WO2022102164A1 - Wiring board - Google Patents

Wiring board Download PDF

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Publication number
WO2022102164A1
WO2022102164A1 PCT/JP2021/024317 JP2021024317W WO2022102164A1 WO 2022102164 A1 WO2022102164 A1 WO 2022102164A1 JP 2021024317 W JP2021024317 W JP 2021024317W WO 2022102164 A1 WO2022102164 A1 WO 2022102164A1
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WO
WIPO (PCT)
Prior art keywords
wiring board
coverlay
tip
layer
outer layer
Prior art date
Application number
PCT/JP2021/024317
Other languages
French (fr)
Japanese (ja)
Inventor
茂樹 大塚
Original Assignee
株式会社フジクラ
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Filing date
Publication date
Application filed by 株式会社フジクラ filed Critical 株式会社フジクラ
Publication of WO2022102164A1 publication Critical patent/WO2022102164A1/en

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    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K1/00—Printed circuits
    • H05K1/02—Details
    • H—ELECTRICITY
    • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
    • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
    • H05K3/00—Apparatus or processes for manufacturing printed circuits
    • H05K3/22—Secondary treatment of printed circuits
    • H05K3/28—Applying non-metallic protective coatings

Definitions

  • the present invention relates to a wiring board.
  • the contents described in Japanese Patent Application No. 2020-188570 filed in Japan on November 12, 2020 are incorporated into the present specification by reference and described in the present specification. To be part of.
  • the flexible printed wiring board is equipped with a base film, a circuit, and a cover layer.
  • a plastic film having excellent flexibility such as polyimide is used as the base film and the cover layer.
  • the circuit is formed by etching a copper foil attached on a base film.
  • the cover layer is adhered onto the circuit via an adhesive (see, for example, Patent Document 1 (see paragraphs [0002]-[0004] and FIG. 1)).
  • the coverlay is laminated on the base material on which the wiring is formed by using a press device.
  • the coverlays are collectively laminated on the base material in order to manufacture a large or long flexible printed wiring board, the cost of the wiring board is increased due to the increase in size of the press device and the decrease in yield. There is a problem that it may end up.
  • the problem to be solved by the present invention is to provide a wiring board capable of suppressing cost increase even in the case of manufacturing a large-sized or long wiring board.
  • the wiring board according to the present invention includes a base material, wiring arranged on the base material, and first and second coverlays arranged side by side on the base material so as to cover the wiring.
  • the first coverlay is a wiring board having an overlapping portion in which a part of the second coverlay overlaps.
  • the first coverlay is laminated on the base material, and is also laminated on the first layer having the first end portion in the overlapping portion and the first layer.
  • the overlapping portion comprises a second layer having a second end, the tip of the first end being more of the first coverlay than the tip of the second end. It may be located on the tip side of the.
  • Equation (1) E 1 ⁇ E 2 ... (1)
  • E 1 is the Young's modulus of the first layer
  • E 2 is the Young's modulus of the second layer.
  • the thickness of at least one of the first and second ends may become thinner toward the tip end side of the first coverlay.
  • the second end portion may approach the base material toward the tip end side of the first coverlay.
  • the coverlay is used as the base material by using an existing device. It can be arranged, and it is possible to suppress the cost increase of the wiring board.
  • the wiring is exposed between the cover lays. Can be prevented.
  • FIG. 1 is a plan view showing a printed wiring board according to an embodiment of the present invention.
  • FIG. 2 is an enlarged view of part II of FIG.
  • FIG. 3 is a cross-sectional view taken along the line III-III of FIG.
  • FIG. 4 is a cross-sectional view showing a first modification of the end portion of the overlapping portion in the embodiment of the present invention.
  • FIG. 5 is a cross-sectional view showing a second modification of the end portion of the overlapping portion in the embodiment of the present invention.
  • FIG. 1 is a plan view showing a printed wiring board in the present embodiment
  • FIG. 2 is an enlarged view of a part II of FIG. 1
  • FIG. 3 is a cross-sectional view taken along the line III-III of FIG.
  • the printed wiring board 1 of the present embodiment is a flexible printed wiring board (FPC) having a long strip shape.
  • the length L 0 (length along the X direction in the figure) of the printed wiring board 1 is 500 mm to 5000 mm (500 mm ⁇ L 0 ⁇ 5000 mm), and the printed circuit board 1 is used.
  • the width W 0 (width along the Y direction in the drawing) of the wiring board 1 is 1 mm to 250 mm (1 mm ⁇ W 0 ⁇ 250 mm).
  • the planar shape of the printed wiring board 1 is not limited to the linear strip shape as described above.
  • the printed wiring board 1 may have a shape in which one band shape is branched into a plurality of band shapes at a branch portion.
  • the width of the printed wiring board 1 does not have to be constant over the entire longitudinal direction, and the width of the printed wiring board 1 may be widened in a part of the longitudinal direction.
  • the printed wiring board 1 may have a large rectangular planar shape by having a width W 0 wider than 250 mm (250 mm ⁇ W 0 ⁇ 1000 mm).
  • the planar shape of the large printed wiring board is not particularly limited to the above, and may be any shape.
  • the virtual rectangle circumscribing the planar shape of the large printed wiring board may have the above-mentioned length L 0 and width W 0 .
  • the printed wiring board 1 having such a long or large planar shape is used, for example, in applications such as automobiles, industrial machines, and medical equipment.
  • the intended use of the printed wiring board 1 of the present embodiment is not particularly limited.
  • the printed wiring board 1 includes a base film 10, a wiring pattern 20, a first cover lay 30, and a second cover lay 40.
  • the second coverlay 40 is shown by a alternate long and short dash line in FIG.
  • the base film 10 in the present embodiment corresponds to an example of the "base material” in the present invention
  • the wiring pattern 20 in the present embodiment corresponds to an example of the "wiring" in the present invention.
  • the base film 10 is a film that is flexible and has a long strip shape.
  • the base film 10 is made of a material having electrical insulation such as a resin material.
  • examples of the material constituting the base film 10 include polyimide (PI), liquid crystal polymer (LCP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetherimide (PEI), and poly. Ether Etherketone (PEEK), aramid and the like can be exemplified.
  • a plurality of wiring patterns 20 are formed on the base film 10.
  • the wiring pattern 20 is made of a conductive material such as metal or carbon. Examples of the metal constituting the wiring pattern 20 include copper, silver, and gold. In this embodiment, copper is used as a material constituting the wiring pattern 20.
  • the wiring pattern 20 is formed by using a method such as a subtractive method or a semi-additive method, and is formed by etching a copper foil laminated on the base film 10 into a predetermined shape. There is.
  • each wiring pattern 20 extends linearly along the X direction on the base film 10, and a plurality of wiring patterns 20 are parallel to each other at equal intervals. Have been placed.
  • the number, shape, arrangement, etc. of the wiring pattern 20 are not particularly limited to this, and can be arbitrarily set. Further, a wiring pattern may be formed on both sides of the base film 10, or a via hole or the like may be included in the wiring pattern.
  • terminal portions 21 are formed at both ends of each wiring pattern 20.
  • a connector provided on another printed wiring board, a cable, or the like is connected to the terminal portion 21, and the printed wiring board 1 is electrically connected to an external electronic circuit via the terminal portion 21.
  • the formation position of the terminal portion 21 is not limited to the end portion of the wiring pattern 20, and an arbitrary position in the wiring pattern 20 can be selected. Further, the number of terminal portions 21 in the wiring pattern 20 is not particularly limited, and the terminal portions 21 may not necessarily be formed in the wiring pattern 20.
  • the first coverlay 30 and the second coverlay 40 are laminated on the base film 10 so as to cover the wiring pattern 20.
  • the first and second coverlays 30 and 40 are laminated on the same base film 10 and arranged on the same main surface of the base film 10.
  • the first and second coverlays 30 and 40 are arranged on the base film 10 along the extending direction (longitudinal direction; X direction in the drawing) of the base film 10.
  • the first and second coverlays 30 and 40 do not cover the terminal portion 21 of the wiring pattern 20, and the terminal portion 21 is exposed from the first and second coverlays 30 and 40.
  • the first coverlay 30 of the present embodiment has a two-layer structure including an outer layer 31 and an inner layer 32.
  • the outer layer 31 is a layer for protecting the wiring pattern 20.
  • the inner layer 32 is a layer for relaxing the stress concentration at the time of bending of the printed wiring board 1.
  • the outer layer 31 in the present embodiment corresponds to an example of the "second layer” in the present invention
  • the inner layer 32 in the present embodiment corresponds to an example of the "first layer” in the present invention.
  • the outer layer 31 is made of a film having a flexible and long strip shape.
  • the outer layer 31 is made of a material having electrical insulation such as a resin material.
  • examples of the material constituting the outer layer 31 include polyimide (PI), liquid crystal polymer (LCP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetherimide (PEI), and poly. Ether Etherketone (PEEK), aramid and the like can be exemplified.
  • the inner layer 32 of the present embodiment has a function of adhering the outer layer 31 to the upper surface 11 of the base film 10 in addition to the function of relaxing the stress concentration at the time of bending of the printed wiring board 1 described above. It is a layer.
  • Specific examples of the adhesive constituting the inner layer 32 include an epoxy-based adhesive and an acrylic-based adhesive.
  • the outer layer 31 is a layer for protecting the wiring pattern 20, while the inner layer 32 is a layer for relaxing the stress concentration at the time of bending of the printed wiring board 1. Therefore, in the present embodiment, the inner layer 32 is softer than the outer layer 31. More specifically, the Young's modulus E 1 of the inner layer 32 and the Young's modulus E 2 of the outer layer 31 satisfy the relationship of the following equation (2).
  • the material constituting the outer layer 31 and the inner layer 32 of the first coverlay 30 is not particularly limited to the above.
  • the outer layer 31 may be formed by using a dry film made of a photosensitive coverlay material instead of the above-mentioned resin film, or a liquid photosensitive coverlay material may be applied onto the inner layer 32.
  • the outer layer 31 may be formed by exposing and developing the film.
