JP2002171067A - Multi-layered three-dimensional circuit board and its manufacturing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a multilayered three-dimensional circuit board which is compact inspect of its being multilayered. SOLUTION: This board is equipped with a three-dimensional circuit board 1 as a molding and a multilayered circuit part formed by laminating multiple layers of circuit patterns 21, 22 and so on at least one surface of the solid circuit board 1 across an insulating layer 4. Circuit patterns 30 and 31 for connection which each have at least one end connected to one of the circuit patterns 21, 22 and so on are provided on a cut end surface, formed at the multilayered circuit part, where end surfaces of the circuit patterns are exposed. The circuit patterns 31 and 32 for connection are provided on the cut end surface, where the end parts of the circuit patterns 21, 22 and so on are exposed by cutting the multilayered circuit part on the solid circuit board 1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multilayer three-dimensional circuit board in which circuit patterns are formed in multiple layers, and a method for manufacturing the same.

[0002]

2. Description of the Related Art There is also a demand for multi-layered circuit boards (MID boards) for high-density mounting and to improve the degree of freedom in circuit design. For this reason, Japanese Patent Application Laid-Open No. Hei. There has been disclosed a combination of a three-dimensional circuit board having a three-dimensional circuit board and a three-dimensional circuit board having a hole, and connecting the circuit patterns of the three-dimensional circuit boards with conductors provided on the protrusions fitted into the holes. Japanese Unexamined Patent Publication No. Hei 7-249873 discloses that a three-dimensional circuit board having a projection is formed by two-color molding to form another three-dimensional circuit board, and the two-dimensional circuit board is formed on the end face of the projection positioned on the surface of the other three-dimensional circuit board. There is disclosed an arrangement in which connection between circuit patterns on a circuit board is performed. In this case, it is possible to avoid problems when using a through hole or a via hole.

[0003]

However, in the two publications described above, since a plurality of three-dimensional circuit boards, which are injection molded products, are stacked, the thickness is inevitably increased. It is difficult to reduce the size of a multi-layered circuit board such as four layers, and this impairs the characteristics of the three-dimensional circuit board regarding miniaturization.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a multilayer three-dimensional circuit board which is multilayer and compact, and a method of manufacturing the same.

[0005]

SUMMARY OF THE INVENTION A multilayer three-dimensional circuit board according to the present invention comprises a three-dimensional circuit board which is a molded product and a plurality of circuit patterns formed by interposing an insulating layer on at least one surface of the three-dimensional circuit board. And a multilayer circuit portion in which the laminated circuit portion is laminated, and at least one end is connected to any of the circuit patterns of the plurality of layers on the cut end surface formed in the multilayer circuit portion and exposing the end surface of the circuit pattern. It is characterized in that a connection circuit pattern is provided. A multi-layer circuit portion in which a plurality of circuit patterns are laminated via an insulating layer is provided on a three-dimensional circuit board, and the connection between the plurality of circuit patterns is cut to expose an end of the circuit pattern. The connection circuit pattern provided on the cut end face is used.

The cut end face may extend over the three-dimensional circuit board, and a part of the connection circuit pattern may be formed on the cut end face of the three-dimensional circuit board.

Further, a component mounting portion may be provided on a cut end surface of the three-dimensional circuit board, and a connection circuit pattern may be connected to the component mounting portion.

[0008] Further, a through recess is formed in the surface of the three-dimensional circuit board through the multilayer circuit portion, and a component mounting portion is formed on the bottom surface of the through recess. A connection circuit pattern formed on a cut end surface that is an inner wall of the through recess may be connected, and a connection circuit pattern may be formed on the bottom surface of the through recess and the cut end surface that is the inner wall of the through recess. It may be formed.

In any case, it is preferable to form the cut end surface as an inclined surface.

[0010] In the method for manufacturing a multilayer three-dimensional circuit board according to the present invention, a multilayer circuit part is formed by laminating a plurality of circuit patterns with an insulating layer interposed on at least one surface of a three-dimensional circuit board which is a molded product. Then, the multilayer circuit portion is cut to expose the end of the circuit pattern at the cut end face, and thereafter, a copper thin film is formed on the cut end face, and the copper thin film is subjected to laser processing to form a portion required as a circuit. Unnecessary portions are separated, and thereafter, plating is performed only on portions necessary as circuits, thereby forming a connection circuit pattern at least one end of which is connected to any of the plurality of circuit patterns. Have.

