JP2009212151A - Wiring board and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To prevent short-circuit between wiring circuits in a manufacturing method of a wiring board. <P>SOLUTION: In the method for manufacturing the wiring board 10, a plurality of lead wiring layers 31 to 37 are formed in an insulating substrate 16 placed in a connector terminal part with silver paste. The insulating substrate 16 where the lead wiring layers are formed is covered with conductive paste and a conductive layer 20 is formed. The conductive layer formed on a circuit board body-side of the connector terminal part is made into an uneven shape, and recesses 42 are formed between the respective lead wiring layers. The circuit board body-side of the connector terminal part in the conductive layer formed in the uneven shape is coated with insulating paste, and a protection layer 22 is formed. A tip side of the connector terminal part in the recess 42 is exposed and insulating grooves 44 are formed. The conductive layers formed between the lead wiring layers are removed by prescribed width by laser processing, and insulating paths 46 to 49 are formed. The insulating paths are connected to the insulating grooves 44, and the lead wiring layers are insulated. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a wiring board and a manufacturing method thereof, and more particularly to a wiring board including a circuit board main body and a connector terminal connected to the circuit board main body and a manufacturing method thereof.

  In recent years, printed wiring boards incorporated in various electronic devices such as mobile phones and digital cameras are increasingly required to be smaller, thinner, lighter and more multifunctional, and to reduce component costs. For example, a membrane wiring board is widely used as a wiring board that is advantageous in reducing component costs.

  Patent Document 1 discloses a method of manufacturing a wiring board by forming a silver circuit with an silver paste on an insulating resin substrate, printing carbon on a connector end of the silver circuit, and printing a resist layer on a portion other than the connector end. Is described.

In Patent Document 2, a silver circuit is formed with a silver paste on an insulating resin substrate, a resist layer is formed at a portion other than the connector end portion in the silver circuit, a conductive layer is formed at the connector end portion, and a silver pattern in the silver circuit is formed. A method of manufacturing a wiring board by removing a conductive layer existing between each of the above by laser light irradiation is described.
JP-A-8-236241 JP 2003-209338 A

  By the way, according to the method for manufacturing a wiring board described in Patent Document 1, in a portion where the silver pattern interval in the silver circuit is narrowed, such as a connector end, the silver circuit is caused by ink bleeding or the like when printing carbon. There is a possibility of short circuit between patterns. In the method for manufacturing a wiring board described in Patent Document 2, a step is generated by forming the conductive layer so as to partially overlap the resist layer so that the silver circuit is not exposed. When removing, the focal point of the laser beam is shifted at the stepped portion, the spot diameter is widened, and the silver circuit may be short-circuited without sufficiently removing the conductive layer.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a wiring board capable of preventing a short circuit of a wiring circuit and a method for manufacturing the same.

  A method for manufacturing a wiring board according to the present invention includes a circuit board main body and a connector terminal connected to the circuit board main body. A lead wiring layer forming step of forming a plurality of lead wiring layers with silver paste, and forming a conductive layer by covering the insulating substrate on which the lead wiring layer is formed with a conductive paste, and the circuit of the connector terminal portion A conductive layer forming step for forming a concave portion between the respective lead wiring layers by forming a conductive layer formed on the substrate main body side into a concavo-convex shape, and a circuit board main body of the connector terminal portion in the conductive layer formed in the concavo-convex shape Forming a protective layer by covering the side with an insulating paste, and forming an insulating groove by exposing the tip side of the connector terminal portion in the recess; and The laser processing which insulates each said lead wiring layer by removing the conductive layer formed between each lead wiring layer by laser processing by a predetermined width, forming an insulating path, and connecting the said insulating path to the said insulating groove And a process.

  In the method for manufacturing a wiring board according to the present invention, the conductive paste contains a conductive filler made of conductive powder formed of a noble metal having a surface that is less ionized than silver.

  In the method for manufacturing a wiring board according to the present invention, the conductive paste contains a conductive filler containing carbon powder.

  In the method for manufacturing a wiring board according to the present invention, the insulating substrate is formed of a synthetic resin that absorbs less laser light than the conductive layer.

