KR100678860B1 - Method for fabricating electrode pattern - Google Patents

Abstract

A method for forming an electrode pattern is provided to simplify a manufacturing process by removing applying, exposing, and developing processes of a photoresist in a lithography process. A method for manufacturing an electrode pattern includes the steps of: forming a seed layer on an upper face of a substrate(S100); attaching a pattern forming film on an upper face of the seed layer and exposing the seed layer by removing a portion of the pattern forming film with a cutting laser(S110,S120); forming a plating layer on the exposed seed layer(S130); and removing the pattern forming film and etching the seed layer by using the plating layer as an etching mask(S140,S150).

Description

Method for fabricating electrode pattern}

1A to 1F are cross-sectional views and plan views showing a method of forming a fine pattern using a conventional lithography process.

2 is a flow chart illustrating a process of forming an electrode pattern using a conventional lithography process.

3A to 3F are cross-sectional views and plan views showing embodiments of the electrode pattern forming method of the present invention.

4 is a flowchart showing a process of forming an electrode pattern of the present invention.

Explanation of symbols on the main parts of the drawings

100 substrate 110 seed layer

120: film for pattern formation 130: plating layer

The present invention relates to a method of forming an electrode pattern, and in particular, instead of applying a photoresist on the substrate, the film for pattern formation is adhered, and a portion of the pattern-forming film is removed through a laser, and then a plating layer is formed on the removed portion. The present invention relates to an electrode pattern forming method for forming an electrode pattern without performing a photoresist coating, exposure, development process, or the like.

As the various components used in the field of electronic devices are required to be multifunctional and integrated, miniaturization and high capacity are rapidly progressing, thus developing into a multi-layered substrate having a complex electrode pattern inside.

These electronic components are mounted on a printed circuit board (PCB) and the like, and are wire bonded or directly connected to a pin to transmit electrical signals.

To this end, an electrode pattern is formed to transmit an electrical signal to the surface of an electronic component. In the related art, a seed layer is formed on a front surface of a ceramic, and then photoresist (PR) is applied and patterned. A lithography process was used to etch to complete the electrode pattern.

1A to 1F are cross-sectional views and plan views illustrating a method of forming an electrode pattern using a conventional lithography process. As shown in FIG. 1, a seed layer 20 is first formed on the substrate 10 (FIG. 1A).

Here, the seed layer 20 may be made of any one metal selected from Cr, Ti, Ti-W, and Cu on the first seed layer made of any one metal selected from Cr, Ti, Ti-W. It may also be formed by laminating a second seed layer made of any one of metals selected from Ni, Au and Au.

In addition, the seed layer 20 may be formed by selecting a metal suitable for the metal in consideration of the characteristics of the electronic component to be implemented.

In this case, the seed layer 20 may be formed using a screen printing method or any method capable of forming a metal layer such as deposition and sputtering using an electron beam (E-Beam).

Next, the photoresist 30 is coated on the seed layer 20, and then dried through a soft baking process (FIG. 1B).

Here, the photoresist 30 may be applied to the liquid phase by spin coating, or may be formed into a thin film by laminating.

The soft baking process is a step of applying heat to remove the solvent (Solvent) remaining after the application of the photoresist 30, if the process is performed with the solvent in the photoresist 30, the following phenomenon Alternatively, during the etching process, the resistance of the photoresist layer 30 may be deteriorated, and the thickness thereof may be continuously changed to maintain constant process conditions.

At this time, it is important to properly control the baking temperature and time so that other components of the photoresist are not thermally decomposed and only the solvent is removed.

Subsequently, after forming a mask on which the pattern to be implemented is formed on the photoresist 30, the pattern 35 is transferred to the photoresist 30 by exposure (FIG. 1C).

Here, the exposure process is mainly a process of placing a mask patterned with a thin chromium film between the substrate 10 and the light source, so that the light from the light source passes through only the portion without the chromium pattern to photosensitive the photoresist layer.

Since the exposure process is completed by exposing different positions several times, an alignment process for precisely controlling the position to be exposed must be performed in parallel.

Subsequently, the exposed photoresist 30 other than the pattern 35 is removed through a development process, and then hardened once more through a hard baking process (FIG. 1D).

The developing step refers to a step of melting a portion of the photoresist that is relatively weakly bonded through the exposure process by using a developer. At this time, the developer is sensitive to temperature and thus affects the development speed, so strict temperature management is required.

The hard baking process removes moisture remaining after development by heating to a temperature below the melting point of the photoresist, and causes crosslinking by heat between the Novolak Resin molecules in the photoresist, thereby causing heat resistance of the pattern 35 and Good physical strength and stable curing.

Thereafter, the seed layer 20 is etched using the pattern 35 remaining on the seed layer 20 as an etching mask (FIG. 1E).

