JP2008258357A - Rigid flexible board and manufacturing method thereof - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of manufacturing a rigid flexible board, capable of simplifying a process after press stacking, forming an interlayer conduction portion without using a plating step and improving layout efficiency by separately manufacturing the rigid portion and the flexible portion. <P>SOLUTION: The manufacturing method for obtaining a rigid flexible substrate stacks at least one or more rigid wiring boards, one or more flexible printed boards and one or more flexible insulating materials. This manufacturing method has a step of drilling through holes on the flexible insulating materials, a step of putting copper balls into the through holes, and a step of sandwiching the flexible insulating material between the rigid wiring board and the flexible printed circuit board and heating/pressurizing it to integrate the rigid wiring board and the flexible printed board by metal bonding of coppers and forming an interlayer conduction portion. Thus, the rigid flexible board can be obtained. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rigid flexible substrate having a rigid portion and a flexible portion (hereinafter referred to as a flexible portion) and a method for manufacturing the same, and more specifically, a rigid wiring board that bears the rigid portion and a flexible printed board that bears the flexible portion. The present invention relates to a method of manufacturing a rigid-flex board that is separately manufactured and connected between the boards with copper balls.

  With the demand for downsizing, weight reduction, and high functionality of electronic devices, it is necessary to incorporate a plurality of substrates three-dimensionally in a small space inside the product. For this purpose, electrical signals must be connected between substrates in a small space. However, as the functionality increases, the types of electrical signals between substrates will increase. As a result, the connection space also increases, which hinders downsizing and weight reduction.

  In recent years, a rigid flexible board in which a rigid wiring board and a flexible flexible printed board are integrated is used in a folding mobile phone, a digital camera, and the like. As shown in FIG. 1, the rigid-flexible substrate 1 is sandwiched between two rigid wiring boards 5 and 6 that are partially punched through interlayer adhesives 3 and 4 that are partially punched. The rigid parts 7 and 8 having no flexibility and the flexible part 9 having flexibility are provided. In such a rigid flexible substrate 1, the through hole 10 is formed in the rigid portion 7, and the conductor layer 11 is formed on the inner wall of the through hole 10, whereby the surface layer circuits 12 and 13 and the interior circuits 14 and 15 are formed. Are conducted to each other.

The manufacturing process of the rigid flexible substrate is performed as shown in FIG. Rigid wiring boards 16 and 17, flexible printed circuit board 18 formed with a circuit, and interlayer adhesives 19 and 20 are overlapped and temporarily stacked using a jig or an image recognition device (see FIG. 2A). The rigid wiring boards 16 and 17 are previously provided with slits 22 and 23 for punching at positions where the flexible flexible substrate 21 becomes the flexible portion 21. Further, the upper part of the flexible part 21 is punched in the interlayer adhesives 19 and 20, and the cover lays 24 and 25 are laminated in advance on the flexible printed circuit board 18 at the position of the flexible part 21. Next, the rigid wiring boards 16 and 17, the interlayer adhesives 9 and 20, and the flexible printed board 18 are heated and pressurized using a press machine in a state of being temporarily laminated (see FIG. 2B). Thereby, the rigid wiring boards 16 and 17, the interlayer adhesives 9 and 20, and the flexible printed circuit board 18 are integrated to produce a rigid flexible circuit board. Next, a through-hole 26 is formed in the integrated rigid-flex board, through-hole plating 27 is performed, and then an outermost layer circuit is formed (see FIG. 2C). Is filled with insulating resin 28, and outermost cover lays 29 and 30 are attached (see FIG. 2D). Next, incisions are made along the slits 22 and 23 of the rigid wiring boards 16 and 17 at the upper part of the flexible portion 21, and the rigid flexible substrates 16 and 17 are punched out along the outer shape. As a result, the rigid wiring boards 16 and 17 on the upper portion of the flexible portion 21 are removed and the rigid flexible substrate is cut into individual pieces, thereby obtaining the rigid flexible substrate shown in FIG.
Japanese Patent Application Laid-Open No. 5-90756 JP 2004-186235 A

