KR100665244B1 - Printed circuit composite board - Google Patents

Abstract

An object of the present invention is to provide a thin circuit wiring composite board by reducing the overall thickness of a composite structure of a rigid wiring board (RPC) and a flexible insulating board (FPC).

The circuit wiring composite board according to the present invention has a film state in which a circuit wiring layer is provided on at least one rigid wiring board 1a and a flexible insulating board 12a, 12b in which a circuit wiring layer is provided on the rigid insulation board 2a. An overlapping portion (Xa1) having first and second flexible wiring boards 11a and 11b, wherein the first and second flexible wiring boards 11a and 11b are respectively overlapped and fixed to both plate surfaces of the rigid wiring board. And Xb1) and deformable portions Ya and Yb not overlapping with the plate surface, and electrically connecting the respective circuit wiring layers of the respective wiring boards to positions where the rigid wiring boards and the flexible wiring boards overlap. At least one of the interlayer conductive paths 4 and 44 penetrates.

Rigid, Flexible, Wiring Board, Conductive Path, Overlap, Wiring Layer

Description

Circuit wiring composite board {PRINTED CIRCUIT COMPOSITE BOARD}

1 is a partial vertical perspective view showing a circuit wiring composite substrate according to Embodiment 1 of the present invention.

2 is a vertical cross-sectional view showing a circuit wiring composite substrate according to a second embodiment of the present invention.

3 is a longitudinal sectional view showing a circuit wiring composite substrate according to a fourth embodiment of the present invention.

4 is an enlarged perspective view of a main portion of a circuit wiring composite substrate for explaining a specific example of the interlayer conductive path according to the present invention.

It is an enlarged perspective view of the principal part of the circuit wiring composite board for demonstrating the specific example of the interlayer conductive path which concerns on this invention.

6 is a partial longitudinal perspective view showing a circuit wiring composite substrate according to a sixth embodiment of the present invention.

Japanese Patent Application Publication No. 2003-133728

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a circuit wiring composite board combining a rigid wiring board and a flexible wiring board, and in particular, a circuit wiring composite board that can be suitably mounted in small electronic devices such as mobile phones and digital cameras. It is about.

For example, small electronic devices such as mobile phones and digital cameras are becoming thinner and lighter. Accordingly, electronic components such as circuit functional elements and circuit wiring boards are compact and light in order to be mounted in devices having a small space. The development of technology is in progress.

As the demands on the functions of the circuit wiring boards increase, the multifunctionalization proceeds, and there is a demand for a structure that is advantageous for accommodating small devices. Conventionally, as an example of a wiring board suitable for such a structure, a combination of a relatively rigid rigid wiring board (hereinafter referred to as RPC) and a flexible flexible wiring board (hereinafter referred to as FPC) is combined. Circuit wiring composite boards were used. The RPC mainly mounts circuit functional elements such as integrated circuit elements, and the FPC mainly plays the role of an internal circuit connection path or a transmission path. FPC is flexible, so it is advantageous to deform and accommodate in small spaces.

Such a conventional circuit wiring composite substrate has an FPC in the center with respect to the thickness direction thereof, and an RPC on both surfaces of a part thereof. In other words, in the part where FPC and RPC overlap, FPC comprises the inner layer which becomes a core, and RPC comprises the outer layer.

In addition, since the wiring layers of the RPC and the FPC are electrically connected to each other at the portion where these RPCs and the FPC overlap, a through hole (through hole) is formed by, for example, a drill, and the through hole is, for example, a metal. The interlayer conductive paths for each of the wiring layers are formed by plating with a thin film (for example, see the printed circuit board of the flex rigid structure of FIG. 4 of JP-A-2003-133728).

By the way, in the conventional technique mentioned above, the insulated substrate widely used for RPC and FPC is comprised, respectively, with a glass epoxy resin material and a polyimide resin material, respectively. The thickness of each insulating substrate is about 0.8 mm and tens of micrometers, respectively, ie the RPC is much thicker than the FPC.

In such a structure in which the thick RPC is superposed on both sides of the FPC, the portion has the largest thickness in the entire composite substrate, and the thickness determines the thickness of the entire composite substrate. If the thickness is too thick, it is necessary to increase the thickness of the metal plating of the inner wall of the through hole in order to secure the reliability of the interlayer conduction.

In general, in the step of thick metal plating in the through hole, plating is also performed on the wiring layer at the outermost side of the RPC at the same time. As a result, the thickness of the outermost wiring layer becomes large, and the overall flatness of the outer surface of the RPC decreases, so that a problem that it is difficult to form a good pattern when subsequent wiring patterning occurs.

In addition, since the portion where the RPC and the FPC overlap is thick, the processing time for forming the through hole by the drill is long, and the drill exchange is frequent, and the process time for forming the thick metal plating in the through hole is long. Therefore, the overall process time is long when manufacturing the circuit wiring composite substrate, and the production cost of the product is increased.

This invention is made | formed in order to solve the said problem, and provides the circuit wiring composite board thinned by reducing the total thickness of the composite structure of RPC and FPC.

