JP2009141115A - Rigid flex multilayer printed wiring board, and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rigid flex multilayer printed wiring board having no risk of separation in a boundary part between a rigid part and a flexible part, without inflow of resin of an insulating adhesive layer to the flexible part. <P>SOLUTION: The rigid flex multilayer printed wiring board has a coverlay 17 having a projection part in the boundary part between the flexible part F and the rigid part R. A manufacturing method of the rigid flex multilayer printed wiring board includes a process of forming the projection part in the boundary part between the rigid part and the flexible part. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rigid-flex multilayer printed wiring board excellent in dimensional stability and adhesiveness at the boundary between a flexible part and a rigid part, and a method for producing the same.

  As devices become smaller and more functional, there is an increasing demand for rigid-flex multilayer printed wiring boards that offer excellent flexibility in installation in products.

  FIG. 8 shows an outline of a conventional method for producing a general rigid-flex multilayer printed wiring board. First, as shown in FIG. 8A, a flexible substrate 3d having a wiring pattern 2 on both sides is shown. An insulating adhesive layer 11 such as a prepreg in which an opening 12 is formed in a portion that will later become a flexible portion F, and a metal foil 5a such as a copper foil are sequentially disposed on the front and back, and then laminated via a cushion material (not shown). The substrate in the state shown in FIG. 8B is obtained by performing press working.

  Next, a through-type through hole (not shown) connecting the vertical wiring patterns (hereinafter referred to as “TH”) and a non-through-type blind via hole (hereinafter referred to as “BVH”) are provided. After forming, as shown in FIG. 8 (c), a rigid-flex multilayer printed wiring board comprising a rigid portion R capable of mounting components and a flexible portion F bendable is formed by forming an outer layer wiring pattern. Pb is obtained.

  However, the above manufacturing method has the following problems.

  That is, the insulating adhesive layer 11 used here is a low flow type resin in order to suppress the resin of the insulating adhesive layer 11 from flowing into the flexible part F during the laminating press. Yes. When the low flow type insulating adhesive layer 11 is laminated, the fluidity is lower than that of the normal flow type and the followability to the surface irregularities of the coverlay 17a generated by the presence of the wiring pattern 2 is poor. In order to compensate, it must be laminated via a cushioning material. However, when the lamination press is performed via the cushion material, a slight resin flow portion L is generated in the flexible portion F as shown in FIG. 8C (in the drawing, for convenience of explanation, the resin flow portion L L is exaggerated from the actual one), and this resin flow part L becomes a loss area where component mounting and bending cannot be performed. Therefore, the size of the rigid-flex multilayer printed wiring board Pb is increased by this loss area. I had to.

  Accordingly, a rigid-flex multilayer printed wiring board having such a structure as shown in FIGS. 9 and 10 that suppresses such resin flow has already been reported (see Patent Document 1).

  First, as shown in FIG. 9A, a single-sided substrate 15a in which a metal foil 5a such as a copper foil is laminated on a hard insulating substrate 14 such as a glass epoxy substrate is prepared, and an opening is formed in a portion that later becomes a flexible portion F. In addition to forming the portion 12, a groove 16 (a groove having the same length as the width of the flexible substrate 3 c) is formed in the hard insulating substrate 14 in the vicinity of the boundary portion between the flexible portion F and the rigid portion R.

  Next, as shown in FIG. 9B, the insulating adhesive layer 11 provided with the opening 12 in the portion corresponding to the flexible portion F is bonded to the surface on which the groove 16 of the single-sided substrate 15a is formed. Next, as shown in FIG. 9C, on both sides of the flexible substrate 3c having a configuration in which the wiring pattern 2 and the coverlay 17a for protecting the wiring pattern 2 are provided on the front and back of the base substrate 1 having flexibility. The single-sided substrate 15a bonded with the insulating adhesive layer 11 is disposed so that the surface of the insulating adhesive layer 11 faces the flexible substrate 3c.