However, in the above-described conventional rigid-flex board manufacturing method, as a process after press lamination, all-layer through-hole drilling, all-layer through-hole plating, outermost circuit protection coverlay lamination, on the flexible part There is a problem that a certain rigid wiring board needs to be removed by punching, and the process after lamination becomes complicated and long.
In addition, drilling through-holes in all layers is unavoidable with a drill due to its thickness, and since layers of different materials are stacked, it is necessary to select drilling conditions that do not cause burrs and break the drill. It becomes difficult.
Further, since through-hole plating and circuit formation are liquid processes, there is a risk that the chemical solution may enter the inner layer. Furthermore, in the step of cutting along the slits of the rigid wiring board, there is a difficulty in requiring accuracy of the position in the thickness direction.

  On the other hand, in the prior art disclosed in Patent Document 2, a circuit is formed on a rigid printed circuit board and a flexible printed circuit board in which a portion corresponding to the upper portion of the flexible part is previously punched before each layer is laminated. The interlayer conductive portion of the flexible printed circuit board is plated up by copper plating to form a filled via. When the rigid wiring board and the flexible printed circuit board are integrated, the layer conductive portions of the rigid wiring board are stacked one above the other so as to be conductive. This eliminates the need for forming through holes, forming a surface layer circuit, and forming a surface layer circuit after stacking, and simplifies the manufacturing process after stacking. An interlayer adhesive is applied to the insulating layers of the rigid wiring board and the flexible printed board.

However, in this method, the interlayer conductive part of the rigid wiring board and the flexible printed board is formed by electrolytic copper plating. For example, a via hole is formed in the insulating layer in the single-sided flexible printed board and the interlayer conductive part is formed by electrolytic copper plating. Then, electrolytic copper plating is also applied to the surface layer copper foil, and the surface layer becomes thick, making it difficult to produce a circuit board with a narrow pitch. Even if a plating resist or the like is formed on the surface layer to prevent the copper foil from becoming thick, a step of resist formation and peeling is added, leading to an increase in lead time and material cost.
Moreover, since electrolytic copper plating is a liquid process, it requires maintenance, adjustment, management, and waste liquid treatment of a large amount of chemical solution, which is very disadvantageous in terms of cost.
Further, since the rigid portion and the flexible portion are simultaneously manufactured without being separated into individual layers until all the layers are laminated, the substrate imposition efficiency in the sheet is very poor, and the material is wasted.

  The present invention has been made in view of the above circumstances, can simplify the process after the press lamination, can form the interlayer conductive part without using the plating process, and further produce the rigid part and the flexible part separately to improve the imposition efficiency. It is an object of the present invention to provide a method of manufacturing a rigid flexible substrate that can improve the above.

In order to achieve the above object, the present invention provides a rigid flexible substrate by laminating at least one or more rigid wiring boards, one or more flexible printed boards, and one or more flexible insulating materials. A manufacturing method to obtain,
Drill a through hole in the flexible insulating material, put a copper ball in the through hole, and then sandwich the flexible insulating material so that it is located between the circuit of the rigid wiring board and the flexible printed circuit board. Provided is a method for manufacturing a rigid flexible board, characterized in that a rigid wiring board and a flexible printed board are integrated by metal bonding between copper by pressurization to form an interlayer conductive portion to obtain a rigid flexible board.

  In the method for manufacturing a rigid flexible substrate according to the present invention, a rigid wiring board, a flexible printed circuit board, and a flexible insulating material are formed on separate sheets, punched into individual pieces, and then embedded in the flexible insulating material. It is preferable that the rigid wiring board and the flexible printed circuit board are connected to each other by a metal bond between copper.

  In the method of manufacturing a rigid flexible substrate of the present invention, a through hole is formed in an insulating layer, a copper ball is pushed into the through hole, and sandwiched between two copper foils from both sides of the insulating layer to be heated and pressed. It is preferable to include a step of manufacturing a rigid wiring board by forming an interlayer conductive portion in which the ball is crushed and embedded in the through hole, and the two copper foils are electrically connected by bonding of copper.

