JP2006128207A - Method for manufacturing rigid flex multilayer printed circuit board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent that a shield layer bonded to the front surface of a laminated internal layer flexible substrate is peeled from the internal layer flexible substrate during the manufacturing process, in the method for manufacturing a rigid flex multilayer printed circuit board where the flexible part having flexibility and the rigid part mounting electronic components are constinuted continuously. <P>SOLUTION: The shield layer 2 is formed on the region as the flexible part in the laminated internal layer flexible substrate 1 where a circuit pattern is formed, and an external rigid board 5 is also bonded on the internal layer flexible substrate 1 and the shield layer 2. These shield layer 2 and the external layer rigid board 5 are prevented from contact thereof by providing a stepped part 2a to the circumference of the shield layer 2. The rigid flex multilayer printed circuit board is completed by removing the external layer rigid board 5 on the shield layer 2 therefrom. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present proposal relates to a method of manufacturing a rigid flex (R-F) multilayer printed wiring board constituted by a flexible portion having flexibility and a rigid portion on which electronic components are mounted.

  Conventionally, as shown in FIG. 3, a rigid flex (R-F) multilayer printed wiring board in which a flexible portion 101 having flexibility and a rigid portion 102 on which electronic components are mounted is continuously formed has been proposed. Has been. In this rigid-flex multilayer printed wiring board, the rigid portion is excellent in component mountability. Such rigid-flex multilayer printed wiring boards are used as internal wiring boards for various electronic devices.

  In order to manufacture such a rigid-flex multilayer printed wiring board, as shown in FIG. 4, first, as shown in FIG. 4A, a circuit pattern is formed on the conductive foil on the surface layer of the inner flexible substrate (FPC) 103. Is formed. And a coverlay is affixed on both surfaces of this inner layer flexible substrate 103. When a plurality of inner layer flexible substrates 103 are used, the inner layer flexible substrates 103 are stacked, and then a coverlay is attached to both surfaces of the plurality of inner layer flexible substrates 103.

  Next, as shown in FIG. 4B, a shield layer 104 is formed in a region to be the flexible portion 101 in the laminated inner layer flexible substrate 103. The shield layer 104 is formed by applying a shield material (shield ink). Then, as shown in FIG. 4C, an outer layer rigid board (RPC) 105 is bonded to the surfaces of the inner layer flexible substrate 103 and the shield layer 104 via an adhesive sheet. The outer layer rigid plate 105 is composed of a substrate and a conductive foil formed on both surfaces of the substrate. The outer rigid plate 105 is provided with a slit that forms the outer edge of the shield layer 104. Then, a hole (through hole) for conducting the conductive foil of each layer is provided, copper plating is formed in the substrate surface and in the hole, and a circuit pattern is formed on the conductive foil of the outer layer rigid board 105. Further, as shown in FIG. 4D, a resist layer 106 is formed in a region that becomes the rigid portion 102 on the outer layer rigid plate 105.

  Then, as shown in FIG. 4 (e), the outer layer rigid board 105 is cut at the slits, and the outer layer rigid board 105 on the shield layer 104 is removed from the shield layer 104, thereby completing the rigid flex multilayer printed wiring board. To do.

  Conventionally, various proposals have been made for a printed wiring board that approximates or is related to such a rigid flex multilayer printed wiring board. For example, in Patent Document 1, on a shield layer having a thickness of 5 μm or less, It is described that by providing an adhesive layer and a fixed insulating layer, good shielding characteristics can be obtained without impairing flexibility.

  Further, in Patent Document 2, in a flexible wiring board that requires flexibility, a conduction hole is provided on the upper surface of the earth circuit pattern, and the conduction hole is filled with a conductive adhesive. It is described that the layers are electrically connected.

  Further, Patent Document 3 describes a structure in which a first cover lay shield layer and a second cover lay are stacked in order on a circuit pattern.

  And in patent document 4, in the flexible wiring board comprised by laminating | stacking an insulating film, an adhesive agent, a circuit pattern, an adhesive agent, a metal film, and an insulating film in this order, the arbitrary locations and metal films of a circuit pattern A structure that is conducted by a conductive paste is described.

