阅读说明：本技术 一种封装结构及光模块 (Packaging structure and optical module ) 是由 贾秀红 汪振中 于 2020-05-18 设计创作，主要内容包括：本申请公开了一种封装结构及光模块,该封装结构包括封装基板和至少一个设于封装基板上的半导体激光芯片和子基板,以及至少部分设于子基板上的匹配电路；其中,半导体激光芯片上设有信号电极,封装基板上设有接地金属和至少一个信号线,该至少一个信号线与激光芯片的信号电极相电连接；匹配电路包括输入端、至少一个电子元件和接地端；该输入端与激光芯片的信号电极相电连接,至少一个电子元件的两端分别与输入端和接地端相电连接,接地端电连接封装基板的接地金属。在封装基板上增加子基板用于设计RC电路等激光器匹配电路,以降低匹配电阻及滤波电容与GND间的耦合,提高了光电带宽,具有良好的高频性能。(The application discloses a packaging structure and an optical module, wherein the packaging structure comprises a packaging substrate, at least one semiconductor laser chip and a sub-substrate which are arranged on the packaging substrate, and at least part of a matching circuit which is arranged on the sub-substrate; the semiconductor laser chip is provided with a signal electrode, the packaging substrate is provided with a grounding metal and at least one signal wire, and the at least one signal wire is electrically connected with the signal electrode of the laser chip; the matching circuit comprises an input end, at least one electronic element and a grounding end; the input end is electrically connected with a signal electrode of the laser chip, two ends of at least one electronic element are respectively electrically connected with the input end and the grounding end, and the grounding end is electrically connected with the grounding metal of the packaging substrate. The sub-substrate is added on the packaging substrate and used for designing laser matching circuits such as RC circuits and the like so as to reduce the coupling between the matching resistor and the filter capacitor and GND, improve the photoelectric bandwidth and have good high-frequency performance.)

1. The utility model provides a packaging structure, includes packaging substrate and at least one locates semiconductor laser chip on the packaging substrate, be equipped with signal electrode on the semiconductor laser chip, its characterized in that:

the packaging structure further comprises at least one sub-substrate arranged on the packaging substrate and at least part of matching circuits arranged on the sub-substrate;

the packaging substrate is provided with a grounding metal and at least one signal wire, and the at least one signal wire is electrically connected with a signal electrode of the laser chip;

the matching circuit comprises an input end, at least one electronic element and a grounding end; the input end is electrically connected with the signal electrode of the laser chip, two ends of the at least one electronic element are respectively electrically connected with the input end and the grounding end, and the grounding end is electrically connected with the grounding metal of the packaging substrate.

2. The package structure of claim 1, wherein: the electronic element comprises a matching resistor and a filter capacitor;

one end of the filter capacitor is electrically connected with the grounding end, and the other end of the filter capacitor is electrically connected with one end of the matching resistor; the other end of the matching resistor is electrically connected with the input end.

3. The package structure of claim 2, wherein: the matching resistor is a thin film resistor plated on the sub-substrate.

4. The package structure of claim 1, wherein:

the packaging substrate is provided with a first upper surface and a second upper surface, and the height of the second upper surface is lower than that of the first upper surface; the signal line and the semiconductor laser chip are arranged on the first upper surface, and the sub-substrate is arranged on the second upper surface;

or the package substrate is provided with a first upper surface, a second upper surface and a third upper surface, and the height of the second upper surface is lower than that of the third upper surface; the signal line is arranged on the first upper surface, the semiconductor laser chip is arranged on the third upper surface, and the sub-substrate is arranged on the second upper surface.

5. The package structure of claim 4, wherein:

the second upper surface is lower than the first upper surface;

the submount has an upper surface that is flush with the first upper surface of the package substrate.

6. The package structure of claim 5, wherein:

the grounding end of the matching circuit is the grounding metal on the first upper surface;

one end of the electronic component electrically connected to the ground terminal is fixed to the ground metal, and the other end is fixed to the upper surface of the sub-substrate.

