JP2003142803A - Manufacturing method for metal transfer plate and manufacturing method for multi-layered printed wiring board using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a multi-layered printed wiring board which solves the problem that a copper wiring pattern is given large damage in a final soft etching process and inter-line insulation reliability is low since a base copper layer between copper wiring pattern which becomes unnecessary can not be completely removed. SOLUTION: A manufacturing method for a multi-layered printed wiring board is characterized in that a pattern forming process of forming the copper wiring patterns, etc., by a transfer process of plating which forms a plating film in a recessed pattern of a transfer plate which is covered with an insulating layer except the recessed pattern, a sticking process for an insulating substrate as a 2nd layer, a 2nd transfer process, and a via-hole forming process are repeated as many times as needed.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method for manufacturing a multilayer printed wiring board on an insulating substrate by a transfer method.

[0002]

2. Description of the Related Art In recent years, the development of the electronics field has been remarkable, and with the miniaturization, high-density packaging and high performance (high speed) of electronic equipment, the wiring board itself has become higher in density, that is, the conductor pattern has become finer. Higher reliability is required.

A subtractive method is generally used to form a copper wiring pattern on an insulating substrate. However, when the copper wiring pattern becomes finer, the subtractive method cannot be applied.

A semi-additive method is used as an effective means for forming a fine copper wiring pattern. First, a thin base copper layer for conducting electroplating is formed on an insulating substrate, and then a photoresist mask pattern for plating is formed on the surface of the base copper layer. Next, a copper plating film is formed on the exposed portion of the mask pattern by electrolytic plating,
Peel off the mask pattern. Finally, a copper wiring pattern is formed by removing unnecessary portions of the underlying copper layer by soft etching. However, when the copper wiring pattern becomes finer, the copper wiring pattern becomes even thinner in the soft etching step for removing the last underlying copper layer, so that disconnection or peeling may occur. In addition, if the width between the copper wiring patterns becomes narrow, it becomes difficult to completely remove the unnecessary underlying copper layer, and there is a problem that the insulation reliability between the copper wiring patterns decreases.

Further, when forming a copper wiring pattern by the semi-additive method, it is necessary to thin the underlying copper layer in order to reduce damage to the copper wiring pattern during soft etching. However, when the base copper layer becomes thin, the thickness of the base copper layer varies, and at the same time, the resistance increases, which also causes a problem of large variation in the copper wiring pattern.

As another method, a fine copper wiring pattern can be formed in a step including an electroless plating method. First, a catalyst for electroless copper plating is applied to the roughened polyimide surface and then a mask pattern for plating is formed, and then a copper plating film is formed on the exposed portion of the mask pattern by electroless plating. Alternatively, first, electroless plating is used to form a coating film of 1 to 5 microns on the exposed portion of the mask pattern, and then electrolytic plating is performed to form a copper plating film. Finally, the plating mask pattern can be peeled off to form a copper wiring pattern. However, the most problematic problem with this method is the catalyst remaining on the polyimide surface between the copper wiring patterns. A Pd-Sn colloid is a catalyst that is currently used most often. However, the corrosion resistance of palladium is so strong that it is difficult to remove the palladium adhering to the polyimide surface by the usual etching process, and the residual palladium eventually deteriorates the insulation between the copper wiring patterns.

[0007]

The problem to be solved by the present invention is that it is difficult to form a fine copper wiring pattern by the subtractive method and that a fine copper wiring pattern can be formed by the semi-additive method. However, in the final soft etching step, the copper wiring pattern was strongly damaged, and the unnecessary underlying copper layer between the copper wiring patterns could not be completely removed, resulting in low reliability of line insulation. By solving these problems, it is possible to provide a multilayer printed wiring board having a fine copper wiring pattern with high insulation reliability.

