KR101856229B1 - Optical Printed Circuit Board and Fabricating method of the same - Google Patents

Abstract

According to an embodiment of the present invention, there is provided an optical printed circuit board comprising: a first insulating layer having at least one receiving groove having an inclination angle at one end; An optical waveguide formed in the receiving groove of the first insulating layer; And a second insulating layer formed on the first insulating layer and filling the optical waveguide formed in the receiving groove.

Description

TECHNICAL FIELD [0001] The present invention relates to an optical printed circuit board and a fabrication method thereof.

The present invention relates to a structure of an optical printed circuit board and a manufacturing method thereof.

A printed circuit board (PCB), which is generally used, is an electrical printed circuit board, which is coated with a substrate on which a copper thin film circuit is implemented, and is used by electric signal transmission by inserting various components. Such a conventional electric printed circuit board has a problem in signal transmission because it can not follow the electric signal transmission capability of the substrate rather than the processing capability of an electric element as a component.

Especially, these electric signals are sensitive to the external environment and generate noises, which is a great obstacle to electronic products requiring high precision. As a complement to this, an optical printed circuit board using an optical waveguide was developed instead of a metallic circuit such as copper of an electric printed circuit board, and it became possible to produce a high-precision high-tech equipment more stable in radio interference and noise phenomenon.

According to the prior art, in the case of an optical printed circuit board, an optical waveguide is manufactured by bending optical fibers at 90 degrees as disclosed in Prior Art 1 (Publication No. 10-2011-0038522) 0112731), a mirror is formed on the inner core layer to produce an optical waveguide.

However, in the above-mentioned prior art document 1, in the manufacture of an optical printed circuit board, a structure is adopted in which optical fibers are folded at 90 degrees to connect optical fibers with a signal transmission unit TX and a signal reception unit RX. The light loss occurs in the process of folding the optical fiber 90 by 90 degrees. In addition, when there is a step between the bent portion of the optical fiber and the printed circuit board layer in the lamination process for embedding in the printed circuit board, high pressure is applied and transmission loss occurs. In addition, the total thickness of the optical module including the bent portion increases the overall thickness of the printed circuit board.

In the prior art 2, the core protruding outward has a problem in that it is difficult to maintain the angle due to deformation (curling or twisting, etc.) due to heat, pressure and resin flow during lamination have.

In an embodiment according to the present invention, an optical printed circuit board having a new structure and a manufacturing method thereof are provided.

 It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are not intended to limit the invention to the precise forms disclosed. .

According to an embodiment of the present invention, there is provided an optical printed circuit board comprising: a first insulating layer having at least one receiving groove having an inclination angle at one end; An optical waveguide formed in the receiving groove of the first insulating layer; And a second insulating layer formed on the first insulating layer and filling the optical waveguide formed in the receiving groove.

The optical waveguide includes a lower clad, a core and an upper clad integrally formed, and at least one end of the lower clad, the core, and the upper clad is exposed to the side of the receiving groove having the inclination angle.

The receiving groove may have a bottom surface, a left side surface extending upward from the one end of the bottom surface and a right side surface extending upward from the other end of the bottom surface, the internal angle between the bottom surface and the left surface, Is 135 deg., And the internal angle between the lower surface and the right surface is 135 deg.

A first mirror formed on a left side surface of the receiving groove and having an inclination angle corresponding to an internal angle between the lower surface and the left side surface and a second mirror formed on the right side surface of the receiving groove, And a second mirror having an inclination angle.

The first mirror reflects the light incident from the outside in a direction perpendicular to the incidence direction, and the second mirror reflects the light reflected from the first mirror in a direction perpendicular to the incidence direction.

In addition, a circuit pattern is formed on at least one surface of the first insulating layer, an optical transmitter is electrically connected to a circuit pattern formed on the first mirror, and a circuit pattern formed on the second mirror includes an optical receiver And is electrically connected.

