JP2010103388A - Laminated flexible wiring board and method of manufacturing the same, and antenna of electronic tag for rfid using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem of complexity and high cost of a manufacturing process due to: the necessity, in the conventional step of forming a laminated flexible wiring board by laminating boards, of thermocompression bonding after formation of an adhesion layer on the board concerned to prevent displacement of upper and lower boards in lamination; and the necessity of the steps of forming and plating the through-hole and of charging a metal paste into the through-hole for electric conduction between the laminated boards. <P>SOLUTION: A flexible base material with a wiring pattern formed on its one surface is bent to form a laminated structure. In order to electrically connect with each other face-to-back opposed first and second layers, a tang-shaped form 4a with a connection electrode part 3a of the first layer is inserted into a slit 5a in the second layer to come into contact with a connection electrode part 6a. Other face-to-back opposed layers are connected in the same manner as the above. Thus, the laminated flexible wiring board can be manufactured without performing conventional complicated steps. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a laminated flexible wiring board mainly used as a component for an electronic device, a manufacturing method thereof, and an RFID electronic tag antenna using the same.

  In recent years, as electronic devices become more sophisticated and smaller in size, the use of a flexible wiring board having a laminated structure is also increasing in order to increase the density and miniaturization of the wiring board.

In order to increase the density of the conventional laminated flexible wiring board, for example, a method of laminating a plurality of polyimide resin sheets formed with an electric circuit and electrically connecting each layer through through holes formed in the sheet is generally used. (See Patent Document 1).
JP-A-5-152755

  In such a laminated flexible wiring board, for example, an adhesive layer is provided on the substrate, and it is necessary to perform thermocompression bonding so that the positions of the upper and lower substrates are not shifted during the lamination. In addition, for electrical conduction between the stacked substrates, it is necessary to form a through hole as described above, and further, plating the through hole or filling a metal paste. For this reason, the manufacturing process is complicated and expensive.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a laminated flexible wiring board that can be manufactured by a simpler process than before, a manufacturing method thereof, and an RFID electronic tag antenna using the same. And

  In order to solve the conventional problems and achieve the object, in the present invention, a wiring pattern is formed on one surface of a flexible base material, and a surface including the wiring pattern is bent to form a laminated structure, and the laminated surface is provided. A part of the base material including one end of the wiring pattern was inserted into the base material of another layer where the wiring pattern opposes the back of the stomach so that the wiring patterns were connected to each other and the manufacturing method thereof.

  Also, a laminated flexible wiring board in which an insulating member is disposed between the two layers so as not to contact the wiring patterns of the two layers facing each other by bending and the manufacturing method thereof are provided.

  Furthermore, the wiring pattern was made into a spiral shape to obtain a laminated flexible wiring board that can be used as an antenna for an RFID electronic tag.

  According to the laminated flexible wiring board and the manufacturing method of the present invention, there is no need for a process of forming a through hole and a process of connecting the boards with a metal material, which are conventionally required to electrically connect the laminated boards. Therefore, it becomes possible to manufacture more easily and inexpensively.

  In addition, when the substrate is bent with the wiring pattern surface inward, the wiring patterns come into contact with each other. However, by interposing an insulating member such as an insulating sheet between them, restrictions on wiring pattern creation can be reduced. .

  Furthermore, if the wiring pattern is spiral, it can be used as an antenna for an RFID electronic tag. In order to reduce the size of the antenna while maintaining the communication distance, it is effective to reduce the spiral shape and increase the number of layers. In the present invention, however, the number of layers can be easily increased by repeatedly arranging the same wiring pattern. Can do. The RFID tag is also supposed to be used in a disposable manner, and this point is advantageous in that it can be manufactured at a low cost.

  The invention according to claim 1 includes a step of forming a wiring pattern on one side of a flexible base material, a step of bending the base material to form a laminated structure, and a base material including one end of the wiring pattern provided in one layer Is a method for manufacturing a laminated flexible wiring board, comprising a step of inserting a part of the substrate into a base material of another layer and connecting the wiring patterns to each other. In this way, an adhesive layer is provided on the substrate, and the positions of the upper and lower substrates are prevented from shifting during lamination, and a through hole is formed for electrical conduction between the laminated substrates, A process of plating the through hole or filling a metal paste is not required, and an inexpensive laminated flexible wiring board can be manufactured with a simple process.

