JP4073673B2 - Resistor manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention belongs to a method for manufacturing a resistor, and can be suitably used particularly in the field of temperature sensors.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, a resistor composed of a resistor whose resistance value greatly changes with a temperature change has been used as a temperature sensor. The resistance value of such a resistor is adjusted by trimming the resistor in the manufacturing stage so as to have a predetermined resistance value according to each temperature.
[0003]
[Problems to be solved by the invention]
However, since the resistor has a large temperature coefficient of resistance, the temperature of the resistor rises due to heat generated during trimming, and the exact relationship between the temperature and the resistance value is unknown during trimming. Therefore, it is difficult to accurately adjust the resistance value, and therefore a highly accurate temperature sensor cannot be obtained.
Therefore, an object of the present invention is to provide a resistor whose resistance value can be easily adjusted and a highly accurate temperature sensor.
[0004]
[Means for Solving the Problems]
In order to solve the problem, a method of manufacturing the resistor of the present invention is as follows.
In a method of manufacturing a resistor having a predetermined combined resistance value by connecting a first resistor and a second resistor in series,
Forming the first resistor and the second resistor on the same plane;
The second resistor has an absolute value of a resistance temperature coefficient of 1/100 or less of that of the first resistor, and the resistance value is not larger than that of the first resistor.
After the first resistor is trimmed, the second resistor is trimmed.
[0005]
According to this resistor, the resistance value is a combined resistance value of the first resistor and the second resistor. First, the combined resistance value is roughly adjusted by trimming the first resistor. Since the resistance value of the first resistor is greater than or equal to that of the second resistor, it can be adjusted to a value approximate to the target combined resistance value in a short time. Next, the second resistor is trimmed until the desired combined resistance value is obtained. Since the absolute value of the temperature coefficient of the second resistor is 1/100 or less of that of the first resistor, the temperature rise of the resistor is small even during trimming, and the relationship between the temperature and the resistance value is monitored. Can be adjusted.
[0006]
Therefore, a resistor having a resistance value very close to the target combined resistance value can be obtained. In addition, the temperature sensor composed of this resistor has high accuracy because the resistance value and the temperature have a designed relationship.
[0008]
In order to solve the above-described problem, a second invention related to the above manufacturing method includes a first resistor having a negative temperature coefficient and a second resistor having a positive temperature coefficient connected in series to the first resistor. A method of manufacturing a compound resistor comprising:
The first resistor is obtained by connecting the first resistor and the second resistor in series on the same plane, and the second resistor has an absolute value of the resistance temperature coefficient of the first resistor. Less than 1 / 100th of the body, the resistance value is not larger than the first resistor,
The second resistor is obtained by connecting the third resistor and the fourth resistor in parallel on the same plane, and the fourth resistor has an absolute value of the resistance temperature coefficient of the third resistor. resistance value less than one hundredth of the body shall not smaller than the third resistor,
After the first resistor is trimmed, the second resistor is trimmed, the third resistor is trimmed, and then the fourth resistor is trimmed .
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Embodiment 1
An embodiment of a resistor of the present invention will be described with reference to the drawings. 1 is a plan view showing a resistor before adjusting a resistance value, and FIG. 2 is a cross-sectional view taken along the line AA ′ of FIG.
The resistor 10 includes a substrate 1 made of an insulating ceramic such as alumina, aluminum nitride, and zirconia, a first resistor 2, terminal electrodes 3 and 3, a comb-like connection electrode 4, and a second resistor. 5.
[0010]
The first resistor 2 is made of a chromium Cr—boron B—silicon Si alloy thin film and is formed on one side of the main surface of the substrate 1. The second resistor 5 is made of a nickel Ni—chrome Cr alloy thin film and is formed on the other side of the main surface of the substrate 1. The first resistor 2 and the second resistor 5 partially overlap each other in the approximate center of the substrate 1. One of the terminal electrodes 3, 3 is formed so as to overlap a part of the first resistor 2 at one end on the main surface of the substrate 1, and the other one is a second resistor at the other end. It is formed so as to overlap with a part of the body 5. The connection electrode 4 is formed so as to further overlap the overlapping portion of the first resistor 2 and the second resistor 5 at the substantially center of the main surface, and the tooth shape thereof faces the first resistor 2 side. Yes. Both the terminal electrode 3 and the connection electrode 4 are made of a nickel Ni thin film.
