JP2006237299A - Wiring board - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wiring board where a resistance value can highly precisely be measured at the time of trimming a resistor even if the resistor and a wiring conductor are formed with high density with an adjacent interval narrowing in accordance with miniaturization of the wiring board. <P>SOLUTION: The wiring board 9 has a plurality of the resistors 1 and a wiring path 2 which electrically connects the resistors 1. A common measurement pad 3 for measuring the electric resistance value of the resistors 2 is installed in the wiring path 2 between the resistors 1 by exposing a surface. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wiring board having a plurality of resistors electrically connected to each other, and in particular, various electronic components are mounted depending on applications and the like for information and communication electronic devices and control systems. The present invention relates to a wiring board used for a substrate or the like.

  Information such as computers and communication equipment, electronic equipment for communication, boards for control systems such as in-vehicle use, etc., are used as parts as wiring boards that are equipped with electronic parts according to the application. It has been.

  Examples of the electronic component include semiconductor integrated circuit elements such as IC and LSI, LD (semiconductor laser), LED (light emitting diode), PD (photodiode), CCD, line sensor, image sensor and other optical semiconductor elements, and piezoelectric vibrators. In addition, vibrators such as crystal vibrators and other various electronic parts are used.

  The wiring board has such a structure that such an electronic component is mounted and the electrode can be led out and electrically connected to the outside. Generally, an aluminum oxide sintered body or a glass ceramic sintered body is used. A wiring path for electrically connecting electronic components is formed on a substrate made of an insulating material such as an aluminum nitride sintered body.

  In recent years, in such wiring boards, those having a plurality of resistors have begun to be widely used.

  The resistor is provided on the wiring board for the purpose of controlling the current transmitted through the wiring path and preventing noise from being applied to the electronic components mounted on the wiring board.

  For such a resistor, it is necessary to ensure that the resistance value of the resistor is within a specified range in order to ensure the accuracy of control, etc., and in order to ensure the accuracy of the resistance value, trimming is performed. The resistance value is adjusted.

Each resistor is formed with a measurement pad for measuring the electric resistance of the resistor adjacent to the resistor so that the resistance value can be measured each time the resistor is trimmed. That is, the resistance value is measured by measuring the resistance value at any time while measuring the resistance value by bringing the probe pin electrically connected to a measuring instrument such as a resistance measuring instrument into contact with the measurement pad, and trimming the resistance value. It can be accurately controlled to a predetermined value.
JP 2003-92353 A JP 2002-93604 A

  However, in the conventional wiring board described above, with the downsizing of the entire structure, the resistors and the wiring paths are formed with high density and the adjacent interval is narrowed. For this reason, it has become difficult to secure a space for providing a measurement pad adjacent to each resistor in the substrate.

  The present invention has been devised in view of the above-described problems, and the object thereof is a case where resistors and wiring paths are formed with high density, and the resistance value is accurately obtained when trimming the resistors. An object of the present invention is to provide a wiring board that can be measured.

  The wiring board of the present invention is a wiring board having a plurality of resistors and a wiring path for electrically connecting the resistors to each other. It is characterized in that a common measurement pad for measuring is provided to be exposed on the surface.

  The wiring board of the present invention is characterized in that the diameter of the measurement pad is larger than the wiring width of the other part of the wiring path.

  The wiring board of the present invention is a wiring board having a plurality of resistors and a wiring path for electrically connecting the resistors to each other. Since the common measurement pad for measuring the surface is provided exposed on the surface, the resistance value of a plurality of resistors electrically connected via the wiring path using the common measurement pad Can be measured. As a result, it is not necessary to form the measurement pads adjacent to the individual resistors, and even if the resistors and the like are formed with a high density and a narrow interval between the adjacent resistors, It becomes possible to accurately measure the resistance value of the resistor.

  In this case, the resistance of the wiring path can be predicted with high precision by using, for example, a combination of means such as increasing the accuracy of the printing technique for forming the wiring path and reducing variations in the specific resistance of the printing material. By setting the resistance value obtained by adding the respective resistances of the resistor to be measured and the wiring path to which the resistor is electrically connected to the target value at the time of trimming, the resistance value of the resistor is The resistance value of each resistor can be accurately measured from the result of measurement as a combined resistance value of both the resistor and the wiring path via the measurement pad.

  Further, according to the wiring board of the present invention, the measurement pad is recognized as a part different from the wiring path (by an image recognition device or the like) by making the diameter of the measuring pad larger than the wiring width of the other part of the wiring path. Since it becomes easier, it becomes easy to contact the terminal (probe pin etc.) of a measuring instrument with respect to a measurement pad, and resistance value measurement can be performed more easily.

  Furthermore, in this case, since the measurement pad width is larger than the wiring path width, the resistance (ratio) of the measurement pad is lower than that of the wiring path. Therefore, it is possible to further improve the accuracy of measurement of the resistance value of the resistor, and also improve the connectivity between the measurement pad and the wiring path.

