JPH08102402A - Resistor and manufacture method thereof - Google Patents

Abstract

PURPOSE: To enable the laser trimming amount to be reduced or eliminated by forming one end part of a resistor below the first electrode and the other end part below the second electrode and an adjust electrode as the third electrode to shorten the interval between the first and third electrodes than that between the first and second electrodes. CONSTITUTION: The first electrode 3c and the second electrode 3d are formed on both ends of the resistor on a substrate 1 comprising ceramics etc. An adjust electrode 4 corresponding to the third electrode covering the resistor 2 is formed on one end of the resistor 2. At this time, one end of this adjust electrode 4 is formed on the upper part of the resistor 2 while the other end of the adjust electrode 4 is formed on the upper part of the second electrode 3d. Besides, the substantial resistor length L corresponds to the length of the resistor 2 held between the first electrode 3c and the adjust electrode 4. Through these procedures, the resistance value can be adjusted simply by adjusting the forming position of the third electrode (the adjust electrode 4), thereby enabling the reduction of the laser trimming amount as well as the elimination of the laser trimming step itself to be made feasible.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rectangular chip resistor, a resistor compounded with a resistor network, a capacitor, a coil, etc., a resistor used as a resistor for a hybrid IC, and a method of manufacturing the same.

[0002]

2. Description of the Related Art In recent years, high performance and low cost have been demanded for resistors such as hybrid ICs and chip resistors.

A conventional rectangular chip resistor will be described below as an example. 8 and 9 show a conventional chip resistor, and for the sake of clarity, the protective layer of the resistor and the end face electrodes for mounting are omitted. In FIGS. 8 and 9, 1 is a substrate made of ceramic, 2 is a resistor, and 3a and 3b are electrodes. In FIG. 8, both ends of the resistor 2 are formed on the electrodes 3a. In FIG. 9, both ends of the resistor 2 are formed below the electrode 3b. The resistor 2 is adjusted to a predetermined resistance value through a trimming process using a laser or the like.

Conventionally, some efforts have been made as a method of adjusting the resistance value to a target value. In Japanese Patent Laid-Open No. 63-141358, an insulating film formed by dispersing ultrafine particles in a resin is formed on a completed resistor, and the resin is decomposed by laser firing or the like to form a conductor pattern. Is. However, in this technique, since laser irradiation is performed while measuring the resistance value for each resistor, the number of steps is the same as or more than the conventional laser trimming, and the manufacturing cost is increased.

In Japanese Patent Laid-Open No. 1-93193, resistance values are individually measured for resistors provided so as to connect between conductors of a substrate, and when the resistance value is higher than a target value, the resistor is used. It is disclosed that the conductor paste is applied on the top, fired, the resistance value is measured, and if the resistance value is still too high, the resistance value is adjusted by repeating the same step again. However, in the case of this case, since the conductor paste is directly applied onto the resistors by the nozzle directly, it takes a lot of time to form thousands of resistors on one substrate, which is not practical.

[0006]

In the above-mentioned conventional configuration, the resistance value is set to a low value and laser trimming is performed to adjust the resistance value to a desired value. For this reason, laser trimming cost is generated, and at the same time, microcracks are generated in the resistor and noise characteristics are deteriorated. In addition, since the resistance value can be adjusted only in the high direction, the trimming amount is inevitably large.

The present invention solves the above-mentioned problems of the prior art, in which the resistance value is adjusted while feeding back in the manufacturing process of the resistor, and the amount of laser trimming is reduced or laser trimming is performed. By omitting it, it is an object to provide a cheaper resistor having excellent noise characteristics.

[0008]

To achieve this object, a resistor according to the present invention comprises a first electrode and a second electrode provided on a substrate.
Electrode, a third electrode, a resistor connected to the first electrode, the second electrode, and the third electrode, and a protective layer covering the resistor, and one end of the resistor is the first electrode. The first electrode is formed below the first electrode and the other end is formed below the second electrode and below the adjustment electrode as the third electrode. And the third electrode is configured to have a short interval.

[0009]

With this configuration, the resistance value can be adjusted to a target value only by adjusting the formation position of the third electrode, the laser trimming amount can be reduced, and the laser trimming step itself can be omitted.

[0010]

【Example】

(Embodiment 1) An embodiment of the present invention will be described below with reference to the drawings.