The optical transmitter and the optical receiver are embedded in the second insulating layer.

A method of manufacturing an optical printed circuit board according to an embodiment of the present invention includes: preparing an insulating substrate having a circuit pattern formed on at least one surface thereof; Forming an accommodating groove having at least one end of the inclined angle by processing the insulating substrate; And forming an optical waveguide in the formed receiving groove.

The forming of the receiving groove may include forming a receiving groove by laser-trenching or precision cutting the upper surface of the insulating substrate.

The receiving groove may have a bottom surface, a left side surface extending upward from the one end of the bottom surface and a right side surface extending upward from the other end of the bottom surface, the internal angle between the bottom surface and the left surface, Or the internal angle between the lower surface and the right surface is 135 degrees.

The method may further include forming a mirror on at least one of a left side surface and a right side surface of the receiving groove.

The step of forming the mirror may include forming a first metal layer having a tilt angle corresponding to an inner angle between a lower surface and a left surface of the receiving groove by coating a metal material on a left surface of the receiving groove, And forming a second metal layer having a tilt angle corresponding to an inner angle between the lower surface and the right surface of the receiving groove by coating a metal material on the right surface of the groove.

In addition, the step of forming the optical waveguide includes the step of inserting the optical waveguide element in which the lower clad, the core, and the upper clad are formed integrally into the receiving groove.

Further, the side surfaces of the lower clad, the core and the upper clad are exposed to the side of the receiving groove in which the mirror is formed.

Further, the method may further include forming an optical transmitter on a circuit pattern formed on the first metal layer, and forming an optical receiver on a circuit pattern formed on the second metal layer.

Further, the method further includes the step of forming an insulating layer for embedding the optical waveguide, the optical transmitter, and the optical receiver on the insulating substrate.

According to the embodiment of the present invention, by forming the receiving groove having the inclination angle through laser trenching or precision cutting, it is possible to eliminate the step due to the thickness of the optical waveguide, thereby facilitating the lamination process of the printed circuit board, It is possible to improve the light loss characteristic by accurately aligning the mirror and the optical waveguide in the embedding of the optical waveguide and also to increase the degree of freedom of designing the copper circuit by embedding the optical waveguide.

1 is a perspective view of an optical printed circuit board according to an embodiment of the present invention.
2 is a sectional view in the direction of AA 'in Fig.
3 is a sectional view in the direction of BB 'in Fig.
Figs. 4 to 17 are views for explaining the manufacturing method of the optical printed circuit board shown in Figs.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

Throughout the specification, when an element is referred to as " comprising ", it means that it can include other elements as well, without excluding other elements unless specifically stated otherwise.

According to the embodiment of the present invention, a receiving groove having an inclination angle is formed through laser trench processing or precision cutting processing, and an optical waveguide is embedded in the formed receiving groove, thereby eliminating a step due to the thickness of the optical waveguide, And improves the optical loss characteristics by accurately aligning the mirror and the optical waveguide when embedding the optical waveguide and increases the degree of freedom of designing the copper circuit by embedding the optical waveguide.

FIG. 1 is a perspective view of an optical printed circuit board according to an embodiment of the present invention, FIG. 2 is a sectional view taken along a line A-A 'of FIG. 1, and FIG. 3 is a sectional view taken along a line B-B' of FIG.

1 to 3, an optical printed circuit board 100 includes a first insulating layer 110, a circuit pattern 125 formed on at least one surface of the first insulating layer 110, An optical waveguide 140 formed in the receiving groove 130 at both ends of the receiving groove 130 at both ends of the receiving groove 130 and formed at the first end of the receiving groove 130, And a second mirror 135 having a tilt angle corresponding to the tilt angle of the second end of the receiving groove 130. The first mirror 132 has a corresponding inclination angle, And a second insulating layer 150 formed on the top and bottom surfaces of the first insulating layer 110 to fill the circuit pattern 125 and the optical waveguide 140.