  The invention according to claim 2 includes a step of disposing an insulating member between the two layers to prevent contact between the wiring patterns of the two layers facing each other by bending. It is a manufacturing method of a wiring board. Thereby, it is possible to prevent the contact of the wiring patterns that face each other on the inside by being folded into valley folds.

  According to a third aspect of the present invention, a plurality of layers are provided on the base material, a step of folding a mountain fold and a valley fold to form a laminated structure, and a wiring pattern of two layers facing each other by the valley fold are as follows: 2. The method for manufacturing a laminated flexible wiring board according to claim 1, comprising a step of providing an insulating member for preventing contact between two layers of wiring patterns that are connected in advance and face each other by valley folding. . As a result, if the wiring patterns of two layers facing each other by valley folding are connected in advance, the connection can be made simply by disposing an insulating member between the wiring patterns of the two layers facing by valley folding. Can be prevented.

  According to a fourth aspect of the present invention, a plurality of layers are provided on the base material, and a step of folding a mountain fold and a valley fold to form a laminated structure and a wiring pattern of two layers facing each other by the valley fold are as follows: Two layers that are not connected in advance but are formed in an insulating member that prevents contact between two wiring patterns facing each other by valley folding, and are opposed by valley folding through the holes. It is a manufacturing method of the lamination | stacking flexible wiring board of Claim 1 including the process of connecting these wiring patterns. Thereby, even when the wiring patterns of the two layers facing each other by the valley fold are not connected in advance, the insulating member having a hole between the wiring patterns of the two layers facing the valley fold is disposed. By doing so, connection can be prevented. The wiring patterns of the two layers facing each other by valley folding are connected in the same way as the first layer, the second layer, the third layer, and the fourth layer through holes provided in the insulating member.

  In the invention according to claim 5, a part of the base material including one end of the wiring pattern provided in one layer of the flexible base material in which the wiring pattern is formed on one side and bent to form a laminated structure is used. It is a laminated flexible wiring board in which the surface is inserted into a base material of another layer that opposes the back of the stomach and the wiring patterns are connected to each other. In this way, an adhesive layer is provided on the substrate, and the positions of the upper and lower substrates are prevented from shifting during lamination, and a through hole is formed for electrical conduction between the laminated substrates, Since a process of plating the through hole or filling a metal paste is not required, an inexpensive laminated flexible wiring board can be manufactured with a simple process.

  The invention according to claim 6 is the laminated flexible wiring board according to claim 5, wherein an insulating member for preventing contact between the wiring patterns of the two layers facing each other by bending is disposed between the two layers. is there. Thereby, it is possible to prevent the contact of the wiring patterns that face each other on the inside by being folded into valley folds.

  The invention according to claim 7 is the antenna of the RFID electronic tag according to claim 5 or 6, wherein the wiring pattern has a spiral shape. Thereby, the antenna of the RFID electronic tag reduced in size can be manufactured at low cost by a simple process.

  Embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a top view of a multilayer planar antenna using a multilayer flexible wiring board according to an embodiment of the present invention, FIG. 2 is a cross-sectional view taken along line AA of the multilayer planar antenna according to the embodiment of the present invention, and FIG. 4 is a plan view showing a wiring pattern of a laminated planar antenna according to an embodiment of the invention, FIG. 4 is a schematic view showing a lamination method of the laminated planar antenna according to the embodiment of the invention, and FIG. It is BB sectional drawing which shows the electrical connection method of the lamination type planar antenna which is the form of.

  First, the configuration of the laminated flexible wiring board according to the embodiment of the present invention will be described with reference to FIGS. 1 and 2.

  First, the base material 1 is an insulating material and is required to have heat resistance that can withstand solder joints with electronic components. In addition, this time, since the base material is folded to form a laminated structure, it must be flexible and thin to some extent. However, since flexibility is not required, a polyimide film or a polyester film used as a general flexible substrate can be used.

  Moreover, the base material 1 forms a desired wiring pattern on one side. In the present embodiment, it is assumed that the antenna is used as an antenna for an RFID electronic tag, and the wiring pattern 2 is spirally formed on one side of the substrate 1 as shown in FIG. At this time, in order to reduce the size while maintaining the communication distance, it is effective to reduce the spiral diameter of the antenna and to laminate in multiple layers. This time, the outer diameter of the spiral is set to 15 mm, and the wiring pattern is miniaturized as a four-layer structure as shown in FIG. The formation of the wiring pattern 2 includes a method of dissolving and removing an unnecessary portion of the pattern from a metal foil previously laminated on a substrate like etching, or a method of leaving a conductive material by printing a conductive paste on a necessary portion. Used. Moreover, the 2nd layer and the 3rd layer are bend | folded in the valley fold, and the insulating sheet 7 is provided so that the wiring pattern 2 may not connect.