  Hereinafter, the present invention will be described in detail with reference to the accompanying drawings. FIG. 1A is a plan view showing an example of an embodiment of a wiring board according to the present invention, and FIG. 1B is an enlarged plan view of a main part thereof.

  1A and 1B, 1 is a resistor, 2 is a wiring path, and 3 is a measurement pad. A wiring board 9 is formed by disposing the resistor 1, the wiring path 2, and the measurement pad 3 on a board 4 made of, for example, an electrically insulating material.

  The wiring substrate 9 is, for example, a semiconductor integrated circuit element such as an IC or LSI, an optical semiconductor element such as an LD (semiconductor laser), LED (light emitting diode), PD (photodiode), CCD, line sensor, image sensor, or piezoelectric vibration. This unit is equipped with a resonator, a crystal resonator, and other various electronic components (not shown) for information such as computers and communication devices, communication electronic devices, and control systems such as in-vehicle devices. Used for applications such as substrates.

  When electronic components are mounted, electronic component mounting portions (not shown) are provided on the main surface and side surfaces of the substrate 4. In the example shown in FIG. 1, the substrate 4 has a substantially flat plate shape. For example, the substrate 4 may have a concave portion (not shown) on the main surface and the bottom surface of the concave portion serves as a mounting portion for electronic components. Good. The recesses may be provided on the side surface of the substrate 4 or on both main surfaces.

  The substrate 4 is made of a ceramic material such as a glass ceramic sintered body, an aluminum oxide sintered body, an aluminum nitride sintered body, a mullite sintered body, a silicon nitride sintered body, a silicon carbide sintered body, or an epoxy. It is made of an electrically insulating material such as a resin material such as resin or polyimide resin, or a composite material of resin material and glass material or ceramic material.

  When the substrate 4 is made of, for example, a glass ceramic sintered body, an appropriate organic binder and solvent are added to and mixed with a glass ceramic raw material powder such as silicon oxide and aluminum oxide to form a slurry, which is formed by a doctor blade method. By adopting it into a sheet, a plurality of ceramic green sheets are obtained. After that, the ceramic green sheets are formed into an appropriate shape by cutting or punching, and a plurality of them are laminated, and finally, this lamination is performed. The ceramic green sheet is produced by firing at a temperature of about 1000 ° C. in a reducing atmosphere.

  The electronic component mounted on the substrate 4 is electrically connected to, for example, a part of the wiring path 2 described later, and is led out to the outer surface of the substrate 4 via the wiring path 2. By connecting the lead-out portion to an external electric circuit, the electronic component is electrically connected to the external electric circuit, and transmission / reception of electric signals, power supply, grounding, and the like are performed.

  The resistor 1 is disposed on the substrate 4 for the purpose of controlling the current transmitted through the wiring path 2 and preventing noise from being applied to electronic components mounted on the wiring substrate 4.

  The resistor 1 is made of a resistive material having an electrical resistivity of about 0.01 Ωm, such as tin oxide.

  For example, if the resistor 1 is made of a resistor such as tin oxide, a paste that becomes a resistor made by adding an organic solvent, a binder, etc. to a tin oxide powder and kneading the substrate 4 is partially used. A predetermined pattern is printed on the surface of the substrate 4 (fired) so as to be in contact with the wiring path 2, and this is heat-treated at a temperature of about 900 ° C. in a nitrogen atmosphere and baked on the substrate 4. Is formed.

  A plurality of such resistors 1 are electrically connected to each other because more accurate control is required.

  The area and shape of each resistor 1 are determined in consideration of electrical characteristics required for the wiring board 4.

  That is, a resistance value necessary for obtaining predetermined electrical characteristics is calculated in advance for each resistor, and the size and shape of the resistor are determined.

  In this case, in consideration of the variation, the resistance value is set to be larger than the resistance value so that a predetermined resistance value and electrical characteristics can be obtained by trimming described later.

  In the example shown in FIG. 1, the resistor 3 has a substantially square quadrilateral shape, but may be an elongated rectangular shape (band shape), a circle, an ellipse, a pentagonal shape or more. Further, it may be a quadrangular shape whose corners are chamfered in an arc shape, or an elliptical shape having a linear portion in part.

  The resistor 3 is trimmed by means such as grinding using laser light and controlled to a predetermined resistance value. Therefore, the resistor 3 needs to be provided exposed on the surface of the substrate 4.

  Electrical connection between the plurality of resistors 1 is performed via the wiring path 2.

  A common measurement pad 3 for measuring the electrical resistance of both resistors is provided in the wiring path 2 between the resistors 1 so as to be exposed on the surface.

  In this way, the wiring path 2 between the resistors 1 is provided with a common measurement pad 3 for measuring the electric resistance value of both resistors 1 exposed on the surface, so that each resistor 1 can be measured. It is not necessary to form the pads 3 adjacent to each other, and even if the resistors 1 and the like are formed with a high density and a narrow interval between adjacent ones, the resistance of the resistors 1 is reduced by the common measuring pad 3. The value can be measured with high accuracy.

