Multilayer wiring board assembly, multilayer wiring board assembly component and method of manufacture thereof Number:6,768,064 from the United States Patent and Trademark Office (PTO) owispatent A multilayer wiring board assembly, a multilayer wiring board assembly component and a method of manufacture thereof are described in which it is possible to easily laminate together flexible FPCs having highly packing densities by via-on-via and chip-on-via. The multilayer wiring board assembly is laminated by laminating together a plurality of multilayer wiring board assembly components, each of which is made by preparing a copper plated resin film 10 made of a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film, and a conductive paste embedded by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.<H manufacture, multilayer, Multilayer, wiri, 6768064.html, Patent, pto, 6768064

Title: Multilayer wiring board assembly, multilayer wiring board assembly component and method of manufacture thereof

Abstract: A multilayer wiring board assembly, a multilayer wiring board assembly component and a method of manufacture thereof are described in which it is possible to easily laminate together flexible FPCs having highly packing densities by via-on-via and chip-on-via. The multilayer wiring board assembly is laminated by laminating together a plurality of multilayer wiring board assembly components, each of which is made by preparing a copper plated resin film 10 made of a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film, and a conductive paste embedded by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

Patent Number: 6,768,064 Issued on 07/27/2004 to Higuchi, et al.

Inventors: Higuchi; Reiji (Chiba, JP), Itou; Shouji (Chiba, JP), Nakao; Osamu (Chiba, JP)
Assignee: Fujikura Ltd. (Tokyo, JP)

Appl. No.: 10/190,496

Filed: July 9, 2002

Foreign Application Priority Data


Jul 10, 2001 [JP]			P2001-209595
Jun 27, 2002 [JP]			P2002-188639
Jun 27, 2002 [JP]			P2002-188640
Jun 27, 2002 [JP]			P2002-188660
Jun 27, 2002 [JP]			P2002-188664

Current U.S. Class: 174/267 ; 174/258; 174/261

Current International Class: H05K 3/40 (20060101); H05K 3/46 (20060101); H05K 1/00 (20060101); H05K 3/24 (20060101)

Field of Search: 174/258-267 361/792-795,778 29/846-852 428/209-210

References Cited [Referenced By]

U.S. Patent Documents


5129142	July 1992	Bindra et al.
5435480	July 1995	Hart et al.
5473120	December 1995	Ito et al.
5601672	February 1997	Casey et al.
6083340	July 2000	Nomura et al.
6108903	August 2000	Nakatani et al.
6125531	October 2000	Farquhar et al.
6195883	March 2001	Bhatt et al.
6440542	August 2002	Kariya
6465084	October 2002	Curcio et al.

Other References

K Takagi, pps. 77-79, "Build-Up Multilayered Printed Circuit Board Technology" (with English translation)..

Primary Examiner: Whitehead, Jr.; Carl
Assistant Examiner: Dinh; Tuan
Attorney, Agent or Firm: Oblon, Spivak, McClelland, Maier & Neustadt, P.C.

Claims

What is claimed is:

1. A multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, the multilayer wiring board assembly being manufactured by a method comprising: preparing the plurality of multilayer wiring board assembly components, wherein each of the plurality of multilayer wiring board assembly components comprises: a resin film having properties of adhesivity, a copper foil bonded to one surface of the resin film, a through hole opened through the copper foil and the resin film, and a conductive paste embedded by screen printing in the through hole from a side of the copper foil such that a leading edge of the conductive paste is projected from the resin film; and laminating the multilayer wiring board assembly components with other multilayer wiring board assembly components such that the leading edge of the conductive paste is pressed against at least one of the conductive paste and the copper foil of an adjacent one of the multilayer wiring board assembly components, wherein the leading edge of the conductive paste is in close contact with at least one of the conductive paste and the copper foil of the adjacent one of the multilayer wiring board assembly components such that an electric connection having electric conductivity is formed.

2. The multilayer wiring board assembly as claimed in claim 1, wherein the conductive paste is embedded in the through hole with part of the conductive paste laterally extending beyond a perimeter of an opening of the through hole of the copper foil.

3. The multilayer wiring board assembly as claimed in claim 1, wherein the resin film comprises a thermoplastic adhesive.