[0008]

According to a first aspect of the present invention, a concave pattern resist forming step of forming a photoresist mask pattern on a metal plate and a concave pattern for forming a copper wiring pattern on the surface of the metal plate by etching are provided. Forming a concave pattern, forming a concave pattern resist for peeling a photoresist mask pattern, forming an insulating layer on the surface of a metal plate, forming an insulating layer on the surface of the metal plate, forming an insulating layer on the surface of the concave pattern Insulating layer resist forming step for forming a photoresist mask pattern for removing the insulating layer, insulating layer removing step for removing the insulating layer on the concave pattern surface of the metal plate by etching, and insulating for removing the photoresist mask pattern The copper wiring pattern and the via land plating are formed on the surface of the metal plate by the layer resist stripping process. There is provided a method for producing a metal transfer plate and forming a use intaglio pattern.

According to a second aspect of the present invention, in a method for manufacturing a multilayer printed wiring board in which a copper wiring pattern and via lands are formed on an insulating substrate by a transfer method, a concave pattern of a transfer plate in which a portion other than the concave pattern is covered with an insulating layer. Forming a required copper wiring pattern and via land, which include a plating step of forming a plating film inside, a roughening step of roughening the exposed surface of the plating film, and a transfer step of transferring onto the insulating substrate. A pattern forming step; a step of attaching a second-layer insulating substrate to the insulating substrate on which the copper wiring pattern and the via land are formed by an adhesive agent;
A second transfer step of forming a copper wiring pattern and a via land on the insulating substrate of the second layer by the transfer method, a via forming step of forming a hole for forming a via with a laser, and a photoresist mask pattern for via plating A method for manufacturing a multilayer printed wiring board, which comprises repeating a required number of times, a resist forming step of forming a via, a via forming step of forming a via by plating, and a resist removing step of removing a via plating photoresist mask pattern. It is provided.

According to a third aspect of the present invention, in a method for manufacturing a multilayer printed wiring board in which a copper wiring pattern and via lands are formed on an insulating substrate by a transfer method, a concave pattern of a transfer plate in which a portion other than the concave pattern is covered with an insulating layer. Forming a required copper wiring pattern and via land, which include a plating step of forming a plating film inside, a roughening step of roughening the exposed surface of the plating film, and a transfer step of transferring onto the insulating substrate. A pattern forming step; a step of adhering a second insulating substrate having a hole directly above the via land on the insulating substrate having the copper wiring pattern and the via land formed thereon with an adhesive; and the second layer. A second transfer step of forming a copper wiring pattern and a via land having a hole at the center on the insulating substrate by the transfer method, and a photoresist mask pattern for via plating. A resist formation step of forming a down,
Provided is a method for manufacturing a multilayer printed wiring board, which comprises repeating a via formation step of forming a via by plating and a resist stripping step of stripping a via plating photoresist mask pattern a required number of times.

A fourth aspect of the present invention provides a method for manufacturing a printed wiring board, wherein the insulating substrate is selected from polyimide and liquid crystal polymer.

According to a fifth aspect, the insulating layer is Si.
The method for producing a multilayer printed wiring board according to claim 2, wherein the method is selected from O ₂ and Al ₂ O ₃ .

As a sixth aspect, the insulating layer has a thickness of 0.
The present invention provides a method for manufacturing a multilayer printed wiring board, which is 01 or more.

According to a seventh aspect, the exposed surface of the plating film formed in the concave pattern on the metal surface is roughened by the plating method, and the surface roughness Rz is 1 μm or more. The present invention provides a method for manufacturing a multilayer printed wiring board.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention will be described in detail below with reference to FIGS. In addition, when forming a concave pattern for forming a copper wiring pattern and a via land (FIG. 1), and when forming a concave pattern for forming a copper wiring pattern and a via land having a hole in the center (FIG. 2) Will also be described.

In the present invention, first, a photoresist mask pattern for forming a concave pattern for forming a copper wiring pattern and a via land is formed on a surface of a stainless steel plate which is a metal plate by etching (FIG. 1 (1)). , FIG. 2 (1)). The metal plate is made of stainless steel because of its ease of transfer and price, but other metal materials may be used.

Next, using FeCl ₃ as an etching solution, a concave pattern is formed on the surface of the stainless steel plate by etching, and then the photoresist pattern is removed with a removing solution (FIGS. 1 (2) and 2 (2)). ). The etching liquid can be appropriately selected according to the metal material. Further, the photoresist can be appropriately selected according to the metal material, the etching condition can be appropriately selected according to the photoresist and the metal material, and the stripping solution or the stripping condition can be appropriately selected depending on the photoresist and the metal material. Is. The depth of the concave pattern is 0.1 to 100 μm, preferably 15 μm.
The width of the concave pattern is 0.1 to 50 μm.

