KR100677938B1 - Manufacturing mehtod of double-sides wiring board and double-sides wiring board - Google Patents

Abstract

Disclosed are a method of manufacturing a double-sided wiring board and a double-sided wiring board, which can form differently different plating layers formed on both sides of a polyimide substrate, and at the same time, form plating layers with different thicknesses. The double-sided wiring board manufacturing method and the double-sided wiring board is improved in performance because the plating layer formed on both sides of the polyimide substrate to form different characteristics and thickness to suit the purpose.

Description

MANUFACTURING METHOD AND DOUBLE-SIDES WIRING BOARD {MANUFACTURING MEHTOD OF DOUBLE-SIDES WIRING BOARD}

1 is a view showing a manufacturing method of a conventional double-sided wiring board.

2 is a view showing a method of manufacturing a double-sided wiring board according to an embodiment of the present invention.

3 is a view showing a method of forming a plating layer on both sides according to an embodiment of the present invention.

4 is a diagram showing current density according to a distance difference between a cathode and an anode shown in FIG. 3;

Explanation of symbols on the main parts of the drawings

110 polyimide substrate 121,125 seed layer

130: via hole 140: first plating layer

151,155: second plating layer

The present invention relates to a method for manufacturing a double-sided wiring board and a double-sided wiring board that can form different thicknesses of the plating layer formed on both sides of the polyimide substrate and at the same time different thicknesses.

BACKGROUND Recently, electronic devices are becoming smaller, lighter, and thinner, and thus, high integration of components used in electronic devices is required. To cope with this, a tape carrier package using a polyimide in the form of a tape, which is an insulator capable of implementing a fine pitch, may be a tape carrier package (hereinafter referred to as "TCP").

In recent years, along with the miniaturization of packages, high frequency of ICs installed in packages is accelerating, and accordingly, high speed of peripheral components including semiconductors is also required. Due to these demands, a double-sided wiring board having double-sided wiring that can improve wiring density and high frequency characteristics is generally used.

A conventional method of manufacturing a double-sided wiring board is disclosed in Japanese Patent Laid-Open No. 2003-77958, which will be described with reference to FIG.

As shown in Fig. 1A, metal layers 13a and 13b such as Ni-Cr alloy are formed on both surfaces of the polyimide tape 11 by sputtering, and plating is performed on both sides of the metal layers 13a and 13b. Copper plating layers 15a and 15b are formed. As shown in FIG. 1B, the resist films 17a and 17a are laminated on both surfaces of the copper plating layers 15a and 15a, and the upper surface resist is formed using a mask (not shown) in which a via hole pattern is formed. The film 17a is exposed and developed, and the via plating pattern 15a on the upper surface and the metal layer 13a on the upper surface are etched to form a via hole pattern 19. Subsequently, as shown in FIG. 1C, the double-sided resist films 17a and 17b are removed, and as shown in FIG. 1D, the polyimide exposed by the via hole pattern 19. The tape 11 is removed to form a blind beehole 21.

Next, as shown in FIG. 1E, a copper plating layer 23 is formed on the inner surface of the blind via hole 21 by direct plating to electrically connect both copper plating layers 15a and 15b. Then, as shown in FIG. 1 (f), the resists 25a and 25b are laminated on both surfaces, and as shown in FIG. 1 (g), the resist 25a, using a mask having a wiring pattern formed thereon. After exposing and developing 25b), the copper plating layers 15a and 15b and the metal layers 13a and 13b are etched to produce a double-sided wiring tape carrier.

Both surfaces of copper plating layers 15a and 15b have suitable characteristics according to their intended use, and have an appropriate thickness according to their intended use, thereby improving the performance of the double-sided wiring board.

However, the conventional manufacturing method as described above is formed by simultaneously plating both surfaces of the copper plating layers 15a and 15b, so that the characteristics and thicknesses of the copper plating layers 15a and 15b of both surfaces are the same. As a result, the performance of the double-sided wiring board is deteriorated.

