KR102535603B1 - Optical module platform structure and fabrication method - Google Patents

Abstract

The present invention relates to an optical module platform structure and manufacturing method, comprising: an optical module platform substrate; a light source element mounted on an upper portion of a light source mount bonded to an upper side of the optical module platform substrate; a waveguide mounted on an upper portion of a waveguide mount bonded to an upper portion of an optical module platform substrate at a distance from the light source device; a lens mount fixed between the light source mount and the waveguide mount; A lens fixed to the top of the lens mount; includes.
The optical module platform structure and manufacturing method according to the present invention has an effect of maximizing optical coupling efficiency between a light source and a waveguide and minimizing an optical alignment error by applying a lens mount.

Description

Optical module platform structure and fabrication method

The present invention relates to an optical module platform structure for mounting a lens in optical alignment between a multi-channel light source and a waveguide and a technology for manufacturing the same.

Recently, with the rapid growth of industries such as data centers and artificial intelligence, the need to transmit and receive more data in a short time has emerged, and optical communication technology is attracting attention. Accordingly, there is a demand for miniaturization and high-speed optical transceiver modules that play a key role in optical communication.

An optical transceiver module for optical communication is largely composed of an OSA (Optical Sub Assembly) that plays a role in converting an optical signal to an electrical signal (electronic/photoelectric) and an ESA (Electrical Sub Assembly) that plays a role in signal processing of electrical signals. do.

Here, the OSA unit is composed of a Transmitter Optical Sub Assembly (TOSA) that converts an electrical signal into an optical signal and transmits the optical signal, and a Receiver Optical Sub Assembly (ROSA) that converts the received optical signal into an electrical signal.

In order to secure maximum optical coupling efficiency when manufacturing core optical components such as TOSA and ROSA, precise optical alignment of optical elements such as LD (Laser Diode), PD (Photo Diode), mirror, lens, and waveguide in the optical transceiver is required.

In the case of a single-mode optical fiber, the diameter of the optical waveguide core is about 9 μm, and the optical alignment error of the lens is allowed within several μm to secure the maximum optical coupling efficiency.

Recently, as miniaturization and high-speed optical modules are required, the use of multi-channel optical modules is rapidly increasing. As the refractive index difference between the core and the cladding of the waveguide used inside the TOSA/ROSA is increased to reduce the size of the optical module, the core layer The thickness of is also decreasing to about 3 μm.

Accordingly, the sensitivity to optical alignment errors is further increased, and time and cost are consumed in optical alignment and bonding processes of lenses when packaging optical components.

In general, as shown in FIG. 1 for optical alignment between the LD and the waveguide, a lens is inserted between the waveguide and the LD, and then the position is adjusted in three axes X-Y-Z so that the amount of light incident on the waveguide is maximized.

At this time, after adjusting the optimal position by finely controlling the lens, epoxy is administered between the lower end of the lens and the optical module platform substrate, and then the lens is fixed by curing the epoxy with heat or ultraviolet light.

The curing process of the epoxy used for fixing the lens is characterized in that it is initially cured in a solid state after changing from a liquid state to a semi-solid gel state by light or heat in the ultraviolet wavelength range.

At this time, during the process of changing from a liquid to a solid state, the curing agent inside the epoxy evaporates, and accordingly, a shrinkage process in which the volume of the epoxy is reduced is accompanied.

In the conventional lens assembly process using epoxy, contraction force due to epoxy contraction occurs between the lens and the platform substrate, and this contraction force acts as a force to change the position of the lens.

In a general lens assembly process, the lens is strongly gripped using a holder such as a lens gripper in order to maintain the lens position at the initial maximum optical alignment point against such contraction force.

However, as shown in FIG. 2, after the epoxy curing process is finished, the gripping force by the lens tongs and the epoxy contraction force maintain the position of the lens by the equilibrium of the forces, and finally separate the lens from the lens tongs. When this is done, the lens gripping force is removed and the force balance is broken, and eventually the lens moves from the initial alignment position to the epoxy contraction direction due to the force acting in the epoxy contraction direction. Optical coupling loss occurs.

