KR20050054042A - Method of forming solder resist pattern of printed circuit board - Google Patents

Abstract

The present invention relates to a method of forming a solder resist pattern of a printed circuit board by applying a solder resist to a printed circuit board, and forming a solder resist pattern by mechanically imprinting a template.

The solder resist pattern forming method of the printed circuit board according to the present invention includes the steps of (A) forming a circuit pattern on the substrate; (B) applying a solder resist to the substrate; And (C) mechanically imprinting a template on which the solder resist pattern is formed to form a solder resist pattern on the substrate, and hardening the patterned solder resist.

Description

Method of forming solder resist pattern of printed circuit board

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of forming a solder resist pattern of a printed circuit board. More particularly, the present invention relates to a method of forming a solder resist pattern on a printed circuit board, and more particularly, to soldering a printed circuit board and mechanically imprinting a template. The present invention relates to a solder resist pattern forming method of a printed circuit board forming a resist pattern.

The term solder refers to soldering, and the term resist refers to a film that protects a process or reaction from being printed.

Accordingly, solder resist means a film that covers the circuit pattern of the printed circuit board and prevents unwanted connection by soldering when the component is mounted, and the insulation between the protective material and the circuit which protects the circuit pattern of the printed circuit board. Play the role of granting.

Since the circuit pattern of the printed circuit board is made by corrosion of the copper foil coated on the board, in principle, it can be called a spiral without an insulation coating. As a result, when the electronic component is mounted on the printed circuit board, the surface of the printed circuit board may be exposed to molten lead, causing unwanted solder bridges. This leads to serious defects that prevent the electronics from operating normally.

In order to prevent such defects, a coating that shields other parts of the land except for lands required for soldering parts for the purpose of covering a spiral circuit pattern is called a solder resist. Solder resist is also called a solder mask by applying the meaning of shielding.

1A to 1I are cross-sectional views of a solder resist pattern forming method of a conventional printed circuit board.

As shown in FIG. 1A, a circuit pattern is formed on a substrate 100 that is a copper clad laminate in which a copper foil layer 110 is coated on a dielectric base layer 120.

As shown in FIG. 1B, a solder resist 200, which is a photosensitive resin in a liquid state, is applied to the substrate 100 on which the circuit pattern is formed.

As shown in FIG. 1C, the substrate 100 to which the solder resist 200 is applied is temporarily dried by heating using the dryer 300.

As shown in FIG. 1D, an art work film 410 having a solder resist pattern formed on the substrate 100 to which the solder resist 200 is temporarily dried is closely attached to the substrate 100, and then exposed to ultraviolet rays 420 to expose the solder. The solder resist 200 corresponding to the resist pattern portion is cured.

As shown in FIG. 1E, the solder resist pattern of the uncured portion is removed by using the developing apparatus 500 on the substrate 100 on which the solder resist pattern portion is cured to form a solder resist pattern.

As shown in FIG. 1F, the substrate 100 on which the solder resist pattern is formed is exposed to ultraviolet rays 420 to cure the solder resist 200.

As shown in FIG. 1G, the solder resist 200 is thermally cured by heating the substrate 100 on which the solder resist pattern is cured using the dryer 300.

As shown in FIG. 1H, a plasma 600 is used to remove the remaining solder resist 200, foreign substances, etc. in the portion where the solder resist 200 of the substrate 100 on which the solder resist pattern is thermoset is removed. After the post-treatment, the printed circuit board 100 having the solder resist pattern formed by the conventional method as shown in FIG. 1I is manufactured.

As shown in FIGS. 1A to 1I, a method of forming a solder resist pattern of a conventional printed circuit board is to apply a solder resist 200 in a liquid state and then expose and develop a solder resist 200 to form a layer. And, due to limitations of the developing process, it is difficult to form a fine solder resist opening pattern of less than 50 μm corresponding to a high density fine circuit pattern formed on the substrate 100.

In addition, the conventional method of forming a solder resist pattern of a printed circuit board is formed by chemically forming a solder resist pattern by performing exposure and development processes using a photosensitive resin in a liquid state with the solder resist 200, thereby forming a solder resist pattern. This complexity also has a problem of lowering productivity, reliability and economics.

In addition, the conventional method of forming a solder resist pattern of a printed circuit board requires a chemical cleaning process according to the development process of the solder resist 200, and thus, waste water is generated to increase environmental pollution.

The technical problem of the present invention for solving the above problems is to provide a solder resist pattern forming method of a printed circuit board to correspond to the fine circuit pattern formed on the substrate.

