JPH097809A - Thin film resistor and its manufacturing method - Google Patents

Abstract

PURPOSE: To manufacture the title resistor having less irregularities on its surface using a simple method by a method wherein a pair of separated of resistor layer striding over both electrodes while measuring the resistance value between these electrodes for finishing the evaporation when the resistance value reaches a specific value. CONSTITUTION: A measuring device 8 is arranged on the back 1A side of a substrate 1 through the intermediary of through holes 7 formed in respective electrodes 5 while a mask 10 and a shutter 11 are successively arranged from the substrate 1 side between a target 9 and the substrate 1. Next, the forming particles of a resistor layer 6 flow out of the target 9 are made to adhere to the surface of the substrate 1 while restricting the formation area of the resistor layer 6 by the mask 10. Next, the resistance values between the electrodes 5, 5 are continuously measured and when the measuring device 8 measures the target resistance value or the measured value enters the range of allowable difference of the target resistance value, the forming particles flew out of the target 9 are shut off from reaching the surface of the substrate 1.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in a chip-shaped thin film resistor and a manufacturing method thereof.

[0002]

2. Description of the Related Art Conventionally, a general chip resistor has a pair of electrodes formed on the surface of a ceramic substrate having a thickness of about 0.5 mm by a thick film method (printing and firing), and a thick film method is provided between both electrodes. Alternatively, the resistor is formed in a film shape by a thin film method (evaporation). In the thick film method and the thin film method, however, a predetermined resistance value can be obtained no matter how accurately the printing conditions and the evaporation time are performed. Since it is difficult, after forming the resistor, it is common to adjust the resistance within a tolerance by notching a part of it by laser trimming or sandblasting while measuring the resistance.

[0003]

However, when the resistance value is adjusted as described above, various problems as described below occur. That is, in recent years, in order to improve the production efficiency and miniaturize the chip resistors described above (minimum size is 1 mm in length and 0.5 mm in width), a plurality of regions divided by vertical and horizontal slits on the surface of a large ceramic substrate. In addition, it is necessary to form the above-mentioned pair of electrodes and the resistor in the form of films, respectively, and then trim by the slit in the state of the substrate before the division. However, when attempting to trim the substrate in such a state, the electrodes that should be electrically separated from each other may be short-circuited due to the capillary phenomenon of the slit for division. As a result of being unable to measure the resistance value of the resistor, there may occur a problem that the target resistance value cannot be trimmed accurately. Also, when trimming is performed by deforming the resistor shape into a notch shape by laser or sandblasting as described above, unevenness may remain on the surface even after covering the resistor film including the notch with glass or resin. There is
Due to such unevenness, there may be a problem that a resistance value or the like may be fainted on the surface at the time of marking, or the resistor may fall off from the collet when it is sucked by the collet and mounted on the circuit board.

Further, as trimming that does not involve shape deformation such as notching the resistor film as described above, in the past, a predetermined value was obtained by applying a pulse voltage or pulse current to the resistor film to reduce the resistance value. There has been proposed a method for obtaining the resistance value of (see Japanese Patent Publication No. 51-4253). However, with this method, it is possible to predict how much the resistance value will decrease with one pulse, but
In order to obtain a desired resistance value with high accuracy, it is necessary to apply a pulse multiple times to gradually reduce the resistance value and perform a troublesome trimming work, and to control this, a complicated control program is required. There was a need to assemble. In such a method, it takes a high cost to adjust (trim) the resistance value, and the efficiency is poor and unsuitable for manufacturing a chip resistor whose unit price is less than one yen.

It is an object of the present invention to provide a method of manufacturing a resistor which eliminates such troublesome trimming work, and a resistor having less surface irregularities.

[0006]

The present inventor has taken the following technical means in the present invention in order to achieve the above technical objects. According to claim 1, a pair of electrodes is provided on the surface of the substrate, the resistance layer between the electrodes is vapor-deposited so that the resistance value between the electrodes is measured while measuring the resistance value between the electrodes. It is characterized in that the vapor deposition is terminated so that the value becomes a predetermined value.

Further, in the second aspect, the measurement is started before the resistance layer is provided in the first aspect, whereas the measurement is started after a predetermined time has elapsed. That is, a pair of electrodes that are spaced apart from each other is provided on the surface of the substrate, and after the vapor deposition of the resistance layer is started across both electrodes, measurement of the resistance value between both electrodes is started after a predetermined time, and the resistance between both electrodes is It is characterized in that the vapor deposition is terminated so that the value becomes a predetermined value.

According to a third aspect of the present invention, there is provided a resistor having a pair of electrodes provided on the surface of a substrate and a resistor provided between the electrodes by a thin film method, wherein the resistor provided between the electrodes is cut out. It is characterized in that the resistance value is set to a predetermined value without performing the strip-shaped trimming or the pulse trimming.

[0009]

The functions and effects of the present invention as described above have the following functions and effects. That is,
By providing a pair of spaced electrodes on the surface of the substrate, measuring the resistance value between the electrodes, and vapor-depositing the resistance layer across the electrodes to gradually increase the layer thickness, the cross-sectional area of the resistance layer increases. However, the resistance value decreases in proportion to it. And
The vapor deposition is completed so that the resistance becomes a predetermined value.

With the resistor manufactured in this way, it is possible to obtain a resistor which is not subjected to notch-shaped trimming or pulse trimming. Further, in the above-mentioned resistor, since the resistance layer is not deformed in a notch shape, even if glass or resin for coating is provided on the resistance layer, it is difficult to cause unevenness on the surface. In that case, the risk of fading can be reduced, and in the case where the collet is mounted on the circuit board, the risk of dropping can be reduced.