And in order to solve the above problems, recently, the curing time is extended by lowering the energy of ultraviolet light for epoxy curing or lowering the curing temperature, which increases the time of the conversion process from the gel state to the solid during the epoxy curing process. As a result, a method of minimizing the optical alignment error is applied by gradually correcting the lens position error finely during the curing process until the gel state, in which the shrinkage force remains and the liquidity remains, is maintained for a relatively long time to become a solid state.

However, this process method has a disadvantage in that the epoxy curing time is long and the product production rate is low and the product price is high.

Therefore, it is necessary to shorten the epoxy curing time in order to secure mass production and price competitiveness of the product.

Republic of Korea Patent Registration No. 10-0757233

The present invention has been proposed in view of the above circumstances, and an optical module platform structure and manufacturing method capable of maximizing optical coupling efficiency between a light source and a waveguide by applying a lens mount and minimizing an epoxy curing time used for fixing a lens. Its purpose is to provide

An optical module platform structure according to an embodiment of the present invention includes an optical module platform substrate; a light source element mounted on an upper portion of a light source mount bonded to an upper side of the optical module platform substrate; a waveguide mounted on an upper portion of a waveguide mount bonded to an upper portion of an optical module platform substrate at a distance from the light source device; a lens mount fixed between the light source mount and the waveguide mount; A lens fixed to an upper portion of the lens mount, wherein a first lens mount guide and a second lens mount guide are mounted between the light source mount and the lens mount and between the waveguide mount and the lens mount, respectively. The lens mount guide and the second lens mount guide are mounted at intervals from the optical module platform substrate.

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In addition, through-holes may be formed in portions corresponding to the lens mount, the first lens mount guide, and the second lens mount guide in the optical module platform substrate.

Also, the lens mount may be formed to be larger than the width of the first lens mount guide or the second lens mount guide, and may be formed to have a height lower than that of the first lens mount guide or the second lens mount guide.

Here, the light source mount and the first lens mount guide are fixed through a first joint, the waveguide mount and the second lens mount guide are fixed through a second joint, and the first lens mount guide and the lens mount are fixed through a fourth joint. It is fixed through the joint, and the second lens mount guide and the lens mount may be fixed through the fifth joint.

In this case, the first, second, fourth, and fifth junctions may be formed of an epoxy resin.

Also, the light source element and the waveguide may be disposed on an optical path.

Another feature of the present invention, a method of manufacturing an optical module platform structure, includes a light source device bonding step of bonding a light source mount having a light source device mounted on one side of an upper portion of an optical module platform substrate; A lens mount adhesion step of adhering the lens mount to the side of the light source mount; a waveguide bonding step of attaching the waveguide mount on which the waveguide is mounted to an opposite side of the lens mount and bonding the waveguide mount to an optical module platform substrate; A lens fixing step of disposing a lens on the upper part of the lens mount and then applying an adhesive to form a third junction; and when the lens mount is raised in the Y-axis direction due to adhesive contraction during curing of the third junction, adhesive is applied to the lens mount, the first lens mount guide, and the second lens mount guide to form fourth and fifth junctions. A lens mount fixing step to do; includes.

In addition, between the light source element bonding step and the lens mount adhesion step, a first lens mount guide is mounted between the light source mount and the lens mount, and then an adhesive is applied between the light source mount and the first lens mount guide to form a first joint portion A first lens mount guide installation step of forming a; may be further included.

In addition, between the lens mount adhering step and the waveguide bonding step, a second lens mount guide is mounted between the lens mount and the waveguide mount, and then an adhesive is applied between the second lens mount guide and the waveguide mount to form a second junction. A second lens mount guide installation step of forming a; may be further included.

In addition, after the lens fixing step, the lens mount is raised above the first and second lens mount guides, and then an adhesive is applied between the lens mount and the first and second lens mount guides to form the fourth and fifth joint portions. A lens mount fixing step of forming a; may include.

In addition, through-holes may be formed in the optical module platform substrate corresponding to the lens mount and the first and second lens mount guides.

Here, the lens mount may be formed lower than the height of the first and second lens mount guides.