  Next, a method for manufacturing the antenna of the RFID electronic tag of this embodiment will be described.

  First, the substrate in the previous stage of lamination will be described. The wiring pattern as shown in FIG. 3 was formed by electroplating copper only on the selected pattern surface on only one surface of the substrate. Specifically, the second layer and the third layer are connected to each other so that a current flows in one direction when an antenna coil is formed by stacking a laminated structure and a wiring pattern to be described later. However, the first layer and the fourth layer are configured such that the wiring pattern is not coupled to the other layers.

  Further, this time, in order to electrically connect the first layer to the fourth layer, two tongue-like shapes 4a and 4c having connection electrode portions 3a and 3c are formed on the first layer. Here, the tongue-like shape 4a can be electrically connected to the first layer and the second layer by the method described later, and the other tongue-like shape 4c can be connected to the first layer and the fourth layer. . Similarly, the third layer also has a tongue-like shape 4b having a connection electrode portion 3b, whereby the third and fourth layers can be electrically connected. Further, the second layer has a slit 5a for inserting the first tongue-like shape 4a, and the fourth layer has a slit 5b for inserting the third tongue-like shape 4b and the first layer tongue. It has the notch 5c which inserts the shape 3c. Each slit and notch has connection electrode portions 6a, 6b and 6c corresponding to the inserted tongue-shaped connection electrode portions. One end of the spiral shape of the fourth layer is an IN side electrode of the antenna, and a part of the connection electrode portion 6c also serves as the OUT side electrode of the antenna.

  The tongue-like shape and slit as described above can be formed simultaneously with the punching of the outer shape of the antenna. For example, if a punched Thomson mold is provided with a tongue-like shape or a blade corresponding to a slit in addition to the outer shape, a desired shape can be obtained at one time.

  Next, as shown in FIG. 4, first, the base material 1 is folded in a mountain fold so that the wiring patterns are outside each other in the first layer and the second layer. By bending in this way, contact between the wiring patterns can be prevented. In the second layer and the third layer, the wiring patterns are bent in a valley fold and are in contact with each other on the inner side. Therefore, the insulating sheet 7 is sandwiched between them to prevent the wiring patterns from contacting each other. In this embodiment, the insulating sheet is used, but it goes without saying that other means for ensuring the insulation of the wiring surface, such as applying an insulating paint to the wiring pattern surface, can be substituted. Also, the third and fourth layers are bent so that the wiring pattern is abdomen-back like the first and second layers.

  Further, the electrical connection of each layer is such that the first tongue-like shape 4a is turned into the second-layer slit 5a and the third-layer tongue-like shape 4b is turned into the fourth-layer slit 5b. This is realized by inserting 4c into the notch 5c in the fourth layer. As a typical example, FIG. 5 shows a cross-sectional view of a state in which the first tongue-like shape is inserted into the second slit. Since the base material 1 has elasticity, the tongue-like shape inserted into the slit tends to return parallel to the base material. For this reason, the connection electrodes are in contact with each other and are electrically connected. Preferably, the tongue-like shapes can be securely bonded by sandwiching the tongue shapes with other members or by connecting the connection electrode portions to each other by soldering or ultrasonic bonding.

  By bending and electrically connecting the base material as described above, a spiral shape extending from the IN side electrode of the fourth layer antenna to the third layer, second layer, first layer, fourth layer OUT side electrode An RFID antenna can be formed.