  Next, as shown in FIG. 9 (d), the single-sided substrate 15a and the flexible substrate 3c bonded with the insulating adhesive layer 11 are integrated by laminating press processing, and then, as shown in FIG. 10 (a). A non-through hole 18 is drilled in the BVH forming portion that connects the wiring patterns 2 in the vertical direction.

  Next, as shown in FIG. 10B, a plating 19 such as copper plating is deposited on the outer layer including the non-through holes 18, and then a circuit such as a well-known photo-etching process is formed to form a wiring pattern (not shown). By forming the BVH 13a that connects the wiring patterns in the vertical direction, the rigid-flex multilayer printed wiring board Pa shown in FIG. 10C having the configuration of the rigid portion R and the flexible portion F is obtained.

  In this conventional method of manufacturing a rigid flex multilayer printed wiring board, the resin of the flowing insulating adhesive layer 11 is caused to flow into the grooves 16 provided in the hard insulating substrate 14 during the laminating press of FIG. Therefore, the resin flow amount flowing into the flexible portion F can be suppressed (50 μm or less).

  However, even with the above method, the resin flow to the flexible portion F cannot be completely prevented, and in particular, it is difficult to cope with a product with a very short specification such as the dimension of the flexible portion F in the length direction of about several millimeters. Therefore, it was necessary to increase the size of the resin flow. Further, since the adhesive surface between the insulating adhesive layer 11 and the flexible substrate 3c (specifically, the cover lay 17a) is only one planar surface, the flexible portion F is bent as shown in FIG. There was a concern that peeling occurred at the boundary between the rigid portion R and the flexible portion F over time.

  Further, since the hard insulating substrate 14 is an indispensable constituent member, it is difficult to reduce the thickness as compared with the case where the wiring pattern 2 is formed after the metal foil 5a is laminated on the insulating adhesive layer 11, and the hard insulating substrate 14 is hard. When the wiring pattern 2 is formed on both surfaces of the insulating substrate 14, the groove 16 provided in the hard insulating substrate 14 becomes a dead space, so that the size cannot be sufficiently reduced.

Furthermore, since it is necessary to use an expensive low-flow type as the insulating adhesive layer 11 and a troublesome process of forming a groove in the hard insulating substrate 14 is required, it is cost-effective. It was also a disadvantageous construction method.
JP 2006-173477 A

  In the present invention, when laminating an insulating adhesive layer, the resin of the insulating adhesive layer does not flow into the flexible part, and even if the number of flexing of the flexible part is repeated, the boundary part between the rigid part and the flexible part It is a first object to provide a rigid flex multilayer printed wiring board that is easy to be thinned and miniaturized without fear of peeling. Another object of the present invention is to provide a manufacturing method that can easily obtain the rigid-flex multilayer printed wiring board at low cost.

  The present invention is a rigid-flex multilayer printed wiring board having a rigid part capable of component mounting and a flexible part that can be bent, and includes at least a flexible substrate having a wiring pattern, and a coverlay for protecting the wiring pattern. Connecting the insulating adhesive layer or the wiring pattern formed via the insulating adhesive layer and the hard insulating substrate to the portion excluding the flexible part of the flexible substrate on which the coverlay is laminated, and the wiring pattern in the vertical direction And the cover lay has a convex portion integrally formed with the cover lay at the boundary between the flexible portion and the rigid portion, and the above problem is achieved by the rigid flex multilayer printed wiring board. It has been solved.

  The present invention is also a method for manufacturing a rigid-flex multilayer printed wiring board having a rigid part capable of component mounting and a flexible part that can be bent, and at least a first step of forming a wiring pattern on a flexible substrate; A second step of forming a coverlay having a convex portion at the boundary between the rigid portion and the flexible portion, and forming a wiring pattern via an insulating adhesive layer having an opening in the portion that will later become the flexible portion, and the vertical direction And a third step of forming a via hole for connecting between the wiring patterns. The above-mentioned problem is solved by a method of manufacturing a rigid-flex multilayer printed wiring board.