7. The package structure according to any one of claims 1 to 5, wherein:

the ground terminal of the matching circuit is arranged on the sub-substrate.

8. The package structure of claim 7, wherein:

the sub-substrate has an upper surface and a lower surface which are opposite to each other, and the input end, the electronic element and the ground end of the matching circuit are arranged on the upper surface of the sub-substrate;

a grounding pad is arranged on the lower surface of the sub-substrate, a conductive through hole is arranged in the sub-substrate or a metal film is arranged on the side wall of the sub-substrate, and the conductive through hole or the metal film is electrically connected with the grounding end on the upper surface and the grounding pad on the lower surface;

the sub-substrate is arranged on the grounding metal of the packaging substrate, and the grounding pad on the lower surface is electrically connected with the grounding metal of the packaging substrate.

9. The package structure of claim 7, wherein: and the grounding end of the matching circuit arranged on the sub-substrate is electrically connected with the grounding metal of the packaging substrate through a bonding lead.

10. The package structure according to any one of claims 1 to 6, wherein:

the sub-substrate is mounted on the grounding metal of the packaging substrate through a surface mounting process;

or, the sub-substrate is directly manufactured on the grounding metal of the packaging substrate.

11. An optical module, characterized in that: comprising the encapsulation structure according to any one of claims 1 to 10.

Technical Field

The application relates to the technical field of optical communication, in particular to a packaging structure and an optical module.

Background

The laser chip in the optical module mostly adopts a package design of a chip on ceramic (chip on chip) package, a common structure is shown in fig. 1, a package substrate 10 ' is designed with a coplanar line including a grounding metal 11 ' and a signal line 12 ', and a semiconductor laser chip 20 ' is mounted on the package substrate 10 '. In order to reduce the size of the optical module, the matching circuit of the laser, such as the filter capacitor 40 ' and the matching resistor 30 ', is generally integrated on the package substrate 10 ', the semiconductor laser chip 20 ' is connected to the matching resistor 30 ' through the gold wire 50 ', and the matching resistor 30 ' is further connected to the ground metal (GND)11 ' through the filter capacitor 40 '. The integrated structure design that the matching resistor 30 ' and the filter capacitor 40 ' are integrated on the package substrate 10 ' improves the integration level and reduces the size of the optical module, but because the links of the matching resistor 30 ' and the filter capacitor 40 ' are on the same surface as the grounding metal GND 11 ', the links of the matching resistor 30 ' and the filter capacitor 40 ' and the grounding metal GND 11 ' are easily coupled, thereby affecting the transmission quality of high-frequency signals and reducing the photoelectric bandwidth.

Disclosure of Invention

The application aims to provide a packaging structure and an optical module, which improve the photoelectric bandwidth and have good high-frequency performance.

In order to achieve one of the above objects, the present application provides a package structure, which includes a package substrate and at least one semiconductor laser chip disposed on the package substrate, the semiconductor laser chip having a signal electrode thereon,

the packaging structure further comprises at least one sub-substrate arranged on the packaging substrate and at least part of matching circuits arranged on the sub-substrate;

the packaging substrate is provided with a grounding metal and at least one signal wire, and the at least one signal wire is electrically connected with a signal electrode of the laser chip;

the matching circuit comprises an input end, at least one electronic element and a grounding end; the input end is electrically connected with the signal electrode of the laser chip, two ends of the at least one electronic element are respectively electrically connected with the input end and the grounding end, and the grounding end is electrically connected with the grounding metal of the packaging substrate.

As a further improvement of the embodiment, the electronic component includes a matching resistance and a filter capacitance;

one end of the filter capacitor is electrically connected with the grounding end, and the other end of the filter capacitor is electrically connected with one end of the matching resistor; the other end of the matching resistor is electrically connected with the input end.

As a further improvement of the embodiment, the matching resistor is a thin film resistor plated on the sub-substrate.

