KR101175300B1 - Optical module and method for fabricating the same - Google Patents

Abstract

PURPOSE: An optical module and a manufacturing method thereof are provided to minimize the mis-alignment of optical fibers using double epoxy. CONSTITUTION: An optical module comprises a substrate(100), spacers(200), covers(300), and optical fibers(400). The substrate has optical device chips. The spacers have one or more through holes where the optical device chips are inserted. The covers are coupled to the spacers and close the through holes of the spacers. The optical fibers are fixed to positions of the covers corresponding to the optical device chips using epoxy.

Description

Optical module and its manufacturing method {OPTICAL MODULE AND METHOD FOR FABRICATING THE SAME}

The present invention relates to an optical module and a method of manufacturing the same, and more particularly, it is possible to miniaturize and manufacture necessary parts using a semiconductor process, so that parts of the same standard can be mass-produced, thereby reducing the unit cost and various forms. Optical transmission / reception module and packaging are possible, and it is possible to attach the optical fiber more firmly by using double epoxy to minimize the distortion of the optical fiber alignment, so that it is possible to manufacture a product with high reliability and multi-channel array type (or The present invention relates to an optical module and a method of manufacturing the same, which can increase the price competitiveness due to a low manufacturing cost since the production yield is high.

With the advent of the information age, there is a need for an optical module using light capable of transmitting a large amount of information. Among them, the optical module using light is required to have a high reliability of not only having excellent characteristics of the module itself but also maintaining its characteristics for a long time.

Low prices must be maintained to facilitate the dissemination of optical modules for the implementation of Fiber To The Home (FTTH). In particular, as the capacity of the optical transmission system increases, efforts have been made to increase the number of modules that can be mounted per unit area by reducing the size of the optical module mounted in the optical transmission system.

Meanwhile, the existing optical module performs a function of a butterfly structure in which an optical device and an electronic device are integrated on a platform-type substrate and inserted into a metal case, and transmit and receive light. There is a thio-can (TO-CAN) structure that covers the upper surface of the stem in which the active devices (for example, photodiode or laser diode, etc.) that can be integrated.

The optical module having the thio-can (TO-CAN) structure is low manufacturing cost, widely applied to various types of high-speed optical communication system, but there is a limit in reducing the volume of the thio-can (TO-CAN) package itself optical module In order to miniaturize, a new optical module is required.

Meanwhile, in the conventional method of aligning an optical device chip and an optical fiber, a method of arranging and aligning an optical fiber in a horizontal direction on the optical device chip and the optical fiber alignment block is common.

Another optical device chip and the optical fiber alignment method, there is a method to configure and align the optical device chip and the optical fiber to be placed vertically. In the conventional alignment method, the optical device chip and the optical fiber are aligned, and then fixed using an ultraviolet curable epoxy on the optical fiber support substrate to fix the optical fiber.

However, since the UV curable epoxy is used once, the optical fiber bonding site is not strong, so the alignment is likely to be misaligned, which may lead to defects beyond the standard characteristics.

Meanwhile, in the method of fabricating an array type (or array) device using a multi-channel optical fiber, at least one optical fiber among the multi-channel (for example, 4, 8, or 16 channel) optical fiber is bad during manufacturing. If this occurs, because all of the multi-channel optical fiber in use in the form of a bundle is badly processed, there is a high possibility of failure, there is also a problem that the manufacturing cost rises.

The present invention has been made to solve the above-described problems, the object of the present invention is to be miniaturized, and to manufacture the necessary parts using a semiconductor process, it is possible to mass-produce parts of the same standard, as well as to reduce the unit cost Various types of optical transmission / reception module and packaging are possible, and it is possible to manufacture the product with high reliability by minimizing the distortion of the optical fiber alignment by attaching the optical fiber more firmly by using double epoxy. The present invention provides an optical module and a method of manufacturing the same which increase the price competitiveness due to a low manufacturing cost since the yield of the manufactured product is high when the device is manufactured in an array type (or array type).

In order to achieve the above object, the first aspect of the present invention, the optical device chip is provided with an array in the form of a substrate; At least one through hole formed therein, the spacer being coupled in an array form on the substrate such that each optical device chip is inserted into the through hole; A cover coupled in array form on each spacer to close through holes in each spacer; An optical fiber fixedly coupled in an array form using a first epoxy so as to correspond to a position of each optical device chip on each cover; And a second epoxy formed to mold a portion of the optical fiber including each spacer, a cover, and a first epoxy on the substrate, and injecting light transmitted through each optical fiber to each optical device chip, or each optical light. It is to provide an optical module, characterized in that configured to inject light emitted from the device chip into each optical fiber.