The first insulating layer 110 and the second insulating layer 150 function as a base member for providing durability to the optical printed circuit board.

The first and second insulating layers 110 and 150 may be a supporting substrate of an optical printed circuit board on which a single circuit pattern is formed, but a circuit pattern 125 is formed among the optical printed circuit boards having a plurality of laminated structures Which may be referred to as an insulating layer region.

In the case where each of the first and second insulating layers 110 and 150 is an insulating layer among a plurality of laminated structures, a plurality of circuit patterns are formed continuously on the upper or lower surface of the first and second insulating layers 110 and 150 As shown in FIG.

A conductive via (not shown) is formed in the first insulating layer 110 to electrically connect circuit patterns between different layers.

The circuit pattern 125 may be formed of an electrically conductive metal such as gold, silver, nickel, and copper for electrical signal transmission, and is preferably formed using copper.

The circuit pattern 125 may be formed by a conventional additive process, a subtractive process, a modified semi- additive process (MSAP), or a semi-additive process (SAP) And detailed description is omitted here.

The first and second insulating layers 110 and 150 may be a thermosetting or thermoplastic polymer substrate, a ceramic substrate, an organic-inorganic composite substrate, or a glass fiber impregnated substrate. In the case of including a polymer resin, FR- Bismaleimide Triazine), and ABF (Ajinomoto Build up Film). Alternatively, the epoxy resin may include a polyimide resin, but the present invention is not limited thereto.

In the first insulating layer 110, a receiving groove 130 (see FIG. 6) formed through laser trenching or really cutting is formed. When the receiving groove 130 is formed by the laser machining, the height of the receiving groove 130 can be easily adjusted. Accordingly, the height of the receiving groove 130 can be adjusted so that the integrated optical waveguide is completely embedded in the receiving groove 130. Alternatively, the height of the receiving groove 130 may be adjusted so that a part of the integrated optical waveguide is exposed above the receiving groove 130. Only the lower clad 141 and the core 142 are buried in the receiving groove 130 and the upper clad 143 is projected over the receiving groove 130 because the light travels through the core 142 .

Both ends of the receiving groove 130 have a predetermined inclination angle. Preferably, the receiving groove 130 has a lower surface 130a, a left side surface 130b extending upward from the one end of the lower surface 130a at an inclination angle upward, and a lower surface 130b extending upward from the other end of the lower surface 130a. And an extended right side surface 130c having an inclined angle.

At this time, the internal angle formed between the lower surface 130a and the left surface 130b is preferably formed at 135 degrees for efficient reflection of the optical signal. In other words, the left surface 130b has an inclination angle of 135 degrees at one end of the lower surface 130a and extends upward.

In addition, the internal angle formed between the lower surface 130a and the right surface 130c is preferably formed at 135 degrees for efficient reflection of the optical signal. In other words, the right side surface 130c has an inclination angle of 135 ° at the other end of the lower surface 130a and extends upward.

At this time, the inclination angle of the receiving groove 130 corresponds to the case where the optical transmitter and the optical receiver are formed on the upper surface of the first insulating layer 110. That is, when the optical transmitter and the optical receiver are formed on the lower surface of the first insulating layer 110, the inclination angle of the receiving groove 130 is preferably different from the above-described angle. For example, when the optical transmitter and the optical receiver are formed on the lower surface of the first insulating layer 110, the internal angle formed between the lower surface 130a and the left surface 130b is preferably 45 degrees, Likewise, the internal angle formed between the lower surface 130a and the right surface 130c is preferably 45 degrees.

A first mirror 132 is formed at one end of the receiving groove 130, and a second mirror 135 is formed at the other end of the receiving groove 130.

The first and second mirrors 132 and 135 are formed by laminating a metal layer including a metal material on both ends of the receiving groove 130. At this time, the first and second mirrors 132 and 135 are preferably formed of a metal material capable of reflecting light.

