JP2006156502A - Rigid flexible printed wiring board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rigid flexible printed wiring board which has no scattering of hardened resin even if it is bent by a flexible portion, and to provide its manufacturing method. <P>SOLUTION: In the rigid flexible printed wiring board 1 wherein a plurality of rigid portions 2 are integrated together via the flexible portion 3, the flexible portion 3 consists of an insulation layer 4 having a flexibility. A rigid board 5 formed with a circuit is embedded in the insulation layer 4, and that part of the insulation layer 4 where the rigid board 5 with the circuit is embedded becomes the rigid portions 2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rigid flexible printed wiring board used for a small and lightweight device such as a portable electronic device and a method for manufacturing the same.

  The rigid flexible printed wiring board 1 is formed by integrating a plurality of rigid portions 2 via flexible portions 3 and can be reduced in size and space by bending at the flexible portions 3. Widely used in portable electronic devices.

  Such a rigid flexible printed wiring board 1 can be manufactured by, for example, a method disclosed in Patent Document 1. That is, as shown in FIG. 4 (a), a rigid substrate 17 is disposed on both surfaces of both ends of the flexible substrate 15 via the prepreg 16, and these are thermocompression bonded. The flexible printed wiring board 1 can be obtained.

Moreover, the rigid flexible printed wiring board 1 can also be manufactured by a method as disclosed in Patent Document 2. First, as shown in FIG. 5A, a rigid sheet 19 formed by providing elongated grooves 18 in parallel is disposed on both surfaces of a flexible sheet 21 via an adhesive film 20, and these are thermocompression bonded. Then, as shown in FIG. 5B, when the portion sandwiched between the two rows of grooves 18 of the rigid sheet 19 is cut out by the cutter 22, the rigid flexible printed wiring board 1 as shown in FIG. 5C is obtained. be able to.
JP-A-7-176836 JP-A-7-135393

  However, in the method disclosed in Patent Document 1, when thermocompression bonding, the resin in the prepreg 16 may ooze out to the flexible part 3 side and be cured as it is. Then, when the rigid flexible printed wiring board 1 is bent by the flexible portion 3, there arises a problem that the resin 23 (see FIG. 4B) that has oozed out and hardened to the flexible portion 3 side is broken and scattered.

  Further, in the method disclosed in Patent Document 2, the same problem as described above occurs, and the circuit of the flexible portion 3 is removed when the portion sandwiched between the two rows of grooves 18 of the rigid sheet 19 is cut by the cutter 22. Problems such as damage to (not shown) and separation of the rigid portion 2 and the flexible portion 3 also occur. The possibility that such a problem occurs is further increased in recent years when the printed wiring board is becoming thinner.

  The present invention has been made in view of the above points, and a rigid flexible printed wiring board in which the cured resin does not break and scatter even when bent at the flexible portion, and the rigid portion and the flexible portion are erroneously separated. It is an object of the present invention to provide a method capable of manufacturing a rigid flexible printed wiring board very easily without causing any damage to the circuit of the flexible part.

  The rigid flexible printed wiring board according to claim 1 of the present invention is a rigid flexible printed wiring board 1 in which a plurality of rigid portions 2 are integrated through a flexible portion 3, and is an insulating layer 4 having flexibility. A flexible portion 3 is formed, and a rigid substrate 5 formed with a circuit is provided inside an insulating layer 4 to form a rigid portion 2.

  The invention of claim 2 is characterized in that, in claim 1, the thickness of the insulating layer 4 forming the flexible portion 3 is 0.2 mm or less.

  The invention of claim 3 is characterized in that, in claim 1 or 2, the insulating layer 4 is formed of resin of the resin sheet 6 with metal foil.

  The manufacturing method of the rigid flexible printed wiring board which concerns on Claim 4 of this invention is a method of manufacturing the rigid flexible printed wiring board 1 in which the some rigid part 2 is integrally formed through the flexible part 3, and is formed. Then, circuits are formed on the plurality of rigid substrates 5, and then the insulating substrates 7 are disposed on both sides of the rigid substrates 5 in a state of being separated from each other, and the rigid substrates 5 are sandwiched between these insulating layers 7 It is characterized by being integrally formed with.

  The manufacturing method of the rigid flexible printed wiring board which concerns on Claim 5 of this invention is a method of manufacturing the rigid flexible printed wiring board 1 in which the some rigid part 2 is integrated and formed through the flexible part 3, A plurality of flexible portion forming holes 8 are formed in the rigid substrate 5 and a circuit is formed. Next, insulating layer forming sheets 7 are arranged on both sides of the rigid substrate 5, and the insulating layer forming sheets 7 are rigid. After the substrate 5 is sandwiched and integrally molded, the molded product is divided into a plurality of parts.

