JP2006054398A - Resistor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resistor in which a very low resistance value is realized on an insulating substrate. <P>SOLUTION: Surface resistance objects 8a and 8b are electrically connected between electrodes 4 and 5, and 6 and 7, respectively, formed on front and rear surfaces of a ceramic substrate 1b, while facing each other. The electrode 4 provided on the front surface and the electrode 6, provided on the rear surface, are connected together with the use of a side electrode 12a. The electrode 5 formed on the front surface and the electrode 7 formed on the rear surface are connected together with the use of a side electrode 12b. The resistance object 8a on the front surface and the resistance object 8b on the rear surface are connected in parallel. With the view to limiting in the development of a material having extremely low resistance value, the very low resistance value which should be essentially demonstrated is cut by half without a specific material, and the resistor having high power ruggedness is obtained. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to low resistance resistors such as low resistance chip resistors and jumper resistors.

A conventional general chip resistor will be described with reference to FIGS. 4, 5, 6 -A and 6 -B.
In an insulating substrate such as a large-sized ceramic substrate 1 in which the dividing lines 2 and 3 are provided in advance in the vertical and horizontal directions as shown in FIG. 4, the dividing lines 2 and 3 form small pieces 1a as shown in FIGS. 6A and 6B. The conductor films constituting the surface electrodes 4, 5 and the back electrodes 6, 7 facing both the front and back surfaces of the partitioned longitudinal edges are formed by printing, drying, and firing silver or a silver-based conductor paste.
Further, a resistor paste mainly composed of ruthenium is printed and fired on the surface of the inner region of the electrodes 4 and 5 to form the resistors 8 independently for each piece 1a.

  Thereafter, as shown in FIGS. 5 and 6-A, after forming an insulating protective film, for example, a glass film 9 on the resistor 8, laser trimming is performed to finish to a predetermined resistance value, and further by the trimming. A protective film 11, for example, a glass film or a resin layer is formed so as to cover the generated trimming groove 10, and a mark (not shown) indicating a resistance value is applied to the surface of the protective film 11.

  Thereafter, the ceramic substrate 1 is divided into strips along the dividing line 2 (FIG. 4), and the fracture surface arranged in the longitudinal direction of the strips is sputtered by Ni—Cr material or the like using a conductor paste. The side electrode 12 is formed by dipping. Thereby, the electrode 4 and the electrode 6 and the electrode 5 and the electrode 7 are electrically connected to each other. Then, it is divided into small pieces (chips) of the smallest unit along the dividing line 3, and exterior plating such as nickel plating 13 and solder plating 14 is applied to obtain a chip resistor 15 as shown in FIG. , Patent Document 2 and Patent Document 3).

JP-A-60-27104 JP-A-4-144203 JP 2003-332101 A

  In the case of a jumper resistor, instead of the resistor 8, when the electrodes 4 and 5 are formed on the surface of the ceramic substrate 1, the conductor layers constituting these electrodes are extended and formed integrally, except for the trimming process. A manufacturing method similar to a chip resistor is employed.

  In order to cope with further miniaturization of handy terminals and mobile devices, chip resistors and chip network resistors in the field of communication equipment are similarly aimed at miniaturization, and the length (product width) in the short side direction is 0.3 mm. “0603” chip resistors are being recognized, and “0402” chip resistors having a length of 0.2 mm in the short side direction are about to enter the market.

On the other hand, according to the prior art, the lower limit value of the resistance value that can appear due to the fact that the resistor and conductor wiring, which are functional elements, can only be formed in one region of the insulating substrate surface is subject to the following restrictions. .
Resistance on the surface of the insulating substrate according to the sheet resistance value ρ of the resistor paste or conductor paste, the effective length (L) of the resistor formed between the conductor layers, the width (W) of the resistor, and the film thickness (t) of the resistor The value R is
Since there is a relationship of R = ρ * L / (W * t) and each value is a finite value, there is a numerical wall as a first problem in the lower limit value of the resistance value that can appear.

