JP2006210873A - Manufacturing method of partial build up wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a partial build up wiring board capable of removing a build up resin layer on a flexible layer while suppressing increase of processes or effect on a circuit board to minimum. <P>SOLUTION: A conductor layer 3 is formed on one side on a rigid layer 1. A slit 5 is formed at the part corresponding to a flexible layer 7 of the rigid layer 1. The rigid layer 1 is laminated on the flexible layer 7. A part of the conductor layer is so left as a lid as to stop the slit. A build up resin layer17 is formed on the rigid layer 1. The build up resin layer 17 and the conductor layer 3 positioned above the slit 5 are removed to open the slit 5. The build up resin layer 17 and the rigid layer 1 positioned above the flexible layer 7 are removed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for manufacturing a partial buildup wiring board, and in particular, manufacturing a partial buildup wiring board in which a buildup resin layer made of epoxy resin or the like is formed in a partial region of a flexible wiring board (core substrate) by a buildup method. Regarding the method.

  In recent years, electronic devices have become smaller and lighter, semiconductor chips and components have been downsized, and the pitch of terminals has been narrowed. In printed wiring boards (wiring boards), the mounting area has been reduced and the wiring has been refined. At the same time, in information-related equipment, it is required to shorten the distance of wiring connecting parts in response to the widening of signal frequency, and it is necessary to increase the number of printed wiring boards to achieve high density and high performance. It has become indispensable.

  Among the multilayer wiring boards, a rigid flex wiring board (hereinafter referred to as a rigid flex circuit board) that can be three-dimensionally mounted in a narrow space in a small electronic device such as a mobile phone, a DVC (digital video camera), and a DSC (digital still camera). Demand is also increasing rapidly. Further, a high-density substrate having 1 to 2 build-up layers formed on the upper and lower layers using a 4 to 6-layer rigid flex wiring board or a multilayer flexible wiring board as a core substrate has been developed to meet the demand for higher density mounting.

  Rigid-flex wiring boards or multilayer flexible wiring boards use single-sided or double-sided flexible PWB (printed wiring board) as a base board to partially layer parts where parts are mounted, and board multilayer parts mounted with these parts by flexible PWBs. Some are electrically connected. This is called a partial build-up wiring board.

  By the way, in the rigid flex circuit board, a substrate in which a circuit is formed on a hard (rigid) material such as glass epoxy is laminated on a substrate in which a circuit is formed on a soft (flexible) material such as polyimide film. At this time, by opening a part of the substrate made of the hard material and exposing the substrate made of the soft material, the substrate made of the soft material can be bent. By stacking a buildup layer on the rigid portion using such a rigid flex substrate as a core, a substrate with higher wiring density can be created.

  A conventional method of manufacturing a rigid flex circuit board (partial buildup wiring board) will be described with reference to FIG.

  As shown in FIG. 10, in the conventional rigid flex circuit board, a copper foil layer (conductor pattern) 103 is formed on one surface of a flexible layer 101, and a cover layer is formed on the entire surface of the flexible layer 101 on which the copper foil layer 103 is formed. The film 105 is laminated. FIG. 10 shows an example in which build-up is performed on one side of the flexible layer 101, but in actuality, build-up is performed on both sides of the flexible layer 101, and the manufacturing method in this case is the same.

  Next, in order to form a multilayer part for mounting components, an adhesive layer 107 is formed at a predetermined position (partial region) on the coverlay film 105, and a rigid layer 109 made of glass epoxy or the like, a copper foil layer thereon, and the like. (Conductor pattern) 103 is formed. Thereafter, although not shown, a through hole is formed in a predetermined portion, and conduction between layers is achieved by through hole plating. Thereby, the core substrate 111 of the partially multilayered rigid flex circuit board is formed.

  Further, a build-up resin layer 113 made of a rigid material such as an epoxy resin is formed on the multilayer portion (adhesive layer 107 + rigid layer 109 + copper foil layer 103) of the core substrate 111 by lamination, printing, coating, or the like. Then, a copper foil layer (conductor pattern) (not shown) for component mounting is formed on the buildup resin layer 113 by plating or the like. This copper foil layer is electrically connected to the copper foil layers 103 and 103 of the core substrate 111 by laser via formation, plating or the like. Thereby, a rigid flex circuit board is obtained.

  Thus, the conventional rigid flex circuit board is a flexible layer in which a copper foil layer 103 is formed by laminating a rigid layer (rigid board) 109 having an opening in advance on a flexible layer (flex board) 101 on which a circuit is formed. (Flexible part) 101 is exposed. Although the build-up resin 113 is laminated on the core substrate 111 formed in this manner, the build-up resin 113 has a certain degree of fluidity in order to ensure embedding in the circuit on the surface of the core substrate 111. If laminated as it is, the build-up resin 113 oozes out to the flexible part as shown in FIG. Therefore, when the build-up resin 113 oozes out, the flexibility of the flexible part is lowered, and the build-up layer on the rigid layer 109 near the flexible part is thinned, which may reduce the reliability of the circuit. There is.

  For this reason, conventionally, many inventions have been devised for suppressing the seepage of the build-up resin. The invention of the typical manufacturing method is disclosed in Patent Document 1. The invention disclosed in this Patent Document 1 is configured such that a dummy circuit or the like is provided around a flexible portion so as to play a role of a bank against a buildup resin that flows.

