KR101261262B1 - Method for fabricating both side copper clad laminate using casting and sputtering - Google Patents

Abstract

The present invention relates to a method for manufacturing a double-sided copper laminated substrate, wherein the copper foil formed on one surface of the copper laminated substrate is formed by using a casting process, and the copper foil formed on the other surface is Ni / Cr seed using sputtering. By forming using a layer and a Cu sputtering layer formation and a Cu plating process, it is related with the invention which improves the adhesive force of copper foil, and makes it easy to manufacture a thin copper clad laminated board.

Description

METHODS FOR FABRICATING BOTH SIDE COPPER CLAD LAMINATE USING CASTING AND SPUTTERING}

The present invention relates to a method for manufacturing a double-sided copper laminated substrate using casting and sputtering, wherein the copper foil formed on one surface of the copper laminated substrate is formed using a casting process, and the copper foil formed on the other surface is sputtered and By forming using a plating (Plating) process, to improve the adhesive force of the copper foil, and relates to a technology that makes it easy to manufacture a thin copper foil laminated substrate.

The printed circuit is a wiring diagram representing electrical wiring to be connected to a component according to a circuit design. The printed circuit is a printed circuit board (PCB) or a printed wiring board (PC), which is reproduced as an electrical conductor on an insulator by a suitable method. PWB).

Printed circuit boards are used in mass production processes in which electronic components are mounted on pre-wired boards to complete wiring work at once.

By using a printed circuit board, there is an advantage in that the electronic device can be reduced in size and weight, and a low production cost and high reliability of wiring can be obtained. Therefore, recent electronic application devices are mostly using printed circuit boards, whether for home use or industrial use.

Recently, miniaturization of printed circuit boards has been required due to the miniaturization of electronic devices such as LCD monitors, PDPs, notebook computers, mobile phones, PDAs, small video cameras, and electronic notebooks. Thinning is required. As described above, in order to make a high-definition circuit board, the thickness of the copper foil layer for forming the circuit must be thin.

Existing fine pattern formation techniques include a method of applying a high etching technique, a method of etching a thick thin copper foil layer through a constant soft etching, followed by etching, and FCCL for chip on film (COF) made through sputtering. Flexible printed circuits have been used. However, these methods are limited in meeting the demand for accelerated high resolution.

According to the present invention, a copper foil formed on one surface of a copper foil laminated substrate is formed using a casting process, and the copper foil formed on the other surface is formed using a sputtering and plating process, thereby achieving high resolution. It is an object of the present invention to provide a method for producing a double-sided copper-clad laminate substrate which can easily manufacture a suitable double-sided copper-clad laminate substrate.

In addition, the present invention is manufactured by the above-described method, the first copper foil layer, polyimide layer that can improve the adhesion of sputtering, Ni / Cr seed layer, Cu plating layer having a thickness that can ensure the electrical performance of the circuit (hereinafter referred to as It is an object of the present invention to provide a double-sided copper-clad laminate substrate formed of a double copper foil layer structure, which has excellent adhesive strength and is capable of high definition.

According to an embodiment of the present invention, a method of manufacturing a double-sided copper clad laminate substrate may include casting an insulating layer on an upper portion of a first copper foil layer and curing the insulating layer, and sputtering Ni and Cr alloy targets on the insulating layer to form Ni / C. Forming a Cr seed layer, a Cu sputtering step of forming a Cu sputtering layer to enable electroplating on the Ni / Cr seed layer, and a Cu plating step of forming a second copper foil layer on the Cu sputtering layer; Characterized in that it comprises a.

The present invention is characterized by the surface roughness of the existing sputtering products and the surface roughness forming technology and manufacturing method of the insulating layer to enable the production of double-sided copper clad substrate.

The method for manufacturing a double-sided copper clad laminate substrate according to the present invention forms a Ni / Cr seed layer by forming an appropriate surface roughness on top of the insulating layer so as to solve the problem of adhesion of the conventional copper clad laminated film suitable for high-definition fine film, thereby forming a subsequent copper foil layer Provides the effect to maximize the adhesion of the.

In addition, by forming a Cu sputtering layer formed on the Ni / Cr seed layer to enable electroplating, an effect of facilitating the Cu plating process for forming a thin second copper foil layer for realizing high definition can be easily achieved. to provide.