  In addition, the surface area of the small piece 1a is reduced as the size is reduced, and the surface area of the region in which the resistor can be formed is reduced in proportion thereto, and the volume of the resistor that can be formed is also reduced. A decrease in power durability exists as a second problem.

  Table 1 shows the relationship between the product size and its durability power. As apparent from Table 1, although the value of the maximum durable power is reduced by downsizing the product, for example, there is a demand for a highly durable product for power in the circuit configuration around the power source. The resolution of the second problem is extremely significant.

  The first challenge for the numerical values shown in Table 1 has evolved with the progress of product development, and it is possible to generate various performance improvements such as extremely low resistance values and power handling characteristics that exceed the limits of the size of conventional products. It has sex. The present invention proposes a chip resistor and a jumper resistor that can be achieved without waiting for the advancement of the peripheral technology, and that can realize an extremely low resistance value that can exhibit the benefits of the advancement of the peripheral technology as a function that doubles the effect. To do.

The resistor of the present invention is configured such that a resistor is connected between electrodes formed to face the front and back surfaces of an insulating substrate, and the resistor is connected via the electrode formed on the front surface and the electrode formed on the back surface. The body is connected in parallel.
Further, the jumper resistor of the present invention connects a conductor between the electrodes formed opposite to the front and back surfaces of the insulating substrate, respectively, via the electrode formed on the front surface and the electrode formed on the back surface. The conductors are connected in parallel.

The resistor is formed by printing and firing conductor layers constituting an electrode formed by mixing silver or silver and palladium in an appropriate amount on opposite end surfaces of the surface of the insulating substrate, and overlapping the electrodes between the electrodes. The surface resistor, the main material of which is ruthenium, is printed and fired.
Further, the resistor is provided by printing and firing a conductive layer that constitutes an electrode formed by mixing silver or silver and palladium in an appropriate amount on opposite end surface portions of the back surface of the insulating substrate so that the electrode overlaps between the electrodes. A resistor on the back surface mainly composed of ruthenium is printed and fired.

  The jumper resistor is provided by printing and baking an integral conductor wiring layer formed by mixing silver or silver and palladium in an appropriate amount between the electrodes on the front surface and the electrodes on the back surface.

  Conventionally, one functional element is mounted on one product by preventing the resistor or conductor wiring layer from overlapping each other except for the lead-out of the outer electrode. In the present invention, two functional elements are mounted on one product. By mounting functional elements and connecting them in parallel, it becomes possible to configure a chip resistor and a jumper resistor with extremely low resistance values by configuring a parallel circuit with a low resistance that can be individually formed.

  When the resistance value of the front surface resistor formed on the surface of the insulating substrate is Ra and the resistance value of the back surface resistor formed on the back surface of the insulating substrate is Rb, the actual resistance value of these resistors is the same resistance value r. Then, the combined resistance value Ra * Rb / (Ra + Rb) = r / 2 connected in parallel is obtained. Here, if the resistance value r is an extremely low resistance value that can be selected by design, the decrease in the resistance value can be further doubled.

  On the other hand, as for the power characteristics, since the two resistors formed on the front and back of the insulating substrate are connected in parallel, it is possible to inject a current twice as large as the current that each resistor can inject. As a result, it has twice the power durability characteristics, and the second problem can be solved. Further, since the resistance values on the front and back sides are substantially equal, there is no imbalance between the resistance values on the front and back sides. Therefore, the current density does not concentrate on one side and it is not biased, and a resistor with high accuracy and reliability can be realized as a product. Moreover, the same characteristic can be obtained also about a jumper resistor.