According to one aspect of the present invention, a circuit wiring composite substrate includes at least one rigid wiring substrate including a rigid insulating substrate and a circuit wiring layer, and a first and second flexible wiring in a film state including a flexible insulating substrate and a circuit wiring layer. A circuit wiring composite substrate having a substrate, wherein the first and second flexible wiring substrates each have overlapping portions fixed to overlap each other on both surfaces of the rigid wiring substrate and fixed parts not overlapping on both surfaces, and The overlapping portion has at least one interlayer conductive path that electrically connects and penetrates each circuit wiring layer of each of these wiring boards.

It is preferable to penetrate the said 1st, 2nd flexible wiring board and the said rigid wiring board as said interlayer conductive path.

The rigid wiring board further includes first and second rigid wiring boards spaced apart from each other in a direction orthogonal to the thickness direction of the rigid wiring board and arranged in parallel. The first and second flexible wiring boards include: It is arranged to bridge the first and second rigid wiring boards.

The rigid wiring board includes first and second rigid wiring boards spaced apart from each other in a direction orthogonal to the thickness direction of the composite board and arranged in parallel, wherein the first flexible wiring board includes the first and second rigid boards. Preferably, the second flexible wiring board overlaps the second surface of one of the first and second rigid wiring boards, so as to mediate each first surface of the wiring board.

In the circuit wiring composite board, the first and second rigid wiring boards and the first and second rigid wiring boards arranged to be spaced apart in parallel to each other in a direction perpendicular to the thickness direction of the composite board and the first and second rigid wiring boards arranged to mediate And first and second rigid wiring boards each having a circuit wiring composite board formed of a second flexible wiring board as a first unit and spaced apart from each other in a direction orthogonal to a thickness direction of the composite board in parallel. 2 overlapped with the surface of the other side of the first rigid wiring board and the first flexible wiring board arranged to mediate the surface of each one side of the rigid wiring board does not overlap the surface of the other side of the first rigid wiring board A circuit wiring composite substrate made of the second flexible wiring board is used as a second unit, and is formed from the first and second units. It is more preferable that it is comprised by overlapping the some selected unit | unit and at least one of the said overlapping part of the said flexible wiring board is arrange | positioned at the outermost layer.

According to another aspect of the present invention, a circuit wiring composite substrate overlaps a rigid wiring board including a rigid insulating substrate and a circuit wiring layer, and overlaps and fixes the overlapping portion and the plate surface, which are overlapped with only the first surface of the rigid wiring board. A flexible wiring board having a deformable portion which is not provided, and at least one interlayer conductive path penetrating through the overlapping portion electrically connecting the flexible wiring board and the circuit wiring layer of the flexible wiring board.

It is preferable that it is a circuit wiring composite board | substrate which penetrates the said flexible wiring board and the said rigid wiring board as said interlayer conductive path.

It is preferable that it is a circuit wiring composite board in any one of the said aspects, Comprising: Another rigid wiring board is laminated | stacked on a part of the said deformable part of the said flexible wiring board.

Moreover, it is preferable that the said rigid wiring board has a laminated structure comprised by laminating | stacking the several rigid wiring board end plates. In addition, it is preferable that at least a part of the flexible wiring board overlapping the rigid wiring board includes a plurality of flexible wiring board end plates stacked thereon. Moreover, it is preferable that the wiring layer of a flexible wiring board is a circuit wiring composite board characterized by only one layer in the thickness direction of a board | substrate. In addition, it is preferable that it is a circuit wiring composite board characterized by including the wiring layer pattern which has a land part for mounting an electronic component in the exposed surface of at least one of the part which overlaps with the said rigid wiring board of the said flexible wiring board.

According to the present invention, a core portion of a circuit wiring composite substrate is constituted by a rigid wiring substrate (RPC), and the contact portions of a plurality of flexible wiring substrates (FPC) are superposed and fixed to both plate surfaces of the rigid wiring substrate, respectively. By making it a structure, the thickness of the overlapping part of RPC and FPC which becomes the largest thickness of a circuit wiring composite board | substrate, and the overall thickness of a composite board | substrate are drastically reduced compared with the prior art.

Therefore, the composite substrate is thinner than the conventional one, and the water solubility of the electronic device case space which becomes narrower is improved, so that the depth of the through hole for forming the interlayer conductive path and the thickness of the plated layer can be reduced, thereby reducing the processing time and the circuit. The effect which can form favorable pattern in subsequent wiring patterning with respect to a wiring composite substrate can be acquired.

EMBODIMENT OF THE INVENTION Below, Example 1-Example 6 of the circuit wiring composite substrate by this invention are demonstrated with reference to FIGS.

Example 1:

1 is a perspective view showing a partial longitudinal section of a circuit wiring composite substrate according to the first embodiment of the present invention. This circuit wiring composite board includes a plurality of rigid wiring boards (RPCs) having relatively high strength, for example, a first RPC 1a and a second RPC 1b, and a plurality of flexible wiring boards in a film state having flexibility. FPC), for example, a combination of the first FPC 11a and the second FPC 11b. The RPC mounts circuit function elements, and the FPC mainly serves as an internal circuit connection path or a transmission path. FPC is flexible and can be deformed to accommodate small spaces.

The said 1st and 2nd RPC is centered in the thickness direction of a composite substrate, and comprises the inner layer used as a core part of a composite substrate. Each of the FPCs is placed on both sides of the RPC and constitutes an outer layer of the composite substrate.