  In the method for manufacturing a wiring board according to the present invention, the plurality of lead wiring layers are arranged in a staggered manner and formed on an insulating substrate.

  In the method for manufacturing a wiring board according to the present invention, the interval between the plurality of lead wiring layers formed on the tip side of the connector terminal portion is such that the plurality of lead wirings formed on the circuit board main body side of the connector terminal portion. It is characterized by being smaller than the layer spacing.

  In the method for manufacturing a wiring board according to the present invention, the plurality of lead wiring layers coated with the conductive layer are connected to a connector.

  In the method for manufacturing a wiring board according to the present invention, the insulating groove is formed larger than a width of the insulating path.

  The wiring board according to the present invention is a wiring board comprising a circuit board body and a connector terminal connected to the circuit board body, wherein a plurality of lead wiring layers are formed with silver paste on an insulating board placed on the connector terminal portion. And forming a conductive layer by coating a conductive paste on the insulating substrate on which the lead wiring layer is formed, and forming the conductive layer formed on the circuit board body side of the connector terminal portion into an uneven shape, A concave portion is formed between the lead wiring layers, and a protective layer is formed by covering an insulating paste on the circuit board body side of the connector terminal portion of the conductive layer formed in an uneven shape, and the connector terminal in the concave portion An insulating groove is formed by exposing the front end side of each part, and a conductive layer formed between each of the lead wiring layers is removed by laser processing with a predetermined width to form an insulating path. By connecting road in the insulating groove, characterized in that it is manufactured by insulating the respective lead wire layer.

  According to the wiring board and the manufacturing method thereof according to the present invention, the thickness of the conductive layer formed between the lead wiring layers removed by laser processing can be made substantially constant, so that the defocus of the laser beam can be suppressed. As a result, the conductive layer formed between the lead wiring layers can be more reliably removed by laser processing, so that a short circuit of the wiring circuit can be prevented.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a diagram showing the configuration of the wiring board 10. The wiring board 10 includes a circuit board body 12 and connector terminals 14 connected to the circuit board body 12. A wiring circuit provided on the circuit board body 12 is omitted.

  The connector terminal 14 includes an insulating substrate 16, a silver wiring circuit 18 provided on the insulating substrate 16, a conductive layer 20 covering the insulating substrate 16 provided with the silver wiring circuit 18, and a protection covering a part of the conductive layer 20. And the layer 22.

  The insulating substrate 16 has, for example, a rectangular ribbon shape, and is composed of a flexible insulating synthetic resin film having flexibility.

  The silver wiring circuit 18 includes a plurality of lead wiring layers 31 to 37 formed on the insulating substrate 16. The lead wiring layers 31 to 37 are formed on the insulating substrate 16 with a silver-containing material. The leading ends of the lead wiring layers 31 to 37 are formed in a substantially circular shape or a substantially elliptical shape because they are electrically connected to the external connector terminals. In FIG. 1, seven lead wiring layers are shown, but the number of lead wiring layers is not particularly limited to seven.

  The silver wiring circuit 18 includes a first group of lead wiring layers 31, 33, 35, and 37 and a second group of lead wiring layers 32, 34, and 36. The first group of lead wiring layers 31, 33, 35, and 37 and the second group of lead wiring layers 32, 34, and 36 are arranged substantially in parallel in a so-called zigzag pattern. , 34 and 36 are alternately arranged so that the tips of the first group lead wiring layers 31, 33, 35 and 37 protrude from the tips. Thus, the connector terminals 14 can be formed smaller by arranging the lead wiring layers 31 to 37 in a staggered manner. Of course, depending on other conditions, the arrangement of the lead wiring layers 31 to 37 is not limited to a staggered pattern. The lead wiring layers 31 to 37 are formed such that the wiring interval of each lead wiring layer on the distal end side of the connector terminal 14 is smaller than the wiring interval of each lead wiring layer on the circuit board main body side of the connector terminal 14. It is preferable.