  • the outer layer 31 may be formed by printing a liquid coverlay ink on the inner layer 32.
  • the outer layer 31 may be made of a so-called solder resist.
  • the outer layer 31 may be formed by using a dry film made of a photosensitive resist material.
  • the outer layer 31 may be formed by applying a liquid photosensitive resist material on the inner layer 32 and then exposing and developing the material.
  • the outer layer 31 may be formed by printing a liquid solder resist ink on the inner layer 32.
  • the inner layer 32 may also be formed by applying a liquid photosensitive coverlay material on the base film 10 and then exposing and developing it instead of the above-mentioned adhesive layer.
  • the inner layer 32 may be formed by printing a liquid coverlay ink on the base film 10.
  • photosensitive coverlay material and photosensitive resist material include those using polyester, epoxy, acrylic, polyimide, polyurethane and the like. Further, as specific examples of the coverlay ink and the solder resist ink described above, those based on polyimide or epoxy can be exemplified.
  • the second coverlay 40 also has a function of protecting the wiring pattern 20.
  • the second coverlay 40 includes a resin layer and an adhesive layer for adhering the resin layer to the base film 10.
  • the second coverlay 40 is shown in a single-layer structure.
  • the resin layer of the second coverlay 40 is the same as the outer layer 31 of the first coverlay 30 described above, for example, polyimide (PI), liquid crystal polymer (LCP), polyethylene terephthalate (PET), polyethylene naphthalate ( It is composed of a resin film made of PEN), polyetherimide (PEI), polyetheretherketone (PEEK), aramid or the like.
  • the adhesive layer is also composed of an adhesive such as an epoxy-based adhesive or an acrylic-based adhesive, as in the case of the inner layer 32 of the first coverlay 30 described above.
  • the second coverlay 40 may be formed by using a dry film, a liquid photosensitive coverlay material or a photosensitive resist material, a coverlay ink, or a solder resist ink. Further, when the base film 10 is made of a liquid crystal polymer (LCP) and the second coverlay 40 is also made of a liquid crystal polymer (LCP), these can be attached to each other by heat fusion. The adhesive layer may be omitted.
  • LCP liquid crystal polymer
  • LCP liquid crystal polymer
  • LCP liquid crystal polymer
  • LCP liquid crystal polymer
  • the tip portion 401 (the end on the + X direction side in the figure) of the second cover lay 40 overlaps the first cover lay 30. That is, the first cover lay 30 has an overlapping portion 301 on which the tip portions 401 of the second cover lay 40 overlap.
  • the printed wiring board 1 of the present embodiment has one first coverlay 30 and two second coverlays 40. Then, these first and second coverlays 30 and 40 extend in the extending direction of the base film 10 (X direction in the drawing) so as to sandwich the first coverlay 30 between the second coverlays 40. ) Are lined up. Therefore, since both ends of the first cover lay 30 are covered by the second cover lay 40, the first cover lay 30 has overlapping portions 301 at both ends thereof.
  • the number of overlapping portions 301 of the printed wiring board 1 is not particularly limited. Since the printed wiring board is provided with two coverlays, it may have only one overlapping portion. Alternatively, by providing four or more coverlays, it may have three or more overlapping portions. Further, when the printed wiring board has a plurality of overlapping portions, the spacing between the overlapping portions can be arbitrarily set. Further, the lengths of the plurality of coverlays of the plurality of printed wiring boards may be substantially the same or may be different from each other.
  • the outer layer 31 of the first coverlay 30 having a two-layer structure is formed on the overlapping portion 301 of one of the first coverlays 30 (on the ⁇ X direction side in the drawing). , Has an end 311.
  • the inner layer 32 also has an end portion 321 at the overlapping portion 301 of one of the first coverlays 30 (on the ⁇ X direction side in the drawing).
  • the tip (end) 322 of the end portion 321 of the inner layer 32 is the tip of the end portion 311 of the outer layer 31. It is located closer to the tip (end) 302 side (-X direction side in FIG. 3) of the first coverlay 30 than the end) 312, and the tip 322 of the inner layer 32 is the tip of the first coverlay 30. It constitutes 302. That is, the tip 312 of the outer layer 31 is located inside the overlapping portion 301 (on the + X direction side in FIG. 3) with respect to the tip 322 of the inner layer 32, and in this overlapping portion 301, the end portion of the inner layer 32. 321 is exposed from the end 311 of the outer layer 31.
  • the outer layer 31 also has an end portion in the overlapping portion 301 and the inner layer 32 also has an overlapping portion 301 on the other side (+ X direction side in the drawing) of the first coverlay 30. Also has an end portion in the overlapping portion 301, and the tip end of the end portion of the inner layer 32 is closer to the tip end 302 side of the first coverlay 30 than the tip end portion of the outer layer 31 (+ X direction in FIG. 3). Located on the side).
  • the coverlay of the flexible printed wiring board is divided into a plurality of parts and an overlapping portion is provided between the coverlays, the wiring pattern is obtained at the change point of the thickness of the overlapping portion when the flexible printed wiring board is bent. Stress concentration occurs. The stress concentrated at this change point tends to increase as the thickness from the wiring pattern to the surface of the coverlay increases.
  • the tip 322 of the inner layer 32 is positioned closer to the tip 302 of the first cover lay 30 than the tip 312 of the outer layer 31, and the shape of the end of the first cover lay 30 is formed.
  • the shape in a stepped shape stress is dispersed when the flexible printed wiring board 1 is bent.
  • the length L 2 of the overlapping portion 301 along the longitudinal direction (X direction in the drawing) of the first coverlay 30 is not particularly limited, but is preferably 0.5 mm to 10 mm (0.5 mm ⁇ L). 2 ⁇ 10 mm), more preferably 0.5 mm to 2.0 mm (0.5 mm ⁇ L 2 ⁇ 2.0 mm).
  • the length L 2 of the overlapping portion 301 is 0.5 mm or more, the positioning of the first and second coverlays 30 and 40 becomes relatively easy.
  • by setting the length L 2 of the overlapping portion 301 to 10 mm or less and shortening the overlapping portion 301 as much as possible it is possible to suppress the influence on the flexibility of the flexible printed wiring board 1.
  • the ratio (L 2 / L 1 ) of the length L 2 of the overlapping portion 301 to the total length L 1 of the first coverlay 30 is preferably 1/20 or less (L 2 / L 1 ⁇ 1 /). 20), more preferably 1/100 or less (L 2 / L 1 ⁇ 1/100).
  • the press pressure and the press temperature during hot pressing using a press device are optimized to optimize the press pressure and the press temperature from the outer layer 31 to the inner side. Since the amount of protrusion of the layer 32 can be adjusted, the staircase shape of the end portion of the first coverlay 30 shown in FIG. 3 can be formed. The thickness and material of the cushion material used in the press device may be optimized in order to form the staircase shape at the end of the first coverlay 30.
  • the outer layer 31 should be formed so that the tip 312 of the outer layer 31 is located inside the overlapping portion 301 with respect to the tip of the inner layer 31. good.
  • the shape of the overlapping portion 301 of the first coverlay 30 is not particularly limited to the staircase shape as described above.
  • FIG. 4 is a cross-sectional view showing a first modification of the end portion of the overlapping portion in the present embodiment
  • FIG. 5 is a cross-sectional view showing a second modification example of the end portion of the overlapping portion in the present embodiment.
  • the thickness of the end portion 321 of the inner layer 32 of the first cover lay 30 may become thinner toward the tip 302 side of the first cover lay 30.
  • the thickness D 3 from the wiring pattern 20 at the tip 322 of the inner layer 32 to the surface of the second coverlay 40 can be reduced as compared with the case shown in FIG. 3 (D 1 > D 3 ).
  • the stress concentration on the wiring pattern 20 when the flexible printed wiring board 1 is bent can be further relaxed.
  • D 1 is the thickness from the wiring pattern 20 at the tip 322 of the inner layer 32 to the surface of the second coverlay 40 in the example shown in FIG.
  • the thickness of the end portion 311 of the outer layer 31 of the first cover lay 30 may become thinner toward the tip 302 side of the first cover lay 30.
  • the thickness D 4 from the wiring pattern 20 at the tip 312 of the outer layer 31 to the surface of the second coverlay 40 can be reduced as compared with the case shown in FIG. 3 (D 2 > D 4 ).
  • the stress concentration on the wiring pattern 20 when the flexible printed wiring board 1 is bent can be further relaxed.
  • D 2 is the thickness from the wiring pattern 20 at the tip 312 of the outer layer 31 to the surface of the second coverlay 40 in the example shown in FIG.
  • the thickness of the end 311 of the outer layer 31 can be gradually reduced by etching or polishing the end of the resin film.
  • the printing conditions for example, the design of the mesh of the printing plate, the squeegee pressure, the printing speed, etc.
  • the coating conditions for example, the coating amount and the relative of the base material.
  • the thickness of the end portion 321 of the inner layer 32 of the first cover lay 30 becomes thinner and thinner toward the tip 302 side of the first cover lay 30.
  • the end portion 311 of the outer layer 31 may protrude onto the end portion 321 of the inner layer 32.
  • the entire end 311 of the outer layer 31 approaches the base film 10 toward the tip 30 side of the first coverlay 30. Therefore, the thickness D 5 from the wiring pattern 20 at the tip 312 of the outer layer 31 to the surface of the second coverlay 40 can be reduced as compared with the case shown in FIG. 3 (D 2 > D 5 ).
  • the stress concentration on the wiring pattern 20 when the flexible printed wiring board 1 is bent can be further relaxed.
  • the existing apparatus can be used even when a large-sized or long printed wiring board 1 is manufactured.
  • the coverlays 30 and 40 can be laminated on the base film 10 by using the cover lays 30 and 40, and the cost increase of the wiring board 1 can be suppressed.
  • the wiring pattern is formed between the cover lays 30 and 40. It is possible to prevent the 20 from being exposed.
  • the tip 322 of the inner layer 32 is positioned closer to the tip 302 of the first coverlay 30 than the tip 312 of the outer layer 31, so that the stress is dispersed when the flexible printed wiring board 1 is bent. ing.
  • the stress concentration that occurs when the flexible printed wiring board 1 is bent can be alleviated, and the occurrence of disconnection of the wiring pattern 20 can be suppressed.
  • the tip 322 of the inner layer 32 is located closer to the tip 302 of the first cover lay 30 than the tip 312 of the outer layer 31, but the end of the first cover lay 30.
  • the shape is not particularly limited to this.
  • the tip 322 of the inner layer 32 may coincide with the tip 312 of the outer layer 31 along the longitudinal direction (X direction in the drawing) of the printed wiring board 1.
  • the first coverlay 30 has a two-layer structure, but the first coverlay 30 may be composed of three or more layers.

