JPH1168312A - Manufacturing method of flex-rigid wiring board - Google Patents

Abstract

[PROBLEMS] To provide a method for manufacturing a flex-rigid wiring board which can surely prevent dissolution of a film cover lay layer due to a roughening treatment of a via hole resist layer. A manufacturing method according to the present invention includes a step of laminating an adhesive layer (5) having an opening (8) having a size corresponding to the conductor wiring (1) of a flexible cable portion (B) on a film cover lay layer (4); A long hole 9 is formed at a position outside the peripheral edge of the opening 8 formed in the agent layer 5 and at the boundary between the rigid multilayer portion A and the flexible cable portion B in a direction matching the peripheral edge of the opening 8. Laminating the outer core base material 6 on the adhesive layer 5, and laminating the via hole resist layer 7 on the outer core base material 6 constituting the rigid multilayer portion A, and then roughening the via hole resist layer 7. Of the outer core base material 6 laminated on the adhesive layer 5
Removing the opening-corresponding portions 6a located between the long holes 9 while covering the openings 8 of the adhesive layer 5.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for manufacturing a flex-rigid wiring board, and more particularly to a method for manufacturing a flex-rigid wiring board having a flexible cable portion and a rigid multilayer portion having a built-up multilayer structure.

[0002]

2. Description of the Related Art In recent years, there has been an increasing demand for wiring boards capable of realizing higher-density integration, and it has been required to employ a built-up multilayer structure for a rigid multilayer part constituting a flex-rigid wiring board. It is becoming possible. In order to meet such a demand, it has been considered to manufacture a flex-rigid wiring board by a procedure described with reference to FIG. That is, FIG. 3 is a cutaway perspective view illustrating the schematic structure of the flex-rigid wiring board.
Denotes a rigid multilayer portion, and B denotes a flexible cable portion. The flexible cable portion B is surrounded by the rigid multilayer portion A.

[0003] First, after preparing an inner core base material 23 in which required conductor wirings 21 and 22 are formed in advance, for example, an inner core base material 23 made of polyimide or the like, and made of a polyimide resin, A film cover lay layer 24 common to the rigid multilayer portion A and the flexible cable portion B is laminated on the surface of the inner core base material 23 by thermocompression bonding. Then, an outer core substrate 25 made of polyimide or the like is laminated on the surface of the film cover lay layer 24 constituting the rigid multilayer portion A. In this case, the outer core base material 25 has an opening 2 having a size corresponding to the conductor wiring 21 of the flexible cable portion B.
6, the film cover lay layer 24 of the flexible cable portion B remains exposed from the opening 26.

[0004] Next, a conductor layer 27 is formed by patterning a conductor layer such as a copper foil on the surface of the outer core substrate 25, and then the conductor layer 27 is formed on the surface of the outer core substrate 25 on which the conductor line 27 is formed. Is formed by laminating a via hole resist layer 28 made of an epoxy resin. Continued
A round hole-shaped via hole (via hole) 29 is formed for each predetermined position of the via hole resist layer 28 by a method such as laser beam irradiation or photo etching, and a via hole resist layer is formed using a chemical such as permanganic acid. A chemical roughening process is performed on the surface of No. 28. The roughening treatment at this time is intended to improve the adhesive strength of the conductor layer to the via hole resist layer 28. Further, via-hole resist layer 2
When a required conductor wiring (not shown) is formed by patterning after copper plating or the like serving as a conductor layer is formed on the surface of 8, a rigid multilayer portion A having a built-up multilayer structure is formed.
Thus, a flex-rigid wiring board including the flexible cable section B having a folding specification is completed.

[0005]

In the manufacturing method according to the prior art, the via hole resist layer 28 is roughened using a chemical such as permanganic acid. From the opening 26 of the core base material 25, the film coverlay layer 2 of the flexible cable portion B
Since the polyimide resin 4 is exposed and the polyimide resin as the film cover lay layer 24 is weak against alkali, the film cover lay layer 24 of the flexible cable portion B is dissolved by the action of the chemical used during the roughening treatment. Things happen. Then, the film cover lay layer 24
Is dissolved, the quality of the flexible cable portion B is remarkably deteriorated, and there arises an inconvenience that performance requirements for the flex-rigid wiring board cannot be satisfied.

The present invention has been made in view of such inconvenience, and has been devised to provide a flex-rigid wiring board capable of reliably preventing a film cover lay layer from being dissolved due to a roughening treatment of a via hole resist layer. It is intended to provide a manufacturing method.

