阅读说明：本技术 一种光通信模块及其制造方法 (Optical communication module and manufacturing method thereof ) 是由 侯新飞 于 2020-06-17 设计创作，主要内容包括：本发明提供了一种光通信模块及其制造方法。本发明的光通信模块选用铝质基板形成在光通孔侧壁和基板上下表面的多孔氧化铝层,该多孔氧化铝层作为吸光层,其具有多孔结构；且多孔结构连成多个通道,可以实现高效的散热。此外,在光通孔的侧壁上还具有导热性较差的金属反射层,提高光通过的同时,隔绝多孔氧化铝层中热量干扰,提高光通信的精确度。(The invention provides an optical communication module and a manufacturing method thereof. The optical communication module adopts an aluminum substrate to form porous alumina layers on the side wall of the optical through hole and the upper and lower surfaces of the substrate, and the porous alumina layers are used as light absorption layers and have porous structures; and the porous structure is connected into a plurality of channels, so that high-efficiency heat dissipation can be realized. In addition, still have the metal reflecting layer that the thermal conductivity is relatively poor on the lateral wall of light through-hole, when improving light and passing through, isolated porous alumina layer heat interference improves optical communication's accuracy.)

1. A method of manufacturing an optical communication module, comprising the steps of:

(1) providing an aluminum substrate, which comprises a first surface and a second surface which are opposite;

(2) forming a groove and a through hole which are communicated with each other in the aluminum substrate, wherein the groove and the through hole jointly penetrate through the aluminum substrate;

(3) forming a first porous alumina layer on the side wall of the groove by utilizing anodic oxidation, and forming a second porous alumina layer on the side wall of the through hole;

(4) forming a metal layer on the second porous alumina layer by using an electroplating process;

(5) and arranging a photoelectric chip in the groove, wherein the active surface of the photoelectric chip is just opposite to the through hole.

2. The method for manufacturing an optical communication module according to claim 1, characterized in that: step (3) further comprises simultaneously forming a third porous alumina layer on the first surface and a fourth porous alumina layer on the second surface using anodization.

3. The method for manufacturing an optical communication module according to claim 2, characterized in that: the first to fourth porous alumina layers are provided with a plurality of pores, and the pores are communicated with each other to form a plurality of channels.

4. The method for manufacturing an optical communication module according to claim 3, wherein: the metal layer includes one of platinum (Pt), zinc (Zn), and aluminum zinc alloy.

5. The method for manufacturing an optical communication module according to claim 4, wherein: the photoelectric chip is arranged on the back surface of the PCB, and the back surface faces the aluminum substrate.

6. The method for manufacturing an optical communication module according to claim 5, wherein: and forming an opening in the third porous aluminum oxide layer, and forming a solder ball in the opening, wherein the PCB is electrically connected with the wiring layer on the aluminum substrate through the solder ball.

7. The method for manufacturing an optical communication module according to claim 6, wherein: the PCB further comprises other chips which are arranged on the front surface of the PCB.

8. The method for manufacturing an optical communication module according to claim 1, characterized in that: the metal layer closes a plurality of pores of an outer surface of the second porous alumina layer.

9. An optical communication module formed by the method of manufacturing the optical communication module according to any one of claims 1 to 8.

Technical Field

The invention relates to the field of semiconductor chip packaging, in particular to an optical communication module and a manufacturing method thereof.

Background

With respect to a semiconductor package, an optical communication module can be miniaturized, made multifunctional, and made low in cost, but as the degree of integration is increased, its heat generation efficiency and optical transmission quality are greatly limited. In the conventional optical communication module, an optoelectronic chip, a control chip, a memory chip, a conversion chip, and the like are often integrated on the same PCB, and then are electrically connected to a package substrate, such as a motherboard. Generally, if the optoelectronic chip faces the motherboard, an optical through hole is formed on the motherboard to facilitate light passing. The collimation and attenuation of light are greatly interfered, and the optical communication module is not favorable.