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  • Engineering & Computer Science (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Manufacturing & Machinery (AREA)
  • Non-Metallic Protective Coatings For Printed Circuits (AREA)
  • Structure Of Printed Boards (AREA)

Abstract

A wiring board 1 comprises a base film 10, a wiring pattern 20 disposed on the base film 10, and first and second coverlays 30, 40 disposed adjacent to each other on the base film 10 so as to cover the wiring pattern 20, wherein the first coverlay 30 has an overlapped portion 301 on which a portion 401 of the second coverlay 40 is overlapped.

Description

配線板Wiring board
　本発明は、配線板に関するものである。
　文献の参照による組み込みが認められる指定国については、２０２０年１１月１２日に日本国に出願された特願２０２０－１８８５７０に記載された内容を参照により本明細書に組み込み、本明細書の記載の一部とする。 The present invention relates to a wiring board.
For designated countries that are permitted to be incorporated by reference in the literature, the contents described in Japanese Patent Application No. 2020-188570 filed in Japan on November 12, 2020 are incorporated into the present specification by reference and described in the present specification. To be part of.
　フレキシブルプリント配線板（ＦＰＣ）は、ベースフィルム、回路、及び、カバーレイヤーを備えている。ベースフィルム及びカバーレイヤーとしては、ポリイミド等の柔軟性に優れたプラスチックフィルムが用いられている。回路は、ベースフィルム上に貼り付けられた銅箔をエッチングすることで形成されている。カバーレイヤーは、接着剤を介して回路上に接着されている（例えば特許文献１（段落［０００２］～［０００４］及び図１）参照）。 The flexible printed wiring board (FPC) is equipped with a base film, a circuit, and a cover layer. As the base film and the cover layer, a plastic film having excellent flexibility such as polyimide is used. The circuit is formed by etching a copper foil attached on a base film. The cover layer is adhered onto the circuit via an adhesive (see, for example, Patent Document 1 (see paragraphs [0002]-[0004] and FIG. 1)).
特開２００３－２１８４８８号公報Japanese Patent Application Laid-Open No. 2003-218488
　配線が形成された基材へのカバーレイの積層は、プレス装置を用いて行なわれる。大型或いは長尺のフレキシブルプリント配線板を製造するために、カバーレイを基材に一括して積層する場合には、当該プレス装置の大型化や歩留まりの低下によって配線板の高コスト化を招来してしまう場合がある、という問題がある。 The coverlay is laminated on the base material on which the wiring is formed by using a press device. When the coverlays are collectively laminated on the base material in order to manufacture a large or long flexible printed wiring board, the cost of the wiring board is increased due to the increase in size of the press device and the decrease in yield. There is a problem that it may end up.
　本発明が解決しようとする課題は、大型或いは長尺の配線板を製造する場合であっても、高コスト化の抑制を図ることが可能な配線板を提供することである。 The problem to be solved by the present invention is to provide a wiring board capable of suppressing cost increase even in the case of manufacturing a large-sized or long wiring board.
　［１］本発明に係る配線板は、基材と、前記基材上に配置された配線と、前記配線を覆うように前記基材上に並んで配置された第１及び第２のカバーレイと、を備え、前記第１のカバーレイは、前記第２のカバーレイの一部が重なっている重複部分を有している配線板である。 [1] The wiring board according to the present invention includes a base material, wiring arranged on the base material, and first and second coverlays arranged side by side on the base material so as to cover the wiring. The first coverlay is a wiring board having an overlapping portion in which a part of the second coverlay overlaps.
　［２］上記発明において、前記第１のカバーレイは、前記基材に積層されていると共に、前記重複部分に第１の端部を有する第１の層と、前記第１の層に積層されていると共に、前記重複部分に第２の端部を有する第２の層と、を備え、前記第１の端部の先端は、前記第２の端部の先端よりも前記第１のカバーレイの先端側に位置していてもよい。 [2] In the above invention, the first coverlay is laminated on the base material, and is also laminated on the first layer having the first end portion in the overlapping portion and the first layer. In addition, the overlapping portion comprises a second layer having a second end, the tip of the first end being more of the first coverlay than the tip of the second end. It may be located on the tip side of the.
　［３］上記発明において、下記の（１）式を満たしてもよい。
　Ｅ１＜Ｅ２　　　・・・　　　（１）
　但し、上記の（１）式において、Ｅ１は前記第１の層のヤング率であり、Ｅ２は前記第２の層のヤング率である。 [3] In the above invention, the following equation (1) may be satisfied.
E 1 <E 2 ... (1)
However, in the above equation (1), E 1 is the Young's modulus of the first layer, and E 2 is the Young's modulus of the second layer.
　［４］上記発明において、前記第１及び第２の端部の少なくとも一方の厚みは、前記第１のカバーレイの先端側に向かうに従って薄くなってもよい。 [4] In the above invention, the thickness of at least one of the first and second ends may become thinner toward the tip end side of the first coverlay.
　［５］上記発明において、前記第２の端部は、前記第１のカバーレイの先端側に向かうに従って、前記基材に近づいてもよい。 [5] In the above invention, the second end portion may approach the base material toward the tip end side of the first coverlay.
　本発明では、基材上に配置されるカバーレイを２つに分割することで、大型或いは長尺の配線板を製造する場合であっても、既存の装置を用いてカバーレイを基材に配置することができ、配線板の高コスト化の抑制を図ることができる。 In the present invention, by dividing the coverlay arranged on the base material into two, even when a large-sized or long wiring board is manufactured, the coverlay is used as the base material by using an existing device. It can be arranged, and it is possible to suppress the cost increase of the wiring board.
　また、本発明では、第２のカバーレイの一部を第１のカバーレイに重ねることで、カバーレイを２つに分割した場合でも、カバーレイ同士の間から配線が露出してしまうことを防止することができる。 Further, in the present invention, by superimposing a part of the second cover lay on the first cover lay, even when the cover lay is divided into two, the wiring is exposed between the cover lays. Can be prevented.
図１は、本発明の実施形態におけるプリント配線板を示す平面図である。FIG. 1 is a plan view showing a printed wiring board according to an embodiment of the present invention. 図２は、図１のII部の拡大図である。FIG. 2 is an enlarged view of part II of FIG. 図３は、図２のIII-III線に沿った断面図である。FIG. 3 is a cross-sectional view taken along the line III-III of FIG. 図４は、本発明の実施形態における重複部分の端部の第１変形例を示す断面図である。FIG. 4 is a cross-sectional view showing a first modification of the end portion of the overlapping portion in the embodiment of the present invention. 図５は、本発明の実施形態における重複部分の端部の第２変形例を示す断面図である。FIG. 5 is a cross-sectional view showing a second modification of the end portion of the overlapping portion in the embodiment of the present invention.
　以下、本発明の実施形態を図面に基づいて説明する。 Hereinafter, embodiments of the present invention will be described with reference to the drawings.
　図１は本実施形態におけるプリント配線板を示す平面図であり、図２は図１のII部の拡大図であり、図３は図２のIII-III線に沿った断面図である。 FIG. 1 is a plan view showing a printed wiring board in the present embodiment, FIG. 2 is an enlarged view of a part II of FIG. 1, and FIG. 3 is a cross-sectional view taken along the line III-III of FIG.
　本実施形態のプリント配線板１は、長尺の帯形状を有しているフレキシブルプリント配線板（ＦＰＣ）である。特に限定されないが、具体的には、このプリント配線板１の長さＬ０（図中のＸ方向に沿った長さ）は、５００ｍｍ～５０００ｍｍであり（５００ｍｍ≦Ｌ０≦５０００ｍｍ）、当該プリント配線板１の幅Ｗ０（図中のＹ方向に沿った幅）は、１ｍｍ～２５０ｍｍである（１ｍｍ≦Ｗ０≦２５０ｍｍ）。 The printed wiring board 1 of the present embodiment is a flexible printed wiring board (FPC) having a long strip shape. Although not particularly limited, specifically, the length L 0 (length along the X direction in the figure) of the printed wiring board 1 is 500 mm to 5000 mm (500 mm ≤ L 0 ≤ 5000 mm), and the printed circuit board 1 is used. The width W 0 (width along the Y direction in the drawing) of the wiring board 1 is 1 mm to 250 mm (1 mm ≤ W 0 ≤ 250 mm).
　なお、プリント配線板１の平面形状は、上記のような直線状の帯形状に限定されない。例えば、プリント配線板１が、一本の帯形状が分岐部で複数の帯形状に枝分かれする形状を有していてもよい。また、プリント配線板１の幅は、長手方向の全体に亘って一定でなくてもよく、長手方向の一部においてプリント配線板１の幅が広くなっていてもよい。 The planar shape of the printed wiring board 1 is not limited to the linear strip shape as described above. For example, the printed wiring board 1 may have a shape in which one band shape is branched into a plurality of band shapes at a branch portion. Further, the width of the printed wiring board 1 does not have to be constant over the entire longitudinal direction, and the width of the printed wiring board 1 may be widened in a part of the longitudinal direction.