FIG. 1B shows a concave pattern for forming a copper wiring pattern and a via land. Figure 2
Shown in (2) are a copper wiring pattern and a concave pattern for forming a via land having a hole in the center.

Next, an insulating layer is formed on the surface of the stainless plate having the concave pattern formed by the sputtering method ((FIG. 1 (3), FIG. 2 (3))). The thickness of the insulating layer is 0.01 to
5 μm, preferably 1 μm. If the thickness is 0.01 μm or less, it is difficult to form a layer.

For the insulating layer, SiO ₂ , Al ₂ O ₃ or the like can be used. The role of this insulating layer is to prevent the plating film from being formed on the portion other than the concave pattern at the time of plating performed later. Other than SiO ₂ and Al ₂ O _3, other materials can be used as long as they do not form a plating film on a portion other than the concave pattern in the subsequent plating.

Next, a resist mask pattern for removing the insulating layer in the concave pattern on the surface of the stainless steel plate is formed by etching (FIGS. 1 (4) and 2 (4)).

Next, the insulating layer in the concave pattern on the surface of the stainless steel plate is removed by etching, and then the photoresist pattern is peeled off with a peeling liquid to produce a copper wiring pattern and a stainless steel transfer plate for transferring via land. This can be done (FIG. 1 (5), FIG. 2 (5)). The etching liquid can be appropriately selected according to the metal material. Also,
The photoresist can also be appropriately selected according to the metal material, the etching condition can be appropriately selected according to the photoresist and the metal material, and the stripping solution or the stripping condition can also be appropriately selected depending on the photoresist and the metal material. .

FIG. 1 (5) shows a stainless transfer plate (first type transfer plate) for transferring the copper wiring pattern and the via land. FIG. 2 (5) shows a stainless transfer plate (second type transfer plate) for transferring a copper wiring pattern and a via land having a hole in the center thereof.

Next, electrolytic copper plating is performed using the first type transfer plate. At this time, since the portion other than the concave pattern is covered with the insulating layer, the plating film can be formed only in the concave pattern. The plating film is over-formed with a height of 1 to 10 μm (FIG. 3 (1)). 5 μm is preferable. The purpose is to improve the adhesion between the plating film and the insulating substrate in the subsequent transfer process.

Next, the over portion of the copper plating film in the concave pattern is roughened (FIG. 3 (2)). The surface roughness Rz is 1 μm or more. If it is less than 1 μm, there is a problem that the adhesive force with the insulating substrate is weak.

As the chemical liquid for roughening in the present invention, CPE-900 manufactured by Mitsubishi Gas Chemical Co., Inc. and Tech SO-G manufactured by Asahi Denka Kogyo Co., Ltd. are preferable, but not limited thereto.

Next, the copper plating film in the concave pattern is transferred onto the insulating substrate to form the first-layer copper wiring pattern and via land on the first-layer insulating substrate (see FIG. 3 ( 3)). Further, since the copper-plated coating portion in contact with the insulating substrate is roughened, the adhesive force with the insulating substrate is enhanced and the peel strength can be improved.

Other materials may be used as the insulating substrate in the present invention, but polyimide, liquid crystal polymer and the like are preferable.

Next, the surfaces of the first-layer copper wiring pattern and via land are roughened if necessary, and then the second-layer is formed on the first-layer insulating substrate on which the first-layer copper wiring pattern and via land are formed. The insulating substrate of is attached with an adhesive (Fig. 3
(4)). The roughening process is the same as 0025 and 0026. The adhesive can be appropriately selected in consideration of the adhesiveness between the insulating substrates and the insulating substrate and copper.

In the same manner as in 0024 to 0027, 2
A second-layer copper wiring pattern and via land can be formed on the second-layer insulating substrate (FIG. 3 (5)).