Disclosure of Invention

In order to solve the above problems, the present invention provides a method for manufacturing an optical communication module, including the steps of:

(1) providing an aluminum substrate, which comprises a first surface and a second surface which are opposite;

(2) forming a groove and a through hole which are communicated with each other in the aluminum substrate, wherein the groove and the through hole jointly penetrate through the aluminum substrate;

(3) forming a first porous alumina layer on the side wall of the groove by utilizing anodic oxidation, and forming a second porous alumina layer on the side wall of the through hole;

(4) forming a metal layer on the second porous alumina layer by using an electroplating process;

(5) and arranging a photoelectric chip in the groove, wherein the active surface of the photoelectric chip is just opposite to the through hole.

Wherein step (3) further comprises simultaneously forming a third porous alumina layer on the first surface and a fourth porous alumina layer on the second surface using anodic oxidation.

The first to fourth porous alumina layers are provided with a plurality of pores, and the pores are communicated with each other to form a plurality of channels.

Wherein the metal layer comprises one of platinum (Pt), zinc (Zn) and aluminum-zinc alloy.

The photoelectric chip is arranged on the back surface of the PCB, and the back surface faces the aluminum substrate.

According to the embodiment of the invention, an opening is formed in the third porous aluminum oxide layer, and a solder ball is formed in the opening, and the PCB is electrically connected with the wiring layer on the aluminum substrate through the solder ball.

According to the embodiment of the invention, the PCB further comprises other chips which are arranged on the front surface of the PCB.

Wherein the metal layer closes a plurality of pores of an outer surface of the second porous alumina.

The invention also provides an optical communication module, which is formed by the manufacturing method of the optical communication module.

The invention has the following advantages:

the optical communication module adopts an aluminum substrate to form porous alumina layers on the side wall of the optical through hole and the upper and lower surfaces of the substrate, and the porous alumina layers are used as light absorption layers and have porous structures; and the porous structure is connected into a plurality of channels, so that high-efficiency heat dissipation can be realized. In addition, still have the metal reflecting layer that the thermal conductivity is relatively poor on the lateral wall of light through-hole, when improving light and passing through, isolated porous alumina layer heat interference improves optical communication's accuracy.

Drawings

Fig. 1 is a cross-sectional view of an optical communication module of the present invention;

fig. 2 to 7 are schematic views illustrating a process of manufacturing the optical communication module.

Detailed Description

The technology will be described with reference to the drawings in the embodiments, and relates to an optical communication module, which selects an aluminum substrate as a motherboard structure, performs anodic oxidation to form a porous alumina layer for light absorption and heat dissipation, and simultaneously performs electroplating of a metal reflective layer with poor thermal conductivity on the side surface of a through hole to improve the accuracy of light transmission.

It will be understood that the present technology may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the technology to those skilled in the art. Indeed, the technology is intended to cover alternatives, modifications and equivalents of these embodiments, which are included within the scope and spirit of the technology as defined by the appended claims. Furthermore, in the following detailed description of the present technology, numerous specific details are set forth in order to provide a thorough understanding of the present technology. It will be apparent, however, to one skilled in the art that the present technology may be practiced without these specific details.

The terms "top" and "bottom," upper "and" lower, "and" vertical "and" horizontal, "and their various forms, as used herein, are for purposes of illustration and description only and are not intended to limit the description of the technology, as the referenced items may be interchanged in position and orientation. Also, as used herein, the terms "substantially" and/or "about" mean that the specified dimensions or parameters may vary within acceptable manufacturing tolerances for a given application.

Referring first to fig. 1, the mother board of the optical communication module of the present invention is selected to be an aluminum substrate, i.e., an aluminum substrate 10. The aluminum substrate 10 may be an aluminum substrate with a minute amount of doping (about less than 5 wt%), which has a certain thickness, for example, 5mm to 7 mm. The aluminum substrate 10 has an insulating layer on its upper and lower surfaces and a wiring layer (not shown) on the insulating layer, and may have a plate-like rectangular shape, a polygonal shape, a circular shape, or the like.

