KR20000069542A - Micro-replication in metal - Google Patents

Abstract

In order to prevent damage to the components due to the heat generation of the chip and also to suppress the effects of such heat generation, the chip having the waveguide connection or the optical fiber connection is firmly soldered on the metal surface or directly soldered on the metal leadframe, The thermal resistance is considerably lower than when soldered onto this ceramic or silicon carrier. By using an incidence tool with an incidence / stamping work 7 it is possible to create microstructures on the metal surface with low cost and high precision, including V-grooves 3 for alignment between waveguides or optical fibers and chips. The relief process may be performed on the metal surface or directly on the metal leadframe. The embossing process can be automated relatively easily because the metal to be embossed can be worked in the form of a strip. The method in which the optical chip is soldered to a metal carrier in which the waveguide accommodating or optical fiber accommodating grooves are highlighted improves the heat dissipation problem and substantially increases the usable life of the final part.

Description

Micro-Replication in Metals {MICRO-REPLICATION IN METAL}

A common method of aligning waveguides or optical fibers and optical chips within an optical component is to etch the desired microstructure in silicon in the form of a V-groove into which the waveguide or optical fibers can be fitted. With current technologies, optical chips are solder mounted on ceramic or silicon carriers. This method has problems with the heat dissipation generated in the mounted parts. This problem is remarkable in the case of small diameter semiconductor lasers where the heat generating region is concentrated in a narrow band of about 2 占 퐉 extending vertically across the chip and close to its surface.

The present invention relates to a method for making a micro-replicated shape on a metal, to an apparatus for making a micro-replicated shape on a metal, and to a micro-replicated device of a metal produced according to the invention. Micro-replication methods and devices are needed to produce replicable accessory optical components, contact devices or other precision devices suitable for aligning waveguides or optical fibers and optical chips, with considerable precision and low cost. Optical component accessories with an alignment facility can be easily mounted on a circuit board while connecting to a waveguide or optical fiber and a laser or photodiode.

1 illustrates a metal element provided with a microstructure according to the present invention.

Figures 2A and B show the bottom and cross sections, respectively, of the relief tool of the invention.

Figures 3A and B are views illustrating in detail the working part of the relief tool of the present invention, seen from one side and from the top.

To prevent damage to the chip due to heat, or to minimize the effects of such heat, the chip carrying the waveguide or optical fiber is soldered to a metal carrier or metal leadframe, where the chip is solder mounted on a ceramic or silicon carrier. The thermal resistance is much lower than when. The present invention allows microstructures to be created on metal surfaces with low precision with respect to the alignment of waveguides or optical fibers with low cost embossing or stamping tools.

The relief process can be done on the metal carrier or directly on the metal leadframe for plastic encapsulation. The relief process can be relatively easy to automate because the material to be raised can be worked in the form of a short strip or in the form of a long strip wound on a reel. An assembly in which the optical chips are soldered onto a metal carrier provided with a waveguide or optical fiber receiving groove, which is highlighted, improves the heat dissipation problem, significantly increasing the usable life of the final part and also improving the mean fault time of the final part; MFT).

Experiments have shown that microstructures can be highlighted in copper with only repeated high dimensional accuracy and minor wear of the used relief tools. The microstructures accentuated by the metal carrier allow the optical components, which are later included as accessories in plastic capsules, to be aligned and mounted directly on leadframes made of copper or some other alloy.

The relief technique offers two distinct advantages over the known technique of mounting lasers on a carrier which will later be mounted on the leadframe. First, the cost of purchasing and producing such carriers can be reduced. Secondly, they are advantages regarding the dissipation of heat generated in the active region of the lasers. However, there is an additional cost for the relief process and an additional cost for the tools required for the relief process. The precision spheres used to highlight the fine replica can be produced by grinding (polishing) the tool material, or can be produced by direct processing of the tool material, or can be manufactured in the following manner.

Apply photoresist on the silicon disk.

-Fix photomask with appropriate groove pattern on silicon disk.

Exposing the photoresist through openings in the photomask.

Wash away the exposed resist or, optionally, not exposed resist.

Etch the desired structure to the disc.

-Wash off the remaining photoresist.

In this way, in the case of the two-dimensional porter mask, a plurality of mutually identical three-dimensional silicon structures are generated. The above mentioned techniques are known in the art, but have been described herein to provide a better overview of the procedures used to produce relief tools with the desired precision. This procedure can continue in accordance with each of the other two alternative methods described below.

