APPARATUS FOR AND METHOD OF POLISHING SURFACE OF SUBSTRATE

According to one or more embodiments, there is provided an apparatus for polishing a surface of a substrate to remove a resin layer formed on the surface of the substrate having a groove, the apparatus including: a laser irradiation apparatus configured to irradiate a laser to the resin layer to remove at least a portion of a resin from the resin layer except for a portion of the resin layer arranged in the groove.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of Korean Patent Application No. 10-2019-0127167, filed on Oct. 14, 2019, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

BACKGROUND

One or more embodiments relate to an apparatus for and method of polishing a surface of a substrate.

2. Description of Related Art

With the development of the electronic industry, the demand for miniaturization and multifunctionalization of electronic components has gradually increased. Also, substrates on which electronic components are mounted are also formed in various structures and shapes.

Substrates are manufactured to have various structures such as a circuit pattern and an insulating layer. In order to manufacture such substrates, a process of removing an unnecessary layer or material by polishing a surface of a substrate may be necessary.

Korean Patent Publication No. 2011-0053753 discloses an apparatus for polishing a substrate, the apparatus having a chemical polishing portion filled with an etchant and a mechanical polishing portion including a brush.

SUMMARY

One or more embodiments include an apparatus for and method of polishing the surface of a substrate.

According to one or more embodiments, there is provided an apparatus for polishing a surface of a substrate to remove a resin layer formed on a surface of a substrate having a groove, the apparatus including: a laser irradiation apparatus configured to irradiate a laser to the resin layer to remove at least a portion of a resin from the resin layer except for a portion of the resin layer arranged in the groove.

The resin layer may include an epoxy resin or a polyimide resin.

The laser irradiation apparatus may irradiate at least one of a pulse wave laser and a continuous wave laser.

The wavelength range of the laser irradiated by the laser irradiation apparatus may be from 355 nm to 1064 nm.

The laser irradiation apparatus may include a plurality of laser irradiation apparatuses.

According to one or more embodiments, there is provided a method of polishing a surface of a substrate includes: forming a groove in at least one surface of the substrate, forming a resin layer on the at least one surface of the substrate in which the groove is formed, and irradiating a laser to the resin layer to remove at least a portion of a resin from the resin layer except for a portion of the resin layer arranged in the groove.

The resin layer may include an epoxy resin or a polyimide resin.

The laser may be irradiated by at least one laser irradiation apparatus.

The laser may include at least one of a pulse wave laser and a continuous wave laser.

The wavelength range of the laser may be from 355 nm to 1064 nm.

DETAILED DESCRIPTION

FIG. 1is a schematic diagram illustrating process steps of polishing a surface of a substrate by using an apparatus100(hereinafter, referred to as a substrate surface polishing apparatus) for polishing a surface of a substrate, according to an embodiment.

As shown inFIG. 1, the substrate surface polishing apparatus100according to the embodiment is used for polishing a surface of a substrate200while transferring the substrate200by a roll-to-roll process. The substrate surface polishing apparatus100according to the embodiment corresponds to one of apparatuses for performing a process of manufacturing a semiconductor package and a substrate for a lead frame.

Although the substrate surface polishing apparatus100according to the present embodiment is an apparatus for polishing the surface of the substrate200while transferring the substrate200by a roll-to-roll process, the disclosure is not limited thereto. That is, when the substrate200has the shape of a panel, the substrate surface polishing apparatus100according to the present embodiment may also polish the surface of the substrate200while transferring the substrate200by using a conveyor transfer method or the like.

The substrate surface polishing apparatus100receives the substrate200from a resin layer forming unit300, which is a device for performing the immediately preceding process, and performs a function of polishing the surface of the substrate200.

The shape of the substrate200emerging from the resin layer forming unit300is illustrated inFIG. 3. The substrate200includes a raw material210and a resin layer220formed on the upper surface of the raw material210. Details are described below.

The substrate surface polishing apparatus100includes a laser irradiation apparatus110.

The laser irradiation apparatus110irradiates a laser to a surface of the substrate200to polish the surface. In this case, the surface of the substrate200to which the laser is irradiated denotes a portion of the substrate200to which the laser is irradiated by the laser irradiation apparatus110. That is, the surface of the substrate200may be a surface of the resin layer220at the beginning of the polishing process, and may be an exposed surface of the raw material210at the end of the polishing process since the resin layer220is gradually polished and removed.

The laser irradiation apparatus110irradiates a laser and has a function of automatically recognizing a distance from the substrate200and keeping a focal length of a laser dot constant, like a general laser irradiator.

The laser irradiated by the laser irradiation apparatus110may be any kind of laser as long as the laser may be irradiated to the resin layer220and the resin layer220may be removed by reaction. For example, the laser irradiation apparatus110may irradiate a single laser or a combination of lasers such as pulse wave lasers and continuous wave lasers, and the wavelength range of the laser irradiated by the laser irradiation apparatus110may be from 355 nm which is the wavelength of ultraviolet (UV) laser, to 1064 nm which is the wavelength of infrared (IR) laser.