The first mirror 132 is formed at a position corresponding to the lower portion of the optical transmitter (not shown). At this time, the first mirror 132 is formed with a predetermined inclination angle. The inclination angle of the first mirror 132 may be the same as the inclination angle of the one end of the receiving groove 130.

That is, the first mirror 132 is formed by coating a metal material on one end of the receiving groove 130 having the inclination angle, and stacking and spraying the metal material. Accordingly, the first mirror 132 is formed with an inclination angle corresponding to the inclination angle of the receiving groove 130 itself.

The first mirror 132 receives light generated from the optical transmitter (not shown) and reflects the received light in a direction perpendicular to the incidence direction.

The second mirror 135 is formed at a position corresponding to the lower portion of the optical receiver (not shown). At this time, the second mirror 135 is formed with a predetermined inclination angle. The inclination angle of the second mirror 135 may be the same as the inclination angle of the other end of the receiving groove 130.

That is, the second mirror 135 is formed by laminating a metal material on the other end of the receiving groove 130 having the inclination angle, by stacking and spraying. Accordingly, the second mirror 135 has an inclination angle corresponding to the inclination angle of the receiving groove 130 itself.

The second mirror 135 receives the light reflected through the first mirror 132, and reflects the received light in a direction perpendicular to the incident direction.

An optical waveguide 140 is embedded in the receiving groove 130 in which the first mirror 132 and the second mirror 135 are formed.

Alternatively, a metal reflection surface may be formed instead of the first mirror 132 and the second mirror 135 by performing a sputtering process on one end and the other end of the receiving groove 130 having the inclination angle.

The optical waveguide 140 includes a lower clad 141, a core 142, and an upper clad 143 layer. At this time, the optical waveguide 140 is a single product in which the lower clad 141, the core 142 and the upper clad 143 are integrally formed, and the optical waveguide 140 formed by the single piece is inserted into the receiving groove 130, As shown in Fig.

The lower clad 141 and the upper clad 143 are formed to surround the core so that light can be efficiently transmitted through the core.

The upper clad 143 and lower clad 141 are made of a polymer material such as acryl, epoxy, polyimide, fluorinated acryl, or fluorinated polyimide.

The core 142 is interposed between the upper clad 143 and the lower clad 141 and functions as a path through which the optical signal is transmitted. The core 142 is made of a polymer material similar to the upper clad 143 and the lower clad 141 and has a refractive index higher than that of the clad layer for efficient optical signal transmission. At this time, the core 142 may be formed of SiO ₂ mixed with silica or polymer.

That is, the optical waveguide 140 includes a lower clad 141, an upper clad 143, and a core 142 integrally formed between the upper clad 143 and the lower clad 141, The optical waveguide 140 can be formed by cutting the optical waveguide formed in the receiving groove 130 according to the size of the receiving groove 130.

A first mirror 132 and a second mirror 135 formed on one end and the other end of the receiving groove 130 are positioned on the cut surface of the core 142 included in the optical waveguide 140. As described above, the first and second mirrors 132 and 135 are formed of a highly reflective material such as aluminum or silver in order to efficiently transmit light.

Since the core 142 is disposed inside the upper clad 143 and the lower clad 141 and has a higher refractive index than the upper clad 143 and the lower clad 141, Is totally reflected at the interface between the core 142 and the upper / lower clad 141 and 143, and travels along the core 142.

Since the light travels through the core 142, the core 142 is disposed in the receiving groove 130 in which the first mirror 132 and the second mirror 135 are formed, and the upper clad 143, May be formed to protrude above the receiving groove 130.

Meanwhile, the optical waveguide 140 may be formed by an embossing process or a photolithography process using a polymer material having excellent light transmittance and flexibility, for example, an organic-inorganic polymer material.