Another technical problem of the present invention is to provide a solder resist pattern forming method of a printed circuit board having excellent productivity, reliability and economy.

Another technical problem of the present invention is to provide a solder resist pattern forming method of an environmentally friendly printed circuit board.

In order to solve the above technical problem, the solder resist pattern forming method of the printed circuit board according to the present invention comprises the steps of (A) forming a circuit pattern on the substrate; (B) applying a solder resist to the substrate; And (C) mechanically imprinting a template on which the solder resist pattern is formed to form a solder resist pattern on the substrate, and hardening the patterned solder resist.

The method of forming a solder resist pattern of a printed circuit board according to the present invention further comprises, after the step (A), (D) cleaning the surface of the substrate and applying a roughness to the surface of the substrate. It is done.

The method of forming a solder resist pattern of a printed circuit board according to the present invention further includes, after step (C), (D) removing solder resist and foreign matter remaining in an open portion of the solder resist pattern. Characterized in that made.

The process of forming the solder resist pattern on the substrate by printing the template of the step (C) of the solder resist pattern forming method of the printed circuit board according to the present invention is performed after the release film is in close contact with the template. It is preferable to form a solder resist pattern on the substrate.

Curing the solder resist in the step (C) of the solder resist pattern forming method of the printed circuit board according to the present invention, at least one of the mold and the substrate is heated at the time of forming the solder resist pattern to cure the solder resist It is preferable to make it.

Curing the solder resist of the step (C) of the solder resist pattern forming method of the printed circuit board according to the present invention (C-1) by heating at least one of the mold and the substrate at the time of forming the solder resist pattern Initial curing the solder resist; And (C-2) separating the mold from the substrate, and then heating and thermally curing the initially cured solder resist.

The solder resist of the solder resist pattern forming method of the printed circuit board according to the present invention is preferably a non-photosensitive semi-cured thermosetting resin film (B-stage).

The solder resist of the method for forming a solder resist pattern of a printed circuit board according to the present invention is preferably a liquid non-photosensitive thermosetting resin.

The method of forming a solder resist pattern of a printed circuit board according to the present invention is characterized in that it further comprises the step (D) after the step (D) of temporarily drying the liquid non-photosensitive thermosetting resin.

The process of applying the liquid non-photosensitive thermosetting resin in the step (B) of the solder resist pattern forming method of the printed circuit board according to the present invention may be performed by screen printing, roll coating, It is preferable to apply the liquid non-photosensitive thermosetting resin in at least one of a curtain coating method and a spray coating method.

Hereinafter, a solder resist pattern forming method of a printed circuit board according to the present invention will be described in detail.

2A to 2F are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a first embodiment of the present invention.

As shown in FIG. 2A, a circuit pattern is formed on the substrate 100, which is a copper clad laminate in which the copper foil layer 110 is coated on the dielectric base layer 120.

If fingerprint, oil, dust, or the like is on the substrate 100 on which the circuit pattern is formed, a problem may occur in which the solder resist 200 layer formed in a later process and the substrate 100 do not come into close contact with each other. Therefore, after the circuit pattern is formed, a pretreatment for cleaning the surface of the substrate 100 and applying roughness to the surface of the substrate 100 is performed in order to improve adhesion between the solder resist 200 layer and the substrate 100. It is preferable to carry out.

As shown in FIG. 2B, a thermosetting resin film, which is an insulating resin in a non-photosensitive semi-cured state (B-stage), is applied to the substrate 100 on which the circuit pattern is formed by the solder resist 200.

As shown in FIG. 2C, the solder resist 200 of the substrate 100 is to be opened in a mechanically imprinting manner using a template 710 in which a solder resist pattern is formed in advance. The thermosetting resin is removed to form a solder resist pattern.

In this case, in order to easily separate the solder resist 200 and the mold 710 of the substrate 100, it is preferable to use a release film 720 in close contact with the mold 710.

As illustrated in FIG. 2D, the solder resist 200, which is a thermosetting resin in a non-photosensitive semi-cured state, is thermally cured by heating the substrate 100 on which the solder resist pattern is formed using the dryer 300.

As another method of thermally curing the solder resist 200, in the step of FIG. 2C, heat is applied to the substrate 100 or the mold 710 to perform initial curing of the solder resist 200, which is a thermosetting resin in a semi-cured state, and the substrate ( After the mold 710 is separated from the mold 100, a method of thermally curing the solder resist 200 may be performed in the step of FIG. 2D.

