JP2005068459A - Method of producing mirror for optical waveguide - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing mirrors for optical waveguides capable of suppressing the loss in the conveyance of light. <P>SOLUTION: The method of producing mirrors for optical waveguides is provided with a process where clads each consisting of a translucent resin layer are formed on a substrate, long and slender cores as optical waveguides are formed inside each clad, slopes each sloped to the substrate are formed so as to face the edge part of each core, a catalyst for electroless plating is stuck to each slope, each resin layer is heated so as to chemically be stabilized, the obtained substrate is dipped into an electroless plating liquid, and the metal in the plating liquid is precipitated by the action of each catalyst to form a metal plating film on each slope. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a method of manufacturing an optical waveguide mirror. More specifically, the present invention relates to a method for manufacturing an optical waveguide mirror capable of performing optical path conversion with higher accuracy.

The prior art related to this invention is a method of manufacturing an electric circuit board, in which a polysilane film is formed on the surface of the substrate, and ultraviolet light is passed through a mask having openings corresponding to circuit patterns on the polysilane film. Irradiate light to hydrophilize the exposed area, and attach a liquid containing palladium salt to the hydrophilic exposed area to form a pattern of palladium salt on the exposed area, and use this pattern as a catalyst for electroless plating 2. Description of the Related Art A method for manufacturing an electric circuit board that performs electroless plating and forms a conductive pattern is known (see, for example, Patent Document 1).
JP 2002-356882 A

  In the advanced information society in the 21st century, information needs are becoming increasingly sophisticated, diversified, and digitized, and the amount of information distributed through the network is expected to increase compared to the present level.

  In order to smoothly transmit and process this enormous amount of information, it is necessary to dramatically improve the processing capability of the communication device and the computer.

  Although the performance of electrical elements such as semiconductor integrated circuits (LSIs) has steadily improved, problems related to electrical wiring such as crosstalk, electromagnetic radiation, and noise associated with higher signal speeds have become bottlenecks.

  In order to solve this problem, it is considered that a part of the electric wiring is replaced with an optical wiring using an optical waveguide and an optical signal is used instead of the electric signal. In the case of optical wiring, the problems related to the electrical wiring can be suppressed.

  The optical waveguide is composed of a core and a cladding surrounding the core. By making the refractive index of the core larger than that of the cladding layer, the light incident on the core propagates while being totally reflected at the interface between the core and the cladding.

  Initially, optical fibers made of quartz have been used as the optical wiring. However, as the number of wirings increases, connection becomes difficult, and recently, polymer optical waveguides have been studied.

  As a polymer optical waveguide material, polymethyl methacrylate (PMMA), epoxy resin, polyimide, polysilane, etc. are used, and in particular, the refractive index decreases and hydrophilicity is exhibited by light irradiation. Attention has been focused on polysilanes whose properties are chemically stable.

  By the way, when a photoelectric conversion element such as a light emitting element or a light receiving element and an electronic component for controlling these photoelectric conversion elements are mounted on a photoelectric circuit board on which an optical wiring and an electric wiring are formed, an electric circuit has been conventionally used. It is desired that the surface mounting technology used for circuit boards can be applied.

  For this reason, it is necessary to optically couple the optical wiring wired in parallel with the substrate surface of the photoelectric circuit board and the photoelectric conversion element mounted on the surface of the photoelectric circuit board. It is necessary to form a mirror for degree conversion.

  For example, in order to make the light propagating through the core portion of the optical waveguide incident on the light receiving surface of the surface-receiving photodiode mounted on the surface of the photoelectric circuit board, a 45 degree reflection near the end of the optical waveguide A mirror having a surface is formed, and the light emitted from the end portion of the optical waveguide by the mirror must be optically converted toward the light receiving surface.

  Various proposals have been made as a method for forming a mirror. For example, a 45-degree inclined surface is formed in the vicinity of an end of an optical waveguide using a semiconductor dicer, and a metal thin film is deposited on the inclined surface to form a mirror. The method of forming is generally used.

  Here, when the optical waveguide is made of polysilane, as introduced in the above-described method for manufacturing an electric circuit board, a liquid containing a palladium salt is attached to a portion where hydrophilicity is expressed, and the attached palladium salt is electrolessly treated. It can be considered that a metal plating film is formed by applying electroless plating as a plating catalyst.

  However, polysilane undergoes mineralization due to elimination of hydrocarbon groups in the side chain, cleavage of the main chain, and oxidation by firing, and the volume shrinks by about 5 to 15%.