[0011]
The resistors 2 and 5 and the electrodes 3 and 4 are formed on the substrate 1 by performing sputtering and etching techniques. The specific resistance of the first resistor 2 is much larger than that of the second resistor 5, and the former is much larger in terms of the absolute value of the resistance temperature coefficient. The absolute value of the resistance temperature coefficient of the connection electrode 4 is between them. The equivalent circuit of the resistor 10 obtained in this way is obtained by connecting the first resistor 2, the connection electrode 4, and the second resistor 5 in series as shown in FIG.
[0012]
When adjusting the combined resistance value of the resistor 10 to the design value, first, either one of the first resistor 2 and the connection electrode 4 is set so that the laser does not cross the terminal electrodes 3 and 3 as shown in FIG. Laser trimming from one side to the other. At this time, if the first resistor 2 is trimmed, the specific resistance of the first resistor 2 is large, so that the resistance value can be increased to a value close to the design value in a short time trimming. Although the connection electrode 4 is made of a conductor and has a comb-like pattern, the resistance value can be increased in a short time by trimming the teeth.
[0013]
Next, the second resistor 5 is similarly trimmed. Since the absolute value of the resistance temperature coefficient of the second resistor 5 is small, the resistance value of the second resistor 5 does not fluctuate greatly due to heat generation during trimming. Further, the heat of the second resistor 5 is not immediately transmitted to the first resistor 2. Accordingly, the combined resistance value during trimming can be regarded as a combined resistance value at room temperature, and the combined resistance value can be finely adjusted. For example, the combined resistance value can be adjusted with accuracy within ± 0.5% of the design value. .
[0014]
More specifically, in order to realize a combined resistance value of 100 kΩ, the first resistor 2 has a temperature coefficient of −3,300 ppm / ° C., a resistance value of about 90 kΩ before trimming, and the second resistor 5 has a temperature coefficient of −10 ppm. It is assumed that the resistor 1 shown in FIGS. 1 and 2 is obtained by combining those having a resistance value of about 2 kΩ before trimming at / ° C.
[0015]
First, the combined resistance value is roughly adjusted to about −2% of the destination, that is, about 98 kΩ by trimming the first resistor 2. Next, the second resistor 5 is finely adjusted to 100 kΩ by trimming. The total temperature coefficient (unit: ppm / ° C.) at this time is 0.98 × (−3,300) + 0.02 × (−10) = − 3,234.2, which is within ± 100 ppm / ° C. of the first resistor 2. Moreover, the heat during trimming of the second resistor 5 hardly affects the resistance value of the first resistor 2. Therefore, an error due to heat generation during trimming only occurs with respect to 2 kΩ of the second resistor 5, and the combined resistance value can be within ± 0.2%.
[0016]
In addition to the above, the first resistor 2 may be made of Pt, Ni, or the like. Examples of the material of the second resistor 5 include a Ni—Cr alloy and a Cr—Al—B alloy. Examples of the material of the terminal electrode 3 and the connection electrode 4 include Cu. The same applies to the following embodiments.
[0019]
-Embodiment 2-
This is an example of a compound resistor composed of a resistor having a positive temperature coefficient and a resistor having a negative temperature coefficient, and a temperature sensor using the compound resistor.
The composite resistor 100 includes terminal electrodes 31, 32, and 33 at both ends and the center on the same substrate 11 as that of the first embodiment, as shown in a plan view in FIG. 5. A comb-like connection electrode 14 is formed between the terminal electrode 31 at one end (on the right side in the drawing) and the central terminal electrode 32, and the first terminal electrode 31 and the connection electrode 14 are connected to each other. The second resistor 15 is formed so as to connect the central terminal electrode 32 and the connection electrode 14. The teeth of the connection electrode 14 are directed toward the first resistor 12.
[0020]
The first resistor 12, the connection electrode 14, the second resistor 15, and the terminal electrodes 31 and 32 function as a resistor (first resistor) having a negative temperature coefficient as a whole, like the resistor of the first embodiment. These materials are the same as those of the first resistor 2, the connection electrode 4, the second resistor 5, and the terminal electrode 3 in the first embodiment. Therefore, by trimming the first resistor 12 and the second resistor 15 in this order, the combined resistance value can be adjusted with high accuracy in a short time.
