KR100722606B1 - Manufacturing method of copper clad laminate for Via on pad - Google Patents

Abstract

The present invention relates to a method for manufacturing a copper foil laminated plate for VOP, and more particularly, by dissipating heat generated during laser processing for via hole formation by using a protective layer formed on the copper foil layer material, even through ultra-thin copper foil layer. It is related with the manufacturing method of the copper foil laminated board for VOP which can be formed.

VOP, Via Hole, Copper Clad Laminate, CO2 Laser, Copper Foil Layer

Description

Manufacturing method of copper clad laminate for via on pad

1A to 1F are process drawings showing a conventional method for manufacturing a copper clad laminate for VOP.

2 is a cross-sectional view of a VOP copper-clad laminate formed by a conventional VOP copper-clad laminate manufacturing method when the copper foil layer has a thickness of 5 μm or less.

3 is a flowchart illustrating a method of manufacturing a VOP copper-clad laminate according to the present invention.

Figures 4a to 4i is a process chart showing a VOP copper-clad laminate manufacturing method according to the present invention.

Explanation of symbols on the main parts of the drawings

100: first copper foil layer 110: first protective layer

120: second copper foil layer 130: second protective layer

140: insulating layer 150: adhesive layer

160: laminate 170: via hole

180: copper foil laminated plate 190: plating layer

The present invention relates to a method for producing a copper foil laminated plate for VOP, and more particularly to a method for manufacturing a copper foil laminated plate for VOP in which a through-hole via hole is formed on an ultra-thin copper foil layer.

Due to the rapid digitalization and networking of the electronics industry, the technology of printed circuit boards is also rapidly progressing. This is because set makers demand high-frequency and high-speed signal processing standards, and new cutting-edge processing technologies are needed to enable the design of ultra-thin and fine circuit line widths. Four to five years ago, the line width and interlayer thickness of a printed circuit board was about 200 μm. Recently, however, circuit line widths and interlayer thicknesses have been reduced to less than 100 μm, accelerating the nano age. In particular, various new technologies such as micro-via and build-up have begun to attract attention as high value-added technologies for high integration and ultra-thin film of substrate for package and portable terminal.

In the case of a double-sided printed circuit board, a conventional plated through hole (PTH) method of electroless copper plating and electrolytic copper plating has been mainly used after processing through holes. However, in recent years, as the size of a package is gradually reduced, the number of chips to be mounted in a limited printed circuit board area is rapidly increasing. In other words, in the case of a BGA (Ball Grid Array) type double-sided printed circuit board, a large number of solder balls is required for a limited printed circuit board area. The distance is decreasing. In other words, the solder ball pitch is becoming increasingly finer. In order to implement the fine ball pitch, application of a VOP (Via on Pad) method is increasing instead of the PTH method recently. Through-hole via holes formed by the PTH method serve only as an interlayer connection, while the through-hole via holes formed by the VOP method can provide a solder ball pad capable of mounting solder balls as well as interlayer connection, which can drastically reduce the solder ball pitch. Has the advantage.

Hereinafter, referring to FIGS. 1A to 1F, a manufacturing method of a conventional copper clad laminate for VOP will be described.

First, as shown in FIG. 1A, the copper foil layers 2 and 2 ′ are arranged on both sides of the insulating layer 1, and as shown in FIG. 1B, the copper foil laminated plates 4 are formed by collectively stacking.

At this time, protective layers 3 and 3 'are formed on one surface of the copper foil layers 2 and 2' to protect the surfaces of the copper foil layers 2 and 2 'during the transport or lamination process.

In addition, the copper foil layers 2 and 2 'may have a thickness of 10 μm or more in consideration of heat generated during the laser process.

Thereafter, as shown in FIG. 1C, the protective layers 3 and 3 ′ formed on one surface of the copper foil layers 2 and 2 ′ are removed.

Next, as shown in FIG. 1D, a portion of the copper foil layer 2 formed on the upper portion is removed by an etching process or the like to expose the insulating layer 1.

Thereafter, as shown in FIG. 1E, the exposed insulating layer 1 is removed by laser processing to form an unthrough via hole 5 in which only the copper foil layer 2 ′ formed below is left.

Lastly, as shown in FIG. 1F, the plating layer 6 providing conductivity is formed in the via hole 5, thereby completing the copper foil laminate for VOP.

As described above, the conventional method of manufacturing the copper foil laminate for VOP as described above is used to prevent the copper foil layer 2 'from being damaged by heat generated during laser processing for forming the via hole 5, and thus, the copper foil layers 2 and 2 There was a problem in that the thickness of ') should be kept above a predetermined thickness.