  Further, as other methods, an ultraviolet curable resin is used for the build-up resin, and the resin exuded on the flexible portion is made easy to be removed without being exposed, as in the invention disclosed in Patent Document 2. In addition, there is a method of removing by irradiating a laser beam.

  Furthermore, there is an invention disclosed in Patent Document 3 in a manufacturing process of a rigid flex circuit board. As shown in FIGS. 12A and 12B, the rigid flex circuit board disclosed in Patent Document 3 has an inner layer circuit pattern 117 formed on both surfaces of the flexible layer 115, and a flexible layer in which the inner layer circuit pattern 117 is formed. A coverlay film 119 is laminated on both sides of 115.

  Next, an adhesive layer 121 is formed at a predetermined position (partial region) on the cover lay film 119 in order to form a multilayer part for mounting components, and a rigid layer 123 made of glass epoxy or the like, and a surface layer circuit pattern are formed thereon. 125 is formed. Thereafter, a build-up resin layer 127 shown in FIGS. 13A and 13B is formed on the surface layer circuit pattern 125 by a rigid material such as an epoxy resin by lamination, printing, coating, or the like.

Therefore, the rigid flex circuit board disclosed in Patent Document 3 does not open the rigid layer 123 in advance when laminating the rigid layer (rigid board) 123, and slits at the boundary between the rigid part and the flexible part. 129 is provided, and the substrate is punched out by external processing, and at the same time, the rigid layer 123 on the flexible portion is removed.
JP 2001-156445 A JP 2003-198133 A JP 2001-185854 A

  However, in the manufacturing method disclosed in Patent Document 1, the provision of the dummy circuit causes a limitation in circuit design, and there is a problem that the number of steps for removing the exuded resin increases, leading to an increase in cost.

  In addition, in the manufacturing method disclosed in Patent Document 2, when removing the resin on the flexible portion using laser light, there is a possibility of damaging the flexible substrate, and measures such as forming a copper foil layer in advance. However, it is not preferable in terms of work to perform processing using laser light directly above the wiring connecting the rigid portions.

  Furthermore, in the manufacturing method disclosed in Patent Document 3, it is important to prevent the build-up resin layer 127 from exuding when the build-up is performed, and the build-up that has exuded as shown in FIGS. If the slit 129 is filled with the up resin layer 127, there is a problem that the rigid layer 123 cannot be removed.

  The present invention has been made in view of the above, and the purpose thereof is a partial build-up wiring capable of removing the build-up resin layer on the flexible layer while minimizing the increase in the number of processes and the influence on the circuit board. It is in providing the manufacturing method of a board.

  The invention described in claim 1 is a method for manufacturing a partial buildup wiring board in which a rigid layer is laminated on a partial region of a flexible layer and a buildup resin layer is laminated on the rigid layer in order to solve the above-mentioned problem. A conductor layer is formed on one side of the rigid layer, and a slit is formed in a portion of the rigid layer corresponding to the flexible layer, and the rigid layer is laminated on the flexible layer and the slit is blocked. As described above, leaving a part of the conductor layer as a lid, forming the build-up resin layer on the rigid layer, removing the conductor layer and the build-up resin layer located on the slit and opening the slit The gist is to remove the rigid layer and the buildup resin layer located on the flexible layer.

  In order to solve the above problems, the invention according to claim 2 is summarized in that the upper surface of the rigid layer is formed flat and the flexible layer is laminated on the upper surface of the rigid layer.

  The gist of the invention described in claim 3 is that the upper surface of the rigid layer is formed flat and the build-up resin layer is laminated on the upper surface of the rigid layer in order to solve the above problems.

  In order to solve the above-mentioned problem, the invention described in claim 4 is summarized in that the slit formed in the rigid layer is formed by notching only the rigid layer by spot facing.

  In order to solve the above-mentioned problem, the build-up resin layer located on the slit is removed simultaneously with the opening of the via hole by irradiating a laser beam. The gist of the invention is that the conductor layer located in is removed at the same time as the circuit is formed.

  In order to solve the above problems, the invention described in claim 6 is summarized in that the rigid layer and the buildup resin layer located on the flexible layer are simultaneously removed by external processing.

  The method for manufacturing a partial buildup wiring board according to the present invention includes a rigid layer in a partial region of the flexible layer, a buildup resin layer laminated on the rigid layer, A manufacturing method of a build-up wiring board having a flexible part only by a flexible layer, wherein the rigid part material includes a part corresponding to the rigid part and the flexible part, and the rigid part of the rigid layer material and the flexible part A step of penetrating and opening a slit along a boundary with a portion corresponding to the portion, a step of bonding a resin film to one surface of the rigid layer material so as to close one side of the slit, and the rigid Plating is performed on the other surface of the layer material, and a plating layer is formed on the other surface of the rigid layer material and the slip is formed. Filling the inside with plating metal, attaching the rigid portion of the rigid layer material only on the flexible layer with the one surface of the rigid layer material as a bonding surface, and the other of the rigid layer material A step of etching the plating layer formed on the surface to leave a plating metal in the slit to form a circuit pattern, and laminating a buildup resin layer on the entire surface of the other surface of the rigid layer material A step, a step of removing the build-up resin layer corresponding to the slit, a step of removing the plating metal filled in the slit, and a removal of the rigid layer material corresponding to the flexible portion. Process.

