JP2003283131A - Laminated circuit and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin laminated circuit which does not need a connector for connection between substrates, which can considerably reduce through holes, and which can gain effects such as improvement of design flexibility, reduction of a manufacturing cost and improvement of flexibility in circuit module shapes. <P>SOLUTION: Circuit substrate sections 13, 14 with flexibility are provided with parts which are in charge of signal transmission or signal processing and a circuit which connects the parts. A connecting section 15 between circuit substrates with flexibility which is integrally formed with the circuit substrate sections 13, 14 mutually electrically or optically connects the circuit substrate sections 13, 14. Plural circuit modules 12 provided with the circuit substrate sections 13, 14 and the connecting sections 15 between the circuit substrates 15 are laminated in many layers. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated circuit (laminated circuit) formed by laminating circuit modules in which a flexible circuit board portion and a circuit board connecting portion are integrally formed, and a manufacturing method thereof.

[0002]

2. Description of the Related Art FIG. 4 shows a cross section of a conventionally proposed flex-rigid wiring board. In this flex-rigid wiring board 1, a range indicated by reference numeral 2 is a rigid portion which is hard and cannot be bent, and a range indicated by reference numeral 3 is a bendable flexible portion. The conductor circuit 5 of the multilayer wiring board 4 in the flexible portion 3 is covered and protected by a cover lay film 6 with an adhesive. In addition, in the rigid portion 2, a multilayer wiring board 4 is formed by using an adhesive bonding sheet or prepreg shown by reference numeral 7.
And the rigid wiring board 8 are bonded or laminated to each other, and the bonding sheet or the prepreg 7 and the rigid wiring board 8 are removed in the flexible portion 3 where the multilayer wiring board 4 is exposed. Further, a plurality of electronic components 9 are mounted on the rigid wiring board 8 in the rigid portion 2, and these electronic components 9 are electrically connected to each other through the through holes 10 penetrating the multilayer wiring board 4 and the rigid wiring board 8. Has been done.

[0003]

As described above, in the conventional flex-rigid wiring board 1, since the circuit board portion constituted by the multilayer wiring board 4 is not flexible, the degree of freedom in shape processing is limited. , For example, it cannot be mounted in conformity with a curved housing. Further, the thickness of the multilayer wiring board 4 is limited, and there is a limit to the reduction of the wiring length in the stacking direction, so that it is not possible to cope with higher frequencies in the future. Furthermore, since it is necessary to arrange through holes in a complicated manner in the stacking direction (thickness direction) in order to electrically connect the stacked circuits,
The degree of freedom in circuit design is reduced, and the miniaturization of the circuit board is limited, and it is difficult to reduce the manufacturing cost due to the complicated circuit configuration.

On the other hand, in the case of a general laminated circuit board, the layers are completely adhered to each other, and there is almost no inspection during the lamination of the circuit boards in the manufacturing process. There is. In the circuit board having the structure in which the respective layers are in close contact with each other as described above, there is a problem that the heat generated in the circuit is difficult to escape and the board itself generates heat. Further, usually, the laminated circuit board is inspected as a finished product such as an operation check. This is because the conventional laminated circuit board exhibits its function only when all layers are laminated, and does not function with one layer or several layers.
In the current situation where inspection cannot be performed by the time the laminated circuit board is completed, defective products generated during the laminating process cannot be sorted out, resulting in a decrease in yield and loss cost.

[0005]

In order to solve the above problems, a laminated circuit according to the present invention is a flexible circuit including a component for signal transmission or signal processing and a circuit for connecting these components. A plurality of circuit modules including a board portion and a circuit for electrically or optically connecting the circuit board portions to each other, and a flexible inter-circuit board connecting portion integrally formed with the circuit board portion, It is laminated in multiple layers.

In another aspect of the present invention, the circuit modules are laminated so that the circuit board connecting portions of the respective circuit modules do not overlap with the circuit board connecting portions of the other circuit modules. Is characterized by.

In another aspect of the present invention, in at least two circuit modules of the plurality of circuit modules, a first circuit board portion included in one circuit module is a first circuit board portion included in the other circuit module. It is characterized in that it is arranged on the circuit board part, and the second circuit board part included in one circuit module is arranged below the second circuit board part included in the other circuit module.

In another aspect of the present invention, at least two adjacent circuit modules of the plurality of circuit modules are partially in contact with each other or bonded between adjacent circuit board portions. Is characterized by.

Another aspect of the present invention is characterized in that the area of the circuit board portions which are in contact with or adhere to each other is 50% or less of the area of the circuit board portion.

In another aspect of the present invention, the adjacent circuit modules are characterized in that the circuits of the adjacent circuit board portions are electrically or optically connected to each other at their adhesive portions.

