JP2011044406A - Small-diameter coaxial cable, multilayer wiring board, and manufacturing method of multilayer wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a small-diameter coaxial cable having an advantageous structure for performing terminal processing which is used for forming wiring on a wiring board, to provide a multilayer wiring board having an advantageous structure for making a noise countermeasure which is structured by using the coaxial cable, and to provide an efficient manufacturing method of the multilayer wiring board. <P>SOLUTION: The small-diameter coaxial cable 1 is used to form wiring on the wiring board. The small-diameter cable 1 has an insulation layer 4, a shield layer 6, and a jacket layer 7 which are sequentially formed on the periphery of a center conductor 3, and is constituted by tightly adhering a plurality of fine wires 5 constituting the shield layer 6 integrating them into one body. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a thin coaxial cable having a structure advantageous for performing terminal processing, which is used for forming wiring on a wiring board, and a multilayer wiring having a structure advantageous for noise countermeasures configured using the coaxial cable. The present invention relates to a board and an efficient manufacturing method of the multilayer wiring board.

  In recent years, electronic devices have become more and more sophisticated. In particular, as a printed wiring board installed inside the device by improving the mounting density and increasing the data transmission speed, (1) 2 insulators and wiring patterns are used. Multi-layer wiring board with multi-layered wiring by stacking steps or three or more stages, (2) A type of multi-layer wiring board, wiring by integrating insulated wires covered with polyimide etc. on one or both sides wiring board In some cases, a multilayer wiring board (refer to Patent Document 1) having a structure generally called a multi-wire wiring board is used.

  For the multilayer wiring board (1), various manufacturing methods have been introduced so far, and generally, a special apparatus or process such as a build-up method is required for manufacturing, and therefore, it is generally expensive.

  On the other hand, for the multilayer wiring board with the structure called (2) multi-wire wiring board, a part of the wiring is composed of insulated wires, and the single-sided or double-sided wiring board requires special equipment and processes. Therefore, it can be manufactured at a relatively low cost. In addition, there is an advantage that cross wiring is easy. However, in order to handle high-speed signals, noise countermeasures are usually taken using coaxial cables with a shield layer (shielding layer) as the insulated wires that make up the wiring. When forming the wiring, it is difficult to perform terminal processing (connection) of the coaxial cable on the wiring board when forming the wiring, that is, when performing terminal processing (connection) on the wiring board, the shield layer of the coaxial cable In the past, it was difficult to efficiently connect the shield layer and the center conductor of the coaxial cable to the corresponding wiring on the wiring board with sufficient electrical continuity due to the variation of the multiple thin wires constituting the The wiring is configured by using an insulated wire such as an enameled wire having a structure without a shield layer. Therefore, in that case, there is a problem in noise countermeasures.

  On the other hand, in Patent Document 2 as a prior art document, a core conductor of a coaxial cable is connected to a signal wiring formed on a surface layer of a multilayer printed circuit board having a ground layer therein, and the outer sheath of the coaxial cable is connected to the ground layer. A method is described in which a conductor of a coaxial cable and an outer conductor are connected to corresponding wirings of a multilayer printed board by connecting conductors. In Patent Document 2, the coaxial cable is connected to the multilayer printed circuit board as described above. In the printed circuit board constituting the high-frequency circuit, it is required to directly connect the coaxial cable to the printed circuit board for measurement of circuit characteristics. This is because that.

JP 2002-43749 A JP 2003-338893 A

  According to the conventional multilayer wiring board having a structure called a multi-wire wiring board, as already described, the wiring is configured by using an insulated wire such as an enameled wire having a structure without a shield layer. On the other hand, when the wiring is configured using a coaxial cable, which is preferable for noise countermeasures, it is difficult to perform terminal processing (connection) on the wiring board when forming the wiring. is there.

  Moreover, the method of connecting a coaxial cable to a multilayer printed circuit board described in Patent Document 1 does not form the wiring of the multilayer wiring board using the coaxial cable in the first place, and connects the coaxial cable on the multilayer printed circuit board. It is not intended to solve the problem of terminal processing (connection) described above. Nothing is said about this issue.

  Accordingly, an object of the present invention is to provide a small-diameter coaxial cable having a structure advantageous in performing terminal processing, which is used for forming wiring on a wiring board, and noise configured using the coaxial cable. It is an object of the present invention to easily provide a multilayer wiring board having a structure advantageous in terms of countermeasures, and to provide an efficient manufacturing method of the multilayer wiring board.