As shown in FIG. 2E, in order to remove the thermosetting resin, the foreign matter, and the like remaining around the land, which is the part where the solder resist 200 of the thermally cured substrate 100 is opened, the plasma ( After the post-treatment using the plasma 600, a printed circuit board 100 manufactured according to the first embodiment of the present invention is formed as shown in FIG. 2F.

Although the method using the plasma 600 is used as the post-processing method in FIG. 2E, a post-processing method such as a chemical method and a laser method may also be used.

3A to 3E are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a second embodiment of the present invention.

As shown in FIG. 3A, a circuit pattern is formed on the substrate 100, which is a copper foil laminate having the copper foil layer 110 coated on the dielectric substrate layer 120.

If fingerprint, oil, dust, or the like is on the substrate 100 on which the circuit pattern is formed, an adhesion problem may occur in which the solder resist 200 layer formed in a subsequent process and the substrate 100 are not completely in contact with each other. Therefore, after forming the circuit pattern, in order to improve the adhesion between the solder resist 200 layer and the substrate 100, it is necessary to perform a pretreatment to clean the surface of the substrate 100 and to impart the roughness to the surface of the substrate 100. desirable.

As shown in FIG. 3B, the thermosetting resin film, which is an insulating resin in a non-photosensitive semi-cured state, is placed on the substrate 100 on which the circuit pattern is formed, and the mold 710 in which the solder resist pattern is formed in advance is placed. By mechanically imprinting and simultaneously applying sufficient heat and pressure, the solder resist pattern of the substrate 100 to be opened is removed to compress the solder resist pattern to remove the portion of the thermosetting resin. The 200 layer is pressed onto the substrate 100.

In this case, in order to easily separate the solder resist 200 and the mold 710 of the substrate 100, the release film 720 is preferably used in close contact with the mold 710.

In addition, an all-layer parallel press process may simultaneously compress and mold a circuit layer, an insulating resin layer, and a solder resist layer of a printed circuit board.

As shown in FIG. 3C, the solder resist 200, which is a thermosetting resin in a semi-cured state, is thermally cured by heating the substrate 100 on which the solder resist pattern is formed by using the dryer 300.

As another method of thermally curing the solder resist 200, in the step of FIG. 3B, heat is applied to the substrate 100 or the mold 710 to perform initial curing of the solder resist 200, which is a thermosetting resin in a semi-cured state, and the substrate ( After the mold 710 is separated from the mold 100, a method of thermosetting the solder resist 200 may be performed in the step of FIG. 3C.

As shown in FIG. 3D, the plasma resist 600 is used to remove the solder resist 200, foreign matters, and the like that remain around the land which is a portion where the solder resist 200 of the thermally cured substrate 100 is opened. When the post-processing using) is performed, a printed circuit board 100 manufactured according to the second embodiment of the present invention, as shown in FIG. 3E, is formed.

Although the method using the plasma 600 is used as a post-processing method in FIG. 3D, a post-processing method such as a chemical method and a laser method may also be used.

4A to 4F are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a third exemplary embodiment of the present invention.

As shown in FIG. 4A, a circuit pattern is formed on the substrate 100, which is a copper foil laminated plate on which the copper foil layer 110 is coated on the dielectric substrate layer 120.

If fingerprint, oil, dust, or the like is on the substrate 100 on which the circuit pattern is formed, an adhesion problem may occur in which the solder resist 200 layer formed in a subsequent process and the substrate 100 are not completely in contact with each other. Therefore, after forming the circuit pattern, in order to improve the adhesion between the solder resist 200 layer and the substrate 100, it is necessary to perform a pretreatment to clean the surface of the substrate 100 and to impart the roughness to the surface of the substrate 100. desirable.

As shown in FIG. 4B, after the liquid non-photosensitive thermosetting resin is applied to the substrate 100 having the circuit pattern formed thereon with the solder resist 200, the thermosetting resin layer is temporarily dried to easily handle the substrate 100. Let's do it.

Here, the liquid non-photosensitive thermosetting resin is coated by using a screen printing method, a roll coating method, a curtain coating method, a spray coating method, or the like. It is preferable to apply a non-photosensitive thermosetting resin to the board | substrate 100.

The screen printing method is a method of applying the solder resist 200 using plate making.

The roller coating method is a method in which the solder resist 200 having a lower viscosity than that used in the screen printing method is applied to the substrate 100 by applying a thin layer to a roller made of rubber.

