JP2002124764A - Manufacturing method for printed wiring board - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for printed wiring board capable of forming an extremely large number of through hole conductor wiring parts at the same time by a simple means, remarkably shortening time required for forming the through hole conductor wiring parts and dealing with the requests of the market of low cost and short time of delivery. SOLUTION: Through holes are simultaneously opened by applying boring pressing at a prescribed position on the prepreg of a B stage at an ordinary temperature while using a metal die, a conductive metal columnar body is formed on one side of conductive metal foil to become a first wiring layer in the other process, a first intermediate setup body is constituted by inserting the conductive metal columnar body formed on the relevant conductive metal foil from one side of the prepreg to the through hole formed at the prescribed position of the prepreg, and conductive metal foil to become second wiring layer is located on the other side of the prepreg of the relevant intermediate setup body, heated and crimped as a whole. Thus, a base material for printed wiring board having the through type conductor wiring part between conductive metal foil is formed.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a printed wiring board, and more particularly to a method for manufacturing a printed wiring board having a structure in which wiring layers are connected by a through-type conductive wiring portion.

[0002]

2. Description of the Related Art Conventionally, in a double-sided printed wiring board or a multilayer printed wiring board, connection between wiring layers provided on both surfaces of an insulating base material is performed by, for example, the following method. First, in the case of a double-sided printed circuit board, a through hole is mechanically drilled at a predetermined position on a double-sided copper-clad base material using a drill, and the entire surface including the inner wall surface of the through hole is subjected to chemical plating and electroplating. To provide copper plating for connection between wiring layers.

In the case of a multilayer printed wiring board,
After patterning a predetermined wiring shape on the copper foil adhered on both sides of the base material, and further laminating and disposing the copper foil on the patterned surface via an insulating base material such as prepreg, this is heated. In the same manner as in the case of the double-sided printed wiring board, a through hole is mechanically formed using a drill at a predetermined position, and the entire surface including the inner wall surface of the through hole is chemically formed. Copper plating is performed by plating and electroplating to connect between wiring layers.

Further, in the case of a high multilayer printed wiring board in which wiring layers are further laminated, a copper foil bonded on both sides of a substrate is patterned with a predetermined wiring shape, and a prepreg is typically formed on the patterned surface. It is manufactured by increasing the number of layers via an insulating base material.

In these conventional methods for manufacturing a printed wiring board, in addition to the case where a through hole is mechanically formed by using a drill at a predetermined position, in recent years, a through hole is formed using a laser. The technology has also been put into practical use, and finer processing has become possible. Regarding the connection between wiring layers, in addition to the method of applying copper plating by chemical plating and electroplating, drilling on prepreg sheets without copper foil stuck And a laser are used to form a through hole, the formed through hole is filled with a conductive paste by a printing method or the like, and the conductive paste filled in the through hole is cured, and then a copper foil is laminated and arranged. There is also a method of integrating by pressing under heating.

[0006]

By the way, in recent years, as electronic devices have become higher in performance and smaller in size, printed wiring boards have been required to have higher densities such as finer wiring patterns and smaller through holes.
Alternatively, at the same time as higher multilayers are required, improvement of productivity such as reduction of manufacturing cost and shortening of manufacturing period is more and more desired.

Here, in the above-mentioned conventional technique, a through hole is mechanically formed by using a drill, or a through hole is formed by using a laser, and the operation is very complicated. At the same time, even in the case of forming a through hole using a laser, there is a limitation on the thickness of a material that can be penetrated, and in any method, the number of through holes per product has been increasing recently. In addition, the equipment for forming the through-holes must be extremely expensive, and the process management becomes complicated, and as a result, these are reflected in the manufacturing cost and yield of the printed wiring board. However, there is a problem that it cannot meet market demands of low cost and short delivery time.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to form a very large number of penetrating conductor wiring portions at the same time by simple means, It is an object of the present invention to provide a method of manufacturing a printed wiring board which can significantly reduce the time required for forming a conductor wiring portion, and which can meet the market demand for low cost and short delivery time.