  The conductive layer 20 is covered with the insulating substrate 16 provided with the silver wiring circuit 18 and has a function of suppressing migration such as ion migration. Since the silver-containing material forming the lead wiring layers 31 to 37 easily causes migration, the occurrence of migration can be prevented by covering the lead wiring layers 31 to 37 with the conductive layer 20. The conductive layer 20 is formed of a material having migration resistance, such as a conductive material or a carbon material, which is formed of a noble metal whose surface is less ionized than silver.

  The conductive layer 20 is formed in an uneven shape on the side of the circuit board body 12 of the connector terminal 14. The convex portions 40 of the conductive layer 20 formed in a concavo-convex shape are formed so as to cover the lead wiring layers 31 to 37, respectively, and the concave portions 42 are formed by the insulating substrate 16 as a base between the lead wiring layers 31 to 37, respectively. It is formed to be exposed. Here, the concavo-convex shape is, for example, a comb-like shape, but is not particularly limited to a comb-teeth shape. The uneven shape may be not only a rectangular shape but also a shape having a curvature such as a circular shape or an elliptical shape.

  The protective layer 22 is covered on the circuit board main body side of the connector terminal 14 in the conductive layer 20 formed in an uneven shape, and has a function such as insulation protection. The protective layer 22 is formed of an insulating material for insulation protection or the like. The protective layer 22 is covered by exposing the tip end side of the connector terminal 14 in the conductive layer 20 formed in an uneven shape, and the lead wiring layers 31 to 37 are respectively formed in the concave portions 42 which are exposed without being covered with the protective layer 22. An insulating groove 44 is formed for insulating between the two.

  Insulation paths 46 to 49 for insulating the lead wiring layers 31 to 37 are formed between the lead wiring layers 31 to 37 with a predetermined width. The insulating paths 46 to 49 are provided between the lead wiring layers in the second group of lead wiring layers 32, 34, and 36, for example, and are further branched to form the first group of lead wiring layers 31, 33, and 35. , 37 and the second group lead wiring layers 32, 34, 36. And the insulation between the lead wiring layers 31-37 is each ensured by connecting the insulation paths 46-49 with the insulation groove | channel 44 by the circuit board main body 12 side of the connector terminal 14. FIG.

  Next, a method for manufacturing the wiring board 10 will be described.

  FIG. 2 is a flowchart showing a method for manufacturing the wiring board 10. The manufacturing method of the wiring substrate 10 includes a lead wiring layer forming step (S10) for forming a plurality of lead wiring layers 31 to 37 on the insulating substrate 16, a conductive layer forming step (S12) for forming the conductive layer 20, and a protective layer. The protective layer forming step (S14) for forming the insulating layer 22 and the laser processing step (S16) for forming the insulating paths 46 to 49 by laser processing the conductive layer 20 are provided.

  The lead wiring layer forming step (S10) is a step of forming a plurality of lead wiring layers 31 to 37 with silver paste on the insulating substrate 16 placed on the connector terminal portion 14a. 3A and 3B are views showing a state in which a plurality of lead wiring layers 31 to 37 are formed on the insulating substrate 16, FIG. 3A is a plan view, and FIG. 3B is a cross-sectional view along the line AA. It is.

  For the insulating substrate 16, for example, an insulating synthetic resin film formed of a synthetic resin such as polyethylene terephthalate resin (PET) or polyimide resin (PI) is used. The insulating substrate 16 is preferably formed of a synthetic resin film that absorbs less laser light than the conductive layer 20. This is because, as will be described later, since the insulating paths 46 to 49 are formed by removing the conductive layer 20 with a predetermined width by laser processing, damage to the insulating substrate 16 during laser processing can be suppressed. As the silver paste, a silver paste material generally used in the production of a printed wiring board can be used. The silver paste includes silver ink and the like.

  The lead wiring layers 31 to 37 are formed, for example, by screen printing a silver paste on the insulating substrate 16. The outer diameter of the tip 50 of the lead wiring layers 31 to 37 is, for example, 0.16 mm, and the width (W) of the lead wiring layers 31 to 37 is, for example, 0.1 mm to 0.2 mm. The lead wiring layers 31 to 37 are arranged in a zigzag pattern, and the wiring pitch (P) is, for example, 0.3 mm.

