JP2006253304A - Blanking mold for printed wiring board and method for manufacturing flex rigid wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To manufacture a high-quality flex rigid wiring board by suppressing the leakage of an adhesive in a step of the lamination or build-up of a rigid board. <P>SOLUTION: The blanking mold for a printed wiring board is provided with a shearing blade 26 having a specified blanking pattern which blanks a printed wiring board material is blanked into a specified shape. It is also provided with an electric heater 27 for increasing the temperature of the sharing blade 26. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a punching die for a printed wiring board and a method for manufacturing a flex-rigid wiring board.

  A flex-rigid circuit board is a flexible substrate (flexible printed circuit board) that is foldable and has a surface coated with a cover lay film made of a plastic film such as a polyimide film. It is constituted by a rigid substrate (rigid printed wiring board) which is laminated by an adhesive layer and forms a multilayer wiring portion. In this flex-rigid wiring board, components are mounted on a multilayer wiring portion (rigid portion), and a portion of the flexible substrate on which the rigid substrate is not laminated forms a flexible cable portion.

  The flexible substrate has a region that remains as a flexible cable portion (flexible portion) without being bonded to the rigid substrate, and an inner layer of the multi-layered portion by the rigid substrate (the rigid substrate is bonded to both surfaces of the flexible substrate, respectively, on both surfaces of the flexible substrate). It is composed of a region that becomes a core layer in the case where a multi-layered portion is formed, and the adhesive layer in that portion is pierced by router processing or the like so that the rigid substrate does not adhere to the flexible cable portion.

  That is, a flexible printed wiring board is formed of a glass epoxy base material with a single-sided copper foil or a base material for a rigid part made of a build-up resin base material having an opening corresponding to a flexible part forming scheduled part by an adhesive layer having an equivalent opening. It is possible to manufacture a flex rigid wiring board by laminating on the flexible printed wiring board by laminating on the flexible printed wiring board and a flexible part obtained by exposing the flexible printed wiring board to the outside through the opening. (For example, Patent Documents 1 and 2).

  In addition, slits are made in the rigid board before the multi-layer lamination by punching at the boundary between the flexible part and the rigid part in advance, and the flexible printed board, coverlay film, adhesive, and rigid board are stacked in order. After the integration by pressing, the circuit pattern of the conductor layer is formed on each rigid board, and the unnecessary rigid board portion which is a non-product part is removed by punching in the final process to expose the flexible printed board in the center part. it can.

  However, in the conventional manufacturing method, the adhesive for laminating the rigid substrate and the adhesive for building up the rigid substrate on which the circuit pattern is formed are fluidized by a heating press when laminating the rigid substrate and the build-up layer. Due to the property, the phenomenon of bleeding out to the outside of the opening, the slit and the substrate occurs.

The seepage of the adhesive causes the bendability between the flexible portion and the rigid portion, the flexibility of the flexible portion, and causes defects such as a decrease in the thickness of the adhesive layer.
JP 2001-156445 A Japanese Patent Laid-Open No. 2002-158445

  The problem to be solved by the present invention is to manufacture a high-quality flex-rigid wiring board by suppressing the bleeding of adhesive in the steps of laminating and building up rigid substrates.

  The punching die for a printed wiring board according to the present invention is a punching die for a printed wiring board having a shearing blade having a predetermined punching pattern and punching and forming a printed wiring board material into a predetermined shape by the shearing blade. And a temperature raising means for raising the temperature of the shearing blade.

  The temperature raising means used in the printed wiring board punching die according to the present invention is preferably a temperature-adjustable heater.

  In the punching die for a printed wiring board according to the present invention, the side surface of the heater is preferably covered with a heat insulating material.

  The manufacturing method of the flex-rigid wiring board according to the present invention includes laminating a rigid part base material having an opening corresponding to a flexible part forming scheduled part on an flexible printed wiring board by an adhesive layer having an equivalent opening. In the manufacturing method of manufacturing a flex-rigid wiring board by a rigid part multilayered on the flexible printed wiring board and a flexible part obtained by exposing the flexible printed wiring board to the outside through the opening, A thermosetting material is used as the adhesive layer and the rigid part base material, and the formation of the openings of the adhesive layer and the rigid part base material is punched by the printed wiring board punching die according to the invention described above. Form.