FIGS. 1 and 2 show a resistor according to a first embodiment of the present invention. FIG. 1 is a partial sectional view in the middle of manufacturing, and FIG. 2 is a sectional view after completion. 1 will be described. A first electrode 3c and a second electrode 3d are formed on both ends of a resistor 2 on a substrate 1 made of ceramic or the like. Reference numeral 4 denotes an adjust electrode, which corresponds to a third electrode and is formed at one end of the resistor 2 so as to cover the resistor 2. One end of the adjusting electrode 4 is formed on the resistor 2, and the other end of the adjusting electrode 4 is formed on the second electrode 3d.
Further, L in FIG. 1 is a substantial resistance length, and the first electrode 3
It corresponds to the length of the resistor 2 sandwiched between c and the adjusting electrode 4.

Next, FIG. 2 will be described. In FIG. 2, reference numeral 5 denotes an end surface electrode, which is connected to the first electrode 3c and the second electrode 3d and is mounted on the circuit board by soldering or the like. 6
Is a protective layer which is formed on the resistor 2 and the adjustment electrode 4 to improve reliability and prevent electrical short circuit with other components during mounting. The end surface electrode 5 and the protective layer 6 shown in FIG. 2 are omitted in FIG.

In the present embodiment, the formation position of the adjusting electrode 4 is changed to increase or decrease the substantial resistance length L to adjust the resistance value to a target value. As shown in FIG. 1, the resistor 2 is formed between the first electrode 3c and the second electrode 3d, but the distance between the first electrode 3c and the adjustment electrode 4 (substantial resistance length L) is Since it is shorter, the resistance value of this resistor is determined by the actual resistance length L.
After adjusting the resistance value at the position where the adjusting electrode 4 is formed as shown in FIG. 1, the end face electrode 5 and the protective layer 6 are formed as shown in FIG.
To form a finished product.

(Embodiment 2) Next, an example of a method of manufacturing a resistor according to a second embodiment of the present invention will be described with reference to FIGS. FIG. 3 illustrates an example of a method of manufacturing a resistor according to the present invention, and FIG. 4 illustrates how to match resistance values.

In FIGS. 3 and 4, reference numeral 7 is a break line, which is used when the substrate 1 made of ceramic or the like is divided into a predetermined shape. Reference numeral 8 is an upper surface electrode, which is divided by the break line 7 to serve as a first electrode 3c and a second electrode 3d. FIG. 3A shows a state in which the resistor 2 is formed on the substrate 1. Next, as shown in FIG. 3B, the upper surface electrodes 8 are formed on both ends of the resistor 2. Then, as shown in FIG. 3C, the adjusting electrode 4 is provided at a position where a desired resistance value is obtained.
Is formed so as to cover one end of the resistor 2 and a part of the upper surface electrode 8. Thereafter, as shown in FIG. 3D, a protective layer 6 is formed so as to cover the resistor 2 and the adjustment electrode 4. After that, the substrate 1 is divided into a predetermined shape along the break lines 7, and end face electrodes are formed to complete a resistor.

Next, a method of adjusting the resistance value will be described with reference to FIG. 4A to 4C, the substantial resistance lengths L1, L2 and L3 are different from each other, and L1 <
There is a relationship of L2 <L3, and one end of the adjust electrode 4 is connected to the resistor 2 and the other end is connected to the upper surface electrode 8. If the sheet resistance of the resistor 2 and its shape are the same,
The resistance value of the completed resistor is in the order of L1 <L2 <L3. Thus, even if the same sample is used, a resistor can be manufactured while adjusting the resistance value to a target value by changing the formation position of the adjustment electrode 4.

A more detailed description will be given. First, as the substrate 1, a 100 mm square alumina substrate having break lines formed so as to obtain a resistor of 1.55 mm × 0.75 mm is used, and the resistor 2 is formed therein as shown in FIG. 3A. did. A commercially available thick film resistor material is used for the resistor 2.
It was baked at 850 ° C. Next, the upper surface electrodes 8 were formed on both ends of the resistor 2, and the break lines 7 were sandwiched therebetween. Here, silver-palladium electrode ink was used as the electrode forming material, and after printing this, it was baked at 850 ° C. to obtain the upper surface electrode 8.