  Further, the silver wiring is such that the distance (D1) between the lead wiring layers 31 to 37 on the distal end side of the connector terminal 14 is smaller than the distance (D2) between the lead wiring layers 31 to 37 on the circuit board main body 12 side of the connector terminal 14. A circuit 18 is provided. The distance (D1) between the lead wiring layers 31 to 37 is, for example, 0.1 mm, and the distance (D2) between the lead wiring layers 31 to 37 is, for example, 0.5 mm.

  In the conductive layer forming step (S12), the conductive substrate 20 is formed by covering the insulating substrate 16 on which the lead wiring layers 31 to 37 are formed with a conductive paste, and the conductive layer 20 is formed on the circuit board main body 12 side of the connector terminal portion 14a. In this step, the conductive layer 20 is formed in a concavo-convex shape, and the concave portions 42 are formed between the lead wiring layers 31 to 37, respectively. 4A and 4B are diagrams showing a state in which the conductive layer 20 is covered. FIG. 4A is a plan view, and FIG. 4B is a cross-sectional view along the line AA.

  The conductive paste contains a conductive filler and a binder. For the conductive filler, a noble metal whose surface has a lower ionization tendency than silver, for example, a conductive powder or carbon powder made of platinum (Pt) or gold (Au) is used. Note that the conductive paste includes conductive ink and the like. The conductive paste is coated on the insulating substrate 16 in which 31 to 37 are formed with a plurality of lead wiring layers, for example, by screen printing or the like. The conductive layer 20 provided at the end of the connector terminal portion 14a on the side of the circuit board body 12 is formed in a concavo-convex shape, and between the convex portion 40 covering the lead wiring layers 31 to 37 and the lead wiring layers 31 to 37, respectively. Screen printing or the like is performed so as to form a recess 42 exposing the insulating substrate 16.

  In the protective layer forming step (S14), an insulating paste is coated on the side of the circuit board body 12 of the connector terminal portion 14a of the conductive layer 20 formed in the concavo-convex shape to form the protective layer 22, and the connector terminal in the concave portion 42 This is a process of forming the insulating groove 44 by exposing the tip side of the portion 14a. FIGS. 5A and 5B are diagrams showing a state in which the protective layer 22 is covered. FIG. 5A is a plan view and FIG. 5B is a cross-sectional view taken along the line AA.

  A solder resist or the like is used for the insulating paste. As the solder resist, a resist material generally used in the production of printed wiring boards can be used. The solder resist or the like is coated on a part of the conductive layer 20 formed in an uneven shape by screen printing or the like, for example. Further, since the protective layer 22 is covered by exposing the tip end side of the connector terminal portion 14a in the conductive layer 20 formed in a concavo-convex shape, the recess 42 is insulated between the lead wiring layers 31 to 37, respectively. An insulating groove 44 is formed.

  In the laser processing step (S16), the insulating layers 46 to 49 are formed by removing the conductive layer 20 formed between the lead wiring layers 31 to 37 with a predetermined width by laser processing to insulate the insulating paths 46 to 49. This is a step of insulating the lead wiring layers 31 to 37 by connecting them to the grooves 44. 6A and 6B are views showing a state after laser processing, where FIG. 6A is a plan view, and FIG. 6B is a cross-sectional view along the line AA.

  By removing a predetermined width of the conductive layer 20 formed between the lead wiring layers 31 to 37 by laser processing, insulating paths 46 to 49 are formed, and the lead wiring layers 31 to 37 are insulated. For example, the insulating path 46 is formed between the lead wiring layer 31 and the lead wiring layer 32 and is connected to the insulating groove 44. Thereby, the lead wiring layer 31 is insulated. For example, the insulating path 47 is branched from the first path 47 a formed between the lead wiring layer 32 and the lead wiring layer 34 and the first path 47 a, and between the lead wiring layer 32 and the lead wiring layer 33. The second path 47b is formed by the first path 47a and the third path 47c is formed between the lead wiring layer 33 and the lead wiring layer 34. The lead wiring layer 32 and the lead wiring layer 33 are insulated by connecting the second path 47b and the third path 47c to the insulating groove 44, respectively.