2 is a cross-sectional view of the VOP copper-clad laminate formed by a conventional VOP copper-clad laminate manufacturing method when the copper foil layers 2 and 2 'have a thickness of 5 µm or less, and the above-described problems will be described with reference to this.

As shown in FIG. 2, when the copper foil layers 2 and 2 ′ are formed to a thickness of 5 μm or less in order to form a fine circuit pattern, and the laser processing is performed, heat generated from the laser beam may not be released smoothly. Therefore, the insulating layer 1 is removed as well as a problem such as a pin hole A in the copper foil layer 2 ′ formed below.

Therefore, in order to prevent such defects, the copper foil layers 2 and 2 'must maintain a predetermined thickness or more, and thus, in the conventional method of manufacturing a copper foil laminated plate for a VOP as described above, a copper foil laminated plate for a VOP for implementing a fine circuit pattern is described. There was a problem that can not be prepared.

The present invention is to provide a method for manufacturing a copper foil laminated plate for VOP that can form a non-penetrating via hole on a copper foil layer of a thin film capable of implementing a fine circuit pattern to solve the above problems.

In order to solve the above technical problem, the present invention, (A) providing a first and a second copper foil layer having a protective layer formed on one surface, (B) the first copper foil layer, the insulating layer, respectively, on the upper and lower sides with respect to the adhesive layer And laminating a second copper foil layer, (C) removing the protective layer formed on one surface of the second copper foil layer and removing a portion of the second copper foil layer, and (D) laser in the region where the second copper foil layer is removed. Forming a via hole by only removing the insulating layer by processing, and (E) removing the protective layer and the adhesive layer formed on one surface of the first copper foil layer to form two copper foil laminated plates, and (B) the first step. The protective layer formed on one surface of the copper foil layer and the second copper foil layer provides a method for producing a copper foil laminated plate for VOP, characterized in that the laminated layer so as not to contact the insulating layer.

In the manufacturing method of the copper foil laminated board for VOP which concerns on this invention, a protective layer is characterized by the metal layer.

Moreover, in the manufacturing method of the copper foil laminated board for VOP which concerns on this invention, the 1st copper foil layer and the 2nd copper foil layer are characterized by having a thickness of 5 micrometers or less.

In addition, in the method for manufacturing a copper foil laminated plate for VOP according to the present invention, the adhesive layer is formed of a material having high thermal conductivity.

In the method of manufacturing a copper foil laminated plate for VOP according to the present invention, a part of the second copper foil layer in (C) is removed by an etching process.

In addition, in the method of manufacturing a copper foil laminated plate for VOP according to the present invention, after the step (E), (F) characterized in that it further comprises the step of forming a plating layer on the copper foil laminated plate.

In addition, the manufacturing method of the copper-clad laminate for VOP according to the present invention, after the step (E), (G) characterized in that it further comprises the step of filling the inside of the via hole with a conductive paste.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

3 is a flowchart illustrating a method of manufacturing a copper foil laminated plate for a VOP according to the present invention, and FIGS. 4A to 4I are flowcharts illustrating a method of manufacturing the copper foil laminated plate for a VOP according to the present invention.

First, referring to Figure 3 when explaining the manufacturing method of the copper foil laminated plate for VOP according to the present invention.

A first copper foil layer and a second copper foil layer having a protective layer formed on one surface thereof are provided (S100).

Since the surfaces of the first copper foil layer and the second copper foil layer may be damaged while transporting or storing the first copper foil layer and the second copper foil layer, the protective layer is provided on one surface of the first copper foil layer and the second copper foil layer. It is common to be.

Here, it is preferable that a protective layer is a metal layer formed from metals, such as copper, nickel, and aluminum.

Thereafter, the first copper foil layer, the insulating layer, and the second copper foil layer are laminated on the upper and lower sides of the adhesive layer (S200).

At this time, the protective layers formed on one surface of the first copper foil layer and the second copper foil layer are aligned and laminated so as not to contact the insulating layer.

The adhesive layer may be a prepreg in a semi-cured state, and in particular, the adhesive layer may be formed of an adhesive material having high thermal conductivity.

Next, the protective layer formed on one surface of the second copper foil layer is removed and a part of the second copper foil layer is removed (S300).

Thereafter, only the insulating layer is removed by laser processing in the region where the second copper foil layer is removed (S400).