  In this case, since the resistance of the line path 2 can be predicted with high accuracy by increasing the precision of the printing technique for forming the wiring path and reducing the variation in the specific resistance of the printing material, the resistance to be measured for the resistance value The resistance value obtained by adding the resistances of the body 1 and the wiring path 2 to which the resistor 1 is electrically connected can be set as a target value at the time of trimming. It can be detected by measuring the resistance value of both the resistor 1 and the wiring path 2 through the measurement pad 3, and each resistor 1 can be accurately measured with the common measurement pad 3.

  The wiring path 2 and the measurement pad 3 are made of a metal material such as copper, silver, palladium, gold, platinum, tungsten, molybdenum, or manganese.

  For example, if the wiring path 2 and the measurement pad 3 are made of copper, a metal paste prepared by adding and kneading an organic solvent and a binder to copper powder is applied to a ceramic green sheet serving as the substrate 4 with a predetermined wiring pattern. It is formed by printing with.

  The wiring path 2 and the measurement pad 3 may be formed of different metal materials. However, in consideration of productivity and cost, it is preferable to form the same metal material.

  Since the measurement pad 3 needs to contact a measurement terminal (probe pin or the like: not shown) when measuring the resistance value of the resistor 1, the surface of the substrate 4 (the resistor 1 is formed). It is necessary to expose it on the same main surface as the above. The part of the substrate 4 on which the measurement pad 3 is formed may be planar or may have a shape in which the periphery of the substrate 4 is concaved to facilitate positioning of the probe pins and the like.

  Further, the wiring path 2 is not necessarily provided on the same surface as the resistor 1 (the main surface of the substrate 4 or the like), and may be provided inside the substrate 4. In this case, a via conductor is formed from the measurement pad 3 or the like to the inside of the substrate 4, and the wiring path 2 inside the substrate 4 and the measurement pad are electrically connected via the via conductor.

  If the wiring path 2 is provided inside the substrate 4, it is easier to secure a space for the resistor 1 and the measurement pad 3 in the substrate 4 that needs to be exposed and formed on the surface of the substrate 4. There is an effect of becoming.

  The measurement of the resistance value of the resistor by the measurement pad 3 is performed as follows, for example.

  First, the two probe pins connected to the resistance measuring device are brought into contact with the two measuring pads 3 positioned with the resistor 1 to be measured interposed therebetween (via the wiring path 2).

Next, the resistance between the two probe pins is measured.

  Then, correction / calculation in consideration of the resistance of the wiring path 2 which has been predicted and calculated in advance is performed by the resistance measuring instrument, and the resistance value of the measurement pad 3 is calculated.

  In the wiring board 9 of the present invention, it is preferable that the diameter of the measurement pad 3 is larger than the wiring width of the other part of the wiring path 2.

  In this case, since it becomes easier to recognize the measurement pad as a part different from the wiring path (with an image recognition device or the like), it becomes easier to make the measurement device terminal (probe pin, etc.) come into contact with the measurement pad. Since it is easy to apply the probe pin to the resistor, the resistance value can be measured more easily.

  Further, since the width of the measurement pad 3 is larger than the width of the wiring path 2, the resistance (rate) of the measurement pad 3 is extremely lower than that of the wiring path 2, and the measurement is prevented more reliably. Therefore, it is possible to further improve the accuracy of measurement of the resistance value of the resistor 1, and at the same time, the connectivity between the measurement pad 3 and the wiring path 2 is improved.

  Note that, in the portion connected to the resistor 1, the long side of the wiring path 2 is orthogonal to the line direction of the wiring path 2 in order to make the connection resistance as low as possible and to secure the area to be trimmed as much as possible. It is preferable that the resistor 1 is set to be connected in the longitudinal direction of the connecting portion.

  This connecting portion is formed as a part of the wiring path 2, and is formed, for example, by providing a pattern of a predetermined connecting portion on a printing plate used for printing a metal paste that becomes the wiring path 2. The

  In addition, except that the measurement pad 3 is connected to the resistor 1 via the wiring path 2 formed inside the substrate 4, the resistance of the wiring path 2 is kept as low as possible. It is preferable to be closer to the connecting portion.

  It should be noted that the present invention is not limited to the above-described embodiment, and various changes and improvements can be made without departing from the gist of the present invention. For example, the exposed surfaces of the wiring path 2 and the measurement pad 3 may be covered with a well-known protective plating layer such as nickel or gold so as to make it easier to prevent oxidative corrosion and to electrically connect probe pins and the like. . The resistor 1 may be covered with glass, resin, etc. after trimming.

(A) is a top view which shows an example of embodiment of the wiring board of this invention, (b) is a principal part enlarged plan view of (a).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Resistance body 2 ... Wiring path 3 ... Connection pad 4 ... Board 9 ... Wiring board

Claims (2)

A wiring board having a plurality of resistors and a wiring path for electrically connecting the resistors to each other, the wiring path between the resistors being a common for measuring the electric resistance value of both resistors A wiring board having a measurement pad exposed on the surface. The wiring board according to claim 1, wherein the diameter of the measurement pad is larger than the wiring width of the other part of the wiring path.

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