Here, the first epoxy is made of an ultraviolet curable epoxy, the second epoxy is preferably made of a thermosetting epoxy that is thermoset at a curing temperature lower than the glass transition temperature (Tg) of the first epoxy.

Preferably, the first epoxy has a glass transition temperature (Tg) of about 120 ~ 140 ℃, photocured by UV (UV) exposure for 1 to 3 minutes at about 90 ~ 110mW, the second epoxy It can be thermally cured by heating for about 2 to 4 hours at about 90 to 110 ℃.

Preferably, the optical fiber may be made of a multi-channel optical fiber.

According to a second aspect of the present invention, there is provided a method including: coupling a plurality of optical device chips in an array form on a substrate; Providing a plurality of spacers having at least one through hole, and then combining the spacers on the substrate in an array so that each optical device chip is inserted into the through holes; Combining the plurality of covers in an array so as to close through holes of each spacer; Fixing the optical fibers in the form of an array using a first epoxy to correspond to the position of each optical device chip on each cover; And molding a portion of the optical fiber including a plurality of spacers, a cover, and a first epoxy on the substrate using a second epoxy.

Here, the first epoxy has a glass transition temperature (Tg) of about 120 ~ 140 ℃, photocured by UV (UV) exposure for 1 to 3 minutes at about 90 ~ 110mW, the second epoxy is It is preferable to heat-set through heating for about 2 to 4 hours at about 90-110 degreeC lower than the glass transition temperature (Tg) of a 1st epoxy.

According to the optical module and the manufacturing method of the present invention as described above, it is possible to miniaturize, and to manufacture the necessary parts using a semiconductor process, it is possible to mass-produce parts of the same standard, not only to reduce the unit cost but also various forms Optical transmission / reception module and packaging are possible, and it is possible to attach the optical fiber more firmly by using double epoxy to minimize the distortion of the optical fiber alignment, so that it is possible to manufacture a product with high reliability and multi-channel array type (or The production yield is high when the device is manufactured in an array type), so the manufacturing cost is low, thereby increasing the price competitiveness.

1 is a cross-sectional view illustrating an optical module according to an embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, embodiments of the present invention illustrated below may be modified in many different forms, and the scope of the present invention is not limited to the embodiments described below. The embodiments of the present invention are provided to more completely explain the present invention to those skilled in the art.

1 is a cross-sectional view illustrating an optical module according to an embodiment of the present invention.

Referring to FIG. 1, an optical module according to an exemplary embodiment of the present invention includes a substrate 100, a spacer 200, a cover 300, and an optical fiber 400.

Here, the substrate 100 is, for example, defined as a plurality of unit device regions in a rectangular plate shape, and the plurality of optical device chips 110 are arranged in a horizontal and / or vertical manner on each unit device region of the substrate 100. , Arranged in an array form and joined.

The substrate 100 serves as a base for fixing the spacer 200 and the cover 300, and as the material of the substrate 100, for example, a semiconductor, a printed circuit board (PCB), a ceramic ( Ceramic, glass or plastic may be used.

In addition, a plurality of electrodes (not shown) capable of, for example, die bonding, wire bonding, or the like may be electrically connected to the optical device chip 110 on the substrate 100. This can be formed. These electrodes are preferably formed to extend to one side of the substrate 100 to facilitate electrical connection with the external circuit.

In addition, the substrate 100 may be slightly larger than the spacer 200 to expose the electrodes for connection with other circuits to the outside of the spacer 200. The substrate 100 may be exposed to a wafer level by using a via hole. Patterning and dicing around the via hole may allow the internal electrodes to be naturally connected.

On the other hand, in the case of a simple laser diode (LD) such as a simple photo diode (PD) or a vertical cavity surface emitting laser diode (VCSLE) that requires only two electrodes, the substrate 100 Only need a two-electrode electrode pattern on the photodiode optical module with integrated TIA (Transimpedance Amplifier) that requires several electrodes, or a monitor photodiode (Monitor PD) for laser diode (LD). It is sufficient to form as many electrodes.

On the other hand, the bonding of the substrate 100 and the spacer 200, the spacer 200 and the cover 300 may be firmly adhered using, for example, epoxy, solder, or metal. . In this case, when solder or metal is used, a metal or solder pattern having a required shape may be formed or deposited on both contact surfaces to be bonded using a conventional semiconductor process. In this case, an additional insulating layer needs to be formed between the electrode pattern and the solder pattern.

On the other hand, in one embodiment of the present invention, but coupled to the spacer 200 directly on the substrate 100, but is not limited to this, optical between the substrate 100 and the optical device chip 110 and the spacer 200. In order to support or adjust the height of the device chip 110, a submount (not shown) die-bonded with an electrode of the substrate 100 may be further provided.