  In Patent Document 5, an insulating resin layer having an opening is provided on a circuit pattern, and after metal plating is applied to the opening, a conductive coating such as silver paste is applied, and an insulating resin layer is further formed on the opening. The structure to provide is described.

  Patent Document 6 describes that the total thickness of the wiring board is reduced by providing a shield layer only at a necessary portion on the upper and lower surfaces of the double-sided wiring board.

  Patent Document 7 describes a configuration in which an upper portion of an exposed surface of a circuit pattern is covered with an insulating film, and a shield layer is further provided on the insulating film.

  Patent Document 8 describes that, in a multilayer wiring board having a rigid flex structure, a shield layer is not provided at a location where a through hole exists.

Further, Patent Document 9 describes a configuration in which the thickness of the hinge portion is made thinner than the thickness of the laminated inner layer flexible board in the rigid-flex structure multilayer wiring board.
JP-A-5-3395 Japanese Patent Laid-Open No. 6-224587 Japanese Patent Laid-Open No. 7-122882 JP-A-7-283579 JP 11-177192 A JP 2002-176231 A JP 2004-119604 A JP 7-79089 A JP-A-7-106766

  In the case of manufacturing a rigid-flex multilayer printed wiring board as described above, when a part of the shield layer 104 to be bonded to the surface of the laminated inner layer flexible substrate 103 is removed from the outer layer rigid board 105, There is a problem that it adheres to the outer layer rigid plate 105 side and is peeled off from the inner layer flexible substrate 103 together with the outer layer rigid plate 105.

  The reason why such a phenomenon occurs is considered as follows. That is, after the shield layer 104 is formed, it is necessary to perform press working in order to stack the outer layer rigid plate 105. In this pressing, the space originally between the shield layer 104 and the outer layer rigid plate 105 is lost due to the pressurization, and the shield layer 104 and the outer layer rigid plate 105 come into contact with each other. Furthermore, by heating in this state, a part of the shield layer 104 adheres to the outer layer rigid plate 105 side.

  Patent Documents 1 to 7 described above all relate to a single-layer plate structure (single-sided plate structure or double-sided plate structure) in which the inner-layer flexible substrate 103 is not laminated. In manufacturing a rigid-flex printed wiring board having such a single-layer board structure, it is necessary to consider protecting the shield layer during the manufacturing process because the shield layer can be processed after all the processing has been completed. There is no.

  Therefore, by using the techniques described in Patent Document 1 to Patent Document 7, a rigid flex multilayer printed wiring board in which a plurality of inner layer flexible substrates 103 are stacked and the shield layer 104 is formed in the middle of the process. In the manufacturing process, it is impossible to prevent the shield layer 104 from being peeled off from the inner layer flexible substrate 103 when the outer layer rigid plate 105 is removed.

  Further, Patent Document 8 describes a technique related to a rigid-flex structure multilayer wiring board, but only describes that a shield layer 104 is not provided at a through hole in a circuit pattern. Depending on the situation, it is not possible to prevent the shield layer 104 from being peeled off from the inner flexible substrate 103.

  Furthermore, Patent Document 9 describes a technique related to a rigid-flex structure multilayer wiring board, but it only describes that the thickness of the hinge portion is made thinner than the thickness of the laminated inner layer flexible substrate. However, this technique cannot prevent the shield layer 104 from being peeled off from the inner flexible substrate 103.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a rigid flex multilayer printed wiring in which a flexible portion having flexibility and a rigid portion on which an electronic component is mounted are continuously formed. To provide a method for producing a rigid-flex multilayer printed wiring board in which a shield layer bonded to the surface of a laminated inner layer flexible substrate is not peeled off from the inner layer flexible substrate during the manufacturing process. It is in.

  In the manufacturing method of a rigid flex multilayer printed wiring board in which a flexible portion having flexibility and a rigid portion on which an electronic component is mounted are continuously formed, the shield layer and the outer layer rigid plate are It came to the knowledge that the above-mentioned subject could be solved by making it not contact.

