CN212725950U

CN212725950U - Packaging structure of optical device

Info

Publication number: CN212725950U
Application number: CN202021246129.8U
Authority: CN
Inventors: 和文娟; 郑庆立; 汪钦; 张莉
Original assignee: Accelink Technologies Co Ltd
Current assignee: Accelink Technologies Co Ltd
Priority date: 2020-06-28
Filing date: 2020-06-28
Publication date: 2021-03-16
Anticipated expiration: 2030-06-28

Abstract

The utility model discloses an optical device's packaging structure, include: the laser comprises a base, a laser heat sink, a conductive circuit, a laser chip and a first gold wire lead; the laser heat sink is arranged on the base and comprises a first surface and a second surface which form a step shape, and the first surface protrudes out of the second surface; the two conductive circuits are respectively arranged on the first surface and the second surface; the laser chip is arranged on the second surface and is connected with the conducting circuit on the second surface; the first gold wire lead is connected with the laser chip and the first surface. Through the technical scheme of the utility model, can greatly shorten gold wire lead wire length, improve data transmission rate to can adopt current production line to carry out seal welding and coupling, practice thrift the cost.

Description

Packaging structure of optical device

Technical Field

The utility model relates to an optical communication technical field specifically relates to an optical device's packaging structure.

Background

With the continuous progress of social science and technology, the communication requirement is continuously improved, the structure of the existing coaxial packaging optical device is widely used for the low-cost packaging of lasers and detector components with the speed of 2.5G and below, and the requirement of the current high speed is difficult to meet, so that the base and the heat sink circuit design can meet the requirements of high-frequency design and the current common gold wire routing process as far as possible, and the length of a gold wire lead directly influences the transmission speed.

SUMMERY OF THE UTILITY MODEL

An object of the embodiment of the utility model is to provide an optical device's packaging structure to gold wire lead length overlength influences data transmission rate's problem in solving prior art.

In order to solve the problem, the utility model discloses a following technical scheme realizes:

an encapsulation structure of a light device, comprising:

a base;

the laser heat sink is arranged on the base and comprises a first surface and a second surface which form a step shape, and the first surface protrudes out of the second surface;

the two conductive circuits are respectively arranged on the first surface and the second surface;

the laser chip is arranged on the second surface and is connected with the conducting circuit on the second surface; and

and the first gold wire lead is connected with the laser chip and the conductive circuit on the first surface.

Furthermore, the base comprises a bearing plate and a boss arranged on the bearing plate, and the packaging structure further comprises two first signal pins arranged on the bearing plate at intervals;

the laser is arranged on the side face, close to the center of the bearing plate, of the boss in a heat sinking mode, and the conducting circuit on the first surface and the conducting circuit on the second surface are connected with the two first signal pins respectively.

Further, the conductive circuit is a microstrip line formed on the laser heat sink.

Furthermore, the laser heat sink is located between the boss and the two first signal pins, and the microstrip line is in eutectic soldering or epoxy glue bonding with the first signal pins.

Further, the laser heat sink and the base are fixed by adopting gold-tin solder.

Further, the laser chip is eutectic-welded on the second surface.

Furthermore, the heat sink of the laser is made of ceramic.

Further, the package structure further includes:

the detector heat sink is arranged on the base;

the detector chip is arranged on the detector heat sink and faces the backlight surface of the laser chip;

the two second signal pins are arranged on the base at intervals; and

and one second gold wire lead is connected with the detector heat sink and one second signal pin, and the other second gold wire lead is connected with the detector chip and the other second signal pin.

Furthermore, the packaging structure further comprises a cap with a central window and a lens arranged on the central window, the cap is covered on the base, and the focus of the lens is coincided with the light emitting point of the laser chip.

The embodiment of the utility model provides a packaging structure of optical device, through designing the laser heat sink into the step form, the laser heat sink includes first surface and second surface, first surface is higher than the second surface; conductive circuits are respectively arranged on the first surface and the second surface, the laser chip is arranged on the second surface, and the conductive circuits on the second surface of the laser chip are connected. Based on step-shaped laser heat sink, reduce the influence of the height of laser chip to the gold wire routing, first gold wire lead wire connection laser chip and the conducting wire on the first surface for first gold wire lead wire length shortens greatly, has strengthened data transmission rate.