The said 1st (1a) and the 2nd RPC 1b are mutually spaced apart and mutually installed in the direction orthogonal to the thickness direction of a composite substrate. Both, for example, a plurality of circuit wiring layers 3a and 3b formed on both surfaces of the rigid insulating substrates 2a and 2b using a glass epoxy resin material by wiring patterning of copper foil by a printed wiring technique. That is, it has a double-sided wiring structure.

The said 1st and 2nd FPCs 11a and 11b are arrange | positioned in the upper and lower surfaces of each RPC, respectively, so that they may all mediate RPC 1a and 1b in facing position relationship, for example.

The first and second FPCs each have a plurality of circuit wiring layers 13a and 13b formed on one side of the flexible insulating substrates 12a and 12b by wiring patterning of copper foil by a printed wiring technique, that is, having a one-side wiring structure. .

These wiring layers 13a and 13b are in a transverse direction along the plate surface on the flexible insulating substrate, in other words, in a direction parallel to the plate surface, in a direction orthogonal to the arrangement direction of the rigid insulating substrates 2a and 2b. The plurality of wiring layers are provided in parallel with each other. On the other hand, these wiring layers 13a and 13b are all arrange | positioned with the wiring structure of one layer in the direction orthogonal to the plate surface of a flexible insulating board, ie, the thickness direction.

Here, even if the wiring layer is formed by stacking a plurality of conductive material layers and integrally, it can be regarded as a wiring structure of one layer substantially as long as it has the same function.

The flexible insulating substrates 12a and 12b of the FPC are formed of a film having a high surface smoothness using a flexible, for example, polyimide resin material, and the flexible insulating cover films 14a and 14b are formed on the wiring layer. (13a, 13b) and the surfaces of the flexible insulating substrates 12a, 12b on the side where these wiring layers are located are entirely coated.

For example, a polyimide resin is used for the cover films 14a and 14b to protect the surfaces of the wiring layers 13a and 13b. In the case where another circuit wiring layer is formed by wiring patterning on the outer surfaces of the cover films 14a and 14b, it is formed on a smooth and flat surface to facilitate formation of a good pattern.

The first and second FPCs 11a and 11b have overlapping portions Xa1, Xa2 and X b1 and Xb2, in which the first and second FPCs 11a and 11b are first and second. It overlaps with RPC1a, 1b, and is respectively fixed. The first and second FPCs 11a and 11b have portions Ya and Yb, which do not overlap with RPC, respectively, and the portions can be modified. When accommodating or embedding the circuit wiring composite substrate in an electronic device, the shape can be freely deformed, such as bending or bending the deformable portions Ya and Yb of the FPC. In particular, in the structure in which the FPCs 11a and 11b mediate between the RPCs 1a and 1b as in the present embodiment, the structure is hollow between the deformable portions Ya and Yb, so that the flexibility is excellent.

Between the overlapping portions Xa1, Xa2 and Xb1 and Xb2 of the first and second FPCs and the first and second RPCs 1a and 1b are fixed by pressing these members in a heat, and the rigid insulating substrates 2a and 2b of the RPC are fixed. It is bonded to each other and fixed by heat-reinforced epoxy resin. In addition, this mutual bonding is not limited to pressing by heat, but can also be performed with an adhesive material.

However, as the amount of information embedded in the device increases, the number of wiring layers on the FPC that serves as the information transmission path needs to increase. In the above prior art, in order to cope with an increase in the amount of information, the wiring layer on a single FPC as a core portion must be provided on both sides of the insulating substrate as well as on both sides, thereby increasing the strength of the FPC. In other words, the deformability of the FPC is lowered. However, in comparison with this, the FPC in this embodiment is mediated to the rigid wiring boards 1a and 1b, and a plurality of (for example, two) FPCs 11a and 11b are opposed to each other. ), It is possible to have a large number of wiring layers even in the one-side wiring structure described above.

Therefore, by making each of the FPCs 11a and 11b of the present embodiment have a wiring structure of one layer of single-sided wiring, flexibility that can be bent can be maintained, so that water solubility can be maintained or increased in the case space of the composite substrate, In addition, it is easy to ensure the number of more wiring layers. And the FPC improves the reliability as a wiring material by the high flexibility.

In addition, since the FPCs 11a and 11b have an arrangement relationship constituting the outermost layer of the circuit wiring composite substrate, when forming another wiring layer at a position corresponding to the RPC, the overlapping portions Xa1, The said other wiring layer can be formed on Xa2) by wiring patterning.

The glass epoxy insulating substrate of the said 1st, 2nd RPC (1a, 1b) is an epoxy resin impregnated into the framed glass fiber, and the flatness of an insulating substrate surface and a wiring layer is formed by the unevenness | corrugation which the mesh eye of glass fiber forms. This is not good. Therefore, when the RPC is disposed in the outermost layer as in the prior art, it is difficult for the wiring layer to form a good pattern. In this embodiment, since the surfaces of the overlapping portions Xa1 and Xa2 of the FPC are flat and smooth, the wiring layer formed on the overlapping portions of the FPC as the outermost layer can easily form a good pattern, and the pitch between the plurality of wiring layers can be precisely set. I can adjust it.