  In the insulating path 47, the first path 47 a is formed at a substantially central portion between the lead wiring layer 32 and the lead wiring layer 34, and the second path 47 b is a substantially central portion between the lead wiring layer 32 and the lead wiring layer 33. It is preferable that the third path 47c is formed at a substantially central portion between the lead wiring layer 33 and the lead wiring layer 34. The first path 47a is formed at a part that is substantially equidistant from the lead wiring layer 32 and the lead wiring layer 34, and the second path 47b is formed at a part that is substantially equidistant from the lead wiring layer 32 and the lead wiring layer 33. In addition, by forming the third path 47c at a portion that is substantially equidistant from the lead wiring layer 33 and the lead wiring layer 34, a part of the lead wiring layers 32, 33, and 34 is removed during laser processing. It is because it can suppress. The width of the insulating path 47 is preferably substantially the same in the first path 47a, the second path 47b, and the third path 47c. The insulating path 48 is formed in the same manner as the insulating path 47, the insulating path 49 is formed in the same manner as the insulating path 46, and the lead wiring layers 34 to 37 are insulated.

  Here, since the thickness of the conductive layer 20 in the portion where the insulating paths 46 to 49 are formed is substantially constant, the laser beam is defocused by a step or the like during laser processing, and the spot diameter is widened. As a result, the lead wiring layers 31 to 37 adjacent to the conductive layer 20 are removed, and the conductive layer 20 remains where the insulating paths 46 to 49 are formed due to a decrease in energy per unit area due to the spread of the spot diameter. Is suppressed. For laser processing, for example, a laser trimming apparatus using a carbon dioxide laser, a YAG laser, an excimer laser, or the like can be used.

  The insulating groove 44 is preferably formed larger than the spot diameter of the laser beam. During laser processing, when the insulating paths 46 to 49 are connected to the insulating groove 44, the laser beam comes into contact with the protective layer 22, so that the laser beam is defocused at a step at the boundary of the protective layer 22 and the spot diameter is widened. This is because it can be avoided. The insulating groove 44 is preferably formed larger than the width of the insulating paths 46 to 49. This is because the insulating paths 46 to 49 are easily connected by the insulating groove 44 during laser processing. Thus, the connector terminal 14 connected to the circuit board body 12 is manufactured, and the manufacturing of the wiring board 10 is completed.

  According to the above configuration, the thickness of the conductive layer removed by laser processing in forming the insulating path can be made substantially constant, so that defocusing of the laser beam can be suppressed, and the conductive layer between the lead wiring layers can be more reliably removed. it can. Thereby, a short circuit between the wiring circuits can be prevented more reliably, so that a wiring board with a reduced wiring pitch can be manufactured. Further, since the processing can be performed without changing the focal length of the laser during the laser processing, the productivity of the wiring board is further improved.

  According to the above configuration, the migration resistance can be further improved by including in the conductive paste a conductive powder made of a noble metal whose surface is less ionized than silver or a conductive filler made of carbon powder. .

  According to the above configuration, by forming the insulating substrate with a material that absorbs less laser light than the conductive layer, damage to the insulating substrate in the laser processing step can be suppressed.

  According to the above configuration, the connector terminals can be made smaller by arranging the plurality of lead wiring layers on the insulating substrate in a staggered manner.

(Example)
A wiring board was manufactured by three types of manufacturing methods, and the inter-terminal insulation resistance of connector terminals provided on the wiring board was evaluated. First, the manufacturing method of the wiring board in Example 1 is demonstrated. The configuration of the wiring board manufactured by the manufacturing method of Example 1 is the same as the configuration shown in FIG.

  In the lead wiring layer forming step (S10), a silver paste was screen printed on a polyethylene terephthalate (PET) substrate, which is the insulating substrate 16, and dried to form a plurality of lead wiring layers 31 to 37 arranged in a staggered manner. A polyethylene terephthalate film (model number: HSL, thickness: 100 μm) manufactured by Teijin DuPont Films, Inc. was used for the polyethylene terephthalate (PET) substrate. As the silver paste, a conductive ink (model number: DX-351H-30) mainly composed of silver manufactured by Toyobo Co., Ltd. was used. And the width | variety of the lead wiring layers 31-37 was 0.1 mm, and the front-end | tip part of the lead wiring layers 31-37 was made into the substantially circular shape of diameter 0.16mm. Further, the distance between the lead wiring layers 31 to 37 on the distal end side of the connector terminal portion 14a is set to 0.3 mm, and the distance between the lead wiring layers 31 to 37 on the circuit board main body 12 side (connector terminal portion base) of the connector terminal portion 14a is set to be 0.3 mm. The lead wiring layers 31 to 37 on the circuit board body 12 side were formed in a comb-teeth shape to form a comb-teeth wiring.

