KR20040081838A - Double-faced and polymer optical backplane and the fabrication method - Google Patents

Abstract

PURPOSE: A double-sided type and a multilayer type optical backplane substrate and a fabricating method thereof are provided to transmit and receive optical signals of high capacity by forming the optical backplane substrate with a both-sided structure or a multilayer structure. CONSTITUTION: A plurality of clad layers(402a,402b) are formed on both sides of a substrate. A plurality of core layers(403a,403b) are patterned on each side of the clad layers. A plurality of over-clad layers(404a,404b) are formed on each side of the core layers. A plurality of metal layers are formed on each side of the over-clad layers. A waveguide is formed by laminating the clad layers, the patterned core layers, and the over-clad layers on the substrate. The clad layers, the patterned core layers, the over-clad layers are repeatedly formed on the waveguide.

Description

DOUBLE-FACED AND POLYMER OPTICAL BACKPLANE AND THE FABRICATION METHOD}

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a double-sided and multilayered optical backplane substrate and a method of manufacturing the same. A backplane substrate and a method of manufacturing the same.

Recently, optical transmission technology for communication and networking systems has attracted attention as a short range chip-to-chip communication solution. Compared with electrical signals, optical signals rarely cause loss problems, and thus can process a large amount of information, and have no influence from EMI.

In addition, the optical signal by the optical transmission technology can implement a transmission speed of 10Gbps or more without using the measuring means for skew, reflection, crosstalk.

Performance is the most important issue when transferring data from chip to chip via an optical signal on a PCB substrate. It should be possible to transfer data much faster than is possible with electronic connections.

At present, such a problem can be implemented in optical transmission technology, and in the future, problems such as reduction of component cost, reduction of actual equipment, and reduction of equipment size are emerging as new challenges.

Conventional electrical backplanes have limitations in high-speed large capacity transmission due to limitations of transmission speeds (~ 2.5Gbps), crosstalk between electrical wirings, constraints on mounting density (50 signal lines / inch), and EMI / EMC.

To overcome these limitations, optical backplanes have emerged that convert electrical signals into optical signals. This is to embed the optical fiber, optical waveguide, etc. in the PCB substrate as the transmission path of the optical signal.

The optical backplane refers to a high-speed large-capacity information on a PCB substrate connected to an optical signal instead of an existing electrical signal, and enables high-speed signal transmission of several hundred Gbps at a transmission distance of several cm to several tens of meters.

Therefore, optical backplanes are attracting attention as communication solutions between chips, boards and backplanes, and backplanes.

This technology solves the problems of information processing speed limitation, EMI / EMC, crosstalk, etc. of the conventional electric backplane, and obtains a large amount of desired information such as high-speed data tens or hundreds of times faster than the electric backplane. Telecom, telecommunications, and computer systems companies believe it will be an optical backplane as the only alternative to the next generation of solutions.

On the other hand, optical backplanes are classified into 1, 2, and 3 generations according to transmission paths.

The first generation optical backplane refers to a system that uses fiber optics to link motherboards and daughtercards, while the second generation refers to systems using flexfoils that couple optical fibers to polymer films.

The third generation optical backplane is an embedding system in which an optical fiber or an optical waveguide is embedded in a PCB substrate. The third generation optical backplane is a hybrid system that converts and transmits an electrical signal to an optical signal. It is expected that 3rd generation technology will occupy.

1 is a diagram illustrating a general embedded polymer waveguide structure. As shown in the drawing, a planar optical waveguide made of silica is widely used, and commercialization of AWG and the like designed by WDM communication is progressing, but the production cost is high during manufacturing.

In order to lower the price of optical waveguides, researches on the use of polymers such as polyimide, epoxy, and acrylate are being conducted. The loss of polymer optical waveguides is quite high, ranging from 0.1 to several dB / cm, but is suitable for use as short-range optical waveguides on PCBs.

2 is a view illustrating a general embedded glass sheet structure. As shown here, the optical backplane technology that embeds a glass sheet is manufactured by the same beam deflection method as the embedded polymer waveguide optical backplane, and the material of the optical waveguide is manufactured. A glass sheet was used instead of the polymer.

Embedded glass sheet The optical backplane has superior light loss characteristics compared to polymers, and has the advantage of making a large area optical backplane possible.

In addition, the coefficient of thermal expansion of glass is similar to that of semiconductor devices and VCSELs, which makes alignment easier than polymer optical waveguides.

Processes for manufacturing the glass waveguide include ion implantation, UV laser ablation, chemical etching, hot embossing, and the like.

PPC uses an ion implantation process. The glass waveguide has an optical loss of about 0.1 dB / cm and a surface roughness of 100 nm. The company has developed an optical backplane prototype with a transmission distance of 1.5m at a 2.5Gbps transmission rate and plans to develop an optical backplane with a 3.3 ~ 5Gbps transmission rate in the future.