As described above, the circuit wiring composite substrate of the present embodiment has first and second RPCs 1a and 1b in the center of the thickness direction of the substrate as a core part constituting the inner layer of the composite substrate, and these RPCs are double-sided. The first and second FPCs 11a and 11b are thin so as to be sandwiched from each other to form an outer layer of the composite substrate. For this reason, the thickness of the overlapping part of RPC and FPC which becomes the largest thickness of a circuit wiring composite board | substrate, and the overall thickness of a composite board | substrate are significantly reduced compared with the prior art. Comparing these thicknesses numerically, when using an RPC using a glass epoxy resin of about 0.8 mm thickness and an FPC using a polyimide film having a thickness of about 25 μm, considering only the thickness of the insulating substrate, the thickness of the overlapping portion is about 1.63 mm. It is roughly half to about 0.85 mm (this embodiment) from the conventional technique.

As such, the thinned composite substrate is remarkably advantageous compared to the prior art when accommodated in a small space inside an increasingly compact electronic device. In particular, when the circuit wiring composite substrate is bent by folding a large number of FPCs and mounted in the device case, it is advantageous to further accommodate.

In general, in the portion where the substrates are superimposed, conduction between the substrates is required for electric signals or power supply. Specifically, the through hole is provided in the overlapping portion, and the interlayer conductive path is formed by plating in the through hole.

In the case where the through hole is provided in the overlapping portion of the RPC and the FPC, and the interlayer conductive path is formed by plating in the through hole, the total thickness of the overlapping portion is small to facilitate the formation of the through hole, and the thickness of the plating layer is smaller than before. Even if formed, the electrically-conductive reliability between layers can fully be obtained.

Therefore, the process time for forming the interlayer conductive path is significantly shortened compared with the conventional one. In addition, since the thickness of the plating layer in the through hole becomes small, the thickness of the plating layer to the wiring layer of the outermost layer of the circuit wiring composite substrate derived from the plating process is also small, and it is easy to obtain good pattern formation in the wiring patterning of the subsequent wiring layer.

In addition, the effect of shortening the through-hole processing time, extending the life of the drill, shortening the plating time, and the like can be obtained, and the synergistic effect of these effects reduces the product cost.

Example 2:

FIG. 2 is a longitudinal cross-sectional view of a circuit wiring composite board according to a second embodiment of the present invention, in which members substantially the same as those of the constituent members of the circuit wiring composite board in the first embodiment are assigned the same reference numerals, and description thereof will be omitted do.

In the present embodiment, the first RPC 1a is spaced apart in the right direction in the drawing, and the third RPCs 1c are provided in parallel. The third RPC 1c has a multilayer wiring structure. That is, the circuit wiring composite substrate of this embodiment uses the first-layer rigid insulated substrate 2c1 in which the plurality of wiring layers 3c1 are printed and wired on both sides, and the second-layer rigid insulated substrate 2c2 stacked thereon. Have. As for the 2nd layer rigid insulation board | substrate 2c2, the wiring layer 3c2 is printed and wired on the surface shown above in the figure.

The lower second FPC 11b does not overlap the overlapping portions Xb1 and Xb3 corresponding to the first and third RPCs 1a and 1c, and the first and third RPCs 1a and 1c, respectively. It has a deformable part Yb. The lower surface of the third RPC 1c is partially overlapped and fixed to one overlapping portion Xb3 of the second FPC 11b, and the upper surface is in contact with all FPCs.

The first FPC 11a disposed above the first and second RPCs 1a and 1b is similar to the first embodiment with respect to the overlapping portions Xa1 and Xa2 with the RPCs 1a and 1b and these RPCs. It has a deformable part Ya which does not overlap with each other. The upper surface of the second RPC 1b is fixed to overlap one of the contact portions Xa2. The lower surface of the second RPC 1b does not overlap with the second FPC 11b and is in a non-contact state with any FPC.

Also, the overlapping portion between the first RPC 1a shown in the center portion of FIG. 2 and the contact portions Xa1 and Xb1 of the respective FPCs is provided with a through hole TH therethrough, so that metal plating is performed in the through hole TH. The interlayer conductive path 4 which implemented this is formed.

In this way, the second RPC 1b and the third RPC 1c are freely spaced from the FPCs or the thick RPCs having a thin substrate thickness because one surface thereof is spatially opened from the respective F PCs 11a and 11b. You can choose to use it. Therefore, as described above, for example, the third RPC 1c having a thicker multilayered wiring structure can be embedded, and more various kinds of composite substrates can be commercialized by embedding RPCs of various structures.

And with respect to the said 1st RPC 1a (approximately center of FIG. 2) used as a core part of a composite substrate, the upper 1st FPC 11a and lower 2nd FPC 11b in a figure are mutually different directions It can arrange | position in various directions, such as arrange | positioning to (left-right direction in FIG. 2). That is, FPC and RPC may be combined in various ways as compared with the prior art.

In addition, circuit elements such as functional elements and wirings mounted on the upper side of the second RPC 1b, and circuit elements mounted on the lower side of the third RPC 1c include the first FPC 11a on the upper surface side, Electrical connection is possible through the said interlayer conductive path 4 and the said lower 2nd FPC 11b. In this way, in particular, the electrical connection between each circuit element mounted three-dimensionally on both front and rear surfaces of the RPC can be easily performed.