　或いは、プリント配線板１が、２５０ｍｍよりも広い幅Ｗ０を有することで（２５０ｍｍ＜Ｗ０≦１０００ｍｍ）、大型の矩形状の平面形状を有してもよい。なお、大型のプリント配線板の平面形状は、特に上記に限定されず、任意の形状とすることができる。この際、当該大型のプリント配線板の平面形状に外接する仮想上の矩形が、上記の長さＬ０と幅Ｗ０を有していればよい。 Alternatively, the printed wiring board 1 may have a large rectangular planar shape by having a width W 0 wider than 250 mm (250 mm <W 0 ≦ 1000 mm). The planar shape of the large printed wiring board is not particularly limited to the above, and may be any shape. At this time, the virtual rectangle circumscribing the planar shape of the large printed wiring board may have the above-mentioned length L 0 and width W 0 .
　こうした長尺或いは大型の平面形状を有するプリント配線板１は、例えば、自動車、産業用機械、医療機器等の用途に用いられる。なお、本実施形態のプリント配線板１の使用用途は、特に限定されない。 The printed wiring board 1 having such a long or large planar shape is used, for example, in applications such as automobiles, industrial machines, and medical equipment. The intended use of the printed wiring board 1 of the present embodiment is not particularly limited.
　図１～図３に示すように、このプリント配線板１は、ベースフィルム１０と、配線パターン２０と、第１のカバーレイ３０と、第２のカバーレイ４０と、を備えている。なお、便宜上、図２において、第２のカバーレイ４０を一点鎖線で示している。本実施形態におけるベースフィルム１０が本発明における「基材」の一例に相当し、本実施形態における配線パターン２０が本発明における「配線」の一例に相当する。 As shown in FIGS. 1 to 3, the printed wiring board 1 includes a base film 10, a wiring pattern 20, a first cover lay 30, and a second cover lay 40. For convenience, the second coverlay 40 is shown by a alternate long and short dash line in FIG. The base film 10 in the present embodiment corresponds to an example of the "base material" in the present invention, and the wiring pattern 20 in the present embodiment corresponds to an example of the "wiring" in the present invention.
　ベースフィルム１０は、可撓性を有すると共に長尺の帯形状を有するフィルムである。このベースフィルム１０は、樹脂材料等の電気絶縁性を有する材料から構成されている。特に限定されないが、このベースフィルム１０を構成する材料としては、例えば、ポリイミド（ＰＩ）、液晶ポリマ（ＬＣＰ）、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリエーテルイミド（ＰＥＩ）、ポリエーテルエーテルケトン（ＰＥＥＫ）、及び、アラミド等を例示することができる。 The base film 10 is a film that is flexible and has a long strip shape. The base film 10 is made of a material having electrical insulation such as a resin material. Although not particularly limited, examples of the material constituting the base film 10 include polyimide (PI), liquid crystal polymer (LCP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetherimide (PEI), and poly. Ether Etherketone (PEEK), aramid and the like can be exemplified.
　このベースフィルム１０上に複数の配線パターン２０が形成されている。この配線パターン２０は、金属又はカーボン等の導電性材料から構成されている。この配線パターン２０を構成する金属としては、例えば、銅、銀、金を例示することができる。本実施形態では、配線パターン２０を構成する材料として銅を用いる。特に限定されないが、この配線パターン２０は、サブトラクティブ法やセミアディティブ法等の方法を用いて形成されており、ベースフィルム１０に積層された銅箔を所定の形状にエッチングすることで形成されている。 A plurality of wiring patterns 20 are formed on the base film 10. The wiring pattern 20 is made of a conductive material such as metal or carbon. Examples of the metal constituting the wiring pattern 20 include copper, silver, and gold. In this embodiment, copper is used as a material constituting the wiring pattern 20. Although not particularly limited, the wiring pattern 20 is formed by using a method such as a subtractive method or a semi-additive method, and is formed by etching a copper foil laminated on the base film 10 into a predetermined shape. There is.
　本実施形態では、図１に示すように、それぞれの配線パターン２０がベースフィルム１０上にＸ方向に沿って直線状に延在しており、複数の配線パターン２０が等間隔で相互に平行に配置されている。なお、配線パターン２０の数や形状、配置等は、特にこれに限定されず、任意に設定することができる。また、ベースフィルム１０の両面に配線パターンを形成してもよいし、配線パターンにバイアホール等を含めてもよい。 In the present embodiment, as shown in FIG. 1, each wiring pattern 20 extends linearly along the X direction on the base film 10, and a plurality of wiring patterns 20 are parallel to each other at equal intervals. Have been placed. The number, shape, arrangement, etc. of the wiring pattern 20 are not particularly limited to this, and can be arbitrarily set. Further, a wiring pattern may be formed on both sides of the base film 10, or a via hole or the like may be included in the wiring pattern.
　また、図１に示すように、各々の配線パターン２０の両端には端子部２１がそれぞれ形成されている。この端子部２１は、例えば、他のプリント配線板やケーブル等に設けられたコネクタが接続されて、この端子部２１を介してプリント配線板１が外部の電子回路と電気的に接続される。なお、端子部２１の形成位置は、配線パターン２０の端部に限定されず、配線パターン２０における任意の位置を選択することができる。また、配線パターン２０における端子部２１の数も特に限定されないし、必ずしも配線パターン２０に端子部２１を形成しなくてもよい。 Further, as shown in FIG. 1, terminal portions 21 are formed at both ends of each wiring pattern 20. For example, a connector provided on another printed wiring board, a cable, or the like is connected to the terminal portion 21, and the printed wiring board 1 is electrically connected to an external electronic circuit via the terminal portion 21. The formation position of the terminal portion 21 is not limited to the end portion of the wiring pattern 20, and an arbitrary position in the wiring pattern 20 can be selected. Further, the number of terminal portions 21 in the wiring pattern 20 is not particularly limited, and the terminal portions 21 may not necessarily be formed in the wiring pattern 20.
　図１～図３に示すように、第１のカバーレイ３０と第２のカバーレイ４０は、配線パターン２０を覆うようにベースフィルム１０上に積層されている。第１及び第２のカバーレイ３０，４０は、同一のベースフィルム１０に積層されており、当該ベースフィルム１０の同一の主面上に配置されている。本実施形態では、第１及び第２のカバーレイ３０，４０は、ベースフィルム１０上において、ベースフィルム１０の延在方向（長手方向。図中のＸ方向）に沿って並べられている。なお、第１及び第２のカバーレイ３０，４０は配線パターン２０の端子部２１を覆っておらず、当該端子部２１は第１及び第２のカバーレイ３０，４０から露出している。 As shown in FIGS. 1 to 3, the first coverlay 30 and the second coverlay 40 are laminated on the base film 10 so as to cover the wiring pattern 20. The first and second coverlays 30 and 40 are laminated on the same base film 10 and arranged on the same main surface of the base film 10. In the present embodiment, the first and second coverlays 30 and 40 are arranged on the base film 10 along the extending direction (longitudinal direction; X direction in the drawing) of the base film 10. The first and second coverlays 30 and 40 do not cover the terminal portion 21 of the wiring pattern 20, and the terminal portion 21 is exposed from the first and second coverlays 30 and 40.
　本実施形態の第１のカバーレイ３０は、外側層３１と内側層３２からなる二層構造を有している。外側層３１は、配線パターン２０を保護するための層である。これに対し、内側層３２は、プリント配線板１の屈曲時の応力集中を緩和するための層である。本実施形態における外側層３１が本発明における「第２の層」の一例に相当し、本実施形態における内側層３２が本発明における「第１の層」の一例に相当する。 The first coverlay 30 of the present embodiment has a two-layer structure including an outer layer 31 and an inner layer 32. The outer layer 31 is a layer for protecting the wiring pattern 20. On the other hand, the inner layer 32 is a layer for relaxing the stress concentration at the time of bending of the printed wiring board 1. The outer layer 31 in the present embodiment corresponds to an example of the "second layer" in the present invention, and the inner layer 32 in the present embodiment corresponds to an example of the "first layer" in the present invention.
　外側層３１は、可撓性を有すると共に長尺の帯形状を有するフィルムから構成されている。この外側層３１は、樹脂材料等の電気絶縁性を有する材料から構成されている。特に限定されないが、この外側層３１を構成する材料としては、例えば、ポリイミド（ＰＩ）、液晶ポリマ（ＬＣＰ）、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリエーテルイミド（ＰＥＩ）、ポリエーテルエーテルケトン（ＰＥＥＫ）、及び、アラミド等を例示することができる。 The outer layer 31 is made of a film having a flexible and long strip shape. The outer layer 31 is made of a material having electrical insulation such as a resin material. Although not particularly limited, examples of the material constituting the outer layer 31 include polyimide (PI), liquid crystal polymer (LCP), polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polyetherimide (PEI), and poly. Ether Etherketone (PEEK), aramid and the like can be exemplified.
