JP2008187159A - Pad pattern for printed wiring board, and method for detecting current or voltage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To accurately detect current or voltage flowing through or applied to wiring patterns on a printed wiring board. <P>SOLUTION: Pad patterns 20R, 20L, which are formed on a printed wiring board to mount a resistor component having electrodes at both ends in the longitudinal direction, include electrode junctions 22R, 22L which are formed at positions where each electrode of the resistor component is located and are bonded to the electrodes of the resistor component, wiring pattern coupling parts 26R, 26L which are formed at peripheral positions of the electrode junctions to be connected with wiring patterns for carrying current or voltage to be detected, and power supply parts 24R, 24L which extend from the wiring pattern coupling parts to an outer central position of the electrode junctions to connect between the electrode junctions and the wiring pattern coupling parts. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a pad pattern for arranging a resistive component on a printed wiring board, and a current or voltage detection method.

  In the conventional technology, when a resistance component is surface-mounted on a circuit board, a pad pattern having the same size as the electrode of the resistance component is formed at a position where the resistance component is placed, and the resistance component is applied to the pad pattern. It was joined. An example of such a prior art is shown in Patent Document 1.

In Patent Document 1, a wiring pattern on a circuit board is drawn out from a pad pattern along a direction in which a current to be detected flows, and is further bent at a right angle and drawn out. As a result, the inductance of the resistance component is canceled out to reduce the detection error.
JP 2002-372551 A

  However, in the conventional pad pattern, depending on the connection state of the wiring pattern that supplies current or voltage (for example, the position of the pad pattern to which the wiring pattern is connected, the width of the wiring pattern, etc.), the bias pattern is biased toward the potential change in the resistance component In some cases, current or voltage cannot be detected with high accuracy.

  The present invention has been made to solve the above-described problem, and an object of the present invention is to provide a pad pattern for arranging a resistive component and a current or voltage detection method capable of accurately detecting current or voltage. And

  In order to achieve the above-described object, the present invention provides a pad pattern formed on a printed wiring board for mounting a resistive component having electrodes at both ends in the longitudinal direction, wherein each electrode of the resistive component is disposed. An electrode joint that is formed at a position that is joined to an electrode of a resistance component, a wiring pattern connection that is formed at a peripheral position of the electrode joint and is connected to a wiring pattern that transmits a current or voltage to be detected, and wiring And a power feeding portion that extends from the pattern connection portion to an outer central position of the electrode joint portion and connects the electrode joint portion and the wiring pattern connection portion.

  The present invention also relates to a method of detecting current or voltage using a resistance component mounted on an electrode joint on a printed wiring board, via a wiring pattern connection formed at a peripheral position of the electrode joint. The current or voltage to be detected from the wiring pattern, and the current or voltage to be detected is supplied to the electrode joint through the power supply section that connects the wiring pattern connection section to the outer center position of the electrode joint section. And a step of applying a current or voltage to be detected to the resistance component via the electrode joint portion.

  ADVANTAGE OF THE INVENTION According to this invention, the pad pattern for resistive component arrangement | positioning which can detect an electric current or a voltage accurately, and the detection method of an electric current or a voltage can be provided.

  Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the description, the same reference numerals are used for the same elements or elements having the same function, and redundant description is omitted.

  With reference to FIG. 1 and FIG. 2, the printed wiring board 1 which concerns on embodiment of this invention is demonstrated. FIG. 1 shows a state before the resistance component 10 is bonded to the printed wiring board 1, and FIG. 2 shows a state where the resistance component 10 is bonded to the printed wiring board 1.

  The resistance component 10 includes a resistor 12 for detecting current or voltage, and a pair of electrodes 14R and 14L formed at both ends of the resistor 12. The resistor 12 has a rectangular parallelepiped shape and extends in the longitudinal direction along the printed wiring board 1. The pair of electrodes 14 </ b> R and 14 </ b> L are formed at both ends in the longitudinal direction of the resistor 12. The pair of electrodes 14R, 14L are bonded to the pad patterns 20R, 20L formed on the printed wiring board 1, so that the resistance component 10 is surface-mounted on the printed wiring board 1.

  The pad patterns 20R and 20L are formed on the printed wiring board 1 at positions where the resistance component 10 is disposed. The pad patterns 20R and 20L are made of copper like the wiring patterns 50R and 50L formed on the printed wiring board 1, and are formed simultaneously with the wiring patterns 50R and 50L in the manufacturing process of the printed wiring board 1.