In this case, an etchant suitable for the metal constituting the seed layer 20 may be used, and etching may be performed by using dry etching using plasma.

Next, the pattern 35 used as the etching mask is removed to form the electrode pattern 25 on the substrate 10 (FIG. 1F). Here, the pattern 35 is removed using a PR remover.

2 is a flowchart illustrating a process of forming an electrode pattern using a conventional lithography process. As shown therein, a seed layer is formed on the substrate in step S 10, a photoresist is applied on the seed layer in step S 20, and then a soft baking process is performed.

In step S 30, the exposure process is performed to transfer the pattern onto the photoresist. In step S 40, portions other than the pattern are removed through the developing process, and a hard baking process is performed.

After the seed layer is etched using the pattern as an etch mask in step S 50, the pattern made of PR is removed in step S 60 to form an electrode pattern on the substrate.

Using such a lithography process, the resolution of the electrode pattern can be improved, and a fine pattern of several tens of μm can be realized.

However, when forming an electrode pattern using a lithography process, there are the following problems.

i) The investment cost of initial equipment for the application, exposure, development, etc. of photoresist is large,

Ii) it is necessary to secure an engineer who owns the relevant technology;

Iii) space is required to secure a clean room,

Iii) There is a disadvantage that the pattern mask must be manufactured separately, resulting in a cost.

Accordingly, an object of the present invention is to apply a photoresist by adhering a pattern forming film instead of applying a photoresist on the substrate, removing a portion of the pattern forming film through a laser, and then forming a plating layer on the removed portion. The present invention provides an electrode pattern forming method for forming an electrode pattern without performing exposure, development, or the like.

In order to achieve the above technical problem, the present invention, the step of forming a seed layer (Seed Layer) on the substrate, and after adhering the pattern forming film on the seed layer, the part of the pattern forming film is removed Exposing the seed layer, forming a plating layer on the exposed seed layer, removing the pattern forming film, and etching the seed layer using the plating layer as an etching mask. Characterized in that made.

Here, the seed layer is a first metal layer made of any one metal selected from Cr, Ti, Ti-W and a second metal layer formed on the first metal layer and made of any one metal selected from Cu, Ni, and Au. Characterized in that made.

The plating layer is formed by electroplating Ni or Au, or by performing an electroplating process to form an alloy of Ni and Pd or an alloy of Au and Sn.

Hereinafter, the electrode pattern forming method of the present invention will be described in detail with reference to FIGS. 3 and 4. 3A to 3F are cross-sectional views and plan views showing an embodiment of the electrode pattern forming method of the present invention.

As shown in the drawing, first, a seed layer 110 is formed on the ceramic substrate 100 (FIG. 3A). That is, the metal layer to be used as the base electrode is formed in the region where the electrode pattern on the ceramic sintered body to be used as the electronic component is to be formed.

Here, the seed layer 110 may be made of any one metal selected from Cr, Ti, and Ti-W.

The seed layer 110 may include a first metal layer made of any one of metals selected from Cr, Ti, and Ti-W, which may improve adhesion to the ceramic substrate 100, and may have a low resistance on the first metal layer. It can also form by laminating | stacking the 2nd metal layer which consists of Cu or Au.

That is, since the first metal layer made of any one of the metals selected from Cr, Ti, and Ti-W has a high resistance value, a second metal layer made of Cu or Au of low resistance is formed on the first metal layer.

In addition, the seed layer 110 may be formed by selecting a metal suitable for the metal in consideration of the characteristics of the electronic component to be implemented.

In this case, the seed layer 110 may be formed using a screen printing method or any method capable of forming a metal layer such as deposition and sputtering using an electron beam (E-Beam).

Next, the pattern forming film 120 is adhered to the seed layer 110 (Fig. 3b).

Here, the pattern forming film 120 uses a film having excellent chemical resistance, and is bonded to the seed layer 110 by a laminating method.

When adhering the pattern forming film 120 to the top of the seed layer 110, care is taken so that air does not flow between the pattern forming film 120 and the seed layer 110.

Subsequently, a pattern to be realized is formed by irradiating laser light having a predetermined wavelength to the pattern forming film 120 (FIG. 3C).

That is, the portion corresponding to the shape of the pattern to be implemented in the pattern forming film 120 is cut out with a laser for cutting.

In this case, the pattern width of the portion cut by the cutting laser corresponds to about 40 to 50 μm, and thus the electrode pattern to be formed on the ceramic substrate 100 also has a width of about 40 to 50 μm.

Thereafter, a portion of the pattern forming film 120 is removed to form a plating layer 130 having a shape of a pattern to be implemented through electroplating on the exposed seed layer 110 (FIG. 3D).