　これに対し、本実施形態の内側層３２は、上述のプリント配線板１の屈曲時の応力集中を緩和する機能に加えて、外側層３１をベースフィルム１０の上面１１に接着する機能を有する接着層である。この内側層３２を構成する接着剤の具体例としては、例えば、エポキシ系接着剤やアクリル系接着剤を例示することができる。 On the other hand, the inner layer 32 of the present embodiment has a function of adhering the outer layer 31 to the upper surface 11 of the base film 10 in addition to the function of relaxing the stress concentration at the time of bending of the printed wiring board 1 described above. It is a layer. Specific examples of the adhesive constituting the inner layer 32 include an epoxy-based adhesive and an acrylic-based adhesive.
　上述のように、外側層３１は、配線パターン２０を保護するための層であるのに対し、内側層３２は、プリント配線板１の屈曲時の応力集中を緩和するための層である。このため、本実施形態では、内側層３２は外側層３１よりも柔らかくなっている。より具体的には、内側層３２のヤング率Ｅ１と外側層３１のヤング率Ｅ２とが以下の（２）式の関係を満たしている。 As described above, the outer layer 31 is a layer for protecting the wiring pattern 20, while the inner layer 32 is a layer for relaxing the stress concentration at the time of bending of the printed wiring board 1. Therefore, in the present embodiment, the inner layer 32 is softer than the outer layer 31. More specifically, the Young's modulus E 1 of the inner layer 32 and the Young's modulus E 2 of the outer layer 31 satisfy the relationship of the following equation (2).
　Ｅ１＜Ｅ２　　　・・・　　　（２） E 1 <E 2 ... (2)
　上記の（２）式の関係式を満たしている限り、第１のカバーレイ３０の外側層３１と内側層３２を構成する材料は、特に上記に限定されない。 As long as the relational expression of the above equation (2) is satisfied, the material constituting the outer layer 31 and the inner layer 32 of the first coverlay 30 is not particularly limited to the above.
　例えば、外側層３１を、上述の樹脂フィルムに代えて、感光性カバーレイ材料からなるドライフィルムを用いて形成してもよいし、或いは、液状の感光性カバーレイ材料を内側層３２上に塗布した後に露光及び現像することで、外側層３１を形成してもよい。或いは、液状のカバーレイインクを内側層３２上に印刷することで、外側層３１を形成してもよい。 For example, the outer layer 31 may be formed by using a dry film made of a photosensitive coverlay material instead of the above-mentioned resin film, or a liquid photosensitive coverlay material may be applied onto the inner layer 32. The outer layer 31 may be formed by exposing and developing the film. Alternatively, the outer layer 31 may be formed by printing a liquid coverlay ink on the inner layer 32.
　或いは、外側層３１を所謂ソルダレジストで構成してもよい。具体的には、感光性レジスト材料からなるドライフィルムを用いて外側層３１を形成してもよい。或いは、液状の感光性レジスト材料を内側層３２上に塗布した後に露光及び現像することで、外側層３１を形成してもよい。或いは、液状のソルダレジストインクを内側層３２上に印刷することで、外側層３１を形成してもよい。 Alternatively, the outer layer 31 may be made of a so-called solder resist. Specifically, the outer layer 31 may be formed by using a dry film made of a photosensitive resist material. Alternatively, the outer layer 31 may be formed by applying a liquid photosensitive resist material on the inner layer 32 and then exposing and developing the material. Alternatively, the outer layer 31 may be formed by printing a liquid solder resist ink on the inner layer 32.
　内側層３２も、上述の接着層に代えて、液状の感光性カバーレイ材料をベースフィルム１０上に塗布した後に露光及び現像することで形成してもよい。或いは、液状のカバーレイインクをベースフィルム１０上に印刷することで、内側層３２を形成してもよい。 The inner layer 32 may also be formed by applying a liquid photosensitive coverlay material on the base film 10 and then exposing and developing it instead of the above-mentioned adhesive layer. Alternatively, the inner layer 32 may be formed by printing a liquid coverlay ink on the base film 10.
　上記の感光性カバーレイ材料や感光性レジスト材料の具体例としては、例えば、ポリエステル、エポキシ、アクリル、ポリイミド、ポリウレタン等を用いたものを例示することができる。また、上記のカバーレイインクやソルダレジストインクの具体例としては、ポリイミドやエポキシをベースとしたものを例示することができる。 Specific examples of the above-mentioned photosensitive coverlay material and photosensitive resist material include those using polyester, epoxy, acrylic, polyimide, polyurethane and the like. Further, as specific examples of the coverlay ink and the solder resist ink described above, those based on polyimide or epoxy can be exemplified.
　第２のカバーレイ４０も、配線パターン２０を保護する機能を備えている。本実施形態では、第２のカバーレイ４０は、樹脂層と、当該樹脂層をベースフィルム１０に接着している接着層を備えている。なお、図３～図５においては、便宜上、第２のカバーレイ４０を一層構造で図示している。 The second coverlay 40 also has a function of protecting the wiring pattern 20. In the present embodiment, the second coverlay 40 includes a resin layer and an adhesive layer for adhering the resin layer to the base film 10. In FIGS. 3 to 5, for convenience, the second coverlay 40 is shown in a single-layer structure.
　第２のカバーレイ４０の樹脂層は、上述の第１のカバーレイ３０の外側層３１と同様に、例えば、ポリイミド（ＰＩ）、液晶ポリマ（ＬＣＰ）、ポリエチレンテレフタレート（ＰＥＴ）、ポリエチレンナフタレート（ＰＥＮ）、ポリエーテルイミド（ＰＥＩ）、ポリエーテルエーテルケトン（ＰＥＥＫ）、又は、アラミド等からなる樹脂フィルムで構成されている。また、接着層も、上述の第１のカバーレイ３０の内側層３２と同様に、例えば、エポキシ系接着剤やアクリル系接着剤等の接着剤から構成されている。 The resin layer of the second coverlay 40 is the same as the outer layer 31 of the first coverlay 30 described above, for example, polyimide (PI), liquid crystal polymer (LCP), polyethylene terephthalate (PET), polyethylene naphthalate ( It is composed of a resin film made of PEN), polyetherimide (PEI), polyetheretherketone (PEEK), aramid or the like. Further, the adhesive layer is also composed of an adhesive such as an epoxy-based adhesive or an acrylic-based adhesive, as in the case of the inner layer 32 of the first coverlay 30 described above.
　なお、第２のカバーレイ４０を、ドライフィルム、液状の感光性カバーレイ材料若しくは感光性レジスト材料、カバーレイインク、又は、ソルダレジストインクを用いて形成してもよい。また、ベースフィルム１０を液晶ポリマ（ＬＣＰ）で構成すると共に、第２のカバーレイ４０も液晶ポリマ（ＬＣＰ）で構成する場合には、熱融着によってこれらを相互に貼り付けることができるので、接着層を省略してもよい。 The second coverlay 40 may be formed by using a dry film, a liquid photosensitive coverlay material or a photosensitive resist material, a coverlay ink, or a solder resist ink. Further, when the base film 10 is made of a liquid crystal polymer (LCP) and the second coverlay 40 is also made of a liquid crystal polymer (LCP), these can be attached to each other by heat fusion. The adhesive layer may be omitted.
　この第２のカバーレイ４０の先端部分４０１（図中の＋Ｘ方向側の端部）が、第１のカバーレイ３０の上に重なっている。すなわち、第１のカバーレイ３０は、第２のカバーレイ４０の先端部分４０１が重なっている重複部分３０１を有している。 The tip portion 401 (the end on the + X direction side in the figure) of the second cover lay 40 overlaps the first cover lay 30. That is, the first cover lay 30 has an overlapping portion 301 on which the tip portions 401 of the second cover lay 40 overlap.
　本実施形態のプリント配線板１は、図１に示すように、１枚の第１のカバーレイ３０を有しているに対し、２枚の第２のカバーレイ４０を有している。そして、これらの第１及び第２のカバーレイ３０，４０は、第２のカバーレイ４０の間に第１のカバーレイ３０を挟むように、ベースフィルム１０の延在方向（図中のＸ方向）に沿って並べられている。従って、第１のカバーレイ３０の両端が第２のカバーレイ４０によってそれぞれ覆われているので、当該第１のカバーレイ３０はその両端に重複部分３０１をそれぞれ有している。 As shown in FIG. 1, the printed wiring board 1 of the present embodiment has one first coverlay 30 and two second coverlays 40. Then, these first and second coverlays 30 and 40 extend in the extending direction of the base film 10 (X direction in the drawing) so as to sandwich the first coverlay 30 between the second coverlays 40. ) Are lined up. Therefore, since both ends of the first cover lay 30 are covered by the second cover lay 40, the first cover lay 30 has overlapping portions 301 at both ends thereof.
　なお、プリント配線板１が有する重複部分３０１の数は特に限定されない。プリント配線板が２枚のカバーレイを備えることで重複部分１つのみ有していてもよい。或いは、４枚以上のカバーレイを備えることで３つ以上の重複部分を有していてもよい。また、プリント配線板が複数の重複部分を有する場合には、重複部分同士の間隔を任意に設定することができる。また、プリント配線板複数が有する複数のカバーレイの長さが実質的に同一であってもよいし、相互に異なっていてもよい。 The number of overlapping portions 301 of the printed wiring board 1 is not particularly limited. Since the printed wiring board is provided with two coverlays, it may have only one overlapping portion. Alternatively, by providing four or more coverlays, it may have three or more overlapping portions. Further, when the printed wiring board has a plurality of overlapping portions, the spacing between the overlapping portions can be arbitrarily set. Further, the lengths of the plurality of coverlays of the plurality of printed wiring boards may be substantially the same or may be different from each other.