3 is a diagram illustrating a general embedded fiber structure. As shown, the optical backplane of the embedded fiber has a structure in which 6U subracks are connected to 128 fibers, and an optical fiber board and an optical right angled connector are shown. And an electrical cable connector and have an optical loss of 0.01 dB / cm or less.

Therefore, the embedded fiber optical backplane has the advantage of low optical loss compared to the embedded waveguide optical backplane, so it will be applied to a system requiring low loss optical characteristics.

As discussed above, optical backplanes of various structures still consider only the installation of one layer of optical backplanes, but as PCBs have evolved into double-sided and multilayered PCBs, optical PCBs also have two-sided optical signal transmission as the degree of integration of optical signals increases. And the evolution to multilayer optical PCBs is also essential.

However, unlike the electrical PCB, the optical PCB is capable of propagating signals independent of each other by overlapping light, but there is a problem in that some signals cannot be prevented from leaking into an unwanted path.

An object of the present invention is to provide a double-sided and multi-layered optical backplane substrate and a method of manufacturing the optical backplane that can be manufactured in a multi-layered optical backplane that connects a high-speed large-capacity information on the PCB substrate by an optical signal instead of an electrical signal.

1 is a diagram illustrating a general embedded polymer waveguide structure.

2 is a view showing a general embedded glass sheet (Embedded Glass Sheet) structure.

3 is a view showing a general embedded fiber (Embedded Fiber) structure.

4 schematically illustrates the structure of a double-sided optical backplane according to the present invention;

5 schematically illustrates the structure of a multilayer optical backplane according to the present invention;

6 is a view schematically showing the structure of a multilayer optical backplane using a mirror according to the present invention;

<Description of the symbols for the main parts of the drawings>

401 --- Substrate 402a, 402b --- Clad Layer

403a, 403b --- core layer 404a, 404b --- overclad layer

405a, 405b --- Metal Pattern 406a, 406b --- Light-Emitting Element

In order to achieve the above object, a double-sided optical backplane substrate according to the present invention,

A cladding layer formed on both sides of the substrate;

A core layer formed by patterning each of the clad layers on both sides;

An over cladding layer formed on both sides of the core layer;

It is characterized in that it comprises a metal layer formed by patterning the over cladding layer on both sides.

In order to achieve the above object, the multilayer optical backplane substrate according to the present invention,

A waveguide formed sequentially on one surface of the substrate by a cladding layer, a patterned core layer, and an overcladding layer;

It is characterized in that it comprises a waveguide of a predetermined layer in which a cladding layer, a core layer and an overcladding layer are formed on the formed waveguide again and again.

Here, in particular, it is characterized in that it further includes a mirror in a waveguide of a predetermined layer in which a cladding layer, a core layer and an overcladding layer are formed on the waveguide again.

In addition, in order to achieve the above object, a method of manufacturing a double-sided optical backplane substrate according to the present invention,

Forming a cladding layer on both sides of the substrate;

Forming and patterning each core layer on the clad layers formed on both surfaces;

Forming an over cladding layer on each of the core layers formed on both sides;

It is characterized in that it comprises the step of forming a patterned metal layer on the over cladding layer formed on both sides.

In addition, in order to achieve the above object, a method of manufacturing a multilayer optical backplane substrate according to the present invention,

Sequentially forming a waveguide comprising a cladding layer, a patterned core layer, and an overcladding layer on one surface of the substrate;

And forming and aligning a waveguide formed of a cladding layer, a core layer, and an overcladding layer as a predetermined layer on the formed waveguide.

Here, in particular, the method further includes the step of installing a mirror on a portion of the waveguide to be aligned in the step of forming and aligning the waveguide consisting of the clad layer, the core layer and the over cladding layer again on the formed waveguide. It has its features.

Here, in particular, in the step of installing the mirror in a portion of the aligned waveguide, the mirror is characterized in that it applies a MEMS process technology using a micro mirror or a photonic crystal.

The present invention relates to a double-sided and multi-layered optical backplane substrate and a method for manufacturing the same, and in particular, it is possible to manufacture a multi-layered optical backplane that connects high-speed large-capacity information with optical signals instead of electrical signals.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

4 is a view schematically showing the structure of a double-sided optical backplane according to the present invention. As shown here, the double-sided optical backplane substrate includes cladding layers 402a and 402b formed on both sides of the substrate 401; Core layers 403a and 403b formed by patterning the clad layers 402a and 402b on both sides thereof, respectively; An over cladding layer (404a, 404b) formed on the double-sided core layers (403a, 403b); And metal layers 405a and 405b formed by patterning the overclad layers 404a and 404b on both surfaces thereof.