  In the manufacturing method of the flex-rigid wiring board according to the present invention, the outer punching of the adhesive layer and the rigid portion base material is further performed by the punching die for a printed wiring board according to the above-described invention.

  In the method for producing a flex-rigid wiring board according to the present invention, the rigid part base material is a thermosetting adhesive layer sheet or a thermosetting buildup resin base material.

  The punching die for a printed wiring board according to the present invention can raise the temperature of the shearing blade by means of a heating means such as a heater, and the opening of the printed wiring board material (slit part) in a state where the shearing blade is heated. By performing the punching and the outer shape punching, the shear end face portion of the thermosetting adhesive layer of the printed wiring board material is thermoset simultaneously with the punching process.

  As a result, the adhesive when laminating the rigid substrate and the adhesive when building up the rigid substrate on which the circuit pattern is formed are punched even if fluidity is generated by the heating press when laminating the rigid substrate and build-up layer. A portion cured at the time of processing, that is, a shear end surface portion of the thermosetting adhesive layer becomes a wall, and the adhesive is prevented from exuding to the outside of the opening, the slit, and the substrate.

  As a result, there is no need for additional steps, and the bendability between the flexible part and the rigid part, the flexibility of the flexible part is not oozed out by the adhesive, and a defect such as a decrease in the thickness of the adhesive layer occurs. No high quality flex-rigid wiring board can be manufactured.

  One embodiment of a printed wiring board punching die according to the present invention will be described with reference to FIGS.

  The printed wiring board punching die includes a lower die 10 having a fixed arrangement and an upper die 20 that is attached to a press ram (not shown) and moves up and down.

  The upper mold 20 is a movable shear mounted on a back plate 21, a clamp mold main body 22 fixedly attached to the back plate 21, and a holding recess 23 formed on the back plate 21 and the clamp mold main body 22 so as to be movable up and down. A blade holder 24. The movable shear blade holder 24 is floatingly supported from the back plate 21 by a compression coil spring 25.

  A shearing blade (convex blade) 26 formed in a predetermined punching pattern is attached to the movable shearing blade holder 24. Electric heaters 27 as temperature raising means are attached to both sides of the shearing blade 26.

  The outside of the electric heater 27 is covered with a heat insulating material 28. The heat insulating material 28 is a heat insulator, suppresses the heat of the heater generated by the electric heater 27 from being transmitted to the movable shear blade holder 24, and efficiently raises the temperature of the shear blade 26 by the heater heat. ing.

  The electric heater 27 is a temperature-adjustable heater that changes the heat generation temperature according to the amount of supplied power, and the amount of supplied power is controlled by the temperature control device 30. The temperature control device 30 sets a target temperature from the outside, acquires temperature information of the shearing blade 26 from a thermocouple 31 attached to the shearing blade 26, so that the temperature of the shearing blade 26 becomes the set target temperature. The amount of power supplied to the electric heater 27 is feedback controlled.

  In the lower mold 10, a shear blade entrance slit (concave blade) 11 that receives the shear blade 26 and performs shearing is formed in the same shape as the punching pattern of the shear blade 26.

  The upper surface 10A of the lower mold 10 is opposed to the lower bottom surface 22A of the clamp mold body 22, and is flat with the lower surface 22A of the clamp mold body 22 sandwiching and clamping the printed wiring board laminate W to be punched. It has a clamping surface.

  Positioning pins 12 for fixing the printed wiring board laminated material W to be punched are fixedly mounted on the upper surface 10A of the lower mold 10. A positioning pin receiving hole 29 into which the positioning pin 12 is fitted is formed in the lower bottom surface 22A of the clamp mold main body 22.

  The operation of punching the printed wiring board laminate W using the printed wiring board punching die having the above-described configuration will be described.

  As shown in FIG. 1, the printed wiring board laminate W to be punched is placed on the upper surface 10 </ b> A of the lower mold 10 in the mold open state, and is provided in advance on the printed wiring board laminate W. The positioning pin receiving hole 29 is fitted into the positioning hole Wa. Thereby, the laminated material W for printed wiring boards on the lower mold 10 is positioned.