Another laminated circuit of the present invention comprises a first circuit module and a second circuit module, each of the first and second circuit modules being provided on a flexible substrate made of an insulating material. The first and second circuit board portions and the inter-circuit board connection portion connecting the first and second circuit board portions are formed, and signal transmission or signal processing is performed on the first and second circuit board portions. A plurality of parts to be performed and a circuit for connecting the plurality of parts are formed, and a circuit for connecting the circuits of the first circuit board part and the second circuit board part to each other is formed in the circuit board connection part. The first and second circuit modules are arranged such that the first and second circuit board portions of the first circuit module are superposed on the first and second circuit board portions of the first circuit module. It is characterized by being.

In another aspect of the present invention, the first circuit board portion of the first circuit module is disposed on the first circuit board portion of the second circuit module, and the first circuit module is disposed. The second circuit board portion of is arranged below the second circuit board portion of the second circuit module.

A method of manufacturing a laminated circuit according to the present invention includes a flexible circuit board portion including a component for signal transmission or signal processing and a circuit for connecting the components, and the circuit board portion to each other. A laminated circuit in which a plurality of circuit modules, each of which has a circuit for electrically or optically connecting to each other, and a flexible inter-circuit-board connecting portion integrally formed with the circuit board portion, are laminated in multiple layers. In the manufacturing process of
It is characterized in that an inspection step for confirming the operation of the signal circuit is provided for each one layer or every several layers until a desired number of layers are laminated and completed.

[0014]

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings. In this specification,
Although terms indicating various directions (for example, “upper”, “lower”, and terms including them) are used to facilitate the understanding of the invention, the present invention is limitedly interpreted by the meanings of the terms. Not what should be done.

I. Embodiment 1 FIG. 1A is a schematic diagram showing a configuration of a thin laminated circuit (multilayer laminated circuit) according to Embodiment 1 of the present invention. As shown in this figure, the thin laminated circuit 11 is configured by laminating a plurality of (at least two) circuit modules 12. Each circuit module 12 includes first and second circuit board portions 13 and 14 represented in a rectangular shape in the drawing, and the first and second circuit board portions 13 and 14.
And a strap-shaped inter-circuit board connection portion 15 for connecting the second circuit board portions 13 and 14. The substrate 16 that constitutes each circuit module 12 is a thin flexible resin sheet made of an insulating material or a flexible insulating metal sheet obtained by coating the surface of a film made of a metal material with an insulating material. Are processed according to the contours of the circuit board portions 13 and 14 of FIG.
Necessary parts and the like are arranged on the upper part 6. For example, components that perform signal transmission or signal processing, such as electronic components 17 such as resistors, capacitors, coils, and LSI chips, are formed or mounted on the substrate portions that form the circuit substrate portions 13 and 14. The component 17 is the circuit board portion 13, 1.
Electrical wiring 18 of metal foil formed on the surface of No. 4 is properly connected. On the other hand, in the board portion constituting the inter-circuit board connecting portion 15, the electronic component 17 and / or the electric wiring 18 provided on the first circuit board portion 13 and the second circuit board portion 1 are provided.
Electrical wirings 19 are formed to electrically or optically connect the electronic components 17 and / or the electrical wirings 18 provided in FIG. In addition, when a plurality of circuit modules 12 are stacked on a part of the circuit board portions 13 and 14 and / or the inter-circuit board connecting portion 15, the electric wiring 18 of each circuit module 12 and other An electrical connection portion or an optical connection portion or a through hole (neither is shown) for electrically or optically connecting to the electrical wiring 18 of the circuit module 12 is formed.

In this embodiment, the boards 16 of the plurality of circuit modules 12 are formed in the same shape, and when the plurality of circuit modules 12 are stacked, the first circuit board portion 13 of each circuit module 12 The first circuit board portion 13, the second circuit board portion 14, and the circuit board connecting portion 15 of another circuit module are located above, below, or below the second circuit board portion 14 and the circuit board connecting portion 15 exactly. It is located. However, the substrate 1 of each circuit module 12
6 does not need to be the same as the electronic components 17 mounted on the board 16 of the other circuit module 12 and the electronic components 17 and the electric wirings 17 and 18 mounted on the other circuit modules 12, and normally, each circuit module 12 has another circuit. Electronic components and electrical wiring different from the module 12 are provided.

As shown in FIG. 1B, the plurality of circuit modules 12 formed in this way have a first circuit board portion 13, a second circuit board portion 14, and a second circuit board portion 14 of each circuit module 12, respectively.
The first circuit board portion 13, the second circuit board portion 14, and the inter-circuit board connecting portion 15 of the other circuit module are stacked so as to be located exactly above, below, or above and below the circuit board connecting portion 15, and are stacked. The thus-formed circuit board connecting portion 15 is pressed from above and below to be compressed and integrated to form the thin laminated circuit 11. If necessary, at least a part of the circuit board portions and / or the circuit board connecting portions which are adjacent to each other in the stacking direction are bonded with an adhesive. However, the area of the adhesive application portion (adhesive portion) of the circuit board portions 13 and 14 is 50% of the area of the circuit board portion for the purpose of efficiently dissipating heat generated by the electronic components of the circuit board portion. The following is desirable. Also,
By setting the area of the adhesive application portion to 50% or less of the area of the circuit board portion, good flexible characteristics of the laminated circuit can be obtained.