In this case, the submount is formed in the same size as the spacer 200, the submount is coupled to the upper surface of the substrate 100, the optical element chip 110 and the spacer 200 on the upper surface of the submount ) Are combined.

The plurality of spacers 200 are intermediate layers for height adjustment, and are layers for maintaining constant optical coupling between the optical device chip 110 and the optical fiber 400.

The spacer 200 is formed in a columnar shape (for example, a square pillar, a cylinder, a hexagonal pillar, etc.) having a predetermined height from the plane of the substrate 100, and surrounds each optical element chip 110 arranged in an array form. It is provided to be spaced apart at regular intervals.

Each of the spacers 200 is formed with a through hole (not shown) so as to penetrate a predetermined region (preferably, a central portion) of the upper and lower surfaces, and the through hole is an optical element chip when the substrate 100 is coupled to the substrate 100. 110 is inserted to perform the function of protecting the optical device chip 110 from the outside and the proper distance setting of the coupling optical system consisting of the optical device chip 110, the cover 300 and the optical fiber 400. .

In addition, the size of the through hole may be larger than that of the optical device chip 110 so that the through hole may be inserted at a predetermined interval from the optical device chip 110.

Meanwhile, the material of the spacer 200 may be, for example, metal, glass, plastic, polymer, ceramic, semiconductor, or the like. In particular, the spacer 200 may be formed of a material having a linear expansion coefficient close to or similar to that of the substrate 100 or the cover 300. It is advantageous to use.

In addition, the plurality of covers 300 support the respective optical fibers 400, and are coupled on the respective spacers 200 so as to close the upper through holes of the spacers 200 arranged in an array form, and are generally square. It has a plate shape.

The cover 300 uses a transparent material at a wavelength of a light source to be used, and may be a glass, a plastic, or a semiconductor substrate polished on both sides. For example, a semiconductor substrate such as silicon, InP, or GaAs is opaque in the visible light region, but can be used as the cover 300 of the present invention because light passes through a wavelength of about 1.3um and 1.5um, which is a wavelength for long wavelength optical communication. have. On the other hand, although not shown in the drawings, it is advantageous to use the cover 300 to reduce the reflection loss by performing an anti-reflective coating on both surfaces polished.

In addition, the plurality of optical fibers 400 are typically used to transmit information using light, and each of the optical fibers 400 is located at the position of each optical element chip 110 on the cover 300 arranged in an array form. Correspondingly aligned and bonded through the first epoxy (450). In addition, the optical fiber 400 is preferably made of a multi-channel (eg, 4, 8 or 16 channels, etc.) optical fiber.

On the other hand, the first epoxy 450 is, for example, an ultraviolet curable epoxy (UV epoxy), and has a high glass transition temperature (Tg) (about 120 to 140 ° C), and about 90 to 110 mW (preferably, about It is photocurable by ultraviolet-curing by ultraviolet (UV) exposure for about 1 to 3 minutes (preferably about 2 minutes) at about 100 mW).

At this time, "Tg" is the "glass transition temperature" of a polymerized phase. The glass transition temperature of a polymer is the temperature at which the polymer transitions from a hard glassy state at temperatures below Tg to a fluid or rubbery state at temperatures above Tg.

In addition, each optical fiber 400 including a plurality of spacers 200, a cover 300, and a first epoxy 450 provided in an array form on the substrate 100 to minimize misalignment of the optical fiber 400. In order to mold a portion of the substrate 100 onto the substrate 100, the second epoxy 500 is fixedly bonded once more.

The second epoxy 500 is a thermosetting epoxy (for example, one-component or two-component epoxy), and is higher than the glass transition temperature (Tg) of the first epoxy 450 so that the first epoxy 450 is not deformed. It becomes thermosetting by thermosetting through the heating for about 2 hours-4 hours (preferably about 3 hours) at low hardening temperature (preferably about 90-110 degreeC).

In this way, the optical fiber 400 of the multi-channel is firmly fixed to the cover 300 to inject light into each optical device chip 110, or conversely, the light emitted from each optical device chip 110 receives light emitted from each optical device chip 110. It is incident to (400).

For example, when the optical device chip 110 is a photodiode (PD) that is a light receiving device, the light output from the optical fiber 400 is aligned so that the light is coupled to the photodiode PD as much as possible. When the 110 is a light emitting device such as a laser diode (LD) or a light emitting diode (LED), the optical fiber 400 is aligned so that the light emitted from the optical device chip 110 is coupled to the optical fiber 400 as much as possible. And firmly secured with second epoxy (450 and 500).

At this time, the alignment of the optical fiber 400 may use both an active alignment or a passive alignment method. In the case of the manual alignment, patterns necessary for precise alignment with each optical device chip 110 attached to the substrate 100 should be formed on the substrate 100 and the cover 300.

