JPH05136573A - Manufacture of multilayer printed wiring board - Google Patents

Abstract

PURPOSE:To provide a method of manufacturing a multilayer printed wiring board whose insulating base material is formed of thermoplastic resin is provided with a conductive paste wiring pattern that contains through-hole connections, where through-hole connections can be easily enhanced in reliability. CONSTITUTION:A process is provided, where a breathing type support 2 is provided onto the surface of a vacuum suction type stage 1, if necessary, and a thermoplastic resin film 4 used for the formation of a required wiring pattern which contains through-hole connections is disposed on a thermoplastic resin film 3 where a through-hole 3a is selectively bored. Furthermore, a process where a required wiring pattern of conductive paste 5 is formed on the surface of the wiring pattern forming thermoplastic resin film 4 sucked by vacuum and another process where a thermoplastic resin film 4' on which a wiring pattern is formed is aligned, laminated on the film 3, and formed into one piece through thermocompression are provided.

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 multilayer printed wiring board, and more particularly to a method for manufacturing a multilayer printed wiring board which uses a thermoplastic resin as an insulating base material and has through-hole connection portions.

[0002]

2. Description of the Related Art Conventionally, multi-layer printed wiring boards have been widely used in order to cope with miniaturization and high functionality of electronic equipment and for high density wiring. Further, as one type of multilayer printed wiring board, a multilayer printed wiring board using a thermoplastic resin such as a polycarbonate resin as an insulating base material has been developed, and is manufactured as follows, for example. That is, a predetermined wiring (circuit) is formed on at least one main surface of the thermoplastic resin film by a conductive paste having a thermoplastic resin as a binder.
Deposit the pattern, for example by screen printing,
It is manufactured by stacking a plurality of dried products and then thermocompressing them to integrate them. Further, in this multilayer printed wiring board, the electrical connection between the outer layer wiring patterns on both sides or between the outer layer wiring pattern and the inner layer wiring pattern is made by the following means. That is, a through hole (through hole) is formed at a predetermined position of the multilayer printed wiring board that is heated and pressed, and a land is printed and formed on the peripheral portion of the through hole with a conductive paste. It is necessary to use the plastic deformation of the thermoplastic resin at the stage where the conductive paste is filled in the through holes formed at the predetermined positions of the thermoplastic resin film, laminated, thermocompressed and integrated. Is performed by connecting the layers (Japanese Patent Laid-Open No. 60-137092).

[0003]

However, in the method of manufacturing a multilayer printed wiring board using such a thermoplastic resin as an insulating base material, secondary land formation by a conductive paste for forming a through hole connection is formed. Not only is the work process complicated and complicated, such as filling in and conductive paste,
There is also a problem with the reliability of the through-hole connection. That is, the complexity or complexity of the working process results in an increase in manufacturing cost and causes a reduction in yield, and the filled conductive paste wets only the inner wall surface of the through hole, so that the laminated Even at the stage of heating and pressure integration,
Since the required through-hole connection may not be formed in some cases, it can be said that the multilayer printed wiring board is still problematic in terms of reliability.

The present invention has been made in consideration of the above circumstances, and in a multilayer printed wiring board having a conductive paste type wiring pattern including a through hole connection as a base material of a thermoplastic resin, a through hole connection is performed. An object of the present invention is to provide a method for manufacturing a multilayer printed wiring board that can easily improve reliability.

[0005]

A method of manufacturing a multilayer printed wiring board according to the present invention comprises a step of disposing a ventilation type support on the surface of a vacuum suction type stage, if necessary, and a step of supporting the vacuum suction type stage surface or the support. A step of arranging a thermoplastic resin film for forming a required wiring pattern including a through-hole connecting portion through a thermoplastic resin film in which through holes in the thickness direction are selectively formed on the body surface; and the wiring pattern formation Step of forming a required wiring pattern with a conductive paste on the upper surface of the thermoplastic resin film while suctioning it under reduced pressure, and aligning and laminating the thermoplastic resin film with the wiring pattern formed thereon and heating. -It is characterized by including a step of integrating by pressure molding.

In the above structure, it is preferable that the ventilation type support is selectively set to have a thickness of about 30 to 100 μm, and the so-called dummy is pierced on the surface of this ventilation type support in the thickness direction. The thermoplastic resin film having the holes selectively formed is interposed so that a desired through-hole connection portion can be formed when the required wiring pattern is formed by the conductive paste on the surface of the wiring pattern forming thermoplastic resin film. This is because it has been experimentally confirmed that it is easy to form further,
Even if the arrangement of the ventilation type support is omitted in the above, the holes formed in the wiring pattern forming thermoplastic resin film, which is the object to be printed, are easily filled with a conductive paste to form a desired conductor region. Formation was also confirmed experimentally.

[0007]

In the production of the present invention, the thermoplastic resin film for forming a wiring pattern is formed when the conductive paste-based wiring pattern is formed on the surface of the thermoplastic resin film for forming a wiring pattern forming the multilayer printed wiring board. Is installed under reduced pressure (vacuum) from the other side, so it can be easily installed even in the through hole that forms the through-hole connection.
In addition, the conductive paste is reliably and precisely filled and applied.
Therefore, even when the required wiring patterns are formed and then laminated and integrated by heating and pressure molding, it is possible to obtain a multilayer printed wiring board having a highly reliable through-hole connection with high yield.

[0008]

Embodiments of the present invention will be described below with reference to FIGS.

FIG. 1 schematically shows a state in which the required wiring pattern is adhered and formed on a surface of a required wiring pattern forming thermoplastic resin film including through-hole connecting portions in the manufacturing method of the present invention. Up to this stage, the following steps are performed.