  For this reason, there is a possibility that the metal plating film is wrinkled due to the difference in area change between the metal plating film formed on the inclined surface and the inclined surface. Alternatively, stress may be applied to the outer edge of the metal plating film due to the difference in area change between the metal plating film and the inclined surface, and the metal plating film may be partially peeled off.

  As a result, light transmission or scattering occurs in the mirror part, and there is a risk that the propagation loss of light increases.

  The present invention has been made in consideration of the above-described circumstances, and provides a method for manufacturing an optical waveguide mirror capable of suppressing light propagation loss.

  In the present invention, a clad made of a translucent resin layer is formed on a substrate, an elongated core is formed as an optical waveguide in the clad, and an inclined surface that is opposed to the end of the core and is inclined with respect to the substrate is formed. The catalyst for electroless plating is attached to the inclined surface, the resin layer is heated and chemically stabilized, the obtained substrate is immersed in the electroless plating solution, and the metal in the plating solution is obtained by the action of the catalyst. The manufacturing method of the mirror for optical waveguides provided with the process of forming a metal plating film in an inclined surface by precipitating a metal is provided.

That is, the method for manufacturing a mirror for an optical waveguide according to the present invention heats and chemically stabilizes the resin layer to which the electroless plating catalyst is attached, and then uses the catalytic action of the electroless plating catalyst to perform electrolysis. Apply plating.
For this reason, when the resin layer is contracted by heating, the metal plating film can be prevented from wrinkling and peeling due to the contraction after heating, and the light propagation loss in the mirror portion can be suppressed.

  According to this invention, the resin layer to which the electroless plating catalyst is attached is heated and chemically stabilized, and then electroless plating is performed using the catalytic action of the electroless plating catalyst. When shrinkage is caused by heating, wrinkles and peeling of the metal plating film due to shrinkage after heating can be prevented, and light propagation loss at the mirror portion can be suppressed.

  In the method of manufacturing an optical waveguide mirror according to the present invention, a clad made of a light-transmitting resin layer is formed on a substrate, an elongated core is formed in the clad, and the end faces the core and is inclined with respect to the substrate. An inclined surface is formed, an electroless plating catalyst is attached to the inclined surface, the resin layer is heated and chemically stabilized, and the obtained substrate is immersed in an electroless plating solution. The method includes a step of depositing a metal in the plating solution by a catalytic action to form a metal plating film on an inclined surface.

  In the method for manufacturing an optical waveguide mirror according to the present invention, for example, a quartz substrate, a polyimide film, or the like can be used as the substrate.

  In the method of manufacturing an optical waveguide mirror according to the present invention, the electroless plating catalyst may be composed of palladium.

  In the method of manufacturing an optical waveguide mirror according to the present invention, the clad is made of a resin that exhibits hydrophilicity by light irradiation, and the step of attaching the electroless plating catalyst to the inclined surface is performed by irradiating the inclined surface with light. There may be included a step of developing hydrophilicity and attaching a liquid containing the electroless plating catalyst to the inclined surface where the hydrophilicity is expressed.

  As the liquid containing the electroless plating catalyst, when the electroless plating catalyst is made of palladium, for example, a mixed solution of palladium chloride and stannous chloride, a palladium chloride solution, or the like can be used.

  In the method for manufacturing a mirror for an optical waveguide according to the present invention, the resin may be made of polysilane.

  Polysilane exhibits hydrophilicity when irradiated with light, and its characteristics are chemically stable after firing at 250 to 350 ° C.

  For this reason, when resin consists of polysilane, the heating temperature of a resin layer may be 250-350 degreeC.

  When polysilane is heated at 250 to 350 ° C., it undergoes mineralization due to elimination of hydrocarbon groups in the side chain, cleavage of the main chain, and oxidation, resulting in volume shrinkage. Since the catalyst for use is deposited on the inclined surface and sparsely scattered, it is not affected by volume shrinkage.

  Thereafter, when the obtained substrate is immersed in the electroless plating solution, the metal in the plating solution is deposited on the inclined surface by the catalytic action of the electroless plating catalyst, and then the metal plating film is formed by the autocatalytic action of the deposited metal. grow up.

  Polysilane also exhibits solubility in an alkaline solution and a decrease in refractive index when irradiated with light.

  For this reason, it is possible to form a desired inclined surface by irradiating light through a gray mask whose light transmittance gradually increases or decreases, and etching and removing the irradiated portion with an alkaline solution, and having a shape corresponding to the pattern of the optical waveguide. An optical waveguide can also be formed by irradiating light through a mask, which is suitable as a resin used in the production method of the present invention.