  The method for manufacturing a partial buildup wiring board according to the present invention includes a rigid layer in a partial region of the flexible layer, a buildup resin layer laminated on the rigid layer, A manufacturing method of a build-up wiring board having a flexible part only by a flexible layer, wherein the rigid part material includes a part corresponding to the rigid part and the flexible part, and the rigid part of the rigid layer material and the flexible part A step of penetrating and opening a slit along a boundary with a portion corresponding to the portion, a step of bonding a resin film to one surface of the rigid layer material so as to close one side of the slit, and the rigid Plating is performed on both sides of the layer material to form a plating layer on both sides of the rigid layer material and fit in the slit. A step of filling the metal layer, a step of etching the plating layer formed on the one surface of the rigid layer material to form a circuit pattern, and the one surface of the rigid layer material as a bonding surface A step of attaching only the rigid portion of the rigid layer material on the flexible layer, and etching the plating layer formed on the other surface of the rigid layer material so as to leave a plating metal in the slit. A step of forming a pattern, a step of laminating a buildup resin layer on the entire surface of the other surface of the rigid layer material, a step of removing the buildup resin layer in a portion corresponding to the slit, and the slit Removing the filled plating metal; and removing the rigid layer material in a portion corresponding to the flexible portion.

  In the method for manufacturing a partial buildup wiring board according to the present invention, preferably, the step of removing the buildup resin layer in the portion corresponding to the slit includes a step of forming a via hole in the buildup resin layer by laser light irradiation. Perform in the same process.

  In the method for manufacturing a partial buildup wiring board according to the present invention, preferably, the step of removing the rigid layer material in the portion corresponding to the flexible portion is performed in the same step as the step of externally processing the partial buildup wiring board.

  According to the present invention, a conductor layer is formed on at least one side of the rigid layer, and a slit is formed in a portion corresponding to the flexible layer of the rigid layer, and this rigid layer is laminated on the flexible layer, By forming a build-up resin layer, removing the conductor layer and build-up resin layer located on the slit to open the slit, and removing the rigid layer and build-up resin layer located on the flexible layer, The buildup resin layer on the flexible layer can be removed while minimizing the increase and the influence on the circuit board.

  Moreover, since it is not necessary to consider the seepage of the build-up resin layer, the types of selectable resins can be greatly increased. And since resin with high fluidity | liquidity can be used for a buildup resin layer, it is easy to embed buildup resin and can make a board | substrate flat.

  According to the present invention, the upper surface of the rigid layer is formed flat, and the buildup resin layer is laminated on the upper surface of the rigid layer, whereby the layer thickness of the buildup resin layer is easily made uniform.

  According to the present invention, the slit formed in the rigid layer can be surely and easily formed by cutting only the rigid layer by spot facing.

  According to the present invention, the build-up resin layer located on the slit is removed simultaneously with the opening of the via hole by irradiating the laser beam, while the conductor layer located on the slit forms the circuit. By removing at the same time, the build-up resin layer and the conductor layer located on the slit can be removed without increasing unnecessary steps.

  According to the present invention, the rigid layer and the build-up resin layer located on the flexible layer are simultaneously removed by the outer shape processing, so that the rigid layer and the build located on the flexible layer are not increased without increasing unnecessary processes. The up resin layer can be removed.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(One embodiment)
1A to 1E are process diagrams showing an embodiment of a method for manufacturing a partial buildup wiring board according to the present invention.

  First, as shown to Fig.1 (a), the glass epoxy base material with the single side | surface copper foil which formed the copper foil layer 3 as a conductor layer in the single side | surface (one side) of the rigid layer 1 is used. In the rigid layer 1, slits 5 are formed from the rigid layer 1 side in a portion corresponding to a joint with a flexible layer to be described later, while the slits are not formed in the copper foil layer 3.

  Next, as shown in FIG. 1B, a circuit pattern 9 is formed on one surface of the flexible layer 7, and a cover lay film 11 is laminated on the entire surface of the flexible layer 7 on which the circuit pattern 9 is formed. An adhesive layer 13 is formed at a predetermined position (partial region) on the lay film 11, and the rigid layer 1 and the copper foil layer 3 are laminated thereon to form a core substrate 15. At this time, in the copper foil layer 3, the portion corresponding to the slit 5 is left as a lid portion 3 a that closes the slit 5. Although FIG. 1 shows a process of laminating only one side of the flexible layer, this process can be applied simultaneously to the front and back surfaces of the flexible layer in which circuits are formed on both sides. (Not limited to one side only)

  Further, as shown in FIG. 1C, a buildup resin layer 17 is laminated on the rigid layer 1 and the copper foil layer 3. At this time, the build-up resin layer 17 is not particularly processed, and the entire core substrate 15 is laminated by the build-up resin layer 17. Here, since the slit 5 is closed by the lid portion 3 a of the copper foil layer 3, the buildup resin layer 17 does not flow in.

  Thereafter, as shown in FIG. 1 (d), the build-up resin layer 17 is irradiated with laser light to form a via hole 19, and at the same time, the part of the build-up resin layer 17 positioned immediately above the slit 5 of the rigid layer 1 is formed. The trimming part 21 is formed by removing with laser light. At this time, since the laser beam is prevented from reaching the deeper portion by the copper foil layer 3, it is not necessary to consider damage to the surface of the core substrate 15. Without using a laser, a photosensitive build-up resin is laminated while leaving the copper foil layer 3 positioned on the slit 5, and the via-hole 19 is opened by exposure and development, and at the same time, the build-up resin layer 17 on the slit 5. There is also a way to remove the.

