JP4828464B2 - Processing blade manufacturing method, processing blade, and optical element manufacturing method using the same - Google Patents

Description

The present invention, machining blade manufacturing method and processing blade, and relates to the production how the optical device using the same, in particular, by grinding the substrate, to form a rib-type structure on the substrate machining blade manufacturing method and processing blade, and relates to the production how the optical device using the same.

Conventionally, in an optical communication field and an optical measurement field, an optical element such as a waveguide type optical modulator in which an optical waveguide or a modulation electrode is formed on a substrate having an electrooptic effect has been widely used.
In order to realize a wider optical modulation frequency, it is important to match the speed of the modulation signal microwave and the light wave, and various methods have been devised, such as a ridge structure for the optical waveguide. Yes.

Etching or grinding is known as a method for forming a ridge structure on a substrate. However, the etching method requires a long time for etching to a depth of several microns, resulting in an increase in manufacturing cost. In addition, the side surface of the ridge formed by etching tends to be rough, and the propagation loss of light waves also increases. On the other hand, in the grinding process, a groove is formed using a dicing saw, and there is an advantage that it can be easily formed. Patent Document 1 or Patent Document 2 discloses that a blade in which diamond abrasive grains are bonded using a resin-based binder is used as the blade.
Japanese Patent Laid-Open No. 10-10348 Japanese Patent Laid-Open No. 2004-341045

  To form a ridge structure, it is necessary to form grooves on both sides of the ridge. Therefore, to form a ridge structure using a dicing saw, two blades are held through spacers at a time. There are a method of forming two grooves and a method of forming grooves one by one. In the method using two blades, the spacer sandwiched between the blades is very thin, about 10 μm or less, and it is difficult to manufacture and handle the spacer itself, and the tip strength is insufficient at the time of grinding, so that a highly accurate groove cannot be formed. It was producing points. Further, when the grooves are formed one by one, it takes time to form the ridge and it is difficult to form the two grooves in parallel with high accuracy. Furthermore, after forming the first groove, when the second groove is formed, the second groove is formed so as to push the ridge portion in the direction of the first groove. There is a risk of damaging the ridge.

The problem to be solved by the present invention is to solve the above-mentioned problems and to provide a processing blade manufacturing method and a processing blade capable of forming a rib-type structure with high accuracy and stability, and using the same. it is to provide a manufacturing how the optical element.

In order to solve the above-mentioned problem, the invention according to claim 1 is a taper shape by polishing only the outer surface of the disk, the bonding step of bonding two disks with an adhesive, and the edge of the disk And a removing step of removing the adhesive so that the peripheral edge of the adhesive is positioned inside the edge tip of the disk.

The invention according to claim 2 is a processing blade manufactured by using the processing blade manufacturing method according to claim 1 .

A third aspect of the present invention is a method of manufacturing an optical element, characterized in that a substrate is ground using the processing blade according to the second aspect, and a rib-type structure is formed on the substrate.

According to the invention of claim 1, a joining step of joining two discs with an adhesive, a polishing step of processing the edges of the disc into a tapered shape by polishing only the outer surface of the disc, and the bonding And a removing step of removing the adhesive so that the peripheral edge of the agent is located inside the edge tip of the disk. Two disks are fixed with an adhesive, increasing the strength of the blade tip. Further, since the edges are formed by joining the two blades and then polishing, the shapes of the two blades, particularly the shapes of both the edge portions with respect to the rotating shaft, can be aligned with high accuracy.

Further, according to the invention of claim 1 , since the tapered shape is formed by polishing only the outer surface of the disk, a ridge type structure is formed in which the side surface of the ridge portion rises perpendicularly to the substrate surface. In addition, since the substrate is ground exclusively on the outer side of the blade edge when forming the groove, the side surface of the ridge portion can have a mirror structure.

According to the second aspect of the present invention, since the processing blade is manufactured using the processing blade manufacturing method according to the first aspect, the mechanical strength of the blade tip portion is high, and the distance between the two blades is high. Can be obtained with high precision, and a blade for machining in which the shape of the tip portion of the blade is formed with high precision can be obtained.

The invention according to claim 3, for billing the substrate by grinding with a machining blade according to claim 2, is a manufacturing method of an optical element characterized in that the rib structure to the substrate, high An optical element having an accurate rib-type structure can be manufactured.