  That is, the manufacturing method of the rigid flex multilayer printed wiring board according to the present invention comprises at least one of the following configurations.

[Configuration 1]
A method of manufacturing a rigid-flex multilayer printed wiring board in which a flexible portion having flexibility and a rigid portion on which an electronic component is mounted is continuously formed, and a circuit pattern is formed on a conductive foil on an inner-layer flexible substrate A step of forming a shield layer by applying a shielding material on a region to be a flexible portion in the inner layer flexible substrate on which the circuit pattern is formed, and an outer edge of the shield layer on the inner layer flexible substrate and the shield layer The outer layer rigid plate having a slit that forms a slit, and the step of cutting the outer layer rigid plate at the slit to remove the outer layer rigid plate on the shield layer, and the shield layer is formed at the periphery of the region to be the flexible portion. Apply a thicker shield material than the area that becomes the flexible part, and It is characterized in that formed as having a differential unit.

[Configuration 2]
In the manufacturing method of the rigid-flex multilayer printed wiring board having the configuration 1, the coating of the shielding material for forming the shielding layer is performed in a plurality of times, and the number of times of coating in the step portion is set to be different from that in other portions of the step portion. It is characterized by an increase.

[Configuration 3]
A method of manufacturing a rigid-flex multilayer printed wiring board in which a flexible portion having flexibility and a rigid portion on which an electronic component is mounted is continuously formed, and a circuit pattern is formed on a conductive foil on an inner-layer flexible substrate A step of forming a shield layer by applying a shielding material on a region to be a flexible portion in the inner layer flexible substrate on which the circuit pattern is formed, and a substrate and the substrate on the inner layer flexible substrate and the shield layer A step of bonding an outer layer rigid plate having a slit formed of a conductive foil formed thereon and having a slit forming the outer edge of the shield layer; and a step of cutting the outer layer rigid plate at the slit and removing the outer layer rigid plate on the shield layer, Before laminating the outer layer rigid board on the inner layer flexible substrate and the shield layer, It is characterized in that you of removing the conductive foil in a region corresponding to the shield layer of the outer rigid plate.

[Configuration 4]
In the manufacturing method of the rigid-flex multilayer printed wiring board having the configuration 3, the shield layer is coated with a shielding material thicker than the region to be the flexible portion in the peripheral portion of the region to be the flexible portion, and has a step portion in the peripheral portion. It is characterized by being formed as a thing.

  In the method of manufacturing the rigid-flex multilayer printed wiring board according to the present invention, the shield layer and the outer-layer rigid board are in contact with each other only at the periphery of the flexible part, so when removing the region corresponding to the shield layer of the outer-layer rigid board Since this shield layer does not adhere to the outer layer rigid plate side, it does not peel from the inner layer flexible substrate.

  In the method for manufacturing a rigid-flex multilayer printed wiring board according to the present invention, the shield layer is formed as having a stepped portion around the periphery, and / or the conductor foil in the region corresponding to the shield layer of the outer-layer rigid board is removed. Therefore, the shield layer and the outer layer rigid board are in contact with each other only at the periphery of the flexible part, and when the outer layer rigid board is removed during the manufacturing process, the shield layer is not peeled off from the inner layer flexible board. .

  That is, the present invention provides a method for manufacturing a rigid-flex multilayer printed wiring board in which a flexible portion having flexibility and a rigid portion on which an electronic component is mounted are continuously formed. It is possible to provide a method for manufacturing a rigid-flex multilayer printed wiring board in which the shield layer adhered to the substrate is not peeled off from the inner flexible substrate during the manufacturing process.

  The best mode for carrying out the present invention will be described below with reference to the drawings. As shown in FIG. 3, the manufacturing method of the rigid-flex multilayer printed wiring board according to the present invention includes a flexible portion 101 having flexibility and a rigid portion 102 on which electronic components are mounted. It is a manufacturing method for manufacturing a rigid flex (R-F) multilayer printed wiring board.