[0011]

The present invention will be described below with reference to FIG. In the figure, 1 is a substrate made of an alumina material. Vertical and horizontal grooves 2 and 3 are formed on the surface of the substrate 1, and the vertical and horizontal grooves 2 and 3 divide the substrate into a plurality of regions 4 ... ing. A pair of separated electrodes 5 and 5 are provided on each surface of the partitioned region 4 by printing and firing, and a resistance layer 6 is formed by sputtering so as to extend between the electrodes 5 and 5. In this embodiment, the resistance layer 6 is formed by sputtering, but the present invention is not limited to this, and it may be formed by vapor deposition. The resistor in which the resistance layer 6 is formed by the above-mentioned sputtering or vapor deposition is generally called a thin film resistor, and as another type, there is a thick film resistor in which the resistance layer 6 is formed by printing / baking.

Next, a method for forming the above-mentioned resistance layer 6 will be described in detail with reference to FIG. FIG. 2 is a schematic view showing a state in which the resistance layer 6 is formed in the one region 4 described above,
Actually, as shown in FIG. 1, a measuring device 8 is arranged on the back surface 1A side of the substrate 1 through the through holes 7 formed in each electrode 5, and a probe (not shown) is inserted from the measuring device 8 into the through hole 7. By electrically connecting, the resistance layers 6, 6 arranged in a line on the substrate 1 are formed to have a target resistance value while being measured by the measuring device 8.

Reference numeral 9 shown in FIG. 2 is a target as a base material for forming the resistance layer 6, the component of which is composed of a ruthenium oxide of 7 to 14% and a metal oxide containing glass other than the above. There is. The material of the other target 9 is not limited to the above-mentioned components, but ruthenium oxide 46.
-17%, silver 0-31%, Pd 0-13%, glass 54
It is also possible to employ a content rate of up to 39%.

A mask 10 and a shutter 11 are sequentially arranged between the target 9 and the substrate 1 from the side of the substrate 1 to form a resistance layer 6 protruding from the target 9 by hitting the target 9 with, for example, argon atoms. The particles are attached to the surface of the substrate 1 by the mask 10 while limiting the formation region of the resistance layer 6. Then, the resistance value between the electrodes 5 and 5 is continuously measured by the measuring device 8, and when the measuring device 8 reaches the target resistance value or is within the tolerance of the target resistance value, the shutter 11 targets the target. The formed particles jumping out of 9 are blocked so as not to reach the surface of the substrate 1. In FIG. 2, the mask 10 and the substrate 1 are illustrated as being separated from each other, but if a resist is used for the mask 10, it is in a state in which the mask 10 and the substrate 1 are in close contact with each other and a region where the forming particles to be irradiated or the resistance layer 6 is to be formed It can be prevented from adhering to the outside. Further, as described above, in this embodiment, since the shutter 11 is provided between the substrate 1 on which the resistance layer 6 is formed and the target 9, the resistance layer 6 of the measuring device 8 has a predetermined resistance value. When it becomes, it becomes possible to prevent the resistance value from changing further in an instant.
The target resistance value can be obtained accurately. If the shutter 11 as described above is not adopted, the resistance value change amount after the sputtering or vapor deposition is stopped is predicted, and the virtual target resistance value obtained by adding the resistance value change amount to the target resistance value is predicted. It is also possible to stop the formation of the resistance layer 6 by the above-described sputtering or vapor deposition when the value is reached or when it falls within the tolerance range of the target resistance value.

After the resistance layer 6 having a predetermined resistance value is thus formed between the electrodes 5 and 5, the surface of the resistance layer 6 is covered with an insulating protective layer 12 made of glass or resin, and the electrodes 5 and 5 are formed. 5, the side electrode 14 is formed so as to extend over the back electrode 13 and the back electrode 13, and the nickel plating 15 and the solder plating 16 that cover the electrode 5, the back electrode 13 and the side electrode 14 are formed to complete the chip resistor. .

FIG. 3 shows another embodiment of the present invention. In the above-described embodiment, the resistance layer 6 is not formed on the surface of the substrate 1.
The measurement was started by the measuring device 8 from the state in which the resistance layer 6 was not formed, but in this other embodiment, the resistance layer 6 close to the target resistance value was previously formed between the electrodes 5 and 5,
A further resistance layer 17 is formed on the resistance layer 6 while measuring the resistance values between the electrodes 5 and 5, and a shutter (not shown) is closed when the target resistance value is reached as in the above-described embodiment. The target resistance value is obtained.

[Brief description of drawings]

FIG. 1 is a perspective view showing an embodiment.

FIG. 2 is a schematic view showing a formation state of a resistance layer.

FIG. 3 is a cross-sectional view showing a completed state of the resistor.

FIG. 4 is a schematic view showing another embodiment.

[Explanation of symbols]

 1 substrate 5 electrodes

Claims (3)

[Claims] 1. A pair of electrodes separated from each other is provided on the surface of a substrate, and a resistance layer is formed by vapor deposition or sputtering so as to extend over both electrodes while measuring a resistance value between the electrodes. A method of manufacturing a thin film resistor, characterized in that the vapor deposition is terminated so that a resistance value between electrodes becomes a predetermined value. 2. A pair of electrodes separated from each other is provided on the surface of a substrate, and after a resistance layer is formed by vapor deposition or sputtering so as to extend over both electrodes, measurement of a resistance value between the electrodes is started after a predetermined time. The method for manufacturing a thin film resistor, wherein the vapor deposition is terminated so that the resistance value between the electrodes becomes a predetermined value. 3. A resistor comprising a pair of electrodes provided on a surface of a substrate, and a resistor provided between the electrodes by a thin film method, wherein the resistor provided between the electrodes is notched or trimmed or pulsed. A thin film resistor, which is set to a predetermined resistance value without trimming.