Also, in the lens fixing step, the lens may be inserted between the light source element and the waveguide through the lens gripper, and then mounted at a point where the light output of the waveguide is maximized.

The optical module platform structure and manufacturing method according to the present invention maximizes the optical coupling efficiency between the light source and the waveguide by applying a lens mount, and configures the internal configuration to minimize the occurrence of errors in the shrinkage direction and optical alignment position of the adhesive. It has the effect of minimizing the error of optical alignment while speeding up the curing speed of the adhesive.

1 is a side view showing optical element optical alignment in a conventional optical component;
2 is a view showing the contraction force of a general epoxy curing process and the reaction force acting on the lens gripper.
3 is a side view showing an optical module platform structure according to the present invention;
Figure 4 is a view showing the installation process of the first lens mount guide in the manufacturing method of the optical module platform structure according to the present invention.
5 is a view showing a second lens mount guide installation process in the manufacturing method of the optical module platform structure according to the present invention.
6 is a view showing an alignment state of lenses for maximum optical coupling efficiency in the manufacturing method of the optical module platform structure according to the present invention.
7 is a view showing an example of movement in the Y-axis direction of the lens mount due to adhesive shrinkage in the manufacturing method of the optical module platform structure according to the present invention.
8 is a view showing a lens mount attachment process in the manufacturing method of the optical module platform structure according to the present invention.
9 is an exemplary graph showing the optical coupling efficiency according to the displacement of the X, Y, and Z axes through the manufacturing method of the optical module platform structure according to the present invention.

Advantages and features of the present invention, and methods of achieving them, will become clear with reference to the detailed description of the following embodiments taken in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in various different forms, only these embodiments make the disclosure of the present invention complete, and common knowledge in the art to which the present invention belongs. It is provided to fully inform the holder of the scope of the invention, and the present invention is defined by the description of the claims. Meanwhile, terms used in this specification are for describing the embodiments and are not intended to limit the present invention. In this specification, singular forms also include plural forms unless specifically stated otherwise in a phrase. As used herein, "comprises" or "comprising" means the presence or absence of one or more other elements, steps, operations and/or elements other than the recited elements, steps, operations and/or elements; do not rule out additions.

Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings, FIG. 3 is a side view showing an optical module platform structure according to the present invention.

The optical module platform structure 10 of the present invention includes an optical module platform substrate 20, a light source device 30, a waveguide 40, a lens mount 50, a lens 60, a first lens mount guide 70, a first It includes 2 lens mount guides (80).

The optical module platform substrate 20 is formed in various ways according to the environment and purpose, and in the present invention, the optical module platform substrate 20 is formed in a plate shape having a predetermined size.

Further, the optical module platform substrate 20 is formed with a through hole 22 corresponding to the lens mount 50, the first lens mount guide 70, and the second lens mount guide 80.

Here, the through hole 22 is formed in the optical module platform substrate 20 so that the lens mount 50, the first lens mount guide 70, and the second lens mount guide 80 are connected to the optical module platform substrate 20. ) and, if necessary, move the lens mount 50 upward to the lens position having the maximum optical coupling efficiency.

The light source element 30 is mounted on top of a light source mount 32 mounted on one upper side of the optical module platform substrate 20 .

That is, the light source element 30 is mounted on the upper part of the light source mount 32 mounted on the upper part of the optical module platform substrate 20 and emits light in the direction of the lens 60 when power is supplied.

The waveguide 40 is mounted on an upper portion of a waveguide mount 42 mounted on one upper side of the optical module platform substrate 20 .

That is, the waveguide 40 is mounted on the upper part of the waveguide mount 42 mounted on the upper part of the optical module platform substrate 20 at a distance from the light source element 30, and transmits light through the lens 60. let it be transmitted

The lens mount 50 is fixed between the light source mount 32 and the waveguide mount 42 .

Here, the lens mount 50 may be formed in various shapes depending on the environment and purpose, and in the present invention, the lens mount 50 is a square or rectangular shape to minimize positional deformation of the lens 60 through the adhesive portion. It is formed of blocks of shape.

A first lens mount guide 70 is mounted between the lens mount 50 and the light source mount 32, and a second lens mount guide 80 is installed between the lens mount 50 and the waveguide mount 42. ) is installed.