In this case, the organic-inorganic polymer material may include, for example, low density polyethylene, low-density polyethylene (LLDPE), high density polyethylene, polypropylene, amide series nylon 6 6, nylon 66, nylon 6/9, nylon 6/10, nylon 6/12, nylon 11, nylon 12, polystyrene Polyvinyl chloride, polyvinylidene chloride, polycarbonate, cellulose acetate, or poly (meth) acrylate. The polyvinylidene chloride may be selected from the group consisting of polystyrene, polyethyleneterephthalate, polybutyl terephthalate, polyvinyl chloride, ) Acrylate (poly (meth) acrylate). Of these materials, any of these materials may be selected in consideration of their thermal and mechanical properties It may be made by a combination thereof.

The sides of the optical waveguide 140 (the side surface of the upper clad 143, the side surface of the lower clad 141, and the side surface of the core 142) are exposed in the receiving groove 130. In addition, the optical waveguide 140 may have a top surface and a side surface that are perpendicular to each other as shown in the drawing, but may have an inclination angle corresponding to an inclination angle of the receiving recess 130 according to an embodiment . In order to do this, the optical waveguide 140 made of the single piece must be cut in consideration of the size of the receiving groove 130 and the inclination angle of the receiving groove 130.

An optical transmitter (not shown) is formed at an upper position of the first mirror 132, and an optical receiver (not shown) is formed at an upper position of the second mirror 134. The optical transmitter is connected to the circuit pattern 125 located on the upper side of the first mirror 132 and the optical receiver is connected to the circuit pattern 125 located on the upper side of the second mirror 135 .

The optical transmitter generates and outputs an optical signal and includes a driver integrated circuit (not shown) and a light emitting element (not shown). The light emitting device is driven by the driver integrated circuit to generate light in a direction in which the first mirror 132 is formed.

In this case, the light emitting device may include a VCSEL (Vertical-Cavity Surface-Emitting Laser), which is a light source device for emitting a light signal. The VCSEL is a light source element that transmits or amplifies a light source signal in a manner of vertically irradiating a laser beam.

The optical receiver includes a receiver integrated circuit (not shown) and a light receiving element (not shown).

The light receiving element receives light generated from the optical transmitter and is driven by the receiver integrated circuit. The light receiving element may include a photo detector (PD), which is an element for detecting an optical signal.

In addition, as shown in the drawing, the optical printed circuit board 100 includes a multi-channel optical waveguide in which a plurality of optical waveguides 140 are formed in the same layer. In addition to the multi-channel optical waveguides, An optical printed circuit board on which the optical waveguides 140 are formed can also be manufactured. The number of the optical waveguides 140 (preferably, the number of the cores 142) may be increased or decreased depending on the embodiment.

As described above, the optical printed circuit board 100 according to the embodiment of the present invention forms the receiving grooves 130 having the inclination angle through the laser trench processing or the precision cutting, By forming the optical waveguide 140, it is possible to eliminate the occurrence of a step due to the thickness of the optical waveguide 140, thereby facilitating the process of laminating the printed circuit board. When the optical waveguide 140 is filled with the mirrors 132 and 135 By accurately aligning the optical waveguide 140, it is possible not only to improve the light loss characteristic, but also to increase the degree of freedom of the copper circuit design by embedding the optical waveguide 140.

Hereinafter, a method of manufacturing the optical printed circuit board 100 shown in FIGS. 1 to 3 will be described with reference to the accompanying drawings.

Figs. 4 to 17 are views for explaining the manufacturing method of the optical printed circuit board 100 shown in Figs. 1 to 3 in the process order.

Referring to FIG. 4, first, an insulating substrate (insulating layer) 110 is prepared. In this case, when the insulating substrate 110 is an insulating layer in which the conductive layer 120 is laminated, the laminated structure of the insulating layer 110 and the conductive layer 120 may be a conventional CCL (Copper Clad Laminate).

Alternatively, the conductive layer 120 may be a plating layer formed by performing non-electrolytic plating on the insulating layer 110. In this case, when the conductive layer 120 is formed by non-electrolytic plating, the top and bottom surfaces of the insulating layer 110 may be illuminated to facilitate plating.