In the curtain coating method, the solder resist 200 having a lower viscosity than that used in the roller coating method is discharged through a slit to form a curtain-type film, which is then applied by passing through the substrate 100.

The spray coating method is a method of spraying and applying the solder resist 200 ink.

As shown in FIG. 4C, the temporary non-sensitized portion of the portion where the solder resist 200 of the substrate 100 is to be opened in a mechanically imprinting manner using a mold 710 in which a solder resist pattern has been previously formed. The thermosetting resin is removed to form a solder resist pattern.

In this case, in order to easily separate the solder resist 200 and the mold 710 of the substrate 100, the release film 720 is preferably used in close contact with the mold 710.

As shown in FIG. 4D, the solder resist 200, which is a thermosetting resin in a dry state, is thermally cured by heating the substrate 100 on which the solder resist pattern is formed by using the dryer 300.

As another method of thermally curing the solder resist 200, in the step of FIG. 2C, heat is applied to the substrate 100 or the mold 710 to perform initial curing of the solder resist 200, which is a thermosetting resin in a dry state, and the substrate ( After the mold 710 is separated from the mold 100, a method of thermally curing the solder resist 200 may be performed in the step of FIG. 2D.

As shown in FIG. 4E, the plasma resist 600 is used to remove the solder resist 200, foreign matters, and the like that remain around the land which is a portion where the solder resist 200 of the thermally cured substrate 100 is opened. After the post-processing using), a printed circuit board 100 manufactured according to the third embodiment of the present invention, as shown in FIG. 4F, is formed.

Although the method using the plasma 600 is used as a post-processing method in FIG. 4E, a post-processing method such as a chemical method and a laser method may also be used.

5A to 5E are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a fourth embodiment of the present invention.

As shown in FIG. 5A, a circuit pattern is formed on the substrate 100, which is a copper foil laminated plate on which the copper foil layer 110 is coated on the dielectric base layer 120.

If fingerprint, oil, dust, or the like is on the substrate 100 on which the circuit pattern is formed, an adhesion problem may occur in which the solder resist 200 layer formed in a subsequent process and the substrate 100 are not completely in contact with each other. Therefore, after forming the circuit pattern, in order to improve the adhesion between the solder resist 200 layer and the substrate 100, it is necessary to perform a pretreatment to clean the surface of the substrate 100 and to impart the roughness to the surface of the substrate 100. desirable.

As shown in FIG. 5B, a liquid non-photosensitive thermosetting resin is applied to the substrate 100 on which the circuit pattern is formed.

Here, it is preferable to apply the non-photosensitive thermosetting resin to the substrate 100 using a screen printing method, a roll coating method, a curtain coating method, a spray coating method, or the like as a method of applying the liquid non-photosensitive thermosetting resin. .

As shown in FIG. 5C, the liquid non-photosensitive of the portion where the solder resist 200 of the substrate 100 is to be opened in a mechanically imprinting manner using a mold 710 having a solder resist pattern previously formed therein. While removing the thermosetting resin to form a solder resist pattern, heat is applied to the substrate 100 or the mold 710 to which the non-photosensitive thermosetting resin is applied to thermally cure the solder resist 200.

In this case, in order to easily separate the solder resist 200 layer of the substrate 100 from the mold 710, the release film 720 is preferably used in close contact with the mold 710.

Meanwhile, as another method of thermally curing the solder resist 200, heat is applied to the substrate 100 or the mold 710 to perform initial curing of the solder resist 200, which is a liquid non-photosensitive thermosetting resin, and the substrate 100. After the mold 710 is separated from the mold 710, a method of thermally curing the solder resist 200 using a separate dryer 300 may be performed.

As shown in FIG. 5D, the plasma resist 600 is used to remove the solder resist 200, foreign matters, and the like that remain around the land which is a portion where the solder resist 200 of the thermally cured substrate 100 is opened. When the post-treatment 600 using) is performed, a printed circuit board 100 manufactured according to the fourth embodiment of the present invention, as shown in FIG. 5E, is formed.

Although the method using the plasma 600 is used as a post-processing method in FIG. 5D, a post-processing method such as a chemical method and a laser method may also be used.

Although not shown in the drawings of the present specification, the solder resist pattern forming method of the printed circuit board according to the present invention, in the case of a double-sided printed circuit board or a multilayer printed circuit board, the solder resist pattern according to the present invention is formed on one surface, the other surface A parallel printed circuit board manufacturing method for performing a general printed circuit board manufacturing process, such as a process of forming a circuit pattern by processing via holes or laminating Resin Coated Copper (RCC), may be performed.