In other words, by having a structure in which one surface of the RPC overlaps the FPC and the other is in a non-contact state, conduction between the two substrate wiring layers at the overlapping portion can be ensured, and design freedom of the wiring pattern is improved. .

In addition, also in this embodiment, since the thickness of the overlapping portion of the RPC and the FPC is small, similarly to the first embodiment, the circuit composite wiring composite substrate is advantageous for accommodating a small space inside the electronic device, The effect of shortening, extending the life of the drill, shortening the plating time, reducing the cost, and forming a good pattern of the subsequent wiring layer can be obtained.

By the way, in the field of printed wiring technology, in recent years, combining RPC, FPC, or RPC and FPC is considered preferable, and the development of the connection technology between boards by these various combinations is progressing. Correspondingly, a multilayer wiring structure can also be constituted by stacking a plurality of units as the units of the circuit wiring composite substrates shown in the first and second embodiments, respectively (Example 3). In this case, another RPC may be interposed between the units (Example 4). In addition, a multilayer wiring structure may be partially configured by stacking only a part of other units with respect to the units of the composite substrate (Example 5).

Next, the specific example of the circuit wiring composite board | substrate of this invention which concerns on the said Example 3-Example 5 suitable for the said board | substrate connection is demonstrated.

Example 3:

In the present embodiment, with respect to the first embodiment, a plurality of the unit pieces are laminated with the circuit wiring composite substrate shown in FIG. 1 as the first unit, and a circuit wiring composite substrate having a laminated structure is configured. It exists in the position which overlaps with each other between 1st RPC 1a of each unit, and is in the position which overlaps with each other between 2nd RPC 1b of the other.

FPCs are disposed on outermost layers of the upper and lower surfaces of the laminated structure, respectively, and the first FPC 11a and the second FPC 11b overlap each other at upper and lower intermediate positions. In other words, the FPCs are connected to each other.

Similarly, a plurality of unit bodies are sequentially stacked in the up-down direction with respect to the sheet of the drawing as the second unit body of the circuit wiring composite substrate shown in FIG. 2 according to the second embodiment, thereby forming a circuit wiring composite substrate of a laminated structure. You may.

In addition, similarly, by laminating the first unit composed of the circuit wiring composite substrate shown in FIG. 1 and the second unit composed of the circuit wiring composite substrate shown in FIG. It may be formed.

That is, the circuit wiring composite substrate of the present embodiment is superimposed by combining a plurality of units arbitrarily selected from the first and second units, and can be combined by various methods.

Example 4:

The circuit wiring composite board of Example 4 is demonstrated with reference to FIG. The first RPC 31 and the second RPC 32 of the laminated structure arranged in the center of the substrate in the thickness direction (up and down direction in the drawing) are mutually intersected in the direction (left and right direction in the drawing) intersecting with the thickness direction of the substrate. It is installed in parallel at predetermined intervals.

The first RPC 31 has RPC end plates 31b and 31c on both sides of the central RPC end plate 31a, and the second RPC 32 has RPC end plates 32b and both sides on the center RPC end plate 32a. 32c) is adhere | attached with an adhesive material, for example, and is comprised, respectively. Comparing the correlations between the plate thicknesses of the respective RPCs, the RPC 31a, the RPC 32a, the RPC 31b, the RPC 32b, the RPC 31c, and the RPC 32c each have almost the same thickness. Has

The first RPC 31 and the second RPC 32 each have a substrate connection between a plurality of stacked RPCs.

The first FPC 11a and the second FPC 11b are disposed and attached to upper and lower surfaces of the first RPC 31 and the second RPC 32 so as to mediate the RPCs.

Here, the 1st FPC 11a and the 2nd FPC 11b have shown the same FPC as each FPC shown in FIG. 1 as an example, The same code | symbol is attached | subjected about the same part as FIG. 1, and the description is abbreviate | omitted. have. Of course, each FPC may use an FPC having a shape different from that of the first embodiment.

Accordingly, the first RPC 31 and the second RPC 32 correspond to the first and second RPCs 1a and 1b in the first embodiment, respectively, and the circuit wiring composite substrate of the fourth embodiment is basically May be similar to the circuit wiring composite substrate of the first embodiment.

In addition, in the present embodiment, the surface of the part Xa1 overlapping the first RPC 31 of the first FPC 11a and the part overlapping the second RPC 32 of the second FPC 11b. All surfaces of (Xb2) are exposed. Each exposed surface may form a different wiring layer pattern and at least one or more surfaces selected from the overlapping portions Xa1, Xa2, Xb1 and Xb2 may be exposed.

The selected exposed surface is secured, and for example, the overlapping portion Xa2 of the first FPC 11a and the second RPC 32, the overlapping portion of the second FPC 11b and the first RPC 31 ( The fourth RPC 33 and the fifth RPC 34 may be attached to the position of Xb1) or the like depending on the function required for the circuit.

In addition, in the FPC 11b, a sixth RPC 35 and a seventh RPC 36 are added to both surfaces of the middle of the first and second RPCs 31 and 32, that is, a part of the deformable portion Yb. Alternatively, it may be laminated. The sixth and seventh RPCs 35 and 36 may have, for example, an electrical relay function between the circuit function of the first RPC 31 and the circuit function of the second RPC 32. . In addition, only one of the RPCs 35 and 36 may be laminated on a part of the deformable portion Yb.