Drawings

Fig. 1 is a schematic structural diagram of an encapsulation structure of an optical device according to an embodiment of the present invention;

FIG. 2 is a schematic view of the structure of FIG. 1 from another perspective, with the addition of a cross-sectional cap; and

fig. 3 is a schematic light path diagram of an encapsulation structure of an optical device according to an embodiment of the present invention;

description of reference numerals:

100-base, 200-laser heat sink, 210-first surface, 220-second surface, 600-conductive circuit, 300-laser chip, 700-first gold wire lead, 130-bearing plate, 120-boss, 111-first signal pin, 400-detector heat sink, 500-detector chip, 112-second signal pin, 800-second gold wire lead, 900-cap, 910-lens.

Detailed Description

The following detailed description of embodiments of the present invention is provided with reference to the accompanying drawings.

It should be noted that, in the present invention, the technical features of the embodiments and the examples can be combined with each other without conflict, and the detailed description in the specific embodiment should be understood as an explanation of the gist of the present invention and should not be construed as an improper limitation of the present invention.

In the description of the present invention, the orientation or positional relationship is based on the orientation or positional relationship shown in the drawings. It is to be understood that such directional terms are merely for convenience in describing the present invention and to simplify the description, and are not intended to indicate or imply that the device or element so referred to must be in a particular orientation, constructed and operative in a particular orientation, and therefore should not be taken as limiting the invention.

As shown in fig. 1-3, an embodiment of the present invention provides a package structure of an optical device, for example, a TO package structure of an optical device, the package structure includes a base 100, a laser heat sink 200, a conductive trace 600, a laser chip 300, and a first gold wire lead 700.

Wherein, the laser heat sink 200 is disposed on the base 100, the laser heat sink 200 includes a first surface 210 and a second surface 220 formed in a step shape, and the first surface 210 protrudes from the second surface 220. The two conductive traces 600 are respectively disposed on the first surface 210 and the second surface 220, and the two conductive traces 600 may be two or two sets or two sheets. The laser chip 300 is disposed on the second surface 220, and the laser chip 300 is connected to the conductive traces 600 on the second surface 220, specifically, the negative electrode of the laser chip 300 is connected to the conductive traces 600 on the second surface 220. The first gold wire lead 700 connects the laser chip 300 and the conductive trace 600 on the second surface, specifically, the first gold wire lead 700 connects the anode of the laser chip 300 and the conductive trace 600 on the first surface 210, and the number of the first gold wire leads 700 may be determined according to design requirements, for example, one or more.

The height difference of the first surface 210 protruding from the second surface 220 is equivalent to the height of the laser chip 300 according to the height of the laser chip 300. According to the requirement of the gold wire bonding process, the laser chip 300 arranged on the second surface 220 is close to the first surface 210, so that the length of the first gold wire lead 700 is greatly shortened, and the data transmission rate is improved.

In an embodiment, the base 100 includes a bearing plate 130 and a boss 120 disposed on the bearing plate 130, and specifically, the bearing plate 130 and the boss 120 may be integrally formed, or may be welded or bonded. The package structure further includes two first signal pins 111 disposed on the carrier 130 at intervals, where the two first signal pins 111 may be two or two, and when the two first signal pins are two, the polarities of the first signal pins 111 in each group are the same. The laser heat sink 200 is disposed on a side of the boss 120 near the center of the loading plate 130, for example, the laser heat sink 200 is located between the boss 120 and the two first signal pins 111. The conductive traces 600 on the first surface 210 and the conductive traces 600 on the second surface 220 are respectively connected to the two first signal pins 111. Specifically, the conductive trace 600 and the first signal pin 111 may be connected by gold wire bonding.

Due to the arrangement of the boss 120 on the bearing plate 130, the arrangement of the laser heat sink 200 and the laser chip 300 is facilitated, the area of the laser heat sink 200 is increased without occupying more area of the bearing plate 130, so that the heat dissipation area can be increased while arranging other elements, and the light emitting surface of the laser chip 300 faces to one side away from the bearing plate 130. After the conductive circuit 600 on the laser heat sink 200 is connected to the first signal pin 111 on the carrier plate 130, the laser chip 300 is electrically connected to the outside.

In an embodiment, the conductive traces 600 may be a conductive layer such as an oxygen-free copper layer or a gold layer formed on the laser heat sink 200, and the two conductive traces 600 of the first surface 210 and the second surface 220 are insulated from each other. Specifically, the conductive circuit 600 may also be a microstrip line formed on the laser heat sink 200, and the microstrip line is favorable for high-speed transmission of signals and improves the anti-interference capability.