Here, a probe was applied to the upper surface electrodes 8 formed on both ends of the resistor 2 by the 4-terminal method, and the resistance value was measured. The average resistance value obtained by measuring a plurality of resistance values is 7.19.
It was kΩ. The target resistance value here is 6.00 kΩ
Was set. The actual resistance length L was obtained by calculation, and the adjust electrode 4 was formed at this position as shown in FIG. Finally, as shown in FIG. 3D, the protective layer 6 was formed of a material mainly composed of resin. Then, the substrate 1 was divided into individual pieces at the break lines 7, and then the end face electrodes 5 were formed.

When a plurality of resistance values were measured with respect to the thus completed resistor, the average resistance value was 6.01 kΩ, and a resistor having a desired resistance value could be manufactured.

Further, when the substantial resistance length L was changed as shown in FIG. 4, it was confirmed that the resistance value of the finished resistor also changed. Generally, it is known that a resistor material formed of a thick film is slightly affected by the lot of the material and the temperature and atmosphere in the furnace at the time of firing, and its resistance value is changed by about several percent. ing. In the present embodiment, the resistance value of the resistor 2 sandwiched between the upper surface electrodes 8 can be formed to a predetermined resistance value after the resistance value is actually measured. Therefore, it is possible to absorb the influence of such resistance value variation and to obtain stable manufacturing conditions. It is possible to manufacture a resistor having a resistance value of

In the manufacturing method of this embodiment, after the resistor 2 is formed, the first electrode 3c, the second electrode 3d, and the adjust electrode 4 as the third electrode are formed. As described above, in this embodiment, since the resistor 2 can be formed on the substrate 1 without any unevenness caused by the electrodes, the method of forming the resistor 2 can be devised. As a method for directly forming the resistor 2 on the substrate 1, intaglio printing (direct and offset) or gravure printing (direct and offset) may be used in addition to the screen printing method to apply the resistor forming member. The amount can be stabilized.

Further, printing methods and drawing methods such as letterpress printing (direct and offset) and lithographic printing (direct and offset) can be used. There is a transfer method as an indirect method of forming the resistor 2 on the substrate 1. In this case, a hot stamp (a solid pattern is used to mold a resistance stamping member formed on a transfer film onto the substrate) is used. There are cases where a predetermined pattern is transferred onto the substrate and cases where the resistor pattern formed on the transfer film is transferred onto the substrate).

(Embodiment 3) Next, as a third embodiment of the present invention, an example of high precision adjustment of resistance value will be described with reference to FIGS. FIG. 5 shows a resistor whose resistance value can be adjusted with higher accuracy. In FIG. 5, the resistor 2 is formed so that the side in contact with the adjustment electrode 4 is wider than the side in contact with the first electrode 3c. By changing the pattern of the resistor 2 in this manner, the resistance value can be adjusted with high accuracy depending on the formation position of the adjustment electrode 4.

FIG. 6 shows the relationship between the substantial resistance length L (mm) and the resistance value R (kΩ) at that time. In FIG. 6, the straight line (1) is the case where the width of the resistor is constant, and the straight line (2) is the case where the width of the resistor is changed as shown in FIG. By forming the resistor partly wide in this way, the resistance value can be adjusted to a target value with a high precision of twice the actual resistance length L.

If desired, laser trimming may be performed. In this case, if a wide portion is selected and trimmed, more accurate trimming can be performed.

(Embodiment 4) Next, as a fourth embodiment of the present invention, another example of highly accurate adjustment of the resistance value will be described with reference to FIG. In FIG. 7, the resistor 2 is the first electrode 3
The thickness (cross-sectional area) is made larger on the side in contact with the adjusting electrode 4 than in the side in contact with c. In this way resistor 2
The resistance value can be adjusted more finely by changing the thickness of the adjusting electrode 4 by changing the thickness of the adjusting electrode 4.

As a result, the resistance value can be adjusted with higher accuracy as in the case shown in FIG. Also, laser trimming can be performed if necessary. In this case, if the thin portion of the resistor 2 is selected, the laser trimming can be performed at a higher speed and the trimming cost can be reduced.

Here, as the substrate 1, aluminum nitride, dielectric ceramics, ferrite ceramics or the like may be used instead of the alumina substrate. Further, when a metal core substrate in which a metal plate is covered with ceramic, resin or the like is used, a resistor which is hard to break can be manufactured.

