TW585837B - Method for fabricating the array mold of a clearance-free 3D micro structure - Google Patents

Abstract

Discloses is a method for fabricating the array mold of a clearance free 3D micro structure, including a polymer buffering layer applied over a substrate to enhance the adhesion of the substrate; a photo-resist compound layer applied over the polymer buffering layer; forming a pattern to the photo-resist compound layer by lithography; heating the photo-resist compound to a silicon transition temperature (Tg), subjecting the photo-resist compound to form micro array structure having clearance; applying conductive layer of a metal thin film over the micro structure surface; filling the clearance by electro-forming so as to obtain an array mold insert with a clearance free structure. A metal mold may be replicated from the insert. A clearance free micro array structure may thus be produced by a simple process and reduced cost.

Description

585837 V. Description of the invention (1) ~----Material shortage, especially for providing a gap-filling process technology that can effectively eliminate the microstructure array pitch. < Microlens is widely used in optical fiber and optical communication electronics products, such as micro-lens arrays for focusing light at the ends of optical fibers, focusing and scanning of optical fibers, and even micro-optical integrated components Light etc. However, in the manufacturing process of general microlens arrays, there is a small gap between each microlens to 1 sub, and these gaps also affect the overall resolution: low, such as Taiwan Patent Application No. 89 1 22〇 No. 15 "Batch production of microspheres through", as shown in Figure 1, which is coated on the substrate OO with a layer of imine composition 2 1 0 and photoresist composition 2 2 0, and then yellow light lith (lithography) the microlens pattern (paUern) is formed on the surface of the plate 100, where the pattern has a bottom layer, that is, a polyurethane group 2 layer 2 2 0, and a top layer, that is, a photoresist composition The material layer 2 2 0 (as in the drawings (B), (c)), and then it is heated to 180 ° c ~ 22 (Tc glass transition temperature for hot melting (re f 1〇w), this The photoresist composition layer 2 2 0 is a spherical microsphere lens 2 3 0 (such as Fig. 1 (d)) formed by the balance of cohesion and surface tension; since the microlens array is converted by ref low Molding, in order to avoid the phenomenon of 'hot-melt overlap between lenses during the hot-melt conversion process, so when the pattern is shaped by yellow light lithography' There is an appropriate gap between the patterns. After the formation of the microlens array, this gap will still exist and affect the resolution of the overall microlens. , Gray scale photomask or excimer laser processing technology, but because of the high unit cost of precision machining, gray scale photomask peripheral technology is less mature, excimer laser processing

P〇2-025.ptd Page 4 585837 V. Description of the invention (2) '' Because of the poor surface fine seam, the curvature is not easy to control, and it is not suitable for mass production, which affects the overall application. With this many years of work experience, the present inventor then developed a "gap-free 3-D microstructure array mold core process" after continuous research and design to effectively improve the shortcomings of various habits. Designed for Ming. a a 丨, that is, the main purpose of the present invention is to provide a micro-interstitial process technology to eliminate the gaps between the micro-structure arrays, thereby improving the overall resolution.

Another object of the present invention is to provide a gapless microstructure array process technology to increase the density of the microstructure array and thereby effectively reduce the unit area of 0. Another object of the present invention is to provide a gapless microstructure array process. Fortunately, It is suitable for the fabrication of microstructure arrays with different shapes, and the simple white process reduces the cost of process and equipment. Detailed description of the preferred embodiments. A process for manufacturing the gapless 3 ~ D microlens array mold core of the present invention. The main method is to coat a polymer buffer layer on the board; then apply it to each polymer layer. A photoresist composition layer; then a pattern is formed on the photoresist composition layer by yellow light lithography method (ijth〇graphy); or the substrate is heated to a temperature higher than the glass transition temperature of the photoresist composition (T 2) Hot melt (reflow) and maintain the working temperature to the photoresistor array. The surface of each microstructure is plated with a layer of metal to collapse. A layer of metal is uniformly scaled on the surface of the microstructure of the array. Layer eliminates gaps between microstructures and completes gapless, gap microstructure arrays

p〇2'〇25.Ptd

585837 V. Description of the invention (3) ~ The production of the mold kernel. By using the mold core of the gap-free 3-D microstructure array of the present invention, a metal mold can be turned out by other methods such as secondary electroforming or electrical discharge machining, and then micro-injection molding or micro-hot pressing molding is used to produce a gap-free microstructure array. . In the process of the present invention of the gap-free 3-D microstructure array mold core, a method for coating a south molecular buffer layer and a photoresist composition layer on a substrate, preferably spin coating, can uniformly disperse coating . The polymer buffer layer can be pre-baking after being coated on the substrate. The polymer buffer layer is used to increase the adhesion of the photoresist composition. The photoresist composition is exposed, etched, and developed with a yellow i light micro-photography method to form a pattern $ (pattern). The polymer buffer layer of the present invention is preferably polyimide or polyamide, and the photoresist composition may preferably have a glass transition temperature (Tg) of 100. c to 350. The polymer between C is preferably a polyfluorene-based acrylic polymer. After the photoresist composition is patterned, it is heated to an operating temperature higher than the glass transition temperature (Tg) of the photoresist composition for hot melt (refl0w). In the present invention, the yellow light lithography method (11 thography) is used to shape the pattern and position, so the patterns of different shapes can be controlled and set by the yellow light lithography method (1 i thography). In the present invention, a metal conductive layer is plated on the surface of the microstructure. A preferred method is to use a sputter-layer copper (Cu) as the conductive layer, and the rust uses nickel (η) as the electroformed layer to eliminate the gap. , Can obtain higher surface accuracy and small grain structure. In order to make your reviewing committee better understand the technical content of the present invention, the production of microlenses is taken as an example, and illustrated with the drawings as follows:

P02-025.ptd Page 6 585837 V. Description of the invention (4) ---------- Please refer to Figure 2 (A). The present invention mainly uses polyimide (f olyhide) composition 3 i 0 The spin-coating = formula is self-coated on the substrate 300 to form a buffer layer, and the coated substrate 300 is subjected to 350. c Pre-baking (pre-baking) for 30 minutes, and then coating the polyacrylic acid polymer photoresist composition 3 2 0 with spin coating (sPln coating) to uniformly coat the polyimide composition layer for 3 hours. ^ . Please refer to FIG. 2 (B), and use yellow light lithography (lithography to form an array pattern on the photoresist composition layer 3 2 〇. Please refer to FIG. 2 ® (C). The substrate is heated to a glass transition temperature (Tg) range of 1 80 C ~ 220 ° C (such as 190 ° C) to thermally fuse the pattern (refl0w) and maintain the temperature to form a microlens array, followed by cooling 3. A copper conductive layer 330 is plated on the surface of the microlenses of the array by a thin film sputtering method. Please refer to FIG. 2 (D), and electroform a microlens array with a conductive layer (Electro f romi ng) With nickel as the electroformed layer 340 uniformly covering the surface of the microlenses, and using the electroformed layer 340 to eliminate the gaps in the array, the production of the gapless 3-D microlens array mold core of the present invention is completed. The present invention The completed mold core can be turned by secondary electric pounds or electrical discharge machining to produce a metal mold. The micro-lens array (such as Figure 3) is not only effective by micro injection molding or micro hot pressing molding. Improve the overall resolution, and can use the simplest and most mature system Significantly reducing manufacturing costs for.

P02.025.ptd

585837 Schematic diagram of the manufacturing process of custom microlenses. The manufacturing process of the gapless microstructure array mold kernel of the present invention. The enlarged image produced by the present invention. Schematic description Schematic description e I Fig. 1 Fig. 2 Fig. 3 Fig. No. Description: Convention part: 1 0 0: substrate 2 2 0: photoresist composition part of the invention 3 0 0: substrate 3 2 0: photoresist composition 3 4 0: electroformed layer 2 1 0: polyimide composition 2 3 0: microsphere lens 3 1 0: polyimide composition 3 3 0: conductive layer

P02-025.ptd Page 8

Claims (1)

585837 6. Scope of patent application-〆1. A process for manufacturing gapless 3_d microstructure array mold kernels, including: (A) providing a substrate; (B) coating a polymer buffer layer (buffer) on a substrate ); (c) coating the photoresist composition layer on the high molecular buffer layer; (D) using yellow light lithography (1 i thography) on the photoresist layer to form a pattern; (E) Heating above the glass transition temperature (Tg) of the photoresist composition for ref low; (F) cooling after forming the microstructure array; (G) uniformly plating a conductive layer on the surface of each microstructure; (H) Uniformly electroforming a microstructured array with gaps, and eliminate gaps between the arrays with the electroformed layer. 2. According to the process of the gapless 3-D microstructure array mold kernel described in item 1 of the scope of the patent application, wherein the polymer buffer layer is a polyimide composition. 3. According to the process of the gapless 3-D microstructure array mold kernel described in item 1 of the scope of patent application, wherein the photoresist composition is a polyacrylic acid polymer. 4 According to the process of the gapless 3 ~ D microstructure array mold core described in item 1 of the scope of the patent application, wherein the polymer buffer layer and the photoresist composition layer are coated on the substrate by spin coating. . According to the process of the gapless 3-D microstructure array mold kernel described in item 1 of the scope of the patent application, the polymer buffer layer is 350 after the polymer buffer layer is coated on the substrate. C Pre-baking. inn P〇2-〇25.ptd Page 9 585837 VI. Application for patent scope 6. The process of the gap-free 3-D microstructure array mold core described in item 1 of the scope of patent application, wherein the photoresist composition is Heat to 180 ° C ~ 220 ° C for hot melt (ref low). 7. According to the process of the gapless 3-D microstructure array mold core described in item 1 of the scope of the patent application, wherein the surface of each microstructure is coated with copper (Cu) to conduct electricity by means of metal sputtering Floor. 8. According to the process of the gapless 3-D microstructure array mold kernel described in item 1 of the scope of the patent application, the gap-free electroformed layer is a nickel (Ni) electroformed layer. " P02-025.ptd page 10