  FIG. 1 is a cross-sectional view showing a manufacturing process of a rigid flex multilayer printed wiring board according to an embodiment of the present invention.

  The manufacturing method of this rigid-flex multilayer printed wiring board has the following processes. That is, in this manufacturing method, first, as shown to (a) in FIG. 1, a circuit pattern is formed in the conductor foil 1a on the inner-layer flexible substrate (FPC) 1. FIG. Then, cover lays 1 b are attached to both surfaces of the inner layer flexible substrate 1. When a plurality of inner layer flexible substrates 1 are used, the inner layer flexible substrates 1 are stacked, and then the cover lays 1 b are attached to both surfaces of the plurality of inner layer flexible substrates 1.

  The inner layer flexible substrate 1 is formed of a material having flexibility, heat resistance and insulation, such as polyimide resin, and a copper foil or the like is attached as a conductor foil 1a on one or both surfaces. Is formed. The cover lay 1b is formed of a material having flexibility, heat resistance and insulation, such as polyimide resin, and an adhesive layer is formed on one surface. When a plurality of inner layer flexible substrates 1 are stacked, these inner layer flexible substrates 1 are stacked via an adhesive layer and bonded to each other.

  Next, as shown in FIG. 1 (b), a shield material is applied to the upper and lower surfaces of the region to be the flexible portion 101 in the inner-layer flexible substrate 1 on which the circuit pattern has been formed and laminated, and shielded. Layer 2 is formed. This shield layer is formed so that the shield material is applied thicker in the periphery of the region to be the flexible portion 101 than in the region to be the flexible portion, and the step portion 2a is provided in the periphery. Further, the shield layer 2 may be formed by applying the shielding material in a plurality of times. In this case, the number of times of application in the stepped portion 2a is set by the number of times of application in other portions of the stepped portion 2a. As a result, the stepped portion 2a can be formed satisfactorily.

  Then, as shown in FIG. 1C, an outer layer rigid plate (RPC) 5 having slits 3 is bonded onto the inner flexible substrate 1 and the upper and lower surfaces of the shield layer 2. The outer layer rigid plate 5 is made of a hard, heat-resistant and insulating material such as glass-epoxy material, for example, and a conductive foil is deposited on one or both surfaces. Is. The slit 3 of the outer layer rigid plate 5 is formed in a shape that forms the outer edge of the shield layer 2. Then, a hole (through hole) for conducting the conductive foil of each layer is provided, copper plating is formed in the substrate surface and in the hole, and a circuit pattern is formed in the conductive foil of the outer layer rigid board 5. Further, a resist layer is formed in a region to be the rigid portion 102 on the outer layer rigid plate 5.

  In this way, after the shield layer 2 is formed, the outer layer rigid plate 5 is laminated by pressing. In this press working, the entire wiring board is heated. At this time, since the shield layer 2 has the stepped portion 2a in the peripheral portion, the shield layer 2 and the outer layer rigid plate 5 are in contact only in the peripheral portion of the flexible portion 101, and the shield layer 2 is in the outer layer rigid. It does not adhere to the plate 5 side.

  Then, as shown in FIG. 1 (d), by cutting the outer layer rigid board 5 at the slit 3 and removing the outer layer rigid board 5 on the shield layer 2 from the shield layer 2, a rigid flex multilayer printed wiring board is obtained. Is completed. At this time, the shield layer 2 is not in contact with the outer layer rigid plate 5 only at the peripheral portion of the flexible portion 101, so that it is not peeled off from the inner layer flexible substrate 1.

  FIG. 2 is a cross-sectional view showing another example of the manufacturing process of the rigid flex multilayer printed wiring board in the embodiment of the present invention.