  The present invention is also a method for manufacturing a rigid-flex multilayer printed wiring board having a rigid part capable of component mounting and a flexible part that can be bent, and at least a first step of forming a wiring pattern on a flexible substrate; A second step of forming a cover lay having a convex portion at the boundary between the rigid portion and the flexible portion, an insulating adhesive layer having an opening in a portion that will later become a flexible portion, and a hard insulating substrate also having an opening. Rigid-flex multilayer printed wiring comprising: a third step of sequentially stacking layers; a fourth step of forming via holes connecting the wiring patterns in the vertical direction; and a fifth step of forming a wiring pattern of the outer layer The above-described problems are solved by a plate manufacturing method.

  According to the present invention, since the resin of the insulating adhesive layer can be completely prevented from flowing into the flexible part during the lamination of the insulating adhesive layer, a rigid flex multilayer printed wiring board having excellent dimensional stability is obtained. (In other words, it is possible to obtain a rigid-flex multilayer printed wiring board that does not require an increase in size of the resin flow). In addition, the adhesive surface between the coverlay and the insulating adhesive layer is bonded not only to a flat surface but also to the side surface of the convex portion integrally formed with the coverlay. In addition, it is possible to eliminate the concern that peeling occurs at the boundary between the rigid portion and the flexible portion.

  Furthermore, since a rigid insulating substrate is not essential, the rigid flex multilayer printed wiring board can be easily reduced in thickness, and even when a hard insulating substrate having wiring patterns on both sides is laminated, it becomes a dead space. Since there is no need to provide a groove, the rigid flex multilayer printed wiring board can be miniaturized.

  Furthermore, an inexpensive flow-type adhesive layer can be used as an interlayer adhesive layer, and a laborious process such as providing a groove in a hard insulating substrate is not required, so that a rigid flex multilayer printed wiring board can be easily manufactured at low cost. It is possible.

  1st Embodiment of this invention is described using the schematic cross-sectional process explanatory drawing shown in FIG.1 and FIG.2.

  First, as shown in FIG. 1A, a flexible substrate 3 having a wiring pattern 2 is prepared on the front and back of a base substrate 1 having flexibility.

  Here, the base substrate is not particularly limited as long as it has insulating properties and flexibility. For example, a substrate made of polyimide, liquid crystal polymer, or the like is used.

  Next, in order to improve the adhesion with the coverlay that protects the wiring pattern 2 provided on the flexible substrate 3, the surface of the wiring pattern 2 is, for example, made by MEC, whose main component is formic acid or an amine complexing agent. Roughening is performed with a soft etching solution “CZ8500, CZ8100” or the like.

  Next, as shown in FIG. 1 (b), a cover film 6 with an adhesive layer made of a cover film 5 such as polyimide and an adhesive layer 4 is disposed on the front and back of the flexible substrate 3, and the rigid portion R is further provided. A release material 7 having a slit 8 and a laminated press intermediate plate 9 are sequentially arranged in a portion corresponding to a boundary portion between the flexible portion F and the flexible portion F (the cover film 6 with an adhesive layer is formed on the flexible portion F later). Function as a cover lay protecting the wiring pattern 2).

  Here, as the release material 7, it is preferable to use a material having a thickness substantially the same as the thickness of the insulating adhesive layer 11 to be laminated on the rigid portion R later.

  The reason for this is that if the thickness of the release material 7 is extremely thinner than the insulating adhesive layer 11, the thickness of the convex portion 10 that will be formed later at the boundary between the rigid portion R and the flexible portion F is also reduced. Sometimes, there is a risk that the resin of the insulating adhesive layer 11 cannot be prevented from flowing into the flexible portion F. On the contrary, if the thickness of the release material 7 is extremely thicker than the thickness of the insulating adhesive layer 11, the convex portion Since the thickness 10 is unnecessarily thick, the portion that is not bonded to the insulating adhesive layer 11 may be peeled off while the flexible portion F is bent, and the reliability of the rigid-flex multilayer printed wiring board that is finally produced is It is because it will reduce.