Therefore, the present invention can secure the surface adhesive strength of the copper foil layer that could not be realized by the copper-clad laminate substrate manufacturing the sputtering process by the surface roughness control technology of the insulating layer using the Ni / Cr seed layer, copper foil suitable for high definition It provides the effect of ensuring the layer thickness.

1 is a cross-sectional view showing a copper foil laminated substrate according to a comparative example of the present invention.
2 is a cross-sectional view showing a copper clad laminate board according to an exemplary embodiment of the present invention.
3 is a flowchart illustrating a method of manufacturing a copper clad laminate board according to an exemplary embodiment of the present invention.
4 to 8 are cross-sectional views illustrating a method of manufacturing a copper clad laminate board according to an exemplary embodiment of the present invention.

Advantages and features of the present invention and methods for achieving them will be apparent with reference to the embodiments and drawings described below in detail. However, the present invention is not limited to the embodiments disclosed below, but can be implemented in various different forms, only the embodiments are to make the disclosure of the present invention complete, it is common in the art It is provided to fully inform those skilled in the art of the scope of the invention, which is to be defined only by the scope of the claims.

Hereinafter, a method of manufacturing a double-sided copper clad laminate substrate and a printed circuit board manufacturing method using the same according to the present invention will be described in detail.

1 is a cross-sectional view showing a copper foil laminated substrate according to a comparative example of the present invention.

Referring to FIG. 1, the first copper foil layer 10 and the second copper foil layer 30 are provided on both surfaces of the insulating layer 20. Conventionally, the first and second copper foil layers 10 and 20 are bonded by a laminating method. At this time, a thin copper foil layer should be applied for high resolution, but until now, a technology for laminating thin copper foil layers has not been secured.

Therefore, a product made by sputtering Cu on the polyimide film (PI film) was used in the field where the thin copper foil layer should be applied. And this was called copper foil laminated film for COF.

 However, the copper foil laminated film for COF had a problem that the adhesion between the insulating layer and the Cu sputtering layer was very low, and it was not a suitable manufacturing method for implementing a double-sided structure, and there is no copper foil laminated film for COF on both sides.

Accordingly, the present invention provides a surface roughness forming technology of the insulating layer to solve the problem of the surface adhesion of the existing sputtering products, and to enable the production of double-sided copper laminated substrate.

More specifically, in the present invention, by forming a sputtering copper foil layer on one side of the single-sided copper foil laminated film to the above problems, it is possible to produce a thin double-sided copper foil layer that can be easily applied to high resolution. Provide a way.

In addition, the adhesion of the sputtering surface is also changed to a structure that can maximize the contact area by adjusting the surface roughness of the insulating layer to achieve an improved adhesion of the copper foil layer.

2 is a cross-sectional view showing a copper clad laminate board according to an exemplary embodiment of the present invention.

Referring to FIG. 2, a copper foil laminated substrate according to the present invention may include a first copper foil layer 100, an insulating layer 110, a Ni / Cr seed layer 120, a Cu sputtering layer 130, and a second copper foil from below. It can be seen that the structure of the layer 140 is provided.

Here, the insulating layer 110 is preferably formed of at least one of polyester (PET) and polyimide layer (PI).

However, in this case, since the adhesive force of the copper foil layer can be significantly lowered, the present invention provides the following production method.

3 is a flowchart illustrating a method of manufacturing a copper clad laminate board according to an exemplary embodiment of the present invention.

Referring to FIG. 3, first, a first copper foil layer is prepared, and an insulating layer is cast on the first copper foil layer (S100). In this case, the casting may include a step of curing the insulating layer continuously after forming the insulating layer.

Next, sputtering using Ni and Cr alloys is performed on the insulating layer to form a Ni / Cr seed layer (S110).

Subsequently, sputtering using Cu is performed on the Ni / Cr seed layer to form a Cu sputtering layer to enable subsequent electroplating (S120).

Next, a Cu plating process is performed on the Cu sputtering layer to form a second copper foil layer (S130).

Here, the first copper foil layer according to the present invention, unlike the method of laminating the copper foil on the existing insulating layer, by using a method of casting the resin composition for manufacturing the insulating layer on the copper foil can be sufficient adhesive force is generated.