As a further improvement of the embodiment, a first upper surface and a second upper surface are arranged on the package substrate, and the height of the second upper surface is lower than that of the first upper surface; the signal line and the semiconductor laser chip are arranged on the first upper surface, and the sub-substrate is arranged on the second upper surface;

or the package substrate is provided with a first upper surface, a second upper surface and a third upper surface, and the height of the second upper surface is lower than that of the third upper surface; the signal line is arranged on the first upper surface, the semiconductor laser chip is arranged on the third upper surface, and the sub-substrate is arranged on the second upper surface.

As a further refinement of the embodiment, the second upper surface is lower than the first upper surface; the submount has an upper surface that is flush with the first upper surface of the package substrate.

As a further improvement of the embodiment, a ground terminal of the matching circuit is the ground metal on the first upper surface; one end of the electronic component electrically connected to the ground terminal is fixed to the ground metal, and the other end is fixed to the upper surface of the sub-substrate.

As a further improvement of the embodiment, a ground terminal of the matching circuit is provided on the submount.

As a further improvement of the embodiment, the sub-substrate has opposite upper and lower surfaces, and the input terminal, the electronic component, and the ground terminal of the matching circuit are provided on the upper surface of the sub-substrate;

a grounding pad is arranged on the lower surface of the sub-substrate, a conductive through hole is arranged in the sub-substrate or a metal film is arranged on the side wall of the sub-substrate, and the conductive through hole or the metal film is electrically connected with the grounding end on the upper surface and the grounding pad on the lower surface;

the sub-substrate is arranged on the grounding metal of the packaging substrate, and the grounding pad on the lower surface is electrically connected with the grounding metal of the packaging substrate.

As a further improvement of the embodiment, the ground terminal of the matching circuit provided on the submount is electrically connected to the ground metal of the package substrate by a bonding wire.

As a further improvement of the embodiment, the submount is mounted on the ground metal of the package substrate by a surface mount process; or, the sub-substrate is directly manufactured on the grounding metal of the packaging substrate.

The application also provides an optical module, which comprises the packaging structure in any embodiment.

The beneficial effect of this application: the application adds the sub-substrate on the packaging substrate for designing laser matching circuits such as RC circuits and the like so as to reduce the coupling between the matching resistor, the filter capacitor and GND, improve the photoelectric bandwidth and have good high-frequency performance.

Drawings

FIG. 1 is a schematic diagram of a conventional COC package structure;

FIG. 2 is a schematic view of a package structure in embodiment 1 of the present application;

FIG. 3 is an exploded view of the package structure shown in FIG. 2;

FIG. 4 is a schematic view of a submount of FIG. 2;

fig. 5 is a graph showing simulation curves of insertion loss of the package structure and the conventional structure in embodiment 1 of the present application;

FIG. 6 is a schematic view of a package structure in embodiment 2 of the present application;

FIG. 7 is a schematic view of a package structure in embodiment 3 of the present application;

FIG. 8 is a schematic view of a package structure in embodiment 4 of the present application;

FIG. 9 is a schematic view of a package structure in embodiment 5 of the present application;

fig. 10 is a schematic view of a package structure in embodiment 6 of the present application.

Detailed Description

The present application will now be described in detail with reference to specific embodiments thereof as illustrated in the accompanying drawings. These embodiments are not intended to limit the present application, and structural, methodological, or functional changes made by those skilled in the art according to these embodiments are included in the scope of the present application.

In the various illustrations of the present application, certain dimensions of structures or portions may be exaggerated relative to other structures or portions for ease of illustration and, thus, are provided to illustrate only the basic structure of the subject matter of the present application.

Also, terms used herein such as "upper," "above," "lower," "below," and the like, denote relative spatial positions of one element or feature with respect to another element or feature as illustrated in the figures for ease of description. The spatially relative positional terms may be intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as "below" or "beneath" other elements or features would then be oriented "above" the other elements or features. Thus, the exemplary term "below" can encompass both an orientation of above and below. The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. When an element or layer is referred to as being "on," or "connected" to another element or layer, it can be directly on, connected to, or intervening elements or layers may be present.