The aluminum substrate 10 includes an upper surface 11 and a lower surface 12, and the upper surface 11 has a groove 13. The recess 13 is bowl-shaped, and the aperture of the opening is larger than the size of the optoelectronic chip 21, so that the optoelectronic chip 21 can be placed in the recess 13. The bottom of the groove 13 is also provided with a through hole 14, the aperture of the through hole 14 is smaller than that of the groove 13, and the groove 13 and the through hole 14 jointly penetrate through the upper surface 11 and the lower surface 12 of the aluminum substrate 10. Wherein the through hole 14 is used as a light through hole through which light passes.

A layer of porous alumina 15 is provided on the upper and lower surfaces 11, 12 and on the side walls of the recesses 13 and the through-holes 14. The porous alumina layer 15 is formed in situ by anodizing the aluminum substrate 10, which has a thickness of approximately 500-1000 μm. The porous alumina layer 15 has nano-sized or micro-sized pores therein, and the pores allow the porous alumina layer 15 to absorb external light or stray light of the optoelectronic chip 21. In addition, the pores are also communicated with each other to form a plurality of channels, and the channels are used for heat dissipation.

In this embodiment, an exhaust fan (not shown) is disposed at the position of the lower surface 12, so that the lower surface 12 is in a negative pressure state, and air in the porous alumina layer 15 overflows from the porous alumina at the position of the lower surface 12 due to the air pressure difference, which is shown by an arrow F3 in fig. 1. As shown by an arrow F1 in fig. 1, heat of the photo chip 21 is radiated to the periphery in the groove 13, and the heat is absorbed into the porous alumina layer 15 along with the gas in the groove 13, and then conveyed to the lower surface 12 along the hollow arrows in fig. 1 along with the plurality of channels in the porous alumina layer 15 until overflowing.

In addition, the heat of the porous alumina layer 15 is partially conducted to the matrix material of the aluminum substrate 10, and a second heat dissipation is achieved, which is indicated by an arrow F2 in fig. 1.

Most importantly, an electroplated metal layer 16 is further disposed on the sidewall of the through hole 14, and the metal layer 16 covers the porous alumina layer 15 and closes a plurality of pores on the outer surface of the porous alumina layer 15. The thickness of the metal layer 16 is less than the thickness of the porous alumina layer 15.

Preferably, the metal layer 16 is a metal material having poor heat dissipation properties but good light reflection properties, such as platinum (Pt), zinc (Zn), aluminum-zinc alloy, and the like. The heat dissipation property is poor, and heat in the porous alumina layer 15 can be prevented from entering the through hole 14, so that the optical communication is prevented from being interfered; and the light reflection performance is better, the light passing rate can be improved, the light attenuation is prevented, and the collimation degree is ensured.

It can be known that a porous alumina layer is provided on both the upper surface 11 and the lower surface 12 of the aluminum substrate 10, which can be used as a light absorbing layer to absorb light interference from the outside using a porous structure. The porous alumina layer in the groove 13 can absorb stray light from the optoelectronic chip 21, which ensures the accuracy of optical communication.

The optoelectronic chip 21 is integrated on an interposer substrate 18, such as a PCB, a DBC substrate, etc. The interposer 18 also has other chips, such as chips 19 and 20. The chips 19, 20, which may be control chips, conversion chips, rectifier chips, etc., are disposed on the upper surface of the interposer 18, while the optoelectronic chip 21 is disposed on the lower surface of the interposer 18.

The interposer 18 is electrically connected to the aluminum substrate 10 by solder balls 22. to achieve this electrical connection, the openings 17 in the porous alumina layer 15 may be formed first, and then the solder balls 22 may be formed by ball-bonding. The interposer 18 is attached to the porous alumina layer 15 for heat dissipation.