  Moreover, the manufacturing method of the rigid-flex multilayer printed wiring board which concerns on this invention is good also as what has the following processes. That is, in this manufacturing method, first, as shown to (a) in FIG. 2, a circuit pattern is formed in the conductor foil 1a on the inner-layer flexible substrate (FPC) 1. FIG. Then, cover lays 1 b are attached to both surfaces of the inner layer flexible substrate 1. When a plurality of inner layer flexible substrates 1 are used, the inner layer flexible substrates 1 are stacked, and then the cover lays 1 b are attached to both surfaces of the plurality of inner layer flexible substrates 1.

  Next, as shown in FIG. 2B, a shield material is applied to the upper and lower surfaces of the region to be the flexible portion 101 in the inner-layer flexible substrate 1 on which the circuit pattern has been formed and laminated to shield it. Layer 2 is formed.

  Then, as shown in FIG. 2C, an outer layer rigid plate (RPC) 5 having slits 3 is bonded on the inner layer flexible substrate 1 and the upper and lower surfaces of the shield layer 2. The outer layer rigid plate 5 is made of a hard, heat-resistant and insulating material such as glass-epoxy material, for example, and a conductive foil is deposited on one or both surfaces. Is. The slit 3 of the outer layer rigid plate 5 is formed in a shape that forms the outer edge of the shield layer 2. In addition, the outer layer rigid plate 5 is removed by removing the conductive foil in the region corresponding to the shield layer 2 of the outer layer rigid plate 5 before being bonded to the inner layer flexible substrate 1 and the shield layer 2. The thickness in the region is reduced.

  Then, a hole (through hole) for conducting the conductive foil of each layer is provided, copper plating is formed in the substrate surface and in the hole, and a circuit pattern is formed in the conductive foil of the outer layer rigid board 5. Further, a resist layer is formed in a region to be the rigid portion 102 on the outer layer rigid plate 5.

  In this way, after the shield layer 2 is formed, the outer layer rigid plate 5 is laminated by pressing. In this press working, the entire wiring board is heated. At this time, since the conductor foil in the region corresponding to the shield layer 2 of the outer layer rigid plate 5 is removed, the shield layer 2 and the outer layer rigid plate 5 are in contact with each other only at the periphery of the flexible portion 101, and the shield layer 2 does not adhere to the outer rigid board 5 side.

  Then, as shown in FIG. 2 (d), by cutting the outer layer rigid board 5 at the slit 3 and removing the outer layer rigid board 5 on the shield layer 2 from the shield layer 2, a rigid flex multilayer printed wiring board is obtained. Is completed. At this time, the shield layer 2 is not in contact with the outer layer rigid plate 5 only at the peripheral portion of the flexible portion 101, so that it is not peeled off from the inner layer flexible substrate 1.

  In addition, although the method of providing a level | step difference in the shield layer 2 and the method of providing a level | step difference by removing the conductor foil of the outer layer rigid board 5 were described, transcription | transfer of a shield layer can be eliminated more by using both together.

  Hereinafter, the manufacturing method of the rigid-flex multilayer printed wiring board according to the present invention will be described in detail with reference to examples.

[Example 1]
In Example 1, a 6-layer rigid flex multilayer printed wiring board was prepared using a double-sided CCL as the inner layer flexible substrate and a double-sided RPC as the outer layer rigid board.

  In addition, the manufacturing method which concerns on this invention may use RPC as an inner-layer flexible substrate, and may produce it using CCL as an outer-layer rigid board. Furthermore, the manufacturing method according to the present invention is not limited to a rigid flex printed wiring board but can be applied to an FPC multilayer printed wiring board and an RPC multilayer printed wiring board. In addition, the manufacturing method according to the present invention can be applied to the substrate material, dimensions, and the number of layers without any particular limitation.

  In Example 1, the thickness of the polyimide substrate in the inner layer flexible substrate was 25 μm, the thickness of the double-sided copper foil was 18 μm, and the thickness of the adhesive layer was 10 μm. As the coverlay laminated on the inner layer flexible substrate, a polyimide substrate having a thickness of 25 μm provided with an adhesive layer having a thickness of 25 μm was used.

  Further, a silver paste was used as a shield ink for forming a shield layer, and it was applied at a thickness of about 10 μm. On this silver paste layer, carbon black was applied at a thickness of about 10 μm to form a shield layer.