At this time, a part of the three-dimensional circuit board is cut off when cutting the multi-layer circuit portion, and a part of the three-dimensional circuit board is formed on the cut end face of the three-dimensional circuit board formed when the connection circuit pattern is formed. By increasing the area of the cut end face on which the connection pattern can be formed, the degree of freedom of the arrangement of the connection circuit pattern can be increased, or the components mounted on the connection circuit pattern when the connection circuit pattern is formed can be mounted. A part may be formed to increase the degree of freedom of arrangement of the component mounting part.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to an example of an embodiment. In FIG. 1, reference numeral 1 denotes a substrate as a molded product by injection molding, and the surface thereof is formed by a conventional method, for example, the entire surface After forming a copper thin film by a copper sputtering method, a portion necessary for a circuit and an unnecessary portion are separated by performing a laser processing or the like on the copper thin film. The circuit pattern 21 is formed by performing plating by plating. Further, the insulating layer 4 is formed on the circuit pattern 21 and another circuit pattern 22 is formed on the insulating layer 4 by a conventional method.
And another circuit pattern 23 is formed on the insulating layer 4 by an ordinary method.
3 and a circuit pattern 24 through an insulating layer 4 in a conventional manner.
Is formed on the substrate 1 for convenience.

An example of the manufacturing method will be described in more detail. A copper thin film layer is formed on the entire surface of the substrate 1 by copper sputtering or CVD, and then a portion necessary and unnecessary for a circuit in the copper thin film layer by a laser. Then, plating is performed by electroplating only on a portion necessary for a circuit, and an unnecessary portion is removed by etching to form a circuit pattern 21.

Thereafter, an insulating layer 4 covering the circuit pattern 21 is formed on the entire surface of the substrate 1, and a copper thin film layer is formed thereon, and a portion of the copper thin film layer necessary and unnecessary as a circuit is formed. Separation by laser processing or the like, and generation of the circuit pattern 22 by plating are performed. After that, the insulating layer 4
By repeating the formation of the above and the formation of the circuit pattern,
Circuit patterns 23 and 24 are formed.

As described above, the multilayer circuit patterns 21 and
After forming a multilayer circuit section having 2, 23, 24,
Next, the circuit patterns 21, 22, 23, and 24 are exposed on the cut end surfaces by cutting the multilayer circuit portion. Note that only the circuit patterns that need to be connected to the circuit patterns of other layers may be exposed.

The cut end face is further subjected to formation of a copper thin film layer, separation of a portion necessary for a circuit and an unnecessary portion of the copper thin film layer by laser processing or the like. Plating is performed by plating to form connection circuit patterns 30, 31 connected to any of the circuit patterns 21, 22, 23, 24 at least one end of which is exposed to the cut end surface.

In cutting the multilayer circuit portion, the substrate 1 is also cut at the same time, and a cut end face is also formed on the substrate 1. When forming the connection circuit patterns 30 and 31, as shown in FIG. A part of the connection circuit patterns 30 and 31 may be located on the cut end surface of the substrate 1 that is continuous with the cut end surface of the portion. Connection circuit pattern 3
Since the area in which 0 and 31 can be formed is increased, the degree of freedom of arrangement of the connection circuit patterns 30 and 31 can be increased.

Further, a component mounting portion for surface mounting components such as ICs and chip components is formed on portions of the connection circuit patterns 30 and 31 located on the cut end surface of the substrate 1 as shown in FIG. By mounting the component 3 on the circuit board 3, the circuit patterns 21, 22, 23, 24 and the component 3 may be connected by the connection circuit patterns 30, 31. When cutting the multilayer circuit portion and the substrate 1, as shown in FIG. 4, in addition to cutting off a part of the substrate 1, a hole may be formed in the substrate 1.

FIG. 5 shows another example. This is provided with a through recess 5 penetrating the multilayer circuit portion and forming a recess on the surface of the three-dimensional circuit board, and for connecting across the cut end face which is the inner wall of the through recess 5 and the bottom surface of the through recess 5. Circuit pattern 3
0, 31 are formed, and component mounting portions are formed on the connection circuit patterns 30, 31 on the bottom surface of the through recess 5, and the component 3 is mounted on the bottom surface.

In this case, the through-hole 5 is formed by cutting off a part of the three-dimensional circuit board at the same time as cutting the multilayer circuit portion, and thereafter, a copper thin film extends from the cut end surface, which is the inner wall of the through-hole 5, to the bottom of the through-hole. After forming a layer, the necessary parts and unnecessary parts of the copper thin film layer are separated by laser processing, etc., and the parts necessary for the circuits are plated by electroplating, so that the component mounting part is The provided connection circuit patterns 30 and 31 are formed.