The electrical wiring 1 of each circuit module 12
8 and 19 are partially electrically connected through a part of the circuit board parts 13 and 14 and / or an electrical connection part or a through hole formed in the circuit board connection part 15. That is, the overlapped circuit board portions 13 and 14 are connected only at the electrical connection portion and are not connected at the other portions. Therefore, the circuit board portions 13 and 14 of the circuit module 12 sandwiched between the upper and lower circuit modules 12
The heat generated in 1 is radiated to the outside through the gap at the non-connection position.

As described above, in the integrated thin laminated circuit 11, a plurality of circuit modules 12 are connected by the flexible circuit board connecting portion 15 formed by stacking thin sheets, and these are stacked. Circuit board connection 1
5 is still flexible and can be easily folded. Therefore, there is a degree of freedom in shape processing,
For example, it can be easily mounted in conformity with a curved housing.

II. Second Embodiment: FIG. 2A is a schematic view of a thin laminated circuit 11A according to a second embodiment. In the thin laminated circuit 11A according to the second embodiment, the position of the inter-circuit-board connecting portion 15 in each circuit module 12 (relative position with respect to the circuit board portions 13 and 14) is different from the positions in other circuit modules 12. This is different from the thin laminated circuit 11 of the first embodiment. Therefore, in the thin laminated circuit 11 according to the second embodiment, a plurality of circuit modules 12 are provided as shown in FIG. 2B (particularly as apparent from comparison between FIG. 2B and FIG. 1B). When the circuit board connecting portion 15 is compressed by stacking the
The overall width of the circuit board connecting portion 15 when viewed from above is larger than that in the first embodiment, but since its thickness is substantially equal to the thickness of one layer, the flexibility and reliability of bending are improved. Can be made. Further, it is possible to design the substrate shape with a higher degree of freedom. In addition, in the case of the present embodiment, necessary electrical connection between the plurality of circuit modules is performed by providing an interlayer connection portion or a connection terminal (electrical connection portion) on a part of the circuit board portions 13 and 14 and connecting the plurality of circuit modules. Electrically connecting or connecting the electric connecting portions, which are located at positions facing each other when stacked, to each other. In this case, an adhesive may be partially disposed between the circuit board portions that are adjacent to each other in the stacking direction, and the circuit board portions may be bonded at the adhesive portions.

III. Third Embodiment FIG. 3 is a schematic diagram showing a thin laminated circuit 11B according to a third embodiment. The thin laminated circuit 11 according to the third embodiment includes a plurality of circuit modules 1 used in the second embodiment.
2 is used, and is characterized by the order of stacking the circuit board portions 13 and 14. Specifically, regarding the circuit board unit 13 shown on the left side of FIG. 3, the circuit board unit 13a of the first (top layer) circuit module 12 is arranged on the top layer, and the second (upper two layers from the top) is arranged immediately below. The circuit board portion 13b of (eye) is arranged. On the other hand, regarding the circuit board portion 14 shown on the right side of FIG. 3, the circuit board portion 14a of the first circuit module 12 is arranged immediately below the second circuit board portion 14b, and the left and right circuit board portions are arranged. The stacking order of parts is incorrect. For the sake of easy understanding, an example is shown in which the circuit board portions 13 and 14 of the circuit modules of the first layer and the second layer are laminated in the reverse order. You can choose.

As described above, by integrally forming the circuit board portion and the circuit board connecting portion, the circuit board connecting portion can be made flexible and the circuit board portion can also be made flexible. be able to. At the same time, by integrally forming the connection part between the circuit boards, it is not necessary to provide a connector or the like on the board, and of course the steps such as mounting can be reduced, the degree of freedom of design is improved, the manufacturing time is shortened, and the manufacturing Cost reduction and further size reduction are possible. Even within the circuit board, it is possible to significantly reduce the circuit distraction and through-hole formation required for board-to-board connection, which also improves design flexibility, reduces costs, and reduces size. .

Further, since the degree of freedom in the shape and size of the substrate is improved, it is expected that the degree of freedom can be expanded to the shape of the product itself which incorporates this circuit module and exerts its function. Also, due to the thinner circuit board,
There is also an effect of shortening the wiring length, and an effect that it is possible to cope with a high frequency circuit can be obtained.