  The electric heater 27 generates heat by controlling the amount of electric power supplied to the electric heater 27 by the temperature control device 30, and the upper blade is pressed by a press ram (not shown) in a state where the shearing blade 26 reaches the set target temperature by the heater heat. The mold 20 is lowered.

  Then, first, the tip of the shearing blade 26 comes into contact with the printed wiring board laminated material W. Further, when the upper die 20 is lowered, the movable shearing blade holder 24 of the floating support sinks into the holding recess 23 against the spring force of the compression coil spring 25, and the clamp die main body 22 is lowered. As shown in FIG. 2, the printed wiring board laminate W is sandwiched and clamped between the lower bottom surface 22A of the clamp mold main body 22 and the upper surface 10A of the lower mold 10, as shown in FIG. At this time, the positioning pin 12 is fitted into the positioning pin receiving hole 29. As the laminated material W for printed wiring boards, a thermosetting adhesive layer sheet or a thermosetting buildup resin base material can be considered.

  When the clamping is completed, the movable shear blade holder 24 is lowered by the spring force of the compression coil spring 25. As a result, the shear blade 26 penetrates the printed wiring board laminate W and enters the shear blade entrance slit 11 of the lower mold 10, and the printed wiring board laminate W is sheared according to a predetermined punching pattern of the shear blade 26. The

  In this shearing process, since the shearing blade 26 is heated to the set target temperature, the printed wiring board laminate W that contacts the shearing blade 26, for example, a thermosetting adhesive layer sheet when laminating a rigid substrate is used. The shear end face portion is thermally cured (semi-cured) as indicated by the symbol Wb.

  Thereby, even if the adhesive of the thermosetting adhesive layer sheet has fluidity by the heating press at the time of laminating the rigid substrate, the portion Wb cured at the time of punching, that is, the shear end face portion of the thermosetting adhesive layer sheet Becomes a wall, and the dam effect prevents the adhesive from seeping into the opening.

  FIG. 1 and FIG. 2 assume that an opening corresponding to a flexible portion formation planned portion is punched and formed in a thermosetting adhesive layer sheet or a thermosetting buildup resin base material. The punching with the punching die for cutting can be similarly performed by punching the slit at the boundary position between the flexible portion and the rigid portion and externally punching the base material for the rigid portion such as the sheet for the thermosetting adhesive layer.

  As a result, there is no need for additional steps, and the bendability between the flexible part and the rigid part, the flexibility of the flexible part is not oozed out by the adhesive, and a defect such as a decrease in the thickness of the adhesive layer occurs. No high quality flex-rigid wiring board can be manufactured.

  The temperature raising means for raising the temperature of the shearing blade 26 is not limited to the electric heater 27, and may be based on infrared irradiation or the like.

  Next, one embodiment of a method for manufacturing a flex-rigid wiring board according to the present invention will be described with reference to FIGS.

  As shown in FIG. 3A, a polyimide base material 50 with a double-sided copper foil having copper foils 52 on both front and back sides of the polyimide film 51 is prepared.

  First, as shown in FIG. 3B, the copper foil 52 is etched (subtractive method) to form a conductor pattern (circuit pattern) 53.

  Next, as shown in FIG. 3C, a coverlay film 54 is laminated by heating and pressing under vacuum on the entire front and back surfaces of the polyimide film 51 on which the conductor pattern 53 is formed. . Thereby, a conductor pattern (circuit pattern) 53 is obtained.

  Next, as shown in FIG. 3 (d), an opening 55 corresponding to the outline punching and flexible portion formation scheduled portion is formed by the above-described punching die for printed wiring board according to the present invention (see FIGS. 1 and 2). A sheet for thermosetting adhesive layer (interlayer adhesive layer) 56 formed by punching is prepared, and as shown in FIG. 3 (e), this is applied on the coverlay film 54 under vacuum. Laminate by heating and pressing.

  The thermosetting adhesive layer sheet 56 is formed by punching the opening 55 corresponding to the outer punching and flexible part formation scheduled portion by the aforementioned printed wiring board punching die according to the present invention (see FIGS. 1 and 2). Therefore, the outer edge portion and the edge portion of the opening 55 are respectively hardened portions (semi-hardened portions) 57 and 58 that are hardened (semi-hardened) during the punching process.