Next, as shown in FIGS. 5 and 6, the circuit patterns 125 are formed by etching the conductive layer 120 formed on the top and bottom surfaces of the insulating layer 110. 6 is a cross-sectional view taken along the line A-A 'in Fig.

The circuit pattern 125 may be formed corresponding to the mounting position of the optical transmitter or the optical receiver.

The circuit pattern 125 may be formed by a dry film lamination, exposure, development, etching and stripping processes.

Next, as shown in FIGS. 7, 8 and 9, the insulating layer 110 is subjected to laser trenching or precision cutting to form receiving grooves 130. FIG. 8 is a cross-sectional view taken along the line A-A 'of FIG. 7, and FIG. 9 is a cross-sectional view taken along the line B-B' of FIG.

The receiving groove 130 provides a seating space for seating the optical waveguide 140 in the insulating layer 110.

The receiving groove 130 is formed with at least one end having a predetermined inclination angle. At this time, the inclination angle may be formed only at one end of the receiving groove 130, or may be formed at one end and the opposite end opposite to the one end.

That is, in order to perform both optical transmission and optical reception in the optical printed circuit board 100, the inclination angle is formed at one end and the other end of the receiving groove 130, and an optical signal transmitted from an external device is received Alternatively, if the optical printed circuit board 100 is manufactured for the purpose of transmitting an optical signal to an external device, the inclination angle may be formed only at one end of the receiving groove 130.

The inclination angle is preferably 45 degrees in order to reflect the optical signal in a direction perpendicular to the incident direction of the optical signal.

9, the receiving groove 130 includes a lower surface 130a, a left side surface 130b extending upward from the one end of the lower surface 130a at a predetermined inclination angle, And a right side surface 130c extending upward from the other end of the side plate 130a at a predetermined inclination angle.

At this time, the internal angle formed between the lower surface 130a and the left surface 130b is preferably formed at 135 degrees for efficient reflection of the optical signal. In other words, the left surface 130b has an inclination angle of 135 degrees at one end of the lower surface 130a and extends upward.

In addition, the internal angle formed between the lower surface 130a and the right surface 130c is preferably formed at 135 degrees for efficient reflection of the optical signal. In other words, the right side surface 130c has an inclination angle of 135 ° at the other end of the lower surface 130a and extends upward.

The inclination angle of the receiving groove 130 corresponds to the case where the optical transmitter and the optical receiver are formed on the upper surface of the first insulating layer 110. That is, when the optical transmitter and the optical receiver are formed on the lower surface of the first insulating layer 110, the inclination angle of the receiving groove 130 is preferably different from the above-described angle. For example, when the optical transmitter and the optical receiver are formed on the lower surface of the first insulating layer 110, the internal angle formed between the lower surface 130a and the left surface 130b is preferably 45 degrees, Likewise, the internal angle formed between the lower surface 130a and the right surface 130c is preferably 45 degrees.

As described above, in the embodiment of the present invention, in order to form the reflecting member for changing the optical signal path in the receiving groove 130 for forming the optical waveguide, (130) are formed to have a predetermined inclination angle.

Next, as shown in FIGS. 10 and 11, the first mirror 132 and the second mirror 135 are formed at both ends of the receiving groove 130 formed as described above. 11 is a sectional view taken along the line B-B 'in Fig.

The first mirror 132 and the second mirror 135 may be formed by coating a metal material on the left side surface 130b and the right side surface 130c of the receiving groove 130, have.

Since the first mirror 132 and the second mirror 135 are formed on the left side 130b and the right side 130c, the inclination angle corresponding to the inclination angle of the left side 130b and the right side 130c And is formed.

In other words, the first mirror 132 has an inclination angle corresponding to (preferably equal to) an inclination angle of the left surface 130b (135 degrees with respect to the lower surface 130a). The second mirror 135 has an inclination angle corresponding to (preferably equal to) an inclination angle of the right side surface 130b (135 degrees with respect to the lower surface 130a).