By the way, when assembling a circuit wiring composite board by combining many RPCs and FPCs, it can divide into various units previously, and can combine and assemble these several units.

Next, the specific example is demonstrated.

(Assembly method example 1):

"First step";

A first unit composed of a composite substrate by the first FPC 11a, the RPCs 31b and 32b, and the fourth RPC 33 is prepared.

"Second step";

A second unit composed of a composite substrate by the second FPC 11b, the RPCs 31c and 32c, and the fifth to seventh RPCs 34 to 36 is prepared.

"Third step";

RPCs 31a and 32a are arranged in parallel on the same plane at predetermined intervals, and the first and second units are stacked so as to have the configuration as shown in FIG. 3 above and below, to assemble the circuit wiring composite substrate.

(Assembly Method Example 2):

"First step";

A third unit composed of the composite substrate by the first FPC 11a and the fourth RPC 33 is prepared.

"Second step";

A fourth unit composed of the composite substrate by the second FPC 11b and the fifth to seventh RPCs 34 to 36 is prepared.

"Third step";

The first RPC 31 (the laminated structure of the RPCs 31a, 31b, and 31c) is used as the fifth unit, and the second RPC 32 (the laminated structure of the RPCs 32a, 32b, and 32c) is used as the sixth unit. Prepare.

"Fourth step";

The fifth unit (the first RPC 31) and the sixth unit (the second RPC 32) are installed in parallel on the same plane at a predetermined interval, and the third and fourth units are shown in FIG. 3 above and below. Laminated | stacked so that it may become a structure like this, and a circuit wiring composite board is assembled.

In addition, the first FPC 11a, the upper RPC 32b and the fourth RPC 33 above the second RPC 32 may be used as a unit, or the second FPC 11b and the first RPC ( The lower RPC 31c and the fifth to seventh RPCs 34 to 36 below 31 may be used as a unit. In this way, it is possible to select a structure and a combination of units suitable for the rationalization of the assembly process line, the reduction of the process cost, and the like. The order of each step can be arbitrarily selected.

The circuit wiring composite substrate of this embodiment has the same effects as those in the above embodiments, and can be connected between the substrates in various forms.

In addition, in the figure of this Example, the illustration of the structure of the interlayer electrically conductive path | route with respect to laminated structures, such as FPC and RPC, is abbreviate | omitted, but the interlayer electrically conductive path is the same as Example 6 and Example 7 mentioned later at a desired position. Is formed. In addition, attachment of structures such as an insulating substrate and a wiring layer of each RPC, and between RPCs and FPCs can be performed by conventional techniques. Accordingly, the illustration and description are simplified here.

Example 5:

In the circuit wiring composite board according to the fifth embodiment, a plurality of units of the circuit wiring composite board according to the first embodiment shown in FIG. 1 are moved left and right in the drawing to be different from the first RPC 1a of one unit. The second RPC 1b of the unit unit is overlapped to have a partially laminated structure.

In addition, the circuit wiring composite board of the present embodiment moves the plurality of units of the circuit wiring composite board shown in FIG. 2 with respect to the second embodiment to the left and right in the drawing, and is different from the first RPC 1a of one unit. The second RPC 1b of the unit of overlap may have a partially stacked structure.

In addition, the unit of each circuit wiring composite substrate according to the first and second embodiments may be partially stacked in a similar manner to form a circuit wiring composite substrate having a laminated structure of this embodiment.

That is, circuit wiring of various forms is made by combining and superimposing a plurality of units arbitrarily selected from these units to the left and right by using each circuit wiring composite substrate according to the first and second embodiments as units, respectively. A composite substrate can be obtained. Such an embodiment can achieve the same effects as those in the above embodiments.

(Interlayer Challenges):

Next, the interlayer conductive path will be described in detail with reference to FIGS. 4 and 5. 4 is an enlarged view of a portion in which the interlayer conductive path and the like are provided in the second RPC 1b of the circuit wiring composite substrate according to the first embodiment shown in FIG. 1. In FIG. 4, the same code | symbol is attached | subjected to the same part as FIG. 1, and the description is abbreviate | omitted.

On the exposed surface of the overlapping portion Xa2 of the first FPC 11a with respect to the second RPC 1b, a separate wiring layer pattern as shown in the dot pattern in the figure is formed with a good pattern, apart from the wiring layer 13a. It is. The wiring layer pattern includes, for example, a plurality of land portions 41 arranged in a rectangular frame shape, a plurality of wiring layers 42 connected to each land portion 41, and a plurality of interlayers connected to some wiring layers 42. The connecting end 43 is included.

Through-holes (through holes) TH passing through the first FPC 11a, the second RPC 1b, and the second FPC 11b are formed at positions corresponding to the interlayer connecting end 43. An interlayer conductive path 44 is formed on the inner surface of each through hole TH by plating a metal having good conductivity such as copper, for example.

In the plurality of land portions 41, for example, a lead terminal (pin) extending from an electronic circuit element such as an individual semiconductor, an IC chip, an individual semiconductor with a package, or an IC device is face-down bonded. Electrically connected and fixed by bonding or soldering.