First, in order to be able to exhibit a vacuum suction function by a vacuum pump (not shown), for example, a vacuum type is provided on the surface of the vacuum suction stage 1 having vacuum suction holes 1a with a diameter of 0.5 mm and a pitch of 10 mm. Support 2, for example 50 μm in thickness
Place m high-quality paper. Here, the ventilation type support 2 is not limited to the above-mentioned high-quality paper, and may be fibrous paper or cloth.

Next, a thermoplastic resin film 3 having through holes in the thickness direction selectively formed on the surface of the support body 2, for example, a through hole 3a having a diameter of 0.4 mm and a thickness of 100 μm.
Place the polysulfone resin film of. Then, on the surface of the thermoplastic resin film 3, a thermoplastic resin film 4 for forming a required wiring pattern including through-hole connecting portions, for example, a through hole 4a having a thickness of about 75 μm and a diameter of 0.2 mm is formed.
The polyphenylene sulfide resin film having the holes formed therein is placed. The position where the through hole 3a is formed in the thermoplastic resin film 3 and the position of the through hole 4a formed in the thermoplastic resin film 4 for forming the wiring pattern are substantially aligned with each other.

As described above, while suctioning the arranged thermoplastic resin film 4 for forming a wiring pattern under reduced pressure, a conductive paste 5, for example, a silver paste having a binder of polysulfone resin (viscosity 50000 to 75) is applied to the upper surface of the film 4.
000 cPs) is screen-printed, for example, to form the required wiring pattern. Then, the thermoplastic resin film 4'on which the required wiring pattern is formed is removed from the surface of the support 3 and dried at 150 ° C. for about 1 hour.

The steps according to the above are repeated to obtain the thermoplastic resin films 4'on which the required wiring patterns required for the production of the intended multilayer printed wiring board are formed, and then these thermoplastic resin films 4'are obtained. Align 4 '
A desired multilayer printed wiring board is manufactured by laminating and integrating by heating and pressure molding. FIG. 2 is a cross-sectional view showing the main part of the structure of the multilayer printed wiring board manufactured in this way, in which each wiring pattern layer 5'including through-hole connecting parts is formed densely and has a function. The wiring pattern was highly reliable.

In the above manufacturing example, the arrangement of the ventilation type support 2 on the surface of the vacuum suction type stage 1 is omitted, except that
When a multilayer printed wiring board was manufactured under the same conditions and each wiring pattern layer including a through-hole connecting portion in cross section was observed and evaluated, the same results as in the case of the above-mentioned manufacturing example were recognized.

The thermoplastic resin used in the present invention preferably has various characteristics such as electrical insulation, heat resistance and moisture resistance which are usually required for circuit boards. For example, polycarbonate. Resin, polysulfone resin, polyallyl sulfone resin, polyether ether ketone resin, polyether imide resin, polyphenyl sulfide resin, polyphenylene oxide resin and the like can be mentioned.

It is desirable that the thermoplastic resin forming the insulating layer of the circuit board and the thermoplastic resin used as the binder of the conductive paste are of the same kind.
A combination of different types may be used as long as they have substantially the same plasticity. Then, the conductive paste is a metal powder such as gold, silver, copper, nickel, tungsten, molybdenum, aluminum or platinum in the thermoplastic resin, or carbon powder, silicon carbide powder, semiconductive powder such as vanadium pentoxide powder. Is added and mixed.

Further, in the above, the diameter of the through hole 3a of the thermoplastic resin film 3 arranged on the breathable support 2 is set to be larger than that of the required through hole 4a of the thermoplastic resin film 4 for forming the wiring pattern. However, these may have the opposite relationship, or may not necessarily have the coaxial positional relationship.

[0018]

As described above, according to the method for manufacturing a multilayer printed wiring board of the present invention, the conductive paste is densely and easily filled in the through holes forming (configuring) the through-hole connecting portions. As a result, it is possible to easily manufacture a multilayer printed wiring board in which a highly reliable interlayer connection portion is formed. In other words, the yield is good without the need for complicated processes,
It is possible to always obtain a highly reliable multilayer printed wiring board.

[Brief description of drawings]

FIG. 1 is a cross-sectional view schematically showing an embodiment example of a method for manufacturing a multilayer printed wiring board according to the present invention.

FIG. 2 is a cross-sectional view showing a configuration example of a multilayer printed wiring board manufactured by the method for manufacturing a multilayer printed wiring board according to the present invention.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum suction stage 1a ... Vacuum suction hole 2 ... Breathable support 3 ... Thermoplastic resin film disposed on the ventilation support surface 3a ... Thermoplastic resin film disposed on the ventilation support surface Through hole
4 ... Thermoplastic resin film on which required wiring pattern is adhered and formed 4a ... Through hole (through hole connection portion forming portion) formed in thermoplastic resin film on which required wiring pattern is adhered and formed 4 '... Wiring Thermoplastic resin film on which pattern is formed 5. Conductive paste
5 '... wiring pattern

Claims (2)

[Claims] 1. A thermoplastic resin film for forming a required wiring pattern including a through-hole connecting portion via a thermoplastic resin film having through holes in the thickness direction selectively formed on a surface of a vacuum suction type stage. A step of arranging, a step of depositing a required wiring pattern with a conductive paste on the upper surface of the wiring pattern forming thermoplastic resin film under vacuum suction, and a thermoplastic resin having the wiring pattern deposited thereon A method for manufacturing a multilayer printed wiring board, comprising the steps of aligning and laminating films and integrating them by heating and pressure molding. 2. The method for manufacturing a multilayer printed wiring board according to claim 1, wherein a vacuum type is provided between the vacuum suction type stage surface and the thermoplastic resin film in which through holes in the thickness direction are selectively formed. A method for manufacturing a multilayer printed wiring board, comprising: disposing and interposing the support of 1.