A portion of the second copper foil layer from which the protective layer is removed may be removed by an etching process, and an unthrough type via hole may be formed by removing the insulating layer by laser processing in the region where the second copper foil layer is removed.

Here, since the heat generated during laser processing can be easily released by the protective layer formed on one surface of the first copper foil layer, even if the first copper foil layer is a thin film of 5 μm or less, no damage is caused by removing only the insulating layer without any damage. The via hole of the mold can be easily formed.

Next, the protective layer and the adhesive layer formed on one surface of the first copper foil layer is removed to form two copper foil laminated plates (S500).

By removing the protective layer formed on one surface of the adhesive layer and the first copper foil layer, it is possible to provide two copper foil laminated plates on which an unperforated via hole is formed.

Finally, to form a plating layer on the copper foil laminated plate to complete the copper foil laminated plate for the VOP (S600).

In order to impart conductivity to the inside of the via hole, a plating layer may be formed on the copper clad laminate. In this case, according to the embodiment, the conductive paste may be filled in the via hole to impart conductivity.

Referring to Figures 4a to 4i will be described in detail the manufacturing method of the copper foil laminate for VOP according to the present invention.

First, as shown in FIGS. 4A and 4B, the first copper foil layer 100 having the first protective layer 110 formed on one surface thereof and the second copper foil layer 120 having the second protective layer 130 formed on one surface formed thereon To provide.

While carrying or storing the first copper foil layer 100 and the second copper foil layer 120, there is a risk that the surfaces of the first copper foil layer 100 and the second copper foil layer 120 may be damaged. The first protective layer 110 and the second protective layer 130 are formed. In addition, the first protective layer 110 and the second protective layer 130 according to an embodiment of the present invention may further have an effect of facilitating heat dissipation during laser processing.

Here, the first protective layer 110 and the second protective layer 130 is preferably formed of a metal layer, such as copper, nickel, aluminum having a thickness of 18㎛ to 35㎛. In addition, in a subsequent process, a release material (not shown) is interposed between the first copper foil layer 100 and the second copper foil layer 120 so as to easily release the first copper foil layer 100 and the second copper foil layer 120. The first passivation layer 110 and the second passivation layer 130 may be formed on one surface.

At this time, it is preferable that the first copper foil layer 100 and the second copper foil layer 120 use a thin film of 5 μm or less for miniaturization of the circuit pattern.

Thereafter, as shown in FIG. 4C, the first copper foil layer 100, the insulating layer 140, and the second copper foil layer 120 are arranged in the upper and lower portions of the adhesive layer 150 in the order shown in FIG. 4D. As described above, the laminated body 160 is formed by collectively laminating.

In this case, the first protective layer 110 and the second protective layer 130 formed on one surface of the first copper foil layer 100 and the second copper foil layer 120 are aligned so as not to contact the insulating layer 140. Should be stacked.

The adhesive layer 150 may be a prepreg in a semi-cured state, it is particularly preferable to form a high thermal conductivity adhesive material.

In this case, when the first copper foil layer 100, the insulating layer 140, and the second copper foil layer 120 are stacked only on one surface of the adhesive layer 150, the laminate may be bent or broken so that the adhesive layer is prevented. The laminate 160 having a vertically symmetrical structure is formed by simultaneously stacking the upper and lower surfaces of the 150.

Next, as shown in FIG. 4E, the second protective layer 130 formed on one surface of the second copper foil layer 120 and positioned at the outermost portion of the laminate 160 is removed.

Since a release material is applied between the second protective layer 130 and the second copper foil layer 120, it may be easily removed by a physical method.

Thereafter, as shown in FIG. 4F, a portion of the second copper foil layer 120 is removed.

That is, a portion of the second copper foil layer 120 corresponding to the region where the via hole is to be formed is removed by an etching process to expose the insulating layer 140. The etching step is, for example, a step of forming an etching resist pattern using a photosensitive material, and then removing copper foil using an iron chloride, copper dichloride, an alkaline etching solution, a sulfuric acid etching solution, and the like, and then peeling off the etching resist pattern.

Next, as shown in FIG. 4G, an unthrough via hole 170 is formed by laser processing in the region where the second copper foil layer 120 is removed.

The second copper foil layer 120 is removed to form a non-penetrating via hole 170 in which only the insulating layer 140 is removed by using a carbon dioxide (CO ₂ ) laser or the like in the region where the insulating layer 140 is exposed.

In the carbon dioxide laser, a predetermined infrared ray is oscillated between the vibration levels of the carbon dioxide molecules and the efficiency is high, thereby easily obtaining a high output.