In addition, on the exposed surface of the overlapping portion Xa2 of the first FPC 11a, an additional or auxiliary other fourth RPC 33 shown in the fourth embodiment, instead of the electronic circuit element (see Fig. 3). You can also install In this case, the pattern of the wiring layer formed in the exposed surface of the said overlapping part Xa2 becomes a pattern shape according to the connection form with the wiring layer of the said 4th RPC 33. In FIG.

As described above, the portions Xa1, Xa2, Xb1, and Xb2 in which the first FPC 11a or the second FPC 11b overlap with the respective RPCs are formed on at least some of their exposed or outer surfaces of the electronic circuit element. Or an electronic component such as an additional or auxiliary RPC, and can be used as a region for forming a wiring layer pattern therefor.

Also in the said Example 1-Example 5, at least one part of the overlapping part with respect to RPC of FPC can be used as such a wiring layer pattern formation area.

The interlayer conductive paths 44 partially overlap both surfaces of the second RPC 1b, and each board wiring layer of the first FPC 11a, the second RPC 1b, and the second FPC 11b. They are electrically connected three-dimensionally to each other.

FIG. 5 is an enlarged view of a portion in which the interlayer conductive path and the like are provided in a portion corresponding to the second RPC 1b of the circuit wiring composite substrate of the second embodiment shown in FIG. 2. The same parts as in FIG. 2 are assigned the same reference numerals, and description thereof is omitted.

That is, the circuit wiring composite substrate of this embodiment is formed by overlapping a part of the first FPC 11a only on one side (upper surface in the figure) of the second RPC 1b, and on the other side of the second RPC 1b. The surface (lower surface in the drawing) is an exposed surface.

In the overlapping portion Xa2 of the second RPC 1b and the first FPC 11a, a through hole TH partially penetrating the first FPC 11a and the second RPC 1b is formed, and is penetrated. On the inner surface of the empty TH, an interlayer conductive path 44 plated with a metal having good conductivity, such as the interlayer conductive path shown in FIG. 4, is formed.

The interlayer conductive path 44 is formed on the exposed surface of the interlayer connecting end 43 of the wiring layer pattern formed on the outer surface of the overlapping portion Xa2 of the first FPC 11a and the second RPC 1b. The interlayer connection end portion of the circuit wiring layer 3b is electrically connected.

According to the circuit wiring composite substrate of this embodiment, the RPC and the FPC overlap, and the overall thickness becomes thinner than that shown in FIG. And the outer surface of the said overlapping part Xa2 is used as an area | region for forming the wiring layer pattern for mounting an electronic component, and a favorable pattern is formed. In addition, as described in the second embodiment, there is an effect that the thickness of the first RPC 1a can be freely selected by the presence of the exposed surface of the first RPC 1a.

The interlayer conductive path may be formed in the same through-hole method as shown in Figs. 4 and 5, may be formed in the via hole method instead, or may be formed by combining both methods. For example, when connecting the circuit wiring layer of the said 2nd RPC 1b and the circuit wiring layer of the said 1st FPC 11a, a through-hole is made only to the said 1st FPC 11a of the overlap part Xa2 of these board | substrates. The interlayer conductive paths between the respective circuit wiring layers of the substrates may be formed by a via hole method.

Example 6:

Next, the circuit wiring composite substrate according to the sixth embodiment will be described with reference to FIG. 6. The circuit wiring composite board of the present embodiment superimposes and adds another FPC to the circuit wiring composite board of Example 1 shown in FIG. The same reference numerals are given to the same parts as in Fig. 1, and description thereof is omitted.

That is, the 1st FPC 11a arrange | positioned at one surface (upper surface in drawing) of the 1st and 2nd RPC 1a, 1b, for example, has two FPC end plates 11a1 and FPC end plates 11a2. It has a laminated structure. The FPC end plate 11a1 is a one-layer wiring structure having the circuit wiring layer 13a similarly to the first FPC in the first embodiment, and the single layer wiring having the circuit wiring layer 13c similarly to the FPC end plate 11a2. Structure. Therefore, the 1st FPC 11a is a multilayer wiring structure by the said circuit wiring layers 13a and 13c in the thickness direction.

Moreover, the 2nd FPC 11b arrange | positioned at the other surface (lower surface of drawing) of said RPC 1a, 1b is laminated structure of two FPC end plates 11b1, and FPC end plate 11b2, for example. Has The FPC end plate 11b1 is a one layer wiring structure having a circuit wiring layer 13b similarly to the second FPC in Embodiment 1, and has a one layer wiring structure having a circuit wiring layer 13d similarly to the FPC end plate 11b2. to be. Therefore, the 2nd FPC 11b is a multilayer wiring structure by the said circuit wiring layers 13b and 13d in the thickness direction.

As described above, the first and second FPCs are not limited to a single layer wiring structure like the FPC in the first embodiment, but are laminated with the FPC 11a1 and the FPC 11a2, and the FPC end plates 11b1 and FPC ( It may be a plurality of layers (multilayer wiring structure) by stacking 11b2).

In Fig. 6, it is shown that a plurality of FPCs are stacked over the entire surface, but the present invention can also be implemented as a structure having a portion to be stacked and a portion not to be stacked. In addition, the wiring pitch or pattern shape of the said circuit wiring layers 13c-13d can be arbitrarily determined according to the requirements to a system, and may differ.