  In the conductive layer forming step (S12), conductive carbon paste was screen printed on the polyethylene terephthalate (PET) substrate on which the lead wiring layers 31 to 37 were formed, and a conductive carbon layer as the conductive layer 20 was formed. As the conductive carbon paste, a conductive carbon paste (model number 581SS) manufactured by Moritex Corporation was used. The conductive carbon layer is formed in a comb-teeth shape at the portions of the lead wiring layers 31 to 37 formed in a comb-teeth shape at a pitch of 0.5 mm on the circuit board body 12 side of the connector terminal portion 14a. Conductive carbon paste was screen printed. Here, the lead wiring layers 31 to 37 are covered with the comb tooth portions that are the convex portions 40 of the conductive carbon layer, and the polyethylene terephthalate is between the comb tooth portions that are the concave portions 42 of the conductive carbon layer and the comb tooth portions. A conductive carbon paste was screen printed so that the (PET) substrate was exposed.

  In the protective layer forming step (S14), a solder resist is screen-printed so as to cover the side of the circuit board body 12 of the connector terminal portion 14a in the conductive carbon layer formed in a comb shape, and a resist layer which is the protective layer 22 Formed. A solder resist (model number: SN9000) manufactured by Hitachi Chemical Co., Ltd. was used as the solder resist. The resist layer is covered with screen printing or the like so that the tip end side of the connector terminal portion 14a in the conductive carbon layer formed in a comb-teeth shape is exposed, and is exposed without being covered with the resist layer. Insulating grooves 44 for insulating between the lead wiring layers 31 to 37 were formed between the teeth.

  In the laser processing step (S16), the conductive carbon layers formed between the lead wiring layers 31 to 37, respectively, were removed by laser processing with a predetermined width to form insulating paths 46 to 49. Then, the insulating paths 46 to 49 were respectively connected to the insulating grooves 44 to insulate the lead wiring layers 31 to 37 by providing gaps.

  Next, a method for manufacturing a wiring board in Comparative Example 1 will be described.

  FIG. 7 is a diagram illustrating a configuration of connector terminals in a wiring board manufactured by the manufacturing method of Comparative Example 1. A silver paste was screen-printed on a polyethylene terephthalate (PET) substrate 60 provided with connector terminals and dried to form a plurality of silver wiring layers 61 to 67 arranged in a staggered manner. The width (X1) of the silver wiring layers 61 to 67 was 0.05 mm, and the pitch (X2) of the silver wiring layers 61 to 67 was 0.3 mm pitch. Next, the conductive carbon layer 68 was formed by screen printing a conductive carbon paste on the silver wiring layers 61 to 67. The width (X3) of the conductive carbon layer 68 was 0.20 mm. Further, a resist layer 69 was formed by screen printing with a solder resist except for the connector terminal portion. The same materials as used in Example 1 were used for the polyethylene terephthalate (PET) substrate, silver paste, conductive carbon paste, and solder resist.

  Next, a method for manufacturing a wiring board in Comparative Example 2 will be described.