The present invention has been made in order to solve the problems of the prior art as described above, the object of the present invention is to form a coating layer formed on both sides of the polyimide substrate having different characteristics and different thicknesses to suit the intended use at the same time different thickness The present invention provides a method for manufacturing a double-sided wiring board and a double-sided wiring board.

It is also an object of the present invention to provide a double-sided wiring board that can improve the performance.

Method for manufacturing a double-sided wiring board according to the present invention for achieving the above object comprises the steps of forming a seed layer (Seed Layer) on both sides of the tape-type polyimide (Polyimide) substrate; Forming a via hole by processing only one of the seed layer and the polyimide substrate among the seed layers formed on both sides of the polyimide substrate; Forming a first plating layer on a surface of the seed layer different from the surface of the polyimide substrate constituting the via hole to electrically connect any one of the seed layers and the other seed layer; Forming a second plating layer on any one of the seed layers by an electroplating method for passing a first plating solution into a first plating bath; Forming a second plating layer on the other seed layer by an electroplating method through which a second plating solution is stored into the second plating bath; A process of forming a wiring pattern is performed by processing from the second plating layer to the seed layer so that the polyimide substrate is exposed.

In addition, a double-sided wiring board for achieving the above object is a polyimide (Polyimide) substrate in the form of a tape; Seed layers formed on both sides of the polyimide substrate; A first plating layer formed on any one of the seed layers and the polyimide substrate to electrically connect the seed layers to each other; Second plating layers each formed on the seed layer at different thicknesses from each other; And a wiring pattern formed from the second plating layer to the seed layer in a form in which the polyimide substrate is exposed.

Hereinafter, a method of manufacturing a double-sided wiring board and a double-sided wiring board according to an exemplary embodiment of the present invention will be described in detail with reference to the accompanying drawings.

2 is a view showing a method of manufacturing a double-sided wiring board according to an embodiment of the present invention.

As illustrated, in step S10, seed layers 121 and 125 are formed on both sides of a polyimide substrate 110 having a tape thickness of 20 to 200 μm, respectively. The seed layers 121 and 125 form any one of Ni, Pd, Cr or Cu or a mixture thereof by electroless plating or sputtering.

In operation S20, only one of the seed layers 121 and the polyimide substrate 110 may be processed to form a via hole 130 among the seed layers 121 and 125 formed on both surfaces of the polyimide substrate 110. do. That is, after processing a part of any one seed layer 121, only the portion of the polyimide substrate 110 positioned immediately below it is processed to form the via hole 130. The via hole 130 is processed by a processing method such as a CO ₂ laser or a YAG laser.

In step S30, the first plating layer 140 is formed of Cu on the via hole 130 by electroless plating to electrically connect one seed layer 121 to another seed layer 125. . In this case, the first plating layer 140 may be formed on both the seed layer 121 and the other seed layer 125 in the plating method.

In steps S40 and S50, the second plating layers 151 and 155 are formed of Cu on the one seed layer 121 and the other seed layer 125 by electroplating. In this case, the second plating layers 151 and 155 may have different characteristics so as to be suitable for the purpose, and are formed to have different thicknesses.

A method of forming the second plating layers 151 and 155 on both sides with different characteristics and different thicknesses will be described with reference to FIGS. 2 and 3. 3 is a view showing a method of forming a plating layer on both sides according to an embodiment of the present invention.

As shown in FIG. 3, since the seed layers 121 and 125 of the polyimide substrate 110 are plated, the polyimide substrate 110 becomes a cathode, and the first plating tank 51 and the second plating tank (to be described later) ( A metal piece 60 provided at 55) and corroded by electrolysis of the plating liquid becomes an anode.

First, in step S40, the first plating solution is put into the first plating bath 51. Then, the metal piece 61 is provided in the first plating bath 51 so that the metal piece 61 faces only one seed layer 121. Then, the polyimide substrate 110 in the form of a tape including the first plating layer 140 is passed through the first plating bath 51. Then, the second plating layer 151 is formed on only one seed layer 121.

The first plating solution may be provided as a plating solution different from the second plating solution to be described later, or a plating solution in which additives are added to the second plating solution.