4. The multilayer wiring board assembly as claimed in claim 1, wherein the resin film has properties-of adhesivity and fluidity.

5. The multilayer wiring board assembly as claimed in claim 1, wherein the laminating of the multilayer wiring board assembly components with the other multilayer wiring board assembly components comprises heating the multilayer wiring board assembly components and the other multilayer wiring board assembly components.

6. The multilayer wiring board assembly as claimed in claim 1, wherein the conductive paste is finally cured at a same time as the conductive paste is pressed.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application is based upon and claims the benefit of priority from prior Japanese Patent Application P2001-209595 filed on Jul. 10th, 2001, prior Japanese Patent Application P2002-188639 filed on Jun. 27th, 2002, prior Japanese Patent Application P2002-188660 filed on Jun. 27th, 2002, prior Japanese Patent Application P2002-188640 filed on Jun. 27th, 2002, prior Japanese Patent Application P2002-188664 filed on Jun. 27th, 2002; the entire contents of which are incorporated by reference herein.

BACKGROUND OF THE INVENTION

1. Field of the invention

The present invention relates to a multilayer wiring board assembly composed of a plurality of printed circuit boards in a multilayered structure, a multilayer wiring board assembly component for use in laminating the same and the manufacturing method of the same. In particular, the present invention relates to a multilayer wiring board assembly, a multilayer wiring board assembly component for use in laminating the same and the manufacturing method of the same, wherein the multilayer wiring board assembly is flexible and implemented with a highly packing density by the Flip Chip Mounting technique and so forth.

2. Description of the Related Art

A flexible printed circuit board (which is simply referred to as an "FPC" in this description) is composed of a resin film having a small thickness for the purpose of maintaining the flexibility thereof. Because of this, in the case of such FPCs, it is essentially very difficult to assemble a plurality of FPCs in a multilayered structure (a multilayer wiring board assembly). However, along with the advent of the implementation of FPCs with a highly packing density, the need for multilayered structures of FPCs has increased in recent years, for example, in consideration of the arrangement of lead wirings as connected to flip chips mounted on FPCs. In this situation, a multilayer wiring board assembly has been manufactured by multilayering a plurality of FPCs with an intervening glass epoxy prepreg sheet and so forth between each adjacent boards while one or both surface of each FPC has been formed with a circuit pattern, forming holes through the entirety of all the layers by means of a drill and the like, and interlayer interconnecting the layers by the use of a through hall plating and the like.

However, in the case of such a conventional method of manufacturing multilayer wiring board assemblies by the use of is a through hall plating, it is impossible to form a via hole anew on another via hole and to mount a chip on a via hole, generally called as via-on-via since a hole remains in the center of a through hall even after plating. Because of this, when a multilayer wiring board assembly is implemented with a highly packing density, there are several impediments such that a lead can not be extended from the position just below the chip while interlayer interconnection tends to excessively occupy a substantial area.

On the other hand, for example, ALIVH (Any Layer Interstitial Via Hole: a registered trademark of Matsushita Electric Industrial Co., Ltd.) is a rigid multilayer wiring board assembly in which via-on-via is possible while a conductive paste is used for interlayer interconnection between each adjacent layers. An ALIVH board is formed by repeating the process sequence including opening a through hole in an uncured resin board, filling the through hole with a conductive paste, joining a copper foil to the uncured resin board, hardening the resin while compression bonding in order to form a multilayered structure and etching the copper foil in order to form a circuit pattern.

However, while via-on-via is possible in the case of the manufacturing method as described above to form ALIVH boards since the interlayer interconnection is made by means of a conductive paste, it is extremely difficult to manufacture FPCs in the form of a multilayer wiring board assembly by applying the manufacturing method to FPCs because it is necessary to open a hole through a resin film such as a polyimide film having a small thickness followed by filling up the hole with a conductive paste. This is because, when opening a hole in a resin film having a small thickness, the position and the size of the hole tend to change due to distortion of the resin film, the sucking force of a drill and the like so that the necessary accuracy of alignment is hardly achieved during the printing operation of the conductive paste and the positioning of the respective layers.