[0021]
A third resistor 16 and a fourth resistor 17 are arranged in parallel between the terminal electrode 33 on the other end (left side in the drawing) of the substrate 11 and the central terminal electrode 32 so as to connect the electrodes. Is formed. Both the third resistor 16 and the fourth resistor 17 have a positive temperature coefficient. Accordingly, the third resistor 16, the fourth resistor 17, and the terminal electrodes 32 and 33 function as a resistor (second resistor) having a positive temperature coefficient as a whole. The fourth resistor 17 has an absolute value of a resistance temperature coefficient that is 1/100 or less of that of the third resistor 16 and has a resistance value larger than that of the third resistor 16. Examples of the material satisfying such conditions include Pt and Ni for the third resistor 16, and Ni—Cr alloy, Cr—Al—B alloy for the fourth resistor 17, and the like. Therefore, by trimming the third resistor 16 and the fourth resistor 17 in this order, the combined resistance value can be adjusted with high accuracy in a short time.
[0022]
The composite resistor 100 has a circuit configuration as shown in FIG. 6, and applies a reference voltage between the terminal electrodes 31 and 33 at both ends as shown in FIG. By taking out the output voltage from the above, it can be used as a voltage dividing type temperature sensor.
[0023]
In particular, the combined resistance value of the first resistor and the combined resistance value of the second resistor are both R, the temperature change amount of the combined resistance value of the first resistor is Δr, and the temperature change of the combined resistance value of the second resistor is room temperature. When the amount is ΔR and the reference voltage is E, the output voltage V is
V = {(R + ΔR) / (R−Δr) + (R + ΔR)} × E
It becomes. If the entire temperature coefficient of the first resistor and the entire temperature coefficient of the second resistor have the same absolute value, ΔR = Δr.
V = {(R + ΔR) / 2R} × E
Thus, a large output proportional to the temperature coefficient of the second resistor can be taken out, and the detection capability is excellent.
[0024]
【The invention's effect】
As described above, since the resistor of the present invention can be easily adjusted in resistance value, a highly accurate resistor and temperature sensor can be obtained at low cost.
[Brief description of the drawings]
FIG. 1 is a plan view illustrating a resistor (before trimming) according to a first embodiment.
FIG. 2 is a cross-sectional view taken along the line AA ′ of the resistor.
FIG. 3 is an equivalent circuit diagram of the resistor.
FIG. 4 is a plan view showing a state in which the resistor is trimmed.
FIG. 5 is a plan view showing a composite resistor (before trimming) according to a second embodiment.
FIG. 6 is an equivalent circuit diagram of the composite resistor.
FIG. 7 is an equivalent circuit diagram when the composite resistor is used as a temperature sensor.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1, 11 Board | substrate 2, 12 1st resistor 3, 31, 32, 33 Terminal electrode 4, 14 Connection electrode 5, 15 2nd resistor 16 3rd resistor 17 4th resistor

Claims (2)

In a method of manufacturing a resistor having a predetermined combined resistance value by connecting a first resistor and a second resistor in series,
Forming the first resistor and the second resistor on the same plane;
The second resistor has an absolute value of a resistance temperature coefficient of 1/100 or less of that of the first resistor, and the resistance value is not larger than that of the first resistor.
A method of manufacturing a resistor, wherein the second resistor is trimmed after the first resistor is trimmed. In a method of manufacturing a composite resistor comprising a first resistor having a negative temperature coefficient and a second resistor having a positive temperature coefficient connected in series thereto,
The first resistor is obtained by connecting the first resistor and the second resistor in series on the same plane, and the second resistor has an absolute value of the resistance temperature coefficient of the first resistor. Less than 1 / 100th of the body, the resistance value is not larger than the first resistor,
The second resistor is obtained by connecting the third resistor and the fourth resistor in parallel on the same plane, and the fourth resistor has an absolute value of the resistance temperature coefficient of the third resistor. resistance value less than one hundredth of the body shall not smaller than the third resistor,
A method of manufacturing a composite resistor, comprising: trimming a first resistor; trimming a second resistor; trimming a third resistor; and trimming a fourth resistor .

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