  The invention of claim 6 is characterized in that in claim 4 or 5, it is integrally formed using a vacuum laminator.

  The invention of claim 7 is characterized in that, in any of claims 4 to 6, the insulating layer forming sheet 7 is a resin sheet 6 with metal foil.

  According to the rigid flexible printed wiring board according to claim 1 of the present invention, the cured resin does not break and scatter even when bent at the flexible portion.

  According to invention of Claim 2, the fall of a flexibility can be prevented.

  According to the invention of claim 3, the metal foil can be processed into an outer layer circuit by etching, which is convenient.

  According to the method for manufacturing a rigid flexible printed wiring board according to claim 4 of the present invention, the rigid part and the flexible part are not accidentally separated, and the circuit of the flexible part is damaged. Therefore, a rigid flexible printed wiring board can be manufactured very simply.

  According to the method for manufacturing a rigid flexible printed wiring board according to claim 5 of the present invention, the rigid part and the flexible part are not accidentally separated, and the circuit of the flexible part is damaged. In addition, it is possible to manufacture a plurality of rigid flexible printed wiring boards all at once in a very simple manner, thereby improving productivity.

  According to the invention of claim 6, the rigid substrate, the insulating layer forming sheet and the insulating layer forming sheet can be adhered to each other while expelling air, and further, deaeration can be promoted under vacuum. It is.

  According to the invention of claim 7, since the metal foil can be processed into an outer layer circuit by etching, it is convenient.

  Embodiments of the present invention will be described below.

  FIG. 1 shows an example of an embodiment of the present invention. The rigid flexible printed wiring board 1 is formed by integrating a plurality of rigid parts 2 via a flexible part 3 and can be manufactured as follows.

  First, the circuit 11 is formed on the surfaces of the plurality of rigid substrates 5. As the rigid substrate 5, a hard metal-clad laminate such as a copper-clad laminate using glass cloth or the like as a reinforcing material can be used. The circuit 11 can be formed by a subtractive method or the like. The thickness of the circuit 11 is about 9 to 70 μm, and the thickness of the rigid substrate 5 is about 0.04 to 0.8 mm. The circuit 11 formed on the rigid substrate 5 later becomes the inner layer circuit 11a.

  Next, as shown in FIG. 1A, the plurality of rigid substrates 5 are separated from each other in substantially the same plane, and the insulating layer forming sheets 7 are arranged on both sides of the plurality of rigid substrates 5 in this state. As the insulating layer forming sheet 7, in addition to a semi-cured resin sheet 12 made of a flexible polyimide resin, a metal sheet 13 such as a copper foil adhered to one side of the resin sheet 12 is used. The resin sheet 6 with foil can be used. When the resin sheet 6 with metal foil is used, the resin sheet 12 is made to face the rigid substrate 5, and the thickness of the resin sheet 12 is preferably 0.03 to 0.1 mm. The thickness of the portion of the foil 13 is about 3 to 35 μm. Use of the resin sheet 6 with metal foil is convenient because the metal foil 13 can be processed into the outer layer circuit 11b by etching. Therefore, below, although the case where the resin sheet 6 with a metal foil is used as the insulating layer formation sheet 7 is demonstrated, it is not limited to this.

  Next, as shown in FIG.1 (b), each rigid board | substrate 5 is inserted | pinched between the two resin sheets 6 with metal foil, and it integrally forms.

  At this time, since the portions of the resin sheet 12 are opposed to each other at a location where the rigid substrate 5 does not exist between the two resin sheets 6 with metal foil, when the resin sheet 12 is integrally molded as described above, The insulating layer 4 having flexibility is formed by fusing the portions together. That is, the flexible part 3 is formed by the insulating layer 4. In addition, the broken line in FIG.1 (b) shows the fused surface of the part of the resin sheet 12, and the location enclosed by the ellipse in FIG. 2 shows the location where the flexible part 3 is formed. However, in FIG. 2, the upper resin sheet 6 with metal foil is not shown.

  On the other hand, in the place where the rigid substrate 5 exists between the two resin sheets 6 with metal foil, the portions of the resin sheets 12 are fused to the front and back of the rigid substrate 5 to insulate both sides of the rigid substrate 5. Layer 4 is formed. In other words, this is equivalent to the provision of the rigid substrate 5 inside the insulating layer 4, and the rigid portion 2 is formed at this location.

