KR20090076117A - Method for inspecting defect of substrate raw material - Google Patents

Abstract

A defect inspection method of the substrate source material is provided, which enables to distinguish the deformity existing in the surface and internal layer of the electroconductive film. The electroconductive film(101) is formed in the substrate source material(100). Photoresist is deposited on the electroconductive film. The photoresist is exposed and developed. The electroconductive film is etched and is peeled off and the lattice form is patterned. The lattice form is tested and normality and abnormal are compared. The lattice is formed in the size of 5-100 micrometers.

Description

Method for inspecting defect of substrate raw material

The present invention relates to a defect inspection, and more particularly, the present invention relates to a defect inspection method of the substrate raw material improved method for the defect of the substrate raw material.

In general, a printed circuit board or a substrate for a semiconductor and a flat panel display device is manufactured by forming a wiring pattern having a desired shape using chemical etching on a metal conductor on the entire surface of a raw material, and as the pattern becomes finer, The influence of fine surface defects on the material is increasing.

Chemical etching used in the manufacture of printed circuit boards and substrates for semiconductors and flat panel display devices, if the uniform working conditions such as liquid concentration, liquid circulation, and temperature, the raw material conductor is etched at the same speed from the surface to realize a uniform pattern. If fine defects are present on the surface of the conductor and the inner layer, the etching of the fine pattern is finished, and the shape of the pattern is uneven.

In order to inspect the defects such as pinholes, depressions, protrusions, scratches, and contaminations formed on the surface of the inspected object, the surface defect inspection method is performed by enlarging the surface of the inspected object with a high magnification microscope, or inspecting the surface of the inspected object. Inspection is performed using an optical method that receives the reflected light of the light irradiated onto or detects surface defects through an image obtained by the image processing apparatus.

Korean Patent Application Publication No. 193-0010527 discloses a light source and an imaging device arranged to face an inspected surface that is recognized as a mirror surface, and irradiates light having a predetermined change pattern, and simultaneously captures a reflected image to identify a change pattern and a different place. By this, the inspection method which detects a defect is disclosed. At this time, the light source to be used has a wavelength of 220 to 350 nanometers.

Japanese Laid-Open Patent Publication No. 1998-010052 uses an illumination having a predetermined contrast pattern for a surface defect inspection apparatus which is not a defect but a very thin unevenness defect and is unlikely to be falsely detected. Determination of a defect is disclosed by an image processing apparatus and time series image processing at an arbitrary imaging angle.

In Korean Laid-Open Patent No. 2004-0020721, the light reflected from the surface to be inspected is detected through a plurality of image sensors, and the focus is determined by checking and comparing brightness differences with respect to the same position of each image to determine whether there is a defect. Disclosed is to determine a defective portion more accurately through two image sensors that are matched and have different installation angles.

However, the conventional defect inspection method uses a light reflection method of inspecting surface defects that vary image imaging and data processing or change the light source itself in order to increase reliability. Although effective for inspection, in addition to defects that appear on the outermost surfaces of metals, such as those used in printed circuit boards and substrates for semiconductors and flat panel displays, the interface between the metal interlayer and the metal / insulator film The defect in) has the problem that it is impossible to detect. In addition, there is a problem in the reliability of defect determination of several micrometers in size, there is a problem that the sampling inspection using a high magnification microscope must be performed in parallel.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and exists at the interface between the metal inner layer and the metal and insulator film as well as the outermost surface of the conductive film of the raw material of the printed circuit board or the substrate for semiconductor and flat panel display devices. It is a main subject to provide the defect inspection method of the board | substrate raw material which inspects the micro defect which becomes a problem with product quality.

In order to achieve the above problems, the defect inspection method of the substrate raw material according to an aspect of the present invention,

 Forming a substrate raw material on which a conductive film is formed;

Patterning the conductive film in a lattice shape; And

And inspecting the grid shape to compare normal and abnormal.

In addition, in the step of patterning the grid,

Coating a photoresist on the conductive film;

Exposing and developing the photoresist; And

Etching and peeling the conductive layer to pattern a grid shape.

Furthermore, the grating is formed in a size of 5 micrometers or more and 100 micrometers or less.

In addition, in the step of comparing the grating normal and abnormal,

The light is irradiated from the light irradiation apparatus to the conductive film from the upper portion of the substrate raw material on which the conductive film is formed, and the light reflected therefrom is image processed by the image processing apparatus.

Furthermore, in the step of comparing the grating normally and abnormally,

When the substrate raw material is a transparent film, it is characterized by irradiating light onto the substrate raw material from the light irradiation apparatus from the lower portion of the substrate raw material in the opposite direction in which the conductive film is formed.

Furthermore, after forming the substrate raw material on which the conductive film is formed, the method may further include etching the conductive film on the whole surface to expose or grow internal and external defects of the conductive film.