The additive is a material having properties suitable for the use of the second plating layer 151 to be formed on any one seed layer 121. The additives include, for example, gelatin for improving mechanical properties, HEC (Hydroxyethyl Cellulose), SPS (bis (sodiumsulfopropyl) disulfide), and water-soluble organic sulfur compounds. The additive promotes nucleation rather than growth of the plating layer to make the grain boundary fine. As a result, growth is promoted, and thus the mechanical properties are improved because the structure becomes very fine grain structure instead of the columnar structure. In addition, due to the additive, the plating layer has improved strength and elongation at high temperature. Thus, what is necessary is just to add a suitable additive to plating liquid and to plating according to the characteristic to provide to a plating layer.

In operation S50, the polyimide substrate 110 in the form of a tape including the second plating layer 151 is passed through the second plating bath 55 in which the second plating solution is stored. At this time, the metal piece 63 installed in the second plating bath 55 is provided to face only the other seed layer 125. Then, the second plating layer 155 is formed only on the other seed layer 125.

The thicknesses of the second plating layers 151 and 155 formed in steps S40 and S50 are adjusted by the metal pieces 60.

First, on the premise that all the conditions are the same, the metal pieces facing the seed layers 121 and 125 formed on the polyimide substrate 110 supported by the roller 70 and passing through the first and second plating baths 51 and 55 ( The thickness of the second plating layers 151 and 155 is controlled by adjusting the number of times of the 61 and 63. In detail, the number of times of the presence of the metal piece 61 facing the one seed layer 121 and the number of times of the presence of the metal piece 63 facing the other seed layer 125 are 1, 2, and 3 times. By controlling the number 4,..., The second plating layers 151 and 155 formed in one seed layer 121 and the other seed layer 125 are formed to have a predetermined thickness. That is, when the number of times of presence of the metal pieces 60 facing the seed layers 121 and 125 is increased, the second plating layers 151 and 155 are thickened.

In addition, the thicknesses of the second plating layers 151 and 155 formed on one of the seed layers 121 and the other seed layer 125 may be the opposite areas of the metal pieces 65 and 67 facing the seed layers 121 and 125, respectively. You can also adjust. This is the same as controlling the number of times the metal piece 60 facing the seed layers 121 and 125 described above.

In addition, as shown by the dotted lines in FIG. 3, on the premise that all the conditions are the same, the opposing distance between one seed layer 121 and the metal piece 61 and the other seed layer 125 and the metal piece 63 are different. The thickness of the second plating layers 151 and 155 may be adjusted by adjusting the opposing distances of the second plating layers 151 and 155. That is, when the distance between the seed layers 121 and 125 and the metal pieces 61 and 63 is close to each other, the second plating layers 151 and 155 having a thin thickness are formed, and when the distance between the seed layers 121 and 125 and the metal pieces 61 and 63 is far from each other. Thick thickness second plating layers 151 and 155 are formed. This will be described with reference to FIG. 4.

4 is a diagram illustrating a current density according to a distance difference between a cathode and an anode illustrated in FIG. 3.

As shown in FIG. 4, when the current is applied to the anode and the cathode under the same conditions with the strengths of 1 A (ampere), 2 A, and 3 A, and the current densities are measured, the distance between the anode and the cathode becomes farther. As a result, the current density gradually increased. If the current density is high, the plating solution is electrolytically transmitted. Therefore, the thicker the plating layer is formed the farther away from the anode.

The thickness of the second plating layers 151 and 155 may be formed to a desired thickness by adjusting the type of plating solution, the strength of the current, the valence of the metal, and the like. For example, the plating rate is 97 to 100% when the plating liquid is Acid sulfate, the plating rate is 30 to 95% when Cyanide, and the plating rate is 40 to 90% when Rotchekke-Cyanide. And when the metal piece 60 is Cu and the current density is 1 A / dm <2>, if Cu valence is monovalent, it will be plated at thickness of 0.442 micrometer / min, and if Cu valency is bivalent, it will be 0.221 micrometer / min. Plated. By controlling these various factors, the thicknesses of the second plating layers 151 and 155 may be formed to have different thicknesses.