　図２及び図３に示すように、二層構造を有する第１のカバーレイ３０の外側層３１は、当該第１のカバーレイ３０の一方（図中の－Ｘ方向側）の重複部分３０１に、端部３１１を有している。同様に、内側層３２も、第１のカバーレイ３０の一方（図中の－Ｘ方向側）の重複部分３０１に端部３２１を有している。 As shown in FIGS. 2 and 3, the outer layer 31 of the first coverlay 30 having a two-layer structure is formed on the overlapping portion 301 of one of the first coverlays 30 (on the −X direction side in the drawing). , Has an end 311. Similarly, the inner layer 32 also has an end portion 321 at the overlapping portion 301 of one of the first coverlays 30 (on the −X direction side in the drawing).
　そして、本実施形態では、図２（平面視）及び図３（断面視）に示すように、内側層３２の端部３２１の先端（末端）３２２が、外側層３１の端部３１１の先端（末端）３１２よりも、第１のカバーレイ３０の先端（末端）３０２側（図３中の－Ｘ方向側）に位置しており、内側層３２の先端３２２が第１のカバーレイ３０の先端３０２を構成している。すなわち、外側層３１の先端３１２が、内側層３２の先端３２２よりも重複部分３０１の内側（図３中の＋Ｘ方向側）に位置しており、この重複部分３０１において、内側層３２の端部３２１が外側層３１の端部３１１から露出している。 Then, in the present embodiment, as shown in FIGS. 2 (planar view) and 3 (cross-sectional view), the tip (end) 322 of the end portion 321 of the inner layer 32 is the tip of the end portion 311 of the outer layer 31. It is located closer to the tip (end) 302 side (-X direction side in FIG. 3) of the first coverlay 30 than the end) 312, and the tip 322 of the inner layer 32 is the tip of the first coverlay 30. It constitutes 302. That is, the tip 312 of the outer layer 31 is located inside the overlapping portion 301 (on the + X direction side in FIG. 3) with respect to the tip 322 of the inner layer 32, and in this overlapping portion 301, the end portion of the inner layer 32. 321 is exposed from the end 311 of the outer layer 31.
　特に図示しないが、第１のカバーレイ３０の他方（図中の＋Ｘ方向側）の重複部分３０１についても同様に、外側層３１が重複部分３０１に端部を有していると共に、内側層３２も重複部分３０１に端部を有しており、内側層３２の端部の先端が外側層３１の端部の先端よりも、第１のカバーレイ３０の先端３０２側（図３中の＋Ｘ方向側）に位置している。 Although not particularly shown, the outer layer 31 also has an end portion in the overlapping portion 301 and the inner layer 32 also has an overlapping portion 301 on the other side (+ X direction side in the drawing) of the first coverlay 30. Also has an end portion in the overlapping portion 301, and the tip end of the end portion of the inner layer 32 is closer to the tip end 302 side of the first coverlay 30 than the tip end portion of the outer layer 31 (+ X direction in FIG. 3). Located on the side).
　ここで、フレキシブルプリント配線板のカバーレイを複数に分割して当該カバーレイ同士の間に重複部分を設けた場合、当該フレキシブルプリント配線板の屈曲時に、その重複部分の厚みの変化点で配線パターンに対する応力集中が発生する。この変化点に集中する応力は、配線パターンからカバーレイの表面までの厚みが厚いほど、大きくなる傾向がある。 Here, when the coverlay of the flexible printed wiring board is divided into a plurality of parts and an overlapping portion is provided between the coverlays, the wiring pattern is obtained at the change point of the thickness of the overlapping portion when the flexible printed wiring board is bent. Stress concentration occurs. The stress concentrated at this change point tends to increase as the thickness from the wiring pattern to the surface of the coverlay increases.
　これに対し、本実施形態では、内側層３２の先端３２２を外側層３１の先端３１２よりも第１のカバーレイ３０の先端３０２側に位置させて、第１のカバーレイ３０の端部の形状を階段状とすることで、フレキシブルプリント配線板１の屈曲時に応力を分散させている。 On the other hand, in the present embodiment, the tip 322 of the inner layer 32 is positioned closer to the tip 302 of the first cover lay 30 than the tip 312 of the outer layer 31, and the shape of the end of the first cover lay 30 is formed. By forming the shape in a stepped shape, stress is dispersed when the flexible printed wiring board 1 is bent.
　第１のカバーレイ３０の長手方向（図中のＸ方向）に沿った重複部分３０１の長さＬ２は、特に限定されないが、０．５ｍｍ～１０ｍｍであることが好ましく（０．５ｍｍ≦Ｌ２≦１０ｍｍ）、０．５ｍｍ～２．０ｍｍであることがより好ましい（０．５ｍｍ≦Ｌ２≦２．０ｍｍ）。重複部分３０１の長さＬ２が０．５ｍｍ以上であることで、第1及び第２のカバーレイ３０，４０の位置決めが比較的容易となる。一方、重複部分３０１の長さＬ２が１０ｍｍ以下として、重複部分３０１をできる限り短くすることで、フレキシブルプリント配線板１の屈曲性への影響を抑制することができる。 The length L 2 of the overlapping portion 301 along the longitudinal direction (X direction in the drawing) of the first coverlay 30 is not particularly limited, but is preferably 0.5 mm to 10 mm (0.5 mm ≦ L). 2 ≤ 10 mm), more preferably 0.5 mm to 2.0 mm (0.5 mm ≤ L 2 ≤ 2.0 mm). When the length L 2 of the overlapping portion 301 is 0.5 mm or more, the positioning of the first and second coverlays 30 and 40 becomes relatively easy. On the other hand, by setting the length L 2 of the overlapping portion 301 to 10 mm or less and shortening the overlapping portion 301 as much as possible, it is possible to suppress the influence on the flexibility of the flexible printed wiring board 1.
　また、第１のカバーレイ３０の全長Ｌ１に対する重複部分３０１の長さＬ２の比率（Ｌ２／Ｌ１）が、１／２０以下であることが好ましく（Ｌ２／Ｌ１≦１／２０）、１／１００以下であることがより好ましい（Ｌ２／Ｌ１≦１／１００）。この比率（Ｌ２／Ｌ１）を１／２０以下として、重複部分３０１をできる限り短くすることで、フレキシブルプリント配線板１の屈曲性への影響を抑制することができる。 Further, the ratio (L 2 / L 1 ) of the length L 2 of the overlapping portion 301 to the total length L 1 of the first coverlay 30 is preferably 1/20 or less (L 2 / L 1 ≦ 1 /). 20), more preferably 1/100 or less (L 2 / L 1 ≦ 1/100). By setting this ratio (L 2 / L 1 ) to 1/20 or less and shortening the overlapping portion 301 as much as possible, it is possible to suppress the influence on the flexibility of the flexible printed wiring board 1.
　第１のカバーレイ３０を、接着剤が塗布された樹脂フィルムから形成する場合には、プレス装置を用いた熱プレス時のプレス圧力やプレス温度を最適化することで、外側層３１からの内側層３２のはみ出し量を調整することができるので、上述の図３に示す第１のカバーレイ３０の端部の階段形状を形成することができる。なお、第１のカバーレイ３０の端部の階段形状を形成するために、プレス装置で使用されるクッション材の厚みや材質等を最適化してもよい。 When the first coverlay 30 is formed from a resin film coated with an adhesive, the press pressure and the press temperature during hot pressing using a press device are optimized to optimize the press pressure and the press temperature from the outer layer 31 to the inner side. Since the amount of protrusion of the layer 32 can be adjusted, the staircase shape of the end portion of the first coverlay 30 shown in FIG. 3 can be formed. The thickness and material of the cushion material used in the press device may be optimized in order to form the staircase shape at the end of the first coverlay 30.
　これに対し、印刷や塗布により内側層３２を形成する場合には、外側層３１の先端３１２が内側層３１の先端よりも重複部３０１の内側に位置するように、外側層３１を形成すればよい。 On the other hand, when the inner layer 32 is formed by printing or coating, the outer layer 31 should be formed so that the tip 312 of the outer layer 31 is located inside the overlapping portion 301 with respect to the tip of the inner layer 31. good.
　なお、第１のカバーレイ３０の重複部分３０１の形状は、上記のような階段形状に特に限定されない。図４は本実施形態における重複部分の端部の第１変形例を示す断面図であり、図５は本実施形態における重複部分の端部の第２変形例を示す断面図である。 The shape of the overlapping portion 301 of the first coverlay 30 is not particularly limited to the staircase shape as described above. FIG. 4 is a cross-sectional view showing a first modification of the end portion of the overlapping portion in the present embodiment, and FIG. 5 is a cross-sectional view showing a second modification example of the end portion of the overlapping portion in the present embodiment.
　例えば、図４に示すように、第１のカバーレイ３０の内側層３２の端部３２１の厚みが、当該第１のカバーレイ３０の先端３０２側に向かうに従って薄くなってもよい。これにより、図３に示す場合と比較して、内側層３２の先端３２２での配線パターン２０から第２のカバーレイ４０の表面までの厚みＤ３を小さくすることができ（Ｄ１＞Ｄ３）、フレキシブルプリント配線板１の屈曲時の配線パターン２０への応力集中を一層緩和することができる。なお、Ｄ１は、図３に示す例において、内側層３２の先端３２２での配線パターン２０から第２のカバーレイ４０の表面までの厚みである。 For example, as shown in FIG. 4, the thickness of the end portion 321 of the inner layer 32 of the first cover lay 30 may become thinner toward the tip 302 side of the first cover lay 30. As a result, the thickness D 3 from the wiring pattern 20 at the tip 322 of the inner layer 32 to the surface of the second coverlay 40 can be reduced as compared with the case shown in FIG. 3 (D 1 > D 3 ). ), The stress concentration on the wiring pattern 20 when the flexible printed wiring board 1 is bent can be further relaxed. Note that D 1 is the thickness from the wiring pattern 20 at the tip 322 of the inner layer 32 to the surface of the second coverlay 40 in the example shown in FIG.