Example 1

As shown in fig. 2 to 4, the present embodiment provides a COC (chip on ceramic) package structure, which includes a package substrate 10, and at least one semiconductor laser chip 20 and at least one submount 30 and a matching circuit, which are disposed on the package substrate 10, wherein there is a single semiconductor laser chip 20 and a single submount 30 on the package substrate 10. The package substrate 10 is provided with a ground metal 11 and at least one signal line 12, and here, a single signal line 12 is provided on the package substrate 10 corresponding to a single semiconductor laser chip 20. In this embodiment, the upper surface of the package substrate 10 has a metal layer, and signal lines are formed on the metal layer to form the ground metal 11 and the signal lines 12 in a coplanar line structure on the upper surface of the package substrate 10, where the upper surface of the package substrate 10 is the first upper surface 13 of the package substrate 10. The matching circuit includes an input terminal, at least one electronic component, and a ground terminal, the submount 30 has an upper surface 31 and a lower surface 32 opposite to each other, the input terminal 37 and the at least one electronic component of the matching circuit are provided on the upper surface 31 of the submount 30, and the ground terminal 33 of the matching circuit is electrically connected to the ground metal 11 of the package substrate 10. In this embodiment, the ground terminal 33 of the matching circuit is a ground pad provided on the upper surface 31 of the sub-substrate 30, and the input terminal 37 is a pad provided on the upper surface 31 of the sub-substrate 30 for bonding a wire. The semiconductor laser chip 20 and the sub-substrate 30 are disposed on the package substrate 10, and the ground terminal 33 of the upper surface 31 of the sub-substrate 30 is electrically connected to the ground metal 11 of the package substrate 10; the upper surface 22 of the semiconductor laser chip 20 is provided with a signal electrode 21, and the signal electrode 21 is electrically connected to the signal line 12 of the package substrate 10 and the input terminal 37 of the matching circuit on the upper surface 31 of the submount 30, respectively, by bonding wires 60.

In this embodiment, the electronic components of the matching circuit on the submount 30 include a matching resistor 40 and a filter capacitor 50. One end of the filter capacitor 50 is electrically connected to the ground terminal 33 of the sub-board 30 on which the matching circuit is provided on the upper surface 31, the other end is electrically connected to one end of the matching resistor 40, and the other end of the matching resistor 40 is electrically connected to the input terminal 37 of the matching circuit. Specifically, the sub-substrate 30 has a ground terminal 33, an intermediate pad 36, and an input terminal 37 on its upper surface. The filter capacitor 50 is a chip component, and two pads are disposed on the bottom surface thereof, and are respectively soldered to the ground terminal 33 and the intermediate pad 36 on the upper surface 31 of the submount 30, and the matching resistor 40 is a thin film resistor plated on the upper surface 31 of the submount 30, and both ends of the thin film resistor are respectively connected to the intermediate pad 36 and the input terminal 37, and the input terminal 37 is electrically connected to the signal electrode 21 of the semiconductor laser chip 20 through a bonding wire 60. That is, in this embodiment, the input terminal 37, the matching resistor 40, the middle pad 36, the filter capacitor 50 and the ground terminal 33 are connected in sequence to form a matching circuit, and in other embodiments, the matching circuit may further include other electronic components. A ground pad 34 is provided on the lower surface 32 of the submount 30, and the submount 30 is soldered to the ground metal 11 of the package substrate 10 via the ground pad 34 so as to be electrically connected to the ground metal 11 of the package substrate 10. In other embodiments, the submount may also be assembled to the package substrate by other surface mount processes, such as by conductive adhesive bonding to a ground metal of the package substrate. Conductive vias 35 are disposed in the submount 30 to electrically connect the ground terminals 33 of the upper surface 31 and the ground pads 34 of the lower surface 32, so as to electrically connect the ground terminals 33 of the upper surface 31 of the submount 30 and the ground metal 11 of the package substrate 10, i.e. the ground terminals 33 of the upper surface 31 of the submount 30 are electrically connected to the ground metal 11 of the package substrate 10 through the conductive vias 35 and the ground pads 34 of the lower surface 32. In other embodiments, a metal film may be plated on the sidewall of the sub-substrate to electrically connect the ground terminal on the upper surface of the sub-substrate and the ground pad on the lower surface of the sub-substrate. The semiconductor laser chip 20 is provided with a ground pad (not shown) on a lower surface thereof, and the semiconductor laser chip 20 is soldered to the ground metal 11 of the package substrate 10 via the ground pad so as to be electrically connected to the ground metal 11 of the package substrate 10. In other embodiments, the ground terminal on the upper surface of the submount may also be electrically connected to the ground metal of the package substrate by wire bonding. Similarly, the ground pad of the semiconductor laser chip may be provided on the upper surface thereof and electrically connected to the ground metal of the package substrate through a bonding wire.