  Next, as shown in FIG. 1C, the flexible substrate 3 and the cover film 6 with the adhesive layer are integrated by performing a lamination press process, and the adhesive layer is formed in the slit 8 provided in the release material 7. FIG. 1 (FIG. 1) in which a convex portion 10 is formed at the boundary between the rigid portion R and the flexible portion F by allowing a part of the cover film 6 to flow in and then removing the release material 7 and the intermediate plate 9 for laminating press. The flexible substrate 3a of d) is obtained.

  Next, as shown in FIG. 2A, on the front and back of the flexible substrate 3a, an insulating adhesive layer 11 having an opening 12 in a portion corresponding to the flexible portion F and a metal foil 5a having no opening are provided. The release material 7a and the laminated press intermediate plate 9 are sequentially arranged.

  Next, as shown in FIG. 2 (b), they are integrated by performing lamination press processing, and then TH13 and BVH 13a for connecting the wiring patterns 2 in the vertical direction are formed and the wiring pattern 2 of the outer layer is formed. By forming by a known photoetching process, the rigid flex multilayer printed wiring board P shown in FIG.

  A notable point in the present embodiment is that the convex portion provided integrally with the cover lay 17 (corresponding to the cover film 6 with the adhesive layer in the present embodiment) at the boundary between the rigid portion R and the flexible portion F. The portion 10 is formed (see the schematic perspective view of the rigid-flex multilayer printed wiring board shown in FIG. 3).

  Accordingly, since the resin of the insulating adhesive layer 11 can be prevented from flowing into the flexible portion F during the lamination press, a rigid flex multilayer printed wiring board having excellent dimensional stability can be obtained (that is, easily). In addition, since the bonding surface between the insulating adhesive layer 11 and the cover lay 17 is bonded not only to a flat surface but also to the side surface of the convex portion 10 formed integrally with the cover lay 17, Even when repeated, it is possible to prevent peeling at the boundary between the rigid portion R and the flexible portion F.

  Further, since the wiring pattern 2 is formed after the metal foil 5a is laminated on the insulating adhesive layer 11 as means for multilayering the rigid portion R, the hard insulating substrate 14 is laminated via the insulating adhesive layer 11. The thickness can be reduced as compared with the prior art.

  In this embodiment, the cover film 6 with a general adhesive layer is used as the cover lay 17. However, even if a flexible insulating adhesive layer having flexibility even after curing is used, the cover film 17 is manufactured in the same process. And the same effect can be obtained.

  Next, a second embodiment will be described using the schematic cross-sectional process explanatory diagrams shown in FIGS. 4 and 5. Since the flexible substrate 3 shown in FIG. 4A is the same as that shown in FIG. 1A, the description starts from FIG. 4B.

  As shown in FIG. 4B, a flexible insulating adhesive layer 4a and a metal foil 5a having flexibility even after curing are sequentially disposed on the front and back of the flexible substrate 3 (in this figure, the metal foil 5a shows a state in which a metal foil 6a with resin in which a flexible insulating adhesive layer 4a is formed in advance is disposed), and a slit is formed in a portion corresponding to the boundary portion between the rigid portion R and the flexible portion F. A release material 7 having 8 and an intermediate plate 9 for laminating press are sequentially arranged.

  Next, as shown in FIG. 4C, by laminating and pressing, the flexible substrate 3 and the resin-attached metal foil 6a are integrated, and the resin is provided in the slit 8 provided in the release material 7. A part of the metal foil 6a is allowed to flow, and then the release material 7 and the intermediate plate 9 for lamination press are removed to obtain a flexible substrate in the state of FIG.

  Next, by etching the metal foil 5a laminated on the outer layer of the flexible substrate of FIG. 4D, the wiring pattern 2 is formed as shown in FIG. The convex part 10 is formed in a part corresponding to the boundary part with the flexible part F.