  A glass epoxy base material 70 with a single-sided copper foil provided with a copper foil 72 on one side of a glass epoxy base material 71 is prepared as a rigid part base material. An opening 73 corresponding to the flexible portion formation scheduled portion similar to the opening 55 of the layer sheet 56 is formed, and this is laminated on the thermosetting adhesive layer sheet 56 by heating and pressing under vacuum (see FIG. 3 (e)).

  At the time of this lamination process, the outer edge portion of the thermosetting adhesive layer sheet 56 and the edge portion of the opening 73 are already hardened portions (semi-hardened portions) 57 and 58 that are hardened (semi-hardened) during the punching process. Therefore, during the laminating process of the glass epoxy base material 70 with the single-sided copper foil, the adhesive of the sheet 56 for thermosetting adhesive layer having fluidity tends to flow out to the outside or the opening 73 side. It is stopped by the dam effect of the parts 57 and 58. As a result, the adhesive of the thermosetting adhesive layer sheet 56 having fluidity is prevented from oozing out to the outside or the opening 73.

  Next, as shown in FIG. 4F, a conductor pattern (circuit pattern) 74 is formed by etching (subtractive method) the copper foil 72 of the glass epoxy base material 70 with a single-sided copper foil. .

  Next, an opening corresponding to the flexible portion formation scheduled portion similar to the opening portion 55 of the outer shape punching and thermosetting adhesive layer sheet 56 by the aforementioned punching die for printed wiring board (see FIGS. 1 and 2) according to the present invention. A build-up resin sheet 82 made of a curable resin in which the portion 81 is formed by punching is prepared (see FIG. 4 (f)), and as shown in FIG. It laminates by heating and pressurizing under vacuum on glass epoxy substrate 70 with copper foil.

  The build-up resin sheet 82 is formed by punching the opening 81 corresponding to the external punching and flexible part formation scheduled portion by the above-described punching die for printed wiring board according to the present invention (see FIGS. 1 and 2). And edge portions of the opening 81 are cured portions (semi-cured portions) 83 and 84 which are cured (semi-cured) during the punching process.

  Accordingly, when the build-up resin sheet 82 is laminated (build-up), the resin of the build-up resin sheet 82 having fluidity tends to flow out to the outside or the opening 81 side. It is stopped by the dam effect of the hardened portions) 83 and 84. Thereby, the resin of the buildup resin sheet 82 having fluidity is prevented from oozing out to the outside or the opening 81, and the thickness and smoothness of the buildup resin sheet 82 are maintained.

  Next, as shown in FIG. 4 (h), electroless copper plating (not shown) is performed on the laminated build-up resin sheet 82, and further, overall panel plating is performed, and then the outer layer is formed by a subtractive method. A conductor pattern 85 was formed.

  As a result, a flex-rigid wiring board is completed by the rigid portions R that are multilayered and the flexible portions F that form cables that connect the rigid portions R to each other.

  In addition, description about formation of the interlayer connection part by a through hole, a via hole, or the like is omitted.

  In this flex-rigid wiring board, during the laminating process of the glass epoxy base material 70 with the single-sided copper foil, the cured portion 58 existing at the boundary between the rigid portion R and the flexible portion F is due to the dam effect of the cured portion 58. By functioning as a dam effect portion that prevents the adhesive of the thermosetting adhesive layer sheet 56 on the rigid portion R side from flowing out to the flexible portion F side, the fluidic thermosetting adhesive layer sheet 56 has fluidity. Since the adhesive is prevented from flowing out to the opening 55 side, the adhesive of the thermosetting adhesive layer sheet 56 does not flow out on the flexible portion F, and the flexible portion F is inherently flexible. And the bending function which is one of the advantages of the flex-rigid wiring board is not hindered.

  Further, due to the dam effect of the hardened portion 57, the adhesive of the sheet 56 for thermosetting adhesive layer having fluidity is prevented from flowing out during the laminating process of the glass epoxy base material 70 with the single-sided copper foil. The thickness of the curable adhesive layer sheet 56 is kept uniform.