That is, after the lens mount 50 is disposed between the light source mount 32 and the waveguide mount 42, the first lens mount guide 70 is installed between the light source mount 32 and the lens mount 50. is fixed, and the second lens mount guide 80 is fixed between the waveguide mount 42 and the lens mount 50.

At this time, the light source mount 32 and the first lens mount guide 70 are fixed through the first joint portion 91, and the waveguide mount 42 and the second lens mount guide 80 are fixed through the second joint portion 92. ), the first lens mount guide 70 and the lens mount 50 are fixed through the fourth junction 94, and the second lens mount guide 80 and the lens mount 50 are It is fixed through 5 joint (95).

Here, the first, second, fourth, and fifth joint portions 91, 92, 94, and 95 are formed of any one of known adhesives, and in the present invention, the first, second, fourth, and fifth joint portions 91, 92, and 94 , 95) is formed of an epoxy resin.

The lens 60 is fixed to the top of the lens mount 50 .

And the lens 60 is fixed through the lens mount 50 and the third junction 93 formed between them. Here, the third joint portion 93 is formed of any one of known adhesives, and in the present invention, the third joint portion 93 is formed of an epoxy resin.

That is, the lens 60 is fixedly mounted on the top of the lens mount 50 through the third junction 93 to focus the light output from the light source device 30 to the waveguide 40 .

Next, the manufacturing method of the optical module platform structure will be described with reference to the drawings, FIG. 4 is a view showing the installation process of the first lens mount guide in the manufacturing method of the optical module platform structure according to the present invention, and FIG. 5 is a view showing the second lens mount guide installation process in the manufacturing method of the optical module platform structure according to the present invention, Figure 6 is the alignment state of the lenses for maximum optical coupling efficiency in the manufacturing method of the optical module platform structure according to the present invention Figure 7 is a view showing an example of movement in the Y-axis direction of the lens mount by adhesive shrinkage in the manufacturing method of the optical module platform structure according to the present invention, Figure 8 is the optical module platform structure according to the present invention It is a drawing showing the lens mount attachment process in the manufacturing method.

First, as shown in FIG. 4, after bonding the light source mount 32 to which the light source element 30 is attached to the optical module platform substrate 20, an adhesive such as epoxy is applied to the side of the light source mount 32. After forming the first bonding portion 91, the first lens mount guide 70 is attached.

Next, as shown in FIG. 5, the lens mount 50 is brought into close contact with the side of the first lens mount guide 70, and then the second lens mount guide 80 is brought into close contact with the opposite side of the lens mount 50. .

Thereafter, the waveguide mount 42 on which the waveguide 40 is mounted is brought into close contact with the side of the second lens mount guide 80, and then the waveguide mount 42 on which the waveguide 40 is mounted on the top and the second lens mount guide After forming the second bonding portion 92 between the portions 80 using an adhesive such as epoxy, the bottom surface of the waveguide mount 42 is bonded to the optical module platform substrate 20 .

At this time, the light source mount 32, the first and second lens mount guides 70 and 80, the lens mount 50, the waveguide mount 42, etc. have a clearance at the left and right sides of each of them in contact with each other. Make it as close as possible so that it doesn't happen.

That is, the light source mount 32, the first lens mount guide 70, the waveguide mount 42, and the second lens mount guide 80 are fixed to the optical module platform substrate 20, and the lens mount 50 ) has degrees of freedom in the two axes directions X and Y shown in FIG. 3 and the degrees of freedom are limited so that they cannot move in the direction of the Z axis.

Next, as shown in FIG. 6, the lens 60 is inserted between the light source element 30 and the waveguide 40 using the lens gripper 100, and the light output of the waveguide 40 is maximized X, By moving the position of the lens 60 in each direction of the Y and Z axes, a point where the lens 60 can achieve the maximum optical coupling efficiency is selected.

Thereafter, a third junction 93 is formed between the lower end of the lens 60 and the upper end of the lens mount 50 using an adhesive such as epoxy to fix the lens 60 to an optimal optical alignment point. do.