In the following, an embodiment of the present invention based on the technical idea of parallel connection will be described with reference to FIG. 1, FIG. 2-A, FIG. 2-B and FIG.
In an insulating substrate such as a large-sized ceramic substrate 1 in which dividing lines 2 and 3 are previously provided in the vertical and horizontal directions as shown in FIG. 4, the longitudinal direction divided into small pieces 1 b as shown in FIGS. 2A and 2B. The conductive films constituting the surface electrodes 4, 5 and the back electrodes 6, 7 are formed on the front and back surfaces of both edges by printing, drying and baking silver or silver-based conductive paste.

Further, as shown in FIG. 2A, the resistor 8a on the surface is formed by printing and baking a resistor paste mainly composed of ruthenium between the electrodes 4 and 5 on the surface of an inner region of these electrodes. Each is formed independently for each small piece 1b.
Further, as shown in FIG. 2B, the resistor 8b on the back surface is formed by printing and baking a resistor paste mainly composed of ruthenium between the electrodes 6 and 7 on the surface of one inner region of these electrodes. Each is formed independently for each small piece 1b.

Thereafter, as shown in FIG. 1 and FIG. 2A, after forming an insulating protective film, for example, a glass film 9a on the resistor 8a on the surface, laser trimming is performed to finish to a predetermined resistance value. A protective film 11a, for example, a glass film or a resin layer is formed so as to cover the trimming groove 10a generated by the trimming, and a mark (not shown) indicating a resistance value is applied to the surface of the protective film 11a.
Further, as shown in FIGS. 1 and 2-B, after forming an insulating protective film, for example, a glass film 9b, on the resistor 8b on the back surface, laser trimming is performed to finish to a predetermined resistance value. A protective film 11b, for example, a glass film or a resin layer is formed so as to cover the trimming groove 10b portion generated by the trimming.

  Thereafter, the ceramic substrate 1 is divided into strips along the dividing line 2 (FIG. 4), and the fractured surface arranged in the longitudinal direction of the strips is sputtered by Ni—Cr material or the like using a conductor paste. Side electrode 12a is formed by a dip method. As a result, the edges of the electrodes 4 and 6 and the electrodes 5 and 7 are electrically connected by overlapping the side electrode 12a. Thereafter, it is divided into small pieces (chips) of the smallest unit along the dividing line 3 and subjected to exterior plating such as nickel plating 13 and solder plating 14 to obtain the chip resistor 15a of the present invention as shown in FIG.

  In the case of a jumper resistor, when forming the electrode 4 and the electrode 5, the electrode 6 and the electrode 7 on the surface of the ceramic substrate 1, instead of the front surface resistor 8a and the back surface resistor 8b, these electrodes In the meantime, the conductor layers constituting these electrodes are extended and formed integrally on the surface, and a manufacturing method similar to the above manufacturing method is adopted except for trimming.

A suitable trimming method will be described.
The resistance values of the front surface resistor 8a and the back surface resistor 8b are as follows. The front surface electrode 4 and the back surface electrode 6 are connected to the front surface electrode 5 and the back surface electrode 7 by the side surface electrodes 12a and 12b, respectively. In consideration of the fact that the two resistors are connected in parallel, the resistance values of the resistors 8a and 8b, which are formed independently of each other, are temporarily set to twice the target resistance value of the finished product before trimming. A target resistance value is determined, and the initial resistance value of the resistor 8a is increased by trimming until the temporary target resistance value is reached, and then the resistance value of the resistor 8b is also increased.

  Here, in order to make the resistance values of the resistor 8a and the resistor 8b substantially equal, assuming that the initial combined resistance value before trimming is R0 and the target combined resistance value is R, the difference (R−R0) First, the resistance value of the resistor 8a is increased to (1/2) * (R-R0), and then the resistor 8b is (1/2) * (R-R0). Increase until the resistance value becomes. As a result, both the resistor 8a and the resistor 8b can reproduce substantially the same trimming state, and the resistance values are almost equal.

