JP2006042097A - Antenna wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an antenna wiring board which is small in planar area and superior in accuracy of signal transfer. <P>SOLUTION: The antenna wiring board comprises an insulation base body 1 with a plurality of insulation layers 2 laminated therein; first and second electrode pads 3, 4 formed on the upper surface of the most upper insulation layer 2; whirl-like wiring conductors 5, which are respectively formed on the upper surface of the insulation layers other than the most upper insulation layer 2 and connected mutually, electrically, and serially; a first through-conductor 6 for electrically and serially connecting the first electrode pad 3 to the wiring conductor 5 formed on the insulation layer 2a, which is directly under the most upper insulation layer 2; and a second through-conductor 4 for electrically and serially connecting the second electrode pad 4 to the wiring conductor 5a which is formed on the most lower insulation layer 2b. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an antenna wiring board used for an IC card, an IC tag, or the like, in which an antenna for transmitting and receiving signals without contact is formed.

  In recent years, information media such as IC cards and IC tags that exchange signals in a non-contact manner have attracted attention and have begun to spread rapidly. Such an information medium is formed using an antenna wiring board in order to enable transmission and reception of signals without contact. The antenna wiring board has a structure including, for example, a flat insulating base made of resin and a spiral wiring conductor formed on the main surface of the insulating base.

  In this antenna wiring board, the spiral wiring conductor functions as an antenna. For example, it is incorporated into a product tag for crime prevention, product management, etc., a prepaid railway, bus or other fee payment card, It is used as an admission ticket for various facilities and used in combination with a corresponding information reader. The information reader also has a built-in antenna mechanism. By bringing the wiring conductor portion of the information medium close to it, signals are exchanged between the spiral wiring conductor and the external reader via radio waves. Is done. The signal is processed by a storage device, an arithmetic device, or the like linked with the reading device, and various processes such as merchandise sales and purchase records, calculation of usage fees, and authenticity determination of a passport are executed. In some cases, a semiconductor element is mounted on the antenna wiring board as a storage device or an arithmetic device.

In such an antenna wiring board, a spiral wiring conductor has a higher signal sensitivity as the number of spiral turns increases. Therefore, in order to exchange information more quickly and accurately, the wiring conductor It is required to increase the number of windings.
JP 2002-31233 A JP 2002-31234 A

  However, in the above-described conventional antenna wiring board, since the spiral wiring conductor is formed on the main surface of the insulating substrate made of a flat resin, the wiring conductor is formed to increase the number of turns. There is a problem in that it is necessary to increase the area, and it is difficult to reduce the outer dimensions. Also, when trying to reduce the outer dimensions, it is difficult to improve the accuracy of signal transmission / reception.

  The present invention has been completed in order to solve such conventional problems, and an object of the present invention is to provide an antenna wiring board having a small planar area and excellent signal transmission / reception accuracy. is there.

  An antenna wiring board according to the present invention includes an insulating base formed by laminating a plurality of insulating layers, first and second electrode pads formed on the upper surface of the uppermost insulating layer, and other than the uppermost insulating layer. A spiral wiring conductor formed on the upper surface of the insulating layer and electrically connected in series to each other, and the wiring formed in the insulating layer immediately below the first electrode pad and the uppermost insulating layer A first through conductor that electrically connects the conductors in series; and a second through conductor that electrically connects the wiring conductors formed in the second electrode pad and the lowermost insulating layer in series. It is characterized by that.

  In the antenna wiring board of the present invention, preferably, the first and second electrode pads are electrically connected to a semiconductor element mounted on the upper surface of the insulating base, and the wiring conductor is all of them. It is formed in the area | region enclosed with the external shape of the said semiconductor element by planar view.

  According to the antenna wiring board of the present invention, with the above configuration, the number of turns can be increased by forming wiring conductors in a plurality of insulating layers and laminating these insulating layers vertically, so that the outer shape of the antenna wiring board can be increased. While keeping the dimensions small, the wiring conductor can improve the accuracy of signal transmission and reception, and a small and highly accurate antenna wiring board can be provided.

  In addition, since the semiconductor element is mounted on the uppermost insulating layer different from the insulating layer on which the wiring conductor is formed, the uppermost insulating layer is more effective than the prior art in electromagnetic waves between the wiring conductor and the semiconductor element. Which can be cut off automatically, can prevent malfunctions such as malfunction of semiconductor elements and noises in signals, and can more reliably prevent signals from being sent and received and processed. It can be set as a wiring board.