Next, as shown in FIGS. 12, 13 and 14, the optical waveguide 140 is formed in the formed receiving groove 130. FIG. 13 is a cross-sectional view taken along the line A-A 'of FIG. 12, and FIG. 14 is a cross-sectional view taken along the line B-B' of FIG. 12.

At this time, the optical waveguide 140 includes a lower clad 141, a core 142, and an upper clad 143 layer.

The optical waveguide 140 is a single piece in which the lower clad 141, the core 142 and the upper clad 143 are integrally formed. The optical waveguide 140 formed of the single piece is inserted into the receiving groove 130, The optical waveguide 40 can be formed in the receiving groove 130 as shown in Figs. 12, 13, and 14.

The lower clad 141 and the upper clad 143 are formed to surround the core so that light can be efficiently transmitted through the core. The upper clad 143 and lower clad 141 are made of a polymer material such as acryl, epoxy, polyimide, fluorinated acryl, or fluorinated polyimide.

The core 142 is interposed between the upper clad 143 and the lower clad 141 and functions as a path through which the optical signal is transmitted. The core 142 is made of a polymer material similar to the upper clad 143 and the lower clad 141 and has a refractive index higher than that of the clad layer for efficient optical signal transmission. At this time, the core 142 may be formed of SiO ₂ mixed with silica or polymer.

That is, the optical waveguide 140 includes a lower clad 141, an upper clad 143, and a core 142 integrally formed between the upper clad 143 and the lower clad 141, The optical waveguide 140 can be formed by cutting the optical waveguide formed in the receiving groove 130 according to the size of the receiving groove 130.

A first mirror 132 and a second mirror 135 formed on one end and the other end of the receiving groove 130 are positioned on the cut surface of the core 142 included in the optical waveguide 140. As described above, the first and second mirrors 132 and 135 are formed of a highly reflective material such as aluminum or silver in order to efficiently transmit light.

Since the core 142 is disposed inside the upper clad 143 and the lower clad 141 and has a higher refractive index than the upper clad 143 and the lower clad 141, Is totally reflected at the interface between the core 142 and the upper / lower clad 141 and 143, and travels along the core 142.

Since the light travels through the core 142, the core 142 is disposed in the receiving groove 130 in which the first mirror 132 and the second mirror 135 are formed, and the upper clad 143, May be formed to protrude above the receiving groove 130.

Meanwhile, the optical waveguide 140 may be formed by an embossing process or a photolithography process using a polymer material having excellent light transmittance and flexibility, for example, an organic-inorganic polymer material.

The sides of the optical waveguide 140 (the side surface of the upper clad 143, the side surface of the lower clad 141, and the side surface of the core 142) are exposed in the receiving groove 130. In addition, the optical waveguide 140 may have a top surface and a side surface that are perpendicular to each other as shown in the drawing, but may have an inclination angle corresponding to an inclination angle of the receiving recess 130 according to an embodiment . For this purpose, the cutting process is performed in consideration of the size of the receiving groove 130 and the inclination angle of the receiving groove 130 when cutting the optical waveguide 140 made of the single product, The cut optical waveguide 140 is inserted into the receiving groove 130.

Since the optical waveguide 140 is cut as described above and then inserted into the receiving groove 130, the lower clad 141, the core 142 and the upper clad 143 included in the optical waveguide 140 Is exposed to the first mirror 132 and the second mirror 135 formed in the receiving groove 130. [

15, 16, and 17, the optical waveguide 140 and the circuit pattern 125 are embedded on the upper and lower surfaces of the insulating layer 110 on which the optical waveguide 140 is formed, An insulating layer 150 is formed. FIG. 16 is a cross-sectional view taken along the line A-A 'of FIG. 15, and FIG. 17 is a cross-sectional view taken along the line B-B' of FIG.