  FIG. 8 is a diagram showing the configuration of the connector terminals in the wiring board manufactured by the manufacturing method of Comparative Example 2. A silver paste was screen printed on a polyethylene terephthalate (PET) substrate 70 provided with connector terminals and dried to form a plurality of silver wiring layers 71 to 77 arranged in a staggered manner. The width (Y1) of the silver wiring layers 71 to 77 was 0.05 mm, and the pitch (Y2) of the silver wiring layers 71 to 77 was 0.3 mm. The tip portions of the silver wiring layers 71 to 77 were formed in a substantially circular shape having a diameter of 0.16 mm. Next, the resist layer 78 was formed by screen-printing a solder resist in places other than the contact part of the silver wiring layers 71-77. A conductive carbon layer 79 was formed by screen printing a conductive carbon paste so that the exposed silver wiring layers 71 to 77 and a part of the resist layer 78 were covered. Thereafter, the conductive carbon layer coated between the silver wiring layers 71 to 77 and a part of the resist layer 78 is removed by laser processing to form insulating regions 80 that insulate the silver wiring layers 71 to 77, respectively. did. The same materials as used in Example 1 were used for the polyethylene terephthalate (PET) substrate, silver paste, conductive carbon paste, and solder resist.

Next, about the wiring board manufactured with the manufacturing method of Example 1 and Comparative Examples 1 and 2, the connector terminal was inserted in the connector, and the resistance value was measured using an insulation resistance measuring instrument. The resistance value was measured for the wiring board manufactured in Example 1, using the lead wiring layers 31, 33, 35, and 37 as positive electrodes and the lead wiring layers 32, 34, and 36 as negative electrodes, and manufactured in Comparative Example 1. For the wiring board, the lead wiring layers 61, 63, 65, and 67 were measured as positive electrodes, and the lead wiring layers 62, 64, and 66 were measured as negative electrodes. For the wiring board manufactured in Comparative Example 2, the lead wiring layers 71, 73, and 75 were measured. , 77 as a positive electrode and lead wiring layers 72, 74, and 76 as a negative electrode. Note that the number of samples (N) was N = 5 for all wiring boards, and an insulation resistance of 1.0 × 10 ⁸ Ω or higher was accepted.

FIG. 9 is a diagram showing the measurement results of the insulation resistance of the wiring board. In the wiring board manufactured by the manufacturing method of Comparative Example 1, an insulation resistance value lower than 1.0 × 10 ⁸ Ω was measured in all samples. This is due to the occurrence of a short circuit due to bleeding of the conductive ink and displacement of printing. In the wiring board manufactured by the manufacturing method of Comparative Example 2, an insulation resistance value lower than 1.0 × 10 ⁸ Ω was measured for one of the five samples. In the manufacturing method of Comparative Example 2, when the conductive carbon layer 79 is coated on the polyethylene terephthalate (PET) substrate 70 on which the silver wiring layers 71 to 77 are formed, the resist layer is not exposed so that the silver wiring layers 71 to 77 are not exposed. The conductive carbon layer 79 is covered with a part of 78. Therefore, when the conductive carbon layer formed between the silver wiring layers 71 to 77 is removed by laser processing to form the insulating region 80, the focus of the laser beam is caused by the step formed at the boundary of the resist layer 78. This is because the spot diameter increases and the conductive carbon layer cannot be sufficiently removed.

On the other hand, in the wiring board manufactured by the manufacturing method of Example 1, an insulation resistance value of 1.0 × 10 ⁸ Ω or more was obtained in all samples. According to the manufacturing method of Example 1, it was confirmed that a wiring board having connector terminals with a pitch (P) of the lead wiring layers 31 to 37 of 0.3 mm can be manufactured. In addition, according to the manufacturing method of Example 1, it is confirmed that laser processing can be stably performed after screen printing of the solder resist, so that it is possible to reliably remove the conductive carbon layer and prevent a short circuit between the lead wiring layers. did it.

In embodiment which concerns on this invention, it is a figure which shows the structure of a wiring board. 4 is a flowchart showing a method for manufacturing a wiring board in the embodiment according to the present invention. In embodiment which concerns on this invention, it is a figure which shows the state which formed the several lead wiring layer in the insulated substrate. In embodiment which concerns on this invention, it is a figure which shows the state which coat | covered the conductive layer. In embodiment which concerns on this invention, it is a figure which shows the state which coat | covered the protective layer. In embodiment which concerns on this invention, it is a figure which shows the state after laser processing. 6 is a diagram showing a configuration of connector terminals in a wiring board manufactured by a manufacturing method of Comparative Example 1. FIG. 6 is a diagram showing a configuration of connector terminals in a wiring board manufactured by a manufacturing method of Comparative Example 2. FIG. In embodiment which concerns on this invention, it is a figure which shows the insulation resistance measurement result of a wiring board.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Wiring board 12 Circuit board main body 14 Connector terminal 14a Connector terminal part 16 Insulating board 18 Silver wiring circuit 20 Conductive layer 22 Protective layer 31-37 Lead wiring layer 40 Convex part 42 Concave part 44 Insulating groove 46-49 Insulating path 47a 1st path 47b Second path 47c Third path 50 Lead wiring layer tip 60, 70 Polyethylene terephthalate (PET) substrate 61-67, 71-77 Silver wiring layer 68, 79 Conductive carbon layer 69, 78 Resist layer 80 Insulating region