At this time, the penetrating concave portion 5 has a rectangular shape whose cut end face is located in four directions as shown in FIG. 6A, or has two cut end faces facing each other as shown in FIG. 6B. May be any of the groove-shaped ones located at Also,
When mounting the component 3 in the through recess 5, the inside of the through recess 5 may be filled with a sealing resin.

As shown in FIG. 7, the connection for connection between the circuit patterns 21 to 24 whose ends are exposed on the left and right cut end surfaces without mounting the component 4 on the bottom surface of the through recess 5. The circuit patterns 30 and 31 may pass through the bottom surface.

In FIG. 7, the cut end surface is formed as an inclined surface. However, if the cut end surface is formed as an inclined surface as described above, a laser is irradiated when the connection circuit patterns 30 and 31 are formed. If you have a process,
Processing becomes easy.

Although the connection circuit patterns 30 and 31 are formed after the formation of the circuit pattern 24 located on the outermost layer, a step before the formation of the circuit pattern 24 located on the outermost layer is shown here. Then, the circuit pattern 24 located on the outermost layer and the connection circuit pattern 3 are cut.
0 and 31 may be formed at the same time.

[0025]

As described above, according to the present invention, a three-dimensional circuit board which is a molded product, and a multilayer circuit part in which a plurality of circuit patterns are laminated on at least one surface of the three-dimensional circuit board with an insulating layer interposed therebetween. A connection circuit pattern having at least one end connected to any of the plurality of circuit patterns is provided on the cut end surface formed on the multilayer circuit portion and exposing the end surface of the circuit pattern. The connection between a plurality of circuit patterns in a multi-layer circuit portion on a three-dimensional circuit board is performed by a connection circuit pattern provided on a cut end surface that cuts the multi-layer circuit portion and exposes an end of the circuit pattern. Since it is intended to be performed, compared to the case of laminating a plurality of three-dimensional circuit boards, it is possible to achieve multilayering while maintaining a small size, and furthermore, the connection circuit pattern is Since it is formed on the stump, the connection circuit pattern can be formed by a normal circuit pattern forming method differently from the case of using a through hole or a via hole. The connection of the circuit pattern can be reliably performed without incurring the problem in the case of using.

If the cut end surface extends over the three-dimensional circuit board and a part of the connection circuit pattern is formed on the cut end surface of the three-dimensional circuit board, the connection circuit pattern can be formed over a wide surface. In addition, the formation of the connection circuit pattern becomes easy, and the connection circuit pattern of a complicated pattern can be formed.

Further, if a component mounting portion is provided on the cut end surface of the three-dimensional circuit board and a connection circuit pattern is connected to the component mounting portion, the mounting surface of the component can be increased, and at the same time, the component mounting time can be reduced. The degree of freedom in designing circuit patterns can be increased.

Further, there is provided a through recess which penetrates the multilayer circuit portion and forms a recess on the surface of the three-dimensional circuit board. A component mounting portion is formed on the bottom surface of the through recess, and the component mounting portion is formed on the component mounting portion. By connecting the connection circuit pattern formed on the cut end face which is the inner wall of the through recess, the connection circuit pattern can be routed to the component mounting portion from the plurality of cut end faces surrounding the through recess, and further the circuit pattern The degree of freedom in design can be increased, and since the through recessed portion may be formed in accordance with the size of the component, mounting of a large component is also possible.

If connection circuit patterns are formed on the bottom surface of the through recess and the cut end surface that is the inner wall of the through recess, the design of the connection circuit pattern for connection between the circuit patterns is free. The degree of improvement is improved, and complicated connections can be easily made.

In any case, if the cut end face is formed as an inclined surface, the exposed area of the end face of the circuit pattern exposed on the cut end face becomes large, so that the connection with the connection circuit pattern can be improved. In addition, when laser processing is performed on the cut end surface during manufacturing, laser processing becomes easy.

In the method of manufacturing a multilayer three-dimensional circuit board according to the present invention, a multilayer circuit part is formed by laminating a plurality of circuit patterns on at least one surface of a molded three-dimensional circuit board with an insulating layer interposed therebetween. Then, the multilayer circuit portion is cut to expose the end of the circuit pattern at the cut end face, and thereafter, a copper thin film is formed on the cut end face, and the copper thin film is subjected to laser processing to form a portion required as a circuit. Separating unnecessary portions from each other, and then plating only necessary portions as circuits to form a connection circuit pattern at least one end of which is connected to any of the plurality of circuit patterns. A multilayer three-dimensional circuit board can be easily manufactured. In particular, the connection circuit pattern having at least one end connected to an end of the circuit pattern exposed on the cut end face is cut. To form the end surface, the connection circuit pattern may be formed by the same method as the formation method of a circuit pattern with respect to the three-dimensional circuit substrate is a molded article.