Alternative Method A

1. Coat the patterned silicon disk with a layer of material of sufficient hardness.

2. Plate the disc with nickel or some other suitable material.

3. Flatten the plating.

4. Etch the silicon to separate the plated and planarized moldings from the silicon. The hardness of the plated surface can be strengthened by sputtering or replating the surface with a suitable material.

5. Cut the molding in two to separate identical structures from each other.

6. In the relief tool, place the structure in a holder made for the structure.

7. Assemble the various parts of the relief tool to create the final relief tool.

Alternative Method B

1-4. Follow Alternative Method A above.

5. Coating on a non-flattened side with a separable layer later.

6. Plate the disc with nickel or some other metal.

7. Flatten the plating.

8. Separate the two flattened moldings from each other.

9. Cut the molding in two to separate multiple identical structures.

10. Place the molding in the holder and spark it in the electric discharger (EDM).

11. In metal / lead frames, sparking is done directly to the material that has to highlight the microstructures.

12. Assemble the various parts of the relief tool to create the final relief tool.

1 shows an example of a microstructure highlighted in a metal element 1 having a recessed or recessed surface 2 comprising a V-groove 3 for aligning an optical fiber or waveguide. In order to facilitate the mounting of the chip, the metal surface may be provided with a chip mounting surface 4 comprising chip positioning markings in the form of grooves 5. Embossed metal surfaces can align the chip with waveguides or optical fibers with significant precision.

As can be clearly seen from FIGS. 2A and 2B, the relief tool 6 may have a stamp form in which a protective holder 8 is disposed around the working part 7 of the tool. The working part of the tool has a shape such that the grooves such as the V-grooves can be highlighted on the metal surface. The protective holder is pushed onto an Adiprene plate 9 to expose the working part of the tool in the actual relief process.

3A and B can be made such that the working part 7 has an inclined surface, in the case of the present invention, the working part has a flat or alternatively recessed surface and a V-groove when the metal surface is inclined. It consists of a flat surface 10 and a ridged region 11 to form. In order to fit the optical fiber in the V-groove, the working part of the tool may have a width of, for example, 1.20 mm, and the width of the ridged area is 0.16 mm and its length is 3.20 mm and the angle ( ) May be 45 °.

With this micro-replication to the metal, V-grooves can be automatically provided in the leadframe, for example a strip-shaped carrier, and the carrier can also be connected to a chip such as a laser or a photodiode. Then, the optical fibers or waveguides can be automatically aligned due to the raised grooves, so that an accurate alignment between the laser or photodiode mounted on the carrier and the waveguide or optical fiber can be achieved. The incidence technique of the present invention allows fine duplication in an automated manufacturing process to be made at low cost with high reliability and great accuracy.

It is to be understood that the invention is not limited to the embodiments described and described above, and that modifications may be made within the scope of the claims.

Claims (5)

A method of making a fine replica of a metal to provide a metal surface with a structure for aligning at least one waveguide or at least one optical fiber, Indenting at least one groove, such as a V-groove, on the metal surface with an indentation tool, the groove being made to receive the waveguide or optical fiber for alignment between the waveguide or optical fiber and a laser or photodiode mounted on the metal surface. How to feature. Means for making a fine replica in a metal to provide a structure for the alignment of at least one waveguide or at least one optical fiber, said means comprising at least one groove, such as a V-groove, in the metal surface when the metal surface is highlighted. The work piece 7 has an incidence tool 6 having a shape that provides a shape, and the groove is made to receive the waveguide or optical fiber for alignment between the waveguide or optical fiber and a laser or photodiode mounted on a metal surface. Means for losing. 3. The work piece 7 according to claim 2 is composed of plated and planarized metal elements, which are separated from the silicon disk from which the structure is etched, wherein the metal structure is provided with V-grooves on the metal surface during the orthogonal process. And means (11) which form a groove for receiving at least one waveguide or optical fiber. 3. The work piece (7) according to claim 2, characterized in that the working part (7) is ground (grinded) into a shape (11) which forms a groove for receiving at least one waveguide or optical fiber, such as a V-groove, on the metal surface during the relief process. Means. In a micro-replicated metal element having a structure for aligning at least one waveguide or at least one optical fiber on one surface thereof, the structure included in the metal surface 1 includes a laser or a photodiode mounted on the metal surface. At least one groove (3), such as a V-groove, into which the waveguide or optical fiber can be fitted for alignment between the waveguide or the optical fiber.