Also, while via-on-via is possible in the case of the manufacturing method making use of a conductive paste for the interlayer interconnection like ALIVH, it is difficult to make electric connection between a copper foil and a conductive paste without compromising the electric characteristics of the copper foil and the conductive paste so that the respective venders make use of proprietary methods respectively. Namely, generally speaking, when interlayer interconnection is made by via-on-via, a copper foil and a conductive paste are connected to each other by inserting the copper foil between adjacent conductive paste layers. In this case, the conductive paste is arranged to pierce the copper foil for the purpose of preserving electric connectivity between the copper foil and the conductive paste. For example, in the case of an ALIVH board, a conductive paste is printed in order to form a projection while the thickness of the board is reduced during thermocompression for bonding because of the use of an uncured resin board so that it becomes possible to make electric connection of a copper foil pierced by the projection of the conductive paste.

However, in the case of a board made of such a substance that the thickness of the board is not reduced during thermocompression for bonding, like a polyimide used for making a resin film in the case of FPCs, the projection of a conductive paste is less effective in piecing the copper foil. As a result, it is difficult to make electric connection between a copper foil and a conductive paste without compromising the electric characteristics.

Furthermore, in the case where a through hole is filled with a conductive paste, the conductive paste is printed in the condition that the surface of the conductive paste is slightly depressed since the conductive paste is pressed during printing. Because of this, there is a problem that, even if boards having through holes filled with a conductive paste are joined to each other, it is impossible to achieve sufficient electric connectivity between the fillers of the conductive paste.

Also, while the resin film having adhesivity is contracted or expanded during heating, the contraction or expansion can be cancelled out if there is a center line of symmetry in the cross section thereof. However, in the case of an adhesive layer having no center line of symmetry, there is observed curl in the cross section of the board during heating for lamination. Particularly, a polyimide film is a highly flexuous material and therefore tends to be significantly curled.

BRIEF SUMMARY OF THE INVENTION

The present invention has been made in order to solve the shortcomings as described above. It is an object of the present invention to provide a multilayer wiring board assembly, a multilayer wiring board assembly component and a method of manufacture thereof in which it is possible to easily laminate together flexible FPCs having highly packing densities by via-on-via and chip-on-via.

It is another object of the present invention to provide a multilayer wiring board assembly which can be manufactured by joining multilayer wiring board assembly components to each other with a uniform pressure and therefore it is possible to fixedly laminate the multilayer wiring board assembly with a better electric connectivity.

It is a further object of the present invention to provide a multilayer wiring board assembly which is manufactured in order that the opening of a through hole near a copper foil is placed on a plane table having a hole of a diameter larger than that of the through hole followed by filling the through hole with a conductive paste from a masking tape in order to form a brim laterally extending beyond the perimeter of the opening of the copper foil, and therefore it is possible to form the brim having a desired profile with a high degree of accuracy and having a smaller thickness than that in the case utilzing a mask, and therefore possible to fixedly laminate the multilayer wiring board assembly with a better electric connectivity.

It is a still further object of the present invention to provide a multilayer wiring board assembly in which the contact area of a conductive paste with a copper foil is increased when compression bonding multilayer wiring board assembly components to each other, and therefore it is possible to improve electric connectivity.

It is a still further object of the present invention to provide a multilayer wiring board assembly in which it is possible to manufacture a multilayer wiring board assembly having a good heat resisting property with little damage to the respective boards during the manufacturing process by the use of a resin film having adhesivity made of a thermosetting resin.

It is a still further object of the present invention to provide a multilayer wiring board assembly in which it is possible to manufacture a multilayer wiring board assembly having a good heat resisting property without damaging the conductive resin components (the conductive paste) by the use of a resin film having adhesivity formed of a thermoplastic resin to which is given a thermosetting property.

In accordance with an aspect of the present invention, a multilayer wiring board assembly component comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with another aspect of the present invention, a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film, wherein the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with the copper foil or the conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a through hole in a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which said through hole is opened through said copper foil and said resin film; and a step of embedding a conductive paste by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of embedding a conductive paste by screen printing in the through hole of said copper plated resin film from said copper foil; and a step of removing said mask layer.