  Next, a conductive layer is formed on the entire surface of the buildup resin layer 17 by plating or the like. Thereafter, a resist for forming a circuit is formed on this conductive layer, and a protective film for etching is formed on the circuit portion by exposure and development. Next, a required circuit is formed by etching the conductive layer. Simultaneously with this etching, as shown in FIG. 1 (e), the lid 3a of the copper foil layer 3 on the slit 5 is removed, and if the outer shape is applied after removing the resist, the build-up resin layer 17 on the flexible layer 7 and the rigid are formed. Layer 1 can be removed.

  As described above, according to the present embodiment, the copper foil layer 3 is formed on one side of the rigid layer 1 and the portion corresponding to the flexible layer 7 of the rigid layer 1, that is, the portion corresponding to the boundary portion with the flexible layer 7. A slit 5 is formed on the rigid layer 1 and the rigid layer 1 is laminated on the flexible layer 7, and a part of the copper foil layer 3 is left as a lid portion 3 a so as to close the slit 5. 17 is formed, the copper foil layer 3 and the buildup resin layer 17 located on the slit 5 are removed, the slit 5 is opened, and the rigid layer 1 and the buildup resin layer 17 located on the flexible layer 7 are removed. Thus, the build-up resin layer 17 on the flexible layer 7 can be easily removed while minimizing the increase in the process and the influence on the circuit board.

  Further, since the lid portion 3a of the copper foil layer 3 is provided so as to close the slit 5, it is not necessary to consider the seepage of the build-up resin layer 17, and the types of selectable resins are greatly increased. Can do. And since resin with high fluidity | liquidity can be used for the buildup resin layer 17, it is easy to embed buildup resin and can make a board | substrate flat.

  Furthermore, according to the present embodiment, the upper surface of the rigid layer 1 is formed flat, and the buildup resin layer 17 is laminated on the upper surface of the rigid layer 1, thereby making it possible to make the layer thickness of the buildup resin layer 17 uniform. Become.

  And according to this Embodiment, the slit 5 formed in the rigid layer 1 can form the slit 5 reliably and easily by notching only the rigid layer 1 by spot facing. .

  According to the present embodiment, the build-up resin layer 17 located on the slit 5 is removed at the same time as opening the via hole 19 by irradiating laser light, while the copper foil layer located on the slit 5 is removed. 3 is removed at the same time as the circuit is formed, so that the build-up resin layer 17 and the copper foil layer 3 located on the slit 5 can be removed without increasing unnecessary steps.

  Moreover, according to this Embodiment, the rigid layer 1 and the buildup resin layer 17 which are located on the flexible layer 7 are removed by external shape processing simultaneously, and without increasing an extra process, the flexible layer 7 The rigid layer 1 and the buildup resin layer 17 located on the upper side can be removed.

(Modification of the embodiment)
Next, a modification of the present embodiment will be described with reference to FIGS. FIGS. 2A to 2D are process diagrams for removing the copper foil layer showing a modification of the present embodiment.

  When removing the copper foil layer 3, as shown in FIG. 2A, the buildup resin layer 17 is irradiated with laser light to laser the portion of the buildup resin layer 17 positioned immediately above the slit 5 of the rigid layer 1. The trimming part 21 is formed by removing with light.

  Then, since the buildup resin layer 17 has fluidity, as shown in FIG. 2B, the trimming portion 21 is closed by the seepage of the buildup resin and the bridge portion 23 is formed.

  Next, as shown in FIG. 2C, the cured portion 23 is removed by desmearing by a wet or dry method.

  Further, as shown in FIG. 2D, the copper foil layer 3 located on the slit 5 is removed by etching. The copper foil layer 3 located on the slit 5 can be removed by such a process.

(Example)
Next, an embodiment of the method for manufacturing a partial buildup wiring board according to the present invention will be described with reference to FIGS.

  First, as shown in FIG. 3A, a flexible layer 31 made of a polyimide film is prepared by bonding a conductor layer 33 made of copper foil to both surfaces, and a circuit is formed on the conductor layer 33 by a subtractive method.

  Next, as shown in FIG. 3B, on both surfaces of the flexible layer 31 to which the conductor layer 33 is bonded, a coverlay film 35 that protects the circuit, and a portion substantially corresponding to the portion that finally exposes the flexible layer are formed. The removed adhesive layer 37 is laminated, and a rigid layer 41 made of a glass epoxy resin provided with a conductor layer 39 made of copper foil on one side is pasted on both sides thereof.

  At this time, slits (cuts) 43 are formed from the rigid layer 41 side toward the conductor layer 39 so that the rigid layer 41 corresponding to the flexible layer 31 can be removed in a later step. This slit 43 removes only the rigid layer 41 made of glass epoxy resin by spot facing using laser light irradiation, router, etching or the like. The slit 43 is not limited in size or shape as long as it does not affect the subsequent process.

