JPH0274007A - Trimming method for thick film resistor - Google Patents

Abstract

PURPOSE:To obtain the desired resistance value as well as to prevent concentration of current by a method wherein the resistance value is adjusted by cutting a part of the first or the second electrode together with a resistor. CONSTITUTION:The first and the second electrodes 14A and 14B are cut together with the resistor 16 located between the first and the second electrodes 14A and 14B which are arranged on a substrate 10 leaving an optional space between them. Accordingly, the contact surface of the first and the second electrodes 14A and 14B and the resistor 16 is reduced when the above-mentioned cutting reaches the prescribed limits, and an effective length is increased without narrowing the relative width resistor 16 against the first and the second electrodes 14A and 14B. Also, a part of the resistor 16, located between the first and the second electrodes 14A and 14B, which are provided in an optional interval on the substrate 10, is cut and the effective length of the resistor 16 can be increased even when a part of the first and the second electrodes 14A and 14B is cut subsequently. As a result, the desired resistance value can be obtained easily in a reliable manner, and the concentration of current can also be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a method for trimming a thick film resistor, which achieves alleviation of current concentration associated with cutting of a resistor constituting the thick film resistor.

[Conventional technology]

Thick film resistors in hybrid ICs are manufactured by printing paired conductor electrodes on a substrate made of ceramic or the like.
It is formed by printing a resistive paste between each conductor electrode, firing it, and solidifying it. Therefore, the resistance value changes slightly depending on manufacturing conditions such as the distribution state due to the viscosity of the resistance paste during printing and the temperature conditions during firing. Therefore, even if you design the area, film thickness, etc. of the resistor installed on the board, there will be an error between it and the target resistance value during the manufacturing stage, so the resistance value will be rough compared to the final resistance value. Trimming is performed by firing and removing a portion of it to adjust the resistance value to the desired resistance value.

In trimming a thick film resistor, a part of the fired resistor is removed and its width and effective length are changed to increase the resistance value and adjust it to a desired resistance value.

[Problem to be solved by the invention]

By the way, in trimming such a thick film resistor, the resistance value is increased by narrowing the width of the resistor and adjusted to the desired resistance value, so current is applied to the narrowed part of the adjusted resistor. is concentrated and Joule heat is generated due to an increase in current density per unit area, which may cause a change in resistance value or deterioration of a thick film resistor.

Furthermore, if it is desired to obtain a thick film resistor with high resistance, the resistor must be trimmed in a more complicated manner, resulting in strain on the structure and reduced reliability.

Furthermore, if complicated trimming is performed, the manufacturing cost of the thick film resistor increases as the number of steps increases.

SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a method for trimming a thick film resistor that is highly reliable, easily obtains a desired resistance value, and prevents current concentration.

[Means to solve the problem]

The thick film resistor trimming method of the present invention includes removing a part of the first or second electrode together with the resistor installed between the first and second electrodes disposed on the substrate; The resistance value is adjusted by changing the effective length of the resistor between the first and second electrodes.

In addition, in this thick film resistor trimming method, after removing a part of the resistor between the first and second electrodes installed on the substrate with an arbitrary interval, the first or second electrode is removed. It is characterized by removing part of it.

[For production]

According to the thick film resistor trimming method of the present invention, by cutting the first or second electrode together with the resistor between the first and second electrodes arranged on the substrate at an arbitrary interval, When this cutting reaches a predetermined area, the first and second
The contact area between the electrode and the resistor is reduced, and the effective length is expanded without narrowing the width of the resistor relative to the first and second electrodes.

Alternatively, it is also possible to cut a part of the resistor between the first and second electrodes installed on the substrate at an arbitrary interval, and then cut a part of the first or second electrode. , the effective length of the resistor can be expanded as well.

〔Example〕

FIG. 1 shows an embodiment of the thick film resistor trimming method of the present invention.

As shown in FIG. 1(A), conductors 12A, 12B,
Trimming electrodes 14A, 1 as the first and second electrodes
4B is installed by printing and firing a conductor paste, and the resistor 16 is installed by printing and firing a resistor paste. The trimming electrodes 14A, 14B are conductors 12A,
Together with 12B, it is formed according to the circuit pattern. Convex trimming introduction pads 18A, 18B representing trimming starting points are formed at the connection points between the conductors 12A, 12B and the trimming electrodes 14A, 14B.

The resistor I6 is installed to completely cover the trimming electrodes 14A and 114B.
It has an irregular rectangular shape with protrusions on the sides.

The trimming is performed by applying a sandblasting method (abbreviated trimming) in which the resistor 16 is cut by high-pressure jetting of abrasive powder, and the resistor 16 and the conductors 12A, 1
Also cut 2B. As shown in FIG. 1B, trimming is started using trimming introduction bands 18A and 18B as introduction points. As a result, each trimming electrode 1
4A114B is determined and trimming is performed precisely along these trimming electrodes 14A, 14B.