At this time, a part of the three-dimensional circuit board is cut off when cutting the multilayer circuit portion, and a part of the three-dimensional circuit board is formed on the cut end face of the three-dimensional circuit board formed by the cutting when forming the circuit pattern for connection. By increasing the area of the cut end face on which the connection pattern can be formed, the degree of freedom of the arrangement of the connection circuit pattern can be increased, and the connection circuit pattern is connected to the connection circuit pattern at the time of formation. By forming the mounted component mounting section, the degree of freedom in arranging the component mounting section can be increased.

[Brief description of the drawings]

FIG. 1 shows an example of an embodiment of the present invention, in which (a)
Is a sectional view, and (b) is an end view.

FIG. 2 is an end view of another example of the above.

FIG. 3 is an end view of still another example of the above.

FIGS. 4A, 4B, and 4C are perspective views showing examples of cut shapes of the above-mentioned substrate.

FIG. 5 is a sectional view of another example of the above.

FIGS. 6 (a) and 6 (b) are perspective views showing examples of the shape of the through recess in the above.

FIG. 7 is a sectional view of still another example of the above.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Three-dimensional circuit board 4 Insulating layer 21 Circuit pattern 22 Circuit pattern 23 Circuit pattern 24 Circuit pattern 30 Connection circuit pattern 31 Connection circuit pattern

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) H05K 1/02 H05K 1/11 F 1/11 3/00 W 3/00 3/40 D 3/40 H01L 23/12 N (72) Inventor Yasushi Masaki 1048 Kazuma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Works, Ltd. 5E317 AA11 AA22 BB01 BB11 CC31 CD25 CD31 CD34 GG14 5E338 AA03 AA05 AA16 BB03 BB19 BB28 BB63 CC01 CD01 CD32 EE22 5E346 AA02 AA12 AA15 AA38 AA60 BB01 FF21 FF42 FF45 GG17 GG22 GG17 GG22

Claims (9)

[Claims] 1. A three-dimensional circuit board, which is a molded product, and a multilayer circuit part in which a plurality of circuit patterns are laminated on at least one surface of the three-dimensional circuit board with an insulating layer interposed therebetween. A connection circuit pattern having at least one end connected to any one of the plurality of circuit patterns on the cut end surface formed by exposing the end surface of the circuit pattern. Circuit board. 2. The multilayer three-dimensional circuit board according to claim 1, wherein the cut end face extends to the three-dimensional circuit board, and a part of the connection circuit pattern is formed on the cut end face of the three-dimensional circuit board. . 3. The multilayer three-dimensional circuit board according to claim 2, wherein a component mounting portion is formed on a cut end surface of the three-dimensional circuit board, and a connection circuit pattern is connected to the component mounting portion. 4. A component mounting portion, wherein the component mounting portion is formed on a bottom surface of the through recess, the component mounting portion being formed on the surface of the three-dimensional circuit board through the multilayer circuit portion. 3. The multilayer three-dimensional circuit board according to claim 2, wherein a connection circuit pattern formed on a cut end surface that is an inner wall of the through recess is connected to the portion. 5. A penetrating recess which penetrates the multilayer circuit portion and forms a recess on the surface of the three-dimensional circuit board, and on a bottom surface of the penetrating recess and a cut end face which is an inner wall of the penetrating recess. 3. The multilayer three-dimensional circuit board according to claim 2, wherein a connection circuit pattern is formed on the three-dimensional circuit board. 6. The multilayer three-dimensional circuit board according to claim 1, wherein the cut end surface is formed as an inclined surface. 7. A multilayer circuit part is formed by laminating a plurality of circuit patterns with an insulating layer interposed on at least one surface of a three-dimensional circuit board that is a molded product, and then cutting the multilayer circuit part to form a cut end surface. Exposing the end of the circuit pattern, then
By forming a copper thin film on the cut end surface and performing laser processing on the copper thin film to separate a portion necessary as a circuit from an unnecessary portion, and then plating only the portion necessary as a circuit A method of manufacturing a multilayer three-dimensional circuit board, comprising forming a connection circuit pattern having at least one end connected to one of the plurality of circuit patterns. 8. A part of the three-dimensional circuit board is cut off when cutting the multilayer circuit part, and a part of the three-dimensional circuit board is positioned on the cut end surface of the three-dimensional circuit board formed by the cutting when forming the connection circuit pattern. The method for manufacturing a multilayer three-dimensional circuit board according to claim 7, characterized in that: 9. The method for manufacturing a multilayer three-dimensional circuit board according to claim 8, wherein a component mounting portion connected to the connection circuit pattern is formed when the connection circuit pattern is formed.