  Further, as shown in FIG. 3C, a through hole 45 is formed through a predetermined portion, and through hole plating 46 is applied to the through hole 45 to establish conduction between layers, and a circuit is formed. In this case, the conductor layer 39 corresponding to the position of the slit 43 has a function of covering the slit 43 by leaving it without being removed.

  Next, as shown in FIG. 3D, the conductor layer 39 is laminated with the buildup resin layer 47. Here, it is desirable that the build-up resin layer 47 is laminated on the entire substrate and embedded in a circuit using a resin having high fluidity to improve the flatness of the build-up resin layer 47.

  Then, as shown in FIG. 4E, the build-up resin layer 47 is irradiated with laser light to form a via hole 49, and at the same time, a laser is applied to the build-up resin layer 47 in a portion located immediately above the slit 43 of the rigid layer 41. The trimming part 51 is formed by removing light by irradiation.

  At this time, since the laser beam is blocked by the conductor layer directly above the slit, it is not necessary to consider damage to the core substrate surface.

  In the step shown in FIG. 4E, when the buildup resin layer 47 on the slit 43 is removed, the conductor layer 39 made of copper foil remains on the slit 43, so that the core is irradiated with laser light. The substrate is not damaged.

  Further, instead of forming the via hole 49 and the trimming portion 51 by irradiating the build-up resin layer 47 with laser light as described above, exposure and development are performed using a photosensitive resin such as an ultraviolet curable resin for the build-up resin. Thus, the photosensitive resin may be partially removed to form the via hole 49 and the trimming portion 51 at the same time.

  Further, as shown in FIG. 4F, a conductive layer 53 is formed on the buildup resin layer 47 by plating or the like. Thereafter, a resist for forming a circuit is formed on the conductive layer 53, and a protective film for etching is formed on the circuit portion by exposure and development. Next, the conductive layer 53 is etched to form a required circuit. Simultaneously with this etching, the copper foil layer 39 on the slit 43 is removed as shown in FIG. 4 (f), and if the outer shape is applied after removing the resist, the build-up resin layer 47 and the rigid layer 41 on the flexible layer 31 are removed. can do.

  The conductive layer 53 formed on the buildup resin layer 47 is specifically desmeared by a wet method or a dry method, and the conductive layer 53 on which component mounting is performed on the buildup resin layer 47 by the plating method. Form. The conductive layer 53 can be formed as a fine circuit by a subtractive method or an additive method. As a result, a partially multilayered rigid flex circuit board having a build-up resin layer 47 with a circuit formed as a surface layer is obtained.

  Thus, according to the present embodiment, the conductor layer 39 is formed on one side of the rigid layer 41, and the slit 43 is formed in the portion corresponding to the flexible layer 31 of the rigid layer 41, and the rigid layer 41 is flexible. The layer 31 is laminated, the build-up resin layer 47 is formed on the rigid layer 41, the conductor layer 39 and the build-up resin layer 47 located on the slit 43 are removed, the slit 43 is opened, and the position is on the flexible layer 31. Since the rigid layer 41 and the buildup resin layer 47 to be removed are removed, the buildup resin layer 47 on the flexible layer 31 can be removed while minimizing the increase in the process and the influence on the circuit board. .

(Other embodiments)
Another embodiment of the method for manufacturing a partial buildup wiring board according to the present invention will be described with reference to FIGS.

  First, a rigid layer material 61 such as a glass epoxy substrate material as shown in FIG. The rigid layer material 61 includes a rigid portion R and a portion Fr corresponding to a flexible portion F (see FIG. 6J). A slit 63 along the boundary B between the rigid portion R of the rigid layer material 61 and the portion Fr corresponding to the flexible portion F is opened by laser processing or the like.

  Next, as shown in FIG. 5B, a resin film 65 is bonded to one surface of the rigid layer material 61 so as to close the opening on one side of the slit 63. As a result, one side of the slit 63 is closed by the resin film 65.

  Here, although there is no restriction | limiting in particular in the material of the resin film 65 to be used, PET, PEN, etc. must have the heat resistance and acid resistance which do not deform | transform, modify | denature, and melt | dissolve in a post process. Further, the resin film 65 needs to be sufficiently cured and closely adhered so that it does not peel off during the operation or adhere to the flexible layer cover lay 75 (see FIG. 5E).

  Next, as shown in FIG. 5C, copper plating is performed on the other surface of the rigid layer material 61 (the surface on which the resin film 65 is not bonded), and the other surface of the rigid layer material 61 is subjected to copper plating. A plating layer 67 is formed on the surface, and plating metal (copper) 69 is filled in the slit 63. This copper plating can be performed in the manner of filling plating in which the plating metal 69 is satisfactorily filled in the slit 63 whose bottom is closed by the resin film 65.

  Next, as shown in FIG. 5D, the portion of the resin film 65 corresponding to the slit 63, that is, the portion that formed the bottom of the slit 63 is removed by laser light irradiation or plasma etching. (Reference E).

  Next, as shown in FIG. 5 (e), a circuit pattern 73 is formed on one side of the flexible layer 71 made of polyimide film or the like, and the circuit pattern 73 is covered on one side of the flexible layer 71. Coverlay 75 is provided. On the cover lay 75, only the rigid portion R of the rigid layer material 61 is adhered by the adhesive layer 77 with the one surface of the rigid layer material 61 as a bonding surface.