Of the plating layers formed on both sides of the polyimide substrate, a pattern is formed on one and the other is used for grounding. However, the thinner the plated layer is, the thinner the fine layer (Pine Pitch) of 40㎛ or less can be easily implemented, the thicker the plated layer is used for grounding can reduce the inductance and noise reduction effect.

According to the manufacturing method according to the present embodiment, when the additive having excellent mechanical properties is added to the plating liquid to form the second plating layer 151, the second plating layer 151 may be formed thinner, thus making it easier to implement fine pitch. . In addition, since the second plating layer 155 may be easily formed to a desired thickness by adjusting the number and distance of the metal pieces 63, a satisfactory inductance reduction and noise reduction effect may be achieved.

The above-described steps S40 and S50 may be performed in reverse order.

Next, when the wiring pattern is formed by processing the second plating layer 151 and 155 to the seed layers 121 and 125 so that the polyimide substrate 100 is exposed, the double-sided wiring board 100 is manufactured. In detail, in step S60, the photoresists 161 and 165 may be applied to the second plating layers 151 and 155 having different thicknesses, and the photoresists 161 and 165 may be exposed using a mask (mask) on which a wiring pattern is formed. To be patterned on the photoresists 161 and 165. In operation S70, the polyimide substrate 110 may be etched by etching the portions of the second plating layers 151 and 155 exposed to the outside by the patterning of the photoresists 161 and 165 and the seed layers 121 and 125 positioned directly below them. To the outside. Then, the double-sided wiring board is manufactured.

As described above, the double-sided wiring board manufacturing method and the manufacturing method according to the present invention is improved in performance because the plating layer formed on both sides of the polyimide substrate to form different characteristics and thickness to suit the purpose.

In the above, the present invention has been described in accordance with one embodiment of the present invention, but those skilled in the art to which the present invention pertains have been changed and modified without departing from the spirit of the present invention. Of course.

Claims (8)

Forming a seed layer on both sides of a tape-type polyimide substrate; Forming a via hole by processing only one of the seed layer and the polyimide substrate among the seed layers formed on both sides of the polyimide substrate; Forming a first plating layer on the via hole to electrically connect one of the seed layers with the other one of the seed layers; Forming a second plating layer on any one of the seed layers by an electroplating method for passing a first plating solution into a first plating bath; Forming a second plating layer on the other seed layer by an electroplating method through which a second plating solution is stored into the second plating bath; And And forming a wiring pattern by processing from the second plating layer to the seed layer so that the polyimide substrate is exposed. The method of claim 1, And the first plating liquid and the second plating liquid are different plating liquids. The method of claim 1, And the first plating solution is a plating solution in which an additive is added to the second plating solution. The method of claim 1, The polarity of the metal piece facing the one of the seed layer and the other one of the seed layer formed on the polyimide substrate including the first plating layer and the polyimide substrate passing through the plating bath and installed inside the plating bath has different polarities. Keep it up, The metal piece provided inside the first plating bath is opposed to any one of the seed layers, and the metal piece installed inside the second plating bath is opposite to the other seed layer. . The method of claim 4, wherein The thickness of the second plating layer respectively formed on one and the other of the seed layer is characterized in that the thickness is set by the number of times of the presence of the metal piece facing each other and one of the other seed layer, respectively. Manufacturing method of double sided wiring board. The method of claim 4, wherein The thickness of the second plating layer formed on each of the one and the other seed layer is characterized in that the thickness is set by the opposing area of the metal piece facing each other and the one and the other seed layer, respectively. Manufacturing method of double sided wiring board. The method of claim 4, wherein Each of the second plating layers formed on one of the seed layers and the other of the seed layers may have a thickness set by a distance between any one of the seed layer and the metal piece and a distance between the other seed layer and the metal piece. Method for producing a double-sided wiring board, characterized in that. Polyimide substrates in tape form; Seed layers formed on both sides of the polyimide substrate; A first plating layer formed on any one of the seed layers and the polyimide substrate to electrically connect the seed layers to each other; Second plating layers each formed on the seed layer at different thicknesses from each other; And a wiring pattern formed from the second plating layer to the seed layer in a form in which the polyimide substrate is exposed.

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