[0009]

According to the present invention, there is provided a method for manufacturing a printed wiring board, the method comprising:
A step (A) of forming a through hole by performing a punch press process using a mold at a predetermined position of a prepreg of a stage;
A step (B) of forming a conductive metal column on one surface of a conductive metal foil to be a first wiring layer, and a conductive metal to be a first wiring layer formed in the step (B). The first intermediate set-up body is inserted by inserting the conductive metal pillar existing on one surface of the foil from one surface of the prepreg into a through hole existing at a predetermined position of the prepreg drilled in the step (A). A step (C) of forming, and a conductive metal foil to be a second wiring layer is disposed on the other surface of the prepreg of the first intermediate setup body formed in the step (C) and the whole is heated. A substrate for a printed wiring board having a through-type conductive wiring portion between conductive metal foils serving as first and second wiring layers disposed on both surfaces of the prepreg as an insulating layer by pressure bonding (D) forming a printed wiring board.

The method of manufacturing a printed wiring board according to the present invention further comprises a step (A) of forming a through hole by performing a punching press process using a mold at a predetermined position of a prepreg of a B stage. A step (B) of forming a conductive metal column on one surface of a conductive metal foil to be a first wiring layer; and a step of forming a conductive layer to be a first wiring layer formed in the step (B). The first intermediate set-up body is inserted by inserting the conductive metal pillar existing on one surface of the metal foil from one surface of the prepreg into a through hole existing at a predetermined position of the prepreg drilled in the step (A). And a conductive metal foil serving as a second-layer wiring layer is disposed on the other surface of the prepreg of the first intermediate set-up body formed in the step (C), and the whole is formed. Heat-press bonding, the above-mentioned prepreg is provided on both sides as an insulating layer. (D) forming a substrate for a printed wiring board having a penetrating conductive wiring portion between the conductive metal foils to be the first and second wiring layers, and (D) The conductive metal foil to be the first and / or second wiring layer of the formed printed wiring board base material is subjected to patterning, and the first and / or second wiring layer is provided with a wiring layer. A step (E) of forming a printed wiring board having the same, a step (F) of forming a through hole by performing a punching press process using a mold at a predetermined position of another prepreg of the B stage, and
A step (G) of forming a conductive metal column on one surface of a conductive metal foil to be a wiring layer of a first layer or higher, and the step (G)
The conductive metal pillars present on one surface of the conductive metal foil to be the third and higher wiring layers formed in the above step are inserted into the through holes existing at predetermined positions of the prepreg drilled in the step (F). A step (H) of inserting from one surface of the prepreg to form a second and subsequent intermediate set-up bodies, and the step (A)
To (E) as a core substrate, and the second and subsequent intermediate set-up bodies obtained in steps (F) to (H) above on one surface and / or the other surface of the core substrate. And the whole is heat-pressed to form a through-type conductive wiring portion between the first and / or second wiring layers and the conductive metal foil to be the third or higher wiring layer. Forming a substrate for a printed wiring board having the method (I).

Further, a method of manufacturing a printed wiring board according to the present invention is characterized in that, in the above-described invention, a plurality of B-stage prepregs are laminated to have an arbitrary thickness.

[0012]

According to the method of manufacturing a printed wiring board according to the present invention, a punching process is performed at a predetermined position of a prepreg of a B stage by using a mold, and through holes are collectively formed. Forming a conductive metal pillar on one surface of a conductive metal foil to be a first wiring layer in the step, and removing the conductive metal pillar formed on the conductive metal foil from one surface of the prepreg; A conductive metal foil to be a second wiring layer on the other surface of the prepreg of the first intermediate set-up body by inserting it into a through-hole formed at a predetermined position of the prepreg. And forming a substrate for a printed wiring board having a penetrating conductive wiring portion between the conductive metal foils by heat-pressing the whole, and the printed wiring obtained by the above. The first layer of the board base material and / or A conductive metal foil serving as a second wiring layer is patterned to form a printed wiring board having a wiring layer on the first and / or second layers, and the printed wiring board is used as a core substrate. A second and subsequent intermediate set-up bodies having a conductive metal foil to be a third or higher wiring layer obtained by the same process as described above on one or both surfaces of the core substrate, and Printed wiring board having a through-type conductive wiring portion between a first and / or second wiring layer and a conductive metal foil to be a third or higher wiring layer by heat-pressing Is characterized in that the base material is formed, so that a very large number of through-type conductor wiring portions can be simultaneously formed by simple means, and the time required for forming the through-type conductor wiring portions is greatly reduced. Meets market demand for low cost and fast delivery Printed wiring board was obtained.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The embodiments of the present invention described above will be described in detail with reference to the drawings, but the present invention is not limited to the following embodiments. FIG. 1 is a schematic cross-sectional view of a prepreg in which a through-hole is formed by a mold, FIGS. 2 to 10 are schematic views illustrating steps, and FIGS. 11 to 13 are schematic views illustrating steps for forming a conductive metal column. is there.