In the case of the active alignment, the light of the light source emitted from each optical device chip 110 fixed to the substrate 100 is actually combined into each optical fiber 400, or the light output from each optical fiber 400 is photodiode. Find a position that is as close as possible to the PD and harden it with the first and second epoxy 450 and 500 to fix it firmly.

The optical module according to the exemplary embodiment of the present invention configured as described above includes a plurality of spacers 200 corresponding to each of the optical device chips 110 and the substrate 100 to which the plurality of optical device chips 110 are attached in an array form. ) And the cover 300 are sequentially stacked in an array form, and then the multi-channel optical fiber 400 is aligned to correspond to the position of each optical device chip 110 at a wavelength to be used (or at a wavelength to be transmitted). The first and second epoxy 450 and 500 are used to fix the cover 300 to complete the cover 300.

On the other hand, the optical module according to an embodiment of the present invention is configured by combining the substrate 100, the spacer 200, the cover 300 and the optical fiber 400, but is not limited thereto, and does not attach the optical fiber 400. Instead, it can be directly attached to the output or input waveguide of a PLC (Planar Lightwave Circuits) substrate.

On the other hand, the optical coupling efficiency of the optical device chip 110 and the optical fiber 400 depends on the shape and thickness of the cover 300, the thickness of the spacer 200 and the position of the optical device chip 110 in the structure. Can be determined.

As described above, in the vertical alignment method of the present invention, since the optical fiber is directed toward the z-axis space and uses a small optical fiber support substrate, that is, the cover 300, a minimum space can be used, and even if various types of components are used. Properly placed, there is a spatial / cost-effective effect of smaller sized packaging compared to conventional horizontal packaging, and the first and second epoxy (450 and 500) consisting of UV curable epoxy and thermosetting epoxy The dual use of the fiber can minimize the distortion of the optical fiber alignment, thus increasing the yield of the manufactured product and producing a competitive product. When manufacturing the multi-channel array (or array) device, the yield of the manufactured product is high. Low price can increase price competitiveness.

Although a preferred embodiment of the optical module according to the present invention and a method for manufacturing the same have been described, the present invention is not limited thereto, and various modifications are made within the scope of the claims and the detailed description of the invention and the accompanying drawings. It is possible to implement and this also belongs to the present invention.

100: substrate, 110: optical element chip,
200: spacer, 300: cover,
400: optical fiber, 450: first epoxy,
500: second epoxy

Claims (6)

A substrate having an optical device chip in an array form thereon;
At least one through hole formed therein, the spacer being coupled in an array form on the substrate such that each optical device chip is inserted into the through hole;
A cover coupled in array form on each spacer to close through holes in each spacer;
An optical fiber fixedly coupled in an array form using a first epoxy so as to correspond to a position of each optical device chip on each cover; And
A second epoxy formed to mold a portion of the optical fiber, including each spacer, cover and first epoxy, onto the substrate,
The light transmitted through each optical fiber is incident to each optical device chip, or the light emitted from each optical device chip is incident to each optical fiber, wherein the first epoxy is made of an ultraviolet curable epoxy, and the second Epoxy is composed of a thermosetting epoxy that is thermoset at a curing temperature lower than the glass transition temperature (Tg) of the first epoxy, the first epoxy has a glass transition temperature (Tg) of 120 ~ 140 ℃ temperature range, 90 ~ Photocuring by ultraviolet (UV) exposure for 1 to 3 minutes at 110mW, the second epoxy is thermally cured by heating for 2 to 4 hours in the temperature range of 90 ~ 110 ℃.
delete delete The method according to claim 1,
The optical fiber is characterized in that the multi-channel optical fiber.
Coupling the plurality of optical device chips in an array form on the substrate;
Providing a plurality of spacers having at least one through hole, and then combining the spacers on the substrate in an array so that each optical device chip is inserted into the through holes;
Combining the plurality of covers in an array so as to close through holes of each spacer;
Fixing the optical fibers in the form of an array using a first epoxy to correspond to the position of each optical device chip on each cover; And
Molding a portion of the optical fiber including a plurality of spacers, a lid and a first epoxy on the substrate using a second epoxy, wherein
The first epoxy is a UV curable epoxy having a glass transition temperature (Tg) in the temperature range of 120 ~ 140 ℃, photocured by UV (UV) exposure for 1 to 3 minutes at 90 ~ 110mW, the second epoxy Is a thermosetting epoxy which is thermoset at a curing temperature lower than the glass transition temperature (Tg) of the first epoxy, and a method of manufacturing an optical module, characterized in that it is thermally cured by heating for 2 to 4 hours in a temperature range of 90 to 110 ° C. . delete

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