[0007]

According to a first aspect of the present invention, there is provided a method of manufacturing a flex-rigid wiring board, comprising: a flexible cable portion comprising a conductor cover formed on an inner core substrate covered with a film coverlay layer. And, covering the inner core substrate on which the conductor wiring is formed with a film cover lay layer,
And a method of manufacturing a flex-rigid wiring board comprising a rigid multilayer portion in which an outer core base material and a via-hole resist layer are sequentially laminated on the film coverlay layer with an adhesive layer interposed therebetween. Laminating an adhesive layer having an opening of a size corresponding to the conductor wiring of the flexible cable part on a film cover lay layer common to the flexible cable part and the rigid multilayer part, and An adhesive layer is formed by bonding an outer core base material having a long hole formed at a position outside the peripheral edge of the formed opening and at a boundary position between the flexible cable portion and the rigid multilayer portion in a direction matching the peripheral edge of the opening. After laminating the via hole resist layer on the outer core base material constituting the rigid multilayer portion, the surface of the via hole resist layer is roughened. And that step, of the outer core substrate laminated on the adhesive layer, and a step of removing the opening corresponding portion which is located between the long hole in terms of covering the opening of the adhesive layer.

According to a second aspect of the present invention, there is provided a method for manufacturing a flex-rigid wiring board, comprising the steps of: applying an adhesive layer over the entire surface of the outer core base material; Having, and after forming a cutout groove cut to the depth to the outer core base material in the adhesive layer, removing the adhesive layer portion surrounded by the cutout groove to form an opening in the adhesive layer. Forming, forming a rigid multilayer part on the film cover lay layer common to the flexible cable part and the rigid multilayer part through the adhesive layer in which the opening is formed, and After laminating the via-hole resist layer on the outer core base material to be processed, a step of roughening the surface of the via-hole resist layer, and of the outer core base material laminated on the adhesive layer,
Removing the opening-corresponding portion surrounded by the cutout groove after corresponding to the opening of the adhesive layer.

According to the above-described manufacturing method, the film cover lay layer of the flexible cable portion at the time of roughening the surface of the via hole resist layer is protected from the chemical by the outer core base material. Dissolution of the film coverlay layer by action will not be possible. Therefore, the quality of the flexible cable portion does not deteriorate, and the performance requirements for the flex-rigid wiring board can be satisfied.

[0010]

Embodiments of the present invention will be described below with reference to the drawings.

(Embodiment 1) FIG. 1 is a process sectional view showing a schematic structure and a manufacturing procedure of a flex-rigid wiring board according to Embodiment 1, and a symbol A in FIG. Reference numeral B indicates a flexible cable portion, and a multilayer portion. That is, this flex-rigid wiring board is configured to include a rigid multilayer portion A having a built-up multilayer structure and a flexible cable portion B surrounded by the rigid multilayer portion A and the flexible cable portion B. Is formed by covering the inner core substrate 3 on which the conductor wiring 1 is formed with a film cover lay layer 4, while the rigid multilayer portion A is formed on the inner core substrate 3 on which the conductor wiring 2 is formed. An outer core base material 6 and a via hole resist layer 7 are sequentially laminated on the film cover lay layer 4 with an adhesive layer 5 interposed therebetween.

First, when manufacturing the flex-rigid wiring board according to the first embodiment, as shown in FIG. 1A, an inner core base material on which required conductor wirings 1 and 2 are formed in advance. For example, after preparing the inner core base material 3 made by using polyimide or the like, a film common to the rigid multilayer portion A and the flexible cable portion B and made using a polyimide resin The coverlay layer 4 is entirely laminated on the surface of the inner core substrate 3 by thermocompression bonding. Then, on the surface of the film cover lay layer 4 constituting the rigid multilayer portion A, the conductor wiring 1 of the flexible cable portion B is formed.
An adhesive layer 5 having an opening 8 having a size corresponding to that of the adhesive layer 5 is formed beforehand.

Subsequently, as shown in FIG. 1B, a flat outer core base material 6 made of polyimide or the like is prepared, and the outer core base material 6 is laminated on the adhesive layer 5. Lamination is performed together. At this time, a predetermined position of the outer core base material 6, that is, a position outside the peripheral edge of the opening 8 of the adhesive layer 5 and a boundary position between the rigid multilayer portion A and the flexible cable portion B, A long hole (slit) 9 opened along a direction coinciding with a peripheral edge of the opening 8 of the layer 5 is formed, and the outer core base material 6 has the opening 8 of the adhesive layer 5 located between the long holes 9. After being adjusted as described above, it is laminated on the adhesive layer 5. At this time, it is not necessary that the overlapping dimension X of the peripheral edge located outside the elongated hole 9 in the outer core base material 6 and the adhesive layer 5 and the width dimension Y of the elongated hole 9 be limited. In the present embodiment, X = 1.1 m in consideration of the mold drop-out operation.
m, Y = 0.6 mm is set.