First, in FIG. 1, a B-stage prepreg 1 composed of a glass woven fabric 3 and an epoxy resin 2 is shown.
Is pressed at room temperature with a mold (not shown),
A through hole 4 having a diameter of about 300 μm is formed at a predetermined position.

At this time, the prepreg used has a thickness of 60 μm, 100 μm, 150 μm, made of a glass woven fabric and an epoxy resin generally used in the industry at present.
A desired thickness may be selected from 80 μm and 200 μm, or two or more prepregs may be laminated and temporarily fixed to form a prepreg having an arbitrary thickness. An example in which a prepreg having a thickness of 100 μm is used will be described.

As the prepreg, it is possible to use a prepreg made of polyimide resin or the like in addition to a prepreg made of glass woven fabric and epoxy resin. It is desirable to use glass woven fabric and epoxy resin, which are the most widely distributed in the industry.

Next, in a separate step, a copper foil 20 is used as a conductive metal foil to be a first wiring layer, and a conductive metal pillar, that is, a copper pillar is provided on one surface of the copper foil 20. 1
3, which will be described with reference to FIGS.

In FIG. 11, first, one surface of a copper foil 20 is covered with an upper mask layer 12 formed of a plating resist material except for a desired position where a copper column 13 is to be formed.

Next, the other surface of the copper foil 20 is entirely covered with a lower surface mask layer 14 also formed of a plating resist material.

Then, when this is plated with copper, copper plating is deposited on a portion not covered by the upper mask layer 12 and the lower mask layer 14, and a copper columnar body 13 is formed as shown in FIG.

Thereafter, the upper mask layer 12 and the lower mask layer 14 are peeled off, so that a copper pillar 13 is formed integrally with the copper foil 20 on one surface of the copper foil 20 as shown in FIG. .

In the present embodiment, the copper columnar body 13 formed by plating deposition has a height of 110 μm to 120 μm.
It has a cylindrical shape with a diameter of about 100 μm and a diameter of about 100 μm.

The means for forming the copper column 13, that is, the conductive metal column, is not limited to the plating method described above, and a conductive metal paste such as a conductive metal paste is formed on one surface of the conductive metal foil. It may be formed by a method in which silver paste is laminated several times by printing, or a method in which a desired portion of a conductive metal plate, for example, a copper plate is covered with an etching resist material, and unnecessary portions are removed by etching.

Then, as shown in FIG. 2, a copper foil 20 is inserted into a through hole 4 formed at a predetermined position of the prepreg 1 of the B stage.
A copper column 13 integrally formed on one surface of the prepreg 1 is inserted from the lower surface of the prepreg 1 to form a first intermediate set-up body 1.
3, and then, as shown in FIG. 3, a copper foil 2 serving as a second wiring layer is formed on the upper surface of the first intermediate setup body 15.
When the first intermediate set-up body 15 and the copper foil 21 are thermocompression-bonded by a vacuum thermocompression press apparatus conventionally used for manufacturing a multilayer printed wiring board, FIG.
As shown in FIG.
Having two wiring layers, that is, a base material 16 for a double-sided printed wiring board.