  The thickness of the glass epoxy substrate in the outer layer rigid plate was 100 μm, and the thickness of the double-sided copper foil was 18 μm. As the adhesive sheet for adhering the outer layer rigid board, an adhesive sheet having a thickness of 40 μm was used.

  In Example 1, a rigid flex multilayer printed wiring board was prepared by the following procedure. That is, first, a circuit pattern was formed on the conductive foils on both sides of the inner layer flexible substrate. Next, a cover lay was laminated on both surfaces of the inner layer flexible substrate, and the adhesive was cured by heating and pressure to be bonded. And the shield ink was apply | coated to the area | region used as the flexible part on this inner layer flexible substrate, and the shield layer was formed. At this time, the coating amount was increased by increasing the number of times the shield ink was applied around the shield layer (overcoating) to form a stepped portion where the shield layer was thick.

  In the outer layer rigid plate, a slit was provided at the outer edge of the region corresponding to the flexible portion. Then, an adhesive sheet was laminated on the outer layer rigid plate.

  And this outer layer rigid board was laminated | stacked and adhered with respect to the inner-layer flexible board | substrate by overlapping on an inner-layer flexible board | substrate, and heating and pressurizing. Next, through-holes were formed to provide interlayer conduction in each conductor foil of the outer layer rigid board and the inner layer flexible board, and a circuit pattern was also formed on the conductor foil of the outer layer rigid board.

  A surface protective film such as a solder resist ridge was formed on the conductor foil of the outer layer rigid board, and the outer layer rigid board was cut at a slit to remove a region corresponding to the flexible portion of the outer layer rigid board.

[Example 2]
In Example 2, a 6-layer rigid-flex multilayer printed wiring board was prepared using double-sided CCL as the inner-layer flexible substrate and double-sided RPC as the outer-layer rigid board, as in Example 1 described above.

  In Example 2, the thickness of the polyimide substrate in the inner layer flexible substrate was 25 μm, the thickness of the double-sided copper foil was 18 μm, and the thickness of the adhesive layer was 10 μm. As the coverlay laminated on the inner layer flexible substrate, a polyimide substrate having a thickness of 25 μm provided with an adhesive layer having a thickness of 25 μm was used.

  Further, a silver paste was used as a shield ink for forming a shield layer, and it was applied at a thickness of about 10 μm. On this silver paste layer, carbon black was applied at a thickness of about 10 μm to form a shield layer.

  The thickness of the glass epoxy substrate in the outer layer rigid plate was 100 μm, and the thickness of the double-sided copper foil was 18 μm. As the adhesive sheet for adhering the outer layer rigid board, an adhesive sheet having a thickness of 40 μm was used.

  In Example 2, a rigid flex multilayer printed wiring board was prepared by the following procedure. That is, first, a circuit pattern was formed on the conductive foils on both sides of the inner layer flexible substrate. Next, a cover lay was laminated on both surfaces of the inner layer flexible substrate, and the adhesive was cured by heating and pressure to be bonded. And the shield ink was apply | coated to the area | region used as the flexible part on this inner layer flexible substrate, and the shield layer was formed.

  In the outer layer rigid plate, a slit was provided at the outer edge of the region corresponding to the flexible portion. In addition, the conductor foil in the region corresponding to the shield layer of the outer layer rigid plate was removed by etching to reduce the thickness in this region. Then, an adhesive sheet was laminated on the outer layer rigid plate.

  And this outer layer rigid board was laminated | stacked and adhered with respect to the inner-layer flexible board | substrate by overlapping on an inner-layer flexible board | substrate, and heating and pressurizing. Next, through-holes were formed to provide interlayer conduction in each conductor foil of the outer layer rigid board and the inner layer flexible board, and a circuit pattern was also formed on the conductor foil of the outer layer rigid board.

  A surface protective film such as a solder resist ridge was formed on the conductor foil of the outer layer rigid board, and the outer layer rigid board was cut at a slit to remove a region corresponding to the flexible portion of the outer layer rigid board.