  Next, as shown in FIG. 5F, the circuit pattern 79 is formed by etching the plating layer 67 formed on the other surface of the rigid layer material 61. In this etching process, the plated metal 69 in the slit 63 is not removed.

  Next, as shown in FIG. 6G, a build-up resin layer 81 is laminated on the entire surface of the other surface (surface on which the circuit pattern 79 is formed) of the rigid layer material 61 by a laminating method or the like. To do.

  The build-up resin layer 81 is made of a resin material that exhibits fluidity when bonded to the rigid layer material 61 by heating breathing in order to ensure the embedding property of the circuit pattern 79. Thereby, the flatness of the surface of the buildup resin layer 81 is obtained, and consequently the flatness of the surface of the rigid portion R is obtained.

  As described above, the build-up resin layer 81 exhibits fluidity during build-up by heating breathing, but the slit 63 is blocked by the plated metal 69, so that the build-up resin layer 81 having fluidity is not satisfactory. The flexible part F (see FIG. 6 (j)) does not ooze out as necessary.

  Next, as shown in FIG. 6H, via holes 83 are formed in the buildup resin layer 81 by laser beam irradiation. During this via hole forming process, that is, in the same process as the via hole forming process, the part of the buildup resin layer 81 corresponding to the slit 63 is removed, and a slit 85 communicating with the slit 63 is formed in the buildup resin layer 81.

  Although the laser beam irradiation for forming the slit 85 is performed on the plated metal 69 of the slit 63 but not the circuit pattern 73, it is necessary to consider the damage on the substrate surface due to the laser beam irradiation. There is no.

  Next, as shown in FIG. 6I, the surface of the build-up resin layer 81 is filling-plated, and the via hole 83 is filled with a plated metal (copper) to form a filled via, and the build-up resin layer 81 is also filled. A plating layer is formed on the surface of the substrate, and this is etched to form a circuit pattern 87. In this circuit pattern forming etching step, that is, in the same step as this etching step, the plating metal 69 filled in the slit 63 is removed.

  Next, as shown in FIG. 6J, the external shape processing of the partial build-up wiring board is performed by a punching press or the like. By this outer shape processing, the rigid layer material 61 of the portion Fr corresponding to the flexible portion F is separated from the rigid portion R together with the buildup resin layer 81 and the resin film 65 of this portion and removed.

  Thereby, the partial buildup wiring board by the rigid part R which was built up and the flexible part F only by the flexible layer 70 is obtained.

  In this construction method, since the resin of the build-up resin layer 81 due to bleeding does not exist in the flexible portion F of the flexible layer 70, the flexibility of the flexible portion F is not impaired.

  Further, in this embodiment, the slit 63 is not a counterbore process that leaves a thin copper foil layer, but may be a drilling process that penetrates the rigid layer material 61, so that the slit 63 can be easily processed and the productivity is improved. Will improve.

  Filling the slit 63 with metal or removing it is an operation that can be performed in the process of plating or circuit formation, so that the manufacturing load can be minimized. Furthermore, if the slit is filled with copper, the copper thickness can be increased. Damage due to laser processing can be further reduced.

(Another embodiment)
Another embodiment of a method for manufacturing a partial buildup wiring board according to the present invention will be described with reference to FIGS. 7 to 9, portions corresponding to those in FIGS. 5 and 6 are described with the same reference numerals as those in FIGS. 5 and 6.

  First, a rigid layer material 61 such as a prepreg (glass epoxy substrate material) as shown in FIG. 7A is prepared. The rigid layer material 61 includes a rigid portion R and a portion Fr corresponding to a flexible portion F (see FIG. 6J). A slit 63 along the boundary B between the rigid portion R of the rigid layer material 61 and the portion Fr corresponding to the flexible portion F is opened by laser processing or the like.

  Next, as shown in FIG. 7B, a resin film 65 is bonded to one surface of the rigid layer material 61 so as to close the opening on one side of the slit 63. As a result, one side of the slit 63 is closed by the resin film 65.

  Here, although there is no restriction | limiting in particular in the material of the resin film 65 to be used, PET, PEN, etc. must have the heat resistance and acid resistance which do not deform | transform, modify | denature, and melt | dissolve in a post process. Further, the resin film 65 needs to be sufficiently cured and closely adhered so that it does not peel off during the operation or adhere to the cover layers 207 and 209 (see FIG. 7G) of the flexible layer.

  Next, as shown in FIG. 7C, copper plating is performed on both surfaces of the rigid layer material 61, plating layers 91 and 93 are formed on both surfaces of the rigid layer material 61, and plating is performed in the slit 63. Fill with metal (copper) 95. This copper plating can be performed in the manner of filling plating in which the plating metal 95 is satisfactorily filled in the slit 63 whose bottom is closed by the resin film 65.

  Next, as shown in FIG. 7D, the circuit pattern 97 is formed by etching the plating layer 93 formed on one surface of the rigid layer material 61 (the surface on which the resin film 65 is bonded). Form. By this etching, the plating layer 93 at the bonded portion of the resin film 65 is removed, and the resin film 65 is exposed to the outside.

  Next, as shown in FIG. 7 (e), the portion of the resin film 65 corresponding to the slit 63, that is, the portion that formed the bottom of the slit 63 is removed by laser light irradiation or plasma etching. (Reference E).

  Next, as shown in FIG. 7F, a core substrate 202 having circuit patterns 203 and 204 formed on both surfaces of an insulating layer 201 made of polyimide film or the like is formed.