Next, (C) in FIG. 1 shows the state of the thick film resistor at the start of trimming, and shows the trimming introduction pad 18A,
18B has already been cut. The trimming electrode 14A is separated from the conductor 12A by cutting, and simply acts as a conductor existing in the resistor 16. Therefore, the trimming electrode 14A serves to short-circuit the left and right resistors 16 sandwiching the trimming electrode 14A. At this time, the conductor 12A makes contact with the resistor 16 only at the hatched contact point 2OA, and the resistance value is increased by reducing the contact area. Further, the trimming electrode 14B is in contact with the conductor 12B, and in this state, there is little substantial change in resistance value due to trimming. In this case, the resistance value change of the thick film resistor almost depends on the cutting of 14A at the end of trimming.

In this trimming state, between the conductors 12A and 12B,
As shown by the arrow, conductor 12A, contact 20A, resistor 1
6. A resistance value is set using a path consisting of the trimming electrode 14B and the conductor 12B.

Next, (D) in FIG. 1 shows the state of the thick film resistor during trimming, with parts of the trimming electrodes 14A and 14B being cut off. The trimming electrode 14B is also the conductor 12
The conductor 12B makes contact with the resistor 16 only at the hatched contact point 20B, and as in the case of the trimming electrode 14A shown in FIG. 1C, the contact area is reduced. Therefore, the ζ resistance value is increased.

When trimmed in this way, the conduction path is such that the current flows through the conductor 12A as shown by the arrow, assuming that the positive and negative electrodes are connected to each conductor 12A and 12B, respectively.
, contact 20A, resistor 16, contact 20B and conductor 12B
It flows through a path consisting of. As a result, the effective length of the resistor 16 increases, resulting in an increase in the resistance value of the thick film resistor.

FIG. 2 shows the state of the thick film resistor at the end of trimming, in which all of the trimming electrodes 14A and 14B have been cut.

When trimmed in this way, the effective length of the resistor 16 increases as shown by the arrow in FIG. 2 compared to the resistor 16 shown in FIG. will further increase.

At the same time as cutting the resistor 16, the trimming electrodes 14A, 1
4B is also cut, so that the trimming electrodes 14A and 14B are formed in a shape corresponding to the width of the resistor 16 to be set. As a result, current concentration is prevented and a thick film resistor with high reliability is realized.

By the way, the width of each conductor 12A, 12B is, for example, 300 mm.
μm (micrometer), trimming electrode 14A,
The width of 14B is, for example, 100 μm, and the width of trimming is:
For example, if the width of each trimming electrode 14A, 14B is determined and the trimming width is made larger than the width of each electrode 14A, 14B, accurate trimming can be performed. Is possible.

Next, FIGS. 3A and 3B show another embodiment of the thick film resistor trimming method of the present invention. That is, a rectangular resistor 16 is formed between the conductors 12A and 12B, and the thick film resistor trimming method of the present invention can be applied in various forms such as the trimming electrodes 14A and 14B and the shape and direction of the resistor 16. is applicable.

Further, as shown in FIG. 4, a trimming start mark 22 may be provided in place of the trimming introduction pads 18A and 18B in the above embodiment, and in this way, a pad for introducing trimming is formed. There's no hassle.

〔Effect of the invention〕

According to this invention, by cutting a part of the first or second electrode together with the resistor, the resistance value can be adjusted, and the electrode can be formed into the optimum electrode corresponding to the set resistance value, so that the desired result can be obtained. In addition to adjusting the resistance value, current concentration can be prevented, and a large change in resistance value can be obtained with a short trimming length, so the size of the thick film resistor itself can be reduced, and, for example, the area occupied on the substrate of a hybrid IC can be reduced. can be reduced and the integration density can be improved.

[Brief explanation of the drawing]

1 and 2 are views showing a method for trimming a thick film resistor according to the present invention, and FIGS. 3 and 4 are views showing other embodiments of the method for trimming a thick film resistor according to the present invention. . 10... Substrate 12A, 12B... Conductor I4A... Trimming electrode (first electrode) 14B Trimming electrode (second electrode) - Resistor diagram diagram diagram diagram

Claims (2)

[Claims] 1. A part of the first or second electrode is removed together with the resistor installed between the first and second electrodes installed on the substrate, and the resistor between the first and second electrodes is removed. A method for trimming a thick film resistor, characterized by adjusting the resistance value by changing the effective length. 2. The first and second parts are installed at an arbitrary interval on the board.
A method for trimming a thick film resistor, the method comprising: removing a portion of the resistor between the electrodes, and then removing a portion of the first or second electrode.