In an embodiment, the laser heat sink 200 is located between the boss 120 and the two first signal pins 111, so as to reduce the distance between the microstrip line and the two first signal pins. The two microstrip lines are respectively in eutectic welding or epoxy glue bonding with the first signal pin 111, and high-frequency loss and parasitic inductance at the joint are reduced.

For example, the microstrip line on the second surface 220 is soldered to the cathode of the laser chip 300 by gold-tin solder to realize the circuit connection.

In one embodiment, laser heat sink 200 and mesa 120 are secured with gold-tin solder, reducing the series resistance introduced.

In one embodiment, the laser chip 300 is eutectic bonded on the second surface 220. For example, the cathode of the laser chip 300 is eutectic-welded on the second surface 220 and connected to the microstrip line, or eutectic-welded on the microstrip line, so that the transmission of high-frequency signals is enhanced and the high-frequency loss caused by the connection process is reduced during the current transmission process of the laser chip 300.

In an embodiment, the material of the laser heat sink 200 is a ceramic material, such as any one of aluminum nitride ceramic, aluminum oxide ceramic, zirconium oxide ceramic, silicon nitride ceramic, silicon carbide ceramic, or boron nitride, and the ceramic material has the characteristics of small thermal expansion rate and high thermal conductivity, so that the heat transfer effect is more remarkable.

In one embodiment, the package structure further includes a probe heat sink 400, a probe chip 500, a second signal pin 112, and a second gold wire lead 800. The detector heat sink 400 is disposed on the base 100, for example, on the carrier plate 130; detector chip 500 is disposed on detector heat sink 400 facing the backlight side of laser chip 300. The two second signal pins 112 are disposed on the base 100, for example, on the carrier plate 130, and there may be two or two sets of the two second signal pins 112, and when there are two sets, the polarities of the second signal pins 112 in each set are the same. A second gold wire lead 800 connects the detector chip 500 and a second signal pin 112, and another second gold wire lead 800 connects the detector heat sink 400 and another second signal pin 112. A second gold wire 800 is shown that may be one or a group, and when a group, the objects to which the respective second gold wires 800 within each group are connected are the same.

The detector heat sink 400 provides heat dissipation for the detector chip, the second gold wire lead 800 electrically connects the detector chip 500 with the outside, and the detector chip 500 faces the backlight surface of the laser chip 300 and is used for monitoring the light emitting power of the laser chip 300.

In an embodiment, the package structure further includes a cap 900 having a central window and a lens 910 disposed on the central window, the cap 900 is covered on the base 100, and a focus of the lens 910 coincides with a light emitting point of the laser chip 300, so that light emitted from the laser chip 300 can be transmitted through the lens 910, thereby implementing coaxial package of the TO package structure.

In one embodiment, the optical device is subjected to conventional device-level packaging, and after the sealing welding and the coupling are performed by adopting the conventional production line, the optical device can be applied to an SFP28 module structure, so that the production capacity is greatly improved, and the production cost is reduced.

The above embodiments are only used to illustrate the technical solution of the present invention, and not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described in the foregoing embodiments, or that equivalents may be substituted for elements thereof; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions.

Claims

1. An encapsulation structure of an optical device, comprising:

a base;

2. The package structure of claim 1, wherein the base comprises a carrier board and a boss disposed on the carrier board, and the package structure further comprises two first signal pins disposed on the carrier board at intervals;

3. The package structure of claim 2, wherein the conductive trace is a microstrip formed on the laser heat sink.

4. The package structure according to claim 3, wherein the laser heat sink is located between the boss and the two first signal pins, and the microstrip line is bonded to the first signal pins by eutectic soldering or epoxy glue.

5. The package structure of claim 1, wherein the laser heat sink and the submount are secured with gold-tin solder.

6. The package structure of claim 1, wherein the laser chip is eutectic soldered on the second surface.

7. The package structure of claim 1, wherein the laser heat sink is made of ceramic.

8. The package structure according to any one of claims 1 to 7, further comprising:

the detector heat sink is arranged on the base;

the two second signal pins are arranged on the base at intervals; and

9. The package structure of claim 8, further comprising a cap having a central window and a lens disposed on the central window, wherein the cap is disposed on the base, and a focal point of the lens coincides with a light emitting point of the laser chip.