In the method for manufacturing a double-sided optical backplane as described above, first, a cladding layer is coated on one surface of a substrate, and a core layer is formed on the cladding layer to pattern the cladding layer.

Then, the overclad is coated on the patterned core layer, and a metal film for transmitting an electrical signal is formed thereon and patterned.

Meanwhile, a process method used for manufacturing the optical backplane will be described. In general, the optical waveguide using a polymer material is easy to manufacture a multimode optical waveguide having a dimension of 50 μm × 50 μm or more, and is used in a photolithography process, an imprint, and hot embossing, which is used in a semiconductor process. The optical waveguide can be manufactured by various methods such as embossing, micro-molding, and direct laser writing.

The photolithography process is applicable to various types of polymer materials, but has a disadvantage in that the process is complicated, such as undergoing a reactive ion etching (RIE) process.

The hot embossing technology has excellent surface characteristics of the optical waveguide and has a simple economical process compared to other processes due to the simple process, but it is also difficult to manufacture a large waveguide of 6 inches or more.

The process of minimizing the shortcomings of the various processing methods is performed.

After the metal pattern is completed, a laser diode such as VCSEL and a photo diode are attached to the point where the waveguide ends.

In addition, the same process is performed on the opposite side to form a waveguide on both sides of one substrate, thereby achieving double the degree of integration.

5 is a view schematically showing the structure of a multilayer optical backplane according to the present invention. As shown here, the multilayer optical backplane includes: a waveguide 502a formed of a cladding layer, a patterned core layer, and an overcladding layer on one surface of the substrate; The waveguide 502b includes a predetermined layer in which a cladding layer, a core layer, and an overcladding layer are repeatedly formed on the formed waveguide.

The method of manufacturing a multilayer optical backplane as described above shows a shape of a multilayer array in which a cladding and a core are raised on top of a waveguide made of one layer and aligned with a waveguide of a lower layer.

In this case, when the size of LD or PD becomes smaller, a higher integration is realized by combining with LD and PD array.

6 is a view schematically showing the structure of a multilayer optical backplane using a mirror according to the present invention. As shown in the drawing, the mirror 503 is further formed on the waveguide of the predetermined layer in which the cladding layer, the core layer, and the overcladding layer are repeatedly formed on the formed waveguide.

By installing the mirror (Mirror) has shown a conceptual diagram that enables the same high integration as the current multilayer PCB. Here, the mirror is manufactured by applying a micro electro mechanical system (MEMS) process technology using a micro mirror or a photonic crystal.

Although the present invention has been described with reference to the embodiments illustrated in the drawings, this is merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent other embodiments are possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

As described above, the present invention relates to a double-sided and multi-layered optical backplane substrate and a method of manufacturing the same. In particular, a multi-layered optical backplane may be manufactured in which a high-speed large-capacity information is connected to an optical signal instead of an electrical signal on a PCB substrate. .

Claims (7)

A cladding layer formed on both sides of the substrate; A core layer formed by patterning each of the clad layers on both sides; An over cladding layer formed on both sides of the core layer; A double-sided optical backplane substrate comprising a metal layer formed by patterning the over cladding layer on both sides. A waveguide formed sequentially on one surface of the substrate by a cladding layer, a patterned core layer, and an overcladding layer; And a waveguide having a predetermined layer in which a cladding layer, a core layer, and an overcladding layer are repeatedly formed on the formed waveguide. The method of claim 2, And a mirror in the waveguide of the predetermined layer in which the cladding layer, the core layer and the overcladding layer are repeatedly formed on the formed waveguide. Forming a cladding layer on both sides of the substrate; Forming and patterning each core layer on the clad layers formed on both surfaces; Forming an over cladding layer on each of the core layers formed on both sides; Forming and patterning a metal layer on the over cladding layer formed on both sides of the double-sided optical backplane substrate manufacturing method characterized in that it comprises. Sequentially forming a waveguide comprising a cladding layer, a patterned core layer, and an overcladding layer on one surface of the substrate; And forming and aligning a waveguide formed of a cladding layer, a core layer, and an overcladding layer as a predetermined layer on the formed waveguide. The method of claim 5, And forming a mirror on a portion of the waveguide to be aligned in the step of forming and aligning the waveguide including the clad layer, the core layer, and the overclad layer as a predetermined layer on the formed waveguide. Method of manufacturing a fluorescent backplane substrate. The method of claim 6, The method of manufacturing a multilayer optical backplane substrate, characterized in that in the step of installing the mirror on the portion of the waveguide to be aligned, the mirror is applied to the MEMS process technology using a micro mirror or photonic crystal.