  Further, since the outer edge portion of the build-up resin sheet 82 and the edge portion of the opening 81 are the hardened portions 83 and 84, the resin of the build-up resin sheet 82 having fluidity at the time of build-up is Since it is prevented from flowing out toward the opening 81 side, the resin of the build-up resin sheet 82 does not flow out on the flexible portion F, and the flexibility inherent in the flexible portion F is ensured. There is no hindrance to the bending function, which is one of the advantages of the wiring board. In addition, the thickness and smoothness of the build-up resin sheet 82 are kept uniform, and the circuit reliability of the outer layer conductor pattern 85 and the component mountability in the outer layer conductor pattern 85 are improved.

  The manufacturing method of the flex-rigid wiring board according to the present invention is similarly applied to the manufacturing method of the flex-rigid wiring board that forms the slit 91 at the boundary between the flexible portion F and the rigid portion R as shown in FIG. It is possible to prevent the adhesive of the thermosetting adhesive layer sheet and the resin of the build-up resin sheet from oozing into the slit 91 during lamination.

  In addition, the laminated material for printed wiring boards to be processed is heated (preheated) to some extent in advance. The clamp surface of the lower mold 10 and the upper mold 20 is coated with Ti-N or the like, and the laminated material for printed wiring boards. It is also within the scope of the present invention to prevent such adhesion.

It is sectional drawing of the mold open state which shows one Embodiment of the punching die for printed wiring boards by this invention. It is sectional drawing of the shearing state which shows one Embodiment of the punching die for printed wiring boards by this invention. (A)-(e) is process drawing (first half) which shows one Embodiment of the manufacturing method of the flex-rigid wiring board by this invention. (F)-(h) is process drawing (latter half) which shows one Embodiment of the manufacturing method of the flex-rigid wiring board by this invention. It is a top view which shows other embodiment of the flex-rigid wiring board manufactured with the manufacturing method by this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Lower metal mold | die 11 Shear blade entrance slit 12 Positioning pin 20 Upper metal mold 21 Back plate 22 Clamp metal mold | die body 23 Retaining recessed part 24 Movable shear blade holder 25 Compression coil spring 26 Shear blade 27 Electric heater 28 Heat insulation material 29 Positioning Pin receiving hole 30 Temperature controller 31 Thermocouple 50 Polyimide substrate with double-sided copper foil 51 Polyimide film 52 Copper foil 53 Conductor pattern 54 Coverlay film 55 Opening (
56 Sheets for thermosetting adhesive layer 57, 58 Curing part 70 Glass epoxy base material with single-sided copper foil 71 Glass epoxy base material 72 Copper foil 73 Opening part 74 Conductive pattern 81 Opening part 82 Build-up resin sheet 83, 84 Curing part 85 Outer layer conductor pattern 91 Slit

Claims (6)

A punching die for a printed wiring board having a shearing blade formed with a predetermined punching pattern, and punching and forming a printed wiring board material into a predetermined shape by the shearing blade,
A printed wiring board punching die having a temperature raising means for raising the temperature of a shearing blade.   The punching die for a printed wiring board according to claim 1, wherein the temperature raising means is a heater.   The punching die for printed wiring boards according to claim 2, wherein the heater is covered with a heat insulating material. On the flexible printed wiring board, a rigid part base material having an opening corresponding to the flexible part forming scheduled part was laminated with an adhesive layer having an equivalent opening, thereby being multilayered on the flexible printed wiring board. In a manufacturing method of manufacturing a flex-rigid wiring board by a rigid part and a flexible part obtained by exposing the flexible printed wiring board to the outside through the opening,
The thermosetting material is used as the adhesive layer and the rigid part base material, and the opening of the adhesive layer and the rigid part base material is formed in any one of claims 1 to 3. A manufacturing method of a flex-rigid wiring board, which is formed by punching with a punching die for a printed wiring board.   The manufacturing method of the flex-rigid wiring board according to claim 4, wherein the outer punching of the adhesive layer and the rigid part base material is performed by the punching die for a printed wiring board according to claim 1. 6. The method of manufacturing a flex-rigid wiring board according to claim 4, wherein the rigid part base material is a thermosetting adhesive layer sheet or a thermosetting buildup resin base material.

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