  In the optical waveguide manufacturing method according to the present invention, the metal plating film may have a multilayer structure in which the lower layer in contact with the inclined surface is made of copper and the surface layer facing the end of the optical waveguide is made of gold or silver. Good.

  In this case, specifically, a configuration in which copper / nickel / gold, copper / nickel / silver, or copper / silver is sequentially laminated from the lower layer side to the surface layer side can be exemplified.

  In the optical waveguide manufacturing method according to the present invention, the metal plating film has a multilayer structure in which the lower layer in contact with the inclined surface is made of a nickel-phosphorus alloy and the surface layer facing the end of the optical waveguide is made of gold or silver. It may be.

  In this case, specifically, a structure in which nickel-phosphorus alloy / gold or nickel-phosphorus alloy / silver is sequentially laminated from the lower layer side to the surface layer side can be exemplified.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. In addition, in several Example, it demonstrates using the same code | symbol to the same member.
Example 1
The manufacturing method of the mirror for optical waveguides by Example 1 of this invention is demonstrated based on FIGS. 1 to 5 are process diagrams showing a method of manufacturing an optical waveguide mirror according to the first embodiment.

  As shown in FIGS. 1 to 5, the method for manufacturing a mirror for an optical waveguide according to the present invention includes first and second cladding portions 2 and 4 made of a translucent resin on a substrate 1, first and second An elongated optical waveguide 5 surrounded by two clad portions 2 and 4 is formed, and an inclined surface 6 that faces the end of the optical waveguide 5 and is inclined with respect to the substrate 1 is formed on a part of the core layer 3. 6 is attached with palladium 7 as a catalyst for electroless plating, and the core layer 3 and the optical waveguide 5 are heated and chemically stabilized. Then, the obtained substrate 1 is immersed in an electroless plating solution, and palladium is added. 7 is used to deposit the metal in the plating solution to form the reflective film 8 on the inclined surface 6. Hereinafter, each step will be described in detail.

  First, as shown in FIG. 1A, a solution containing polysilane as a main component (Nippon Paint, Gracia WG-005) is spun on a substrate 1 made of quartz using a spinner so as to have a film thickness of 10 μm. It is coated, pre-dried at 250 ° C., and further baked at 350 ° C. to form the first cladding portion 2 having a refractive index of 1.58 (wavelength 633 nm).

  Next, as shown in FIG. 1B, a solution containing polysilane having a higher refractive index than that of polysilane constituting the first cladding portion 2 (Nippon Paint, Gracia WG-004) as a first cladding portion. 2 is spin-coated to a thickness of 20 μm and pre-dried at 250 ° C. to form the core layer 3.

  Next, as shown in FIG. 1C, a photomask 30 is disposed on the core layer 3, and then, as shown in FIG. 1D, ultraviolet light L is transmitted through the photomask 30 to the core layer. 3 is selectively formed.

Here, a 500 W deep UV lamp is used as the light source, and exposure is performed so that the amount of ultraviolet light irradiation with a wavelength of 300 to 400 nm is 200 mJ / cm ² per 1 μm of film thickness.

  Next, the obtained substrate is immersed in an alkaline aqueous solution, for example, a 10-20% aqueous solution of tetramethylammonium hydroxide, and the exposed portion 9 (see FIG. 1 (d)) as shown in FIG. 1 (e). Etch away.

  Next, as shown in FIG. 2F, the inclined surface 6 is formed using a blade 10 having a predetermined angle on the blade surface.

  Next, as shown in FIG. 2G, the inclined surface 6 is irradiated with ultraviolet light L for about 2 minutes through the photomask 40 using the same light source as the light source, and the surface of the inclined surface 6 is hydrophilic. To express. Specifically, silanol groups are formed on the surface of the inclined surface 6 by irradiation with the ultraviolet light L, and the silanol groups adsorb metals. For this reason, palladium 7 (see FIG. 2H) selectively adheres only to the inclined surface 6 that has been irradiated with the ultraviolet light L in a later step.

  Next, the obtained substrate was immersed in a catalyst solution (liquid temperature 25 ° C.) containing 0.03% palladium chloride, 2% stannous chloride, and 20% hydrochloric acid for 5 minutes, and the immersed substrate was washed with water. It is immersed in a 10% hydrochloric acid aqueous solution for 2 minutes and further washed with water to deposit palladium 7 on the inclined surface 6 as shown in FIG.