  The pad patterns 20R and 20L are formed corresponding to the electrodes 14R and 14L of the resistance component 10, respectively. The pad pattern 20R corresponding to the electrode 14R on the right side in the drawing includes an electrode bonding portion 22R, a wiring pattern connection portion 26R, and a power feeding portion 24R. Similarly, the pad pattern 20L corresponding to the left electrode 14L in the drawing includes an electrode bonding portion 22L, a wiring pattern connection portion 26L, and a power feeding portion 24L.

  The electrode joint portions 22R and 22L are formed at positions where the electrodes 14R and 14L of the resistance component 10 are disposed. The electrode joint portions 22R and 22L have the same rectangular shape as the electrodes 14R and 14L, corresponding to the rectangular shape of one surface of the electrodes 14R and 14L. The electrodes 14R and 14L of the resistance component 10 are placed on and joined to the electrode joint portions 22R and 22L.

  The wiring pattern connection portions 26R and 26L are formed at positions around the electrode joint portions 22R and 22L, and are connected to the wiring patterns 50R and 50L that transmit the current or voltage to be detected. In particular, the wiring pattern connection portions 26R and 26L extend from positions spaced outward in the longitudinal direction of the electrode bonding portions 22R and 22L to positions spaced on both sides in the width direction of the electrode bonding portions 22R and 22L. It is formed so as to surround 22L.

  The power feeding portions 24R and 24L extend straight from the center position outside the electrode joint portions 22R and 22L to the outside in the longitudinal direction of the resistance component 10, and are connected to the wiring pattern connection portions 26R and 26L. Since the power feeding units 24R and 24L have a long and narrow shape, uniform potential changes can be generated inside the resistor 12. The line lengths of the power feeding units 24R and 24L for generating a uniform potential change depend on the line thickness of the power feeding units 24R and 24L.

  An example of specific dimensions of the resistor component 10 and the pad patterns 20R and 20L will be described. In the resistance component 10, the dimension of the resistor 12 in the longitudinal direction is about 5 mm, and the dimension in the width direction is about 3 mm. In the pad patterns 20R and 20L, the dimension in the longitudinal direction of the electrode joint portions 22R and 22L is about 2 mm, and the dimension in the width direction is about 3 mm. The line lengths (dimensions in the longitudinal direction) of the power feeding units 24R and 24L are about 5 mm, and the line widths (dimensions in the width direction) are about 100 μm. Here, in order to generate a uniform potential change, the line lengths of the power feeding units 24R and 24L are set to 40 times or more of the line width. In FIG. 1 and FIG. 2, for convenience of explanation, the resistance component 10 and the pad patterns 20R and 20L are shown with dimensions different from actual dimensions.

  In the present embodiment, by adopting the above-described pad patterns 20R and 20L, uniform potential changes can be generated inside the resistor 12. Regarding this effect, a voltage phase distribution diagram (FIGS. 3, 4, and 5) that is a DC analysis result of a pad pattern different from the present embodiment, and a voltage that is a DC analysis result of the pad patterns 20R and 20L of the present embodiment. This will be described in comparison with the phase distribution diagram (FIG. 6). 3 to 6, equipotential surfaces for each constant potential are shown inside the resistor component and the pattern.

  As shown in FIG. 3, when the resistive component is joined to a wide wiring pattern extending from the side of the resistive component, the equipotential surface inside the resistive component is larger than the longitudinal direction of the resistive component. Inclined. Further, as shown in FIG. 4, even when the resistive component is joined to a narrow pattern extending from the side of the resistive component, the equipotential surface inside the resistive component is larger than the longitudinal direction of the resistive component. Inclined. Further, as shown in FIG. 5, when the resistance component is bonded to a thick pattern that bends at a right angle on the outside in the longitudinal direction of the resistance component, the equipotential surface inside the resistance component is as shown in FIGS. Compared to the longitudinal direction of the resistance component, it is still fairly uniform. Therefore, in the pad patterns shown in FIGS. 3 to 5, the equipotential surface inside the resistance component is inclined, and a current flows in the oblique direction inside the resistance component. Therefore, if the connection position of the wiring pattern changes, the potential difference generated in the resistance component changes, so that it becomes difficult to detect the current or voltage with high accuracy.