  Here, the integral molding can be performed by heating and pressurizing using a laminating press. In this case, air may remain at the boundary portion between the rigid portion 2 and the flexible portion 3 to form a void. . Therefore, the integral molding is preferably performed by heating and pressurizing using a vacuum laminator. In this case, while expelling air, the rigid substrate 5, the resin sheet 6 with metal foil, and the resin sheet 6 with metal foil can be adhered to each other, and further, deaeration can be promoted because it is under vacuum. is there.

  After the integral molding as described above, as shown in FIG. 1 (c), the plated through hole 14 is formed in each rigid portion 2, and the outer layer circuit 11b is formed on the surface of the rigid portion 2 and the flexible portion 3. By forming, the rigid flexible printed wiring board 1 can be obtained. Here, since the metal foil 13 of the resin sheet 6 with the metal foil originally existed on the surfaces of the rigid portion 2 and the flexible portion 3, the outer layer circuit 11b can be easily formed by etching. The inner layer circuits 11a formed on the plurality of rigid substrates 5 are electrically connected by the plated through hole 14 and the outer layer circuit 11b. Although not shown, a solder resist may be applied to the surfaces of the flexible part 3 and the rigid part 2 in order to protect the outer layer circuit 11b.

  As described above, in the present invention, unlike the method shown in FIG. 5, it is not necessary to use the cutter 22, so that the rigid portion 2 and the flexible portion 3 are not accidentally separated from each other. The rigid flexible printed wiring board 1 can be manufactured very simply without damaging the circuit.

  Further, in the present invention, the rigid substrate 5 on which the circuit is formed is provided inside the insulating layer 4, and the interface between the rigid substrate 5 and the insulating layer 4 is not exposed in the flexible portion 3. Unlike the case, even when the flexible portion 3 is bent, the cured resin 23 is not broken and scattered. Since the flexible part 3 is formed of the insulating layer 4 having flexibility, the flexible part 3 can be bent. However, if the thickness of the insulating layer 4 forming the flexible part 3 exceeds 0.2 mm, the flexible part 3 is bent. Therefore, the thickness of the insulating layer 4 forming the flexible portion 3 is preferably 0.2 mm or less (substantially lower limit is 0.06 mm). A plurality of flexible parts 3 may be formed on one rigid flexible printed wiring board 1.

  FIG. 3 shows another example of the embodiment of the present invention. In this example, a plurality of rigid flexible printed wiring boards 1 can be manufactured at once as follows.

  First, as shown in FIG. 3, a plurality of flexible portion forming holes 8 are formed in the rigid substrate 5 by punching or router processing. Although the shape of the hole part 8 for flexible part formation is not specifically limited, For example, it can be set as a rectangular shape. As the rigid substrate 5, the same one as described above can be used. Further, circuits (not shown) are formed on both sides of each flexible portion forming hole 8.

  Next, as in FIG. 1A, insulating layer forming sheets 7 are arranged on both sides of the rigid substrate 5. Since the same thing as what was mentioned above can be used as the insulating layer forming sheet 7, the case where the resin sheet 6 with a metal foil is used as the insulating layer forming sheet 7 will be described in this example, but it is not limited thereto. It is not something. In FIG. 3, the upper resin sheet 6 with metal foil is not shown.

  Next, as in FIG. 1 (b), the rigid substrate 5 is sandwiched between the two resin sheets 6 with metal foil, and is integrally formed.

  At this time, since the portions of the resin sheet 12 of the two metal foil-attached resin sheets 6 are opposed to each other at the location where the flexible part forming hole 8 is formed in the rigid substrate 5, as described above. When the resin sheet 12 is integrally molded, the insulating layer 4 having flexibility is formed by fusing the portions of the resin sheet 12 together. That is, the flexible part 3 is formed by the insulating layer 4. In addition, the location enclosed by the ellipse in FIG. 3 shows the location where the flexible part 3 is formed.

  On the other hand, in the place where the rigid substrate 5 exists between the two resin sheets 6 with the metal foil, the portions of the resin sheets 12 are fused to the front and back of the rigid substrate 5, so that an insulating layer is formed on both sides of the rigid substrate 5. 4 is formed. In other words, this is equivalent to the provision of the rigid substrate 5 inside the insulating layer 4, and the rigid portion 2 is formed at this location.

  Here, as described above, the integral molding is preferably performed by heating and pressurizing using a vacuum laminator.