  In the method for manufacturing a rigid flexible substrate according to the present invention, a through hole is formed in a flexible insulating layer, a copper ball is pushed into the through hole, and sandwiched between two copper foils from both sides of the flexible insulating layer is heated. It is preferable to include a step of manufacturing a flexible printed circuit board by forming an interlayer conductive portion in which a copper ball is crushed by pressurization and embedded in the through hole, and the two copper foils are electrically connected by bonding of copper to each other. .

  In the method for manufacturing a rigid flexible substrate of the present invention, the step of drilling a through hole in the flexible insulating material, the insulating layer of the rigid wiring board, and the flexible insulating layer of the flexible printed board is performed by drilling or laser processing. It is preferable.

  In the method for manufacturing a rigid flexible substrate of the present invention, it is preferable that the diameter of the through hole is smaller than the diameter of the copper ball so that the copper ball is sandwiched in the through hole.

  In the method for manufacturing a rigid flexible substrate of the present invention, it is preferable that the volume of the through hole is smaller than the volume of the copper ball.

  The present invention also provides a rigid flexible substrate obtained by the above-described method for producing a rigid flexible substrate according to the present invention.

  According to the method of manufacturing a rigid flexible board of the present invention, a rigid wiring board that bears a rigid part, a flexible printed board that bears a flexible part, and a flexible insulating material that connects the two boards are separately prepared. After that, by pressing a flexible insulating material between the rigid wiring board and the flexible printed circuit board, the copper ball in the through hole of the flexible insulating material is crushed and the interlayer between the rigid wiring board and the flexible printed circuit board is crushed. By forming a conductive part to obtain a rigid flexible substrate, the process after press lamination is not complicated, and the liquid part process by plating is not performed, and the rigid part and the flexible part are separately manufactured and impositioned. Efficiency can be increased.

  The manufacturing method of the rigid-flexible board of the present invention includes a rigid wiring board that bears the rigid part, a flexible printed board that bears the flexible part, and a flexible insulating material that connects the two boards separately. By pressing the flexible insulating material between the rigid wiring board and the flexible printed circuit board, the copper ball in the through hole of the flexible insulating material is crushed and the interlayer conductive portion between the rigid wiring board and the flexible printed circuit board is crushed. Forming a rigid flexible substrate. In addition, the formation of the interlayer conductive portion by the copper ball is performed using a CBIC (Copper Ball Interconnection Co-laminated) technique.

FIG. 3 shows a manufacturing process of a double-sided rigid wiring board using CBIC technology. First, a through-hole 33 for fitting a copper ball 32 is formed on the insulating layer 31 having a thermoplastic or adhesive applied on both sides by using a drilling means such as a drill, YAG laser, CO ₂ laser or the like ( (See FIG. 3 (a)). Next, while sucking air from one side of the insulating layer 31, the copper ball 32 is fitted into the through hole 33 from the opposite side (see FIG. 3B). Thereafter, the insulating layer 31 is sandwiched between the copper foils 34 and 35 (see FIG. 3C), and heated and pressurized with a vacuum press. Thus, the through hole 33 of the insulating layer 31 is filled with the copper ball 32, and the copper ball 32 and the copper foils 34 and 35 are connected by metal bonding (see FIG. 3D).

FIG. 4 is a diagram showing a process of fitting a copper ball 37 as an interlayer conductive portion into a flexible insulating material 36 made of a thermoplastic resin using the CBIC technique. First, a through-hole 38 for fitting a copper ball 37 is formed in the flexible insulating material 36 shown in FIG. 4A using a drilling means such as a drill, YAG laser, CO ₂ laser or the like (FIG. 4). 4 (b)). Next, air is sucked from one side of the flexible insulating material 36 having the through hole 38 formed therein, and the copper ball 37 is fitted into the through hole 38 from the opposite side (see FIG. 4C). When another substrate is laminated in this state, the through hole 38 of the flexible insulating material 36 is filled with the copper ball 37 by heating and pressing with a vacuum press or the like.