As described above, the defect inspection method of the substrate raw material of the present invention forms a conductive film having a lattice pattern on the substrate raw material to inspect the internal defects or external defects, and thus the surface of the conductive film as well as the inner layer and the metal-insulator interface. Defects that exist can be determined.

Hereinafter, preferred embodiments will be described in detail with reference to the accompanying drawings.

1 illustrates a substrate raw material 100 according to an exemplary embodiment of the present invention, and FIG. 2 illustrates a portion of the substrate raw material of FIG.

1 and 2, the substrate raw material 100 is an insulator, for example, a polymer resin, for example, a glass cloth and an epoxy matrix or a poly matrix used for a substrate such as FR4 or FR5. And a conductive film 101 formed on the surface of the substrate raw material 100. The conductive film 101 is preferably a material having excellent conductivity, such as a copper film.

In this case, a fine lattice pattern 102 having a regular shape is formed on the conductive layer 101 by etching. The grid pattern 102 may be formed in various sizes and arrangements depending on the design. For example, a lattice of 20 micrometers x 20 micrometers can be arranged on the entire surface of the substrate raw material 100 sampled at an interval of up to 20 micrometers.

Effective grid sizes include polygons, such as squares (501, see FIG. 5A) that are greater than or equal to 5 micrometers and less than or equal to 100 micrometers, geometric shapes such as circles (502, see FIG. 5B), ellipticals, etc. 503, see FIG. 5C), and the size of the sampled substrate raw material 100 is preferably 156 millimeters, 158 millimeters, 320 millimeters, 340 millimeters, or 524 millimeters in width.

Here, the fine grid pattern 102 is formed by performing a certain amount of etching through the chemical etching of the conductive film 101, by comparing the grid pattern 102, the normal grid pattern 103 ) And sensitivity of defect inspection of the metal interlayer to the abnormal lattice pattern 104 can be increased.

3A to 3D illustrate a step-by-step method for inspecting a defect of a substrate raw material on which a conductive film is formed according to an embodiment of the present invention.

Hereinafter, the same reference numerals as in the above-described drawings indicate the same members having the same function.

First, as shown in FIG. 3A, the substrate raw material 100 is supplied. The substrate raw material 100 is preferably formed of an insulator such as a thick film glass cloth and an epoxy matrix or a polyimide-based transparent thin film.

The conductive film 101 is formed on one surface of the substrate raw material 100. The conductive film 101 is made of a thin metal plate having excellent conductivity such as copper. As a result, a metal insulator interface 309 is formed between the substrate raw material 100 and the conductive film 101.

At this time, the conductive film 100 has a plurality of defects, such as a groove 301 recessed from the surface, a defect projecting like the protrusion 302, or a cavity 303 formed in the metal inner layer.

Next, as shown in FIG. 3B, to inspect the defect, the photoresist layer 304 is coated on the surface of the conductive film 101. Accordingly, grooves 301 formed from the surface of the conductive film 101, external defects such as the projections 302, or internal defects such as the cavity 303 formed in the metal inner layer may be formed in the photoresist layer 304. Is covered.

Subsequently, as shown in FIG. 3C, the photoresist layer 304 (FIG. 3B) is patterned 310 by exposing from the top of the conductive film 101 and developing it, thereby patterning the photoresist layer 310. The conductive film 101 present in the space between the layers 304 is etched to remove the remaining photoresist layer 304.

By the above exposure, development, etching and peeling, the conductive film 101 is patterned into a lattice pattern 102 on the substrate raw material 100 as shown in FIG. 3D. In this case, the grid pattern 102 is formed in a fine shape of a regular regular shape during the photolithography process. In this embodiment, a fine lattice pattern 102 of 20 micrometers x 20 micrometers is formed.

Next, it is determined whether there is a defect such as a groove 301, a protrusion 302, or a cavity 303 in the grid pattern 102 to measure quantitative surface defects whether the grid is normal or abnormal. .

That is, the conductive film 101 is patterned into a lattice pattern 102, and then light is irradiated to the lattice pattern 102 from the light irradiation apparatus 305 disposed thereon. Subsequently, the light reflected from the grid pattern 102 is received and image processed by the image processing apparatus 307. Accordingly, internal defects such as grooves 301 and protrusions 302 formed in the lattice pattern 102, and the defects in the cavity 303 and the metal-insulator interface 309 are examined. Thus, it is determined whether the lattice pattern 102 is normal or abnormal.

On the other hand, when the substrate raw material 100 is a transparent film such as polyimide, it is transparent from the lower part of the substrate raw material 100 on which the lattice pattern 102 is formed to inspect the external defect or the internal defect. Light is irradiated onto the substrate raw material 100 using the light irradiation device 306.

4A to 4E illustrate step by step a method for inspecting a defect of a substrate raw material on which a conductive film is formed according to another embodiment of the present invention.

The substrate raw material 400 made of an insulator is supplied. The conductive film 401 is formed on the upper surface of the substrate raw material 4001. At this time, an external defect such as a groove 403, a protrusion 404, or an internal defect such as a cavity 405 formed in the metal inner layer is generated in the conductive film 401 (FIG. 4A).