  Here, the flexible insulating adhesive layer 4a arranged in FIG. 4B is used as a cover lay 17 that protects the wiring pattern 2 formed in the flexible portion F after the lamination in FIG. The convex part 10 which act | operates and becomes the structure integrally molded with the said coverlay 17 is comprised.

  Next, as shown in FIG. 5 (b), the insulating adhesive layer 11 having openings 12 in the portions corresponding to the flexible portions F and the openings on the front and back of the flexible substrate 3b whose surface of the wiring pattern 2 is roughened. The metal foil 5a having no part is sequentially arranged, and the release material 7a and the intermediate plate 9 for laminating press are sequentially arranged.

  Next, as shown in FIG.5 (c), it integrates by performing a lamination press process, Then, TH13 and BVH13a which connect between the wiring patterns 2 of an up-down direction are formed, and the wiring pattern 2 of an outer layer is formed. By forming by a known photoetching process, the rigid flex multilayer printed wiring board P shown in FIG.

  What should be noted in the present embodiment is that the coverlay 17 is formed by laminating a flexible insulating adhesive layer 4a having flexibility even after curing and a metal foil 6a with resin made of the metal foil 5a.

  As a result, in addition to the effects obtained in the first embodiment, the wiring pattern 2 can be easily formed on the surface of the cover lay 17 located in the rigid portion R, so that the rigid flex multilayer printed wiring board can be formed with high density wiring. It can be easily carried out (the wiring pattern 2 can be formed by etching the metal foil 5a previously laminated on the flexible insulating adhesive layer 4a, so compared with the case where the wiring pattern 2 is formed by plating. Thus, it is possible to easily form the wiring pattern 2. Incidentally, the adhesion to the flexible insulating adhesive layer 4a can be improved as compared with the case where it is formed by plating.

  Next, a third embodiment will be described using the schematic cross-sectional process explanatory diagram shown in FIG. Since the flexible substrate 3a shown in FIG. 6A is the same as that shown in FIG. 1D, the description starts from FIG. 6B.

  On the front and back of the flexible substrate 3a, an insulating adhesive layer 11 having an opening 12 in a portion corresponding to the flexible portion F, and a double-sided substrate 15 having the opening 12 (the double-sided substrate 15 is one of the hard insulating substrates 14). The surface is composed of a metal foil 5a and the other surface formed with a wiring pattern 2. At least the surface of the wiring pattern 2 is roughened to improve the adhesion to the insulating adhesive layer 11). Are sequentially disposed, and the release material 7a and the intermediate plate 9 for laminating press are sequentially disposed (see FIG. 6B).

  Next, as shown in FIG.6 (c), it integrates by performing a lamination press process, Then, TH13 and BVH13a which connect between the wiring patterns 2 of an up-down direction are formed, and the wiring pattern 2 of an outer layer is formed. By forming by a known photoetching process, the rigid flex multilayer printed wiring board P shown in FIG.

  This embodiment is a modification of the first embodiment, and instead of forming the wiring pattern 2 directly on the surface of the insulating adhesive layer 11, a double-sided board 15 having a conductor layer on both sides of the hard insulating board 14 is laminated. It is a thing.

  The feature of this configuration is that even if the double-sided substrate 15 is laminated, the resin flow to the flexible portion F can be completely prevented by the convex portion 10, so that the resin is prevented from flowing out to the hard insulating substrate 14 as in the prior art. There is no need to provide a groove. Accordingly, since the dead space due to the groove is eliminated, the rigid-flex multilayer printed wiring board can be reduced in size as compared with the prior art.

  Next, a fourth embodiment will be described using the schematic cross-sectional process explanatory diagram shown in FIG. Since the flexible substrate 3b shown in FIG. 7A is the same as that shown in FIG. 5A, the description starts from FIG. 7B.