  In the antenna wiring board of the present invention, preferably, the first and second electrode pads are electrically connected to a semiconductor element mounted on the upper surface of the insulating base, and the wiring conductors are all in plan view. Since the semiconductor element is formed in a region surrounded by the outer shape of the semiconductor element, the semiconductor element can be connected to perform signal exchange and information processing integrally, and the outer dimensions of the antenna wiring board can be The antenna wiring board can be made as small as possible, more excellent in practicality, and more reliable in size.

  The wiring board of the present invention will be described with reference to the drawings. FIG. 1 is an exploded perspective view showing an example of an embodiment of an antenna wiring board according to the present invention, disassembled for each insulating layer. In FIG. 1, 1 is an insulating substrate formed by laminating a plurality of insulating layers 2, 3 is a first electrode pad, 4 is a second electrode pad, 5 is a wiring conductor, 6 is a first through conductor, and 7 is a first electrode pad. 2 through conductors. The antenna wiring board 9 of the present invention is mainly constituted by the insulating base 1, the first electrode pad 3, the second electrode pad 4, the wiring conductor 5, the first through conductor 6, and the second through conductor 7. Is done.

  The insulating layer 2 has a square shape, a circular shape or the like in plan view, and is made of an aluminum oxide sintered body (alumina ceramic), an aluminum nitride sintered body, a mullite sintered body, or a silicon nitride sintered body. , A silicon carbide sintered body, a glass ceramic sintered body and the like. The insulating substrate 1 is formed by laminating a plurality of the insulating layers 2.

  In order to prevent unnecessary unevenness from occurring on the side surface of the insulating substrate 1, it is preferable that each insulating layer 2 has the same outer shape and dimensions from the uppermost layer to the lowermost layer.

  For example, in the case where each insulating layer 2 is made of an aluminum oxide sintered body, the insulating substrate 1 is prepared by adding an appropriate resin binder and solvent to a raw material powder such as aluminum oxide, silicon oxide, calcium oxide, magnesium oxide, etc. A plurality of ceramic green sheets (ceramic green sheets, hereinafter also referred to as green sheets) are formed by using a sheet forming technique such as a doctor blade method or a calender roll method. After that, the green sheet is formed into an appropriate shape by cutting or punching, and the green sheets are laminated to form a laminate. Finally, the laminate is reduced to about 1600 ° C. in a reducing atmosphere. It is manufactured by firing at a temperature of

  A first electrode pad 3 and a second electrode pad 4 are formed on the upper surface of the uppermost one of the plurality of insulating layers 2. A spiral wiring conductor 5 is formed on the upper surface of the plurality of insulating layers 2 other than the uppermost layer.

  The wiring conductor 5 formed on the first electrode pad 3 and the insulating layer 2a immediately below the uppermost insulating layer 2 is electrically connected in series via the first through conductor 6, and the second conductor The electrode pad 4 and the wiring conductor 5a formed in the lowermost insulating layer 2 are electrically connected in series via a second through conductor 7 that penetrates the plurality of insulating layers 2 from the lowermost layer to the uppermost layer. Has been.

  The wiring conductor 5 and the first and second through conductors 6 and 7 form a spiral wiring conductor 5 that is electrically interconnected as a whole and functions as an antenna. Moreover, the antenna and the semiconductor element are electrically connected by electrically connecting the first and second electrode pads 3 and 4 to a semiconductor element such as a semiconductor integrated circuit element. Thereby, a signal received by the antenna is transmitted to the semiconductor element for processing, and a signal transmitted from the semiconductor element is transmitted from the antenna to the outside.

  The electrical connection between the wiring conductors 5 of the upper and lower insulating layers 2 is an interlayer conductor (penetrating conductor) penetrating in the thickness direction so as to connect the upper and lower wiring conductors 5 to each insulating layer 2. ) 8 can be formed. In this case, in order to effectively increase the number of turns of the wiring conductor 5, it is necessary to make the direction of the signal flowing through the wiring conductor 5 the same between the upper and lower insulating layers 2. That is, the signal flows in either the right-handed direction or the left-handed direction of the spiral wiring conductor 5. When the direction of the signal flowing through the wiring conductor 5 is reversed between the upper and lower insulating layers 2, the direction of the induction component due to electromagnetic induction generated between the wiring conductors 5 is reversed from the direction of the signal transmitted through the wiring conductor 5. The signal is not normally transmitted through the wiring conductor 5 and does not function as an antenna.