  On the other hand, in the pad patterns 20R and 20L of the present embodiment, the wiring pattern connection portions 26R and 26L are formed around the electrode joint portions 22R and 22L, and the long and thin power supply portions 24R and 24L are formed. , 26L to the outer center position of the electrode joints 22R, 22L, and the current or voltage to be detected is supplied to the electrode joints 22R, 22L, the result shown in FIG. 6 can be obtained. That is, as shown in FIG. 6, the equipotential surfaces in the electrode joint portions 22 </ b> R and 22 </ b> L spread in a ripple shape from the connection position of the power feeding portions 24 </ b> R and 24 </ b> L, and are almost planar from the center of the resistance component 10. In any position, the equipotential surface is axisymmetric with respect to the center line of the resistance component 10. As described above, in the pad patterns 20R and 20L of the present embodiment, no matter which direction the wiring patterns 50R and 50L extend, and how wide the wiring patterns 50R and 50L are, the inside of the resistance component 10 Can generate a uniform potential change. Therefore, in the pad patterns 20R and 20L of the present embodiment, even if the connection positions of the wiring patterns 50R and 50L are changed, the potential difference generated in the resistance component 10 hardly changes. Therefore, the current difference is measured by measuring the potential difference generated in the resistance component 10. Alternatively, the voltage can be detected with high accuracy.

  Further, in the pad patterns 20R and 20L of the present embodiment, since the wiring pattern connection portions 26R and 26L are formed so as to surround the electrode joint portions 22R and 22L, the wiring patterns 50R and 50L can extend from any direction. The wiring patterns 50R and 50L can be connected to the wiring pattern connection portions 26R and 26L. For this reason, at the time of designing the printed wiring board 1, the designer does not need to consider the extending direction of the wiring patterns 50R, 50L, and can reduce the design burden of the wiring patterns 50R, 50L.

  Next, a modification of the above-described embodiment will be described with reference to FIG. FIG. 7 shows a state before the resistance component 10 is bonded to the printed wiring board 3 in the modification.

  In the pad patterns 30R, 30L according to the modified example, the wiring pattern connection portions 36R, 36L only extend from positions spaced outward in the longitudinal direction of the electrode joint portions 32R, 32L to the connection positions with the wiring patterns 50R, 50L. Yes, it is not formed so as to surround the electrode joints 32R, 32L. As described above, the wiring pattern connection portions 36R and 36L may be connected to the wiring patterns 50R and 50L even if they are not formed so as to surround the electrode bonding portions 32R and 32L. Even in the pad patterns 30R and 30L of this modified example, since the current or voltage to be detected is supplied via the power feeding units 34R and 34L, an equal potential change can be generated inside the resistance component 10, and the current Alternatively, the voltage can be detected with high accuracy.

It is a 1st perspective view which shows the pad pattern of this embodiment. It is a 2nd perspective view which shows the pad pattern of this embodiment. It is a figure which shows the DC analysis result of the 1st comparative example of a pad pattern. It is a figure which shows the DC analysis result of the 2nd comparative example of a pad pattern. It is a figure which shows the DC analysis result of the 3rd comparative example of a pad pattern. It is a figure which shows the DC analysis result of the pad pattern of this embodiment. It is a perspective view which shows the pad pattern of a modification.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Printed wiring board, 10 ... Resistor component, 12 ... Resistor, 14R, 14L ... Electrode, 20R, 20L ... Pad pattern, 22R, 22L ... Electrode junction part, 24R, 24L ... Power feeding part, 26R, 26L ... Wiring pattern Connection part, 50R, 50L ... wiring pattern.

Claims (4)

A pad pattern formed on a printed wiring board for mounting a resistive component having electrodes at both ends in the longitudinal direction,
An electrode bonding portion formed at a position where each electrode of the resistance component is disposed, and bonded to an electrode of the resistance component;
A wiring pattern connecting portion formed at a peripheral position of the electrode joint portion and connected to a wiring pattern for transmitting a current or voltage to be detected;
A power feeding part that extends from the wiring pattern connection part to an outer central position of the electrode joint part and connects the electrode joint part and the wiring pattern connection part,
A pad pattern characterized by comprising:   The pad pattern according to claim 1, wherein the wiring pattern connection portion is formed so as to surround the electrode bonding portion. A method of detecting current or voltage using a resistance component mounted on an electrode joint on a printed wiring board,
Capturing the current or voltage to be detected from the wiring pattern via the wiring pattern connecting portion formed at the peripheral position of the electrode joint; and
Supplying the current or voltage to be detected to the electrode joint through a power feeding part that connects the wiring pattern connection part to the outer center position of the electrode joint; and
Applying the current or voltage to be detected to the resistance component via the electrode junction;
A current or voltage detection method including:   The current or voltage detection method according to claim 3, wherein the wiring pattern connection portion is formed so as to surround the electrode joint portion.