Next, the adhesive force of the second copper foil layer formed on the insulating layer should be secured. In the present invention, the composition of the insulating layer resin is optimized to adjust the roughness of the surface of the insulating layer, thereby increasing the adhesion area with the seed layer. To improve adhesion.

Moreover, in order to improve the roughness of an insulating layer, the filler which can participate in roughening formation is added to the resin composition which comprises an insulating layer.

In this case, the filler may be oxides such as silica, alumina, titania, magnesium oxide, complex oxides such as kaolin, talc, montmorillonite, carbonates such as calcium carbonate and barium carbonate, calcium sulfate, barium sulfate and the like. One or more kinds of substances may be used, but is not limited to, sulfates, titanates such as barium titanate and potassium titanate, and phosphates such as first calcium phosphate, second calcium phosphate, and third calcium phosphate.

However, the surface roughness (Rz) according to the present invention is preferably to be 0.5 ~ 2.0㎛ in order to maximize the adhesive force, the optimal filler for this is suitable talc.

If the surface roughness is less than 0.5 μm, the adhesive strength of the second copper foil layer is lowered. If the surface roughness is more than 2.0 μm, the adhesive force may be improved, but the surface is roughened, making it difficult to form a circuit pattern using the copper foil. In other words, high definition is impossible.

In addition, for optimum surface roughness, it is preferable to make the filler content to 10 to 30% by weight based on the solid content.

When the content of the filler was lower than 10% by weight, the surface roughness was not formed normally and the adhesive strength with the second copper foil layer was lowered. On the contrary, when the content of the filler was higher than 30% by weight, the surface roughness was too high, resulting in pattern defects when forming a high-resolution circuit.

As described above, the surface roughness of the insulating layer according to the present invention is transferred to the surface roughness of the seed layer, the surface roughness of the seed layer again affects the surface roughness of the Cu sputtering layer, and consequently of the second copper foil layer Adhesion can be improved.

Thus, the details of each layer for surface roughness control can be determined as follows.

4 to 8 are cross-sectional views illustrating a method of manufacturing a copper clad laminate board according to an exemplary embodiment of the present invention.

First, referring to FIG. 4, first, a copper foil of 9 μm to 35 μm is prepared as the first copper foil layer 200.

In this case, when the thickness of the first copper foil layer 200 is less than 9 μm, sufficient adhesive strength may not be exerted during the subsequent insulation layer casting, and when the thickness exceeds 35 μm, the thickness of the entire copper clad laminate substrate may be too thick. High-definition circuit patterns can be difficult to form.

Next, referring to FIG. 5, an insulating layer 210 is formed on the first copper foil layer 200 by a casting method.

At this time, the insulating layer 210 is preferably formed using at least one of polyester (PET) and polyimide layer (PI), it is preferable to form a thickness of 12 ~ 25㎛.

When the thickness of the insulating layer is formed to be less than 12㎛, it may be difficult to fully implement the surface roughness (Rz) of the above 0.5 ~ 2.0㎛. On the contrary, when the thickness of the insulating layer exceeds 25㎛, it may be difficult to implement a flexible printed circuit board for high definition.

Next, referring to FIG. 6, the Ni / Cr seed layer 220 is formed to have a thickness of 100 to 300 μm on the insulating layer 210 according to the sputtering condition described with reference to FIG. 3.

At this time, the Ni / Cr seed layer serves as a buffer layer for improving the adhesion of the subsequent Cu sputtering layer, when the thickness is less than 100Å can not normally perform the function. On the contrary, when the thickness of the seed layer exceeds 300 kPa, the thickness thereof may be too thick to properly transfer the surface roughness of the insulating layer 210.

Next, referring to FIG. 7, a Cu sputtering layer 230 having a thickness of 500 ˜1500 에 is formed on the Ni / Cr seed layer 220 by using a sputtering process.

At this time, the Cu sputtering layer is a layer formed so that the subsequent Cu plating process, which is a second copper foil layer forming process, may be easily performed. When the thickness is less than 500 kPa, the second copper foil layer may not be normally formed. have. On the contrary, when the thickness of the Cu sputtering layer exceeds 1500 kPa, the surface roughness effect of the seed layer is lost and the adhesion of the second copper foil layer may be remarkably reduced, and may also act as a factor for inhibiting high definition.