[Comparative Example]
In this comparative example, a 6-layer rigid-flex multilayer printed wiring board was prepared using double-sided CCL as the inner-layer flexible board and double-sided RPC as the outer-layer rigid board, as in the previous examples. The substrate size and the thickness of each layer were also the same as in each example.

  However, in this comparative example, the step portion was not provided in the shield layer, and the conductor foil in the region corresponding to the shield layer was not removed in the outer layer rigid plate. Then, a rigid flex multilayer printed wiring board was prepared by the same procedure as in the example.

[Contrast between Example and Comparative Example]
With respect to the rigid flex multilayer printed wiring boards in each of the above-described examples and comparative examples, the presence or absence of peeling (transfer) of the shield layer from the inner layer flexible substrate accompanying the removal of the outer layer rigid board was examined. As a result, in [Comparative Example], a part of the shield layer was peeled off from the inner flexible substrate with the removal of the outer rigid plate and transferred to the outer rigid plate. On the other hand, in the rigid-flex multilayer printed wiring board in Example 1 and Example 2, peeling due to the removal of the outer-layer rigid board of the shield layer was not observed.

It is sectional drawing which shows the manufacturing process of the rigid flex multilayer printed wiring board in embodiment of this invention. It is sectional drawing which shows the other example of the manufacturing process of the rigid flex multilayer printed wiring board in embodiment of this invention. It is a perspective view which shows the structure of a rigid flex multilayer printed wiring board. It is sectional drawing which shows the manufacturing process of the conventional rigid flex multilayer printed wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Inner layer flexible substrate 1a Conductive foil 1b Coverlay 2 Shield layer 2a Step part 3 Slit 5 Outer layer rigid board 101 Flexible part 102 Rigid part

Claims (4)

A method for producing a rigid-flex multilayer printed wiring board comprising a flexible portion having flexibility and a rigid portion on which electronic components are mounted,
Forming a circuit pattern on the conductive foil on the inner layer flexible substrate; and
A step of applying a shielding material on the region to be the flexible portion of the inner layer flexible substrate on which the circuit pattern has been formed to form a shielding layer;
Bonding an outer layer rigid board having a slit that forms an outer edge of the shield layer on the inner layer flexible substrate and the shield layer;
Cutting the outer layer rigid plate in the slit and removing the outer layer rigid plate on the shield layer, and
The shield layer is formed by applying the shield material thicker than the region to be the flexible portion in a peripheral portion of the region to be the flexible portion, and forming a step portion on the peripheral portion. A method for manufacturing a flex multilayer printed wiring board.   2. The rigid according to claim 1, wherein the coating of the shielding material for forming the shielding layer is performed in a plurality of times, and the number of times of coating in the stepped portion is made larger than that in other portions of the stepped portion. A method for manufacturing a flex multilayer printed wiring board. A method for producing a rigid-flex multilayer printed wiring board comprising a flexible portion having flexibility and a rigid portion on which electronic components are mounted,
Forming a circuit pattern on the conductive foil on the inner layer flexible substrate; and
A step of applying a shielding material on the region to be the flexible portion of the inner layer flexible substrate on which the circuit pattern has been formed to form a shielding layer;
A step of bonding an outer layer rigid board having a slit that forms an outer edge of the shield layer, which is made of a substrate and a conductive foil formed on the inner layer flexible substrate and the shield layer, and
Cutting the outer layer rigid plate in the slit and removing the outer layer rigid plate on the shield layer, and
Rigid flex multilayer print, characterized in that the conductive foil in the region corresponding to the shield layer of the outer layer rigid board is removed before the outer layer rigid board is bonded to the inner layer flexible board and the shield layer. A method for manufacturing a wiring board.   The shield layer is formed by applying the shield material thicker than a region to be the flexible portion in a peripheral portion of the region to be the flexible portion, and having a stepped portion in the peripheral portion. Item 4. A method for producing a rigid-flex multilayer printed wiring board according to Item 3.

Images