At this time, in the process of forming the third bonding portion 93, if necessary, the lens mount 50 may be moved in the Y-axis upward direction to bring the lens mount 50 into close contact with the lower surface of the lens.

Next, when the third junction part 93 is hardened, the lens mount 50 moves in the Y-axis upward direction due to the degree of freedom of the lens mount 50 in the Y-axis direction, and even after curing, reaction force is not generated in the contraction direction. The lens 60 positioned above the lens mount 50 can be maintained in an initial optimal optical alignment position.

To supplement this, the third bonding portion 93 is formed by curing an adhesive such as epoxy, so that shrinkage force is generated due to volume reduction due to evaporation of the curing agent during the curing process.

That is, when the lens is fixed to the bottom surface of the optical module platform board using an adhesive such as epoxy, as shown in FIG. 1, contraction force in the Y-axis downward direction is generated, thereby maintaining the optimal optical alignment point of the lens. The lens gripper must apply a reaction force in the Y-axis upward direction.

This reaction force is removed in the process of separating the lens from the lens gripper after the curing of the adhesive such as epoxy is completed, and only the contractive force of the adhesive such as the epoxy acting in the Y-axis downward direction of the lens remains, eventually leaving the lens mount. The lens attached to is not only moved in the Y-axis downward direction, but also eventually causes an optical alignment error.

However, the shrinkage in the curing process of the third junction part 93 of the present invention can solve the above problems by moving the lens mount 50 in the Y-axis upward direction.

At this time, a through hole 22 is formed in a certain area of the optical module platform substrate 20 at the lower end of the lens mount 50 to prevent contraction of the lens mount 50 due to an adhesive such as epoxy. The through hole 22 may also be used to move the lens mount 50 to a position of a lens having maximum optical coupling efficiency, if necessary.

Next, after complete curing to prevent shrinkage and deformation of the third joint 93, as shown in FIG. 8, the lens mount 50 and the side surface between the first and second lens mount guides 70 and 80 An adhesive such as epoxy is cured to form the fourth and fifth joint portions 94 and 95 .

Thereafter, when the lens gripper 100 is separated from the lens 60, all optical alignment between the light source element 30 and the waveguide 40 by the lens 60 is completed.

As such, the main cause of shrinkage in the Y-axis direction occurring during the curing process of adhesives such as epoxy is the shrinkage of the adhesive at the third junction between the lens and the lens mount, and the shrinkage in the Z-axis direction is caused by the adhesive at the fourth and fifth junctions Shrinkage is key.

However, the adhesive shrinkage of the third joint in the Y-axis direction does not generate a reaction force on the lens gripper because the lens mount has a degree of freedom during the curing process, so even if the lens gripper is removed after curing is completed, no change in the position of the lens occurs. .

In addition, the contraction of the fourth and fifth junctions occurring in the Z-axis direction exists symmetrically on the left and right sides with respect to the lens mount, so that the contraction force due to the adhesive contraction is parallel to each other in the Z-axis direction.

Moreover, since parts such as the light source mount, lens mount, first and second lens mount guides, and waveguide mount are closely arranged without gap, the thickness of the junction is thin, and the contraction force generated by the adhesive shrinkage is insignificant.

In addition, in general, in optical alignment between a light source and a waveguide using a lens as in this patent, the Z-axis optical alignment tolerance is 5 times larger than that of the X and Y axes.

For example, as shown in FIG. 9, in the case of optical alignment between optical fiber light sources, the optical alignment tolerances of the X and Y axes require precision within several μm to achieve an efficiency of 90% or more, whereas in the case of the Z axis, the X, It is relatively very large compared to the Y-axis.

Therefore, considering the above conditions, the optical alignment position error due to the shrinkage of the adhesive on the Z axis is insignificant.

As a result, this patent proposes a structure and manufacturing process for the arrangement of internal parts to minimize optical alignment position errors by considering the shrinkage direction of the adhesive. The effect of minimizing the optical alignment error can be expected.

The above description is merely an example of the technical idea of the present invention, and various modifications and variations can be made by those skilled in the art without departing from the essential characteristics of the present invention.