In accordance with a still further aspect of the present invention, in a manufacturing method of a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film, wherein said multilayer wiring board assembly is laminated with a plurality of said multilayer wiring board assembly components through said resin film in order that the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly component comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a through hole in a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which said through hole is opened through said copper foil and said resin film; and a step of embedding a conductive paste in the through hole from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly component comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film with one end of said conductive paste being projected from said resin film and the tail end of said conductive paste being projected to the same height as said copper foil.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly component comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, the most outer layer of said multilayer wiring board assembly components comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with one end of said conductive paste being projected from said resin film and the tail end of said conductive paste being projected to the same height as said copper foil, wherein the leading end of said conductive paste of said most outer multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components includes: a first multilayer wiring board assembly component comprising a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film, and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a second multilayer wiring board assembly component comprising a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film, and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and the tail end of said conductive paste being projected to the same height as said copper foil, wherein said second multilayer wiring board assembly component is located as the most outer layer of the multilayer wiring board assembly while said first multilayer wiring board assembly component is located as an inner layer of the multilayer wiring board assembly other than said second multilayer wiring board assembly, and wherein the leading end of said conductive paste of one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components includes: a first multilayer wiring board assembly component comprising a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film, and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a second multilayer wiring board assembly component comprising a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film, and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and the tail end of said conductive paste being projected to the same height as said copper foil, wherein said second multilayer wiring board assembly component is located as the most outer layer of the multilayer wiring board assembly while said first multilayer wiring board assembly component is located as an inner layer of the multilayer wiring board assembly other than said second multilayer wiring board assembly, and wherein said multilayer wiring board assembly is laminated with a plurality of said multilayer wiring board assembly components through said resin film in order that the leading end of said conductive paste of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a through hole in a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which said through hole is opened through said copper foil and said resin film; and a step of embedding a conductive paste in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and the tail end of said conductive paste being projected-to the same height as said copper foil.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a mask layer on an adhesive layer bonded to one surface of a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to the other surface thereof; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of embedding a conductive paste in the through hole with the tail end of said conductive paste being located at the same height as said copper foil; and a step of removing said mask layer to leave the tail end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a through hole in a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which said through hole is opened through said copper foil and said resin film; and a step of embedding a conductive paste by screen printing in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of embedding a conductive paste by screen printing in the through hole of said copper plated resin film from said copper foil with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a step of removing said mask layer to leave the tail end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; is a step of placing, on said copper foil over said through hole, a mask of a thickness larger than that of said through hole; a step of embedding a conductive paste in said through hole with the tail end of said conductive paste being located at the same height as said mask; a step of removing said mask to leave said tail end of said conductive paste being projected from said copper foil with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a step of removing said mask to leave the tail end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, in a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components is manufactured by: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of placing, on said copper foil over said through hole, a mask of a thickness larger than that of said through hole; a step of embedding a conductive paste in said through hole with the tail end of said conductive paste being located at the same height as said mask; a step of removing said mask to leave said tail end of said conductive paste being projected from said copper foil with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a step of removing said mask to leave the tail end of said conductive paste being projected from said resin film, wherein the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, in a manufacturing method of a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components is manufactured by: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of placing, on said copper foil over said through hole, a mask of a thickness larger than that of said through hole; a step of embedding a conductive paste in said through hole with the tail end of said conductive paste being located at the same height as said mask; a step of removing said mask to leave said tail end of said conductive paste being projected from said copper foil with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a step of removing said mask to leave the tail end of said conductive paste being projected from said resin film, wherein said multilayer wiring board assembly is laminated with a plurality of said multilayer wiring board assembly components through said resin film in order that the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of placing said copper plated resin film on a plane table in which a hole is opened with a thickness larger than that of said through hole in order that said copper foil is located in a lower position with the through hole located over the hole of said plane table; a step of embedding a conductive paste by screen printing in the through hole of said copper plated resin film from said mask layer with a leading end of said conductive paste being projected from said copper foil with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a step of removing said mask layer to leave the leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, in a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components is manufactured by: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of placing said copper plated resin film on a plane table in which a hole is opened with a thickness larger than that of said through hole in order that said copper foil is located in a lower position with the through hole located over the hole of said plane table; a step of embedding a conductive paste in the through hole of said copper plated resin film from said mask layer with a leading end of said conductive paste being projected from said copper foil with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a step of removing said mask layer to leave the tail end of said conductive paste being projected from said resin film, wherein said tail end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, in a manufacturing method of a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components is manufactured by: a step of etching a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of placing said copper plated resin film on a plane table in which a hole is opened with a thickness larger than that of said through hole in order that said copper foil is located in a lower position with the through hole located over the hole of said plane table; a step of embedding a conductive paste in the through hole of said copper plated resin film from said mask layer with a leading end of said conductive paste being projected from said copper foil with part of said conductive paste being laterally extending beyond the perimeter of the opening of the through hole of said copper foil; and a step of removing said mask layer to leave the tail end of said conductive paste being projected from said resin film, wherein said multilayer wiring board assembly is laminated with a plurality of said multilayer wiring board assembly components through said resin film in order that said tail end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present is invention, a multilayer wiring board assembly component comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and with the tail end of said conductive paste being projected from said copper foil.