Next, a laser is used to penetrate the second-layer via land and the insulating layer immediately thereunder to form a hole for forming a via (FIG. 4 (6)). As the laser, lasers of various wavelengths and outputs can be used as long as they can form holes for forming vias.

Next, a photoresist mask pattern for via plating is formed (FIG. 4 (7)). The purpose is to prevent the plating film from being formed on other copper wiring patterns during the subsequent via plating. Therefore, this mask pattern has only holes in the second-layer via land. Also, the photoresist can be appropriately selected according to the insulating substrate, and the exposure and development conditions can be appropriately selected according to the photoresist.

Next, vias are formed by copper plating, and the copper wiring patterns of the first and second layers can be connected through the vias (FIG. 4 (8)).

Finally, the photoresist mask pattern for via plating is stripped with a stripping solution to form a two-layer printed wiring board (FIG. 4).
(9)). Also, the stripping solution can be appropriately selected according to the photoresist and the insulating substrate, and the stripping condition can also be appropriately selected according to the photoresist.

By repeating this process, a multilayer printed wiring board can be formed.

A multilayer printed wiring board can also be formed by the following steps.

First, 1 by the method of 0024 to 0027.
The copper wiring pattern and via land of the first layer can be formed on the insulating substrate of the first layer (FIG. 3 (3)).

Next, after roughening the surfaces of the first-layer copper wiring pattern and via land, the second-layer insulating substrate is placed on the first-layer insulating substrate on which the first-layer copper wiring pattern and via land are formed. Stick with adhesive. This second-layer insulating substrate is pre-patterned and has holes for forming vias (FIG. 5 (1)).

Next, using a second type stainless steel transfer plate,
The second layer copper wiring pattern and via land can be formed on the second layer insulating substrate by the method of 0024 to 0027 (FIG. 5 (2)).

Next, a multilayer printed wiring board can be formed by the method of 0032 to 0035.

In this method, since the pattern for via plating is previously formed in the center portion of the formed second insulating substrate and via land, there is a feature that it is possible to omit the laser drilling and the subsequent processing steps.

[0042]

Example 1 First, a photoresist mask pattern 2 (photoresist Tokyo Ohka Kabushiki Kaisha) for forming a concave pattern for forming a copper wiring pattern and a via land on a surface of a stainless steel plate 1 having a thickness of 1 mm by etching Co., Ltd .: product name PMER P-6000) was formed (see FIG. 1 (1) and FIG. 2 (1)).

Next, using FeCl ₃ , etching was performed on the surface of the stainless steel plate to form a concave pattern 3 having a depth of 15 μm.
After forming 4 and 5, a stripping solution (manufactured by Tokyo Ohka Co., Ltd .:
The photoresist pattern was stripped with the product name PMER stripping solution PS (see FIGS. 1 (2) and 2 (2)). 3, 4,
Reference numeral 5 is a copper wiring pattern, and a concave pattern for forming a via land and a via land having a hole at its center.

Next, the stainless steel plate 1 is formed by the sputtering method.
A SiO ₂ insulating layer 6 having a thickness of 1 μm was formed on the surface of the (see FIG. 1 (3) and FIG. 2 (3)).

Next, in order to remove the SiO ₂ insulating layer in the concave pattern on the surface of the stainless plate 1, a photoresist pattern 7 (manufactured by Photoresist Tokyo Ohka Co., Ltd .: product name PMER P) is formed on the SiO ₂ insulating layer. -6000) was formed (see FIGS. 1 (4) and 2 (4)).

Next, the SiO ₂ insulating layer in the concave pattern on the surface of the stainless steel plate was removed by etching with hydrofluoric acid, and then a stripping solution (manufactured by Tokyo Ohka Co., Ltd .: product name PM
The first type transfer plate 8 (see FIG. 1 (5)) and the second type transfer plate 9 (see FIG. 2 (5)) can be produced by removing the photoresist pattern with the ER stripping solution PS). .

(Embodiment 2) The height of 2 μm is formed in the concave pattern by electrolytic copper plating using the first type transfer plate.
To form copper wiring patterns 10 and 11 (see FIG. 3A).