  Moreover, it is preferable that the direction of the spiral is different between the upper and lower wiring conductors 5. If the direction of the spiral between the upper and lower wiring conductors 5 is the same, the direction of the signal flowing between the upper and lower wiring conductors 5 is reversed and the electromagnetic induction cancels out, so that the signal (high frequency signal) does not flow accurately. Become.

  The wiring conductor 5, the first and second electrode pads 3, 4, the first and second through conductors 6, 7 and the interlayer conductor 8 are made of tungsten, molybdenum, manganese, copper, silver, gold, palladium, platinum or the like. Made of metal material.

  When the wiring conductor 5, the first and second electrode pads 3, 4, the first and second through conductors 6, 7 and the interlayer conductor 8 are all made of tungsten, for example, an organic binder suitable for tungsten powder, The metal paste obtained by adding and mixing the solvent is printed on the upper surface of the green sheet to be each insulating layer 2, and is printed on the inside of the through-holes previously formed in each insulating layer 2 by punching or the like. It is formed by filling. In consideration of productivity, it is preferable to form all of these with the same kind of material. In addition, the filler powder such as ceramic powder or glass powder is used for the metal paste for the purpose of ensuring the strength of adhesion to the insulating substrate 1 by adjusting the shrinkage ratio during firing between the metal paste and the green sheet. May be added, or the ratio of addition may be different for each part.

  According to the antenna wiring substrate 9 of the present invention, since the wiring conductor 5 is formed on the upper surface of the insulating layer 2, in addition to increasing the number of turns on the upper surface of the insulating layer 2, the number of layers of the insulating layer 2 is increased. The number of windings can also be increased by increasing the number. Therefore, while maintaining the external dimensions of the antenna wiring board 9 to be small, the wiring conductor 5 can provide excellent signal transmission / reception accuracy, and a small and highly accurate antenna wiring board 9 can be provided. . In this case, in order to keep the thickness of the antenna wiring board 9 thin, it is preferable to reduce the thickness of each insulating layer 2. For example, in the use of an IC card, the thickness of the insulating base 1 is preferably 0.5 mm or less, and the thickness of each insulating layer 2 is satisfied in order to satisfy the above thickness while ensuring the sensitivity of antenna transmission / reception. The thickness is preferably 0.1 mm or less.

  Further, the number of turns of the spiral wiring conductor 5 is preferably three or more turns on the upper surface of each insulating layer 2 in order to ensure the sensitivity of signal transmission and reception more reliably.

  When the thickness of the insulating layer 2 is reduced, in order to prevent electrical insulation deterioration between the upper and lower wiring conductors 5, the wiring conductors 5 adjacent to each other in the upper and lower sides are formed so as not to overlap in plan view, that is, the upper layer Preferably, the lower spiral wiring conductor 5 is formed so as to be positioned in the spiral gap between the spiral wiring conductors 5. Further, in this case, since the portion where the wiring conductor 5 is formed can be shifted between the upper and lower insulating layers 2, the upper and lower surfaces of the insulating substrate 1 are uneven due to the thickness of the wiring conductor 5. Can be effectively prevented. As a result, the flatness of the surface on which the first and second electrode pads 3 and 4 are formed is good. For example, the antenna wiring board 9 can be easily and firmly electrically connected to the external electric circuit board. Can be installed.

  The external electric circuit (not shown) to which the first and second electrode pads 3 and 4 are connected is, for example, an integrated circuit of a semiconductor element, an amplifier circuit, a filter circuit, etc., and a predetermined position of the external electric circuit Are electrically connected to each other through a conductive connecting material such as solder. The first and second electrode pads 3 and 4 are formed in, for example, a circular shape, an elliptical shape, a quadrangular shape, etc. It is so preferable that it is large in the range which can ensure insulation. Further, the first and second electrode pads 3 and 4 may have different shapes and sizes for identification. An identification mark may be formed on the upper surface of the insulating substrate 1.