Therefore, the opening 8 of the adhesive layer 5 is sealed with the film cover lay layer 4 and the outer core base material 6, and the film cover lay layer 4 of the flexible cable portion B exposed in the opening 8 is The outer core base material 6 sealing the opening 8 is protected from the outside. Subsequently, after a conductor layer made of copper foil or the like is applied on the surface of the outer core base material 6 constituting the rigid multilayer portion A, a conductor layer 10 is formed by patterning, and then the outside on which the conductor line 10 is formed is formed. When a via-hole resist layer 7 made of an epoxy resin is laminated on the surface of the core base material 6, an intermediate structure as shown in FIG. 1C is obtained. Further, after forming via holes 11 at predetermined positions of the via hole resist layer 7 by employing a technique such as laser beam irradiation or photo etching, a roughening process using a chemical such as permanganic acid is performed. Performed on the surface of layer 7. In this case, the film cover lay layer 4 of the flexible cable portion B
Is protected by the outer core base material 6, so that the film cover lay layer 4 cannot be affected by the action of the chemical solution used for the roughening treatment.

Subsequently, after the surface of the via-hole resist layer 7 is subjected to copper plating or the like serving as a conductor layer, an electrical connection with the conductor wiring 10 on the outer core base material 6 is obtained through the via hole 11. When patterning is performed on the formed conductor layer, the necessary conductor wiring is formed on the via-hole resist layer 7, though not shown. Thereafter, the outer core base material 6 laminated on the adhesive layer 5 after the mold removal operation is performed, covers the opening 8 of the adhesive layer 5 and is located between the long holes 9. When the opening corresponding portion 6a is removed, a flex-rigid wiring board including a rigid multilayer portion A having a built-up multilayer structure and a flexible cable portion B having a folding specification is completed. In this case, since the overlap between the opening corresponding portion 6a of the outer core base material 6 and the adhesive layer 5 is only about XY = 0.5 mm, it is extremely easy to peel off the opening corresponding portion 6a. is there.

(Embodiment 2) FIG. 2 is a process sectional view showing a schematic structure and a manufacturing procedure of a flex-rigid wiring board according to Embodiment 2, and reference symbol A in FIG. Reference symbol B indicates a flexible cable portion. That is, this flex-rigid wiring board includes a rigid multilayer portion A having a built-up multilayer structure and a flexible cable portion B surrounded by the rigid multilayer portion A and the flexible cable portion B as in the first embodiment. Is formed by covering the inner core substrate 3 on which the conductor wiring 1 is formed with a film cover lay layer 4, while the rigid multilayer portion A is formed on the inner core substrate 3 on which the conductor wiring 2 is formed. It is covered with a film cover lay layer 4, and an outer core base material 6 and a via hole resist layer 7 are sequentially laminated on the film cover lay layer 4 with an adhesive layer 5 interposed therebetween. ing. In FIG. 2, the same or corresponding parts and portions as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof will be omitted.

In manufacturing the flex-rigid wiring board according to the second embodiment, first, as shown in FIG. After preparing the formed inner core substrate 3, the film cover lay layer 4 produced by using a polyimide resin is used to form the inner core substrate 3 common to both the rigid multilayer portion A and the flexible cable portion B. Lamination is performed over the entire surface by thermocompression bonding. On the other hand, a flat plate-shaped outer core base material 6 made of polyimide or the like is separately prepared, and an adhesive layer 5 having a predetermined thickness is formed over the entire surface located inside the outer core base material 6. To adhere. Subsequently, a cutout groove 13 having a size corresponding to the conductor wiring 1 of the flexible cable portion B and cut to a depth reaching the inside of the outer core base material 6 is formed in the adhesive layer 5. After the formation, the opening 8 of the adhesive layer 5 is formed by removing only the adhesive layer portion 5a surrounded by the cutout groove 13.

Next, as shown in FIG. 2B, the outer core base material 6 is shared by the rigid multilayer portion A and the flexible cable portion B via the adhesive layer 5 having the openings 8 formed therebetween. The conductor wiring 10 is formed by superimposing and laminating on the film cover lay layer 4 and then patterning a conductor layer made of copper foil or the like on the surface of the outer core base material 6 constituting the rigid multilayer portion A. Form. Therefore, the opening 8 of the adhesive layer 5 is sealed by the film cover lay layer 4 and the outer core base material 6, and the film cover lay layer 4 of the flexible cable portion B exposed in the opening 8 It is protected by the sealing outer core substrate 6.

Further, as shown in FIG. 2C, a via-hole resist layer 7 made of an epoxy resin is laminated on the surface of the outer core base material 6 on which the conductor wiring 10 is formed. After the via holes 11 are formed by employing a technique such as photo etching, a roughening process using a chemical such as permanganic acid is performed on the surface of the via hole resist layer 7. In addition,
At this time, since the film cover lay layer 4 of the flexible cable portion B is protected by the outer core base material 6, the film cover lay layer 4 may be affected by the action of the chemical solution used for the roughening treatment. You will not get it.