The packaging structure designs the matching circuit of the semiconductor laser chip on the independent sub-substrate, so that the matched RC link and the grounding metal GND of the packaging substrate are not on the same surface, the integrity of the grounding metal GND of the packaging substrate cannot be damaged, the coupling between the matching resistor and the filtering capacitor and the GND is reduced, the photoelectric bandwidth of the packaging structure is improved, and the packaging structure has good high-frequency performance. As shown in the insertion loss simulation curve of fig. 5, a curve a is the insertion loss simulation result of the common structure shown in fig. 1, and a curve b is the insertion loss simulation result of the package structure of this embodiment, the 3dB bandwidth of the package structure of the present application is 37.3GHz, which is 3.3GHz higher than the 3dB bandwidth of 34GHz of the common structure.

Example 2

As shown in fig. 6, unlike embodiment 1, in this embodiment, the package substrate 10 is provided with a first upper surface 13 and a second upper surface 14, the signal line 12 and the semiconductor laser chip 20 of the package substrate 10 are provided on the first upper surface 13, and the sub-substrate 30 is provided on the second upper surface 14, wherein the height of the second upper surface 14 is lower than that of the first upper surface. Here, the first upper surface 13 is the same as the upper surface of the package substrate in embodiment 1, and has the signal line 12 and the ground metal 11 in a coplanar line structure. Specifically, a step plane is formed on the side of the package substrate 10 away from the signal line 12 as the second upper surface 14, and the second upper surface 14 is lower than the first upper surface 13 of the package substrate 10, so that the upper surface 31 of the sub-substrate 30 mounted thereon is flush with the first upper surface 13 of the package substrate 10 or flush with the upper surface 22 of the semiconductor laser chip 20. The high frequency performance of the package structure is further improved by reducing the height of the second upper surface 14 of the mounting submount 30 to bring the matching circuit on the submount 30 close to the height of the semiconductor laser chip 20 to shorten the length of the bonding wire 60 between the semiconductor laser chip 20 and the matching circuit.

In this embodiment, the second upper surface 14 may also be provided with a grounding metal 11, and the sub-substrate 30 is soldered to the grounding metal 11 of the second upper surface 14 through a grounding pad on the lower surface thereof, or fixed to the grounding metal 11 of the second upper surface 14 by using other surface mount technology such as conductive adhesive bonding, so as to achieve electrical connection with the grounding metal 11 of the package substrate 10. In other embodiments, the ground pad on the upper surface of the submount may also be electrically connected to the ground metal of the package substrate by a wire bond, where the ground metal of the package substrate may be the ground metal of the first or second upper surface thereof.