FIG. 5 is a view showing a first example of a method for manufacturing a rigid flexible board using the CBIC technique according to the present invention, before lamination of a rigid wiring board, a flexible printed board, and a flexible insulating material (FIG. )) And after lamination (FIG. 5B).
In this example, filled via interlayer conductive portions 41 and 42 are previously formed with copper balls on both sides of the rigid wiring boards 39 and 40 that bear the rigid portion of the rigid flexible substrate, and copper foil circuits 43 and 44 are formed on the surface. On the copper foil circuits 43 and 44, cover lays 45 and 46 made of a flexible insulating resin are laminated except for a portion overlapping the flexible insulating material 47.
Further, a copper foil circuit 49 is formed in advance on a single-sided flexible printed circuit board 48 that bears the flexible portion of the rigid flexible board, and the coverlay 50 made of the copper foil circuit 49 flexible insulating resin is formed by the flexible insulating material 47. It is laminated except for the overlapping part.

  Further, a copper ball 51 is fitted into a through hole formed in advance by a drill, a YAG laser or the like in a flexible insulating material 47 made of a thermoplastic resin. The conduction between the rigid wiring boards 39, 40 and the flexible printed circuit board 48, which are separately manufactured, is ensured by Cu-Cu metal bonding.

  As a result, all the interlayer conductive portions are formed of copper balls using the CBIC technology, and therefore, compared with the case of forming by copper plating, the surface layer copper foil does not become thick and the fine pitch circuit board has a narrow pitch. Easy to manufacture. In addition, since the interlayer conductive portion can be formed without going through the liquid process, maintenance, adjustment, management, and waste liquid treatment of a large amount of chemical solution is not required, and cost can be reduced. In addition, the rigid wiring board that bears the rigid part and the flexible printed board that bears the flexible part and the flexible insulating material between the boards are aligned at the time of connection after cutting into individual pieces, so the imposition efficiency in the sheet is improved It is possible to manufacture a substrate by raising it, and it becomes possible to reduce waste materials and costs.

  In the manufacturing method of the present invention, the diameter of the through hole formed in the flexible insulating material, the insulating layer of the rigid wiring board, and the flexible insulating layer of the flexible printed circuit board is slightly smaller than the diameter of the copper ball. A structure in which the ball is sandwiched in the through hole is preferable. Thereby, it is possible to prevent the copper ball from falling out of the through hole when the flexible insulating material is moved, and to improve the production efficiency.

  In the method for manufacturing a rigid flexible substrate of the present invention, it is preferable that the volume of the through hole is smaller than the volume of the copper ball. By making the volume of the through hole smaller than the volume of the copper ball, when the parts are overlapped and pressed, the copper ball is crushed to fill the through hole, and there is no gap in the through hole. A metal bond with the copper foil sandwiching both sides can be reliably formed.

A three-layer rigid flexible substrate shown in FIG. 5 was produced.
The rigid wiring boards 39 and 40, which are rigid portions of the rigid flexible substrate, use a glass epoxy resin base material having a thickness of 100 μm and a surface coated with a thermoplastic agent. The glass epoxy resin base material is drilled, YAG laser, CO A through-hole having a diameter of 145 μm was formed by a drilling means such as ₂ laser. While performing air suction, a copper ball having a diameter of 150 μm was fitted therein, sandwiched between both sides by a copper foil having a thickness of 18 μm, and heated and pressurized with a vacuum press. Thereby, the inside of the through hole was filled with the copper ball, and the copper ball and the copper foil were metal-bonded to form the interlayer via portions 41 and 42 of the filled via. After the circuit formation of the produced double-sided rigid wiring boards 39 and 40 was performed, 50 μm coverlays 45 and 46 were laminated on the circuits 43 and 44 except for portions overlapping the flexible insulating material.

A flexible insulating material 47 for connecting between the rigid wiring boards 39 and 40 and the flexible printed circuit board 48 is made of a drilling means such as a drill, YAG laser, CO ₂ laser, etc. on a plastic polyimide resin substrate having a thickness of 50 μm. Thus, a through hole having a diameter of 95 μm was formed, and a copper ball 51 having a diameter of 100 μm was fitted into the through hole while performing air suction.

  Next, these are aligned and arranged in the order of rigid wiring board-flexible insulating material-flexible printed circuit board by image recognition, and heated and pressurized with a constant heater, so that a through hole of the flexible insulating material 47 is obtained. The inside is filled with the copper ball 51, and the copper ball 51, the rigid wiring boards 39 and 40, and the copper foils 44 and 49 of the flexible printed circuit board 48 are metal-bonded to ensure interlayer conduction of filled vias in all layers, as shown in FIG. A three-layer rigid flexible substrate shown in FIG.