Claims (9)

In a method for manufacturing a wiring board comprising a circuit board main body and a connector terminal connected to the circuit board main body,
A lead wiring layer forming step of forming a plurality of lead wiring layers with silver paste on an insulating substrate placed on the connector terminal portion;
A conductive layer is formed by coating a conductive paste on the insulating substrate on which the lead wiring layer is formed, and the conductive layer formed on the circuit board main body side of the connector terminal portion is formed in a concavo-convex shape so that each of the lead wiring layers A conductive layer forming step of forming a recess between
A protective layer is formed by coating an insulating paste on the circuit board body side of the connector terminal portion of the conductive layer formed in a concavo-convex shape, and an insulating groove is formed by exposing the distal end side of the connector terminal portion in the recess. A protective layer forming step to be formed;
Laser processing for forming an insulating path by removing a conductive layer formed between the respective lead wiring layers with a predetermined width by laser processing, and insulating each of the lead wiring layers by connecting the insulating path to the insulating groove Process,
A method for manufacturing a wiring board, comprising: In the manufacturing method of the wiring board of Claim 1,
The method of manufacturing a wiring board, wherein the conductive paste contains a conductive filler made of a conductive powder having at least a surface made of a noble metal having a smaller ionization tendency than silver. In the manufacturing method of the wiring board according to claim 1 or 2,
The method for manufacturing a wiring board, wherein the conductive paste contains a conductive filler containing carbon powder. In the manufacturing method of the wiring board as described in any one of Claim 1 to 3,
The method of manufacturing a wiring board, wherein the insulating substrate is formed of a synthetic resin that absorbs less laser light than the conductive layer. In the manufacturing method of the wiring board as described in any one of Claim 1 to 4,
The method for manufacturing a wiring board, wherein the plurality of lead wiring layers are arranged in a staggered pattern on an insulating substrate. In the manufacturing method of the wiring board as described in any one of Claim 1 to 5,
Wiring characterized in that an interval between the plurality of lead wiring layers formed on the distal end side of the connector terminal portion is smaller than an interval between the plurality of lead wiring layers formed on the circuit board main body side of the connector terminal portion. A method for manufacturing a substrate. In the manufacturing method of the wiring board as described in any one of Claim 1 to 6,
A method of manufacturing a wiring board, wherein the plurality of lead wiring layers covered with the conductive layer are connected to a connector. In the manufacturing method of the wiring board as described in any one of Claim 1 to 7,
The method of manufacturing a wiring board, wherein the insulating groove is formed larger than a width of the insulating path. In a wiring board comprising a circuit board body and a connector terminal coupled to the circuit board body,
Form multiple lead wiring layers with silver paste on an insulating substrate placed on the connector terminal,
A conductive layer is formed by coating a conductive paste on the insulating substrate on which the lead wiring layer is formed, and the conductive layer formed on the circuit board main body side of the connector terminal portion is formed in a concavo-convex shape so that each of the lead wiring layers A recess is formed between
A protective layer is formed by coating an insulating paste on the circuit board body side of the connector terminal portion of the conductive layer formed in a concavo-convex shape, and an insulating groove is formed by exposing the distal end side of the connector terminal portion in the recess. Forming,
The conductive layer formed between the respective lead wiring layers is removed with a predetermined width by laser processing to form an insulating path, and each of the lead wiring layers is insulated by connecting the insulating path to the insulating groove. A wiring board manufactured.

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