Example 3

As shown in fig. 7, unlike embodiment 2, in this embodiment, the package substrate 10 is further provided with a third upper surface 15, that is, the package substrate 10 is provided with a first upper surface 13, a second upper surface 14 and a third upper surface 15. Wherein the height of the second upper surface 14 is lower than the height of the third upper surface 15, and the height of the third upper surface 15 is lower than the height of the first upper surface 13. Here, the first upper surface 13 is the same as the upper surface of the package substrate in embodiment 1, the signal line 12 and the ground metal 11 having a coplanar line structure, the sub-substrate 30 is provided on the second upper surface 14, and the semiconductor laser 20 is provided on the third upper surface 15. In this embodiment, the third upper surface 15 is located between the second upper surface 14 and the signal line 12, and the third upper surface 15 is lower than the first upper surface 13 of the package substrate 10 and higher than the second upper surface 14, so that the upper surface 22 of the semiconductor laser chip 20 mounted thereon is flush with the first upper surface 13 of the package substrate 10, while the upper surface 31 of the sub-substrate 30 mounted on the second upper surface 14 is also flush with the upper surface 22 of the semiconductor laser chip 20. The high frequency performance of the package structure is further improved by reducing the height of the third upper surface 15 and the second upper surface 14 on which the semiconductor laser chip 20 and the sub-substrate 30 are mounted, respectively, to bring the matching circuit on the sub-substrate 30 close to the height of the semiconductor laser chip 20 and the height of the signal line 12 on the first upper surface 13 of the package substrate 10, to shorten the length of the bonding wire 60 between the semiconductor laser chip 20 and the matching circuit, and the length of the bonding wire 60 between the signal line 12.

In this embodiment, the third upper surface 15 may also be provided with a grounding metal 11, and the semiconductor laser chip 20 is soldered to the grounding metal 11 of the third upper surface 15 through a grounding pad on the lower surface thereof, or fixed to the grounding metal of the third upper surface by using other surface mount technology such as conductive adhesive bonding, so as to achieve electrical connection with the grounding metal 11 of the package substrate 10. In other embodiments, the semiconductor laser chip upper surface may be provided with a grounding pad and electrically connected to a grounding metal of the package substrate by a bonding wire, where the grounding metal of the package substrate may be one of the first upper surface, the second upper surface or the third upper surface thereof.

Example 4

As shown in fig. 8, unlike the above-described embodiments 1 to 3, in this embodiment, a plurality of semiconductor laser chips 20 and matching circuits thereof are mounted on a package substrate 10, and the matching circuits of the semiconductor laser chips 20 are provided on a plurality of sub-substrates 30, respectively. In this embodiment, taking four channels as an example, the package substrate 10 is provided with the grounding metals 11, and four signal lines 12, four semiconductor laser chips 20, and four sub-substrates 30 arranged between the grounding metals 11 at intervals, and each sub-substrate 30 is provided with an RC matching circuit corresponding to each semiconductor laser chip 20. The signal electrodes 21 on the semiconductor laser chips 20 are electrically connected to the corresponding signal lines 12 and the matching circuits on the submount 30 via bonding wires 60, respectively. The packaging structure can be designed into a structure with a plurality of channels arranged in parallel according to actual needs, a plurality of semiconductor laser chips and sub-substrates are arranged on the packaging substrate, matching circuits corresponding to the semiconductor laser chips are respectively arranged on the sub-substrates, and the number of signal lines and the number of the sub-substrates on the packaging substrate are consistent with the number of the semiconductor laser chips.

Example 5

As shown in fig. 9, unlike the above embodiments 1 to 4, in this embodiment, the grounding metal 11 on the upper surface of the package substrate 10 is used as the grounding terminal of the matching circuit, and the electronic components and the input terminals 37 of the matching circuit are disposed on the upper surface 31 of the sub-substrate 30, i.e., there is no need to dispose the grounding terminal and the grounding pad on the sub-substrate 30. In this embodiment, the electronic components of the matching circuit include a matching resistor 40 and a filter capacitor 50, and the upper surface of the sub-substrate 30 is further provided with an intermediate pad 36.