An example of the trimming will be specifically described using numerical values.
For example, if the resistance value of the finished chip resistor is 1Ω, the resistance values of the resistor 8a and the resistor 8b are set to the same value so that the resistors are connected in parallel. Assuming that the resistance value of the resistor 8a and the resistor 8b is approximately ½, the resistance value of each resistor is set to twice the resistance value of the finished product at the time of trimming. Set 2Ω.
Here, if the rate of increase in resistance value due to trimming is set to 1.2 times, a resistor having a resistance value 2Ω ÷ 1.2≈1.67Ω before trimming is formed.

  Thereafter, the resistance value is increased by laser trimming until the initial resistance value of 1.67Ω of the resistor 8a becomes the temporary target resistance value of 2Ω. Next, the resistance value is increased by laser trimming until the initial resistance value of 1.67Ω of the resistor 8b becomes the temporary target resistance value of 2Ω. Thus, by adjusting the resistance values of the two resistors by laser trimming, the two resistors have the same target resistance value of 2Ω, and both resistors have the same trimming traces 10a, 10b. As shown in FIG. 3, both of the remaining widths 16 that are not trimmed of the resistors are secured to approximately the same level, and the resistance values of the resistors on the front and back of the finished product are equal. As a result, it is possible to finish without unevenness between the front and back units so that the combined resistance of both resistors is 1Ω. In FIG. 3, the illustration of the glass film provided on the resistor is omitted.

Thus, when the resistors 8a and 8b are connected in parallel, the resistance value of the finished product is replaced by 1Ω, which is 1/2, from the temporary target resistance value 2Ω.
That is, when the two resistors are viewed using the pair of side electrodes of each chip resistor as a product as a terminal, a parallel circuit including the two resistors is formed between the pair of side electrodes.

In the case of a jumper resistor, instead of the resistor, when forming the front and back electrodes 4, 5, 6 and 7, the conductor layer serving as an electrode is extended to form a conductor wiring layer.
Currently, there is a limit to the development of extreme resistance materials, and the resistors and jumper resistance components of the present invention can be implemented within the range of conventional manufacturing processes, and are inherently demonstrated in conventional materials without the need for special materials. The value of the extremely low resistance to be reduced can be further halved, and it has approximately twice the size of the product with respect to power durability. However, a chip component having an extremely low resistance value and high power durability can be provided.

  As an example of the resistor of the present invention, a thick film chip resistor in which the resistor is embodied by a thick film printing method is shown. However, the resistor based on the technical idea of the present invention is a NiCr resistor. It can also be diverted to a thin film resistor formed of a Ta-based thin film resistor.

It is sectional drawing of this invention resistor. It is a principal part top view of the surface of this invention resistor. It is a principal part top view of the back surface of this invention resistor. It is a principal part top view explaining the trimming state of the resistor of this invention resistor. It is a top view of the large format ceramic substrate with which it uses for manufacture of this invention resistor and the conventional resistor. It is sectional drawing of the conventional resistor. It is a principal part top view of the surface of the conventional resistor. It is a principal part top view of the back surface of the conventional resistor.

Explanation of symbols

4, 5 .. Front electrode 6, 7, .. Back electrode 8a .. Front resistor 8b .. Back resistor 12a, 12b .. Side electrode for connecting front resistor and back resistor in parallel

Claims (5)

  A resistor comprising resistors formed on the front and back surfaces of an insulating substrate, respectively, connected in parallel.   A resistor is connected between the electrodes formed opposite to the front and back surfaces of the insulating substrate, and the resistors are connected in parallel via the electrode formed on the front surface and the electrode formed on the back surface. Feature resistor. 3. The resistor according to claim 1, wherein the resistance values of the resistors formed on the front surface and the back surface of the insulating substrate are trimmed approximately equally.   A jumper resistor comprising conductors respectively formed on the front and back surfaces of an insulating substrate connected in parallel.   Conductors are connected between the electrodes formed facing the front and back surfaces of the insulating substrate, respectively, and the conductors are connected in parallel via the electrodes formed on the front surface and the electrodes formed on the back surface. Characteristic jumper resistor.

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