Therefore, the embodiments expressed in the present invention are not intended to limit the technical idea of the present invention, but to explain, and the scope of the present invention is not limited by these embodiments. The protection scope of the present invention should be construed according to the claims below, and all technical ideas that are equivalent or within the scope of equivalents should be construed as being included in the scope of the present invention.

10: optical module platform structure 20: optical module platform substrate
22: through hole 30: light source element
40: waveguide 50: lens mount
60: lens 70: first lens mount guide
80: second lens mount guide

Claims (15)

optical module platform substrate;
a light source element mounted on an upper portion of a light source mount bonded to an upper side of the optical module platform substrate;
a waveguide mounted on an upper portion of a waveguide mount bonded to an upper portion of an optical module platform substrate at a distance from the light source device; and
a lens mount fixed between the light source mount and the waveguide mount; Including; a lens fixed to an upper portion of the lens mount,
A first lens mount guide and a second lens mount guide are mounted between the light source mount and the lens mount and between the waveguide mount and the lens mount, respectively;
The optical module platform structure of claim 1, wherein the first lens mount guide and the second lens mount guide are mounted at a distance from the optical module platform substrate.
delete delete According to claim 1,
The optical module platform structure of claim 1 , wherein the optical module platform substrate has a through hole formed in a portion corresponding to a lens mount, a first lens mount guide, and a second lens mount guide.
According to claim 1,
The optical module platform structure of claim 1 , wherein the lens mount has a width larger than that of the first lens mount guide or the second lens mount guide and a height lower than that of the first lens mount guide or the second lens mount guide.
According to claim 1,
The light source mount and the first lens mount guide are fixed through a first joint, the waveguide mount and the second lens mount guide are fixed through a second joint, and the first lens mount guide and the lens mount are fixed through a fourth joint. and the second lens mount guide and the lens mount are fixed through a fifth joint.
According to claim 6,
The optical module platform structure of claim 1, wherein the first, second, fourth, and fifth junctions are formed of epoxy resin.
According to claim 1,
An optical module platform structure wherein the light source element and the waveguide are disposed on an optical path.
A light source device bonding step of bonding a light source mount having a light source device mounted on one side of an upper portion of an optical module platform substrate;
A lens mount adhesion step of adhering the lens mount to the side of the light source mount;
a waveguide bonding step of attaching the waveguide mount on which the waveguide is mounted to an opposite side of the lens mount and bonding the waveguide mount to an optical module platform substrate;
A lens fixing step of disposing a lens on the upper part of the lens mount and then applying an adhesive to form a third junction; and
When the lens mount is raised in the Y-axis direction due to adhesive shrinkage during the curing of the third joint, adhesive is applied to the lens mount, the first lens mount guide, and the second lens mount guide to form fourth and fifth joints. A method of manufacturing an optical module platform structure comprising a; lens mount fixing step.
According to claim 9,
Between the light source element bonding step and the lens mount adhesion step, a first lens mount guide is mounted between the light source mount and the lens mount, and then an adhesive is applied between the light source mount and the first lens mount guide to form a first junction. A method of manufacturing an optical module platform structure further comprising: forming a first lens mount guide installation step.
According to claim 9,
Between the lens mount adhering step and the waveguide bonding step, a second lens mount guide is mounted between the lens mount and the waveguide mount, and then an adhesive is applied between the second lens mount guide and the waveguide mount to form a second junction A method of manufacturing an optical module platform structure that includes; a second lens mount guide installation step to do.
According to claim 9,
After the lens fixing step, the lens mount is raised above the first and second lens mount guides, and then an adhesive is applied between the lens mount and the first and second lens mount guides to form fourth and fifth junctions. A method of manufacturing an optical module platform structure comprising a; lens mount fixing step.
According to claim 9,
Forming a through hole in the optical module platform substrate corresponding to the lens mount and the first and second lens mount guides.
According to claim 12,
The method of manufacturing an optical module platform structure in which the lens mount is formed lower than the height of the first and second lens mount guides.
According to claim 9,
In the lens fixing step, the lens is inserted between the light source element and the waveguide through the lens gripper and then mounted at a point where the light output of the waveguide is maximized.

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