In this case, since the heat generated during the carbon dioxide laser processing is easily released by the first protective layer 110 formed on one surface of the first copper foil layer 100, the first copper foil layer 100 of the thin film having a thickness of 5 μm or less. Also, the non-through via hole 170 may be formed.

That is, in the conventional manufacturing method, the thickness of the first copper foil layer 100 is 5 μm or less even if the heat generated during laser processing is adjusted to penetrate only the insulating layer 140 and not penetrate the first copper foil layer 100. In the case of a thin film, the first copper foil layer 100 is easily affected by heat, resulting in damage such as pinholes. However, according to an embodiment of the present invention, the first protective layer 110 having a thickness of 18 μm to 35 μm is formed on one surface of the first copper foil layer 100 of the thin film, thereby facilitating heat generated during laser processing. It is possible to form a through-hole via hole 170 that does not damage the first copper foil layer 100 to be discharged.

Thereafter, as shown in FIG. 4H, the first protective layer 110 and the adhesive layer 150 formed on one surface of the first copper foil layer 100 are removed to form two copper foil laminated plates 180.

Since a release material is coated between the first protective layer 110 and the first copper foil layer 100, the first protective layer 110 and the adhesive layer 150 can be easily removed.

Finally, as shown in FIG. 4I, the plating layer 190 is formed on the copper clad laminate 180 to complete the copper clad laminate for VOP.

The via hole 170 is for electrically connecting a circuit pattern to be formed on the first copper foil layer 100 and the second copper foil layer 120 to form a plating layer 190 to impart conductivity.

In this case, since the via hole 170 is formed to include the insulating layer 140, the plating layer 190 may be formed by performing electroless copper plating and electrolytic copper plating.

In some embodiments, a conductive paste (not shown) may be filled in the via hole 170 to impart conductivity.

In the method of manufacturing a copper foil laminated plate for a VOP according to an embodiment of the present invention, in order to form a non-penetrating via hole 170 on the copper foil layer of the thin film using a separate reinforcement or the like for the heat dissipation layer to help heat release. By using the protective layers 110 and 130, which are formed together during the production of the first copper foil layer 100 and the second copper foil layer 120 material, as a heat dissipation layer, without forming through the process, there is no additional process and no additional cost. The non-penetrating via hole 170 may have an effect of manufacturing a copper foil laminated plate for a VOP.

As described above, the present invention has been described through specific embodiments, but the scope of the present invention is not limited to the above embodiments, and various modifications are possible within the scope of the present invention. It is intended that the scope of the invention only be limited by the following claims.

According to the manufacturing method of the copper foil laminated plate for VOP of this invention, by using the protective layer formed together with the copper foil layer factory as a heat emission layer, without separately forming the heat emission layer for dissipating the heat which arises at the time of laser processing, Copper foil laminates for VOP can be produced with no through-holes and no additional costs.

In addition, according to the manufacturing method of the copper foil laminated plate for VOP of the present invention, when forming a through-through via hole on the ultra-thin copper foil layer, defects such as pin holes do not occur, thereby manufacturing a copper foil laminated plate for VOP for implementing a fine circuit pattern. have.

Claims (7)

(A) providing first and second copper foil layers having a protective layer formed on one surface thereof; (B) stacking a first copper foil layer, an insulating layer, and a second copper foil layer, respectively, on the upper and lower sides of the adhesive layer; (C) removing a protective layer formed on one surface of the second copper foil layer and removing a portion of the second copper foil layer; (D) forming a via hole by removing only the insulating layer by laser processing in the region where the second copper foil layer is removed; And (E) forming two copper foil laminated plates by removing the protective layer and the adhesive layer formed on one surface of the first copper foil layer; And a protective layer formed on one surface of the first copper foil layer and the second copper foil layer in the step (B) so as not to be in contact with an insulating layer. The method according to claim 1, wherein the protective layer is a metal layer. The method of manufacturing a copper foil laminated plate for a VOP according to claim 1, wherein the first copper foil layer and the second copper foil layer have a thickness of 5 µm or less. delete The method of manufacturing a copper clad laminate for VOP according to claim 1, wherein a part of the second copper foil layer is removed by an etching process in the step (C). According to claim 1, After the step (E), (F) forming a plating layer on the copper clad laminate; Method for producing a copper clad laminate for VOP further comprising a. According to claim 1, After the step (E), (G) filling the inside of the via hole with a conductive paste; Method for producing a copper clad laminate for VOP further comprising a.

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