  Next, as shown in FIG. 3I, the core layer 3 is irradiated with ultraviolet light L through a photomask 50 having a light shielding portion 51 having a shape corresponding to the core portion 5. As a result, the refractive index of the irradiated portion is lowered and the refractive index of the non-irradiated portion is relatively increased. As a result, a core portion 5 having a refractive index of 1.6 (wavelength 633 nm) is formed in a part of the core layer 3. The

  Next, as shown in FIG. 3 (j), the obtained substrate is baked at 350 ° C. for 30 minutes to chemically stabilize the core layer 3 and the optical waveguide 5. At this time, the core layer 3 and the optical waveguide 5 contract, but the palladium 7 deposited on the inclined surface 6 in the previous step is only sparsely scattered on the surface of the inclined surface 6, and is therefore affected by the contraction. Absent.

  Next, the obtained substrate is washed with water and immersed in an electroless copper plating solution (liquid temperature 25 ° C.) containing 1% copper sulfate, 4% Rochelle salt, 1% formaldehyde, and 1% sodium hydroxide for 15 minutes.

  As a result, the copper in the electroless copper plating solution is deposited on the inclined surface 6 by the catalytic action of palladium 7 (see FIG. 3 (j)) that has been deposited on the inclined surface 6 in the previous step. A plating film grows by the catalytic action, and a copper plating film 11 having a thickness of 0.2 μm is formed on the inclined surface 6 as shown in FIG.

  Next, the obtained substrate is washed with water, washed with a 10% aqueous sulfuric acid solution, washed again with water, and immersed in a catalyst solution (solution temperature 25 ° C.) containing 0.02% palladium chloride for 5 minutes. Thereby, a substitution reaction between the copper plating film 11 formed in the previous step and palladium ions occurs, and palladium 7 is deposited on the copper plating film 11 as shown in FIG.

  Next, the obtained substrate is washed with water and immersed in an electroless nickel plating solution (solution temperature 80 ° C.) containing 2% nickel sulfate, 1.5% sodium phosphinate, and 3% sodium citrate for 5 minutes. As a result, a nickel-phosphorus plating film 12 having a thickness of 2 μm is formed on the copper plating film 11 as shown in FIG.

  Next, the obtained substrate was washed with water, immersed in a gold plating solution (solution temperature 85 ° C.) containing 0.1% potassium gold cyanide and 1% sodium cyanide for 10 minutes, and then 1% sodium gold sulfite, Immerse in an electroless plating solution (solution temperature 60 ° C.) containing 2% of dimethylamine borane for 60 minutes.

  As a result, as shown in FIG. 4 (n), a gold plating film 13 having a film thickness of 0.5 μm is formed on the nickel-phosphorous plating film 12 formed in the previous step, as shown in FIG. As shown, a reflective film 8 having a three-layer structure of copper plating film 11 / nickel-phosphorous plating film 12 / gold plating film 13 is formed on the surface of the inclined surface 6.

  Next, as shown in FIG. 4 (p), a spinner is used on the core layer 3 and the optical waveguide 5 so that a solution containing polysilane, which is the same as the polysilane constituting the core layer 3, as a main component has a film thickness of 30 μm. The second clad portion 4 is formed by spin coating and predrying at 250 ° C.

Next, as shown in FIG. 5 (q), the second cladding portion 4 is irradiated with ultraviolet light L through a photomask 45, and the portions other than the mirror 14 are exposed to form an exposed portion 19. Using a 500 W deep UV lamp as the light source, exposure is performed so that the amount of ultraviolet irradiation light having a wavelength of 300 to 400 nm is 200 mJ / cm ² per 1 μm of polysilane film thickness.

  After that, as shown in FIG. 5 (r), the substrate is baked at about 350 ° C., and the second clad part 4 having a refractive index of 1.58 (wavelength 633 nm) and the upper part of the mirror 14 have a higher refractive index than the surroundings. A waveguide 5 'is formed. In this manner, the optical waveguide substrate 100 including the mirrors 14 in the vicinity of both ends of the optical waveguide 5 sandwiched between the first cladding portion 2 and the second cladding portion 4 is completed.

  At this time, since the core layer 3 has already undergone the firing process, peeling or wrinkles or the like does not occur in the reflective film 8 due to the firing of the second cladding portion 4.

  In addition, a copper plating film having a film thickness of 2 to 3 μm is formed using an electroless copper plating solution for forming a thick film as an electroless copper plating solution. Instead of the electroless nickel plating solution, 1% silver nitrate, 7% ammonium hydroxide, It is also possible to form a silver plating film on a copper plating film using a silver plating solution containing 10% sodium sulfite.