That is, the copper foil 21 to be the second wiring layer is provided on the upper surface of the first intermediate set-up body 15, and the whole is heat-pressed by a vacuum heat-pressing press under a predetermined condition. Then, the copper pillars 13 are integrated with the copper foil 21 serving as the second wiring layer while being crushed by the applied temperature and pressure, and the epoxy resin 2 is melted to form the copper pillars 13 and the through holes 4. As shown in FIG. 4, a space 16 formed between the inner wall portion and the inner wall portion is buried, and the base material 16 for a double-sided printed wiring board having the copper columnar body 13 as the penetrating conductor wiring portion 40 is obtained.

Next, the copper foil 2 serving as the first wiring layer of the base material 16 for a double-sided printed wiring board obtained by the above-described process is described.
When the copper foil 21 serving as the first and second wiring layers is patterned in a predetermined wiring shape, the first wiring layer 31 and the second wiring layer are formed on both surfaces as shown in FIG. Thus, a double-sided printed wiring board having the wiring layers 31 and 32 connected by the through-type conductor wiring portions 40 is obtained.

The patterning of the predetermined wiring shape is not particularly specified, but for example, exposure and development using a hot resist or a hot mask as conventionally performed in the art. After that, a pattern may be formed by etching using an iron solution, a copper solution, or the like.

Then, in the same manner as when the first intermediate set-up body 15 is formed, a copper columnar body 24 is formed on the copper foil 23 serving as a third or higher wiring layer to form a second column.
The subsequent intermediate set-up body 25 is formed, and as shown in FIG. 6, the double-sided printed wiring board obtained as described above is used as a core substrate 17 on both sides of the core substrate 17 to form a copper columnar body 2.
The second and subsequent intermediate set-up bodies 25 are disposed in such a manner that the front end side of each of the first and second wiring layers comes into contact with the first wiring layer 31 and the second wiring layer 32, respectively. Similarly to 16, when the entire body is thermocompressed by a vacuum thermocompression press under a predetermined condition, the copper columnar body 24 is crushed by the applied temperature and pressure while the first wiring layer 31 and the second Second wiring layer 32
And the epoxy resin 2 is melted and the copper columnar body 24 is melted.
A space 30 formed between the inner wall of the through hole 4 and the through hole 4 is buried, and as shown in FIG. Is obtained.

Next, the copper foil 23 to be the third or higher wiring layer of the four-layer printed wiring board base material 18 obtained by the above process is patterned in a predetermined wiring shape, as shown in FIG. A four-layer printed wiring board in which the first to fourth wiring layers are connected by the through-type conductor wiring portions 40 is obtained.

Then, as shown in FIGS. 9 and 10, the same method is repeated using the four-layer printed wiring board as the second core substrate 26, so that the first to sixth wiring layers are respectively formed as through-type wiring layers. A six-layer printed wiring board connected by the conductor wiring portion 40 is obtained.

Thereafter, if necessary, a column made of copper is formed on a copper foil to be a wiring layer of an arbitrary layer or more to form the second and subsequent intermediate set-up bodies 25, and the number of wiring layers is formed in the same manner. Can be increased.

The first substrate 16 for a double-sided printed wiring board
Only one of the copper foil 20 serving as the second wiring layer and the copper foil 21 serving as the second wiring layer is subjected to patterning in a predetermined wiring shape, and the copper foil 20 is patterned as a core substrate. The second and subsequent intermediate setup bodies 2
When the whole is heated and press-fitted by a vacuum heat-pressing press device under predetermined conditions, a printed wiring board having a three-layer structure can be obtained. Is obtained.

[0033]

As described above, in the method for manufacturing a printed wiring board according to the present invention, a through hole is formed by performing a punch press process using a die at a predetermined position of a prepreg of a B stage. A step (A), a step (B) of forming a conductive metal pillar on one surface of a conductive metal foil to be a first wiring layer, and a first layer formed in the step (B). The conductive metal columnar body present on one surface of the conductive metal foil to be the wiring layer is inserted from one surface of the prepreg into a through hole present at a predetermined position of the prepreg drilled in the step (A). (C) configuring a first intermediate setup body by using
A conductive metal foil to be a second wiring layer is provided on the other surface of the prepreg of the first intermediate set-up body formed in the above step (C), and the whole is heat-pressed to form an insulating layer. Forming a base material for a printed wiring board having a penetrating conductive wiring portion between conductive metal foils serving as first and second wiring layers disposed on both surfaces thereof; By having a feature, it is possible to simultaneously form an extremely large number of through-holes and through-type conductor wiring portions by simple means, greatly reducing the time required for forming the through-holes, and at a low cost. In addition, a highly reliable double-sided printed wiring board can be obtained.