Hereinafter, the present invention will be described in detail using preferred examples.
The present invention, machining blade manufacturing method and processing blade, as well as about the preparation how the optical device using the same.
As shown in FIG. 1, the manufacturing method of the processing blade of the present invention includes a joining step (a) in which two discs 1 are joined with an adhesive 2 and an edge 3 of the disc 1 is connected to the outside of the disc 1. A polishing step (b) in which only the side surface is polished to be tapered, and a removing step (c) in which the adhesive is removed so that the peripheral edge 4 of the adhesive is located inside the edge tip of the disk. ). An edge portion formed by polishing is indicated by reference numeral 5.

  In the processing blade manufactured using the processing blade manufacturing method of the present invention, since the two disks 1 are fixed to the vicinity of the tip of the blade with the adhesive 2, the tip strength of the blade is increased. . For this reason, it becomes possible to form a highly accurate ridge type structure by using this processing blade.

  In addition, after joining the two disks, the edge portion 3 of the disk is simultaneously polished with the grindstone while rotating the blade to form the edge, so that the shape of the two disks (blades), particularly the edge with respect to the rotation axis It becomes possible to match both shapes of the portions with high accuracy (symmetrical in FIG. 1C). For this reason, when the ridge structure is formed by using the manufactured processing blade, it is possible to form the grooves on both sides of the ridge symmetrically with the ridge interposed therebetween. Since uniform stress is applied to the ridge portion, the ridge is not easily damaged, and a stable and highly accurate ridge structure can be formed.

  Furthermore, since the taper shape of the edge portion 5 of the blade is formed by polishing only the outer surface of the disk 1, it is possible to form a ridge type structure in which the side surface of the ridge portion rises perpendicularly to the substrate surface. It becomes.

  As a material used for the disk 1 itself, a resin-based blade in which diamond abrasive grains are dispersed and sintered in a thermosetting resin can be suitably used. As the size of the blade, a blade having a thickness of 0.2 mm or more and a radius of 30 mm or less can be suitably used. In addition, when using the blade, the blade is accurately faced (parallelism between the front and back surfaces) and accurately shaped into a circle.

  In the processing blade manufacturing method of the present invention, it is necessary to keep the distance between the two disks at a high accuracy with a width of about 10 μm or less. For this reason, acrylic, epoxy, or the like can be suitably used as an adhesive material, and the method of applying the adhesive to the disk 1 can also be applied to the entire disk 1 using spin coating. After the layers are formed, the other disk 1 is overlapped so that the air layer does not enter, and the two disks are joined so as to be held at an equal interval.

  The edge of the processing blade is formed by rotating a laminate of two disks and polishing with a grindstone. For this reason, since the diamond abrasive grains constituting the blade (disk 1) are always exposed on the surface of the edge portion of the blade, even if the blade is used for a long period of time, the grinding performance does not deteriorate. .

Next, a method for manufacturing an optical element having a ridge structure using the processing blade manufactured using the above-described processing blade manufacturing method will be described.
As shown in FIG. 2, relative to the substrate 10 made of materials having various electro-optic effects such as lithium niobate (LN) or various materials, the processing blade 20 is rotated and moved on the substrate. Then, two grooves 30 are formed on the substrate.

2B is a cross-sectional view taken along arrow X1 in FIG. 2A, and FIG. 2C is a cross-sectional view taken along arrow X2 in FIG.
As shown in FIG. 2 (b), the two disks 1 constituting the blade 20 are formed with high accuracy and the distance between them is held with high accuracy, so that the drawing is extremely stable and accurate. Two grooves 30 such as 2 (c) can be formed, and a ridge structure sandwiched between the grooves 30 is obtained. Further, since two grooves are formed at the same time, the processing time can be greatly shortened.

  When the ridge type structure itself obtained as shown in FIG. 2C has a high precision shape and the side surface of the ridge is formed in a mirror surface, the ridge type structure is used as an optical waveguide. An optical element with little propagation loss can be provided.

According to the present invention, it is possible to provide a rib-type structure high accuracy of possible machining blade be stably formed manufacturing method and processing blade, and manufacturing how an optical element using it Become.

It is the schematic which shows the manufacturing method of the braid | blade for a process. It is the schematic which shows the manufacturing method of the optical element using the blade for processing.

DESCRIPTION OF SYMBOLS 1 Disc 2 Adhesives 3, 5 Edge part 4 Circumferential front-end | tip part 10 Substrate 20 Blade 30 for processing

Claims (3)

A joining step of joining two disks with an adhesive;
A polishing step of processing the edge of the disk into a tapered shape by polishing only the outer surface of the disk ;
And a removing step of removing the adhesive so that the peripheral edge of the adhesive is located inside the edge tip of the disk. A processing blade manufactured by using the processing blade manufacturing method according to claim 1 . A method for manufacturing an optical element, comprising: grinding a substrate using the processing blade according to claim 2 to form a rib-type structure on the substrate.

Images