Subsequently, the entire surface of the conductive layer 401 is etched. The entire surface of the conductive film 401 is etched to increase external defects such as the grooves 403 and the projections 404, or to expose internal defects such as the cavity 405 formed in the metal inner layer to the surface. 4b)

Next, the photoresist layer 406 is coated on the surface of the conductive film 401 (FIG. 4C).

After the coating of the photoresist layer 406 is completed, the photoresist layer 406 is exposed from the top of the conductive film 401, developed, and etched and the remaining photoresist layer is removed (FIG. 4D).

By the photolithography process as described above, the conductive film 401 is patterned into a lattice pattern 402 on the substrate raw material 400 as shown in FIG. 4E.

When the lattice pattern 402 is completed, whether the groove 403, the external defect such as the protrusion 404, or the internal defect such as the cavity 405, which is enlarged through the front surface etched or exposed on the surface is present. In order to discriminate, light is irradiated from the light irradiation device 408 to the lattice pattern 402, and the reflected light is received and image processed by the image processing device 410. Accordingly, it is possible to quantitatively measure surface defects whether the grid pattern 402 is a normal or abnormal grid.

On the other hand, when the substrate raw material 400 is a transparent film such as polyimide, light translucent from the lower part of the substrate raw material 400 on which the lattice pattern 402 is formed to inspect external defects or internal defects. Inspection is performed by irradiating light onto the substrate raw material 400 using the irradiator 409.

Although the present invention has been described with reference to one embodiment shown in the drawings, this is merely exemplary, and those skilled in the art will understand that various modifications and equivalent other embodiments are possible therefrom. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

1 is a plan view showing a substrate raw material according to an embodiment of the present invention,

2 is an enlarged cross-sectional view showing a defective portion of the substrate raw material of FIG. 1;

3A to 3D are diagrams illustrating states for inspecting defects of a substrate raw material according to one embodiment of the present invention.

3A is a cross-sectional view showing a state after forming a conductive film on a substrate raw material of the present invention;

3B is a cross-sectional view showing a state after forming a photoresist layer on the substrate raw material of FIG. 3A;

3C is a cross-sectional view showing a state after exposure, development, etching, and peeling off on the substrate raw material of FIG. 3B;

3D is a cross-sectional view illustrating a state after a lattice pattern is formed on the substrate raw material of FIG. 3C;

4A through 4D are diagrams illustrating states for inspecting defects of a substrate raw material according to another embodiment of the present invention.

4A is a cross-sectional view showing a state after forming a conductive film on a substrate raw material of the present invention;

4B is a cross-sectional view illustrating a state after the entire surface of the conductive film of FIG. 4A is etched;

4C is a cross-sectional view showing a state after forming a photoresist layer on the substrate raw material of FIG. 4B;

4D is a cross-sectional view showing a state after exposure, development, etching, and peeling off on the substrate raw material of FIG. 4C;

4E is a cross-sectional view illustrating a state after a lattice pattern is formed on the substrate raw material of FIG. 4D;

5A is a plan view showing a lattice pattern according to a first embodiment of the present invention;

5B is a plan view showing a lattice pattern according to a second embodiment of the present invention;

5C is a plan view showing a lattice pattern according to a third embodiment of the present invention;

<Brief description of the major symbols in the drawings>

100 ... substrate material 101 ... conductive film

301 groove 302 projection

303 ... common 304 ... photoresist layer

305,306 ... Irradiation device 307 ... Image processing device

Claims (7)

Forming a substrate raw material on which a conductive film is formed; Patterning the conductive film in a lattice shape; And Inspecting the grid shape to compare normal and abnormality; and a defect inspection method of a substrate raw material comprising a. The method of claim 1, In the step of patterning into a grid shape, Coating a photoresist on the conductive film; Exposing and developing the photoresist; And Etching the conductive film and patterning a lattice shape to form a lattice shape. The method of claim 1, And the grating is formed in a size of 5 micrometers or more and 100 micrometers or less. The method of claim 1, The grating is a polygon, or a defect inspection method of a substrate raw material, characterized in that formed in any one of the shape selected from linear, linear. The method of claim 1, In the step of comparing the grid to normal and abnormal, And irradiating light from the light irradiation apparatus onto the conductive film from the upper portion of the substrate raw material on which the conductive film is formed, and image light reflected from the image processing device to the image processing device. The method of claim 1, In the step of comparing the grid to normal and abnormal, And when the substrate raw material is a transparent film, image processing is performed by irradiating light onto the substrate raw material from a light irradiation apparatus from a lower portion of the substrate raw material in an opposite direction in which a conductive film is formed. The method of claim 1, And forming a substrate raw material on which the conductive film is formed, and then etching the conductive film on the entire surface to expose or grow internal and external defects on the surface.

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