Thus, the 1st, 2nd FPC arrange | positioned at the said upper surface and lower surface is a laminated structure which has a some layer (for example, two layers) in all at least one part. The number of floors of the FPC can be appropriately increased or decreased depending on the amount of information handled in the electronic device system. Of course, it can be variously combined, such as two layers of the upper surface FPC, one layer of the lower surface FPC, four layers of the upper surface FPC, and three layers of the lower surface FPC.

The number of overlapping layers of each FPC of the laminated structure is appropriate depending on the length and width of the deformable portion required for accommodation in the device box, the degree of deformation (flexibility), the number of wiring layers related to the amount of information of the electronic device system, and the like. Can be selected. Accordingly, the needs of various electronic device systems can be satisfied. The circuit wiring composite substrate of this embodiment can also obtain the same effects as those of the respective embodiments.

In addition, although the structure of the interlayer conductive path in laminated structures, such as FPC and RPC, is abbreviate | omitted in FIG. 6, the interlayer conductive path 44 as shown in FIG. 4 or FIG. 5 is the same in a desired position. Can be formed. In addition, the laminated structure like the said 1st, 2nd FPC can be applied also in any said Example.

As mentioned above, although this invention was demonstrated with reference to the preferable embodiment, this invention is not limited to the said embodiment. According to the above disclosure, a person having ordinary skill in the art of the present invention can implement the present invention by modification or modification of the embodiment.

By properly combining Examples 1 to 6 according to the present invention to construct a circuit wiring composite substrate, the overall thickness of the composite substrate can be reduced, forming a good pattern circuit for mounting electronic components on the outermost layer of the substrate, and designing a circuit. Effects such as the degree of freedom and the built-inness of the device box, the reduction of through-hole machining time, the extension of drill life, the reduction of plating time, and the reduction of manufacturing process cost can be obtained.

Claims (12)

A circuit wiring composite board having at least one rigid wiring board including a rigid insulating board and a circuit wiring layer, and a first and second flexible wiring board in a film state including a flexible insulating board and a circuit wiring layer. And the first and second flexible wiring boards respectively have overlapping portions fixed by overlapping on both surfaces of the rigid wiring boards and deformable portions not overlapping on both surfaces, and the overlapping portions each have their respective wirings. A circuit wiring composite board, comprising at least one interlayer conductive path electrically connected to and passing through each circuit wiring layer of the substrate. The method of claim 1, The interlayer conductive path penetrates through the first and second flexible wiring boards and the rigid wiring board. The method of claim 1, The rigid wiring board includes first and second rigid wiring boards spaced apart from each other in a direction orthogonal to the thickness direction of the rigid wiring board and arranged in parallel, wherein the first and second flexible wiring boards are each of the first and second flexible wiring boards. And a second rigid wiring board arranged to bridge the second rigid wiring board. The method of claim 1, The rigid wiring board includes first and second rigid wiring boards spaced apart from each other in a direction orthogonal to the thickness direction of the composite substrate, and the first flexible wiring board includes the first and second rigid wiring boards. And a second flexible wiring board overlapping a second surface of either one of the first and second rigid wiring boards. The first and second rigid wiring boards and the first and second rigid wiring boards arranged to be spaced apart from each other in a direction perpendicular to the thickness direction of the circuit wiring composite substrate according to claim 3 and the first and second rigid wiring boards arranged to mediate And first and second rigid wiring boards each having a circuit wiring composite board formed of a second flexible wiring board as a first unit and spaced apart from each other in parallel in a direction orthogonal to the thickness direction of the composite board according to claim 4, wherein Overlap the other side of the first flexible wiring board and the second flexible wiring board, the first flexible wiring board disposed to mediate one side of each of the first and second rigid wiring boards, and not the other side of the first rigid wiring board The circuit wiring composite board which consists of the said 2nd flexible wiring board is used as a 2nd unit body, and is arbitrarily chosen from the said 1st and 2nd unit body. And a plurality of selected units overlapping each other, wherein at least one of the overlapping portions of the flexible wiring board is disposed at an outermost layer. A rigid wiring board comprising a rigid insulating board and a circuit wiring layer, a flexible wiring board having an overlapping portion fixed by overlapping only the first surface of the rigid wiring board and a deformable portion not overlapping the plate surface, and the flexible wiring board And at least one interlayer conductive path passing through the overlapping portion electrically connecting the circuit wiring layer of the flexible wiring board. The method of claim 6, The interlayer conductive path penetrates through the flexible wiring board and the rigid wiring board. The method according to claim 1 or 6, The other rigid wiring board is laminated | stacked on a part of said deformable part of the said flexible wiring board, The circuit wiring composite board | substrate characterized by the above-mentioned. The method according to claim 1 or 6, The said rigid wiring board has a laminated structure comprised by laminating a plurality of rigid wiring board end plates, The circuit wiring composite board characterized by the above-mentioned. The method according to claim 1 or 6, And at least some of the flexible wiring boards superimposed on the rigid wiring boards include a plurality of flexible wiring board end plates stacked thereon. The method according to claim 1 or 6, A circuit wiring composite board, wherein the wiring layer of the flexible wiring board is only one layer in the thickness direction of the board. The method according to claim 1 or 6, And a wiring layer pattern having a land portion for mounting an electronic component on at least one exposed surface of an overlapping portion of the flexible wiring board and the rigid wiring board.

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