  In order to achieve the above object, the invention of claim 1 is a thin coaxial cable used for forming a wiring on a wiring board, wherein an insulator layer, a shield layer, a jacket layer are provided on the circumference of the central conductor. Are provided in order, and a plurality of fine wires constituting the shield layer are closely integrated to provide a small-diameter coaxial cable.

  According to this small-diameter coaxial cable, by adopting the above-described configuration, in particular, by integrally integrating a plurality of fine wires constituting the shield layer, the terminal processing of the coaxial cable on the wiring board ( When the terminal of the coaxial cable is peeled off, the thin wire is not scattered, and for the shield layer, the entire shield layer is simply connected at one location on the outer periphery. It can be efficiently connected with sufficient electrical conduction to the corresponding wiring on the wiring board, and the central conductor can be efficiently connected with sufficient electrical conduction as well. It is possible to provide a small-diameter coaxial cable having a structure advantageous in performing terminal processing on a wiring board in forming.

  According to a second aspect of the present invention, there is provided the small-diameter coaxial cable according to the first aspect, wherein the fine wires constituting the shield layer are closely integrated by heating.

  According to this thin coaxial cable, in addition to the above effects, by adopting the above configuration, for example, as the thin wire constituting the shield layer, when a tin plated copper alloy wire, a silver plated copper alloy wire is employed, The plated surfaces of a tin-plated copper alloy wire and a silver-plated copper alloy wire can be brought into close contact with each other, and the fine wires can be efficiently closely integrated by heating. In this case, it is preferable to carry out heating to such an extent that the plated surface is melted, whereby the fine wires can be tightly integrated tightly.

  According to a third aspect of the present invention, there is provided the small-diameter coaxial cable according to the first aspect, wherein the fine wires constituting the shield layer are configured to be tightly integrated by plating.

  According to this thin coaxial cable, in addition to the above effects, by adopting the above configuration, for example, as the thin wire constituting the shield layer, when a tin plated copper alloy wire, a silver plated copper alloy wire is employed, By tin-plating the fine wire through a molten tin bath having affinity with tin, silver, etc., the fine wire can be efficiently closely integrated by plating.

  According to a fourth aspect of the present invention, there is provided a coaxial cable formed by sequentially forming an insulator layer, a shield layer, and a jacket layer on a circumference of a central conductor, and by closely integrating a plurality of fine wires constituting the shield layer. Provided is a multilayer wiring board characterized in that wiring is integrated on a wiring board.

  According to this multilayer wiring board, by adopting the above configuration, in particular, the coaxial cable constructed as described above is integrated on the wiring board to obtain and provide a multilayer wiring board having a structure advantageous for noise countermeasures. can do.

  The invention according to claim 5 is a coaxial cable formed by sequentially forming an insulator layer, a shield layer, and a jacket layer on the circumference of the central inner conductor, and closely integrating a plurality of fine wires constituting the shield layer. Is provided on the wiring board, and the central conductor and the shield layer are connected to the corresponding wirings of the wiring board, respectively.

  According to this multilayer wiring board manufacturing method, by adopting the above configuration, in particular, the coaxial cable configured as described above is integrated with the wiring on the wiring board, and the central conductor and the shield layer are provided on the wiring board. By connecting to the corresponding wirings respectively, it is possible to easily obtain a multilayer wiring board having a structure advantageous for noise countermeasures, and to provide an efficient manufacturing method of the multilayer wiring board.

  According to the thin coaxial cable, multilayer wiring board, and multilayer wiring board manufacturing method of the present invention, a thin coaxial cable having a structure advantageous for terminal processing, used for forming wiring on a wiring board. It is possible to provide a multilayer wiring board having a structure advantageous for noise countermeasures, which is configured using the coaxial cable, and to provide an efficient manufacturing method of the multilayer wiring board. .

It is a cross-sectional view of the thin coaxial cable which concerns on one embodiment of this invention. It is a cross-sectional view of a two-core parallel small-diameter coaxial cable according to another embodiment of the present invention. It is a cross-sectional view of a 4-core diagonal thin coaxial cable according to still another embodiment of the present invention. It is a cross-sectional view of a thin coaxial cable according to still another embodiment of the present invention. It is explanatory drawing regarding the multilayer wiring board which concerns on one embodiment of this invention, and its manufacturing method. It is explanatory drawing regarding the multilayer wiring board which concerns on other embodiment of this invention, and its manufacturing method.

  DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, preferred embodiments of the invention will be described with reference to FIGS.