Further, in the method of manufacturing a printed wiring board according to the present invention, a step (A) of forming a through hole by performing a punch press process using a die at a predetermined position of a prepreg of a B stage; A step (B) of forming a conductive metal column on one surface of a conductive metal foil to be a first wiring layer; and a step of forming a conductive layer to be a first wiring layer formed in the step (B). The first intermediate set-up body is inserted by inserting the conductive metal pillar existing on one surface of the metal foil from one surface of the prepreg into a through hole existing at a predetermined position of the prepreg drilled in the step (A). And a conductive metal foil serving as a second-layer wiring layer is disposed on the other surface of the prepreg of the first intermediate set-up body formed in the step (C), and the whole is formed. Heat-press bonding, the above-mentioned prepreg is provided on both sides as an insulating layer. (D) forming a substrate for a printed wiring board having a penetrating conductive wiring portion between the conductive metal foils to be the first and second wiring layers, and (D) The conductive metal foil to be the first and / or second wiring layer of the formed printed wiring board base material is subjected to patterning, and the first and / or second wiring layer is provided with a wiring layer. A step (E) of forming a printed wiring board having the same, a step (F) of forming a through hole by performing a punching press process using a mold at a predetermined position of another prepreg of the B stage, and
A step (G) of forming a conductive metal column on one surface of a conductive metal foil to be a wiring layer of a first layer or higher, and the step (G)
The conductive metal pillars present on one surface of the conductive metal foil to be the third and higher wiring layers formed in the above step are inserted into the through holes existing at predetermined positions of the prepreg drilled in the step (F). A step (H) of inserting from one surface of the prepreg to form a second and subsequent intermediate set-up bodies, and the step (A)
To (E) as a core substrate, and the second and subsequent intermediate set-up bodies obtained in steps (F) to (H) above on one surface and / or the other surface of the core substrate. And the whole is heat-pressed to form a through-type conductive wiring portion between the first and / or second wiring layers and the conductive metal foil to be the third or higher wiring layer. The step (I) of forming a printed wiring board base material having a large number of through-holes and through-type conductive wiring portions can be simultaneously formed by simple means. The time required for forming the holes is greatly reduced, and a low-cost and highly reliable multilayer printed wiring board can be obtained.

Further, the method of manufacturing a printed wiring board according to the present invention is characterized in that a plurality of B-stage prepregs are laminated to have an arbitrary thickness in the above-described invention, so that an extremely large number of The hole and the through-type conductive wiring portion can be formed by simple means, the time required for forming the through hole is greatly reduced, the cost is low, the reliability is high, and both surfaces of arbitrary thickness over a wide range are provided. There is an effect that a printed wiring board and a multilayer printed wiring board can be obtained.

[Brief description of the drawings]

FIG. 1 is a schematic sectional view of a prepreg in which a through hole is formed by a mold.

FIG. 2 is an explanatory schematic diagram of an intermediate setup body.

FIG. 3 is an explanatory schematic diagram illustrating a state where a copper foil is arranged on an upper surface of an intermediate setup body.

FIG. 4 is an explanatory schematic view of a base material for a double-sided printed wiring board.

FIG. 5 is an explanatory schematic diagram of a double-sided printed wiring board (core substrate).

FIG. 6 is an explanatory schematic diagram illustrating a state in which an intermediate setup body is provided on a core substrate.

FIG. 7 is an explanatory schematic view of a base material for a four-layer printed wiring board.

FIG. 8 is an explanatory schematic diagram of a four-layer printed wiring board (second core substrate).

FIG. 9 is a schematic diagram illustrating a state in which an intermediate setup body is provided on a second core substrate.