In accordance with a still further aspect of the present invention, in a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and with the tail end of said conductive paste being projected from said copper foil, wherein the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, in a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film and with the tail end of said conductive paste being projected from said copper foil, wherein said multilayer wiring board assembly is laminated with a plurality of said multilayer wiring board assembly components through said resin film in order that the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a through hole in a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which said through hole is opened through said copper foil and said resin film; and a step of embedding a conductive paste in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film with the tail end of said conductive paste being projected from said copper foil.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of preparing a copper plated resin film made of a resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and forming first and second mask layers on said one surface and the other surface opposed to said one surface of said copper plated resin film; a step of forming a through hole opened through said copper foil, said resin film and said first and second mask layers; a step of embedding a conductive paste in said through hole with the leading and tail ends of said conductive paste being located at the same height as said mask layers; and a step of removing said first and second mask layers to leave the leading end of said conductive paste being projected from said resin film with the tail end of said conductive paste being projected from said copper foil.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly component comprises: a copper plated resin film made of a thermosetting resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, in a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a thermosetting resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film, wherein the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a through hole in a copper plated resin film made of a thermosetting resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which said through hole is opened through said copper foil and said resin film; and a step of embedding a conductive paste in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of etching a copper plated resin film made of a thermosetting resin film having adhesivity which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of embedding a conductive paste in the through hole of said copper plated resin film from said copper foil; and a step of removing said mask layer.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a thermosetting resin film having adhesivity which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film, wherein said multilayer wiring board assembly is laminated with a plurality of said multilayer wiring board assembly components through said resin film in order that the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly component comprises: a copper plated resin film made of a thermosetting resin film having adhesivity and which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a resin film to which is given a thermosetting property and which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film, wherein the leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of forming a through hole in a copper plated resin film made of a resin film to which is given a thermosetting property and which is provided with a copper foil bonded to one surface thereof and in which said through hole is opened through said copper foil and said resin film; and a step of embedding a conductive paste in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film.

In accordance with a still further aspect of the present invention, a manufacturing method of a multilayer wiring board assembly component comprises: a step of etching a copper plated resin film made of a resin film to which is given a thermosetting property and which is provided with a copper foil bonded to one surface thereof in order to form a predetermined circuit pattern; a step of forming a mask layer on said resin film of the copper plated resin film having been formed with said circuit pattern; a step of forming a through hole opened through said copper foil, said resin film and said mask layer; a step of embedding a conductive paste by screen printing in the through hole of said copper plated resin film from said copper foil; and a step of removing said mask layer.

In accordance with a still further aspect of the present invention, in a manufacturing method of a multilayer wiring board assembly laminated with a plurality of multilayer wiring board assembly components, at least one of said multilayer wiring board assembly components comprises: a copper plated resin film made of a resin film to which is given a thermosetting property and which is provided with a copper foil bonded to one surface thereof and in which a through hole is opened through said copper foil and said resin film; and a conductive paste embedded in the through hole of said copper plated resin film from said copper foil with a leading end of said conductive paste being projected from said resin film, wherein said multilayer wiring board assembly is laminated with said resin film having adhesivity by thermocompression at about 180.degree. C. in order that said leading end of said conductive paste of said at least one of said multilayer wiring board assembly components makes electric contact with said copper foil or said conductive paste of an adjacent one of said multilayer wiring board assembly components.