At this time, on the exposed seed layer 110, Ni and Au are electroplated or electroplated according to characteristics such as soldering or wire bonding required in the final electrode pattern, and an alloy of Ni and Pd and Form an alloy of Au and Sn.

That is, when a current flows through the exposed seed layer 110 in an electrolyte containing metal ions such as Ni and Au or Ni-Pd and Au-Sn, the metal ions may be exposed to the surface of the exposed seed layer 110. Are deposited and plated.

In this case, the plating layer 130 formed on the exposed seed layer 110 is formed so as not to exceed the thickness of the pattern forming film 120, it is preferably formed to have a thickness of 10 ~ 20 ㎛.

When the plating layer 130 formed on the exposed seed layer 110 is formed beyond the thickness of the pattern forming film 120, the plating layers 130 adjacent to each other may be connected to each other so that an electrical short may occur. When the plating layer is formed, the thickness of the plating layer 130 may not exceed the thickness of the pattern forming film 120.

Next, the pattern forming film 120 remaining on the seed layer 110 is removed to form a pattern including the electroplated plating layer 130 on the seed layer 110 (FIG. 3E).

Here, the pattern forming film 120 remaining on the seed layer 110 is removed using a corresponding film remover.

Subsequently, the seed layer 110 is etched using the plating layer 130 formed on the seed layer 110 as an etching mask (FIG. 3F).

When the seed layer 110 is etched using the plating layer 130 formed on the seed layer 110 as an etch mask, an electrode including the seed layer 110 and the plating layer 130 on the ceramic substrate 100 is etched. A pattern is formed.

In this case, the seed layer 110 is etched using an etchant that can be etched according to the type of metal constituting the seed layer 110, and the seed layer 110 is dried by dry etching using plasma. It can also be etched.

As such, instead of applying the photoresist on the seed layer 110, the pattern forming film 120 having excellent chemical resistance is adhered thereto, and then a part of the pattern forming film 120 is removed through laser processing. If the plating layer is formed on the removed portion, it is possible to form an electrode pattern having a line width of several tens of micrometers and excellent resolution without using a lithography process.

Therefore, in the lithography process, the cost of investing in the equipment necessary for performing the photoresist coating, exposure, and developing process can be reduced, and there is no need to manufacture a separate pattern mask, thereby simplifying the manufacturing process, and clean room Since no separate space is required, the electrode pattern can be easily formed.

4 is a flowchart illustrating a process of forming an electrode pattern of the present invention. As shown in FIG. 1, after forming the seed layer on the substrate in step S 100, the film for pattern formation is adhered on the seed layer in step S 110.

After removing a portion of the pattern forming film using a laser in step S 120, the pattern forming film is removed in step S 130 to form a plating layer on the exposed seed layer.

After removing the pattern forming film remaining on the seed layer in step S 140, the seed layer is etched using the plating layer as an etch mask in step S 150 to form an electrode pattern formed of the seed layer and the plating layer on the substrate.

On the other hand, while the present invention has been shown and described with respect to specific preferred embodiments, various modifications and variations of the present invention without departing from the spirit or field of the invention provided by the claims below It will be readily apparent to one of ordinary skill in the art that it can be used.

As described above, according to the present invention, instead of applying the photoresist on the seed layer on the substrate, after adhering the pattern forming film having excellent chemical resistance, a part of the pattern forming film is removed through laser processing, By forming the plating layer on the removed portion, an electrode pattern can be formed without using a lithography process.

As a result, it is not necessary to perform the application, exposure, development, etc. of the photoresist in the lithography process, which simplifies the manufacturing process, thereby reducing the cost of purchasing the equipment.

In addition, according to the present invention, since it is not necessary to manufacture a separate pattern mask, when manufacturing an electronic component having various electrode patterns, it is possible to reduce the manufacturing cost and time accordingly.

Claims (7)

Forming a seed layer on the substrate; Adhering the pattern forming film on the seed layer and exposing the seed layer by removing a portion of the pattern forming film with a cutting laser; Forming a plating layer on the exposed seed layer; And After removing the pattern forming film, etching the seed layer using the plating layer as an etching mask. The method of claim 1, wherein the seed layer is formed of any one metal selected from Cr, Ti, and Ti-W. The method of claim 1, wherein the seed layer is formed on the first metal layer made of any one metal selected from Cr, Ti, Ti-W and the first metal layer made of any one metal selected from Cu, Ni, Au. An electrode pattern forming method comprising a second metal layer. The method of claim 1, wherein the pattern forming film is adhered to the seed layer by a laminating process. delete The method of claim 1, wherein the plating layer is formed by electroplating Ni or Au. The method of claim 1, wherein the plating layer is formed by performing an electroplating process to form an alloy of Ni and Pd or an alloy of Au and Sn.

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