FIG. 10 is an explanatory schematic view of a base material for a six-layer printed wiring board.

FIG. 11 is a schematic diagram illustrating a state where a copper foil is covered with a mask layer.

FIG. 12 is a schematic diagram illustrating a state where plating is deposited on a portion not covered by a mask layer.

FIG. 13 is an explanatory schematic diagram showing a state where a mask layer is peeled off to form a copper columnar body.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pre-preg 2 Epoxy resin 3 Glass woven cloth 4 Through-hole 12 Upper surface mask layer 13 Copper pillar 14 Lower surface mask layer 15 First intermediate setup body 16 Substrate for double-sided printed wiring board 17 Core substrate 18 Base for 4-layer printed wiring board Material 21 Copper foil 22 Copper foil 23 Copper foil 24 Copper pillar 25 Second intermediate setup body 26 Second core substrate 30 Space 31 First wiring layer 32 Second wiring layer 40 Penetrating type Conductor wiring

Claims (3)

[Claims] 1. A step (A) of forming a through hole by performing a punch press process using a mold at a predetermined position of a prepreg of a B stage, and a conductive metal foil to be a first wiring layer. (B) forming a conductive metal column on one surface of the conductive metal foil, and a conductive metal present on one surface of the conductive metal foil to be the first wiring layer formed in the step (B). A step (C) of inserting a columnar body from one surface of the prepreg into a through hole existing at a predetermined position of the prepreg drilled in the step (A) to constitute a first intermediate set-up body; On the other surface of the prepreg of the first intermediate set-up body constituted in C), a conductive metal foil to be a second wiring layer is provided and the whole is heat-pressed, and the prepreg is used as an insulating layer to form an insulating layer on both surfaces thereof. Conductive gold to be the first and second wiring layers disposed on the substrate Method for manufacturing a printed wiring board, characterized in that a step (D) to form a printed wiring board substrate having a conductor wiring portion of the feedthrough between the foil. 2. A step (A) of forming a through hole by performing a punch press process using a mold at a predetermined position of a prepreg of a B stage, and a conductive metal foil to be a first wiring layer. (B) forming a conductive metal column on one surface of the conductive metal foil, and a conductive metal present on one surface of the conductive metal foil to be the first wiring layer formed in the step (B). A step (C) of inserting a columnar body from one surface of the prepreg into a through hole existing at a predetermined position of the prepreg drilled in the step (A) to constitute a first intermediate set-up body; On the other surface of the prepreg of the first intermediate set-up body constituted in C), a conductive metal foil to be a second wiring layer is provided and the whole is heat-pressed, and the prepreg is used as an insulating layer to form an insulating layer on both surfaces thereof. Conductive gold to be the first and second wiring layers disposed on the substrate And step (D) to form a printed wiring board substrate having a conductor wiring portion of the feedthrough between the foil, the first printed circuit board base material formed in the above step (D)
(E) forming a printed wiring board having a wiring layer on the first and / or second layer by patterning the conductive metal foil serving as the first and / or second wiring layer.
Step (F) of forming a through hole by performing a punch press process using a mold at a predetermined position of another prepreg of the B stage.
A step (G) of forming a conductive metal pillar on one surface of a conductive metal foil to be a third or higher wiring layer; and a third or higher wiring formed in the step (G). The conductive metal pillar present on one surface of the conductive metal foil to be a layer is inserted from one surface of the prepreg into a through hole existing at a predetermined position of the prepreg drilled in the step (F). 2
A step (H) of forming a subsequent intermediate set-up body, and a printed wiring board obtained in the above steps (A) to (E) as a core substrate, and the above-described one surface and / or the other surface of the core substrate The second and subsequent intermediate set-up bodies obtained in steps (F) to (H) are provided, and the whole is heat-pressed to form a first and / or second wiring layer and a third layer. Step (I) of forming a substrate for a printed wiring board having a penetrating conductive wiring portion between conductive metal foils serving as wiring layers as described above
And a method of manufacturing a printed wiring board. 3. The method for manufacturing a printed wiring board according to claim 1, wherein the prepreg of the B stage has an arbitrary thickness by laminating a plurality of prepregs.