As a second example of the method for producing a rigid flexible substrate of the present invention, a four-layer rigid flexible substrate shown in FIG. 6 was produced.
The rigid wiring boards 39 and 40 to be the rigid portion of the rigid flexible substrate use a glass epixy resin base material having a thickness of 100 μm and a surface coated with a thermoplastic agent. The glass epoxy resin base material is drilled, YAG laser, CO _2. A through hole having a diameter of 145 μm was formed by a drilling means such as a laser. A copper ball having a diameter of 150 μm was fitted into this while performing air suction, and sandwiched with copper foil having a thickness of 18 μm from both sides and heated and pressurized with a vacuum press. Thereby, the inside of the through hole was filled with the copper ball, and the copper ball and the copper foil were metal-bonded to form the interlayer via portions 41 and 42 of the filled via. After the circuit formation of the produced double-sided rigid wiring boards 39 and 40 was performed, 50 μm coverlays 45 and 46 were laminated on the circuits 43 and 44 except for portions overlapping the flexible insulating material 47.

The flexible printed circuit board 48 which is a flexible part of the rigid flexible circuit board uses a thermoplastic polyimide resin base material having a thickness of 50 μm, and the polyimide resin base material has a diameter by drilling means such as a drill, YAG laser, CO ₂ laser, etc. A through hole of 95 μm was formed. While carrying out air suction, a copper ball having a diameter of 100 μm was fitted into the through hole, sandwiched between both sides by a copper foil having a thickness of 18 μm, and heated and pressurized with a vacuum press. Thereby, the inside of the through hole was filled with the copper ball, and the copper ball and the copper foil were metal-bonded to form an interlayer conductive portion of the filled via. After forming the circuit of the produced double-sided flexible printed circuit board 48, a coverlay 50 of 50 μm was laminated on the circuit 49 except for a portion overlapping the flexible insulating material.

A flexible insulating material 47 for connecting the rigid wiring boards 39 and 40 and the flexible printed circuit board 48 is formed on a thermoplastic polyimide resin base material having a thickness of 50 μm by drilling, YAG laser, CO ₂ laser or the like. By means, a through hole having a diameter of 95 μm was formed, and a copper ball 51 having a diameter of 100 μm was fitted into the through hole while air was sucked.

  Next, these are positioned and overlapped in the order of rigid wiring board-flexible insulating material-flexible printed circuit board by image recognition, and heated and pressurized with a constant heater, so that the inside of the through hole of the flexible insulating material 47 Is filled with the copper ball 51, and the copper ball 51, the rigid wiring boards 39 and 40, and the copper foil of the flexible printed circuit board 48 are metal-bonded, and the interlayer conduction of filled vias is secured in all layers, and the four layers shown in FIG. A rigid flexible substrate was prepared.

As a third example of the method for producing a rigid flexible substrate of the present invention, as shown in FIG. 7, a four-layer rigid flexible substrate including a rigid wiring board having connection portions on both sides was produced.
The rigid wiring boards 39 and 40, which are rigid portions of the rigid flexible substrate, use a glass epoxy resin base material having a thickness of 100 μm and a surface coated with a thermoplastic agent. The glass epoxy resin base material is drilled, YAG laser, CO A through-hole having a diameter of 145 μm was formed by a drilling means such as ₂ laser. While performing air suction, a copper ball having a diameter of 150 μm was fitted into the through hole, sandwiched between both sides by a copper foil having a thickness of 18 μm, and heated and pressurized with a vacuum press. Thereby, the inside of the through hole was filled with the copper ball, and the copper ball and the copper foil were metal-bonded to form an interlayer conductive portion of the filled via. After the circuit formation of the produced double-sided rigid wiring boards 39 and 40 is performed, 50 μm coverlays 45 and 46 are laminated on the circuit except for a portion overlapping the flexible insulating material, and a rigid having a connection portion only on one side. Wiring boards 39 and 40 were produced.