　同様に、第１のカバーレイ３０の外側層３１の端部３１１の厚みが、当該第１のカバーレイ３０の先端３０２側に向かうに従って薄くなってもよい。これにより、図３に示す場合と比較して、外側層３１の先端３１２での配線パターン２０から第２のカバーレイ４０の表面までの厚みＤ４を小さくすることができ（Ｄ２＞Ｄ４）、フレキシブルプリント配線板１の屈曲時の配線パターン２０への応力集中を一層緩和することができる。なお、Ｄ２は、図３に示す例において、外側層３１の先端３１２での配線パターン２０から第２のカバーレイ４０の表面までの厚みである。 Similarly, the thickness of the end portion 311 of the outer layer 31 of the first cover lay 30 may become thinner toward the tip 302 side of the first cover lay 30. As a result, the thickness D 4 from the wiring pattern 20 at the tip 312 of the outer layer 31 to the surface of the second coverlay 40 can be reduced as compared with the case shown in FIG. 3 (D 2 > D 4 ). ), The stress concentration on the wiring pattern 20 when the flexible printed wiring board 1 is bent can be further relaxed. Note that D 2 is the thickness from the wiring pattern 20 at the tip 312 of the outer layer 31 to the surface of the second coverlay 40 in the example shown in FIG.
　外側層３１を樹脂フィルムで形成する場合には、当該樹脂フィルムの端部をエッチングや研磨することで、外側層３１の端部３１１の厚みを徐々に薄くすることができる。一方、外側層３１を印刷や塗布により形成する場合には、印刷条件（例えば、印刷版のメッシュの設計、スキージ圧、印刷速度等）や塗布条件（例えば、塗布量、基材の相対的な送り速度等）を最適化することで、外側層３１の端部３１１の厚みを徐々に薄くすることができる。内側層３２についても同様に、印刷条件や塗布条件を最適化することで、内側層３２の端部３２１の厚みを徐々に薄くすることができる。 When the outer layer 31 is formed of a resin film, the thickness of the end 311 of the outer layer 31 can be gradually reduced by etching or polishing the end of the resin film. On the other hand, when the outer layer 31 is formed by printing or coating, the printing conditions (for example, the design of the mesh of the printing plate, the squeegee pressure, the printing speed, etc.) and the coating conditions (for example, the coating amount and the relative of the base material) are used. By optimizing the feed rate, etc.), the thickness of the end portion 311 of the outer layer 31 can be gradually reduced. Similarly, by optimizing the printing conditions and coating conditions for the inner layer 32, the thickness of the end portion 321 of the inner layer 32 can be gradually reduced.
　なお、内側層３２の端部３２１と外側層３１の端部３１１のいずれか一方が、第１のカバーレイ３０の先端３０２側に向かうに従って薄くなっていればよい。 It is sufficient that either the end portion 321 of the inner layer 32 or the end portion 311 of the outer layer 31 becomes thinner toward the tip 302 side of the first coverlay 30.
　また、図５に示すように、第１のカバーレイ３０の内側層３２の端部３２１の厚みが、当該第１のカバーレイ３０の先端３０２側に向かうに従って薄くなっていると共に、この薄くなっている内側層３２の端部３２１の上に外側層３１の端部３１１がせり出していてもよい。これにより、第１のカバーレイ３０の先端３０側に向かうに従って、外側層３１の端部３１１全体がベースフィルム１０に近づいている。従って、図３に示す場合と比較して、外側層３１の先端３１２での配線パターン２０から第２のカバーレイ４０の表面までの厚みＤ５を小さくすることができ（Ｄ２＞Ｄ５）、フレキシブルプリント配線板１の屈曲時の配線パターン２０への応力集中を一層緩和することができる。 Further, as shown in FIG. 5, the thickness of the end portion 321 of the inner layer 32 of the first cover lay 30 becomes thinner and thinner toward the tip 302 side of the first cover lay 30. The end portion 311 of the outer layer 31 may protrude onto the end portion 321 of the inner layer 32. As a result, the entire end 311 of the outer layer 31 approaches the base film 10 toward the tip 30 side of the first coverlay 30. Therefore, the thickness D 5 from the wiring pattern 20 at the tip 312 of the outer layer 31 to the surface of the second coverlay 40 can be reduced as compared with the case shown in FIG. 3 (D 2 > D 5 ). The stress concentration on the wiring pattern 20 when the flexible printed wiring board 1 is bent can be further relaxed.
　以上のように、本実施形態では、ベースフィルム１０上に配置されるカバーレイを２つに分割することで、大型或いは長尺のプリント配線板１を製造する場合であっても既存の装置を用いてカバーレイ３０，４０をベースフィルム１０に積層することができ、配線板１の高コスト化の抑制を図ることができる。 As described above, in the present embodiment, by dividing the coverlay arranged on the base film 10 into two, the existing apparatus can be used even when a large-sized or long printed wiring board 1 is manufactured. The coverlays 30 and 40 can be laminated on the base film 10 by using the cover lays 30 and 40, and the cost increase of the wiring board 1 can be suppressed.
　また、本実施形態では、第２のカバーレイ４０の一部を第１のカバーレイ３０に重ねることで、カバーレイを２つに分割した場合でも、カバーレイ３０，４０同士の間から配線パターン２０が露出してしまうことを防止することができる。 Further, in the present embodiment, by superimposing a part of the second cover lay 40 on the first cover lay 30, even when the cover lay is divided into two, the wiring pattern is formed between the cover lays 30 and 40. It is possible to prevent the 20 from being exposed.
　さらに、本実施形態では、内側層３２の先端３２２を外側層３１の先端３１２よりも第１のカバーレイ３０の先端３０２側に位置させることで、フレキシブルプリント配線板１の屈曲時に応力を分散させている。これにより、フレキシブルプリント配線板１の屈曲時に生じる応力集中を緩和することができ、配線パターン２０の断線の発生を抑制することができる。 Further, in the present embodiment, the tip 322 of the inner layer 32 is positioned closer to the tip 302 of the first coverlay 30 than the tip 312 of the outer layer 31, so that the stress is dispersed when the flexible printed wiring board 1 is bent. ing. As a result, the stress concentration that occurs when the flexible printed wiring board 1 is bent can be alleviated, and the occurrence of disconnection of the wiring pattern 20 can be suppressed.
　また、内側層３２の先端３２２を外側層３１の先端３１２よりも第１のカバーレイ３０の先端３０２側に位置させることで、硬い外側層３１が配線パターン２０に直接接触してしまうのを防止することもできる。 Further, by locating the tip 322 of the inner layer 32 closer to the tip 302 of the first coverlay 30 than the tip 312 of the outer layer 31, it is possible to prevent the hard outer layer 31 from coming into direct contact with the wiring pattern 20. You can also do it.
　なお、以上説明した実施形態は、本発明の理解を容易にするために記載されたものであって、本発明を限定するために記載されたものではない。したがって、上記の実施形態に開示された各要素は、本発明の技術的範囲に属する全ての設計変更や均等物をも含む趣旨である。 It should be noted that the embodiments described above are described for facilitating the understanding of the present invention, and are not described for limiting the present invention. Therefore, each element disclosed in the above-described embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.
　例えば、上述の実施形態では、内側層３２の先端３２２が外側層３１の先端３１２よりも第１のカバーレイ３０の先端３０２側に位置しているが、第１のカバーレイ３０の端部の形状は特にこれに限定されない。プリント配線板１の長手方向（図中のＸ方向）に沿って、内側層３２の先端３２２が、外側層３１の先端３１２と一致していてもよい。 For example, in the above embodiment, the tip 322 of the inner layer 32 is located closer to the tip 302 of the first cover lay 30 than the tip 312 of the outer layer 31, but the end of the first cover lay 30. The shape is not particularly limited to this. The tip 322 of the inner layer 32 may coincide with the tip 312 of the outer layer 31 along the longitudinal direction (X direction in the drawing) of the printed wiring board 1.
　また、上述の実施形態では、第１のカバーレイ３０が２層構造を有しているが、第１のカバーレイ３０を３以上の層で構成してもよい。 Further, in the above-described embodiment, the first coverlay 30 has a two-layer structure, but the first coverlay 30 may be composed of three or more layers.
１…プリント配線板
　１０…ベースフィルム
　　１１…上面
　２０…配線パターン
　　２１…端子部
　３０…第１のカバーレイ
　　　３０１…重複部分
　　　３０２…先端
　　３１…外側層
　　　３１１…端部
　　　３１２…先端
　　３２…内側層
　　　３２１…端部
　　　３２２…先端
　４０…第２のカバーレイ
　　　４０１…先端部分 1 ... Printed wiring board 10 ... Base film 11 ... Top surface 20 ... Wiring pattern 21 ... Terminal part 30 ... First coverlay 301 ... Overlapping part 302 ... Tip 31 ... Outer layer 311 ... End part 312 ... Tip 32 ... Inner layer 321 … End 322… Tip 40… Second coverlay 401… Tip