  On the front and back of the flexible substrate 3b, an insulating adhesive layer 11 having an opening 12 in a portion corresponding to the flexible portion F, and a double-sided substrate 15 having the opening 12 (the double-sided substrate 15 is one of the hard insulating substrates 14). The surface is composed of a metal foil 5a and the other surface formed with a wiring pattern 2. At least the surface of the wiring pattern 2 is roughened to improve the adhesion to the insulating adhesive layer 11). Are sequentially disposed, and the release material 7a and the intermediate plate 9 for laminating press are sequentially disposed (see FIG. 7B).

  Next, as shown in FIG. 7 (c), they are integrated by performing lamination press processing, and then TH13 and BVH 13a that connect the wiring patterns 2 in the vertical direction are formed, and the wiring pattern 2 of the outer layer is formed. By forming by a known photoetching process, the rigid flex multilayer printed wiring board P shown in FIG.

  This embodiment is a modification of the second embodiment. Like the third embodiment, instead of forming the wiring pattern 2 directly on the surface of the insulating adhesive layer 11, both sides of the hard insulating substrate 14 are formed. A double-sided substrate 15 having a conductor layer is laminated on the substrate.

  As described in the second embodiment, the feature of this configuration is that the wiring pattern can be easily formed on the surface of the insulating adhesive layer 11 located in the rigid portion R, so that the effect of the third embodiment is achieved. In addition, high-density wiring can be easily achieved.

  In explaining the present invention, as a means for laminating a cover lay having a convex portion, an example is used in which a laminating press process using a cover film with an adhesive layer or a metal foil with a resin and a release material having a slit is used. A cover lay having projections is laminated in advance (for example, a resin such as polyimide is poured into a mold having projections to form a cover film having projections, and this is laminated via an adhesive layer). It doesn't matter if you do.

  Moreover, although it demonstrated using the example of the rigid-flex multilayer printed wiring board of 6 layers or 8 layers, as a structure, it is not this limitation, If it is in the scope of the present invention, a structure may be changed as needed. Is possible.

  Further, in the description of the present invention, explanation of solder resist formation for protecting the outer layer wiring pattern and outer shape processing for separating the rigid flex multilayer printed wiring board is omitted. Of course, in the actual manufacturing process, these steps are omitted. Needless to say, is included.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic cross-sectional process explanatory drawing which shows 1st embodiment of the manufacturing method of the rigid-flex multilayer printed wiring board of this invention. FIG. 2 is a schematic cross-sectional process explanatory diagram following FIG. 1. The principal part schematic perspective view of the rigid-flex multilayer printed wiring board of this invention. The schematic cross-sectional process explanatory drawing which shows 2nd embodiment of the manufacturing method of the rigid-flex multilayer printed wiring board of this invention. FIG. 5 is a schematic cross-sectional process explanatory diagram subsequent to FIG. 4. The schematic cross-sectional process explanatory drawing which shows 3rd embodiment of the manufacturing method of the rigid-flex multilayer printed wiring board of this invention. The schematic cross-sectional process explanatory drawing which shows 4th embodiment of the manufacturing method of the rigid-flex multilayer printed wiring board of this invention. Schematic cross-sectional process explanatory drawing which shows the manufacturing method of the conventional rigid flex multilayer printed wiring board. Schematic cross-sectional process explanatory drawing which shows the manufacturing method of the other conventional rigid-flex multilayer printed wiring board. FIG. 10 is a schematic cross-sectional process explanatory diagram following FIG. 9. Schematic cross-sectional explanatory drawing for demonstrating the boundary part of a rigid part and a flexible part.