Specifically, the package substrate 10 is provided with a first upper surface 13 and a second upper surface 14, the signal line 12, the grounding metal 11 and the semiconductor laser chip 20 of the package substrate 10 are provided on the first upper surface 13, and the sub-substrate 30 is provided on the second upper surface 14. Here, the sub-substrate 30 may be mounted on the second upper surface 14 of the package substrate 10 through a surface mount process, and in other embodiments, the sub-substrate 30 may be directly fabricated on the second upper surface 14 of the package substrate 10 through a package substrate fabrication process. The second upper surface 14 is lower than the first upper surface 13 of the package substrate 10, so that the upper surface 31 of the sub-substrate 30 is flush with the first upper surface 13 of the package substrate 10, and the middle pad 36 of the upper surface 31 of the sub-substrate 30 is flush with the grounding metal 11 of the first upper surface 13 of the package substrate 10. The filter capacitor 50 of the matching resistor is a chip component, and two pads are disposed on the bottom surface of the chip component and are respectively soldered to the middle pad 36 on the upper surface of the submount 30 and the grounding metal 11 on the first upper surface 13 of the package substrate 10. The matching resistor 40 is a thin film resistor plated on the upper surface 31 of the submount 30, both ends of the thin film resistor are connected to the intermediate pad 36 and the input terminal 37, respectively, and the input terminal 37 is electrically connected to the signal electrode 21 of the semiconductor laser chip 20 via a bonding wire 60. That is, in this embodiment, the input terminal 37 provided on the upper surface 31 of the submount 30, the matching resistor 40, the intermediate pad 36, the filter capacitor 50, and the ground metal 11 provided on the first upper surface 13 of the package substrate 10 are connected in this order to constitute a matching circuit. In other embodiments, the matching circuit may also include other electronic components.

In other embodiments, the package substrate may further have a third upper surface on which the semiconductor laser chip is disposed. The third upper surface is lower than the first upper surface and higher than the second upper surface. Alternatively, the third upper surface is also provided with a grounding metal, and when the upper surface of the sub-substrate arranged on the second upper surface is flush with the third upper surface, the grounding metal can be used as a grounding end of the matching circuit.

Example 6

As shown in fig. 10, unlike embodiments 1 to 5, the sub-substrate in the above embodiments is mounted on the ground metal of the package substrate by surface mount process, soldering, or the like, and the sub-substrate in the embodiments is directly fabricated on the ground metal of the package substrate. That is, the sub-substrate 30 is directly formed on the grounding metal 11 at a position (e.g., a side far from the signal line) of the grounding metal 11 on the upper surface (i.e., the first upper surface 13) of the package substrate 10 corresponding to the sub-substrate 30 by using a common package substrate forming process. For example, when the package substrate 10 is manufactured, the sub-substrate 30 is directly manufactured on the ground metal 11 by the package substrate manufacturing process. Here, the package substrate is manufactured by a conventional process such as a subtractive process, an additive process, a semi-additive process, or the like. The structure of the embodiment directly manufactures the sub-substrate on the packaging substrate, thereby saving the subsequent assembly steps, simplifying the assembly process and improving the assembly efficiency and the reliability of the product. In the above embodiments, the semiconductor Laser chip may be an electro absorption Modulated Laser (EML) or a Laser of another modulation method. The bonding lead is generally a gold wire with good conductivity, and other conductive metal wires such as copper wire and the like can also be adopted. The package substrate and the sub-substrate are commonly used chip package substrates, and in other embodiments, other related circuits may be disposed on the package substrate. The package substrate and the sub-substrate may be an aluminum nitride substrate, an aluminum oxide substrate, a quartz glass substrate, or the like, and the material of the sub-substrate may be the same as or different from that of the package substrate.

The optical module of this application adopts the packaging structure of any above-mentioned embodiment, can effectively improve the photoelectricity bandwidth, has good high frequency performance. The optical module also comprises a shell, and a circuit board, a heat sink and an optical assembly which are arranged in the shell. The packaging structure is arranged on the heat sink in the shell, and the signal wire and the grounding metal on the packaging substrate are respectively and electrically connected with the signal wire and the grounding wire on the circuit board. Here, the circuit board may be a rigid circuit board or a flexible circuit board, and the heat sink may be a TEC (thermal Electric Cooler), or a heat conductive metal block such as a copper block. The optical module can be an optical transmission module or an optical transceiver module, and the optical transmission module can be in a packaging form of various specifications, such as coaxial packaging or butterfly packaging.

The above list of details is only for the concrete description of the feasible embodiments of the present application, they are not intended to limit the scope of the present application, and all equivalent embodiments or modifications that do not depart from the technical spirit of the present application are intended to be included within the scope of the present application.