3, the outer lead 4 is positioned on the back of the HTCC substrate 5, and the other end face of the Kovar frame 3 is provided with an optical fiber sealing frame 6.

Referring to fig. 2, fig. 2 is an exploded view of a housing of a highly reliable optical transceiver integrated circuit module, and it can be seen that the assembly sequence from top to bottom is as follows: the integrated Kovar frame 3, the optical fiber sealing frame 6, the HTCC substrate 5, the outer lead 4, the integrated metal bottom plate 1 and the stepped radiating boss 2; an optical fiber sealing frame 6 is arranged on the end face of the Kovar frame 3, and a stepped heat dissipation boss 2 is arranged on the metal base plate 1.

The high reliability is mainly reflected in that: on the one hand, based on the fact that the HTCC substrate 5 is a U-shaped step desk type irregular structure, the U-shaped structure is an open through cavity, low-power-consumption circuits required by module work, such as a control circuit, a power management circuit, a monitoring circuit and the like, and multi-path high-speed differential signal wiring are arranged in the open cavity, the external lead 4 is wired to an external pin bonding pad through the substrate, and the reliability of a leading-out end is improved through simplification of an assembling process. On the other hand, the stepped heat dissipation boss 2 matched with the HTCC substrate 5 in size is designed at the hollow part of the open cavity, and the key devices of light receiving and transmitting, a high-power device driver, an amplifier, a laser array, a detector array and the like are arranged on the stepped heat dissipation boss 2. And the gold bonding wire of the optical transceiver on the stepped radiating boss 2 is connected with the high-speed differential wire on the HTCC substrate. The stepped radiating boss is positioned on the metal base plate 1, so that the radiating of the optical chip on the stepped radiating boss can be improved, and the working reliability of the circuit at high temperature is improved.

The integration of the structure is mainly embodied in that: the metal bottom plate 1, the HTCC substrate 5 and the Kovar frame 3 cover plate are integrated by adopting a sintering process to realize the substrate shell, the optical fiber sealing frame 6 is locally welded to realize the sealing of the optical fiber and the Kovar frame 3, and the air tightness requirement is met while the structural integration is realized.

2. Multi-path differential signal wiring design

As shown in fig. 3, the optical transceiver integrated circuit module includes multiple high-speed differential signals, has a single-channel transmission rate as high as 10Gbps, and is distributed on the surface layer of the HTCC substrate 5 mainly in a 6-layer wiring manner.

As shown in fig. 4, the high-speed signal path includes bonding fingers from the stepped heat-dissipating boss optical transceiver chip to the surface layer of the HTCC substrate, the chip and the bonding fingers are connected by gold bonding wires, and the wire is routed from the bonding fingers to the surface layer of the HTCC substrate 5 at the edge of the surface layer; the paths are connected by multiple layers of blind buried vias from the edge of the substrate surface to the high speed pins at the bottom of the substrate.

As shown in fig. 5, the differential signals in the module are concentrated on the surface layer of the open cavity of the HTCC substrate 5. The stepped heat dissipation boss 2 on the metal base plate 1 heightens the plane where the chip is located, so that horizontal bonding of a gold bonding wire of a high-speed signal channel can be realized, and the problem of poor signal quality caused by high-speed signal loss and reflection can be solved. On the transmission path of the differential signal, the line width and the line interval of the differential signal are adjusted to adapt to the change that the microstrip line brought by the stepped open cavity of the substrate is changed into the strip line, so that the impedance on the whole differential path is continuous, and the signal loss caused by impedance mismatching is reduced. Meanwhile, between different differential signals, through the design of the ground hole between the signal lines, the adjacent differential signals are shielded, so that the crosstalk between the differential signals is reduced, and the signal quality is improved.

The optical transceiving technology replaces electric transmission with the advantages of high speed, high bandwidth, low loss, strong anti-interference and the like to be applied to broadband data and image transmission in radars and aerospace systems, and the bottleneck problems of large signal capacity, large data transmission loss and the like in the system are solved; the high-reliability optical transceiver integrated circuit structure based on the HTCC process has a compact appearance structure, reduces the volume and the weight of a module, shortens a signal transmission path by utilizing an integrated design structure of a substrate and a shell, and improves the signal quality; the circuit module based on the structure provides a convenient and reliable mode for board-level interconnection, interconnection among racks and system-level interconnection, has very wide application prospect and market potential, and has important strategic significance and social benefit.

The above-mentioned contents are only for illustrating the technical idea of the present invention, and the protection scope of the present invention is not limited thereby, and any modification made on the basis of the technical idea of the present invention falls within the protection scope of the claims of the present invention.

Claims

1. A high-reliability light receiving and transmitting integrated circuit is characterized by comprising a metal base plate (1), wherein a stepped heat dissipation boss (2) and an HTCC base plate (5) are arranged on the metal base plate (1), a U-shaped stepped platform type through cavity is arranged on the HTCC base plate (5), and the stepped heat dissipation boss (2) is positioned in the U-shaped stepped platform type through cavity;

a Kovar frame (3) is arranged on the periphery of the HTCC substrate (5), an outer lead (4) is arranged on the back of the HTCC substrate (5), and an optical fiber sealing frame (6) is arranged on the other end face of the Kovar frame (3);

a control circuit, a power management circuit, a monitoring circuit and a plurality of paths of high-speed differential signal wiring are arranged in an open cavity of the HTCC substrate (5);

the stepped radiating boss (2) is provided with a light transceiving device, and the light transceiving device on the stepped radiating boss (2) is connected with the high-speed differential wiring through a gold bonding wire.

2. The integrated circuit for high-reliability optical transceiving according to claim 1, wherein the metal base plate (1), the HTCC substrate (5) and the cover plate of the kovar frame (3) are integrated into the substrate housing by a sintering process.

3. The integrated circuit for high-reliability optical transceiver of claim 1, wherein the optical fiber sealing frame (6) adopts local welding to seal the optical fiber with the kovar frame (3).

4. The integrated circuit of claim 1, wherein the multiple high-speed differential signal traces are distributed on the HTCC substrate (5) in 6-layer wiring.

5. The integrated circuit for high-reliability optical transceiver according to claim 4, wherein the high-speed differential signal path comprises bonding fingers from the optical transceiver chip located on the stepped heat dissipation boss (2) to the surface layer of the HTCC substrate (5).

6. The integrated circuit for high-reliability optical transceiver of claim 5, wherein the path of the high-speed differential signal further comprises: and the wire from the bonding finger to the edge of the surface layer of the HTCC substrate (5).

7. The integrated circuit for high-reliability optical transceiver of claim 6, wherein the path of the high-speed differential signal further comprises:

from the edge of the substrate surface layer to the high-speed pins at the bottom of the HTCC substrate (5).

8. The integrated circuit of claim 5, 6 or 7, wherein the optical transceiver chip is connected to the bonding fingers by gold bonding wires.