The following describes a method for manufacturing the optical communication module with reference to fig. 2 to 7, which specifically includes the following steps:

(1) providing an aluminum substrate, which comprises a first surface and a second surface which are opposite;

(2) forming a groove and a through hole which are communicated with each other in the aluminum substrate, wherein the groove and the through hole jointly penetrate through the aluminum substrate;

(3) forming a first porous alumina layer on the side wall of the groove by utilizing anodic oxidation, and forming a second porous alumina layer on the side wall of the through hole;

(4) forming a metal layer on the second porous alumina layer by using an electroplating process;

(5) and arranging a photoelectric chip in the groove, wherein the active surface of the photoelectric chip is just opposite to the through hole.

Referring first to fig. 2, an aluminum substrate 10 is provided that includes opposing upper and lower surfaces 11 and 12.

Then, referring to fig. 3, a groove 13 and a through hole 14 communicating with each other are formed in the aluminum substrate 10, wherein the groove 13 and the through hole 14 commonly penetrate the aluminum substrate 10. Wherein the aperture R2 of the through hole 14 is smaller than the aperture R1 of the groove 13. The grooves 13 and the through holes 14 are formed by two-step wet etching or two-step laser drilling, and the grooves 13 and the through holes 14 have relatively smooth surfaces.

Referring to fig. 4, the aluminum substrate having the grooves 13 and the through-holes 14 described above is anodized. Specifically, the aluminum substrate 10 is anodized using an aluminum substrate 10 as an anode and Pt or graphite as a cathode, and a porous alumina layer 15 is formed on the upper surface 11, the lower surface 12, and the side walls of the grooves 13 and the through-holes 14. And after the preset thickness is reached, stopping oxidation, drying and cleaning.

Referring next to fig. 5, a metal layer 16 is formed on the porous alumina layer 15 on the sidewalls of the via hole 14 using an electroplating process. The metal layer 16 closes a plurality of pores of the outer surface of the porous alumina layer 15, and includes one of platinum (Pt), zinc (Zn), and aluminum-zinc alloy.

Referring to fig. 6, an opening 17 is formed in the porous alumina layer 15 of the upper surface 11, and the opening 17 should expose the wiring layer structure on the aluminum substrate 10.

Referring then to fig. 7, an integrated structure with an interposer substrate 18 is provided, which includes other chips 19, 20 on the interposer substrate 18 and an optoelectronic chip 20 under the interposer substrate 18. The solder balls 22 are formed by ball-planting in the openings 17, and the interposer 18 is soldered to the upper surface 11 through the solder balls 22. Preferably, the intermediate substrate 18 is closely attached to the porous alumina layer 15.

In summary, the optical communication module of the present invention selects the porous alumina layer formed on the sidewall of the optical through hole and the upper and lower surfaces of the substrate by the aluminum substrate, and the porous alumina layer is used as the light absorbing layer and has a porous structure; and the porous structure is connected into a plurality of channels, so that high-efficiency heat dissipation can be realized. In addition, still have the metal reflecting layer that the thermal conductivity is relatively poor on the lateral wall of light through-hole, when improving light and passing through, isolated porous alumina layer heat interference improves optical communication's accuracy.

The foregoing detailed description of the technology has been presented for purposes of illustration and description. It is not intended to be exhaustive or to limit the technology to the precise form disclosed. Many modifications and variations are possible in light of the above teaching. The described embodiments were chosen in order to best explain the principles of the technology and its practical application to thereby enable others skilled in the art to best utilize the technology in various embodiments and with various modifications as are suited to the particular use contemplated. The scope of the present technology is defined by the appended claims.

The expressions "exemplary embodiment," "example," and the like, as used herein, do not refer to the same embodiment, but are provided to emphasize different particular features. However, the above examples and exemplary embodiments do not preclude their implementation in combination with features of other examples. For example, even in a case where a description of a specific example is not provided in another example, unless otherwise stated or contrary to the description in the other example, the description may be understood as an explanation relating to the other example.

The terminology used in the present invention is for the purpose of illustrating examples only and is not intended to be limiting of the invention. Unless the context clearly dictates otherwise, singular expressions include plural expressions.

While example embodiments have been shown and described, it will be apparent to those skilled in the art that modifications and changes may be made without departing from the scope of the invention as defined by the claims.