In addition, the laser irradiation apparatus110is configured to be able to freely change various conditions, such as output, irradiation direction, and irradiation movement. To this end, the laser irradiation apparatus110may include a movement driver B, a controller C, an input unit K, and the like.

InFIG. 1, one laser irradiation apparatus110is used, but the disclosure is not limited thereto. That is, according to an embodiment, a plurality of laser irradiation apparatuses may be provided. One such example is a substrate surface polishing apparatus100A shown inFIG. 5. InFIG. 5, a structure in which the substrate surface polishing apparatus100A includes a plurality of laser irradiation apparatuses110a,110b, and110cis shown.

In addition, according to the present embodiment, the resin layer220is formed on one surface of the substrate200and the substrate surface polishing apparatus100has a structure for removing only the resin layer220on one surface of the substrate200. However, the disclosure is not limited thereto. That is, according to the present embodiment, the resin layer220may be formed on both surfaces of the substrate200and the substrate surface polishing apparatus100may have at least one device for removing the resin layer220on both surfaces or one surface of the substrate200. Accordingly, the number and position of laser irradiation apparatuses may be appropriately modified.

Hereinafter, with reference toFIGS. 1 to 4, a process of polishing a surface of a substrate by using the substrate surface polishing apparatus100described above is described.

FIG. 2is a schematic cross-sectional view showing the state of the substrate200at the point I ofFIG. 1, andFIG. 3is a schematic cross-sectional view showing the state of the substrate200at the point II ofFIG. 1.FIG. 4is a schematic cross-sectional view showing the state of the substrate200at the point III ofFIG. 1.

First, the state of the substrate200before entering into the resin layer forming unit300is described.

FIG. 2shows a cross-sectional view of the substrate200at the point I before the substrate200enters the resin layer forming unit300. Grooves210aare formed in the raw material210of the substrate200through an etching process of a previous step. In this case, the raw material210of the substrate200includes a copper material, but the disclosure is not limited thereto. That is, the raw material210of the substrate200may include, in addition to copper, various types of metals, plastics, and the like used in lead frames and semiconductor packages.

Next, the substrate200enters the resin layer forming unit300.

In the resin layer forming unit300, the resin layer220is formed on a surface, in which the grooves210aare formed, among surfaces of the raw material210of the substrate200. As a resin material constituting the resin layer220, various polymer materials such as epoxy resin and polyimide resin, or a composite material including a polymer material, a ceramic filler, and the like may be used. A material that may be removed in response to a certain wavelength range of the laser irradiated by the laser irradiation apparatus110may be used as the resin material.

Subsequently, the substrate200enters the substrate surface polishing apparatus100.

A user or the controller C controls the laser irradiation apparatus110to irradiate a laser to a surface, on which the resin layer220is formed, among surfaces of the substrate200.

When the laser is irradiated to the resin layer220, the resin layer220reacts with the laser and begins to be removed as the resin of the resin layer220is vaporized. The resin layer220is removed by a predetermined depth. To this end, the user or the controller C may use various methods such as adjusting the output amount of irradiated laser, appropriately setting the pitch between laser dots, and controlling a laser movement speed. In this case, since the wavelength of the irradiated laser has little reaction with the raw material210of the substrate220, damage of the raw material210hardly progresses.

FIG. 4shows a cross-sectional view of the substrate200at the point III, i.e., at a point where the substrate200has been polished by the substrate surface polishing apparatus100. In the substrate200, the remaining resin layer220except for a resin220aarranged in the groove210aare removed.

In the present embodiment, although, in the substrate200that has been polished by the substrate surface polishing apparatus100, the remaining resin layer220except for the resin220aarranged in the groove210ahas been removed, the disclosure is not limited thereto. That is, according to another embodiment, the polishing process may be performed by controlling the output and the direction of the laser so that a portion of the resin layer220around the groove210aremains(first process), and in this case, an additional polishing process (second process) may be required. One such example is the example shown inFIG. 6.FIG. 6shows a process of removing a residual resin by polishing, in an additional friction type polishing apparatus400, the substrate200passing through the substrate surface polishing apparatus100. In this case, a conventional friction type polishing apparatus may be used as the additional friction type polishing apparatus400.

As described above, in the substrate surface polishing apparatus100and the polishing method according to the embodiment, the resin layer220of the substrate200is removed using a laser, and thus, a load is not directly applied to the substrate200for polishing. Therefore, the warpage or damage of the substrate200does not occur during the polishing process.

In addition, the substrate surface polishing apparatus100and the polishing method according to the embodiment may freely change the output and conditions of a laser to be irradiated. Therefore, the user may easily remove the resin layer220to a desired level, and thus, a precise polishing may be implemented.

Since a substrate surface polishing apparatus and method according to one or more embodiments remove a resin layer of a substrate by using a laser, the warpage and damage of the substrate can be prevented without applying a load to the substrate for polishing.

In addition, since the substrate surface polishing apparatus and method according to one or more embodiments may freely change the output and conditions of a laser to be irradiated, the resin layer can be easily removed to a desired level.