It is also possible to form a silver plating film on the nickel-phosphorous plating film using the above electroless silver plating solution instead of the gold plating solution.
Example 2
The manufacturing method of the mirror for optical waveguides by Example 2 of this invention is demonstrated based on FIGS. 6 to 9 are process diagrams showing a method of manufacturing an optical waveguide mirror according to the second embodiment.

  First, as shown in FIG. 6A, a solution containing polysilane as a main component (Nippon Paint, Gracia WG-005) is formed to a thickness of 10 μm on a film substrate 21 made of a polyimide film having a thickness of 100 μm. The first clad part 2 having a refractive index of 1.58 (wavelength 633 nm) is formed by spin coating using a spinner, pre-drying at 250 ° C., and baking at 350 ° C.

  Next, as shown in FIG. 6B, a solution containing polysilane having a refractive index higher than that of polysilane constituting the first cladding portion 2 (Nippon Paint, Gracia WG-004) as a first cladding portion. 2 is spin-coated to a thickness of 20 μm and pre-dried at 250 ° C. to form the core layer 3.

  Next, as shown in FIG. 6C, a photomask 60 is disposed on the core layer 3, and then, as shown in FIG. 6D, the ultraviolet light L is transmitted through the photomask 60 through the core layer. 3 is selectively formed.

Here, a 500 W deep UV lamp is used as the light source, and exposure is performed so that the amount of ultraviolet light irradiation with a wavelength of 300 to 400 nm is 200 mJ / cm ² per 1 μm of film thickness.

  Further, the photomask 60 has a gray mask pattern in which the light transmittance gradually decreases to 100 to 0% at a position corresponding to the inclined surface 6 in order to form a latent image of the inclined surface 6 (see FIG. 6E). A light transmission part 61 is provided.

  For this reason, in the light transmitting portion 61, the portion exposed through the portion with high light transmittance proceeds to the depth of the second cladding portion 3, and the portion exposed through the portion with low light transmittance is Only the vicinity of the surface layer of the core layer 3 is exposed, and as a result, an exposed portion 29 having a latent image of the inclined surface 6 is formed in the exposed portion.

  Next, the obtained film substrate is immersed in an alkaline aqueous solution, for example, a 10-20% aqueous solution of tetramethylammonium hydroxide, and the exposed portion 29 is removed by etching as shown in FIG. Form.

  Next, as shown in FIG. 7F, the inclined surface 6 is irradiated with ultraviolet light L for about 2 minutes through the photomask 40 using the same light source as the light source, and the surface of the inclined surface 6 is hydrophilic. To express.

  Next, the obtained film substrate is immersed in a catalyst solution (liquid temperature 25 ° C.) containing 0.03% palladium chloride for 5 minutes.

  As a result, palladium ions are adsorbed on the inclined surface 6, and the adsorbed palladium ions are reduced by silanol groups on the surface of the inclined surface 6, and palladium 7 is formed on the surface of the inclined surface 6 as shown in FIG. Precipitate.

  Next, as shown in FIG. 7 (h), the core layer 3 is irradiated with ultraviolet light L through a photomask 50 having a light shielding part 51 having a shape corresponding to the core part 5. As a result, the refractive index of the irradiated portion is lowered and the refractive index of the non-irradiated portion is relatively increased. As a result, a core portion 5 having a refractive index of 1.6 (wavelength 633 nm) is formed in a part of the core layer 3. The

  Next, as shown in FIG. 8 (i), the obtained film substrate is baked at 350 ° C. for 30 minutes to chemically stabilize the core layer 3 and the optical waveguide 5. At this time, the core layer 3 and the optical waveguide 5 contract, but the palladium 7 deposited on the inclined surface 6 in the previous step is only sparsely scattered on the surface of the inclined surface 6, and is therefore affected by the contraction. Absent.

  Next, the obtained film substrate is washed with water and immersed in an electroless nickel plating solution (solution temperature 80 ° C.) containing 2% nickel sulfate, 1.5% sodium phosphinate, and 3% sodium citrate for 5 minutes.

  As a result, nickel-phosphorus in the electroless nickel plating solution is deposited on the inclined surface 6 by the catalytic action of palladium 7 (see FIG. 8 (i)) that has been deposited on the inclined surface 6 in the previous step. -A plating film grows by the autocatalytic action of phosphorus, and a nickel-phosphorous plating film 12 having a film thickness of 2 m is formed on the inclined surface 6 as shown in FIG.