BRIEF DESCRIPTION OF DRAWINGS

The aforementioned and other features and objects of the present invention and the manner of attaining them will become more apparent and the invention itself will be best understood by reference to the following description of a preferred embodiment taken in conjunction with the accompanying drawings, wherein:

FIG. 1 shows cross sectional views of the intermediate structures of a multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with an embodiment of the present invention in the order of the manufacturing steps.

FIG. 2 shows cross sectional views showing the multilayer wiring board assembly in accordance with the embodiment of the present invention in the order of the manufacturing steps.

FIG. 3 shows cross sectional views showing the multilayer wiring board assembly in accordance with the embodiment of the present invention in the order of the manufacturing steps.

FIG. 4 shows cross sectional views of an exemplary connection terminal structure of the multilayer wiring board assembly in accordance with an embodiment of the present invention.

FIG. 5 shows cross sectional views of another exemplary connection terminal structure of the multilayer wiring board assembly in accordance with an embodiment of the present invention.

FIG. 6 shows cross sectional views of a further exemplary connection terminal structure of the multilayer wiring board assembly in accordance with an embodiment of the present invention.

FIG. 7 shows cross sectional views of the intermediate structures of a first multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with a further embodiment of the present invention in the order of the manufacturing steps.

FIG. 8 shows cross sectional views of the intermediate structures of a second multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with the further embodiment of the present invention in the order of the manufacturing steps.

FIG. 9 shows cross sectional views of the intermediate structures of a second multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with an still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 10 shows cross sectional views showing the multilayer wiring board assembly in accordance with a still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 11 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 12 shows cross sectional views of the intermediate structures of a multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 13 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 14 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 15 shows cross sectional views of the intermediate structures of a multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with a still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 16 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 17 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 18 shows cross sectional views of the intermediate structures of a multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with a still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 19 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 20 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 21 shows cross sectional views of the intermediate structures of a multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly )in accordance with a still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 22 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 23 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 24 shows cross sectional views of the intermediate structures of a multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with a still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 25 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

FIG. 26 shows cross sectional views showing the multilayer wiring board assembly in accordance with the still further embodiment of the present invention in the order of the manufacturing steps.

DETAILED DESCRIPTION OF THE INVENTION

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

FIG. 1 shows cross sectional views of the intermediate structures of a multilayer wiring board assembly component for use in manufacturing a multilayer wiring board assembly in accordance with an embodiment of the present invention in the order of the manufacturing steps. FIG. 2 and FIG. 3 are cross sectional views showing the multilayer wiring board assembly in accordance with the embodiment of the present invention in the order of the manufacturing steps.

The multilayer wiring board assembly component 20 is a connection unit for use in the process of laminating a multilayer wiring board assembly and comprises an FPC as a base element made of a single sided copper plated resin film. Namely, as illustrated in FIG. 1(i), the multilayer wiring board assembly component 20 is composed of a copper plated resin film 10 composed of a flexible resin film 1 having adhesivity and made of a thermoplastic polyimide (TPI) and the like and provided with a copper foil 2 bonded to one surface thereof, and a conductive paste 8 embedded in a through hole 7 (refer to FIG. 1(g)) passed through the resin film 10 to form an inner via hole. A predetermined circuit pattern is formed in the copper foil 2 by etching and the like. The conductive paste 8 is embedded in the through hole 7 from the surface of the copper foil 2 by screen printing and so forth with a brim formed laterally extending on the upper surface of the copper foil 2 beyond the perimeter of the opening thereof in order that the leading end thereof is projected through the opposed surface of the copper plated resin film 10 having the resin film 1.

A multilayer wiring board assembly is laminated by stacking a plurality of the multilayer wiring board assembly components as illustrated in FIG. 1(i) (three units in the case of the embodiment as illustrated in FIG. 2 and FIG. 3). As illustrated in FIG. 2 and FIG. 3, since the through hole 7 of the multilayer wiring board assembly component is filled with the conductive paste 8, it is possible to make interlayer connection via-on-via.

Also, as illustrated in FIG. 1(i), the conductive paste 8 is printed in order that a projection is formed in the surface opposed to the printing surface. Meanwhile, the height of the projection of the conductive paste 8 depends on the size of the r