  The first and second electrode pads 3 and 4 are coated with a plating layer made of nickel, gold, copper, silver, platinum, palladium, tin, solder or the like on the exposed surface to prevent oxidative corrosion or contact. You may make it perform reduction of resistance, improvement of the wettability of connection materials, such as solder.

  In the antenna wiring board 9 of the present invention, the first and second electrode pads 3 and 4 are electrically connected to a semiconductor element (not shown) mounted on the upper surface of the insulating base 1, The conductors 5 are preferably formed in a region surrounded by the outer shape of the semiconductor element in plan view. As a result, the semiconductor elements can be connected so that signals can be exchanged and information can be processed integrally, and the external dimensions of the antenna wiring board 9 can be kept as small as the semiconductor elements, making it more practical. The antenna wiring board 9 that is excellent and more reliable in size can be obtained.

  Further, since the semiconductor element is mounted on the uppermost insulating layer 2 different from the insulating layer 2 on which the wiring conductor 5 is formed, the uppermost insulating layer 2 is used to connect the wiring conductor 5 and the semiconductor element. It is possible to more effectively electromagnetically cut off, and it is possible to more reliably prevent malfunctions such as malfunctions of semiconductor elements and noises in signals, and more accurate signal transmission and reception. The antenna wiring board 9 can be formed. In this case, the thickness of the uppermost insulating layer 2 is preferably made thicker than the thicknesses of the other insulating layers 2 and 2a, and electromagnetic shielding can be performed more effectively.

  Further, an electromagnetic shielding layer (shield layer: not shown) made of an electromagnetic shielding material such as ferrite may be formed on the lower surface of the uppermost insulating layer 2. The electromagnetic shielding layer needs to cover the lower surface of the electromagnetic shielding layer with an insulating layer such as a ceramic layer in order to avoid an electrical short circuit with the spiral wiring conductor 5 on the lower layer side.

  Further, a recess (not shown) may be formed in the uppermost insulating layer 2, and the semiconductor element may be accommodated in the recess. Further, an electromagnetic shielding layer as described above may be attached to the inner surface of the recess to further improve the electromagnetic shielding with respect to the semiconductor element accommodated in the recess.

  The semiconductor element functions as a storage device or an arithmetic device in the antenna wiring board 9. For example, the signal received from the outside is compared with the stored data, and calculation processing is performed to perform predetermined processing such as charge calculation, authenticity determination, and transmission of processing results.

  The number of semiconductor elements is not limited to one, and a plurality of semiconductor elements may be mounted according to the purpose and function of the antenna wiring board 9. Further, in addition to the semiconductor element, an electronic component such as a capacitor element or a resistor may be mounted.

  It should be noted that the present invention is not limited to the above-described embodiments, and various modifications and improvements can be made without departing from the scope of the present invention. For example, the insulating substrate 1 has a square plate shape in the example of FIG. 1, but the corner portion may be chamfered to prevent mechanical breakage at the corner portion, or may be a disk shape. Good. Further, a buffer layer made of resin or the like may be formed on the outer surface such as the side surface of the insulating substrate 1.

1 is an exploded perspective view showing an example of an embodiment of an antenna wiring board according to the present invention, disassembled for each insulating layer.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Insulating base | substrate 2 ... Insulating layer 3 ... 1st electrode pad 4 ... 2nd electrode pad 5 ... Wiring conductor 6 ... 1st penetration conductor 7 ... 1st 2 through conductors 8 ... interlayer conductor 9 ... antenna wiring board

Claims (2)

An insulating substrate formed by laminating a plurality of insulating layers, first and second electrode pads formed on the upper surface of the uppermost insulating layer, and formed on the upper surface of the insulating layer other than the uppermost insulating layer, respectively. And a spiral wiring conductor electrically connected in series with each other and the wiring conductor formed in the insulating layer immediately below the first electrode pad and the uppermost insulating layer are electrically connected in series. A first through conductor, and a second through conductor that electrically connects in series the wiring conductor formed in the second electrode pad and the lowermost insulating layer. Antenna wiring board. The first and second electrode pads are electrically connected to a semiconductor element mounted on the upper surface of the insulating base, and the wiring conductor is surrounded by the outline of the semiconductor element in plan view. The antenna wiring board according to claim 1, wherein the antenna wiring board is formed in a region to be connected.

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