  Next, the obtained film substrate was washed with water, immersed in a gold plating solution (solution temperature 85 ° C.) containing potassium gold cyanide 0.1% and sodium cyanide 1% for 10 minutes, and then sodium gold sulfite 1% And dipping in an electroless plating solution (solution temperature 60 ° C.) containing 2% of dimethylamine borane for 60 minutes.

  As a result, as shown in FIG. 8 (k), a gold plating film 13 having a film thickness of 0.5 μm is formed on the nickel-phosphorous plating film 12 formed in the previous step, as shown in FIG. 9 (l). As shown, a reflective film 28 having a two-layer structure of nickel-phosphorous plating film 12 / gold plating film 13 is formed on the surface of the inclined surface 6.

  Next, as shown in FIG. 9 (m), a spinner is used on the core layer 3 and the optical waveguide 5 so that a solution containing as a main component the same polysilane as that constituting the core layer 3 has a film thickness of 30 μm. The second clad portion 4 is formed by spin coating and predrying at 250 ° C.

Next, as shown in FIG. 9 (n), ultraviolet light L is irradiated to the second cladding part 4 through a photomask 65, and the part other than the mirror 34 is exposed to form an exposed part 39. Using a 500 W deep UV lamp as the light source, exposure is performed so that the amount of ultraviolet irradiation light having a wavelength of 300 to 400 nm is 200 mJ / cm ² per 1 μm of polysilane film thickness.

  Thereafter, as shown in FIG. 9 (o), the substrate is baked at about 300 ° C., and the second clad part 4 having a refractive index of 1.58 (wavelength 633 nm) and the upper part of the mirror 34 have a higher refractive index than the surroundings. A waveguide 5 'is formed. In this manner, the optical waveguide substrate 200 including the mirrors 34 in the vicinity of both ends of the optical waveguide 5 sandwiched between the first cladding portion 2 and the second cladding portion 4 is completed.

  This can be used when manufacturing a mirror made of a metal plating film at the end of the optical waveguide.

It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 1 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 1 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 1 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 1 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 1 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 2 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 2 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 2 of this invention. It is process drawing which shows the manufacturing method of the mirror for optical waveguides by Example 2 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Substrate 2 ... 1st clad part 3 ... Core layer 4 ... 2nd clad part 5, 5 '... Optical waveguide 6 ... Inclined surface 7 ... Palladium 8,28 ... Reflection film 9, 19, 29, 39 ... Exposure part 10 ... Blade 11 ... Copper plating film 12 ... Nickel-phosphorus plating film 13 ... Gold plating film 14,34 ... -Mirror 21 ... Film substrate 30, 40, 45, 50, 60, 65 ... Photomask 51 ... Light shielding part 61 ... Light transmission part L ... Ultraviolet light

Claims (6)

  A clad made of a light-transmitting resin layer is formed on a substrate, an elongated core is formed as an optical waveguide in the clad, an inclined surface that faces the end of the core and is inclined with respect to the substrate is formed on the inclined surface. A catalyst for electroless plating is attached, the resin layer is heated and chemically stabilized, the obtained substrate is immersed in an electroless plating solution, and the metal in the plating solution is precipitated by the action of the catalyst. A manufacturing method of a mirror for optical waveguides provided with a process of forming a metal plating film on an inclined surface.   The manufacturing method of the mirror for optical waveguides of Claim 1 in which a catalyst consists of palladium. The clad is made of a resin that develops hydrophilicity when irradiated with light, and the step of attaching the electroless plating catalyst to the inclined surface irradiates the inclined surface with light to develop hydrophilicity, and the inclined surface that exhibits hydrophilicity is formed. The manufacturing method of the mirror for optical waveguides of Claim 1 or 2 including the process of making the liquid containing the catalyst for electroless plating adhere. The method for producing a mirror for an optical waveguide according to claim 3, wherein the resin is made of polysilane, and the heating temperature of the resin layer is 250 to 350 ° C. 5. The optical plating film according to claim 1, wherein the metal plating film has a multilayer structure in which a lower layer in contact with the inclined surface is made of copper and a surface layer facing an end of the optical waveguide is made of gold or silver. Mirror manufacturing method. 5. The metal plating film according to claim 1, wherein the metal plating film has a multilayer structure in which a lower layer in contact with the inclined surface is made of a nickel-phosphorous alloy and a surface layer facing the end of the optical waveguide is made of gold or silver. Manufacturing method of mirror for optical waveguide.

Images