Further, this resistor can be applied not only to a single resistor or a resistor array but also to a composite component other than the hybrid IC. For example, it is easy to form a composite by combining with a multilayer ceramic capacitor, a chip coil, a chip inductor, a chip ceramic module, or the like. In particular, when combined with an ordinary capacitor or inductor, it is difficult to trim structurally, and the trimming deteriorates the noise characteristic. By using the resistor described in the present invention for such a purpose, it is possible to manufacture a highly accurate composite component without deteriorating characteristics such as noise.

As the resistor forming member, a thin film resistor material such as nichrome may be used in addition to the thick film resistor material such as ruthenium oxide to form the resistor by the thin film method.
Further, in the present invention, the resistance value can be adjusted with high accuracy even when the resistor is formed by electroless plating, matrix plating, or the like, even when the resistor is directly attached to the substrate or sprayed.

[0031]

As described above, according to the present invention, the accurate resistance value of the resistor itself formed between the first electrode and the second electrode provided on the substrate is known, and the resistance value is used as a basis. By forming the third electrode as the adjusting electrode at a predetermined position on the resistor, the resistance value can be accurately formed to a target value. Therefore, it is possible to manufacture a resistor that can obtain a target resistance value with a high yield without being affected by variations in the resistor material or the substrate and without performing laser trimming.

[Brief description of drawings]

FIG. 1 is a partially cutaway perspective view showing a resistor according to a first embodiment of the present invention.

FIG. 2 is a sectional view of the same.

FIG. 3 is a sectional view illustrating an example of a method of manufacturing a resistor showing a second embodiment of the present invention.

FIG. 4 is a sectional view illustrating a method of adjusting resistance values according to a second embodiment of the present invention.

FIG. 5 is a partially cutaway perspective view showing a resistor capable of adjusting a resistance value with higher accuracy according to a third embodiment of the present invention.

FIG. 6 is a substantial resistance length L in the third embodiment of the present invention.
(Mm) and a characteristic diagram showing the relationship between the resistance value R (kΩ) at that time

FIG. 7 is a partially cutaway perspective view illustrating another example of highly accurate resistance value adjustment according to the fourth embodiment of the present invention.

FIG. 8 is a perspective view showing a conventional chip resistor.

FIG. 9 is a perspective view showing another conventional resistor.

[Explanation of symbols]

 1 Substrate 2 Resistor 3c First Electrode 3d Second Electrode 4 Adjust Electrode 5 End Face Electrode 6 Protective Layer 7 Breakline 8 Top Electrode

Claims (4)

[Claims] 1. A first electrode, a second electrode, and a third electrode provided on a substrate, a resistor connected to the first electrode, the second electrode, and the third electrode, and A protective layer covering the resistor, one end of the resistor is formed under the first electrode, the other end is formed under the second electrode and under the adjust electrode as the third electrode, A resistor configured such that the distance between the first electrode and the third electrode is shorter than the distance between the first electrode and the second electrode. 2. A first electrode, a second electrode, and a third electrode provided on a substrate, a resistor connected to the first electrode, the second electrode, and the third electrode, and A protective layer covering the resistor, one end of the resistor is formed under the first electrode, the other end is formed under the second electrode and under the adjust electrode as the third electrode, The distance between the first electrode and the third electrode is shorter than the distance between the first electrode and the second electrode, and the portion of the resistor that is in contact with the first electrode is wider than the portion of the resistor that is in contact with the third electrode. Configured resistor. 3. A first electrode, a second electrode, and a third electrode provided on a substrate, a resistor connected to the first electrode, the second electrode, and the third electrode, and A protective layer covering the resistor, one end of the resistor is formed under the first electrode, the other end is formed under the second electrode and under the adjust electrode as the third electrode, A film in which the distance between the first electrode and the third electrode is shorter than the distance between the first electrode and the second electrode, and the portion of the resistor which is in contact with the first electrode is in contact with the third electrode. A resistor with a thick structure. 4. A resistor is formed on a substrate, and then a first electrode and a second electrode are formed on both ends of the resistor, respectively, and a first electrode and a second electrode are formed between the first electrode and the second electrode. 4. The method of manufacturing a resistor according to claim 1, wherein a resistance value is measured, and an adjust electrode as a third electrode is formed on the resistor at a position where a target resistance value is obtained. .