Next, referring to FIG. 8, the second copper foil layer 240 is formed on the Cu sputtering layer 230 by using a Cu plating process.

At this time, it is preferable that the second copper foil layer 240 is formed to have a thickness of 3 to 20 μm. When the thickness of the second copper foil layer is formed to be less than 3 μm, sufficient adhesive force may not be exhibited and the peeling strength may decrease. On the contrary, when the thickness of the second copper foil layer is thickened to a thickness exceeding 20 μm, it is difficult to form a high-definition circuit pattern, which may lower productivity.

Hereinafter, for the embodiment of the copper-clad laminate substrate actually formed by the above-described manufacturing method of the present invention, look at the adhesive force improvement characteristics according to the present invention.

Example

First, a 20 μm thick polyimide layer is formed on a 12 μm thick copper foil, a 200 μm Ni / Cr seed layer is formed on the polyimide layer, and a 1000 μm Cu sputtering layer is formed on the Ni / Cr seed layer. Next, a Cu plating layer having a thickness of 5 μm is formed on the Cu sputtering layer.

In this case, the condition range for forming the Ni / Cr seed layer is to use the range according to the description of FIG. 3, and all other ranges are to be treated as comparative examples.

Next, a mask pattern having a size of 15 cm * 1 mm was formed using an acid resistant tape or a photoresist on the copper foil laminated substrate according to the embodiment. Subsequently, the copper foil laminated substrate was immersed in an etching solution of 45% FeCl ₃ and 45 ° C. for 40 seconds to remove the copper foil layer except for the portion where the mask pattern was formed. Then, the mixture was washed 3 to 5 times at room temperature, and washed twice or more for 10 minutes using an ultrasonic cleaner to completely remove the residue, blowing compressed nitrogen to remove moisture to complete the sample preparation.

After completing the preparation of the sample through the same method as described above, the peel strength was measured.

[Table 1]

As can be seen with reference to Table 1, the copper foil laminated substrate according to the present invention has a high surface roughness according to the content of the filler (Filler), and as the roughness increases, the adhesive area of the second copper foil layer is widened so that the adhesive strength is increased. Increasing experimental results were obtained.

On the other hand, if the filler content is too high exceeding 30% by weight, the surface roughness of the insulating layer may be increased, but the high-definition circuit pattern forming process becomes difficult, the threshold value for the adhesive strength of the second copper foil layer in this process is lowered It was found that the phenomenon that the peeling strength was lowered.

While the present invention has been described in connection with what is presently considered to be practical exemplary embodiments, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, It will be understood by those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof.

10, 100, 200: first copper foil layer 20, 110, 210: insulating layer
120, 220: Ni / Cr seed layer 130, 230: Cu sputtering layer
140, 240: second copper foil layer

Claims (6)

Casting an insulating layer on the first copper foil layer and curing the insulating layer;
Sputtering Ni and Cr alloy targets on the insulating layer to form a Ni / Cr seed layer;
A Cu sputtering step of forming a Cu sputtering layer on the Ni / Cr seed layer to enable electroplating; And
It includes; Cu plating step of forming a second copper foil layer on the Cu sputtering layer,
The insulating layer includes a filler for adjusting the surface roughness of 10 to 30% by weight based on solids in order to increase the adhesion area with the Ni / Cr seed layer, wherein the filler is a talc,
The thickness of the insulating layer is 12 ~ 25㎛, the surface roughness (Rz) of the insulating layer is a double-sided copper foil laminated substrate manufacturing method, characterized in that.
The method of claim 1,
The thickness of the first copper foil layer is 9 ~ 35㎛, the thickness of the Ni / Cr seed layer is 100 ~ 300Å, the thickness of the Cu sputtering layer is 500 ~ 1500Å, the thickness of the second copper foil layer is 3 ~ 20 A method for producing a double-sided copper clad laminated substrate, characterized in that it is m.
The method of claim 1,
The insulating layer
A method for producing a double-sided copper clad laminate, characterized in that at least one of polyester (PET) and polyimide layer (PI).
delete delete delete

Images