  And after integrally forming as mentioned above and obtaining a molding, while forming the plating through hole 14 in each rigid part 2 similarly to FIG.1 (c), the surface of the rigid part 2 and the flexible part 3 is formed. The outer layer circuit 11b is formed on the substrate. Here, since the metal foil 13 of the resin sheet 6 with the metal foil originally existed on the surfaces of the rigid portion 2 and the flexible portion 3, the outer layer circuit 11b can be easily formed by etching. The inner layer circuits 11a formed on the rigid substrate 5 are electrically connected by the plated through hole 14 and the outer layer circuit 11b. Although not shown, a solder resist may be applied to the surfaces of the flexible part 3 and the rigid part 2 in order to protect the outer layer circuit 11b.

  Thereafter, the molded product obtained as described above is divided into a plurality of pieces by router processing or the like, whereby a plurality of rigid flexible printed wiring boards 1 can be obtained at a time. Needless to say, it is divided by, for example, a broken line indicated by a in FIG. 3 so that the rigid portions 2 located on both sides of the flexible portion forming hole 8 to be the flexible portion 3 are not directly connected to each other. Further, in the example shown in FIG. 3, six rigid flexible holes 5 are formed in a single rigid substrate 5 and divided into flexible hole forming holes 8. Although the printed wiring board 1 is obtained, the number of the flexible portion forming holes 8 formed in one rigid substrate 5 is not particularly limited, and one rigid flexible print is provided. A plurality of flexible portions 3 may be formed on the wiring board 1.

  In the present invention, in order to obtain a plurality of rigid flexible printed wiring boards 1, it is necessary to perform router processing or the like. However, unlike the method shown in FIG. 5, a blade is inserted at the boundary between the rigid portion 2 and the flexible portion 3. Since it is not a thing, the rigid part 2 and the flexible part 3 are not accidentally cut off, and the circuit of the flexible part 3 is not damaged. The board 1 can be manufactured collectively at once, and productivity can be improved.

  Also in the present invention, the rigid substrate 5 formed with a circuit is provided inside the insulating layer 4, and the interface between the rigid substrate 5 and the insulating layer 4 is not exposed in the flexible portion 3. Unlike the case, even when the flexible portion 3 is bent, the cured resin 23 is not broken and scattered. Since the flexible part 3 is formed of the insulating layer 4 having flexibility, the flexible part 3 can be bent. However, if the thickness of the insulating layer 4 forming the flexible part 3 exceeds 0.1 mm, the flexible part 3 is bent. In this case as well, the thickness of the insulating layer 4 forming the flexible portion 3 is preferably 0.2 mm or less (substantially lower limit is 0.06 mm).

An example of embodiment of this invention is shown and (a)-(c) is sectional drawing. It is a top view same as the above. However, the upper insulating layer forming sheet is not shown. It is a top view which shows the other example of embodiment of this invention. However, the upper insulating layer forming sheet is not shown. An example of a prior art is shown, (a) (b) is sectional drawing. The other example of a prior art is shown, (a)-(c) is sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rigid flexible printed wiring board 2 Rigid part 3 Flexible part 4 Insulating layer 5 Rigid board 6 Resin sheet with metal foil 7 Insulating layer forming sheet 8 Hole part for flexible part formation

Claims (7)

  In a rigid flexible printed wiring board formed by integrating a plurality of rigid portions via a flexible portion, the flexible portion is formed of a flexible insulating layer, and the rigid substrate formed with a circuit is formed of an insulating layer. A rigid flexible printed wiring board having a rigid portion provided therein.   The rigid flexible printed wiring board according to claim 1, wherein the insulating layer forming the flexible portion has a thickness of 0.2 mm or less.   The rigid flexible printed wiring board according to claim 1, wherein an insulating layer is formed of a resin of a resin sheet with a metal foil.   A method of manufacturing a rigid flexible printed wiring board in which a plurality of rigid parts are integrated through a flexible part, wherein a circuit is formed on a plurality of rigid boards, and then these rigid boards are separated from each other A method for producing a rigid flexible printed wiring board, comprising: forming insulating layer forming sheets on both sides of the insulating layer forming sheets and sandwiching each rigid substrate between the insulating layer forming sheets.   A method of manufacturing a rigid flexible printed wiring board in which a plurality of rigid parts are integrated through a flexible part, wherein a plurality of holes for forming a flexible part are drilled in a rigid substrate, and a circuit is formed. Next, an insulating layer forming sheet is arranged on both sides of the rigid substrate, and the rigid substrate is sandwiched between these insulating layer forming sheets and integrally molded, and then the molded product is divided into a plurality of rigid flexible printed wirings. A manufacturing method of a board.   6. The method for producing a rigid flexible printed wiring board according to claim 4, wherein the molding is integrally performed using a vacuum laminator.   The method for producing a rigid flexible printed wiring board according to any one of claims 4 to 6, wherein the insulating layer forming sheet is a resin sheet with a metal foil.

Images