Claims (5)

  1. 　基材と、
    　前記基材上に配置された配線と、
    　前記配線を覆うように前記基材上に並んで配置された第１及び第２のカバーレイと、を備え、
    　前記第１のカバーレイは、前記第２のカバーレイの一部が重なっている重複部分を有している配線板。     With the base material
    The wiring arranged on the base material and
    The first and second coverlays arranged side by side on the substrate so as to cover the wiring are provided.
    The first cover lay is a wiring board having an overlapping portion where a part of the second cover lay overlaps.
  2. 　請求項１に記載の配線板であって、
    　前記第１のカバーレイは、
    　前記基材に積層されていると共に、前記重複部分に第１の端部を有する第１の層と、
    　前記第１の層に積層されていると共に、前記重複部分に第２の端部を有する第２の層と、を備え、
    　前記第１の端部の先端は、前記第２の端部の先端よりも前記第１のカバーレイの先端側に位置している配線板。     The wiring board according to claim 1.
    The first coverlay is
    A first layer that is laminated on the substrate and has a first end at the overlap.
    A second layer, which is laminated on the first layer and has a second end at the overlapping portion, is provided.
    The tip of the first end is a wiring board located closer to the tip of the first coverlay than the tip of the second end.
  3. 　請求項２に記載の配線板であって、
    　下記の（１）式を満たす配線板。
    　Ｅ１＜Ｅ２　　　・・・　　　（１）
    　但し、上記の（１）式において、Ｅ１は前記第１の層のヤング率であり、Ｅ２は前記第２の層のヤング率である。     The wiring board according to claim 2.
    A wiring board that satisfies the following formula (1).
    E 1 <E 2 ... (1)
    However, in the above equation (1), E 1 is the Young's modulus of the first layer, and E 2 is the Young's modulus of the second layer.
  4. 　請求項２又は３に記載の配線板であって、
    　前記第１及び第２の端部の少なくとも一方の厚みは、前記第１のカバーレイの先端側に向かうに従って薄くなる配線板。     The wiring board according to claim 2 or 3.
    A wiring board in which the thickness of at least one of the first and second ends becomes thinner toward the tip end side of the first coverlay.
  5. 　請求項２～４のいずれか一項に記載の配線板であって、
    　前記第２の端部は、前記第１のカバーレイの先端側に向かうに従って、前記基材に近づく配線板。     The wiring board according to any one of claims 2 to 4.
    The second end portion is a wiring board that approaches the base material toward the tip end side of the first coverlay.
PCT/JP2021/024317 2020-11-12 2021-06-28 Wiring board WO2022102164A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JP2020-188570 2020-11-12
JP2020188570A JP2023182871A (en) 2020-11-12 2020-11-12 wiring board

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WO2022102164A1 true WO2022102164A1 (en) 2022-05-19

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58116269U (en) * 1982-01-30 1983-08-08 日本メクトロン株式会社 flexible circuit board
JP2004031729A (en) * 2002-06-27 2004-01-29 Nippon Mektron Ltd Flexible circuit board and manufacturing method thereof
JP2010287781A (en) * 2009-06-12 2010-12-24 Fujikura Ltd Flexible printed board, and method of manufacturing the same
JP2015058691A (en) * 2013-09-20 2015-03-30 三井化学東セロ株式会社 Multilayer release film

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS58116269U (en) * 1982-01-30 1983-08-08 日本メクトロン株式会社 flexible circuit board
JP2004031729A (en) * 2002-06-27 2004-01-29 Nippon Mektron Ltd Flexible circuit board and manufacturing method thereof
JP2010287781A (en) * 2009-06-12 2010-12-24 Fujikura Ltd Flexible printed board, and method of manufacturing the same
JP2015058691A (en) * 2013-09-20 2015-03-30 三井化学東セロ株式会社 Multilayer release film

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TW202220503A (en) 2022-05-16

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