  A flexible printed circuit board 48, which is a flexible part of the rigid flexible circuit board, uses a single-sided CCL with a copper foil thickness of 18 μm and a thermosetting polyimide thickness of 25 μm to form a circuit. A coverlay 50 having a thickness of 50 μm was laminated except for a portion overlapping with the substrate. In this example, two flexible printed boards 48 were produced.

A flexible insulating material 47 for connecting between the rigid wiring boards 39 and 40 and the flexible printed circuit board 48 is formed on a thermoplastic polyimide resin base material having a thickness of 50 μm by drilling means such as a drill, YAG laser, CO ₂ laser, etc. Thus, a through hole having a diameter of 95 μm was formed, and a copper ball 51 having a diameter of 100 μm was fitted into the through hole while performing air suction.

  Next, by aligning these in order of flexible printed circuit board-flexible insulating material-rigid wiring board-flexible insulating material-flexible printed circuit board by image recognition, by heating and pressing with a constant heater, The inside of the through hole of the flexible insulating material 47 is filled with the copper ball 51, and the copper ball 51, the rigid wiring boards 39 and 40, and the copper foil of the flexible printed circuit board 48 are metal-bonded, and the interlayer conductive portion of the filled via is secured in all layers. Then, as shown in FIG. 7B, a four-layer rigid flexible substrate including a rigid wiring board having connection portions on both sides was produced.

  Although the embodiments have been described above, the rigid flexible substrate of the present invention is not limited to the above-described embodiments, and various changes and modifications can be made. For example, the flexible insulating material may be made of a resin in which a thermoplastic agent is applied to a thermosetting flexible insulating material.

  Furthermore, since the rigid wiring board, the flexible printed circuit board, and the flexible insulating material are each punched into individual pieces, the connecting portion between the rigid wiring board and the flexible printed circuit board must be limited to the end of each board. Instead, as shown in FIG. 8, a connection portion may be provided in the center of the rigid wiring boards 39 and 40. The rigid flexible board shown in FIG. 8 includes a copper ball 51 and a rigid wiring board in which circuits provided at the center portions of the rigid wiring boards 39 and 40 and both ends of the flexible printed board 48 are fitted in a flexible insulating material. 39 and 40 and the copper foil of the flexible printed circuit board 48 are metal-bonded to ensure an interlayer conductive portion of filled vias in all layers.

  Further, the double-sided rigid wiring board and the double-sided flexible printed board may use a base material having a copper foil attached to one side as a starting material. As an example, FIG. 9 shows a process of fitting a copper ball 3 as an interlayer conductive portion in a flexible insulating layer 52 of a single-sided flexible printed board using CBIC.

First, via holes 54 for fitting the copper balls 53 are formed in the flexible insulating layer 52 by drilling means such as YAG laser or CO ₂ laser (see FIG. 9A).
Next, a small hole 56 having a diameter smaller than that of the via hole 54 is formed in the copper foil 55 at the via bottom of the via hole 54 by a drilling means such as a YAG laser or a CO ₂ laser (see FIG. 9B).
Next, the copper ball 53 is fitted into the via hole 54 while sucking air from the copper foil 55 side where the small hole 56 is formed (see FIG. 9C).
In this state, a copper foil 57 is laminated from the side on which the copper ball 53 is fitted (see FIG. 9D), and heated and pressed by a vacuum press or the like, as shown in FIG. 9E. A double-sided rigid wiring board and a double-sided flexible printed board in which the via holes 54 and the small holes 56 of the flexible insulating layer 52 are filled with copper balls 53 and the copper balls 53 and the copper foils 55 and 57 are connected by metal bonding are obtained.