Further, when heat press or the like is applied to the laminated substrates, it is possible to process each circuit board portion, so that the capability of the press machine is only required to have an area of one circuit board portion. Can be downsized. Further, since this circuit board can reduce the number of through holes between layers, it is not necessary that all the surfaces of the circuit board portion are in close contact with each other. Therefore, it is not necessary to bond the parts other than the parts that require electrical connection between the layers. This has the effect of simplifying the bonding process and providing a heat dissipation effect because the circuit board has a gap.

Furthermore, in this circuit board, each layer is composed of electronic components and circuits, and is composed of a circuit board layer that also functions independently. Therefore, it is possible to perform an operation inspection in a step before stacking. Therefore, by performing an operation inspection at the time of stacking each layer or several layers, there is an effect that a defective product generated in the manufacturing process can be selected. As a result, it is possible to improve the yield and reduce the loss cost as compared with the manufacturing process which has hitherto depended on the finished product inspection.

[0026]

As is apparent from the above description, according to the laminated circuit of the present invention, it is possible to improve the degree of freedom of design, shorten the manufacturing time, reduce the manufacturing cost, downsize, and support high frequencies. Further, according to the method for manufacturing a laminated circuit according to the present invention, it is possible to confirm the electrical characteristics and the like of each circuit module before lamination, so that the yield of the laminated circuit is improved and the cost of the product can be reduced. Become.

[Brief description of drawings]

FIG. 1 is a schematic diagram of a thin laminated circuit according to a first embodiment.

FIG. 2 is a schematic diagram of a thin laminated circuit according to a second embodiment.

FIG. 3 is a schematic diagram of a thin laminated circuit according to a third embodiment.

FIG. 4 is a cross-sectional view of a conventional flex-rigid board.

[Explanation of symbols]

11: Thin laminated circuit 12: Circuit module 13, 14: Circuit board part 15: Connection between circuit boards 16: substrate 17: Electronic parts 18, 19: Electric wiring

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Takaaki Higashida             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Kenichi Yamamoto             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Daisuke Suetsugu             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Seiji Nakajima             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5E346 AA60 EE44 FF45 HH06 HH22                       HH33

Claims (9)

[Claims] 1. A flexible circuit board portion including a component for signal transmission or signal processing and a circuit for connecting these components, and a circuit for electrically or optically connecting the circuit substrate portion to each other. A laminated circuit comprising a plurality of circuit modules, each of which is provided with the above-mentioned circuit board section and a flexible inter-circuit board connection section integrally formed with the circuit board section. 2. The circuit module is stacked so that the inter-circuit-board connecting portion of each circuit module does not overlap with the inter-circuit-board connecting portion of another circuit module. 1. The laminated circuit according to 1. 3. In at least two circuit modules of the plurality of circuit modules, a first circuit board portion included in one circuit module is placed on a first circuit board portion included in the other circuit module. The second circuit board portion that is arranged and is included in one of the circuit modules is arranged below the second circuit board portion that is included in the other circuit module. 1. The laminated circuit according to 1. 4. The at least two adjacent circuit modules among the plurality of circuit modules are partially in contact with each other or bonded between adjacent circuit board parts. The laminated circuit according to any one of 1 to 3. 5. The area of the circuit board portions that are in contact with or bonded to each other is 50% of the area of the circuit board portion.
The laminated circuit according to claim 4, wherein: 6. The adjoining circuit module according to claim 4, wherein the circuits of the adjoining circuit board portions are electrically or optically connected to each other at their adhesive portions. The laminated circuit according to item 1. 7. A first circuit module and a second circuit module, wherein each of the first and second circuit modules is a flexible substrate made of an insulating material, and the first and second circuit substrates are provided on the flexible substrate. And a plurality of parts for performing signal transmission or signal processing to the first and second circuit board parts, and the plurality of parts and the plurality of circuit board connection parts for connecting the first and second circuit board parts to each other. And a circuit for connecting the circuits of the first circuit board section and the circuit of the second circuit board section to each other is formed in the inter-circuit board connection section. And the second circuit module, wherein the first and second circuit board portions of the first circuit module are arranged so as to overlap the first and second circuit board portions of the first circuit module. Laminated circuit. 8. The first circuit board portion of the first circuit module is disposed on the first circuit board portion of the second circuit module, and the second circuit board portion of the first circuit module is provided. The laminated circuit according to claim 7, wherein the portion is arranged below the second circuit board portion of the second circuit module. 9. A flexible circuit board portion including a component that carries out signal transmission or signal processing and a circuit that connects these components, and a circuit that electrically or optically connects the circuit substrate portion to each other. And a desired number of layers in a manufacturing process of a laminated circuit, characterized in that a plurality of circuit modules each having a flexible inter-circuit board connecting portion integrally formed with the circuit board portion are laminated in a multilayer. A method for manufacturing a laminated circuit, characterized in that an inspection step for confirming the operation of the signal circuit is provided for each one layer or every several layers until the layers are laminated and completed.