Next, CPE-9 manufactured by Mitsubishi Gas Chemical Co., Inc.
The exposed surfaces of the plated coatings 10 and 11 were roughened with 00 (see FIG. 3 (2)). The surface roughness Rz was 1 μm or more.

Next, the plating film having the roughened exposed surface is transferred onto the polyimide substrate 13 to form the first-layer copper wiring pattern and the via land 12 on the first-layer polyimide substrate 13 ( See FIG. 3 (3).

Next, CPE-9 manufactured by Mitsubishi Gas Chemical Co., Inc.
The surface of the copper wiring pattern and the via land is roughened with 00 (surface roughness Rz is 1 μm or more), and then the second layer of polyimide is formed on the first layer of polyimide substrate on which the first layer of copper wiring pattern and via land is formed. Substrate 14 adhesive 14 '(epoxy adhesive: manufactured by Hitachi Chemical Co., Ltd .: product name AS2700
It was attached via a thickness of 25 μm (see FIG. 3 (4)).

Next, the second layer copper wiring pattern and the via land 15 were formed on the surface of the second layer polyimide substrate 14 by the method of 0047 to 0049 (see FIG. 3 (5)).

Next, a hole 1 for forming a via with a laser
6 was formed (see FIG. 4 (6)).

Next, a photoresist mask pattern 17 for via plating (manufactured by Photoresist Tokyo Ohka Co., Ltd .:
Product name PMER P-6000) was formed (Fig. 4
(See (7)).

Next, the via 18 is plated with copper to a thickness of 25 μm.
Formed (see FIG. 4 (8)).

Finally, the photoresist mask pattern 17 for via plating was stripped with a stripping solution (manufactured by Tokyo Ohka Co., Ltd .: product name PMER stripping solution PS) to form a two-layer printed wiring board (FIG. 4). (See (9)).

By repeating this process, a multilayer printed wiring board can be formed.

(Example 3) The steps 0047 to 0049 are the same as those in Example 1.

Next, a laser was previously placed at the position of the via (Example 2).
(The same as the laser in Example 2), the second-layer polyimide substrate in which the hole 20 is formed is bonded via an adhesive (the same as the adhesive in Example 2).
It was attached to the first-layer polyimide substrate on which the first-layer copper wiring pattern and via land were formed (see FIG. 5 (1)).

Next, using the second type transfer plate, the above-mentioned 0047
~ 0049 can form the second layer copper wiring pattern and via land on the second layer insulating substrate (Fig. 5).
(See (2)). At that time, since the hole 21 is formed in the center of the via land, it is not necessary to make a hole with a laser.

Next, in steps 0053 to 0056, a multilayer printed wiring board can be formed.

[0061]

According to the present invention, since the copper wiring pattern is first formed in the concave pattern on the surface of the metal transfer plate and then transferred to the polyimide substrate, there is little variation in height.
Further, it is possible to form a multilayer printed circuit board having a fine copper wiring pattern having excellent insulation between lines.

[Brief description of drawings]

FIG. 1 is a cross-sectional view showing a manufacturing process of a stainless steel transfer plate of the present invention.

FIG. 2 is a cross-sectional view showing another manufacturing process of the stainless steel transfer plate of the present invention, which is different from FIG.

FIG. 3 is a cross-sectional view showing a manufacturing process of a multilayer printed wiring board according to the present invention.

FIG. 4 is a cross-sectional view showing a continuation of the manufacturing process of the multilayer printed wiring board according to the present invention.

FIG. 5 is a cross-sectional view showing the manufacturing process of the multilayer printed wiring board of the present invention which is different from FIGS. 4 and 5;

[Explanation of symbols]

1 stainless steel plate 2 resist mask pattern 3 for forming a concave pattern on the surface of stainless steel 3 concave pattern for forming a copper wiring pattern 4 concave pattern for forming a via land 5 for forming a via land having a hole in the center Recessed pattern 6 Insulating layer 7 Resist mask pattern for removing the insulating layer in the recessed pattern 8 First type transfer plate 9 Second type transfer plate (having a hole in the center of via land) 10 Plating film (copper wiring pattern) 11 plated film (via land) 12 first layer copper wiring pattern and via land 13 first layer insulating substrate 14 second layer insulating substrate 14 'adhesive 15 second layer copper wiring pattern and via land 16 via formed by laser Hole for plating 17 Resist mask pattern for via plating 18 Via 19 Two-layer printed wiring 20 second layer of the hole pattern formed on the polyimide substrate 21 holes for the via plating

Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) H05K 3/46 H05K 3/46 XY F term (reference) 5E343 AA02 AA12 BB02 BB15 BB24 BB66 CC62 DD56 DD63 ER52 FF08 GG08 GG14 5E346 AA02 AA15 AA16 AA22 AA32 AA35 AA43 BB01 CC10 CC32 CC54 DD02 DD33 EE02 EE06 EE12 EE18 EE19 EE31 EE38 FF04 GG17 GG27 GG28 HH08 HH26

Claims (7)

[Claims] 1. A resist pattern forming step for forming a photoresist mask pattern on a metal plate; a concave pattern forming step for forming a concave pattern for forming a copper wiring pattern on a surface of a metal plate by etching; Recessed pattern resist removing step for removing the resist mask pattern, insulating layer forming step for forming an insulating layer on the surface of the metal plate, and photoresist mask pattern for removing the insulating layer on the concave pattern surface of the metal plate An insulating layer resist forming step of forming, an insulating layer removing step of removing the insulating layer on the concave pattern surface of the surface of the metal plate by etching, and an insulating layer resist removing step of removing the photoresist mask pattern, To form a copper wiring pattern and a concave pattern for via land plating on the surface of a metal plate. Method for producing a metal transfer plate to symptoms. 2. A method for manufacturing a multilayer printed wiring board, wherein a copper wiring pattern and via lands are formed on an insulating substrate by a transfer method, wherein a portion other than the concave pattern is covered with an insulating layer in a concave pattern of the transfer board. A pattern forming step of forming a required copper wiring pattern and a via land constituted by a plating step of forming a plating film, a roughening step of roughening an exposed surface of the plating film, and a transfer step of transferring onto an insulating substrate. And a step of sticking a second-layer insulating substrate on the insulating substrate having the copper wiring pattern and the via land formed thereon with an adhesive, and copper wiring on the second-layer insulating substrate by the transfer method. A second transfer step of forming a pattern and a via land, a via forming step of forming a hole for forming a via with a laser, and a photoresist mask pattern for via plating are formed. A resist formation step of forming a via forming step of forming the via by plating, a method for manufacturing a multilayer printed wiring board a resist stripping step of stripping the photoresist mask pattern for via plating, and repeating predetermined number of times. 3. A method for manufacturing a multi-layer printed wiring board in which a copper wiring pattern and via lands are formed on an insulating substrate by a transfer method, wherein a portion other than the concave pattern is formed in a concave pattern of the transfer plate covered with an insulating layer. A pattern forming step of forming a required copper wiring pattern and a via land constituted by a plating step of forming a plating film, a roughening step of roughening an exposed surface of the plating film, and a transfer step of transferring onto an insulating substrate. And a step of adhering a second-layer insulating substrate having a hole directly above the via-land on the insulating substrate on which the copper wiring pattern and the via land are formed with an adhesive, and the second-layer insulating substrate. Forming a via land having a copper wiring pattern and a hole in the center by the transfer method
The transfer step, the resist forming step of forming a photoresist mask pattern for via plating, the via forming step of forming a via by plating, and the resist removing step of removing the via plating photoresist mask pattern are repeated a required number of times. A method for manufacturing a multilayer printed wiring board, comprising: 4. The method for manufacturing a multilayer printed wiring board according to claim 2, wherein the insulating substrate is selected from polyimide and liquid crystal polymer. 5. The method for manufacturing a multilayer printed wiring board according to claim ₂ , wherein the insulating layer is selected from SiO ₂ and Al ₂ O ₃ . 6. The method for manufacturing a multilayer printed wiring board according to claim 2, wherein the insulating layer has a thickness of 0.01 or more. 7. A roughening treatment is applied to an exposed surface of a plating film formed in a concave pattern on a metal surface by the plating method,
The method for producing a multilayer printed wiring board according to claim 2, wherein the surface roughness Rz is 1 μm or more.