  Next, as shown in FIG. 7G, both sides of the core substrate 202 are bonded to each other with electrically insulating coverlays 207 and 209 so as to cover the circuit patterns 203 and 205, respectively. The layer 200 is formed, and only the rigid portion R of the rigid layer material 61 is adhered to each of the coverlays 207 and 209 by using the adhesive layers 211 and 213 with the one surface of the rigid layer material 61 as a bonding surface.

  Then, the circuit patterns 99 are formed by etching the plating layers 91 of the rigid layer material 61 on both surfaces of the flexible layer 200. In this etching process, the plated metal 95 in the slit 63 is not removed. Further, a plated through hole 215 for performing interlayer conduction is formed.

  Next, as shown in FIG. 8 (h), build-up resin is formed on the entire surface of the other surface (surface on which the circuit pattern 99 is formed) of each of the rigid layer materials 61 on both surfaces of the flexible layer 200. The layers 217 and 219 are laminated by a laminating method or the like.

  In order to secure the embedding property of the build-up resin layers 217 and 219 and the circuit pattern 99, the resin layer is made of a resin material that exhibits fluidity when bonded to the rigid layer material 61 by heating brace. Thereby, the flatness of the surface of the buildup resin layers 217 and 219 is obtained, and consequently the flatness of the surface of the rigid portion R is obtained.

  As described above, the build-up resin layers 217 and 219 exhibit fluidity at the time of build-up by heating breathing. However, since the slit 63 is blocked by the plating metal 95, the build-up resin layer 217 having fluidity is provided. 219 does not unnecessarily ooze into the flexible portion F (see FIG. 9K).

  Next, as shown in FIG. 8I, via holes 221 and 223 are formed in each of the build-up resin layers 217 and 219 by laser light irradiation. During this via hole formation process, that is, in the same process as the via hole formation process, the buildup resin layers 217 and 219 corresponding to the slit 63 are removed, and the slits 225 and 227 communicating with the slit 63 are replaced with the buildup resin layer 221. 223.

  Although the laser beam irradiation for forming the slits 225 and 227 is performed on the plated metal 95 of the slit 63 but not the circuit pattern 93, the damage on the substrate surface due to the laser beam irradiation is taken into consideration. There is no need to do.

  Next, as shown in FIG. 8J, the surfaces of the build-up resin layers 221 and 223 are filling-plated, and the via holes 221 and 223 are filled with plated metals (copper) 233 and 235 to form filled vias. In both cases, plating layers are formed on the surfaces of the build-up resin layers 221 and 223, and this is etched to form circuit patterns 229 and 231. In this circuit pattern forming etching step, that is, in the same step as this etching step, the plating metal 95 filled in the slit 63 is removed.

  Next, as shown in FIG. 9 (k), the external shape processing of the partial buildup wiring board is performed by a punching press or the like. By this outer shape processing, the rigid layer material 61 of the portion Fr corresponding to the flexible portion F is separated from the rigid portion R together with the buildup resin layers 221 and 223 of this portion, and the rigid layer material of the portion Fr corresponding to the flexible portion F is obtained. 61 is removed together with the build-up resin layers 221 and 223 of this portion.

  Thereby, the partial buildup wiring board by the rigid part R built up and the flexible part F only by the flexible layer 200 is obtained.

  In this construction method, since the resin of the build-up resin layer 81 due to bleeding does not exist in the flexible portion F of the flexible layer 200, the flexibility of the flexible portion F is not impaired.

  Also in this embodiment, the slit 63 is not a counterbore process that leaves a thin copper foil layer, but may be a drilling process that penetrates the rigid layer material 61, so that the process of the slit 63 is facilitated and productivity is improved. Will improve.

  Filling the slit 63 with metal or removing it is an operation that can be performed in the process of plating or circuit formation, so that the manufacturing load can be minimized. Furthermore, if the slit is filled with copper, the copper thickness can be increased. Damage due to laser processing can be further reduced.

(A)-(e) is process drawing which shows one Embodiment in the manufacturing method of the partial buildup wiring board which concerns on this invention. (A)-(d) is process drawing which removes the copper foil layer which shows the modification of this Embodiment. (A)-(d) is process drawing which shows the process (first half) of the Example in the manufacturing method of the partial buildup wiring board which concerns on this invention. (E), (f) is process drawing which shows the process (second half) of the Example in the manufacturing method of the partial buildup wiring board based on this invention. (A)-(f) is process drawing which shows the process (first half) of other embodiment of the manufacturing method of the partial buildup wiring board by this invention. (G- (j) is process drawing which shows the process (latter half) of other embodiment of the manufacturing method of the partial buildup wiring board by this invention. (A)-(g) is process drawing which shows the process (first half) of another embodiment of the manufacturing method of the partial buildup wiring board by this invention. (H)-(j) is process drawing which shows the process (second half) of another embodiment of the manufacturing method of the partial buildup wiring board by this invention. (K) is process drawing which shows the process (second half) of another embodiment of the manufacturing method of the partial buildup wiring board by this invention. It is sectional drawing which shows the buildup circuit of the conventional rigid flex circuit board. It is sectional drawing which shows the state which the buildup resin oozed out in the conventional rigid flex circuit board. (A), (b) is the top view and sectional drawing which show the rigid flex circuit board disclosed by patent document 3. FIG. (A), (b) is the top view and sectional drawing which show the state which the buildup resin oozed out in the rigid flex circuit board of FIG.