It is sectional drawing which illustrates the structure of a rigid flexible substrate. It is sectional drawing which shows an example of the manufacturing method of the conventional rigid flexible substrate in order of a process. It is sectional drawing which shows the manufacturing process of the double-sided rigid wiring board by CBIC technique. It is sectional drawing which shows the copper ball fitting process to the flexible insulating material by CBIC technique. It is sectional drawing which shows the 1st example of the manufacturing method of the rigid flexible substrate of this invention. It is sectional drawing which shows the 2nd example of the manufacturing method of the rigid flexible substrate of this invention. It is sectional drawing which shows the 3rd example of the manufacturing method of the rigid flexible substrate of this invention. It is sectional drawing which shows another structure of the rigid flexible substrate of this invention. It is sectional drawing which shows the manufacturing process of the flexible printed circuit board using CBIC.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Rigid flexible substrate, 2 ... Flexible printed circuit board, 3, 4 ... Interlayer adhesive, 5, 6 ... Rigid wiring board, 7, 8 ... Rigid part, 9 ... Flexible part, 10 ... Through hole, 11 ... Conductor layer, DESCRIPTION OF SYMBOLS 12,13 ... Surface layer circuit, 14,15 ... Inner layer circuit, 16, 17 ... Rigid wiring board, 18 ... Flexible printed circuit board, 19, 20 ... Interlayer adhesive, 21 ... Flexible part, 22, 23 ... Slit, 24, 25 ... Coverlay, 26 ... Through hole, 27 ... Through hole plating, 28 ... Insulating resin, 29, 30 ... Coverlay, 31 ... Insulating layer, 32 ... Copper ball, 33 ... Through hole, 34, 35 ... Copper foil, 36 ... Flexible insulating layer, 37 ... Copper ball, 38 ... Through hole, 39, 40 ... Double-sided rigid wiring board, 41, 42 ... Interlayer conduction part, 43, 44 ... Copper foil circuit, 45, 46 ... Coverlay 47 ... flexible insulating material, 48 ... flexible printed circuit board, 49 ... copper foil circuit, 50 ... cover lay, 51 ... copper ball, 52 ... flexible insulating layer, 53 ... copper ball, 54 ... via hole, 55 ... copper Foil, 56 ... small hole, 57 ... copper foil.

Claims (8)

A manufacturing method for obtaining a rigid flexible board by laminating at least one or more rigid wiring boards, one or more flexible printed boards, and one or more flexible insulating materials,
Drill a through hole in the flexible insulating material, put a copper ball in the through hole, and then sandwich the flexible insulating material so that it is located between the circuit of the rigid wiring board and the flexible printed circuit board. A method for producing a rigid flexible substrate, comprising: forming an interlayer conductive portion by applying pressure to integrate a rigid wiring board and a flexible printed circuit board by metal bonding between coppers to obtain a rigid flexible substrate.   A rigid wiring board, a flexible printed circuit board, and a flexible insulating material are formed on separate sheets and punched into individual pieces, and then the rigid wiring board and the flexible printed circuit board are connected to each other by copper balls embedded in the flexible insulating material. The method for manufacturing a rigid-flexible substrate according to claim 1, wherein the substrates are connected to each other by metal bonding.   A through-hole is drilled in the insulating layer, a copper ball is pushed into the through-hole, the copper ball is crushed by being sandwiched between two copper foils from both sides of the insulating layer and heated and pressed, and the inside of the through-hole is embedded, 3. The method for manufacturing a rigid flexible substrate according to claim 1, further comprising a step of manufacturing a rigid wiring board by forming an interlayer conductive portion that is conductive between two copper foils by bonding between copper.   A through hole is formed in the flexible insulating layer, a copper ball is pushed into the through hole, and the copper ball is crushed by being sandwiched between two copper foils from both sides of the flexible insulating layer and heated and pressed. 4. The method according to claim 1, further comprising a step of manufacturing a flexible printed circuit board by forming an interlayer conductive portion that is embedded in a through hole and is electrically connected between two copper foils by bonding between copper. The manufacturing method of the rigid-flexible board | substrate of description.   5. The step of drilling a through hole in a flexible insulating material, an insulating layer of a rigid wiring board, and a flexible insulating layer of a flexible printed board is performed by drilling or laser processing. The manufacturing method of the rigid flexible substrate in any one.   6. The method of manufacturing a rigid flexible substrate according to claim 1, wherein a diameter of the through hole is made smaller than a diameter of the copper ball, and the copper ball is sandwiched in the through hole.   The method for manufacturing a rigid flexible substrate according to claim 1, wherein the volume of the through hole is made smaller than the volume of the copper ball.   A rigid-flexible substrate obtained by the method for producing a rigid-flexible substrate according to claim 1.

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