Although not shown in the figure, copper plating or the like serving as a conductor layer is applied to the surface of the via hole resist layer 7 so as to make electrical contact with the conductor wiring 10 on the outer core base material 6 via the via hole 11. After the connection is obtained, patterning of the formed conductor layer is performed, so that the required conductor wiring is formed on the via-hole resist layer 7. After that, after the mold is removed, the outer core base material 6 laminated on the adhesive layer 5 has an opening corresponding to the opening 8 of the adhesive layer 5 surrounded by the cutout groove 13. When the corresponding portion 6a is removed, a flex-rigid wiring board including a rigid multilayer portion A having a built-up multilayer structure and a flexible cable portion B having a folding specification, that is, a flex having the same configuration as the conventional technology shown in FIG. The rigid wiring board is completed.

By the way, Embodiments 1 and 2
Describes that the flexible cable portion B is of a folding type, but the manufacturing method according to the present invention is also applied to a flex-rigid wiring board having a flying tail type flexible cable portion with the conductor wiring 1 exposed. Is of course possible.

[0022]

As described above, when the method for manufacturing a flex-rigid wiring board according to the present invention is employed, the film cover lay layer of the flexible cable portion at the time of roughening the via-hole resist layer has the outer core base. Since the material is protected from the chemical solution, the film coverlay layer cannot be dissolved by the action of the chemical solution. Therefore, it is possible to prevent the quality of the flexible cable portion from deteriorating while reliably preventing the dissolution of the film cover lay layer due to the roughening treatment of the via hole resist layer, thereby sufficiently satisfying the performance requirements for the flex-rigid wiring board. The effect that it can be obtained is obtained.

[Brief description of the drawings]

FIG. 1 is a process cross-sectional view showing a schematic structure and a manufacturing procedure of a flex-rigid wiring board according to a first embodiment.

FIG. 2 is a process cross-sectional view showing a schematic structure and a manufacturing procedure of a flex-rigid wiring board according to a second embodiment.

FIG. 3 is a cutaway perspective view illustrating a schematic structure of a flex-rigid wiring board according to a conventional embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Conductor wiring 4 Film cover lay layer 5 Adhesive layer 6 Outer core base material 6a Opening corresponding part 7 Via hole resist layer 8 Opening 9 Slot A Rigid multilayer part B Flexible cable part

Claims (2)

[Claims] 1. A flexible cable portion comprising a conductor cover formed on an inner core base material covered with a film cover lay layer, and a conductor cover formed on an inner core base material covered by a film cover lay layer. And manufacturing a flex-rigid wiring board comprising a rigid multilayer portion in which an outer core base material and a via-hole resist layer are sequentially laminated on the film coverlay layer with an adhesive layer interposed therebetween. A method comprising: laminating an adhesive layer having an opening having a size corresponding to conductor wiring of a flexible cable portion on a film cover lay layer common to the flexible cable portion and the rigid multilayer portion; It is located outside the peripheral edge of the opening formed in the layer and coincides with the peripheral edge of the opening at the boundary position between the flexible cable part and the rigid multilayer part Laminating an outer core base material having a long hole formed thereon on the adhesive layer, and laminating a via hole resist layer on the outer core base material constituting the rigid multilayer portion. A step of performing a roughening process, and a step of removing an opening corresponding portion located between the long holes in the outer core base material laminated on the adhesive layer, while covering the opening of the adhesive layer. A method for manufacturing a flex-rigid wiring board. 2. A flexible cable portion in which a conductive wiring is formed on an inner core base material covered with a film cover lay layer, and an inner core base material on which conductive wiring is formed is covered with a film cover lay layer. And manufacturing a flex-rigid wiring board comprising a rigid multilayer portion in which an outer core base material and a via-hole resist layer are sequentially laminated on the film coverlay layer with an adhesive layer interposed therebetween. A method of applying an adhesive layer over the entire surface of the outer core base material, and having a size corresponding to the conductor wiring of the flexible cable portion, and cutting to a depth reaching the outer core base material. Forming a cutout groove in the adhesive layer and then removing the adhesive layer portion surrounded by the cutout groove to form an opening in the adhesive layer; And then laminating the outer core base material on the film cover lay layer common to the flexible cable part and the rigid multilayer part, and after laminating the via hole resist layer on the outer core base material constituting the rigid multilayer part, A step of roughening the surface of the via-hole resist layer; and, of the outer core base material laminated on the adhesive layer, a portion corresponding to the opening corresponding to the opening of the adhesive layer and surrounded by the cutout groove. A method for manufacturing a flex-rigid wiring board.