  First, each structural example of the thin coaxial cable employ | adopted in this invention is shown by FIGS. 1-4, respectively. A thin coaxial cable 1 having a structure shown in FIG. 1 is formed by twisting seven tin-plated copper alloy wires 2 having a diameter of 0.05 mm as a central conductor 3, and can be melt-formed on the circumference of the central conductor 3. An insulating layer 4 having a thickness of 0.03 mm is formed by coating PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer), which is a kind of fluororesin, on the circumference of the insulating layer 4, A plurality of fine wires 5 made of a tin-plated copper alloy wire having a diameter of 0.02 mm were horizontally wound, and at this time, the adjacent thin wires 5 were horizontally wound so as to be closely integrated with each other, whereby the shield layer 6 was formed. A jacket layer 7 having a thickness of 0.02 mm is formed on the periphery of the shield layer 6 by covering the same PFA (tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer) as the insulator layer 4. It is a composition.

  In the thin coaxial cable 1 having the structure shown in FIG. 1, the insulation core 8 having the insulator layer 4 formed on the circumference of the center conductor 3 is a single core. However, as shown in FIG. A thin coaxial cable 20 having a structure in which two cores 8 are arranged in parallel, or a thin coaxial cable 30 having a structure in which insulated cores 8 are arranged diagonally as shown in FIG. it can. The coaxial cables 20 and 30 having the structure shown in FIGS. 2 and 3 can transmit a large amount of data. In the case of the thin coaxial cable 30 having the structure shown in FIG. 3, an inner jacket layer 9 is formed so as to surround the entire insulated wire core 8 arranged diagonally to the four cores. It is preferable to form the shield layer 6 collectively on the periphery. Thereby, formation of the shield layer 6 becomes easy.

  In the thin coaxial cable 1 having the structure shown in FIG. 1, the shield layer 6 is formed by horizontally winding the thin wire 5 on the periphery of the insulator layer 4. The shield layer 6 may be formed by vertically attaching the thin wire 5 on the circumference of the jacket layer 9 or spirally winding it.

  Further, in the thin coaxial cable 1 having the structure shown in FIG. 1, tin-plated copper alloy wires are used as the wires constituting the central conductor 3 and the thin wires 5, but silver plating is used instead of the tin-plated copper alloy wires. A copper alloy wire may be used.

  Further, in the thin coaxial cable 1 having the structure shown in FIG. 1, PFA is used as the resin constituting the insulator layer 4, but instead of PFA, FEP (tetrafluoroethylene · (Hexafluoropropylene copolymer) or FH may be used.

  Here, as the coaxial cable 1 used for forming the wiring on the wiring board, the terminal is stripped in advance in consideration of terminal processing (connection) of the coaxial cable 1 on the wiring board. By doing so, a product in which the center conductor 3 and the shield layer 6 having a predetermined length were exposed was prepared and prepared. In the step stripping process, a laser is used to cut the jacket layer 7 and the shield layer 6 of the coaxial cable 1, respectively, and a part of the jacket layer 7 of the coaxial cable 1 and the shield layer 6. Part of each was peeled off to expose the center conductor 3 and the shield layer 6 each having a predetermined length.

  On the other hand, by using the coaxial cable 1 whose terminal has been stripped as described above, the exposed shield layer 6 is irradiated with a laser to tin-plat the fine wire 5 made of a tin-plated copper alloy wire constituting the shield layer 6 A coaxial cable 40 having the structure shown in FIG. 4 in which the tin-plated surfaces of the thin wires 5 are metallurgically closely integrated by melting and solidifying the surface was separately prepared and prepared.

  Furthermore, as an example of producing the coaxial cable 40 having the structure shown in FIG. 4 by another method, the shield layer 6 is formed at the stage where the shield layer 6 is formed before the jacket layer 7 of the coaxial cable 1 is formed. The fine wire 5 made of a tin-plated copper alloy wire is heated to a temperature equal to or higher than the melting point of tin, for example, at 300 ° C. for 5 seconds, and the tin-plated surface of the fine wire 5 is melted and solidified. A coaxial cable 40 'having the same structure as described above, in which the tin-plated surfaces are metallurgically closely integrated, was prepared and prepared. In this method, when the tin-plated surface of the thin wire 5 is melted, the insulator layer 4 under the shield layer 6 is softened and deformed, so that desired insulation characteristics and electrical characteristics cannot be obtained. It is preferable to set the heating conditions so as not to occur. According to the coaxial cable 40 ′ manufactured by this method, when the terminal process (connection) of the coaxial cable 40 ′ is performed, the terminal of the coaxial cable 40 ′ is stripped to expose the central conductor 3 and the shield layer 6. At this time, the thin wire 5 is not scattered, and the chips of the thin wire 5 are not scattered, so that the stripping process can be easily performed.