Explanation of symbols

1: base substrate 2: wiring patterns 3, 3a, 3b, 3c: flexible substrate 4: adhesive layer 4a: flexible insulating adhesive layer 5: cover film 5a: metal foil 6: cover film 6a with adhesive layer: metal with resin Foil 7, 7 a: Release material 8: Slit 9: Laminated press intermediate plate 10: Convex part 11: Insulating adhesive layer 12: Opening part 13: Through hole (TH)
13a: Blind via hole (BVH)
14: Hard insulating substrate 15: Double-sided substrate 15a: Single-sided substrate 16: Grooves 17, 17a: Coverlay 18: Non-through hole 19: Plating P, Pa, Pb: Rigid flex multilayer printed wiring board R: Rigid part F: Flexible part L: Resin flow part

Claims (8)

  A rigid-flex multilayer printed wiring board having a rigid part capable of component mounting and a flexible part that can be bent, comprising at least a flexible substrate having a wiring pattern, a coverlay for protecting the wiring pattern, and the coverlay An insulating adhesive layer or a wiring pattern formed via an insulating adhesive layer and a hard insulating substrate on a portion excluding a flexible portion of the flexible substrate laminated with a via hole connecting between the wiring patterns in the vertical direction And the cover lay has a convex portion integrally formed with the cover lay at a boundary portion between the flexible portion and the rigid portion.   The rigid-flex multilayer printed wiring board according to claim 1, wherein the height of the convex portion is at least equal to or greater than the thickness of the insulating adhesive layer.   The rigid-flex multilayer printed wiring board according to claim 1 or 2, wherein the coverlay has a wiring pattern on a surface opposite to the bonding surface of the flexible substrate and in a portion corresponding to the rigid portion.   A method of manufacturing a rigid-flex multilayer printed wiring board having a rigid part capable of mounting components and a flexible part that can be bent, and includes at least a first step of forming a wiring pattern on a flexible substrate, a rigid part, and a flexible part A wiring pattern is formed through an insulating adhesive layer having an opening in the second step of forming a cover lay having a convex portion at the boundary portion and a portion that will later become a flexible portion, and the wiring patterns in the vertical direction are connected. And a third step of forming a via hole. A method for manufacturing a rigid-flex multilayer printed wiring board.   A method of manufacturing a rigid-flex multilayer printed wiring board having a rigid part capable of mounting components and a flexible part that can be bent, and includes at least a first step of forming a wiring pattern on a flexible substrate, a rigid part, and a flexible part A third step of sequentially laminating a second step of forming a cover lay having a convex portion at the boundary portion, an insulating adhesive layer having an opening in a portion that will later become a flexible portion, and a hard insulating substrate also having an opening. A method of manufacturing a rigid-flex multilayer printed wiring board, comprising: a step, a fourth step of forming a via hole for connecting wiring patterns in the vertical direction, and a fifth step of forming a wiring pattern of an outer layer.   The second step of forming the cover lay having the convex part is a step of arranging a cover film with an adhesive layer on the flexible substrate or a flexible insulating adhesive layer having flexibility even after curing, and with the adhesive layer. A step of sequentially disposing a release material having a slit at a portion corresponding to a boundary portion between the rigid portion and the flexible portion and an intermediate plate for the lamination press on the cover film or the flexible insulating adhesive layer, And a step of laminating a cover film with an adhesive layer or a flexible insulating adhesive layer, and flowing a part of the cover film with an adhesive layer or the flexible insulating adhesive layer into a slit provided in the release material. The manufacturing method of the rigid-flex multilayer printed wiring board of Claim 4 or 5.   The second step of forming the cover lay having the convex part is to sequentially arrange a flexible insulating adhesive layer and a metal foil having flexibility even after curing on the flexible substrate, or to cure on one side of the metal foil. The step of arranging a metal foil with resin on which a flexible insulating adhesive layer having flexibility is formed later, and a slit on the metal foil corresponding to a boundary portion between the rigid portion and the flexible portion A step of placing the release material and a lamination press laminate the flexible adhesive layer and the metal foil on the flexible substrate, and the flexible insulating adhesive layer and a part of the metal foil are placed on the slit provided in the release material. 6. The method according to claim 4, further comprising: forming the wiring pattern in the rigid portion by etching and removing the metal foil in other portions by etching. The method for producing rigid-flex multilayer printed wiring board.   The method of manufacturing a rigid-flex multilayer printed wiring board according to claim 6 or 7, wherein a thickness of the release material is substantially the same as a thickness of the insulating adhesive layer.