  In this embodiment, the wiring patterns are connected to the second layer and the third layer, but even when they are not connected, they should be connected in the same way as the first layer, the second layer, the third layer, and the fourth layer. A similar effect can be obtained. First, in the second-layer wiring pattern, a tongue-shaped portion having a connection electrode portion is newly provided at the opposite end of the connection electrode portion 6a. Further, a slit having a connection electrode portion is newly provided at the opposite end of the connection electrode portion 3b in the third-layer wiring pattern. The insulating sheet 7 sandwiched between the second layer and the third layer has a hole formed in the second layer tongue-shaped portion and the third layer slit portion. When applying the insulating paint to the wiring pattern surface, the insulating layer may be applied while avoiding the second layer tongue-shaped portion and the third layer slit portion. The second layer and the third layer can be electrically connected by inserting the second layer tongue-shaped portion into the third layer slit with the insulating sheet 7 interposed therebetween. However, unlike the connection of the first layer, the second layer, the third layer and the fourth layer, there is an insulating sheet between the second layer and the third layer. It is necessary to provide longer than the tongue-like shapes 4a, 4b, 4c. A slit may be provided on the second layer, and a tongue-shaped portion may be provided on the third layer.

  In this embodiment, a wiring pattern having a four-layer structure is illustrated, but the number of layers can be increased further. For example, a plurality of patterns (hereinafter referred to as intermediate patterns) having the same shape as the second-layer and third-layer wiring patterns of this embodiment shown in FIG. 3 are arranged, and the first-layer wiring pattern and the fourth-layer wiring pattern are arranged in the plurality of patterns. Arranged at both ends of the intermediate pattern. When arranged in this way, the intermediate pattern has a laminated structure of 2 × (N + 1) layers in the case of N sets of intermediate patterns, such as four layers in the case of one set and six layers in the case of two sets as in this embodiment. Can be formed. If the intermediate pattern is eliminated and only the first and fourth wiring patterns are provided, it can be used as a double-sided board.

  According to the multilayer flexible wiring board and the method of manufacturing the same according to the present invention, a process that is simpler than the conventional multilayer flexible wiring board in that it is not necessary to form a through hole and further perform plating for electrical connection. Can be manufactured at a low cost. Moreover, even when it is necessary to increase the number of stacked layers, it is advantageous in that it can be easily increased using the same pattern.

The top view of the lamination type plane antenna by the lamination flexible wiring board which is an embodiment of the invention AA sectional view of a multilayer planar antenna according to an embodiment of the present invention The top view which showed the wiring pattern of the lamination | stacking type | mold planar antenna which is embodiment of this invention Schematic showing a method for stacking stacked planar antennas according to an embodiment of the present invention BB sectional drawing which shows the electrical connection method of the lamination type planar antenna which is embodiment of this invention

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Wiring pattern 3a, 3b, 3c Connection electrode part 4a, 4b, 4c Tongue shape 5a, 5b Slit 5c Notch 6a, 6b, 6c Connection electrode part 7 Insulation sheet

Claims (7)

A step of forming a wiring pattern on one surface of a flexible base material, a step of bending the base material to form a laminated structure, and a part of the base material including one end of the wiring pattern provided in one layer, A method for manufacturing a laminated flexible wiring board, comprising a step of inserting a substrate into a substrate and connecting the wiring patterns to each other. 2. The manufacturing of a laminated flexible wiring board according to claim 1, further comprising a step of disposing an insulating member between the two layers to prevent contact between two wiring patterns facing each other by bending. Method. A plurality of layers are provided on the base material, and a step of folding a mountain fold and a valley fold to form a laminated structure;
The wiring patterns of the two layers facing each other by valley folding are connected in advance,
2. The method for manufacturing a laminated flexible wiring board according to claim 1, further comprising a step of disposing an insulating member for preventing contact between two wiring patterns facing each other by valley folding. A plurality of layers are provided on the base material, and a step of folding a mountain fold and a valley fold to form a laminated structure;
The wiring patterns of the two layers facing each other by valley folding are not connected in advance,
A hole is formed in an insulating member that prevents contact between two wiring patterns facing each other by valley folding, and the two wiring patterns facing each other by valley folding are connected through the holes. The manufacturing method of the lamination | stacking flexible wiring board of Claim 1 characterized by including the process to perform. Another layer whose wiring pattern surface opposes the back of a part of the base material including one end of the wiring pattern provided in one layer of the flexible base material which is formed with a wiring pattern on one side and bent to form a laminated structure A laminated flexible wiring board, wherein the wiring patterns are connected to each other by being inserted into a base material. 6. The laminated flexible wiring board according to claim 5, wherein an insulating member for preventing contact between the wiring patterns of two layers facing each other by bending is disposed between the two layers. 7. The RFID electronic tag antenna according to claim 5, wherein the wiring pattern has a spiral shape.

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