  According to these coaxial cables 1, 20, 30, 40, 40 ', the coaxial cables 1, 20 are formed on the wiring substrate by closely integrating the plurality of fine wires 5 constituting the shield layer 6. , 30, 40, 40 ′, when the terminal of the coaxial cable 1, 20, 30, 40, 40 ′ is stripped, the thin wire 5 is not broken, The shield layer 6 can be efficiently connected with sufficient electrical continuity to the corresponding wiring on the wiring board only by connecting one place on the outer periphery. Similarly, the central conductors 3 of the coaxial cables 1, 20, 30, 40, 40 ′ can be efficiently connected with sufficient electrical conduction. Accordingly, the thin coaxial cables 1, 20, 30, 40, and 40 ′ having a structure advantageous for performing terminal processing on the wiring board can be provided (when forming the wiring).

  Next, an embodiment of a multilayer wiring board and a method for manufacturing the multilayer wiring board will be described. First, as shown in FIG. 5, a base is formed and integrated by stacking two or more insulators 10 and wiring patterns 11. A multilayer wiring board 12 is prepared, and through holes 13 and 13 communicating with the wiring patterns 11 and 11 formed inside the multilayer wiring board 12 are formed in the insulator 10, so that the wiring pattern 11 is formed. , 11 are exposed (connection portion for central conductor, connection portion for shield layer). Here, a part of the prepared coaxial cables 1, 40, 40 ′ are embedded in the insulator 10, and the coaxial cables 1, 40, 40 ′ are integrated on the multilayer wiring board 12. The central conductor 3 and the shield layer 6 of the coaxial cables 1, 40, 40 ′ are respectively connected to the corresponding wiring patterns 11, 11 of the multilayer wiring board 12 by the solder 14 via the through holes 13, 13. A desired multi-wire multilayer wiring board 15 was produced by electrical connection.

  As another embodiment, as shown in FIG. 6, a wiring pattern 17 having connection pads 16 and 16 (a connection pad for a central conductor and a connection pad for a shield layer) is formed and integrated on the insulator 10, respectively. A wiring board 18 serving as a base is prepared, and a part of the coaxial cables 1, 40, 40 ′ is embedded in the insulator 10, and the coaxial cables 1, 40, 40 ′ are wired on the wiring board 18. The central conductor 3 and the shield layer 6 of the coaxial cables 1, 40, 40 ′ are integrated with the corresponding connection pads 16, 16 of the wiring pattern 17 of the wiring board 18 by solder 14. The desired multi-wire multilayer wiring board 19 was produced by connection.

  According to the multilayer wiring board and the method of manufacturing the multilayer wiring board, the coaxial cables 1, 40, 40 ′ are integrated on the multilayer wiring board 12 and the wiring board 18, and the central conductor 3 and the shield are integrated. By connecting the layer 6 to the corresponding wiring portions of the multilayer wiring board 12 and the wiring board 18 respectively, it is possible to obtain multi-wire multilayer wiring boards 15 and 19 having a structure advantageous for noise countermeasures, and efficient production thereof. A method can be provided.

  Of course, the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the invention.

DESCRIPTION OF SYMBOLS 1, 20, 30, 40, 40 'Thin coaxial cable 2 Tin plating copper alloy wire 3 Center conductor 4 Insulator layer 5 Fine wire 6 Shield layer 7 Jacket layer 8 Insulation core 9 Internal jacket layer 10 Insulator 11, 17 Wiring Pattern 12 Multilayer Wiring Board 13 Through Hole 14 Solder 15, 19 Multi-Wire Multilayer Wiring Board 16 Connection Pad 18 Wiring Board

Claims (5)

  A thin coaxial cable used for forming a wiring on a wiring board, wherein an insulator layer, a shield layer, and a jacket layer are sequentially formed on the circumference of a central conductor, and a plurality of wires constituting the shield layer A small-diameter coaxial cable, which is formed by closely integrating the thin wires.   The thin coaxial cable according to claim 1, wherein the fine wires constituting the shield layer are closely integrated by heating.   The small-diameter coaxial cable according to claim 1, wherein the fine wires constituting the shield layer are configured to be closely integrated by plating.   An insulator layer, a shield layer, and a jacket layer are sequentially formed on the circumference of the center conductor, and a coaxial cable formed by closely integrating a plurality of fine wires constituting the shield layer is integrated on the wiring board. A multilayer wiring board characterized by being made into a structure.   An insulator layer, a shield layer, and a jacket layer are sequentially formed on the circumference of the central inner conductor, and a coaxial cable formed by closely integrating a plurality of fine wires constituting the shield layer is integrated on the wiring board. And manufacturing the multilayer wiring board, wherein the central conductor and the shield layer are connected to the corresponding wirings of the wiring board, respectively.

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