Although the present invention has been described above, it is only an embodiment, and it will be apparent to those skilled in the art that various changes and modifications can be made without departing from the technical spirit of the present invention. However, it will be apparent from the following claims that they fall within the scope of the invention.

As described above, the method of forming a solder resist pattern of a printed circuit board according to the present invention forms a solder resist pattern in a mechanically imprinting manner using a template capable of forming a fine pattern, so that it is less than 50 μm. Provided is a printed circuit board capable of forming a fine solder resist opening pattern.

In addition, the solder resist pattern forming method of the printed circuit board according to the present invention is simplified compared to the conventional exposure and development process, the productivity of the printed circuit board is increased, thereby reducing the production cost.

In addition, the method of forming a solder resist pattern of a printed circuit board according to the present invention is to reduce the equipment cost and the space required for the process due to the simplification of the process, and the use of a lower cost thermosetting resin than the conventional photosensitive thermosetting resin of the printed circuit board The cost of production is reduced.

In addition, the method of forming a solder resist pattern of a printed circuit board according to the present invention by using a non-photosensitive thermosetting resin, which is an insulating resin in the form of a film, the defect rate caused by the thickness variation of the solder resist, foreign matter defect, whitening, poor cleaning, etc. There is an effect of increasing reliability.

In addition, the solder resist pattern forming method of the printed circuit board according to the present invention, there is no cleaning process according to the development process, thereby providing a solder resist pattern forming method of an environmentally friendly printed circuit board to prevent environmental pollution.

1A to 1I are cross-sectional views of a solder resist pattern forming method of a conventional printed circuit board.

2A to 2F are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a first embodiment of the present invention.

3A to 3E are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a second embodiment of the present invention.

4A to 4F are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a third exemplary embodiment of the present invention.

5A to 5E are cross-sectional views of a solder resist pattern forming method of a printed circuit board according to a fourth embodiment of the present invention.

* Description of the symbols for the main parts of the drawings *

100: substrate 110: copper foil layer

120: dielectric substrate layer 200: solder resist

300: dryer 410: artwork film

420: ultraviolet ray 500: developing device

600: plasma 710: template

720: release film

Claims (10)

(A) forming a circuit pattern on the substrate; (B) applying a solder resist to the substrate; And (C) mechanically imprinting a template on which a solder resist pattern is formed, forming a solder resist pattern on the substrate, and hardening the patterned solder resist. Method of forming a solder resist pattern on a substrate. According to claim 1, After the step (A), (D) cleaning the surface of the substrate and imparting roughness to the surface of the substrate, the method comprising the steps of forming a solder resist pattern on a printed circuit board. The method of claim 1, wherein after step (C), (D) a method of forming a solder resist pattern of a printed circuit board, further comprising the step of removing the solder resist and foreign matter remaining in the open portion of the solder resist pattern. The method of claim 1, The process of forming the solder resist pattern on the substrate by printing the template of the step (C) is characterized in that after the release film is in close contact with the mold to print to form a solder resist pattern on the substrate Method of forming a solder resist pattern on a printed circuit board. The method of claim 1, The step of curing the solder resist of the step (C) is a method of forming a solder resist pattern of a printed circuit board, characterized in that at least one of the mold and the substrate is heated to form the solder resist when forming the solder resist pattern . The method of claim 1, Curing the solder resist of the step (C) is (C-1) initial curing the solder resist by heating at least one of the mold and the substrate when the solder resist pattern is formed; And (C-2) The method of forming a solder resist pattern on a printed circuit board comprising the step of separating the mold from the substrate and then heating and thermally curing the initially cured solder resist. The method of claim 1, The soldering resist is a method of forming a solder resist pattern on a printed circuit board, characterized in that the thermosensitive resin film in a non-photosensitive semi-cured state (B-stage). The method of claim 1, The soldering resist is a solder resist pattern forming method of a printed circuit board, characterized in that the liquid photosensitive thermosetting resin. The method of claim 8, wherein after step (B), (D) further drying the liquid non-photosensitive thermosetting resin in a liquid state, the method of forming a solder resist pattern of a printed circuit board. The method according to claim 8 or 9, The coating of the liquid non-photosensitive thermosetting resin in the step (B) may be performed by screen printing, roll coating, curtain coating, and spray coating. A method of forming a solder resist pattern on a printed circuit board, characterized in that the coating of the liquid non-photosensitive thermosetting resin by at least one of the methods.