An optical transmitter (not shown) may be formed at an upper position of the first mirror 132, and an optical receiver (not shown) may be formed at an upper position of the second mirror 134. More preferably, the optical transmitter is formed on the circuit pattern 125 located on the upper side of the first mirror 132, and the optical receiver is formed on the circuit pattern 125 located on the upper side of the second mirror 135 do.

The optical transmitter generates and outputs an optical signal and includes a driver integrated circuit (not shown) and a light emitting element (not shown). The light emitting device is driven by the driver integrated circuit to generate light in a direction in which the first mirror 132 is formed.

In this case, the light emitting device may include a VCSEL (Vertical-Cavity Surface-Emitting Laser), which is a light source device for emitting a light signal. The VCSEL is a light source element that transmits or amplifies a light source signal in a manner of vertically irradiating a laser beam.

The optical receiver includes a receiver integrated circuit (not shown) and a light receiving element (not shown).

The light receiving element receives light generated from the optical transmitter and is driven by the receiver integrated circuit. The light receiving element may include a photo detector (PD), which is an element for detecting an optical signal.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, It belongs to the scope of right.

100: optical printed circuit board
110, 150: insulating layer
125: Circuit pattern
130: receiving groove
132, 135: mirror
140: optical waveguide

Claims (18)

A first insulating layer on the upper surface, the first insulating layer including a receiving groove having a predetermined depth as a lower surface opposite to the upper surface;
A first mirror disposed at one end of the receiving groove and having a first inclination angle;
A second mirror disposed at the other end of the receiving groove and having a second inclination angle;
A first circuit pattern disposed on an upper surface of the first insulating layer in a region vertically overlapped with the first mirror;
A second circuit pattern disposed on an upper surface of the first insulating layer, the second circuit pattern being vertically overlapped with the second mirror;
An optical transmitter electrically connected to the first circuit pattern and transmitting light in a direction in which the first mirror is formed;
An optical receiver electrically connected to the second circuit pattern and receiving light reflected through the second mirror;
A plurality of lower clads disposed at predetermined intervals in the receiving groove of the first insulating layer; a plurality of cores respectively disposed on the plurality of lower clads; and a plurality of upper clads respectively disposed on the plurality of cores A plurality of optical waveguides; And
And a second insulating layer disposed on the first insulating layer and covering the plurality of optical waveguides disposed in the receiving groove, the optical transmitter, and the optical receiver,
Wherein the plurality of optical waveguides include:
Wherein each of the optical waveguides in which the lower clad, the core and the upper clad are formed integrally is disposed at a constant distance from each other in one receiving groove of the first insulating layer. delete delete delete delete delete delete delete delete Preparing a first insulating layer;
Forming a circuit pattern on the upper surface of the prepared first insulating layer;
Forming a receiving groove having a predetermined depth from an upper surface of the first insulating layer, the lower surface being opposite to the upper surface, on the first insulating layer;
Disposing a first mirror having a first inclination angle at one end in the formed receiving groove and a second mirror having a second inclination angle at the other end of the receiving groove;
A plurality of optical waveguides including a plurality of lower clads arranged at predetermined intervals in the receiving groove, a plurality of cores respectively disposed on the plurality of lower clads, and a plurality of upper clads respectively disposed on the plurality of cores, Placing;
Disposing an optical transmitter in an upper surface of the first insulating layer, the optical transmitter being electrically connected to a circuit pattern disposed in a region vertically overlapped with the first mirror;
Disposing an optical receiver electrically connected to a circuit pattern disposed on an upper surface of the first insulating layer in a region vertically overlapped with the second mirror;
And forming a second insulating layer covering the optical waveguide, the optical transmitter, and the optical receiver on the first insulating layer,
Wherein the step of arranging the plurality of optical waveguides comprises:
And arranging each optical waveguide in which the lower clad, the core and the upper clad are formed integrally with each other in a receiving groove of the first insulating layer. delete delete delete delete delete delete delete delete

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