Explanation of symbols

1 Rigid layer 3 Copper foil layer (conductor layer)
5 Slit 7 Flexible Layer 9 Circuit Pattern 11 Coverlay Film 13 Adhesive Layer 15 Core Substrate 17 Build-up Resin Layer 19 Via Hole 21 Trimming Part 23 Cure Part 61 Rigid Layer Material 63 Slit 65 Resin Film 67 Plating Layer 69 Plating Metal 70 Flexible Layer 81 Build-up resin layers 91 and 93 Plating layer 95 Plating metal 200 Flexible layer 202 Core substrate 217 and 219 Build-up resin layer

Claims (10)

A method for producing a partial buildup wiring board in which a rigid layer is laminated on a partial region of a flexible layer, and a buildup resin layer is laminated on the rigid layer,
A conductor layer is formed on one side of the rigid layer, and a slit is formed in a portion of the rigid layer corresponding to the flexible layer, and the rigid layer is laminated on the flexible layer and the slit is closed. A part of the conductor layer is left as a lid, the build-up resin layer is formed on the rigid layer, the conductor layer located on the slit and the slit are removed to open the slit, and the flexible layer The manufacturing method of the partial buildup wiring board characterized by removing the rigid layer and the buildup resin layer which are located on the top.   2. The method of manufacturing a partial buildup wiring board according to claim 1, wherein an upper surface of the rigid layer is formed flat, and the flexible layer is laminated on the upper surface of the rigid layer.   2. The method of manufacturing a partial buildup wiring board according to claim 1, wherein an upper surface of the rigid layer is formed flat, and the buildup resin layer is laminated on the upper surface of the rigid layer.   2. The method of manufacturing a partial buildup wiring board according to claim 1, wherein the slit formed in the rigid layer is formed by notching only the rigid layer by spot facing.   The build-up resin layer located on the slit is removed at the same time as opening the via hole by irradiating laser light, while the conductor layer located on the slit is removed at the same time as forming the circuit. The manufacturing method of the partial buildup wiring board of Claim 1 characterized by the above-mentioned.   2. The method of manufacturing a partial build-up wiring board according to claim 1, wherein the rigid layer and the build-up resin layer located on the flexible layer are simultaneously removed by external processing. Manufacture of a build-up wiring board having a rigid layer in a partial region of a flexible layer, a build-up resin layer laminated on the rigid layer, and having a multi-layered rigid portion and a flexible portion only by the flexible layer A method,
Using a rigid layer material including the rigid portion and a portion corresponding to the flexible portion, and through-opening a slit along a boundary between the rigid portion of the rigid layer material and the portion corresponding to the flexible portion;
A step of bonding a resin film to one surface of the rigid layer material so as to close the opening on one side of the slit;
Performing plating on the other surface of the rigid layer material, forming a plating layer on the other surface of the rigid layer material and filling a plating metal in the slit;
A step of attaching only the rigid portion of the rigid layer material on the flexible layer with the one surface of the rigid layer material as a bonding surface;
Etching the plating layer formed on the other surface of the rigid layer material to leave a plating metal in the slit to form a circuit pattern;
Laminating a buildup resin layer over the entire surface of the other surface of the rigid layer material;
Removing the build-up resin layer corresponding to the slit;
Removing the plating metal filled in the slit;
Removing the rigid layer material in a portion corresponding to the flexible portion;
Method of manufacturing a partial build-up wiring board including Manufacture of a build-up wiring board having a rigid layer in a partial region of a flexible layer, a build-up resin layer laminated on the rigid layer, and having a multi-layered rigid portion and a flexible portion only by the flexible layer A method,
Using a rigid layer material including the rigid portion and a portion corresponding to the flexible portion, and through-opening a slit along a boundary between the rigid portion of the rigid layer material and the portion corresponding to the flexible portion;
A step of bonding a resin film to one surface of the rigid layer material so as to close the opening on one side of the slit;
Performing plating on both surfaces of the rigid layer material, forming a plating layer on both surfaces of the rigid layer material and filling the slit with a plating metal; and
Etching the plating layer formed on the one surface of the rigid layer material to form a circuit pattern;
A step of attaching only the rigid portion of the rigid layer material on the flexible layer with the one surface of the rigid layer material as a bonding surface;
Etching the plating layer formed on the other surface of the rigid layer material to leave a plating metal in the slit to form a circuit pattern;
Laminating a buildup resin layer over the entire surface of the other surface of the rigid layer material;
Removing the build-up resin layer corresponding to the slit;
Removing the plating metal filled in the slit;
Removing the rigid layer material in a portion corresponding to the flexible portion;
Method of manufacturing a partial build-up wiring board including The partial buildup wiring board according to claim 7 or 8, wherein the step of removing the buildup resin layer in a portion corresponding to the slit is performed in the same step as the step of forming a via hole in the buildup resin layer by laser light irradiation. Manufacturing method.
Manufacturing method.   The partial buildup wiring board according to any one of claims 7 to 9, wherein the step of removing the rigid layer material in a portion corresponding to the flexible portion is performed in the same step as the step of externally processing the partial buildup wiring board. Manufacturing method.

Images